1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * SPI driver for NVIDIA's Tegra114 SPI Controller.
4 *
5 * Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved.
6 */
7
8 #include <linux/clk.h>
9 #include <linux/completion.h>
10 #include <linux/delay.h>
11 #include <linux/dmaengine.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/dmapool.h>
14 #include <linux/err.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/kernel.h>
18 #include <linux/kthread.h>
19 #include <linux/module.h>
20 #include <linux/platform_device.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/of.h>
23 #include <linux/of_device.h>
24 #include <linux/reset.h>
25 #include <linux/spi/spi.h>
26
27 #define SPI_COMMAND1 0x000
28 #define SPI_BIT_LENGTH(x) (((x) & 0x1f) << 0)
29 #define SPI_PACKED (1 << 5)
30 #define SPI_TX_EN (1 << 11)
31 #define SPI_RX_EN (1 << 12)
32 #define SPI_BOTH_EN_BYTE (1 << 13)
33 #define SPI_BOTH_EN_BIT (1 << 14)
34 #define SPI_LSBYTE_FE (1 << 15)
35 #define SPI_LSBIT_FE (1 << 16)
36 #define SPI_BIDIROE (1 << 17)
37 #define SPI_IDLE_SDA_DRIVE_LOW (0 << 18)
38 #define SPI_IDLE_SDA_DRIVE_HIGH (1 << 18)
39 #define SPI_IDLE_SDA_PULL_LOW (2 << 18)
40 #define SPI_IDLE_SDA_PULL_HIGH (3 << 18)
41 #define SPI_IDLE_SDA_MASK (3 << 18)
42 #define SPI_CS_SW_VAL (1 << 20)
43 #define SPI_CS_SW_HW (1 << 21)
44 /* SPI_CS_POL_INACTIVE bits are default high */
45 /* n from 0 to 3 */
46 #define SPI_CS_POL_INACTIVE(n) (1 << (22 + (n)))
47 #define SPI_CS_POL_INACTIVE_MASK (0xF << 22)
48
49 #define SPI_CS_SEL_0 (0 << 26)
50 #define SPI_CS_SEL_1 (1 << 26)
51 #define SPI_CS_SEL_2 (2 << 26)
52 #define SPI_CS_SEL_3 (3 << 26)
53 #define SPI_CS_SEL_MASK (3 << 26)
54 #define SPI_CS_SEL(x) (((x) & 0x3) << 26)
55 #define SPI_CONTROL_MODE_0 (0 << 28)
56 #define SPI_CONTROL_MODE_1 (1 << 28)
57 #define SPI_CONTROL_MODE_2 (2 << 28)
58 #define SPI_CONTROL_MODE_3 (3 << 28)
59 #define SPI_CONTROL_MODE_MASK (3 << 28)
60 #define SPI_MODE_SEL(x) (((x) & 0x3) << 28)
61 #define SPI_M_S (1 << 30)
62 #define SPI_PIO (1 << 31)
63
64 #define SPI_COMMAND2 0x004
65 #define SPI_TX_TAP_DELAY(x) (((x) & 0x3F) << 6)
66 #define SPI_RX_TAP_DELAY(x) (((x) & 0x3F) << 0)
67
68 #define SPI_CS_TIMING1 0x008
69 #define SPI_SETUP_HOLD(setup, hold) (((setup) << 4) | (hold))
70 #define SPI_CS_SETUP_HOLD(reg, cs, val) \
71 ((((val) & 0xFFu) << ((cs) * 8)) | \
72 ((reg) & ~(0xFFu << ((cs) * 8))))
73
74 #define SPI_CS_TIMING2 0x00C
75 #define CYCLES_BETWEEN_PACKETS_0(x) (((x) & 0x1F) << 0)
76 #define CS_ACTIVE_BETWEEN_PACKETS_0 (1 << 5)
77 #define CYCLES_BETWEEN_PACKETS_1(x) (((x) & 0x1F) << 8)
78 #define CS_ACTIVE_BETWEEN_PACKETS_1 (1 << 13)
79 #define CYCLES_BETWEEN_PACKETS_2(x) (((x) & 0x1F) << 16)
80 #define CS_ACTIVE_BETWEEN_PACKETS_2 (1 << 21)
81 #define CYCLES_BETWEEN_PACKETS_3(x) (((x) & 0x1F) << 24)
82 #define CS_ACTIVE_BETWEEN_PACKETS_3 (1 << 29)
83 #define SPI_SET_CS_ACTIVE_BETWEEN_PACKETS(reg, cs, val) \
84 (reg = (((val) & 0x1) << ((cs) * 8 + 5)) | \
85 ((reg) & ~(1 << ((cs) * 8 + 5))))
86 #define SPI_SET_CYCLES_BETWEEN_PACKETS(reg, cs, val) \
87 (reg = (((val) & 0x1F) << ((cs) * 8)) | \
88 ((reg) & ~(0x1F << ((cs) * 8))))
89 #define MAX_SETUP_HOLD_CYCLES 16
90 #define MAX_INACTIVE_CYCLES 32
91
92 #define SPI_TRANS_STATUS 0x010
93 #define SPI_BLK_CNT(val) (((val) >> 0) & 0xFFFF)
94 #define SPI_SLV_IDLE_COUNT(val) (((val) >> 16) & 0xFF)
95 #define SPI_RDY (1 << 30)
96
97 #define SPI_FIFO_STATUS 0x014
98 #define SPI_RX_FIFO_EMPTY (1 << 0)
99 #define SPI_RX_FIFO_FULL (1 << 1)
100 #define SPI_TX_FIFO_EMPTY (1 << 2)
101 #define SPI_TX_FIFO_FULL (1 << 3)
102 #define SPI_RX_FIFO_UNF (1 << 4)
103 #define SPI_RX_FIFO_OVF (1 << 5)
104 #define SPI_TX_FIFO_UNF (1 << 6)
105 #define SPI_TX_FIFO_OVF (1 << 7)
106 #define SPI_ERR (1 << 8)
107 #define SPI_TX_FIFO_FLUSH (1 << 14)
108 #define SPI_RX_FIFO_FLUSH (1 << 15)
109 #define SPI_TX_FIFO_EMPTY_COUNT(val) (((val) >> 16) & 0x7F)
110 #define SPI_RX_FIFO_FULL_COUNT(val) (((val) >> 23) & 0x7F)
111 #define SPI_FRAME_END (1 << 30)
112 #define SPI_CS_INACTIVE (1 << 31)
113
114 #define SPI_FIFO_ERROR (SPI_RX_FIFO_UNF | \
115 SPI_RX_FIFO_OVF | SPI_TX_FIFO_UNF | SPI_TX_FIFO_OVF)
116 #define SPI_FIFO_EMPTY (SPI_RX_FIFO_EMPTY | SPI_TX_FIFO_EMPTY)
117
118 #define SPI_TX_DATA 0x018
119 #define SPI_RX_DATA 0x01C
120
121 #define SPI_DMA_CTL 0x020
122 #define SPI_TX_TRIG_1 (0 << 15)
123 #define SPI_TX_TRIG_4 (1 << 15)
124 #define SPI_TX_TRIG_8 (2 << 15)
125 #define SPI_TX_TRIG_16 (3 << 15)
126 #define SPI_TX_TRIG_MASK (3 << 15)
127 #define SPI_RX_TRIG_1 (0 << 19)
128 #define SPI_RX_TRIG_4 (1 << 19)
129 #define SPI_RX_TRIG_8 (2 << 19)
130 #define SPI_RX_TRIG_16 (3 << 19)
131 #define SPI_RX_TRIG_MASK (3 << 19)
132 #define SPI_IE_TX (1 << 28)
133 #define SPI_IE_RX (1 << 29)
134 #define SPI_CONT (1 << 30)
135 #define SPI_DMA (1 << 31)
136 #define SPI_DMA_EN SPI_DMA
137
138 #define SPI_DMA_BLK 0x024
139 #define SPI_DMA_BLK_SET(x) (((x) & 0xFFFF) << 0)
140
141 #define SPI_TX_FIFO 0x108
142 #define SPI_RX_FIFO 0x188
143 #define SPI_INTR_MASK 0x18c
144 #define SPI_INTR_ALL_MASK (0x1fUL << 25)
145 #define MAX_CHIP_SELECT 4
146 #define SPI_FIFO_DEPTH 64
147 #define DATA_DIR_TX (1 << 0)
148 #define DATA_DIR_RX (1 << 1)
149
150 #define SPI_DMA_TIMEOUT (msecs_to_jiffies(1000))
151 #define DEFAULT_SPI_DMA_BUF_LEN (16*1024)
152 #define TX_FIFO_EMPTY_COUNT_MAX SPI_TX_FIFO_EMPTY_COUNT(0x40)
153 #define RX_FIFO_FULL_COUNT_ZERO SPI_RX_FIFO_FULL_COUNT(0)
154 #define MAX_HOLD_CYCLES 16
155 #define SPI_DEFAULT_SPEED 25000000
156
157 struct tegra_spi_soc_data {
158 bool has_intr_mask_reg;
159 };
160
161 struct tegra_spi_client_data {
162 int tx_clk_tap_delay;
163 int rx_clk_tap_delay;
164 };
165
166 struct tegra_spi_data {
167 struct device *dev;
168 struct spi_master *master;
169 spinlock_t lock;
170
171 struct clk *clk;
172 struct reset_control *rst;
173 void __iomem *base;
174 phys_addr_t phys;
175 unsigned irq;
176 u32 cur_speed;
177
178 struct spi_device *cur_spi;
179 struct spi_device *cs_control;
180 unsigned cur_pos;
181 unsigned words_per_32bit;
182 unsigned bytes_per_word;
183 unsigned curr_dma_words;
184 unsigned cur_direction;
185
186 unsigned cur_rx_pos;
187 unsigned cur_tx_pos;
188
189 unsigned dma_buf_size;
190 unsigned max_buf_size;
191 bool is_curr_dma_xfer;
192 bool use_hw_based_cs;
193
194 struct completion rx_dma_complete;
195 struct completion tx_dma_complete;
196
197 u32 tx_status;
198 u32 rx_status;
199 u32 status_reg;
200 bool is_packed;
201
202 u32 command1_reg;
203 u32 dma_control_reg;
204 u32 def_command1_reg;
205 u32 def_command2_reg;
206 u32 spi_cs_timing1;
207 u32 spi_cs_timing2;
208 u8 last_used_cs;
209
210 struct completion xfer_completion;
211 struct spi_transfer *curr_xfer;
212 struct dma_chan *rx_dma_chan;
213 u32 *rx_dma_buf;
214 dma_addr_t rx_dma_phys;
215 struct dma_async_tx_descriptor *rx_dma_desc;
216
217 struct dma_chan *tx_dma_chan;
218 u32 *tx_dma_buf;
219 dma_addr_t tx_dma_phys;
220 struct dma_async_tx_descriptor *tx_dma_desc;
221 const struct tegra_spi_soc_data *soc_data;
222 };
223
224 static int tegra_spi_runtime_suspend(struct device *dev);
225 static int tegra_spi_runtime_resume(struct device *dev);
226
tegra_spi_readl(struct tegra_spi_data * tspi,unsigned long reg)227 static inline u32 tegra_spi_readl(struct tegra_spi_data *tspi,
228 unsigned long reg)
229 {
230 return readl(tspi->base + reg);
231 }
232
tegra_spi_writel(struct tegra_spi_data * tspi,u32 val,unsigned long reg)233 static inline void tegra_spi_writel(struct tegra_spi_data *tspi,
234 u32 val, unsigned long reg)
235 {
236 writel(val, tspi->base + reg);
237
238 /* Read back register to make sure that register writes completed */
239 if (reg != SPI_TX_FIFO)
240 readl(tspi->base + SPI_COMMAND1);
241 }
242
tegra_spi_clear_status(struct tegra_spi_data * tspi)243 static void tegra_spi_clear_status(struct tegra_spi_data *tspi)
244 {
245 u32 val;
246
247 /* Write 1 to clear status register */
248 val = tegra_spi_readl(tspi, SPI_TRANS_STATUS);
249 tegra_spi_writel(tspi, val, SPI_TRANS_STATUS);
250
251 /* Clear fifo status error if any */
252 val = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
253 if (val & SPI_ERR)
254 tegra_spi_writel(tspi, SPI_ERR | SPI_FIFO_ERROR,
255 SPI_FIFO_STATUS);
256 }
257
tegra_spi_calculate_curr_xfer_param(struct spi_device * spi,struct tegra_spi_data * tspi,struct spi_transfer * t)258 static unsigned tegra_spi_calculate_curr_xfer_param(
259 struct spi_device *spi, struct tegra_spi_data *tspi,
260 struct spi_transfer *t)
261 {
262 unsigned remain_len = t->len - tspi->cur_pos;
263 unsigned max_word;
264 unsigned bits_per_word = t->bits_per_word;
265 unsigned max_len;
266 unsigned total_fifo_words;
267
268 tspi->bytes_per_word = DIV_ROUND_UP(bits_per_word, 8);
269
270 if ((bits_per_word == 8 || bits_per_word == 16 ||
271 bits_per_word == 32) && t->len > 3) {
272 tspi->is_packed = true;
273 tspi->words_per_32bit = 32/bits_per_word;
274 } else {
275 tspi->is_packed = false;
276 tspi->words_per_32bit = 1;
277 }
278
279 if (tspi->is_packed) {
280 max_len = min(remain_len, tspi->max_buf_size);
281 tspi->curr_dma_words = max_len/tspi->bytes_per_word;
282 total_fifo_words = (max_len + 3) / 4;
283 } else {
284 max_word = (remain_len - 1) / tspi->bytes_per_word + 1;
285 max_word = min(max_word, tspi->max_buf_size/4);
286 tspi->curr_dma_words = max_word;
287 total_fifo_words = max_word;
288 }
289 return total_fifo_words;
290 }
291
tegra_spi_fill_tx_fifo_from_client_txbuf(struct tegra_spi_data * tspi,struct spi_transfer * t)292 static unsigned tegra_spi_fill_tx_fifo_from_client_txbuf(
293 struct tegra_spi_data *tspi, struct spi_transfer *t)
294 {
295 unsigned nbytes;
296 unsigned tx_empty_count;
297 u32 fifo_status;
298 unsigned max_n_32bit;
299 unsigned i, count;
300 unsigned int written_words;
301 unsigned fifo_words_left;
302 u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
303
304 fifo_status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
305 tx_empty_count = SPI_TX_FIFO_EMPTY_COUNT(fifo_status);
306
307 if (tspi->is_packed) {
308 fifo_words_left = tx_empty_count * tspi->words_per_32bit;
309 written_words = min(fifo_words_left, tspi->curr_dma_words);
310 nbytes = written_words * tspi->bytes_per_word;
311 max_n_32bit = DIV_ROUND_UP(nbytes, 4);
312 for (count = 0; count < max_n_32bit; count++) {
313 u32 x = 0;
314
315 for (i = 0; (i < 4) && nbytes; i++, nbytes--)
316 x |= (u32)(*tx_buf++) << (i * 8);
317 tegra_spi_writel(tspi, x, SPI_TX_FIFO);
318 }
319
320 tspi->cur_tx_pos += written_words * tspi->bytes_per_word;
321 } else {
322 unsigned int write_bytes;
323 max_n_32bit = min(tspi->curr_dma_words, tx_empty_count);
324 written_words = max_n_32bit;
325 nbytes = written_words * tspi->bytes_per_word;
326 if (nbytes > t->len - tspi->cur_pos)
327 nbytes = t->len - tspi->cur_pos;
328 write_bytes = nbytes;
329 for (count = 0; count < max_n_32bit; count++) {
330 u32 x = 0;
331
332 for (i = 0; nbytes && (i < tspi->bytes_per_word);
333 i++, nbytes--)
334 x |= (u32)(*tx_buf++) << (i * 8);
335 tegra_spi_writel(tspi, x, SPI_TX_FIFO);
336 }
337
338 tspi->cur_tx_pos += write_bytes;
339 }
340
341 return written_words;
342 }
343
tegra_spi_read_rx_fifo_to_client_rxbuf(struct tegra_spi_data * tspi,struct spi_transfer * t)344 static unsigned int tegra_spi_read_rx_fifo_to_client_rxbuf(
345 struct tegra_spi_data *tspi, struct spi_transfer *t)
346 {
347 unsigned rx_full_count;
348 u32 fifo_status;
349 unsigned i, count;
350 unsigned int read_words = 0;
351 unsigned len;
352 u8 *rx_buf = (u8 *)t->rx_buf + tspi->cur_rx_pos;
353
354 fifo_status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
355 rx_full_count = SPI_RX_FIFO_FULL_COUNT(fifo_status);
356 if (tspi->is_packed) {
357 len = tspi->curr_dma_words * tspi->bytes_per_word;
358 for (count = 0; count < rx_full_count; count++) {
359 u32 x = tegra_spi_readl(tspi, SPI_RX_FIFO);
360
361 for (i = 0; len && (i < 4); i++, len--)
362 *rx_buf++ = (x >> i*8) & 0xFF;
363 }
364 read_words += tspi->curr_dma_words;
365 tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
366 } else {
367 u32 rx_mask = ((u32)1 << t->bits_per_word) - 1;
368 u8 bytes_per_word = tspi->bytes_per_word;
369 unsigned int read_bytes;
370
371 len = rx_full_count * bytes_per_word;
372 if (len > t->len - tspi->cur_pos)
373 len = t->len - tspi->cur_pos;
374 read_bytes = len;
375 for (count = 0; count < rx_full_count; count++) {
376 u32 x = tegra_spi_readl(tspi, SPI_RX_FIFO) & rx_mask;
377
378 for (i = 0; len && (i < bytes_per_word); i++, len--)
379 *rx_buf++ = (x >> (i*8)) & 0xFF;
380 }
381 read_words += rx_full_count;
382 tspi->cur_rx_pos += read_bytes;
383 }
384
385 return read_words;
386 }
387
tegra_spi_copy_client_txbuf_to_spi_txbuf(struct tegra_spi_data * tspi,struct spi_transfer * t)388 static void tegra_spi_copy_client_txbuf_to_spi_txbuf(
389 struct tegra_spi_data *tspi, struct spi_transfer *t)
390 {
391 /* Make the dma buffer to read by cpu */
392 dma_sync_single_for_cpu(tspi->dev, tspi->tx_dma_phys,
393 tspi->dma_buf_size, DMA_TO_DEVICE);
394
395 if (tspi->is_packed) {
396 unsigned len = tspi->curr_dma_words * tspi->bytes_per_word;
397
398 memcpy(tspi->tx_dma_buf, t->tx_buf + tspi->cur_pos, len);
399 tspi->cur_tx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
400 } else {
401 unsigned int i;
402 unsigned int count;
403 u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
404 unsigned consume = tspi->curr_dma_words * tspi->bytes_per_word;
405 unsigned int write_bytes;
406
407 if (consume > t->len - tspi->cur_pos)
408 consume = t->len - tspi->cur_pos;
409 write_bytes = consume;
410 for (count = 0; count < tspi->curr_dma_words; count++) {
411 u32 x = 0;
412
413 for (i = 0; consume && (i < tspi->bytes_per_word);
414 i++, consume--)
415 x |= (u32)(*tx_buf++) << (i * 8);
416 tspi->tx_dma_buf[count] = x;
417 }
418
419 tspi->cur_tx_pos += write_bytes;
420 }
421
422 /* Make the dma buffer to read by dma */
423 dma_sync_single_for_device(tspi->dev, tspi->tx_dma_phys,
424 tspi->dma_buf_size, DMA_TO_DEVICE);
425 }
426
tegra_spi_copy_spi_rxbuf_to_client_rxbuf(struct tegra_spi_data * tspi,struct spi_transfer * t)427 static void tegra_spi_copy_spi_rxbuf_to_client_rxbuf(
428 struct tegra_spi_data *tspi, struct spi_transfer *t)
429 {
430 /* Make the dma buffer to read by cpu */
431 dma_sync_single_for_cpu(tspi->dev, tspi->rx_dma_phys,
432 tspi->dma_buf_size, DMA_FROM_DEVICE);
433
434 if (tspi->is_packed) {
435 unsigned len = tspi->curr_dma_words * tspi->bytes_per_word;
436
437 memcpy(t->rx_buf + tspi->cur_rx_pos, tspi->rx_dma_buf, len);
438 tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
439 } else {
440 unsigned int i;
441 unsigned int count;
442 unsigned char *rx_buf = t->rx_buf + tspi->cur_rx_pos;
443 u32 rx_mask = ((u32)1 << t->bits_per_word) - 1;
444 unsigned consume = tspi->curr_dma_words * tspi->bytes_per_word;
445 unsigned int read_bytes;
446
447 if (consume > t->len - tspi->cur_pos)
448 consume = t->len - tspi->cur_pos;
449 read_bytes = consume;
450 for (count = 0; count < tspi->curr_dma_words; count++) {
451 u32 x = tspi->rx_dma_buf[count] & rx_mask;
452
453 for (i = 0; consume && (i < tspi->bytes_per_word);
454 i++, consume--)
455 *rx_buf++ = (x >> (i*8)) & 0xFF;
456 }
457
458 tspi->cur_rx_pos += read_bytes;
459 }
460
461 /* Make the dma buffer to read by dma */
462 dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
463 tspi->dma_buf_size, DMA_FROM_DEVICE);
464 }
465
tegra_spi_dma_complete(void * args)466 static void tegra_spi_dma_complete(void *args)
467 {
468 struct completion *dma_complete = args;
469
470 complete(dma_complete);
471 }
472
tegra_spi_start_tx_dma(struct tegra_spi_data * tspi,int len)473 static int tegra_spi_start_tx_dma(struct tegra_spi_data *tspi, int len)
474 {
475 reinit_completion(&tspi->tx_dma_complete);
476 tspi->tx_dma_desc = dmaengine_prep_slave_single(tspi->tx_dma_chan,
477 tspi->tx_dma_phys, len, DMA_MEM_TO_DEV,
478 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
479 if (!tspi->tx_dma_desc) {
480 dev_err(tspi->dev, "Not able to get desc for Tx\n");
481 return -EIO;
482 }
483
484 tspi->tx_dma_desc->callback = tegra_spi_dma_complete;
485 tspi->tx_dma_desc->callback_param = &tspi->tx_dma_complete;
486
487 dmaengine_submit(tspi->tx_dma_desc);
488 dma_async_issue_pending(tspi->tx_dma_chan);
489 return 0;
490 }
491
tegra_spi_start_rx_dma(struct tegra_spi_data * tspi,int len)492 static int tegra_spi_start_rx_dma(struct tegra_spi_data *tspi, int len)
493 {
494 reinit_completion(&tspi->rx_dma_complete);
495 tspi->rx_dma_desc = dmaengine_prep_slave_single(tspi->rx_dma_chan,
496 tspi->rx_dma_phys, len, DMA_DEV_TO_MEM,
497 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
498 if (!tspi->rx_dma_desc) {
499 dev_err(tspi->dev, "Not able to get desc for Rx\n");
500 return -EIO;
501 }
502
503 tspi->rx_dma_desc->callback = tegra_spi_dma_complete;
504 tspi->rx_dma_desc->callback_param = &tspi->rx_dma_complete;
505
506 dmaengine_submit(tspi->rx_dma_desc);
507 dma_async_issue_pending(tspi->rx_dma_chan);
508 return 0;
509 }
510
tegra_spi_flush_fifos(struct tegra_spi_data * tspi)511 static int tegra_spi_flush_fifos(struct tegra_spi_data *tspi)
512 {
513 unsigned long timeout = jiffies + HZ;
514 u32 status;
515
516 status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
517 if ((status & SPI_FIFO_EMPTY) != SPI_FIFO_EMPTY) {
518 status |= SPI_RX_FIFO_FLUSH | SPI_TX_FIFO_FLUSH;
519 tegra_spi_writel(tspi, status, SPI_FIFO_STATUS);
520 while ((status & SPI_FIFO_EMPTY) != SPI_FIFO_EMPTY) {
521 status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
522 if (time_after(jiffies, timeout)) {
523 dev_err(tspi->dev,
524 "timeout waiting for fifo flush\n");
525 return -EIO;
526 }
527
528 udelay(1);
529 }
530 }
531
532 return 0;
533 }
534
tegra_spi_start_dma_based_transfer(struct tegra_spi_data * tspi,struct spi_transfer * t)535 static int tegra_spi_start_dma_based_transfer(
536 struct tegra_spi_data *tspi, struct spi_transfer *t)
537 {
538 u32 val;
539 unsigned int len;
540 int ret = 0;
541 u8 dma_burst;
542 struct dma_slave_config dma_sconfig = {0};
543
544 val = SPI_DMA_BLK_SET(tspi->curr_dma_words - 1);
545 tegra_spi_writel(tspi, val, SPI_DMA_BLK);
546
547 if (tspi->is_packed)
548 len = DIV_ROUND_UP(tspi->curr_dma_words * tspi->bytes_per_word,
549 4) * 4;
550 else
551 len = tspi->curr_dma_words * 4;
552
553 /* Set attention level based on length of transfer */
554 if (len & 0xF) {
555 val |= SPI_TX_TRIG_1 | SPI_RX_TRIG_1;
556 dma_burst = 1;
557 } else if (((len) >> 4) & 0x1) {
558 val |= SPI_TX_TRIG_4 | SPI_RX_TRIG_4;
559 dma_burst = 4;
560 } else {
561 val |= SPI_TX_TRIG_8 | SPI_RX_TRIG_8;
562 dma_burst = 8;
563 }
564
565 if (!tspi->soc_data->has_intr_mask_reg) {
566 if (tspi->cur_direction & DATA_DIR_TX)
567 val |= SPI_IE_TX;
568
569 if (tspi->cur_direction & DATA_DIR_RX)
570 val |= SPI_IE_RX;
571 }
572
573 tegra_spi_writel(tspi, val, SPI_DMA_CTL);
574 tspi->dma_control_reg = val;
575
576 dma_sconfig.device_fc = true;
577 if (tspi->cur_direction & DATA_DIR_TX) {
578 dma_sconfig.dst_addr = tspi->phys + SPI_TX_FIFO;
579 dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
580 dma_sconfig.dst_maxburst = dma_burst;
581 ret = dmaengine_slave_config(tspi->tx_dma_chan, &dma_sconfig);
582 if (ret < 0) {
583 dev_err(tspi->dev,
584 "DMA slave config failed: %d\n", ret);
585 return ret;
586 }
587
588 tegra_spi_copy_client_txbuf_to_spi_txbuf(tspi, t);
589 ret = tegra_spi_start_tx_dma(tspi, len);
590 if (ret < 0) {
591 dev_err(tspi->dev,
592 "Starting tx dma failed, err %d\n", ret);
593 return ret;
594 }
595 }
596
597 if (tspi->cur_direction & DATA_DIR_RX) {
598 dma_sconfig.src_addr = tspi->phys + SPI_RX_FIFO;
599 dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
600 dma_sconfig.src_maxburst = dma_burst;
601 ret = dmaengine_slave_config(tspi->rx_dma_chan, &dma_sconfig);
602 if (ret < 0) {
603 dev_err(tspi->dev,
604 "DMA slave config failed: %d\n", ret);
605 return ret;
606 }
607
608 /* Make the dma buffer to read by dma */
609 dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
610 tspi->dma_buf_size, DMA_FROM_DEVICE);
611
612 ret = tegra_spi_start_rx_dma(tspi, len);
613 if (ret < 0) {
614 dev_err(tspi->dev,
615 "Starting rx dma failed, err %d\n", ret);
616 if (tspi->cur_direction & DATA_DIR_TX)
617 dmaengine_terminate_all(tspi->tx_dma_chan);
618 return ret;
619 }
620 }
621 tspi->is_curr_dma_xfer = true;
622 tspi->dma_control_reg = val;
623
624 val |= SPI_DMA_EN;
625 tegra_spi_writel(tspi, val, SPI_DMA_CTL);
626 return ret;
627 }
628
tegra_spi_start_cpu_based_transfer(struct tegra_spi_data * tspi,struct spi_transfer * t)629 static int tegra_spi_start_cpu_based_transfer(
630 struct tegra_spi_data *tspi, struct spi_transfer *t)
631 {
632 u32 val;
633 unsigned cur_words;
634
635 if (tspi->cur_direction & DATA_DIR_TX)
636 cur_words = tegra_spi_fill_tx_fifo_from_client_txbuf(tspi, t);
637 else
638 cur_words = tspi->curr_dma_words;
639
640 val = SPI_DMA_BLK_SET(cur_words - 1);
641 tegra_spi_writel(tspi, val, SPI_DMA_BLK);
642
643 val = 0;
644 if (tspi->cur_direction & DATA_DIR_TX)
645 val |= SPI_IE_TX;
646
647 if (tspi->cur_direction & DATA_DIR_RX)
648 val |= SPI_IE_RX;
649
650 tegra_spi_writel(tspi, val, SPI_DMA_CTL);
651 tspi->dma_control_reg = val;
652
653 tspi->is_curr_dma_xfer = false;
654
655 val = tspi->command1_reg;
656 val |= SPI_PIO;
657 tegra_spi_writel(tspi, val, SPI_COMMAND1);
658 return 0;
659 }
660
tegra_spi_init_dma_param(struct tegra_spi_data * tspi,bool dma_to_memory)661 static int tegra_spi_init_dma_param(struct tegra_spi_data *tspi,
662 bool dma_to_memory)
663 {
664 struct dma_chan *dma_chan;
665 u32 *dma_buf;
666 dma_addr_t dma_phys;
667
668 dma_chan = dma_request_chan(tspi->dev, dma_to_memory ? "rx" : "tx");
669 if (IS_ERR(dma_chan))
670 return dev_err_probe(tspi->dev, PTR_ERR(dma_chan),
671 "Dma channel is not available\n");
672
673 dma_buf = dma_alloc_coherent(tspi->dev, tspi->dma_buf_size,
674 &dma_phys, GFP_KERNEL);
675 if (!dma_buf) {
676 dev_err(tspi->dev, " Not able to allocate the dma buffer\n");
677 dma_release_channel(dma_chan);
678 return -ENOMEM;
679 }
680
681 if (dma_to_memory) {
682 tspi->rx_dma_chan = dma_chan;
683 tspi->rx_dma_buf = dma_buf;
684 tspi->rx_dma_phys = dma_phys;
685 } else {
686 tspi->tx_dma_chan = dma_chan;
687 tspi->tx_dma_buf = dma_buf;
688 tspi->tx_dma_phys = dma_phys;
689 }
690 return 0;
691 }
692
tegra_spi_deinit_dma_param(struct tegra_spi_data * tspi,bool dma_to_memory)693 static void tegra_spi_deinit_dma_param(struct tegra_spi_data *tspi,
694 bool dma_to_memory)
695 {
696 u32 *dma_buf;
697 dma_addr_t dma_phys;
698 struct dma_chan *dma_chan;
699
700 if (dma_to_memory) {
701 dma_buf = tspi->rx_dma_buf;
702 dma_chan = tspi->rx_dma_chan;
703 dma_phys = tspi->rx_dma_phys;
704 tspi->rx_dma_chan = NULL;
705 tspi->rx_dma_buf = NULL;
706 } else {
707 dma_buf = tspi->tx_dma_buf;
708 dma_chan = tspi->tx_dma_chan;
709 dma_phys = tspi->tx_dma_phys;
710 tspi->tx_dma_buf = NULL;
711 tspi->tx_dma_chan = NULL;
712 }
713 if (!dma_chan)
714 return;
715
716 dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
717 dma_release_channel(dma_chan);
718 }
719
tegra_spi_set_hw_cs_timing(struct spi_device * spi)720 static int tegra_spi_set_hw_cs_timing(struct spi_device *spi)
721 {
722 struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
723 struct spi_delay *setup = &spi->cs_setup;
724 struct spi_delay *hold = &spi->cs_hold;
725 struct spi_delay *inactive = &spi->cs_inactive;
726 u8 setup_dly, hold_dly, inactive_dly;
727 u32 setup_hold;
728 u32 spi_cs_timing;
729 u32 inactive_cycles;
730 u8 cs_state;
731
732 if ((setup && setup->unit != SPI_DELAY_UNIT_SCK) ||
733 (hold && hold->unit != SPI_DELAY_UNIT_SCK) ||
734 (inactive && inactive->unit != SPI_DELAY_UNIT_SCK)) {
735 dev_err(&spi->dev,
736 "Invalid delay unit %d, should be SPI_DELAY_UNIT_SCK\n",
737 SPI_DELAY_UNIT_SCK);
738 return -EINVAL;
739 }
740
741 setup_dly = setup ? setup->value : 0;
742 hold_dly = hold ? hold->value : 0;
743 inactive_dly = inactive ? inactive->value : 0;
744
745 setup_dly = min_t(u8, setup_dly, MAX_SETUP_HOLD_CYCLES);
746 hold_dly = min_t(u8, hold_dly, MAX_SETUP_HOLD_CYCLES);
747 if (setup_dly && hold_dly) {
748 setup_hold = SPI_SETUP_HOLD(setup_dly - 1, hold_dly - 1);
749 spi_cs_timing = SPI_CS_SETUP_HOLD(tspi->spi_cs_timing1,
750 spi->chip_select,
751 setup_hold);
752 if (tspi->spi_cs_timing1 != spi_cs_timing) {
753 tspi->spi_cs_timing1 = spi_cs_timing;
754 tegra_spi_writel(tspi, spi_cs_timing, SPI_CS_TIMING1);
755 }
756 }
757
758 inactive_cycles = min_t(u8, inactive_dly, MAX_INACTIVE_CYCLES);
759 if (inactive_cycles)
760 inactive_cycles--;
761 cs_state = inactive_cycles ? 0 : 1;
762 spi_cs_timing = tspi->spi_cs_timing2;
763 SPI_SET_CS_ACTIVE_BETWEEN_PACKETS(spi_cs_timing, spi->chip_select,
764 cs_state);
765 SPI_SET_CYCLES_BETWEEN_PACKETS(spi_cs_timing, spi->chip_select,
766 inactive_cycles);
767 if (tspi->spi_cs_timing2 != spi_cs_timing) {
768 tspi->spi_cs_timing2 = spi_cs_timing;
769 tegra_spi_writel(tspi, spi_cs_timing, SPI_CS_TIMING2);
770 }
771
772 return 0;
773 }
774
tegra_spi_setup_transfer_one(struct spi_device * spi,struct spi_transfer * t,bool is_first_of_msg,bool is_single_xfer)775 static u32 tegra_spi_setup_transfer_one(struct spi_device *spi,
776 struct spi_transfer *t,
777 bool is_first_of_msg,
778 bool is_single_xfer)
779 {
780 struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
781 struct tegra_spi_client_data *cdata = spi->controller_data;
782 u32 speed = t->speed_hz;
783 u8 bits_per_word = t->bits_per_word;
784 u32 command1, command2;
785 int req_mode;
786 u32 tx_tap = 0, rx_tap = 0;
787
788 if (speed != tspi->cur_speed) {
789 clk_set_rate(tspi->clk, speed);
790 tspi->cur_speed = speed;
791 }
792
793 tspi->cur_spi = spi;
794 tspi->cur_pos = 0;
795 tspi->cur_rx_pos = 0;
796 tspi->cur_tx_pos = 0;
797 tspi->curr_xfer = t;
798
799 if (is_first_of_msg) {
800 tegra_spi_clear_status(tspi);
801
802 command1 = tspi->def_command1_reg;
803 command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
804
805 command1 &= ~SPI_CONTROL_MODE_MASK;
806 req_mode = spi->mode & 0x3;
807 if (req_mode == SPI_MODE_0)
808 command1 |= SPI_CONTROL_MODE_0;
809 else if (req_mode == SPI_MODE_1)
810 command1 |= SPI_CONTROL_MODE_1;
811 else if (req_mode == SPI_MODE_2)
812 command1 |= SPI_CONTROL_MODE_2;
813 else if (req_mode == SPI_MODE_3)
814 command1 |= SPI_CONTROL_MODE_3;
815
816 if (spi->mode & SPI_LSB_FIRST)
817 command1 |= SPI_LSBIT_FE;
818 else
819 command1 &= ~SPI_LSBIT_FE;
820
821 if (spi->mode & SPI_3WIRE)
822 command1 |= SPI_BIDIROE;
823 else
824 command1 &= ~SPI_BIDIROE;
825
826 if (tspi->cs_control) {
827 if (tspi->cs_control != spi)
828 tegra_spi_writel(tspi, command1, SPI_COMMAND1);
829 tspi->cs_control = NULL;
830 } else
831 tegra_spi_writel(tspi, command1, SPI_COMMAND1);
832
833 /* GPIO based chip select control */
834 if (spi->cs_gpiod)
835 gpiod_set_value(spi->cs_gpiod, 1);
836
837 if (is_single_xfer && !(t->cs_change)) {
838 tspi->use_hw_based_cs = true;
839 command1 &= ~(SPI_CS_SW_HW | SPI_CS_SW_VAL);
840 } else {
841 tspi->use_hw_based_cs = false;
842 command1 |= SPI_CS_SW_HW;
843 if (spi->mode & SPI_CS_HIGH)
844 command1 |= SPI_CS_SW_VAL;
845 else
846 command1 &= ~SPI_CS_SW_VAL;
847 }
848
849 if (tspi->last_used_cs != spi->chip_select) {
850 if (cdata && cdata->tx_clk_tap_delay)
851 tx_tap = cdata->tx_clk_tap_delay;
852 if (cdata && cdata->rx_clk_tap_delay)
853 rx_tap = cdata->rx_clk_tap_delay;
854 command2 = SPI_TX_TAP_DELAY(tx_tap) |
855 SPI_RX_TAP_DELAY(rx_tap);
856 if (command2 != tspi->def_command2_reg)
857 tegra_spi_writel(tspi, command2, SPI_COMMAND2);
858 tspi->last_used_cs = spi->chip_select;
859 }
860
861 } else {
862 command1 = tspi->command1_reg;
863 command1 &= ~SPI_BIT_LENGTH(~0);
864 command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
865 }
866
867 return command1;
868 }
869
tegra_spi_start_transfer_one(struct spi_device * spi,struct spi_transfer * t,u32 command1)870 static int tegra_spi_start_transfer_one(struct spi_device *spi,
871 struct spi_transfer *t, u32 command1)
872 {
873 struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
874 unsigned total_fifo_words;
875 int ret;
876
877 total_fifo_words = tegra_spi_calculate_curr_xfer_param(spi, tspi, t);
878
879 if (t->rx_nbits == SPI_NBITS_DUAL || t->tx_nbits == SPI_NBITS_DUAL)
880 command1 |= SPI_BOTH_EN_BIT;
881 else
882 command1 &= ~SPI_BOTH_EN_BIT;
883
884 if (tspi->is_packed)
885 command1 |= SPI_PACKED;
886 else
887 command1 &= ~SPI_PACKED;
888
889 command1 &= ~(SPI_CS_SEL_MASK | SPI_TX_EN | SPI_RX_EN);
890 tspi->cur_direction = 0;
891 if (t->rx_buf) {
892 command1 |= SPI_RX_EN;
893 tspi->cur_direction |= DATA_DIR_RX;
894 }
895 if (t->tx_buf) {
896 command1 |= SPI_TX_EN;
897 tspi->cur_direction |= DATA_DIR_TX;
898 }
899 command1 |= SPI_CS_SEL(spi->chip_select);
900 tegra_spi_writel(tspi, command1, SPI_COMMAND1);
901 tspi->command1_reg = command1;
902
903 dev_dbg(tspi->dev, "The def 0x%x and written 0x%x\n",
904 tspi->def_command1_reg, (unsigned)command1);
905
906 ret = tegra_spi_flush_fifos(tspi);
907 if (ret < 0)
908 return ret;
909 if (total_fifo_words > SPI_FIFO_DEPTH)
910 ret = tegra_spi_start_dma_based_transfer(tspi, t);
911 else
912 ret = tegra_spi_start_cpu_based_transfer(tspi, t);
913 return ret;
914 }
915
916 static struct tegra_spi_client_data
tegra_spi_parse_cdata_dt(struct spi_device * spi)917 *tegra_spi_parse_cdata_dt(struct spi_device *spi)
918 {
919 struct tegra_spi_client_data *cdata;
920 struct device_node *slave_np;
921
922 slave_np = spi->dev.of_node;
923 if (!slave_np) {
924 dev_dbg(&spi->dev, "device node not found\n");
925 return NULL;
926 }
927
928 cdata = kzalloc(sizeof(*cdata), GFP_KERNEL);
929 if (!cdata)
930 return NULL;
931
932 of_property_read_u32(slave_np, "nvidia,tx-clk-tap-delay",
933 &cdata->tx_clk_tap_delay);
934 of_property_read_u32(slave_np, "nvidia,rx-clk-tap-delay",
935 &cdata->rx_clk_tap_delay);
936 return cdata;
937 }
938
tegra_spi_cleanup(struct spi_device * spi)939 static void tegra_spi_cleanup(struct spi_device *spi)
940 {
941 struct tegra_spi_client_data *cdata = spi->controller_data;
942
943 spi->controller_data = NULL;
944 if (spi->dev.of_node)
945 kfree(cdata);
946 }
947
tegra_spi_setup(struct spi_device * spi)948 static int tegra_spi_setup(struct spi_device *spi)
949 {
950 struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
951 struct tegra_spi_client_data *cdata = spi->controller_data;
952 u32 val;
953 unsigned long flags;
954 int ret;
955
956 dev_dbg(&spi->dev, "setup %d bpw, %scpol, %scpha, %dHz\n",
957 spi->bits_per_word,
958 spi->mode & SPI_CPOL ? "" : "~",
959 spi->mode & SPI_CPHA ? "" : "~",
960 spi->max_speed_hz);
961
962 if (!cdata) {
963 cdata = tegra_spi_parse_cdata_dt(spi);
964 spi->controller_data = cdata;
965 }
966
967 ret = pm_runtime_resume_and_get(tspi->dev);
968 if (ret < 0) {
969 dev_err(tspi->dev, "pm runtime failed, e = %d\n", ret);
970 if (cdata)
971 tegra_spi_cleanup(spi);
972 return ret;
973 }
974
975 if (tspi->soc_data->has_intr_mask_reg) {
976 val = tegra_spi_readl(tspi, SPI_INTR_MASK);
977 val &= ~SPI_INTR_ALL_MASK;
978 tegra_spi_writel(tspi, val, SPI_INTR_MASK);
979 }
980
981 spin_lock_irqsave(&tspi->lock, flags);
982 /* GPIO based chip select control */
983 if (spi->cs_gpiod)
984 gpiod_set_value(spi->cs_gpiod, 0);
985
986 val = tspi->def_command1_reg;
987 if (spi->mode & SPI_CS_HIGH)
988 val &= ~SPI_CS_POL_INACTIVE(spi->chip_select);
989 else
990 val |= SPI_CS_POL_INACTIVE(spi->chip_select);
991 tspi->def_command1_reg = val;
992 tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
993 spin_unlock_irqrestore(&tspi->lock, flags);
994
995 pm_runtime_put(tspi->dev);
996 return 0;
997 }
998
tegra_spi_transfer_end(struct spi_device * spi)999 static void tegra_spi_transfer_end(struct spi_device *spi)
1000 {
1001 struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
1002 int cs_val = (spi->mode & SPI_CS_HIGH) ? 0 : 1;
1003
1004 /* GPIO based chip select control */
1005 if (spi->cs_gpiod)
1006 gpiod_set_value(spi->cs_gpiod, 0);
1007
1008 if (!tspi->use_hw_based_cs) {
1009 if (cs_val)
1010 tspi->command1_reg |= SPI_CS_SW_VAL;
1011 else
1012 tspi->command1_reg &= ~SPI_CS_SW_VAL;
1013 tegra_spi_writel(tspi, tspi->command1_reg, SPI_COMMAND1);
1014 }
1015
1016 tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
1017 }
1018
tegra_spi_dump_regs(struct tegra_spi_data * tspi)1019 static void tegra_spi_dump_regs(struct tegra_spi_data *tspi)
1020 {
1021 dev_dbg(tspi->dev, "============ SPI REGISTER DUMP ============\n");
1022 dev_dbg(tspi->dev, "Command1: 0x%08x | Command2: 0x%08x\n",
1023 tegra_spi_readl(tspi, SPI_COMMAND1),
1024 tegra_spi_readl(tspi, SPI_COMMAND2));
1025 dev_dbg(tspi->dev, "DMA_CTL: 0x%08x | DMA_BLK: 0x%08x\n",
1026 tegra_spi_readl(tspi, SPI_DMA_CTL),
1027 tegra_spi_readl(tspi, SPI_DMA_BLK));
1028 dev_dbg(tspi->dev, "TRANS_STAT: 0x%08x | FIFO_STATUS: 0x%08x\n",
1029 tegra_spi_readl(tspi, SPI_TRANS_STATUS),
1030 tegra_spi_readl(tspi, SPI_FIFO_STATUS));
1031 }
1032
tegra_spi_transfer_one_message(struct spi_master * master,struct spi_message * msg)1033 static int tegra_spi_transfer_one_message(struct spi_master *master,
1034 struct spi_message *msg)
1035 {
1036 bool is_first_msg = true;
1037 struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1038 struct spi_transfer *xfer;
1039 struct spi_device *spi = msg->spi;
1040 int ret;
1041 bool skip = false;
1042 int single_xfer;
1043
1044 msg->status = 0;
1045 msg->actual_length = 0;
1046
1047 single_xfer = list_is_singular(&msg->transfers);
1048 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1049 u32 cmd1;
1050
1051 reinit_completion(&tspi->xfer_completion);
1052
1053 cmd1 = tegra_spi_setup_transfer_one(spi, xfer, is_first_msg,
1054 single_xfer);
1055
1056 if (!xfer->len) {
1057 ret = 0;
1058 skip = true;
1059 goto complete_xfer;
1060 }
1061
1062 ret = tegra_spi_start_transfer_one(spi, xfer, cmd1);
1063 if (ret < 0) {
1064 dev_err(tspi->dev,
1065 "spi can not start transfer, err %d\n", ret);
1066 goto complete_xfer;
1067 }
1068
1069 is_first_msg = false;
1070 ret = wait_for_completion_timeout(&tspi->xfer_completion,
1071 SPI_DMA_TIMEOUT);
1072 if (WARN_ON(ret == 0)) {
1073 dev_err(tspi->dev, "spi transfer timeout\n");
1074 if (tspi->is_curr_dma_xfer &&
1075 (tspi->cur_direction & DATA_DIR_TX))
1076 dmaengine_terminate_all(tspi->tx_dma_chan);
1077 if (tspi->is_curr_dma_xfer &&
1078 (tspi->cur_direction & DATA_DIR_RX))
1079 dmaengine_terminate_all(tspi->rx_dma_chan);
1080 ret = -EIO;
1081 tegra_spi_dump_regs(tspi);
1082 tegra_spi_flush_fifos(tspi);
1083 reset_control_assert(tspi->rst);
1084 udelay(2);
1085 reset_control_deassert(tspi->rst);
1086 tspi->last_used_cs = master->num_chipselect + 1;
1087 goto complete_xfer;
1088 }
1089
1090 if (tspi->tx_status || tspi->rx_status) {
1091 dev_err(tspi->dev, "Error in Transfer\n");
1092 ret = -EIO;
1093 tegra_spi_dump_regs(tspi);
1094 goto complete_xfer;
1095 }
1096 msg->actual_length += xfer->len;
1097
1098 complete_xfer:
1099 if (ret < 0 || skip) {
1100 tegra_spi_transfer_end(spi);
1101 spi_transfer_delay_exec(xfer);
1102 goto exit;
1103 } else if (list_is_last(&xfer->transfer_list,
1104 &msg->transfers)) {
1105 if (xfer->cs_change)
1106 tspi->cs_control = spi;
1107 else {
1108 tegra_spi_transfer_end(spi);
1109 spi_transfer_delay_exec(xfer);
1110 }
1111 } else if (xfer->cs_change) {
1112 tegra_spi_transfer_end(spi);
1113 spi_transfer_delay_exec(xfer);
1114 }
1115
1116 }
1117 ret = 0;
1118 exit:
1119 msg->status = ret;
1120 spi_finalize_current_message(master);
1121 return ret;
1122 }
1123
handle_cpu_based_xfer(struct tegra_spi_data * tspi)1124 static irqreturn_t handle_cpu_based_xfer(struct tegra_spi_data *tspi)
1125 {
1126 struct spi_transfer *t = tspi->curr_xfer;
1127 unsigned long flags;
1128
1129 spin_lock_irqsave(&tspi->lock, flags);
1130 if (tspi->tx_status || tspi->rx_status) {
1131 dev_err(tspi->dev, "CpuXfer ERROR bit set 0x%x\n",
1132 tspi->status_reg);
1133 dev_err(tspi->dev, "CpuXfer 0x%08x:0x%08x\n",
1134 tspi->command1_reg, tspi->dma_control_reg);
1135 tegra_spi_dump_regs(tspi);
1136 tegra_spi_flush_fifos(tspi);
1137 complete(&tspi->xfer_completion);
1138 spin_unlock_irqrestore(&tspi->lock, flags);
1139 reset_control_assert(tspi->rst);
1140 udelay(2);
1141 reset_control_deassert(tspi->rst);
1142 return IRQ_HANDLED;
1143 }
1144
1145 if (tspi->cur_direction & DATA_DIR_RX)
1146 tegra_spi_read_rx_fifo_to_client_rxbuf(tspi, t);
1147
1148 if (tspi->cur_direction & DATA_DIR_TX)
1149 tspi->cur_pos = tspi->cur_tx_pos;
1150 else
1151 tspi->cur_pos = tspi->cur_rx_pos;
1152
1153 if (tspi->cur_pos == t->len) {
1154 complete(&tspi->xfer_completion);
1155 goto exit;
1156 }
1157
1158 tegra_spi_calculate_curr_xfer_param(tspi->cur_spi, tspi, t);
1159 tegra_spi_start_cpu_based_transfer(tspi, t);
1160 exit:
1161 spin_unlock_irqrestore(&tspi->lock, flags);
1162 return IRQ_HANDLED;
1163 }
1164
handle_dma_based_xfer(struct tegra_spi_data * tspi)1165 static irqreturn_t handle_dma_based_xfer(struct tegra_spi_data *tspi)
1166 {
1167 struct spi_transfer *t = tspi->curr_xfer;
1168 long wait_status;
1169 int err = 0;
1170 unsigned total_fifo_words;
1171 unsigned long flags;
1172
1173 /* Abort dmas if any error */
1174 if (tspi->cur_direction & DATA_DIR_TX) {
1175 if (tspi->tx_status) {
1176 dmaengine_terminate_all(tspi->tx_dma_chan);
1177 err += 1;
1178 } else {
1179 wait_status = wait_for_completion_interruptible_timeout(
1180 &tspi->tx_dma_complete, SPI_DMA_TIMEOUT);
1181 if (wait_status <= 0) {
1182 dmaengine_terminate_all(tspi->tx_dma_chan);
1183 dev_err(tspi->dev, "TxDma Xfer failed\n");
1184 err += 1;
1185 }
1186 }
1187 }
1188
1189 if (tspi->cur_direction & DATA_DIR_RX) {
1190 if (tspi->rx_status) {
1191 dmaengine_terminate_all(tspi->rx_dma_chan);
1192 err += 2;
1193 } else {
1194 wait_status = wait_for_completion_interruptible_timeout(
1195 &tspi->rx_dma_complete, SPI_DMA_TIMEOUT);
1196 if (wait_status <= 0) {
1197 dmaengine_terminate_all(tspi->rx_dma_chan);
1198 dev_err(tspi->dev, "RxDma Xfer failed\n");
1199 err += 2;
1200 }
1201 }
1202 }
1203
1204 spin_lock_irqsave(&tspi->lock, flags);
1205 if (err) {
1206 dev_err(tspi->dev, "DmaXfer: ERROR bit set 0x%x\n",
1207 tspi->status_reg);
1208 dev_err(tspi->dev, "DmaXfer 0x%08x:0x%08x\n",
1209 tspi->command1_reg, tspi->dma_control_reg);
1210 tegra_spi_dump_regs(tspi);
1211 tegra_spi_flush_fifos(tspi);
1212 complete(&tspi->xfer_completion);
1213 spin_unlock_irqrestore(&tspi->lock, flags);
1214 reset_control_assert(tspi->rst);
1215 udelay(2);
1216 reset_control_deassert(tspi->rst);
1217 return IRQ_HANDLED;
1218 }
1219
1220 if (tspi->cur_direction & DATA_DIR_RX)
1221 tegra_spi_copy_spi_rxbuf_to_client_rxbuf(tspi, t);
1222
1223 if (tspi->cur_direction & DATA_DIR_TX)
1224 tspi->cur_pos = tspi->cur_tx_pos;
1225 else
1226 tspi->cur_pos = tspi->cur_rx_pos;
1227
1228 if (tspi->cur_pos == t->len) {
1229 complete(&tspi->xfer_completion);
1230 goto exit;
1231 }
1232
1233 /* Continue transfer in current message */
1234 total_fifo_words = tegra_spi_calculate_curr_xfer_param(tspi->cur_spi,
1235 tspi, t);
1236 if (total_fifo_words > SPI_FIFO_DEPTH)
1237 err = tegra_spi_start_dma_based_transfer(tspi, t);
1238 else
1239 err = tegra_spi_start_cpu_based_transfer(tspi, t);
1240
1241 exit:
1242 spin_unlock_irqrestore(&tspi->lock, flags);
1243 return IRQ_HANDLED;
1244 }
1245
tegra_spi_isr_thread(int irq,void * context_data)1246 static irqreturn_t tegra_spi_isr_thread(int irq, void *context_data)
1247 {
1248 struct tegra_spi_data *tspi = context_data;
1249
1250 if (!tspi->is_curr_dma_xfer)
1251 return handle_cpu_based_xfer(tspi);
1252 return handle_dma_based_xfer(tspi);
1253 }
1254
tegra_spi_isr(int irq,void * context_data)1255 static irqreturn_t tegra_spi_isr(int irq, void *context_data)
1256 {
1257 struct tegra_spi_data *tspi = context_data;
1258
1259 tspi->status_reg = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
1260 if (tspi->cur_direction & DATA_DIR_TX)
1261 tspi->tx_status = tspi->status_reg &
1262 (SPI_TX_FIFO_UNF | SPI_TX_FIFO_OVF);
1263
1264 if (tspi->cur_direction & DATA_DIR_RX)
1265 tspi->rx_status = tspi->status_reg &
1266 (SPI_RX_FIFO_OVF | SPI_RX_FIFO_UNF);
1267 tegra_spi_clear_status(tspi);
1268
1269 return IRQ_WAKE_THREAD;
1270 }
1271
1272 static struct tegra_spi_soc_data tegra114_spi_soc_data = {
1273 .has_intr_mask_reg = false,
1274 };
1275
1276 static struct tegra_spi_soc_data tegra124_spi_soc_data = {
1277 .has_intr_mask_reg = false,
1278 };
1279
1280 static struct tegra_spi_soc_data tegra210_spi_soc_data = {
1281 .has_intr_mask_reg = true,
1282 };
1283
1284 static const struct of_device_id tegra_spi_of_match[] = {
1285 {
1286 .compatible = "nvidia,tegra114-spi",
1287 .data = &tegra114_spi_soc_data,
1288 }, {
1289 .compatible = "nvidia,tegra124-spi",
1290 .data = &tegra124_spi_soc_data,
1291 }, {
1292 .compatible = "nvidia,tegra210-spi",
1293 .data = &tegra210_spi_soc_data,
1294 },
1295 {}
1296 };
1297 MODULE_DEVICE_TABLE(of, tegra_spi_of_match);
1298
tegra_spi_probe(struct platform_device * pdev)1299 static int tegra_spi_probe(struct platform_device *pdev)
1300 {
1301 struct spi_master *master;
1302 struct tegra_spi_data *tspi;
1303 struct resource *r;
1304 int ret, spi_irq;
1305 int bus_num;
1306
1307 master = spi_alloc_master(&pdev->dev, sizeof(*tspi));
1308 if (!master) {
1309 dev_err(&pdev->dev, "master allocation failed\n");
1310 return -ENOMEM;
1311 }
1312 platform_set_drvdata(pdev, master);
1313 tspi = spi_master_get_devdata(master);
1314
1315 if (of_property_read_u32(pdev->dev.of_node, "spi-max-frequency",
1316 &master->max_speed_hz))
1317 master->max_speed_hz = 25000000; /* 25MHz */
1318
1319 /* the spi->mode bits understood by this driver: */
1320 master->use_gpio_descriptors = true;
1321 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST |
1322 SPI_TX_DUAL | SPI_RX_DUAL | SPI_3WIRE;
1323 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1324 master->setup = tegra_spi_setup;
1325 master->cleanup = tegra_spi_cleanup;
1326 master->transfer_one_message = tegra_spi_transfer_one_message;
1327 master->set_cs_timing = tegra_spi_set_hw_cs_timing;
1328 master->num_chipselect = MAX_CHIP_SELECT;
1329 master->auto_runtime_pm = true;
1330 bus_num = of_alias_get_id(pdev->dev.of_node, "spi");
1331 if (bus_num >= 0)
1332 master->bus_num = bus_num;
1333
1334 tspi->master = master;
1335 tspi->dev = &pdev->dev;
1336 spin_lock_init(&tspi->lock);
1337
1338 tspi->soc_data = of_device_get_match_data(&pdev->dev);
1339 if (!tspi->soc_data) {
1340 dev_err(&pdev->dev, "unsupported tegra\n");
1341 ret = -ENODEV;
1342 goto exit_free_master;
1343 }
1344
1345 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1346 tspi->base = devm_ioremap_resource(&pdev->dev, r);
1347 if (IS_ERR(tspi->base)) {
1348 ret = PTR_ERR(tspi->base);
1349 goto exit_free_master;
1350 }
1351 tspi->phys = r->start;
1352
1353 spi_irq = platform_get_irq(pdev, 0);
1354 if (spi_irq < 0) {
1355 ret = spi_irq;
1356 goto exit_free_master;
1357 }
1358 tspi->irq = spi_irq;
1359
1360 tspi->clk = devm_clk_get(&pdev->dev, "spi");
1361 if (IS_ERR(tspi->clk)) {
1362 dev_err(&pdev->dev, "can not get clock\n");
1363 ret = PTR_ERR(tspi->clk);
1364 goto exit_free_master;
1365 }
1366
1367 tspi->rst = devm_reset_control_get_exclusive(&pdev->dev, "spi");
1368 if (IS_ERR(tspi->rst)) {
1369 dev_err(&pdev->dev, "can not get reset\n");
1370 ret = PTR_ERR(tspi->rst);
1371 goto exit_free_master;
1372 }
1373
1374 tspi->max_buf_size = SPI_FIFO_DEPTH << 2;
1375 tspi->dma_buf_size = DEFAULT_SPI_DMA_BUF_LEN;
1376
1377 ret = tegra_spi_init_dma_param(tspi, true);
1378 if (ret < 0)
1379 goto exit_free_master;
1380 ret = tegra_spi_init_dma_param(tspi, false);
1381 if (ret < 0)
1382 goto exit_rx_dma_free;
1383 tspi->max_buf_size = tspi->dma_buf_size;
1384 init_completion(&tspi->tx_dma_complete);
1385 init_completion(&tspi->rx_dma_complete);
1386
1387 init_completion(&tspi->xfer_completion);
1388
1389 pm_runtime_enable(&pdev->dev);
1390 if (!pm_runtime_enabled(&pdev->dev)) {
1391 ret = tegra_spi_runtime_resume(&pdev->dev);
1392 if (ret)
1393 goto exit_pm_disable;
1394 }
1395
1396 ret = pm_runtime_resume_and_get(&pdev->dev);
1397 if (ret < 0) {
1398 dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret);
1399 goto exit_pm_disable;
1400 }
1401
1402 reset_control_assert(tspi->rst);
1403 udelay(2);
1404 reset_control_deassert(tspi->rst);
1405 tspi->def_command1_reg = SPI_M_S;
1406 tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
1407 tspi->spi_cs_timing1 = tegra_spi_readl(tspi, SPI_CS_TIMING1);
1408 tspi->spi_cs_timing2 = tegra_spi_readl(tspi, SPI_CS_TIMING2);
1409 tspi->def_command2_reg = tegra_spi_readl(tspi, SPI_COMMAND2);
1410 tspi->last_used_cs = master->num_chipselect + 1;
1411 pm_runtime_put(&pdev->dev);
1412 ret = request_threaded_irq(tspi->irq, tegra_spi_isr,
1413 tegra_spi_isr_thread, IRQF_ONESHOT,
1414 dev_name(&pdev->dev), tspi);
1415 if (ret < 0) {
1416 dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
1417 tspi->irq);
1418 goto exit_pm_disable;
1419 }
1420
1421 master->dev.of_node = pdev->dev.of_node;
1422 ret = devm_spi_register_master(&pdev->dev, master);
1423 if (ret < 0) {
1424 dev_err(&pdev->dev, "can not register to master err %d\n", ret);
1425 goto exit_free_irq;
1426 }
1427 return ret;
1428
1429 exit_free_irq:
1430 free_irq(spi_irq, tspi);
1431 exit_pm_disable:
1432 pm_runtime_disable(&pdev->dev);
1433 if (!pm_runtime_status_suspended(&pdev->dev))
1434 tegra_spi_runtime_suspend(&pdev->dev);
1435 tegra_spi_deinit_dma_param(tspi, false);
1436 exit_rx_dma_free:
1437 tegra_spi_deinit_dma_param(tspi, true);
1438 exit_free_master:
1439 spi_master_put(master);
1440 return ret;
1441 }
1442
tegra_spi_remove(struct platform_device * pdev)1443 static int tegra_spi_remove(struct platform_device *pdev)
1444 {
1445 struct spi_master *master = platform_get_drvdata(pdev);
1446 struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1447
1448 free_irq(tspi->irq, tspi);
1449
1450 if (tspi->tx_dma_chan)
1451 tegra_spi_deinit_dma_param(tspi, false);
1452
1453 if (tspi->rx_dma_chan)
1454 tegra_spi_deinit_dma_param(tspi, true);
1455
1456 pm_runtime_disable(&pdev->dev);
1457 if (!pm_runtime_status_suspended(&pdev->dev))
1458 tegra_spi_runtime_suspend(&pdev->dev);
1459
1460 return 0;
1461 }
1462
1463 #ifdef CONFIG_PM_SLEEP
tegra_spi_suspend(struct device * dev)1464 static int tegra_spi_suspend(struct device *dev)
1465 {
1466 struct spi_master *master = dev_get_drvdata(dev);
1467
1468 return spi_master_suspend(master);
1469 }
1470
tegra_spi_resume(struct device * dev)1471 static int tegra_spi_resume(struct device *dev)
1472 {
1473 struct spi_master *master = dev_get_drvdata(dev);
1474 struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1475 int ret;
1476
1477 ret = pm_runtime_resume_and_get(dev);
1478 if (ret < 0) {
1479 dev_err(dev, "pm runtime failed, e = %d\n", ret);
1480 return ret;
1481 }
1482 tegra_spi_writel(tspi, tspi->command1_reg, SPI_COMMAND1);
1483 tegra_spi_writel(tspi, tspi->def_command2_reg, SPI_COMMAND2);
1484 tspi->last_used_cs = master->num_chipselect + 1;
1485 pm_runtime_put(dev);
1486
1487 return spi_master_resume(master);
1488 }
1489 #endif
1490
tegra_spi_runtime_suspend(struct device * dev)1491 static int tegra_spi_runtime_suspend(struct device *dev)
1492 {
1493 struct spi_master *master = dev_get_drvdata(dev);
1494 struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1495
1496 /* Flush all write which are in PPSB queue by reading back */
1497 tegra_spi_readl(tspi, SPI_COMMAND1);
1498
1499 clk_disable_unprepare(tspi->clk);
1500 return 0;
1501 }
1502
tegra_spi_runtime_resume(struct device * dev)1503 static int tegra_spi_runtime_resume(struct device *dev)
1504 {
1505 struct spi_master *master = dev_get_drvdata(dev);
1506 struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1507 int ret;
1508
1509 ret = clk_prepare_enable(tspi->clk);
1510 if (ret < 0) {
1511 dev_err(tspi->dev, "clk_prepare failed: %d\n", ret);
1512 return ret;
1513 }
1514 return 0;
1515 }
1516
1517 static const struct dev_pm_ops tegra_spi_pm_ops = {
1518 SET_RUNTIME_PM_OPS(tegra_spi_runtime_suspend,
1519 tegra_spi_runtime_resume, NULL)
1520 SET_SYSTEM_SLEEP_PM_OPS(tegra_spi_suspend, tegra_spi_resume)
1521 };
1522 static struct platform_driver tegra_spi_driver = {
1523 .driver = {
1524 .name = "spi-tegra114",
1525 .pm = &tegra_spi_pm_ops,
1526 .of_match_table = tegra_spi_of_match,
1527 },
1528 .probe = tegra_spi_probe,
1529 .remove = tegra_spi_remove,
1530 };
1531 module_platform_driver(tegra_spi_driver);
1532
1533 MODULE_ALIAS("platform:spi-tegra114");
1534 MODULE_DESCRIPTION("NVIDIA Tegra114 SPI Controller Driver");
1535 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1536 MODULE_LICENSE("GPL v2");
1537
