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pcmcia: CompactFlash driver for PA Semi Electra boards
[pv_ops_mirror.git] / drivers / spi / pxa2xx_spi.c
blob5f3d808cbc299d7b1c71dca412ebf250ec4ccf3f
1 /*
2 * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19 #include <linux/init.h>
20 #include <linux/module.h>
21 #include <linux/device.h>
22 #include <linux/ioport.h>
23 #include <linux/errno.h>
24 #include <linux/interrupt.h>
25 #include <linux/platform_device.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/spi/spi.h>
28 #include <linux/workqueue.h>
29 #include <linux/delay.h>
30
31 #include <asm/io.h>
32 #include <asm/irq.h>
33 #include <asm/hardware.h>
34 #include <asm/delay.h>
35 #include <asm/dma.h>
36
37 #include <asm/arch/hardware.h>
38 #include <asm/arch/pxa-regs.h>
39 #include <asm/arch/pxa2xx_spi.h>
40
41 MODULE_AUTHOR("Stephen Street");
42 MODULE_DESCRIPTION("PXA2xx SSP SPI Contoller");
43 MODULE_LICENSE("GPL");
44
45 #define MAX_BUSES 3
46
47 #define DMA_INT_MASK (DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR)
48 #define RESET_DMA_CHANNEL (DCSR_NODESC | DMA_INT_MASK)
49 #define IS_DMA_ALIGNED(x) (((u32)(x)&0x07)==0)
50
51 /* for testing SSCR1 changes that require SSP restart, basically
52 * everything except the service and interrupt enables */
53 #define SSCR1_CHANGE_MASK (SSCR1_TTELP | SSCR1_TTE | SSCR1_EBCEI | SSCR1_SCFR \
54 | SSCR1_ECRA | SSCR1_ECRB | SSCR1_SCLKDIR \
55 | SSCR1_RWOT | SSCR1_TRAIL | SSCR1_PINTE \
56 | SSCR1_STRF | SSCR1_EFWR |SSCR1_RFT \
57 | SSCR1_TFT | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
58
59 #define DEFINE_SSP_REG(reg, off) \
60 static inline u32 read_##reg(void *p) { return __raw_readl(p + (off)); } \
61 static inline void write_##reg(u32 v, void *p) { __raw_writel(v, p + (off)); }
62
63 DEFINE_SSP_REG(SSCR0, 0x00)
64 DEFINE_SSP_REG(SSCR1, 0x04)
65 DEFINE_SSP_REG(SSSR, 0x08)
66 DEFINE_SSP_REG(SSITR, 0x0c)
67 DEFINE_SSP_REG(SSDR, 0x10)
68 DEFINE_SSP_REG(SSTO, 0x28)
69 DEFINE_SSP_REG(SSPSP, 0x2c)
70
71 #define START_STATE ((void*)0)
72 #define RUNNING_STATE ((void*)1)
73 #define DONE_STATE ((void*)2)
74 #define ERROR_STATE ((void*)-1)
75
76 #define QUEUE_RUNNING 0
77 #define QUEUE_STOPPED 1
78
79 struct driver_data {
80 /* Driver model hookup */
81 struct platform_device *pdev;
82
83 /* SPI framework hookup */
84 enum pxa_ssp_type ssp_type;
85 struct spi_master *master;
86
87 /* PXA hookup */
88 struct pxa2xx_spi_master *master_info;
89
90 /* DMA setup stuff */
91 int rx_channel;
92 int tx_channel;
93 u32 *null_dma_buf;
94
95 /* SSP register addresses */
96 void *ioaddr;
97 u32 ssdr_physical;
98
99 /* SSP masks*/
100 u32 dma_cr1;
101 u32 int_cr1;
102 u32 clear_sr;
103 u32 mask_sr;
104
105 /* Driver message queue */
106 struct workqueue_struct *workqueue;
107 struct work_struct pump_messages;
108 spinlock_t lock;
109 struct list_head queue;
110 int busy;
111 int run;
112
113 /* Message Transfer pump */
114 struct tasklet_struct pump_transfers;
115
116 /* Current message transfer state info */
117 struct spi_message* cur_msg;
118 struct spi_transfer* cur_transfer;
119 struct chip_data *cur_chip;
120 size_t len;
121 void *tx;
122 void *tx_end;
123 void *rx;
124 void *rx_end;
125 int dma_mapped;
126 dma_addr_t rx_dma;
127 dma_addr_t tx_dma;
128 size_t rx_map_len;
129 size_t tx_map_len;
130 u8 n_bytes;
131 u32 dma_width;
132 int cs_change;
133 int (*write)(struct driver_data *drv_data);
134 int (*read)(struct driver_data *drv_data);
135 irqreturn_t (*transfer_handler)(struct driver_data *drv_data);
136 void (*cs_control)(u32 command);
137 };
138
139 struct chip_data {
140 u32 cr0;
141 u32 cr1;
142 u32 psp;
143 u32 timeout;
144 u8 n_bytes;
145 u32 dma_width;
146 u32 dma_burst_size;
147 u32 threshold;
148 u32 dma_threshold;
149 u8 enable_dma;
150 u8 bits_per_word;
151 u32 speed_hz;
152 int (*write)(struct driver_data *drv_data);
153 int (*read)(struct driver_data *drv_data);
154 void (*cs_control)(u32 command);
155 };
156
157 static void pump_messages(struct work_struct *work);
158
159 static int flush(struct driver_data *drv_data)
160 {
161 unsigned long limit = loops_per_jiffy << 1;
162
163 void *reg = drv_data->ioaddr;
164
165 do {
166 while (read_SSSR(reg) & SSSR_RNE) {
167 read_SSDR(reg);
168 }
169 } while ((read_SSSR(reg) & SSSR_BSY) && limit--);
170 write_SSSR(SSSR_ROR, reg);
171
172 return limit;
173 }
174
175 static void null_cs_control(u32 command)
176 {
177 }
178
179 static int null_writer(struct driver_data *drv_data)
180 {
181 void *reg = drv_data->ioaddr;
182 u8 n_bytes = drv_data->n_bytes;
183
184 if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00)
185 || (drv_data->tx == drv_data->tx_end))
186 return 0;
187
188 write_SSDR(0, reg);
189 drv_data->tx += n_bytes;
190
191 return 1;
192 }
193
194 static int null_reader(struct driver_data *drv_data)
195 {
196 void *reg = drv_data->ioaddr;
197 u8 n_bytes = drv_data->n_bytes;
198
199 while ((read_SSSR(reg) & SSSR_RNE)
200 && (drv_data->rx < drv_data->rx_end)) {
201 read_SSDR(reg);
202 drv_data->rx += n_bytes;
203 }
204
205 return drv_data->rx == drv_data->rx_end;
206 }
207
208 static int u8_writer(struct driver_data *drv_data)
209 {
210 void *reg = drv_data->ioaddr;
211
212 if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00)
213 || (drv_data->tx == drv_data->tx_end))
214 return 0;
215
216 write_SSDR(*(u8 *)(drv_data->tx), reg);
217 ++drv_data->tx;
218
219 return 1;
220 }
221
222 static int u8_reader(struct driver_data *drv_data)
223 {
224 void *reg = drv_data->ioaddr;
225
226 while ((read_SSSR(reg) & SSSR_RNE)
227 && (drv_data->rx < drv_data->rx_end)) {
228 *(u8 *)(drv_data->rx) = read_SSDR(reg);
229 ++drv_data->rx;
230 }
231
232 return drv_data->rx == drv_data->rx_end;
233 }
234
235 static int u16_writer(struct driver_data *drv_data)
236 {
237 void *reg = drv_data->ioaddr;
238
239 if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00)
240 || (drv_data->tx == drv_data->tx_end))
241 return 0;
242
243 write_SSDR(*(u16 *)(drv_data->tx), reg);
244 drv_data->tx += 2;
245
246 return 1;
247 }
248
249 static int u16_reader(struct driver_data *drv_data)
250 {
251 void *reg = drv_data->ioaddr;
252
253 while ((read_SSSR(reg) & SSSR_RNE)
254 && (drv_data->rx < drv_data->rx_end)) {
255 *(u16 *)(drv_data->rx) = read_SSDR(reg);
256 drv_data->rx += 2;
257 }
258
259 return drv_data->rx == drv_data->rx_end;
260 }
261
262 static int u32_writer(struct driver_data *drv_data)
263 {
264 void *reg = drv_data->ioaddr;
265
266 if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00)
267 || (drv_data->tx == drv_data->tx_end))
268 return 0;
269
270 write_SSDR(*(u32 *)(drv_data->tx), reg);
271 drv_data->tx += 4;
272
273 return 1;
274 }
275
276 static int u32_reader(struct driver_data *drv_data)
277 {
278 void *reg = drv_data->ioaddr;
279
280 while ((read_SSSR(reg) & SSSR_RNE)
281 && (drv_data->rx < drv_data->rx_end)) {
282 *(u32 *)(drv_data->rx) = read_SSDR(reg);
283 drv_data->rx += 4;
284 }
285
286 return drv_data->rx == drv_data->rx_end;
287 }
288
289 static void *next_transfer(struct driver_data *drv_data)
290 {
291 struct spi_message *msg = drv_data->cur_msg;
292 struct spi_transfer *trans = drv_data->cur_transfer;
293
294 /* Move to next transfer */
295 if (trans->transfer_list.next != &msg->transfers) {
296 drv_data->cur_transfer =
297 list_entry(trans->transfer_list.next,
298 struct spi_transfer,
299 transfer_list);
300 return RUNNING_STATE;
301 } else
302 return DONE_STATE;
303 }
304
305 static int map_dma_buffers(struct driver_data *drv_data)
306 {
307 struct spi_message *msg = drv_data->cur_msg;
308 struct device *dev = &msg->spi->dev;
309
310 if (!drv_data->cur_chip->enable_dma)
311 return 0;
312
313 if (msg->is_dma_mapped)
314 return drv_data->rx_dma && drv_data->tx_dma;
315
316 if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx))
317 return 0;
318
319 /* Modify setup if rx buffer is null */
320 if (drv_data->rx == NULL) {
321 *drv_data->null_dma_buf = 0;
322 drv_data->rx = drv_data->null_dma_buf;
323 drv_data->rx_map_len = 4;
324 } else
325 drv_data->rx_map_len = drv_data->len;
326
327
328 /* Modify setup if tx buffer is null */
329 if (drv_data->tx == NULL) {
330 *drv_data->null_dma_buf = 0;
331 drv_data->tx = drv_data->null_dma_buf;
332 drv_data->tx_map_len = 4;
333 } else
334 drv_data->tx_map_len = drv_data->len;
335
336 /* Stream map the rx buffer */
337 drv_data->rx_dma = dma_map_single(dev, drv_data->rx,
338 drv_data->rx_map_len,
339 DMA_FROM_DEVICE);
340 if (dma_mapping_error(drv_data->rx_dma))
341 return 0;
342
343 /* Stream map the tx buffer */
344 drv_data->tx_dma = dma_map_single(dev, drv_data->tx,
345 drv_data->tx_map_len,
346 DMA_TO_DEVICE);
347
348 if (dma_mapping_error(drv_data->tx_dma)) {
349 dma_unmap_single(dev, drv_data->rx_dma,
350 drv_data->rx_map_len, DMA_FROM_DEVICE);
351 return 0;
352 }
353
354 return 1;
355 }
356
357 static void unmap_dma_buffers(struct driver_data *drv_data)
358 {
359 struct device *dev;
360
361 if (!drv_data->dma_mapped)
362 return;
363
364 if (!drv_data->cur_msg->is_dma_mapped) {
365 dev = &drv_data->cur_msg->spi->dev;
366 dma_unmap_single(dev, drv_data->rx_dma,
367 drv_data->rx_map_len, DMA_FROM_DEVICE);
368 dma_unmap_single(dev, drv_data->tx_dma,
369 drv_data->tx_map_len, DMA_TO_DEVICE);
370 }
371
372 drv_data->dma_mapped = 0;
373 }
374
375 /* caller already set message->status; dma and pio irqs are blocked */
376 static void giveback(struct driver_data *drv_data)
377 {
378 struct spi_transfer* last_transfer;
379 unsigned long flags;
380 struct spi_message *msg;
381
382 spin_lock_irqsave(&drv_data->lock, flags);
383 msg = drv_data->cur_msg;
384 drv_data->cur_msg = NULL;
385 drv_data->cur_transfer = NULL;
386 drv_data->cur_chip = NULL;
387 queue_work(drv_data->workqueue, &drv_data->pump_messages);
388 spin_unlock_irqrestore(&drv_data->lock, flags);
389
390 last_transfer = list_entry(msg->transfers.prev,
391 struct spi_transfer,
392 transfer_list);
393
394 if (!last_transfer->cs_change)
395 drv_data->cs_control(PXA2XX_CS_DEASSERT);
396
397 msg->state = NULL;
398 if (msg->complete)
399 msg->complete(msg->context);
400 }
401
402 static int wait_ssp_rx_stall(void *ioaddr)
403 {
404 unsigned long limit = loops_per_jiffy << 1;
405
406 while ((read_SSSR(ioaddr) & SSSR_BSY) && limit--)
407 cpu_relax();
408
409 return limit;
410 }
411
412 static int wait_dma_channel_stop(int channel)
413 {
414 unsigned long limit = loops_per_jiffy << 1;
415
416 while (!(DCSR(channel) & DCSR_STOPSTATE) && limit--)
417 cpu_relax();
418
419 return limit;
420 }
421
422 void dma_error_stop(struct driver_data *drv_data, const char *msg)
423 {
424 void *reg = drv_data->ioaddr;
425
426 /* Stop and reset */
427 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
428 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
429 write_SSSR(drv_data->clear_sr, reg);
430 write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
431 if (drv_data->ssp_type != PXA25x_SSP)
432 write_SSTO(0, reg);
433 flush(drv_data);
434 write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
435
436 unmap_dma_buffers(drv_data);
437
438 dev_err(&drv_data->pdev->dev, "%s\n", msg);
439
440 drv_data->cur_msg->state = ERROR_STATE;
441 tasklet_schedule(&drv_data->pump_transfers);
442 }
443
444 static void dma_transfer_complete(struct driver_data *drv_data)
445 {
446 void *reg = drv_data->ioaddr;
447 struct spi_message *msg = drv_data->cur_msg;
448
449 /* Clear and disable interrupts on SSP and DMA channels*/
450 write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
451 write_SSSR(drv_data->clear_sr, reg);
452 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
453 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
454
455 if (wait_dma_channel_stop(drv_data->rx_channel) == 0)
456 dev_err(&drv_data->pdev->dev,
457 "dma_handler: dma rx channel stop failed\n");
458
459 if (wait_ssp_rx_stall(drv_data->ioaddr) == 0)
460 dev_err(&drv_data->pdev->dev,
461 "dma_transfer: ssp rx stall failed\n");
462
463 unmap_dma_buffers(drv_data);
464
465 /* update the buffer pointer for the amount completed in dma */
466 drv_data->rx += drv_data->len -
467 (DCMD(drv_data->rx_channel) & DCMD_LENGTH);
468
469 /* read trailing data from fifo, it does not matter how many
470 * bytes are in the fifo just read until buffer is full
471 * or fifo is empty, which ever occurs first */
472 drv_data->read(drv_data);
473
474 /* return count of what was actually read */
475 msg->actual_length += drv_data->len -
476 (drv_data->rx_end - drv_data->rx);
477
478 /* Release chip select if requested, transfer delays are
479 * handled in pump_transfers */
480 if (drv_data->cs_change)
481 drv_data->cs_control(PXA2XX_CS_DEASSERT);
482
483 /* Move to next transfer */
484 msg->state = next_transfer(drv_data);
485
486 /* Schedule transfer tasklet */
487 tasklet_schedule(&drv_data->pump_transfers);
488 }
489
490 static void dma_handler(int channel, void *data)
491 {
492 struct driver_data *drv_data = data;
493 u32 irq_status = DCSR(channel) & DMA_INT_MASK;
494
495 if (irq_status & DCSR_BUSERR) {
496
497 if (channel == drv_data->tx_channel)
498 dma_error_stop(drv_data,
499 "dma_handler: "
500 "bad bus address on tx channel");
501 else
502 dma_error_stop(drv_data,
503 "dma_handler: "
504 "bad bus address on rx channel");
505 return;
506 }
507
508 /* PXA255x_SSP has no timeout interrupt, wait for tailing bytes */
509 if ((channel == drv_data->tx_channel)
510 && (irq_status & DCSR_ENDINTR)
511 && (drv_data->ssp_type == PXA25x_SSP)) {
512
513 /* Wait for rx to stall */
514 if (wait_ssp_rx_stall(drv_data->ioaddr) == 0)
515 dev_err(&drv_data->pdev->dev,
516 "dma_handler: ssp rx stall failed\n");
517
518 /* finish this transfer, start the next */
519 dma_transfer_complete(drv_data);
520 }
521 }
522
523 static irqreturn_t dma_transfer(struct driver_data *drv_data)
524 {
525 u32 irq_status;
526 void *reg = drv_data->ioaddr;
527
528 irq_status = read_SSSR(reg) & drv_data->mask_sr;
529 if (irq_status & SSSR_ROR) {
530 dma_error_stop(drv_data, "dma_transfer: fifo overrun");
531 return IRQ_HANDLED;
532 }
533
534 /* Check for false positive timeout */
535 if ((irq_status & SSSR_TINT)
536 && (DCSR(drv_data->tx_channel) & DCSR_RUN)) {
537 write_SSSR(SSSR_TINT, reg);
538 return IRQ_HANDLED;
539 }
540
541 if (irq_status & SSSR_TINT || drv_data->rx == drv_data->rx_end) {
542
543 /* Clear and disable timeout interrupt, do the rest in
544 * dma_transfer_complete */
545 if (drv_data->ssp_type != PXA25x_SSP)
546 write_SSTO(0, reg);
547
548 /* finish this transfer, start the next */
549 dma_transfer_complete(drv_data);
550
551 return IRQ_HANDLED;
552 }
553
554 /* Opps problem detected */
555 return IRQ_NONE;
556 }
557
558 static void int_error_stop(struct driver_data *drv_data, const char* msg)
559 {
560 void *reg = drv_data->ioaddr;
561
562 /* Stop and reset SSP */
563 write_SSSR(drv_data->clear_sr, reg);
564 write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
565 if (drv_data->ssp_type != PXA25x_SSP)
566 write_SSTO(0, reg);
567 flush(drv_data);
568 write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
569
570 dev_err(&drv_data->pdev->dev, "%s\n", msg);
571
572 drv_data->cur_msg->state = ERROR_STATE;
573 tasklet_schedule(&drv_data->pump_transfers);
574 }
575
576 static void int_transfer_complete(struct driver_data *drv_data)
577 {
578 void *reg = drv_data->ioaddr;
579
580 /* Stop SSP */
581 write_SSSR(drv_data->clear_sr, reg);
582 write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
583 if (drv_data->ssp_type != PXA25x_SSP)
584 write_SSTO(0, reg);
585
586 /* Update total byte transfered return count actual bytes read */
587 drv_data->cur_msg->actual_length += drv_data->len -
588 (drv_data->rx_end - drv_data->rx);
589
590 /* Release chip select if requested, transfer delays are
591 * handled in pump_transfers */
592 if (drv_data->cs_change)
593 drv_data->cs_control(PXA2XX_CS_DEASSERT);
594
595 /* Move to next transfer */
596 drv_data->cur_msg->state = next_transfer(drv_data);
597
598 /* Schedule transfer tasklet */
599 tasklet_schedule(&drv_data->pump_transfers);
600 }
601
602 static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
603 {
604 void *reg = drv_data->ioaddr;
605
606 u32 irq_mask = (read_SSCR1(reg) & SSCR1_TIE) ?
607 drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS;
608
609 u32 irq_status = read_SSSR(reg) & irq_mask;
610
611 if (irq_status & SSSR_ROR) {
612 int_error_stop(drv_data, "interrupt_transfer: fifo overrun");
613 return IRQ_HANDLED;
614 }
615
616 if (irq_status & SSSR_TINT) {
617 write_SSSR(SSSR_TINT, reg);
618 if (drv_data->read(drv_data)) {
619 int_transfer_complete(drv_data);
620 return IRQ_HANDLED;
621 }
622 }
623
624 /* Drain rx fifo, Fill tx fifo and prevent overruns */
625 do {
626 if (drv_data->read(drv_data)) {
627 int_transfer_complete(drv_data);
628 return IRQ_HANDLED;
629 }
630 } while (drv_data->write(drv_data));
631
632 if (drv_data->read(drv_data)) {
633 int_transfer_complete(drv_data);
634 return IRQ_HANDLED;
635 }
636
637 if (drv_data->tx == drv_data->tx_end) {
638 write_SSCR1(read_SSCR1(reg) & ~SSCR1_TIE, reg);
639 /* PXA25x_SSP has no timeout, read trailing bytes */
640 if (drv_data->ssp_type == PXA25x_SSP) {
641 if (!wait_ssp_rx_stall(reg))
642 {
643 int_error_stop(drv_data, "interrupt_transfer: "
644 "rx stall failed");
645 return IRQ_HANDLED;
646 }
647 if (!drv_data->read(drv_data))
648 {
649 int_error_stop(drv_data,
650 "interrupt_transfer: "
651 "trailing byte read failed");
652 return IRQ_HANDLED;
653 }
654 int_transfer_complete(drv_data);
655 }
656 }
657
658 /* We did something */
659 return IRQ_HANDLED;
660 }
661
662 static irqreturn_t ssp_int(int irq, void *dev_id)
663 {
664 struct driver_data *drv_data = dev_id;
665 void *reg = drv_data->ioaddr;
666
667 if (!drv_data->cur_msg) {
668
669 write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
670 write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
671 if (drv_data->ssp_type != PXA25x_SSP)
672 write_SSTO(0, reg);
673 write_SSSR(drv_data->clear_sr, reg);
674
675 dev_err(&drv_data->pdev->dev, "bad message state "
676 "in interrupt handler\n");
677
678 /* Never fail */
679 return IRQ_HANDLED;
680 }
681
682 return drv_data->transfer_handler(drv_data);
683 }
684
685 int set_dma_burst_and_threshold(struct chip_data *chip, struct spi_device *spi,
686 u8 bits_per_word, u32 *burst_code,
687 u32 *threshold)
688 {
689 struct pxa2xx_spi_chip *chip_info =
690 (struct pxa2xx_spi_chip *)spi->controller_data;
691 int bytes_per_word;
692 int burst_bytes;
693 int thresh_words;
694 int req_burst_size;
695 int retval = 0;
696
697 /* Set the threshold (in registers) to equal the same amount of data
698 * as represented by burst size (in bytes). The computation below
699 * is (burst_size rounded up to nearest 8 byte, word or long word)
700 * divided by (bytes/register); the tx threshold is the inverse of
701 * the rx, so that there will always be enough data in the rx fifo
702 * to satisfy a burst, and there will always be enough space in the
703 * tx fifo to accept a burst (a tx burst will overwrite the fifo if
704 * there is not enough space), there must always remain enough empty
705 * space in the rx fifo for any data loaded to the tx fifo.
706 * Whenever burst_size (in bytes) equals bits/word, the fifo threshold
707 * will be 8, or half the fifo;
708 * The threshold can only be set to 2, 4 or 8, but not 16, because
709 * to burst 16 to the tx fifo, the fifo would have to be empty;
710 * however, the minimum fifo trigger level is 1, and the tx will
711 * request service when the fifo is at this level, with only 15 spaces.
712 */
713
714 /* find bytes/word */
715 if (bits_per_word <= 8)
716 bytes_per_word = 1;
717 else if (bits_per_word <= 16)
718 bytes_per_word = 2;
719 else
720 bytes_per_word = 4;
721
722 /* use struct pxa2xx_spi_chip->dma_burst_size if available */
723 if (chip_info)
724 req_burst_size = chip_info->dma_burst_size;
725 else {
726 switch (chip->dma_burst_size) {
727 default:
728 /* if the default burst size is not set,
729 * do it now */
730 chip->dma_burst_size = DCMD_BURST8;
731 case DCMD_BURST8:
732 req_burst_size = 8;
733 break;
734 case DCMD_BURST16:
735 req_burst_size = 16;
736 break;
737 case DCMD_BURST32:
738 req_burst_size = 32;
739 break;
740 }
741 }
742 if (req_burst_size <= 8) {
743 *burst_code = DCMD_BURST8;
744 burst_bytes = 8;
745 } else if (req_burst_size <= 16) {
746 if (bytes_per_word == 1) {
747 /* don't burst more than 1/2 the fifo */
748 *burst_code = DCMD_BURST8;
749 burst_bytes = 8;
750 retval = 1;
751 } else {
752 *burst_code = DCMD_BURST16;
753 burst_bytes = 16;
754 }
755 } else {
756 if (bytes_per_word == 1) {
757 /* don't burst more than 1/2 the fifo */
758 *burst_code = DCMD_BURST8;
759 burst_bytes = 8;
760 retval = 1;
761 } else if (bytes_per_word == 2) {
762 /* don't burst more than 1/2 the fifo */
763 *burst_code = DCMD_BURST16;
764 burst_bytes = 16;
765 retval = 1;
766 } else {
767 *burst_code = DCMD_BURST32;
768 burst_bytes = 32;
769 }
770 }
771
772 thresh_words = burst_bytes / bytes_per_word;
773
774 /* thresh_words will be between 2 and 8 */
775 *threshold = (SSCR1_RxTresh(thresh_words) & SSCR1_RFT)
776 | (SSCR1_TxTresh(16-thresh_words) & SSCR1_TFT);
777
778 return retval;
779 }
780
781 static void pump_transfers(unsigned long data)
782 {
783 struct driver_data *drv_data = (struct driver_data *)data;
784 struct spi_message *message = NULL;
785 struct spi_transfer *transfer = NULL;
786 struct spi_transfer *previous = NULL;
787 struct chip_data *chip = NULL;
788 void *reg = drv_data->ioaddr;
789 u32 clk_div = 0;
790 u8 bits = 0;
791 u32 speed = 0;
792 u32 cr0;
793 u32 cr1;
794 u32 dma_thresh = drv_data->cur_chip->dma_threshold;
795 u32 dma_burst = drv_data->cur_chip->dma_burst_size;
796
797 /* Get current state information */
798 message = drv_data->cur_msg;
799 transfer = drv_data->cur_transfer;
800 chip = drv_data->cur_chip;
801
802 /* Handle for abort */
803 if (message->state == ERROR_STATE) {
804 message->status = -EIO;
805 giveback(drv_data);
806 return;
807 }
808
809 /* Handle end of message */
810 if (message->state == DONE_STATE) {
811 message->status = 0;
812 giveback(drv_data);
813 return;
814 }
815
816 /* Delay if requested at end of transfer*/
817 if (message->state == RUNNING_STATE) {
818 previous = list_entry(transfer->transfer_list.prev,
819 struct spi_transfer,
820 transfer_list);
821 if (previous->delay_usecs)
822 udelay(previous->delay_usecs);
823 }
824
825 /* Check transfer length */
826 if (transfer->len > 8191)
827 {
828 dev_warn(&drv_data->pdev->dev, "pump_transfers: transfer "
829 "length greater than 8191\n");
830 message->status = -EINVAL;
831 giveback(drv_data);
832 return;
833 }
834
835 /* Setup the transfer state based on the type of transfer */
836 if (flush(drv_data) == 0) {
837 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
838 message->status = -EIO;
839 giveback(drv_data);
840 return;
841 }
842 drv_data->n_bytes = chip->n_bytes;
843 drv_data->dma_width = chip->dma_width;
844 drv_data->cs_control = chip->cs_control;
845 drv_data->tx = (void *)transfer->tx_buf;
846 drv_data->tx_end = drv_data->tx + transfer->len;
847 drv_data->rx = transfer->rx_buf;
848 drv_data->rx_end = drv_data->rx + transfer->len;
849 drv_data->rx_dma = transfer->rx_dma;
850 drv_data->tx_dma = transfer->tx_dma;
851 drv_data->len = transfer->len & DCMD_LENGTH;
852 drv_data->write = drv_data->tx ? chip->write : null_writer;
853 drv_data->read = drv_data->rx ? chip->read : null_reader;
854 drv_data->cs_change = transfer->cs_change;
855
856 /* Change speed and bit per word on a per transfer */
857 cr0 = chip->cr0;
858 if (transfer->speed_hz || transfer->bits_per_word) {
859
860 bits = chip->bits_per_word;
861 speed = chip->speed_hz;
862
863 if (transfer->speed_hz)
864 speed = transfer->speed_hz;
865
866 if (transfer->bits_per_word)
867 bits = transfer->bits_per_word;
868
869 if (reg == SSP1_VIRT)
870 clk_div = SSP1_SerClkDiv(speed);
871 else if (reg == SSP2_VIRT)
872 clk_div = SSP2_SerClkDiv(speed);
873 else if (reg == SSP3_VIRT)
874 clk_div = SSP3_SerClkDiv(speed);
875
876 if (bits <= 8) {
877 drv_data->n_bytes = 1;
878 drv_data->dma_width = DCMD_WIDTH1;
879 drv_data->read = drv_data->read != null_reader ?
880 u8_reader : null_reader;
881 drv_data->write = drv_data->write != null_writer ?
882 u8_writer : null_writer;
883 } else if (bits <= 16) {
884 drv_data->n_bytes = 2;
885 drv_data->dma_width = DCMD_WIDTH2;
886 drv_data->read = drv_data->read != null_reader ?
887 u16_reader : null_reader;
888 drv_data->write = drv_data->write != null_writer ?
889 u16_writer : null_writer;
890 } else if (bits <= 32) {
891 drv_data->n_bytes = 4;
892 drv_data->dma_width = DCMD_WIDTH4;
893 drv_data->read = drv_data->read != null_reader ?
894 u32_reader : null_reader;
895 drv_data->write = drv_data->write != null_writer ?
896 u32_writer : null_writer;
897 }
898 /* if bits/word is changed in dma mode, then must check the
899 * thresholds and burst also */
900 if (chip->enable_dma) {
901 if (set_dma_burst_and_threshold(chip, message->spi,
902 bits, &dma_burst,
903 &dma_thresh))
904 if (printk_ratelimit())
905 dev_warn(&message->spi->dev,
906 "pump_transfer: "
907 "DMA burst size reduced to "
908 "match bits_per_word\n");
909 }
910
911 cr0 = clk_div
912 | SSCR0_Motorola
913 | SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
914 | SSCR0_SSE
915 | (bits > 16 ? SSCR0_EDSS : 0);
916 }
917
918 message->state = RUNNING_STATE;
919
920 /* Try to map dma buffer and do a dma transfer if successful */
921 if ((drv_data->dma_mapped = map_dma_buffers(drv_data))) {
922
923 /* Ensure we have the correct interrupt handler */
924 drv_data->transfer_handler = dma_transfer;
925
926 /* Setup rx DMA Channel */
927 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
928 DSADR(drv_data->rx_channel) = drv_data->ssdr_physical;
929 DTADR(drv_data->rx_channel) = drv_data->rx_dma;
930 if (drv_data->rx == drv_data->null_dma_buf)
931 /* No target address increment */
932 DCMD(drv_data->rx_channel) = DCMD_FLOWSRC
933 | drv_data->dma_width
934 | dma_burst
935 | drv_data->len;
936 else
937 DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR
938 | DCMD_FLOWSRC
939 | drv_data->dma_width
940 | dma_burst
941 | drv_data->len;
942
943 /* Setup tx DMA Channel */
944 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
945 DSADR(drv_data->tx_channel) = drv_data->tx_dma;
946 DTADR(drv_data->tx_channel) = drv_data->ssdr_physical;
947 if (drv_data->tx == drv_data->null_dma_buf)
948 /* No source address increment */
949 DCMD(drv_data->tx_channel) = DCMD_FLOWTRG
950 | drv_data->dma_width
951 | dma_burst
952 | drv_data->len;
953 else
954 DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR
955 | DCMD_FLOWTRG
956 | drv_data->dma_width
957 | dma_burst
958 | drv_data->len;
959
960 /* Enable dma end irqs on SSP to detect end of transfer */
961 if (drv_data->ssp_type == PXA25x_SSP)
962 DCMD(drv_data->tx_channel) |= DCMD_ENDIRQEN;
963
964 /* Fix me, need to handle cs polarity */
965 drv_data->cs_control(PXA2XX_CS_ASSERT);
966
967 /* Clear status and start DMA engine */
968 cr1 = chip->cr1 | dma_thresh | drv_data->dma_cr1;
969 write_SSSR(drv_data->clear_sr, reg);
970 DCSR(drv_data->rx_channel) |= DCSR_RUN;
971 DCSR(drv_data->tx_channel) |= DCSR_RUN;
972 } else {
973 /* Ensure we have the correct interrupt handler */
974 drv_data->transfer_handler = interrupt_transfer;
975
976 /* Fix me, need to handle cs polarity */
977 drv_data->cs_control(PXA2XX_CS_ASSERT);
978
979 /* Clear status */
980 cr1 = chip->cr1 | chip->threshold | drv_data->int_cr1;
981 write_SSSR(drv_data->clear_sr, reg);
982 }
983
984 /* see if we need to reload the config registers */
985 if ((read_SSCR0(reg) != cr0)
986 || (read_SSCR1(reg) & SSCR1_CHANGE_MASK) !=
987 (cr1 & SSCR1_CHANGE_MASK)) {
988
989 write_SSCR0(cr0 & ~SSCR0_SSE, reg);
990 if (drv_data->ssp_type != PXA25x_SSP)
991 write_SSTO(chip->timeout, reg);
992 write_SSCR1(cr1, reg);
993 write_SSCR0(cr0, reg);
994 } else {
995 if (drv_data->ssp_type != PXA25x_SSP)
996 write_SSTO(chip->timeout, reg);
997 write_SSCR1(cr1, reg);
998 }
999 }
1000
1001 static void pump_messages(struct work_struct *work)
1002 {
1003 struct driver_data *drv_data =
1004 container_of(work, struct driver_data, pump_messages);
1005 unsigned long flags;
1006
1007 /* Lock queue and check for queue work */
1008 spin_lock_irqsave(&drv_data->lock, flags);
1009 if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
1010 drv_data->busy = 0;
1011 spin_unlock_irqrestore(&drv_data->lock, flags);
1012 return;
1013 }
1014
1015 /* Make sure we are not already running a message */
1016 if (drv_data->cur_msg) {
1017 spin_unlock_irqrestore(&drv_data->lock, flags);
1018 return;
1019 }
1020
1021 /* Extract head of queue */
1022 drv_data->cur_msg = list_entry(drv_data->queue.next,
1023 struct spi_message, queue);
1024 list_del_init(&drv_data->cur_msg->queue);
1025
1026 /* Initial message state*/
1027 drv_data->cur_msg->state = START_STATE;
1028 drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
1029 struct spi_transfer,
1030 transfer_list);
1031
1032 /* prepare to setup the SSP, in pump_transfers, using the per
1033 * chip configuration */
1034 drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
1035
1036 /* Mark as busy and launch transfers */
1037 tasklet_schedule(&drv_data->pump_transfers);
1038
1039 drv_data->busy = 1;
1040 spin_unlock_irqrestore(&drv_data->lock, flags);
1041 }
1042
1043 static int transfer(struct spi_device *spi, struct spi_message *msg)
1044 {
1045 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1046 unsigned long flags;
1047
1048 spin_lock_irqsave(&drv_data->lock, flags);
1049
1050 if (drv_data->run == QUEUE_STOPPED) {
1051 spin_unlock_irqrestore(&drv_data->lock, flags);
1052 return -ESHUTDOWN;
1053 }
1054
1055 msg->actual_length = 0;
1056 msg->status = -EINPROGRESS;
1057 msg->state = START_STATE;
1058
1059 list_add_tail(&msg->queue, &drv_data->queue);
1060
1061 if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
1062 queue_work(drv_data->workqueue, &drv_data->pump_messages);
1063
1064 spin_unlock_irqrestore(&drv_data->lock, flags);
1065
1066 return 0;
1067 }
1068
1069 /* the spi->mode bits understood by this driver: */
1070 #define MODEBITS (SPI_CPOL | SPI_CPHA)
1071
1072 static int setup(struct spi_device *spi)
1073 {
1074 struct pxa2xx_spi_chip *chip_info = NULL;
1075 struct chip_data *chip;
1076 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1077 unsigned int clk_div;
1078
1079 if (!spi->bits_per_word)
1080 spi->bits_per_word = 8;
1081
1082 if (drv_data->ssp_type != PXA25x_SSP
1083 && (spi->bits_per_word < 4 || spi->bits_per_word > 32)) {
1084 dev_err(&spi->dev, "failed setup: ssp_type=%d, bits/wrd=%d "
1085 "b/w not 4-32 for type non-PXA25x_SSP\n",
1086 drv_data->ssp_type, spi->bits_per_word);
1087 return -EINVAL;
1088 }
1089 else if (drv_data->ssp_type == PXA25x_SSP
1090 && (spi->bits_per_word < 4
1091 || spi->bits_per_word > 16)) {
1092 dev_err(&spi->dev, "failed setup: ssp_type=%d, bits/wrd=%d "
1093 "b/w not 4-16 for type PXA25x_SSP\n",
1094 drv_data->ssp_type, spi->bits_per_word);
1095 return -EINVAL;
1096 }
1097
1098 if (spi->mode & ~MODEBITS) {
1099 dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
1100 spi->mode & ~MODEBITS);
1101 return -EINVAL;
1102 }
1103
1104 /* Only alloc on first setup */
1105 chip = spi_get_ctldata(spi);
1106 if (!chip) {
1107 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1108 if (!chip) {
1109 dev_err(&spi->dev,
1110 "failed setup: can't allocate chip data\n");
1111 return -ENOMEM;
1112 }
1113
1114 chip->cs_control = null_cs_control;
1115 chip->enable_dma = 0;
1116 chip->timeout = 1000;
1117 chip->threshold = SSCR1_RxTresh(1) | SSCR1_TxTresh(1);
1118 chip->dma_burst_size = drv_data->master_info->enable_dma ?
1119 DCMD_BURST8 : 0;
1120 }
1121
1122 /* protocol drivers may change the chip settings, so...
1123 * if chip_info exists, use it */
1124 chip_info = spi->controller_data;
1125
1126 /* chip_info isn't always needed */
1127 chip->cr1 = 0;
1128 if (chip_info) {
1129 if (chip_info->cs_control)
1130 chip->cs_control = chip_info->cs_control;
1131
1132 chip->timeout = chip_info->timeout;
1133
1134 chip->threshold = (SSCR1_RxTresh(chip_info->rx_threshold) &
1135 SSCR1_RFT) |
1136 (SSCR1_TxTresh(chip_info->tx_threshold) &
1137 SSCR1_TFT);
1138
1139 chip->enable_dma = chip_info->dma_burst_size != 0
1140 && drv_data->master_info->enable_dma;
1141 chip->dma_threshold = 0;
1142
1143 if (chip_info->enable_loopback)
1144 chip->cr1 = SSCR1_LBM;
1145 }
1146
1147 /* set dma burst and threshold outside of chip_info path so that if
1148 * chip_info goes away after setting chip->enable_dma, the
1149 * burst and threshold can still respond to changes in bits_per_word */
1150 if (chip->enable_dma) {
1151 /* set up legal burst and threshold for dma */
1152 if (set_dma_burst_and_threshold(chip, spi, spi->bits_per_word,
1153 &chip->dma_burst_size,
1154 &chip->dma_threshold)) {
1155 dev_warn(&spi->dev, "in setup: DMA burst size reduced "
1156 "to match bits_per_word\n");
1157 }
1158 }
1159
1160 if (drv_data->ioaddr == SSP1_VIRT)
1161 clk_div = SSP1_SerClkDiv(spi->max_speed_hz);
1162 else if (drv_data->ioaddr == SSP2_VIRT)
1163 clk_div = SSP2_SerClkDiv(spi->max_speed_hz);
1164 else if (drv_data->ioaddr == SSP3_VIRT)
1165 clk_div = SSP3_SerClkDiv(spi->max_speed_hz);
1166 else
1167 {
1168 dev_err(&spi->dev, "failed setup: unknown IO address=0x%p\n",
1169 drv_data->ioaddr);
1170 return -ENODEV;
1171 }
1172 chip->speed_hz = spi->max_speed_hz;
1173
1174 chip->cr0 = clk_div
1175 | SSCR0_Motorola
1176 | SSCR0_DataSize(spi->bits_per_word > 16 ?
1177 spi->bits_per_word - 16 : spi->bits_per_word)
1178 | SSCR0_SSE
1179 | (spi->bits_per_word > 16 ? SSCR0_EDSS : 0);
1180 chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH);
1181 chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
1182 | (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);
1183
1184 /* NOTE: PXA25x_SSP _could_ use external clocking ... */
1185 if (drv_data->ssp_type != PXA25x_SSP)
1186 dev_dbg(&spi->dev, "%d bits/word, %d Hz, mode %d\n",
1187 spi->bits_per_word,
1188 (CLOCK_SPEED_HZ)
1189 / (1 + ((chip->cr0 & SSCR0_SCR) >> 8)),
1190 spi->mode & 0x3);
1191 else
1192 dev_dbg(&spi->dev, "%d bits/word, %d Hz, mode %d\n",
1193 spi->bits_per_word,
1194 (CLOCK_SPEED_HZ/2)
1195 / (1 + ((chip->cr0 & SSCR0_SCR) >> 8)),
1196 spi->mode & 0x3);
1197
1198 if (spi->bits_per_word <= 8) {
1199 chip->n_bytes = 1;
1200 chip->dma_width = DCMD_WIDTH1;
1201 chip->read = u8_reader;
1202 chip->write = u8_writer;
1203 } else if (spi->bits_per_word <= 16) {
1204 chip->n_bytes = 2;
1205 chip->dma_width = DCMD_WIDTH2;
1206 chip->read = u16_reader;
1207 chip->write = u16_writer;
1208 } else if (spi->bits_per_word <= 32) {
1209 chip->cr0 |= SSCR0_EDSS;
1210 chip->n_bytes = 4;
1211 chip->dma_width = DCMD_WIDTH4;
1212 chip->read = u32_reader;
1213 chip->write = u32_writer;
1214 } else {
1215 dev_err(&spi->dev, "invalid wordsize\n");
1216 return -ENODEV;
1217 }
1218 chip->bits_per_word = spi->bits_per_word;
1219
1220 spi_set_ctldata(spi, chip);
1221
1222 return 0;
1223 }
1224
1225 static void cleanup(struct spi_device *spi)
1226 {
1227 struct chip_data *chip = spi_get_ctldata(spi);
1228
1229 kfree(chip);
1230 }
1231
1232 static int __init init_queue(struct driver_data *drv_data)
1233 {
1234 INIT_LIST_HEAD(&drv_data->queue);
1235 spin_lock_init(&drv_data->lock);
1236
1237 drv_data->run = QUEUE_STOPPED;
1238 drv_data->busy = 0;
1239
1240 tasklet_init(&drv_data->pump_transfers,
1241 pump_transfers, (unsigned long)drv_data);
1242
1243 INIT_WORK(&drv_data->pump_messages, pump_messages);
1244 drv_data->workqueue = create_singlethread_workqueue(
1245 drv_data->master->dev.parent->bus_id);
1246 if (drv_data->workqueue == NULL)
1247 return -EBUSY;
1248
1249 return 0;
1250 }
1251
1252 static int start_queue(struct driver_data *drv_data)
1253 {
1254 unsigned long flags;
1255
1256 spin_lock_irqsave(&drv_data->lock, flags);
1257
1258 if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
1259 spin_unlock_irqrestore(&drv_data->lock, flags);
1260 return -EBUSY;
1261 }
1262
1263 drv_data->run = QUEUE_RUNNING;
1264 drv_data->cur_msg = NULL;
1265 drv_data->cur_transfer = NULL;
1266 drv_data->cur_chip = NULL;
1267 spin_unlock_irqrestore(&drv_data->lock, flags);
1268
1269 queue_work(drv_data->workqueue, &drv_data->pump_messages);
1270
1271 return 0;
1272 }
1273
1274 static int stop_queue(struct driver_data *drv_data)
1275 {
1276 unsigned long flags;
1277 unsigned limit = 500;
1278 int status = 0;
1279
1280 spin_lock_irqsave(&drv_data->lock, flags);
1281
1282 /* This is a bit lame, but is optimized for the common execution path.
1283 * A wait_queue on the drv_data->busy could be used, but then the common
1284 * execution path (pump_messages) would be required to call wake_up or
1285 * friends on every SPI message. Do this instead */
1286 drv_data->run = QUEUE_STOPPED;
1287 while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
1288 spin_unlock_irqrestore(&drv_data->lock, flags);
1289 msleep(10);
1290 spin_lock_irqsave(&drv_data->lock, flags);
1291 }
1292
1293 if (!list_empty(&drv_data->queue) || drv_data->busy)
1294 status = -EBUSY;
1295
1296 spin_unlock_irqrestore(&drv_data->lock, flags);
1297
1298 return status;
1299 }
1300
1301 static int destroy_queue(struct driver_data *drv_data)
1302 {
1303 int status;
1304
1305 status = stop_queue(drv_data);
1306 /* we are unloading the module or failing to load (only two calls
1307 * to this routine), and neither call can handle a return value.
1308 * However, destroy_workqueue calls flush_workqueue, and that will
1309 * block until all work is done. If the reason that stop_queue
1310 * timed out is that the work will never finish, then it does no
1311 * good to call destroy_workqueue, so return anyway. */
1312 if (status != 0)
1313 return status;
1314
1315 destroy_workqueue(drv_data->workqueue);
1316
1317 return 0;
1318 }
1319
1320 static int __init pxa2xx_spi_probe(struct platform_device *pdev)
1321 {
1322 struct device *dev = &pdev->dev;
1323 struct pxa2xx_spi_master *platform_info;
1324 struct spi_master *master;
1325 struct driver_data *drv_data = 0;
1326 struct resource *memory_resource;
1327 int irq;
1328 int status = 0;
1329
1330 platform_info = dev->platform_data;
1331
1332 if (platform_info->ssp_type == SSP_UNDEFINED) {
1333 dev_err(&pdev->dev, "undefined SSP\n");
1334 return -ENODEV;
1335 }
1336
1337 /* Allocate master with space for drv_data and null dma buffer */
1338 master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
1339 if (!master) {
1340 dev_err(&pdev->dev, "can not alloc spi_master\n");
1341 return -ENOMEM;
1342 }
1343 drv_data = spi_master_get_devdata(master);
1344 drv_data->master = master;
1345 drv_data->master_info = platform_info;
1346 drv_data->pdev = pdev;
1347
1348 master->bus_num = pdev->id;
1349 master->num_chipselect = platform_info->num_chipselect;
1350 master->cleanup = cleanup;
1351 master->setup = setup;
1352 master->transfer = transfer;
1353
1354 drv_data->ssp_type = platform_info->ssp_type;
1355 drv_data->null_dma_buf = (u32 *)ALIGN((u32)(drv_data +
1356 sizeof(struct driver_data)), 8);
1357
1358 /* Setup register addresses */
1359 memory_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1360 if (!memory_resource) {
1361 dev_err(&pdev->dev, "memory resources not defined\n");
1362 status = -ENODEV;
1363 goto out_error_master_alloc;
1364 }
1365
1366 drv_data->ioaddr = (void *)io_p2v((unsigned long)(memory_resource->start));
1367 drv_data->ssdr_physical = memory_resource->start + 0x00000010;
1368 if (platform_info->ssp_type == PXA25x_SSP) {
1369 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE;
1370 drv_data->dma_cr1 = 0;
1371 drv_data->clear_sr = SSSR_ROR;
1372 drv_data->mask_sr = SSSR_RFS | SSSR_TFS | SSSR_ROR;
1373 } else {
1374 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE;
1375 drv_data->dma_cr1 = SSCR1_TSRE | SSCR1_RSRE | SSCR1_TINTE;
1376 drv_data->clear_sr = SSSR_ROR | SSSR_TINT;
1377 drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR;
1378 }
1379
1380 /* Attach to IRQ */
1381 irq = platform_get_irq(pdev, 0);
1382 if (irq < 0) {
1383 dev_err(&pdev->dev, "irq resource not defined\n");
1384 status = -ENODEV;
1385 goto out_error_master_alloc;
1386 }
1387
1388 status = request_irq(irq, ssp_int, 0, dev->bus_id, drv_data);
1389 if (status < 0) {
1390 dev_err(&pdev->dev, "can not get IRQ\n");
1391 goto out_error_master_alloc;
1392 }
1393
1394 /* Setup DMA if requested */
1395 drv_data->tx_channel = -1;
1396 drv_data->rx_channel = -1;
1397 if (platform_info->enable_dma) {
1398
1399 /* Get two DMA channels (rx and tx) */
1400 drv_data->rx_channel = pxa_request_dma("pxa2xx_spi_ssp_rx",
1401 DMA_PRIO_HIGH,
1402 dma_handler,
1403 drv_data);
1404 if (drv_data->rx_channel < 0) {
1405 dev_err(dev, "problem (%d) requesting rx channel\n",
1406 drv_data->rx_channel);
1407 status = -ENODEV;
1408 goto out_error_irq_alloc;
1409 }
1410 drv_data->tx_channel = pxa_request_dma("pxa2xx_spi_ssp_tx",
1411 DMA_PRIO_MEDIUM,
1412 dma_handler,
1413 drv_data);
1414 if (drv_data->tx_channel < 0) {
1415 dev_err(dev, "problem (%d) requesting tx channel\n",
1416 drv_data->tx_channel);
1417 status = -ENODEV;
1418 goto out_error_dma_alloc;
1419 }
1420
1421 if (drv_data->ioaddr == SSP1_VIRT) {
1422 DRCMRRXSSDR = DRCMR_MAPVLD
1423 | drv_data->rx_channel;
1424 DRCMRTXSSDR = DRCMR_MAPVLD
1425 | drv_data->tx_channel;
1426 } else if (drv_data->ioaddr == SSP2_VIRT) {
1427 DRCMRRXSS2DR = DRCMR_MAPVLD
1428 | drv_data->rx_channel;
1429 DRCMRTXSS2DR = DRCMR_MAPVLD
1430 | drv_data->tx_channel;
1431 } else if (drv_data->ioaddr == SSP3_VIRT) {
1432 DRCMRRXSS3DR = DRCMR_MAPVLD
1433 | drv_data->rx_channel;
1434 DRCMRTXSS3DR = DRCMR_MAPVLD
1435 | drv_data->tx_channel;
1436 } else {
1437 dev_err(dev, "bad SSP type\n");
1438 goto out_error_dma_alloc;
1439 }
1440 }
1441
1442 /* Enable SOC clock */
1443 pxa_set_cken(platform_info->clock_enable, 1);
1444
1445 /* Load default SSP configuration */
1446 write_SSCR0(0, drv_data->ioaddr);
1447 write_SSCR1(SSCR1_RxTresh(4) | SSCR1_TxTresh(12), drv_data->ioaddr);
1448 write_SSCR0(SSCR0_SerClkDiv(2)
1449 | SSCR0_Motorola
1450 | SSCR0_DataSize(8),
1451 drv_data->ioaddr);
1452 if (drv_data->ssp_type != PXA25x_SSP)
1453 write_SSTO(0, drv_data->ioaddr);
1454 write_SSPSP(0, drv_data->ioaddr);
1455
1456 /* Initial and start queue */
1457 status = init_queue(drv_data);
1458 if (status != 0) {
1459 dev_err(&pdev->dev, "problem initializing queue\n");
1460 goto out_error_clock_enabled;
1461 }
1462 status = start_queue(drv_data);
1463 if (status != 0) {
1464 dev_err(&pdev->dev, "problem starting queue\n");
1465 goto out_error_clock_enabled;
1466 }
1467
1468 /* Register with the SPI framework */
1469 platform_set_drvdata(pdev, drv_data);
1470 status = spi_register_master(master);
1471 if (status != 0) {
1472 dev_err(&pdev->dev, "problem registering spi master\n");
1473 goto out_error_queue_alloc;
1474 }
1475
1476 return status;
1477
1478 out_error_queue_alloc:
1479 destroy_queue(drv_data);
1480
1481 out_error_clock_enabled:
1482 pxa_set_cken(platform_info->clock_enable, 0);
1483
1484 out_error_dma_alloc:
1485 if (drv_data->tx_channel != -1)
1486 pxa_free_dma(drv_data->tx_channel);
1487 if (drv_data->rx_channel != -1)
1488 pxa_free_dma(drv_data->rx_channel);
1489
1490 out_error_irq_alloc:
1491 free_irq(irq, drv_data);
1492
1493 out_error_master_alloc:
1494 spi_master_put(master);
1495 return status;
1496 }
1497
1498 static int pxa2xx_spi_remove(struct platform_device *pdev)
1499 {
1500 struct driver_data *drv_data = platform_get_drvdata(pdev);
1501 int irq;
1502 int status = 0;
1503
1504 if (!drv_data)
1505 return 0;
1506
1507 /* Remove the queue */
1508 status = destroy_queue(drv_data);
1509 if (status != 0)
1510 /* the kernel does not check the return status of this
1511 * this routine (mod->exit, within the kernel). Therefore
1512 * nothing is gained by returning from here, the module is
1513 * going away regardless, and we should not leave any more
1514 * resources allocated than necessary. We cannot free the
1515 * message memory in drv_data->queue, but we can release the
1516 * resources below. I think the kernel should honor -EBUSY
1517 * returns but... */
1518 dev_err(&pdev->dev, "pxa2xx_spi_remove: workqueue will not "
1519 "complete, message memory not freed\n");
1520
1521 /* Disable the SSP at the peripheral and SOC level */
1522 write_SSCR0(0, drv_data->ioaddr);
1523 pxa_set_cken(drv_data->master_info->clock_enable, 0);
1524
1525 /* Release DMA */
1526 if (drv_data->master_info->enable_dma) {
1527 if (drv_data->ioaddr == SSP1_VIRT) {
1528 DRCMRRXSSDR = 0;
1529 DRCMRTXSSDR = 0;
1530 } else if (drv_data->ioaddr == SSP2_VIRT) {
1531 DRCMRRXSS2DR = 0;
1532 DRCMRTXSS2DR = 0;
1533 } else if (drv_data->ioaddr == SSP3_VIRT) {
1534 DRCMRRXSS3DR = 0;
1535 DRCMRTXSS3DR = 0;
1536 }
1537 pxa_free_dma(drv_data->tx_channel);
1538 pxa_free_dma(drv_data->rx_channel);
1539 }
1540
1541 /* Release IRQ */
1542 irq = platform_get_irq(pdev, 0);
1543 if (irq >= 0)
1544 free_irq(irq, drv_data);
1545
1546 /* Disconnect from the SPI framework */
1547 spi_unregister_master(drv_data->master);
1548
1549 /* Prevent double remove */
1550 platform_set_drvdata(pdev, NULL);
1551
1552 return 0;
1553 }
1554
1555 static void pxa2xx_spi_shutdown(struct platform_device *pdev)
1556 {
1557 int status = 0;
1558
1559 if ((status = pxa2xx_spi_remove(pdev)) != 0)
1560 dev_err(&pdev->dev, "shutdown failed with %d\n", status);
1561 }
1562
1563 #ifdef CONFIG_PM
1564 static int suspend_devices(struct device *dev, void *pm_message)
1565 {
1566 pm_message_t *state = pm_message;
1567
1568 if (dev->power.power_state.event != state->event) {
1569 dev_warn(dev, "pm state does not match request\n");
1570 return -1;
1571 }
1572
1573 return 0;
1574 }
1575
1576 static int pxa2xx_spi_suspend(struct platform_device *pdev, pm_message_t state)
1577 {
1578 struct driver_data *drv_data = platform_get_drvdata(pdev);
1579 int status = 0;
1580
1581 /* Check all childern for current power state */
1582 if (device_for_each_child(&pdev->dev, &state, suspend_devices) != 0) {
1583 dev_warn(&pdev->dev, "suspend aborted\n");
1584 return -1;
1585 }
1586
1587 status = stop_queue(drv_data);
1588 if (status != 0)
1589 return status;
1590 write_SSCR0(0, drv_data->ioaddr);
1591 pxa_set_cken(drv_data->master_info->clock_enable, 0);
1592
1593 return 0;
1594 }
1595
1596 static int pxa2xx_spi_resume(struct platform_device *pdev)
1597 {
1598 struct driver_data *drv_data = platform_get_drvdata(pdev);
1599 int status = 0;
1600
1601 /* Enable the SSP clock */
1602 pxa_set_cken(drv_data->master_info->clock_enable, 1);
1603
1604 /* Start the queue running */
1605 status = start_queue(drv_data);
1606 if (status != 0) {
1607 dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
1608 return status;
1609 }
1610
1611 return 0;
1612 }
1613 #else
1614 #define pxa2xx_spi_suspend NULL
1615 #define pxa2xx_spi_resume NULL
1616 #endif /* CONFIG_PM */
1617
1618 static struct platform_driver driver = {
1619 .driver = {
1620 .name = "pxa2xx-spi",
1621 .bus = &platform_bus_type,
1622 .owner = THIS_MODULE,
1623 },
1624 .remove = pxa2xx_spi_remove,
1625 .shutdown = pxa2xx_spi_shutdown,
1626 .suspend = pxa2xx_spi_suspend,
1627 .resume = pxa2xx_spi_resume,
1628 };
1629
1630 static int __init pxa2xx_spi_init(void)
1631 {
1632 return platform_driver_probe(&driver, pxa2xx_spi_probe);
1633 }
1634 module_init(pxa2xx_spi_init);
1635
1636 static void __exit pxa2xx_spi_exit(void)
1637 {
1638 platform_driver_unregister(&driver);
1639 }
1640 module_exit(pxa2xx_spi_exit);
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