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V4L/DVB (9179): S2API: frontend.h cleanup
[linux-2.6/x86.git] / drivers / spi / pxa2xx_spi.c
blobd47d3636227fe90e435fc03a8f59fd49860b1220
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 #include <linux/clk.h>
31
32 #include <asm/io.h>
33 #include <asm/irq.h>
34 #include <asm/delay.h>
35 #include <asm/dma.h>
36
37 #include <mach/hardware.h>
38 #include <mach/pxa-regs.h>
39 #include <mach/regs-ssp.h>
40 #include <mach/ssp.h>
41 #include <mach/pxa2xx_spi.h>
42
43 MODULE_AUTHOR("Stephen Street");
44 MODULE_DESCRIPTION("PXA2xx SSP SPI Controller");
45 MODULE_LICENSE("GPL");
46 MODULE_ALIAS("platform:pxa2xx-spi");
47
48 #define MAX_BUSES 3
49
50 #define DMA_INT_MASK (DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR)
51 #define RESET_DMA_CHANNEL (DCSR_NODESC | DMA_INT_MASK)
52 #define IS_DMA_ALIGNED(x) ((((u32)(x)) & 0x07) == 0)
53 #define MAX_DMA_LEN 8191
54
55 /*
56 * for testing SSCR1 changes that require SSP restart, basically
57 * everything except the service and interrupt enables, the pxa270 developer
58 * manual says only SSCR1_SCFR, SSCR1_SPH, SSCR1_SPO need to be in this
59 * list, but the PXA255 dev man says all bits without really meaning the
60 * service and interrupt enables
61 */
62 #define SSCR1_CHANGE_MASK (SSCR1_TTELP | SSCR1_TTE | SSCR1_SCFR \
63 | SSCR1_ECRA | SSCR1_ECRB | SSCR1_SCLKDIR \
64 | SSCR1_SFRMDIR | SSCR1_RWOT | SSCR1_TRAIL \
65 | SSCR1_IFS | SSCR1_STRF | SSCR1_EFWR \
66 | SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \
67 | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
68
69 #define DEFINE_SSP_REG(reg, off) \
70 static inline u32 read_##reg(void const __iomem *p) \
71 { return __raw_readl(p + (off)); } \
72 \
73 static inline void write_##reg(u32 v, void __iomem *p) \
74 { __raw_writel(v, p + (off)); }
75
76 DEFINE_SSP_REG(SSCR0, 0x00)
77 DEFINE_SSP_REG(SSCR1, 0x04)
78 DEFINE_SSP_REG(SSSR, 0x08)
79 DEFINE_SSP_REG(SSITR, 0x0c)
80 DEFINE_SSP_REG(SSDR, 0x10)
81 DEFINE_SSP_REG(SSTO, 0x28)
82 DEFINE_SSP_REG(SSPSP, 0x2c)
83
84 #define START_STATE ((void*)0)
85 #define RUNNING_STATE ((void*)1)
86 #define DONE_STATE ((void*)2)
87 #define ERROR_STATE ((void*)-1)
88
89 #define QUEUE_RUNNING 0
90 #define QUEUE_STOPPED 1
91
92 struct driver_data {
93 /* Driver model hookup */
94 struct platform_device *pdev;
95
96 /* SSP Info */
97 struct ssp_device *ssp;
98
99 /* SPI framework hookup */
100 enum pxa_ssp_type ssp_type;
101 struct spi_master *master;
102
103 /* PXA hookup */
104 struct pxa2xx_spi_master *master_info;
105
106 /* DMA setup stuff */
107 int rx_channel;
108 int tx_channel;
109 u32 *null_dma_buf;
110
111 /* SSP register addresses */
112 void __iomem *ioaddr;
113 u32 ssdr_physical;
114
115 /* SSP masks*/
116 u32 dma_cr1;
117 u32 int_cr1;
118 u32 clear_sr;
119 u32 mask_sr;
120
121 /* Driver message queue */
122 struct workqueue_struct *workqueue;
123 struct work_struct pump_messages;
124 spinlock_t lock;
125 struct list_head queue;
126 int busy;
127 int run;
128
129 /* Message Transfer pump */
130 struct tasklet_struct pump_transfers;
131
132 /* Current message transfer state info */
133 struct spi_message* cur_msg;
134 struct spi_transfer* cur_transfer;
135 struct chip_data *cur_chip;
136 size_t len;
137 void *tx;
138 void *tx_end;
139 void *rx;
140 void *rx_end;
141 int dma_mapped;
142 dma_addr_t rx_dma;
143 dma_addr_t tx_dma;
144 size_t rx_map_len;
145 size_t tx_map_len;
146 u8 n_bytes;
147 u32 dma_width;
148 int (*write)(struct driver_data *drv_data);
149 int (*read)(struct driver_data *drv_data);
150 irqreturn_t (*transfer_handler)(struct driver_data *drv_data);
151 void (*cs_control)(u32 command);
152 };
153
154 struct chip_data {
155 u32 cr0;
156 u32 cr1;
157 u32 psp;
158 u32 timeout;
159 u8 n_bytes;
160 u32 dma_width;
161 u32 dma_burst_size;
162 u32 threshold;
163 u32 dma_threshold;
164 u8 enable_dma;
165 u8 bits_per_word;
166 u32 speed_hz;
167 int (*write)(struct driver_data *drv_data);
168 int (*read)(struct driver_data *drv_data);
169 void (*cs_control)(u32 command);
170 };
171
172 static void pump_messages(struct work_struct *work);
173
174 static int flush(struct driver_data *drv_data)
175 {
176 unsigned long limit = loops_per_jiffy << 1;
177
178 void __iomem *reg = drv_data->ioaddr;
179
180 do {
181 while (read_SSSR(reg) & SSSR_RNE) {
182 read_SSDR(reg);
183 }
184 } while ((read_SSSR(reg) & SSSR_BSY) && limit--);
185 write_SSSR(SSSR_ROR, reg);
186
187 return limit;
188 }
189
190 static void null_cs_control(u32 command)
191 {
192 }
193
194 static int null_writer(struct driver_data *drv_data)
195 {
196 void __iomem *reg = drv_data->ioaddr;
197 u8 n_bytes = drv_data->n_bytes;
198
199 if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00)
200 || (drv_data->tx == drv_data->tx_end))
201 return 0;
202
203 write_SSDR(0, reg);
204 drv_data->tx += n_bytes;
205
206 return 1;
207 }
208
209 static int null_reader(struct driver_data *drv_data)
210 {
211 void __iomem *reg = drv_data->ioaddr;
212 u8 n_bytes = drv_data->n_bytes;
213
214 while ((read_SSSR(reg) & SSSR_RNE)
215 && (drv_data->rx < drv_data->rx_end)) {
216 read_SSDR(reg);
217 drv_data->rx += n_bytes;
218 }
219
220 return drv_data->rx == drv_data->rx_end;
221 }
222
223 static int u8_writer(struct driver_data *drv_data)
224 {
225 void __iomem *reg = drv_data->ioaddr;
226
227 if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00)
228 || (drv_data->tx == drv_data->tx_end))
229 return 0;
230
231 write_SSDR(*(u8 *)(drv_data->tx), reg);
232 ++drv_data->tx;
233
234 return 1;
235 }
236
237 static int u8_reader(struct driver_data *drv_data)
238 {
239 void __iomem *reg = drv_data->ioaddr;
240
241 while ((read_SSSR(reg) & SSSR_RNE)
242 && (drv_data->rx < drv_data->rx_end)) {
243 *(u8 *)(drv_data->rx) = read_SSDR(reg);
244 ++drv_data->rx;
245 }
246
247 return drv_data->rx == drv_data->rx_end;
248 }
249
250 static int u16_writer(struct driver_data *drv_data)
251 {
252 void __iomem *reg = drv_data->ioaddr;
253
254 if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00)
255 || (drv_data->tx == drv_data->tx_end))
256 return 0;
257
258 write_SSDR(*(u16 *)(drv_data->tx), reg);
259 drv_data->tx += 2;
260
261 return 1;
262 }
263
264 static int u16_reader(struct driver_data *drv_data)
265 {
266 void __iomem *reg = drv_data->ioaddr;
267
268 while ((read_SSSR(reg) & SSSR_RNE)
269 && (drv_data->rx < drv_data->rx_end)) {
270 *(u16 *)(drv_data->rx) = read_SSDR(reg);
271 drv_data->rx += 2;
272 }
273
274 return drv_data->rx == drv_data->rx_end;
275 }
276
277 static int u32_writer(struct driver_data *drv_data)
278 {
279 void __iomem *reg = drv_data->ioaddr;
280
281 if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00)
282 || (drv_data->tx == drv_data->tx_end))
283 return 0;
284
285 write_SSDR(*(u32 *)(drv_data->tx), reg);
286 drv_data->tx += 4;
287
288 return 1;
289 }
290
291 static int u32_reader(struct driver_data *drv_data)
292 {
293 void __iomem *reg = drv_data->ioaddr;
294
295 while ((read_SSSR(reg) & SSSR_RNE)
296 && (drv_data->rx < drv_data->rx_end)) {
297 *(u32 *)(drv_data->rx) = read_SSDR(reg);
298 drv_data->rx += 4;
299 }
300
301 return drv_data->rx == drv_data->rx_end;
302 }
303
304 static void *next_transfer(struct driver_data *drv_data)
305 {
306 struct spi_message *msg = drv_data->cur_msg;
307 struct spi_transfer *trans = drv_data->cur_transfer;
308
309 /* Move to next transfer */
310 if (trans->transfer_list.next != &msg->transfers) {
311 drv_data->cur_transfer =
312 list_entry(trans->transfer_list.next,
313 struct spi_transfer,
314 transfer_list);
315 return RUNNING_STATE;
316 } else
317 return DONE_STATE;
318 }
319
320 static int map_dma_buffers(struct driver_data *drv_data)
321 {
322 struct spi_message *msg = drv_data->cur_msg;
323 struct device *dev = &msg->spi->dev;
324
325 if (!drv_data->cur_chip->enable_dma)
326 return 0;
327
328 if (msg->is_dma_mapped)
329 return drv_data->rx_dma && drv_data->tx_dma;
330
331 if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx))
332 return 0;
333
334 /* Modify setup if rx buffer is null */
335 if (drv_data->rx == NULL) {
336 *drv_data->null_dma_buf = 0;
337 drv_data->rx = drv_data->null_dma_buf;
338 drv_data->rx_map_len = 4;
339 } else
340 drv_data->rx_map_len = drv_data->len;
341
342
343 /* Modify setup if tx buffer is null */
344 if (drv_data->tx == NULL) {
345 *drv_data->null_dma_buf = 0;
346 drv_data->tx = drv_data->null_dma_buf;
347 drv_data->tx_map_len = 4;
348 } else
349 drv_data->tx_map_len = drv_data->len;
350
351 /* Stream map the rx buffer */
352 drv_data->rx_dma = dma_map_single(dev, drv_data->rx,
353 drv_data->rx_map_len,
354 DMA_FROM_DEVICE);
355 if (dma_mapping_error(dev, drv_data->rx_dma))
356 return 0;
357
358 /* Stream map the tx buffer */
359 drv_data->tx_dma = dma_map_single(dev, drv_data->tx,
360 drv_data->tx_map_len,
361 DMA_TO_DEVICE);
362
363 if (dma_mapping_error(dev, drv_data->tx_dma)) {
364 dma_unmap_single(dev, drv_data->rx_dma,
365 drv_data->rx_map_len, DMA_FROM_DEVICE);
366 return 0;
367 }
368
369 return 1;
370 }
371
372 static void unmap_dma_buffers(struct driver_data *drv_data)
373 {
374 struct device *dev;
375
376 if (!drv_data->dma_mapped)
377 return;
378
379 if (!drv_data->cur_msg->is_dma_mapped) {
380 dev = &drv_data->cur_msg->spi->dev;
381 dma_unmap_single(dev, drv_data->rx_dma,
382 drv_data->rx_map_len, DMA_FROM_DEVICE);
383 dma_unmap_single(dev, drv_data->tx_dma,
384 drv_data->tx_map_len, DMA_TO_DEVICE);
385 }
386
387 drv_data->dma_mapped = 0;
388 }
389
390 /* caller already set message->status; dma and pio irqs are blocked */
391 static void giveback(struct driver_data *drv_data)
392 {
393 struct spi_transfer* last_transfer;
394 unsigned long flags;
395 struct spi_message *msg;
396
397 spin_lock_irqsave(&drv_data->lock, flags);
398 msg = drv_data->cur_msg;
399 drv_data->cur_msg = NULL;
400 drv_data->cur_transfer = NULL;
401 drv_data->cur_chip = NULL;
402 queue_work(drv_data->workqueue, &drv_data->pump_messages);
403 spin_unlock_irqrestore(&drv_data->lock, flags);
404
405 last_transfer = list_entry(msg->transfers.prev,
406 struct spi_transfer,
407 transfer_list);
408
409 /* Delay if requested before any change in chip select */
410 if (last_transfer->delay_usecs)
411 udelay(last_transfer->delay_usecs);
412
413 /* Drop chip select UNLESS cs_change is true or we are returning
414 * a message with an error, or next message is for another chip
415 */
416 if (!last_transfer->cs_change)
417 drv_data->cs_control(PXA2XX_CS_DEASSERT);
418 else {
419 struct spi_message *next_msg;
420
421 /* Holding of cs was hinted, but we need to make sure
422 * the next message is for the same chip. Don't waste
423 * time with the following tests unless this was hinted.
424 *
425 * We cannot postpone this until pump_messages, because
426 * after calling msg->complete (below) the driver that
427 * sent the current message could be unloaded, which
428 * could invalidate the cs_control() callback...
429 */
430
431 /* get a pointer to the next message, if any */
432 spin_lock_irqsave(&drv_data->lock, flags);
433 if (list_empty(&drv_data->queue))
434 next_msg = NULL;
435 else
436 next_msg = list_entry(drv_data->queue.next,
437 struct spi_message, queue);
438 spin_unlock_irqrestore(&drv_data->lock, flags);
439
440 /* see if the next and current messages point
441 * to the same chip
442 */
443 if (next_msg && next_msg->spi != msg->spi)
444 next_msg = NULL;
445 if (!next_msg || msg->state == ERROR_STATE)
446 drv_data->cs_control(PXA2XX_CS_DEASSERT);
447 }
448
449 msg->state = NULL;
450 if (msg->complete)
451 msg->complete(msg->context);
452 }
453
454 static int wait_ssp_rx_stall(void const __iomem *ioaddr)
455 {
456 unsigned long limit = loops_per_jiffy << 1;
457
458 while ((read_SSSR(ioaddr) & SSSR_BSY) && limit--)
459 cpu_relax();
460
461 return limit;
462 }
463
464 static int wait_dma_channel_stop(int channel)
465 {
466 unsigned long limit = loops_per_jiffy << 1;
467
468 while (!(DCSR(channel) & DCSR_STOPSTATE) && limit--)
469 cpu_relax();
470
471 return limit;
472 }
473
474 static void dma_error_stop(struct driver_data *drv_data, const char *msg)
475 {
476 void __iomem *reg = drv_data->ioaddr;
477
478 /* Stop and reset */
479 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
480 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
481 write_SSSR(drv_data->clear_sr, reg);
482 write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
483 if (drv_data->ssp_type != PXA25x_SSP)
484 write_SSTO(0, reg);
485 flush(drv_data);
486 write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
487
488 unmap_dma_buffers(drv_data);
489
490 dev_err(&drv_data->pdev->dev, "%s\n", msg);
491
492 drv_data->cur_msg->state = ERROR_STATE;
493 tasklet_schedule(&drv_data->pump_transfers);
494 }
495
496 static void dma_transfer_complete(struct driver_data *drv_data)
497 {
498 void __iomem *reg = drv_data->ioaddr;
499 struct spi_message *msg = drv_data->cur_msg;
500
501 /* Clear and disable interrupts on SSP and DMA channels*/
502 write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
503 write_SSSR(drv_data->clear_sr, reg);
504 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
505 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
506
507 if (wait_dma_channel_stop(drv_data->rx_channel) == 0)
508 dev_err(&drv_data->pdev->dev,
509 "dma_handler: dma rx channel stop failed\n");
510
511 if (wait_ssp_rx_stall(drv_data->ioaddr) == 0)
512 dev_err(&drv_data->pdev->dev,
513 "dma_transfer: ssp rx stall failed\n");
514
515 unmap_dma_buffers(drv_data);
516
517 /* update the buffer pointer for the amount completed in dma */
518 drv_data->rx += drv_data->len -
519 (DCMD(drv_data->rx_channel) & DCMD_LENGTH);
520
521 /* read trailing data from fifo, it does not matter how many
522 * bytes are in the fifo just read until buffer is full
523 * or fifo is empty, which ever occurs first */
524 drv_data->read(drv_data);
525
526 /* return count of what was actually read */
527 msg->actual_length += drv_data->len -
528 (drv_data->rx_end - drv_data->rx);
529
530 /* Transfer delays and chip select release are
531 * handled in pump_transfers or giveback
532 */
533
534 /* Move to next transfer */
535 msg->state = next_transfer(drv_data);
536
537 /* Schedule transfer tasklet */
538 tasklet_schedule(&drv_data->pump_transfers);
539 }
540
541 static void dma_handler(int channel, void *data)
542 {
543 struct driver_data *drv_data = data;
544 u32 irq_status = DCSR(channel) & DMA_INT_MASK;
545
546 if (irq_status & DCSR_BUSERR) {
547
548 if (channel == drv_data->tx_channel)
549 dma_error_stop(drv_data,
550 "dma_handler: "
551 "bad bus address on tx channel");
552 else
553 dma_error_stop(drv_data,
554 "dma_handler: "
555 "bad bus address on rx channel");
556 return;
557 }
558
559 /* PXA255x_SSP has no timeout interrupt, wait for tailing bytes */
560 if ((channel == drv_data->tx_channel)
561 && (irq_status & DCSR_ENDINTR)
562 && (drv_data->ssp_type == PXA25x_SSP)) {
563
564 /* Wait for rx to stall */
565 if (wait_ssp_rx_stall(drv_data->ioaddr) == 0)
566 dev_err(&drv_data->pdev->dev,
567 "dma_handler: ssp rx stall failed\n");
568
569 /* finish this transfer, start the next */
570 dma_transfer_complete(drv_data);
571 }
572 }
573
574 static irqreturn_t dma_transfer(struct driver_data *drv_data)
575 {
576 u32 irq_status;
577 void __iomem *reg = drv_data->ioaddr;
578
579 irq_status = read_SSSR(reg) & drv_data->mask_sr;
580 if (irq_status & SSSR_ROR) {
581 dma_error_stop(drv_data, "dma_transfer: fifo overrun");
582 return IRQ_HANDLED;
583 }
584
585 /* Check for false positive timeout */
586 if ((irq_status & SSSR_TINT)
587 && (DCSR(drv_data->tx_channel) & DCSR_RUN)) {
588 write_SSSR(SSSR_TINT, reg);
589 return IRQ_HANDLED;
590 }
591
592 if (irq_status & SSSR_TINT || drv_data->rx == drv_data->rx_end) {
593
594 /* Clear and disable timeout interrupt, do the rest in
595 * dma_transfer_complete */
596 if (drv_data->ssp_type != PXA25x_SSP)
597 write_SSTO(0, reg);
598
599 /* finish this transfer, start the next */
600 dma_transfer_complete(drv_data);
601
602 return IRQ_HANDLED;
603 }
604
605 /* Opps problem detected */
606 return IRQ_NONE;
607 }
608
609 static void int_error_stop(struct driver_data *drv_data, const char* msg)
610 {
611 void __iomem *reg = drv_data->ioaddr;
612
613 /* Stop and reset SSP */
614 write_SSSR(drv_data->clear_sr, reg);
615 write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
616 if (drv_data->ssp_type != PXA25x_SSP)
617 write_SSTO(0, reg);
618 flush(drv_data);
619 write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
620
621 dev_err(&drv_data->pdev->dev, "%s\n", msg);
622
623 drv_data->cur_msg->state = ERROR_STATE;
624 tasklet_schedule(&drv_data->pump_transfers);
625 }
626
627 static void int_transfer_complete(struct driver_data *drv_data)
628 {
629 void __iomem *reg = drv_data->ioaddr;
630
631 /* Stop SSP */
632 write_SSSR(drv_data->clear_sr, reg);
633 write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
634 if (drv_data->ssp_type != PXA25x_SSP)
635 write_SSTO(0, reg);
636
637 /* Update total byte transfered return count actual bytes read */
638 drv_data->cur_msg->actual_length += drv_data->len -
639 (drv_data->rx_end - drv_data->rx);
640
641 /* Transfer delays and chip select release are
642 * handled in pump_transfers or giveback
643 */
644
645 /* Move to next transfer */
646 drv_data->cur_msg->state = next_transfer(drv_data);
647
648 /* Schedule transfer tasklet */
649 tasklet_schedule(&drv_data->pump_transfers);
650 }
651
652 static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
653 {
654 void __iomem *reg = drv_data->ioaddr;
655
656 u32 irq_mask = (read_SSCR1(reg) & SSCR1_TIE) ?
657 drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS;
658
659 u32 irq_status = read_SSSR(reg) & irq_mask;
660
661 if (irq_status & SSSR_ROR) {
662 int_error_stop(drv_data, "interrupt_transfer: fifo overrun");
663 return IRQ_HANDLED;
664 }
665
666 if (irq_status & SSSR_TINT) {
667 write_SSSR(SSSR_TINT, reg);
668 if (drv_data->read(drv_data)) {
669 int_transfer_complete(drv_data);
670 return IRQ_HANDLED;
671 }
672 }
673
674 /* Drain rx fifo, Fill tx fifo and prevent overruns */
675 do {
676 if (drv_data->read(drv_data)) {
677 int_transfer_complete(drv_data);
678 return IRQ_HANDLED;
679 }
680 } while (drv_data->write(drv_data));
681
682 if (drv_data->read(drv_data)) {
683 int_transfer_complete(drv_data);
684 return IRQ_HANDLED;
685 }
686
687 if (drv_data->tx == drv_data->tx_end) {
688 write_SSCR1(read_SSCR1(reg) & ~SSCR1_TIE, reg);
689 /* PXA25x_SSP has no timeout, read trailing bytes */
690 if (drv_data->ssp_type == PXA25x_SSP) {
691 if (!wait_ssp_rx_stall(reg))
692 {
693 int_error_stop(drv_data, "interrupt_transfer: "
694 "rx stall failed");
695 return IRQ_HANDLED;
696 }
697 if (!drv_data->read(drv_data))
698 {
699 int_error_stop(drv_data,
700 "interrupt_transfer: "
701 "trailing byte read failed");
702 return IRQ_HANDLED;
703 }
704 int_transfer_complete(drv_data);
705 }
706 }
707
708 /* We did something */
709 return IRQ_HANDLED;
710 }
711
712 static irqreturn_t ssp_int(int irq, void *dev_id)
713 {
714 struct driver_data *drv_data = dev_id;
715 void __iomem *reg = drv_data->ioaddr;
716
717 if (!drv_data->cur_msg) {
718
719 write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
720 write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
721 if (drv_data->ssp_type != PXA25x_SSP)
722 write_SSTO(0, reg);
723 write_SSSR(drv_data->clear_sr, reg);
724
725 dev_err(&drv_data->pdev->dev, "bad message state "
726 "in interrupt handler\n");
727
728 /* Never fail */
729 return IRQ_HANDLED;
730 }
731
732 return drv_data->transfer_handler(drv_data);
733 }
734
735 static int set_dma_burst_and_threshold(struct chip_data *chip,
736 struct spi_device *spi,
737 u8 bits_per_word, u32 *burst_code,
738 u32 *threshold)
739 {
740 struct pxa2xx_spi_chip *chip_info =
741 (struct pxa2xx_spi_chip *)spi->controller_data;
742 int bytes_per_word;
743 int burst_bytes;
744 int thresh_words;
745 int req_burst_size;
746 int retval = 0;
747
748 /* Set the threshold (in registers) to equal the same amount of data
749 * as represented by burst size (in bytes). The computation below
750 * is (burst_size rounded up to nearest 8 byte, word or long word)
751 * divided by (bytes/register); the tx threshold is the inverse of
752 * the rx, so that there will always be enough data in the rx fifo
753 * to satisfy a burst, and there will always be enough space in the
754 * tx fifo to accept a burst (a tx burst will overwrite the fifo if
755 * there is not enough space), there must always remain enough empty
756 * space in the rx fifo for any data loaded to the tx fifo.
757 * Whenever burst_size (in bytes) equals bits/word, the fifo threshold
758 * will be 8, or half the fifo;
759 * The threshold can only be set to 2, 4 or 8, but not 16, because
760 * to burst 16 to the tx fifo, the fifo would have to be empty;
761 * however, the minimum fifo trigger level is 1, and the tx will
762 * request service when the fifo is at this level, with only 15 spaces.
763 */
764
765 /* find bytes/word */
766 if (bits_per_word <= 8)
767 bytes_per_word = 1;
768 else if (bits_per_word <= 16)
769 bytes_per_word = 2;
770 else
771 bytes_per_word = 4;
772
773 /* use struct pxa2xx_spi_chip->dma_burst_size if available */
774 if (chip_info)
775 req_burst_size = chip_info->dma_burst_size;
776 else {
777 switch (chip->dma_burst_size) {
778 default:
779 /* if the default burst size is not set,
780 * do it now */
781 chip->dma_burst_size = DCMD_BURST8;
782 case DCMD_BURST8:
783 req_burst_size = 8;
784 break;
785 case DCMD_BURST16:
786 req_burst_size = 16;
787 break;
788 case DCMD_BURST32:
789 req_burst_size = 32;
790 break;
791 }
792 }
793 if (req_burst_size <= 8) {
794 *burst_code = DCMD_BURST8;
795 burst_bytes = 8;
796 } else if (req_burst_size <= 16) {
797 if (bytes_per_word == 1) {
798 /* don't burst more than 1/2 the fifo */
799 *burst_code = DCMD_BURST8;
800 burst_bytes = 8;
801 retval = 1;
802 } else {
803 *burst_code = DCMD_BURST16;
804 burst_bytes = 16;
805 }
806 } else {
807 if (bytes_per_word == 1) {
808 /* don't burst more than 1/2 the fifo */
809 *burst_code = DCMD_BURST8;
810 burst_bytes = 8;
811 retval = 1;
812 } else if (bytes_per_word == 2) {
813 /* don't burst more than 1/2 the fifo */
814 *burst_code = DCMD_BURST16;
815 burst_bytes = 16;
816 retval = 1;
817 } else {
818 *burst_code = DCMD_BURST32;
819 burst_bytes = 32;
820 }
821 }
822
823 thresh_words = burst_bytes / bytes_per_word;
824
825 /* thresh_words will be between 2 and 8 */
826 *threshold = (SSCR1_RxTresh(thresh_words) & SSCR1_RFT)
827 | (SSCR1_TxTresh(16-thresh_words) & SSCR1_TFT);
828
829 return retval;
830 }
831
832 static unsigned int ssp_get_clk_div(struct ssp_device *ssp, int rate)
833 {
834 unsigned long ssp_clk = clk_get_rate(ssp->clk);
835
836 if (ssp->type == PXA25x_SSP)
837 return ((ssp_clk / (2 * rate) - 1) & 0xff) << 8;
838 else
839 return ((ssp_clk / rate - 1) & 0xfff) << 8;
840 }
841
842 static void pump_transfers(unsigned long data)
843 {
844 struct driver_data *drv_data = (struct driver_data *)data;
845 struct spi_message *message = NULL;
846 struct spi_transfer *transfer = NULL;
847 struct spi_transfer *previous = NULL;
848 struct chip_data *chip = NULL;
849 struct ssp_device *ssp = drv_data->ssp;
850 void __iomem *reg = drv_data->ioaddr;
851 u32 clk_div = 0;
852 u8 bits = 0;
853 u32 speed = 0;
854 u32 cr0;
855 u32 cr1;
856 u32 dma_thresh = drv_data->cur_chip->dma_threshold;
857 u32 dma_burst = drv_data->cur_chip->dma_burst_size;
858
859 /* Get current state information */
860 message = drv_data->cur_msg;
861 transfer = drv_data->cur_transfer;
862 chip = drv_data->cur_chip;
863
864 /* Handle for abort */
865 if (message->state == ERROR_STATE) {
866 message->status = -EIO;
867 giveback(drv_data);
868 return;
869 }
870
871 /* Handle end of message */
872 if (message->state == DONE_STATE) {
873 message->status = 0;
874 giveback(drv_data);
875 return;
876 }
877
878 /* Delay if requested at end of transfer before CS change */
879 if (message->state == RUNNING_STATE) {
880 previous = list_entry(transfer->transfer_list.prev,
881 struct spi_transfer,
882 transfer_list);
883 if (previous->delay_usecs)
884 udelay(previous->delay_usecs);
885
886 /* Drop chip select only if cs_change is requested */
887 if (previous->cs_change)
888 drv_data->cs_control(PXA2XX_CS_DEASSERT);
889 }
890
891 /* Check for transfers that need multiple DMA segments */
892 if (transfer->len > MAX_DMA_LEN && chip->enable_dma) {
893
894 /* reject already-mapped transfers; PIO won't always work */
895 if (message->is_dma_mapped
896 || transfer->rx_dma || transfer->tx_dma) {
897 dev_err(&drv_data->pdev->dev,
898 "pump_transfers: mapped transfer length "
899 "of %u is greater than %d\n",
900 transfer->len, MAX_DMA_LEN);
901 message->status = -EINVAL;
902 giveback(drv_data);
903 return;
904 }
905
906 /* warn ... we force this to PIO mode */
907 if (printk_ratelimit())
908 dev_warn(&message->spi->dev, "pump_transfers: "
909 "DMA disabled for transfer length %ld "
910 "greater than %d\n",
911 (long)drv_data->len, MAX_DMA_LEN);
912 }
913
914 /* Setup the transfer state based on the type of transfer */
915 if (flush(drv_data) == 0) {
916 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
917 message->status = -EIO;
918 giveback(drv_data);
919 return;
920 }
921 drv_data->n_bytes = chip->n_bytes;
922 drv_data->dma_width = chip->dma_width;
923 drv_data->cs_control = chip->cs_control;
924 drv_data->tx = (void *)transfer->tx_buf;
925 drv_data->tx_end = drv_data->tx + transfer->len;
926 drv_data->rx = transfer->rx_buf;
927 drv_data->rx_end = drv_data->rx + transfer->len;
928 drv_data->rx_dma = transfer->rx_dma;
929 drv_data->tx_dma = transfer->tx_dma;
930 drv_data->len = transfer->len & DCMD_LENGTH;
931 drv_data->write = drv_data->tx ? chip->write : null_writer;
932 drv_data->read = drv_data->rx ? chip->read : null_reader;
933
934 /* Change speed and bit per word on a per transfer */
935 cr0 = chip->cr0;
936 if (transfer->speed_hz || transfer->bits_per_word) {
937
938 bits = chip->bits_per_word;
939 speed = chip->speed_hz;
940
941 if (transfer->speed_hz)
942 speed = transfer->speed_hz;
943
944 if (transfer->bits_per_word)
945 bits = transfer->bits_per_word;
946
947 clk_div = ssp_get_clk_div(ssp, speed);
948
949 if (bits <= 8) {
950 drv_data->n_bytes = 1;
951 drv_data->dma_width = DCMD_WIDTH1;
952 drv_data->read = drv_data->read != null_reader ?
953 u8_reader : null_reader;
954 drv_data->write = drv_data->write != null_writer ?
955 u8_writer : null_writer;
956 } else if (bits <= 16) {
957 drv_data->n_bytes = 2;
958 drv_data->dma_width = DCMD_WIDTH2;
959 drv_data->read = drv_data->read != null_reader ?
960 u16_reader : null_reader;
961 drv_data->write = drv_data->write != null_writer ?
962 u16_writer : null_writer;
963 } else if (bits <= 32) {
964 drv_data->n_bytes = 4;
965 drv_data->dma_width = DCMD_WIDTH4;
966 drv_data->read = drv_data->read != null_reader ?
967 u32_reader : null_reader;
968 drv_data->write = drv_data->write != null_writer ?
969 u32_writer : null_writer;
970 }
971 /* if bits/word is changed in dma mode, then must check the
972 * thresholds and burst also */
973 if (chip->enable_dma) {
974 if (set_dma_burst_and_threshold(chip, message->spi,
975 bits, &dma_burst,
976 &dma_thresh))
977 if (printk_ratelimit())
978 dev_warn(&message->spi->dev,
979 "pump_transfers: "
980 "DMA burst size reduced to "
981 "match bits_per_word\n");
982 }
983
984 cr0 = clk_div
985 | SSCR0_Motorola
986 | SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
987 | SSCR0_SSE
988 | (bits > 16 ? SSCR0_EDSS : 0);
989 }
990
991 message->state = RUNNING_STATE;
992
993 /* Try to map dma buffer and do a dma transfer if successful, but
994 * only if the length is non-zero and less than MAX_DMA_LEN.
995 *
996 * Zero-length non-descriptor DMA is illegal on PXA2xx; force use
997 * of PIO instead. Care is needed above because the transfer may
998 * have have been passed with buffers that are already dma mapped.
999 * A zero-length transfer in PIO mode will not try to write/read
1000 * to/from the buffers
1001 *
1002 * REVISIT large transfers are exactly where we most want to be
1003 * using DMA. If this happens much, split those transfers into
1004 * multiple DMA segments rather than forcing PIO.
1005 */
1006 drv_data->dma_mapped = 0;
1007 if (drv_data->len > 0 && drv_data->len <= MAX_DMA_LEN)
1008 drv_data->dma_mapped = map_dma_buffers(drv_data);
1009 if (drv_data->dma_mapped) {
1010
1011 /* Ensure we have the correct interrupt handler */
1012 drv_data->transfer_handler = dma_transfer;
1013
1014 /* Setup rx DMA Channel */
1015 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
1016 DSADR(drv_data->rx_channel) = drv_data->ssdr_physical;
1017 DTADR(drv_data->rx_channel) = drv_data->rx_dma;
1018 if (drv_data->rx == drv_data->null_dma_buf)
1019 /* No target address increment */
1020 DCMD(drv_data->rx_channel) = DCMD_FLOWSRC
1021 | drv_data->dma_width
1022 | dma_burst
1023 | drv_data->len;
1024 else
1025 DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR
1026 | DCMD_FLOWSRC
1027 | drv_data->dma_width
1028 | dma_burst
1029 | drv_data->len;
1030
1031 /* Setup tx DMA Channel */
1032 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
1033 DSADR(drv_data->tx_channel) = drv_data->tx_dma;
1034 DTADR(drv_data->tx_channel) = drv_data->ssdr_physical;
1035 if (drv_data->tx == drv_data->null_dma_buf)
1036 /* No source address increment */
1037 DCMD(drv_data->tx_channel) = DCMD_FLOWTRG
1038 | drv_data->dma_width
1039 | dma_burst
1040 | drv_data->len;
1041 else
1042 DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR
1043 | DCMD_FLOWTRG
1044 | drv_data->dma_width
1045 | dma_burst
1046 | drv_data->len;
1047
1048 /* Enable dma end irqs on SSP to detect end of transfer */
1049 if (drv_data->ssp_type == PXA25x_SSP)
1050 DCMD(drv_data->tx_channel) |= DCMD_ENDIRQEN;
1051
1052 /* Clear status and start DMA engine */
1053 cr1 = chip->cr1 | dma_thresh | drv_data->dma_cr1;
1054 write_SSSR(drv_data->clear_sr, reg);
1055 DCSR(drv_data->rx_channel) |= DCSR_RUN;
1056 DCSR(drv_data->tx_channel) |= DCSR_RUN;
1057 } else {
1058 /* Ensure we have the correct interrupt handler */
1059 drv_data->transfer_handler = interrupt_transfer;
1060
1061 /* Clear status */
1062 cr1 = chip->cr1 | chip->threshold | drv_data->int_cr1;
1063 write_SSSR(drv_data->clear_sr, reg);
1064 }
1065
1066 /* see if we need to reload the config registers */
1067 if ((read_SSCR0(reg) != cr0)
1068 || (read_SSCR1(reg) & SSCR1_CHANGE_MASK) !=
1069 (cr1 & SSCR1_CHANGE_MASK)) {
1070
1071 /* stop the SSP, and update the other bits */
1072 write_SSCR0(cr0 & ~SSCR0_SSE, reg);
1073 if (drv_data->ssp_type != PXA25x_SSP)
1074 write_SSTO(chip->timeout, reg);
1075 /* first set CR1 without interrupt and service enables */
1076 write_SSCR1(cr1 & SSCR1_CHANGE_MASK, reg);
1077 /* restart the SSP */
1078 write_SSCR0(cr0, reg);
1079
1080 } else {
1081 if (drv_data->ssp_type != PXA25x_SSP)
1082 write_SSTO(chip->timeout, reg);
1083 }
1084
1085 /* FIXME, need to handle cs polarity,
1086 * this driver uses struct pxa2xx_spi_chip.cs_control to
1087 * specify a CS handling function, and it ignores most
1088 * struct spi_device.mode[s], including SPI_CS_HIGH */
1089 drv_data->cs_control(PXA2XX_CS_ASSERT);
1090
1091 /* after chip select, release the data by enabling service
1092 * requests and interrupts, without changing any mode bits */
1093 write_SSCR1(cr1, reg);
1094 }
1095
1096 static void pump_messages(struct work_struct *work)
1097 {
1098 struct driver_data *drv_data =
1099 container_of(work, struct driver_data, pump_messages);
1100 unsigned long flags;
1101
1102 /* Lock queue and check for queue work */
1103 spin_lock_irqsave(&drv_data->lock, flags);
1104 if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
1105 drv_data->busy = 0;
1106 spin_unlock_irqrestore(&drv_data->lock, flags);
1107 return;
1108 }
1109
1110 /* Make sure we are not already running a message */
1111 if (drv_data->cur_msg) {
1112 spin_unlock_irqrestore(&drv_data->lock, flags);
1113 return;
1114 }
1115
1116 /* Extract head of queue */
1117 drv_data->cur_msg = list_entry(drv_data->queue.next,
1118 struct spi_message, queue);
1119 list_del_init(&drv_data->cur_msg->queue);
1120
1121 /* Initial message state*/
1122 drv_data->cur_msg->state = START_STATE;
1123 drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
1124 struct spi_transfer,
1125 transfer_list);
1126
1127 /* prepare to setup the SSP, in pump_transfers, using the per
1128 * chip configuration */
1129 drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
1130
1131 /* Mark as busy and launch transfers */
1132 tasklet_schedule(&drv_data->pump_transfers);
1133
1134 drv_data->busy = 1;
1135 spin_unlock_irqrestore(&drv_data->lock, flags);
1136 }
1137
1138 static int transfer(struct spi_device *spi, struct spi_message *msg)
1139 {
1140 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1141 unsigned long flags;
1142
1143 spin_lock_irqsave(&drv_data->lock, flags);
1144
1145 if (drv_data->run == QUEUE_STOPPED) {
1146 spin_unlock_irqrestore(&drv_data->lock, flags);
1147 return -ESHUTDOWN;
1148 }
1149
1150 msg->actual_length = 0;
1151 msg->status = -EINPROGRESS;
1152 msg->state = START_STATE;
1153
1154 list_add_tail(&msg->queue, &drv_data->queue);
1155
1156 if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
1157 queue_work(drv_data->workqueue, &drv_data->pump_messages);
1158
1159 spin_unlock_irqrestore(&drv_data->lock, flags);
1160
1161 return 0;
1162 }
1163
1164 /* the spi->mode bits understood by this driver: */
1165 #define MODEBITS (SPI_CPOL | SPI_CPHA)
1166
1167 static int setup(struct spi_device *spi)
1168 {
1169 struct pxa2xx_spi_chip *chip_info = NULL;
1170 struct chip_data *chip;
1171 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1172 struct ssp_device *ssp = drv_data->ssp;
1173 unsigned int clk_div;
1174
1175 if (!spi->bits_per_word)
1176 spi->bits_per_word = 8;
1177
1178 if (drv_data->ssp_type != PXA25x_SSP
1179 && (spi->bits_per_word < 4 || spi->bits_per_word > 32)) {
1180 dev_err(&spi->dev, "failed setup: ssp_type=%d, bits/wrd=%d "
1181 "b/w not 4-32 for type non-PXA25x_SSP\n",
1182 drv_data->ssp_type, spi->bits_per_word);
1183 return -EINVAL;
1184 }
1185 else if (drv_data->ssp_type == PXA25x_SSP
1186 && (spi->bits_per_word < 4
1187 || spi->bits_per_word > 16)) {
1188 dev_err(&spi->dev, "failed setup: ssp_type=%d, bits/wrd=%d "
1189 "b/w not 4-16 for type PXA25x_SSP\n",
1190 drv_data->ssp_type, spi->bits_per_word);
1191 return -EINVAL;
1192 }
1193
1194 if (spi->mode & ~MODEBITS) {
1195 dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
1196 spi->mode & ~MODEBITS);
1197 return -EINVAL;
1198 }
1199
1200 /* Only alloc on first setup */
1201 chip = spi_get_ctldata(spi);
1202 if (!chip) {
1203 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1204 if (!chip) {
1205 dev_err(&spi->dev,
1206 "failed setup: can't allocate chip data\n");
1207 return -ENOMEM;
1208 }
1209
1210 chip->cs_control = null_cs_control;
1211 chip->enable_dma = 0;
1212 chip->timeout = 1000;
1213 chip->threshold = SSCR1_RxTresh(1) | SSCR1_TxTresh(1);
1214 chip->dma_burst_size = drv_data->master_info->enable_dma ?
1215 DCMD_BURST8 : 0;
1216 }
1217
1218 /* protocol drivers may change the chip settings, so...
1219 * if chip_info exists, use it */
1220 chip_info = spi->controller_data;
1221
1222 /* chip_info isn't always needed */
1223 chip->cr1 = 0;
1224 if (chip_info) {
1225 if (chip_info->cs_control)
1226 chip->cs_control = chip_info->cs_control;
1227
1228 chip->timeout = chip_info->timeout;
1229
1230 chip->threshold = (SSCR1_RxTresh(chip_info->rx_threshold) &
1231 SSCR1_RFT) |
1232 (SSCR1_TxTresh(chip_info->tx_threshold) &
1233 SSCR1_TFT);
1234
1235 chip->enable_dma = chip_info->dma_burst_size != 0
1236 && drv_data->master_info->enable_dma;
1237 chip->dma_threshold = 0;
1238
1239 if (chip_info->enable_loopback)
1240 chip->cr1 = SSCR1_LBM;
1241 }
1242
1243 /* set dma burst and threshold outside of chip_info path so that if
1244 * chip_info goes away after setting chip->enable_dma, the
1245 * burst and threshold can still respond to changes in bits_per_word */
1246 if (chip->enable_dma) {
1247 /* set up legal burst and threshold for dma */
1248 if (set_dma_burst_and_threshold(chip, spi, spi->bits_per_word,
1249 &chip->dma_burst_size,
1250 &chip->dma_threshold)) {
1251 dev_warn(&spi->dev, "in setup: DMA burst size reduced "
1252 "to match bits_per_word\n");
1253 }
1254 }
1255
1256 clk_div = ssp_get_clk_div(ssp, spi->max_speed_hz);
1257 chip->speed_hz = spi->max_speed_hz;
1258
1259 chip->cr0 = clk_div
1260 | SSCR0_Motorola
1261 | SSCR0_DataSize(spi->bits_per_word > 16 ?
1262 spi->bits_per_word - 16 : spi->bits_per_word)
1263 | SSCR0_SSE
1264 | (spi->bits_per_word > 16 ? SSCR0_EDSS : 0);
1265 chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH);
1266 chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
1267 | (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);
1268
1269 /* NOTE: PXA25x_SSP _could_ use external clocking ... */
1270 if (drv_data->ssp_type != PXA25x_SSP)
1271 dev_dbg(&spi->dev, "%d bits/word, %ld Hz, mode %d\n",
1272 spi->bits_per_word,
1273 clk_get_rate(ssp->clk)
1274 / (1 + ((chip->cr0 & SSCR0_SCR) >> 8)),
1275 spi->mode & 0x3);
1276 else
1277 dev_dbg(&spi->dev, "%d bits/word, %ld Hz, mode %d\n",
1278 spi->bits_per_word,
1279 clk_get_rate(ssp->clk)
1280 / (1 + ((chip->cr0 & SSCR0_SCR) >> 8)),
1281 spi->mode & 0x3);
1282
1283 if (spi->bits_per_word <= 8) {
1284 chip->n_bytes = 1;
1285 chip->dma_width = DCMD_WIDTH1;
1286 chip->read = u8_reader;
1287 chip->write = u8_writer;
1288 } else if (spi->bits_per_word <= 16) {
1289 chip->n_bytes = 2;
1290 chip->dma_width = DCMD_WIDTH2;
1291 chip->read = u16_reader;
1292 chip->write = u16_writer;
1293 } else if (spi->bits_per_word <= 32) {
1294 chip->cr0 |= SSCR0_EDSS;
1295 chip->n_bytes = 4;
1296 chip->dma_width = DCMD_WIDTH4;
1297 chip->read = u32_reader;
1298 chip->write = u32_writer;
1299 } else {
1300 dev_err(&spi->dev, "invalid wordsize\n");
1301 return -ENODEV;
1302 }
1303 chip->bits_per_word = spi->bits_per_word;
1304
1305 spi_set_ctldata(spi, chip);
1306
1307 return 0;
1308 }
1309
1310 static void cleanup(struct spi_device *spi)
1311 {
1312 struct chip_data *chip = spi_get_ctldata(spi);
1313
1314 kfree(chip);
1315 }
1316
1317 static int __init init_queue(struct driver_data *drv_data)
1318 {
1319 INIT_LIST_HEAD(&drv_data->queue);
1320 spin_lock_init(&drv_data->lock);
1321
1322 drv_data->run = QUEUE_STOPPED;
1323 drv_data->busy = 0;
1324
1325 tasklet_init(&drv_data->pump_transfers,
1326 pump_transfers, (unsigned long)drv_data);
1327
1328 INIT_WORK(&drv_data->pump_messages, pump_messages);
1329 drv_data->workqueue = create_singlethread_workqueue(
1330 drv_data->master->dev.parent->bus_id);
1331 if (drv_data->workqueue == NULL)
1332 return -EBUSY;
1333
1334 return 0;
1335 }
1336
1337 static int start_queue(struct driver_data *drv_data)
1338 {
1339 unsigned long flags;
1340
1341 spin_lock_irqsave(&drv_data->lock, flags);
1342
1343 if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
1344 spin_unlock_irqrestore(&drv_data->lock, flags);
1345 return -EBUSY;
1346 }
1347
1348 drv_data->run = QUEUE_RUNNING;
1349 drv_data->cur_msg = NULL;
1350 drv_data->cur_transfer = NULL;
1351 drv_data->cur_chip = NULL;
1352 spin_unlock_irqrestore(&drv_data->lock, flags);
1353
1354 queue_work(drv_data->workqueue, &drv_data->pump_messages);
1355
1356 return 0;
1357 }
1358
1359 static int stop_queue(struct driver_data *drv_data)
1360 {
1361 unsigned long flags;
1362 unsigned limit = 500;
1363 int status = 0;
1364
1365 spin_lock_irqsave(&drv_data->lock, flags);
1366
1367 /* This is a bit lame, but is optimized for the common execution path.
1368 * A wait_queue on the drv_data->busy could be used, but then the common
1369 * execution path (pump_messages) would be required to call wake_up or
1370 * friends on every SPI message. Do this instead */
1371 drv_data->run = QUEUE_STOPPED;
1372 while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
1373 spin_unlock_irqrestore(&drv_data->lock, flags);
1374 msleep(10);
1375 spin_lock_irqsave(&drv_data->lock, flags);
1376 }
1377
1378 if (!list_empty(&drv_data->queue) || drv_data->busy)
1379 status = -EBUSY;
1380
1381 spin_unlock_irqrestore(&drv_data->lock, flags);
1382
1383 return status;
1384 }
1385
1386 static int destroy_queue(struct driver_data *drv_data)
1387 {
1388 int status;
1389
1390 status = stop_queue(drv_data);
1391 /* we are unloading the module or failing to load (only two calls
1392 * to this routine), and neither call can handle a return value.
1393 * However, destroy_workqueue calls flush_workqueue, and that will
1394 * block until all work is done. If the reason that stop_queue
1395 * timed out is that the work will never finish, then it does no
1396 * good to call destroy_workqueue, so return anyway. */
1397 if (status != 0)
1398 return status;
1399
1400 destroy_workqueue(drv_data->workqueue);
1401
1402 return 0;
1403 }
1404
1405 static int __init pxa2xx_spi_probe(struct platform_device *pdev)
1406 {
1407 struct device *dev = &pdev->dev;
1408 struct pxa2xx_spi_master *platform_info;
1409 struct spi_master *master;
1410 struct driver_data *drv_data = NULL;
1411 struct ssp_device *ssp;
1412 int status = 0;
1413
1414 platform_info = dev->platform_data;
1415
1416 ssp = ssp_request(pdev->id, pdev->name);
1417 if (ssp == NULL) {
1418 dev_err(&pdev->dev, "failed to request SSP%d\n", pdev->id);
1419 return -ENODEV;
1420 }
1421
1422 /* Allocate master with space for drv_data and null dma buffer */
1423 master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
1424 if (!master) {
1425 dev_err(&pdev->dev, "can not alloc spi_master\n");
1426 ssp_free(ssp);
1427 return -ENOMEM;
1428 }
1429 drv_data = spi_master_get_devdata(master);
1430 drv_data->master = master;
1431 drv_data->master_info = platform_info;
1432 drv_data->pdev = pdev;
1433 drv_data->ssp = ssp;
1434
1435 master->bus_num = pdev->id;
1436 master->num_chipselect = platform_info->num_chipselect;
1437 master->cleanup = cleanup;
1438 master->setup = setup;
1439 master->transfer = transfer;
1440
1441 drv_data->ssp_type = ssp->type;
1442 drv_data->null_dma_buf = (u32 *)ALIGN((u32)(drv_data +
1443 sizeof(struct driver_data)), 8);
1444
1445 drv_data->ioaddr = ssp->mmio_base;
1446 drv_data->ssdr_physical = ssp->phys_base + SSDR;
1447 if (ssp->type == PXA25x_SSP) {
1448 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE;
1449 drv_data->dma_cr1 = 0;
1450 drv_data->clear_sr = SSSR_ROR;
1451 drv_data->mask_sr = SSSR_RFS | SSSR_TFS | SSSR_ROR;
1452 } else {
1453 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE;
1454 drv_data->dma_cr1 = SSCR1_TSRE | SSCR1_RSRE | SSCR1_TINTE;
1455 drv_data->clear_sr = SSSR_ROR | SSSR_TINT;
1456 drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR;
1457 }
1458
1459 status = request_irq(ssp->irq, ssp_int, 0, dev->bus_id, drv_data);
1460 if (status < 0) {
1461 dev_err(&pdev->dev, "can not get IRQ\n");
1462 goto out_error_master_alloc;
1463 }
1464
1465 /* Setup DMA if requested */
1466 drv_data->tx_channel = -1;
1467 drv_data->rx_channel = -1;
1468 if (platform_info->enable_dma) {
1469
1470 /* Get two DMA channels (rx and tx) */
1471 drv_data->rx_channel = pxa_request_dma("pxa2xx_spi_ssp_rx",
1472 DMA_PRIO_HIGH,
1473 dma_handler,
1474 drv_data);
1475 if (drv_data->rx_channel < 0) {
1476 dev_err(dev, "problem (%d) requesting rx channel\n",
1477 drv_data->rx_channel);
1478 status = -ENODEV;
1479 goto out_error_irq_alloc;
1480 }
1481 drv_data->tx_channel = pxa_request_dma("pxa2xx_spi_ssp_tx",
1482 DMA_PRIO_MEDIUM,
1483 dma_handler,
1484 drv_data);
1485 if (drv_data->tx_channel < 0) {
1486 dev_err(dev, "problem (%d) requesting tx channel\n",
1487 drv_data->tx_channel);
1488 status = -ENODEV;
1489 goto out_error_dma_alloc;
1490 }
1491
1492 DRCMR(ssp->drcmr_rx) = DRCMR_MAPVLD | drv_data->rx_channel;
1493 DRCMR(ssp->drcmr_tx) = DRCMR_MAPVLD | drv_data->tx_channel;
1494 }
1495
1496 /* Enable SOC clock */
1497 clk_enable(ssp->clk);
1498
1499 /* Load default SSP configuration */
1500 write_SSCR0(0, drv_data->ioaddr);
1501 write_SSCR1(SSCR1_RxTresh(4) | SSCR1_TxTresh(12), drv_data->ioaddr);
1502 write_SSCR0(SSCR0_SerClkDiv(2)
1503 | SSCR0_Motorola
1504 | SSCR0_DataSize(8),
1505 drv_data->ioaddr);
1506 if (drv_data->ssp_type != PXA25x_SSP)
1507 write_SSTO(0, drv_data->ioaddr);
1508 write_SSPSP(0, drv_data->ioaddr);
1509
1510 /* Initial and start queue */
1511 status = init_queue(drv_data);
1512 if (status != 0) {
1513 dev_err(&pdev->dev, "problem initializing queue\n");
1514 goto out_error_clock_enabled;
1515 }
1516 status = start_queue(drv_data);
1517 if (status != 0) {
1518 dev_err(&pdev->dev, "problem starting queue\n");
1519 goto out_error_clock_enabled;
1520 }
1521
1522 /* Register with the SPI framework */
1523 platform_set_drvdata(pdev, drv_data);
1524 status = spi_register_master(master);
1525 if (status != 0) {
1526 dev_err(&pdev->dev, "problem registering spi master\n");
1527 goto out_error_queue_alloc;
1528 }
1529
1530 return status;
1531
1532 out_error_queue_alloc:
1533 destroy_queue(drv_data);
1534
1535 out_error_clock_enabled:
1536 clk_disable(ssp->clk);
1537
1538 out_error_dma_alloc:
1539 if (drv_data->tx_channel != -1)
1540 pxa_free_dma(drv_data->tx_channel);
1541 if (drv_data->rx_channel != -1)
1542 pxa_free_dma(drv_data->rx_channel);
1543
1544 out_error_irq_alloc:
1545 free_irq(ssp->irq, drv_data);
1546
1547 out_error_master_alloc:
1548 spi_master_put(master);
1549 ssp_free(ssp);
1550 return status;
1551 }
1552
1553 static int pxa2xx_spi_remove(struct platform_device *pdev)
1554 {
1555 struct driver_data *drv_data = platform_get_drvdata(pdev);
1556 struct ssp_device *ssp = drv_data->ssp;
1557 int status = 0;
1558
1559 if (!drv_data)
1560 return 0;
1561
1562 /* Remove the queue */
1563 status = destroy_queue(drv_data);
1564 if (status != 0)
1565 /* the kernel does not check the return status of this
1566 * this routine (mod->exit, within the kernel). Therefore
1567 * nothing is gained by returning from here, the module is
1568 * going away regardless, and we should not leave any more
1569 * resources allocated than necessary. We cannot free the
1570 * message memory in drv_data->queue, but we can release the
1571 * resources below. I think the kernel should honor -EBUSY
1572 * returns but... */
1573 dev_err(&pdev->dev, "pxa2xx_spi_remove: workqueue will not "
1574 "complete, message memory not freed\n");
1575
1576 /* Disable the SSP at the peripheral and SOC level */
1577 write_SSCR0(0, drv_data->ioaddr);
1578 clk_disable(ssp->clk);
1579
1580 /* Release DMA */
1581 if (drv_data->master_info->enable_dma) {
1582 DRCMR(ssp->drcmr_rx) = 0;
1583 DRCMR(ssp->drcmr_tx) = 0;
1584 pxa_free_dma(drv_data->tx_channel);
1585 pxa_free_dma(drv_data->rx_channel);
1586 }
1587
1588 /* Release IRQ */
1589 free_irq(ssp->irq, drv_data);
1590
1591 /* Release SSP */
1592 ssp_free(ssp);
1593
1594 /* Disconnect from the SPI framework */
1595 spi_unregister_master(drv_data->master);
1596
1597 /* Prevent double remove */
1598 platform_set_drvdata(pdev, NULL);
1599
1600 return 0;
1601 }
1602
1603 static void pxa2xx_spi_shutdown(struct platform_device *pdev)
1604 {
1605 int status = 0;
1606
1607 if ((status = pxa2xx_spi_remove(pdev)) != 0)
1608 dev_err(&pdev->dev, "shutdown failed with %d\n", status);
1609 }
1610
1611 #ifdef CONFIG_PM
1612
1613 static int pxa2xx_spi_suspend(struct platform_device *pdev, pm_message_t state)
1614 {
1615 struct driver_data *drv_data = platform_get_drvdata(pdev);
1616 struct ssp_device *ssp = drv_data->ssp;
1617 int status = 0;
1618
1619 status = stop_queue(drv_data);
1620 if (status != 0)
1621 return status;
1622 write_SSCR0(0, drv_data->ioaddr);
1623 clk_disable(ssp->clk);
1624
1625 return 0;
1626 }
1627
1628 static int pxa2xx_spi_resume(struct platform_device *pdev)
1629 {
1630 struct driver_data *drv_data = platform_get_drvdata(pdev);
1631 struct ssp_device *ssp = drv_data->ssp;
1632 int status = 0;
1633
1634 /* Enable the SSP clock */
1635 clk_enable(ssp->clk);
1636
1637 /* Start the queue running */
1638 status = start_queue(drv_data);
1639 if (status != 0) {
1640 dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
1641 return status;
1642 }
1643
1644 return 0;
1645 }
1646 #else
1647 #define pxa2xx_spi_suspend NULL
1648 #define pxa2xx_spi_resume NULL
1649 #endif /* CONFIG_PM */
1650
1651 static struct platform_driver driver = {
1652 .driver = {
1653 .name = "pxa2xx-spi",
1654 .owner = THIS_MODULE,
1655 },
1656 .remove = pxa2xx_spi_remove,
1657 .shutdown = pxa2xx_spi_shutdown,
1658 .suspend = pxa2xx_spi_suspend,
1659 .resume = pxa2xx_spi_resume,
1660 };
1661
1662 static int __init pxa2xx_spi_init(void)
1663 {
1664 return platform_driver_probe(&driver, pxa2xx_spi_probe);
1665 }
1666 module_init(pxa2xx_spi_init);
1667
1668 static void __exit pxa2xx_spi_exit(void)
1669 {
1670 platform_driver_unregister(&driver);
1671 }
1672 module_exit(pxa2xx_spi_exit);
x86 "subsystem" repository