xref: /openbmc/linux/drivers/spi/spi-tegra114.c (revision 77d84ff8)
1 /*
2  * SPI driver for NVIDIA's Tegra114 SPI Controller.
3  *
4  * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
5  *
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.
9  *
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
13  * more details.
14  *
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/>.
17  */
18 
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>
29 #include <linux/io.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>
35 #include <linux/of.h>
36 #include <linux/of_device.h>
37 #include <linux/spi/spi.h>
38 
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)
63 
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)
78 
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)
82 
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))))
88 
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))))
104 
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)
109 
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)
126 
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)
130 
131 #define SPI_TX_DATA				0x018
132 #define SPI_RX_DATA				0x01C
133 
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
150 
151 #define SPI_DMA_BLK				0x024
152 #define SPI_DMA_BLK_SET(x)			(((x) & 0xFFFF) << 0)
153 
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)
160 
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
167 
168 #define MAX_CHIP_SELECT				4
169 #define SPI_FIFO_DEPTH				64
170 
171 struct tegra_spi_data {
172 	struct device				*dev;
173 	struct spi_master			*master;
174 	spinlock_t				lock;
175 
176 	struct clk				*clk;
177 	void __iomem				*base;
178 	phys_addr_t				phys;
179 	unsigned				irq;
180 	int					dma_req_sel;
181 	u32					spi_max_frequency;
182 	u32					cur_speed;
183 
184 	struct spi_device			*cur_spi;
185 	struct spi_device			*cs_control;
186 	unsigned				cur_pos;
187 	unsigned				cur_len;
188 	unsigned				words_per_32bit;
189 	unsigned				bytes_per_word;
190 	unsigned				curr_dma_words;
191 	unsigned				cur_direction;
192 
193 	unsigned				cur_rx_pos;
194 	unsigned				cur_tx_pos;
195 
196 	unsigned				dma_buf_size;
197 	unsigned				max_buf_size;
198 	bool					is_curr_dma_xfer;
199 
200 	struct completion			rx_dma_complete;
201 	struct completion			tx_dma_complete;
202 
203 	u32					tx_status;
204 	u32					rx_status;
205 	u32					status_reg;
206 	bool					is_packed;
207 	unsigned long				packed_size;
208 
209 	u32					command1_reg;
210 	u32					dma_control_reg;
211 	u32					def_command1_reg;
212 	u32					spi_cs_timing;
213 
214 	struct completion			xfer_completion;
215 	struct spi_transfer			*curr_xfer;
216 	struct dma_chan				*rx_dma_chan;
217 	u32					*rx_dma_buf;
218 	dma_addr_t				rx_dma_phys;
219 	struct dma_async_tx_descriptor		*rx_dma_desc;
220 
221 	struct dma_chan				*tx_dma_chan;
222 	u32					*tx_dma_buf;
223 	dma_addr_t				tx_dma_phys;
224 	struct dma_async_tx_descriptor		*tx_dma_desc;
225 };
226 
227 static int tegra_spi_runtime_suspend(struct device *dev);
228 static int tegra_spi_runtime_resume(struct device *dev);
229 
230 static inline unsigned long tegra_spi_readl(struct tegra_spi_data *tspi,
231 		unsigned long reg)
232 {
233 	return readl(tspi->base + reg);
234 }
235 
236 static inline void tegra_spi_writel(struct tegra_spi_data *tspi,
237 		unsigned long val, unsigned long reg)
238 {
239 	writel(val, tspi->base + reg);
240 
241 	/* Read back register to make sure that register writes completed */
242 	if (reg != SPI_TX_FIFO)
243 		readl(tspi->base + SPI_COMMAND1);
244 }
245 
246 static void tegra_spi_clear_status(struct tegra_spi_data *tspi)
247 {
248 	unsigned long val;
249 
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);
253 
254 	/* Clear fifo status error if any */
255 	val = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
256 	if (val & SPI_ERR)
257 		tegra_spi_writel(tspi, SPI_ERR | SPI_FIFO_ERROR,
258 				SPI_FIFO_STATUS);
259 }
260 
261 static unsigned tegra_spi_calculate_curr_xfer_param(
262 	struct spi_device *spi, struct tegra_spi_data *tspi,
263 	struct spi_transfer *t)
264 {
265 	unsigned remain_len = t->len - tspi->cur_pos;
266 	unsigned max_word;
267 	unsigned bits_per_word = t->bits_per_word;
268 	unsigned max_len;
269 	unsigned total_fifo_words;
270 
271 	tspi->bytes_per_word = DIV_ROUND_UP(bits_per_word, 8);
272 
273 	if (bits_per_word == 8 || bits_per_word == 16) {
274 		tspi->is_packed = 1;
275 		tspi->words_per_32bit = 32/bits_per_word;
276 	} else {
277 		tspi->is_packed = 0;
278 		tspi->words_per_32bit = 1;
279 	}
280 
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;
285 	} else {
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;
290 	}
291 	return total_fifo_words;
292 }
293 
294 static unsigned tegra_spi_fill_tx_fifo_from_client_txbuf(
295 	struct tegra_spi_data *tspi, struct spi_transfer *t)
296 {
297 	unsigned nbytes;
298 	unsigned tx_empty_count;
299 	unsigned long fifo_status;
300 	unsigned max_n_32bit;
301 	unsigned i, count;
302 	unsigned long x;
303 	unsigned int written_words;
304 	unsigned fifo_words_left;
305 	u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
306 
307 	fifo_status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
308 	tx_empty_count = SPI_TX_FIFO_EMPTY_COUNT(fifo_status);
309 
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++) {
316 			x = 0;
317 			for (i = 0; (i < 4) && nbytes; i++, nbytes--)
318 				x |= (*tx_buf++) << (i*8);
319 			tegra_spi_writel(tspi, x, SPI_TX_FIFO);
320 		}
321 	} else {
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++) {
326 			x = 0;
327 			for (i = 0; nbytes && (i < tspi->bytes_per_word);
328 							i++, nbytes--)
329 				x |= ((*tx_buf++) << i*8);
330 			tegra_spi_writel(tspi, x, SPI_TX_FIFO);
331 		}
332 	}
333 	tspi->cur_tx_pos += written_words * tspi->bytes_per_word;
334 	return written_words;
335 }
336 
337 static unsigned int tegra_spi_read_rx_fifo_to_client_rxbuf(
338 		struct tegra_spi_data *tspi, struct spi_transfer *t)
339 {
340 	unsigned rx_full_count;
341 	unsigned long fifo_status;
342 	unsigned i, count;
343 	unsigned long x;
344 	unsigned int read_words = 0;
345 	unsigned len;
346 	u8 *rx_buf = (u8 *)t->rx_buf + tspi->cur_rx_pos;
347 
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;
356 		}
357 		tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
358 		read_words += tspi->curr_dma_words;
359 	} else {
360 		unsigned int rx_mask;
361 		unsigned int bits_per_word = t->bits_per_word;
362 
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);
366 			x &= rx_mask;
367 			for (i = 0; (i < tspi->bytes_per_word); i++)
368 				*rx_buf++ = (x >> (i*8)) & 0xFF;
369 		}
370 		tspi->cur_rx_pos += rx_full_count * tspi->bytes_per_word;
371 		read_words += rx_full_count;
372 	}
373 	return read_words;
374 }
375 
376 static void tegra_spi_copy_client_txbuf_to_spi_txbuf(
377 		struct tegra_spi_data *tspi, struct spi_transfer *t)
378 {
379 	unsigned len;
380 
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);
384 
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);
388 	} else {
389 		unsigned int i;
390 		unsigned int count;
391 		u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
392 		unsigned consume = tspi->curr_dma_words * tspi->bytes_per_word;
393 		unsigned int x;
394 
395 		for (count = 0; count < tspi->curr_dma_words; count++) {
396 			x = 0;
397 			for (i = 0; consume && (i < tspi->bytes_per_word);
398 							i++, consume--)
399 				x |= ((*tx_buf++) << i * 8);
400 			tspi->tx_dma_buf[count] = x;
401 		}
402 	}
403 	tspi->cur_tx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
404 
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);
408 }
409 
410 static void tegra_spi_copy_spi_rxbuf_to_client_rxbuf(
411 		struct tegra_spi_data *tspi, struct spi_transfer *t)
412 {
413 	unsigned len;
414 
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);
418 
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);
422 	} else {
423 		unsigned int i;
424 		unsigned int count;
425 		unsigned char *rx_buf = t->rx_buf + tspi->cur_rx_pos;
426 		unsigned int x;
427 		unsigned int rx_mask;
428 		unsigned int bits_per_word = t->bits_per_word;
429 
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];
433 			x &= rx_mask;
434 			for (i = 0; (i < tspi->bytes_per_word); i++)
435 				*rx_buf++ = (x >> (i*8)) & 0xFF;
436 		}
437 	}
438 	tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
439 
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);
443 }
444 
445 static void tegra_spi_dma_complete(void *args)
446 {
447 	struct completion *dma_complete = args;
448 
449 	complete(dma_complete);
450 }
451 
452 static int tegra_spi_start_tx_dma(struct tegra_spi_data *tspi, int len)
453 {
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");
460 		return -EIO;
461 	}
462 
463 	tspi->tx_dma_desc->callback = tegra_spi_dma_complete;
464 	tspi->tx_dma_desc->callback_param = &tspi->tx_dma_complete;
465 
466 	dmaengine_submit(tspi->tx_dma_desc);
467 	dma_async_issue_pending(tspi->tx_dma_chan);
468 	return 0;
469 }
470 
471 static int tegra_spi_start_rx_dma(struct tegra_spi_data *tspi, int len)
472 {
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");
479 		return -EIO;
480 	}
481 
482 	tspi->rx_dma_desc->callback = tegra_spi_dma_complete;
483 	tspi->rx_dma_desc->callback_param = &tspi->rx_dma_complete;
484 
485 	dmaengine_submit(tspi->rx_dma_desc);
486 	dma_async_issue_pending(tspi->rx_dma_chan);
487 	return 0;
488 }
489 
490 static int tegra_spi_start_dma_based_transfer(
491 		struct tegra_spi_data *tspi, struct spi_transfer *t)
492 {
493 	unsigned long val;
494 	unsigned int len;
495 	int ret = 0;
496 	unsigned long status;
497 
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) {
501 		dev_err(tspi->dev,
502 			"Rx/Tx fifo are not empty status 0x%08lx\n", status);
503 		return -EIO;
504 	}
505 
506 	val = SPI_DMA_BLK_SET(tspi->curr_dma_words - 1);
507 	tegra_spi_writel(tspi, val, SPI_DMA_BLK);
508 
509 	if (tspi->is_packed)
510 		len = DIV_ROUND_UP(tspi->curr_dma_words * tspi->bytes_per_word,
511 					4) * 4;
512 	else
513 		len = tspi->curr_dma_words * 4;
514 
515 	/* Set attention level based on length of transfer */
516 	if (len & 0xF)
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;
520 	else
521 		val |= SPI_TX_TRIG_8 | SPI_RX_TRIG_8;
522 
523 	if (tspi->cur_direction & DATA_DIR_TX)
524 		val |= SPI_IE_TX;
525 
526 	if (tspi->cur_direction & DATA_DIR_RX)
527 		val |= SPI_IE_RX;
528 
529 	tegra_spi_writel(tspi, val, SPI_DMA_CTL);
530 	tspi->dma_control_reg = val;
531 
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);
535 		if (ret < 0) {
536 			dev_err(tspi->dev,
537 				"Starting tx dma failed, err %d\n", ret);
538 			return ret;
539 		}
540 	}
541 
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);
546 
547 		ret = tegra_spi_start_rx_dma(tspi, len);
548 		if (ret < 0) {
549 			dev_err(tspi->dev,
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);
553 			return ret;
554 		}
555 	}
556 	tspi->is_curr_dma_xfer = true;
557 	tspi->dma_control_reg = val;
558 
559 	val |= SPI_DMA_EN;
560 	tegra_spi_writel(tspi, val, SPI_DMA_CTL);
561 	return ret;
562 }
563 
564 static int tegra_spi_start_cpu_based_transfer(
565 		struct tegra_spi_data *tspi, struct spi_transfer *t)
566 {
567 	unsigned long val;
568 	unsigned cur_words;
569 
570 	if (tspi->cur_direction & DATA_DIR_TX)
571 		cur_words = tegra_spi_fill_tx_fifo_from_client_txbuf(tspi, t);
572 	else
573 		cur_words = tspi->curr_dma_words;
574 
575 	val = SPI_DMA_BLK_SET(cur_words - 1);
576 	tegra_spi_writel(tspi, val, SPI_DMA_BLK);
577 
578 	val = 0;
579 	if (tspi->cur_direction & DATA_DIR_TX)
580 		val |= SPI_IE_TX;
581 
582 	if (tspi->cur_direction & DATA_DIR_RX)
583 		val |= SPI_IE_RX;
584 
585 	tegra_spi_writel(tspi, val, SPI_DMA_CTL);
586 	tspi->dma_control_reg = val;
587 
588 	tspi->is_curr_dma_xfer = false;
589 
590 	val |= SPI_DMA_EN;
591 	tegra_spi_writel(tspi, val, SPI_DMA_CTL);
592 	return 0;
593 }
594 
595 static int tegra_spi_init_dma_param(struct tegra_spi_data *tspi,
596 			bool dma_to_memory)
597 {
598 	struct dma_chan *dma_chan;
599 	u32 *dma_buf;
600 	dma_addr_t dma_phys;
601 	int ret;
602 	struct dma_slave_config dma_sconfig;
603 	dma_cap_mask_t mask;
604 
605 	dma_cap_zero(mask);
606 	dma_cap_set(DMA_SLAVE, mask);
607 	dma_chan = dma_request_channel(mask, NULL, NULL);
608 	if (!dma_chan) {
609 		dev_err(tspi->dev,
610 			"Dma channel is not available, will try later\n");
611 		return -EPROBE_DEFER;
612 	}
613 
614 	dma_buf = dma_alloc_coherent(tspi->dev, tspi->dma_buf_size,
615 				&dma_phys, GFP_KERNEL);
616 	if (!dma_buf) {
617 		dev_err(tspi->dev, " Not able to allocate the dma buffer\n");
618 		dma_release_channel(dma_chan);
619 		return -ENOMEM;
620 	}
621 
622 	dma_sconfig.slave_id = tspi->dma_req_sel;
623 	if (dma_to_memory) {
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;
627 	} else {
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;
631 	}
632 
633 	ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
634 	if (ret)
635 		goto scrub;
636 	if (dma_to_memory) {
637 		tspi->rx_dma_chan = dma_chan;
638 		tspi->rx_dma_buf = dma_buf;
639 		tspi->rx_dma_phys = dma_phys;
640 	} else {
641 		tspi->tx_dma_chan = dma_chan;
642 		tspi->tx_dma_buf = dma_buf;
643 		tspi->tx_dma_phys = dma_phys;
644 	}
645 	return 0;
646 
647 scrub:
648 	dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
649 	dma_release_channel(dma_chan);
650 	return ret;
651 }
652 
653 static void tegra_spi_deinit_dma_param(struct tegra_spi_data *tspi,
654 	bool dma_to_memory)
655 {
656 	u32 *dma_buf;
657 	dma_addr_t dma_phys;
658 	struct dma_chan *dma_chan;
659 
660 	if (dma_to_memory) {
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;
666 	} else {
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;
672 	}
673 	if (!dma_chan)
674 		return;
675 
676 	dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
677 	dma_release_channel(dma_chan);
678 }
679 
680 static unsigned long tegra_spi_setup_transfer_one(struct spi_device *spi,
681 		struct spi_transfer *t, bool is_first_of_msg)
682 {
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;
687 	int req_mode;
688 
689 	if (speed != tspi->cur_speed) {
690 		clk_set_rate(tspi->clk, speed);
691 		tspi->cur_speed = speed;
692 	}
693 
694 	tspi->cur_spi = spi;
695 	tspi->cur_pos = 0;
696 	tspi->cur_rx_pos = 0;
697 	tspi->cur_tx_pos = 0;
698 	tspi->curr_xfer = t;
699 
700 	if (is_first_of_msg) {
701 		tegra_spi_clear_status(tspi);
702 
703 		command1 = tspi->def_command1_reg;
704 		command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
705 
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;
716 
717 		if (tspi->cs_control) {
718 			if (tspi->cs_control != spi)
719 				tegra_spi_writel(tspi, command1, SPI_COMMAND1);
720 			tspi->cs_control = NULL;
721 		} else
722 			tegra_spi_writel(tspi, command1, SPI_COMMAND1);
723 
724 		command1 |= SPI_CS_SW_HW;
725 		if (spi->mode & SPI_CS_HIGH)
726 			command1 |= SPI_CS_SS_VAL;
727 		else
728 			command1 &= ~SPI_CS_SS_VAL;
729 
730 		tegra_spi_writel(tspi, 0, SPI_COMMAND2);
731 	} else {
732 		command1 = tspi->command1_reg;
733 		command1 &= ~SPI_BIT_LENGTH(~0);
734 		command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
735 	}
736 
737 	return command1;
738 }
739 
740 static int tegra_spi_start_transfer_one(struct spi_device *spi,
741 		struct spi_transfer *t, unsigned long command1)
742 {
743 	struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
744 	unsigned total_fifo_words;
745 	int ret;
746 
747 	total_fifo_words = tegra_spi_calculate_curr_xfer_param(spi, tspi, t);
748 
749 	if (tspi->is_packed)
750 		command1 |= SPI_PACKED;
751 
752 	command1 &= ~(SPI_CS_SEL_MASK | SPI_TX_EN | SPI_RX_EN);
753 	tspi->cur_direction = 0;
754 	if (t->rx_buf) {
755 		command1 |= SPI_RX_EN;
756 		tspi->cur_direction |= DATA_DIR_RX;
757 	}
758 	if (t->tx_buf) {
759 		command1 |= SPI_TX_EN;
760 		tspi->cur_direction |= DATA_DIR_TX;
761 	}
762 	command1 |= SPI_CS_SEL(spi->chip_select);
763 	tegra_spi_writel(tspi, command1, SPI_COMMAND1);
764 	tspi->command1_reg = command1;
765 
766 	dev_dbg(tspi->dev, "The def 0x%x and written 0x%lx\n",
767 				tspi->def_command1_reg, command1);
768 
769 	if (total_fifo_words > SPI_FIFO_DEPTH)
770 		ret = tegra_spi_start_dma_based_transfer(tspi, t);
771 	else
772 		ret = tegra_spi_start_cpu_based_transfer(tspi, t);
773 	return ret;
774 }
775 
776 static int tegra_spi_setup(struct spi_device *spi)
777 {
778 	struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
779 	unsigned long val;
780 	unsigned long flags;
781 	int ret;
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,
787 	};
788 
789 	dev_dbg(&spi->dev, "setup %d bpw, %scpol, %scpha, %dHz\n",
790 		spi->bits_per_word,
791 		spi->mode & SPI_CPOL ? "" : "~",
792 		spi->mode & SPI_CPHA ? "" : "~",
793 		spi->max_speed_hz);
794 
795 	BUG_ON(spi->chip_select >= MAX_CHIP_SELECT);
796 
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;
799 
800 	ret = pm_runtime_get_sync(tspi->dev);
801 	if (ret < 0) {
802 		dev_err(tspi->dev, "pm runtime failed, e = %d\n", ret);
803 		return ret;
804 	}
805 
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];
810 	else
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);
815 
816 	pm_runtime_put(tspi->dev);
817 	return 0;
818 }
819 
820 static void tegra_spi_transfer_delay(int delay)
821 {
822 	if (!delay)
823 		return;
824 
825 	if (delay >= 1000)
826 		mdelay(delay / 1000);
827 
828 	udelay(delay % 1000);
829 }
830 
831 static int tegra_spi_transfer_one_message(struct spi_master *master,
832 			struct spi_message *msg)
833 {
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;
838 	int ret;
839 	bool skip = false;
840 
841 	msg->status = 0;
842 	msg->actual_length = 0;
843 
844 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
845 		unsigned long cmd1;
846 
847 		reinit_completion(&tspi->xfer_completion);
848 
849 		cmd1 = tegra_spi_setup_transfer_one(spi, xfer, is_first_msg);
850 
851 		if (!xfer->len) {
852 			ret = 0;
853 			skip = true;
854 			goto complete_xfer;
855 		}
856 
857 		ret = tegra_spi_start_transfer_one(spi, xfer, cmd1);
858 		if (ret < 0) {
859 			dev_err(tspi->dev,
860 				"spi can not start transfer, err %d\n", ret);
861 			goto complete_xfer;
862 		}
863 
864 		is_first_msg = false;
865 		ret = wait_for_completion_timeout(&tspi->xfer_completion,
866 						SPI_DMA_TIMEOUT);
867 		if (WARN_ON(ret == 0)) {
868 			dev_err(tspi->dev,
869 				"spi trasfer timeout, err %d\n", ret);
870 			ret = -EIO;
871 			goto complete_xfer;
872 		}
873 
874 		if (tspi->tx_status ||  tspi->rx_status) {
875 			dev_err(tspi->dev, "Error in Transfer\n");
876 			ret = -EIO;
877 			goto complete_xfer;
878 		}
879 		msg->actual_length += xfer->len;
880 
881 complete_xfer:
882 		if (ret < 0 || skip) {
883 			tegra_spi_writel(tspi, tspi->def_command1_reg,
884 					SPI_COMMAND1);
885 			tegra_spi_transfer_delay(xfer->delay_usecs);
886 			goto exit;
887 		} else if (msg->transfers.prev == &xfer->transfer_list) {
888 			/* This is the last transfer in message */
889 			if (xfer->cs_change)
890 				tspi->cs_control = spi;
891 			else {
892 				tegra_spi_writel(tspi, tspi->def_command1_reg,
893 						SPI_COMMAND1);
894 				tegra_spi_transfer_delay(xfer->delay_usecs);
895 			}
896 		} else if (xfer->cs_change) {
897 			tegra_spi_writel(tspi, tspi->def_command1_reg,
898 					SPI_COMMAND1);
899 			tegra_spi_transfer_delay(xfer->delay_usecs);
900 		}
901 
902 	}
903 	ret = 0;
904 exit:
905 	msg->status = ret;
906 	spi_finalize_current_message(master);
907 	return ret;
908 }
909 
910 static irqreturn_t handle_cpu_based_xfer(struct tegra_spi_data *tspi)
911 {
912 	struct spi_transfer *t = tspi->curr_xfer;
913 	unsigned long flags;
914 
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",
918 			tspi->status_reg);
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);
922 		udelay(2);
923 		tegra_periph_reset_deassert(tspi->clk);
924 		complete(&tspi->xfer_completion);
925 		goto exit;
926 	}
927 
928 	if (tspi->cur_direction & DATA_DIR_RX)
929 		tegra_spi_read_rx_fifo_to_client_rxbuf(tspi, t);
930 
931 	if (tspi->cur_direction & DATA_DIR_TX)
932 		tspi->cur_pos = tspi->cur_tx_pos;
933 	else
934 		tspi->cur_pos = tspi->cur_rx_pos;
935 
936 	if (tspi->cur_pos == t->len) {
937 		complete(&tspi->xfer_completion);
938 		goto exit;
939 	}
940 
941 	tegra_spi_calculate_curr_xfer_param(tspi->cur_spi, tspi, t);
942 	tegra_spi_start_cpu_based_transfer(tspi, t);
943 exit:
944 	spin_unlock_irqrestore(&tspi->lock, flags);
945 	return IRQ_HANDLED;
946 }
947 
948 static irqreturn_t handle_dma_based_xfer(struct tegra_spi_data *tspi)
949 {
950 	struct spi_transfer *t = tspi->curr_xfer;
951 	long wait_status;
952 	int err = 0;
953 	unsigned total_fifo_words;
954 	unsigned long flags;
955 
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);
960 			err += 1;
961 		} else {
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");
967 				err += 1;
968 			}
969 		}
970 	}
971 
972 	if (tspi->cur_direction & DATA_DIR_RX) {
973 		if (tspi->rx_status) {
974 			dmaengine_terminate_all(tspi->rx_dma_chan);
975 			err += 2;
976 		} else {
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");
982 				err += 2;
983 			}
984 		}
985 	}
986 
987 	spin_lock_irqsave(&tspi->lock, flags);
988 	if (err) {
989 		dev_err(tspi->dev, "DmaXfer: ERROR bit set 0x%x\n",
990 			tspi->status_reg);
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);
994 		udelay(2);
995 		tegra_periph_reset_deassert(tspi->clk);
996 		complete(&tspi->xfer_completion);
997 		spin_unlock_irqrestore(&tspi->lock, flags);
998 		return IRQ_HANDLED;
999 	}
1000 
1001 	if (tspi->cur_direction & DATA_DIR_RX)
1002 		tegra_spi_copy_spi_rxbuf_to_client_rxbuf(tspi, t);
1003 
1004 	if (tspi->cur_direction & DATA_DIR_TX)
1005 		tspi->cur_pos = tspi->cur_tx_pos;
1006 	else
1007 		tspi->cur_pos = tspi->cur_rx_pos;
1008 
1009 	if (tspi->cur_pos == t->len) {
1010 		complete(&tspi->xfer_completion);
1011 		goto exit;
1012 	}
1013 
1014 	/* Continue transfer in current message */
1015 	total_fifo_words = tegra_spi_calculate_curr_xfer_param(tspi->cur_spi,
1016 							tspi, t);
1017 	if (total_fifo_words > SPI_FIFO_DEPTH)
1018 		err = tegra_spi_start_dma_based_transfer(tspi, t);
1019 	else
1020 		err = tegra_spi_start_cpu_based_transfer(tspi, t);
1021 
1022 exit:
1023 	spin_unlock_irqrestore(&tspi->lock, flags);
1024 	return IRQ_HANDLED;
1025 }
1026 
1027 static irqreturn_t tegra_spi_isr_thread(int irq, void *context_data)
1028 {
1029 	struct tegra_spi_data *tspi = context_data;
1030 
1031 	if (!tspi->is_curr_dma_xfer)
1032 		return handle_cpu_based_xfer(tspi);
1033 	return handle_dma_based_xfer(tspi);
1034 }
1035 
1036 static irqreturn_t tegra_spi_isr(int irq, void *context_data)
1037 {
1038 	struct tegra_spi_data *tspi = context_data;
1039 
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);
1044 
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);
1049 
1050 	return IRQ_WAKE_THREAD;
1051 }
1052 
1053 static void tegra_spi_parse_dt(struct platform_device *pdev,
1054 	struct tegra_spi_data *tspi)
1055 {
1056 	struct device_node *np = pdev->dev.of_node;
1057 	u32 of_dma[2];
1058 
1059 	if (of_property_read_u32_array(np, "nvidia,dma-request-selector",
1060 				of_dma, 2) >= 0)
1061 		tspi->dma_req_sel = of_dma[1];
1062 
1063 	if (of_property_read_u32(np, "spi-max-frequency",
1064 				&tspi->spi_max_frequency))
1065 		tspi->spi_max_frequency = 25000000; /* 25MHz */
1066 }
1067 
1068 static struct of_device_id tegra_spi_of_match[] = {
1069 	{ .compatible = "nvidia,tegra114-spi", },
1070 	{}
1071 };
1072 MODULE_DEVICE_TABLE(of, tegra_spi_of_match);
1073 
1074 static int tegra_spi_probe(struct platform_device *pdev)
1075 {
1076 	struct spi_master	*master;
1077 	struct tegra_spi_data	*tspi;
1078 	struct resource		*r;
1079 	int ret, spi_irq;
1080 
1081 	master = spi_alloc_master(&pdev->dev, sizeof(*tspi));
1082 	if (!master) {
1083 		dev_err(&pdev->dev, "master allocation failed\n");
1084 		return -ENOMEM;
1085 	}
1086 	platform_set_drvdata(pdev, master);
1087 	tspi = spi_master_get_devdata(master);
1088 
1089 	/* Parse DT */
1090 	tegra_spi_parse_dt(pdev, tspi);
1091 
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;
1099 
1100 	tspi->master = master;
1101 	tspi->dev = &pdev->dev;
1102 	spin_lock_init(&tspi->lock);
1103 
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;
1109 	}
1110 	tspi->phys = r->start;
1111 
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);
1117 	if (ret < 0) {
1118 		dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
1119 					tspi->irq);
1120 		goto exit_free_master;
1121 	}
1122 
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);
1127 		goto exit_free_irq;
1128 	}
1129 
1130 	tspi->max_buf_size = SPI_FIFO_DEPTH << 2;
1131 	tspi->dma_buf_size = DEFAULT_SPI_DMA_BUF_LEN;
1132 
1133 	if (tspi->dma_req_sel) {
1134 		ret = tegra_spi_init_dma_param(tspi, true);
1135 		if (ret < 0) {
1136 			dev_err(&pdev->dev, "RxDma Init failed, err %d\n", ret);
1137 			goto exit_free_irq;
1138 		}
1139 
1140 		ret = tegra_spi_init_dma_param(tspi, false);
1141 		if (ret < 0) {
1142 			dev_err(&pdev->dev, "TxDma Init failed, err %d\n", ret);
1143 			goto exit_rx_dma_free;
1144 		}
1145 		tspi->max_buf_size = tspi->dma_buf_size;
1146 		init_completion(&tspi->tx_dma_complete);
1147 		init_completion(&tspi->rx_dma_complete);
1148 	}
1149 
1150 	init_completion(&tspi->xfer_completion);
1151 
1152 	pm_runtime_enable(&pdev->dev);
1153 	if (!pm_runtime_enabled(&pdev->dev)) {
1154 		ret = tegra_spi_runtime_resume(&pdev->dev);
1155 		if (ret)
1156 			goto exit_pm_disable;
1157 	}
1158 
1159 	ret = pm_runtime_get_sync(&pdev->dev);
1160 	if (ret < 0) {
1161 		dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret);
1162 		goto exit_pm_disable;
1163 	}
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);
1167 
1168 	master->dev.of_node = pdev->dev.of_node;
1169 	ret = devm_spi_register_master(&pdev->dev, master);
1170 	if (ret < 0) {
1171 		dev_err(&pdev->dev, "can not register to master err %d\n", ret);
1172 		goto exit_pm_disable;
1173 	}
1174 	return ret;
1175 
1176 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);
1181 exit_rx_dma_free:
1182 	tegra_spi_deinit_dma_param(tspi, true);
1183 exit_free_irq:
1184 	free_irq(spi_irq, tspi);
1185 exit_free_master:
1186 	spi_master_put(master);
1187 	return ret;
1188 }
1189 
1190 static int tegra_spi_remove(struct platform_device *pdev)
1191 {
1192 	struct spi_master *master = platform_get_drvdata(pdev);
1193 	struct tegra_spi_data	*tspi = spi_master_get_devdata(master);
1194 
1195 	free_irq(tspi->irq, tspi);
1196 
1197 	if (tspi->tx_dma_chan)
1198 		tegra_spi_deinit_dma_param(tspi, false);
1199 
1200 	if (tspi->rx_dma_chan)
1201 		tegra_spi_deinit_dma_param(tspi, true);
1202 
1203 	pm_runtime_disable(&pdev->dev);
1204 	if (!pm_runtime_status_suspended(&pdev->dev))
1205 		tegra_spi_runtime_suspend(&pdev->dev);
1206 
1207 	return 0;
1208 }
1209 
1210 #ifdef CONFIG_PM_SLEEP
1211 static int tegra_spi_suspend(struct device *dev)
1212 {
1213 	struct spi_master *master = dev_get_drvdata(dev);
1214 
1215 	return spi_master_suspend(master);
1216 }
1217 
1218 static int tegra_spi_resume(struct device *dev)
1219 {
1220 	struct spi_master *master = dev_get_drvdata(dev);
1221 	struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1222 	int ret;
1223 
1224 	ret = pm_runtime_get_sync(dev);
1225 	if (ret < 0) {
1226 		dev_err(dev, "pm runtime failed, e = %d\n", ret);
1227 		return ret;
1228 	}
1229 	tegra_spi_writel(tspi, tspi->command1_reg, SPI_COMMAND1);
1230 	pm_runtime_put(dev);
1231 
1232 	return spi_master_resume(master);
1233 }
1234 #endif
1235 
1236 static int tegra_spi_runtime_suspend(struct device *dev)
1237 {
1238 	struct spi_master *master = dev_get_drvdata(dev);
1239 	struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1240 
1241 	/* Flush all write which are in PPSB queue by reading back */
1242 	tegra_spi_readl(tspi, SPI_COMMAND1);
1243 
1244 	clk_disable_unprepare(tspi->clk);
1245 	return 0;
1246 }
1247 
1248 static int tegra_spi_runtime_resume(struct device *dev)
1249 {
1250 	struct spi_master *master = dev_get_drvdata(dev);
1251 	struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1252 	int ret;
1253 
1254 	ret = clk_prepare_enable(tspi->clk);
1255 	if (ret < 0) {
1256 		dev_err(tspi->dev, "clk_prepare failed: %d\n", ret);
1257 		return ret;
1258 	}
1259 	return 0;
1260 }
1261 
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)
1266 };
1267 static struct platform_driver tegra_spi_driver = {
1268 	.driver = {
1269 		.name		= "spi-tegra114",
1270 		.owner		= THIS_MODULE,
1271 		.pm		= &tegra_spi_pm_ops,
1272 		.of_match_table	= tegra_spi_of_match,
1273 	},
1274 	.probe =	tegra_spi_probe,
1275 	.remove =	tegra_spi_remove,
1276 };
1277 module_platform_driver(tegra_spi_driver);
1278 
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");
1283