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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/spi/pxa2xx_spi.h>
27#include <linux/dma-mapping.h>
28#include <linux/spi/spi.h>
29#include <linux/workqueue.h>
30#include <linux/delay.h>
31#include <linux/gpio.h>
32#include <linux/slab.h>
33
34#include <asm/io.h>
35#include <asm/irq.h>
36#include <asm/delay.h>
37
38
39MODULE_AUTHOR("Stephen Street");
40MODULE_DESCRIPTION("PXA2xx SSP SPI Controller");
41MODULE_LICENSE("GPL");
42MODULE_ALIAS("platform:pxa2xx-spi");
43
44#define MAX_BUSES 3
45
46#define TIMOUT_DFLT 1000
47
48#define DMA_INT_MASK (DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR)
49#define RESET_DMA_CHANNEL (DCSR_NODESC | DMA_INT_MASK)
50#define IS_DMA_ALIGNED(x) ((((u32)(x)) & 0x07) == 0)
51#define MAX_DMA_LEN 8191
52#define DMA_ALIGNMENT 8
53
54/*
55 * for testing SSCR1 changes that require SSP restart, basically
56 * everything except the service and interrupt enables, the pxa270 developer
57 * manual says only SSCR1_SCFR, SSCR1_SPH, SSCR1_SPO need to be in this
58 * list, but the PXA255 dev man says all bits without really meaning the
59 * service and interrupt enables
60 */
61#define SSCR1_CHANGE_MASK (SSCR1_TTELP | SSCR1_TTE | SSCR1_SCFR \
62 | SSCR1_ECRA | SSCR1_ECRB | SSCR1_SCLKDIR \
63 | SSCR1_SFRMDIR | SSCR1_RWOT | SSCR1_TRAIL \
64 | SSCR1_IFS | SSCR1_STRF | SSCR1_EFWR \
65 | SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \
66 | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
67
68#define DEFINE_SSP_REG(reg, off) \
69static inline u32 read_##reg(void const __iomem *p) \
70{ return __raw_readl(p + (off)); } \
71\
72static inline void write_##reg(u32 v, void __iomem *p) \
73{ __raw_writel(v, p + (off)); }
74
75DEFINE_SSP_REG(SSCR0, 0x00)
76DEFINE_SSP_REG(SSCR1, 0x04)
77DEFINE_SSP_REG(SSSR, 0x08)
78DEFINE_SSP_REG(SSITR, 0x0c)
79DEFINE_SSP_REG(SSDR, 0x10)
80DEFINE_SSP_REG(SSTO, 0x28)
81DEFINE_SSP_REG(SSPSP, 0x2c)
82
83#define START_STATE ((void*)0)
84#define RUNNING_STATE ((void*)1)
85#define DONE_STATE ((void*)2)
86#define ERROR_STATE ((void*)-1)
87
88#define QUEUE_RUNNING 0
89#define QUEUE_STOPPED 1
90
91struct driver_data {
92 /* Driver model hookup */
93 struct platform_device *pdev;
94
95 /* SSP Info */
96 struct ssp_device *ssp;
97
98 /* SPI framework hookup */
99 enum pxa_ssp_type ssp_type;
100 struct spi_master *master;
101
102 /* PXA hookup */
103 struct pxa2xx_spi_master *master_info;
104
105 /* DMA setup stuff */
106 int rx_channel;
107 int tx_channel;
108 u32 *null_dma_buf;
109
110 /* SSP register addresses */
111 void __iomem *ioaddr;
112 u32 ssdr_physical;
113
114 /* SSP masks*/
115 u32 dma_cr1;
116 u32 int_cr1;
117 u32 clear_sr;
118 u32 mask_sr;
119
120 /* Driver message queue */
121 struct workqueue_struct *workqueue;
122 struct work_struct pump_messages;
123 spinlock_t lock;
124 struct list_head queue;
125 int busy;
126 int run;
127
128 /* Message Transfer pump */
129 struct tasklet_struct pump_transfers;
130
131 /* Current message transfer state info */
132 struct spi_message* cur_msg;
133 struct spi_transfer* cur_transfer;
134 struct chip_data *cur_chip;
135 size_t len;
136 void *tx;
137 void *tx_end;
138 void *rx;
139 void *rx_end;
140 int dma_mapped;
141 dma_addr_t rx_dma;
142 dma_addr_t tx_dma;
143 size_t rx_map_len;
144 size_t tx_map_len;
145 u8 n_bytes;
146 u32 dma_width;
147 int (*write)(struct driver_data *drv_data);
148 int (*read)(struct driver_data *drv_data);
149 irqreturn_t (*transfer_handler)(struct driver_data *drv_data);
150 void (*cs_control)(u32 command);
151};
152
153struct chip_data {
154 u32 cr0;
155 u32 cr1;
156 u32 psp;
157 u32 timeout;
158 u8 n_bytes;
159 u32 dma_width;
160 u32 dma_burst_size;
161 u32 threshold;
162 u32 dma_threshold;
163 u8 enable_dma;
164 u8 bits_per_word;
165 u32 speed_hz;
166 union {
167 int gpio_cs;
168 unsigned int frm;
169 };
170 int gpio_cs_inverted;
171 int (*write)(struct driver_data *drv_data);
172 int (*read)(struct driver_data *drv_data);
173 void (*cs_control)(u32 command);
174};
175
176static void pump_messages(struct work_struct *work);
177
178static void cs_assert(struct driver_data *drv_data)
179{
180 struct chip_data *chip = drv_data->cur_chip;
181
182 if (drv_data->ssp_type == CE4100_SSP) {
183 write_SSSR(drv_data->cur_chip->frm, drv_data->ioaddr);
184 return;
185 }
186
187 if (chip->cs_control) {
188 chip->cs_control(PXA2XX_CS_ASSERT);
189 return;
190 }
191
192 if (gpio_is_valid(chip->gpio_cs))
193 gpio_set_value(chip->gpio_cs, chip->gpio_cs_inverted);
194}
195
196static void cs_deassert(struct driver_data *drv_data)
197{
198 struct chip_data *chip = drv_data->cur_chip;
199
200 if (drv_data->ssp_type == CE4100_SSP)
201 return;
202
203 if (chip->cs_control) {
204 chip->cs_control(PXA2XX_CS_DEASSERT);
205 return;
206 }
207
208 if (gpio_is_valid(chip->gpio_cs))
209 gpio_set_value(chip->gpio_cs, !chip->gpio_cs_inverted);
210}
211
212static void write_SSSR_CS(struct driver_data *drv_data, u32 val)
213{
214 void __iomem *reg = drv_data->ioaddr;
215
216 if (drv_data->ssp_type == CE4100_SSP)
217 val |= read_SSSR(reg) & SSSR_ALT_FRM_MASK;
218
219 write_SSSR(val, reg);
220}
221
222static int pxa25x_ssp_comp(struct driver_data *drv_data)
223{
224 if (drv_data->ssp_type == PXA25x_SSP)
225 return 1;
226 if (drv_data->ssp_type == CE4100_SSP)
227 return 1;
228 return 0;
229}
230
231static int flush(struct driver_data *drv_data)
232{
233 unsigned long limit = loops_per_jiffy << 1;
234
235 void __iomem *reg = drv_data->ioaddr;
236
237 do {
238 while (read_SSSR(reg) & SSSR_RNE) {
239 read_SSDR(reg);
240 }
241 } while ((read_SSSR(reg) & SSSR_BSY) && --limit);
242 write_SSSR_CS(drv_data, SSSR_ROR);
243
244 return limit;
245}
246
247static int null_writer(struct driver_data *drv_data)
248{
249 void __iomem *reg = drv_data->ioaddr;
250 u8 n_bytes = drv_data->n_bytes;
251
252 if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
253 || (drv_data->tx == drv_data->tx_end))
254 return 0;
255
256 write_SSDR(0, reg);
257 drv_data->tx += n_bytes;
258
259 return 1;
260}
261
262static int null_reader(struct driver_data *drv_data)
263{
264 void __iomem *reg = drv_data->ioaddr;
265 u8 n_bytes = drv_data->n_bytes;
266
267 while ((read_SSSR(reg) & SSSR_RNE)
268 && (drv_data->rx < drv_data->rx_end)) {
269 read_SSDR(reg);
270 drv_data->rx += n_bytes;
271 }
272
273 return drv_data->rx == drv_data->rx_end;
274}
275
276static int u8_writer(struct driver_data *drv_data)
277{
278 void __iomem *reg = drv_data->ioaddr;
279
280 if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
281 || (drv_data->tx == drv_data->tx_end))
282 return 0;
283
284 write_SSDR(*(u8 *)(drv_data->tx), reg);
285 ++drv_data->tx;
286
287 return 1;
288}
289
290static int u8_reader(struct driver_data *drv_data)
291{
292 void __iomem *reg = drv_data->ioaddr;
293
294 while ((read_SSSR(reg) & SSSR_RNE)
295 && (drv_data->rx < drv_data->rx_end)) {
296 *(u8 *)(drv_data->rx) = read_SSDR(reg);
297 ++drv_data->rx;
298 }
299
300 return drv_data->rx == drv_data->rx_end;
301}
302
303static int u16_writer(struct driver_data *drv_data)
304{
305 void __iomem *reg = drv_data->ioaddr;
306
307 if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
308 || (drv_data->tx == drv_data->tx_end))
309 return 0;
310
311 write_SSDR(*(u16 *)(drv_data->tx), reg);
312 drv_data->tx += 2;
313
314 return 1;
315}
316
317static int u16_reader(struct driver_data *drv_data)
318{
319 void __iomem *reg = drv_data->ioaddr;
320
321 while ((read_SSSR(reg) & SSSR_RNE)
322 && (drv_data->rx < drv_data->rx_end)) {
323 *(u16 *)(drv_data->rx) = read_SSDR(reg);
324 drv_data->rx += 2;
325 }
326
327 return drv_data->rx == drv_data->rx_end;
328}
329
330static int u32_writer(struct driver_data *drv_data)
331{
332 void __iomem *reg = drv_data->ioaddr;
333
334 if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
335 || (drv_data->tx == drv_data->tx_end))
336 return 0;
337
338 write_SSDR(*(u32 *)(drv_data->tx), reg);
339 drv_data->tx += 4;
340
341 return 1;
342}
343
344static int u32_reader(struct driver_data *drv_data)
345{
346 void __iomem *reg = drv_data->ioaddr;
347
348 while ((read_SSSR(reg) & SSSR_RNE)
349 && (drv_data->rx < drv_data->rx_end)) {
350 *(u32 *)(drv_data->rx) = read_SSDR(reg);
351 drv_data->rx += 4;
352 }
353
354 return drv_data->rx == drv_data->rx_end;
355}
356
357static void *next_transfer(struct driver_data *drv_data)
358{
359 struct spi_message *msg = drv_data->cur_msg;
360 struct spi_transfer *trans = drv_data->cur_transfer;
361
362 /* Move to next transfer */
363 if (trans->transfer_list.next != &msg->transfers) {
364 drv_data->cur_transfer =
365 list_entry(trans->transfer_list.next,
366 struct spi_transfer,
367 transfer_list);
368 return RUNNING_STATE;
369 } else
370 return DONE_STATE;
371}
372
373static int map_dma_buffers(struct driver_data *drv_data)
374{
375 struct spi_message *msg = drv_data->cur_msg;
376 struct device *dev = &msg->spi->dev;
377
378 if (!drv_data->cur_chip->enable_dma)
379 return 0;
380
381 if (msg->is_dma_mapped)
382 return drv_data->rx_dma && drv_data->tx_dma;
383
384 if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx))
385 return 0;
386
387 /* Modify setup if rx buffer is null */
388 if (drv_data->rx == NULL) {
389 *drv_data->null_dma_buf = 0;
390 drv_data->rx = drv_data->null_dma_buf;
391 drv_data->rx_map_len = 4;
392 } else
393 drv_data->rx_map_len = drv_data->len;
394
395
396 /* Modify setup if tx buffer is null */
397 if (drv_data->tx == NULL) {
398 *drv_data->null_dma_buf = 0;
399 drv_data->tx = drv_data->null_dma_buf;
400 drv_data->tx_map_len = 4;
401 } else
402 drv_data->tx_map_len = drv_data->len;
403
404 /* Stream map the tx buffer. Always do DMA_TO_DEVICE first
405 * so we flush the cache *before* invalidating it, in case
406 * the tx and rx buffers overlap.
407 */
408 drv_data->tx_dma = dma_map_single(dev, drv_data->tx,
409 drv_data->tx_map_len, DMA_TO_DEVICE);
410 if (dma_mapping_error(dev, drv_data->tx_dma))
411 return 0;
412
413 /* Stream map the rx buffer */
414 drv_data->rx_dma = dma_map_single(dev, drv_data->rx,
415 drv_data->rx_map_len, DMA_FROM_DEVICE);
416 if (dma_mapping_error(dev, drv_data->rx_dma)) {
417 dma_unmap_single(dev, drv_data->tx_dma,
418 drv_data->tx_map_len, DMA_TO_DEVICE);
419 return 0;
420 }
421
422 return 1;
423}
424
425static void unmap_dma_buffers(struct driver_data *drv_data)
426{
427 struct device *dev;
428
429 if (!drv_data->dma_mapped)
430 return;
431
432 if (!drv_data->cur_msg->is_dma_mapped) {
433 dev = &drv_data->cur_msg->spi->dev;
434 dma_unmap_single(dev, drv_data->rx_dma,
435 drv_data->rx_map_len, DMA_FROM_DEVICE);
436 dma_unmap_single(dev, drv_data->tx_dma,
437 drv_data->tx_map_len, DMA_TO_DEVICE);
438 }
439
440 drv_data->dma_mapped = 0;
441}
442
443/* caller already set message->status; dma and pio irqs are blocked */
444static void giveback(struct driver_data *drv_data)
445{
446 struct spi_transfer* last_transfer;
447 unsigned long flags;
448 struct spi_message *msg;
449
450 spin_lock_irqsave(&drv_data->lock, flags);
451 msg = drv_data->cur_msg;
452 drv_data->cur_msg = NULL;
453 drv_data->cur_transfer = NULL;
454 queue_work(drv_data->workqueue, &drv_data->pump_messages);
455 spin_unlock_irqrestore(&drv_data->lock, flags);
456
457 last_transfer = list_entry(msg->transfers.prev,
458 struct spi_transfer,
459 transfer_list);
460
461 /* Delay if requested before any change in chip select */
462 if (last_transfer->delay_usecs)
463 udelay(last_transfer->delay_usecs);
464
465 /* Drop chip select UNLESS cs_change is true or we are returning
466 * a message with an error, or next message is for another chip
467 */
468 if (!last_transfer->cs_change)
469 cs_deassert(drv_data);
470 else {
471 struct spi_message *next_msg;
472
473 /* Holding of cs was hinted, but we need to make sure
474 * the next message is for the same chip. Don't waste
475 * time with the following tests unless this was hinted.
476 *
477 * We cannot postpone this until pump_messages, because
478 * after calling msg->complete (below) the driver that
479 * sent the current message could be unloaded, which
480 * could invalidate the cs_control() callback...
481 */
482
483 /* get a pointer to the next message, if any */
484 spin_lock_irqsave(&drv_data->lock, flags);
485 if (list_empty(&drv_data->queue))
486 next_msg = NULL;
487 else
488 next_msg = list_entry(drv_data->queue.next,
489 struct spi_message, queue);
490 spin_unlock_irqrestore(&drv_data->lock, flags);
491
492 /* see if the next and current messages point
493 * to the same chip
494 */
495 if (next_msg && next_msg->spi != msg->spi)
496 next_msg = NULL;
497 if (!next_msg || msg->state == ERROR_STATE)
498 cs_deassert(drv_data);
499 }
500
501 msg->state = NULL;
502 if (msg->complete)
503 msg->complete(msg->context);
504
505 drv_data->cur_chip = NULL;
506}
507
508static int wait_ssp_rx_stall(void const __iomem *ioaddr)
509{
510 unsigned long limit = loops_per_jiffy << 1;
511
512 while ((read_SSSR(ioaddr) & SSSR_BSY) && --limit)
513 cpu_relax();
514
515 return limit;
516}
517
518static int wait_dma_channel_stop(int channel)
519{
520 unsigned long limit = loops_per_jiffy << 1;
521
522 while (!(DCSR(channel) & DCSR_STOPSTATE) && --limit)
523 cpu_relax();
524
525 return limit;
526}
527
528static void dma_error_stop(struct driver_data *drv_data, const char *msg)
529{
530 void __iomem *reg = drv_data->ioaddr;
531
532 /* Stop and reset */
533 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
534 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
535 write_SSSR_CS(drv_data, drv_data->clear_sr);
536 write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
537 if (!pxa25x_ssp_comp(drv_data))
538 write_SSTO(0, reg);
539 flush(drv_data);
540 write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
541
542 unmap_dma_buffers(drv_data);
543
544 dev_err(&drv_data->pdev->dev, "%s\n", msg);
545
546 drv_data->cur_msg->state = ERROR_STATE;
547 tasklet_schedule(&drv_data->pump_transfers);
548}
549
550static void dma_transfer_complete(struct driver_data *drv_data)
551{
552 void __iomem *reg = drv_data->ioaddr;
553 struct spi_message *msg = drv_data->cur_msg;
554
555 /* Clear and disable interrupts on SSP and DMA channels*/
556 write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
557 write_SSSR_CS(drv_data, drv_data->clear_sr);
558 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
559 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
560
561 if (wait_dma_channel_stop(drv_data->rx_channel) == 0)
562 dev_err(&drv_data->pdev->dev,
563 "dma_handler: dma rx channel stop failed\n");
564
565 if (wait_ssp_rx_stall(drv_data->ioaddr) == 0)
566 dev_err(&drv_data->pdev->dev,
567 "dma_transfer: ssp rx stall failed\n");
568
569 unmap_dma_buffers(drv_data);
570
571 /* update the buffer pointer for the amount completed in dma */
572 drv_data->rx += drv_data->len -
573 (DCMD(drv_data->rx_channel) & DCMD_LENGTH);
574
575 /* read trailing data from fifo, it does not matter how many
576 * bytes are in the fifo just read until buffer is full
577 * or fifo is empty, which ever occurs first */
578 drv_data->read(drv_data);
579
580 /* return count of what was actually read */
581 msg->actual_length += drv_data->len -
582 (drv_data->rx_end - drv_data->rx);
583
584 /* Transfer delays and chip select release are
585 * handled in pump_transfers or giveback
586 */
587
588 /* Move to next transfer */
589 msg->state = next_transfer(drv_data);
590
591 /* Schedule transfer tasklet */
592 tasklet_schedule(&drv_data->pump_transfers);
593}
594
595static void dma_handler(int channel, void *data)
596{
597 struct driver_data *drv_data = data;
598 u32 irq_status = DCSR(channel) & DMA_INT_MASK;
599
600 if (irq_status & DCSR_BUSERR) {
601
602 if (channel == drv_data->tx_channel)
603 dma_error_stop(drv_data,
604 "dma_handler: "
605 "bad bus address on tx channel");
606 else
607 dma_error_stop(drv_data,
608 "dma_handler: "
609 "bad bus address on rx channel");
610 return;
611 }
612
613 /* PXA255x_SSP has no timeout interrupt, wait for tailing bytes */
614 if ((channel == drv_data->tx_channel)
615 && (irq_status & DCSR_ENDINTR)
616 && (drv_data->ssp_type == PXA25x_SSP)) {
617
618 /* Wait for rx to stall */
619 if (wait_ssp_rx_stall(drv_data->ioaddr) == 0)
620 dev_err(&drv_data->pdev->dev,
621 "dma_handler: ssp rx stall failed\n");
622
623 /* finish this transfer, start the next */
624 dma_transfer_complete(drv_data);
625 }
626}
627
628static irqreturn_t dma_transfer(struct driver_data *drv_data)
629{
630 u32 irq_status;
631 void __iomem *reg = drv_data->ioaddr;
632
633 irq_status = read_SSSR(reg) & drv_data->mask_sr;
634 if (irq_status & SSSR_ROR) {
635 dma_error_stop(drv_data, "dma_transfer: fifo overrun");
636 return IRQ_HANDLED;
637 }
638
639 /* Check for false positive timeout */
640 if ((irq_status & SSSR_TINT)
641 && (DCSR(drv_data->tx_channel) & DCSR_RUN)) {
642 write_SSSR(SSSR_TINT, reg);
643 return IRQ_HANDLED;
644 }
645
646 if (irq_status & SSSR_TINT || drv_data->rx == drv_data->rx_end) {
647
648 /* Clear and disable timeout interrupt, do the rest in
649 * dma_transfer_complete */
650 if (!pxa25x_ssp_comp(drv_data))
651 write_SSTO(0, reg);
652
653 /* finish this transfer, start the next */
654 dma_transfer_complete(drv_data);
655
656 return IRQ_HANDLED;
657 }
658
659 /* Opps problem detected */
660 return IRQ_NONE;
661}
662
663static void reset_sccr1(struct driver_data *drv_data)
664{
665 void __iomem *reg = drv_data->ioaddr;
666 struct chip_data *chip = drv_data->cur_chip;
667 u32 sccr1_reg;
668
669 sccr1_reg = read_SSCR1(reg) & ~drv_data->int_cr1;
670 sccr1_reg &= ~SSCR1_RFT;
671 sccr1_reg |= chip->threshold;
672 write_SSCR1(sccr1_reg, reg);
673}
674
675static void int_error_stop(struct driver_data *drv_data, const char* msg)
676{
677 void __iomem *reg = drv_data->ioaddr;
678
679 /* Stop and reset SSP */
680 write_SSSR_CS(drv_data, drv_data->clear_sr);
681 reset_sccr1(drv_data);
682 if (!pxa25x_ssp_comp(drv_data))
683 write_SSTO(0, reg);
684 flush(drv_data);
685 write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
686
687 dev_err(&drv_data->pdev->dev, "%s\n", msg);
688
689 drv_data->cur_msg->state = ERROR_STATE;
690 tasklet_schedule(&drv_data->pump_transfers);
691}
692
693static void int_transfer_complete(struct driver_data *drv_data)
694{
695 void __iomem *reg = drv_data->ioaddr;
696
697 /* Stop SSP */
698 write_SSSR_CS(drv_data, drv_data->clear_sr);
699 reset_sccr1(drv_data);
700 if (!pxa25x_ssp_comp(drv_data))
701 write_SSTO(0, reg);
702
703 /* Update total byte transferred return count actual bytes read */
704 drv_data->cur_msg->actual_length += drv_data->len -
705 (drv_data->rx_end - drv_data->rx);
706
707 /* Transfer delays and chip select release are
708 * handled in pump_transfers or giveback
709 */
710
711 /* Move to next transfer */
712 drv_data->cur_msg->state = next_transfer(drv_data);
713
714 /* Schedule transfer tasklet */
715 tasklet_schedule(&drv_data->pump_transfers);
716}
717
718static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
719{
720 void __iomem *reg = drv_data->ioaddr;
721
722 u32 irq_mask = (read_SSCR1(reg) & SSCR1_TIE) ?
723 drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS;
724
725 u32 irq_status = read_SSSR(reg) & irq_mask;
726
727 if (irq_status & SSSR_ROR) {
728 int_error_stop(drv_data, "interrupt_transfer: fifo overrun");
729 return IRQ_HANDLED;
730 }
731
732 if (irq_status & SSSR_TINT) {
733 write_SSSR(SSSR_TINT, reg);
734 if (drv_data->read(drv_data)) {
735 int_transfer_complete(drv_data);
736 return IRQ_HANDLED;
737 }
738 }
739
740 /* Drain rx fifo, Fill tx fifo and prevent overruns */
741 do {
742 if (drv_data->read(drv_data)) {
743 int_transfer_complete(drv_data);
744 return IRQ_HANDLED;
745 }
746 } while (drv_data->write(drv_data));
747
748 if (drv_data->read(drv_data)) {
749 int_transfer_complete(drv_data);
750 return IRQ_HANDLED;
751 }
752
753 if (drv_data->tx == drv_data->tx_end) {
754 u32 bytes_left;
755 u32 sccr1_reg;
756
757 sccr1_reg = read_SSCR1(reg);
758 sccr1_reg &= ~SSCR1_TIE;
759
760 /*
761 * PXA25x_SSP has no timeout, set up rx threshould for the
762 * remaining RX bytes.
763 */
764 if (pxa25x_ssp_comp(drv_data)) {
765
766 sccr1_reg &= ~SSCR1_RFT;
767
768 bytes_left = drv_data->rx_end - drv_data->rx;
769 switch (drv_data->n_bytes) {
770 case 4:
771 bytes_left >>= 1;
772 case 2:
773 bytes_left >>= 1;
774 }
775
776 if (bytes_left > RX_THRESH_DFLT)
777 bytes_left = RX_THRESH_DFLT;
778
779 sccr1_reg |= SSCR1_RxTresh(bytes_left);
780 }
781 write_SSCR1(sccr1_reg, reg);
782 }
783
784 /* We did something */
785 return IRQ_HANDLED;
786}
787
788static irqreturn_t ssp_int(int irq, void *dev_id)
789{
790 struct driver_data *drv_data = dev_id;
791 void __iomem *reg = drv_data->ioaddr;
792 u32 sccr1_reg = read_SSCR1(reg);
793 u32 mask = drv_data->mask_sr;
794 u32 status;
795
796 status = read_SSSR(reg);
797
798 /* Ignore possible writes if we don't need to write */
799 if (!(sccr1_reg & SSCR1_TIE))
800 mask &= ~SSSR_TFS;
801
802 if (!(status & mask))
803 return IRQ_NONE;
804
805 if (!drv_data->cur_msg) {
806
807 write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
808 write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
809 if (!pxa25x_ssp_comp(drv_data))
810 write_SSTO(0, reg);
811 write_SSSR_CS(drv_data, drv_data->clear_sr);
812
813 dev_err(&drv_data->pdev->dev, "bad message state "
814 "in interrupt handler\n");
815
816 /* Never fail */
817 return IRQ_HANDLED;
818 }
819
820 return drv_data->transfer_handler(drv_data);
821}
822
823static int set_dma_burst_and_threshold(struct chip_data *chip,
824 struct spi_device *spi,
825 u8 bits_per_word, u32 *burst_code,
826 u32 *threshold)
827{
828 struct pxa2xx_spi_chip *chip_info =
829 (struct pxa2xx_spi_chip *)spi->controller_data;
830 int bytes_per_word;
831 int burst_bytes;
832 int thresh_words;
833 int req_burst_size;
834 int retval = 0;
835
836 /* Set the threshold (in registers) to equal the same amount of data
837 * as represented by burst size (in bytes). The computation below
838 * is (burst_size rounded up to nearest 8 byte, word or long word)
839 * divided by (bytes/register); the tx threshold is the inverse of
840 * the rx, so that there will always be enough data in the rx fifo
841 * to satisfy a burst, and there will always be enough space in the
842 * tx fifo to accept a burst (a tx burst will overwrite the fifo if
843 * there is not enough space), there must always remain enough empty
844 * space in the rx fifo for any data loaded to the tx fifo.
845 * Whenever burst_size (in bytes) equals bits/word, the fifo threshold
846 * will be 8, or half the fifo;
847 * The threshold can only be set to 2, 4 or 8, but not 16, because
848 * to burst 16 to the tx fifo, the fifo would have to be empty;
849 * however, the minimum fifo trigger level is 1, and the tx will
850 * request service when the fifo is at this level, with only 15 spaces.
851 */
852
853 /* find bytes/word */
854 if (bits_per_word <= 8)
855 bytes_per_word = 1;
856 else if (bits_per_word <= 16)
857 bytes_per_word = 2;
858 else
859 bytes_per_word = 4;
860
861 /* use struct pxa2xx_spi_chip->dma_burst_size if available */
862 if (chip_info)
863 req_burst_size = chip_info->dma_burst_size;
864 else {
865 switch (chip->dma_burst_size) {
866 default:
867 /* if the default burst size is not set,
868 * do it now */
869 chip->dma_burst_size = DCMD_BURST8;
870 case DCMD_BURST8:
871 req_burst_size = 8;
872 break;
873 case DCMD_BURST16:
874 req_burst_size = 16;
875 break;
876 case DCMD_BURST32:
877 req_burst_size = 32;
878 break;
879 }
880 }
881 if (req_burst_size <= 8) {
882 *burst_code = DCMD_BURST8;
883 burst_bytes = 8;
884 } else if (req_burst_size <= 16) {
885 if (bytes_per_word == 1) {
886 /* don't burst more than 1/2 the fifo */
887 *burst_code = DCMD_BURST8;
888 burst_bytes = 8;
889 retval = 1;
890 } else {
891 *burst_code = DCMD_BURST16;
892 burst_bytes = 16;
893 }
894 } else {
895 if (bytes_per_word == 1) {
896 /* don't burst more than 1/2 the fifo */
897 *burst_code = DCMD_BURST8;
898 burst_bytes = 8;
899 retval = 1;
900 } else if (bytes_per_word == 2) {
901 /* don't burst more than 1/2 the fifo */
902 *burst_code = DCMD_BURST16;
903 burst_bytes = 16;
904 retval = 1;
905 } else {
906 *burst_code = DCMD_BURST32;
907 burst_bytes = 32;
908 }
909 }
910
911 thresh_words = burst_bytes / bytes_per_word;
912
913 /* thresh_words will be between 2 and 8 */
914 *threshold = (SSCR1_RxTresh(thresh_words) & SSCR1_RFT)
915 | (SSCR1_TxTresh(16-thresh_words) & SSCR1_TFT);
916
917 return retval;
918}
919
920static unsigned int ssp_get_clk_div(struct ssp_device *ssp, int rate)
921{
922 unsigned long ssp_clk = clk_get_rate(ssp->clk);
923
924 if (ssp->type == PXA25x_SSP || ssp->type == CE4100_SSP)
925 return ((ssp_clk / (2 * rate) - 1) & 0xff) << 8;
926 else
927 return ((ssp_clk / rate - 1) & 0xfff) << 8;
928}
929
930static void pump_transfers(unsigned long data)
931{
932 struct driver_data *drv_data = (struct driver_data *)data;
933 struct spi_message *message = NULL;
934 struct spi_transfer *transfer = NULL;
935 struct spi_transfer *previous = NULL;
936 struct chip_data *chip = NULL;
937 struct ssp_device *ssp = drv_data->ssp;
938 void __iomem *reg = drv_data->ioaddr;
939 u32 clk_div = 0;
940 u8 bits = 0;
941 u32 speed = 0;
942 u32 cr0;
943 u32 cr1;
944 u32 dma_thresh = drv_data->cur_chip->dma_threshold;
945 u32 dma_burst = drv_data->cur_chip->dma_burst_size;
946
947 /* Get current state information */
948 message = drv_data->cur_msg;
949 transfer = drv_data->cur_transfer;
950 chip = drv_data->cur_chip;
951
952 /* Handle for abort */
953 if (message->state == ERROR_STATE) {
954 message->status = -EIO;
955 giveback(drv_data);
956 return;
957 }
958
959 /* Handle end of message */
960 if (message->state == DONE_STATE) {
961 message->status = 0;
962 giveback(drv_data);
963 return;
964 }
965
966 /* Delay if requested at end of transfer before CS change */
967 if (message->state == RUNNING_STATE) {
968 previous = list_entry(transfer->transfer_list.prev,
969 struct spi_transfer,
970 transfer_list);
971 if (previous->delay_usecs)
972 udelay(previous->delay_usecs);
973
974 /* Drop chip select only if cs_change is requested */
975 if (previous->cs_change)
976 cs_deassert(drv_data);
977 }
978
979 /* Check for transfers that need multiple DMA segments */
980 if (transfer->len > MAX_DMA_LEN && chip->enable_dma) {
981
982 /* reject already-mapped transfers; PIO won't always work */
983 if (message->is_dma_mapped
984 || transfer->rx_dma || transfer->tx_dma) {
985 dev_err(&drv_data->pdev->dev,
986 "pump_transfers: mapped transfer length "
987 "of %u is greater than %d\n",
988 transfer->len, MAX_DMA_LEN);
989 message->status = -EINVAL;
990 giveback(drv_data);
991 return;
992 }
993
994 /* warn ... we force this to PIO mode */
995 if (printk_ratelimit())
996 dev_warn(&message->spi->dev, "pump_transfers: "
997 "DMA disabled for transfer length %ld "
998 "greater than %d\n",
999 (long)drv_data->len, MAX_DMA_LEN);
1000 }
1001
1002 /* Setup the transfer state based on the type of transfer */
1003 if (flush(drv_data) == 0) {
1004 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
1005 message->status = -EIO;
1006 giveback(drv_data);
1007 return;
1008 }
1009 drv_data->n_bytes = chip->n_bytes;
1010 drv_data->dma_width = chip->dma_width;
1011 drv_data->tx = (void *)transfer->tx_buf;
1012 drv_data->tx_end = drv_data->tx + transfer->len;
1013 drv_data->rx = transfer->rx_buf;
1014 drv_data->rx_end = drv_data->rx + transfer->len;
1015 drv_data->rx_dma = transfer->rx_dma;
1016 drv_data->tx_dma = transfer->tx_dma;
1017 drv_data->len = transfer->len & DCMD_LENGTH;
1018 drv_data->write = drv_data->tx ? chip->write : null_writer;
1019 drv_data->read = drv_data->rx ? chip->read : null_reader;
1020
1021 /* Change speed and bit per word on a per transfer */
1022 cr0 = chip->cr0;
1023 if (transfer->speed_hz || transfer->bits_per_word) {
1024
1025 bits = chip->bits_per_word;
1026 speed = chip->speed_hz;
1027
1028 if (transfer->speed_hz)
1029 speed = transfer->speed_hz;
1030
1031 if (transfer->bits_per_word)
1032 bits = transfer->bits_per_word;
1033
1034 clk_div = ssp_get_clk_div(ssp, speed);
1035
1036 if (bits <= 8) {
1037 drv_data->n_bytes = 1;
1038 drv_data->dma_width = DCMD_WIDTH1;
1039 drv_data->read = drv_data->read != null_reader ?
1040 u8_reader : null_reader;
1041 drv_data->write = drv_data->write != null_writer ?
1042 u8_writer : null_writer;
1043 } else if (bits <= 16) {
1044 drv_data->n_bytes = 2;
1045 drv_data->dma_width = DCMD_WIDTH2;
1046 drv_data->read = drv_data->read != null_reader ?
1047 u16_reader : null_reader;
1048 drv_data->write = drv_data->write != null_writer ?
1049 u16_writer : null_writer;
1050 } else if (bits <= 32) {
1051 drv_data->n_bytes = 4;
1052 drv_data->dma_width = DCMD_WIDTH4;
1053 drv_data->read = drv_data->read != null_reader ?
1054 u32_reader : null_reader;
1055 drv_data->write = drv_data->write != null_writer ?
1056 u32_writer : null_writer;
1057 }
1058 /* if bits/word is changed in dma mode, then must check the
1059 * thresholds and burst also */
1060 if (chip->enable_dma) {
1061 if (set_dma_burst_and_threshold(chip, message->spi,
1062 bits, &dma_burst,
1063 &dma_thresh))
1064 if (printk_ratelimit())
1065 dev_warn(&message->spi->dev,
1066 "pump_transfers: "
1067 "DMA burst size reduced to "
1068 "match bits_per_word\n");
1069 }
1070
1071 cr0 = clk_div
1072 | SSCR0_Motorola
1073 | SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
1074 | SSCR0_SSE
1075 | (bits > 16 ? SSCR0_EDSS : 0);
1076 }
1077
1078 message->state = RUNNING_STATE;
1079
1080 /* Try to map dma buffer and do a dma transfer if successful, but
1081 * only if the length is non-zero and less than MAX_DMA_LEN.
1082 *
1083 * Zero-length non-descriptor DMA is illegal on PXA2xx; force use
1084 * of PIO instead. Care is needed above because the transfer may
1085 * have have been passed with buffers that are already dma mapped.
1086 * A zero-length transfer in PIO mode will not try to write/read
1087 * to/from the buffers
1088 *
1089 * REVISIT large transfers are exactly where we most want to be
1090 * using DMA. If this happens much, split those transfers into
1091 * multiple DMA segments rather than forcing PIO.
1092 */
1093 drv_data->dma_mapped = 0;
1094 if (drv_data->len > 0 && drv_data->len <= MAX_DMA_LEN)
1095 drv_data->dma_mapped = map_dma_buffers(drv_data);
1096 if (drv_data->dma_mapped) {
1097
1098 /* Ensure we have the correct interrupt handler */
1099 drv_data->transfer_handler = dma_transfer;
1100
1101 /* Setup rx DMA Channel */
1102 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
1103 DSADR(drv_data->rx_channel) = drv_data->ssdr_physical;
1104 DTADR(drv_data->rx_channel) = drv_data->rx_dma;
1105 if (drv_data->rx == drv_data->null_dma_buf)
1106 /* No target address increment */
1107 DCMD(drv_data->rx_channel) = DCMD_FLOWSRC
1108 | drv_data->dma_width
1109 | dma_burst
1110 | drv_data->len;
1111 else
1112 DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR
1113 | DCMD_FLOWSRC
1114 | drv_data->dma_width
1115 | dma_burst
1116 | drv_data->len;
1117
1118 /* Setup tx DMA Channel */
1119 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
1120 DSADR(drv_data->tx_channel) = drv_data->tx_dma;
1121 DTADR(drv_data->tx_channel) = drv_data->ssdr_physical;
1122 if (drv_data->tx == drv_data->null_dma_buf)
1123 /* No source address increment */
1124 DCMD(drv_data->tx_channel) = DCMD_FLOWTRG
1125 | drv_data->dma_width
1126 | dma_burst
1127 | drv_data->len;
1128 else
1129 DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR
1130 | DCMD_FLOWTRG
1131 | drv_data->dma_width
1132 | dma_burst
1133 | drv_data->len;
1134
1135 /* Enable dma end irqs on SSP to detect end of transfer */
1136 if (drv_data->ssp_type == PXA25x_SSP)
1137 DCMD(drv_data->tx_channel) |= DCMD_ENDIRQEN;
1138
1139 /* Clear status and start DMA engine */
1140 cr1 = chip->cr1 | dma_thresh | drv_data->dma_cr1;
1141 write_SSSR(drv_data->clear_sr, reg);
1142 DCSR(drv_data->rx_channel) |= DCSR_RUN;
1143 DCSR(drv_data->tx_channel) |= DCSR_RUN;
1144 } else {
1145 /* Ensure we have the correct interrupt handler */
1146 drv_data->transfer_handler = interrupt_transfer;
1147
1148 /* Clear status */
1149 cr1 = chip->cr1 | chip->threshold | drv_data->int_cr1;
1150 write_SSSR_CS(drv_data, drv_data->clear_sr);
1151 }
1152
1153 /* see if we need to reload the config registers */
1154 if ((read_SSCR0(reg) != cr0)
1155 || (read_SSCR1(reg) & SSCR1_CHANGE_MASK) !=
1156 (cr1 & SSCR1_CHANGE_MASK)) {
1157
1158 /* stop the SSP, and update the other bits */
1159 write_SSCR0(cr0 & ~SSCR0_SSE, reg);
1160 if (!pxa25x_ssp_comp(drv_data))
1161 write_SSTO(chip->timeout, reg);
1162 /* first set CR1 without interrupt and service enables */
1163 write_SSCR1(cr1 & SSCR1_CHANGE_MASK, reg);
1164 /* restart the SSP */
1165 write_SSCR0(cr0, reg);
1166
1167 } else {
1168 if (!pxa25x_ssp_comp(drv_data))
1169 write_SSTO(chip->timeout, reg);
1170 }
1171
1172 cs_assert(drv_data);
1173
1174 /* after chip select, release the data by enabling service
1175 * requests and interrupts, without changing any mode bits */
1176 write_SSCR1(cr1, reg);
1177}
1178
1179static void pump_messages(struct work_struct *work)
1180{
1181 struct driver_data *drv_data =
1182 container_of(work, struct driver_data, pump_messages);
1183 unsigned long flags;
1184
1185 /* Lock queue and check for queue work */
1186 spin_lock_irqsave(&drv_data->lock, flags);
1187 if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
1188 drv_data->busy = 0;
1189 spin_unlock_irqrestore(&drv_data->lock, flags);
1190 return;
1191 }
1192
1193 /* Make sure we are not already running a message */
1194 if (drv_data->cur_msg) {
1195 spin_unlock_irqrestore(&drv_data->lock, flags);
1196 return;
1197 }
1198
1199 /* Extract head of queue */
1200 drv_data->cur_msg = list_entry(drv_data->queue.next,
1201 struct spi_message, queue);
1202 list_del_init(&drv_data->cur_msg->queue);
1203
1204 /* Initial message state*/
1205 drv_data->cur_msg->state = START_STATE;
1206 drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
1207 struct spi_transfer,
1208 transfer_list);
1209
1210 /* prepare to setup the SSP, in pump_transfers, using the per
1211 * chip configuration */
1212 drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
1213
1214 /* Mark as busy and launch transfers */
1215 tasklet_schedule(&drv_data->pump_transfers);
1216
1217 drv_data->busy = 1;
1218 spin_unlock_irqrestore(&drv_data->lock, flags);
1219}
1220
1221static int transfer(struct spi_device *spi, struct spi_message *msg)
1222{
1223 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1224 unsigned long flags;
1225
1226 spin_lock_irqsave(&drv_data->lock, flags);
1227
1228 if (drv_data->run == QUEUE_STOPPED) {
1229 spin_unlock_irqrestore(&drv_data->lock, flags);
1230 return -ESHUTDOWN;
1231 }
1232
1233 msg->actual_length = 0;
1234 msg->status = -EINPROGRESS;
1235 msg->state = START_STATE;
1236
1237 list_add_tail(&msg->queue, &drv_data->queue);
1238
1239 if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
1240 queue_work(drv_data->workqueue, &drv_data->pump_messages);
1241
1242 spin_unlock_irqrestore(&drv_data->lock, flags);
1243
1244 return 0;
1245}
1246
1247static int setup_cs(struct spi_device *spi, struct chip_data *chip,
1248 struct pxa2xx_spi_chip *chip_info)
1249{
1250 int err = 0;
1251
1252 if (chip == NULL || chip_info == NULL)
1253 return 0;
1254
1255 /* NOTE: setup() can be called multiple times, possibly with
1256 * different chip_info, release previously requested GPIO
1257 */
1258 if (gpio_is_valid(chip->gpio_cs))
1259 gpio_free(chip->gpio_cs);
1260
1261 /* If (*cs_control) is provided, ignore GPIO chip select */
1262 if (chip_info->cs_control) {
1263 chip->cs_control = chip_info->cs_control;
1264 return 0;
1265 }
1266
1267 if (gpio_is_valid(chip_info->gpio_cs)) {
1268 err = gpio_request(chip_info->gpio_cs, "SPI_CS");
1269 if (err) {
1270 dev_err(&spi->dev, "failed to request chip select "
1271 "GPIO%d\n", chip_info->gpio_cs);
1272 return err;
1273 }
1274
1275 chip->gpio_cs = chip_info->gpio_cs;
1276 chip->gpio_cs_inverted = spi->mode & SPI_CS_HIGH;
1277
1278 err = gpio_direction_output(chip->gpio_cs,
1279 !chip->gpio_cs_inverted);
1280 }
1281
1282 return err;
1283}
1284
1285static int setup(struct spi_device *spi)
1286{
1287 struct pxa2xx_spi_chip *chip_info = NULL;
1288 struct chip_data *chip;
1289 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1290 struct ssp_device *ssp = drv_data->ssp;
1291 unsigned int clk_div;
1292 uint tx_thres = TX_THRESH_DFLT;
1293 uint rx_thres = RX_THRESH_DFLT;
1294
1295 if (!pxa25x_ssp_comp(drv_data)
1296 && (spi->bits_per_word < 4 || spi->bits_per_word > 32)) {
1297 dev_err(&spi->dev, "failed setup: ssp_type=%d, bits/wrd=%d "
1298 "b/w not 4-32 for type non-PXA25x_SSP\n",
1299 drv_data->ssp_type, spi->bits_per_word);
1300 return -EINVAL;
1301 } else if (pxa25x_ssp_comp(drv_data)
1302 && (spi->bits_per_word < 4
1303 || spi->bits_per_word > 16)) {
1304 dev_err(&spi->dev, "failed setup: ssp_type=%d, bits/wrd=%d "
1305 "b/w not 4-16 for type PXA25x_SSP\n",
1306 drv_data->ssp_type, spi->bits_per_word);
1307 return -EINVAL;
1308 }
1309
1310 /* Only alloc on first setup */
1311 chip = spi_get_ctldata(spi);
1312 if (!chip) {
1313 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1314 if (!chip) {
1315 dev_err(&spi->dev,
1316 "failed setup: can't allocate chip data\n");
1317 return -ENOMEM;
1318 }
1319
1320 if (drv_data->ssp_type == CE4100_SSP) {
1321 if (spi->chip_select > 4) {
1322 dev_err(&spi->dev, "failed setup: "
1323 "cs number must not be > 4.\n");
1324 kfree(chip);
1325 return -EINVAL;
1326 }
1327
1328 chip->frm = spi->chip_select;
1329 } else
1330 chip->gpio_cs = -1;
1331 chip->enable_dma = 0;
1332 chip->timeout = TIMOUT_DFLT;
1333 chip->dma_burst_size = drv_data->master_info->enable_dma ?
1334 DCMD_BURST8 : 0;
1335 }
1336
1337 /* protocol drivers may change the chip settings, so...
1338 * if chip_info exists, use it */
1339 chip_info = spi->controller_data;
1340
1341 /* chip_info isn't always needed */
1342 chip->cr1 = 0;
1343 if (chip_info) {
1344 if (chip_info->timeout)
1345 chip->timeout = chip_info->timeout;
1346 if (chip_info->tx_threshold)
1347 tx_thres = chip_info->tx_threshold;
1348 if (chip_info->rx_threshold)
1349 rx_thres = chip_info->rx_threshold;
1350 chip->enable_dma = drv_data->master_info->enable_dma;
1351 chip->dma_threshold = 0;
1352 if (chip_info->enable_loopback)
1353 chip->cr1 = SSCR1_LBM;
1354 }
1355
1356 chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) |
1357 (SSCR1_TxTresh(tx_thres) & SSCR1_TFT);
1358
1359 /* set dma burst and threshold outside of chip_info path so that if
1360 * chip_info goes away after setting chip->enable_dma, the
1361 * burst and threshold can still respond to changes in bits_per_word */
1362 if (chip->enable_dma) {
1363 /* set up legal burst and threshold for dma */
1364 if (set_dma_burst_and_threshold(chip, spi, spi->bits_per_word,
1365 &chip->dma_burst_size,
1366 &chip->dma_threshold)) {
1367 dev_warn(&spi->dev, "in setup: DMA burst size reduced "
1368 "to match bits_per_word\n");
1369 }
1370 }
1371
1372 clk_div = ssp_get_clk_div(ssp, spi->max_speed_hz);
1373 chip->speed_hz = spi->max_speed_hz;
1374
1375 chip->cr0 = clk_div
1376 | SSCR0_Motorola
1377 | SSCR0_DataSize(spi->bits_per_word > 16 ?
1378 spi->bits_per_word - 16 : spi->bits_per_word)
1379 | SSCR0_SSE
1380 | (spi->bits_per_word > 16 ? SSCR0_EDSS : 0);
1381 chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH);
1382 chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
1383 | (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);
1384
1385 /* NOTE: PXA25x_SSP _could_ use external clocking ... */
1386 if (!pxa25x_ssp_comp(drv_data))
1387 dev_dbg(&spi->dev, "%ld Hz actual, %s\n",
1388 clk_get_rate(ssp->clk)
1389 / (1 + ((chip->cr0 & SSCR0_SCR(0xfff)) >> 8)),
1390 chip->enable_dma ? "DMA" : "PIO");
1391 else
1392 dev_dbg(&spi->dev, "%ld Hz actual, %s\n",
1393 clk_get_rate(ssp->clk) / 2
1394 / (1 + ((chip->cr0 & SSCR0_SCR(0x0ff)) >> 8)),
1395 chip->enable_dma ? "DMA" : "PIO");
1396
1397 if (spi->bits_per_word <= 8) {
1398 chip->n_bytes = 1;
1399 chip->dma_width = DCMD_WIDTH1;
1400 chip->read = u8_reader;
1401 chip->write = u8_writer;
1402 } else if (spi->bits_per_word <= 16) {
1403 chip->n_bytes = 2;
1404 chip->dma_width = DCMD_WIDTH2;
1405 chip->read = u16_reader;
1406 chip->write = u16_writer;
1407 } else if (spi->bits_per_word <= 32) {
1408 chip->cr0 |= SSCR0_EDSS;
1409 chip->n_bytes = 4;
1410 chip->dma_width = DCMD_WIDTH4;
1411 chip->read = u32_reader;
1412 chip->write = u32_writer;
1413 } else {
1414 dev_err(&spi->dev, "invalid wordsize\n");
1415 return -ENODEV;
1416 }
1417 chip->bits_per_word = spi->bits_per_word;
1418
1419 spi_set_ctldata(spi, chip);
1420
1421 if (drv_data->ssp_type == CE4100_SSP)
1422 return 0;
1423
1424 return setup_cs(spi, chip, chip_info);
1425}
1426
1427static void cleanup(struct spi_device *spi)
1428{
1429 struct chip_data *chip = spi_get_ctldata(spi);
1430 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1431
1432 if (!chip)
1433 return;
1434
1435 if (drv_data->ssp_type != CE4100_SSP && gpio_is_valid(chip->gpio_cs))
1436 gpio_free(chip->gpio_cs);
1437
1438 kfree(chip);
1439}
1440
1441static int __devinit init_queue(struct driver_data *drv_data)
1442{
1443 INIT_LIST_HEAD(&drv_data->queue);
1444 spin_lock_init(&drv_data->lock);
1445
1446 drv_data->run = QUEUE_STOPPED;
1447 drv_data->busy = 0;
1448
1449 tasklet_init(&drv_data->pump_transfers,
1450 pump_transfers, (unsigned long)drv_data);
1451
1452 INIT_WORK(&drv_data->pump_messages, pump_messages);
1453 drv_data->workqueue = create_singlethread_workqueue(
1454 dev_name(drv_data->master->dev.parent));
1455 if (drv_data->workqueue == NULL)
1456 return -EBUSY;
1457
1458 return 0;
1459}
1460
1461static int start_queue(struct driver_data *drv_data)
1462{
1463 unsigned long flags;
1464
1465 spin_lock_irqsave(&drv_data->lock, flags);
1466
1467 if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
1468 spin_unlock_irqrestore(&drv_data->lock, flags);
1469 return -EBUSY;
1470 }
1471
1472 drv_data->run = QUEUE_RUNNING;
1473 drv_data->cur_msg = NULL;
1474 drv_data->cur_transfer = NULL;
1475 drv_data->cur_chip = NULL;
1476 spin_unlock_irqrestore(&drv_data->lock, flags);
1477
1478 queue_work(drv_data->workqueue, &drv_data->pump_messages);
1479
1480 return 0;
1481}
1482
1483static int stop_queue(struct driver_data *drv_data)
1484{
1485 unsigned long flags;
1486 unsigned limit = 500;
1487 int status = 0;
1488
1489 spin_lock_irqsave(&drv_data->lock, flags);
1490
1491 /* This is a bit lame, but is optimized for the common execution path.
1492 * A wait_queue on the drv_data->busy could be used, but then the common
1493 * execution path (pump_messages) would be required to call wake_up or
1494 * friends on every SPI message. Do this instead */
1495 drv_data->run = QUEUE_STOPPED;
1496 while ((!list_empty(&drv_data->queue) || drv_data->busy) && limit--) {
1497 spin_unlock_irqrestore(&drv_data->lock, flags);
1498 msleep(10);
1499 spin_lock_irqsave(&drv_data->lock, flags);
1500 }
1501
1502 if (!list_empty(&drv_data->queue) || drv_data->busy)
1503 status = -EBUSY;
1504
1505 spin_unlock_irqrestore(&drv_data->lock, flags);
1506
1507 return status;
1508}
1509
1510static int destroy_queue(struct driver_data *drv_data)
1511{
1512 int status;
1513
1514 status = stop_queue(drv_data);
1515 /* we are unloading the module or failing to load (only two calls
1516 * to this routine), and neither call can handle a return value.
1517 * However, destroy_workqueue calls flush_workqueue, and that will
1518 * block until all work is done. If the reason that stop_queue
1519 * timed out is that the work will never finish, then it does no
1520 * good to call destroy_workqueue, so return anyway. */
1521 if (status != 0)
1522 return status;
1523
1524 destroy_workqueue(drv_data->workqueue);
1525
1526 return 0;
1527}
1528
1529static int __devinit pxa2xx_spi_probe(struct platform_device *pdev)
1530{
1531 struct device *dev = &pdev->dev;
1532 struct pxa2xx_spi_master *platform_info;
1533 struct spi_master *master;
1534 struct driver_data *drv_data;
1535 struct ssp_device *ssp;
1536 int status;
1537
1538 platform_info = dev->platform_data;
1539
1540 ssp = pxa_ssp_request(pdev->id, pdev->name);
1541 if (ssp == NULL) {
1542 dev_err(&pdev->dev, "failed to request SSP%d\n", pdev->id);
1543 return -ENODEV;
1544 }
1545
1546 /* Allocate master with space for drv_data and null dma buffer */
1547 master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
1548 if (!master) {
1549 dev_err(&pdev->dev, "cannot alloc spi_master\n");
1550 pxa_ssp_free(ssp);
1551 return -ENOMEM;
1552 }
1553 drv_data = spi_master_get_devdata(master);
1554 drv_data->master = master;
1555 drv_data->master_info = platform_info;
1556 drv_data->pdev = pdev;
1557 drv_data->ssp = ssp;
1558
1559 master->dev.parent = &pdev->dev;
1560 master->dev.of_node = pdev->dev.of_node;
1561 /* the spi->mode bits understood by this driver: */
1562 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1563
1564 master->bus_num = pdev->id;
1565 master->num_chipselect = platform_info->num_chipselect;
1566 master->dma_alignment = DMA_ALIGNMENT;
1567 master->cleanup = cleanup;
1568 master->setup = setup;
1569 master->transfer = transfer;
1570
1571 drv_data->ssp_type = ssp->type;
1572 drv_data->null_dma_buf = (u32 *)ALIGN((u32)(drv_data +
1573 sizeof(struct driver_data)), 8);
1574
1575 drv_data->ioaddr = ssp->mmio_base;
1576 drv_data->ssdr_physical = ssp->phys_base + SSDR;
1577 if (pxa25x_ssp_comp(drv_data)) {
1578 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE;
1579 drv_data->dma_cr1 = 0;
1580 drv_data->clear_sr = SSSR_ROR;
1581 drv_data->mask_sr = SSSR_RFS | SSSR_TFS | SSSR_ROR;
1582 } else {
1583 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE;
1584 drv_data->dma_cr1 = SSCR1_TSRE | SSCR1_RSRE | SSCR1_TINTE;
1585 drv_data->clear_sr = SSSR_ROR | SSSR_TINT;
1586 drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR;
1587 }
1588
1589 status = request_irq(ssp->irq, ssp_int, IRQF_SHARED, dev_name(dev),
1590 drv_data);
1591 if (status < 0) {
1592 dev_err(&pdev->dev, "cannot get IRQ %d\n", ssp->irq);
1593 goto out_error_master_alloc;
1594 }
1595
1596 /* Setup DMA if requested */
1597 drv_data->tx_channel = -1;
1598 drv_data->rx_channel = -1;
1599 if (platform_info->enable_dma) {
1600
1601 /* Get two DMA channels (rx and tx) */
1602 drv_data->rx_channel = pxa_request_dma("pxa2xx_spi_ssp_rx",
1603 DMA_PRIO_HIGH,
1604 dma_handler,
1605 drv_data);
1606 if (drv_data->rx_channel < 0) {
1607 dev_err(dev, "problem (%d) requesting rx channel\n",
1608 drv_data->rx_channel);
1609 status = -ENODEV;
1610 goto out_error_irq_alloc;
1611 }
1612 drv_data->tx_channel = pxa_request_dma("pxa2xx_spi_ssp_tx",
1613 DMA_PRIO_MEDIUM,
1614 dma_handler,
1615 drv_data);
1616 if (drv_data->tx_channel < 0) {
1617 dev_err(dev, "problem (%d) requesting tx channel\n",
1618 drv_data->tx_channel);
1619 status = -ENODEV;
1620 goto out_error_dma_alloc;
1621 }
1622
1623 DRCMR(ssp->drcmr_rx) = DRCMR_MAPVLD | drv_data->rx_channel;
1624 DRCMR(ssp->drcmr_tx) = DRCMR_MAPVLD | drv_data->tx_channel;
1625 }
1626
1627 /* Enable SOC clock */
1628 clk_enable(ssp->clk);
1629
1630 /* Load default SSP configuration */
1631 write_SSCR0(0, drv_data->ioaddr);
1632 write_SSCR1(SSCR1_RxTresh(RX_THRESH_DFLT) |
1633 SSCR1_TxTresh(TX_THRESH_DFLT),
1634 drv_data->ioaddr);
1635 write_SSCR0(SSCR0_SCR(2)
1636 | SSCR0_Motorola
1637 | SSCR0_DataSize(8),
1638 drv_data->ioaddr);
1639 if (!pxa25x_ssp_comp(drv_data))
1640 write_SSTO(0, drv_data->ioaddr);
1641 write_SSPSP(0, drv_data->ioaddr);
1642
1643 /* Initial and start queue */
1644 status = init_queue(drv_data);
1645 if (status != 0) {
1646 dev_err(&pdev->dev, "problem initializing queue\n");
1647 goto out_error_clock_enabled;
1648 }
1649 status = start_queue(drv_data);
1650 if (status != 0) {
1651 dev_err(&pdev->dev, "problem starting queue\n");
1652 goto out_error_clock_enabled;
1653 }
1654
1655 /* Register with the SPI framework */
1656 platform_set_drvdata(pdev, drv_data);
1657 status = spi_register_master(master);
1658 if (status != 0) {
1659 dev_err(&pdev->dev, "problem registering spi master\n");
1660 goto out_error_queue_alloc;
1661 }
1662
1663 return status;
1664
1665out_error_queue_alloc:
1666 destroy_queue(drv_data);
1667
1668out_error_clock_enabled:
1669 clk_disable(ssp->clk);
1670
1671out_error_dma_alloc:
1672 if (drv_data->tx_channel != -1)
1673 pxa_free_dma(drv_data->tx_channel);
1674 if (drv_data->rx_channel != -1)
1675 pxa_free_dma(drv_data->rx_channel);
1676
1677out_error_irq_alloc:
1678 free_irq(ssp->irq, drv_data);
1679
1680out_error_master_alloc:
1681 spi_master_put(master);
1682 pxa_ssp_free(ssp);
1683 return status;
1684}
1685
1686static int pxa2xx_spi_remove(struct platform_device *pdev)
1687{
1688 struct driver_data *drv_data = platform_get_drvdata(pdev);
1689 struct ssp_device *ssp;
1690 int status = 0;
1691
1692 if (!drv_data)
1693 return 0;
1694 ssp = drv_data->ssp;
1695
1696 /* Remove the queue */
1697 status = destroy_queue(drv_data);
1698 if (status != 0)
1699 /* the kernel does not check the return status of this
1700 * this routine (mod->exit, within the kernel). Therefore
1701 * nothing is gained by returning from here, the module is
1702 * going away regardless, and we should not leave any more
1703 * resources allocated than necessary. We cannot free the
1704 * message memory in drv_data->queue, but we can release the
1705 * resources below. I think the kernel should honor -EBUSY
1706 * returns but... */
1707 dev_err(&pdev->dev, "pxa2xx_spi_remove: workqueue will not "
1708 "complete, message memory not freed\n");
1709
1710 /* Disable the SSP at the peripheral and SOC level */
1711 write_SSCR0(0, drv_data->ioaddr);
1712 clk_disable(ssp->clk);
1713
1714 /* Release DMA */
1715 if (drv_data->master_info->enable_dma) {
1716 DRCMR(ssp->drcmr_rx) = 0;
1717 DRCMR(ssp->drcmr_tx) = 0;
1718 pxa_free_dma(drv_data->tx_channel);
1719 pxa_free_dma(drv_data->rx_channel);
1720 }
1721
1722 /* Release IRQ */
1723 free_irq(ssp->irq, drv_data);
1724
1725 /* Release SSP */
1726 pxa_ssp_free(ssp);
1727
1728 /* Disconnect from the SPI framework */
1729 spi_unregister_master(drv_data->master);
1730
1731 /* Prevent double remove */
1732 platform_set_drvdata(pdev, NULL);
1733
1734 return 0;
1735}
1736
1737static void pxa2xx_spi_shutdown(struct platform_device *pdev)
1738{
1739 int status = 0;
1740
1741 if ((status = pxa2xx_spi_remove(pdev)) != 0)
1742 dev_err(&pdev->dev, "shutdown failed with %d\n", status);
1743}
1744
1745#ifdef CONFIG_PM
1746static int pxa2xx_spi_suspend(struct device *dev)
1747{
1748 struct driver_data *drv_data = dev_get_drvdata(dev);
1749 struct ssp_device *ssp = drv_data->ssp;
1750 int status = 0;
1751
1752 status = stop_queue(drv_data);
1753 if (status != 0)
1754 return status;
1755 write_SSCR0(0, drv_data->ioaddr);
1756 clk_disable(ssp->clk);
1757
1758 return 0;
1759}
1760
1761static int pxa2xx_spi_resume(struct device *dev)
1762{
1763 struct driver_data *drv_data = dev_get_drvdata(dev);
1764 struct ssp_device *ssp = drv_data->ssp;
1765 int status = 0;
1766
1767 if (drv_data->rx_channel != -1)
1768 DRCMR(drv_data->ssp->drcmr_rx) =
1769 DRCMR_MAPVLD | drv_data->rx_channel;
1770 if (drv_data->tx_channel != -1)
1771 DRCMR(drv_data->ssp->drcmr_tx) =
1772 DRCMR_MAPVLD | drv_data->tx_channel;
1773
1774 /* Enable the SSP clock */
1775 clk_enable(ssp->clk);
1776
1777 /* Start the queue running */
1778 status = start_queue(drv_data);
1779 if (status != 0) {
1780 dev_err(dev, "problem starting queue (%d)\n", status);
1781 return status;
1782 }
1783
1784 return 0;
1785}
1786
1787static const struct dev_pm_ops pxa2xx_spi_pm_ops = {
1788 .suspend = pxa2xx_spi_suspend,
1789 .resume = pxa2xx_spi_resume,
1790};
1791#endif
1792
1793static struct platform_driver driver = {
1794 .driver = {
1795 .name = "pxa2xx-spi",
1796 .owner = THIS_MODULE,
1797#ifdef CONFIG_PM
1798 .pm = &pxa2xx_spi_pm_ops,
1799#endif
1800 },
1801 .probe = pxa2xx_spi_probe,
1802 .remove = pxa2xx_spi_remove,
1803 .shutdown = pxa2xx_spi_shutdown,
1804};
1805
1806static int __init pxa2xx_spi_init(void)
1807{
1808 return platform_driver_register(&driver);
1809}
1810subsys_initcall(pxa2xx_spi_init);
1811
1812static void __exit pxa2xx_spi_exit(void)
1813{
1814 platform_driver_unregister(&driver);
1815}
1816module_exit(pxa2xx_spi_exit);
1/*
2 * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
3 * Copyright (C) 2013, Intel Corporation
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16#include <linux/bitops.h>
17#include <linux/init.h>
18#include <linux/module.h>
19#include <linux/device.h>
20#include <linux/ioport.h>
21#include <linux/errno.h>
22#include <linux/err.h>
23#include <linux/interrupt.h>
24#include <linux/kernel.h>
25#include <linux/pci.h>
26#include <linux/platform_device.h>
27#include <linux/spi/pxa2xx_spi.h>
28#include <linux/spi/spi.h>
29#include <linux/delay.h>
30#include <linux/gpio.h>
31#include <linux/slab.h>
32#include <linux/clk.h>
33#include <linux/pm_runtime.h>
34#include <linux/acpi.h>
35
36#include "spi-pxa2xx.h"
37
38MODULE_AUTHOR("Stephen Street");
39MODULE_DESCRIPTION("PXA2xx SSP SPI Controller");
40MODULE_LICENSE("GPL");
41MODULE_ALIAS("platform:pxa2xx-spi");
42
43#define TIMOUT_DFLT 1000
44
45/*
46 * for testing SSCR1 changes that require SSP restart, basically
47 * everything except the service and interrupt enables, the pxa270 developer
48 * manual says only SSCR1_SCFR, SSCR1_SPH, SSCR1_SPO need to be in this
49 * list, but the PXA255 dev man says all bits without really meaning the
50 * service and interrupt enables
51 */
52#define SSCR1_CHANGE_MASK (SSCR1_TTELP | SSCR1_TTE | SSCR1_SCFR \
53 | SSCR1_ECRA | SSCR1_ECRB | SSCR1_SCLKDIR \
54 | SSCR1_SFRMDIR | SSCR1_RWOT | SSCR1_TRAIL \
55 | SSCR1_IFS | SSCR1_STRF | SSCR1_EFWR \
56 | SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \
57 | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
58
59#define QUARK_X1000_SSCR1_CHANGE_MASK (QUARK_X1000_SSCR1_STRF \
60 | QUARK_X1000_SSCR1_EFWR \
61 | QUARK_X1000_SSCR1_RFT \
62 | QUARK_X1000_SSCR1_TFT \
63 | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
64
65#define LPSS_GENERAL_REG_RXTO_HOLDOFF_DISABLE BIT(24)
66#define LPSS_CS_CONTROL_SW_MODE BIT(0)
67#define LPSS_CS_CONTROL_CS_HIGH BIT(1)
68#define LPSS_CAPS_CS_EN_SHIFT 9
69#define LPSS_CAPS_CS_EN_MASK (0xf << LPSS_CAPS_CS_EN_SHIFT)
70
71struct lpss_config {
72 /* LPSS offset from drv_data->ioaddr */
73 unsigned offset;
74 /* Register offsets from drv_data->lpss_base or -1 */
75 int reg_general;
76 int reg_ssp;
77 int reg_cs_ctrl;
78 int reg_capabilities;
79 /* FIFO thresholds */
80 u32 rx_threshold;
81 u32 tx_threshold_lo;
82 u32 tx_threshold_hi;
83 /* Chip select control */
84 unsigned cs_sel_shift;
85 unsigned cs_sel_mask;
86 unsigned cs_num;
87};
88
89/* Keep these sorted with enum pxa_ssp_type */
90static const struct lpss_config lpss_platforms[] = {
91 { /* LPSS_LPT_SSP */
92 .offset = 0x800,
93 .reg_general = 0x08,
94 .reg_ssp = 0x0c,
95 .reg_cs_ctrl = 0x18,
96 .reg_capabilities = -1,
97 .rx_threshold = 64,
98 .tx_threshold_lo = 160,
99 .tx_threshold_hi = 224,
100 },
101 { /* LPSS_BYT_SSP */
102 .offset = 0x400,
103 .reg_general = 0x08,
104 .reg_ssp = 0x0c,
105 .reg_cs_ctrl = 0x18,
106 .reg_capabilities = -1,
107 .rx_threshold = 64,
108 .tx_threshold_lo = 160,
109 .tx_threshold_hi = 224,
110 },
111 { /* LPSS_BSW_SSP */
112 .offset = 0x400,
113 .reg_general = 0x08,
114 .reg_ssp = 0x0c,
115 .reg_cs_ctrl = 0x18,
116 .reg_capabilities = -1,
117 .rx_threshold = 64,
118 .tx_threshold_lo = 160,
119 .tx_threshold_hi = 224,
120 .cs_sel_shift = 2,
121 .cs_sel_mask = 1 << 2,
122 .cs_num = 2,
123 },
124 { /* LPSS_SPT_SSP */
125 .offset = 0x200,
126 .reg_general = -1,
127 .reg_ssp = 0x20,
128 .reg_cs_ctrl = 0x24,
129 .reg_capabilities = -1,
130 .rx_threshold = 1,
131 .tx_threshold_lo = 32,
132 .tx_threshold_hi = 56,
133 },
134 { /* LPSS_BXT_SSP */
135 .offset = 0x200,
136 .reg_general = -1,
137 .reg_ssp = 0x20,
138 .reg_cs_ctrl = 0x24,
139 .reg_capabilities = 0xfc,
140 .rx_threshold = 1,
141 .tx_threshold_lo = 16,
142 .tx_threshold_hi = 48,
143 .cs_sel_shift = 8,
144 .cs_sel_mask = 3 << 8,
145 },
146};
147
148static inline const struct lpss_config
149*lpss_get_config(const struct driver_data *drv_data)
150{
151 return &lpss_platforms[drv_data->ssp_type - LPSS_LPT_SSP];
152}
153
154static bool is_lpss_ssp(const struct driver_data *drv_data)
155{
156 switch (drv_data->ssp_type) {
157 case LPSS_LPT_SSP:
158 case LPSS_BYT_SSP:
159 case LPSS_BSW_SSP:
160 case LPSS_SPT_SSP:
161 case LPSS_BXT_SSP:
162 return true;
163 default:
164 return false;
165 }
166}
167
168static bool is_quark_x1000_ssp(const struct driver_data *drv_data)
169{
170 return drv_data->ssp_type == QUARK_X1000_SSP;
171}
172
173static u32 pxa2xx_spi_get_ssrc1_change_mask(const struct driver_data *drv_data)
174{
175 switch (drv_data->ssp_type) {
176 case QUARK_X1000_SSP:
177 return QUARK_X1000_SSCR1_CHANGE_MASK;
178 default:
179 return SSCR1_CHANGE_MASK;
180 }
181}
182
183static u32
184pxa2xx_spi_get_rx_default_thre(const struct driver_data *drv_data)
185{
186 switch (drv_data->ssp_type) {
187 case QUARK_X1000_SSP:
188 return RX_THRESH_QUARK_X1000_DFLT;
189 default:
190 return RX_THRESH_DFLT;
191 }
192}
193
194static bool pxa2xx_spi_txfifo_full(const struct driver_data *drv_data)
195{
196 u32 mask;
197
198 switch (drv_data->ssp_type) {
199 case QUARK_X1000_SSP:
200 mask = QUARK_X1000_SSSR_TFL_MASK;
201 break;
202 default:
203 mask = SSSR_TFL_MASK;
204 break;
205 }
206
207 return (pxa2xx_spi_read(drv_data, SSSR) & mask) == mask;
208}
209
210static void pxa2xx_spi_clear_rx_thre(const struct driver_data *drv_data,
211 u32 *sccr1_reg)
212{
213 u32 mask;
214
215 switch (drv_data->ssp_type) {
216 case QUARK_X1000_SSP:
217 mask = QUARK_X1000_SSCR1_RFT;
218 break;
219 default:
220 mask = SSCR1_RFT;
221 break;
222 }
223 *sccr1_reg &= ~mask;
224}
225
226static void pxa2xx_spi_set_rx_thre(const struct driver_data *drv_data,
227 u32 *sccr1_reg, u32 threshold)
228{
229 switch (drv_data->ssp_type) {
230 case QUARK_X1000_SSP:
231 *sccr1_reg |= QUARK_X1000_SSCR1_RxTresh(threshold);
232 break;
233 default:
234 *sccr1_reg |= SSCR1_RxTresh(threshold);
235 break;
236 }
237}
238
239static u32 pxa2xx_configure_sscr0(const struct driver_data *drv_data,
240 u32 clk_div, u8 bits)
241{
242 switch (drv_data->ssp_type) {
243 case QUARK_X1000_SSP:
244 return clk_div
245 | QUARK_X1000_SSCR0_Motorola
246 | QUARK_X1000_SSCR0_DataSize(bits > 32 ? 8 : bits)
247 | SSCR0_SSE;
248 default:
249 return clk_div
250 | SSCR0_Motorola
251 | SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
252 | SSCR0_SSE
253 | (bits > 16 ? SSCR0_EDSS : 0);
254 }
255}
256
257/*
258 * Read and write LPSS SSP private registers. Caller must first check that
259 * is_lpss_ssp() returns true before these can be called.
260 */
261static u32 __lpss_ssp_read_priv(struct driver_data *drv_data, unsigned offset)
262{
263 WARN_ON(!drv_data->lpss_base);
264 return readl(drv_data->lpss_base + offset);
265}
266
267static void __lpss_ssp_write_priv(struct driver_data *drv_data,
268 unsigned offset, u32 value)
269{
270 WARN_ON(!drv_data->lpss_base);
271 writel(value, drv_data->lpss_base + offset);
272}
273
274/*
275 * lpss_ssp_setup - perform LPSS SSP specific setup
276 * @drv_data: pointer to the driver private data
277 *
278 * Perform LPSS SSP specific setup. This function must be called first if
279 * one is going to use LPSS SSP private registers.
280 */
281static void lpss_ssp_setup(struct driver_data *drv_data)
282{
283 const struct lpss_config *config;
284 u32 value;
285
286 config = lpss_get_config(drv_data);
287 drv_data->lpss_base = drv_data->ioaddr + config->offset;
288
289 /* Enable software chip select control */
290 value = __lpss_ssp_read_priv(drv_data, config->reg_cs_ctrl);
291 value &= ~(LPSS_CS_CONTROL_SW_MODE | LPSS_CS_CONTROL_CS_HIGH);
292 value |= LPSS_CS_CONTROL_SW_MODE | LPSS_CS_CONTROL_CS_HIGH;
293 __lpss_ssp_write_priv(drv_data, config->reg_cs_ctrl, value);
294
295 /* Enable multiblock DMA transfers */
296 if (drv_data->master_info->enable_dma) {
297 __lpss_ssp_write_priv(drv_data, config->reg_ssp, 1);
298
299 if (config->reg_general >= 0) {
300 value = __lpss_ssp_read_priv(drv_data,
301 config->reg_general);
302 value |= LPSS_GENERAL_REG_RXTO_HOLDOFF_DISABLE;
303 __lpss_ssp_write_priv(drv_data,
304 config->reg_general, value);
305 }
306 }
307}
308
309static void lpss_ssp_select_cs(struct driver_data *drv_data,
310 const struct lpss_config *config)
311{
312 u32 value, cs;
313
314 if (!config->cs_sel_mask)
315 return;
316
317 value = __lpss_ssp_read_priv(drv_data, config->reg_cs_ctrl);
318
319 cs = drv_data->cur_msg->spi->chip_select;
320 cs <<= config->cs_sel_shift;
321 if (cs != (value & config->cs_sel_mask)) {
322 /*
323 * When switching another chip select output active the
324 * output must be selected first and wait 2 ssp_clk cycles
325 * before changing state to active. Otherwise a short
326 * glitch will occur on the previous chip select since
327 * output select is latched but state control is not.
328 */
329 value &= ~config->cs_sel_mask;
330 value |= cs;
331 __lpss_ssp_write_priv(drv_data,
332 config->reg_cs_ctrl, value);
333 ndelay(1000000000 /
334 (drv_data->master->max_speed_hz / 2));
335 }
336}
337
338static void lpss_ssp_cs_control(struct driver_data *drv_data, bool enable)
339{
340 const struct lpss_config *config;
341 u32 value;
342
343 config = lpss_get_config(drv_data);
344
345 if (enable)
346 lpss_ssp_select_cs(drv_data, config);
347
348 value = __lpss_ssp_read_priv(drv_data, config->reg_cs_ctrl);
349 if (enable)
350 value &= ~LPSS_CS_CONTROL_CS_HIGH;
351 else
352 value |= LPSS_CS_CONTROL_CS_HIGH;
353 __lpss_ssp_write_priv(drv_data, config->reg_cs_ctrl, value);
354}
355
356static void cs_assert(struct driver_data *drv_data)
357{
358 struct chip_data *chip = drv_data->cur_chip;
359
360 if (drv_data->ssp_type == CE4100_SSP) {
361 pxa2xx_spi_write(drv_data, SSSR, drv_data->cur_chip->frm);
362 return;
363 }
364
365 if (chip->cs_control) {
366 chip->cs_control(PXA2XX_CS_ASSERT);
367 return;
368 }
369
370 if (gpio_is_valid(chip->gpio_cs)) {
371 gpio_set_value(chip->gpio_cs, chip->gpio_cs_inverted);
372 return;
373 }
374
375 if (is_lpss_ssp(drv_data))
376 lpss_ssp_cs_control(drv_data, true);
377}
378
379static void cs_deassert(struct driver_data *drv_data)
380{
381 struct chip_data *chip = drv_data->cur_chip;
382
383 if (drv_data->ssp_type == CE4100_SSP)
384 return;
385
386 if (chip->cs_control) {
387 chip->cs_control(PXA2XX_CS_DEASSERT);
388 return;
389 }
390
391 if (gpio_is_valid(chip->gpio_cs)) {
392 gpio_set_value(chip->gpio_cs, !chip->gpio_cs_inverted);
393 return;
394 }
395
396 if (is_lpss_ssp(drv_data))
397 lpss_ssp_cs_control(drv_data, false);
398}
399
400int pxa2xx_spi_flush(struct driver_data *drv_data)
401{
402 unsigned long limit = loops_per_jiffy << 1;
403
404 do {
405 while (pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
406 pxa2xx_spi_read(drv_data, SSDR);
407 } while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_BSY) && --limit);
408 write_SSSR_CS(drv_data, SSSR_ROR);
409
410 return limit;
411}
412
413static int null_writer(struct driver_data *drv_data)
414{
415 u8 n_bytes = drv_data->n_bytes;
416
417 if (pxa2xx_spi_txfifo_full(drv_data)
418 || (drv_data->tx == drv_data->tx_end))
419 return 0;
420
421 pxa2xx_spi_write(drv_data, SSDR, 0);
422 drv_data->tx += n_bytes;
423
424 return 1;
425}
426
427static int null_reader(struct driver_data *drv_data)
428{
429 u8 n_bytes = drv_data->n_bytes;
430
431 while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
432 && (drv_data->rx < drv_data->rx_end)) {
433 pxa2xx_spi_read(drv_data, SSDR);
434 drv_data->rx += n_bytes;
435 }
436
437 return drv_data->rx == drv_data->rx_end;
438}
439
440static int u8_writer(struct driver_data *drv_data)
441{
442 if (pxa2xx_spi_txfifo_full(drv_data)
443 || (drv_data->tx == drv_data->tx_end))
444 return 0;
445
446 pxa2xx_spi_write(drv_data, SSDR, *(u8 *)(drv_data->tx));
447 ++drv_data->tx;
448
449 return 1;
450}
451
452static int u8_reader(struct driver_data *drv_data)
453{
454 while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
455 && (drv_data->rx < drv_data->rx_end)) {
456 *(u8 *)(drv_data->rx) = pxa2xx_spi_read(drv_data, SSDR);
457 ++drv_data->rx;
458 }
459
460 return drv_data->rx == drv_data->rx_end;
461}
462
463static int u16_writer(struct driver_data *drv_data)
464{
465 if (pxa2xx_spi_txfifo_full(drv_data)
466 || (drv_data->tx == drv_data->tx_end))
467 return 0;
468
469 pxa2xx_spi_write(drv_data, SSDR, *(u16 *)(drv_data->tx));
470 drv_data->tx += 2;
471
472 return 1;
473}
474
475static int u16_reader(struct driver_data *drv_data)
476{
477 while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
478 && (drv_data->rx < drv_data->rx_end)) {
479 *(u16 *)(drv_data->rx) = pxa2xx_spi_read(drv_data, SSDR);
480 drv_data->rx += 2;
481 }
482
483 return drv_data->rx == drv_data->rx_end;
484}
485
486static int u32_writer(struct driver_data *drv_data)
487{
488 if (pxa2xx_spi_txfifo_full(drv_data)
489 || (drv_data->tx == drv_data->tx_end))
490 return 0;
491
492 pxa2xx_spi_write(drv_data, SSDR, *(u32 *)(drv_data->tx));
493 drv_data->tx += 4;
494
495 return 1;
496}
497
498static int u32_reader(struct driver_data *drv_data)
499{
500 while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
501 && (drv_data->rx < drv_data->rx_end)) {
502 *(u32 *)(drv_data->rx) = pxa2xx_spi_read(drv_data, SSDR);
503 drv_data->rx += 4;
504 }
505
506 return drv_data->rx == drv_data->rx_end;
507}
508
509void *pxa2xx_spi_next_transfer(struct driver_data *drv_data)
510{
511 struct spi_message *msg = drv_data->cur_msg;
512 struct spi_transfer *trans = drv_data->cur_transfer;
513
514 /* Move to next transfer */
515 if (trans->transfer_list.next != &msg->transfers) {
516 drv_data->cur_transfer =
517 list_entry(trans->transfer_list.next,
518 struct spi_transfer,
519 transfer_list);
520 return RUNNING_STATE;
521 } else
522 return DONE_STATE;
523}
524
525/* caller already set message->status; dma and pio irqs are blocked */
526static void giveback(struct driver_data *drv_data)
527{
528 struct spi_transfer* last_transfer;
529 struct spi_message *msg;
530 unsigned long timeout;
531
532 msg = drv_data->cur_msg;
533 drv_data->cur_msg = NULL;
534 drv_data->cur_transfer = NULL;
535
536 last_transfer = list_last_entry(&msg->transfers, struct spi_transfer,
537 transfer_list);
538
539 /* Delay if requested before any change in chip select */
540 if (last_transfer->delay_usecs)
541 udelay(last_transfer->delay_usecs);
542
543 /* Wait until SSP becomes idle before deasserting the CS */
544 timeout = jiffies + msecs_to_jiffies(10);
545 while (pxa2xx_spi_read(drv_data, SSSR) & SSSR_BSY &&
546 !time_after(jiffies, timeout))
547 cpu_relax();
548
549 /* Drop chip select UNLESS cs_change is true or we are returning
550 * a message with an error, or next message is for another chip
551 */
552 if (!last_transfer->cs_change)
553 cs_deassert(drv_data);
554 else {
555 struct spi_message *next_msg;
556
557 /* Holding of cs was hinted, but we need to make sure
558 * the next message is for the same chip. Don't waste
559 * time with the following tests unless this was hinted.
560 *
561 * We cannot postpone this until pump_messages, because
562 * after calling msg->complete (below) the driver that
563 * sent the current message could be unloaded, which
564 * could invalidate the cs_control() callback...
565 */
566
567 /* get a pointer to the next message, if any */
568 next_msg = spi_get_next_queued_message(drv_data->master);
569
570 /* see if the next and current messages point
571 * to the same chip
572 */
573 if (next_msg && next_msg->spi != msg->spi)
574 next_msg = NULL;
575 if (!next_msg || msg->state == ERROR_STATE)
576 cs_deassert(drv_data);
577 }
578
579 drv_data->cur_chip = NULL;
580 spi_finalize_current_message(drv_data->master);
581}
582
583static void reset_sccr1(struct driver_data *drv_data)
584{
585 struct chip_data *chip = drv_data->cur_chip;
586 u32 sccr1_reg;
587
588 sccr1_reg = pxa2xx_spi_read(drv_data, SSCR1) & ~drv_data->int_cr1;
589 sccr1_reg &= ~SSCR1_RFT;
590 sccr1_reg |= chip->threshold;
591 pxa2xx_spi_write(drv_data, SSCR1, sccr1_reg);
592}
593
594static void int_error_stop(struct driver_data *drv_data, const char* msg)
595{
596 /* Stop and reset SSP */
597 write_SSSR_CS(drv_data, drv_data->clear_sr);
598 reset_sccr1(drv_data);
599 if (!pxa25x_ssp_comp(drv_data))
600 pxa2xx_spi_write(drv_data, SSTO, 0);
601 pxa2xx_spi_flush(drv_data);
602 pxa2xx_spi_write(drv_data, SSCR0,
603 pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE);
604
605 dev_err(&drv_data->pdev->dev, "%s\n", msg);
606
607 drv_data->cur_msg->state = ERROR_STATE;
608 tasklet_schedule(&drv_data->pump_transfers);
609}
610
611static void int_transfer_complete(struct driver_data *drv_data)
612{
613 /* Clear and disable interrupts */
614 write_SSSR_CS(drv_data, drv_data->clear_sr);
615 reset_sccr1(drv_data);
616 if (!pxa25x_ssp_comp(drv_data))
617 pxa2xx_spi_write(drv_data, SSTO, 0);
618
619 /* Update total byte transferred return count actual bytes read */
620 drv_data->cur_msg->actual_length += drv_data->len -
621 (drv_data->rx_end - drv_data->rx);
622
623 /* Transfer delays and chip select release are
624 * handled in pump_transfers or giveback
625 */
626
627 /* Move to next transfer */
628 drv_data->cur_msg->state = pxa2xx_spi_next_transfer(drv_data);
629
630 /* Schedule transfer tasklet */
631 tasklet_schedule(&drv_data->pump_transfers);
632}
633
634static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
635{
636 u32 irq_mask = (pxa2xx_spi_read(drv_data, SSCR1) & SSCR1_TIE) ?
637 drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS;
638
639 u32 irq_status = pxa2xx_spi_read(drv_data, SSSR) & irq_mask;
640
641 if (irq_status & SSSR_ROR) {
642 int_error_stop(drv_data, "interrupt_transfer: fifo overrun");
643 return IRQ_HANDLED;
644 }
645
646 if (irq_status & SSSR_TINT) {
647 pxa2xx_spi_write(drv_data, SSSR, SSSR_TINT);
648 if (drv_data->read(drv_data)) {
649 int_transfer_complete(drv_data);
650 return IRQ_HANDLED;
651 }
652 }
653
654 /* Drain rx fifo, Fill tx fifo and prevent overruns */
655 do {
656 if (drv_data->read(drv_data)) {
657 int_transfer_complete(drv_data);
658 return IRQ_HANDLED;
659 }
660 } while (drv_data->write(drv_data));
661
662 if (drv_data->read(drv_data)) {
663 int_transfer_complete(drv_data);
664 return IRQ_HANDLED;
665 }
666
667 if (drv_data->tx == drv_data->tx_end) {
668 u32 bytes_left;
669 u32 sccr1_reg;
670
671 sccr1_reg = pxa2xx_spi_read(drv_data, SSCR1);
672 sccr1_reg &= ~SSCR1_TIE;
673
674 /*
675 * PXA25x_SSP has no timeout, set up rx threshould for the
676 * remaining RX bytes.
677 */
678 if (pxa25x_ssp_comp(drv_data)) {
679 u32 rx_thre;
680
681 pxa2xx_spi_clear_rx_thre(drv_data, &sccr1_reg);
682
683 bytes_left = drv_data->rx_end - drv_data->rx;
684 switch (drv_data->n_bytes) {
685 case 4:
686 bytes_left >>= 1;
687 case 2:
688 bytes_left >>= 1;
689 }
690
691 rx_thre = pxa2xx_spi_get_rx_default_thre(drv_data);
692 if (rx_thre > bytes_left)
693 rx_thre = bytes_left;
694
695 pxa2xx_spi_set_rx_thre(drv_data, &sccr1_reg, rx_thre);
696 }
697 pxa2xx_spi_write(drv_data, SSCR1, sccr1_reg);
698 }
699
700 /* We did something */
701 return IRQ_HANDLED;
702}
703
704static irqreturn_t ssp_int(int irq, void *dev_id)
705{
706 struct driver_data *drv_data = dev_id;
707 u32 sccr1_reg;
708 u32 mask = drv_data->mask_sr;
709 u32 status;
710
711 /*
712 * The IRQ might be shared with other peripherals so we must first
713 * check that are we RPM suspended or not. If we are we assume that
714 * the IRQ was not for us (we shouldn't be RPM suspended when the
715 * interrupt is enabled).
716 */
717 if (pm_runtime_suspended(&drv_data->pdev->dev))
718 return IRQ_NONE;
719
720 /*
721 * If the device is not yet in RPM suspended state and we get an
722 * interrupt that is meant for another device, check if status bits
723 * are all set to one. That means that the device is already
724 * powered off.
725 */
726 status = pxa2xx_spi_read(drv_data, SSSR);
727 if (status == ~0)
728 return IRQ_NONE;
729
730 sccr1_reg = pxa2xx_spi_read(drv_data, SSCR1);
731
732 /* Ignore possible writes if we don't need to write */
733 if (!(sccr1_reg & SSCR1_TIE))
734 mask &= ~SSSR_TFS;
735
736 /* Ignore RX timeout interrupt if it is disabled */
737 if (!(sccr1_reg & SSCR1_TINTE))
738 mask &= ~SSSR_TINT;
739
740 if (!(status & mask))
741 return IRQ_NONE;
742
743 if (!drv_data->cur_msg) {
744
745 pxa2xx_spi_write(drv_data, SSCR0,
746 pxa2xx_spi_read(drv_data, SSCR0)
747 & ~SSCR0_SSE);
748 pxa2xx_spi_write(drv_data, SSCR1,
749 pxa2xx_spi_read(drv_data, SSCR1)
750 & ~drv_data->int_cr1);
751 if (!pxa25x_ssp_comp(drv_data))
752 pxa2xx_spi_write(drv_data, SSTO, 0);
753 write_SSSR_CS(drv_data, drv_data->clear_sr);
754
755 dev_err(&drv_data->pdev->dev,
756 "bad message state in interrupt handler\n");
757
758 /* Never fail */
759 return IRQ_HANDLED;
760 }
761
762 return drv_data->transfer_handler(drv_data);
763}
764
765/*
766 * The Quark SPI has an additional 24 bit register (DDS_CLK_RATE) to multiply
767 * input frequency by fractions of 2^24. It also has a divider by 5.
768 *
769 * There are formulas to get baud rate value for given input frequency and
770 * divider parameters, such as DDS_CLK_RATE and SCR:
771 *
772 * Fsys = 200MHz
773 *
774 * Fssp = Fsys * DDS_CLK_RATE / 2^24 (1)
775 * Baud rate = Fsclk = Fssp / (2 * (SCR + 1)) (2)
776 *
777 * DDS_CLK_RATE either 2^n or 2^n / 5.
778 * SCR is in range 0 .. 255
779 *
780 * Divisor = 5^i * 2^j * 2 * k
781 * i = [0, 1] i = 1 iff j = 0 or j > 3
782 * j = [0, 23] j = 0 iff i = 1
783 * k = [1, 256]
784 * Special case: j = 0, i = 1: Divisor = 2 / 5
785 *
786 * Accordingly to the specification the recommended values for DDS_CLK_RATE
787 * are:
788 * Case 1: 2^n, n = [0, 23]
789 * Case 2: 2^24 * 2 / 5 (0x666666)
790 * Case 3: less than or equal to 2^24 / 5 / 16 (0x33333)
791 *
792 * In all cases the lowest possible value is better.
793 *
794 * The function calculates parameters for all cases and chooses the one closest
795 * to the asked baud rate.
796 */
797static unsigned int quark_x1000_get_clk_div(int rate, u32 *dds)
798{
799 unsigned long xtal = 200000000;
800 unsigned long fref = xtal / 2; /* mandatory division by 2,
801 see (2) */
802 /* case 3 */
803 unsigned long fref1 = fref / 2; /* case 1 */
804 unsigned long fref2 = fref * 2 / 5; /* case 2 */
805 unsigned long scale;
806 unsigned long q, q1, q2;
807 long r, r1, r2;
808 u32 mul;
809
810 /* Case 1 */
811
812 /* Set initial value for DDS_CLK_RATE */
813 mul = (1 << 24) >> 1;
814
815 /* Calculate initial quot */
816 q1 = DIV_ROUND_UP(fref1, rate);
817
818 /* Scale q1 if it's too big */
819 if (q1 > 256) {
820 /* Scale q1 to range [1, 512] */
821 scale = fls_long(q1 - 1);
822 if (scale > 9) {
823 q1 >>= scale - 9;
824 mul >>= scale - 9;
825 }
826
827 /* Round the result if we have a remainder */
828 q1 += q1 & 1;
829 }
830
831 /* Decrease DDS_CLK_RATE as much as we can without loss in precision */
832 scale = __ffs(q1);
833 q1 >>= scale;
834 mul >>= scale;
835
836 /* Get the remainder */
837 r1 = abs(fref1 / (1 << (24 - fls_long(mul))) / q1 - rate);
838
839 /* Case 2 */
840
841 q2 = DIV_ROUND_UP(fref2, rate);
842 r2 = abs(fref2 / q2 - rate);
843
844 /*
845 * Choose the best between two: less remainder we have the better. We
846 * can't go case 2 if q2 is greater than 256 since SCR register can
847 * hold only values 0 .. 255.
848 */
849 if (r2 >= r1 || q2 > 256) {
850 /* case 1 is better */
851 r = r1;
852 q = q1;
853 } else {
854 /* case 2 is better */
855 r = r2;
856 q = q2;
857 mul = (1 << 24) * 2 / 5;
858 }
859
860 /* Check case 3 only if the divisor is big enough */
861 if (fref / rate >= 80) {
862 u64 fssp;
863 u32 m;
864
865 /* Calculate initial quot */
866 q1 = DIV_ROUND_UP(fref, rate);
867 m = (1 << 24) / q1;
868
869 /* Get the remainder */
870 fssp = (u64)fref * m;
871 do_div(fssp, 1 << 24);
872 r1 = abs(fssp - rate);
873
874 /* Choose this one if it suits better */
875 if (r1 < r) {
876 /* case 3 is better */
877 q = 1;
878 mul = m;
879 }
880 }
881
882 *dds = mul;
883 return q - 1;
884}
885
886static unsigned int ssp_get_clk_div(struct driver_data *drv_data, int rate)
887{
888 unsigned long ssp_clk = drv_data->master->max_speed_hz;
889 const struct ssp_device *ssp = drv_data->ssp;
890
891 rate = min_t(int, ssp_clk, rate);
892
893 if (ssp->type == PXA25x_SSP || ssp->type == CE4100_SSP)
894 return (ssp_clk / (2 * rate) - 1) & 0xff;
895 else
896 return (ssp_clk / rate - 1) & 0xfff;
897}
898
899static unsigned int pxa2xx_ssp_get_clk_div(struct driver_data *drv_data,
900 int rate)
901{
902 struct chip_data *chip = drv_data->cur_chip;
903 unsigned int clk_div;
904
905 switch (drv_data->ssp_type) {
906 case QUARK_X1000_SSP:
907 clk_div = quark_x1000_get_clk_div(rate, &chip->dds_rate);
908 break;
909 default:
910 clk_div = ssp_get_clk_div(drv_data, rate);
911 break;
912 }
913 return clk_div << 8;
914}
915
916static void pump_transfers(unsigned long data)
917{
918 struct driver_data *drv_data = (struct driver_data *)data;
919 struct spi_message *message = NULL;
920 struct spi_transfer *transfer = NULL;
921 struct spi_transfer *previous = NULL;
922 struct chip_data *chip = NULL;
923 u32 clk_div = 0;
924 u8 bits = 0;
925 u32 speed = 0;
926 u32 cr0;
927 u32 cr1;
928 u32 dma_thresh = drv_data->cur_chip->dma_threshold;
929 u32 dma_burst = drv_data->cur_chip->dma_burst_size;
930 u32 change_mask = pxa2xx_spi_get_ssrc1_change_mask(drv_data);
931
932 /* Get current state information */
933 message = drv_data->cur_msg;
934 transfer = drv_data->cur_transfer;
935 chip = drv_data->cur_chip;
936
937 /* Handle for abort */
938 if (message->state == ERROR_STATE) {
939 message->status = -EIO;
940 giveback(drv_data);
941 return;
942 }
943
944 /* Handle end of message */
945 if (message->state == DONE_STATE) {
946 message->status = 0;
947 giveback(drv_data);
948 return;
949 }
950
951 /* Delay if requested at end of transfer before CS change */
952 if (message->state == RUNNING_STATE) {
953 previous = list_entry(transfer->transfer_list.prev,
954 struct spi_transfer,
955 transfer_list);
956 if (previous->delay_usecs)
957 udelay(previous->delay_usecs);
958
959 /* Drop chip select only if cs_change is requested */
960 if (previous->cs_change)
961 cs_deassert(drv_data);
962 }
963
964 /* Check if we can DMA this transfer */
965 if (!pxa2xx_spi_dma_is_possible(transfer->len) && chip->enable_dma) {
966
967 /* reject already-mapped transfers; PIO won't always work */
968 if (message->is_dma_mapped
969 || transfer->rx_dma || transfer->tx_dma) {
970 dev_err(&drv_data->pdev->dev,
971 "pump_transfers: mapped transfer length of "
972 "%u is greater than %d\n",
973 transfer->len, MAX_DMA_LEN);
974 message->status = -EINVAL;
975 giveback(drv_data);
976 return;
977 }
978
979 /* warn ... we force this to PIO mode */
980 dev_warn_ratelimited(&message->spi->dev,
981 "pump_transfers: DMA disabled for transfer length %ld "
982 "greater than %d\n",
983 (long)drv_data->len, MAX_DMA_LEN);
984 }
985
986 /* Setup the transfer state based on the type of transfer */
987 if (pxa2xx_spi_flush(drv_data) == 0) {
988 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
989 message->status = -EIO;
990 giveback(drv_data);
991 return;
992 }
993 drv_data->n_bytes = chip->n_bytes;
994 drv_data->tx = (void *)transfer->tx_buf;
995 drv_data->tx_end = drv_data->tx + transfer->len;
996 drv_data->rx = transfer->rx_buf;
997 drv_data->rx_end = drv_data->rx + transfer->len;
998 drv_data->len = transfer->len;
999 drv_data->write = drv_data->tx ? chip->write : null_writer;
1000 drv_data->read = drv_data->rx ? chip->read : null_reader;
1001
1002 /* Change speed and bit per word on a per transfer */
1003 bits = transfer->bits_per_word;
1004 speed = transfer->speed_hz;
1005
1006 clk_div = pxa2xx_ssp_get_clk_div(drv_data, speed);
1007
1008 if (bits <= 8) {
1009 drv_data->n_bytes = 1;
1010 drv_data->read = drv_data->read != null_reader ?
1011 u8_reader : null_reader;
1012 drv_data->write = drv_data->write != null_writer ?
1013 u8_writer : null_writer;
1014 } else if (bits <= 16) {
1015 drv_data->n_bytes = 2;
1016 drv_data->read = drv_data->read != null_reader ?
1017 u16_reader : null_reader;
1018 drv_data->write = drv_data->write != null_writer ?
1019 u16_writer : null_writer;
1020 } else if (bits <= 32) {
1021 drv_data->n_bytes = 4;
1022 drv_data->read = drv_data->read != null_reader ?
1023 u32_reader : null_reader;
1024 drv_data->write = drv_data->write != null_writer ?
1025 u32_writer : null_writer;
1026 }
1027 /*
1028 * if bits/word is changed in dma mode, then must check the
1029 * thresholds and burst also
1030 */
1031 if (chip->enable_dma) {
1032 if (pxa2xx_spi_set_dma_burst_and_threshold(chip,
1033 message->spi,
1034 bits, &dma_burst,
1035 &dma_thresh))
1036 dev_warn_ratelimited(&message->spi->dev,
1037 "pump_transfers: DMA burst size reduced to match bits_per_word\n");
1038 }
1039
1040 message->state = RUNNING_STATE;
1041
1042 drv_data->dma_mapped = 0;
1043 if (pxa2xx_spi_dma_is_possible(drv_data->len))
1044 drv_data->dma_mapped = pxa2xx_spi_map_dma_buffers(drv_data);
1045 if (drv_data->dma_mapped) {
1046
1047 /* Ensure we have the correct interrupt handler */
1048 drv_data->transfer_handler = pxa2xx_spi_dma_transfer;
1049
1050 pxa2xx_spi_dma_prepare(drv_data, dma_burst);
1051
1052 /* Clear status and start DMA engine */
1053 cr1 = chip->cr1 | dma_thresh | drv_data->dma_cr1;
1054 pxa2xx_spi_write(drv_data, SSSR, drv_data->clear_sr);
1055
1056 pxa2xx_spi_dma_start(drv_data);
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_CS(drv_data, drv_data->clear_sr);
1064 }
1065
1066 /* NOTE: PXA25x_SSP _could_ use external clocking ... */
1067 cr0 = pxa2xx_configure_sscr0(drv_data, clk_div, bits);
1068 if (!pxa25x_ssp_comp(drv_data))
1069 dev_dbg(&message->spi->dev, "%u Hz actual, %s\n",
1070 drv_data->master->max_speed_hz
1071 / (1 + ((cr0 & SSCR0_SCR(0xfff)) >> 8)),
1072 drv_data->dma_mapped ? "DMA" : "PIO");
1073 else
1074 dev_dbg(&message->spi->dev, "%u Hz actual, %s\n",
1075 drv_data->master->max_speed_hz / 2
1076 / (1 + ((cr0 & SSCR0_SCR(0x0ff)) >> 8)),
1077 drv_data->dma_mapped ? "DMA" : "PIO");
1078
1079 if (is_lpss_ssp(drv_data)) {
1080 if ((pxa2xx_spi_read(drv_data, SSIRF) & 0xff)
1081 != chip->lpss_rx_threshold)
1082 pxa2xx_spi_write(drv_data, SSIRF,
1083 chip->lpss_rx_threshold);
1084 if ((pxa2xx_spi_read(drv_data, SSITF) & 0xffff)
1085 != chip->lpss_tx_threshold)
1086 pxa2xx_spi_write(drv_data, SSITF,
1087 chip->lpss_tx_threshold);
1088 }
1089
1090 if (is_quark_x1000_ssp(drv_data) &&
1091 (pxa2xx_spi_read(drv_data, DDS_RATE) != chip->dds_rate))
1092 pxa2xx_spi_write(drv_data, DDS_RATE, chip->dds_rate);
1093
1094 /* see if we need to reload the config registers */
1095 if ((pxa2xx_spi_read(drv_data, SSCR0) != cr0)
1096 || (pxa2xx_spi_read(drv_data, SSCR1) & change_mask)
1097 != (cr1 & change_mask)) {
1098 /* stop the SSP, and update the other bits */
1099 pxa2xx_spi_write(drv_data, SSCR0, cr0 & ~SSCR0_SSE);
1100 if (!pxa25x_ssp_comp(drv_data))
1101 pxa2xx_spi_write(drv_data, SSTO, chip->timeout);
1102 /* first set CR1 without interrupt and service enables */
1103 pxa2xx_spi_write(drv_data, SSCR1, cr1 & change_mask);
1104 /* restart the SSP */
1105 pxa2xx_spi_write(drv_data, SSCR0, cr0);
1106
1107 } else {
1108 if (!pxa25x_ssp_comp(drv_data))
1109 pxa2xx_spi_write(drv_data, SSTO, chip->timeout);
1110 }
1111
1112 cs_assert(drv_data);
1113
1114 /* after chip select, release the data by enabling service
1115 * requests and interrupts, without changing any mode bits */
1116 pxa2xx_spi_write(drv_data, SSCR1, cr1);
1117}
1118
1119static int pxa2xx_spi_transfer_one_message(struct spi_master *master,
1120 struct spi_message *msg)
1121{
1122 struct driver_data *drv_data = spi_master_get_devdata(master);
1123
1124 drv_data->cur_msg = msg;
1125 /* Initial message state*/
1126 drv_data->cur_msg->state = START_STATE;
1127 drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
1128 struct spi_transfer,
1129 transfer_list);
1130
1131 /* prepare to setup the SSP, in pump_transfers, using the per
1132 * chip configuration */
1133 drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
1134
1135 /* Mark as busy and launch transfers */
1136 tasklet_schedule(&drv_data->pump_transfers);
1137 return 0;
1138}
1139
1140static int pxa2xx_spi_unprepare_transfer(struct spi_master *master)
1141{
1142 struct driver_data *drv_data = spi_master_get_devdata(master);
1143
1144 /* Disable the SSP now */
1145 pxa2xx_spi_write(drv_data, SSCR0,
1146 pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE);
1147
1148 return 0;
1149}
1150
1151static int setup_cs(struct spi_device *spi, struct chip_data *chip,
1152 struct pxa2xx_spi_chip *chip_info)
1153{
1154 int err = 0;
1155
1156 if (chip == NULL || chip_info == NULL)
1157 return 0;
1158
1159 /* NOTE: setup() can be called multiple times, possibly with
1160 * different chip_info, release previously requested GPIO
1161 */
1162 if (gpio_is_valid(chip->gpio_cs))
1163 gpio_free(chip->gpio_cs);
1164
1165 /* If (*cs_control) is provided, ignore GPIO chip select */
1166 if (chip_info->cs_control) {
1167 chip->cs_control = chip_info->cs_control;
1168 return 0;
1169 }
1170
1171 if (gpio_is_valid(chip_info->gpio_cs)) {
1172 err = gpio_request(chip_info->gpio_cs, "SPI_CS");
1173 if (err) {
1174 dev_err(&spi->dev, "failed to request chip select GPIO%d\n",
1175 chip_info->gpio_cs);
1176 return err;
1177 }
1178
1179 chip->gpio_cs = chip_info->gpio_cs;
1180 chip->gpio_cs_inverted = spi->mode & SPI_CS_HIGH;
1181
1182 err = gpio_direction_output(chip->gpio_cs,
1183 !chip->gpio_cs_inverted);
1184 }
1185
1186 return err;
1187}
1188
1189static int setup(struct spi_device *spi)
1190{
1191 struct pxa2xx_spi_chip *chip_info = NULL;
1192 struct chip_data *chip;
1193 const struct lpss_config *config;
1194 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1195 uint tx_thres, tx_hi_thres, rx_thres;
1196
1197 switch (drv_data->ssp_type) {
1198 case QUARK_X1000_SSP:
1199 tx_thres = TX_THRESH_QUARK_X1000_DFLT;
1200 tx_hi_thres = 0;
1201 rx_thres = RX_THRESH_QUARK_X1000_DFLT;
1202 break;
1203 case LPSS_LPT_SSP:
1204 case LPSS_BYT_SSP:
1205 case LPSS_BSW_SSP:
1206 case LPSS_SPT_SSP:
1207 case LPSS_BXT_SSP:
1208 config = lpss_get_config(drv_data);
1209 tx_thres = config->tx_threshold_lo;
1210 tx_hi_thres = config->tx_threshold_hi;
1211 rx_thres = config->rx_threshold;
1212 break;
1213 default:
1214 tx_thres = TX_THRESH_DFLT;
1215 tx_hi_thres = 0;
1216 rx_thres = RX_THRESH_DFLT;
1217 break;
1218 }
1219
1220 /* Only alloc on first setup */
1221 chip = spi_get_ctldata(spi);
1222 if (!chip) {
1223 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1224 if (!chip)
1225 return -ENOMEM;
1226
1227 if (drv_data->ssp_type == CE4100_SSP) {
1228 if (spi->chip_select > 4) {
1229 dev_err(&spi->dev,
1230 "failed setup: cs number must not be > 4.\n");
1231 kfree(chip);
1232 return -EINVAL;
1233 }
1234
1235 chip->frm = spi->chip_select;
1236 } else
1237 chip->gpio_cs = -1;
1238 chip->enable_dma = 0;
1239 chip->timeout = TIMOUT_DFLT;
1240 }
1241
1242 /* protocol drivers may change the chip settings, so...
1243 * if chip_info exists, use it */
1244 chip_info = spi->controller_data;
1245
1246 /* chip_info isn't always needed */
1247 chip->cr1 = 0;
1248 if (chip_info) {
1249 if (chip_info->timeout)
1250 chip->timeout = chip_info->timeout;
1251 if (chip_info->tx_threshold)
1252 tx_thres = chip_info->tx_threshold;
1253 if (chip_info->tx_hi_threshold)
1254 tx_hi_thres = chip_info->tx_hi_threshold;
1255 if (chip_info->rx_threshold)
1256 rx_thres = chip_info->rx_threshold;
1257 chip->enable_dma = drv_data->master_info->enable_dma;
1258 chip->dma_threshold = 0;
1259 if (chip_info->enable_loopback)
1260 chip->cr1 = SSCR1_LBM;
1261 } else if (ACPI_HANDLE(&spi->dev)) {
1262 /*
1263 * Slave devices enumerated from ACPI namespace don't
1264 * usually have chip_info but we still might want to use
1265 * DMA with them.
1266 */
1267 chip->enable_dma = drv_data->master_info->enable_dma;
1268 }
1269
1270 chip->lpss_rx_threshold = SSIRF_RxThresh(rx_thres);
1271 chip->lpss_tx_threshold = SSITF_TxLoThresh(tx_thres)
1272 | SSITF_TxHiThresh(tx_hi_thres);
1273
1274 /* set dma burst and threshold outside of chip_info path so that if
1275 * chip_info goes away after setting chip->enable_dma, the
1276 * burst and threshold can still respond to changes in bits_per_word */
1277 if (chip->enable_dma) {
1278 /* set up legal burst and threshold for dma */
1279 if (pxa2xx_spi_set_dma_burst_and_threshold(chip, spi,
1280 spi->bits_per_word,
1281 &chip->dma_burst_size,
1282 &chip->dma_threshold)) {
1283 dev_warn(&spi->dev,
1284 "in setup: DMA burst size reduced to match bits_per_word\n");
1285 }
1286 }
1287
1288 switch (drv_data->ssp_type) {
1289 case QUARK_X1000_SSP:
1290 chip->threshold = (QUARK_X1000_SSCR1_RxTresh(rx_thres)
1291 & QUARK_X1000_SSCR1_RFT)
1292 | (QUARK_X1000_SSCR1_TxTresh(tx_thres)
1293 & QUARK_X1000_SSCR1_TFT);
1294 break;
1295 default:
1296 chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) |
1297 (SSCR1_TxTresh(tx_thres) & SSCR1_TFT);
1298 break;
1299 }
1300
1301 chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH);
1302 chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
1303 | (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);
1304
1305 if (spi->mode & SPI_LOOP)
1306 chip->cr1 |= SSCR1_LBM;
1307
1308 if (spi->bits_per_word <= 8) {
1309 chip->n_bytes = 1;
1310 chip->read = u8_reader;
1311 chip->write = u8_writer;
1312 } else if (spi->bits_per_word <= 16) {
1313 chip->n_bytes = 2;
1314 chip->read = u16_reader;
1315 chip->write = u16_writer;
1316 } else if (spi->bits_per_word <= 32) {
1317 chip->n_bytes = 4;
1318 chip->read = u32_reader;
1319 chip->write = u32_writer;
1320 }
1321
1322 spi_set_ctldata(spi, chip);
1323
1324 if (drv_data->ssp_type == CE4100_SSP)
1325 return 0;
1326
1327 return setup_cs(spi, chip, chip_info);
1328}
1329
1330static void cleanup(struct spi_device *spi)
1331{
1332 struct chip_data *chip = spi_get_ctldata(spi);
1333 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1334
1335 if (!chip)
1336 return;
1337
1338 if (drv_data->ssp_type != CE4100_SSP && gpio_is_valid(chip->gpio_cs))
1339 gpio_free(chip->gpio_cs);
1340
1341 kfree(chip);
1342}
1343
1344#ifdef CONFIG_PCI
1345#ifdef CONFIG_ACPI
1346
1347static const struct acpi_device_id pxa2xx_spi_acpi_match[] = {
1348 { "INT33C0", LPSS_LPT_SSP },
1349 { "INT33C1", LPSS_LPT_SSP },
1350 { "INT3430", LPSS_LPT_SSP },
1351 { "INT3431", LPSS_LPT_SSP },
1352 { "80860F0E", LPSS_BYT_SSP },
1353 { "8086228E", LPSS_BSW_SSP },
1354 { },
1355};
1356MODULE_DEVICE_TABLE(acpi, pxa2xx_spi_acpi_match);
1357
1358static int pxa2xx_spi_get_port_id(struct acpi_device *adev)
1359{
1360 unsigned int devid;
1361 int port_id = -1;
1362
1363 if (adev && adev->pnp.unique_id &&
1364 !kstrtouint(adev->pnp.unique_id, 0, &devid))
1365 port_id = devid;
1366 return port_id;
1367}
1368#else /* !CONFIG_ACPI */
1369static int pxa2xx_spi_get_port_id(struct acpi_device *adev)
1370{
1371 return -1;
1372}
1373#endif
1374
1375/*
1376 * PCI IDs of compound devices that integrate both host controller and private
1377 * integrated DMA engine. Please note these are not used in module
1378 * autoloading and probing in this module but matching the LPSS SSP type.
1379 */
1380static const struct pci_device_id pxa2xx_spi_pci_compound_match[] = {
1381 /* SPT-LP */
1382 { PCI_VDEVICE(INTEL, 0x9d29), LPSS_SPT_SSP },
1383 { PCI_VDEVICE(INTEL, 0x9d2a), LPSS_SPT_SSP },
1384 /* SPT-H */
1385 { PCI_VDEVICE(INTEL, 0xa129), LPSS_SPT_SSP },
1386 { PCI_VDEVICE(INTEL, 0xa12a), LPSS_SPT_SSP },
1387 /* BXT A-Step */
1388 { PCI_VDEVICE(INTEL, 0x0ac2), LPSS_BXT_SSP },
1389 { PCI_VDEVICE(INTEL, 0x0ac4), LPSS_BXT_SSP },
1390 { PCI_VDEVICE(INTEL, 0x0ac6), LPSS_BXT_SSP },
1391 /* BXT B-Step */
1392 { PCI_VDEVICE(INTEL, 0x1ac2), LPSS_BXT_SSP },
1393 { PCI_VDEVICE(INTEL, 0x1ac4), LPSS_BXT_SSP },
1394 { PCI_VDEVICE(INTEL, 0x1ac6), LPSS_BXT_SSP },
1395 /* APL */
1396 { PCI_VDEVICE(INTEL, 0x5ac2), LPSS_BXT_SSP },
1397 { PCI_VDEVICE(INTEL, 0x5ac4), LPSS_BXT_SSP },
1398 { PCI_VDEVICE(INTEL, 0x5ac6), LPSS_BXT_SSP },
1399 { },
1400};
1401
1402static bool pxa2xx_spi_idma_filter(struct dma_chan *chan, void *param)
1403{
1404 struct device *dev = param;
1405
1406 if (dev != chan->device->dev->parent)
1407 return false;
1408
1409 return true;
1410}
1411
1412static struct pxa2xx_spi_master *
1413pxa2xx_spi_init_pdata(struct platform_device *pdev)
1414{
1415 struct pxa2xx_spi_master *pdata;
1416 struct acpi_device *adev;
1417 struct ssp_device *ssp;
1418 struct resource *res;
1419 const struct acpi_device_id *adev_id = NULL;
1420 const struct pci_device_id *pcidev_id = NULL;
1421 int type;
1422
1423 adev = ACPI_COMPANION(&pdev->dev);
1424
1425 if (dev_is_pci(pdev->dev.parent))
1426 pcidev_id = pci_match_id(pxa2xx_spi_pci_compound_match,
1427 to_pci_dev(pdev->dev.parent));
1428 else if (adev)
1429 adev_id = acpi_match_device(pdev->dev.driver->acpi_match_table,
1430 &pdev->dev);
1431 else
1432 return NULL;
1433
1434 if (adev_id)
1435 type = (int)adev_id->driver_data;
1436 else if (pcidev_id)
1437 type = (int)pcidev_id->driver_data;
1438 else
1439 return NULL;
1440
1441 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
1442 if (!pdata)
1443 return NULL;
1444
1445 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1446 if (!res)
1447 return NULL;
1448
1449 ssp = &pdata->ssp;
1450
1451 ssp->phys_base = res->start;
1452 ssp->mmio_base = devm_ioremap_resource(&pdev->dev, res);
1453 if (IS_ERR(ssp->mmio_base))
1454 return NULL;
1455
1456 if (pcidev_id) {
1457 pdata->tx_param = pdev->dev.parent;
1458 pdata->rx_param = pdev->dev.parent;
1459 pdata->dma_filter = pxa2xx_spi_idma_filter;
1460 }
1461
1462 ssp->clk = devm_clk_get(&pdev->dev, NULL);
1463 ssp->irq = platform_get_irq(pdev, 0);
1464 ssp->type = type;
1465 ssp->pdev = pdev;
1466 ssp->port_id = pxa2xx_spi_get_port_id(adev);
1467
1468 pdata->num_chipselect = 1;
1469 pdata->enable_dma = true;
1470
1471 return pdata;
1472}
1473
1474#else /* !CONFIG_PCI */
1475static inline struct pxa2xx_spi_master *
1476pxa2xx_spi_init_pdata(struct platform_device *pdev)
1477{
1478 return NULL;
1479}
1480#endif
1481
1482static int pxa2xx_spi_fw_translate_cs(struct spi_master *master, unsigned cs)
1483{
1484 struct driver_data *drv_data = spi_master_get_devdata(master);
1485
1486 if (has_acpi_companion(&drv_data->pdev->dev)) {
1487 switch (drv_data->ssp_type) {
1488 /*
1489 * For Atoms the ACPI DeviceSelection used by the Windows
1490 * driver starts from 1 instead of 0 so translate it here
1491 * to match what Linux expects.
1492 */
1493 case LPSS_BYT_SSP:
1494 case LPSS_BSW_SSP:
1495 return cs - 1;
1496
1497 default:
1498 break;
1499 }
1500 }
1501
1502 return cs;
1503}
1504
1505static int pxa2xx_spi_probe(struct platform_device *pdev)
1506{
1507 struct device *dev = &pdev->dev;
1508 struct pxa2xx_spi_master *platform_info;
1509 struct spi_master *master;
1510 struct driver_data *drv_data;
1511 struct ssp_device *ssp;
1512 const struct lpss_config *config;
1513 int status;
1514 u32 tmp;
1515
1516 platform_info = dev_get_platdata(dev);
1517 if (!platform_info) {
1518 platform_info = pxa2xx_spi_init_pdata(pdev);
1519 if (!platform_info) {
1520 dev_err(&pdev->dev, "missing platform data\n");
1521 return -ENODEV;
1522 }
1523 }
1524
1525 ssp = pxa_ssp_request(pdev->id, pdev->name);
1526 if (!ssp)
1527 ssp = &platform_info->ssp;
1528
1529 if (!ssp->mmio_base) {
1530 dev_err(&pdev->dev, "failed to get ssp\n");
1531 return -ENODEV;
1532 }
1533
1534 master = spi_alloc_master(dev, sizeof(struct driver_data));
1535 if (!master) {
1536 dev_err(&pdev->dev, "cannot alloc spi_master\n");
1537 pxa_ssp_free(ssp);
1538 return -ENOMEM;
1539 }
1540 drv_data = spi_master_get_devdata(master);
1541 drv_data->master = master;
1542 drv_data->master_info = platform_info;
1543 drv_data->pdev = pdev;
1544 drv_data->ssp = ssp;
1545
1546 master->dev.parent = &pdev->dev;
1547 master->dev.of_node = pdev->dev.of_node;
1548 /* the spi->mode bits understood by this driver: */
1549 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
1550
1551 master->bus_num = ssp->port_id;
1552 master->dma_alignment = DMA_ALIGNMENT;
1553 master->cleanup = cleanup;
1554 master->setup = setup;
1555 master->transfer_one_message = pxa2xx_spi_transfer_one_message;
1556 master->unprepare_transfer_hardware = pxa2xx_spi_unprepare_transfer;
1557 master->fw_translate_cs = pxa2xx_spi_fw_translate_cs;
1558 master->auto_runtime_pm = true;
1559
1560 drv_data->ssp_type = ssp->type;
1561
1562 drv_data->ioaddr = ssp->mmio_base;
1563 drv_data->ssdr_physical = ssp->phys_base + SSDR;
1564 if (pxa25x_ssp_comp(drv_data)) {
1565 switch (drv_data->ssp_type) {
1566 case QUARK_X1000_SSP:
1567 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1568 break;
1569 default:
1570 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
1571 break;
1572 }
1573
1574 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE;
1575 drv_data->dma_cr1 = 0;
1576 drv_data->clear_sr = SSSR_ROR;
1577 drv_data->mask_sr = SSSR_RFS | SSSR_TFS | SSSR_ROR;
1578 } else {
1579 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1580 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE;
1581 drv_data->dma_cr1 = DEFAULT_DMA_CR1;
1582 drv_data->clear_sr = SSSR_ROR | SSSR_TINT;
1583 drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR;
1584 }
1585
1586 status = request_irq(ssp->irq, ssp_int, IRQF_SHARED, dev_name(dev),
1587 drv_data);
1588 if (status < 0) {
1589 dev_err(&pdev->dev, "cannot get IRQ %d\n", ssp->irq);
1590 goto out_error_master_alloc;
1591 }
1592
1593 /* Setup DMA if requested */
1594 if (platform_info->enable_dma) {
1595 status = pxa2xx_spi_dma_setup(drv_data);
1596 if (status) {
1597 dev_dbg(dev, "no DMA channels available, using PIO\n");
1598 platform_info->enable_dma = false;
1599 }
1600 }
1601
1602 /* Enable SOC clock */
1603 clk_prepare_enable(ssp->clk);
1604
1605 master->max_speed_hz = clk_get_rate(ssp->clk);
1606
1607 /* Load default SSP configuration */
1608 pxa2xx_spi_write(drv_data, SSCR0, 0);
1609 switch (drv_data->ssp_type) {
1610 case QUARK_X1000_SSP:
1611 tmp = QUARK_X1000_SSCR1_RxTresh(RX_THRESH_QUARK_X1000_DFLT)
1612 | QUARK_X1000_SSCR1_TxTresh(TX_THRESH_QUARK_X1000_DFLT);
1613 pxa2xx_spi_write(drv_data, SSCR1, tmp);
1614
1615 /* using the Motorola SPI protocol and use 8 bit frame */
1616 pxa2xx_spi_write(drv_data, SSCR0,
1617 QUARK_X1000_SSCR0_Motorola
1618 | QUARK_X1000_SSCR0_DataSize(8));
1619 break;
1620 default:
1621 tmp = SSCR1_RxTresh(RX_THRESH_DFLT) |
1622 SSCR1_TxTresh(TX_THRESH_DFLT);
1623 pxa2xx_spi_write(drv_data, SSCR1, tmp);
1624 tmp = SSCR0_SCR(2) | SSCR0_Motorola | SSCR0_DataSize(8);
1625 pxa2xx_spi_write(drv_data, SSCR0, tmp);
1626 break;
1627 }
1628
1629 if (!pxa25x_ssp_comp(drv_data))
1630 pxa2xx_spi_write(drv_data, SSTO, 0);
1631
1632 if (!is_quark_x1000_ssp(drv_data))
1633 pxa2xx_spi_write(drv_data, SSPSP, 0);
1634
1635 if (is_lpss_ssp(drv_data)) {
1636 lpss_ssp_setup(drv_data);
1637 config = lpss_get_config(drv_data);
1638 if (config->reg_capabilities >= 0) {
1639 tmp = __lpss_ssp_read_priv(drv_data,
1640 config->reg_capabilities);
1641 tmp &= LPSS_CAPS_CS_EN_MASK;
1642 tmp >>= LPSS_CAPS_CS_EN_SHIFT;
1643 platform_info->num_chipselect = ffz(tmp);
1644 } else if (config->cs_num) {
1645 platform_info->num_chipselect = config->cs_num;
1646 }
1647 }
1648 master->num_chipselect = platform_info->num_chipselect;
1649
1650 tasklet_init(&drv_data->pump_transfers, pump_transfers,
1651 (unsigned long)drv_data);
1652
1653 pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
1654 pm_runtime_use_autosuspend(&pdev->dev);
1655 pm_runtime_set_active(&pdev->dev);
1656 pm_runtime_enable(&pdev->dev);
1657
1658 /* Register with the SPI framework */
1659 platform_set_drvdata(pdev, drv_data);
1660 status = devm_spi_register_master(&pdev->dev, master);
1661 if (status != 0) {
1662 dev_err(&pdev->dev, "problem registering spi master\n");
1663 goto out_error_clock_enabled;
1664 }
1665
1666 return status;
1667
1668out_error_clock_enabled:
1669 clk_disable_unprepare(ssp->clk);
1670 pxa2xx_spi_dma_release(drv_data);
1671 free_irq(ssp->irq, drv_data);
1672
1673out_error_master_alloc:
1674 spi_master_put(master);
1675 pxa_ssp_free(ssp);
1676 return status;
1677}
1678
1679static int pxa2xx_spi_remove(struct platform_device *pdev)
1680{
1681 struct driver_data *drv_data = platform_get_drvdata(pdev);
1682 struct ssp_device *ssp;
1683
1684 if (!drv_data)
1685 return 0;
1686 ssp = drv_data->ssp;
1687
1688 pm_runtime_get_sync(&pdev->dev);
1689
1690 /* Disable the SSP at the peripheral and SOC level */
1691 pxa2xx_spi_write(drv_data, SSCR0, 0);
1692 clk_disable_unprepare(ssp->clk);
1693
1694 /* Release DMA */
1695 if (drv_data->master_info->enable_dma)
1696 pxa2xx_spi_dma_release(drv_data);
1697
1698 pm_runtime_put_noidle(&pdev->dev);
1699 pm_runtime_disable(&pdev->dev);
1700
1701 /* Release IRQ */
1702 free_irq(ssp->irq, drv_data);
1703
1704 /* Release SSP */
1705 pxa_ssp_free(ssp);
1706
1707 return 0;
1708}
1709
1710static void pxa2xx_spi_shutdown(struct platform_device *pdev)
1711{
1712 int status = 0;
1713
1714 if ((status = pxa2xx_spi_remove(pdev)) != 0)
1715 dev_err(&pdev->dev, "shutdown failed with %d\n", status);
1716}
1717
1718#ifdef CONFIG_PM_SLEEP
1719static int pxa2xx_spi_suspend(struct device *dev)
1720{
1721 struct driver_data *drv_data = dev_get_drvdata(dev);
1722 struct ssp_device *ssp = drv_data->ssp;
1723 int status = 0;
1724
1725 status = spi_master_suspend(drv_data->master);
1726 if (status != 0)
1727 return status;
1728 pxa2xx_spi_write(drv_data, SSCR0, 0);
1729
1730 if (!pm_runtime_suspended(dev))
1731 clk_disable_unprepare(ssp->clk);
1732
1733 return 0;
1734}
1735
1736static int pxa2xx_spi_resume(struct device *dev)
1737{
1738 struct driver_data *drv_data = dev_get_drvdata(dev);
1739 struct ssp_device *ssp = drv_data->ssp;
1740 int status = 0;
1741
1742 /* Enable the SSP clock */
1743 if (!pm_runtime_suspended(dev))
1744 clk_prepare_enable(ssp->clk);
1745
1746 /* Restore LPSS private register bits */
1747 if (is_lpss_ssp(drv_data))
1748 lpss_ssp_setup(drv_data);
1749
1750 /* Start the queue running */
1751 status = spi_master_resume(drv_data->master);
1752 if (status != 0) {
1753 dev_err(dev, "problem starting queue (%d)\n", status);
1754 return status;
1755 }
1756
1757 return 0;
1758}
1759#endif
1760
1761#ifdef CONFIG_PM
1762static int pxa2xx_spi_runtime_suspend(struct device *dev)
1763{
1764 struct driver_data *drv_data = dev_get_drvdata(dev);
1765
1766 clk_disable_unprepare(drv_data->ssp->clk);
1767 return 0;
1768}
1769
1770static int pxa2xx_spi_runtime_resume(struct device *dev)
1771{
1772 struct driver_data *drv_data = dev_get_drvdata(dev);
1773
1774 clk_prepare_enable(drv_data->ssp->clk);
1775 return 0;
1776}
1777#endif
1778
1779static const struct dev_pm_ops pxa2xx_spi_pm_ops = {
1780 SET_SYSTEM_SLEEP_PM_OPS(pxa2xx_spi_suspend, pxa2xx_spi_resume)
1781 SET_RUNTIME_PM_OPS(pxa2xx_spi_runtime_suspend,
1782 pxa2xx_spi_runtime_resume, NULL)
1783};
1784
1785static struct platform_driver driver = {
1786 .driver = {
1787 .name = "pxa2xx-spi",
1788 .pm = &pxa2xx_spi_pm_ops,
1789 .acpi_match_table = ACPI_PTR(pxa2xx_spi_acpi_match),
1790 },
1791 .probe = pxa2xx_spi_probe,
1792 .remove = pxa2xx_spi_remove,
1793 .shutdown = pxa2xx_spi_shutdown,
1794};
1795
1796static int __init pxa2xx_spi_init(void)
1797{
1798 return platform_driver_register(&driver);
1799}
1800subsys_initcall(pxa2xx_spi_init);
1801
1802static void __exit pxa2xx_spi_exit(void)
1803{
1804 platform_driver_unregister(&driver);
1805}
1806module_exit(pxa2xx_spi_exit);