TTY: call tty_port_destroy in the rest of drivers
[linux-3.10.git] / arch / ia64 / hp / sim / simserial.c
1 /*
2  * Simulated Serial Driver (fake serial)
3  *
4  * This driver is mostly used for bringup purposes and will go away.
5  * It has a strong dependency on the system console. All outputs
6  * are rerouted to the same facility as the one used by printk which, in our
7  * case means sys_sim.c console (goes via the simulator).
8  *
9  * Copyright (C) 1999-2000, 2002-2003 Hewlett-Packard Co
10  *      Stephane Eranian <eranian@hpl.hp.com>
11  *      David Mosberger-Tang <davidm@hpl.hp.com>
12  */
13
14 #include <linux/init.h>
15 #include <linux/errno.h>
16 #include <linux/sched.h>
17 #include <linux/tty.h>
18 #include <linux/tty_flip.h>
19 #include <linux/major.h>
20 #include <linux/fcntl.h>
21 #include <linux/mm.h>
22 #include <linux/seq_file.h>
23 #include <linux/slab.h>
24 #include <linux/capability.h>
25 #include <linux/circ_buf.h>
26 #include <linux/console.h>
27 #include <linux/irq.h>
28 #include <linux/module.h>
29 #include <linux/serial.h>
30 #include <linux/sysrq.h>
31 #include <linux/uaccess.h>
32
33 #include <asm/hpsim.h>
34
35 #include "hpsim_ssc.h"
36
37 #undef SIMSERIAL_DEBUG  /* define this to get some debug information */
38
39 #define KEYBOARD_INTR   3       /* must match with simulator! */
40
41 #define NR_PORTS        1       /* only one port for now */
42
43 struct serial_state {
44         struct tty_port port;
45         struct circ_buf xmit;
46         int irq;
47         int x_char;
48 };
49
50 static struct serial_state rs_table[NR_PORTS];
51
52 struct tty_driver *hp_simserial_driver;
53
54 static struct console *console;
55
56 static void receive_chars(struct tty_struct *tty)
57 {
58         unsigned char ch;
59         static unsigned char seen_esc = 0;
60
61         while ( (ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR)) ) {
62                 if (ch == 27 && seen_esc == 0) {
63                         seen_esc = 1;
64                         continue;
65                 } else if (seen_esc == 1 && ch == 'O') {
66                         seen_esc = 2;
67                         continue;
68                 } else if (seen_esc == 2) {
69                         if (ch == 'P') /* F1 */
70                                 show_state();
71 #ifdef CONFIG_MAGIC_SYSRQ
72                         if (ch == 'S') { /* F4 */
73                                 do {
74                                         ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR);
75                                 } while (!ch);
76                                 handle_sysrq(ch);
77                         }
78 #endif
79                         seen_esc = 0;
80                         continue;
81                 }
82                 seen_esc = 0;
83
84                 if (tty_insert_flip_char(tty, ch, TTY_NORMAL) == 0)
85                         break;
86         }
87         tty_flip_buffer_push(tty);
88 }
89
90 /*
91  * This is the serial driver's interrupt routine for a single port
92  */
93 static irqreturn_t rs_interrupt_single(int irq, void *dev_id)
94 {
95         struct serial_state *info = dev_id;
96         struct tty_struct *tty = tty_port_tty_get(&info->port);
97
98         if (!tty) {
99                 printk(KERN_INFO "%s: tty=0 problem\n", __func__);
100                 return IRQ_NONE;
101         }
102         /*
103          * pretty simple in our case, because we only get interrupts
104          * on inbound traffic
105          */
106         receive_chars(tty);
107         tty_kref_put(tty);
108         return IRQ_HANDLED;
109 }
110
111 /*
112  * -------------------------------------------------------------------
113  * Here ends the serial interrupt routines.
114  * -------------------------------------------------------------------
115  */
116
117 static int rs_put_char(struct tty_struct *tty, unsigned char ch)
118 {
119         struct serial_state *info = tty->driver_data;
120         unsigned long flags;
121
122         if (!info->xmit.buf)
123                 return 0;
124
125         local_irq_save(flags);
126         if (CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) == 0) {
127                 local_irq_restore(flags);
128                 return 0;
129         }
130         info->xmit.buf[info->xmit.head] = ch;
131         info->xmit.head = (info->xmit.head + 1) & (SERIAL_XMIT_SIZE-1);
132         local_irq_restore(flags);
133         return 1;
134 }
135
136 static void transmit_chars(struct tty_struct *tty, struct serial_state *info,
137                 int *intr_done)
138 {
139         int count;
140         unsigned long flags;
141
142         local_irq_save(flags);
143
144         if (info->x_char) {
145                 char c = info->x_char;
146
147                 console->write(console, &c, 1);
148
149                 info->x_char = 0;
150
151                 goto out;
152         }
153
154         if (info->xmit.head == info->xmit.tail || tty->stopped ||
155                         tty->hw_stopped) {
156 #ifdef SIMSERIAL_DEBUG
157                 printk("transmit_chars: head=%d, tail=%d, stopped=%d\n",
158                        info->xmit.head, info->xmit.tail, tty->stopped);
159 #endif
160                 goto out;
161         }
162         /*
163          * We removed the loop and try to do it in to chunks. We need
164          * 2 operations maximum because it's a ring buffer.
165          *
166          * First from current to tail if possible.
167          * Then from the beginning of the buffer until necessary
168          */
169
170         count = min(CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE),
171                     SERIAL_XMIT_SIZE - info->xmit.tail);
172         console->write(console, info->xmit.buf+info->xmit.tail, count);
173
174         info->xmit.tail = (info->xmit.tail+count) & (SERIAL_XMIT_SIZE-1);
175
176         /*
177          * We have more at the beginning of the buffer
178          */
179         count = CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
180         if (count) {
181                 console->write(console, info->xmit.buf, count);
182                 info->xmit.tail += count;
183         }
184 out:
185         local_irq_restore(flags);
186 }
187
188 static void rs_flush_chars(struct tty_struct *tty)
189 {
190         struct serial_state *info = tty->driver_data;
191
192         if (info->xmit.head == info->xmit.tail || tty->stopped ||
193                         tty->hw_stopped || !info->xmit.buf)
194                 return;
195
196         transmit_chars(tty, info, NULL);
197 }
198
199 static int rs_write(struct tty_struct * tty,
200                     const unsigned char *buf, int count)
201 {
202         struct serial_state *info = tty->driver_data;
203         int     c, ret = 0;
204         unsigned long flags;
205
206         if (!info->xmit.buf)
207                 return 0;
208
209         local_irq_save(flags);
210         while (1) {
211                 c = CIRC_SPACE_TO_END(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
212                 if (count < c)
213                         c = count;
214                 if (c <= 0) {
215                         break;
216                 }
217                 memcpy(info->xmit.buf + info->xmit.head, buf, c);
218                 info->xmit.head = ((info->xmit.head + c) &
219                                    (SERIAL_XMIT_SIZE-1));
220                 buf += c;
221                 count -= c;
222                 ret += c;
223         }
224         local_irq_restore(flags);
225         /*
226          * Hey, we transmit directly from here in our case
227          */
228         if (CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) &&
229                         !tty->stopped && !tty->hw_stopped)
230                 transmit_chars(tty, info, NULL);
231
232         return ret;
233 }
234
235 static int rs_write_room(struct tty_struct *tty)
236 {
237         struct serial_state *info = tty->driver_data;
238
239         return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
240 }
241
242 static int rs_chars_in_buffer(struct tty_struct *tty)
243 {
244         struct serial_state *info = tty->driver_data;
245
246         return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
247 }
248
249 static void rs_flush_buffer(struct tty_struct *tty)
250 {
251         struct serial_state *info = tty->driver_data;
252         unsigned long flags;
253
254         local_irq_save(flags);
255         info->xmit.head = info->xmit.tail = 0;
256         local_irq_restore(flags);
257
258         tty_wakeup(tty);
259 }
260
261 /*
262  * This function is used to send a high-priority XON/XOFF character to
263  * the device
264  */
265 static void rs_send_xchar(struct tty_struct *tty, char ch)
266 {
267         struct serial_state *info = tty->driver_data;
268
269         info->x_char = ch;
270         if (ch) {
271                 /*
272                  * I guess we could call console->write() directly but
273                  * let's do that for now.
274                  */
275                 transmit_chars(tty, info, NULL);
276         }
277 }
278
279 /*
280  * ------------------------------------------------------------
281  * rs_throttle()
282  *
283  * This routine is called by the upper-layer tty layer to signal that
284  * incoming characters should be throttled.
285  * ------------------------------------------------------------
286  */
287 static void rs_throttle(struct tty_struct * tty)
288 {
289         if (I_IXOFF(tty))
290                 rs_send_xchar(tty, STOP_CHAR(tty));
291
292         printk(KERN_INFO "simrs_throttle called\n");
293 }
294
295 static void rs_unthrottle(struct tty_struct * tty)
296 {
297         struct serial_state *info = tty->driver_data;
298
299         if (I_IXOFF(tty)) {
300                 if (info->x_char)
301                         info->x_char = 0;
302                 else
303                         rs_send_xchar(tty, START_CHAR(tty));
304         }
305         printk(KERN_INFO "simrs_unthrottle called\n");
306 }
307
308 static int rs_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
309 {
310         if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
311             (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
312             (cmd != TIOCMIWAIT)) {
313                 if (tty->flags & (1 << TTY_IO_ERROR))
314                     return -EIO;
315         }
316
317         switch (cmd) {
318         case TIOCGSERIAL:
319         case TIOCSSERIAL:
320         case TIOCSERGSTRUCT:
321         case TIOCMIWAIT:
322                 return 0;
323         case TIOCSERCONFIG:
324         case TIOCSERGETLSR: /* Get line status register */
325                 return -EINVAL;
326         case TIOCSERGWILD:
327         case TIOCSERSWILD:
328                 /* "setserial -W" is called in Debian boot */
329                 printk (KERN_INFO "TIOCSER?WILD ioctl obsolete, ignored.\n");
330                 return 0;
331         }
332         return -ENOIOCTLCMD;
333 }
334
335 #define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
336
337 static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
338 {
339         /* Handle turning off CRTSCTS */
340         if ((old_termios->c_cflag & CRTSCTS) &&
341             !(tty->termios.c_cflag & CRTSCTS)) {
342                 tty->hw_stopped = 0;
343         }
344 }
345 /*
346  * This routine will shutdown a serial port; interrupts are disabled, and
347  * DTR is dropped if the hangup on close termio flag is on.
348  */
349 static void shutdown(struct tty_port *port)
350 {
351         struct serial_state *info = container_of(port, struct serial_state,
352                         port);
353         unsigned long flags;
354
355         local_irq_save(flags);
356         if (info->irq)
357                 free_irq(info->irq, info);
358
359         if (info->xmit.buf) {
360                 free_page((unsigned long) info->xmit.buf);
361                 info->xmit.buf = NULL;
362         }
363         local_irq_restore(flags);
364 }
365
366 static void rs_close(struct tty_struct *tty, struct file * filp)
367 {
368         struct serial_state *info = tty->driver_data;
369
370         tty_port_close(&info->port, tty, filp);
371 }
372
373 static void rs_hangup(struct tty_struct *tty)
374 {
375         struct serial_state *info = tty->driver_data;
376
377         rs_flush_buffer(tty);
378         tty_port_hangup(&info->port);
379 }
380
381 static int activate(struct tty_port *port, struct tty_struct *tty)
382 {
383         struct serial_state *state = container_of(port, struct serial_state,
384                         port);
385         unsigned long flags, page;
386         int retval = 0;
387
388         page = get_zeroed_page(GFP_KERNEL);
389         if (!page)
390                 return -ENOMEM;
391
392         local_irq_save(flags);
393
394         if (state->xmit.buf)
395                 free_page(page);
396         else
397                 state->xmit.buf = (unsigned char *) page;
398
399         if (state->irq) {
400                 retval = request_irq(state->irq, rs_interrupt_single, 0,
401                                 "simserial", state);
402                 if (retval)
403                         goto errout;
404         }
405
406         state->xmit.head = state->xmit.tail = 0;
407
408         /*
409          * Set up the tty->alt_speed kludge
410          */
411         if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
412                 tty->alt_speed = 57600;
413         if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
414                 tty->alt_speed = 115200;
415         if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
416                 tty->alt_speed = 230400;
417         if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
418                 tty->alt_speed = 460800;
419
420 errout:
421         local_irq_restore(flags);
422         return retval;
423 }
424
425
426 /*
427  * This routine is called whenever a serial port is opened.  It
428  * enables interrupts for a serial port, linking in its async structure into
429  * the IRQ chain.   It also performs the serial-specific
430  * initialization for the tty structure.
431  */
432 static int rs_open(struct tty_struct *tty, struct file * filp)
433 {
434         struct serial_state *info = rs_table + tty->index;
435         struct tty_port *port = &info->port;
436
437         tty->driver_data = info;
438         tty->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
439
440         /*
441          * figure out which console to use (should be one already)
442          */
443         console = console_drivers;
444         while (console) {
445                 if ((console->flags & CON_ENABLED) && console->write) break;
446                 console = console->next;
447         }
448
449         return tty_port_open(port, tty, filp);
450 }
451
452 /*
453  * /proc fs routines....
454  */
455
456 static int rs_proc_show(struct seq_file *m, void *v)
457 {
458         int i;
459
460         seq_printf(m, "simserinfo:1.0\n");
461         for (i = 0; i < NR_PORTS; i++)
462                 seq_printf(m, "%d: uart:16550 port:3F8 irq:%d\n",
463                        i, rs_table[i].irq);
464         return 0;
465 }
466
467 static int rs_proc_open(struct inode *inode, struct file *file)
468 {
469         return single_open(file, rs_proc_show, NULL);
470 }
471
472 static const struct file_operations rs_proc_fops = {
473         .owner          = THIS_MODULE,
474         .open           = rs_proc_open,
475         .read           = seq_read,
476         .llseek         = seq_lseek,
477         .release        = single_release,
478 };
479
480 static const struct tty_operations hp_ops = {
481         .open = rs_open,
482         .close = rs_close,
483         .write = rs_write,
484         .put_char = rs_put_char,
485         .flush_chars = rs_flush_chars,
486         .write_room = rs_write_room,
487         .chars_in_buffer = rs_chars_in_buffer,
488         .flush_buffer = rs_flush_buffer,
489         .ioctl = rs_ioctl,
490         .throttle = rs_throttle,
491         .unthrottle = rs_unthrottle,
492         .send_xchar = rs_send_xchar,
493         .set_termios = rs_set_termios,
494         .hangup = rs_hangup,
495         .proc_fops = &rs_proc_fops,
496 };
497
498 static const struct tty_port_operations hp_port_ops = {
499         .activate = activate,
500         .shutdown = shutdown,
501 };
502
503 static int __init simrs_init(void)
504 {
505         struct serial_state *state;
506         int retval;
507
508         if (!ia64_platform_is("hpsim"))
509                 return -ENODEV;
510
511         hp_simserial_driver = alloc_tty_driver(NR_PORTS);
512         if (!hp_simserial_driver)
513                 return -ENOMEM;
514
515         printk(KERN_INFO "SimSerial driver with no serial options enabled\n");
516
517         /* Initialize the tty_driver structure */
518
519         hp_simserial_driver->driver_name = "simserial";
520         hp_simserial_driver->name = "ttyS";
521         hp_simserial_driver->major = TTY_MAJOR;
522         hp_simserial_driver->minor_start = 64;
523         hp_simserial_driver->type = TTY_DRIVER_TYPE_SERIAL;
524         hp_simserial_driver->subtype = SERIAL_TYPE_NORMAL;
525         hp_simserial_driver->init_termios = tty_std_termios;
526         hp_simserial_driver->init_termios.c_cflag =
527                 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
528         hp_simserial_driver->flags = TTY_DRIVER_REAL_RAW;
529         tty_set_operations(hp_simserial_driver, &hp_ops);
530
531         state = rs_table;
532         tty_port_init(&state->port);
533         state->port.ops = &hp_port_ops;
534         state->port.close_delay = 0; /* XXX really 0? */
535
536         retval = hpsim_get_irq(KEYBOARD_INTR);
537         if (retval < 0) {
538                 printk(KERN_ERR "%s: out of interrupt vectors!\n",
539                                 __func__);
540                 goto err_free_tty;
541         }
542
543         state->irq = retval;
544
545         /* the port is imaginary */
546         printk(KERN_INFO "ttyS0 at 0x03f8 (irq = %d) is a 16550\n", state->irq);
547
548         tty_port_link_device(&state->port, hp_simserial_driver, 0);
549         retval = tty_register_driver(hp_simserial_driver);
550         if (retval) {
551                 printk(KERN_ERR "Couldn't register simserial driver\n");
552                 goto err_free_tty;
553         }
554
555         return 0;
556 err_free_tty:
557         put_tty_driver(hp_simserial_driver);
558         tty_port_destroy(&state->port);
559         return retval;
560 }
561
562 #ifndef MODULE
563 __initcall(simrs_init);
564 #endif