2 * SPI driver for NVIDIA's Tegra114 SPI Controller.
4 * Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 #include <linux/clk.h>
20 #include <linux/clk/tegra.h>
21 #include <linux/completion.h>
22 #include <linux/delay.h>
23 #include <linux/dmaengine.h>
24 #include <linux/dma-mapping.h>
25 #include <linux/dmapool.h>
26 #include <linux/err.h>
27 #include <linux/init.h>
28 #include <linux/interrupt.h>
30 #include <linux/kernel.h>
31 #include <linux/kthread.h>
32 #include <linux/module.h>
33 #include <linux/platform_device.h>
34 #include <linux/pm_runtime.h>
36 #include <linux/of_device.h>
37 #include <linux/spi/spi.h>
39 #define SPI_COMMAND1 0x000
40 #define SPI_BIT_LENGTH(x) (((x) & 0x1f) << 0)
41 #define SPI_PACKED (1 << 5)
42 #define SPI_TX_EN (1 << 11)
43 #define SPI_RX_EN (1 << 12)
44 #define SPI_BOTH_EN_BYTE (1 << 13)
45 #define SPI_BOTH_EN_BIT (1 << 14)
46 #define SPI_LSBYTE_FE (1 << 15)
47 #define SPI_LSBIT_FE (1 << 16)
48 #define SPI_BIDIROE (1 << 17)
49 #define SPI_IDLE_SDA_DRIVE_LOW (0 << 18)
50 #define SPI_IDLE_SDA_DRIVE_HIGH (1 << 18)
51 #define SPI_IDLE_SDA_PULL_LOW (2 << 18)
52 #define SPI_IDLE_SDA_PULL_HIGH (3 << 18)
53 #define SPI_IDLE_SDA_MASK (3 << 18)
54 #define SPI_CS_SS_VAL (1 << 20)
55 #define SPI_CS_SW_HW (1 << 21)
56 /* SPI_CS_POL_INACTIVE bits are default high */
57 #define SPI_CS_POL_INACTIVE 22
58 #define SPI_CS_POL_INACTIVE_0 (1 << 22)
59 #define SPI_CS_POL_INACTIVE_1 (1 << 23)
60 #define SPI_CS_POL_INACTIVE_2 (1 << 24)
61 #define SPI_CS_POL_INACTIVE_3 (1 << 25)
62 #define SPI_CS_POL_INACTIVE_MASK (0xF << 22)
64 #define SPI_CS_SEL_0 (0 << 26)
65 #define SPI_CS_SEL_1 (1 << 26)
66 #define SPI_CS_SEL_2 (2 << 26)
67 #define SPI_CS_SEL_3 (3 << 26)
68 #define SPI_CS_SEL_MASK (3 << 26)
69 #define SPI_CS_SEL(x) (((x) & 0x3) << 26)
70 #define SPI_CONTROL_MODE_0 (0 << 28)
71 #define SPI_CONTROL_MODE_1 (1 << 28)
72 #define SPI_CONTROL_MODE_2 (2 << 28)
73 #define SPI_CONTROL_MODE_3 (3 << 28)
74 #define SPI_CONTROL_MODE_MASK (3 << 28)
75 #define SPI_MODE_SEL(x) (((x) & 0x3) << 28)
76 #define SPI_M_S (1 << 30)
77 #define SPI_PIO (1 << 31)
79 #define SPI_COMMAND2 0x004
80 #define SPI_TX_TAP_DELAY(x) (((x) & 0x3F) << 6)
81 #define SPI_RX_TAP_DELAY(x) (((x) & 0x3F) << 0)
83 #define SPI_CS_TIMING1 0x008
84 #define SPI_SETUP_HOLD(setup, hold) (((setup) << 4) | (hold))
85 #define SPI_CS_SETUP_HOLD(reg, cs, val) \
86 ((((val) & 0xFFu) << ((cs) * 8)) | \
87 ((reg) & ~(0xFFu << ((cs) * 8))))
89 #define SPI_CS_TIMING2 0x00C
90 #define CYCLES_BETWEEN_PACKETS_0(x) (((x) & 0x1F) << 0)
91 #define CS_ACTIVE_BETWEEN_PACKETS_0 (1 << 5)
92 #define CYCLES_BETWEEN_PACKETS_1(x) (((x) & 0x1F) << 8)
93 #define CS_ACTIVE_BETWEEN_PACKETS_1 (1 << 13)
94 #define CYCLES_BETWEEN_PACKETS_2(x) (((x) & 0x1F) << 16)
95 #define CS_ACTIVE_BETWEEN_PACKETS_2 (1 << 21)
96 #define CYCLES_BETWEEN_PACKETS_3(x) (((x) & 0x1F) << 24)
97 #define CS_ACTIVE_BETWEEN_PACKETS_3 (1 << 29)
98 #define SPI_SET_CS_ACTIVE_BETWEEN_PACKETS(reg, cs, val) \
99 (reg = (((val) & 0x1) << ((cs) * 8 + 5)) | \
100 ((reg) & ~(1 << ((cs) * 8 + 5))))
101 #define SPI_SET_CYCLES_BETWEEN_PACKETS(reg, cs, val) \
102 (reg = (((val) & 0xF) << ((cs) * 8)) | \
103 ((reg) & ~(0xF << ((cs) * 8))))
105 #define SPI_TRANS_STATUS 0x010
106 #define SPI_BLK_CNT(val) (((val) >> 0) & 0xFFFF)
107 #define SPI_SLV_IDLE_COUNT(val) (((val) >> 16) & 0xFF)
108 #define SPI_RDY (1 << 30)
110 #define SPI_FIFO_STATUS 0x014
111 #define SPI_RX_FIFO_EMPTY (1 << 0)
112 #define SPI_RX_FIFO_FULL (1 << 1)
113 #define SPI_TX_FIFO_EMPTY (1 << 2)
114 #define SPI_TX_FIFO_FULL (1 << 3)
115 #define SPI_RX_FIFO_UNF (1 << 4)
116 #define SPI_RX_FIFO_OVF (1 << 5)
117 #define SPI_TX_FIFO_UNF (1 << 6)
118 #define SPI_TX_FIFO_OVF (1 << 7)
119 #define SPI_ERR (1 << 8)
120 #define SPI_TX_FIFO_FLUSH (1 << 14)
121 #define SPI_RX_FIFO_FLUSH (1 << 15)
122 #define SPI_TX_FIFO_EMPTY_COUNT(val) (((val) >> 16) & 0x7F)
123 #define SPI_RX_FIFO_FULL_COUNT(val) (((val) >> 23) & 0x7F)
124 #define SPI_FRAME_END (1 << 30)
125 #define SPI_CS_INACTIVE (1 << 31)
127 #define SPI_FIFO_ERROR (SPI_RX_FIFO_UNF | \
128 SPI_RX_FIFO_OVF | SPI_TX_FIFO_UNF | SPI_TX_FIFO_OVF)
129 #define SPI_FIFO_EMPTY (SPI_RX_FIFO_EMPTY | SPI_TX_FIFO_EMPTY)
131 #define SPI_TX_DATA 0x018
132 #define SPI_RX_DATA 0x01C
134 #define SPI_DMA_CTL 0x020
135 #define SPI_TX_TRIG_1 (0 << 15)
136 #define SPI_TX_TRIG_4 (1 << 15)
137 #define SPI_TX_TRIG_8 (2 << 15)
138 #define SPI_TX_TRIG_16 (3 << 15)
139 #define SPI_TX_TRIG_MASK (3 << 15)
140 #define SPI_RX_TRIG_1 (0 << 19)
141 #define SPI_RX_TRIG_4 (1 << 19)
142 #define SPI_RX_TRIG_8 (2 << 19)
143 #define SPI_RX_TRIG_16 (3 << 19)
144 #define SPI_RX_TRIG_MASK (3 << 19)
145 #define SPI_IE_TX (1 << 28)
146 #define SPI_IE_RX (1 << 29)
147 #define SPI_CONT (1 << 30)
148 #define SPI_DMA (1 << 31)
149 #define SPI_DMA_EN SPI_DMA
151 #define SPI_DMA_BLK 0x024
152 #define SPI_DMA_BLK_SET(x) (((x) & 0xFFFF) << 0)
154 #define SPI_TX_FIFO 0x108
155 #define SPI_RX_FIFO 0x188
156 #define MAX_CHIP_SELECT 4
157 #define SPI_FIFO_DEPTH 64
158 #define DATA_DIR_TX (1 << 0)
159 #define DATA_DIR_RX (1 << 1)
161 #define SPI_DMA_TIMEOUT (msecs_to_jiffies(1000))
162 #define DEFAULT_SPI_DMA_BUF_LEN (16*1024)
163 #define TX_FIFO_EMPTY_COUNT_MAX SPI_TX_FIFO_EMPTY_COUNT(0x40)
164 #define RX_FIFO_FULL_COUNT_ZERO SPI_RX_FIFO_FULL_COUNT(0)
165 #define MAX_HOLD_CYCLES 16
166 #define SPI_DEFAULT_SPEED 25000000
168 #define MAX_CHIP_SELECT 4
169 #define SPI_FIFO_DEPTH 64
171 struct tegra_spi_data {
173 struct spi_master *master;
181 u32 spi_max_frequency;
184 struct spi_device *cur_spi;
185 struct spi_device *cs_control;
188 unsigned words_per_32bit;
189 unsigned bytes_per_word;
190 unsigned curr_dma_words;
191 unsigned cur_direction;
196 unsigned dma_buf_size;
197 unsigned max_buf_size;
198 bool is_curr_dma_xfer;
200 struct completion rx_dma_complete;
201 struct completion tx_dma_complete;
207 unsigned long packed_size;
211 u32 def_command1_reg;
214 struct completion xfer_completion;
215 struct spi_transfer *curr_xfer;
216 struct dma_chan *rx_dma_chan;
218 dma_addr_t rx_dma_phys;
219 struct dma_async_tx_descriptor *rx_dma_desc;
221 struct dma_chan *tx_dma_chan;
223 dma_addr_t tx_dma_phys;
224 struct dma_async_tx_descriptor *tx_dma_desc;
227 static int tegra_spi_runtime_suspend(struct device *dev);
228 static int tegra_spi_runtime_resume(struct device *dev);
230 static inline unsigned long tegra_spi_readl(struct tegra_spi_data *tspi,
233 return readl(tspi->base + reg);
236 static inline void tegra_spi_writel(struct tegra_spi_data *tspi,
237 unsigned long val, unsigned long reg)
239 writel(val, tspi->base + reg);
241 /* Read back register to make sure that register writes completed */
242 if (reg != SPI_TX_FIFO)
243 readl(tspi->base + SPI_COMMAND1);
246 static void tegra_spi_clear_status(struct tegra_spi_data *tspi)
250 /* Write 1 to clear status register */
251 val = tegra_spi_readl(tspi, SPI_TRANS_STATUS);
252 tegra_spi_writel(tspi, val, SPI_TRANS_STATUS);
254 /* Clear fifo status error if any */
255 val = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
257 tegra_spi_writel(tspi, SPI_ERR | SPI_FIFO_ERROR,
261 static unsigned tegra_spi_calculate_curr_xfer_param(
262 struct spi_device *spi, struct tegra_spi_data *tspi,
263 struct spi_transfer *t)
265 unsigned remain_len = t->len - tspi->cur_pos;
267 unsigned bits_per_word = t->bits_per_word;
269 unsigned total_fifo_words;
271 tspi->bytes_per_word = DIV_ROUND_UP(bits_per_word, 8);
273 if (bits_per_word == 8 || bits_per_word == 16) {
275 tspi->words_per_32bit = 32/bits_per_word;
278 tspi->words_per_32bit = 1;
281 if (tspi->is_packed) {
282 max_len = min(remain_len, tspi->max_buf_size);
283 tspi->curr_dma_words = max_len/tspi->bytes_per_word;
284 total_fifo_words = (max_len + 3) / 4;
286 max_word = (remain_len - 1) / tspi->bytes_per_word + 1;
287 max_word = min(max_word, tspi->max_buf_size/4);
288 tspi->curr_dma_words = max_word;
289 total_fifo_words = max_word;
291 return total_fifo_words;
294 static unsigned tegra_spi_fill_tx_fifo_from_client_txbuf(
295 struct tegra_spi_data *tspi, struct spi_transfer *t)
298 unsigned tx_empty_count;
299 unsigned long fifo_status;
300 unsigned max_n_32bit;
303 unsigned int written_words;
304 unsigned fifo_words_left;
305 u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
307 fifo_status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
308 tx_empty_count = SPI_TX_FIFO_EMPTY_COUNT(fifo_status);
310 if (tspi->is_packed) {
311 fifo_words_left = tx_empty_count * tspi->words_per_32bit;
312 written_words = min(fifo_words_left, tspi->curr_dma_words);
313 nbytes = written_words * tspi->bytes_per_word;
314 max_n_32bit = DIV_ROUND_UP(nbytes, 4);
315 for (count = 0; count < max_n_32bit; count++) {
317 for (i = 0; (i < 4) && nbytes; i++, nbytes--)
318 x |= (*tx_buf++) << (i*8);
319 tegra_spi_writel(tspi, x, SPI_TX_FIFO);
322 max_n_32bit = min(tspi->curr_dma_words, tx_empty_count);
323 written_words = max_n_32bit;
324 nbytes = written_words * tspi->bytes_per_word;
325 for (count = 0; count < max_n_32bit; count++) {
327 for (i = 0; nbytes && (i < tspi->bytes_per_word);
329 x |= ((*tx_buf++) << i*8);
330 tegra_spi_writel(tspi, x, SPI_TX_FIFO);
333 tspi->cur_tx_pos += written_words * tspi->bytes_per_word;
334 return written_words;
337 static unsigned int tegra_spi_read_rx_fifo_to_client_rxbuf(
338 struct tegra_spi_data *tspi, struct spi_transfer *t)
340 unsigned rx_full_count;
341 unsigned long fifo_status;
344 unsigned int read_words = 0;
346 u8 *rx_buf = (u8 *)t->rx_buf + tspi->cur_rx_pos;
348 fifo_status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
349 rx_full_count = SPI_RX_FIFO_FULL_COUNT(fifo_status);
350 if (tspi->is_packed) {
351 len = tspi->curr_dma_words * tspi->bytes_per_word;
352 for (count = 0; count < rx_full_count; count++) {
353 x = tegra_spi_readl(tspi, SPI_RX_FIFO);
354 for (i = 0; len && (i < 4); i++, len--)
355 *rx_buf++ = (x >> i*8) & 0xFF;
357 tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
358 read_words += tspi->curr_dma_words;
360 unsigned int rx_mask;
361 unsigned int bits_per_word = t->bits_per_word;
363 rx_mask = (1 << bits_per_word) - 1;
364 for (count = 0; count < rx_full_count; count++) {
365 x = tegra_spi_readl(tspi, SPI_RX_FIFO);
367 for (i = 0; (i < tspi->bytes_per_word); i++)
368 *rx_buf++ = (x >> (i*8)) & 0xFF;
370 tspi->cur_rx_pos += rx_full_count * tspi->bytes_per_word;
371 read_words += rx_full_count;
376 static void tegra_spi_copy_client_txbuf_to_spi_txbuf(
377 struct tegra_spi_data *tspi, struct spi_transfer *t)
381 /* Make the dma buffer to read by cpu */
382 dma_sync_single_for_cpu(tspi->dev, tspi->tx_dma_phys,
383 tspi->dma_buf_size, DMA_TO_DEVICE);
385 if (tspi->is_packed) {
386 len = tspi->curr_dma_words * tspi->bytes_per_word;
387 memcpy(tspi->tx_dma_buf, t->tx_buf + tspi->cur_pos, len);
391 u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
392 unsigned consume = tspi->curr_dma_words * tspi->bytes_per_word;
395 for (count = 0; count < tspi->curr_dma_words; count++) {
397 for (i = 0; consume && (i < tspi->bytes_per_word);
399 x |= ((*tx_buf++) << i * 8);
400 tspi->tx_dma_buf[count] = x;
403 tspi->cur_tx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
405 /* Make the dma buffer to read by dma */
406 dma_sync_single_for_device(tspi->dev, tspi->tx_dma_phys,
407 tspi->dma_buf_size, DMA_TO_DEVICE);
410 static void tegra_spi_copy_spi_rxbuf_to_client_rxbuf(
411 struct tegra_spi_data *tspi, struct spi_transfer *t)
415 /* Make the dma buffer to read by cpu */
416 dma_sync_single_for_cpu(tspi->dev, tspi->rx_dma_phys,
417 tspi->dma_buf_size, DMA_FROM_DEVICE);
419 if (tspi->is_packed) {
420 len = tspi->curr_dma_words * tspi->bytes_per_word;
421 memcpy(t->rx_buf + tspi->cur_rx_pos, tspi->rx_dma_buf, len);
425 unsigned char *rx_buf = t->rx_buf + tspi->cur_rx_pos;
427 unsigned int rx_mask;
428 unsigned int bits_per_word = t->bits_per_word;
430 rx_mask = (1 << bits_per_word) - 1;
431 for (count = 0; count < tspi->curr_dma_words; count++) {
432 x = tspi->rx_dma_buf[count];
434 for (i = 0; (i < tspi->bytes_per_word); i++)
435 *rx_buf++ = (x >> (i*8)) & 0xFF;
438 tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
440 /* Make the dma buffer to read by dma */
441 dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
442 tspi->dma_buf_size, DMA_FROM_DEVICE);
445 static void tegra_spi_dma_complete(void *args)
447 struct completion *dma_complete = args;
449 complete(dma_complete);
452 static int tegra_spi_start_tx_dma(struct tegra_spi_data *tspi, int len)
454 reinit_completion(&tspi->tx_dma_complete);
455 tspi->tx_dma_desc = dmaengine_prep_slave_single(tspi->tx_dma_chan,
456 tspi->tx_dma_phys, len, DMA_MEM_TO_DEV,
457 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
458 if (!tspi->tx_dma_desc) {
459 dev_err(tspi->dev, "Not able to get desc for Tx\n");
463 tspi->tx_dma_desc->callback = tegra_spi_dma_complete;
464 tspi->tx_dma_desc->callback_param = &tspi->tx_dma_complete;
466 dmaengine_submit(tspi->tx_dma_desc);
467 dma_async_issue_pending(tspi->tx_dma_chan);
471 static int tegra_spi_start_rx_dma(struct tegra_spi_data *tspi, int len)
473 reinit_completion(&tspi->rx_dma_complete);
474 tspi->rx_dma_desc = dmaengine_prep_slave_single(tspi->rx_dma_chan,
475 tspi->rx_dma_phys, len, DMA_DEV_TO_MEM,
476 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
477 if (!tspi->rx_dma_desc) {
478 dev_err(tspi->dev, "Not able to get desc for Rx\n");
482 tspi->rx_dma_desc->callback = tegra_spi_dma_complete;
483 tspi->rx_dma_desc->callback_param = &tspi->rx_dma_complete;
485 dmaengine_submit(tspi->rx_dma_desc);
486 dma_async_issue_pending(tspi->rx_dma_chan);
490 static int tegra_spi_start_dma_based_transfer(
491 struct tegra_spi_data *tspi, struct spi_transfer *t)
496 unsigned long status;
498 /* Make sure that Rx and Tx fifo are empty */
499 status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
500 if ((status & SPI_FIFO_EMPTY) != SPI_FIFO_EMPTY) {
502 "Rx/Tx fifo are not empty status 0x%08lx\n", status);
506 val = SPI_DMA_BLK_SET(tspi->curr_dma_words - 1);
507 tegra_spi_writel(tspi, val, SPI_DMA_BLK);
510 len = DIV_ROUND_UP(tspi->curr_dma_words * tspi->bytes_per_word,
513 len = tspi->curr_dma_words * 4;
515 /* Set attention level based on length of transfer */
517 val |= SPI_TX_TRIG_1 | SPI_RX_TRIG_1;
518 else if (((len) >> 4) & 0x1)
519 val |= SPI_TX_TRIG_4 | SPI_RX_TRIG_4;
521 val |= SPI_TX_TRIG_8 | SPI_RX_TRIG_8;
523 if (tspi->cur_direction & DATA_DIR_TX)
526 if (tspi->cur_direction & DATA_DIR_RX)
529 tegra_spi_writel(tspi, val, SPI_DMA_CTL);
530 tspi->dma_control_reg = val;
532 if (tspi->cur_direction & DATA_DIR_TX) {
533 tegra_spi_copy_client_txbuf_to_spi_txbuf(tspi, t);
534 ret = tegra_spi_start_tx_dma(tspi, len);
537 "Starting tx dma failed, err %d\n", ret);
542 if (tspi->cur_direction & DATA_DIR_RX) {
543 /* Make the dma buffer to read by dma */
544 dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
545 tspi->dma_buf_size, DMA_FROM_DEVICE);
547 ret = tegra_spi_start_rx_dma(tspi, len);
550 "Starting rx dma failed, err %d\n", ret);
551 if (tspi->cur_direction & DATA_DIR_TX)
552 dmaengine_terminate_all(tspi->tx_dma_chan);
556 tspi->is_curr_dma_xfer = true;
557 tspi->dma_control_reg = val;
560 tegra_spi_writel(tspi, val, SPI_DMA_CTL);
564 static int tegra_spi_start_cpu_based_transfer(
565 struct tegra_spi_data *tspi, struct spi_transfer *t)
570 if (tspi->cur_direction & DATA_DIR_TX)
571 cur_words = tegra_spi_fill_tx_fifo_from_client_txbuf(tspi, t);
573 cur_words = tspi->curr_dma_words;
575 val = SPI_DMA_BLK_SET(cur_words - 1);
576 tegra_spi_writel(tspi, val, SPI_DMA_BLK);
579 if (tspi->cur_direction & DATA_DIR_TX)
582 if (tspi->cur_direction & DATA_DIR_RX)
585 tegra_spi_writel(tspi, val, SPI_DMA_CTL);
586 tspi->dma_control_reg = val;
588 tspi->is_curr_dma_xfer = false;
591 tegra_spi_writel(tspi, val, SPI_DMA_CTL);
595 static int tegra_spi_init_dma_param(struct tegra_spi_data *tspi,
598 struct dma_chan *dma_chan;
602 struct dma_slave_config dma_sconfig;
606 dma_cap_set(DMA_SLAVE, mask);
607 dma_chan = dma_request_channel(mask, NULL, NULL);
610 "Dma channel is not available, will try later\n");
611 return -EPROBE_DEFER;
614 dma_buf = dma_alloc_coherent(tspi->dev, tspi->dma_buf_size,
615 &dma_phys, GFP_KERNEL);
617 dev_err(tspi->dev, " Not able to allocate the dma buffer\n");
618 dma_release_channel(dma_chan);
622 dma_sconfig.slave_id = tspi->dma_req_sel;
624 dma_sconfig.src_addr = tspi->phys + SPI_RX_FIFO;
625 dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
626 dma_sconfig.src_maxburst = 0;
628 dma_sconfig.dst_addr = tspi->phys + SPI_TX_FIFO;
629 dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
630 dma_sconfig.dst_maxburst = 0;
633 ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
637 tspi->rx_dma_chan = dma_chan;
638 tspi->rx_dma_buf = dma_buf;
639 tspi->rx_dma_phys = dma_phys;
641 tspi->tx_dma_chan = dma_chan;
642 tspi->tx_dma_buf = dma_buf;
643 tspi->tx_dma_phys = dma_phys;
648 dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
649 dma_release_channel(dma_chan);
653 static void tegra_spi_deinit_dma_param(struct tegra_spi_data *tspi,
658 struct dma_chan *dma_chan;
661 dma_buf = tspi->rx_dma_buf;
662 dma_chan = tspi->rx_dma_chan;
663 dma_phys = tspi->rx_dma_phys;
664 tspi->rx_dma_chan = NULL;
665 tspi->rx_dma_buf = NULL;
667 dma_buf = tspi->tx_dma_buf;
668 dma_chan = tspi->tx_dma_chan;
669 dma_phys = tspi->tx_dma_phys;
670 tspi->tx_dma_buf = NULL;
671 tspi->tx_dma_chan = NULL;
676 dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
677 dma_release_channel(dma_chan);
680 static unsigned long tegra_spi_setup_transfer_one(struct spi_device *spi,
681 struct spi_transfer *t, bool is_first_of_msg)
683 struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
684 u32 speed = t->speed_hz;
685 u8 bits_per_word = t->bits_per_word;
686 unsigned long command1;
689 if (speed != tspi->cur_speed) {
690 clk_set_rate(tspi->clk, speed);
691 tspi->cur_speed = speed;
696 tspi->cur_rx_pos = 0;
697 tspi->cur_tx_pos = 0;
700 if (is_first_of_msg) {
701 tegra_spi_clear_status(tspi);
703 command1 = tspi->def_command1_reg;
704 command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
706 command1 &= ~SPI_CONTROL_MODE_MASK;
707 req_mode = spi->mode & 0x3;
708 if (req_mode == SPI_MODE_0)
709 command1 |= SPI_CONTROL_MODE_0;
710 else if (req_mode == SPI_MODE_1)
711 command1 |= SPI_CONTROL_MODE_1;
712 else if (req_mode == SPI_MODE_2)
713 command1 |= SPI_CONTROL_MODE_2;
714 else if (req_mode == SPI_MODE_3)
715 command1 |= SPI_CONTROL_MODE_3;
717 if (tspi->cs_control) {
718 if (tspi->cs_control != spi)
719 tegra_spi_writel(tspi, command1, SPI_COMMAND1);
720 tspi->cs_control = NULL;
722 tegra_spi_writel(tspi, command1, SPI_COMMAND1);
724 command1 |= SPI_CS_SW_HW;
725 if (spi->mode & SPI_CS_HIGH)
726 command1 |= SPI_CS_SS_VAL;
728 command1 &= ~SPI_CS_SS_VAL;
730 tegra_spi_writel(tspi, 0, SPI_COMMAND2);
732 command1 = tspi->command1_reg;
733 command1 &= ~SPI_BIT_LENGTH(~0);
734 command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
740 static int tegra_spi_start_transfer_one(struct spi_device *spi,
741 struct spi_transfer *t, unsigned long command1)
743 struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
744 unsigned total_fifo_words;
747 total_fifo_words = tegra_spi_calculate_curr_xfer_param(spi, tspi, t);
750 command1 |= SPI_PACKED;
752 command1 &= ~(SPI_CS_SEL_MASK | SPI_TX_EN | SPI_RX_EN);
753 tspi->cur_direction = 0;
755 command1 |= SPI_RX_EN;
756 tspi->cur_direction |= DATA_DIR_RX;
759 command1 |= SPI_TX_EN;
760 tspi->cur_direction |= DATA_DIR_TX;
762 command1 |= SPI_CS_SEL(spi->chip_select);
763 tegra_spi_writel(tspi, command1, SPI_COMMAND1);
764 tspi->command1_reg = command1;
766 dev_dbg(tspi->dev, "The def 0x%x and written 0x%lx\n",
767 tspi->def_command1_reg, command1);
769 if (total_fifo_words > SPI_FIFO_DEPTH)
770 ret = tegra_spi_start_dma_based_transfer(tspi, t);
772 ret = tegra_spi_start_cpu_based_transfer(tspi, t);
776 static int tegra_spi_setup(struct spi_device *spi)
778 struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
782 unsigned int cs_pol_bit[MAX_CHIP_SELECT] = {
783 SPI_CS_POL_INACTIVE_0,
784 SPI_CS_POL_INACTIVE_1,
785 SPI_CS_POL_INACTIVE_2,
786 SPI_CS_POL_INACTIVE_3,
789 dev_dbg(&spi->dev, "setup %d bpw, %scpol, %scpha, %dHz\n",
791 spi->mode & SPI_CPOL ? "" : "~",
792 spi->mode & SPI_CPHA ? "" : "~",
795 BUG_ON(spi->chip_select >= MAX_CHIP_SELECT);
797 /* Set speed to the spi max fequency if spi device has not set */
798 spi->max_speed_hz = spi->max_speed_hz ? : tspi->spi_max_frequency;
800 ret = pm_runtime_get_sync(tspi->dev);
802 dev_err(tspi->dev, "pm runtime failed, e = %d\n", ret);
806 spin_lock_irqsave(&tspi->lock, flags);
807 val = tspi->def_command1_reg;
808 if (spi->mode & SPI_CS_HIGH)
809 val &= ~cs_pol_bit[spi->chip_select];
811 val |= cs_pol_bit[spi->chip_select];
812 tspi->def_command1_reg = val;
813 tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
814 spin_unlock_irqrestore(&tspi->lock, flags);
816 pm_runtime_put(tspi->dev);
820 static void tegra_spi_transfer_delay(int delay)
826 mdelay(delay / 1000);
828 udelay(delay % 1000);
831 static int tegra_spi_transfer_one_message(struct spi_master *master,
832 struct spi_message *msg)
834 bool is_first_msg = true;
835 struct tegra_spi_data *tspi = spi_master_get_devdata(master);
836 struct spi_transfer *xfer;
837 struct spi_device *spi = msg->spi;
842 msg->actual_length = 0;
844 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
847 reinit_completion(&tspi->xfer_completion);
849 cmd1 = tegra_spi_setup_transfer_one(spi, xfer, is_first_msg);
857 ret = tegra_spi_start_transfer_one(spi, xfer, cmd1);
860 "spi can not start transfer, err %d\n", ret);
864 is_first_msg = false;
865 ret = wait_for_completion_timeout(&tspi->xfer_completion,
867 if (WARN_ON(ret == 0)) {
869 "spi trasfer timeout, err %d\n", ret);
874 if (tspi->tx_status || tspi->rx_status) {
875 dev_err(tspi->dev, "Error in Transfer\n");
879 msg->actual_length += xfer->len;
882 if (ret < 0 || skip) {
883 tegra_spi_writel(tspi, tspi->def_command1_reg,
885 tegra_spi_transfer_delay(xfer->delay_usecs);
887 } else if (msg->transfers.prev == &xfer->transfer_list) {
888 /* This is the last transfer in message */
890 tspi->cs_control = spi;
892 tegra_spi_writel(tspi, tspi->def_command1_reg,
894 tegra_spi_transfer_delay(xfer->delay_usecs);
896 } else if (xfer->cs_change) {
897 tegra_spi_writel(tspi, tspi->def_command1_reg,
899 tegra_spi_transfer_delay(xfer->delay_usecs);
906 spi_finalize_current_message(master);
910 static irqreturn_t handle_cpu_based_xfer(struct tegra_spi_data *tspi)
912 struct spi_transfer *t = tspi->curr_xfer;
915 spin_lock_irqsave(&tspi->lock, flags);
916 if (tspi->tx_status || tspi->rx_status) {
917 dev_err(tspi->dev, "CpuXfer ERROR bit set 0x%x\n",
919 dev_err(tspi->dev, "CpuXfer 0x%08x:0x%08x\n",
920 tspi->command1_reg, tspi->dma_control_reg);
921 tegra_periph_reset_assert(tspi->clk);
923 tegra_periph_reset_deassert(tspi->clk);
924 complete(&tspi->xfer_completion);
928 if (tspi->cur_direction & DATA_DIR_RX)
929 tegra_spi_read_rx_fifo_to_client_rxbuf(tspi, t);
931 if (tspi->cur_direction & DATA_DIR_TX)
932 tspi->cur_pos = tspi->cur_tx_pos;
934 tspi->cur_pos = tspi->cur_rx_pos;
936 if (tspi->cur_pos == t->len) {
937 complete(&tspi->xfer_completion);
941 tegra_spi_calculate_curr_xfer_param(tspi->cur_spi, tspi, t);
942 tegra_spi_start_cpu_based_transfer(tspi, t);
944 spin_unlock_irqrestore(&tspi->lock, flags);
948 static irqreturn_t handle_dma_based_xfer(struct tegra_spi_data *tspi)
950 struct spi_transfer *t = tspi->curr_xfer;
953 unsigned total_fifo_words;
956 /* Abort dmas if any error */
957 if (tspi->cur_direction & DATA_DIR_TX) {
958 if (tspi->tx_status) {
959 dmaengine_terminate_all(tspi->tx_dma_chan);
962 wait_status = wait_for_completion_interruptible_timeout(
963 &tspi->tx_dma_complete, SPI_DMA_TIMEOUT);
964 if (wait_status <= 0) {
965 dmaengine_terminate_all(tspi->tx_dma_chan);
966 dev_err(tspi->dev, "TxDma Xfer failed\n");
972 if (tspi->cur_direction & DATA_DIR_RX) {
973 if (tspi->rx_status) {
974 dmaengine_terminate_all(tspi->rx_dma_chan);
977 wait_status = wait_for_completion_interruptible_timeout(
978 &tspi->rx_dma_complete, SPI_DMA_TIMEOUT);
979 if (wait_status <= 0) {
980 dmaengine_terminate_all(tspi->rx_dma_chan);
981 dev_err(tspi->dev, "RxDma Xfer failed\n");
987 spin_lock_irqsave(&tspi->lock, flags);
989 dev_err(tspi->dev, "DmaXfer: ERROR bit set 0x%x\n",
991 dev_err(tspi->dev, "DmaXfer 0x%08x:0x%08x\n",
992 tspi->command1_reg, tspi->dma_control_reg);
993 tegra_periph_reset_assert(tspi->clk);
995 tegra_periph_reset_deassert(tspi->clk);
996 complete(&tspi->xfer_completion);
997 spin_unlock_irqrestore(&tspi->lock, flags);
1001 if (tspi->cur_direction & DATA_DIR_RX)
1002 tegra_spi_copy_spi_rxbuf_to_client_rxbuf(tspi, t);
1004 if (tspi->cur_direction & DATA_DIR_TX)
1005 tspi->cur_pos = tspi->cur_tx_pos;
1007 tspi->cur_pos = tspi->cur_rx_pos;
1009 if (tspi->cur_pos == t->len) {
1010 complete(&tspi->xfer_completion);
1014 /* Continue transfer in current message */
1015 total_fifo_words = tegra_spi_calculate_curr_xfer_param(tspi->cur_spi,
1017 if (total_fifo_words > SPI_FIFO_DEPTH)
1018 err = tegra_spi_start_dma_based_transfer(tspi, t);
1020 err = tegra_spi_start_cpu_based_transfer(tspi, t);
1023 spin_unlock_irqrestore(&tspi->lock, flags);
1027 static irqreturn_t tegra_spi_isr_thread(int irq, void *context_data)
1029 struct tegra_spi_data *tspi = context_data;
1031 if (!tspi->is_curr_dma_xfer)
1032 return handle_cpu_based_xfer(tspi);
1033 return handle_dma_based_xfer(tspi);
1036 static irqreturn_t tegra_spi_isr(int irq, void *context_data)
1038 struct tegra_spi_data *tspi = context_data;
1040 tspi->status_reg = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
1041 if (tspi->cur_direction & DATA_DIR_TX)
1042 tspi->tx_status = tspi->status_reg &
1043 (SPI_TX_FIFO_UNF | SPI_TX_FIFO_OVF);
1045 if (tspi->cur_direction & DATA_DIR_RX)
1046 tspi->rx_status = tspi->status_reg &
1047 (SPI_RX_FIFO_OVF | SPI_RX_FIFO_UNF);
1048 tegra_spi_clear_status(tspi);
1050 return IRQ_WAKE_THREAD;
1053 static void tegra_spi_parse_dt(struct platform_device *pdev,
1054 struct tegra_spi_data *tspi)
1056 struct device_node *np = pdev->dev.of_node;
1059 if (of_property_read_u32_array(np, "nvidia,dma-request-selector",
1061 tspi->dma_req_sel = of_dma[1];
1063 if (of_property_read_u32(np, "spi-max-frequency",
1064 &tspi->spi_max_frequency))
1065 tspi->spi_max_frequency = 25000000; /* 25MHz */
1068 static struct of_device_id tegra_spi_of_match[] = {
1069 { .compatible = "nvidia,tegra114-spi", },
1072 MODULE_DEVICE_TABLE(of, tegra_spi_of_match);
1074 static int tegra_spi_probe(struct platform_device *pdev)
1076 struct spi_master *master;
1077 struct tegra_spi_data *tspi;
1081 master = spi_alloc_master(&pdev->dev, sizeof(*tspi));
1083 dev_err(&pdev->dev, "master allocation failed\n");
1086 platform_set_drvdata(pdev, master);
1087 tspi = spi_master_get_devdata(master);
1090 tegra_spi_parse_dt(pdev, tspi);
1092 /* the spi->mode bits understood by this driver: */
1093 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1094 master->setup = tegra_spi_setup;
1095 master->transfer_one_message = tegra_spi_transfer_one_message;
1096 master->num_chipselect = MAX_CHIP_SELECT;
1097 master->bus_num = -1;
1098 master->auto_runtime_pm = true;
1100 tspi->master = master;
1101 tspi->dev = &pdev->dev;
1102 spin_lock_init(&tspi->lock);
1104 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1105 tspi->base = devm_ioremap_resource(&pdev->dev, r);
1106 if (IS_ERR(tspi->base)) {
1107 ret = PTR_ERR(tspi->base);
1108 goto exit_free_master;
1110 tspi->phys = r->start;
1112 spi_irq = platform_get_irq(pdev, 0);
1113 tspi->irq = spi_irq;
1114 ret = request_threaded_irq(tspi->irq, tegra_spi_isr,
1115 tegra_spi_isr_thread, IRQF_ONESHOT,
1116 dev_name(&pdev->dev), tspi);
1118 dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
1120 goto exit_free_master;
1123 tspi->clk = devm_clk_get(&pdev->dev, "spi");
1124 if (IS_ERR(tspi->clk)) {
1125 dev_err(&pdev->dev, "can not get clock\n");
1126 ret = PTR_ERR(tspi->clk);
1130 tspi->max_buf_size = SPI_FIFO_DEPTH << 2;
1131 tspi->dma_buf_size = DEFAULT_SPI_DMA_BUF_LEN;
1133 if (tspi->dma_req_sel) {
1134 ret = tegra_spi_init_dma_param(tspi, true);
1136 dev_err(&pdev->dev, "RxDma Init failed, err %d\n", ret);
1140 ret = tegra_spi_init_dma_param(tspi, false);
1142 dev_err(&pdev->dev, "TxDma Init failed, err %d\n", ret);
1143 goto exit_rx_dma_free;
1145 tspi->max_buf_size = tspi->dma_buf_size;
1146 init_completion(&tspi->tx_dma_complete);
1147 init_completion(&tspi->rx_dma_complete);
1150 init_completion(&tspi->xfer_completion);
1152 pm_runtime_enable(&pdev->dev);
1153 if (!pm_runtime_enabled(&pdev->dev)) {
1154 ret = tegra_spi_runtime_resume(&pdev->dev);
1156 goto exit_pm_disable;
1159 ret = pm_runtime_get_sync(&pdev->dev);
1161 dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret);
1162 goto exit_pm_disable;
1164 tspi->def_command1_reg = SPI_M_S;
1165 tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
1166 pm_runtime_put(&pdev->dev);
1168 master->dev.of_node = pdev->dev.of_node;
1169 ret = devm_spi_register_master(&pdev->dev, master);
1171 dev_err(&pdev->dev, "can not register to master err %d\n", ret);
1172 goto exit_pm_disable;
1177 pm_runtime_disable(&pdev->dev);
1178 if (!pm_runtime_status_suspended(&pdev->dev))
1179 tegra_spi_runtime_suspend(&pdev->dev);
1180 tegra_spi_deinit_dma_param(tspi, false);
1182 tegra_spi_deinit_dma_param(tspi, true);
1184 free_irq(spi_irq, tspi);
1186 spi_master_put(master);
1190 static int tegra_spi_remove(struct platform_device *pdev)
1192 struct spi_master *master = platform_get_drvdata(pdev);
1193 struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1195 free_irq(tspi->irq, tspi);
1197 if (tspi->tx_dma_chan)
1198 tegra_spi_deinit_dma_param(tspi, false);
1200 if (tspi->rx_dma_chan)
1201 tegra_spi_deinit_dma_param(tspi, true);
1203 pm_runtime_disable(&pdev->dev);
1204 if (!pm_runtime_status_suspended(&pdev->dev))
1205 tegra_spi_runtime_suspend(&pdev->dev);
1210 #ifdef CONFIG_PM_SLEEP
1211 static int tegra_spi_suspend(struct device *dev)
1213 struct spi_master *master = dev_get_drvdata(dev);
1215 return spi_master_suspend(master);
1218 static int tegra_spi_resume(struct device *dev)
1220 struct spi_master *master = dev_get_drvdata(dev);
1221 struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1224 ret = pm_runtime_get_sync(dev);
1226 dev_err(dev, "pm runtime failed, e = %d\n", ret);
1229 tegra_spi_writel(tspi, tspi->command1_reg, SPI_COMMAND1);
1230 pm_runtime_put(dev);
1232 return spi_master_resume(master);
1236 static int tegra_spi_runtime_suspend(struct device *dev)
1238 struct spi_master *master = dev_get_drvdata(dev);
1239 struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1241 /* Flush all write which are in PPSB queue by reading back */
1242 tegra_spi_readl(tspi, SPI_COMMAND1);
1244 clk_disable_unprepare(tspi->clk);
1248 static int tegra_spi_runtime_resume(struct device *dev)
1250 struct spi_master *master = dev_get_drvdata(dev);
1251 struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1254 ret = clk_prepare_enable(tspi->clk);
1256 dev_err(tspi->dev, "clk_prepare failed: %d\n", ret);
1262 static const struct dev_pm_ops tegra_spi_pm_ops = {
1263 SET_RUNTIME_PM_OPS(tegra_spi_runtime_suspend,
1264 tegra_spi_runtime_resume, NULL)
1265 SET_SYSTEM_SLEEP_PM_OPS(tegra_spi_suspend, tegra_spi_resume)
1267 static struct platform_driver tegra_spi_driver = {
1269 .name = "spi-tegra114",
1270 .owner = THIS_MODULE,
1271 .pm = &tegra_spi_pm_ops,
1272 .of_match_table = tegra_spi_of_match,
1274 .probe = tegra_spi_probe,
1275 .remove = tegra_spi_remove,
1277 module_platform_driver(tegra_spi_driver);
1279 MODULE_ALIAS("platform:spi-tegra114");
1280 MODULE_DESCRIPTION("NVIDIA Tegra114 SPI Controller Driver");
1281 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1282 MODULE_LICENSE("GPL v2");