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SPI driver hotplug/coldplug fixes
[linux-2.6/libata-dev.git] / drivers / spi / spi_bfin5xx.c
blobf540ed77a1021cda053c72d3e8c293606b31e099
1 /*
2 * File: drivers/spi/bfin5xx_spi.c
3 * Based on: N/A
4 * Author: Luke Yang (Analog Devices Inc.)
5 *
6 * Created: March. 10th 2006
7 * Description: SPI controller driver for Blackfin 5xx
8 * Bugs: Enter bugs at http://blackfin.uclinux.org/
9 *
10 * Modified:
11 * March 10, 2006 bfin5xx_spi.c Created. (Luke Yang)
12 * August 7, 2006 added full duplex mode (Axel Weiss & Luke Yang)
13 *
14 * Copyright 2004-2006 Analog Devices Inc.
15 *
16 * This program is free software ; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation ; either version 2, or (at your option)
19 * any later version.
20 *
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY ; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with this program ; see the file COPYING.
28 * If not, write to the Free Software Foundation,
29 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
30 */
31
32 #include <linux/init.h>
33 #include <linux/module.h>
34 #include <linux/device.h>
35 #include <linux/ioport.h>
36 #include <linux/errno.h>
37 #include <linux/interrupt.h>
38 #include <linux/platform_device.h>
39 #include <linux/dma-mapping.h>
40 #include <linux/spi/spi.h>
41 #include <linux/workqueue.h>
42 #include <linux/errno.h>
43 #include <linux/delay.h>
44
45 #include <asm/io.h>
46 #include <asm/irq.h>
47 #include <asm/delay.h>
48 #include <asm/dma.h>
49
50 #include <asm/bfin5xx_spi.h>
51
52 MODULE_AUTHOR("Luke Yang");
53 MODULE_DESCRIPTION("Blackfin 5xx SPI Contoller");
54 MODULE_LICENSE("GPL");
55
56 #define IS_DMA_ALIGNED(x) (((u32)(x)&0x07)==0)
57
58 #define DEFINE_SPI_REG(reg, off) \
59 static inline u16 read_##reg(void) \
60 { return *(volatile unsigned short*)(SPI0_REGBASE + off); } \
61 static inline void write_##reg(u16 v) \
62 {*(volatile unsigned short*)(SPI0_REGBASE + off) = v;\
63 SSYNC();}
64
65 DEFINE_SPI_REG(CTRL, 0x00)
66 DEFINE_SPI_REG(FLAG, 0x04)
67 DEFINE_SPI_REG(STAT, 0x08)
68 DEFINE_SPI_REG(TDBR, 0x0C)
69 DEFINE_SPI_REG(RDBR, 0x10)
70 DEFINE_SPI_REG(BAUD, 0x14)
71 DEFINE_SPI_REG(SHAW, 0x18)
72 #define START_STATE ((void*)0)
73 #define RUNNING_STATE ((void*)1)
74 #define DONE_STATE ((void*)2)
75 #define ERROR_STATE ((void*)-1)
76 #define QUEUE_RUNNING 0
77 #define QUEUE_STOPPED 1
78 int dma_requested;
79
80 struct driver_data {
81 /* Driver model hookup */
82 struct platform_device *pdev;
83
84 /* SPI framework hookup */
85 struct spi_master *master;
86
87 /* BFIN hookup */
88 struct bfin5xx_spi_master *master_info;
89
90 /* Driver message queue */
91 struct workqueue_struct *workqueue;
92 struct work_struct pump_messages;
93 spinlock_t lock;
94 struct list_head queue;
95 int busy;
96 int run;
97
98 /* Message Transfer pump */
99 struct tasklet_struct pump_transfers;
100
101 /* Current message transfer state info */
102 struct spi_message *cur_msg;
103 struct spi_transfer *cur_transfer;
104 struct chip_data *cur_chip;
105 size_t len_in_bytes;
106 size_t len;
107 void *tx;
108 void *tx_end;
109 void *rx;
110 void *rx_end;
111 int dma_mapped;
112 dma_addr_t rx_dma;
113 dma_addr_t tx_dma;
114 size_t rx_map_len;
115 size_t tx_map_len;
116 u8 n_bytes;
117 void (*write) (struct driver_data *);
118 void (*read) (struct driver_data *);
119 void (*duplex) (struct driver_data *);
120 };
121
122 struct chip_data {
123 u16 ctl_reg;
124 u16 baud;
125 u16 flag;
126
127 u8 chip_select_num;
128 u8 n_bytes;
129 u8 width; /* 0 or 1 */
130 u8 enable_dma;
131 u8 bits_per_word; /* 8 or 16 */
132 u8 cs_change_per_word;
133 u8 cs_chg_udelay;
134 void (*write) (struct driver_data *);
135 void (*read) (struct driver_data *);
136 void (*duplex) (struct driver_data *);
137 };
138
139 static void bfin_spi_enable(struct driver_data *drv_data)
140 {
141 u16 cr;
142
143 cr = read_CTRL();
144 write_CTRL(cr | BIT_CTL_ENABLE);
145 SSYNC();
146 }
147
148 static void bfin_spi_disable(struct driver_data *drv_data)
149 {
150 u16 cr;
151
152 cr = read_CTRL();
153 write_CTRL(cr & (~BIT_CTL_ENABLE));
154 SSYNC();
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 /* stop controller and re-config current chip*/
183 static void restore_state(struct driver_data *drv_data)
184 {
185 struct chip_data *chip = drv_data->cur_chip;
186
187 /* Clear status and disable clock */
188 write_STAT(BIT_STAT_CLR);
189 bfin_spi_disable(drv_data);
190 dev_dbg(&drv_data->pdev->dev, "restoring spi ctl state\n");
191
192 #if defined(CONFIG_BF534) || defined(CONFIG_BF536) || defined(CONFIG_BF537)
193 dev_dbg(&drv_data->pdev->dev,
194 "chip select number is %d\n", chip->chip_select_num);
195
196 switch (chip->chip_select_num) {
197 case 1:
198 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3c00);
199 SSYNC();
200 break;
201
202 case 2:
203 case 3:
204 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PJSE_SPI);
205 SSYNC();
206 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3800);
207 SSYNC();
208 break;
209
210 case 4:
211 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS4E_SPI);
212 SSYNC();
213 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3840);
214 SSYNC();
215 break;
216
217 case 5:
218 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS5E_SPI);
219 SSYNC();
220 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3820);
221 SSYNC();
222 break;
223
224 case 6:
225 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS6E_SPI);
226 SSYNC();
227 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3810);
228 SSYNC();
229 break;
230
231 case 7:
232 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PJCE_SPI);
233 SSYNC();
234 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3800);
235 SSYNC();
236 break;
237 }
238 #endif
239
240 /* Load the registers */
241 write_CTRL(chip->ctl_reg);
242 write_BAUD(chip->baud);
243 write_FLAG(chip->flag);
244 }
245
246 /* used to kick off transfer in rx mode */
247 static unsigned short dummy_read(void)
248 {
249 unsigned short tmp;
250 tmp = read_RDBR();
251 return tmp;
252 }
253
254 static void null_writer(struct driver_data *drv_data)
255 {
256 u8 n_bytes = drv_data->n_bytes;
257
258 while (drv_data->tx < drv_data->tx_end) {
259 write_TDBR(0);
260 while ((read_STAT() & BIT_STAT_TXS))
261 continue;
262 drv_data->tx += n_bytes;
263 }
264 }
265
266 static void null_reader(struct driver_data *drv_data)
267 {
268 u8 n_bytes = drv_data->n_bytes;
269 dummy_read();
270
271 while (drv_data->rx < drv_data->rx_end) {
272 while (!(read_STAT() & BIT_STAT_RXS))
273 continue;
274 dummy_read();
275 drv_data->rx += n_bytes;
276 }
277 }
278
279 static void u8_writer(struct driver_data *drv_data)
280 {
281 dev_dbg(&drv_data->pdev->dev,
282 "cr8-s is 0x%x\n", read_STAT());
283 while (drv_data->tx < drv_data->tx_end) {
284 write_TDBR(*(u8 *) (drv_data->tx));
285 while (read_STAT() & BIT_STAT_TXS)
286 continue;
287 ++drv_data->tx;
288 }
289
290 /* poll for SPI completion before returning */
291 while (!(read_STAT() & BIT_STAT_SPIF))
292 continue;
293 }
294
295 static void u8_cs_chg_writer(struct driver_data *drv_data)
296 {
297 struct chip_data *chip = drv_data->cur_chip;
298
299 while (drv_data->tx < drv_data->tx_end) {
300 write_FLAG(chip->flag);
301 SSYNC();
302
303 write_TDBR(*(u8 *) (drv_data->tx));
304 while (read_STAT() & BIT_STAT_TXS)
305 continue;
306 while (!(read_STAT() & BIT_STAT_SPIF))
307 continue;
308 write_FLAG(0xFF00 | chip->flag);
309 SSYNC();
310 if (chip->cs_chg_udelay)
311 udelay(chip->cs_chg_udelay);
312 ++drv_data->tx;
313 }
314 write_FLAG(0xFF00);
315 SSYNC();
316 }
317
318 static void u8_reader(struct driver_data *drv_data)
319 {
320 dev_dbg(&drv_data->pdev->dev,
321 "cr-8 is 0x%x\n", read_STAT());
322
323 /* clear TDBR buffer before read(else it will be shifted out) */
324 write_TDBR(0xFFFF);
325
326 dummy_read();
327
328 while (drv_data->rx < drv_data->rx_end - 1) {
329 while (!(read_STAT() & BIT_STAT_RXS))
330 continue;
331 *(u8 *) (drv_data->rx) = read_RDBR();
332 ++drv_data->rx;
333 }
334
335 while (!(read_STAT() & BIT_STAT_RXS))
336 continue;
337 *(u8 *) (drv_data->rx) = read_SHAW();
338 ++drv_data->rx;
339 }
340
341 static void u8_cs_chg_reader(struct driver_data *drv_data)
342 {
343 struct chip_data *chip = drv_data->cur_chip;
344
345 while (drv_data->rx < drv_data->rx_end) {
346 write_FLAG(chip->flag);
347 SSYNC();
348
349 read_RDBR(); /* kick off */
350 while (!(read_STAT() & BIT_STAT_RXS))
351 continue;
352 while (!(read_STAT() & BIT_STAT_SPIF))
353 continue;
354 *(u8 *) (drv_data->rx) = read_SHAW();
355 write_FLAG(0xFF00 | chip->flag);
356 SSYNC();
357 if (chip->cs_chg_udelay)
358 udelay(chip->cs_chg_udelay);
359 ++drv_data->rx;
360 }
361 write_FLAG(0xFF00);
362 SSYNC();
363 }
364
365 static void u8_duplex(struct driver_data *drv_data)
366 {
367 /* in duplex mode, clk is triggered by writing of TDBR */
368 while (drv_data->rx < drv_data->rx_end) {
369 write_TDBR(*(u8 *) (drv_data->tx));
370 while (!(read_STAT() & BIT_STAT_SPIF))
371 continue;
372 while (!(read_STAT() & BIT_STAT_RXS))
373 continue;
374 *(u8 *) (drv_data->rx) = read_RDBR();
375 ++drv_data->rx;
376 ++drv_data->tx;
377 }
378 }
379
380 static void u8_cs_chg_duplex(struct driver_data *drv_data)
381 {
382 struct chip_data *chip = drv_data->cur_chip;
383
384 while (drv_data->rx < drv_data->rx_end) {
385 write_FLAG(chip->flag);
386 SSYNC();
387
388 write_TDBR(*(u8 *) (drv_data->tx));
389 while (!(read_STAT() & BIT_STAT_SPIF))
390 continue;
391 while (!(read_STAT() & BIT_STAT_RXS))
392 continue;
393 *(u8 *) (drv_data->rx) = read_RDBR();
394 write_FLAG(0xFF00 | chip->flag);
395 SSYNC();
396 if (chip->cs_chg_udelay)
397 udelay(chip->cs_chg_udelay);
398 ++drv_data->rx;
399 ++drv_data->tx;
400 }
401 write_FLAG(0xFF00);
402 SSYNC();
403 }
404
405 static void u16_writer(struct driver_data *drv_data)
406 {
407 dev_dbg(&drv_data->pdev->dev,
408 "cr16 is 0x%x\n", read_STAT());
409
410 while (drv_data->tx < drv_data->tx_end) {
411 write_TDBR(*(u16 *) (drv_data->tx));
412 while ((read_STAT() & BIT_STAT_TXS))
413 continue;
414 drv_data->tx += 2;
415 }
416
417 /* poll for SPI completion before returning */
418 while (!(read_STAT() & BIT_STAT_SPIF))
419 continue;
420 }
421
422 static void u16_cs_chg_writer(struct driver_data *drv_data)
423 {
424 struct chip_data *chip = drv_data->cur_chip;
425
426 while (drv_data->tx < drv_data->tx_end) {
427 write_FLAG(chip->flag);
428 SSYNC();
429
430 write_TDBR(*(u16 *) (drv_data->tx));
431 while ((read_STAT() & BIT_STAT_TXS))
432 continue;
433 while (!(read_STAT() & BIT_STAT_SPIF))
434 continue;
435 write_FLAG(0xFF00 | chip->flag);
436 SSYNC();
437 if (chip->cs_chg_udelay)
438 udelay(chip->cs_chg_udelay);
439 drv_data->tx += 2;
440 }
441 write_FLAG(0xFF00);
442 SSYNC();
443 }
444
445 static void u16_reader(struct driver_data *drv_data)
446 {
447 dev_dbg(&drv_data->pdev->dev,
448 "cr-16 is 0x%x\n", read_STAT());
449 dummy_read();
450
451 while (drv_data->rx < (drv_data->rx_end - 2)) {
452 while (!(read_STAT() & BIT_STAT_RXS))
453 continue;
454 *(u16 *) (drv_data->rx) = read_RDBR();
455 drv_data->rx += 2;
456 }
457
458 while (!(read_STAT() & BIT_STAT_RXS))
459 continue;
460 *(u16 *) (drv_data->rx) = read_SHAW();
461 drv_data->rx += 2;
462 }
463
464 static void u16_cs_chg_reader(struct driver_data *drv_data)
465 {
466 struct chip_data *chip = drv_data->cur_chip;
467
468 while (drv_data->rx < drv_data->rx_end) {
469 write_FLAG(chip->flag);
470 SSYNC();
471
472 read_RDBR(); /* kick off */
473 while (!(read_STAT() & BIT_STAT_RXS))
474 continue;
475 while (!(read_STAT() & BIT_STAT_SPIF))
476 continue;
477 *(u16 *) (drv_data->rx) = read_SHAW();
478 write_FLAG(0xFF00 | chip->flag);
479 SSYNC();
480 if (chip->cs_chg_udelay)
481 udelay(chip->cs_chg_udelay);
482 drv_data->rx += 2;
483 }
484 write_FLAG(0xFF00);
485 SSYNC();
486 }
487
488 static void u16_duplex(struct driver_data *drv_data)
489 {
490 /* in duplex mode, clk is triggered by writing of TDBR */
491 while (drv_data->tx < drv_data->tx_end) {
492 write_TDBR(*(u16 *) (drv_data->tx));
493 while (!(read_STAT() & BIT_STAT_SPIF))
494 continue;
495 while (!(read_STAT() & BIT_STAT_RXS))
496 continue;
497 *(u16 *) (drv_data->rx) = read_RDBR();
498 drv_data->rx += 2;
499 drv_data->tx += 2;
500 }
501 }
502
503 static void u16_cs_chg_duplex(struct driver_data *drv_data)
504 {
505 struct chip_data *chip = drv_data->cur_chip;
506
507 while (drv_data->tx < drv_data->tx_end) {
508 write_FLAG(chip->flag);
509 SSYNC();
510
511 write_TDBR(*(u16 *) (drv_data->tx));
512 while (!(read_STAT() & BIT_STAT_SPIF))
513 continue;
514 while (!(read_STAT() & BIT_STAT_RXS))
515 continue;
516 *(u16 *) (drv_data->rx) = read_RDBR();
517 write_FLAG(0xFF00 | chip->flag);
518 SSYNC();
519 if (chip->cs_chg_udelay)
520 udelay(chip->cs_chg_udelay);
521 drv_data->rx += 2;
522 drv_data->tx += 2;
523 }
524 write_FLAG(0xFF00);
525 SSYNC();
526 }
527
528 /* test if ther is more transfer to be done */
529 static void *next_transfer(struct driver_data *drv_data)
530 {
531 struct spi_message *msg = drv_data->cur_msg;
532 struct spi_transfer *trans = drv_data->cur_transfer;
533
534 /* Move to next transfer */
535 if (trans->transfer_list.next != &msg->transfers) {
536 drv_data->cur_transfer =
537 list_entry(trans->transfer_list.next,
538 struct spi_transfer, transfer_list);
539 return RUNNING_STATE;
540 } else
541 return DONE_STATE;
542 }
543
544 /*
545 * caller already set message->status;
546 * dma and pio irqs are blocked give finished message back
547 */
548 static void giveback(struct driver_data *drv_data)
549 {
550 struct spi_transfer *last_transfer;
551 unsigned long flags;
552 struct spi_message *msg;
553
554 spin_lock_irqsave(&drv_data->lock, flags);
555 msg = drv_data->cur_msg;
556 drv_data->cur_msg = NULL;
557 drv_data->cur_transfer = NULL;
558 drv_data->cur_chip = NULL;
559 queue_work(drv_data->workqueue, &drv_data->pump_messages);
560 spin_unlock_irqrestore(&drv_data->lock, flags);
561
562 last_transfer = list_entry(msg->transfers.prev,
563 struct spi_transfer, transfer_list);
564
565 msg->state = NULL;
566
567 /* disable chip select signal. And not stop spi in autobuffer mode */
568 if (drv_data->tx_dma != 0xFFFF) {
569 write_FLAG(0xFF00);
570 bfin_spi_disable(drv_data);
571 }
572
573 if (msg->complete)
574 msg->complete(msg->context);
575 }
576
577 static irqreturn_t dma_irq_handler(int irq, void *dev_id)
578 {
579 struct driver_data *drv_data = (struct driver_data *)dev_id;
580 struct spi_message *msg = drv_data->cur_msg;
581
582 dev_dbg(&drv_data->pdev->dev, "in dma_irq_handler\n");
583 clear_dma_irqstat(CH_SPI);
584
585 /* Wait for DMA to complete */
586 while (get_dma_curr_irqstat(CH_SPI) & DMA_RUN)
587 continue;
588
589 /*
590 * wait for the last transaction shifted out. HRM states:
591 * at this point there may still be data in the SPI DMA FIFO waiting
592 * to be transmitted ... software needs to poll TXS in the SPI_STAT
593 * register until it goes low for 2 successive reads
594 */
595 if (drv_data->tx != NULL) {
596 while ((bfin_read_SPI_STAT() & TXS) ||
597 (bfin_read_SPI_STAT() & TXS))
598 continue;
599 }
600
601 while (!(bfin_read_SPI_STAT() & SPIF))
602 continue;
603
604 bfin_spi_disable(drv_data);
605
606 msg->actual_length += drv_data->len_in_bytes;
607
608 /* Move to next transfer */
609 msg->state = next_transfer(drv_data);
610
611 /* Schedule transfer tasklet */
612 tasklet_schedule(&drv_data->pump_transfers);
613
614 /* free the irq handler before next transfer */
615 dev_dbg(&drv_data->pdev->dev,
616 "disable dma channel irq%d\n",
617 CH_SPI);
618 dma_disable_irq(CH_SPI);
619
620 return IRQ_HANDLED;
621 }
622
623 static void pump_transfers(unsigned long data)
624 {
625 struct driver_data *drv_data = (struct driver_data *)data;
626 struct spi_message *message = NULL;
627 struct spi_transfer *transfer = NULL;
628 struct spi_transfer *previous = NULL;
629 struct chip_data *chip = NULL;
630 u8 width;
631 u16 cr, dma_width, dma_config;
632 u32 tranf_success = 1;
633
634 /* Get current state information */
635 message = drv_data->cur_msg;
636 transfer = drv_data->cur_transfer;
637 chip = drv_data->cur_chip;
638
639 /*
640 * if msg is error or done, report it back using complete() callback
641 */
642
643 /* Handle for abort */
644 if (message->state == ERROR_STATE) {
645 message->status = -EIO;
646 giveback(drv_data);
647 return;
648 }
649
650 /* Handle end of message */
651 if (message->state == DONE_STATE) {
652 message->status = 0;
653 giveback(drv_data);
654 return;
655 }
656
657 /* Delay if requested at end of transfer */
658 if (message->state == RUNNING_STATE) {
659 previous = list_entry(transfer->transfer_list.prev,
660 struct spi_transfer, transfer_list);
661 if (previous->delay_usecs)
662 udelay(previous->delay_usecs);
663 }
664
665 /* Setup the transfer state based on the type of transfer */
666 if (flush(drv_data) == 0) {
667 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
668 message->status = -EIO;
669 giveback(drv_data);
670 return;
671 }
672
673 if (transfer->tx_buf != NULL) {
674 drv_data->tx = (void *)transfer->tx_buf;
675 drv_data->tx_end = drv_data->tx + transfer->len;
676 dev_dbg(&drv_data->pdev->dev, "tx_buf is %p, tx_end is %p\n",
677 transfer->tx_buf, drv_data->tx_end);
678 } else {
679 drv_data->tx = NULL;
680 }
681
682 if (transfer->rx_buf != NULL) {
683 drv_data->rx = transfer->rx_buf;
684 drv_data->rx_end = drv_data->rx + transfer->len;
685 dev_dbg(&drv_data->pdev->dev, "rx_buf is %p, rx_end is %p\n",
686 transfer->rx_buf, drv_data->rx_end);
687 } else {
688 drv_data->rx = NULL;
689 }
690
691 drv_data->rx_dma = transfer->rx_dma;
692 drv_data->tx_dma = transfer->tx_dma;
693 drv_data->len_in_bytes = transfer->len;
694
695 width = chip->width;
696 if (width == CFG_SPI_WORDSIZE16) {
697 drv_data->len = (transfer->len) >> 1;
698 } else {
699 drv_data->len = transfer->len;
700 }
701 drv_data->write = drv_data->tx ? chip->write : null_writer;
702 drv_data->read = drv_data->rx ? chip->read : null_reader;
703 drv_data->duplex = chip->duplex ? chip->duplex : null_writer;
704 dev_dbg(&drv_data->pdev->dev,
705 "transfer: drv_data->write is %p, chip->write is %p, null_wr is %p\n",
706 drv_data->write, chip->write, null_writer);
707
708 /* speed and width has been set on per message */
709 message->state = RUNNING_STATE;
710 dma_config = 0;
711
712 /* restore spi status for each spi transfer */
713 if (transfer->speed_hz) {
714 write_BAUD(hz_to_spi_baud(transfer->speed_hz));
715 } else {
716 write_BAUD(chip->baud);
717 }
718 write_FLAG(chip->flag);
719
720 dev_dbg(&drv_data->pdev->dev,
721 "now pumping a transfer: width is %d, len is %d\n",
722 width, transfer->len);
723
724 /*
725 * Try to map dma buffer and do a dma transfer if
726 * successful use different way to r/w according to
727 * drv_data->cur_chip->enable_dma
728 */
729 if (drv_data->cur_chip->enable_dma && drv_data->len > 6) {
730
731 write_STAT(BIT_STAT_CLR);
732 disable_dma(CH_SPI);
733 clear_dma_irqstat(CH_SPI);
734 bfin_spi_disable(drv_data);
735
736 /* config dma channel */
737 dev_dbg(&drv_data->pdev->dev, "doing dma transfer\n");
738 if (width == CFG_SPI_WORDSIZE16) {
739 set_dma_x_count(CH_SPI, drv_data->len);
740 set_dma_x_modify(CH_SPI, 2);
741 dma_width = WDSIZE_16;
742 } else {
743 set_dma_x_count(CH_SPI, drv_data->len);
744 set_dma_x_modify(CH_SPI, 1);
745 dma_width = WDSIZE_8;
746 }
747
748 /* set transfer width,direction. And enable spi */
749 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
750
751 /* dirty hack for autobuffer DMA mode */
752 if (drv_data->tx_dma == 0xFFFF) {
753 dev_dbg(&drv_data->pdev->dev,
754 "doing autobuffer DMA out.\n");
755
756 /* no irq in autobuffer mode */
757 dma_config =
758 (DMAFLOW_AUTO | RESTART | dma_width | DI_EN);
759 set_dma_config(CH_SPI, dma_config);
760 set_dma_start_addr(CH_SPI, (unsigned long)drv_data->tx);
761 enable_dma(CH_SPI);
762 write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) |
763 (CFG_SPI_ENABLE << 14));
764
765 /* just return here, there can only be one transfer in this mode */
766 message->status = 0;
767 giveback(drv_data);
768 return;
769 }
770
771 /* In dma mode, rx or tx must be NULL in one transfer */
772 if (drv_data->rx != NULL) {
773 /* set transfer mode, and enable SPI */
774 dev_dbg(&drv_data->pdev->dev, "doing DMA in.\n");
775
776 /* disable SPI before write to TDBR */
777 write_CTRL(cr & ~BIT_CTL_ENABLE);
778
779 /* clear tx reg soformer data is not shifted out */
780 write_TDBR(0xFF);
781
782 set_dma_x_count(CH_SPI, drv_data->len);
783
784 /* start dma */
785 dma_enable_irq(CH_SPI);
786 dma_config = (WNR | RESTART | dma_width | DI_EN);
787 set_dma_config(CH_SPI, dma_config);
788 set_dma_start_addr(CH_SPI, (unsigned long)drv_data->rx);
789 enable_dma(CH_SPI);
790
791 cr |=
792 CFG_SPI_DMAREAD | (width << 8) | (CFG_SPI_ENABLE <<
793 14);
794 /* set transfer mode, and enable SPI */
795 write_CTRL(cr);
796 } else if (drv_data->tx != NULL) {
797 dev_dbg(&drv_data->pdev->dev, "doing DMA out.\n");
798
799 /* start dma */
800 dma_enable_irq(CH_SPI);
801 dma_config = (RESTART | dma_width | DI_EN);
802 set_dma_config(CH_SPI, dma_config);
803 set_dma_start_addr(CH_SPI, (unsigned long)drv_data->tx);
804 enable_dma(CH_SPI);
805
806 write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) |
807 (CFG_SPI_ENABLE << 14));
808
809 }
810 } else {
811 /* IO mode write then read */
812 dev_dbg(&drv_data->pdev->dev, "doing IO transfer\n");
813
814 write_STAT(BIT_STAT_CLR);
815
816 if (drv_data->tx != NULL && drv_data->rx != NULL) {
817 /* full duplex mode */
818 BUG_ON((drv_data->tx_end - drv_data->tx) !=
819 (drv_data->rx_end - drv_data->rx));
820 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
821 cr |= CFG_SPI_WRITE | (width << 8) |
822 (CFG_SPI_ENABLE << 14);
823 dev_dbg(&drv_data->pdev->dev,
824 "IO duplex: cr is 0x%x\n", cr);
825
826 write_CTRL(cr);
827 SSYNC();
828
829 drv_data->duplex(drv_data);
830
831 if (drv_data->tx != drv_data->tx_end)
832 tranf_success = 0;
833 } else if (drv_data->tx != NULL) {
834 /* write only half duplex */
835 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
836 cr |= CFG_SPI_WRITE | (width << 8) |
837 (CFG_SPI_ENABLE << 14);
838 dev_dbg(&drv_data->pdev->dev,
839 "IO write: cr is 0x%x\n", cr);
840
841 write_CTRL(cr);
842 SSYNC();
843
844 drv_data->write(drv_data);
845
846 if (drv_data->tx != drv_data->tx_end)
847 tranf_success = 0;
848 } else if (drv_data->rx != NULL) {
849 /* read only half duplex */
850 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
851 cr |= CFG_SPI_READ | (width << 8) |
852 (CFG_SPI_ENABLE << 14);
853 dev_dbg(&drv_data->pdev->dev,
854 "IO read: cr is 0x%x\n", cr);
855
856 write_CTRL(cr);
857 SSYNC();
858
859 drv_data->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 transfered */
870 message->actual_length += drv_data->len;
871
872 /* Move to next transfer of this msg */
873 message->state = next_transfer(drv_data);
874 }
875
876 /* Schedule next transfer tasklet */
877 tasklet_schedule(&drv_data->pump_transfers);
878
879 }
880 }
881
882 /* pop a msg from queue and kick off real transfer */
883 static void pump_messages(struct work_struct *work)
884 {
885 struct driver_data *drv_data = container_of(work, struct driver_data, pump_messages);
886 unsigned long flags;
887
888 /* Lock queue and check for queue work */
889 spin_lock_irqsave(&drv_data->lock, flags);
890 if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
891 /* pumper kicked off but no work to do */
892 drv_data->busy = 0;
893 spin_unlock_irqrestore(&drv_data->lock, flags);
894 return;
895 }
896
897 /* Make sure we are not already running a message */
898 if (drv_data->cur_msg) {
899 spin_unlock_irqrestore(&drv_data->lock, flags);
900 return;
901 }
902
903 /* Extract head of queue */
904 drv_data->cur_msg = list_entry(drv_data->queue.next,
905 struct spi_message, queue);
906 list_del_init(&drv_data->cur_msg->queue);
907
908 /* Initial message state */
909 drv_data->cur_msg->state = START_STATE;
910 drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
911 struct spi_transfer, transfer_list);
912
913 /* Setup the SSP using the per chip configuration */
914 drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
915 restore_state(drv_data);
916 dev_dbg(&drv_data->pdev->dev,
917 "got a message to pump, state is set to: baud %d, flag 0x%x, ctl 0x%x\n",
918 drv_data->cur_chip->baud, drv_data->cur_chip->flag,
919 drv_data->cur_chip->ctl_reg);
920
921 dev_dbg(&drv_data->pdev->dev,
922 "the first transfer len is %d\n",
923 drv_data->cur_transfer->len);
924
925 /* Mark as busy and launch transfers */
926 tasklet_schedule(&drv_data->pump_transfers);
927
928 drv_data->busy = 1;
929 spin_unlock_irqrestore(&drv_data->lock, flags);
930 }
931
932 /*
933 * got a msg to transfer, queue it in drv_data->queue.
934 * And kick off message pumper
935 */
936 static int transfer(struct spi_device *spi, struct spi_message *msg)
937 {
938 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
939 unsigned long flags;
940
941 spin_lock_irqsave(&drv_data->lock, flags);
942
943 if (drv_data->run == QUEUE_STOPPED) {
944 spin_unlock_irqrestore(&drv_data->lock, flags);
945 return -ESHUTDOWN;
946 }
947
948 msg->actual_length = 0;
949 msg->status = -EINPROGRESS;
950 msg->state = START_STATE;
951
952 dev_dbg(&spi->dev, "adding an msg in transfer() \n");
953 list_add_tail(&msg->queue, &drv_data->queue);
954
955 if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
956 queue_work(drv_data->workqueue, &drv_data->pump_messages);
957
958 spin_unlock_irqrestore(&drv_data->lock, flags);
959
960 return 0;
961 }
962
963 /* first setup for new devices */
964 static int setup(struct spi_device *spi)
965 {
966 struct bfin5xx_spi_chip *chip_info = NULL;
967 struct chip_data *chip;
968 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
969 u8 spi_flg;
970
971 /* Abort device setup if requested features are not supported */
972 if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) {
973 dev_err(&spi->dev, "requested mode not fully supported\n");
974 return -EINVAL;
975 }
976
977 /* Zero (the default) here means 8 bits */
978 if (!spi->bits_per_word)
979 spi->bits_per_word = 8;
980
981 if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
982 return -EINVAL;
983
984 /* Only alloc (or use chip_info) on first setup */
985 chip = spi_get_ctldata(spi);
986 if (chip == NULL) {
987 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
988 if (!chip)
989 return -ENOMEM;
990
991 chip->enable_dma = 0;
992 chip_info = spi->controller_data;
993 }
994
995 /* chip_info isn't always needed */
996 if (chip_info) {
997 chip->enable_dma = chip_info->enable_dma != 0
998 && drv_data->master_info->enable_dma;
999 chip->ctl_reg = chip_info->ctl_reg;
1000 chip->bits_per_word = chip_info->bits_per_word;
1001 chip->cs_change_per_word = chip_info->cs_change_per_word;
1002 chip->cs_chg_udelay = chip_info->cs_chg_udelay;
1003 }
1004
1005 /* translate common spi framework into our register */
1006 if (spi->mode & SPI_CPOL)
1007 chip->ctl_reg |= CPOL;
1008 if (spi->mode & SPI_CPHA)
1009 chip->ctl_reg |= CPHA;
1010 if (spi->mode & SPI_LSB_FIRST)
1011 chip->ctl_reg |= LSBF;
1012 /* we dont support running in slave mode (yet?) */
1013 chip->ctl_reg |= MSTR;
1014
1015 /*
1016 * if any one SPI chip is registered and wants DMA, request the
1017 * DMA channel for it
1018 */
1019 if (chip->enable_dma && !dma_requested) {
1020 /* register dma irq handler */
1021 if (request_dma(CH_SPI, "BF53x_SPI_DMA") < 0) {
1022 dev_dbg(&spi->dev,
1023 "Unable to request BlackFin SPI DMA channel\n");
1024 return -ENODEV;
1025 }
1026 if (set_dma_callback(CH_SPI, (void *)dma_irq_handler, drv_data)
1027 < 0) {
1028 dev_dbg(&spi->dev, "Unable to set dma callback\n");
1029 return -EPERM;
1030 }
1031 dma_disable_irq(CH_SPI);
1032 dma_requested = 1;
1033 }
1034
1035 /*
1036 * Notice: for blackfin, the speed_hz is the value of register
1037 * SPI_BAUD, not the real baudrate
1038 */
1039 chip->baud = hz_to_spi_baud(spi->max_speed_hz);
1040 spi_flg = ~(1 << (spi->chip_select));
1041 chip->flag = ((u16) spi_flg << 8) | (1 << (spi->chip_select));
1042 chip->chip_select_num = spi->chip_select;
1043
1044 switch (chip->bits_per_word) {
1045 case 8:
1046 chip->n_bytes = 1;
1047 chip->width = CFG_SPI_WORDSIZE8;
1048 chip->read = chip->cs_change_per_word ?
1049 u8_cs_chg_reader : u8_reader;
1050 chip->write = chip->cs_change_per_word ?
1051 u8_cs_chg_writer : u8_writer;
1052 chip->duplex = chip->cs_change_per_word ?
1053 u8_cs_chg_duplex : u8_duplex;
1054 break;
1055
1056 case 16:
1057 chip->n_bytes = 2;
1058 chip->width = CFG_SPI_WORDSIZE16;
1059 chip->read = chip->cs_change_per_word ?
1060 u16_cs_chg_reader : u16_reader;
1061 chip->write = chip->cs_change_per_word ?
1062 u16_cs_chg_writer : u16_writer;
1063 chip->duplex = chip->cs_change_per_word ?
1064 u16_cs_chg_duplex : u16_duplex;
1065 break;
1066
1067 default:
1068 dev_err(&spi->dev, "%d bits_per_word is not supported\n",
1069 chip->bits_per_word);
1070 kfree(chip);
1071 return -ENODEV;
1072 }
1073
1074 dev_dbg(&spi->dev, "setup spi chip %s, width is %d, dma is %d,",
1075 spi->modalias, chip->width, chip->enable_dma);
1076 dev_dbg(&spi->dev, "ctl_reg is 0x%x, flag_reg is 0x%x\n",
1077 chip->ctl_reg, chip->flag);
1078
1079 spi_set_ctldata(spi, chip);
1080
1081 return 0;
1082 }
1083
1084 /*
1085 * callback for spi framework.
1086 * clean driver specific data
1087 */
1088 static void cleanup(struct spi_device *spi)
1089 {
1090 struct chip_data *chip = spi_get_ctldata(spi);
1091
1092 kfree(chip);
1093 }
1094
1095 static inline int init_queue(struct driver_data *drv_data)
1096 {
1097 INIT_LIST_HEAD(&drv_data->queue);
1098 spin_lock_init(&drv_data->lock);
1099
1100 drv_data->run = QUEUE_STOPPED;
1101 drv_data->busy = 0;
1102
1103 /* init transfer tasklet */
1104 tasklet_init(&drv_data->pump_transfers,
1105 pump_transfers, (unsigned long)drv_data);
1106
1107 /* init messages workqueue */
1108 INIT_WORK(&drv_data->pump_messages, pump_messages);
1109 drv_data->workqueue =
1110 create_singlethread_workqueue(drv_data->master->cdev.dev->bus_id);
1111 if (drv_data->workqueue == NULL)
1112 return -EBUSY;
1113
1114 return 0;
1115 }
1116
1117 static inline int start_queue(struct driver_data *drv_data)
1118 {
1119 unsigned long flags;
1120
1121 spin_lock_irqsave(&drv_data->lock, flags);
1122
1123 if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
1124 spin_unlock_irqrestore(&drv_data->lock, flags);
1125 return -EBUSY;
1126 }
1127
1128 drv_data->run = QUEUE_RUNNING;
1129 drv_data->cur_msg = NULL;
1130 drv_data->cur_transfer = NULL;
1131 drv_data->cur_chip = NULL;
1132 spin_unlock_irqrestore(&drv_data->lock, flags);
1133
1134 queue_work(drv_data->workqueue, &drv_data->pump_messages);
1135
1136 return 0;
1137 }
1138
1139 static inline int stop_queue(struct driver_data *drv_data)
1140 {
1141 unsigned long flags;
1142 unsigned limit = 500;
1143 int status = 0;
1144
1145 spin_lock_irqsave(&drv_data->lock, flags);
1146
1147 /*
1148 * This is a bit lame, but is optimized for the common execution path.
1149 * A wait_queue on the drv_data->busy could be used, but then the common
1150 * execution path (pump_messages) would be required to call wake_up or
1151 * friends on every SPI message. Do this instead
1152 */
1153 drv_data->run = QUEUE_STOPPED;
1154 while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
1155 spin_unlock_irqrestore(&drv_data->lock, flags);
1156 msleep(10);
1157 spin_lock_irqsave(&drv_data->lock, flags);
1158 }
1159
1160 if (!list_empty(&drv_data->queue) || drv_data->busy)
1161 status = -EBUSY;
1162
1163 spin_unlock_irqrestore(&drv_data->lock, flags);
1164
1165 return status;
1166 }
1167
1168 static inline int destroy_queue(struct driver_data *drv_data)
1169 {
1170 int status;
1171
1172 status = stop_queue(drv_data);
1173 if (status != 0)
1174 return status;
1175
1176 destroy_workqueue(drv_data->workqueue);
1177
1178 return 0;
1179 }
1180
1181 static int __init bfin5xx_spi_probe(struct platform_device *pdev)
1182 {
1183 struct device *dev = &pdev->dev;
1184 struct bfin5xx_spi_master *platform_info;
1185 struct spi_master *master;
1186 struct driver_data *drv_data = 0;
1187 int status = 0;
1188
1189 platform_info = dev->platform_data;
1190
1191 /* Allocate master with space for drv_data */
1192 master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
1193 if (!master) {
1194 dev_err(&pdev->dev, "can not alloc spi_master\n");
1195 return -ENOMEM;
1196 }
1197 drv_data = spi_master_get_devdata(master);
1198 drv_data->master = master;
1199 drv_data->master_info = platform_info;
1200 drv_data->pdev = pdev;
1201
1202 master->bus_num = pdev->id;
1203 master->num_chipselect = platform_info->num_chipselect;
1204 master->cleanup = cleanup;
1205 master->setup = setup;
1206 master->transfer = transfer;
1207
1208 /* Initial and start queue */
1209 status = init_queue(drv_data);
1210 if (status != 0) {
1211 dev_err(&pdev->dev, "problem initializing queue\n");
1212 goto out_error_queue_alloc;
1213 }
1214 status = start_queue(drv_data);
1215 if (status != 0) {
1216 dev_err(&pdev->dev, "problem starting queue\n");
1217 goto out_error_queue_alloc;
1218 }
1219
1220 /* Register with the SPI framework */
1221 platform_set_drvdata(pdev, drv_data);
1222 status = spi_register_master(master);
1223 if (status != 0) {
1224 dev_err(&pdev->dev, "problem registering spi master\n");
1225 goto out_error_queue_alloc;
1226 }
1227 dev_dbg(&pdev->dev, "controller probe successfully\n");
1228 return status;
1229
1230 out_error_queue_alloc:
1231 destroy_queue(drv_data);
1232 spi_master_put(master);
1233 return status;
1234 }
1235
1236 /* stop hardware and remove the driver */
1237 static int __devexit bfin5xx_spi_remove(struct platform_device *pdev)
1238 {
1239 struct driver_data *drv_data = platform_get_drvdata(pdev);
1240 int status = 0;
1241
1242 if (!drv_data)
1243 return 0;
1244
1245 /* Remove the queue */
1246 status = destroy_queue(drv_data);
1247 if (status != 0)
1248 return status;
1249
1250 /* Disable the SSP at the peripheral and SOC level */
1251 bfin_spi_disable(drv_data);
1252
1253 /* Release DMA */
1254 if (drv_data->master_info->enable_dma) {
1255 if (dma_channel_active(CH_SPI))
1256 free_dma(CH_SPI);
1257 }
1258
1259 /* Disconnect from the SPI framework */
1260 spi_unregister_master(drv_data->master);
1261
1262 /* Prevent double remove */
1263 platform_set_drvdata(pdev, NULL);
1264
1265 return 0;
1266 }
1267
1268 #ifdef CONFIG_PM
1269 static int bfin5xx_spi_suspend(struct platform_device *pdev, pm_message_t state)
1270 {
1271 struct driver_data *drv_data = platform_get_drvdata(pdev);
1272 int status = 0;
1273
1274 status = stop_queue(drv_data);
1275 if (status != 0)
1276 return status;
1277
1278 /* stop hardware */
1279 bfin_spi_disable(drv_data);
1280
1281 return 0;
1282 }
1283
1284 static int bfin5xx_spi_resume(struct platform_device *pdev)
1285 {
1286 struct driver_data *drv_data = platform_get_drvdata(pdev);
1287 int status = 0;
1288
1289 /* Enable the SPI interface */
1290 bfin_spi_enable(drv_data);
1291
1292 /* Start the queue running */
1293 status = start_queue(drv_data);
1294 if (status != 0) {
1295 dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
1296 return status;
1297 }
1298
1299 return 0;
1300 }
1301 #else
1302 #define bfin5xx_spi_suspend NULL
1303 #define bfin5xx_spi_resume NULL
1304 #endif /* CONFIG_PM */
1305
1306 MODULE_ALIAS("bfin-spi-master"); /* for platform bus hotplug */
1307 static struct platform_driver bfin5xx_spi_driver = {
1308 .driver = {
1309 .name = "bfin-spi-master",
1310 .owner = THIS_MODULE,
1311 },
1312 .suspend = bfin5xx_spi_suspend,
1313 .resume = bfin5xx_spi_resume,
1314 .remove = __devexit_p(bfin5xx_spi_remove),
1315 };
1316
1317 static int __init bfin5xx_spi_init(void)
1318 {
1319 return platform_driver_probe(&bfin5xx_spi_driver, bfin5xx_spi_probe);
1320 }
1321 module_init(bfin5xx_spi_init);
1322
1323 static void __exit bfin5xx_spi_exit(void)
1324 {
1325 platform_driver_unregister(&bfin5xx_spi_driver);
1326 }
1327 module_exit(bfin5xx_spi_exit);
Linux 2.6 libata-dev (mirror)