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spi: spi_bfin cleanups, error handling
[linux-2.6/openmoko-kernel/knife-kernel.git] / drivers / spi / spi_bfin5xx.c
blob803c5b25db505faca18218a20c5c6516a91f8f3d
1 /*
2 * File: drivers/spi/bfin5xx_spi.c
3 * Maintainer:
4 * Bryan Wu <bryan.wu@analog.com>
5 * Original Author:
6 * Luke Yang (Analog Devices Inc.)
7 *
8 * Created: March. 10th 2006
9 * Description: SPI controller driver for Blackfin BF5xx
10 * Bugs: Enter bugs at http://blackfin.uclinux.org/
11 *
12 * Modified:
13 * March 10, 2006 bfin5xx_spi.c Created. (Luke Yang)
14 * August 7, 2006 added full duplex mode (Axel Weiss & Luke Yang)
15 * July 17, 2007 add support for BF54x SPI0 controller (Bryan Wu)
16 *
17 * Copyright 2004-2007 Analog Devices Inc.
18 *
19 * This program is free software ; you can redistribute it and/or modify
20 * it under the terms of the GNU General Public License as published by
21 * the Free Software Foundation ; either version 2, or (at your option)
22 * any later version.
23 *
24 * This program is distributed in the hope that it will be useful,
25 * but WITHOUT ANY WARRANTY ; without even the implied warranty of
26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
27 * GNU General Public License for more details.
28 *
29 * You should have received a copy of the GNU General Public License
30 * along with this program ; see the file COPYING.
31 * If not, write to the Free Software Foundation,
32 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
33 */
34
35 #include <linux/init.h>
36 #include <linux/module.h>
37 #include <linux/delay.h>
38 #include <linux/device.h>
39 #include <linux/io.h>
40 #include <linux/ioport.h>
41 #include <linux/irq.h>
42 #include <linux/errno.h>
43 #include <linux/interrupt.h>
44 #include <linux/platform_device.h>
45 #include <linux/dma-mapping.h>
46 #include <linux/spi/spi.h>
47 #include <linux/workqueue.h>
48
49 #include <asm/dma.h>
50 #include <asm/portmux.h>
51 #include <asm/bfin5xx_spi.h>
52
53 MODULE_AUTHOR("Bryan Wu, Luke Yang");
54 MODULE_DESCRIPTION("Blackfin BF5xx SPI Contoller Driver");
55 MODULE_LICENSE("GPL");
56
57 #define DRV_NAME "bfin-spi-master"
58 #define IS_DMA_ALIGNED(x) (((u32)(x)&0x07)==0)
59
60 #define DEFINE_SPI_REG(reg, off) \
61 static inline u16 read_##reg(void) \
62 { return bfin_read16(SPI0_REGBASE + off); } \
63 static inline void write_##reg(u16 v) \
64 {bfin_write16(SPI0_REGBASE + off, v); }
65
66 DEFINE_SPI_REG(CTRL, 0x00)
67 DEFINE_SPI_REG(FLAG, 0x04)
68 DEFINE_SPI_REG(STAT, 0x08)
69 DEFINE_SPI_REG(TDBR, 0x0C)
70 DEFINE_SPI_REG(RDBR, 0x10)
71 DEFINE_SPI_REG(BAUD, 0x14)
72 DEFINE_SPI_REG(SHAW, 0x18)
73 #define START_STATE ((void*)0)
74 #define RUNNING_STATE ((void*)1)
75 #define DONE_STATE ((void*)2)
76 #define ERROR_STATE ((void*)-1)
77 #define QUEUE_RUNNING 0
78 #define QUEUE_STOPPED 1
79 int dma_requested;
80
81 struct driver_data {
82 /* Driver model hookup */
83 struct platform_device *pdev;
84
85 /* SPI framework hookup */
86 struct spi_master *master;
87
88 /* BFIN hookup */
89 struct bfin5xx_spi_master *master_info;
90
91 /* Driver message queue */
92 struct workqueue_struct *workqueue;
93 struct work_struct pump_messages;
94 spinlock_t lock;
95 struct list_head queue;
96 int busy;
97 int run;
98
99 /* Message Transfer pump */
100 struct tasklet_struct pump_transfers;
101
102 /* Current message transfer state info */
103 struct spi_message *cur_msg;
104 struct spi_transfer *cur_transfer;
105 struct chip_data *cur_chip;
106 size_t len_in_bytes;
107 size_t len;
108 void *tx;
109 void *tx_end;
110 void *rx;
111 void *rx_end;
112 int dma_mapped;
113 dma_addr_t rx_dma;
114 dma_addr_t tx_dma;
115 size_t rx_map_len;
116 size_t tx_map_len;
117 u8 n_bytes;
118 void (*write) (struct driver_data *);
119 void (*read) (struct driver_data *);
120 void (*duplex) (struct driver_data *);
121 };
122
123 struct chip_data {
124 u16 ctl_reg;
125 u16 baud;
126 u16 flag;
127
128 u8 chip_select_num;
129 u8 chip_select_requested;
130 u8 n_bytes;
131 u8 width; /* 0 or 1 */
132 u8 enable_dma;
133 u8 bits_per_word; /* 8 or 16 */
134 u8 cs_change_per_word;
135 u8 cs_chg_udelay;
136 void (*write) (struct driver_data *);
137 void (*read) (struct driver_data *);
138 void (*duplex) (struct driver_data *);
139 };
140
141 static void bfin_spi_enable(struct driver_data *drv_data)
142 {
143 u16 cr;
144
145 cr = read_CTRL();
146 write_CTRL(cr | BIT_CTL_ENABLE);
147 }
148
149 static void bfin_spi_disable(struct driver_data *drv_data)
150 {
151 u16 cr;
152
153 cr = read_CTRL();
154 write_CTRL(cr & (~BIT_CTL_ENABLE));
155 }
156
157 /* Caculate the SPI_BAUD register value based on input HZ */
158 static u16 hz_to_spi_baud(u32 speed_hz)
159 {
160 u_long sclk = get_sclk();
161 u16 spi_baud = (sclk / (2 * speed_hz));
162
163 if ((sclk % (2 * speed_hz)) > 0)
164 spi_baud++;
165
166 return spi_baud;
167 }
168
169 static int flush(struct driver_data *drv_data)
170 {
171 unsigned long limit = loops_per_jiffy << 1;
172
173 /* wait for stop and clear stat */
174 while (!(read_STAT() & BIT_STAT_SPIF) && limit--)
175 continue;
176
177 write_STAT(BIT_STAT_CLR);
178
179 return limit;
180 }
181
182 #define MAX_SPI0_SSEL 7
183
184 /* stop controller and re-config current chip*/
185 static int restore_state(struct driver_data *drv_data)
186 {
187 struct chip_data *chip = drv_data->cur_chip;
188 int ret = 0;
189 u16 ssel[MAX_SPI0_SSEL] = {P_SPI0_SSEL1, P_SPI0_SSEL2, P_SPI0_SSEL3,
190 P_SPI0_SSEL4, P_SPI0_SSEL5,
191 P_SPI0_SSEL6, P_SPI0_SSEL7,};
192
193 /* Clear status and disable clock */
194 write_STAT(BIT_STAT_CLR);
195 bfin_spi_disable(drv_data);
196 dev_dbg(&drv_data->pdev->dev, "restoring spi ctl state\n");
197
198 /* Load the registers */
199 write_CTRL(chip->ctl_reg);
200 write_BAUD(chip->baud);
201 write_FLAG(chip->flag);
202
203 if (!chip->chip_select_requested) {
204 int i = chip->chip_select_num;
205
206 dev_dbg(&drv_data->pdev->dev, "chip select number is %d\n", i);
207
208 if ((i > 0) && (i <= MAX_SPI0_SSEL))
209 ret = peripheral_request(ssel[i-1], DRV_NAME);
210
211 chip->chip_select_requested = 1;
212 }
213
214 if (ret)
215 dev_dbg(&drv_data->pdev->dev,
216 ": request chip select number %d failed\n",
217 chip->chip_select_num);
218
219 return ret;
220 }
221
222 /* used to kick off transfer in rx mode */
223 static unsigned short dummy_read(void)
224 {
225 unsigned short tmp;
226 tmp = read_RDBR();
227 return tmp;
228 }
229
230 static void null_writer(struct driver_data *drv_data)
231 {
232 u8 n_bytes = drv_data->n_bytes;
233
234 while (drv_data->tx < drv_data->tx_end) {
235 write_TDBR(0);
236 while ((read_STAT() & BIT_STAT_TXS))
237 continue;
238 drv_data->tx += n_bytes;
239 }
240 }
241
242 static void null_reader(struct driver_data *drv_data)
243 {
244 u8 n_bytes = drv_data->n_bytes;
245 dummy_read();
246
247 while (drv_data->rx < drv_data->rx_end) {
248 while (!(read_STAT() & BIT_STAT_RXS))
249 continue;
250 dummy_read();
251 drv_data->rx += n_bytes;
252 }
253 }
254
255 static void u8_writer(struct driver_data *drv_data)
256 {
257 dev_dbg(&drv_data->pdev->dev,
258 "cr8-s is 0x%x\n", read_STAT());
259 while (drv_data->tx < drv_data->tx_end) {
260 write_TDBR(*(u8 *) (drv_data->tx));
261 while (read_STAT() & BIT_STAT_TXS)
262 continue;
263 ++drv_data->tx;
264 }
265
266 /* poll for SPI completion before returning */
267 while (!(read_STAT() & BIT_STAT_SPIF))
268 continue;
269 }
270
271 static void u8_cs_chg_writer(struct driver_data *drv_data)
272 {
273 struct chip_data *chip = drv_data->cur_chip;
274
275 while (drv_data->tx < drv_data->tx_end) {
276 write_FLAG(chip->flag);
277
278 write_TDBR(*(u8 *) (drv_data->tx));
279 while (read_STAT() & BIT_STAT_TXS)
280 continue;
281 while (!(read_STAT() & BIT_STAT_SPIF))
282 continue;
283 write_FLAG(0xFF00 | chip->flag);
284
285 if (chip->cs_chg_udelay)
286 udelay(chip->cs_chg_udelay);
287 ++drv_data->tx;
288 }
289 write_FLAG(0xFF00);
290
291 }
292
293 static void u8_reader(struct driver_data *drv_data)
294 {
295 dev_dbg(&drv_data->pdev->dev,
296 "cr-8 is 0x%x\n", read_STAT());
297
298 /* clear TDBR buffer before read(else it will be shifted out) */
299 write_TDBR(0xFFFF);
300
301 dummy_read();
302
303 while (drv_data->rx < drv_data->rx_end - 1) {
304 while (!(read_STAT() & BIT_STAT_RXS))
305 continue;
306 *(u8 *) (drv_data->rx) = read_RDBR();
307 ++drv_data->rx;
308 }
309
310 while (!(read_STAT() & BIT_STAT_RXS))
311 continue;
312 *(u8 *) (drv_data->rx) = read_SHAW();
313 ++drv_data->rx;
314 }
315
316 static void u8_cs_chg_reader(struct driver_data *drv_data)
317 {
318 struct chip_data *chip = drv_data->cur_chip;
319
320 while (drv_data->rx < drv_data->rx_end) {
321 write_FLAG(chip->flag);
322
323 read_RDBR(); /* kick off */
324 while (!(read_STAT() & BIT_STAT_RXS))
325 continue;
326 while (!(read_STAT() & BIT_STAT_SPIF))
327 continue;
328 *(u8 *) (drv_data->rx) = read_SHAW();
329 write_FLAG(0xFF00 | chip->flag);
330
331 if (chip->cs_chg_udelay)
332 udelay(chip->cs_chg_udelay);
333 ++drv_data->rx;
334 }
335 write_FLAG(0xFF00);
336
337 }
338
339 static void u8_duplex(struct driver_data *drv_data)
340 {
341 /* in duplex mode, clk is triggered by writing of TDBR */
342 while (drv_data->rx < drv_data->rx_end) {
343 write_TDBR(*(u8 *) (drv_data->tx));
344 while (!(read_STAT() & BIT_STAT_SPIF))
345 continue;
346 while (!(read_STAT() & BIT_STAT_RXS))
347 continue;
348 *(u8 *) (drv_data->rx) = read_RDBR();
349 ++drv_data->rx;
350 ++drv_data->tx;
351 }
352 }
353
354 static void u8_cs_chg_duplex(struct driver_data *drv_data)
355 {
356 struct chip_data *chip = drv_data->cur_chip;
357
358 while (drv_data->rx < drv_data->rx_end) {
359 write_FLAG(chip->flag);
360
361
362 write_TDBR(*(u8 *) (drv_data->tx));
363 while (!(read_STAT() & BIT_STAT_SPIF))
364 continue;
365 while (!(read_STAT() & BIT_STAT_RXS))
366 continue;
367 *(u8 *) (drv_data->rx) = read_RDBR();
368 write_FLAG(0xFF00 | chip->flag);
369
370 if (chip->cs_chg_udelay)
371 udelay(chip->cs_chg_udelay);
372 ++drv_data->rx;
373 ++drv_data->tx;
374 }
375 write_FLAG(0xFF00);
376
377 }
378
379 static void u16_writer(struct driver_data *drv_data)
380 {
381 dev_dbg(&drv_data->pdev->dev,
382 "cr16 is 0x%x\n", read_STAT());
383
384 while (drv_data->tx < drv_data->tx_end) {
385 write_TDBR(*(u16 *) (drv_data->tx));
386 while ((read_STAT() & BIT_STAT_TXS))
387 continue;
388 drv_data->tx += 2;
389 }
390
391 /* poll for SPI completion before returning */
392 while (!(read_STAT() & BIT_STAT_SPIF))
393 continue;
394 }
395
396 static void u16_cs_chg_writer(struct driver_data *drv_data)
397 {
398 struct chip_data *chip = drv_data->cur_chip;
399
400 while (drv_data->tx < drv_data->tx_end) {
401 write_FLAG(chip->flag);
402
403 write_TDBR(*(u16 *) (drv_data->tx));
404 while ((read_STAT() & BIT_STAT_TXS))
405 continue;
406 while (!(read_STAT() & BIT_STAT_SPIF))
407 continue;
408 write_FLAG(0xFF00 | chip->flag);
409
410 if (chip->cs_chg_udelay)
411 udelay(chip->cs_chg_udelay);
412 drv_data->tx += 2;
413 }
414 write_FLAG(0xFF00);
415 }
416
417 static void u16_reader(struct driver_data *drv_data)
418 {
419 dev_dbg(&drv_data->pdev->dev,
420 "cr-16 is 0x%x\n", read_STAT());
421 dummy_read();
422
423 while (drv_data->rx < (drv_data->rx_end - 2)) {
424 while (!(read_STAT() & BIT_STAT_RXS))
425 continue;
426 *(u16 *) (drv_data->rx) = read_RDBR();
427 drv_data->rx += 2;
428 }
429
430 while (!(read_STAT() & BIT_STAT_RXS))
431 continue;
432 *(u16 *) (drv_data->rx) = read_SHAW();
433 drv_data->rx += 2;
434 }
435
436 static void u16_cs_chg_reader(struct driver_data *drv_data)
437 {
438 struct chip_data *chip = drv_data->cur_chip;
439
440 while (drv_data->rx < drv_data->rx_end) {
441 write_FLAG(chip->flag);
442
443 read_RDBR(); /* kick off */
444 while (!(read_STAT() & BIT_STAT_RXS))
445 continue;
446 while (!(read_STAT() & BIT_STAT_SPIF))
447 continue;
448 *(u16 *) (drv_data->rx) = read_SHAW();
449 write_FLAG(0xFF00 | chip->flag);
450
451 if (chip->cs_chg_udelay)
452 udelay(chip->cs_chg_udelay);
453 drv_data->rx += 2;
454 }
455 write_FLAG(0xFF00);
456 }
457
458 static void u16_duplex(struct driver_data *drv_data)
459 {
460 /* in duplex mode, clk is triggered by writing of TDBR */
461 while (drv_data->tx < drv_data->tx_end) {
462 write_TDBR(*(u16 *) (drv_data->tx));
463 while (!(read_STAT() & BIT_STAT_SPIF))
464 continue;
465 while (!(read_STAT() & BIT_STAT_RXS))
466 continue;
467 *(u16 *) (drv_data->rx) = read_RDBR();
468 drv_data->rx += 2;
469 drv_data->tx += 2;
470 }
471 }
472
473 static void u16_cs_chg_duplex(struct driver_data *drv_data)
474 {
475 struct chip_data *chip = drv_data->cur_chip;
476
477 while (drv_data->tx < drv_data->tx_end) {
478 write_FLAG(chip->flag);
479
480 write_TDBR(*(u16 *) (drv_data->tx));
481 while (!(read_STAT() & BIT_STAT_SPIF))
482 continue;
483 while (!(read_STAT() & BIT_STAT_RXS))
484 continue;
485 *(u16 *) (drv_data->rx) = read_RDBR();
486 write_FLAG(0xFF00 | chip->flag);
487
488 if (chip->cs_chg_udelay)
489 udelay(chip->cs_chg_udelay);
490 drv_data->rx += 2;
491 drv_data->tx += 2;
492 }
493 write_FLAG(0xFF00);
494 }
495
496 /* test if ther is more transfer to be done */
497 static void *next_transfer(struct driver_data *drv_data)
498 {
499 struct spi_message *msg = drv_data->cur_msg;
500 struct spi_transfer *trans = drv_data->cur_transfer;
501
502 /* Move to next transfer */
503 if (trans->transfer_list.next != &msg->transfers) {
504 drv_data->cur_transfer =
505 list_entry(trans->transfer_list.next,
506 struct spi_transfer, transfer_list);
507 return RUNNING_STATE;
508 } else
509 return DONE_STATE;
510 }
511
512 /*
513 * caller already set message->status;
514 * dma and pio irqs are blocked give finished message back
515 */
516 static void giveback(struct driver_data *drv_data)
517 {
518 struct spi_transfer *last_transfer;
519 unsigned long flags;
520 struct spi_message *msg;
521
522 spin_lock_irqsave(&drv_data->lock, flags);
523 msg = drv_data->cur_msg;
524 drv_data->cur_msg = NULL;
525 drv_data->cur_transfer = NULL;
526 drv_data->cur_chip = NULL;
527 queue_work(drv_data->workqueue, &drv_data->pump_messages);
528 spin_unlock_irqrestore(&drv_data->lock, flags);
529
530 last_transfer = list_entry(msg->transfers.prev,
531 struct spi_transfer, transfer_list);
532
533 msg->state = NULL;
534
535 /* disable chip select signal. And not stop spi in autobuffer mode */
536 if (drv_data->tx_dma != 0xFFFF) {
537 write_FLAG(0xFF00);
538 bfin_spi_disable(drv_data);
539 }
540
541 if (msg->complete)
542 msg->complete(msg->context);
543 }
544
545 static irqreturn_t dma_irq_handler(int irq, void *dev_id)
546 {
547 struct driver_data *drv_data = (struct driver_data *)dev_id;
548 struct spi_message *msg = drv_data->cur_msg;
549
550 dev_dbg(&drv_data->pdev->dev, "in dma_irq_handler\n");
551 clear_dma_irqstat(CH_SPI);
552
553 /* Wait for DMA to complete */
554 while (get_dma_curr_irqstat(CH_SPI) & DMA_RUN)
555 continue;
556
557 /*
558 * wait for the last transaction shifted out. HRM states:
559 * at this point there may still be data in the SPI DMA FIFO waiting
560 * to be transmitted ... software needs to poll TXS in the SPI_STAT
561 * register until it goes low for 2 successive reads
562 */
563 if (drv_data->tx != NULL) {
564 while ((bfin_read_SPI_STAT() & TXS) ||
565 (bfin_read_SPI_STAT() & TXS))
566 continue;
567 }
568
569 while (!(bfin_read_SPI_STAT() & SPIF))
570 continue;
571
572 bfin_spi_disable(drv_data);
573
574 msg->actual_length += drv_data->len_in_bytes;
575
576 /* Move to next transfer */
577 msg->state = next_transfer(drv_data);
578
579 /* Schedule transfer tasklet */
580 tasklet_schedule(&drv_data->pump_transfers);
581
582 /* free the irq handler before next transfer */
583 dev_dbg(&drv_data->pdev->dev,
584 "disable dma channel irq%d\n",
585 CH_SPI);
586 dma_disable_irq(CH_SPI);
587
588 return IRQ_HANDLED;
589 }
590
591 static void pump_transfers(unsigned long data)
592 {
593 struct driver_data *drv_data = (struct driver_data *)data;
594 struct spi_message *message = NULL;
595 struct spi_transfer *transfer = NULL;
596 struct spi_transfer *previous = NULL;
597 struct chip_data *chip = NULL;
598 u8 width;
599 u16 cr, dma_width, dma_config;
600 u32 tranf_success = 1;
601
602 /* Get current state information */
603 message = drv_data->cur_msg;
604 transfer = drv_data->cur_transfer;
605 chip = drv_data->cur_chip;
606
607 /*
608 * if msg is error or done, report it back using complete() callback
609 */
610
611 /* Handle for abort */
612 if (message->state == ERROR_STATE) {
613 message->status = -EIO;
614 giveback(drv_data);
615 return;
616 }
617
618 /* Handle end of message */
619 if (message->state == DONE_STATE) {
620 message->status = 0;
621 giveback(drv_data);
622 return;
623 }
624
625 /* Delay if requested at end of transfer */
626 if (message->state == RUNNING_STATE) {
627 previous = list_entry(transfer->transfer_list.prev,
628 struct spi_transfer, transfer_list);
629 if (previous->delay_usecs)
630 udelay(previous->delay_usecs);
631 }
632
633 /* Setup the transfer state based on the type of transfer */
634 if (flush(drv_data) == 0) {
635 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
636 message->status = -EIO;
637 giveback(drv_data);
638 return;
639 }
640
641 if (transfer->tx_buf != NULL) {
642 drv_data->tx = (void *)transfer->tx_buf;
643 drv_data->tx_end = drv_data->tx + transfer->len;
644 dev_dbg(&drv_data->pdev->dev, "tx_buf is %p, tx_end is %p\n",
645 transfer->tx_buf, drv_data->tx_end);
646 } else {
647 drv_data->tx = NULL;
648 }
649
650 if (transfer->rx_buf != NULL) {
651 drv_data->rx = transfer->rx_buf;
652 drv_data->rx_end = drv_data->rx + transfer->len;
653 dev_dbg(&drv_data->pdev->dev, "rx_buf is %p, rx_end is %p\n",
654 transfer->rx_buf, drv_data->rx_end);
655 } else {
656 drv_data->rx = NULL;
657 }
658
659 drv_data->rx_dma = transfer->rx_dma;
660 drv_data->tx_dma = transfer->tx_dma;
661 drv_data->len_in_bytes = transfer->len;
662
663 width = chip->width;
664 if (width == CFG_SPI_WORDSIZE16) {
665 drv_data->len = (transfer->len) >> 1;
666 } else {
667 drv_data->len = transfer->len;
668 }
669 drv_data->write = drv_data->tx ? chip->write : null_writer;
670 drv_data->read = drv_data->rx ? chip->read : null_reader;
671 drv_data->duplex = chip->duplex ? chip->duplex : null_writer;
672 dev_dbg(&drv_data->pdev->dev, "transfer: ",
673 "drv_data->write is %p, chip->write is %p, null_wr is %p\n",
674 drv_data->write, chip->write, null_writer);
675
676 /* speed and width has been set on per message */
677 message->state = RUNNING_STATE;
678 dma_config = 0;
679
680 /* restore spi status for each spi transfer */
681 if (transfer->speed_hz) {
682 write_BAUD(hz_to_spi_baud(transfer->speed_hz));
683 } else {
684 write_BAUD(chip->baud);
685 }
686 write_FLAG(chip->flag);
687
688 dev_dbg(&drv_data->pdev->dev,
689 "now pumping a transfer: width is %d, len is %d\n",
690 width, transfer->len);
691
692 /*
693 * Try to map dma buffer and do a dma transfer if
694 * successful use different way to r/w according to
695 * drv_data->cur_chip->enable_dma
696 */
697 if (drv_data->cur_chip->enable_dma && drv_data->len > 6) {
698
699 write_STAT(BIT_STAT_CLR);
700 disable_dma(CH_SPI);
701 clear_dma_irqstat(CH_SPI);
702 bfin_spi_disable(drv_data);
703
704 /* config dma channel */
705 dev_dbg(&drv_data->pdev->dev, "doing dma transfer\n");
706 if (width == CFG_SPI_WORDSIZE16) {
707 set_dma_x_count(CH_SPI, drv_data->len);
708 set_dma_x_modify(CH_SPI, 2);
709 dma_width = WDSIZE_16;
710 } else {
711 set_dma_x_count(CH_SPI, drv_data->len);
712 set_dma_x_modify(CH_SPI, 1);
713 dma_width = WDSIZE_8;
714 }
715
716 /* set transfer width,direction. And enable spi */
717 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
718
719 /* dirty hack for autobuffer DMA mode */
720 if (drv_data->tx_dma == 0xFFFF) {
721 dev_dbg(&drv_data->pdev->dev,
722 "doing autobuffer DMA out.\n");
723
724 /* no irq in autobuffer mode */
725 dma_config =
726 (DMAFLOW_AUTO | RESTART | dma_width | DI_EN);
727 set_dma_config(CH_SPI, dma_config);
728 set_dma_start_addr(CH_SPI, (unsigned long)drv_data->tx);
729 enable_dma(CH_SPI);
730 write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) |
731 (CFG_SPI_ENABLE << 14));
732
733 /* just return here, there can only be one transfer in this mode */
734 message->status = 0;
735 giveback(drv_data);
736 return;
737 }
738
739 /* In dma mode, rx or tx must be NULL in one transfer */
740 if (drv_data->rx != NULL) {
741 /* set transfer mode, and enable SPI */
742 dev_dbg(&drv_data->pdev->dev, "doing DMA in.\n");
743
744 /* disable SPI before write to TDBR */
745 write_CTRL(cr & ~BIT_CTL_ENABLE);
746
747 /* clear tx reg soformer data is not shifted out */
748 write_TDBR(0xFF);
749
750 set_dma_x_count(CH_SPI, drv_data->len);
751
752 /* start dma */
753 dma_enable_irq(CH_SPI);
754 dma_config = (WNR | RESTART | dma_width | DI_EN);
755 set_dma_config(CH_SPI, dma_config);
756 set_dma_start_addr(CH_SPI, (unsigned long)drv_data->rx);
757 enable_dma(CH_SPI);
758
759 cr |=
760 CFG_SPI_DMAREAD | (width << 8) | (CFG_SPI_ENABLE <<
761 14);
762 /* set transfer mode, and enable SPI */
763 write_CTRL(cr);
764 } else if (drv_data->tx != NULL) {
765 dev_dbg(&drv_data->pdev->dev, "doing DMA out.\n");
766
767 /* start dma */
768 dma_enable_irq(CH_SPI);
769 dma_config = (RESTART | dma_width | DI_EN);
770 set_dma_config(CH_SPI, dma_config);
771 set_dma_start_addr(CH_SPI, (unsigned long)drv_data->tx);
772 enable_dma(CH_SPI);
773
774 write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) |
775 (CFG_SPI_ENABLE << 14));
776
777 }
778 } else {
779 /* IO mode write then read */
780 dev_dbg(&drv_data->pdev->dev, "doing IO transfer\n");
781
782 write_STAT(BIT_STAT_CLR);
783
784 if (drv_data->tx != NULL && drv_data->rx != NULL) {
785 /* full duplex mode */
786 BUG_ON((drv_data->tx_end - drv_data->tx) !=
787 (drv_data->rx_end - drv_data->rx));
788 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
789 cr |= CFG_SPI_WRITE | (width << 8) |
790 (CFG_SPI_ENABLE << 14);
791 dev_dbg(&drv_data->pdev->dev,
792 "IO duplex: cr is 0x%x\n", cr);
793
794 write_CTRL(cr);
795
796 drv_data->duplex(drv_data);
797
798 if (drv_data->tx != drv_data->tx_end)
799 tranf_success = 0;
800 } else if (drv_data->tx != NULL) {
801 /* write only half duplex */
802 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
803 cr |= CFG_SPI_WRITE | (width << 8) |
804 (CFG_SPI_ENABLE << 14);
805 dev_dbg(&drv_data->pdev->dev,
806 "IO write: cr is 0x%x\n", cr);
807
808 write_CTRL(cr);
809
810 drv_data->write(drv_data);
811
812 if (drv_data->tx != drv_data->tx_end)
813 tranf_success = 0;
814 } else if (drv_data->rx != NULL) {
815 /* read only half duplex */
816 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
817 cr |= CFG_SPI_READ | (width << 8) |
818 (CFG_SPI_ENABLE << 14);
819 dev_dbg(&drv_data->pdev->dev,
820 "IO read: cr is 0x%x\n", cr);
821
822 write_CTRL(cr);
823
824 drv_data->read(drv_data);
825 if (drv_data->rx != drv_data->rx_end)
826 tranf_success = 0;
827 }
828
829 if (!tranf_success) {
830 dev_dbg(&drv_data->pdev->dev,
831 "IO write error!\n");
832 message->state = ERROR_STATE;
833 } else {
834 /* Update total byte transfered */
835 message->actual_length += drv_data->len;
836
837 /* Move to next transfer of this msg */
838 message->state = next_transfer(drv_data);
839 }
840
841 /* Schedule next transfer tasklet */
842 tasklet_schedule(&drv_data->pump_transfers);
843
844 }
845 }
846
847 /* pop a msg from queue and kick off real transfer */
848 static void pump_messages(struct work_struct *work)
849 {
850 struct driver_data *drv_data;
851 unsigned long flags;
852
853 drv_data = container_of(work, struct driver_data, pump_messages);
854
855 /* Lock queue and check for queue work */
856 spin_lock_irqsave(&drv_data->lock, flags);
857 if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
858 /* pumper kicked off but no work to do */
859 drv_data->busy = 0;
860 spin_unlock_irqrestore(&drv_data->lock, flags);
861 return;
862 }
863
864 /* Make sure we are not already running a message */
865 if (drv_data->cur_msg) {
866 spin_unlock_irqrestore(&drv_data->lock, flags);
867 return;
868 }
869
870 /* Extract head of queue */
871 drv_data->cur_msg = list_entry(drv_data->queue.next,
872 struct spi_message, queue);
873
874 /* Setup the SSP using the per chip configuration */
875 drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
876 if (restore_state(drv_data)) {
877 spin_unlock_irqrestore(&drv_data->lock, flags);
878 return;
879 };
880
881 list_del_init(&drv_data->cur_msg->queue);
882
883 /* Initial message state */
884 drv_data->cur_msg->state = START_STATE;
885 drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
886 struct spi_transfer, transfer_list);
887
888 dev_dbg(&drv_data->pdev->dev, "got a message to pump, "
889 "state is set to: baud %d, flag 0x%x, ctl 0x%x\n",
890 drv_data->cur_chip->baud, drv_data->cur_chip->flag,
891 drv_data->cur_chip->ctl_reg);
892
893 dev_dbg(&drv_data->pdev->dev,
894 "the first transfer len is %d\n",
895 drv_data->cur_transfer->len);
896
897 /* Mark as busy and launch transfers */
898 tasklet_schedule(&drv_data->pump_transfers);
899
900 drv_data->busy = 1;
901 spin_unlock_irqrestore(&drv_data->lock, flags);
902 }
903
904 /*
905 * got a msg to transfer, queue it in drv_data->queue.
906 * And kick off message pumper
907 */
908 static int transfer(struct spi_device *spi, struct spi_message *msg)
909 {
910 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
911 unsigned long flags;
912
913 spin_lock_irqsave(&drv_data->lock, flags);
914
915 if (drv_data->run == QUEUE_STOPPED) {
916 spin_unlock_irqrestore(&drv_data->lock, flags);
917 return -ESHUTDOWN;
918 }
919
920 msg->actual_length = 0;
921 msg->status = -EINPROGRESS;
922 msg->state = START_STATE;
923
924 dev_dbg(&spi->dev, "adding an msg in transfer() \n");
925 list_add_tail(&msg->queue, &drv_data->queue);
926
927 if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
928 queue_work(drv_data->workqueue, &drv_data->pump_messages);
929
930 spin_unlock_irqrestore(&drv_data->lock, flags);
931
932 return 0;
933 }
934
935 /* first setup for new devices */
936 static int setup(struct spi_device *spi)
937 {
938 struct bfin5xx_spi_chip *chip_info = NULL;
939 struct chip_data *chip;
940 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
941 u8 spi_flg;
942
943 /* Abort device setup if requested features are not supported */
944 if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) {
945 dev_err(&spi->dev, "requested mode not fully supported\n");
946 return -EINVAL;
947 }
948
949 /* Zero (the default) here means 8 bits */
950 if (!spi->bits_per_word)
951 spi->bits_per_word = 8;
952
953 if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
954 return -EINVAL;
955
956 /* Only alloc (or use chip_info) on first setup */
957 chip = spi_get_ctldata(spi);
958 if (chip == NULL) {
959 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
960 if (!chip)
961 return -ENOMEM;
962
963 chip->enable_dma = 0;
964 chip_info = spi->controller_data;
965 }
966
967 /* chip_info isn't always needed */
968 if (chip_info) {
969 chip->enable_dma = chip_info->enable_dma != 0
970 && drv_data->master_info->enable_dma;
971 chip->ctl_reg = chip_info->ctl_reg;
972 chip->bits_per_word = chip_info->bits_per_word;
973 chip->cs_change_per_word = chip_info->cs_change_per_word;
974 chip->cs_chg_udelay = chip_info->cs_chg_udelay;
975 }
976
977 /* translate common spi framework into our register */
978 if (spi->mode & SPI_CPOL)
979 chip->ctl_reg |= CPOL;
980 if (spi->mode & SPI_CPHA)
981 chip->ctl_reg |= CPHA;
982 if (spi->mode & SPI_LSB_FIRST)
983 chip->ctl_reg |= LSBF;
984 /* we dont support running in slave mode (yet?) */
985 chip->ctl_reg |= MSTR;
986
987 /*
988 * if any one SPI chip is registered and wants DMA, request the
989 * DMA channel for it
990 */
991 if (chip->enable_dma && !dma_requested) {
992 /* register dma irq handler */
993 if (request_dma(CH_SPI, "BF53x_SPI_DMA") < 0) {
994 dev_dbg(&spi->dev,
995 "Unable to request BlackFin SPI DMA channel\n");
996 return -ENODEV;
997 }
998 if (set_dma_callback(CH_SPI, (void *)dma_irq_handler, drv_data)
999 < 0) {
1000 dev_dbg(&spi->dev, "Unable to set dma callback\n");
1001 return -EPERM;
1002 }
1003 dma_disable_irq(CH_SPI);
1004 dma_requested = 1;
1005 }
1006
1007 /*
1008 * Notice: for blackfin, the speed_hz is the value of register
1009 * SPI_BAUD, not the real baudrate
1010 */
1011 chip->baud = hz_to_spi_baud(spi->max_speed_hz);
1012 spi_flg = ~(1 << (spi->chip_select));
1013 chip->flag = ((u16) spi_flg << 8) | (1 << (spi->chip_select));
1014 chip->chip_select_num = spi->chip_select;
1015
1016 switch (chip->bits_per_word) {
1017 case 8:
1018 chip->n_bytes = 1;
1019 chip->width = CFG_SPI_WORDSIZE8;
1020 chip->read = chip->cs_change_per_word ?
1021 u8_cs_chg_reader : u8_reader;
1022 chip->write = chip->cs_change_per_word ?
1023 u8_cs_chg_writer : u8_writer;
1024 chip->duplex = chip->cs_change_per_word ?
1025 u8_cs_chg_duplex : u8_duplex;
1026 break;
1027
1028 case 16:
1029 chip->n_bytes = 2;
1030 chip->width = CFG_SPI_WORDSIZE16;
1031 chip->read = chip->cs_change_per_word ?
1032 u16_cs_chg_reader : u16_reader;
1033 chip->write = chip->cs_change_per_word ?
1034 u16_cs_chg_writer : u16_writer;
1035 chip->duplex = chip->cs_change_per_word ?
1036 u16_cs_chg_duplex : u16_duplex;
1037 break;
1038
1039 default:
1040 dev_err(&spi->dev, "%d bits_per_word is not supported\n",
1041 chip->bits_per_word);
1042 kfree(chip);
1043 return -ENODEV;
1044 }
1045
1046 dev_dbg(&spi->dev, "setup spi chip %s, width is %d, dma is %d\n",
1047 spi->modalias, chip->width, chip->enable_dma);
1048 dev_dbg(&spi->dev, "ctl_reg is 0x%x, flag_reg is 0x%x\n",
1049 chip->ctl_reg, chip->flag);
1050
1051 spi_set_ctldata(spi, chip);
1052
1053 return 0;
1054 }
1055
1056 /*
1057 * callback for spi framework.
1058 * clean driver specific data
1059 */
1060 static void cleanup(struct spi_device *spi)
1061 {
1062 struct chip_data *chip = spi_get_ctldata(spi);
1063
1064 kfree(chip);
1065 }
1066
1067 static inline int init_queue(struct driver_data *drv_data)
1068 {
1069 INIT_LIST_HEAD(&drv_data->queue);
1070 spin_lock_init(&drv_data->lock);
1071
1072 drv_data->run = QUEUE_STOPPED;
1073 drv_data->busy = 0;
1074
1075 /* init transfer tasklet */
1076 tasklet_init(&drv_data->pump_transfers,
1077 pump_transfers, (unsigned long)drv_data);
1078
1079 /* init messages workqueue */
1080 INIT_WORK(&drv_data->pump_messages, pump_messages);
1081 drv_data->workqueue =
1082 create_singlethread_workqueue(drv_data->master->dev.parent->bus_id);
1083 if (drv_data->workqueue == NULL)
1084 return -EBUSY;
1085
1086 return 0;
1087 }
1088
1089 static inline int start_queue(struct driver_data *drv_data)
1090 {
1091 unsigned long flags;
1092
1093 spin_lock_irqsave(&drv_data->lock, flags);
1094
1095 if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
1096 spin_unlock_irqrestore(&drv_data->lock, flags);
1097 return -EBUSY;
1098 }
1099
1100 drv_data->run = QUEUE_RUNNING;
1101 drv_data->cur_msg = NULL;
1102 drv_data->cur_transfer = NULL;
1103 drv_data->cur_chip = NULL;
1104 spin_unlock_irqrestore(&drv_data->lock, flags);
1105
1106 queue_work(drv_data->workqueue, &drv_data->pump_messages);
1107
1108 return 0;
1109 }
1110
1111 static inline int stop_queue(struct driver_data *drv_data)
1112 {
1113 unsigned long flags;
1114 unsigned limit = 500;
1115 int status = 0;
1116
1117 spin_lock_irqsave(&drv_data->lock, flags);
1118
1119 /*
1120 * This is a bit lame, but is optimized for the common execution path.
1121 * A wait_queue on the drv_data->busy could be used, but then the common
1122 * execution path (pump_messages) would be required to call wake_up or
1123 * friends on every SPI message. Do this instead
1124 */
1125 drv_data->run = QUEUE_STOPPED;
1126 while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
1127 spin_unlock_irqrestore(&drv_data->lock, flags);
1128 msleep(10);
1129 spin_lock_irqsave(&drv_data->lock, flags);
1130 }
1131
1132 if (!list_empty(&drv_data->queue) || drv_data->busy)
1133 status = -EBUSY;
1134
1135 spin_unlock_irqrestore(&drv_data->lock, flags);
1136
1137 return status;
1138 }
1139
1140 static inline int destroy_queue(struct driver_data *drv_data)
1141 {
1142 int status;
1143
1144 status = stop_queue(drv_data);
1145 if (status != 0)
1146 return status;
1147
1148 destroy_workqueue(drv_data->workqueue);
1149
1150 return 0;
1151 }
1152
1153 static int setup_pin_mux(int action)
1154 {
1155
1156 u16 pin_req[] = {P_SPI0_SCK, P_SPI0_MISO, P_SPI0_MOSI, 0};
1157
1158 if (action) {
1159 if (peripheral_request_list(pin_req, DRV_NAME))
1160 return -EFAULT;
1161 } else {
1162 peripheral_free_list(pin_req);
1163 }
1164
1165 return 0;
1166 }
1167
1168 static int __init bfin5xx_spi_probe(struct platform_device *pdev)
1169 {
1170 struct device *dev = &pdev->dev;
1171 struct bfin5xx_spi_master *platform_info;
1172 struct spi_master *master;
1173 struct driver_data *drv_data = 0;
1174 int status = 0;
1175
1176 platform_info = dev->platform_data;
1177
1178 /* Allocate master with space for drv_data */
1179 master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
1180 if (!master) {
1181 dev_err(&pdev->dev, "can not alloc spi_master\n");
1182 return -ENOMEM;
1183 }
1184
1185 if (setup_pin_mux(1)) {
1186 dev_err(&pdev->dev, ": Requesting Peripherals failed\n");
1187 goto out_error;
1188 }
1189
1190 drv_data = spi_master_get_devdata(master);
1191 drv_data->master = master;
1192 drv_data->master_info = platform_info;
1193 drv_data->pdev = pdev;
1194
1195 master->bus_num = pdev->id;
1196 master->num_chipselect = platform_info->num_chipselect;
1197 master->cleanup = cleanup;
1198 master->setup = setup;
1199 master->transfer = transfer;
1200
1201 /* Initial and start queue */
1202 status = init_queue(drv_data);
1203 if (status != 0) {
1204 dev_err(&pdev->dev, "problem initializing queue\n");
1205 goto out_error_queue_alloc;
1206 }
1207 status = start_queue(drv_data);
1208 if (status != 0) {
1209 dev_err(&pdev->dev, "problem starting queue\n");
1210 goto out_error_queue_alloc;
1211 }
1212
1213 /* Register with the SPI framework */
1214 platform_set_drvdata(pdev, drv_data);
1215 status = spi_register_master(master);
1216 if (status != 0) {
1217 dev_err(&pdev->dev, "problem registering spi master\n");
1218 goto out_error_queue_alloc;
1219 }
1220 dev_dbg(&pdev->dev, "controller probe successfully\n");
1221 return status;
1222
1223 out_error_queue_alloc:
1224 destroy_queue(drv_data);
1225 out_error:
1226 spi_master_put(master);
1227
1228 return status;
1229 }
1230
1231 /* stop hardware and remove the driver */
1232 static int __devexit bfin5xx_spi_remove(struct platform_device *pdev)
1233 {
1234 struct driver_data *drv_data = platform_get_drvdata(pdev);
1235 int status = 0;
1236
1237 if (!drv_data)
1238 return 0;
1239
1240 /* Remove the queue */
1241 status = destroy_queue(drv_data);
1242 if (status != 0)
1243 return status;
1244
1245 /* Disable the SSP at the peripheral and SOC level */
1246 bfin_spi_disable(drv_data);
1247
1248 /* Release DMA */
1249 if (drv_data->master_info->enable_dma) {
1250 if (dma_channel_active(CH_SPI))
1251 free_dma(CH_SPI);
1252 }
1253
1254 /* Disconnect from the SPI framework */
1255 spi_unregister_master(drv_data->master);
1256
1257 setup_pin_mux(0);
1258
1259 /* Prevent double remove */
1260 platform_set_drvdata(pdev, NULL);
1261
1262 return 0;
1263 }
1264
1265 #ifdef CONFIG_PM
1266 static int bfin5xx_spi_suspend(struct platform_device *pdev, pm_message_t state)
1267 {
1268 struct driver_data *drv_data = platform_get_drvdata(pdev);
1269 int status = 0;
1270
1271 status = stop_queue(drv_data);
1272 if (status != 0)
1273 return status;
1274
1275 /* stop hardware */
1276 bfin_spi_disable(drv_data);
1277
1278 return 0;
1279 }
1280
1281 static int bfin5xx_spi_resume(struct platform_device *pdev)
1282 {
1283 struct driver_data *drv_data = platform_get_drvdata(pdev);
1284 int status = 0;
1285
1286 /* Enable the SPI interface */
1287 bfin_spi_enable(drv_data);
1288
1289 /* Start the queue running */
1290 status = start_queue(drv_data);
1291 if (status != 0) {
1292 dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
1293 return status;
1294 }
1295
1296 return 0;
1297 }
1298 #else
1299 #define bfin5xx_spi_suspend NULL
1300 #define bfin5xx_spi_resume NULL
1301 #endif /* CONFIG_PM */
1302
1303 MODULE_ALIAS("bfin-spi-master"); /* for platform bus hotplug */
1304 static struct platform_driver bfin5xx_spi_driver = {
1305 .driver = {
1306 .name = "bfin-spi-master",
1307 .owner = THIS_MODULE,
1308 },
1309 .suspend = bfin5xx_spi_suspend,
1310 .resume = bfin5xx_spi_resume,
1311 .remove = __devexit_p(bfin5xx_spi_remove),
1312 };
1313
1314 static int __init bfin5xx_spi_init(void)
1315 {
1316 return platform_driver_probe(&bfin5xx_spi_driver, bfin5xx_spi_probe);
1317 }
1318 module_init(bfin5xx_spi_init);
1319
1320 static void __exit bfin5xx_spi_exit(void)
1321 {
1322 platform_driver_unregister(&bfin5xx_spi_driver);
1323 }
1324 module_exit(bfin5xx_spi_exit);
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