rcu: Fix wrong check in list_splice_init_rcu()
[linux-2.6.git] / drivers / spi / spi-bfin5xx.c
1 /*
2  * Blackfin On-Chip SPI Driver
3  *
4  * Copyright 2004-2010 Analog Devices Inc.
5  *
6  * Enter bugs at http://blackfin.uclinux.org/
7  *
8  * Licensed under the GPL-2 or later.
9  */
10
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/slab.h>
16 #include <linux/io.h>
17 #include <linux/ioport.h>
18 #include <linux/irq.h>
19 #include <linux/errno.h>
20 #include <linux/interrupt.h>
21 #include <linux/platform_device.h>
22 #include <linux/dma-mapping.h>
23 #include <linux/spi/spi.h>
24 #include <linux/workqueue.h>
25
26 #include <asm/dma.h>
27 #include <asm/portmux.h>
28 #include <asm/bfin5xx_spi.h>
29 #include <asm/cacheflush.h>
30
31 #define DRV_NAME        "bfin-spi"
32 #define DRV_AUTHOR      "Bryan Wu, Luke Yang"
33 #define DRV_DESC        "Blackfin on-chip SPI Controller Driver"
34 #define DRV_VERSION     "1.0"
35
36 MODULE_AUTHOR(DRV_AUTHOR);
37 MODULE_DESCRIPTION(DRV_DESC);
38 MODULE_LICENSE("GPL");
39
40 #define START_STATE     ((void *)0)
41 #define RUNNING_STATE   ((void *)1)
42 #define DONE_STATE      ((void *)2)
43 #define ERROR_STATE     ((void *)-1)
44
45 struct bfin_spi_master_data;
46
47 struct bfin_spi_transfer_ops {
48         void (*write) (struct bfin_spi_master_data *);
49         void (*read) (struct bfin_spi_master_data *);
50         void (*duplex) (struct bfin_spi_master_data *);
51 };
52
53 struct bfin_spi_master_data {
54         /* Driver model hookup */
55         struct platform_device *pdev;
56
57         /* SPI framework hookup */
58         struct spi_master *master;
59
60         /* Regs base of SPI controller */
61         struct bfin_spi_regs __iomem *regs;
62
63         /* Pin request list */
64         u16 *pin_req;
65
66         /* BFIN hookup */
67         struct bfin5xx_spi_master *master_info;
68
69         /* Driver message queue */
70         struct workqueue_struct *workqueue;
71         struct work_struct pump_messages;
72         spinlock_t lock;
73         struct list_head queue;
74         int busy;
75         bool running;
76
77         /* Message Transfer pump */
78         struct tasklet_struct pump_transfers;
79
80         /* Current message transfer state info */
81         struct spi_message *cur_msg;
82         struct spi_transfer *cur_transfer;
83         struct bfin_spi_slave_data *cur_chip;
84         size_t len_in_bytes;
85         size_t len;
86         void *tx;
87         void *tx_end;
88         void *rx;
89         void *rx_end;
90
91         /* DMA stuffs */
92         int dma_channel;
93         int dma_mapped;
94         int dma_requested;
95         dma_addr_t rx_dma;
96         dma_addr_t tx_dma;
97
98         int irq_requested;
99         int spi_irq;
100
101         size_t rx_map_len;
102         size_t tx_map_len;
103         u8 n_bytes;
104         u16 ctrl_reg;
105         u16 flag_reg;
106
107         int cs_change;
108         const struct bfin_spi_transfer_ops *ops;
109 };
110
111 struct bfin_spi_slave_data {
112         u16 ctl_reg;
113         u16 baud;
114         u16 flag;
115
116         u8 chip_select_num;
117         u8 enable_dma;
118         u16 cs_chg_udelay;      /* Some devices require > 255usec delay */
119         u32 cs_gpio;
120         u16 idle_tx_val;
121         u8 pio_interrupt;       /* use spi data irq */
122         const struct bfin_spi_transfer_ops *ops;
123 };
124
125 static void bfin_spi_enable(struct bfin_spi_master_data *drv_data)
126 {
127         bfin_write_or(&drv_data->regs->ctl, BIT_CTL_ENABLE);
128 }
129
130 static void bfin_spi_disable(struct bfin_spi_master_data *drv_data)
131 {
132         bfin_write_and(&drv_data->regs->ctl, ~BIT_CTL_ENABLE);
133 }
134
135 /* Caculate the SPI_BAUD register value based on input HZ */
136 static u16 hz_to_spi_baud(u32 speed_hz)
137 {
138         u_long sclk = get_sclk();
139         u16 spi_baud = (sclk / (2 * speed_hz));
140
141         if ((sclk % (2 * speed_hz)) > 0)
142                 spi_baud++;
143
144         if (spi_baud < MIN_SPI_BAUD_VAL)
145                 spi_baud = MIN_SPI_BAUD_VAL;
146
147         return spi_baud;
148 }
149
150 static int bfin_spi_flush(struct bfin_spi_master_data *drv_data)
151 {
152         unsigned long limit = loops_per_jiffy << 1;
153
154         /* wait for stop and clear stat */
155         while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_SPIF) && --limit)
156                 cpu_relax();
157
158         bfin_write(&drv_data->regs->stat, BIT_STAT_CLR);
159
160         return limit;
161 }
162
163 /* Chip select operation functions for cs_change flag */
164 static void bfin_spi_cs_active(struct bfin_spi_master_data *drv_data, struct bfin_spi_slave_data *chip)
165 {
166         if (likely(chip->chip_select_num < MAX_CTRL_CS))
167                 bfin_write_and(&drv_data->regs->flg, ~chip->flag);
168         else
169                 gpio_set_value(chip->cs_gpio, 0);
170 }
171
172 static void bfin_spi_cs_deactive(struct bfin_spi_master_data *drv_data,
173                                  struct bfin_spi_slave_data *chip)
174 {
175         if (likely(chip->chip_select_num < MAX_CTRL_CS))
176                 bfin_write_or(&drv_data->regs->flg, chip->flag);
177         else
178                 gpio_set_value(chip->cs_gpio, 1);
179
180         /* Move delay here for consistency */
181         if (chip->cs_chg_udelay)
182                 udelay(chip->cs_chg_udelay);
183 }
184
185 /* enable or disable the pin muxed by GPIO and SPI CS to work as SPI CS */
186 static inline void bfin_spi_cs_enable(struct bfin_spi_master_data *drv_data,
187                                       struct bfin_spi_slave_data *chip)
188 {
189         if (chip->chip_select_num < MAX_CTRL_CS)
190                 bfin_write_or(&drv_data->regs->flg, chip->flag >> 8);
191 }
192
193 static inline void bfin_spi_cs_disable(struct bfin_spi_master_data *drv_data,
194                                        struct bfin_spi_slave_data *chip)
195 {
196         if (chip->chip_select_num < MAX_CTRL_CS)
197                 bfin_write_and(&drv_data->regs->flg, ~(chip->flag >> 8));
198 }
199
200 /* stop controller and re-config current chip*/
201 static void bfin_spi_restore_state(struct bfin_spi_master_data *drv_data)
202 {
203         struct bfin_spi_slave_data *chip = drv_data->cur_chip;
204
205         /* Clear status and disable clock */
206         bfin_write(&drv_data->regs->stat, BIT_STAT_CLR);
207         bfin_spi_disable(drv_data);
208         dev_dbg(&drv_data->pdev->dev, "restoring spi ctl state\n");
209
210         SSYNC();
211
212         /* Load the registers */
213         bfin_write(&drv_data->regs->ctl, chip->ctl_reg);
214         bfin_write(&drv_data->regs->baud, chip->baud);
215
216         bfin_spi_enable(drv_data);
217         bfin_spi_cs_active(drv_data, chip);
218 }
219
220 /* used to kick off transfer in rx mode and read unwanted RX data */
221 static inline void bfin_spi_dummy_read(struct bfin_spi_master_data *drv_data)
222 {
223         (void) bfin_read(&drv_data->regs->rdbr);
224 }
225
226 static void bfin_spi_u8_writer(struct bfin_spi_master_data *drv_data)
227 {
228         /* clear RXS (we check for RXS inside the loop) */
229         bfin_spi_dummy_read(drv_data);
230
231         while (drv_data->tx < drv_data->tx_end) {
232                 bfin_write(&drv_data->regs->tdbr, (*(u8 *) (drv_data->tx++)));
233                 /* wait until transfer finished.
234                    checking SPIF or TXS may not guarantee transfer completion */
235                 while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_RXS))
236                         cpu_relax();
237                 /* discard RX data and clear RXS */
238                 bfin_spi_dummy_read(drv_data);
239         }
240 }
241
242 static void bfin_spi_u8_reader(struct bfin_spi_master_data *drv_data)
243 {
244         u16 tx_val = drv_data->cur_chip->idle_tx_val;
245
246         /* discard old RX data and clear RXS */
247         bfin_spi_dummy_read(drv_data);
248
249         while (drv_data->rx < drv_data->rx_end) {
250                 bfin_write(&drv_data->regs->tdbr, tx_val);
251                 while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_RXS))
252                         cpu_relax();
253                 *(u8 *) (drv_data->rx++) = bfin_read(&drv_data->regs->rdbr);
254         }
255 }
256
257 static void bfin_spi_u8_duplex(struct bfin_spi_master_data *drv_data)
258 {
259         /* discard old RX data and clear RXS */
260         bfin_spi_dummy_read(drv_data);
261
262         while (drv_data->rx < drv_data->rx_end) {
263                 bfin_write(&drv_data->regs->tdbr, (*(u8 *) (drv_data->tx++)));
264                 while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_RXS))
265                         cpu_relax();
266                 *(u8 *) (drv_data->rx++) = bfin_read(&drv_data->regs->rdbr);
267         }
268 }
269
270 static const struct bfin_spi_transfer_ops bfin_bfin_spi_transfer_ops_u8 = {
271         .write  = bfin_spi_u8_writer,
272         .read   = bfin_spi_u8_reader,
273         .duplex = bfin_spi_u8_duplex,
274 };
275
276 static void bfin_spi_u16_writer(struct bfin_spi_master_data *drv_data)
277 {
278         /* clear RXS (we check for RXS inside the loop) */
279         bfin_spi_dummy_read(drv_data);
280
281         while (drv_data->tx < drv_data->tx_end) {
282                 bfin_write(&drv_data->regs->tdbr, (*(u16 *) (drv_data->tx)));
283                 drv_data->tx += 2;
284                 /* wait until transfer finished.
285                    checking SPIF or TXS may not guarantee transfer completion */
286                 while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_RXS))
287                         cpu_relax();
288                 /* discard RX data and clear RXS */
289                 bfin_spi_dummy_read(drv_data);
290         }
291 }
292
293 static void bfin_spi_u16_reader(struct bfin_spi_master_data *drv_data)
294 {
295         u16 tx_val = drv_data->cur_chip->idle_tx_val;
296
297         /* discard old RX data and clear RXS */
298         bfin_spi_dummy_read(drv_data);
299
300         while (drv_data->rx < drv_data->rx_end) {
301                 bfin_write(&drv_data->regs->tdbr, tx_val);
302                 while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_RXS))
303                         cpu_relax();
304                 *(u16 *) (drv_data->rx) = bfin_read(&drv_data->regs->rdbr);
305                 drv_data->rx += 2;
306         }
307 }
308
309 static void bfin_spi_u16_duplex(struct bfin_spi_master_data *drv_data)
310 {
311         /* discard old RX data and clear RXS */
312         bfin_spi_dummy_read(drv_data);
313
314         while (drv_data->rx < drv_data->rx_end) {
315                 bfin_write(&drv_data->regs->tdbr, (*(u16 *) (drv_data->tx)));
316                 drv_data->tx += 2;
317                 while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_RXS))
318                         cpu_relax();
319                 *(u16 *) (drv_data->rx) = bfin_read(&drv_data->regs->rdbr);
320                 drv_data->rx += 2;
321         }
322 }
323
324 static const struct bfin_spi_transfer_ops bfin_bfin_spi_transfer_ops_u16 = {
325         .write  = bfin_spi_u16_writer,
326         .read   = bfin_spi_u16_reader,
327         .duplex = bfin_spi_u16_duplex,
328 };
329
330 /* test if there is more transfer to be done */
331 static void *bfin_spi_next_transfer(struct bfin_spi_master_data *drv_data)
332 {
333         struct spi_message *msg = drv_data->cur_msg;
334         struct spi_transfer *trans = drv_data->cur_transfer;
335
336         /* Move to next transfer */
337         if (trans->transfer_list.next != &msg->transfers) {
338                 drv_data->cur_transfer =
339                     list_entry(trans->transfer_list.next,
340                                struct spi_transfer, transfer_list);
341                 return RUNNING_STATE;
342         } else
343                 return DONE_STATE;
344 }
345
346 /*
347  * caller already set message->status;
348  * dma and pio irqs are blocked give finished message back
349  */
350 static void bfin_spi_giveback(struct bfin_spi_master_data *drv_data)
351 {
352         struct bfin_spi_slave_data *chip = drv_data->cur_chip;
353         struct spi_transfer *last_transfer;
354         unsigned long flags;
355         struct spi_message *msg;
356
357         spin_lock_irqsave(&drv_data->lock, flags);
358         msg = drv_data->cur_msg;
359         drv_data->cur_msg = NULL;
360         drv_data->cur_transfer = NULL;
361         drv_data->cur_chip = NULL;
362         queue_work(drv_data->workqueue, &drv_data->pump_messages);
363         spin_unlock_irqrestore(&drv_data->lock, flags);
364
365         last_transfer = list_entry(msg->transfers.prev,
366                                    struct spi_transfer, transfer_list);
367
368         msg->state = NULL;
369
370         if (!drv_data->cs_change)
371                 bfin_spi_cs_deactive(drv_data, chip);
372
373         /* Not stop spi in autobuffer mode */
374         if (drv_data->tx_dma != 0xFFFF)
375                 bfin_spi_disable(drv_data);
376
377         if (msg->complete)
378                 msg->complete(msg->context);
379 }
380
381 /* spi data irq handler */
382 static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id)
383 {
384         struct bfin_spi_master_data *drv_data = dev_id;
385         struct bfin_spi_slave_data *chip = drv_data->cur_chip;
386         struct spi_message *msg = drv_data->cur_msg;
387         int n_bytes = drv_data->n_bytes;
388         int loop = 0;
389
390         /* wait until transfer finished. */
391         while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_RXS))
392                 cpu_relax();
393
394         if ((drv_data->tx && drv_data->tx >= drv_data->tx_end) ||
395                 (drv_data->rx && drv_data->rx >= (drv_data->rx_end - n_bytes))) {
396                 /* last read */
397                 if (drv_data->rx) {
398                         dev_dbg(&drv_data->pdev->dev, "last read\n");
399                         if (n_bytes % 2) {
400                                 u16 *buf = (u16 *)drv_data->rx;
401                                 for (loop = 0; loop < n_bytes / 2; loop++)
402                                         *buf++ = bfin_read(&drv_data->regs->rdbr);
403                         } else {
404                                 u8 *buf = (u8 *)drv_data->rx;
405                                 for (loop = 0; loop < n_bytes; loop++)
406                                         *buf++ = bfin_read(&drv_data->regs->rdbr);
407                         }
408                         drv_data->rx += n_bytes;
409                 }
410
411                 msg->actual_length += drv_data->len_in_bytes;
412                 if (drv_data->cs_change)
413                         bfin_spi_cs_deactive(drv_data, chip);
414                 /* Move to next transfer */
415                 msg->state = bfin_spi_next_transfer(drv_data);
416
417                 disable_irq_nosync(drv_data->spi_irq);
418
419                 /* Schedule transfer tasklet */
420                 tasklet_schedule(&drv_data->pump_transfers);
421                 return IRQ_HANDLED;
422         }
423
424         if (drv_data->rx && drv_data->tx) {
425                 /* duplex */
426                 dev_dbg(&drv_data->pdev->dev, "duplex: write_TDBR\n");
427                 if (n_bytes % 2) {
428                         u16 *buf = (u16 *)drv_data->rx;
429                         u16 *buf2 = (u16 *)drv_data->tx;
430                         for (loop = 0; loop < n_bytes / 2; loop++) {
431                                 *buf++ = bfin_read(&drv_data->regs->rdbr);
432                                 bfin_write(&drv_data->regs->tdbr, *buf2++);
433                         }
434                 } else {
435                         u8 *buf = (u8 *)drv_data->rx;
436                         u8 *buf2 = (u8 *)drv_data->tx;
437                         for (loop = 0; loop < n_bytes; loop++) {
438                                 *buf++ = bfin_read(&drv_data->regs->rdbr);
439                                 bfin_write(&drv_data->regs->tdbr, *buf2++);
440                         }
441                 }
442         } else if (drv_data->rx) {
443                 /* read */
444                 dev_dbg(&drv_data->pdev->dev, "read: write_TDBR\n");
445                 if (n_bytes % 2) {
446                         u16 *buf = (u16 *)drv_data->rx;
447                         for (loop = 0; loop < n_bytes / 2; loop++) {
448                                 *buf++ = bfin_read(&drv_data->regs->rdbr);
449                                 bfin_write(&drv_data->regs->tdbr, chip->idle_tx_val);
450                         }
451                 } else {
452                         u8 *buf = (u8 *)drv_data->rx;
453                         for (loop = 0; loop < n_bytes; loop++) {
454                                 *buf++ = bfin_read(&drv_data->regs->rdbr);
455                                 bfin_write(&drv_data->regs->tdbr, chip->idle_tx_val);
456                         }
457                 }
458         } else if (drv_data->tx) {
459                 /* write */
460                 dev_dbg(&drv_data->pdev->dev, "write: write_TDBR\n");
461                 if (n_bytes % 2) {
462                         u16 *buf = (u16 *)drv_data->tx;
463                         for (loop = 0; loop < n_bytes / 2; loop++) {
464                                 bfin_read(&drv_data->regs->rdbr);
465                                 bfin_write(&drv_data->regs->tdbr, *buf++);
466                         }
467                 } else {
468                         u8 *buf = (u8 *)drv_data->tx;
469                         for (loop = 0; loop < n_bytes; loop++) {
470                                 bfin_read(&drv_data->regs->rdbr);
471                                 bfin_write(&drv_data->regs->tdbr, *buf++);
472                         }
473                 }
474         }
475
476         if (drv_data->tx)
477                 drv_data->tx += n_bytes;
478         if (drv_data->rx)
479                 drv_data->rx += n_bytes;
480
481         return IRQ_HANDLED;
482 }
483
484 static irqreturn_t bfin_spi_dma_irq_handler(int irq, void *dev_id)
485 {
486         struct bfin_spi_master_data *drv_data = dev_id;
487         struct bfin_spi_slave_data *chip = drv_data->cur_chip;
488         struct spi_message *msg = drv_data->cur_msg;
489         unsigned long timeout;
490         unsigned short dmastat = get_dma_curr_irqstat(drv_data->dma_channel);
491         u16 spistat = bfin_read(&drv_data->regs->stat);
492
493         dev_dbg(&drv_data->pdev->dev,
494                 "in dma_irq_handler dmastat:0x%x spistat:0x%x\n",
495                 dmastat, spistat);
496
497         if (drv_data->rx != NULL) {
498                 u16 cr = bfin_read(&drv_data->regs->ctl);
499                 /* discard old RX data and clear RXS */
500                 bfin_spi_dummy_read(drv_data);
501                 bfin_write(&drv_data->regs->ctl, cr & ~BIT_CTL_ENABLE); /* Disable SPI */
502                 bfin_write(&drv_data->regs->ctl, cr & ~BIT_CTL_TIMOD); /* Restore State */
503                 bfin_write(&drv_data->regs->stat, BIT_STAT_CLR); /* Clear Status */
504         }
505
506         clear_dma_irqstat(drv_data->dma_channel);
507
508         /*
509          * wait for the last transaction shifted out.  HRM states:
510          * at this point there may still be data in the SPI DMA FIFO waiting
511          * to be transmitted ... software needs to poll TXS in the SPI_STAT
512          * register until it goes low for 2 successive reads
513          */
514         if (drv_data->tx != NULL) {
515                 while ((bfin_read(&drv_data->regs->stat) & BIT_STAT_TXS) ||
516                        (bfin_read(&drv_data->regs->stat) & BIT_STAT_TXS))
517                         cpu_relax();
518         }
519
520         dev_dbg(&drv_data->pdev->dev,
521                 "in dma_irq_handler dmastat:0x%x spistat:0x%x\n",
522                 dmastat, bfin_read(&drv_data->regs->stat));
523
524         timeout = jiffies + HZ;
525         while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_SPIF))
526                 if (!time_before(jiffies, timeout)) {
527                         dev_warn(&drv_data->pdev->dev, "timeout waiting for SPIF");
528                         break;
529                 } else
530                         cpu_relax();
531
532         if ((dmastat & DMA_ERR) && (spistat & BIT_STAT_RBSY)) {
533                 msg->state = ERROR_STATE;
534                 dev_err(&drv_data->pdev->dev, "dma receive: fifo/buffer overflow\n");
535         } else {
536                 msg->actual_length += drv_data->len_in_bytes;
537
538                 if (drv_data->cs_change)
539                         bfin_spi_cs_deactive(drv_data, chip);
540
541                 /* Move to next transfer */
542                 msg->state = bfin_spi_next_transfer(drv_data);
543         }
544
545         /* Schedule transfer tasklet */
546         tasklet_schedule(&drv_data->pump_transfers);
547
548         /* free the irq handler before next transfer */
549         dev_dbg(&drv_data->pdev->dev,
550                 "disable dma channel irq%d\n",
551                 drv_data->dma_channel);
552         dma_disable_irq_nosync(drv_data->dma_channel);
553
554         return IRQ_HANDLED;
555 }
556
557 static void bfin_spi_pump_transfers(unsigned long data)
558 {
559         struct bfin_spi_master_data *drv_data = (struct bfin_spi_master_data *)data;
560         struct spi_message *message = NULL;
561         struct spi_transfer *transfer = NULL;
562         struct spi_transfer *previous = NULL;
563         struct bfin_spi_slave_data *chip = NULL;
564         unsigned int bits_per_word;
565         u16 cr, cr_width, dma_width, dma_config;
566         u32 tranf_success = 1;
567         u8 full_duplex = 0;
568
569         /* Get current state information */
570         message = drv_data->cur_msg;
571         transfer = drv_data->cur_transfer;
572         chip = drv_data->cur_chip;
573
574         /*
575          * if msg is error or done, report it back using complete() callback
576          */
577
578          /* Handle for abort */
579         if (message->state == ERROR_STATE) {
580                 dev_dbg(&drv_data->pdev->dev, "transfer: we've hit an error\n");
581                 message->status = -EIO;
582                 bfin_spi_giveback(drv_data);
583                 return;
584         }
585
586         /* Handle end of message */
587         if (message->state == DONE_STATE) {
588                 dev_dbg(&drv_data->pdev->dev, "transfer: all done!\n");
589                 message->status = 0;
590                 bfin_spi_giveback(drv_data);
591                 return;
592         }
593
594         /* Delay if requested at end of transfer */
595         if (message->state == RUNNING_STATE) {
596                 dev_dbg(&drv_data->pdev->dev, "transfer: still running ...\n");
597                 previous = list_entry(transfer->transfer_list.prev,
598                                       struct spi_transfer, transfer_list);
599                 if (previous->delay_usecs)
600                         udelay(previous->delay_usecs);
601         }
602
603         /* Flush any existing transfers that may be sitting in the hardware */
604         if (bfin_spi_flush(drv_data) == 0) {
605                 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
606                 message->status = -EIO;
607                 bfin_spi_giveback(drv_data);
608                 return;
609         }
610
611         if (transfer->len == 0) {
612                 /* Move to next transfer of this msg */
613                 message->state = bfin_spi_next_transfer(drv_data);
614                 /* Schedule next transfer tasklet */
615                 tasklet_schedule(&drv_data->pump_transfers);
616                 return;
617         }
618
619         if (transfer->tx_buf != NULL) {
620                 drv_data->tx = (void *)transfer->tx_buf;
621                 drv_data->tx_end = drv_data->tx + transfer->len;
622                 dev_dbg(&drv_data->pdev->dev, "tx_buf is %p, tx_end is %p\n",
623                         transfer->tx_buf, drv_data->tx_end);
624         } else {
625                 drv_data->tx = NULL;
626         }
627
628         if (transfer->rx_buf != NULL) {
629                 full_duplex = transfer->tx_buf != NULL;
630                 drv_data->rx = transfer->rx_buf;
631                 drv_data->rx_end = drv_data->rx + transfer->len;
632                 dev_dbg(&drv_data->pdev->dev, "rx_buf is %p, rx_end is %p\n",
633                         transfer->rx_buf, drv_data->rx_end);
634         } else {
635                 drv_data->rx = NULL;
636         }
637
638         drv_data->rx_dma = transfer->rx_dma;
639         drv_data->tx_dma = transfer->tx_dma;
640         drv_data->len_in_bytes = transfer->len;
641         drv_data->cs_change = transfer->cs_change;
642
643         /* Bits per word setup */
644         bits_per_word = transfer->bits_per_word ? :
645                 message->spi->bits_per_word ? : 8;
646         if (bits_per_word % 16 == 0) {
647                 drv_data->n_bytes = bits_per_word/8;
648                 drv_data->len = (transfer->len) >> 1;
649                 cr_width = BIT_CTL_WORDSIZE;
650                 drv_data->ops = &bfin_bfin_spi_transfer_ops_u16;
651         } else if (bits_per_word % 8 == 0) {
652                 drv_data->n_bytes = bits_per_word/8;
653                 drv_data->len = transfer->len;
654                 cr_width = 0;
655                 drv_data->ops = &bfin_bfin_spi_transfer_ops_u8;
656         } else {
657                 dev_err(&drv_data->pdev->dev, "transfer: unsupported bits_per_word\n");
658                 message->status = -EINVAL;
659                 bfin_spi_giveback(drv_data);
660                 return;
661         }
662         cr = bfin_read(&drv_data->regs->ctl) & ~(BIT_CTL_TIMOD | BIT_CTL_WORDSIZE);
663         cr |= cr_width;
664         bfin_write(&drv_data->regs->ctl, cr);
665
666         dev_dbg(&drv_data->pdev->dev,
667                 "transfer: drv_data->ops is %p, chip->ops is %p, u8_ops is %p\n",
668                 drv_data->ops, chip->ops, &bfin_bfin_spi_transfer_ops_u8);
669
670         message->state = RUNNING_STATE;
671         dma_config = 0;
672
673         /* Speed setup (surely valid because already checked) */
674         if (transfer->speed_hz)
675                 bfin_write(&drv_data->regs->baud, hz_to_spi_baud(transfer->speed_hz));
676         else
677                 bfin_write(&drv_data->regs->baud, chip->baud);
678
679         bfin_write(&drv_data->regs->stat, BIT_STAT_CLR);
680         bfin_spi_cs_active(drv_data, chip);
681
682         dev_dbg(&drv_data->pdev->dev,
683                 "now pumping a transfer: width is %d, len is %d\n",
684                 cr_width, transfer->len);
685
686         /*
687          * Try to map dma buffer and do a dma transfer.  If successful use,
688          * different way to r/w according to the enable_dma settings and if
689          * we are not doing a full duplex transfer (since the hardware does
690          * not support full duplex DMA transfers).
691          */
692         if (!full_duplex && drv_data->cur_chip->enable_dma
693                                 && drv_data->len > 6) {
694
695                 unsigned long dma_start_addr, flags;
696
697                 disable_dma(drv_data->dma_channel);
698                 clear_dma_irqstat(drv_data->dma_channel);
699
700                 /* config dma channel */
701                 dev_dbg(&drv_data->pdev->dev, "doing dma transfer\n");
702                 set_dma_x_count(drv_data->dma_channel, drv_data->len);
703                 if (cr_width == BIT_CTL_WORDSIZE) {
704                         set_dma_x_modify(drv_data->dma_channel, 2);
705                         dma_width = WDSIZE_16;
706                 } else {
707                         set_dma_x_modify(drv_data->dma_channel, 1);
708                         dma_width = WDSIZE_8;
709                 }
710
711                 /* poll for SPI completion before start */
712                 while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_SPIF))
713                         cpu_relax();
714
715                 /* dirty hack for autobuffer DMA mode */
716                 if (drv_data->tx_dma == 0xFFFF) {
717                         dev_dbg(&drv_data->pdev->dev,
718                                 "doing autobuffer DMA out.\n");
719
720                         /* no irq in autobuffer mode */
721                         dma_config =
722                             (DMAFLOW_AUTO | RESTART | dma_width | DI_EN);
723                         set_dma_config(drv_data->dma_channel, dma_config);
724                         set_dma_start_addr(drv_data->dma_channel,
725                                         (unsigned long)drv_data->tx);
726                         enable_dma(drv_data->dma_channel);
727
728                         /* start SPI transfer */
729                         bfin_write(&drv_data->regs->ctl, cr | BIT_CTL_TIMOD_DMA_TX);
730
731                         /* just return here, there can only be one transfer
732                          * in this mode
733                          */
734                         message->status = 0;
735                         bfin_spi_giveback(drv_data);
736                         return;
737                 }
738
739                 /* In dma mode, rx or tx must be NULL in one transfer */
740                 dma_config = (RESTART | dma_width | DI_EN);
741                 if (drv_data->rx != NULL) {
742                         /* set transfer mode, and enable SPI */
743                         dev_dbg(&drv_data->pdev->dev, "doing DMA in to %p (size %zx)\n",
744                                 drv_data->rx, drv_data->len_in_bytes);
745
746                         /* invalidate caches, if needed */
747                         if (bfin_addr_dcacheable((unsigned long) drv_data->rx))
748                                 invalidate_dcache_range((unsigned long) drv_data->rx,
749                                                         (unsigned long) (drv_data->rx +
750                                                         drv_data->len_in_bytes));
751
752                         dma_config |= WNR;
753                         dma_start_addr = (unsigned long)drv_data->rx;
754                         cr |= BIT_CTL_TIMOD_DMA_RX | BIT_CTL_SENDOPT;
755
756                 } else if (drv_data->tx != NULL) {
757                         dev_dbg(&drv_data->pdev->dev, "doing DMA out.\n");
758
759                         /* flush caches, if needed */
760                         if (bfin_addr_dcacheable((unsigned long) drv_data->tx))
761                                 flush_dcache_range((unsigned long) drv_data->tx,
762                                                 (unsigned long) (drv_data->tx +
763                                                 drv_data->len_in_bytes));
764
765                         dma_start_addr = (unsigned long)drv_data->tx;
766                         cr |= BIT_CTL_TIMOD_DMA_TX;
767
768                 } else
769                         BUG();
770
771                 /* oh man, here there be monsters ... and i dont mean the
772                  * fluffy cute ones from pixar, i mean the kind that'll eat
773                  * your data, kick your dog, and love it all.  do *not* try
774                  * and change these lines unless you (1) heavily test DMA
775                  * with SPI flashes on a loaded system (e.g. ping floods),
776                  * (2) know just how broken the DMA engine interaction with
777                  * the SPI peripheral is, and (3) have someone else to blame
778                  * when you screw it all up anyways.
779                  */
780                 set_dma_start_addr(drv_data->dma_channel, dma_start_addr);
781                 set_dma_config(drv_data->dma_channel, dma_config);
782                 local_irq_save(flags);
783                 SSYNC();
784                 bfin_write(&drv_data->regs->ctl, cr);
785                 enable_dma(drv_data->dma_channel);
786                 dma_enable_irq(drv_data->dma_channel);
787                 local_irq_restore(flags);
788
789                 return;
790         }
791
792         /*
793          * We always use SPI_WRITE mode (transfer starts with TDBR write).
794          * SPI_READ mode (transfer starts with RDBR read) seems to have
795          * problems with setting up the output value in TDBR prior to the
796          * start of the transfer.
797          */
798         bfin_write(&drv_data->regs->ctl, cr | BIT_CTL_TXMOD);
799
800         if (chip->pio_interrupt) {
801                 /* SPI irq should have been disabled by now */
802
803                 /* discard old RX data and clear RXS */
804                 bfin_spi_dummy_read(drv_data);
805
806                 /* start transfer */
807                 if (drv_data->tx == NULL)
808                         bfin_write(&drv_data->regs->tdbr, chip->idle_tx_val);
809                 else {
810                         int loop;
811                         if (bits_per_word % 16 == 0) {
812                                 u16 *buf = (u16 *)drv_data->tx;
813                                 for (loop = 0; loop < bits_per_word / 16;
814                                                 loop++) {
815                                         bfin_write(&drv_data->regs->tdbr, *buf++);
816                                 }
817                         } else if (bits_per_word % 8 == 0) {
818                                 u8 *buf = (u8 *)drv_data->tx;
819                                 for (loop = 0; loop < bits_per_word / 8; loop++)
820                                         bfin_write(&drv_data->regs->tdbr, *buf++);
821                         }
822
823                         drv_data->tx += drv_data->n_bytes;
824                 }
825
826                 /* once TDBR is empty, interrupt is triggered */
827                 enable_irq(drv_data->spi_irq);
828                 return;
829         }
830
831         /* IO mode */
832         dev_dbg(&drv_data->pdev->dev, "doing IO transfer\n");
833
834         if (full_duplex) {
835                 /* full duplex mode */
836                 BUG_ON((drv_data->tx_end - drv_data->tx) !=
837                        (drv_data->rx_end - drv_data->rx));
838                 dev_dbg(&drv_data->pdev->dev,
839                         "IO duplex: cr is 0x%x\n", cr);
840
841                 drv_data->ops->duplex(drv_data);
842
843                 if (drv_data->tx != drv_data->tx_end)
844                         tranf_success = 0;
845         } else if (drv_data->tx != NULL) {
846                 /* write only half duplex */
847                 dev_dbg(&drv_data->pdev->dev,
848                         "IO write: cr is 0x%x\n", cr);
849
850                 drv_data->ops->write(drv_data);
851
852                 if (drv_data->tx != drv_data->tx_end)
853                         tranf_success = 0;
854         } else if (drv_data->rx != NULL) {
855                 /* read only half duplex */
856                 dev_dbg(&drv_data->pdev->dev,
857                         "IO read: cr is 0x%x\n", cr);
858
859                 drv_data->ops->read(drv_data);
860                 if (drv_data->rx != drv_data->rx_end)
861                         tranf_success = 0;
862         }
863
864         if (!tranf_success) {
865                 dev_dbg(&drv_data->pdev->dev,
866                         "IO write error!\n");
867                 message->state = ERROR_STATE;
868         } else {
869                 /* Update total byte transferred */
870                 message->actual_length += drv_data->len_in_bytes;
871                 /* Move to next transfer of this msg */
872                 message->state = bfin_spi_next_transfer(drv_data);
873                 if (drv_data->cs_change)
874                         bfin_spi_cs_deactive(drv_data, chip);
875         }
876
877         /* Schedule next transfer tasklet */
878         tasklet_schedule(&drv_data->pump_transfers);
879 }
880
881 /* pop a msg from queue and kick off real transfer */
882 static void bfin_spi_pump_messages(struct work_struct *work)
883 {
884         struct bfin_spi_master_data *drv_data;
885         unsigned long flags;
886
887         drv_data = container_of(work, struct bfin_spi_master_data, pump_messages);
888
889         /* Lock queue and check for queue work */
890         spin_lock_irqsave(&drv_data->lock, flags);
891         if (list_empty(&drv_data->queue) || !drv_data->running) {
892                 /* pumper kicked off but no work to do */
893                 drv_data->busy = 0;
894                 spin_unlock_irqrestore(&drv_data->lock, flags);
895                 return;
896         }
897
898         /* Make sure we are not already running a message */
899         if (drv_data->cur_msg) {
900                 spin_unlock_irqrestore(&drv_data->lock, flags);
901                 return;
902         }
903
904         /* Extract head of queue */
905         drv_data->cur_msg = list_entry(drv_data->queue.next,
906                                        struct spi_message, queue);
907
908         /* Setup the SSP using the per chip configuration */
909         drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
910         bfin_spi_restore_state(drv_data);
911
912         list_del_init(&drv_data->cur_msg->queue);
913
914         /* Initial message state */
915         drv_data->cur_msg->state = START_STATE;
916         drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
917                                             struct spi_transfer, transfer_list);
918
919         dev_dbg(&drv_data->pdev->dev, "got a message to pump, "
920                 "state is set to: baud %d, flag 0x%x, ctl 0x%x\n",
921                 drv_data->cur_chip->baud, drv_data->cur_chip->flag,
922                 drv_data->cur_chip->ctl_reg);
923
924         dev_dbg(&drv_data->pdev->dev,
925                 "the first transfer len is %d\n",
926                 drv_data->cur_transfer->len);
927
928         /* Mark as busy and launch transfers */
929         tasklet_schedule(&drv_data->pump_transfers);
930
931         drv_data->busy = 1;
932         spin_unlock_irqrestore(&drv_data->lock, flags);
933 }
934
935 /*
936  * got a msg to transfer, queue it in drv_data->queue.
937  * And kick off message pumper
938  */
939 static int bfin_spi_transfer(struct spi_device *spi, struct spi_message *msg)
940 {
941         struct bfin_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
942         unsigned long flags;
943
944         spin_lock_irqsave(&drv_data->lock, flags);
945
946         if (!drv_data->running) {
947                 spin_unlock_irqrestore(&drv_data->lock, flags);
948                 return -ESHUTDOWN;
949         }
950
951         msg->actual_length = 0;
952         msg->status = -EINPROGRESS;
953         msg->state = START_STATE;
954
955         dev_dbg(&spi->dev, "adding an msg in transfer() \n");
956         list_add_tail(&msg->queue, &drv_data->queue);
957
958         if (drv_data->running && !drv_data->busy)
959                 queue_work(drv_data->workqueue, &drv_data->pump_messages);
960
961         spin_unlock_irqrestore(&drv_data->lock, flags);
962
963         return 0;
964 }
965
966 #define MAX_SPI_SSEL    7
967
968 static const u16 ssel[][MAX_SPI_SSEL] = {
969         {P_SPI0_SSEL1, P_SPI0_SSEL2, P_SPI0_SSEL3,
970         P_SPI0_SSEL4, P_SPI0_SSEL5,
971         P_SPI0_SSEL6, P_SPI0_SSEL7},
972
973         {P_SPI1_SSEL1, P_SPI1_SSEL2, P_SPI1_SSEL3,
974         P_SPI1_SSEL4, P_SPI1_SSEL5,
975         P_SPI1_SSEL6, P_SPI1_SSEL7},
976
977         {P_SPI2_SSEL1, P_SPI2_SSEL2, P_SPI2_SSEL3,
978         P_SPI2_SSEL4, P_SPI2_SSEL5,
979         P_SPI2_SSEL6, P_SPI2_SSEL7},
980 };
981
982 /* setup for devices (may be called multiple times -- not just first setup) */
983 static int bfin_spi_setup(struct spi_device *spi)
984 {
985         struct bfin5xx_spi_chip *chip_info;
986         struct bfin_spi_slave_data *chip = NULL;
987         struct bfin_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
988         u16 bfin_ctl_reg;
989         int ret = -EINVAL;
990
991         /* Only alloc (or use chip_info) on first setup */
992         chip_info = NULL;
993         chip = spi_get_ctldata(spi);
994         if (chip == NULL) {
995                 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
996                 if (!chip) {
997                         dev_err(&spi->dev, "cannot allocate chip data\n");
998                         ret = -ENOMEM;
999                         goto error;
1000                 }
1001
1002                 chip->enable_dma = 0;
1003                 chip_info = spi->controller_data;
1004         }
1005
1006         /* Let people set non-standard bits directly */
1007         bfin_ctl_reg = BIT_CTL_OPENDRAIN | BIT_CTL_EMISO |
1008                 BIT_CTL_PSSE | BIT_CTL_GM | BIT_CTL_SZ;
1009
1010         /* chip_info isn't always needed */
1011         if (chip_info) {
1012                 /* Make sure people stop trying to set fields via ctl_reg
1013                  * when they should actually be using common SPI framework.
1014                  * Currently we let through: WOM EMISO PSSE GM SZ.
1015                  * Not sure if a user actually needs/uses any of these,
1016                  * but let's assume (for now) they do.
1017                  */
1018                 if (chip_info->ctl_reg & ~bfin_ctl_reg) {
1019                         dev_err(&spi->dev, "do not set bits in ctl_reg "
1020                                 "that the SPI framework manages\n");
1021                         goto error;
1022                 }
1023                 chip->enable_dma = chip_info->enable_dma != 0
1024                     && drv_data->master_info->enable_dma;
1025                 chip->ctl_reg = chip_info->ctl_reg;
1026                 chip->cs_chg_udelay = chip_info->cs_chg_udelay;
1027                 chip->idle_tx_val = chip_info->idle_tx_val;
1028                 chip->pio_interrupt = chip_info->pio_interrupt;
1029                 spi->bits_per_word = chip_info->bits_per_word;
1030         } else {
1031                 /* force a default base state */
1032                 chip->ctl_reg &= bfin_ctl_reg;
1033         }
1034
1035         if (spi->bits_per_word % 8) {
1036                 dev_err(&spi->dev, "%d bits_per_word is not supported\n",
1037                                 spi->bits_per_word);
1038                 goto error;
1039         }
1040
1041         /* translate common spi framework into our register */
1042         if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) {
1043                 dev_err(&spi->dev, "unsupported spi modes detected\n");
1044                 goto error;
1045         }
1046         if (spi->mode & SPI_CPOL)
1047                 chip->ctl_reg |= BIT_CTL_CPOL;
1048         if (spi->mode & SPI_CPHA)
1049                 chip->ctl_reg |= BIT_CTL_CPHA;
1050         if (spi->mode & SPI_LSB_FIRST)
1051                 chip->ctl_reg |= BIT_CTL_LSBF;
1052         /* we dont support running in slave mode (yet?) */
1053         chip->ctl_reg |= BIT_CTL_MASTER;
1054
1055         /*
1056          * Notice: for blackfin, the speed_hz is the value of register
1057          * SPI_BAUD, not the real baudrate
1058          */
1059         chip->baud = hz_to_spi_baud(spi->max_speed_hz);
1060         chip->chip_select_num = spi->chip_select;
1061         if (chip->chip_select_num < MAX_CTRL_CS) {
1062                 if (!(spi->mode & SPI_CPHA))
1063                         dev_warn(&spi->dev, "Warning: SPI CPHA not set:"
1064                                 " Slave Select not under software control!\n"
1065                                 " See Documentation/blackfin/bfin-spi-notes.txt");
1066
1067                 chip->flag = (1 << spi->chip_select) << 8;
1068         } else
1069                 chip->cs_gpio = chip->chip_select_num - MAX_CTRL_CS;
1070
1071         if (chip->enable_dma && chip->pio_interrupt) {
1072                 dev_err(&spi->dev, "enable_dma is set, "
1073                                 "do not set pio_interrupt\n");
1074                 goto error;
1075         }
1076         /*
1077          * if any one SPI chip is registered and wants DMA, request the
1078          * DMA channel for it
1079          */
1080         if (chip->enable_dma && !drv_data->dma_requested) {
1081                 /* register dma irq handler */
1082                 ret = request_dma(drv_data->dma_channel, "BFIN_SPI_DMA");
1083                 if (ret) {
1084                         dev_err(&spi->dev,
1085                                 "Unable to request BlackFin SPI DMA channel\n");
1086                         goto error;
1087                 }
1088                 drv_data->dma_requested = 1;
1089
1090                 ret = set_dma_callback(drv_data->dma_channel,
1091                         bfin_spi_dma_irq_handler, drv_data);
1092                 if (ret) {
1093                         dev_err(&spi->dev, "Unable to set dma callback\n");
1094                         goto error;
1095                 }
1096                 dma_disable_irq(drv_data->dma_channel);
1097         }
1098
1099         if (chip->pio_interrupt && !drv_data->irq_requested) {
1100                 ret = request_irq(drv_data->spi_irq, bfin_spi_pio_irq_handler,
1101                         IRQF_DISABLED, "BFIN_SPI", drv_data);
1102                 if (ret) {
1103                         dev_err(&spi->dev, "Unable to register spi IRQ\n");
1104                         goto error;
1105                 }
1106                 drv_data->irq_requested = 1;
1107                 /* we use write mode, spi irq has to be disabled here */
1108                 disable_irq(drv_data->spi_irq);
1109         }
1110
1111         if (chip->chip_select_num >= MAX_CTRL_CS) {
1112                 /* Only request on first setup */
1113                 if (spi_get_ctldata(spi) == NULL) {
1114                         ret = gpio_request(chip->cs_gpio, spi->modalias);
1115                         if (ret) {
1116                                 dev_err(&spi->dev, "gpio_request() error\n");
1117                                 goto pin_error;
1118                         }
1119                         gpio_direction_output(chip->cs_gpio, 1);
1120                 }
1121         }
1122
1123         dev_dbg(&spi->dev, "setup spi chip %s, width is %d, dma is %d\n",
1124                         spi->modalias, spi->bits_per_word, chip->enable_dma);
1125         dev_dbg(&spi->dev, "ctl_reg is 0x%x, flag_reg is 0x%x\n",
1126                         chip->ctl_reg, chip->flag);
1127
1128         spi_set_ctldata(spi, chip);
1129
1130         dev_dbg(&spi->dev, "chip select number is %d\n", chip->chip_select_num);
1131         if (chip->chip_select_num < MAX_CTRL_CS) {
1132                 ret = peripheral_request(ssel[spi->master->bus_num]
1133                                          [chip->chip_select_num-1], spi->modalias);
1134                 if (ret) {
1135                         dev_err(&spi->dev, "peripheral_request() error\n");
1136                         goto pin_error;
1137                 }
1138         }
1139
1140         bfin_spi_cs_enable(drv_data, chip);
1141         bfin_spi_cs_deactive(drv_data, chip);
1142
1143         return 0;
1144
1145  pin_error:
1146         if (chip->chip_select_num >= MAX_CTRL_CS)
1147                 gpio_free(chip->cs_gpio);
1148         else
1149                 peripheral_free(ssel[spi->master->bus_num]
1150                         [chip->chip_select_num - 1]);
1151  error:
1152         if (chip) {
1153                 if (drv_data->dma_requested)
1154                         free_dma(drv_data->dma_channel);
1155                 drv_data->dma_requested = 0;
1156
1157                 kfree(chip);
1158                 /* prevent free 'chip' twice */
1159                 spi_set_ctldata(spi, NULL);
1160         }
1161
1162         return ret;
1163 }
1164
1165 /*
1166  * callback for spi framework.
1167  * clean driver specific data
1168  */
1169 static void bfin_spi_cleanup(struct spi_device *spi)
1170 {
1171         struct bfin_spi_slave_data *chip = spi_get_ctldata(spi);
1172         struct bfin_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
1173
1174         if (!chip)
1175                 return;
1176
1177         if (chip->chip_select_num < MAX_CTRL_CS) {
1178                 peripheral_free(ssel[spi->master->bus_num]
1179                                         [chip->chip_select_num-1]);
1180                 bfin_spi_cs_disable(drv_data, chip);
1181         } else
1182                 gpio_free(chip->cs_gpio);
1183
1184         kfree(chip);
1185         /* prevent free 'chip' twice */
1186         spi_set_ctldata(spi, NULL);
1187 }
1188
1189 static int bfin_spi_init_queue(struct bfin_spi_master_data *drv_data)
1190 {
1191         INIT_LIST_HEAD(&drv_data->queue);
1192         spin_lock_init(&drv_data->lock);
1193
1194         drv_data->running = false;
1195         drv_data->busy = 0;
1196
1197         /* init transfer tasklet */
1198         tasklet_init(&drv_data->pump_transfers,
1199                      bfin_spi_pump_transfers, (unsigned long)drv_data);
1200
1201         /* init messages workqueue */
1202         INIT_WORK(&drv_data->pump_messages, bfin_spi_pump_messages);
1203         drv_data->workqueue = create_singlethread_workqueue(
1204                                 dev_name(drv_data->master->dev.parent));
1205         if (drv_data->workqueue == NULL)
1206                 return -EBUSY;
1207
1208         return 0;
1209 }
1210
1211 static int bfin_spi_start_queue(struct bfin_spi_master_data *drv_data)
1212 {
1213         unsigned long flags;
1214
1215         spin_lock_irqsave(&drv_data->lock, flags);
1216
1217         if (drv_data->running || drv_data->busy) {
1218                 spin_unlock_irqrestore(&drv_data->lock, flags);
1219                 return -EBUSY;
1220         }
1221
1222         drv_data->running = true;
1223         drv_data->cur_msg = NULL;
1224         drv_data->cur_transfer = NULL;
1225         drv_data->cur_chip = NULL;
1226         spin_unlock_irqrestore(&drv_data->lock, flags);
1227
1228         queue_work(drv_data->workqueue, &drv_data->pump_messages);
1229
1230         return 0;
1231 }
1232
1233 static int bfin_spi_stop_queue(struct bfin_spi_master_data *drv_data)
1234 {
1235         unsigned long flags;
1236         unsigned limit = 500;
1237         int status = 0;
1238
1239         spin_lock_irqsave(&drv_data->lock, flags);
1240
1241         /*
1242          * This is a bit lame, but is optimized for the common execution path.
1243          * A wait_queue on the drv_data->busy could be used, but then the common
1244          * execution path (pump_messages) would be required to call wake_up or
1245          * friends on every SPI message. Do this instead
1246          */
1247         drv_data->running = false;
1248         while ((!list_empty(&drv_data->queue) || drv_data->busy) && limit--) {
1249                 spin_unlock_irqrestore(&drv_data->lock, flags);
1250                 msleep(10);
1251                 spin_lock_irqsave(&drv_data->lock, flags);
1252         }
1253
1254         if (!list_empty(&drv_data->queue) || drv_data->busy)
1255                 status = -EBUSY;
1256
1257         spin_unlock_irqrestore(&drv_data->lock, flags);
1258
1259         return status;
1260 }
1261
1262 static int bfin_spi_destroy_queue(struct bfin_spi_master_data *drv_data)
1263 {
1264         int status;
1265
1266         status = bfin_spi_stop_queue(drv_data);
1267         if (status != 0)
1268                 return status;
1269
1270         destroy_workqueue(drv_data->workqueue);
1271
1272         return 0;
1273 }
1274
1275 static int __init bfin_spi_probe(struct platform_device *pdev)
1276 {
1277         struct device *dev = &pdev->dev;
1278         struct bfin5xx_spi_master *platform_info;
1279         struct spi_master *master;
1280         struct bfin_spi_master_data *drv_data;
1281         struct resource *res;
1282         int status = 0;
1283
1284         platform_info = dev->platform_data;
1285
1286         /* Allocate master with space for drv_data */
1287         master = spi_alloc_master(dev, sizeof(*drv_data));
1288         if (!master) {
1289                 dev_err(&pdev->dev, "can not alloc spi_master\n");
1290                 return -ENOMEM;
1291         }
1292
1293         drv_data = spi_master_get_devdata(master);
1294         drv_data->master = master;
1295         drv_data->master_info = platform_info;
1296         drv_data->pdev = pdev;
1297         drv_data->pin_req = platform_info->pin_req;
1298
1299         /* the spi->mode bits supported by this driver: */
1300         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
1301
1302         master->bus_num = pdev->id;
1303         master->num_chipselect = platform_info->num_chipselect;
1304         master->cleanup = bfin_spi_cleanup;
1305         master->setup = bfin_spi_setup;
1306         master->transfer = bfin_spi_transfer;
1307
1308         /* Find and map our resources */
1309         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1310         if (res == NULL) {
1311                 dev_err(dev, "Cannot get IORESOURCE_MEM\n");
1312                 status = -ENOENT;
1313                 goto out_error_get_res;
1314         }
1315
1316         drv_data->regs = ioremap(res->start, resource_size(res));
1317         if (drv_data->regs == NULL) {
1318                 dev_err(dev, "Cannot map IO\n");
1319                 status = -ENXIO;
1320                 goto out_error_ioremap;
1321         }
1322
1323         res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
1324         if (res == NULL) {
1325                 dev_err(dev, "No DMA channel specified\n");
1326                 status = -ENOENT;
1327                 goto out_error_free_io;
1328         }
1329         drv_data->dma_channel = res->start;
1330
1331         drv_data->spi_irq = platform_get_irq(pdev, 0);
1332         if (drv_data->spi_irq < 0) {
1333                 dev_err(dev, "No spi pio irq specified\n");
1334                 status = -ENOENT;
1335                 goto out_error_free_io;
1336         }
1337
1338         /* Initial and start queue */
1339         status = bfin_spi_init_queue(drv_data);
1340         if (status != 0) {
1341                 dev_err(dev, "problem initializing queue\n");
1342                 goto out_error_queue_alloc;
1343         }
1344
1345         status = bfin_spi_start_queue(drv_data);
1346         if (status != 0) {
1347                 dev_err(dev, "problem starting queue\n");
1348                 goto out_error_queue_alloc;
1349         }
1350
1351         status = peripheral_request_list(drv_data->pin_req, DRV_NAME);
1352         if (status != 0) {
1353                 dev_err(&pdev->dev, ": Requesting Peripherals failed\n");
1354                 goto out_error_queue_alloc;
1355         }
1356
1357         /* Reset SPI registers. If these registers were used by the boot loader,
1358          * the sky may fall on your head if you enable the dma controller.
1359          */
1360         bfin_write(&drv_data->regs->ctl, BIT_CTL_CPHA | BIT_CTL_MASTER);
1361         bfin_write(&drv_data->regs->flg, 0xFF00);
1362
1363         /* Register with the SPI framework */
1364         platform_set_drvdata(pdev, drv_data);
1365         status = spi_register_master(master);
1366         if (status != 0) {
1367                 dev_err(dev, "problem registering spi master\n");
1368                 goto out_error_queue_alloc;
1369         }
1370
1371         dev_info(dev, "%s, Version %s, regs@%p, dma channel@%d\n",
1372                 DRV_DESC, DRV_VERSION, drv_data->regs,
1373                 drv_data->dma_channel);
1374         return status;
1375
1376 out_error_queue_alloc:
1377         bfin_spi_destroy_queue(drv_data);
1378 out_error_free_io:
1379         iounmap(drv_data->regs);
1380 out_error_ioremap:
1381 out_error_get_res:
1382         spi_master_put(master);
1383
1384         return status;
1385 }
1386
1387 /* stop hardware and remove the driver */
1388 static int __devexit bfin_spi_remove(struct platform_device *pdev)
1389 {
1390         struct bfin_spi_master_data *drv_data = platform_get_drvdata(pdev);
1391         int status = 0;
1392
1393         if (!drv_data)
1394                 return 0;
1395
1396         /* Remove the queue */
1397         status = bfin_spi_destroy_queue(drv_data);
1398         if (status != 0)
1399                 return status;
1400
1401         /* Disable the SSP at the peripheral and SOC level */
1402         bfin_spi_disable(drv_data);
1403
1404         /* Release DMA */
1405         if (drv_data->master_info->enable_dma) {
1406                 if (dma_channel_active(drv_data->dma_channel))
1407                         free_dma(drv_data->dma_channel);
1408         }
1409
1410         if (drv_data->irq_requested) {
1411                 free_irq(drv_data->spi_irq, drv_data);
1412                 drv_data->irq_requested = 0;
1413         }
1414
1415         /* Disconnect from the SPI framework */
1416         spi_unregister_master(drv_data->master);
1417
1418         peripheral_free_list(drv_data->pin_req);
1419
1420         /* Prevent double remove */
1421         platform_set_drvdata(pdev, NULL);
1422
1423         return 0;
1424 }
1425
1426 #ifdef CONFIG_PM
1427 static int bfin_spi_suspend(struct platform_device *pdev, pm_message_t state)
1428 {
1429         struct bfin_spi_master_data *drv_data = platform_get_drvdata(pdev);
1430         int status = 0;
1431
1432         status = bfin_spi_stop_queue(drv_data);
1433         if (status != 0)
1434                 return status;
1435
1436         drv_data->ctrl_reg = bfin_read(&drv_data->regs->ctl);
1437         drv_data->flag_reg = bfin_read(&drv_data->regs->flg);
1438
1439         /*
1440          * reset SPI_CTL and SPI_FLG registers
1441          */
1442         bfin_write(&drv_data->regs->ctl, BIT_CTL_CPHA | BIT_CTL_MASTER);
1443         bfin_write(&drv_data->regs->flg, 0xFF00);
1444
1445         return 0;
1446 }
1447
1448 static int bfin_spi_resume(struct platform_device *pdev)
1449 {
1450         struct bfin_spi_master_data *drv_data = platform_get_drvdata(pdev);
1451         int status = 0;
1452
1453         bfin_write(&drv_data->regs->ctl, drv_data->ctrl_reg);
1454         bfin_write(&drv_data->regs->flg, drv_data->flag_reg);
1455
1456         /* Start the queue running */
1457         status = bfin_spi_start_queue(drv_data);
1458         if (status != 0) {
1459                 dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
1460                 return status;
1461         }
1462
1463         return 0;
1464 }
1465 #else
1466 #define bfin_spi_suspend NULL
1467 #define bfin_spi_resume NULL
1468 #endif                          /* CONFIG_PM */
1469
1470 MODULE_ALIAS("platform:bfin-spi");
1471 static struct platform_driver bfin_spi_driver = {
1472         .driver = {
1473                 .name   = DRV_NAME,
1474                 .owner  = THIS_MODULE,
1475         },
1476         .suspend        = bfin_spi_suspend,
1477         .resume         = bfin_spi_resume,
1478         .remove         = __devexit_p(bfin_spi_remove),
1479 };
1480
1481 static int __init bfin_spi_init(void)
1482 {
1483         return platform_driver_probe(&bfin_spi_driver, bfin_spi_probe);
1484 }
1485 subsys_initcall(bfin_spi_init);
1486
1487 static void __exit bfin_spi_exit(void)
1488 {
1489         platform_driver_unregister(&bfin_spi_driver);
1490 }
1491 module_exit(bfin_spi_exit);