xref: /openbmc/linux/drivers/spi/spi-tegra114.c (revision 7b6d864b)
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 	unsigned				cur_pos;
186 	unsigned				cur_len;
187 	unsigned				words_per_32bit;
188 	unsigned				bytes_per_word;
189 	unsigned				curr_dma_words;
190 	unsigned				cur_direction;
191 
192 	unsigned				cur_rx_pos;
193 	unsigned				cur_tx_pos;
194 
195 	unsigned				dma_buf_size;
196 	unsigned				max_buf_size;
197 	bool					is_curr_dma_xfer;
198 
199 	struct completion			rx_dma_complete;
200 	struct completion			tx_dma_complete;
201 
202 	u32					tx_status;
203 	u32					rx_status;
204 	u32					status_reg;
205 	bool					is_packed;
206 	unsigned long				packed_size;
207 
208 	u32					command1_reg;
209 	u32					dma_control_reg;
210 	u32					def_command1_reg;
211 	u32					spi_cs_timing;
212 
213 	struct completion			xfer_completion;
214 	struct spi_transfer			*curr_xfer;
215 	struct dma_chan				*rx_dma_chan;
216 	u32					*rx_dma_buf;
217 	dma_addr_t				rx_dma_phys;
218 	struct dma_async_tx_descriptor		*rx_dma_desc;
219 
220 	struct dma_chan				*tx_dma_chan;
221 	u32					*tx_dma_buf;
222 	dma_addr_t				tx_dma_phys;
223 	struct dma_async_tx_descriptor		*tx_dma_desc;
224 };
225 
226 static int tegra_spi_runtime_suspend(struct device *dev);
227 static int tegra_spi_runtime_resume(struct device *dev);
228 
229 static inline unsigned long tegra_spi_readl(struct tegra_spi_data *tspi,
230 		unsigned long reg)
231 {
232 	return readl(tspi->base + reg);
233 }
234 
235 static inline void tegra_spi_writel(struct tegra_spi_data *tspi,
236 		unsigned long val, unsigned long reg)
237 {
238 	writel(val, tspi->base + reg);
239 
240 	/* Read back register to make sure that register writes completed */
241 	if (reg != SPI_TX_FIFO)
242 		readl(tspi->base + SPI_COMMAND1);
243 }
244 
245 static void tegra_spi_clear_status(struct tegra_spi_data *tspi)
246 {
247 	unsigned long val;
248 
249 	/* Write 1 to clear status register */
250 	val = tegra_spi_readl(tspi, SPI_TRANS_STATUS);
251 	tegra_spi_writel(tspi, val, SPI_TRANS_STATUS);
252 
253 	/* Clear fifo status error if any */
254 	val = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
255 	if (val & SPI_ERR)
256 		tegra_spi_writel(tspi, SPI_ERR | SPI_FIFO_ERROR,
257 				SPI_FIFO_STATUS);
258 }
259 
260 static unsigned tegra_spi_calculate_curr_xfer_param(
261 	struct spi_device *spi, struct tegra_spi_data *tspi,
262 	struct spi_transfer *t)
263 {
264 	unsigned remain_len = t->len - tspi->cur_pos;
265 	unsigned max_word;
266 	unsigned bits_per_word = t->bits_per_word;
267 	unsigned max_len;
268 	unsigned total_fifo_words;
269 
270 	tspi->bytes_per_word = (bits_per_word - 1) / 8 + 1;
271 
272 	if (bits_per_word == 8 || bits_per_word == 16) {
273 		tspi->is_packed = 1;
274 		tspi->words_per_32bit = 32/bits_per_word;
275 	} else {
276 		tspi->is_packed = 0;
277 		tspi->words_per_32bit = 1;
278 	}
279 
280 	if (tspi->is_packed) {
281 		max_len = min(remain_len, tspi->max_buf_size);
282 		tspi->curr_dma_words = max_len/tspi->bytes_per_word;
283 		total_fifo_words = (max_len + 3) / 4;
284 	} else {
285 		max_word = (remain_len - 1) / tspi->bytes_per_word + 1;
286 		max_word = min(max_word, tspi->max_buf_size/4);
287 		tspi->curr_dma_words = max_word;
288 		total_fifo_words = max_word;
289 	}
290 	return total_fifo_words;
291 }
292 
293 static unsigned tegra_spi_fill_tx_fifo_from_client_txbuf(
294 	struct tegra_spi_data *tspi, struct spi_transfer *t)
295 {
296 	unsigned nbytes;
297 	unsigned tx_empty_count;
298 	unsigned long fifo_status;
299 	unsigned max_n_32bit;
300 	unsigned i, count;
301 	unsigned long x;
302 	unsigned int written_words;
303 	unsigned fifo_words_left;
304 	u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
305 
306 	fifo_status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
307 	tx_empty_count = SPI_TX_FIFO_EMPTY_COUNT(fifo_status);
308 
309 	if (tspi->is_packed) {
310 		fifo_words_left = tx_empty_count * tspi->words_per_32bit;
311 		written_words = min(fifo_words_left, tspi->curr_dma_words);
312 		nbytes = written_words * tspi->bytes_per_word;
313 		max_n_32bit = DIV_ROUND_UP(nbytes, 4);
314 		for (count = 0; count < max_n_32bit; count++) {
315 			x = 0;
316 			for (i = 0; (i < 4) && nbytes; i++, nbytes--)
317 				x |= (*tx_buf++) << (i*8);
318 			tegra_spi_writel(tspi, x, SPI_TX_FIFO);
319 		}
320 	} else {
321 		max_n_32bit = min(tspi->curr_dma_words,  tx_empty_count);
322 		written_words = max_n_32bit;
323 		nbytes = written_words * tspi->bytes_per_word;
324 		for (count = 0; count < max_n_32bit; count++) {
325 			x = 0;
326 			for (i = 0; nbytes && (i < tspi->bytes_per_word);
327 							i++, nbytes--)
328 				x |= ((*tx_buf++) << i*8);
329 			tegra_spi_writel(tspi, x, SPI_TX_FIFO);
330 		}
331 	}
332 	tspi->cur_tx_pos += written_words * tspi->bytes_per_word;
333 	return written_words;
334 }
335 
336 static unsigned int tegra_spi_read_rx_fifo_to_client_rxbuf(
337 		struct tegra_spi_data *tspi, struct spi_transfer *t)
338 {
339 	unsigned rx_full_count;
340 	unsigned long fifo_status;
341 	unsigned i, count;
342 	unsigned long x;
343 	unsigned int read_words = 0;
344 	unsigned len;
345 	u8 *rx_buf = (u8 *)t->rx_buf + tspi->cur_rx_pos;
346 
347 	fifo_status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
348 	rx_full_count = SPI_RX_FIFO_FULL_COUNT(fifo_status);
349 	if (tspi->is_packed) {
350 		len = tspi->curr_dma_words * tspi->bytes_per_word;
351 		for (count = 0; count < rx_full_count; count++) {
352 			x = tegra_spi_readl(tspi, SPI_RX_FIFO);
353 			for (i = 0; len && (i < 4); i++, len--)
354 				*rx_buf++ = (x >> i*8) & 0xFF;
355 		}
356 		tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
357 		read_words += tspi->curr_dma_words;
358 	} else {
359 		unsigned int rx_mask;
360 		unsigned int bits_per_word = t->bits_per_word;
361 
362 		rx_mask = (1 << bits_per_word) - 1;
363 		for (count = 0; count < rx_full_count; count++) {
364 			x = tegra_spi_readl(tspi, SPI_RX_FIFO);
365 			x &= rx_mask;
366 			for (i = 0; (i < tspi->bytes_per_word); i++)
367 				*rx_buf++ = (x >> (i*8)) & 0xFF;
368 		}
369 		tspi->cur_rx_pos += rx_full_count * tspi->bytes_per_word;
370 		read_words += rx_full_count;
371 	}
372 	return read_words;
373 }
374 
375 static void tegra_spi_copy_client_txbuf_to_spi_txbuf(
376 		struct tegra_spi_data *tspi, struct spi_transfer *t)
377 {
378 	unsigned len;
379 
380 	/* Make the dma buffer to read by cpu */
381 	dma_sync_single_for_cpu(tspi->dev, tspi->tx_dma_phys,
382 				tspi->dma_buf_size, DMA_TO_DEVICE);
383 
384 	if (tspi->is_packed) {
385 		len = tspi->curr_dma_words * tspi->bytes_per_word;
386 		memcpy(tspi->tx_dma_buf, t->tx_buf + tspi->cur_pos, len);
387 	} else {
388 		unsigned int i;
389 		unsigned int count;
390 		u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
391 		unsigned consume = tspi->curr_dma_words * tspi->bytes_per_word;
392 		unsigned int x;
393 
394 		for (count = 0; count < tspi->curr_dma_words; count++) {
395 			x = 0;
396 			for (i = 0; consume && (i < tspi->bytes_per_word);
397 							i++, consume--)
398 				x |= ((*tx_buf++) << i * 8);
399 			tspi->tx_dma_buf[count] = x;
400 		}
401 	}
402 	tspi->cur_tx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
403 
404 	/* Make the dma buffer to read by dma */
405 	dma_sync_single_for_device(tspi->dev, tspi->tx_dma_phys,
406 				tspi->dma_buf_size, DMA_TO_DEVICE);
407 }
408 
409 static void tegra_spi_copy_spi_rxbuf_to_client_rxbuf(
410 		struct tegra_spi_data *tspi, struct spi_transfer *t)
411 {
412 	unsigned len;
413 
414 	/* Make the dma buffer to read by cpu */
415 	dma_sync_single_for_cpu(tspi->dev, tspi->rx_dma_phys,
416 		tspi->dma_buf_size, DMA_FROM_DEVICE);
417 
418 	if (tspi->is_packed) {
419 		len = tspi->curr_dma_words * tspi->bytes_per_word;
420 		memcpy(t->rx_buf + tspi->cur_rx_pos, tspi->rx_dma_buf, len);
421 	} else {
422 		unsigned int i;
423 		unsigned int count;
424 		unsigned char *rx_buf = t->rx_buf + tspi->cur_rx_pos;
425 		unsigned int x;
426 		unsigned int rx_mask;
427 		unsigned int bits_per_word = t->bits_per_word;
428 
429 		rx_mask = (1 << bits_per_word) - 1;
430 		for (count = 0; count < tspi->curr_dma_words; count++) {
431 			x = tspi->rx_dma_buf[count];
432 			x &= rx_mask;
433 			for (i = 0; (i < tspi->bytes_per_word); i++)
434 				*rx_buf++ = (x >> (i*8)) & 0xFF;
435 		}
436 	}
437 	tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
438 
439 	/* Make the dma buffer to read by dma */
440 	dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
441 		tspi->dma_buf_size, DMA_FROM_DEVICE);
442 }
443 
444 static void tegra_spi_dma_complete(void *args)
445 {
446 	struct completion *dma_complete = args;
447 
448 	complete(dma_complete);
449 }
450 
451 static int tegra_spi_start_tx_dma(struct tegra_spi_data *tspi, int len)
452 {
453 	INIT_COMPLETION(tspi->tx_dma_complete);
454 	tspi->tx_dma_desc = dmaengine_prep_slave_single(tspi->tx_dma_chan,
455 				tspi->tx_dma_phys, len, DMA_MEM_TO_DEV,
456 				DMA_PREP_INTERRUPT |  DMA_CTRL_ACK);
457 	if (!tspi->tx_dma_desc) {
458 		dev_err(tspi->dev, "Not able to get desc for Tx\n");
459 		return -EIO;
460 	}
461 
462 	tspi->tx_dma_desc->callback = tegra_spi_dma_complete;
463 	tspi->tx_dma_desc->callback_param = &tspi->tx_dma_complete;
464 
465 	dmaengine_submit(tspi->tx_dma_desc);
466 	dma_async_issue_pending(tspi->tx_dma_chan);
467 	return 0;
468 }
469 
470 static int tegra_spi_start_rx_dma(struct tegra_spi_data *tspi, int len)
471 {
472 	INIT_COMPLETION(tspi->rx_dma_complete);
473 	tspi->rx_dma_desc = dmaengine_prep_slave_single(tspi->rx_dma_chan,
474 				tspi->rx_dma_phys, len, DMA_DEV_TO_MEM,
475 				DMA_PREP_INTERRUPT |  DMA_CTRL_ACK);
476 	if (!tspi->rx_dma_desc) {
477 		dev_err(tspi->dev, "Not able to get desc for Rx\n");
478 		return -EIO;
479 	}
480 
481 	tspi->rx_dma_desc->callback = tegra_spi_dma_complete;
482 	tspi->rx_dma_desc->callback_param = &tspi->rx_dma_complete;
483 
484 	dmaengine_submit(tspi->rx_dma_desc);
485 	dma_async_issue_pending(tspi->rx_dma_chan);
486 	return 0;
487 }
488 
489 static int tegra_spi_start_dma_based_transfer(
490 		struct tegra_spi_data *tspi, struct spi_transfer *t)
491 {
492 	unsigned long val;
493 	unsigned int len;
494 	int ret = 0;
495 	unsigned long status;
496 
497 	/* Make sure that Rx and Tx fifo are empty */
498 	status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
499 	if ((status & SPI_FIFO_EMPTY) != SPI_FIFO_EMPTY) {
500 		dev_err(tspi->dev,
501 			"Rx/Tx fifo are not empty status 0x%08lx\n", status);
502 		return -EIO;
503 	}
504 
505 	val = SPI_DMA_BLK_SET(tspi->curr_dma_words - 1);
506 	tegra_spi_writel(tspi, val, SPI_DMA_BLK);
507 
508 	if (tspi->is_packed)
509 		len = DIV_ROUND_UP(tspi->curr_dma_words * tspi->bytes_per_word,
510 					4) * 4;
511 	else
512 		len = tspi->curr_dma_words * 4;
513 
514 	/* Set attention level based on length of transfer */
515 	if (len & 0xF)
516 		val |= SPI_TX_TRIG_1 | SPI_RX_TRIG_1;
517 	else if (((len) >> 4) & 0x1)
518 		val |= SPI_TX_TRIG_4 | SPI_RX_TRIG_4;
519 	else
520 		val |= SPI_TX_TRIG_8 | SPI_RX_TRIG_8;
521 
522 	if (tspi->cur_direction & DATA_DIR_TX)
523 		val |= SPI_IE_TX;
524 
525 	if (tspi->cur_direction & DATA_DIR_RX)
526 		val |= SPI_IE_RX;
527 
528 	tegra_spi_writel(tspi, val, SPI_DMA_CTL);
529 	tspi->dma_control_reg = val;
530 
531 	if (tspi->cur_direction & DATA_DIR_TX) {
532 		tegra_spi_copy_client_txbuf_to_spi_txbuf(tspi, t);
533 		ret = tegra_spi_start_tx_dma(tspi, len);
534 		if (ret < 0) {
535 			dev_err(tspi->dev,
536 				"Starting tx dma failed, err %d\n", ret);
537 			return ret;
538 		}
539 	}
540 
541 	if (tspi->cur_direction & DATA_DIR_RX) {
542 		/* Make the dma buffer to read by dma */
543 		dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
544 				tspi->dma_buf_size, DMA_FROM_DEVICE);
545 
546 		ret = tegra_spi_start_rx_dma(tspi, len);
547 		if (ret < 0) {
548 			dev_err(tspi->dev,
549 				"Starting rx dma failed, err %d\n", ret);
550 			if (tspi->cur_direction & DATA_DIR_TX)
551 				dmaengine_terminate_all(tspi->tx_dma_chan);
552 			return ret;
553 		}
554 	}
555 	tspi->is_curr_dma_xfer = true;
556 	tspi->dma_control_reg = val;
557 
558 	val |= SPI_DMA_EN;
559 	tegra_spi_writel(tspi, val, SPI_DMA_CTL);
560 	return ret;
561 }
562 
563 static int tegra_spi_start_cpu_based_transfer(
564 		struct tegra_spi_data *tspi, struct spi_transfer *t)
565 {
566 	unsigned long val;
567 	unsigned cur_words;
568 
569 	if (tspi->cur_direction & DATA_DIR_TX)
570 		cur_words = tegra_spi_fill_tx_fifo_from_client_txbuf(tspi, t);
571 	else
572 		cur_words = tspi->curr_dma_words;
573 
574 	val = SPI_DMA_BLK_SET(cur_words - 1);
575 	tegra_spi_writel(tspi, val, SPI_DMA_BLK);
576 
577 	val = 0;
578 	if (tspi->cur_direction & DATA_DIR_TX)
579 		val |= SPI_IE_TX;
580 
581 	if (tspi->cur_direction & DATA_DIR_RX)
582 		val |= SPI_IE_RX;
583 
584 	tegra_spi_writel(tspi, val, SPI_DMA_CTL);
585 	tspi->dma_control_reg = val;
586 
587 	tspi->is_curr_dma_xfer = false;
588 
589 	val |= SPI_DMA_EN;
590 	tegra_spi_writel(tspi, val, SPI_DMA_CTL);
591 	return 0;
592 }
593 
594 static int tegra_spi_init_dma_param(struct tegra_spi_data *tspi,
595 			bool dma_to_memory)
596 {
597 	struct dma_chan *dma_chan;
598 	u32 *dma_buf;
599 	dma_addr_t dma_phys;
600 	int ret;
601 	struct dma_slave_config dma_sconfig;
602 	dma_cap_mask_t mask;
603 
604 	dma_cap_zero(mask);
605 	dma_cap_set(DMA_SLAVE, mask);
606 	dma_chan = dma_request_channel(mask, NULL, NULL);
607 	if (!dma_chan) {
608 		dev_err(tspi->dev,
609 			"Dma channel is not available, will try later\n");
610 		return -EPROBE_DEFER;
611 	}
612 
613 	dma_buf = dma_alloc_coherent(tspi->dev, tspi->dma_buf_size,
614 				&dma_phys, GFP_KERNEL);
615 	if (!dma_buf) {
616 		dev_err(tspi->dev, " Not able to allocate the dma buffer\n");
617 		dma_release_channel(dma_chan);
618 		return -ENOMEM;
619 	}
620 
621 	dma_sconfig.slave_id = tspi->dma_req_sel;
622 	if (dma_to_memory) {
623 		dma_sconfig.src_addr = tspi->phys + SPI_RX_FIFO;
624 		dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
625 		dma_sconfig.src_maxburst = 0;
626 	} else {
627 		dma_sconfig.dst_addr = tspi->phys + SPI_TX_FIFO;
628 		dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
629 		dma_sconfig.dst_maxburst = 0;
630 	}
631 
632 	ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
633 	if (ret)
634 		goto scrub;
635 	if (dma_to_memory) {
636 		tspi->rx_dma_chan = dma_chan;
637 		tspi->rx_dma_buf = dma_buf;
638 		tspi->rx_dma_phys = dma_phys;
639 	} else {
640 		tspi->tx_dma_chan = dma_chan;
641 		tspi->tx_dma_buf = dma_buf;
642 		tspi->tx_dma_phys = dma_phys;
643 	}
644 	return 0;
645 
646 scrub:
647 	dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
648 	dma_release_channel(dma_chan);
649 	return ret;
650 }
651 
652 static void tegra_spi_deinit_dma_param(struct tegra_spi_data *tspi,
653 	bool dma_to_memory)
654 {
655 	u32 *dma_buf;
656 	dma_addr_t dma_phys;
657 	struct dma_chan *dma_chan;
658 
659 	if (dma_to_memory) {
660 		dma_buf = tspi->rx_dma_buf;
661 		dma_chan = tspi->rx_dma_chan;
662 		dma_phys = tspi->rx_dma_phys;
663 		tspi->rx_dma_chan = NULL;
664 		tspi->rx_dma_buf = NULL;
665 	} else {
666 		dma_buf = tspi->tx_dma_buf;
667 		dma_chan = tspi->tx_dma_chan;
668 		dma_phys = tspi->tx_dma_phys;
669 		tspi->tx_dma_buf = NULL;
670 		tspi->tx_dma_chan = NULL;
671 	}
672 	if (!dma_chan)
673 		return;
674 
675 	dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
676 	dma_release_channel(dma_chan);
677 }
678 
679 static int tegra_spi_start_transfer_one(struct spi_device *spi,
680 		struct spi_transfer *t, bool is_first_of_msg,
681 		bool is_single_xfer)
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 total_fifo_words;
687 	int ret;
688 	unsigned long command1;
689 	int req_mode;
690 
691 	if (speed != tspi->cur_speed) {
692 		clk_set_rate(tspi->clk, speed);
693 		tspi->cur_speed = speed;
694 	}
695 
696 	tspi->cur_spi = spi;
697 	tspi->cur_pos = 0;
698 	tspi->cur_rx_pos = 0;
699 	tspi->cur_tx_pos = 0;
700 	tspi->curr_xfer = t;
701 	total_fifo_words = tegra_spi_calculate_curr_xfer_param(spi, tspi, t);
702 
703 	if (is_first_of_msg) {
704 		tegra_spi_clear_status(tspi);
705 
706 		command1 = tspi->def_command1_reg;
707 		command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
708 
709 		command1 &= ~SPI_CONTROL_MODE_MASK;
710 		req_mode = spi->mode & 0x3;
711 		if (req_mode == SPI_MODE_0)
712 			command1 |= SPI_CONTROL_MODE_0;
713 		else if (req_mode == SPI_MODE_1)
714 			command1 |= SPI_CONTROL_MODE_1;
715 		else if (req_mode == SPI_MODE_2)
716 			command1 |= SPI_CONTROL_MODE_2;
717 		else if (req_mode == SPI_MODE_3)
718 			command1 |= SPI_CONTROL_MODE_3;
719 
720 		tegra_spi_writel(tspi, command1, SPI_COMMAND1);
721 
722 		command1 |= SPI_CS_SW_HW;
723 		if (spi->mode & SPI_CS_HIGH)
724 			command1 |= SPI_CS_SS_VAL;
725 		else
726 			command1 &= ~SPI_CS_SS_VAL;
727 
728 		tegra_spi_writel(tspi, 0, SPI_COMMAND2);
729 	} else {
730 		command1 = tspi->command1_reg;
731 		command1 &= ~SPI_BIT_LENGTH(~0);
732 		command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
733 	}
734 
735 	if (tspi->is_packed)
736 		command1 |= SPI_PACKED;
737 
738 	command1 &= ~(SPI_CS_SEL_MASK | SPI_TX_EN | SPI_RX_EN);
739 	tspi->cur_direction = 0;
740 	if (t->rx_buf) {
741 		command1 |= SPI_RX_EN;
742 		tspi->cur_direction |= DATA_DIR_RX;
743 	}
744 	if (t->tx_buf) {
745 		command1 |= SPI_TX_EN;
746 		tspi->cur_direction |= DATA_DIR_TX;
747 	}
748 	command1 |= SPI_CS_SEL(spi->chip_select);
749 	tegra_spi_writel(tspi, command1, SPI_COMMAND1);
750 	tspi->command1_reg = command1;
751 
752 	dev_dbg(tspi->dev, "The def 0x%x and written 0x%lx\n",
753 				tspi->def_command1_reg, command1);
754 
755 	if (total_fifo_words > SPI_FIFO_DEPTH)
756 		ret = tegra_spi_start_dma_based_transfer(tspi, t);
757 	else
758 		ret = tegra_spi_start_cpu_based_transfer(tspi, t);
759 	return ret;
760 }
761 
762 static int tegra_spi_setup(struct spi_device *spi)
763 {
764 	struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
765 	unsigned long val;
766 	unsigned long flags;
767 	int ret;
768 	unsigned int cs_pol_bit[MAX_CHIP_SELECT] = {
769 			SPI_CS_POL_INACTIVE_0,
770 			SPI_CS_POL_INACTIVE_1,
771 			SPI_CS_POL_INACTIVE_2,
772 			SPI_CS_POL_INACTIVE_3,
773 	};
774 
775 	dev_dbg(&spi->dev, "setup %d bpw, %scpol, %scpha, %dHz\n",
776 		spi->bits_per_word,
777 		spi->mode & SPI_CPOL ? "" : "~",
778 		spi->mode & SPI_CPHA ? "" : "~",
779 		spi->max_speed_hz);
780 
781 	BUG_ON(spi->chip_select >= MAX_CHIP_SELECT);
782 
783 	/* Set speed to the spi max fequency if spi device has not set */
784 	spi->max_speed_hz = spi->max_speed_hz ? : tspi->spi_max_frequency;
785 
786 	ret = pm_runtime_get_sync(tspi->dev);
787 	if (ret < 0) {
788 		dev_err(tspi->dev, "pm runtime failed, e = %d\n", ret);
789 		return ret;
790 	}
791 
792 	spin_lock_irqsave(&tspi->lock, flags);
793 	val = tspi->def_command1_reg;
794 	if (spi->mode & SPI_CS_HIGH)
795 		val &= ~cs_pol_bit[spi->chip_select];
796 	else
797 		val |= cs_pol_bit[spi->chip_select];
798 	tspi->def_command1_reg = val;
799 	tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
800 	spin_unlock_irqrestore(&tspi->lock, flags);
801 
802 	pm_runtime_put(tspi->dev);
803 	return 0;
804 }
805 
806 static int tegra_spi_transfer_one_message(struct spi_master *master,
807 			struct spi_message *msg)
808 {
809 	bool is_first_msg = true;
810 	int single_xfer;
811 	struct tegra_spi_data *tspi = spi_master_get_devdata(master);
812 	struct spi_transfer *xfer;
813 	struct spi_device *spi = msg->spi;
814 	int ret;
815 
816 	msg->status = 0;
817 	msg->actual_length = 0;
818 
819 	ret = pm_runtime_get_sync(tspi->dev);
820 	if (ret < 0) {
821 		dev_err(tspi->dev, "runtime PM get failed: %d\n", ret);
822 		msg->status = ret;
823 		spi_finalize_current_message(master);
824 		return ret;
825 	}
826 
827 	single_xfer = list_is_singular(&msg->transfers);
828 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
829 		INIT_COMPLETION(tspi->xfer_completion);
830 		ret = tegra_spi_start_transfer_one(spi, xfer,
831 					is_first_msg, single_xfer);
832 		if (ret < 0) {
833 			dev_err(tspi->dev,
834 				"spi can not start transfer, err %d\n", ret);
835 			goto exit;
836 		}
837 		is_first_msg = false;
838 		ret = wait_for_completion_timeout(&tspi->xfer_completion,
839 						SPI_DMA_TIMEOUT);
840 		if (WARN_ON(ret == 0)) {
841 			dev_err(tspi->dev,
842 				"spi trasfer timeout, err %d\n", ret);
843 			ret = -EIO;
844 			goto exit;
845 		}
846 
847 		if (tspi->tx_status ||  tspi->rx_status) {
848 			dev_err(tspi->dev, "Error in Transfer\n");
849 			ret = -EIO;
850 			goto exit;
851 		}
852 		msg->actual_length += xfer->len;
853 		if (xfer->cs_change && xfer->delay_usecs) {
854 			tegra_spi_writel(tspi, tspi->def_command1_reg,
855 					SPI_COMMAND1);
856 			udelay(xfer->delay_usecs);
857 		}
858 	}
859 	ret = 0;
860 exit:
861 	tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
862 	pm_runtime_put(tspi->dev);
863 	msg->status = ret;
864 	spi_finalize_current_message(master);
865 	return ret;
866 }
867 
868 static irqreturn_t handle_cpu_based_xfer(struct tegra_spi_data *tspi)
869 {
870 	struct spi_transfer *t = tspi->curr_xfer;
871 	unsigned long flags;
872 
873 	spin_lock_irqsave(&tspi->lock, flags);
874 	if (tspi->tx_status ||  tspi->rx_status) {
875 		dev_err(tspi->dev, "CpuXfer ERROR bit set 0x%x\n",
876 			tspi->status_reg);
877 		dev_err(tspi->dev, "CpuXfer 0x%08x:0x%08x\n",
878 			tspi->command1_reg, tspi->dma_control_reg);
879 		tegra_periph_reset_assert(tspi->clk);
880 		udelay(2);
881 		tegra_periph_reset_deassert(tspi->clk);
882 		complete(&tspi->xfer_completion);
883 		goto exit;
884 	}
885 
886 	if (tspi->cur_direction & DATA_DIR_RX)
887 		tegra_spi_read_rx_fifo_to_client_rxbuf(tspi, t);
888 
889 	if (tspi->cur_direction & DATA_DIR_TX)
890 		tspi->cur_pos = tspi->cur_tx_pos;
891 	else
892 		tspi->cur_pos = tspi->cur_rx_pos;
893 
894 	if (tspi->cur_pos == t->len) {
895 		complete(&tspi->xfer_completion);
896 		goto exit;
897 	}
898 
899 	tegra_spi_calculate_curr_xfer_param(tspi->cur_spi, tspi, t);
900 	tegra_spi_start_cpu_based_transfer(tspi, t);
901 exit:
902 	spin_unlock_irqrestore(&tspi->lock, flags);
903 	return IRQ_HANDLED;
904 }
905 
906 static irqreturn_t handle_dma_based_xfer(struct tegra_spi_data *tspi)
907 {
908 	struct spi_transfer *t = tspi->curr_xfer;
909 	long wait_status;
910 	int err = 0;
911 	unsigned total_fifo_words;
912 	unsigned long flags;
913 
914 	/* Abort dmas if any error */
915 	if (tspi->cur_direction & DATA_DIR_TX) {
916 		if (tspi->tx_status) {
917 			dmaengine_terminate_all(tspi->tx_dma_chan);
918 			err += 1;
919 		} else {
920 			wait_status = wait_for_completion_interruptible_timeout(
921 				&tspi->tx_dma_complete, SPI_DMA_TIMEOUT);
922 			if (wait_status <= 0) {
923 				dmaengine_terminate_all(tspi->tx_dma_chan);
924 				dev_err(tspi->dev, "TxDma Xfer failed\n");
925 				err += 1;
926 			}
927 		}
928 	}
929 
930 	if (tspi->cur_direction & DATA_DIR_RX) {
931 		if (tspi->rx_status) {
932 			dmaengine_terminate_all(tspi->rx_dma_chan);
933 			err += 2;
934 		} else {
935 			wait_status = wait_for_completion_interruptible_timeout(
936 				&tspi->rx_dma_complete, SPI_DMA_TIMEOUT);
937 			if (wait_status <= 0) {
938 				dmaengine_terminate_all(tspi->rx_dma_chan);
939 				dev_err(tspi->dev, "RxDma Xfer failed\n");
940 				err += 2;
941 			}
942 		}
943 	}
944 
945 	spin_lock_irqsave(&tspi->lock, flags);
946 	if (err) {
947 		dev_err(tspi->dev, "DmaXfer: ERROR bit set 0x%x\n",
948 			tspi->status_reg);
949 		dev_err(tspi->dev, "DmaXfer 0x%08x:0x%08x\n",
950 			tspi->command1_reg, tspi->dma_control_reg);
951 		tegra_periph_reset_assert(tspi->clk);
952 		udelay(2);
953 		tegra_periph_reset_deassert(tspi->clk);
954 		complete(&tspi->xfer_completion);
955 		spin_unlock_irqrestore(&tspi->lock, flags);
956 		return IRQ_HANDLED;
957 	}
958 
959 	if (tspi->cur_direction & DATA_DIR_RX)
960 		tegra_spi_copy_spi_rxbuf_to_client_rxbuf(tspi, t);
961 
962 	if (tspi->cur_direction & DATA_DIR_TX)
963 		tspi->cur_pos = tspi->cur_tx_pos;
964 	else
965 		tspi->cur_pos = tspi->cur_rx_pos;
966 
967 	if (tspi->cur_pos == t->len) {
968 		complete(&tspi->xfer_completion);
969 		goto exit;
970 	}
971 
972 	/* Continue transfer in current message */
973 	total_fifo_words = tegra_spi_calculate_curr_xfer_param(tspi->cur_spi,
974 							tspi, t);
975 	if (total_fifo_words > SPI_FIFO_DEPTH)
976 		err = tegra_spi_start_dma_based_transfer(tspi, t);
977 	else
978 		err = tegra_spi_start_cpu_based_transfer(tspi, t);
979 
980 exit:
981 	spin_unlock_irqrestore(&tspi->lock, flags);
982 	return IRQ_HANDLED;
983 }
984 
985 static irqreturn_t tegra_spi_isr_thread(int irq, void *context_data)
986 {
987 	struct tegra_spi_data *tspi = context_data;
988 
989 	if (!tspi->is_curr_dma_xfer)
990 		return handle_cpu_based_xfer(tspi);
991 	return handle_dma_based_xfer(tspi);
992 }
993 
994 static irqreturn_t tegra_spi_isr(int irq, void *context_data)
995 {
996 	struct tegra_spi_data *tspi = context_data;
997 
998 	tspi->status_reg = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
999 	if (tspi->cur_direction & DATA_DIR_TX)
1000 		tspi->tx_status = tspi->status_reg &
1001 					(SPI_TX_FIFO_UNF | SPI_TX_FIFO_OVF);
1002 
1003 	if (tspi->cur_direction & DATA_DIR_RX)
1004 		tspi->rx_status = tspi->status_reg &
1005 					(SPI_RX_FIFO_OVF | SPI_RX_FIFO_UNF);
1006 	tegra_spi_clear_status(tspi);
1007 
1008 	return IRQ_WAKE_THREAD;
1009 }
1010 
1011 static void tegra_spi_parse_dt(struct platform_device *pdev,
1012 	struct tegra_spi_data *tspi)
1013 {
1014 	struct device_node *np = pdev->dev.of_node;
1015 	u32 of_dma[2];
1016 
1017 	if (of_property_read_u32_array(np, "nvidia,dma-request-selector",
1018 				of_dma, 2) >= 0)
1019 		tspi->dma_req_sel = of_dma[1];
1020 
1021 	if (of_property_read_u32(np, "spi-max-frequency",
1022 				&tspi->spi_max_frequency))
1023 		tspi->spi_max_frequency = 25000000; /* 25MHz */
1024 }
1025 
1026 static struct of_device_id tegra_spi_of_match[] = {
1027 	{ .compatible = "nvidia,tegra114-spi", },
1028 	{}
1029 };
1030 MODULE_DEVICE_TABLE(of, tegra_spi_of_match);
1031 
1032 static int tegra_spi_probe(struct platform_device *pdev)
1033 {
1034 	struct spi_master	*master;
1035 	struct tegra_spi_data	*tspi;
1036 	struct resource		*r;
1037 	int ret, spi_irq;
1038 
1039 	master = spi_alloc_master(&pdev->dev, sizeof(*tspi));
1040 	if (!master) {
1041 		dev_err(&pdev->dev, "master allocation failed\n");
1042 		return -ENOMEM;
1043 	}
1044 	platform_set_drvdata(pdev, master);
1045 	tspi = spi_master_get_devdata(master);
1046 
1047 	/* Parse DT */
1048 	tegra_spi_parse_dt(pdev, tspi);
1049 
1050 	/* the spi->mode bits understood by this driver: */
1051 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1052 	master->setup = tegra_spi_setup;
1053 	master->transfer_one_message = tegra_spi_transfer_one_message;
1054 	master->num_chipselect = MAX_CHIP_SELECT;
1055 	master->bus_num = -1;
1056 
1057 	tspi->master = master;
1058 	tspi->dev = &pdev->dev;
1059 	spin_lock_init(&tspi->lock);
1060 
1061 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1062 	if (!r) {
1063 		dev_err(&pdev->dev, "No IO memory resource\n");
1064 		ret = -ENODEV;
1065 		goto exit_free_master;
1066 	}
1067 	tspi->phys = r->start;
1068 	tspi->base = devm_ioremap_resource(&pdev->dev, r);
1069 	if (IS_ERR(tspi->base)) {
1070 		ret = PTR_ERR(tspi->base);
1071 		dev_err(&pdev->dev, "ioremap failed: err = %d\n", ret);
1072 		goto exit_free_master;
1073 	}
1074 
1075 	spi_irq = platform_get_irq(pdev, 0);
1076 	tspi->irq = spi_irq;
1077 	ret = request_threaded_irq(tspi->irq, tegra_spi_isr,
1078 			tegra_spi_isr_thread, IRQF_ONESHOT,
1079 			dev_name(&pdev->dev), tspi);
1080 	if (ret < 0) {
1081 		dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
1082 					tspi->irq);
1083 		goto exit_free_master;
1084 	}
1085 
1086 	tspi->clk = devm_clk_get(&pdev->dev, "spi");
1087 	if (IS_ERR(tspi->clk)) {
1088 		dev_err(&pdev->dev, "can not get clock\n");
1089 		ret = PTR_ERR(tspi->clk);
1090 		goto exit_free_irq;
1091 	}
1092 
1093 	tspi->max_buf_size = SPI_FIFO_DEPTH << 2;
1094 	tspi->dma_buf_size = DEFAULT_SPI_DMA_BUF_LEN;
1095 
1096 	if (tspi->dma_req_sel) {
1097 		ret = tegra_spi_init_dma_param(tspi, true);
1098 		if (ret < 0) {
1099 			dev_err(&pdev->dev, "RxDma Init failed, err %d\n", ret);
1100 			goto exit_free_irq;
1101 		}
1102 
1103 		ret = tegra_spi_init_dma_param(tspi, false);
1104 		if (ret < 0) {
1105 			dev_err(&pdev->dev, "TxDma Init failed, err %d\n", ret);
1106 			goto exit_rx_dma_free;
1107 		}
1108 		tspi->max_buf_size = tspi->dma_buf_size;
1109 		init_completion(&tspi->tx_dma_complete);
1110 		init_completion(&tspi->rx_dma_complete);
1111 	}
1112 
1113 	init_completion(&tspi->xfer_completion);
1114 
1115 	pm_runtime_enable(&pdev->dev);
1116 	if (!pm_runtime_enabled(&pdev->dev)) {
1117 		ret = tegra_spi_runtime_resume(&pdev->dev);
1118 		if (ret)
1119 			goto exit_pm_disable;
1120 	}
1121 
1122 	ret = pm_runtime_get_sync(&pdev->dev);
1123 	if (ret < 0) {
1124 		dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret);
1125 		goto exit_pm_disable;
1126 	}
1127 	tspi->def_command1_reg  = SPI_M_S;
1128 	tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
1129 	pm_runtime_put(&pdev->dev);
1130 
1131 	master->dev.of_node = pdev->dev.of_node;
1132 	ret = spi_register_master(master);
1133 	if (ret < 0) {
1134 		dev_err(&pdev->dev, "can not register to master err %d\n", ret);
1135 		goto exit_pm_disable;
1136 	}
1137 	return ret;
1138 
1139 exit_pm_disable:
1140 	pm_runtime_disable(&pdev->dev);
1141 	if (!pm_runtime_status_suspended(&pdev->dev))
1142 		tegra_spi_runtime_suspend(&pdev->dev);
1143 	tegra_spi_deinit_dma_param(tspi, false);
1144 exit_rx_dma_free:
1145 	tegra_spi_deinit_dma_param(tspi, true);
1146 exit_free_irq:
1147 	free_irq(spi_irq, tspi);
1148 exit_free_master:
1149 	spi_master_put(master);
1150 	return ret;
1151 }
1152 
1153 static int tegra_spi_remove(struct platform_device *pdev)
1154 {
1155 	struct spi_master *master = platform_get_drvdata(pdev);
1156 	struct tegra_spi_data	*tspi = spi_master_get_devdata(master);
1157 
1158 	free_irq(tspi->irq, tspi);
1159 	spi_unregister_master(master);
1160 
1161 	if (tspi->tx_dma_chan)
1162 		tegra_spi_deinit_dma_param(tspi, false);
1163 
1164 	if (tspi->rx_dma_chan)
1165 		tegra_spi_deinit_dma_param(tspi, true);
1166 
1167 	pm_runtime_disable(&pdev->dev);
1168 	if (!pm_runtime_status_suspended(&pdev->dev))
1169 		tegra_spi_runtime_suspend(&pdev->dev);
1170 
1171 	return 0;
1172 }
1173 
1174 #ifdef CONFIG_PM_SLEEP
1175 static int tegra_spi_suspend(struct device *dev)
1176 {
1177 	struct spi_master *master = dev_get_drvdata(dev);
1178 
1179 	return spi_master_suspend(master);
1180 }
1181 
1182 static int tegra_spi_resume(struct device *dev)
1183 {
1184 	struct spi_master *master = dev_get_drvdata(dev);
1185 	struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1186 	int ret;
1187 
1188 	ret = pm_runtime_get_sync(dev);
1189 	if (ret < 0) {
1190 		dev_err(dev, "pm runtime failed, e = %d\n", ret);
1191 		return ret;
1192 	}
1193 	tegra_spi_writel(tspi, tspi->command1_reg, SPI_COMMAND1);
1194 	pm_runtime_put(dev);
1195 
1196 	return spi_master_resume(master);
1197 }
1198 #endif
1199 
1200 static int tegra_spi_runtime_suspend(struct device *dev)
1201 {
1202 	struct spi_master *master = dev_get_drvdata(dev);
1203 	struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1204 
1205 	/* Flush all write which are in PPSB queue by reading back */
1206 	tegra_spi_readl(tspi, SPI_COMMAND1);
1207 
1208 	clk_disable_unprepare(tspi->clk);
1209 	return 0;
1210 }
1211 
1212 static int tegra_spi_runtime_resume(struct device *dev)
1213 {
1214 	struct spi_master *master = dev_get_drvdata(dev);
1215 	struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1216 	int ret;
1217 
1218 	ret = clk_prepare_enable(tspi->clk);
1219 	if (ret < 0) {
1220 		dev_err(tspi->dev, "clk_prepare failed: %d\n", ret);
1221 		return ret;
1222 	}
1223 	return 0;
1224 }
1225 
1226 static const struct dev_pm_ops tegra_spi_pm_ops = {
1227 	SET_RUNTIME_PM_OPS(tegra_spi_runtime_suspend,
1228 		tegra_spi_runtime_resume, NULL)
1229 	SET_SYSTEM_SLEEP_PM_OPS(tegra_spi_suspend, tegra_spi_resume)
1230 };
1231 static struct platform_driver tegra_spi_driver = {
1232 	.driver = {
1233 		.name		= "spi-tegra114",
1234 		.owner		= THIS_MODULE,
1235 		.pm		= &tegra_spi_pm_ops,
1236 		.of_match_table	= tegra_spi_of_match,
1237 	},
1238 	.probe =	tegra_spi_probe,
1239 	.remove =	tegra_spi_remove,
1240 };
1241 module_platform_driver(tegra_spi_driver);
1242 
1243 MODULE_ALIAS("platform:spi-tegra114");
1244 MODULE_DESCRIPTION("NVIDIA Tegra114 SPI Controller Driver");
1245 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1246 MODULE_LICENSE("GPL v2");
1247