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19#include <linux/clk.h>
20#include <linux/completion.h>
21#include <linux/delay.h>
22#include <linux/dmaengine.h>
23#include <linux/dma-mapping.h>
24#include <linux/dmapool.h>
25#include <linux/err.h>
26#include <linux/init.h>
27#include <linux/interrupt.h>
28#include <linux/io.h>
29#include <linux/kernel.h>
30#include <linux/kthread.h>
31#include <linux/module.h>
32#include <linux/platform_device.h>
33#include <linux/pm_runtime.h>
34#include <linux/of.h>
35#include <linux/of_device.h>
36#include <linux/spi/spi.h>
37#include <linux/clk/tegra.h>
38
39#define SLINK_COMMAND 0x000
40#define SLINK_BIT_LENGTH(x) (((x) & 0x1f) << 0)
41#define SLINK_WORD_SIZE(x) (((x) & 0x1f) << 5)
42#define SLINK_BOTH_EN (1 << 10)
43#define SLINK_CS_SW (1 << 11)
44#define SLINK_CS_VALUE (1 << 12)
45#define SLINK_CS_POLARITY (1 << 13)
46#define SLINK_IDLE_SDA_DRIVE_LOW (0 << 16)
47#define SLINK_IDLE_SDA_DRIVE_HIGH (1 << 16)
48#define SLINK_IDLE_SDA_PULL_LOW (2 << 16)
49#define SLINK_IDLE_SDA_PULL_HIGH (3 << 16)
50#define SLINK_IDLE_SDA_MASK (3 << 16)
51#define SLINK_CS_POLARITY1 (1 << 20)
52#define SLINK_CK_SDA (1 << 21)
53#define SLINK_CS_POLARITY2 (1 << 22)
54#define SLINK_CS_POLARITY3 (1 << 23)
55#define SLINK_IDLE_SCLK_DRIVE_LOW (0 << 24)
56#define SLINK_IDLE_SCLK_DRIVE_HIGH (1 << 24)
57#define SLINK_IDLE_SCLK_PULL_LOW (2 << 24)
58#define SLINK_IDLE_SCLK_PULL_HIGH (3 << 24)
59#define SLINK_IDLE_SCLK_MASK (3 << 24)
60#define SLINK_M_S (1 << 28)
61#define SLINK_WAIT (1 << 29)
62#define SLINK_GO (1 << 30)
63#define SLINK_ENB (1 << 31)
64
65#define SLINK_MODES (SLINK_IDLE_SCLK_MASK | SLINK_CK_SDA)
66
67#define SLINK_COMMAND2 0x004
68#define SLINK_LSBFE (1 << 0)
69#define SLINK_SSOE (1 << 1)
70#define SLINK_SPIE (1 << 4)
71#define SLINK_BIDIROE (1 << 6)
72#define SLINK_MODFEN (1 << 7)
73#define SLINK_INT_SIZE(x) (((x) & 0x1f) << 8)
74#define SLINK_CS_ACTIVE_BETWEEN (1 << 17)
75#define SLINK_SS_EN_CS(x) (((x) & 0x3) << 18)
76#define SLINK_SS_SETUP(x) (((x) & 0x3) << 20)
77#define SLINK_FIFO_REFILLS_0 (0 << 22)
78#define SLINK_FIFO_REFILLS_1 (1 << 22)
79#define SLINK_FIFO_REFILLS_2 (2 << 22)
80#define SLINK_FIFO_REFILLS_3 (3 << 22)
81#define SLINK_FIFO_REFILLS_MASK (3 << 22)
82#define SLINK_WAIT_PACK_INT(x) (((x) & 0x7) << 26)
83#define SLINK_SPC0 (1 << 29)
84#define SLINK_TXEN (1 << 30)
85#define SLINK_RXEN (1 << 31)
86
87#define SLINK_STATUS 0x008
88#define SLINK_COUNT(val) (((val) >> 0) & 0x1f)
89#define SLINK_WORD(val) (((val) >> 5) & 0x1f)
90#define SLINK_BLK_CNT(val) (((val) >> 0) & 0xffff)
91#define SLINK_MODF (1 << 16)
92#define SLINK_RX_UNF (1 << 18)
93#define SLINK_TX_OVF (1 << 19)
94#define SLINK_TX_FULL (1 << 20)
95#define SLINK_TX_EMPTY (1 << 21)
96#define SLINK_RX_FULL (1 << 22)
97#define SLINK_RX_EMPTY (1 << 23)
98#define SLINK_TX_UNF (1 << 24)
99#define SLINK_RX_OVF (1 << 25)
100#define SLINK_TX_FLUSH (1 << 26)
101#define SLINK_RX_FLUSH (1 << 27)
102#define SLINK_SCLK (1 << 28)
103#define SLINK_ERR (1 << 29)
104#define SLINK_RDY (1 << 30)
105#define SLINK_BSY (1 << 31)
106#define SLINK_FIFO_ERROR (SLINK_TX_OVF | SLINK_RX_UNF | \
107 SLINK_TX_UNF | SLINK_RX_OVF)
108
109#define SLINK_FIFO_EMPTY (SLINK_TX_EMPTY | SLINK_RX_EMPTY)
110
111#define SLINK_MAS_DATA 0x010
112#define SLINK_SLAVE_DATA 0x014
113
114#define SLINK_DMA_CTL 0x018
115#define SLINK_DMA_BLOCK_SIZE(x) (((x) & 0xffff) << 0)
116#define SLINK_TX_TRIG_1 (0 << 16)
117#define SLINK_TX_TRIG_4 (1 << 16)
118#define SLINK_TX_TRIG_8 (2 << 16)
119#define SLINK_TX_TRIG_16 (3 << 16)
120#define SLINK_TX_TRIG_MASK (3 << 16)
121#define SLINK_RX_TRIG_1 (0 << 18)
122#define SLINK_RX_TRIG_4 (1 << 18)
123#define SLINK_RX_TRIG_8 (2 << 18)
124#define SLINK_RX_TRIG_16 (3 << 18)
125#define SLINK_RX_TRIG_MASK (3 << 18)
126#define SLINK_PACKED (1 << 20)
127#define SLINK_PACK_SIZE_4 (0 << 21)
128#define SLINK_PACK_SIZE_8 (1 << 21)
129#define SLINK_PACK_SIZE_16 (2 << 21)
130#define SLINK_PACK_SIZE_32 (3 << 21)
131#define SLINK_PACK_SIZE_MASK (3 << 21)
132#define SLINK_IE_TXC (1 << 26)
133#define SLINK_IE_RXC (1 << 27)
134#define SLINK_DMA_EN (1 << 31)
135
136#define SLINK_STATUS2 0x01c
137#define SLINK_TX_FIFO_EMPTY_COUNT(val) (((val) & 0x3f) >> 0)
138#define SLINK_RX_FIFO_FULL_COUNT(val) (((val) & 0x3f0000) >> 16)
139#define SLINK_SS_HOLD_TIME(val) (((val) & 0xF) << 6)
140
141#define SLINK_TX_FIFO 0x100
142#define SLINK_RX_FIFO 0x180
143
144#define DATA_DIR_TX (1 << 0)
145#define DATA_DIR_RX (1 << 1)
146
147#define SLINK_DMA_TIMEOUT (msecs_to_jiffies(1000))
148
149#define DEFAULT_SPI_DMA_BUF_LEN (16*1024)
150#define TX_FIFO_EMPTY_COUNT_MAX SLINK_TX_FIFO_EMPTY_COUNT(0x20)
151#define RX_FIFO_FULL_COUNT_ZERO SLINK_RX_FIFO_FULL_COUNT(0)
152
153#define SLINK_STATUS2_RESET \
154 (TX_FIFO_EMPTY_COUNT_MAX | RX_FIFO_FULL_COUNT_ZERO << 16)
155
156#define MAX_CHIP_SELECT 4
157#define SLINK_FIFO_DEPTH 32
158
159struct tegra_slink_chip_data {
160 bool cs_hold_time;
161};
162
163struct tegra_slink_data {
164 struct device *dev;
165 struct spi_master *master;
166 const struct tegra_slink_chip_data *chip_data;
167 spinlock_t lock;
168
169 struct clk *clk;
170 void __iomem *base;
171 phys_addr_t phys;
172 unsigned irq;
173 int dma_req_sel;
174 u32 spi_max_frequency;
175 u32 cur_speed;
176
177 struct spi_device *cur_spi;
178 unsigned cur_pos;
179 unsigned cur_len;
180 unsigned words_per_32bit;
181 unsigned bytes_per_word;
182 unsigned curr_dma_words;
183 unsigned cur_direction;
184
185 unsigned cur_rx_pos;
186 unsigned cur_tx_pos;
187
188 unsigned dma_buf_size;
189 unsigned max_buf_size;
190 bool is_curr_dma_xfer;
191
192 struct completion rx_dma_complete;
193 struct completion tx_dma_complete;
194
195 u32 tx_status;
196 u32 rx_status;
197 u32 status_reg;
198 bool is_packed;
199 unsigned long packed_size;
200
201 u32 command_reg;
202 u32 command2_reg;
203 u32 dma_control_reg;
204 u32 def_command_reg;
205 u32 def_command2_reg;
206
207 struct completion xfer_completion;
208 struct spi_transfer *curr_xfer;
209 struct dma_chan *rx_dma_chan;
210 u32 *rx_dma_buf;
211 dma_addr_t rx_dma_phys;
212 struct dma_async_tx_descriptor *rx_dma_desc;
213
214 struct dma_chan *tx_dma_chan;
215 u32 *tx_dma_buf;
216 dma_addr_t tx_dma_phys;
217 struct dma_async_tx_descriptor *tx_dma_desc;
218};
219
220static int tegra_slink_runtime_suspend(struct device *dev);
221static int tegra_slink_runtime_resume(struct device *dev);
222
223static inline unsigned long tegra_slink_readl(struct tegra_slink_data *tspi,
224 unsigned long reg)
225{
226 return readl(tspi->base + reg);
227}
228
229static inline void tegra_slink_writel(struct tegra_slink_data *tspi,
230 unsigned long val, unsigned long reg)
231{
232 writel(val, tspi->base + reg);
233
234
235 if (reg != SLINK_TX_FIFO)
236 readl(tspi->base + SLINK_MAS_DATA);
237}
238
239static void tegra_slink_clear_status(struct tegra_slink_data *tspi)
240{
241 unsigned long val;
242 unsigned long val_write = 0;
243
244 val = tegra_slink_readl(tspi, SLINK_STATUS);
245
246
247 val_write = SLINK_RDY | SLINK_FIFO_ERROR;
248 tegra_slink_writel(tspi, val_write, SLINK_STATUS);
249}
250
251static unsigned long tegra_slink_get_packed_size(struct tegra_slink_data *tspi,
252 struct spi_transfer *t)
253{
254 unsigned long val;
255
256 switch (tspi->bytes_per_word) {
257 case 0:
258 val = SLINK_PACK_SIZE_4;
259 break;
260 case 1:
261 val = SLINK_PACK_SIZE_8;
262 break;
263 case 2:
264 val = SLINK_PACK_SIZE_16;
265 break;
266 case 4:
267 val = SLINK_PACK_SIZE_32;
268 break;
269 default:
270 val = 0;
271 }
272 return val;
273}
274
275static unsigned tegra_slink_calculate_curr_xfer_param(
276 struct spi_device *spi, struct tegra_slink_data *tspi,
277 struct spi_transfer *t)
278{
279 unsigned remain_len = t->len - tspi->cur_pos;
280 unsigned max_word;
281 unsigned bits_per_word ;
282 unsigned max_len;
283 unsigned total_fifo_words;
284
285 bits_per_word = t->bits_per_word;
286 tspi->bytes_per_word = (bits_per_word - 1) / 8 + 1;
287
288 if (bits_per_word == 8 || bits_per_word == 16) {
289 tspi->is_packed = 1;
290 tspi->words_per_32bit = 32/bits_per_word;
291 } else {
292 tspi->is_packed = 0;
293 tspi->words_per_32bit = 1;
294 }
295 tspi->packed_size = tegra_slink_get_packed_size(tspi, t);
296
297 if (tspi->is_packed) {
298 max_len = min(remain_len, tspi->max_buf_size);
299 tspi->curr_dma_words = max_len/tspi->bytes_per_word;
300 total_fifo_words = max_len/4;
301 } else {
302 max_word = (remain_len - 1) / tspi->bytes_per_word + 1;
303 max_word = min(max_word, tspi->max_buf_size/4);
304 tspi->curr_dma_words = max_word;
305 total_fifo_words = max_word;
306 }
307 return total_fifo_words;
308}
309
310static unsigned tegra_slink_fill_tx_fifo_from_client_txbuf(
311 struct tegra_slink_data *tspi, struct spi_transfer *t)
312{
313 unsigned nbytes;
314 unsigned tx_empty_count;
315 unsigned long fifo_status;
316 unsigned max_n_32bit;
317 unsigned i, count;
318 unsigned long x;
319 unsigned int written_words;
320 unsigned fifo_words_left;
321 u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
322
323 fifo_status = tegra_slink_readl(tspi, SLINK_STATUS2);
324 tx_empty_count = SLINK_TX_FIFO_EMPTY_COUNT(fifo_status);
325
326 if (tspi->is_packed) {
327 fifo_words_left = tx_empty_count * tspi->words_per_32bit;
328 written_words = min(fifo_words_left, tspi->curr_dma_words);
329 nbytes = written_words * tspi->bytes_per_word;
330 max_n_32bit = DIV_ROUND_UP(nbytes, 4);
331 for (count = 0; count < max_n_32bit; count++) {
332 x = 0;
333 for (i = 0; (i < 4) && nbytes; i++, nbytes--)
334 x |= (*tx_buf++) << (i*8);
335 tegra_slink_writel(tspi, x, SLINK_TX_FIFO);
336 }
337 } else {
338 max_n_32bit = min(tspi->curr_dma_words, tx_empty_count);
339 written_words = max_n_32bit;
340 nbytes = written_words * tspi->bytes_per_word;
341 for (count = 0; count < max_n_32bit; count++) {
342 x = 0;
343 for (i = 0; nbytes && (i < tspi->bytes_per_word);
344 i++, nbytes--)
345 x |= ((*tx_buf++) << i*8);
346 tegra_slink_writel(tspi, x, SLINK_TX_FIFO);
347 }
348 }
349 tspi->cur_tx_pos += written_words * tspi->bytes_per_word;
350 return written_words;
351}
352
353static unsigned int tegra_slink_read_rx_fifo_to_client_rxbuf(
354 struct tegra_slink_data *tspi, struct spi_transfer *t)
355{
356 unsigned rx_full_count;
357 unsigned long fifo_status;
358 unsigned i, count;
359 unsigned long x;
360 unsigned int read_words = 0;
361 unsigned len;
362 u8 *rx_buf = (u8 *)t->rx_buf + tspi->cur_rx_pos;
363
364 fifo_status = tegra_slink_readl(tspi, SLINK_STATUS2);
365 rx_full_count = SLINK_RX_FIFO_FULL_COUNT(fifo_status);
366 if (tspi->is_packed) {
367 len = tspi->curr_dma_words * tspi->bytes_per_word;
368 for (count = 0; count < rx_full_count; count++) {
369 x = tegra_slink_readl(tspi, SLINK_RX_FIFO);
370 for (i = 0; len && (i < 4); i++, len--)
371 *rx_buf++ = (x >> i*8) & 0xFF;
372 }
373 tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
374 read_words += tspi->curr_dma_words;
375 } else {
376 for (count = 0; count < rx_full_count; count++) {
377 x = tegra_slink_readl(tspi, SLINK_RX_FIFO);
378 for (i = 0; (i < tspi->bytes_per_word); i++)
379 *rx_buf++ = (x >> (i*8)) & 0xFF;
380 }
381 tspi->cur_rx_pos += rx_full_count * tspi->bytes_per_word;
382 read_words += rx_full_count;
383 }
384 return read_words;
385}
386
387static void tegra_slink_copy_client_txbuf_to_spi_txbuf(
388 struct tegra_slink_data *tspi, struct spi_transfer *t)
389{
390 unsigned len;
391
392
393 dma_sync_single_for_cpu(tspi->dev, tspi->tx_dma_phys,
394 tspi->dma_buf_size, DMA_TO_DEVICE);
395
396 if (tspi->is_packed) {
397 len = tspi->curr_dma_words * tspi->bytes_per_word;
398 memcpy(tspi->tx_dma_buf, t->tx_buf + tspi->cur_pos, len);
399 } else {
400 unsigned int i;
401 unsigned int count;
402 u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
403 unsigned consume = tspi->curr_dma_words * tspi->bytes_per_word;
404 unsigned int x;
405
406 for (count = 0; count < tspi->curr_dma_words; count++) {
407 x = 0;
408 for (i = 0; consume && (i < tspi->bytes_per_word);
409 i++, consume--)
410 x |= ((*tx_buf++) << i * 8);
411 tspi->tx_dma_buf[count] = x;
412 }
413 }
414 tspi->cur_tx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
415
416
417 dma_sync_single_for_device(tspi->dev, tspi->tx_dma_phys,
418 tspi->dma_buf_size, DMA_TO_DEVICE);
419}
420
421static void tegra_slink_copy_spi_rxbuf_to_client_rxbuf(
422 struct tegra_slink_data *tspi, struct spi_transfer *t)
423{
424 unsigned len;
425
426
427 dma_sync_single_for_cpu(tspi->dev, tspi->rx_dma_phys,
428 tspi->dma_buf_size, DMA_FROM_DEVICE);
429
430 if (tspi->is_packed) {
431 len = tspi->curr_dma_words * tspi->bytes_per_word;
432 memcpy(t->rx_buf + tspi->cur_rx_pos, tspi->rx_dma_buf, len);
433 } else {
434 unsigned int i;
435 unsigned int count;
436 unsigned char *rx_buf = t->rx_buf + tspi->cur_rx_pos;
437 unsigned int x;
438 unsigned int rx_mask, bits_per_word;
439
440 bits_per_word = t->bits_per_word;
441 rx_mask = (1 << bits_per_word) - 1;
442 for (count = 0; count < tspi->curr_dma_words; count++) {
443 x = tspi->rx_dma_buf[count];
444 x &= rx_mask;
445 for (i = 0; (i < tspi->bytes_per_word); i++)
446 *rx_buf++ = (x >> (i*8)) & 0xFF;
447 }
448 }
449 tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
450
451
452 dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
453 tspi->dma_buf_size, DMA_FROM_DEVICE);
454}
455
456static void tegra_slink_dma_complete(void *args)
457{
458 struct completion *dma_complete = args;
459
460 complete(dma_complete);
461}
462
463static int tegra_slink_start_tx_dma(struct tegra_slink_data *tspi, int len)
464{
465 INIT_COMPLETION(tspi->tx_dma_complete);
466 tspi->tx_dma_desc = dmaengine_prep_slave_single(tspi->tx_dma_chan,
467 tspi->tx_dma_phys, len, DMA_MEM_TO_DEV,
468 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
469 if (!tspi->tx_dma_desc) {
470 dev_err(tspi->dev, "Not able to get desc for Tx\n");
471 return -EIO;
472 }
473
474 tspi->tx_dma_desc->callback = tegra_slink_dma_complete;
475 tspi->tx_dma_desc->callback_param = &tspi->tx_dma_complete;
476
477 dmaengine_submit(tspi->tx_dma_desc);
478 dma_async_issue_pending(tspi->tx_dma_chan);
479 return 0;
480}
481
482static int tegra_slink_start_rx_dma(struct tegra_slink_data *tspi, int len)
483{
484 INIT_COMPLETION(tspi->rx_dma_complete);
485 tspi->rx_dma_desc = dmaengine_prep_slave_single(tspi->rx_dma_chan,
486 tspi->rx_dma_phys, len, DMA_DEV_TO_MEM,
487 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
488 if (!tspi->rx_dma_desc) {
489 dev_err(tspi->dev, "Not able to get desc for Rx\n");
490 return -EIO;
491 }
492
493 tspi->rx_dma_desc->callback = tegra_slink_dma_complete;
494 tspi->rx_dma_desc->callback_param = &tspi->rx_dma_complete;
495
496 dmaengine_submit(tspi->rx_dma_desc);
497 dma_async_issue_pending(tspi->rx_dma_chan);
498 return 0;
499}
500
501static int tegra_slink_start_dma_based_transfer(
502 struct tegra_slink_data *tspi, struct spi_transfer *t)
503{
504 unsigned long val;
505 unsigned long test_val;
506 unsigned int len;
507 int ret = 0;
508 unsigned long status;
509
510
511 status = tegra_slink_readl(tspi, SLINK_STATUS);
512 if ((status & SLINK_FIFO_EMPTY) != SLINK_FIFO_EMPTY) {
513 dev_err(tspi->dev,
514 "Rx/Tx fifo are not empty status 0x%08lx\n", status);
515 return -EIO;
516 }
517
518 val = SLINK_DMA_BLOCK_SIZE(tspi->curr_dma_words - 1);
519 val |= tspi->packed_size;
520 if (tspi->is_packed)
521 len = DIV_ROUND_UP(tspi->curr_dma_words * tspi->bytes_per_word,
522 4) * 4;
523 else
524 len = tspi->curr_dma_words * 4;
525
526
527 if (len & 0xF)
528 val |= SLINK_TX_TRIG_1 | SLINK_RX_TRIG_1;
529 else if (((len) >> 4) & 0x1)
530 val |= SLINK_TX_TRIG_4 | SLINK_RX_TRIG_4;
531 else
532 val |= SLINK_TX_TRIG_8 | SLINK_RX_TRIG_8;
533
534 if (tspi->cur_direction & DATA_DIR_TX)
535 val |= SLINK_IE_TXC;
536
537 if (tspi->cur_direction & DATA_DIR_RX)
538 val |= SLINK_IE_RXC;
539
540 tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
541 tspi->dma_control_reg = val;
542
543 if (tspi->cur_direction & DATA_DIR_TX) {
544 tegra_slink_copy_client_txbuf_to_spi_txbuf(tspi, t);
545 wmb();
546 ret = tegra_slink_start_tx_dma(tspi, len);
547 if (ret < 0) {
548 dev_err(tspi->dev,
549 "Starting tx dma failed, err %d\n", ret);
550 return ret;
551 }
552
553
554 test_val = tegra_slink_readl(tspi, SLINK_STATUS);
555 while (!(test_val & SLINK_TX_FULL))
556 test_val = tegra_slink_readl(tspi, SLINK_STATUS);
557 }
558
559 if (tspi->cur_direction & DATA_DIR_RX) {
560
561 dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
562 tspi->dma_buf_size, DMA_FROM_DEVICE);
563
564 ret = tegra_slink_start_rx_dma(tspi, len);
565 if (ret < 0) {
566 dev_err(tspi->dev,
567 "Starting rx dma failed, err %d\n", ret);
568 if (tspi->cur_direction & DATA_DIR_TX)
569 dmaengine_terminate_all(tspi->tx_dma_chan);
570 return ret;
571 }
572 }
573 tspi->is_curr_dma_xfer = true;
574 if (tspi->is_packed) {
575 val |= SLINK_PACKED;
576 tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
577
578 udelay(1);
579 }
580 tspi->dma_control_reg = val;
581
582 val |= SLINK_DMA_EN;
583 tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
584 return ret;
585}
586
587static int tegra_slink_start_cpu_based_transfer(
588 struct tegra_slink_data *tspi, struct spi_transfer *t)
589{
590 unsigned long val;
591 unsigned cur_words;
592
593 val = tspi->packed_size;
594 if (tspi->cur_direction & DATA_DIR_TX)
595 val |= SLINK_IE_TXC;
596
597 if (tspi->cur_direction & DATA_DIR_RX)
598 val |= SLINK_IE_RXC;
599
600 tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
601 tspi->dma_control_reg = val;
602
603 if (tspi->cur_direction & DATA_DIR_TX)
604 cur_words = tegra_slink_fill_tx_fifo_from_client_txbuf(tspi, t);
605 else
606 cur_words = tspi->curr_dma_words;
607 val |= SLINK_DMA_BLOCK_SIZE(cur_words - 1);
608 tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
609 tspi->dma_control_reg = val;
610
611 tspi->is_curr_dma_xfer = false;
612 if (tspi->is_packed) {
613 val |= SLINK_PACKED;
614 tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
615 udelay(1);
616 wmb();
617 }
618 tspi->dma_control_reg = val;
619 val |= SLINK_DMA_EN;
620 tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
621 return 0;
622}
623
624static int tegra_slink_init_dma_param(struct tegra_slink_data *tspi,
625 bool dma_to_memory)
626{
627 struct dma_chan *dma_chan;
628 u32 *dma_buf;
629 dma_addr_t dma_phys;
630 int ret;
631 struct dma_slave_config dma_sconfig;
632 dma_cap_mask_t mask;
633
634 dma_cap_zero(mask);
635 dma_cap_set(DMA_SLAVE, mask);
636 dma_chan = dma_request_channel(mask, NULL, NULL);
637 if (!dma_chan) {
638 dev_err(tspi->dev,
639 "Dma channel is not available, will try later\n");
640 return -EPROBE_DEFER;
641 }
642
643 dma_buf = dma_alloc_coherent(tspi->dev, tspi->dma_buf_size,
644 &dma_phys, GFP_KERNEL);
645 if (!dma_buf) {
646 dev_err(tspi->dev, " Not able to allocate the dma buffer\n");
647 dma_release_channel(dma_chan);
648 return -ENOMEM;
649 }
650
651 dma_sconfig.slave_id = tspi->dma_req_sel;
652 if (dma_to_memory) {
653 dma_sconfig.src_addr = tspi->phys + SLINK_RX_FIFO;
654 dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
655 dma_sconfig.src_maxburst = 0;
656 } else {
657 dma_sconfig.dst_addr = tspi->phys + SLINK_TX_FIFO;
658 dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
659 dma_sconfig.dst_maxburst = 0;
660 }
661
662 ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
663 if (ret)
664 goto scrub;
665 if (dma_to_memory) {
666 tspi->rx_dma_chan = dma_chan;
667 tspi->rx_dma_buf = dma_buf;
668 tspi->rx_dma_phys = dma_phys;
669 } else {
670 tspi->tx_dma_chan = dma_chan;
671 tspi->tx_dma_buf = dma_buf;
672 tspi->tx_dma_phys = dma_phys;
673 }
674 return 0;
675
676scrub:
677 dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
678 dma_release_channel(dma_chan);
679 return ret;
680}
681
682static void tegra_slink_deinit_dma_param(struct tegra_slink_data *tspi,
683 bool dma_to_memory)
684{
685 u32 *dma_buf;
686 dma_addr_t dma_phys;
687 struct dma_chan *dma_chan;
688
689 if (dma_to_memory) {
690 dma_buf = tspi->rx_dma_buf;
691 dma_chan = tspi->rx_dma_chan;
692 dma_phys = tspi->rx_dma_phys;
693 tspi->rx_dma_chan = NULL;
694 tspi->rx_dma_buf = NULL;
695 } else {
696 dma_buf = tspi->tx_dma_buf;
697 dma_chan = tspi->tx_dma_chan;
698 dma_phys = tspi->tx_dma_phys;
699 tspi->tx_dma_buf = NULL;
700 tspi->tx_dma_chan = NULL;
701 }
702 if (!dma_chan)
703 return;
704
705 dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
706 dma_release_channel(dma_chan);
707}
708
709static int tegra_slink_start_transfer_one(struct spi_device *spi,
710 struct spi_transfer *t, bool is_first_of_msg,
711 bool is_single_xfer)
712{
713 struct tegra_slink_data *tspi = spi_master_get_devdata(spi->master);
714 u32 speed;
715 u8 bits_per_word;
716 unsigned total_fifo_words;
717 int ret;
718 unsigned long command;
719 unsigned long command2;
720
721 bits_per_word = t->bits_per_word;
722 speed = t->speed_hz;
723 if (speed != tspi->cur_speed) {
724 clk_set_rate(tspi->clk, speed * 4);
725 tspi->cur_speed = speed;
726 }
727
728 tspi->cur_spi = spi;
729 tspi->cur_pos = 0;
730 tspi->cur_rx_pos = 0;
731 tspi->cur_tx_pos = 0;
732 tspi->curr_xfer = t;
733 total_fifo_words = tegra_slink_calculate_curr_xfer_param(spi, tspi, t);
734
735 if (is_first_of_msg) {
736 tegra_slink_clear_status(tspi);
737
738 command = tspi->def_command_reg;
739 command |= SLINK_BIT_LENGTH(bits_per_word - 1);
740 command |= SLINK_CS_SW | SLINK_CS_VALUE;
741
742 command2 = tspi->def_command2_reg;
743 command2 |= SLINK_SS_EN_CS(spi->chip_select);
744
745 command &= ~SLINK_MODES;
746 if (spi->mode & SPI_CPHA)
747 command |= SLINK_CK_SDA;
748
749 if (spi->mode & SPI_CPOL)
750 command |= SLINK_IDLE_SCLK_DRIVE_HIGH;
751 else
752 command |= SLINK_IDLE_SCLK_DRIVE_LOW;
753 } else {
754 command = tspi->command_reg;
755 command &= ~SLINK_BIT_LENGTH(~0);
756 command |= SLINK_BIT_LENGTH(bits_per_word - 1);
757
758 command2 = tspi->command2_reg;
759 command2 &= ~(SLINK_RXEN | SLINK_TXEN);
760 }
761
762 tegra_slink_writel(tspi, command, SLINK_COMMAND);
763 tspi->command_reg = command;
764
765 tspi->cur_direction = 0;
766 if (t->rx_buf) {
767 command2 |= SLINK_RXEN;
768 tspi->cur_direction |= DATA_DIR_RX;
769 }
770 if (t->tx_buf) {
771 command2 |= SLINK_TXEN;
772 tspi->cur_direction |= DATA_DIR_TX;
773 }
774 tegra_slink_writel(tspi, command2, SLINK_COMMAND2);
775 tspi->command2_reg = command2;
776
777 if (total_fifo_words > SLINK_FIFO_DEPTH)
778 ret = tegra_slink_start_dma_based_transfer(tspi, t);
779 else
780 ret = tegra_slink_start_cpu_based_transfer(tspi, t);
781 return ret;
782}
783
784static int tegra_slink_setup(struct spi_device *spi)
785{
786 struct tegra_slink_data *tspi = spi_master_get_devdata(spi->master);
787 unsigned long val;
788 unsigned long flags;
789 int ret;
790 unsigned int cs_pol_bit[MAX_CHIP_SELECT] = {
791 SLINK_CS_POLARITY,
792 SLINK_CS_POLARITY1,
793 SLINK_CS_POLARITY2,
794 SLINK_CS_POLARITY3,
795 };
796
797 dev_dbg(&spi->dev, "setup %d bpw, %scpol, %scpha, %dHz\n",
798 spi->bits_per_word,
799 spi->mode & SPI_CPOL ? "" : "~",
800 spi->mode & SPI_CPHA ? "" : "~",
801 spi->max_speed_hz);
802
803 BUG_ON(spi->chip_select >= MAX_CHIP_SELECT);
804
805
806 spi->max_speed_hz = spi->max_speed_hz ? : tspi->spi_max_frequency;
807 ret = pm_runtime_get_sync(tspi->dev);
808 if (ret < 0) {
809 dev_err(tspi->dev, "pm runtime failed, e = %d\n", ret);
810 return ret;
811 }
812
813 spin_lock_irqsave(&tspi->lock, flags);
814 val = tspi->def_command_reg;
815 if (spi->mode & SPI_CS_HIGH)
816 val |= cs_pol_bit[spi->chip_select];
817 else
818 val &= ~cs_pol_bit[spi->chip_select];
819 tspi->def_command_reg = val;
820 tegra_slink_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
821 spin_unlock_irqrestore(&tspi->lock, flags);
822
823 pm_runtime_put(tspi->dev);
824 return 0;
825}
826
827static int tegra_slink_transfer_one_message(struct spi_master *master,
828 struct spi_message *msg)
829{
830 bool is_first_msg = true;
831 int single_xfer;
832 struct tegra_slink_data *tspi = spi_master_get_devdata(master);
833 struct spi_transfer *xfer;
834 struct spi_device *spi = msg->spi;
835 int ret;
836
837 msg->status = 0;
838 msg->actual_length = 0;
839 ret = pm_runtime_get_sync(tspi->dev);
840 if (ret < 0) {
841 dev_err(tspi->dev, "runtime get failed: %d\n", ret);
842 goto done;
843 }
844
845 single_xfer = list_is_singular(&msg->transfers);
846 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
847 INIT_COMPLETION(tspi->xfer_completion);
848 ret = tegra_slink_start_transfer_one(spi, xfer,
849 is_first_msg, single_xfer);
850 if (ret < 0) {
851 dev_err(tspi->dev,
852 "spi can not start transfer, err %d\n", ret);
853 goto exit;
854 }
855 is_first_msg = false;
856 ret = wait_for_completion_timeout(&tspi->xfer_completion,
857 SLINK_DMA_TIMEOUT);
858 if (WARN_ON(ret == 0)) {
859 dev_err(tspi->dev,
860 "spi trasfer timeout, err %d\n", ret);
861 ret = -EIO;
862 goto exit;
863 }
864
865 if (tspi->tx_status || tspi->rx_status) {
866 dev_err(tspi->dev, "Error in Transfer\n");
867 ret = -EIO;
868 goto exit;
869 }
870 msg->actual_length += xfer->len;
871 if (xfer->cs_change && xfer->delay_usecs) {
872 tegra_slink_writel(tspi, tspi->def_command_reg,
873 SLINK_COMMAND);
874 udelay(xfer->delay_usecs);
875 }
876 }
877 ret = 0;
878exit:
879 tegra_slink_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
880 tegra_slink_writel(tspi, tspi->def_command2_reg, SLINK_COMMAND2);
881 pm_runtime_put(tspi->dev);
882done:
883 msg->status = ret;
884 spi_finalize_current_message(master);
885 return ret;
886}
887
888static irqreturn_t handle_cpu_based_xfer(struct tegra_slink_data *tspi)
889{
890 struct spi_transfer *t = tspi->curr_xfer;
891 unsigned long flags;
892
893 spin_lock_irqsave(&tspi->lock, flags);
894 if (tspi->tx_status || tspi->rx_status ||
895 (tspi->status_reg & SLINK_BSY)) {
896 dev_err(tspi->dev,
897 "CpuXfer ERROR bit set 0x%x\n", tspi->status_reg);
898 dev_err(tspi->dev,
899 "CpuXfer 0x%08x:0x%08x:0x%08x\n", tspi->command_reg,
900 tspi->command2_reg, tspi->dma_control_reg);
901 tegra_periph_reset_assert(tspi->clk);
902 udelay(2);
903 tegra_periph_reset_deassert(tspi->clk);
904 complete(&tspi->xfer_completion);
905 goto exit;
906 }
907
908 if (tspi->cur_direction & DATA_DIR_RX)
909 tegra_slink_read_rx_fifo_to_client_rxbuf(tspi, t);
910
911 if (tspi->cur_direction & DATA_DIR_TX)
912 tspi->cur_pos = tspi->cur_tx_pos;
913 else
914 tspi->cur_pos = tspi->cur_rx_pos;
915
916 if (tspi->cur_pos == t->len) {
917 complete(&tspi->xfer_completion);
918 goto exit;
919 }
920
921 tegra_slink_calculate_curr_xfer_param(tspi->cur_spi, tspi, t);
922 tegra_slink_start_cpu_based_transfer(tspi, t);
923exit:
924 spin_unlock_irqrestore(&tspi->lock, flags);
925 return IRQ_HANDLED;
926}
927
928static irqreturn_t handle_dma_based_xfer(struct tegra_slink_data *tspi)
929{
930 struct spi_transfer *t = tspi->curr_xfer;
931 long wait_status;
932 int err = 0;
933 unsigned total_fifo_words;
934 unsigned long flags;
935
936
937 if (tspi->cur_direction & DATA_DIR_TX) {
938 if (tspi->tx_status) {
939 dmaengine_terminate_all(tspi->tx_dma_chan);
940 err += 1;
941 } else {
942 wait_status = wait_for_completion_interruptible_timeout(
943 &tspi->tx_dma_complete, SLINK_DMA_TIMEOUT);
944 if (wait_status <= 0) {
945 dmaengine_terminate_all(tspi->tx_dma_chan);
946 dev_err(tspi->dev, "TxDma Xfer failed\n");
947 err += 1;
948 }
949 }
950 }
951
952 if (tspi->cur_direction & DATA_DIR_RX) {
953 if (tspi->rx_status) {
954 dmaengine_terminate_all(tspi->rx_dma_chan);
955 err += 2;
956 } else {
957 wait_status = wait_for_completion_interruptible_timeout(
958 &tspi->rx_dma_complete, SLINK_DMA_TIMEOUT);
959 if (wait_status <= 0) {
960 dmaengine_terminate_all(tspi->rx_dma_chan);
961 dev_err(tspi->dev, "RxDma Xfer failed\n");
962 err += 2;
963 }
964 }
965 }
966
967 spin_lock_irqsave(&tspi->lock, flags);
968 if (err) {
969 dev_err(tspi->dev,
970 "DmaXfer: ERROR bit set 0x%x\n", tspi->status_reg);
971 dev_err(tspi->dev,
972 "DmaXfer 0x%08x:0x%08x:0x%08x\n", tspi->command_reg,
973 tspi->command2_reg, tspi->dma_control_reg);
974 tegra_periph_reset_assert(tspi->clk);
975 udelay(2);
976 tegra_periph_reset_deassert(tspi->clk);
977 complete(&tspi->xfer_completion);
978 spin_unlock_irqrestore(&tspi->lock, flags);
979 return IRQ_HANDLED;
980 }
981
982 if (tspi->cur_direction & DATA_DIR_RX)
983 tegra_slink_copy_spi_rxbuf_to_client_rxbuf(tspi, t);
984
985 if (tspi->cur_direction & DATA_DIR_TX)
986 tspi->cur_pos = tspi->cur_tx_pos;
987 else
988 tspi->cur_pos = tspi->cur_rx_pos;
989
990 if (tspi->cur_pos == t->len) {
991 complete(&tspi->xfer_completion);
992 goto exit;
993 }
994
995
996 total_fifo_words = tegra_slink_calculate_curr_xfer_param(tspi->cur_spi,
997 tspi, t);
998 if (total_fifo_words > SLINK_FIFO_DEPTH)
999 err = tegra_slink_start_dma_based_transfer(tspi, t);
1000 else
1001 err = tegra_slink_start_cpu_based_transfer(tspi, t);
1002
1003exit:
1004 spin_unlock_irqrestore(&tspi->lock, flags);
1005 return IRQ_HANDLED;
1006}
1007
1008static irqreturn_t tegra_slink_isr_thread(int irq, void *context_data)
1009{
1010 struct tegra_slink_data *tspi = context_data;
1011
1012 if (!tspi->is_curr_dma_xfer)
1013 return handle_cpu_based_xfer(tspi);
1014 return handle_dma_based_xfer(tspi);
1015}
1016
1017static irqreturn_t tegra_slink_isr(int irq, void *context_data)
1018{
1019 struct tegra_slink_data *tspi = context_data;
1020
1021 tspi->status_reg = tegra_slink_readl(tspi, SLINK_STATUS);
1022 if (tspi->cur_direction & DATA_DIR_TX)
1023 tspi->tx_status = tspi->status_reg &
1024 (SLINK_TX_OVF | SLINK_TX_UNF);
1025
1026 if (tspi->cur_direction & DATA_DIR_RX)
1027 tspi->rx_status = tspi->status_reg &
1028 (SLINK_RX_OVF | SLINK_RX_UNF);
1029 tegra_slink_clear_status(tspi);
1030
1031 return IRQ_WAKE_THREAD;
1032}
1033
1034static void tegra_slink_parse_dt(struct tegra_slink_data *tspi)
1035{
1036 struct device_node *np = tspi->dev->of_node;
1037 u32 of_dma[2];
1038
1039 if (of_property_read_u32_array(np, "nvidia,dma-request-selector",
1040 of_dma, 2) >= 0)
1041 tspi->dma_req_sel = of_dma[1];
1042
1043 if (of_property_read_u32(np, "spi-max-frequency",
1044 &tspi->spi_max_frequency))
1045 tspi->spi_max_frequency = 25000000;
1046}
1047
1048static const struct tegra_slink_chip_data tegra30_spi_cdata = {
1049 .cs_hold_time = true,
1050};
1051
1052static const struct tegra_slink_chip_data tegra20_spi_cdata = {
1053 .cs_hold_time = false,
1054};
1055
1056static struct of_device_id tegra_slink_of_match[] = {
1057 { .compatible = "nvidia,tegra30-slink", .data = &tegra30_spi_cdata, },
1058 { .compatible = "nvidia,tegra20-slink", .data = &tegra20_spi_cdata, },
1059 {}
1060};
1061MODULE_DEVICE_TABLE(of, tegra_slink_of_match);
1062
1063static int tegra_slink_probe(struct platform_device *pdev)
1064{
1065 struct spi_master *master;
1066 struct tegra_slink_data *tspi;
1067 struct resource *r;
1068 int ret, spi_irq;
1069 const struct tegra_slink_chip_data *cdata = NULL;
1070 const struct of_device_id *match;
1071
1072 match = of_match_device(tegra_slink_of_match, &pdev->dev);
1073 if (!match) {
1074 dev_err(&pdev->dev, "Error: No device match found\n");
1075 return -ENODEV;
1076 }
1077 cdata = match->data;
1078
1079 master = spi_alloc_master(&pdev->dev, sizeof(*tspi));
1080 if (!master) {
1081 dev_err(&pdev->dev, "master allocation failed\n");
1082 return -ENOMEM;
1083 }
1084
1085
1086 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1087 master->setup = tegra_slink_setup;
1088 master->transfer_one_message = tegra_slink_transfer_one_message;
1089 master->num_chipselect = MAX_CHIP_SELECT;
1090 master->bus_num = -1;
1091
1092 platform_set_drvdata(pdev, master);
1093 tspi = spi_master_get_devdata(master);
1094 tspi->master = master;
1095 tspi->dev = &pdev->dev;
1096 tspi->chip_data = cdata;
1097 spin_lock_init(&tspi->lock);
1098
1099 tegra_slink_parse_dt(tspi);
1100
1101 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1102 if (!r) {
1103 dev_err(&pdev->dev, "No IO memory resource\n");
1104 ret = -ENODEV;
1105 goto exit_free_master;
1106 }
1107 tspi->phys = r->start;
1108 tspi->base = devm_ioremap_resource(&pdev->dev, r);
1109 if (IS_ERR(tspi->base)) {
1110 ret = PTR_ERR(tspi->base);
1111 goto exit_free_master;
1112 }
1113
1114 spi_irq = platform_get_irq(pdev, 0);
1115 tspi->irq = spi_irq;
1116 ret = request_threaded_irq(tspi->irq, tegra_slink_isr,
1117 tegra_slink_isr_thread, IRQF_ONESHOT,
1118 dev_name(&pdev->dev), tspi);
1119 if (ret < 0) {
1120 dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
1121 tspi->irq);
1122 goto exit_free_master;
1123 }
1124
1125 tspi->clk = devm_clk_get(&pdev->dev, NULL);
1126 if (IS_ERR(tspi->clk)) {
1127 dev_err(&pdev->dev, "can not get clock\n");
1128 ret = PTR_ERR(tspi->clk);
1129 goto exit_free_irq;
1130 }
1131
1132 tspi->max_buf_size = SLINK_FIFO_DEPTH << 2;
1133 tspi->dma_buf_size = DEFAULT_SPI_DMA_BUF_LEN;
1134
1135 if (tspi->dma_req_sel) {
1136 ret = tegra_slink_init_dma_param(tspi, true);
1137 if (ret < 0) {
1138 dev_err(&pdev->dev, "RxDma Init failed, err %d\n", ret);
1139 goto exit_free_irq;
1140 }
1141
1142 ret = tegra_slink_init_dma_param(tspi, false);
1143 if (ret < 0) {
1144 dev_err(&pdev->dev, "TxDma Init failed, err %d\n", ret);
1145 goto exit_rx_dma_free;
1146 }
1147 tspi->max_buf_size = tspi->dma_buf_size;
1148 init_completion(&tspi->tx_dma_complete);
1149 init_completion(&tspi->rx_dma_complete);
1150 }
1151
1152 init_completion(&tspi->xfer_completion);
1153
1154 pm_runtime_enable(&pdev->dev);
1155 if (!pm_runtime_enabled(&pdev->dev)) {
1156 ret = tegra_slink_runtime_resume(&pdev->dev);
1157 if (ret)
1158 goto exit_pm_disable;
1159 }
1160
1161 ret = pm_runtime_get_sync(&pdev->dev);
1162 if (ret < 0) {
1163 dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret);
1164 goto exit_pm_disable;
1165 }
1166 tspi->def_command_reg = SLINK_M_S;
1167 tspi->def_command2_reg = SLINK_CS_ACTIVE_BETWEEN;
1168 tegra_slink_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
1169 tegra_slink_writel(tspi, tspi->def_command2_reg, SLINK_COMMAND2);
1170 pm_runtime_put(&pdev->dev);
1171
1172 master->dev.of_node = pdev->dev.of_node;
1173 ret = spi_register_master(master);
1174 if (ret < 0) {
1175 dev_err(&pdev->dev, "can not register to master err %d\n", ret);
1176 goto exit_pm_disable;
1177 }
1178 return ret;
1179
1180exit_pm_disable:
1181 pm_runtime_disable(&pdev->dev);
1182 if (!pm_runtime_status_suspended(&pdev->dev))
1183 tegra_slink_runtime_suspend(&pdev->dev);
1184 tegra_slink_deinit_dma_param(tspi, false);
1185exit_rx_dma_free:
1186 tegra_slink_deinit_dma_param(tspi, true);
1187exit_free_irq:
1188 free_irq(spi_irq, tspi);
1189exit_free_master:
1190 spi_master_put(master);
1191 return ret;
1192}
1193
1194static int tegra_slink_remove(struct platform_device *pdev)
1195{
1196 struct spi_master *master = platform_get_drvdata(pdev);
1197 struct tegra_slink_data *tspi = spi_master_get_devdata(master);
1198
1199 free_irq(tspi->irq, tspi);
1200 spi_unregister_master(master);
1201
1202 if (tspi->tx_dma_chan)
1203 tegra_slink_deinit_dma_param(tspi, false);
1204
1205 if (tspi->rx_dma_chan)
1206 tegra_slink_deinit_dma_param(tspi, true);
1207
1208 pm_runtime_disable(&pdev->dev);
1209 if (!pm_runtime_status_suspended(&pdev->dev))
1210 tegra_slink_runtime_suspend(&pdev->dev);
1211
1212 return 0;
1213}
1214
1215#ifdef CONFIG_PM_SLEEP
1216static int tegra_slink_suspend(struct device *dev)
1217{
1218 struct spi_master *master = dev_get_drvdata(dev);
1219
1220 return spi_master_suspend(master);
1221}
1222
1223static int tegra_slink_resume(struct device *dev)
1224{
1225 struct spi_master *master = dev_get_drvdata(dev);
1226 struct tegra_slink_data *tspi = spi_master_get_devdata(master);
1227 int ret;
1228
1229 ret = pm_runtime_get_sync(dev);
1230 if (ret < 0) {
1231 dev_err(dev, "pm runtime failed, e = %d\n", ret);
1232 return ret;
1233 }
1234 tegra_slink_writel(tspi, tspi->command_reg, SLINK_COMMAND);
1235 tegra_slink_writel(tspi, tspi->command2_reg, SLINK_COMMAND2);
1236 pm_runtime_put(dev);
1237
1238 return spi_master_resume(master);
1239}
1240#endif
1241
1242static int tegra_slink_runtime_suspend(struct device *dev)
1243{
1244 struct spi_master *master = dev_get_drvdata(dev);
1245 struct tegra_slink_data *tspi = spi_master_get_devdata(master);
1246
1247
1248 tegra_slink_readl(tspi, SLINK_MAS_DATA);
1249
1250 clk_disable_unprepare(tspi->clk);
1251 return 0;
1252}
1253
1254static int tegra_slink_runtime_resume(struct device *dev)
1255{
1256 struct spi_master *master = dev_get_drvdata(dev);
1257 struct tegra_slink_data *tspi = spi_master_get_devdata(master);
1258 int ret;
1259
1260 ret = clk_prepare_enable(tspi->clk);
1261 if (ret < 0) {
1262 dev_err(tspi->dev, "clk_prepare failed: %d\n", ret);
1263 return ret;
1264 }
1265 return 0;
1266}
1267
1268static const struct dev_pm_ops slink_pm_ops = {
1269 SET_RUNTIME_PM_OPS(tegra_slink_runtime_suspend,
1270 tegra_slink_runtime_resume, NULL)
1271 SET_SYSTEM_SLEEP_PM_OPS(tegra_slink_suspend, tegra_slink_resume)
1272};
1273static struct platform_driver tegra_slink_driver = {
1274 .driver = {
1275 .name = "spi-tegra-slink",
1276 .owner = THIS_MODULE,
1277 .pm = &slink_pm_ops,
1278 .of_match_table = tegra_slink_of_match,
1279 },
1280 .probe = tegra_slink_probe,
1281 .remove = tegra_slink_remove,
1282};
1283module_platform_driver(tegra_slink_driver);
1284
1285MODULE_ALIAS("platform:spi-tegra-slink");
1286MODULE_DESCRIPTION("NVIDIA Tegra20/Tegra30 SLINK Controller Driver");
1287MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1288MODULE_LICENSE("GPL v2");
1289
