2 * SPI driver for Nvidia's Tegra20/Tegra30 SLINK Controller.
4 * Copyright (c) 2012, 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/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>
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>
35 #include <linux/of_device.h>
36 #include <linux/reset.h>
37 #include <linux/spi/spi.h>
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)
65 #define SLINK_MODES (SLINK_IDLE_SCLK_MASK | SLINK_CK_SDA)
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)
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)
109 #define SLINK_FIFO_EMPTY (SLINK_TX_EMPTY | SLINK_RX_EMPTY)
111 #define SLINK_MAS_DATA 0x010
112 #define SLINK_SLAVE_DATA 0x014
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)
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)
141 #define SLINK_TX_FIFO 0x100
142 #define SLINK_RX_FIFO 0x180
144 #define DATA_DIR_TX (1 << 0)
145 #define DATA_DIR_RX (1 << 1)
147 #define SLINK_DMA_TIMEOUT (msecs_to_jiffies(1000))
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)
153 #define SLINK_STATUS2_RESET \
154 (TX_FIFO_EMPTY_COUNT_MAX | RX_FIFO_FULL_COUNT_ZERO << 16)
156 #define MAX_CHIP_SELECT 4
157 #define SLINK_FIFO_DEPTH 32
159 struct tegra_slink_chip_data {
163 struct tegra_slink_data {
165 struct spi_master *master;
166 const struct tegra_slink_chip_data *chip_data;
170 struct reset_control *rst;
175 u32 spi_max_frequency;
178 struct spi_device *cur_spi;
181 unsigned words_per_32bit;
182 unsigned bytes_per_word;
183 unsigned curr_dma_words;
184 unsigned cur_direction;
189 unsigned dma_buf_size;
190 unsigned max_buf_size;
191 bool is_curr_dma_xfer;
193 struct completion rx_dma_complete;
194 struct completion tx_dma_complete;
200 unsigned long packed_size;
206 u32 def_command2_reg;
208 struct completion xfer_completion;
209 struct spi_transfer *curr_xfer;
210 struct dma_chan *rx_dma_chan;
212 dma_addr_t rx_dma_phys;
213 struct dma_async_tx_descriptor *rx_dma_desc;
215 struct dma_chan *tx_dma_chan;
217 dma_addr_t tx_dma_phys;
218 struct dma_async_tx_descriptor *tx_dma_desc;
221 static int tegra_slink_runtime_suspend(struct device *dev);
222 static int tegra_slink_runtime_resume(struct device *dev);
224 static inline unsigned long tegra_slink_readl(struct tegra_slink_data *tspi,
227 return readl(tspi->base + reg);
230 static inline void tegra_slink_writel(struct tegra_slink_data *tspi,
231 unsigned long val, unsigned long reg)
233 writel(val, tspi->base + reg);
235 /* Read back register to make sure that register writes completed */
236 if (reg != SLINK_TX_FIFO)
237 readl(tspi->base + SLINK_MAS_DATA);
240 static void tegra_slink_clear_status(struct tegra_slink_data *tspi)
243 unsigned long val_write = 0;
245 val = tegra_slink_readl(tspi, SLINK_STATUS);
247 /* Write 1 to clear status register */
248 val_write = SLINK_RDY | SLINK_FIFO_ERROR;
249 tegra_slink_writel(tspi, val_write, SLINK_STATUS);
252 static unsigned long tegra_slink_get_packed_size(struct tegra_slink_data *tspi,
253 struct spi_transfer *t)
257 switch (tspi->bytes_per_word) {
259 val = SLINK_PACK_SIZE_4;
262 val = SLINK_PACK_SIZE_8;
265 val = SLINK_PACK_SIZE_16;
268 val = SLINK_PACK_SIZE_32;
276 static unsigned tegra_slink_calculate_curr_xfer_param(
277 struct spi_device *spi, struct tegra_slink_data *tspi,
278 struct spi_transfer *t)
280 unsigned remain_len = t->len - tspi->cur_pos;
282 unsigned bits_per_word;
284 unsigned total_fifo_words;
286 bits_per_word = t->bits_per_word;
287 tspi->bytes_per_word = DIV_ROUND_UP(bits_per_word, 8);
289 if (bits_per_word == 8 || bits_per_word == 16) {
291 tspi->words_per_32bit = 32/bits_per_word;
294 tspi->words_per_32bit = 1;
296 tspi->packed_size = tegra_slink_get_packed_size(tspi, t);
298 if (tspi->is_packed) {
299 max_len = min(remain_len, tspi->max_buf_size);
300 tspi->curr_dma_words = max_len/tspi->bytes_per_word;
301 total_fifo_words = max_len/4;
303 max_word = (remain_len - 1) / tspi->bytes_per_word + 1;
304 max_word = min(max_word, tspi->max_buf_size/4);
305 tspi->curr_dma_words = max_word;
306 total_fifo_words = max_word;
308 return total_fifo_words;
311 static unsigned tegra_slink_fill_tx_fifo_from_client_txbuf(
312 struct tegra_slink_data *tspi, struct spi_transfer *t)
315 unsigned tx_empty_count;
316 unsigned long fifo_status;
317 unsigned max_n_32bit;
320 unsigned int written_words;
321 unsigned fifo_words_left;
322 u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
324 fifo_status = tegra_slink_readl(tspi, SLINK_STATUS2);
325 tx_empty_count = SLINK_TX_FIFO_EMPTY_COUNT(fifo_status);
327 if (tspi->is_packed) {
328 fifo_words_left = tx_empty_count * tspi->words_per_32bit;
329 written_words = min(fifo_words_left, tspi->curr_dma_words);
330 nbytes = written_words * tspi->bytes_per_word;
331 max_n_32bit = DIV_ROUND_UP(nbytes, 4);
332 for (count = 0; count < max_n_32bit; count++) {
334 for (i = 0; (i < 4) && nbytes; i++, nbytes--)
335 x |= (*tx_buf++) << (i*8);
336 tegra_slink_writel(tspi, x, SLINK_TX_FIFO);
339 max_n_32bit = min(tspi->curr_dma_words, tx_empty_count);
340 written_words = max_n_32bit;
341 nbytes = written_words * tspi->bytes_per_word;
342 for (count = 0; count < max_n_32bit; count++) {
344 for (i = 0; nbytes && (i < tspi->bytes_per_word);
346 x |= ((*tx_buf++) << i*8);
347 tegra_slink_writel(tspi, x, SLINK_TX_FIFO);
350 tspi->cur_tx_pos += written_words * tspi->bytes_per_word;
351 return written_words;
354 static unsigned int tegra_slink_read_rx_fifo_to_client_rxbuf(
355 struct tegra_slink_data *tspi, struct spi_transfer *t)
357 unsigned rx_full_count;
358 unsigned long fifo_status;
361 unsigned int read_words = 0;
363 u8 *rx_buf = (u8 *)t->rx_buf + tspi->cur_rx_pos;
365 fifo_status = tegra_slink_readl(tspi, SLINK_STATUS2);
366 rx_full_count = SLINK_RX_FIFO_FULL_COUNT(fifo_status);
367 if (tspi->is_packed) {
368 len = tspi->curr_dma_words * tspi->bytes_per_word;
369 for (count = 0; count < rx_full_count; count++) {
370 x = tegra_slink_readl(tspi, SLINK_RX_FIFO);
371 for (i = 0; len && (i < 4); i++, len--)
372 *rx_buf++ = (x >> i*8) & 0xFF;
374 tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
375 read_words += tspi->curr_dma_words;
377 for (count = 0; count < rx_full_count; count++) {
378 x = tegra_slink_readl(tspi, SLINK_RX_FIFO);
379 for (i = 0; (i < tspi->bytes_per_word); i++)
380 *rx_buf++ = (x >> (i*8)) & 0xFF;
382 tspi->cur_rx_pos += rx_full_count * tspi->bytes_per_word;
383 read_words += rx_full_count;
388 static void tegra_slink_copy_client_txbuf_to_spi_txbuf(
389 struct tegra_slink_data *tspi, struct spi_transfer *t)
393 /* Make the dma buffer to read by cpu */
394 dma_sync_single_for_cpu(tspi->dev, tspi->tx_dma_phys,
395 tspi->dma_buf_size, DMA_TO_DEVICE);
397 if (tspi->is_packed) {
398 len = tspi->curr_dma_words * tspi->bytes_per_word;
399 memcpy(tspi->tx_dma_buf, t->tx_buf + tspi->cur_pos, len);
403 u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
404 unsigned consume = tspi->curr_dma_words * tspi->bytes_per_word;
407 for (count = 0; count < tspi->curr_dma_words; count++) {
409 for (i = 0; consume && (i < tspi->bytes_per_word);
411 x |= ((*tx_buf++) << i * 8);
412 tspi->tx_dma_buf[count] = x;
415 tspi->cur_tx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
417 /* Make the dma buffer to read by dma */
418 dma_sync_single_for_device(tspi->dev, tspi->tx_dma_phys,
419 tspi->dma_buf_size, DMA_TO_DEVICE);
422 static void tegra_slink_copy_spi_rxbuf_to_client_rxbuf(
423 struct tegra_slink_data *tspi, struct spi_transfer *t)
427 /* Make the dma buffer to read by cpu */
428 dma_sync_single_for_cpu(tspi->dev, tspi->rx_dma_phys,
429 tspi->dma_buf_size, DMA_FROM_DEVICE);
431 if (tspi->is_packed) {
432 len = tspi->curr_dma_words * tspi->bytes_per_word;
433 memcpy(t->rx_buf + tspi->cur_rx_pos, tspi->rx_dma_buf, len);
437 unsigned char *rx_buf = t->rx_buf + tspi->cur_rx_pos;
439 unsigned int rx_mask, bits_per_word;
441 bits_per_word = t->bits_per_word;
442 rx_mask = (1 << bits_per_word) - 1;
443 for (count = 0; count < tspi->curr_dma_words; count++) {
444 x = tspi->rx_dma_buf[count];
446 for (i = 0; (i < tspi->bytes_per_word); i++)
447 *rx_buf++ = (x >> (i*8)) & 0xFF;
450 tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
452 /* Make the dma buffer to read by dma */
453 dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
454 tspi->dma_buf_size, DMA_FROM_DEVICE);
457 static void tegra_slink_dma_complete(void *args)
459 struct completion *dma_complete = args;
461 complete(dma_complete);
464 static int tegra_slink_start_tx_dma(struct tegra_slink_data *tspi, int len)
466 reinit_completion(&tspi->tx_dma_complete);
467 tspi->tx_dma_desc = dmaengine_prep_slave_single(tspi->tx_dma_chan,
468 tspi->tx_dma_phys, len, DMA_MEM_TO_DEV,
469 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
470 if (!tspi->tx_dma_desc) {
471 dev_err(tspi->dev, "Not able to get desc for Tx\n");
475 tspi->tx_dma_desc->callback = tegra_slink_dma_complete;
476 tspi->tx_dma_desc->callback_param = &tspi->tx_dma_complete;
478 dmaengine_submit(tspi->tx_dma_desc);
479 dma_async_issue_pending(tspi->tx_dma_chan);
483 static int tegra_slink_start_rx_dma(struct tegra_slink_data *tspi, int len)
485 reinit_completion(&tspi->rx_dma_complete);
486 tspi->rx_dma_desc = dmaengine_prep_slave_single(tspi->rx_dma_chan,
487 tspi->rx_dma_phys, len, DMA_DEV_TO_MEM,
488 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
489 if (!tspi->rx_dma_desc) {
490 dev_err(tspi->dev, "Not able to get desc for Rx\n");
494 tspi->rx_dma_desc->callback = tegra_slink_dma_complete;
495 tspi->rx_dma_desc->callback_param = &tspi->rx_dma_complete;
497 dmaengine_submit(tspi->rx_dma_desc);
498 dma_async_issue_pending(tspi->rx_dma_chan);
502 static int tegra_slink_start_dma_based_transfer(
503 struct tegra_slink_data *tspi, struct spi_transfer *t)
506 unsigned long test_val;
509 unsigned long status;
511 /* Make sure that Rx and Tx fifo are empty */
512 status = tegra_slink_readl(tspi, SLINK_STATUS);
513 if ((status & SLINK_FIFO_EMPTY) != SLINK_FIFO_EMPTY) {
515 "Rx/Tx fifo are not empty status 0x%08lx\n", status);
519 val = SLINK_DMA_BLOCK_SIZE(tspi->curr_dma_words - 1);
520 val |= tspi->packed_size;
522 len = DIV_ROUND_UP(tspi->curr_dma_words * tspi->bytes_per_word,
525 len = tspi->curr_dma_words * 4;
527 /* Set attention level based on length of transfer */
529 val |= SLINK_TX_TRIG_1 | SLINK_RX_TRIG_1;
530 else if (((len) >> 4) & 0x1)
531 val |= SLINK_TX_TRIG_4 | SLINK_RX_TRIG_4;
533 val |= SLINK_TX_TRIG_8 | SLINK_RX_TRIG_8;
535 if (tspi->cur_direction & DATA_DIR_TX)
538 if (tspi->cur_direction & DATA_DIR_RX)
541 tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
542 tspi->dma_control_reg = val;
544 if (tspi->cur_direction & DATA_DIR_TX) {
545 tegra_slink_copy_client_txbuf_to_spi_txbuf(tspi, t);
547 ret = tegra_slink_start_tx_dma(tspi, len);
550 "Starting tx dma failed, err %d\n", ret);
554 /* Wait for tx fifo to be fill before starting slink */
555 test_val = tegra_slink_readl(tspi, SLINK_STATUS);
556 while (!(test_val & SLINK_TX_FULL))
557 test_val = tegra_slink_readl(tspi, SLINK_STATUS);
560 if (tspi->cur_direction & DATA_DIR_RX) {
561 /* Make the dma buffer to read by dma */
562 dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
563 tspi->dma_buf_size, DMA_FROM_DEVICE);
565 ret = tegra_slink_start_rx_dma(tspi, len);
568 "Starting rx dma failed, err %d\n", ret);
569 if (tspi->cur_direction & DATA_DIR_TX)
570 dmaengine_terminate_all(tspi->tx_dma_chan);
574 tspi->is_curr_dma_xfer = true;
575 if (tspi->is_packed) {
577 tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
578 /* HW need small delay after settign Packed mode */
581 tspi->dma_control_reg = val;
584 tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
588 static int tegra_slink_start_cpu_based_transfer(
589 struct tegra_slink_data *tspi, struct spi_transfer *t)
594 val = tspi->packed_size;
595 if (tspi->cur_direction & DATA_DIR_TX)
598 if (tspi->cur_direction & DATA_DIR_RX)
601 tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
602 tspi->dma_control_reg = val;
604 if (tspi->cur_direction & DATA_DIR_TX)
605 cur_words = tegra_slink_fill_tx_fifo_from_client_txbuf(tspi, t);
607 cur_words = tspi->curr_dma_words;
608 val |= SLINK_DMA_BLOCK_SIZE(cur_words - 1);
609 tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
610 tspi->dma_control_reg = val;
612 tspi->is_curr_dma_xfer = false;
613 if (tspi->is_packed) {
615 tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
619 tspi->dma_control_reg = val;
621 tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
625 static int tegra_slink_init_dma_param(struct tegra_slink_data *tspi,
628 struct dma_chan *dma_chan;
632 struct dma_slave_config dma_sconfig;
636 dma_cap_set(DMA_SLAVE, mask);
637 dma_chan = dma_request_channel(mask, NULL, NULL);
640 "Dma channel is not available, will try later\n");
641 return -EPROBE_DEFER;
644 dma_buf = dma_alloc_coherent(tspi->dev, tspi->dma_buf_size,
645 &dma_phys, GFP_KERNEL);
647 dev_err(tspi->dev, " Not able to allocate the dma buffer\n");
648 dma_release_channel(dma_chan);
652 dma_sconfig.slave_id = tspi->dma_req_sel;
654 dma_sconfig.src_addr = tspi->phys + SLINK_RX_FIFO;
655 dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
656 dma_sconfig.src_maxburst = 0;
658 dma_sconfig.dst_addr = tspi->phys + SLINK_TX_FIFO;
659 dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
660 dma_sconfig.dst_maxburst = 0;
663 ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
667 tspi->rx_dma_chan = dma_chan;
668 tspi->rx_dma_buf = dma_buf;
669 tspi->rx_dma_phys = dma_phys;
671 tspi->tx_dma_chan = dma_chan;
672 tspi->tx_dma_buf = dma_buf;
673 tspi->tx_dma_phys = dma_phys;
678 dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
679 dma_release_channel(dma_chan);
683 static void tegra_slink_deinit_dma_param(struct tegra_slink_data *tspi,
688 struct dma_chan *dma_chan;
691 dma_buf = tspi->rx_dma_buf;
692 dma_chan = tspi->rx_dma_chan;
693 dma_phys = tspi->rx_dma_phys;
694 tspi->rx_dma_chan = NULL;
695 tspi->rx_dma_buf = NULL;
697 dma_buf = tspi->tx_dma_buf;
698 dma_chan = tspi->tx_dma_chan;
699 dma_phys = tspi->tx_dma_phys;
700 tspi->tx_dma_buf = NULL;
701 tspi->tx_dma_chan = NULL;
706 dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
707 dma_release_channel(dma_chan);
710 static int tegra_slink_start_transfer_one(struct spi_device *spi,
711 struct spi_transfer *t)
713 struct tegra_slink_data *tspi = spi_master_get_devdata(spi->master);
716 unsigned total_fifo_words;
718 unsigned long command;
719 unsigned long command2;
721 bits_per_word = t->bits_per_word;
723 if (speed != tspi->cur_speed) {
724 clk_set_rate(tspi->clk, speed * 4);
725 tspi->cur_speed = speed;
730 tspi->cur_rx_pos = 0;
731 tspi->cur_tx_pos = 0;
733 total_fifo_words = tegra_slink_calculate_curr_xfer_param(spi, tspi, t);
735 command = tspi->command_reg;
736 command &= ~SLINK_BIT_LENGTH(~0);
737 command |= SLINK_BIT_LENGTH(bits_per_word - 1);
739 command2 = tspi->command2_reg;
740 command2 &= ~(SLINK_RXEN | SLINK_TXEN);
742 tegra_slink_writel(tspi, command, SLINK_COMMAND);
743 tspi->command_reg = command;
745 tspi->cur_direction = 0;
747 command2 |= SLINK_RXEN;
748 tspi->cur_direction |= DATA_DIR_RX;
751 command2 |= SLINK_TXEN;
752 tspi->cur_direction |= DATA_DIR_TX;
754 tegra_slink_writel(tspi, command2, SLINK_COMMAND2);
755 tspi->command2_reg = command2;
757 if (total_fifo_words > SLINK_FIFO_DEPTH)
758 ret = tegra_slink_start_dma_based_transfer(tspi, t);
760 ret = tegra_slink_start_cpu_based_transfer(tspi, t);
764 static int tegra_slink_setup(struct spi_device *spi)
766 struct tegra_slink_data *tspi = spi_master_get_devdata(spi->master);
770 unsigned int cs_pol_bit[MAX_CHIP_SELECT] = {
777 dev_dbg(&spi->dev, "setup %d bpw, %scpol, %scpha, %dHz\n",
779 spi->mode & SPI_CPOL ? "" : "~",
780 spi->mode & SPI_CPHA ? "" : "~",
783 BUG_ON(spi->chip_select >= MAX_CHIP_SELECT);
785 /* Set speed to the spi max fequency if spi device has not set */
786 spi->max_speed_hz = spi->max_speed_hz ? : tspi->spi_max_frequency;
787 ret = pm_runtime_get_sync(tspi->dev);
789 dev_err(tspi->dev, "pm runtime failed, e = %d\n", ret);
793 spin_lock_irqsave(&tspi->lock, flags);
794 val = tspi->def_command_reg;
795 if (spi->mode & SPI_CS_HIGH)
796 val |= cs_pol_bit[spi->chip_select];
798 val &= ~cs_pol_bit[spi->chip_select];
799 tspi->def_command_reg = val;
800 tegra_slink_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
801 spin_unlock_irqrestore(&tspi->lock, flags);
803 pm_runtime_put(tspi->dev);
807 static int tegra_slink_prepare_message(struct spi_master *master,
808 struct spi_message *msg)
810 struct tegra_slink_data *tspi = spi_master_get_devdata(master);
811 struct spi_device *spi = msg->spi;
813 tegra_slink_clear_status(tspi);
815 tspi->command_reg = tspi->def_command_reg;
816 tspi->command_reg |= SLINK_CS_SW | SLINK_CS_VALUE;
818 tspi->command2_reg = tspi->def_command2_reg;
819 tspi->command2_reg |= SLINK_SS_EN_CS(spi->chip_select);
821 tspi->command_reg &= ~SLINK_MODES;
822 if (spi->mode & SPI_CPHA)
823 tspi->command_reg |= SLINK_CK_SDA;
825 if (spi->mode & SPI_CPOL)
826 tspi->command_reg |= SLINK_IDLE_SCLK_DRIVE_HIGH;
828 tspi->command_reg |= SLINK_IDLE_SCLK_DRIVE_LOW;
833 static int tegra_slink_transfer_one(struct spi_master *master,
834 struct spi_device *spi,
835 struct spi_transfer *xfer)
837 struct tegra_slink_data *tspi = spi_master_get_devdata(master);
840 reinit_completion(&tspi->xfer_completion);
841 ret = tegra_slink_start_transfer_one(spi, xfer);
844 "spi can not start transfer, err %d\n", ret);
848 ret = wait_for_completion_timeout(&tspi->xfer_completion,
850 if (WARN_ON(ret == 0)) {
852 "spi trasfer timeout, err %d\n", ret);
857 return tspi->tx_status;
859 return tspi->rx_status;
864 static int tegra_slink_unprepare_message(struct spi_master *master,
865 struct spi_message *msg)
867 struct tegra_slink_data *tspi = spi_master_get_devdata(master);
869 tegra_slink_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
870 tegra_slink_writel(tspi, tspi->def_command2_reg, SLINK_COMMAND2);
875 static irqreturn_t handle_cpu_based_xfer(struct tegra_slink_data *tspi)
877 struct spi_transfer *t = tspi->curr_xfer;
880 spin_lock_irqsave(&tspi->lock, flags);
881 if (tspi->tx_status || tspi->rx_status ||
882 (tspi->status_reg & SLINK_BSY)) {
884 "CpuXfer ERROR bit set 0x%x\n", tspi->status_reg);
886 "CpuXfer 0x%08x:0x%08x:0x%08x\n", tspi->command_reg,
887 tspi->command2_reg, tspi->dma_control_reg);
888 reset_control_assert(tspi->rst);
890 reset_control_deassert(tspi->rst);
891 complete(&tspi->xfer_completion);
895 if (tspi->cur_direction & DATA_DIR_RX)
896 tegra_slink_read_rx_fifo_to_client_rxbuf(tspi, t);
898 if (tspi->cur_direction & DATA_DIR_TX)
899 tspi->cur_pos = tspi->cur_tx_pos;
901 tspi->cur_pos = tspi->cur_rx_pos;
903 if (tspi->cur_pos == t->len) {
904 complete(&tspi->xfer_completion);
908 tegra_slink_calculate_curr_xfer_param(tspi->cur_spi, tspi, t);
909 tegra_slink_start_cpu_based_transfer(tspi, t);
911 spin_unlock_irqrestore(&tspi->lock, flags);
915 static irqreturn_t handle_dma_based_xfer(struct tegra_slink_data *tspi)
917 struct spi_transfer *t = tspi->curr_xfer;
920 unsigned total_fifo_words;
923 /* Abort dmas if any error */
924 if (tspi->cur_direction & DATA_DIR_TX) {
925 if (tspi->tx_status) {
926 dmaengine_terminate_all(tspi->tx_dma_chan);
929 wait_status = wait_for_completion_interruptible_timeout(
930 &tspi->tx_dma_complete, SLINK_DMA_TIMEOUT);
931 if (wait_status <= 0) {
932 dmaengine_terminate_all(tspi->tx_dma_chan);
933 dev_err(tspi->dev, "TxDma Xfer failed\n");
939 if (tspi->cur_direction & DATA_DIR_RX) {
940 if (tspi->rx_status) {
941 dmaengine_terminate_all(tspi->rx_dma_chan);
944 wait_status = wait_for_completion_interruptible_timeout(
945 &tspi->rx_dma_complete, SLINK_DMA_TIMEOUT);
946 if (wait_status <= 0) {
947 dmaengine_terminate_all(tspi->rx_dma_chan);
948 dev_err(tspi->dev, "RxDma Xfer failed\n");
954 spin_lock_irqsave(&tspi->lock, flags);
957 "DmaXfer: ERROR bit set 0x%x\n", tspi->status_reg);
959 "DmaXfer 0x%08x:0x%08x:0x%08x\n", tspi->command_reg,
960 tspi->command2_reg, tspi->dma_control_reg);
961 reset_control_assert(tspi->rst);
963 reset_control_assert(tspi->rst);
964 complete(&tspi->xfer_completion);
965 spin_unlock_irqrestore(&tspi->lock, flags);
969 if (tspi->cur_direction & DATA_DIR_RX)
970 tegra_slink_copy_spi_rxbuf_to_client_rxbuf(tspi, t);
972 if (tspi->cur_direction & DATA_DIR_TX)
973 tspi->cur_pos = tspi->cur_tx_pos;
975 tspi->cur_pos = tspi->cur_rx_pos;
977 if (tspi->cur_pos == t->len) {
978 complete(&tspi->xfer_completion);
982 /* Continue transfer in current message */
983 total_fifo_words = tegra_slink_calculate_curr_xfer_param(tspi->cur_spi,
985 if (total_fifo_words > SLINK_FIFO_DEPTH)
986 err = tegra_slink_start_dma_based_transfer(tspi, t);
988 err = tegra_slink_start_cpu_based_transfer(tspi, t);
991 spin_unlock_irqrestore(&tspi->lock, flags);
995 static irqreturn_t tegra_slink_isr_thread(int irq, void *context_data)
997 struct tegra_slink_data *tspi = context_data;
999 if (!tspi->is_curr_dma_xfer)
1000 return handle_cpu_based_xfer(tspi);
1001 return handle_dma_based_xfer(tspi);
1004 static irqreturn_t tegra_slink_isr(int irq, void *context_data)
1006 struct tegra_slink_data *tspi = context_data;
1008 tspi->status_reg = tegra_slink_readl(tspi, SLINK_STATUS);
1009 if (tspi->cur_direction & DATA_DIR_TX)
1010 tspi->tx_status = tspi->status_reg &
1011 (SLINK_TX_OVF | SLINK_TX_UNF);
1013 if (tspi->cur_direction & DATA_DIR_RX)
1014 tspi->rx_status = tspi->status_reg &
1015 (SLINK_RX_OVF | SLINK_RX_UNF);
1016 tegra_slink_clear_status(tspi);
1018 return IRQ_WAKE_THREAD;
1021 static void tegra_slink_parse_dt(struct tegra_slink_data *tspi)
1023 struct device_node *np = tspi->dev->of_node;
1026 if (of_property_read_u32_array(np, "nvidia,dma-request-selector",
1028 tspi->dma_req_sel = of_dma[1];
1030 if (of_property_read_u32(np, "spi-max-frequency",
1031 &tspi->spi_max_frequency))
1032 tspi->spi_max_frequency = 25000000; /* 25MHz */
1035 static const struct tegra_slink_chip_data tegra30_spi_cdata = {
1036 .cs_hold_time = true,
1039 static const struct tegra_slink_chip_data tegra20_spi_cdata = {
1040 .cs_hold_time = false,
1043 static struct of_device_id tegra_slink_of_match[] = {
1044 { .compatible = "nvidia,tegra30-slink", .data = &tegra30_spi_cdata, },
1045 { .compatible = "nvidia,tegra20-slink", .data = &tegra20_spi_cdata, },
1048 MODULE_DEVICE_TABLE(of, tegra_slink_of_match);
1050 static int tegra_slink_probe(struct platform_device *pdev)
1052 struct spi_master *master;
1053 struct tegra_slink_data *tspi;
1056 const struct tegra_slink_chip_data *cdata = NULL;
1057 const struct of_device_id *match;
1059 match = of_match_device(tegra_slink_of_match, &pdev->dev);
1061 dev_err(&pdev->dev, "Error: No device match found\n");
1064 cdata = match->data;
1066 master = spi_alloc_master(&pdev->dev, sizeof(*tspi));
1068 dev_err(&pdev->dev, "master allocation failed\n");
1072 /* the spi->mode bits understood by this driver: */
1073 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1074 master->setup = tegra_slink_setup;
1075 master->prepare_message = tegra_slink_prepare_message;
1076 master->transfer_one = tegra_slink_transfer_one;
1077 master->unprepare_message = tegra_slink_unprepare_message;
1078 master->auto_runtime_pm = true;
1079 master->num_chipselect = MAX_CHIP_SELECT;
1080 master->bus_num = -1;
1082 platform_set_drvdata(pdev, master);
1083 tspi = spi_master_get_devdata(master);
1084 tspi->master = master;
1085 tspi->dev = &pdev->dev;
1086 tspi->chip_data = cdata;
1087 spin_lock_init(&tspi->lock);
1089 tegra_slink_parse_dt(tspi);
1091 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1093 dev_err(&pdev->dev, "No IO memory resource\n");
1095 goto exit_free_master;
1097 tspi->phys = r->start;
1098 tspi->base = devm_ioremap_resource(&pdev->dev, r);
1099 if (IS_ERR(tspi->base)) {
1100 ret = PTR_ERR(tspi->base);
1101 goto exit_free_master;
1104 spi_irq = platform_get_irq(pdev, 0);
1105 tspi->irq = spi_irq;
1106 ret = request_threaded_irq(tspi->irq, tegra_slink_isr,
1107 tegra_slink_isr_thread, IRQF_ONESHOT,
1108 dev_name(&pdev->dev), tspi);
1110 dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
1112 goto exit_free_master;
1115 tspi->clk = devm_clk_get(&pdev->dev, NULL);
1116 if (IS_ERR(tspi->clk)) {
1117 dev_err(&pdev->dev, "can not get clock\n");
1118 ret = PTR_ERR(tspi->clk);
1122 tspi->rst = devm_reset_control_get(&pdev->dev, "spi");
1123 if (IS_ERR(tspi->rst)) {
1124 dev_err(&pdev->dev, "can not get reset\n");
1125 ret = PTR_ERR(tspi->rst);
1129 tspi->max_buf_size = SLINK_FIFO_DEPTH << 2;
1130 tspi->dma_buf_size = DEFAULT_SPI_DMA_BUF_LEN;
1132 if (tspi->dma_req_sel) {
1133 ret = tegra_slink_init_dma_param(tspi, true);
1135 dev_err(&pdev->dev, "RxDma Init failed, err %d\n", ret);
1139 ret = tegra_slink_init_dma_param(tspi, false);
1141 dev_err(&pdev->dev, "TxDma Init failed, err %d\n", ret);
1142 goto exit_rx_dma_free;
1144 tspi->max_buf_size = tspi->dma_buf_size;
1145 init_completion(&tspi->tx_dma_complete);
1146 init_completion(&tspi->rx_dma_complete);
1149 init_completion(&tspi->xfer_completion);
1151 pm_runtime_enable(&pdev->dev);
1152 if (!pm_runtime_enabled(&pdev->dev)) {
1153 ret = tegra_slink_runtime_resume(&pdev->dev);
1155 goto exit_pm_disable;
1158 ret = pm_runtime_get_sync(&pdev->dev);
1160 dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret);
1161 goto exit_pm_disable;
1163 tspi->def_command_reg = SLINK_M_S;
1164 tspi->def_command2_reg = SLINK_CS_ACTIVE_BETWEEN;
1165 tegra_slink_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
1166 tegra_slink_writel(tspi, tspi->def_command2_reg, SLINK_COMMAND2);
1167 pm_runtime_put(&pdev->dev);
1169 master->dev.of_node = pdev->dev.of_node;
1170 ret = devm_spi_register_master(&pdev->dev, master);
1172 dev_err(&pdev->dev, "can not register to master err %d\n", ret);
1173 goto exit_pm_disable;
1178 pm_runtime_disable(&pdev->dev);
1179 if (!pm_runtime_status_suspended(&pdev->dev))
1180 tegra_slink_runtime_suspend(&pdev->dev);
1181 tegra_slink_deinit_dma_param(tspi, false);
1183 tegra_slink_deinit_dma_param(tspi, true);
1185 free_irq(spi_irq, tspi);
1187 spi_master_put(master);
1191 static int tegra_slink_remove(struct platform_device *pdev)
1193 struct spi_master *master = platform_get_drvdata(pdev);
1194 struct tegra_slink_data *tspi = spi_master_get_devdata(master);
1196 free_irq(tspi->irq, tspi);
1198 if (tspi->tx_dma_chan)
1199 tegra_slink_deinit_dma_param(tspi, false);
1201 if (tspi->rx_dma_chan)
1202 tegra_slink_deinit_dma_param(tspi, true);
1204 pm_runtime_disable(&pdev->dev);
1205 if (!pm_runtime_status_suspended(&pdev->dev))
1206 tegra_slink_runtime_suspend(&pdev->dev);
1211 #ifdef CONFIG_PM_SLEEP
1212 static int tegra_slink_suspend(struct device *dev)
1214 struct spi_master *master = dev_get_drvdata(dev);
1216 return spi_master_suspend(master);
1219 static int tegra_slink_resume(struct device *dev)
1221 struct spi_master *master = dev_get_drvdata(dev);
1222 struct tegra_slink_data *tspi = spi_master_get_devdata(master);
1225 ret = pm_runtime_get_sync(dev);
1227 dev_err(dev, "pm runtime failed, e = %d\n", ret);
1230 tegra_slink_writel(tspi, tspi->command_reg, SLINK_COMMAND);
1231 tegra_slink_writel(tspi, tspi->command2_reg, SLINK_COMMAND2);
1232 pm_runtime_put(dev);
1234 return spi_master_resume(master);
1238 static int tegra_slink_runtime_suspend(struct device *dev)
1240 struct spi_master *master = dev_get_drvdata(dev);
1241 struct tegra_slink_data *tspi = spi_master_get_devdata(master);
1243 /* Flush all write which are in PPSB queue by reading back */
1244 tegra_slink_readl(tspi, SLINK_MAS_DATA);
1246 clk_disable_unprepare(tspi->clk);
1250 static int tegra_slink_runtime_resume(struct device *dev)
1252 struct spi_master *master = dev_get_drvdata(dev);
1253 struct tegra_slink_data *tspi = spi_master_get_devdata(master);
1256 ret = clk_prepare_enable(tspi->clk);
1258 dev_err(tspi->dev, "clk_prepare failed: %d\n", ret);
1264 static const struct dev_pm_ops slink_pm_ops = {
1265 SET_RUNTIME_PM_OPS(tegra_slink_runtime_suspend,
1266 tegra_slink_runtime_resume, NULL)
1267 SET_SYSTEM_SLEEP_PM_OPS(tegra_slink_suspend, tegra_slink_resume)
1269 static struct platform_driver tegra_slink_driver = {
1271 .name = "spi-tegra-slink",
1272 .owner = THIS_MODULE,
1273 .pm = &slink_pm_ops,
1274 .of_match_table = tegra_slink_of_match,
1276 .probe = tegra_slink_probe,
1277 .remove = tegra_slink_remove,
1279 module_platform_driver(tegra_slink_driver);
1281 MODULE_ALIAS("platform:spi-tegra-slink");
1282 MODULE_DESCRIPTION("NVIDIA Tegra20/Tegra30 SLINK Controller Driver");
1283 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1284 MODULE_LICENSE("GPL v2");