esp: use tty_port
[linux-2.6.git] / drivers / char / esp.c
1 /*
2  *  esp.c - driver for Hayes ESP serial cards
3  *
4  *  --- Notices from serial.c, upon which this driver is based ---
5  *
6  *  Copyright (C) 1991, 1992  Linus Torvalds
7  *
8  *  Extensively rewritten by Theodore Ts'o, 8/16/92 -- 9/14/92.  Now
9  *  much more extensible to support other serial cards based on the
10  *  16450/16550A UART's.  Added support for the AST FourPort and the
11  *  Accent Async board.
12  *
13  *  set_serial_info fixed to set the flags, custom divisor, and uart
14  *      type fields.  Fix suggested by Michael K. Johnson 12/12/92.
15  *
16  *  11/95: TIOCMIWAIT, TIOCGICOUNT by Angelo Haritsis <ah@doc.ic.ac.uk>
17  *
18  *  03/96: Modularised by Angelo Haritsis <ah@doc.ic.ac.uk>
19  *
20  *  rs_set_termios fixed to look also for changes of the input
21  *      flags INPCK, BRKINT, PARMRK, IGNPAR and IGNBRK.
22  *                                            Bernd Anhäupl 05/17/96.
23  *
24  * --- End of notices from serial.c ---
25  *
26  * Support for the ESP serial card by Andrew J. Robinson
27  *     <arobinso@nyx.net> (Card detection routine taken from a patch
28  *     by Dennis J. Boylan).  Patches to allow use with 2.1.x contributed
29  *     by Chris Faylor.
30  *
31  * Most recent changes: (Andrew J. Robinson)
32  *   Support for PIO mode.  This allows the driver to work properly with
33  *     multiport cards.
34  *
35  * Arnaldo Carvalho de Melo <acme@conectiva.com.br> -
36  * several cleanups, use module_init/module_exit, etc
37  *
38  * This module exports the following rs232 io functions:
39  *
40  *      int espserial_init(void);
41  */
42
43 #include <linux/module.h>
44 #include <linux/errno.h>
45 #include <linux/signal.h>
46 #include <linux/sched.h>
47 #include <linux/interrupt.h>
48 #include <linux/tty.h>
49 #include <linux/tty_flip.h>
50 #include <linux/serial.h>
51 #include <linux/serialP.h>
52 #include <linux/serial_reg.h>
53 #include <linux/major.h>
54 #include <linux/string.h>
55 #include <linux/fcntl.h>
56 #include <linux/ptrace.h>
57 #include <linux/ioport.h>
58 #include <linux/mm.h>
59 #include <linux/init.h>
60 #include <linux/delay.h>
61 #include <linux/bitops.h>
62
63 #include <asm/system.h>
64 #include <linux/io.h>
65
66 #include <asm/dma.h>
67 #include <linux/slab.h>
68 #include <linux/uaccess.h>
69
70 #include <linux/hayesesp.h>
71
72 #define NR_PORTS 64     /* maximum number of ports */
73 #define NR_PRIMARY 8    /* maximum number of primary ports */
74 #define REGION_SIZE 8   /* size of io region to request */
75
76 /* The following variables can be set by giving module options */
77 static int irq[NR_PRIMARY];     /* IRQ for each base port */
78 static unsigned int divisor[NR_PRIMARY]; /* custom divisor for each port */
79 static unsigned int dma = ESP_DMA_CHANNEL; /* DMA channel */
80 static unsigned int rx_trigger = ESP_RX_TRIGGER;
81 static unsigned int tx_trigger = ESP_TX_TRIGGER;
82 static unsigned int flow_off = ESP_FLOW_OFF;
83 static unsigned int flow_on = ESP_FLOW_ON;
84 static unsigned int rx_timeout = ESP_RX_TMOUT;
85 static unsigned int pio_threshold = ESP_PIO_THRESHOLD;
86
87 MODULE_LICENSE("GPL");
88
89 module_param_array(irq, int, NULL, 0);
90 module_param_array(divisor, uint, NULL, 0);
91 module_param(dma, uint, 0);
92 module_param(rx_trigger, uint, 0);
93 module_param(tx_trigger, uint, 0);
94 module_param(flow_off, uint, 0);
95 module_param(flow_on, uint, 0);
96 module_param(rx_timeout, uint, 0);
97 module_param(pio_threshold, uint, 0);
98
99 /* END */
100
101 static char *dma_buffer;
102 static int dma_bytes;
103 static struct esp_pio_buffer *free_pio_buf;
104
105 #define DMA_BUFFER_SZ 1024
106
107 #define WAKEUP_CHARS 1024
108
109 static char serial_name[] __initdata = "ESP serial driver";
110 static char serial_version[] __initdata = "2.2";
111
112 static struct tty_driver *esp_driver;
113
114 /*
115  * Serial driver configuration section.  Here are the various options:
116  *
117  * SERIAL_PARANOIA_CHECK
118  *              Check the magic number for the esp_structure where
119  *              ever possible.
120  */
121
122 #undef SERIAL_PARANOIA_CHECK
123 #define SERIAL_DO_RESTART
124
125 #undef SERIAL_DEBUG_INTR
126 #undef SERIAL_DEBUG_OPEN
127 #undef SERIAL_DEBUG_FLOW
128
129 #if defined(MODULE) && defined(SERIAL_DEBUG_MCOUNT)
130 #define DBG_CNT(s) printk(KERN_DEBUG "(%s): [%x] refc=%d, serc=%d, ttyc=%d -> %s\n", \
131                                 tty->name, info->port.flags, \
132                                 serial_driver.refcount, \
133                                 info->port.count, tty->count, s)
134 #else
135 #define DBG_CNT(s)
136 #endif
137
138 static struct esp_struct *ports;
139
140 static void change_speed(struct esp_struct *info);
141 static void rs_wait_until_sent(struct tty_struct *, int);
142
143 /*
144  * The ESP card has a clock rate of 14.7456 MHz (that is, 2**ESPC_SCALE
145  * times the normal 1.8432 Mhz clock of most serial boards).
146  */
147 #define BASE_BAUD ((1843200 / 16) * (1 << ESPC_SCALE))
148
149 /* Standard COM flags (except for COM4, because of the 8514 problem) */
150 #define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST)
151
152 static inline int serial_paranoia_check(struct esp_struct *info,
153                                         char *name, const char *routine)
154 {
155 #ifdef SERIAL_PARANOIA_CHECK
156         static const char badmagic[] = KERN_WARNING
157                 "Warning: bad magic number for serial struct (%s) in %s\n";
158         static const char badinfo[] = KERN_WARNING
159                 "Warning: null esp_struct for (%s) in %s\n";
160
161         if (!info) {
162                 printk(badinfo, name, routine);
163                 return 1;
164         }
165         if (info->magic != ESP_MAGIC) {
166                 printk(badmagic, name, routine);
167                 return 1;
168         }
169 #endif
170         return 0;
171 }
172
173 static inline unsigned int serial_in(struct esp_struct *info, int offset)
174 {
175         return inb(info->io_port + offset);
176 }
177
178 static inline void serial_out(struct esp_struct *info, int offset,
179                               unsigned char value)
180 {
181         outb(value, info->io_port+offset);
182 }
183
184 /*
185  * ------------------------------------------------------------
186  * rs_stop() and rs_start()
187  *
188  * This routines are called before setting or resetting tty->stopped.
189  * They enable or disable transmitter interrupts, as necessary.
190  * ------------------------------------------------------------
191  */
192 static void rs_stop(struct tty_struct *tty)
193 {
194         struct esp_struct *info = tty->driver_data;
195         unsigned long flags;
196
197         if (serial_paranoia_check(info, tty->name, "rs_stop"))
198                 return;
199
200         spin_lock_irqsave(&info->lock, flags);
201         if (info->IER & UART_IER_THRI) {
202                 info->IER &= ~UART_IER_THRI;
203                 serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
204                 serial_out(info, UART_ESI_CMD2, info->IER);
205         }
206         spin_unlock_irqrestore(&info->lock, flags);
207 }
208
209 static void rs_start(struct tty_struct *tty)
210 {
211         struct esp_struct *info = tty->driver_data;
212         unsigned long flags;
213
214         if (serial_paranoia_check(info, tty->name, "rs_start"))
215                 return;
216
217         spin_lock_irqsave(&info->lock, flags);
218         if (info->xmit_cnt && info->xmit_buf && !(info->IER & UART_IER_THRI)) {
219                 info->IER |= UART_IER_THRI;
220                 serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
221                 serial_out(info, UART_ESI_CMD2, info->IER);
222         }
223         spin_unlock_irqrestore(&info->lock, flags);
224 }
225
226 /*
227  * ----------------------------------------------------------------------
228  *
229  * Here starts the interrupt handling routines.  All of the following
230  * subroutines are declared as inline and are folded into
231  * rs_interrupt().  They were separated out for readability's sake.
232  *
233  * Note: rs_interrupt() is a "fast" interrupt, which means that it
234  * runs with interrupts turned off.  People who may want to modify
235  * rs_interrupt() should try to keep the interrupt handler as fast as
236  * possible.  After you are done making modifications, it is not a bad
237  * idea to do:
238  *
239  * gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
240  *
241  * and look at the resulting assemble code in serial.s.
242  *
243  *                              - Ted Ts'o (tytso@mit.edu), 7-Mar-93
244  * -----------------------------------------------------------------------
245  */
246
247 static DEFINE_SPINLOCK(pio_lock);
248
249 static inline struct esp_pio_buffer *get_pio_buffer(void)
250 {
251         struct esp_pio_buffer *buf;
252         unsigned long flags;
253
254         spin_lock_irqsave(&pio_lock, flags);
255         if (free_pio_buf) {
256                 buf = free_pio_buf;
257                 free_pio_buf = buf->next;
258         } else {
259                 buf = kmalloc(sizeof(struct esp_pio_buffer), GFP_ATOMIC);
260         }
261         spin_unlock_irqrestore(&pio_lock, flags);
262         return buf;
263 }
264
265 static inline void release_pio_buffer(struct esp_pio_buffer *buf)
266 {
267         unsigned long flags;
268         spin_lock_irqsave(&pio_lock, flags);
269         buf->next = free_pio_buf;
270         free_pio_buf = buf;
271         spin_unlock_irqrestore(&pio_lock, flags);
272 }
273
274 static inline void receive_chars_pio(struct esp_struct *info, int num_bytes)
275 {
276         struct tty_struct *tty = info->port.tty;
277         int i;
278         struct esp_pio_buffer *pio_buf;
279         struct esp_pio_buffer *err_buf;
280         unsigned char status_mask;
281
282         pio_buf = get_pio_buffer();
283
284         if (!pio_buf)
285                 return;
286
287         err_buf = get_pio_buffer();
288
289         if (!err_buf) {
290                 release_pio_buffer(pio_buf);
291                 return;
292         }
293
294         status_mask = (info->read_status_mask >> 2) & 0x07;
295
296         for (i = 0; i < num_bytes - 1; i += 2) {
297                 *((unsigned short *)(pio_buf->data + i)) =
298                         inw(info->io_port + UART_ESI_RX);
299                 err_buf->data[i] = serial_in(info, UART_ESI_RWS);
300                 err_buf->data[i + 1] = (err_buf->data[i] >> 3) & status_mask;
301                 err_buf->data[i] &= status_mask;
302         }
303
304         if (num_bytes & 0x0001) {
305                 pio_buf->data[num_bytes - 1] = serial_in(info, UART_ESI_RX);
306                 err_buf->data[num_bytes - 1] =
307                         (serial_in(info, UART_ESI_RWS) >> 3) & status_mask;
308         }
309
310         /* make sure everything is still ok since interrupts were enabled */
311         tty = info->port.tty;
312
313         if (!tty) {
314                 release_pio_buffer(pio_buf);
315                 release_pio_buffer(err_buf);
316                 info->stat_flags &= ~ESP_STAT_RX_TIMEOUT;
317                 return;
318         }
319
320         status_mask = (info->ignore_status_mask >> 2) & 0x07;
321
322         for (i = 0; i < num_bytes; i++) {
323                 if (!(err_buf->data[i] & status_mask)) {
324                         int flag = 0;
325
326                         if (err_buf->data[i] & 0x04) {
327                                 flag = TTY_BREAK;
328                                 if (info->port.flags & ASYNC_SAK)
329                                         do_SAK(tty);
330                         } else if (err_buf->data[i] & 0x02)
331                                 flag = TTY_FRAME;
332                         else if (err_buf->data[i] & 0x01)
333                                 flag = TTY_PARITY;
334                         tty_insert_flip_char(tty, pio_buf->data[i], flag);
335                 }
336         }
337
338         tty_schedule_flip(tty);
339
340         info->stat_flags &= ~ESP_STAT_RX_TIMEOUT;
341         release_pio_buffer(pio_buf);
342         release_pio_buffer(err_buf);
343 }
344
345 static void program_isa_dma(int dma, int dir, unsigned long addr, int len)
346 {
347         unsigned long flags;
348
349         flags = claim_dma_lock();
350         disable_dma(dma);
351         clear_dma_ff(dma);
352         set_dma_mode(dma, dir);
353         set_dma_addr(dma, addr);
354         set_dma_count(dma, len);
355         enable_dma(dma);
356         release_dma_lock(flags);
357 }
358
359 static void receive_chars_dma(struct esp_struct *info, int num_bytes)
360 {
361         info->stat_flags &= ~ESP_STAT_RX_TIMEOUT;
362         dma_bytes = num_bytes;
363         info->stat_flags |= ESP_STAT_DMA_RX;
364
365         program_isa_dma(dma, DMA_MODE_READ, isa_virt_to_bus(dma_buffer),
366                                                                 dma_bytes);
367         serial_out(info, UART_ESI_CMD1, ESI_START_DMA_RX);
368 }
369
370 static inline void receive_chars_dma_done(struct esp_struct *info,
371                                             int status)
372 {
373         struct tty_struct *tty = info->port.tty;
374         int num_bytes;
375         unsigned long flags;
376
377         flags = claim_dma_lock();
378         disable_dma(dma);
379         clear_dma_ff(dma);
380
381         info->stat_flags &= ~ESP_STAT_DMA_RX;
382         num_bytes = dma_bytes - get_dma_residue(dma);
383         release_dma_lock(flags);
384
385         info->icount.rx += num_bytes;
386
387         if (num_bytes > 0) {
388                 tty_insert_flip_string(tty, dma_buffer, num_bytes - 1);
389
390                 status &= (0x1c & info->read_status_mask);
391
392                 /* Is the status significant or do we throw the last byte ? */
393                 if (!(status & info->ignore_status_mask)) {
394                         int statflag = 0;
395
396                         if (status & 0x10) {
397                                 statflag = TTY_BREAK;
398                                 (info->icount.brk)++;
399                                 if (info->port.flags & ASYNC_SAK)
400                                         do_SAK(tty);
401                         } else if (status & 0x08) {
402                                 statflag = TTY_FRAME;
403                                 info->icount.frame++;
404                         } else if (status & 0x04) {
405                                 statflag = TTY_PARITY;
406                                 info->icount.parity++;
407                         }
408                         tty_insert_flip_char(tty, dma_buffer[num_bytes - 1],
409                                                                 statflag);
410                 }
411                 tty_schedule_flip(tty);
412         }
413
414         if (dma_bytes != num_bytes) {
415                 num_bytes = dma_bytes - num_bytes;
416                 dma_bytes = 0;
417                 receive_chars_dma(info, num_bytes);
418         } else
419                 dma_bytes = 0;
420 }
421
422 /* Caller must hold info->lock */
423
424 static inline void transmit_chars_pio(struct esp_struct *info,
425                                         int space_avail)
426 {
427         int i;
428         struct esp_pio_buffer *pio_buf;
429
430         pio_buf = get_pio_buffer();
431
432         if (!pio_buf)
433                 return;
434
435         while (space_avail && info->xmit_cnt) {
436                 if (info->xmit_tail + space_avail <= ESP_XMIT_SIZE) {
437                         memcpy(pio_buf->data,
438                                &(info->xmit_buf[info->xmit_tail]),
439                                space_avail);
440                 } else {
441                         i = ESP_XMIT_SIZE - info->xmit_tail;
442                         memcpy(pio_buf->data,
443                                &(info->xmit_buf[info->xmit_tail]), i);
444                         memcpy(&(pio_buf->data[i]), info->xmit_buf,
445                                space_avail - i);
446                 }
447
448                 info->xmit_cnt -= space_avail;
449                 info->xmit_tail = (info->xmit_tail + space_avail) &
450                         (ESP_XMIT_SIZE - 1);
451
452                 for (i = 0; i < space_avail - 1; i += 2) {
453                         outw(*((unsigned short *)(pio_buf->data + i)),
454                              info->io_port + UART_ESI_TX);
455                 }
456
457                 if (space_avail & 0x0001)
458                         serial_out(info, UART_ESI_TX,
459                                    pio_buf->data[space_avail - 1]);
460
461                 if (info->xmit_cnt) {
462                         serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
463                         serial_out(info, UART_ESI_CMD1, ESI_GET_TX_AVAIL);
464                         space_avail = serial_in(info, UART_ESI_STAT1) << 8;
465                         space_avail |= serial_in(info, UART_ESI_STAT2);
466
467                         if (space_avail > info->xmit_cnt)
468                                 space_avail = info->xmit_cnt;
469                 }
470         }
471
472         if (info->xmit_cnt < WAKEUP_CHARS) {
473                 if (info->port.tty)
474                         tty_wakeup(info->port.tty);
475
476 #ifdef SERIAL_DEBUG_INTR
477                 printk("THRE...");
478 #endif
479
480                 if (info->xmit_cnt <= 0) {
481                         info->IER &= ~UART_IER_THRI;
482                         serial_out(info, UART_ESI_CMD1,
483                                    ESI_SET_SRV_MASK);
484                         serial_out(info, UART_ESI_CMD2, info->IER);
485                 }
486         }
487
488         release_pio_buffer(pio_buf);
489 }
490
491 /* Caller must hold info->lock */
492 static inline void transmit_chars_dma(struct esp_struct *info, int num_bytes)
493 {
494         dma_bytes = num_bytes;
495
496         if (info->xmit_tail + dma_bytes <= ESP_XMIT_SIZE) {
497                 memcpy(dma_buffer, &(info->xmit_buf[info->xmit_tail]),
498                        dma_bytes);
499         } else {
500                 int i = ESP_XMIT_SIZE - info->xmit_tail;
501                 memcpy(dma_buffer, &(info->xmit_buf[info->xmit_tail]),
502                         i);
503                 memcpy(&(dma_buffer[i]), info->xmit_buf, dma_bytes - i);
504         }
505
506         info->xmit_cnt -= dma_bytes;
507         info->xmit_tail = (info->xmit_tail + dma_bytes) & (ESP_XMIT_SIZE - 1);
508
509         if (info->xmit_cnt < WAKEUP_CHARS) {
510                 if (info->port.tty)
511                         tty_wakeup(info->port.tty);
512
513 #ifdef SERIAL_DEBUG_INTR
514                 printk("THRE...");
515 #endif
516
517                 if (info->xmit_cnt <= 0) {
518                         info->IER &= ~UART_IER_THRI;
519                         serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
520                         serial_out(info, UART_ESI_CMD2, info->IER);
521                 }
522         }
523
524         info->stat_flags |= ESP_STAT_DMA_TX;
525
526         program_isa_dma(dma, DMA_MODE_WRITE, isa_virt_to_bus(dma_buffer),
527                                                                 dma_bytes);
528         serial_out(info, UART_ESI_CMD1, ESI_START_DMA_TX);
529 }
530
531 static inline void transmit_chars_dma_done(struct esp_struct *info)
532 {
533         int num_bytes;
534         unsigned long flags;
535
536         flags = claim_dma_lock();
537         disable_dma(dma);
538         clear_dma_ff(dma);
539
540         num_bytes = dma_bytes - get_dma_residue(dma);
541         info->icount.tx += dma_bytes;
542         release_dma_lock(flags);
543
544         if (dma_bytes != num_bytes) {
545                 dma_bytes -= num_bytes;
546                 memmove(dma_buffer, dma_buffer + num_bytes, dma_bytes);
547
548                 program_isa_dma(dma, DMA_MODE_WRITE,
549                                 isa_virt_to_bus(dma_buffer), dma_bytes);
550
551                 serial_out(info, UART_ESI_CMD1, ESI_START_DMA_TX);
552         } else {
553                 dma_bytes = 0;
554                 info->stat_flags &= ~ESP_STAT_DMA_TX;
555         }
556 }
557
558 static void check_modem_status(struct esp_struct *info)
559 {
560         int     status;
561
562         serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);
563         status = serial_in(info, UART_ESI_STAT2);
564
565         if (status & UART_MSR_ANY_DELTA) {
566                 /* update input line counters */
567                 if (status & UART_MSR_TERI)
568                         info->icount.rng++;
569                 if (status & UART_MSR_DDSR)
570                         info->icount.dsr++;
571                 if (status & UART_MSR_DDCD)
572                         info->icount.dcd++;
573                 if (status & UART_MSR_DCTS)
574                         info->icount.cts++;
575                 wake_up_interruptible(&info->delta_msr_wait);
576         }
577
578         if ((info->port.flags & ASYNC_CHECK_CD) && (status & UART_MSR_DDCD)) {
579 #if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
580                 printk("ttys%d CD now %s...", info->line,
581                        (status & UART_MSR_DCD) ? "on" : "off");
582 #endif
583                 if (status & UART_MSR_DCD)
584                         wake_up_interruptible(&info->port.open_wait);
585                 else {
586 #ifdef SERIAL_DEBUG_OPEN
587                         printk("scheduling hangup...");
588 #endif
589                         tty_hangup(info->port.tty);
590                 }
591         }
592 }
593
594 /*
595  * This is the serial driver's interrupt routine
596  */
597 static irqreturn_t rs_interrupt_single(int irq, void *dev_id)
598 {
599         struct esp_struct *info;
600         unsigned err_status;
601         unsigned int scratch;
602
603 #ifdef SERIAL_DEBUG_INTR
604         printk("rs_interrupt_single(%d)...", irq);
605 #endif
606         info = (struct esp_struct *)dev_id;
607         err_status = 0;
608         scratch = serial_in(info, UART_ESI_SID);
609
610         spin_lock(&info->lock);
611
612         if (!info->port.tty) {
613                 spin_unlock(&info->lock);
614                 return IRQ_NONE;
615         }
616
617         if (scratch & 0x04) { /* error */
618                 serial_out(info, UART_ESI_CMD1, ESI_GET_ERR_STAT);
619                 err_status = serial_in(info, UART_ESI_STAT1);
620                 serial_in(info, UART_ESI_STAT2);
621
622                 if (err_status & 0x01)
623                         info->stat_flags |= ESP_STAT_RX_TIMEOUT;
624
625                 if (err_status & 0x20) /* UART status */
626                         check_modem_status(info);
627
628                 if (err_status & 0x80) /* Start break */
629                         wake_up_interruptible(&info->break_wait);
630         }
631
632         if ((scratch & 0x88) || /* DMA completed or timed out */
633             (err_status & 0x1c) /* receive error */) {
634                 if (info->stat_flags & ESP_STAT_DMA_RX)
635                         receive_chars_dma_done(info, err_status);
636                 else if (info->stat_flags & ESP_STAT_DMA_TX)
637                         transmit_chars_dma_done(info);
638         }
639
640         if (!(info->stat_flags & (ESP_STAT_DMA_RX | ESP_STAT_DMA_TX)) &&
641             ((scratch & 0x01) || (info->stat_flags & ESP_STAT_RX_TIMEOUT)) &&
642             (info->IER & UART_IER_RDI)) {
643                 int num_bytes;
644
645                 serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
646                 serial_out(info, UART_ESI_CMD1, ESI_GET_RX_AVAIL);
647                 num_bytes = serial_in(info, UART_ESI_STAT1) << 8;
648                 num_bytes |= serial_in(info, UART_ESI_STAT2);
649
650                 num_bytes = tty_buffer_request_room(info->port.tty, num_bytes);
651
652                 if (num_bytes) {
653                         if (dma_bytes ||
654                             (info->stat_flags & ESP_STAT_USE_PIO) ||
655                             (num_bytes <= info->config.pio_threshold))
656                                 receive_chars_pio(info, num_bytes);
657                         else
658                                 receive_chars_dma(info, num_bytes);
659                 }
660         }
661
662         if (!(info->stat_flags & (ESP_STAT_DMA_RX | ESP_STAT_DMA_TX)) &&
663             (scratch & 0x02) && (info->IER & UART_IER_THRI)) {
664                 if ((info->xmit_cnt <= 0) || info->port.tty->stopped) {
665                         info->IER &= ~UART_IER_THRI;
666                         serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
667                         serial_out(info, UART_ESI_CMD2, info->IER);
668                 } else {
669                         int num_bytes;
670
671                         serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
672                         serial_out(info, UART_ESI_CMD1, ESI_GET_TX_AVAIL);
673                         num_bytes = serial_in(info, UART_ESI_STAT1) << 8;
674                         num_bytes |= serial_in(info, UART_ESI_STAT2);
675
676                         if (num_bytes > info->xmit_cnt)
677                                 num_bytes = info->xmit_cnt;
678
679                         if (num_bytes) {
680                                 if (dma_bytes ||
681                                     (info->stat_flags & ESP_STAT_USE_PIO) ||
682                                     (num_bytes <= info->config.pio_threshold))
683                                         transmit_chars_pio(info, num_bytes);
684                                 else
685                                         transmit_chars_dma(info, num_bytes);
686                         }
687                 }
688         }
689
690         info->last_active = jiffies;
691
692 #ifdef SERIAL_DEBUG_INTR
693         printk("end.\n");
694 #endif
695         spin_unlock(&info->lock);
696         return IRQ_HANDLED;
697 }
698
699 /*
700  * -------------------------------------------------------------------
701  * Here ends the serial interrupt routines.
702  * -------------------------------------------------------------------
703  */
704
705 /*
706  * ---------------------------------------------------------------
707  * Low level utility subroutines for the serial driver:  routines to
708  * figure out the appropriate timeout for an interrupt chain, routines
709  * to initialize and startup a serial port, and routines to shutdown a
710  * serial port.  Useful stuff like that.
711  *
712  * Caller should hold lock
713  * ---------------------------------------------------------------
714  */
715
716 static void esp_basic_init(struct esp_struct *info)
717 {
718         /* put ESPC in enhanced mode */
719         serial_out(info, UART_ESI_CMD1, ESI_SET_MODE);
720
721         if (info->stat_flags & ESP_STAT_NEVER_DMA)
722                 serial_out(info, UART_ESI_CMD2, 0x01);
723         else
724                 serial_out(info, UART_ESI_CMD2, 0x31);
725
726         /* disable interrupts for now */
727         serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
728         serial_out(info, UART_ESI_CMD2, 0x00);
729
730         /* set interrupt and DMA channel */
731         serial_out(info, UART_ESI_CMD1, ESI_SET_IRQ);
732
733         if (info->stat_flags & ESP_STAT_NEVER_DMA)
734                 serial_out(info, UART_ESI_CMD2, 0x01);
735         else
736                 serial_out(info, UART_ESI_CMD2, (dma << 4) | 0x01);
737
738         serial_out(info, UART_ESI_CMD1, ESI_SET_ENH_IRQ);
739
740         if (info->line % 8)     /* secondary port */
741                 serial_out(info, UART_ESI_CMD2, 0x0d);  /* shared */
742         else if (info->irq == 9)
743                 serial_out(info, UART_ESI_CMD2, 0x02);
744         else
745                 serial_out(info, UART_ESI_CMD2, info->irq);
746
747         /* set error status mask (check this) */
748         serial_out(info, UART_ESI_CMD1, ESI_SET_ERR_MASK);
749
750         if (info->stat_flags & ESP_STAT_NEVER_DMA)
751                 serial_out(info, UART_ESI_CMD2, 0xa1);
752         else
753                 serial_out(info, UART_ESI_CMD2, 0xbd);
754
755         serial_out(info, UART_ESI_CMD2, 0x00);
756
757         /* set DMA timeout */
758         serial_out(info, UART_ESI_CMD1, ESI_SET_DMA_TMOUT);
759         serial_out(info, UART_ESI_CMD2, 0xff);
760
761         /* set FIFO trigger levels */
762         serial_out(info, UART_ESI_CMD1, ESI_SET_TRIGGER);
763         serial_out(info, UART_ESI_CMD2, info->config.rx_trigger >> 8);
764         serial_out(info, UART_ESI_CMD2, info->config.rx_trigger);
765         serial_out(info, UART_ESI_CMD2, info->config.tx_trigger >> 8);
766         serial_out(info, UART_ESI_CMD2, info->config.tx_trigger);
767
768         /* Set clock scaling and wait states */
769         serial_out(info, UART_ESI_CMD1, ESI_SET_PRESCALAR);
770         serial_out(info, UART_ESI_CMD2, 0x04 | ESPC_SCALE);
771
772         /* set reinterrupt pacing */
773         serial_out(info, UART_ESI_CMD1, ESI_SET_REINTR);
774         serial_out(info, UART_ESI_CMD2, 0xff);
775 }
776
777 static int startup(struct esp_struct *info)
778 {
779         unsigned long flags;
780         int     retval = 0;
781         unsigned int num_chars;
782
783         spin_lock_irqsave(&info->lock, flags);
784
785         if (info->port.flags & ASYNC_INITIALIZED)
786                 goto out;
787
788         if (!info->xmit_buf) {
789                 info->xmit_buf = (unsigned char *)get_zeroed_page(GFP_ATOMIC);
790                 retval = -ENOMEM;
791                 if (!info->xmit_buf)
792                         goto out;
793         }
794
795 #ifdef SERIAL_DEBUG_OPEN
796         printk(KERN_DEBUG "starting up ttys%d (irq %d)...",
797                                                 info->line, info->irq);
798 #endif
799
800         /* Flush the RX buffer.  Using the ESI flush command may cause */
801         /* wild interrupts, so read all the data instead. */
802
803         serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
804         serial_out(info, UART_ESI_CMD1, ESI_GET_RX_AVAIL);
805         num_chars = serial_in(info, UART_ESI_STAT1) << 8;
806         num_chars |= serial_in(info, UART_ESI_STAT2);
807
808         while (num_chars > 1) {
809                 inw(info->io_port + UART_ESI_RX);
810                 num_chars -= 2;
811         }
812
813         if (num_chars)
814                 serial_in(info, UART_ESI_RX);
815
816         /* set receive character timeout */
817         serial_out(info, UART_ESI_CMD1, ESI_SET_RX_TIMEOUT);
818         serial_out(info, UART_ESI_CMD2, info->config.rx_timeout);
819
820         /* clear all flags except the "never DMA" flag */
821         info->stat_flags &= ESP_STAT_NEVER_DMA;
822
823         if (info->stat_flags & ESP_STAT_NEVER_DMA)
824                 info->stat_flags |= ESP_STAT_USE_PIO;
825
826         spin_unlock_irqrestore(&info->lock, flags);
827
828         /*
829          * Allocate the IRQ
830          */
831
832         retval = request_irq(info->irq, rs_interrupt_single, IRQF_SHARED,
833                              "esp serial", info);
834
835         if (retval) {
836                 if (capable(CAP_SYS_ADMIN)) {
837                         if (info->port.tty)
838                                 set_bit(TTY_IO_ERROR,
839                                         &info->port.tty->flags);
840                         retval = 0;
841                 }
842                 goto out_unlocked;
843         }
844
845         if (!(info->stat_flags & ESP_STAT_USE_PIO) && !dma_buffer) {
846                 dma_buffer = (char *)__get_dma_pages(
847                         GFP_KERNEL, get_order(DMA_BUFFER_SZ));
848
849                 /* use PIO mode if DMA buf/chan cannot be allocated */
850                 if (!dma_buffer)
851                         info->stat_flags |= ESP_STAT_USE_PIO;
852                 else if (request_dma(dma, "esp serial")) {
853                         free_pages((unsigned long)dma_buffer,
854                                    get_order(DMA_BUFFER_SZ));
855                         dma_buffer = NULL;
856                         info->stat_flags |= ESP_STAT_USE_PIO;
857                 }
858
859         }
860
861         info->MCR = UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2;
862
863         spin_lock_irqsave(&info->lock, flags);
864         serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
865         serial_out(info, UART_ESI_CMD2, UART_MCR);
866         serial_out(info, UART_ESI_CMD2, info->MCR);
867
868         /*
869          * Finally, enable interrupts
870          */
871         /* info->IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI; */
872         info->IER = UART_IER_RLSI | UART_IER_RDI | UART_IER_DMA_TMOUT |
873                         UART_IER_DMA_TC;
874         serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
875         serial_out(info, UART_ESI_CMD2, info->IER);
876
877         if (info->port.tty)
878                 clear_bit(TTY_IO_ERROR, &info->port.tty->flags);
879         info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
880         spin_unlock_irqrestore(&info->lock, flags);
881
882         /*
883          * Set up the tty->alt_speed kludge
884          */
885         if (info->port.tty) {
886                 if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
887                         info->port.tty->alt_speed = 57600;
888                 if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
889                         info->port.tty->alt_speed = 115200;
890                 if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
891                         info->port.tty->alt_speed = 230400;
892                 if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
893                         info->port.tty->alt_speed = 460800;
894         }
895
896         /*
897          * set the speed of the serial port
898          */
899         change_speed(info);
900         info->port.flags |= ASYNC_INITIALIZED;
901         return 0;
902
903 out:
904         spin_unlock_irqrestore(&info->lock, flags);
905 out_unlocked:
906         return retval;
907 }
908
909 /*
910  * This routine will shutdown a serial port; interrupts are disabled, and
911  * DTR is dropped if the hangup on close termio flag is on.
912  */
913 static void shutdown(struct esp_struct *info)
914 {
915         unsigned long   flags, f;
916
917         if (!(info->port.flags & ASYNC_INITIALIZED))
918                 return;
919
920 #ifdef SERIAL_DEBUG_OPEN
921         printk("Shutting down serial port %d (irq %d)....", info->line,
922                info->irq);
923 #endif
924
925         spin_lock_irqsave(&info->lock, flags);
926         /*
927          * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
928          * here so the queue might never be waken up
929          */
930         wake_up_interruptible(&info->delta_msr_wait);
931         wake_up_interruptible(&info->break_wait);
932
933         /* stop a DMA transfer on the port being closed */
934         /* DMA lock is higher priority always */
935         if (info->stat_flags & (ESP_STAT_DMA_RX | ESP_STAT_DMA_TX)) {
936                 f = claim_dma_lock();
937                 disable_dma(dma);
938                 clear_dma_ff(dma);
939                 release_dma_lock(f);
940
941                 dma_bytes = 0;
942         }
943
944         /*
945          * Free the IRQ
946          */
947         free_irq(info->irq, info);
948
949         if (dma_buffer) {
950                 struct esp_struct *current_port = ports;
951
952                 while (current_port) {
953                         if ((current_port != info) &&
954                             (current_port->port.flags & ASYNC_INITIALIZED))
955                                 break;
956
957                         current_port = current_port->next_port;
958                 }
959
960                 if (!current_port) {
961                         free_dma(dma);
962                         free_pages((unsigned long)dma_buffer,
963                                    get_order(DMA_BUFFER_SZ));
964                         dma_buffer = NULL;
965                 }
966         }
967
968         if (info->xmit_buf) {
969                 free_page((unsigned long) info->xmit_buf);
970                 info->xmit_buf = NULL;
971         }
972
973         info->IER = 0;
974         serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
975         serial_out(info, UART_ESI_CMD2, 0x00);
976
977         if (!info->port.tty || (info->port.tty->termios->c_cflag & HUPCL))
978                 info->MCR &= ~(UART_MCR_DTR|UART_MCR_RTS);
979
980         info->MCR &= ~UART_MCR_OUT2;
981         serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
982         serial_out(info, UART_ESI_CMD2, UART_MCR);
983         serial_out(info, UART_ESI_CMD2, info->MCR);
984
985         if (info->port.tty)
986                 set_bit(TTY_IO_ERROR, &info->port.tty->flags);
987
988         info->port.flags &= ~ASYNC_INITIALIZED;
989         spin_unlock_irqrestore(&info->lock, flags);
990 }
991
992 /*
993  * This routine is called to set the UART divisor registers to match
994  * the specified baud rate for a serial port.
995  */
996 static void change_speed(struct esp_struct *info)
997 {
998         unsigned short port;
999         int     quot = 0;
1000         unsigned cflag, cval;
1001         int     baud, bits;
1002         unsigned char flow1 = 0, flow2 = 0;
1003         unsigned long flags;
1004
1005         if (!info->port.tty || !info->port.tty->termios)
1006                 return;
1007         cflag = info->port.tty->termios->c_cflag;
1008         port = info->io_port;
1009
1010         /* byte size and parity */
1011         switch (cflag & CSIZE) {
1012         case CS5: cval = 0x00; bits = 7; break;
1013         case CS6: cval = 0x01; bits = 8; break;
1014         case CS7: cval = 0x02; bits = 9; break;
1015         case CS8: cval = 0x03; bits = 10; break;
1016         default:  cval = 0x00; bits = 7; break;
1017         }
1018         if (cflag & CSTOPB) {
1019                 cval |= 0x04;
1020                 bits++;
1021         }
1022         if (cflag & PARENB) {
1023                 cval |= UART_LCR_PARITY;
1024                 bits++;
1025         }
1026         if (!(cflag & PARODD))
1027                 cval |= UART_LCR_EPAR;
1028 #ifdef CMSPAR
1029         if (cflag & CMSPAR)
1030                 cval |= UART_LCR_SPAR;
1031 #endif
1032         baud = tty_get_baud_rate(info->port.tty);
1033         if (baud == 38400 &&
1034                 ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST))
1035                 quot = info->custom_divisor;
1036         else {
1037                 if (baud == 134) /* Special case since 134 is really 134.5 */
1038                         quot = (2*BASE_BAUD / 269);
1039                 else if (baud)
1040                         quot = BASE_BAUD / baud;
1041         }
1042         /* If the quotient is ever zero, default to 9600 bps */
1043         if (!quot)
1044                 quot = BASE_BAUD / 9600;
1045
1046         if (baud) {
1047                 /* Actual rate */
1048                 baud = BASE_BAUD/quot;
1049                 tty_encode_baud_rate(info->port.tty, baud, baud);
1050         }
1051         info->timeout = ((1024 * HZ * bits * quot) / BASE_BAUD) + (HZ / 50);
1052
1053         /* CTS flow control flag and modem status interrupts */
1054         /* info->IER &= ~UART_IER_MSI; */
1055         if (cflag & CRTSCTS) {
1056                 info->port.flags |= ASYNC_CTS_FLOW;
1057                 /* info->IER |= UART_IER_MSI; */
1058                 flow1 = 0x04;
1059                 flow2 = 0x10;
1060         } else
1061                 info->port.flags &= ~ASYNC_CTS_FLOW;
1062         if (cflag & CLOCAL)
1063                 info->port.flags &= ~ASYNC_CHECK_CD;
1064         else
1065                 info->port.flags |= ASYNC_CHECK_CD;
1066
1067         /*
1068          * Set up parity check flag
1069          */
1070         info->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
1071         if (I_INPCK(info->port.tty))
1072                 info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
1073         if (I_BRKINT(info->port.tty) || I_PARMRK(info->port.tty))
1074                 info->read_status_mask |= UART_LSR_BI;
1075
1076         info->ignore_status_mask = 0;
1077 #if 0
1078         /* This should be safe, but for some broken bits of hardware... */
1079         if (I_IGNPAR(info->port.tty)) {
1080                 info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
1081                 info->read_status_mask |= UART_LSR_PE | UART_LSR_FE;
1082         }
1083 #endif
1084         if (I_IGNBRK(info->port.tty)) {
1085                 info->ignore_status_mask |= UART_LSR_BI;
1086                 info->read_status_mask |= UART_LSR_BI;
1087                 /*
1088                  * If we're ignore parity and break indicators, ignore
1089                  * overruns too.  (For real raw support).
1090                  */
1091                 if (I_IGNPAR(info->port.tty)) {
1092                         info->ignore_status_mask |= UART_LSR_OE | \
1093                                 UART_LSR_PE | UART_LSR_FE;
1094                         info->read_status_mask |= UART_LSR_OE | \
1095                                 UART_LSR_PE | UART_LSR_FE;
1096                 }
1097         }
1098
1099         if (I_IXOFF(info->port.tty))
1100                 flow1 |= 0x81;
1101
1102         spin_lock_irqsave(&info->lock, flags);
1103         /* set baud */
1104         serial_out(info, UART_ESI_CMD1, ESI_SET_BAUD);
1105         serial_out(info, UART_ESI_CMD2, quot >> 8);
1106         serial_out(info, UART_ESI_CMD2, quot & 0xff);
1107
1108         /* set data bits, parity, etc. */
1109         serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
1110         serial_out(info, UART_ESI_CMD2, UART_LCR);
1111         serial_out(info, UART_ESI_CMD2, cval);
1112
1113         /* Enable flow control */
1114         serial_out(info, UART_ESI_CMD1, ESI_SET_FLOW_CNTL);
1115         serial_out(info, UART_ESI_CMD2, flow1);
1116         serial_out(info, UART_ESI_CMD2, flow2);
1117
1118         /* set flow control characters (XON/XOFF only) */
1119         if (I_IXOFF(info->port.tty)) {
1120                 serial_out(info, UART_ESI_CMD1, ESI_SET_FLOW_CHARS);
1121                 serial_out(info, UART_ESI_CMD2, START_CHAR(info->port.tty));
1122                 serial_out(info, UART_ESI_CMD2, STOP_CHAR(info->port.tty));
1123                 serial_out(info, UART_ESI_CMD2, 0x10);
1124                 serial_out(info, UART_ESI_CMD2, 0x21);
1125                 switch (cflag & CSIZE) {
1126                 case CS5:
1127                         serial_out(info, UART_ESI_CMD2, 0x1f);
1128                         break;
1129                 case CS6:
1130                         serial_out(info, UART_ESI_CMD2, 0x3f);
1131                         break;
1132                 case CS7:
1133                 case CS8:
1134                         serial_out(info, UART_ESI_CMD2, 0x7f);
1135                         break;
1136                 default:
1137                         serial_out(info, UART_ESI_CMD2, 0xff);
1138                         break;
1139                 }
1140         }
1141
1142         /* Set high/low water */
1143         serial_out(info, UART_ESI_CMD1, ESI_SET_FLOW_LVL);
1144         serial_out(info, UART_ESI_CMD2, info->config.flow_off >> 8);
1145         serial_out(info, UART_ESI_CMD2, info->config.flow_off);
1146         serial_out(info, UART_ESI_CMD2, info->config.flow_on >> 8);
1147         serial_out(info, UART_ESI_CMD2, info->config.flow_on);
1148
1149         spin_unlock_irqrestore(&info->lock, flags);
1150 }
1151
1152 static int rs_put_char(struct tty_struct *tty, unsigned char ch)
1153 {
1154         struct esp_struct *info = tty->driver_data;
1155         unsigned long flags;
1156         int ret = 0;
1157
1158         if (serial_paranoia_check(info, tty->name, "rs_put_char"))
1159                 return 0;
1160
1161         if (!info->xmit_buf)
1162                 return 0;
1163
1164         spin_lock_irqsave(&info->lock, flags);
1165         if (info->xmit_cnt < ESP_XMIT_SIZE - 1) {
1166                 info->xmit_buf[info->xmit_head++] = ch;
1167                 info->xmit_head &= ESP_XMIT_SIZE-1;
1168                 info->xmit_cnt++;
1169                 ret = 1;
1170         }
1171         spin_unlock_irqrestore(&info->lock, flags);
1172         return ret;
1173 }
1174
1175 static void rs_flush_chars(struct tty_struct *tty)
1176 {
1177         struct esp_struct *info = tty->driver_data;
1178         unsigned long flags;
1179
1180         if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
1181                 return;
1182
1183         spin_lock_irqsave(&info->lock, flags);
1184
1185         if (info->xmit_cnt <= 0 || tty->stopped || !info->xmit_buf)
1186                 goto out;
1187
1188         if (!(info->IER & UART_IER_THRI)) {
1189                 info->IER |= UART_IER_THRI;
1190                 serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
1191                 serial_out(info, UART_ESI_CMD2, info->IER);
1192         }
1193 out:
1194         spin_unlock_irqrestore(&info->lock, flags);
1195 }
1196
1197 static int rs_write(struct tty_struct *tty,
1198                     const unsigned char *buf, int count)
1199 {
1200         int     c, t, ret = 0;
1201         struct esp_struct *info = tty->driver_data;
1202         unsigned long flags;
1203
1204         if (serial_paranoia_check(info, tty->name, "rs_write"))
1205                 return 0;
1206
1207         if (!info->xmit_buf)
1208                 return 0;
1209
1210         while (1) {
1211                 /* Thanks to R. Wolff for suggesting how to do this with */
1212                 /* interrupts enabled */
1213
1214                 c = count;
1215                 t = ESP_XMIT_SIZE - info->xmit_cnt - 1;
1216
1217                 if (t < c)
1218                         c = t;
1219
1220                 t = ESP_XMIT_SIZE - info->xmit_head;
1221
1222                 if (t < c)
1223                         c = t;
1224
1225                 if (c <= 0)
1226                         break;
1227
1228                 memcpy(info->xmit_buf + info->xmit_head, buf, c);
1229
1230                 info->xmit_head = (info->xmit_head + c) & (ESP_XMIT_SIZE-1);
1231                 info->xmit_cnt += c;
1232                 buf += c;
1233                 count -= c;
1234                 ret += c;
1235         }
1236
1237         spin_lock_irqsave(&info->lock, flags);
1238
1239         if (info->xmit_cnt && !tty->stopped && !(info->IER & UART_IER_THRI)) {
1240                 info->IER |= UART_IER_THRI;
1241                 serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
1242                 serial_out(info, UART_ESI_CMD2, info->IER);
1243         }
1244
1245         spin_unlock_irqrestore(&info->lock, flags);
1246         return ret;
1247 }
1248
1249 static int rs_write_room(struct tty_struct *tty)
1250 {
1251         struct esp_struct *info = tty->driver_data;
1252         int     ret;
1253         unsigned long flags;
1254
1255         if (serial_paranoia_check(info, tty->name, "rs_write_room"))
1256                 return 0;
1257
1258         spin_lock_irqsave(&info->lock, flags);
1259
1260         ret = ESP_XMIT_SIZE - info->xmit_cnt - 1;
1261         if (ret < 0)
1262                 ret = 0;
1263         spin_unlock_irqrestore(&info->lock, flags);
1264         return ret;
1265 }
1266
1267 static int rs_chars_in_buffer(struct tty_struct *tty)
1268 {
1269         struct esp_struct *info = tty->driver_data;
1270
1271         if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
1272                 return 0;
1273         return info->xmit_cnt;
1274 }
1275
1276 static void rs_flush_buffer(struct tty_struct *tty)
1277 {
1278         struct esp_struct *info = tty->driver_data;
1279         unsigned long flags;
1280
1281         if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
1282                 return;
1283         spin_lock_irqsave(&info->lock, flags);
1284         info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
1285         spin_unlock_irqrestore(&info->lock, flags);
1286         tty_wakeup(tty);
1287 }
1288
1289 /*
1290  * ------------------------------------------------------------
1291  * rs_throttle()
1292  *
1293  * This routine is called by the upper-layer tty layer to signal that
1294  * incoming characters should be throttled.
1295  * ------------------------------------------------------------
1296  */
1297 static void rs_throttle(struct tty_struct *tty)
1298 {
1299         struct esp_struct *info = tty->driver_data;
1300         unsigned long flags;
1301 #ifdef SERIAL_DEBUG_THROTTLE
1302         char    buf[64];
1303
1304         printk("throttle %s: %d....\n", tty_name(tty, buf),
1305                                                 tty_chars_in_buffer(tty));
1306 #endif
1307
1308         if (serial_paranoia_check(info, tty->name, "rs_throttle"))
1309                 return;
1310
1311         spin_lock_irqsave(&info->lock, flags);
1312         info->IER &= ~UART_IER_RDI;
1313         serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
1314         serial_out(info, UART_ESI_CMD2, info->IER);
1315         serial_out(info, UART_ESI_CMD1, ESI_SET_RX_TIMEOUT);
1316         serial_out(info, UART_ESI_CMD2, 0x00);
1317         spin_unlock_irqrestore(&info->lock, flags);
1318 }
1319
1320 static void rs_unthrottle(struct tty_struct *tty)
1321 {
1322         struct esp_struct *info = tty->driver_data;
1323         unsigned long flags;
1324 #ifdef SERIAL_DEBUG_THROTTLE
1325         char    buf[64];
1326
1327         printk(KERN_DEBUG "unthrottle %s: %d....\n", tty_name(tty, buf),
1328                tty_chars_in_buffer(tty));
1329 #endif
1330
1331         if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
1332                 return;
1333
1334         spin_lock_irqsave(&info->lock, flags);
1335         info->IER |= UART_IER_RDI;
1336         serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
1337         serial_out(info, UART_ESI_CMD2, info->IER);
1338         serial_out(info, UART_ESI_CMD1, ESI_SET_RX_TIMEOUT);
1339         serial_out(info, UART_ESI_CMD2, info->config.rx_timeout);
1340         spin_unlock_irqrestore(&info->lock, flags);
1341 }
1342
1343 /*
1344  * ------------------------------------------------------------
1345  * rs_ioctl() and friends
1346  * ------------------------------------------------------------
1347  */
1348
1349 static int get_serial_info(struct esp_struct *info,
1350                            struct serial_struct __user *retinfo)
1351 {
1352         struct serial_struct tmp;
1353
1354         lock_kernel();
1355         memset(&tmp, 0, sizeof(tmp));
1356         tmp.type = PORT_16550A;
1357         tmp.line = info->line;
1358         tmp.port = info->io_port;
1359         tmp.irq = info->irq;
1360         tmp.flags = info->port.flags;
1361         tmp.xmit_fifo_size = 1024;
1362         tmp.baud_base = BASE_BAUD;
1363         tmp.close_delay = info->close_delay;
1364         tmp.closing_wait = info->closing_wait;
1365         tmp.custom_divisor = info->custom_divisor;
1366         tmp.hub6 = 0;
1367         unlock_kernel();
1368         if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
1369                 return -EFAULT;
1370         return 0;
1371 }
1372
1373 static int get_esp_config(struct esp_struct *info,
1374                           struct hayes_esp_config __user *retinfo)
1375 {
1376         struct hayes_esp_config tmp;
1377
1378         if (!retinfo)
1379                 return -EFAULT;
1380
1381         memset(&tmp, 0, sizeof(tmp));
1382         lock_kernel();
1383         tmp.rx_timeout = info->config.rx_timeout;
1384         tmp.rx_trigger = info->config.rx_trigger;
1385         tmp.tx_trigger = info->config.tx_trigger;
1386         tmp.flow_off = info->config.flow_off;
1387         tmp.flow_on = info->config.flow_on;
1388         tmp.pio_threshold = info->config.pio_threshold;
1389         tmp.dma_channel = (info->stat_flags & ESP_STAT_NEVER_DMA ? 0 : dma);
1390         unlock_kernel();
1391
1392         return copy_to_user(retinfo, &tmp, sizeof(*retinfo)) ? -EFAULT : 0;
1393 }
1394
1395 static int set_serial_info(struct esp_struct *info,
1396                            struct serial_struct __user *new_info)
1397 {
1398         struct serial_struct new_serial;
1399         struct esp_struct old_info;
1400         unsigned int change_irq;
1401         int retval = 0;
1402         struct esp_struct *current_async;
1403
1404         if (copy_from_user(&new_serial, new_info, sizeof(new_serial)))
1405                 return -EFAULT;
1406         old_info = *info;
1407
1408         if ((new_serial.type != PORT_16550A) ||
1409             (new_serial.hub6) ||
1410             (info->io_port != new_serial.port) ||
1411             (new_serial.baud_base != BASE_BAUD) ||
1412             (new_serial.irq > 15) ||
1413             (new_serial.irq < 2) ||
1414             (new_serial.irq == 6) ||
1415             (new_serial.irq == 8) ||
1416             (new_serial.irq == 13))
1417                 return -EINVAL;
1418
1419         change_irq = new_serial.irq != info->irq;
1420
1421         if (change_irq && (info->line % 8))
1422                 return -EINVAL;
1423
1424         if (!capable(CAP_SYS_ADMIN)) {
1425                 if (change_irq ||
1426                     (new_serial.close_delay != info->close_delay) ||
1427                     ((new_serial.flags & ~ASYNC_USR_MASK) !=
1428                      (info->port.flags & ~ASYNC_USR_MASK)))
1429                         return -EPERM;
1430                 info->port.flags = ((info->port.flags & ~ASYNC_USR_MASK) |
1431                                (new_serial.flags & ASYNC_USR_MASK));
1432                 info->custom_divisor = new_serial.custom_divisor;
1433         } else {
1434                 if (new_serial.irq == 2)
1435                         new_serial.irq = 9;
1436
1437                 if (change_irq) {
1438                         current_async = ports;
1439
1440                         while (current_async) {
1441                                 if ((current_async->line >= info->line) &&
1442                                     (current_async->line < (info->line + 8))) {
1443                                         if (current_async == info) {
1444                                                 if (current_async->port.count > 1)
1445                                                         return -EBUSY;
1446                                         } else if (current_async->port.count)
1447                                                 return -EBUSY;
1448                                 }
1449
1450                                 current_async = current_async->next_port;
1451                         }
1452                 }
1453
1454                 /*
1455                  * OK, past this point, all the error checking has been done.
1456                  * At this point, we start making changes.....
1457                  */
1458
1459                 info->port.flags = ((info->port.flags & ~ASYNC_FLAGS) |
1460                                (new_serial.flags & ASYNC_FLAGS));
1461                 info->custom_divisor = new_serial.custom_divisor;
1462                 info->close_delay = new_serial.close_delay * HZ/100;
1463                 info->closing_wait = new_serial.closing_wait * HZ/100;
1464
1465                 if (change_irq) {
1466                         /*
1467                          * We need to shutdown the serial port at the old
1468                          * port/irq combination.
1469                          */
1470                         shutdown(info);
1471
1472                         current_async = ports;
1473
1474                         while (current_async) {
1475                                 if ((current_async->line >= info->line) &&
1476                                     (current_async->line < (info->line + 8)))
1477                                         current_async->irq = new_serial.irq;
1478
1479                                 current_async = current_async->next_port;
1480                         }
1481
1482                         serial_out(info, UART_ESI_CMD1, ESI_SET_ENH_IRQ);
1483                         if (info->irq == 9)
1484                                 serial_out(info, UART_ESI_CMD2, 0x02);
1485                         else
1486                                 serial_out(info, UART_ESI_CMD2, info->irq);
1487                 }
1488         }
1489
1490         if (info->port.flags & ASYNC_INITIALIZED) {
1491                 if (((old_info.port.flags & ASYNC_SPD_MASK) !=
1492                      (info->port.flags & ASYNC_SPD_MASK)) ||
1493                     (old_info.custom_divisor != info->custom_divisor)) {
1494                         if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
1495                                 info->port.tty->alt_speed = 57600;
1496                         if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
1497                                 info->port.tty->alt_speed = 115200;
1498                         if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
1499                                 info->port.tty->alt_speed = 230400;
1500                         if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
1501                                 info->port.tty->alt_speed = 460800;
1502                         change_speed(info);
1503                 }
1504         } else
1505                 retval = startup(info);
1506
1507         return retval;
1508 }
1509
1510 static int set_esp_config(struct esp_struct *info,
1511                           struct hayes_esp_config __user *new_info)
1512 {
1513         struct hayes_esp_config new_config;
1514         unsigned int change_dma;
1515         int retval = 0;
1516         struct esp_struct *current_async;
1517         unsigned long flags;
1518
1519         /* Perhaps a non-sysadmin user should be able to do some of these */
1520         /* operations.  I haven't decided yet. */
1521
1522         if (!capable(CAP_SYS_ADMIN))
1523                 return -EPERM;
1524
1525         if (copy_from_user(&new_config, new_info, sizeof(new_config)))
1526                 return -EFAULT;
1527
1528         if ((new_config.flow_on >= new_config.flow_off) ||
1529             (new_config.rx_trigger < 1) ||
1530             (new_config.tx_trigger < 1) ||
1531             (new_config.flow_off < 1) ||
1532             (new_config.flow_on < 1) ||
1533             (new_config.rx_trigger > 1023) ||
1534             (new_config.tx_trigger > 1023) ||
1535             (new_config.flow_off > 1023) ||
1536             (new_config.flow_on > 1023) ||
1537             (new_config.pio_threshold < 0) ||
1538             (new_config.pio_threshold > 1024))
1539                 return -EINVAL;
1540
1541         if ((new_config.dma_channel != 1) && (new_config.dma_channel != 3))
1542                 new_config.dma_channel = 0;
1543
1544         if (info->stat_flags & ESP_STAT_NEVER_DMA)
1545                 change_dma = new_config.dma_channel;
1546         else
1547                 change_dma = (new_config.dma_channel != dma);
1548
1549         if (change_dma) {
1550                 if (new_config.dma_channel) {
1551                         /* PIO mode to DMA mode transition OR */
1552                         /* change current DMA channel */
1553                         current_async = ports;
1554
1555                         while (current_async) {
1556                                 if (current_async == info) {
1557                                         if (current_async->port.count > 1)
1558                                                 return -EBUSY;
1559                                 } else if (current_async->port.count)
1560                                         return -EBUSY;
1561
1562                                 current_async = current_async->next_port;
1563                         }
1564
1565                         shutdown(info);
1566                         dma = new_config.dma_channel;
1567                         info->stat_flags &= ~ESP_STAT_NEVER_DMA;
1568
1569                         /* all ports must use the same DMA channel */
1570
1571                         spin_lock_irqsave(&info->lock, flags);
1572                         current_async = ports;
1573
1574                         while (current_async) {
1575                                 esp_basic_init(current_async);
1576                                 current_async = current_async->next_port;
1577                         }
1578                         spin_unlock_irqrestore(&info->lock, flags);
1579                 } else {
1580                         /* DMA mode to PIO mode only */
1581                         if (info->port.count > 1)
1582                                 return -EBUSY;
1583
1584                         shutdown(info);
1585                         spin_lock_irqsave(&info->lock, flags);
1586                         info->stat_flags |= ESP_STAT_NEVER_DMA;
1587                         esp_basic_init(info);
1588                         spin_unlock_irqrestore(&info->lock, flags);
1589                 }
1590         }
1591
1592         info->config.pio_threshold = new_config.pio_threshold;
1593
1594         if ((new_config.flow_off != info->config.flow_off) ||
1595             (new_config.flow_on != info->config.flow_on)) {
1596                 info->config.flow_off = new_config.flow_off;
1597                 info->config.flow_on = new_config.flow_on;
1598
1599                 spin_lock_irqsave(&info->lock, flags);
1600                 serial_out(info, UART_ESI_CMD1, ESI_SET_FLOW_LVL);
1601                 serial_out(info, UART_ESI_CMD2, new_config.flow_off >> 8);
1602                 serial_out(info, UART_ESI_CMD2, new_config.flow_off);
1603                 serial_out(info, UART_ESI_CMD2, new_config.flow_on >> 8);
1604                 serial_out(info, UART_ESI_CMD2, new_config.flow_on);
1605                 spin_unlock_irqrestore(&info->lock, flags);
1606         }
1607
1608         if ((new_config.rx_trigger != info->config.rx_trigger) ||
1609             (new_config.tx_trigger != info->config.tx_trigger)) {
1610                 info->config.rx_trigger = new_config.rx_trigger;
1611                 info->config.tx_trigger = new_config.tx_trigger;
1612                 spin_lock_irqsave(&info->lock, flags);
1613                 serial_out(info, UART_ESI_CMD1, ESI_SET_TRIGGER);
1614                 serial_out(info, UART_ESI_CMD2,
1615                            new_config.rx_trigger >> 8);
1616                 serial_out(info, UART_ESI_CMD2, new_config.rx_trigger);
1617                 serial_out(info, UART_ESI_CMD2,
1618                            new_config.tx_trigger >> 8);
1619                 serial_out(info, UART_ESI_CMD2, new_config.tx_trigger);
1620                 spin_unlock_irqrestore(&info->lock, flags);
1621         }
1622
1623         if (new_config.rx_timeout != info->config.rx_timeout) {
1624                 info->config.rx_timeout = new_config.rx_timeout;
1625                 spin_lock_irqsave(&info->lock, flags);
1626
1627                 if (info->IER & UART_IER_RDI) {
1628                         serial_out(info, UART_ESI_CMD1,
1629                                    ESI_SET_RX_TIMEOUT);
1630                         serial_out(info, UART_ESI_CMD2,
1631                                    new_config.rx_timeout);
1632                 }
1633
1634                 spin_unlock_irqrestore(&info->lock, flags);
1635         }
1636
1637         if (!(info->port.flags & ASYNC_INITIALIZED))
1638                 retval = startup(info);
1639
1640         return retval;
1641 }
1642
1643 /*
1644  * get_lsr_info - get line status register info
1645  *
1646  * Purpose: Let user call ioctl() to get info when the UART physically
1647  *          is emptied.  On bus types like RS485, the transmitter must
1648  *          release the bus after transmitting. This must be done when
1649  *          the transmit shift register is empty, not be done when the
1650  *          transmit holding register is empty.  This functionality
1651  *          allows an RS485 driver to be written in user space.
1652  */
1653 static int get_lsr_info(struct esp_struct *info, unsigned int __user *value)
1654 {
1655         unsigned char status;
1656         unsigned int result;
1657         unsigned long flags;
1658
1659         spin_lock_irqsave(&info->lock, flags);
1660         serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);
1661         status = serial_in(info, UART_ESI_STAT1);
1662         spin_unlock_irqrestore(&info->lock, flags);
1663         result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);
1664         return put_user(result, value);
1665 }
1666
1667
1668 static int esp_tiocmget(struct tty_struct *tty, struct file *file)
1669 {
1670         struct esp_struct *info = tty->driver_data;
1671         unsigned char control, status;
1672         unsigned long flags;
1673
1674         if (serial_paranoia_check(info, tty->name, __func__))
1675                 return -ENODEV;
1676         if (tty->flags & (1 << TTY_IO_ERROR))
1677                 return -EIO;
1678
1679         control = info->MCR;
1680
1681         spin_lock_irqsave(&info->lock, flags);
1682         serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);
1683         status = serial_in(info, UART_ESI_STAT2);
1684         spin_unlock_irqrestore(&info->lock, flags);
1685
1686         return    ((control & UART_MCR_RTS) ? TIOCM_RTS : 0)
1687                 | ((control & UART_MCR_DTR) ? TIOCM_DTR : 0)
1688                 | ((status  & UART_MSR_DCD) ? TIOCM_CAR : 0)
1689                 | ((status  & UART_MSR_RI) ? TIOCM_RNG : 0)
1690                 | ((status  & UART_MSR_DSR) ? TIOCM_DSR : 0)
1691                 | ((status  & UART_MSR_CTS) ? TIOCM_CTS : 0);
1692 }
1693
1694 static int esp_tiocmset(struct tty_struct *tty, struct file *file,
1695                         unsigned int set, unsigned int clear)
1696 {
1697         struct esp_struct *info = tty->driver_data;
1698         unsigned long flags;
1699
1700         if (serial_paranoia_check(info, tty->name, __func__))
1701                 return -ENODEV;
1702         if (tty->flags & (1 << TTY_IO_ERROR))
1703                 return -EIO;
1704
1705         spin_lock_irqsave(&info->lock, flags);
1706
1707         if (set & TIOCM_RTS)
1708                 info->MCR |= UART_MCR_RTS;
1709         if (set & TIOCM_DTR)
1710                 info->MCR |= UART_MCR_DTR;
1711
1712         if (clear & TIOCM_RTS)
1713                 info->MCR &= ~UART_MCR_RTS;
1714         if (clear & TIOCM_DTR)
1715                 info->MCR &= ~UART_MCR_DTR;
1716
1717         serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
1718         serial_out(info, UART_ESI_CMD2, UART_MCR);
1719         serial_out(info, UART_ESI_CMD2, info->MCR);
1720
1721         spin_unlock_irqrestore(&info->lock, flags);
1722         return 0;
1723 }
1724
1725 /*
1726  * rs_break() --- routine which turns the break handling on or off
1727  */
1728 static void esp_break(struct tty_struct *tty, int break_state)
1729 {
1730         struct esp_struct *info = tty->driver_data;
1731         unsigned long flags;
1732
1733         if (serial_paranoia_check(info, tty->name, "esp_break"))
1734                 return;
1735
1736         if (break_state == -1) {
1737                 spin_lock_irqsave(&info->lock, flags);
1738                 serial_out(info, UART_ESI_CMD1, ESI_ISSUE_BREAK);
1739                 serial_out(info, UART_ESI_CMD2, 0x01);
1740                 spin_unlock_irqrestore(&info->lock, flags);
1741
1742                 /* FIXME - new style wait needed here */
1743                 interruptible_sleep_on(&info->break_wait);
1744         } else {
1745                 spin_lock_irqsave(&info->lock, flags);
1746                 serial_out(info, UART_ESI_CMD1, ESI_ISSUE_BREAK);
1747                 serial_out(info, UART_ESI_CMD2, 0x00);
1748                 spin_unlock_irqrestore(&info->lock, flags);
1749         }
1750 }
1751
1752 static int rs_ioctl(struct tty_struct *tty, struct file *file,
1753                     unsigned int cmd, unsigned long arg)
1754 {
1755         struct esp_struct *info = tty->driver_data;
1756         struct async_icount cprev, cnow;        /* kernel counter temps */
1757         struct serial_icounter_struct __user *p_cuser;  /* user space */
1758         void __user *argp = (void __user *)arg;
1759         unsigned long flags;
1760         int ret;
1761
1762         if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1763                 return -ENODEV;
1764
1765         if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
1766             (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD)  &&
1767             (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT) &&
1768             (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT) &&
1769             (cmd != TIOCGHAYESESP) && (cmd != TIOCSHAYESESP)) {
1770                 if (tty->flags & (1 << TTY_IO_ERROR))
1771                     return -EIO;
1772         }
1773
1774         switch (cmd) {
1775         case TIOCGSERIAL:
1776                 return get_serial_info(info, argp);
1777         case TIOCSSERIAL:
1778                 lock_kernel();
1779                 ret = set_serial_info(info, argp);
1780                 unlock_kernel();
1781                 return ret;
1782         case TIOCSERGWILD:
1783                 return put_user(0L, (unsigned long __user *)argp);
1784         case TIOCSERGETLSR: /* Get line status register */
1785                 return get_lsr_info(info, argp);
1786         case TIOCSERSWILD:
1787                 if (!capable(CAP_SYS_ADMIN))
1788                         return -EPERM;
1789                 return 0;
1790         /*
1791          * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1792          * - mask passed in arg for lines of interest
1793          *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1794          * Caller should use TIOCGICOUNT to see which one it was
1795          */
1796         case TIOCMIWAIT:
1797                 spin_lock_irqsave(&info->lock, flags);
1798                 cprev = info->icount;   /* note the counters on entry */
1799                 spin_unlock_irqrestore(&info->lock, flags);
1800                 while (1) {
1801                         /* FIXME: convert to new style wakeup */
1802                         interruptible_sleep_on(&info->delta_msr_wait);
1803                         /* see if a signal did it */
1804                         if (signal_pending(current))
1805                                 return -ERESTARTSYS;
1806                         spin_lock_irqsave(&info->lock, flags);
1807                         cnow = info->icount;    /* atomic copy */
1808                         spin_unlock_irqrestore(&info->lock, flags);
1809                         if (cnow.rng == cprev.rng &&
1810                             cnow.dsr == cprev.dsr &&
1811                             cnow.dcd == cprev.dcd &&
1812                             cnow.cts == cprev.cts)
1813                                 return -EIO; /* no change => error */
1814                         if (((arg & TIOCM_RNG) &&
1815                              (cnow.rng != cprev.rng)) ||
1816                              ((arg & TIOCM_DSR) &&
1817                               (cnow.dsr != cprev.dsr)) ||
1818                              ((arg & TIOCM_CD) &&
1819                               (cnow.dcd != cprev.dcd)) ||
1820                              ((arg & TIOCM_CTS) &&
1821                               (cnow.cts != cprev.cts))) {
1822                                 return 0;
1823                         }
1824                         cprev = cnow;
1825                 }
1826                 /* NOTREACHED */
1827         /*
1828          * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1829          * Return: write counters to the user passed counter struct
1830          * NB: both 1->0 and 0->1 transitions are counted except for
1831          *     RI where only 0->1 is counted.
1832          */
1833         case TIOCGICOUNT:
1834                 spin_lock_irqsave(&info->lock, flags);
1835                 cnow = info->icount;
1836                 spin_unlock_irqrestore(&info->lock, flags);
1837                 p_cuser = argp;
1838                 if (put_user(cnow.cts, &p_cuser->cts) ||
1839                     put_user(cnow.dsr, &p_cuser->dsr) ||
1840                     put_user(cnow.rng, &p_cuser->rng) ||
1841                     put_user(cnow.dcd, &p_cuser->dcd))
1842                         return -EFAULT;
1843                         return 0;
1844         case TIOCGHAYESESP:
1845                 return get_esp_config(info, argp);
1846         case TIOCSHAYESESP:
1847                 lock_kernel();
1848                 ret = set_esp_config(info, argp);
1849                 unlock_kernel();
1850                 return ret;
1851         default:
1852                 return -ENOIOCTLCMD;
1853         }
1854         return 0;
1855 }
1856
1857 static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
1858 {
1859         struct esp_struct *info = tty->driver_data;
1860         unsigned long flags;
1861
1862         change_speed(info);
1863
1864         spin_lock_irqsave(&info->lock, flags);
1865
1866         /* Handle transition to B0 status */
1867         if ((old_termios->c_cflag & CBAUD) &&
1868                 !(tty->termios->c_cflag & CBAUD)) {
1869                 info->MCR &= ~(UART_MCR_DTR|UART_MCR_RTS);
1870                 serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
1871                 serial_out(info, UART_ESI_CMD2, UART_MCR);
1872                 serial_out(info, UART_ESI_CMD2, info->MCR);
1873         }
1874
1875         /* Handle transition away from B0 status */
1876         if (!(old_termios->c_cflag & CBAUD) &&
1877                 (tty->termios->c_cflag & CBAUD)) {
1878                 info->MCR |= (UART_MCR_DTR | UART_MCR_RTS);
1879                 serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
1880                 serial_out(info, UART_ESI_CMD2, UART_MCR);
1881                 serial_out(info, UART_ESI_CMD2, info->MCR);
1882         }
1883
1884         spin_unlock_irqrestore(&info->lock, flags);
1885
1886         /* Handle turning of CRTSCTS */
1887         if ((old_termios->c_cflag & CRTSCTS) &&
1888             !(tty->termios->c_cflag & CRTSCTS)) {
1889                 rs_start(tty);
1890         }
1891 }
1892
1893 /*
1894  * ------------------------------------------------------------
1895  * rs_close()
1896  *
1897  * This routine is called when the serial port gets closed.  First, we
1898  * wait for the last remaining data to be sent.  Then, we unlink its
1899  * async structure from the interrupt chain if necessary, and we free
1900  * that IRQ if nothing is left in the chain.
1901  * ------------------------------------------------------------
1902  */
1903 static void rs_close(struct tty_struct *tty, struct file *filp)
1904 {
1905         struct esp_struct *info = tty->driver_data;
1906         unsigned long flags;
1907
1908         if (!info || serial_paranoia_check(info, tty->name, "rs_close"))
1909                 return;
1910
1911         spin_lock_irqsave(&info->lock, flags);
1912
1913         if (tty_hung_up_p(filp)) {
1914                 DBG_CNT("before DEC-hung");
1915                 goto out;
1916         }
1917
1918 #ifdef SERIAL_DEBUG_OPEN
1919         printk(KERN_DEBUG "rs_close ttys%d, count = %d\n",
1920                                                 info->line, info->port.count);
1921 #endif
1922         if (tty->count == 1 && info->port.count != 1) {
1923                 /*
1924                  * Uh, oh.  tty->count is 1, which means that the tty
1925                  * structure will be freed.  Info->count should always
1926                  * be one in these conditions.  If it's greater than
1927                  * one, we've got real problems, since it means the
1928                  * serial port won't be shutdown.
1929                  */
1930                 printk(KERN_DEBUG "rs_close: bad serial port count; tty->count is 1, info->port.count is %d\n", info->port.count);
1931                 info->port.count = 1;
1932         }
1933         if (--info->port.count < 0) {
1934                 printk(KERN_ERR "rs_close: bad serial port count for ttys%d: %d\n",
1935                        info->line, info->port.count);
1936                 info->port.count = 0;
1937         }
1938         if (info->port.count) {
1939                 DBG_CNT("before DEC-2");
1940                 goto out;
1941         }
1942         info->port.flags |= ASYNC_CLOSING;
1943
1944         spin_unlock_irqrestore(&info->lock, flags);
1945         /*
1946          * Now we wait for the transmit buffer to clear; and we notify
1947          * the line discipline to only process XON/XOFF characters.
1948          */
1949         tty->closing = 1;
1950         if (info->closing_wait != ASYNC_CLOSING_WAIT_NONE)
1951                 tty_wait_until_sent(tty, info->closing_wait);
1952         /*
1953          * At this point we stop accepting input.  To do this, we
1954          * disable the receive line status interrupts, and tell the
1955          * interrupt driver to stop checking the data ready bit in the
1956          * line status register.
1957          */
1958         /* info->IER &= ~UART_IER_RLSI; */
1959         info->IER &= ~UART_IER_RDI;
1960         info->read_status_mask &= ~UART_LSR_DR;
1961         if (info->port.flags & ASYNC_INITIALIZED) {
1962
1963                 spin_lock_irqsave(&info->lock, flags);
1964                 serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
1965                 serial_out(info, UART_ESI_CMD2, info->IER);
1966
1967                 /* disable receive timeout */
1968                 serial_out(info, UART_ESI_CMD1, ESI_SET_RX_TIMEOUT);
1969                 serial_out(info, UART_ESI_CMD2, 0x00);
1970
1971                 spin_unlock_irqrestore(&info->lock, flags);
1972
1973                 /*
1974                  * Before we drop DTR, make sure the UART transmitter
1975                  * has completely drained; this is especially
1976                  * important if there is a transmit FIFO!
1977                  */
1978                 rs_wait_until_sent(tty, info->timeout);
1979         }
1980         shutdown(info);
1981         rs_flush_buffer(tty);
1982         tty_ldisc_flush(tty);
1983         tty->closing = 0;
1984         info->port.tty = NULL;
1985
1986         if (info->port.blocked_open) {
1987                 if (info->close_delay)
1988                         msleep_interruptible(jiffies_to_msecs(info->close_delay));
1989                 wake_up_interruptible(&info->port.open_wait);
1990         }
1991         info->port.flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
1992         wake_up_interruptible(&info->port.close_wait);
1993         return;
1994
1995 out:
1996         spin_unlock_irqrestore(&info->lock, flags);
1997 }
1998
1999 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
2000 {
2001         struct esp_struct *info = tty->driver_data;
2002         unsigned long orig_jiffies, char_time;
2003         unsigned long flags;
2004
2005         if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))
2006                 return;
2007
2008         orig_jiffies = jiffies;
2009         char_time = ((info->timeout - HZ / 50) / 1024) / 5;
2010
2011         if (!char_time)
2012                 char_time = 1;
2013
2014         spin_lock_irqsave(&info->lock, flags);
2015         serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
2016         serial_out(info, UART_ESI_CMD1, ESI_GET_TX_AVAIL);
2017
2018         while ((serial_in(info, UART_ESI_STAT1) != 0x03) ||
2019                 (serial_in(info, UART_ESI_STAT2) != 0xff)) {
2020
2021                 spin_unlock_irqrestore(&info->lock, flags);
2022                 msleep_interruptible(jiffies_to_msecs(char_time));
2023
2024                 if (signal_pending(current))
2025                         return;
2026
2027                 if (timeout && time_after(jiffies, orig_jiffies + timeout))
2028                         return;
2029
2030                 spin_lock_irqsave(&info->lock, flags);
2031                 serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
2032                 serial_out(info, UART_ESI_CMD1, ESI_GET_TX_AVAIL);
2033         }
2034         spin_unlock_irqrestore(&info->lock, flags);
2035         set_current_state(TASK_RUNNING);
2036 }
2037
2038 /*
2039  * esp_hangup() --- called by tty_hangup() when a hangup is signaled.
2040  */
2041 static void esp_hangup(struct tty_struct *tty)
2042 {
2043         struct esp_struct *info = tty->driver_data;
2044
2045         if (serial_paranoia_check(info, tty->name, "esp_hangup"))
2046                 return;
2047
2048         rs_flush_buffer(tty);
2049         shutdown(info);
2050         info->port.count = 0;
2051         info->port.flags &= ~ASYNC_NORMAL_ACTIVE;
2052         info->port.tty = NULL;
2053         wake_up_interruptible(&info->port.open_wait);
2054 }
2055
2056 /*
2057  * ------------------------------------------------------------
2058  * esp_open() and friends
2059  * ------------------------------------------------------------
2060  */
2061 static int block_til_ready(struct tty_struct *tty, struct file *filp,
2062                            struct esp_struct *info)
2063 {
2064         DECLARE_WAITQUEUE(wait, current);
2065         int             retval;
2066         int             do_clocal = 0;
2067         unsigned long   flags;
2068
2069         /*
2070          * If the device is in the middle of being closed, then block
2071          * until it's done, and then try again.
2072          */
2073         if (tty_hung_up_p(filp) ||
2074             (info->port.flags & ASYNC_CLOSING)) {
2075                 if (info->port.flags & ASYNC_CLOSING)
2076                         interruptible_sleep_on(&info->port.close_wait);
2077 #ifdef SERIAL_DO_RESTART
2078                 if (info->port.flags & ASYNC_HUP_NOTIFY)
2079                         return -EAGAIN;
2080                 else
2081                         return -ERESTARTSYS;
2082 #else
2083                 return -EAGAIN;
2084 #endif
2085         }
2086
2087         /*
2088          * If non-blocking mode is set, or the port is not enabled,
2089          * then make the check up front and then exit.
2090          */
2091         if ((filp->f_flags & O_NONBLOCK) ||
2092             (tty->flags & (1 << TTY_IO_ERROR))) {
2093                 info->port.flags |= ASYNC_NORMAL_ACTIVE;
2094                 return 0;
2095         }
2096
2097         if (tty->termios->c_cflag & CLOCAL)
2098                 do_clocal = 1;
2099
2100         /*
2101          * Block waiting for the carrier detect and the line to become
2102          * free (i.e., not in use by the callout).  While we are in
2103          * this loop, info->port.count is dropped by one, so that
2104          * rs_close() knows when to free things.  We restore it upon
2105          * exit, either normal or abnormal.
2106          */
2107         retval = 0;
2108         add_wait_queue(&info->port.open_wait, &wait);
2109 #ifdef SERIAL_DEBUG_OPEN
2110         printk(KERN_DEBUG "block_til_ready before block: ttys%d, count = %d\n",
2111                info->line, info->port.count);
2112 #endif
2113         spin_lock_irqsave(&info->lock, flags);
2114         if (!tty_hung_up_p(filp))
2115                 info->port.count--;
2116         info->port.blocked_open++;
2117         while (1) {
2118                 if ((tty->termios->c_cflag & CBAUD)) {
2119                         unsigned int scratch;
2120
2121                         serial_out(info, UART_ESI_CMD1, ESI_READ_UART);
2122                         serial_out(info, UART_ESI_CMD2, UART_MCR);
2123                         scratch = serial_in(info, UART_ESI_STAT1);
2124                         serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
2125                         serial_out(info, UART_ESI_CMD2, UART_MCR);
2126                         serial_out(info, UART_ESI_CMD2,
2127                                 scratch | UART_MCR_DTR | UART_MCR_RTS);
2128                 }
2129                 set_current_state(TASK_INTERRUPTIBLE);
2130                 if (tty_hung_up_p(filp) ||
2131                     !(info->port.flags & ASYNC_INITIALIZED)) {
2132 #ifdef SERIAL_DO_RESTART
2133                         if (info->port.flags & ASYNC_HUP_NOTIFY)
2134                                 retval = -EAGAIN;
2135                         else
2136                                 retval = -ERESTARTSYS;
2137 #else
2138                         retval = -EAGAIN;
2139 #endif
2140                         break;
2141                 }
2142
2143                 serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);
2144                 if (serial_in(info, UART_ESI_STAT2) & UART_MSR_DCD)
2145                         do_clocal = 1;
2146
2147                 if (!(info->port.flags & ASYNC_CLOSING) &&
2148                     (do_clocal))
2149                         break;
2150                 if (signal_pending(current)) {
2151                         retval = -ERESTARTSYS;
2152                         break;
2153                 }
2154 #ifdef SERIAL_DEBUG_OPEN
2155                 printk(KERN_DEBUG "block_til_ready blocking: ttys%d, count = %d\n",
2156                        info->line, info->port.count);
2157 #endif
2158                 spin_unlock_irqrestore(&info->lock, flags);
2159                 schedule();
2160                 spin_lock_irqsave(&info->lock, flags);
2161         }
2162         set_current_state(TASK_RUNNING);
2163         remove_wait_queue(&info->port.open_wait, &wait);
2164         if (!tty_hung_up_p(filp))
2165                 info->port.count++;
2166         info->port.blocked_open--;
2167         spin_unlock_irqrestore(&info->lock, flags);
2168 #ifdef SERIAL_DEBUG_OPEN
2169         printk(KERN_DEBUG "block_til_ready after blocking: ttys%d, count = %d\n",
2170                info->line, info->port.count);
2171 #endif
2172         if (retval)
2173                 return retval;
2174         info->port.flags |= ASYNC_NORMAL_ACTIVE;
2175         return 0;
2176 }
2177
2178 /*
2179  * This routine is called whenever a serial port is opened.  It
2180  * enables interrupts for a serial port, linking in its async structure into
2181  * the IRQ chain.   It also performs the serial-specific
2182  * initialization for the tty structure.
2183  */
2184 static int esp_open(struct tty_struct *tty, struct file *filp)
2185 {
2186         struct esp_struct       *info;
2187         int                     retval, line;
2188         unsigned long           flags;
2189
2190         line = tty->index;
2191         if ((line < 0) || (line >= NR_PORTS))
2192                 return -ENODEV;
2193
2194         /* find the port in the chain */
2195
2196         info = ports;
2197
2198         while (info && (info->line != line))
2199                 info = info->next_port;
2200
2201         if (!info) {
2202                 serial_paranoia_check(info, tty->name, "esp_open");
2203                 return -ENODEV;
2204         }
2205
2206 #ifdef SERIAL_DEBUG_OPEN
2207         printk(KERN_DEBUG "esp_open %s, count = %d\n", tty->name, info->port.count);
2208 #endif
2209         spin_lock_irqsave(&info->lock, flags);
2210         info->port.count++;
2211         tty->driver_data = info;
2212         info->port.tty = tty;
2213
2214         spin_unlock_irqrestore(&info->lock, flags);
2215
2216         /*
2217          * Start up serial port
2218          */
2219         retval = startup(info);
2220         if (retval)
2221                 return retval;
2222
2223         retval = block_til_ready(tty, filp, info);
2224         if (retval) {
2225 #ifdef SERIAL_DEBUG_OPEN
2226                 printk(KERN_DEBUG "esp_open returning after block_til_ready with %d\n",
2227                        retval);
2228 #endif
2229                 return retval;
2230         }
2231 #ifdef SERIAL_DEBUG_OPEN
2232         printk(KERN_DEBUG "esp_open %s successful...", tty->name);
2233 #endif
2234         return 0;
2235 }
2236
2237 /*
2238  * ---------------------------------------------------------------------
2239  * espserial_init() and friends
2240  *
2241  * espserial_init() is called at boot-time to initialize the serial driver.
2242  * ---------------------------------------------------------------------
2243  */
2244
2245 /*
2246  * This routine prints out the appropriate serial driver version
2247  * number, and identifies which options were configured into this
2248  * driver.
2249  */
2250
2251 static void show_serial_version(void)
2252 {
2253         printk(KERN_INFO "%s version %s (DMA %u)\n",
2254                 serial_name, serial_version, dma);
2255 }
2256
2257 /*
2258  * This routine is called by espserial_init() to initialize a specific serial
2259  * port.
2260  */
2261 static int autoconfig(struct esp_struct *info)
2262 {
2263         int port_detected = 0;
2264         unsigned long flags;
2265
2266         if (!request_region(info->io_port, REGION_SIZE, "esp serial"))
2267                 return -EIO;
2268
2269         spin_lock_irqsave(&info->lock, flags);
2270         /*
2271          * Check for ESP card
2272          */
2273
2274         if (serial_in(info, UART_ESI_BASE) == 0xf3) {
2275                 serial_out(info, UART_ESI_CMD1, 0x00);
2276                 serial_out(info, UART_ESI_CMD1, 0x01);
2277
2278                 if ((serial_in(info, UART_ESI_STAT2) & 0x70) == 0x20) {
2279                         port_detected = 1;
2280
2281                         if (!(info->irq)) {
2282                                 serial_out(info, UART_ESI_CMD1, 0x02);
2283
2284                                 if (serial_in(info, UART_ESI_STAT1) & 0x01)
2285                                         info->irq = 3;
2286                                 else
2287                                         info->irq = 4;
2288                         }
2289
2290
2291                         /* put card in enhanced mode */
2292                         /* this prevents access through */
2293                         /* the "old" IO ports */
2294                         esp_basic_init(info);
2295
2296                         /* clear out MCR */
2297                         serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
2298                         serial_out(info, UART_ESI_CMD2, UART_MCR);
2299                         serial_out(info, UART_ESI_CMD2, 0x00);
2300                 }
2301         }
2302         if (!port_detected)
2303                 release_region(info->io_port, REGION_SIZE);
2304
2305         spin_unlock_irqrestore(&info->lock, flags);
2306         return (port_detected);
2307 }
2308
2309 static const struct tty_operations esp_ops = {
2310         .open = esp_open,
2311         .close = rs_close,
2312         .write = rs_write,
2313         .put_char = rs_put_char,
2314         .flush_chars = rs_flush_chars,
2315         .write_room = rs_write_room,
2316         .chars_in_buffer = rs_chars_in_buffer,
2317         .flush_buffer = rs_flush_buffer,
2318         .ioctl = rs_ioctl,
2319         .throttle = rs_throttle,
2320         .unthrottle = rs_unthrottle,
2321         .set_termios = rs_set_termios,
2322         .stop = rs_stop,
2323         .start = rs_start,
2324         .hangup = esp_hangup,
2325         .break_ctl = esp_break,
2326         .wait_until_sent = rs_wait_until_sent,
2327         .tiocmget = esp_tiocmget,
2328         .tiocmset = esp_tiocmset,
2329 };
2330
2331 /*
2332  * The serial driver boot-time initialization code!
2333  */
2334 static int __init espserial_init(void)
2335 {
2336         int i, offset;
2337         struct esp_struct *info;
2338         struct esp_struct *last_primary = NULL;
2339         int esp[] = { 0x100, 0x140, 0x180, 0x200, 0x240, 0x280, 0x300, 0x380 };
2340
2341         esp_driver = alloc_tty_driver(NR_PORTS);
2342         if (!esp_driver)
2343                 return -ENOMEM;
2344
2345         for (i = 0; i < NR_PRIMARY; i++) {
2346                 if (irq[i] != 0) {
2347                         if ((irq[i] < 2) || (irq[i] > 15) || (irq[i] == 6) ||
2348                             (irq[i] == 8) || (irq[i] == 13))
2349                                 irq[i] = 0;
2350                         else if (irq[i] == 2)
2351                                 irq[i] = 9;
2352                 }
2353         }
2354
2355         if ((dma != 1) && (dma != 3))
2356                 dma = 0;
2357
2358         if ((rx_trigger < 1) || (rx_trigger > 1023))
2359                 rx_trigger = 768;
2360
2361         if ((tx_trigger < 1) || (tx_trigger > 1023))
2362                 tx_trigger = 768;
2363
2364         if ((flow_off < 1) || (flow_off > 1023))
2365                 flow_off = 1016;
2366
2367         if ((flow_on < 1) || (flow_on > 1023))
2368                 flow_on = 944;
2369
2370         if ((rx_timeout < 0) || (rx_timeout > 255))
2371                 rx_timeout = 128;
2372
2373         if (flow_on >= flow_off)
2374                 flow_on = flow_off - 1;
2375
2376         show_serial_version();
2377
2378         /* Initialize the tty_driver structure */
2379
2380         esp_driver->owner = THIS_MODULE;
2381         esp_driver->name = "ttyP";
2382         esp_driver->major = ESP_IN_MAJOR;
2383         esp_driver->minor_start = 0;
2384         esp_driver->type = TTY_DRIVER_TYPE_SERIAL;
2385         esp_driver->subtype = SERIAL_TYPE_NORMAL;
2386         esp_driver->init_termios = tty_std_termios;
2387         esp_driver->init_termios.c_cflag =
2388                 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2389         esp_driver->init_termios.c_ispeed = 9600;
2390         esp_driver->init_termios.c_ospeed = 9600;
2391         esp_driver->flags = TTY_DRIVER_REAL_RAW;
2392         tty_set_operations(esp_driver, &esp_ops);
2393         if (tty_register_driver(esp_driver)) {
2394                 printk(KERN_ERR "Couldn't register esp serial driver");
2395                 put_tty_driver(esp_driver);
2396                 return 1;
2397         }
2398
2399         info = kzalloc(sizeof(struct esp_struct), GFP_KERNEL);
2400
2401         if (!info) {
2402                 printk(KERN_ERR "Couldn't allocate memory for esp serial device information\n");
2403                 tty_unregister_driver(esp_driver);
2404                 put_tty_driver(esp_driver);
2405                 return 1;
2406         }
2407
2408         spin_lock_init(&info->lock);
2409         /* rx_trigger, tx_trigger are needed by autoconfig */
2410         info->config.rx_trigger = rx_trigger;
2411         info->config.tx_trigger = tx_trigger;
2412
2413         i = 0;
2414         offset = 0;
2415
2416         do {
2417                 info->io_port = esp[i] + offset;
2418                 info->irq = irq[i];
2419                 info->line = (i * 8) + (offset / 8);
2420
2421                 if (!autoconfig(info)) {
2422                         i++;
2423                         offset = 0;
2424                         continue;
2425                 }
2426
2427                 info->custom_divisor = (divisor[i] >> (offset / 2)) & 0xf;
2428                 info->port.flags = STD_COM_FLAGS;
2429                 if (info->custom_divisor)
2430                         info->port.flags |= ASYNC_SPD_CUST;
2431                 info->magic = ESP_MAGIC;
2432                 info->close_delay = 5*HZ/10;
2433                 info->closing_wait = 30*HZ;
2434                 info->config.rx_timeout = rx_timeout;
2435                 info->config.flow_on = flow_on;
2436                 info->config.flow_off = flow_off;
2437                 info->config.pio_threshold = pio_threshold;
2438                 info->next_port = ports;
2439                 init_waitqueue_head(&info->port.open_wait);
2440                 init_waitqueue_head(&info->port.close_wait);
2441                 init_waitqueue_head(&info->delta_msr_wait);
2442                 init_waitqueue_head(&info->break_wait);
2443                 ports = info;
2444                 printk(KERN_INFO "ttyP%d at 0x%04x (irq = %d) is an ESP ",
2445                         info->line, info->io_port, info->irq);
2446
2447                 if (info->line % 8) {
2448                         printk("secondary port\n");
2449                         /* 8 port cards can't do DMA */
2450                         info->stat_flags |= ESP_STAT_NEVER_DMA;
2451
2452                         if (last_primary)
2453                                 last_primary->stat_flags |= ESP_STAT_NEVER_DMA;
2454                 } else {
2455                         printk("primary port\n");
2456                         last_primary = info;
2457                         irq[i] = info->irq;
2458                 }
2459
2460                 if (!dma)
2461                         info->stat_flags |= ESP_STAT_NEVER_DMA;
2462
2463                 info = kzalloc(sizeof(struct esp_struct), GFP_KERNEL);
2464                 if (!info) {
2465                         printk(KERN_ERR "Couldn't allocate memory for esp serial device information\n");
2466                         /* allow use of the already detected ports */
2467                         return 0;
2468                 }
2469
2470                 spin_lock_init(&info->lock);
2471                 /* rx_trigger, tx_trigger are needed by autoconfig */
2472                 info->config.rx_trigger = rx_trigger;
2473                 info->config.tx_trigger = tx_trigger;
2474
2475                 if (offset == 56) {
2476                         i++;
2477                         offset = 0;
2478                 } else {
2479                         offset += 8;
2480                 }
2481         } while (i < NR_PRIMARY);
2482
2483         /* free the last port memory allocation */
2484         kfree(info);
2485
2486         return 0;
2487 }
2488
2489 static void __exit espserial_exit(void)
2490 {
2491         int e1;
2492         struct esp_struct *temp_async;
2493         struct esp_pio_buffer *pio_buf;
2494
2495         e1 = tty_unregister_driver(esp_driver);
2496         if (e1)
2497                 printk(KERN_ERR "esp: failed to unregister driver (%d)\n", e1);
2498         put_tty_driver(esp_driver);
2499
2500         while (ports) {
2501                 if (ports->io_port)
2502                         release_region(ports->io_port, REGION_SIZE);
2503                 temp_async = ports->next_port;
2504                 kfree(ports);
2505                 ports = temp_async;
2506         }
2507
2508         if (dma_buffer)
2509                 free_pages((unsigned long)dma_buffer,
2510                         get_order(DMA_BUFFER_SZ));
2511
2512         while (free_pio_buf) {
2513                 pio_buf = free_pio_buf->next;
2514                 kfree(free_pio_buf);
2515                 free_pio_buf = pio_buf;
2516         }
2517 }
2518
2519 module_init(espserial_init);
2520 module_exit(espserial_exit);