xref: /openbmc/linux/drivers/spi/spi-tegra114.c (revision 715f23b6)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * SPI driver for NVIDIA's Tegra114 SPI Controller.
4  *
5  * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
6  */
7 
8 #include <linux/clk.h>
9 #include <linux/completion.h>
10 #include <linux/delay.h>
11 #include <linux/dmaengine.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/dmapool.h>
14 #include <linux/err.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/kernel.h>
18 #include <linux/kthread.h>
19 #include <linux/module.h>
20 #include <linux/platform_device.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/of.h>
23 #include <linux/of_device.h>
24 #include <linux/reset.h>
25 #include <linux/spi/spi.h>
26 
27 #define SPI_COMMAND1				0x000
28 #define SPI_BIT_LENGTH(x)			(((x) & 0x1f) << 0)
29 #define SPI_PACKED				(1 << 5)
30 #define SPI_TX_EN				(1 << 11)
31 #define SPI_RX_EN				(1 << 12)
32 #define SPI_BOTH_EN_BYTE			(1 << 13)
33 #define SPI_BOTH_EN_BIT				(1 << 14)
34 #define SPI_LSBYTE_FE				(1 << 15)
35 #define SPI_LSBIT_FE				(1 << 16)
36 #define SPI_BIDIROE				(1 << 17)
37 #define SPI_IDLE_SDA_DRIVE_LOW			(0 << 18)
38 #define SPI_IDLE_SDA_DRIVE_HIGH			(1 << 18)
39 #define SPI_IDLE_SDA_PULL_LOW			(2 << 18)
40 #define SPI_IDLE_SDA_PULL_HIGH			(3 << 18)
41 #define SPI_IDLE_SDA_MASK			(3 << 18)
42 #define SPI_CS_SW_VAL				(1 << 20)
43 #define SPI_CS_SW_HW				(1 << 21)
44 /* SPI_CS_POL_INACTIVE bits are default high */
45 						/* n from 0 to 3 */
46 #define SPI_CS_POL_INACTIVE(n)			(1 << (22 + (n)))
47 #define SPI_CS_POL_INACTIVE_MASK		(0xF << 22)
48 
49 #define SPI_CS_SEL_0				(0 << 26)
50 #define SPI_CS_SEL_1				(1 << 26)
51 #define SPI_CS_SEL_2				(2 << 26)
52 #define SPI_CS_SEL_3				(3 << 26)
53 #define SPI_CS_SEL_MASK				(3 << 26)
54 #define SPI_CS_SEL(x)				(((x) & 0x3) << 26)
55 #define SPI_CONTROL_MODE_0			(0 << 28)
56 #define SPI_CONTROL_MODE_1			(1 << 28)
57 #define SPI_CONTROL_MODE_2			(2 << 28)
58 #define SPI_CONTROL_MODE_3			(3 << 28)
59 #define SPI_CONTROL_MODE_MASK			(3 << 28)
60 #define SPI_MODE_SEL(x)				(((x) & 0x3) << 28)
61 #define SPI_M_S					(1 << 30)
62 #define SPI_PIO					(1 << 31)
63 
64 #define SPI_COMMAND2				0x004
65 #define SPI_TX_TAP_DELAY(x)			(((x) & 0x3F) << 6)
66 #define SPI_RX_TAP_DELAY(x)			(((x) & 0x3F) << 0)
67 
68 #define SPI_CS_TIMING1				0x008
69 #define SPI_SETUP_HOLD(setup, hold)		(((setup) << 4) | (hold))
70 #define SPI_CS_SETUP_HOLD(reg, cs, val)			\
71 		((((val) & 0xFFu) << ((cs) * 8)) |	\
72 		((reg) & ~(0xFFu << ((cs) * 8))))
73 
74 #define SPI_CS_TIMING2				0x00C
75 #define CYCLES_BETWEEN_PACKETS_0(x)		(((x) & 0x1F) << 0)
76 #define CS_ACTIVE_BETWEEN_PACKETS_0		(1 << 5)
77 #define CYCLES_BETWEEN_PACKETS_1(x)		(((x) & 0x1F) << 8)
78 #define CS_ACTIVE_BETWEEN_PACKETS_1		(1 << 13)
79 #define CYCLES_BETWEEN_PACKETS_2(x)		(((x) & 0x1F) << 16)
80 #define CS_ACTIVE_BETWEEN_PACKETS_2		(1 << 21)
81 #define CYCLES_BETWEEN_PACKETS_3(x)		(((x) & 0x1F) << 24)
82 #define CS_ACTIVE_BETWEEN_PACKETS_3		(1 << 29)
83 #define SPI_SET_CS_ACTIVE_BETWEEN_PACKETS(reg, cs, val)		\
84 		(reg = (((val) & 0x1) << ((cs) * 8 + 5)) |	\
85 			((reg) & ~(1 << ((cs) * 8 + 5))))
86 #define SPI_SET_CYCLES_BETWEEN_PACKETS(reg, cs, val)		\
87 		(reg = (((val) & 0x1F) << ((cs) * 8)) |		\
88 			((reg) & ~(0x1F << ((cs) * 8))))
89 #define MAX_SETUP_HOLD_CYCLES			16
90 #define MAX_INACTIVE_CYCLES			32
91 
92 #define SPI_TRANS_STATUS			0x010
93 #define SPI_BLK_CNT(val)			(((val) >> 0) & 0xFFFF)
94 #define SPI_SLV_IDLE_COUNT(val)			(((val) >> 16) & 0xFF)
95 #define SPI_RDY					(1 << 30)
96 
97 #define SPI_FIFO_STATUS				0x014
98 #define SPI_RX_FIFO_EMPTY			(1 << 0)
99 #define SPI_RX_FIFO_FULL			(1 << 1)
100 #define SPI_TX_FIFO_EMPTY			(1 << 2)
101 #define SPI_TX_FIFO_FULL			(1 << 3)
102 #define SPI_RX_FIFO_UNF				(1 << 4)
103 #define SPI_RX_FIFO_OVF				(1 << 5)
104 #define SPI_TX_FIFO_UNF				(1 << 6)
105 #define SPI_TX_FIFO_OVF				(1 << 7)
106 #define SPI_ERR					(1 << 8)
107 #define SPI_TX_FIFO_FLUSH			(1 << 14)
108 #define SPI_RX_FIFO_FLUSH			(1 << 15)
109 #define SPI_TX_FIFO_EMPTY_COUNT(val)		(((val) >> 16) & 0x7F)
110 #define SPI_RX_FIFO_FULL_COUNT(val)		(((val) >> 23) & 0x7F)
111 #define SPI_FRAME_END				(1 << 30)
112 #define SPI_CS_INACTIVE				(1 << 31)
113 
114 #define SPI_FIFO_ERROR				(SPI_RX_FIFO_UNF | \
115 			SPI_RX_FIFO_OVF | SPI_TX_FIFO_UNF | SPI_TX_FIFO_OVF)
116 #define SPI_FIFO_EMPTY			(SPI_RX_FIFO_EMPTY | SPI_TX_FIFO_EMPTY)
117 
118 #define SPI_TX_DATA				0x018
119 #define SPI_RX_DATA				0x01C
120 
121 #define SPI_DMA_CTL				0x020
122 #define SPI_TX_TRIG_1				(0 << 15)
123 #define SPI_TX_TRIG_4				(1 << 15)
124 #define SPI_TX_TRIG_8				(2 << 15)
125 #define SPI_TX_TRIG_16				(3 << 15)
126 #define SPI_TX_TRIG_MASK			(3 << 15)
127 #define SPI_RX_TRIG_1				(0 << 19)
128 #define SPI_RX_TRIG_4				(1 << 19)
129 #define SPI_RX_TRIG_8				(2 << 19)
130 #define SPI_RX_TRIG_16				(3 << 19)
131 #define SPI_RX_TRIG_MASK			(3 << 19)
132 #define SPI_IE_TX				(1 << 28)
133 #define SPI_IE_RX				(1 << 29)
134 #define SPI_CONT				(1 << 30)
135 #define SPI_DMA					(1 << 31)
136 #define SPI_DMA_EN				SPI_DMA
137 
138 #define SPI_DMA_BLK				0x024
139 #define SPI_DMA_BLK_SET(x)			(((x) & 0xFFFF) << 0)
140 
141 #define SPI_TX_FIFO				0x108
142 #define SPI_RX_FIFO				0x188
143 #define SPI_INTR_MASK				0x18c
144 #define SPI_INTR_ALL_MASK			(0x1fUL << 25)
145 #define MAX_CHIP_SELECT				4
146 #define SPI_FIFO_DEPTH				64
147 #define DATA_DIR_TX				(1 << 0)
148 #define DATA_DIR_RX				(1 << 1)
149 
150 #define SPI_DMA_TIMEOUT				(msecs_to_jiffies(1000))
151 #define DEFAULT_SPI_DMA_BUF_LEN			(16*1024)
152 #define TX_FIFO_EMPTY_COUNT_MAX			SPI_TX_FIFO_EMPTY_COUNT(0x40)
153 #define RX_FIFO_FULL_COUNT_ZERO			SPI_RX_FIFO_FULL_COUNT(0)
154 #define MAX_HOLD_CYCLES				16
155 #define SPI_DEFAULT_SPEED			25000000
156 
157 struct tegra_spi_soc_data {
158 	bool has_intr_mask_reg;
159 };
160 
161 struct tegra_spi_client_data {
162 	int tx_clk_tap_delay;
163 	int rx_clk_tap_delay;
164 };
165 
166 struct tegra_spi_data {
167 	struct device				*dev;
168 	struct spi_master			*master;
169 	spinlock_t				lock;
170 
171 	struct clk				*clk;
172 	struct reset_control			*rst;
173 	void __iomem				*base;
174 	phys_addr_t				phys;
175 	unsigned				irq;
176 	u32					cur_speed;
177 
178 	struct spi_device			*cur_spi;
179 	struct spi_device			*cs_control;
180 	unsigned				cur_pos;
181 	unsigned				words_per_32bit;
182 	unsigned				bytes_per_word;
183 	unsigned				curr_dma_words;
184 	unsigned				cur_direction;
185 
186 	unsigned				cur_rx_pos;
187 	unsigned				cur_tx_pos;
188 
189 	unsigned				dma_buf_size;
190 	unsigned				max_buf_size;
191 	bool					is_curr_dma_xfer;
192 	bool					use_hw_based_cs;
193 
194 	struct completion			rx_dma_complete;
195 	struct completion			tx_dma_complete;
196 
197 	u32					tx_status;
198 	u32					rx_status;
199 	u32					status_reg;
200 	bool					is_packed;
201 
202 	u32					command1_reg;
203 	u32					dma_control_reg;
204 	u32					def_command1_reg;
205 	u32					def_command2_reg;
206 	u32					spi_cs_timing1;
207 	u32					spi_cs_timing2;
208 	u8					last_used_cs;
209 
210 	struct completion			xfer_completion;
211 	struct spi_transfer			*curr_xfer;
212 	struct dma_chan				*rx_dma_chan;
213 	u32					*rx_dma_buf;
214 	dma_addr_t				rx_dma_phys;
215 	struct dma_async_tx_descriptor		*rx_dma_desc;
216 
217 	struct dma_chan				*tx_dma_chan;
218 	u32					*tx_dma_buf;
219 	dma_addr_t				tx_dma_phys;
220 	struct dma_async_tx_descriptor		*tx_dma_desc;
221 	const struct tegra_spi_soc_data		*soc_data;
222 };
223 
224 static int tegra_spi_runtime_suspend(struct device *dev);
225 static int tegra_spi_runtime_resume(struct device *dev);
226 
227 static inline u32 tegra_spi_readl(struct tegra_spi_data *tspi,
228 		unsigned long reg)
229 {
230 	return readl(tspi->base + reg);
231 }
232 
233 static inline void tegra_spi_writel(struct tegra_spi_data *tspi,
234 		u32 val, unsigned long reg)
235 {
236 	writel(val, tspi->base + reg);
237 
238 	/* Read back register to make sure that register writes completed */
239 	if (reg != SPI_TX_FIFO)
240 		readl(tspi->base + SPI_COMMAND1);
241 }
242 
243 static void tegra_spi_clear_status(struct tegra_spi_data *tspi)
244 {
245 	u32 val;
246 
247 	/* Write 1 to clear status register */
248 	val = tegra_spi_readl(tspi, SPI_TRANS_STATUS);
249 	tegra_spi_writel(tspi, val, SPI_TRANS_STATUS);
250 
251 	/* Clear fifo status error if any */
252 	val = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
253 	if (val & SPI_ERR)
254 		tegra_spi_writel(tspi, SPI_ERR | SPI_FIFO_ERROR,
255 				SPI_FIFO_STATUS);
256 }
257 
258 static unsigned tegra_spi_calculate_curr_xfer_param(
259 	struct spi_device *spi, struct tegra_spi_data *tspi,
260 	struct spi_transfer *t)
261 {
262 	unsigned remain_len = t->len - tspi->cur_pos;
263 	unsigned max_word;
264 	unsigned bits_per_word = t->bits_per_word;
265 	unsigned max_len;
266 	unsigned total_fifo_words;
267 
268 	tspi->bytes_per_word = DIV_ROUND_UP(bits_per_word, 8);
269 
270 	if ((bits_per_word == 8 || bits_per_word == 16 ||
271 	     bits_per_word == 32) && t->len > 3) {
272 		tspi->is_packed = 1;
273 		tspi->words_per_32bit = 32/bits_per_word;
274 	} else {
275 		tspi->is_packed = 0;
276 		tspi->words_per_32bit = 1;
277 	}
278 
279 	if (tspi->is_packed) {
280 		max_len = min(remain_len, tspi->max_buf_size);
281 		tspi->curr_dma_words = max_len/tspi->bytes_per_word;
282 		total_fifo_words = (max_len + 3) / 4;
283 	} else {
284 		max_word = (remain_len - 1) / tspi->bytes_per_word + 1;
285 		max_word = min(max_word, tspi->max_buf_size/4);
286 		tspi->curr_dma_words = max_word;
287 		total_fifo_words = max_word;
288 	}
289 	return total_fifo_words;
290 }
291 
292 static unsigned tegra_spi_fill_tx_fifo_from_client_txbuf(
293 	struct tegra_spi_data *tspi, struct spi_transfer *t)
294 {
295 	unsigned nbytes;
296 	unsigned tx_empty_count;
297 	u32 fifo_status;
298 	unsigned max_n_32bit;
299 	unsigned i, count;
300 	unsigned int written_words;
301 	unsigned fifo_words_left;
302 	u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
303 
304 	fifo_status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
305 	tx_empty_count = SPI_TX_FIFO_EMPTY_COUNT(fifo_status);
306 
307 	if (tspi->is_packed) {
308 		fifo_words_left = tx_empty_count * tspi->words_per_32bit;
309 		written_words = min(fifo_words_left, tspi->curr_dma_words);
310 		nbytes = written_words * tspi->bytes_per_word;
311 		max_n_32bit = DIV_ROUND_UP(nbytes, 4);
312 		for (count = 0; count < max_n_32bit; count++) {
313 			u32 x = 0;
314 
315 			for (i = 0; (i < 4) && nbytes; i++, nbytes--)
316 				x |= (u32)(*tx_buf++) << (i * 8);
317 			tegra_spi_writel(tspi, x, SPI_TX_FIFO);
318 		}
319 
320 		tspi->cur_tx_pos += written_words * tspi->bytes_per_word;
321 	} else {
322 		unsigned int write_bytes;
323 		max_n_32bit = min(tspi->curr_dma_words,  tx_empty_count);
324 		written_words = max_n_32bit;
325 		nbytes = written_words * tspi->bytes_per_word;
326 		if (nbytes > t->len - tspi->cur_pos)
327 			nbytes = t->len - tspi->cur_pos;
328 		write_bytes = nbytes;
329 		for (count = 0; count < max_n_32bit; count++) {
330 			u32 x = 0;
331 
332 			for (i = 0; nbytes && (i < tspi->bytes_per_word);
333 							i++, nbytes--)
334 				x |= (u32)(*tx_buf++) << (i * 8);
335 			tegra_spi_writel(tspi, x, SPI_TX_FIFO);
336 		}
337 
338 		tspi->cur_tx_pos += write_bytes;
339 	}
340 
341 	return written_words;
342 }
343 
344 static unsigned int tegra_spi_read_rx_fifo_to_client_rxbuf(
345 		struct tegra_spi_data *tspi, struct spi_transfer *t)
346 {
347 	unsigned rx_full_count;
348 	u32 fifo_status;
349 	unsigned i, count;
350 	unsigned int read_words = 0;
351 	unsigned len;
352 	u8 *rx_buf = (u8 *)t->rx_buf + tspi->cur_rx_pos;
353 
354 	fifo_status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
355 	rx_full_count = SPI_RX_FIFO_FULL_COUNT(fifo_status);
356 	if (tspi->is_packed) {
357 		len = tspi->curr_dma_words * tspi->bytes_per_word;
358 		for (count = 0; count < rx_full_count; count++) {
359 			u32 x = tegra_spi_readl(tspi, SPI_RX_FIFO);
360 
361 			for (i = 0; len && (i < 4); i++, len--)
362 				*rx_buf++ = (x >> i*8) & 0xFF;
363 		}
364 		read_words += tspi->curr_dma_words;
365 		tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
366 	} else {
367 		u32 rx_mask = ((u32)1 << t->bits_per_word) - 1;
368 		u8 bytes_per_word = tspi->bytes_per_word;
369 		unsigned int read_bytes;
370 
371 		len = rx_full_count * bytes_per_word;
372 		if (len > t->len - tspi->cur_pos)
373 			len = t->len - tspi->cur_pos;
374 		read_bytes = len;
375 		for (count = 0; count < rx_full_count; count++) {
376 			u32 x = tegra_spi_readl(tspi, SPI_RX_FIFO) & rx_mask;
377 
378 			for (i = 0; len && (i < bytes_per_word); i++, len--)
379 				*rx_buf++ = (x >> (i*8)) & 0xFF;
380 		}
381 		read_words += rx_full_count;
382 		tspi->cur_rx_pos += read_bytes;
383 	}
384 
385 	return read_words;
386 }
387 
388 static void tegra_spi_copy_client_txbuf_to_spi_txbuf(
389 		struct tegra_spi_data *tspi, struct spi_transfer *t)
390 {
391 	/* Make the dma buffer to read by cpu */
392 	dma_sync_single_for_cpu(tspi->dev, tspi->tx_dma_phys,
393 				tspi->dma_buf_size, DMA_TO_DEVICE);
394 
395 	if (tspi->is_packed) {
396 		unsigned len = tspi->curr_dma_words * tspi->bytes_per_word;
397 
398 		memcpy(tspi->tx_dma_buf, t->tx_buf + tspi->cur_pos, len);
399 		tspi->cur_tx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
400 	} else {
401 		unsigned int i;
402 		unsigned int count;
403 		u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
404 		unsigned consume = tspi->curr_dma_words * tspi->bytes_per_word;
405 		unsigned int write_bytes;
406 
407 		if (consume > t->len - tspi->cur_pos)
408 			consume = t->len - tspi->cur_pos;
409 		write_bytes = consume;
410 		for (count = 0; count < tspi->curr_dma_words; count++) {
411 			u32 x = 0;
412 
413 			for (i = 0; consume && (i < tspi->bytes_per_word);
414 							i++, consume--)
415 				x |= (u32)(*tx_buf++) << (i * 8);
416 			tspi->tx_dma_buf[count] = x;
417 		}
418 
419 		tspi->cur_tx_pos += write_bytes;
420 	}
421 
422 	/* Make the dma buffer to read by dma */
423 	dma_sync_single_for_device(tspi->dev, tspi->tx_dma_phys,
424 				tspi->dma_buf_size, DMA_TO_DEVICE);
425 }
426 
427 static void tegra_spi_copy_spi_rxbuf_to_client_rxbuf(
428 		struct tegra_spi_data *tspi, struct spi_transfer *t)
429 {
430 	/* Make the dma buffer to read by cpu */
431 	dma_sync_single_for_cpu(tspi->dev, tspi->rx_dma_phys,
432 		tspi->dma_buf_size, DMA_FROM_DEVICE);
433 
434 	if (tspi->is_packed) {
435 		unsigned len = tspi->curr_dma_words * tspi->bytes_per_word;
436 
437 		memcpy(t->rx_buf + tspi->cur_rx_pos, tspi->rx_dma_buf, len);
438 		tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
439 	} else {
440 		unsigned int i;
441 		unsigned int count;
442 		unsigned char *rx_buf = t->rx_buf + tspi->cur_rx_pos;
443 		u32 rx_mask = ((u32)1 << t->bits_per_word) - 1;
444 		unsigned consume = tspi->curr_dma_words * tspi->bytes_per_word;
445 		unsigned int read_bytes;
446 
447 		if (consume > t->len - tspi->cur_pos)
448 			consume = t->len - tspi->cur_pos;
449 		read_bytes = consume;
450 		for (count = 0; count < tspi->curr_dma_words; count++) {
451 			u32 x = tspi->rx_dma_buf[count] & rx_mask;
452 
453 			for (i = 0; consume && (i < tspi->bytes_per_word);
454 							i++, consume--)
455 				*rx_buf++ = (x >> (i*8)) & 0xFF;
456 		}
457 
458 		tspi->cur_rx_pos += read_bytes;
459 	}
460 
461 	/* Make the dma buffer to read by dma */
462 	dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
463 		tspi->dma_buf_size, DMA_FROM_DEVICE);
464 }
465 
466 static void tegra_spi_dma_complete(void *args)
467 {
468 	struct completion *dma_complete = args;
469 
470 	complete(dma_complete);
471 }
472 
473 static int tegra_spi_start_tx_dma(struct tegra_spi_data *tspi, int len)
474 {
475 	reinit_completion(&tspi->tx_dma_complete);
476 	tspi->tx_dma_desc = dmaengine_prep_slave_single(tspi->tx_dma_chan,
477 				tspi->tx_dma_phys, len, DMA_MEM_TO_DEV,
478 				DMA_PREP_INTERRUPT |  DMA_CTRL_ACK);
479 	if (!tspi->tx_dma_desc) {
480 		dev_err(tspi->dev, "Not able to get desc for Tx\n");
481 		return -EIO;
482 	}
483 
484 	tspi->tx_dma_desc->callback = tegra_spi_dma_complete;
485 	tspi->tx_dma_desc->callback_param = &tspi->tx_dma_complete;
486 
487 	dmaengine_submit(tspi->tx_dma_desc);
488 	dma_async_issue_pending(tspi->tx_dma_chan);
489 	return 0;
490 }
491 
492 static int tegra_spi_start_rx_dma(struct tegra_spi_data *tspi, int len)
493 {
494 	reinit_completion(&tspi->rx_dma_complete);
495 	tspi->rx_dma_desc = dmaengine_prep_slave_single(tspi->rx_dma_chan,
496 				tspi->rx_dma_phys, len, DMA_DEV_TO_MEM,
497 				DMA_PREP_INTERRUPT |  DMA_CTRL_ACK);
498 	if (!tspi->rx_dma_desc) {
499 		dev_err(tspi->dev, "Not able to get desc for Rx\n");
500 		return -EIO;
501 	}
502 
503 	tspi->rx_dma_desc->callback = tegra_spi_dma_complete;
504 	tspi->rx_dma_desc->callback_param = &tspi->rx_dma_complete;
505 
506 	dmaengine_submit(tspi->rx_dma_desc);
507 	dma_async_issue_pending(tspi->rx_dma_chan);
508 	return 0;
509 }
510 
511 static int tegra_spi_flush_fifos(struct tegra_spi_data *tspi)
512 {
513 	unsigned long timeout = jiffies + HZ;
514 	u32 status;
515 
516 	status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
517 	if ((status & SPI_FIFO_EMPTY) != SPI_FIFO_EMPTY) {
518 		status |= SPI_RX_FIFO_FLUSH | SPI_TX_FIFO_FLUSH;
519 		tegra_spi_writel(tspi, status, SPI_FIFO_STATUS);
520 		while ((status & SPI_FIFO_EMPTY) != SPI_FIFO_EMPTY) {
521 			status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
522 			if (time_after(jiffies, timeout)) {
523 				dev_err(tspi->dev,
524 					"timeout waiting for fifo flush\n");
525 				return -EIO;
526 			}
527 
528 			udelay(1);
529 		}
530 	}
531 
532 	return 0;
533 }
534 
535 static int tegra_spi_start_dma_based_transfer(
536 		struct tegra_spi_data *tspi, struct spi_transfer *t)
537 {
538 	u32 val;
539 	unsigned int len;
540 	int ret = 0;
541 	u8 dma_burst;
542 	struct dma_slave_config dma_sconfig = {0};
543 
544 	val = SPI_DMA_BLK_SET(tspi->curr_dma_words - 1);
545 	tegra_spi_writel(tspi, val, SPI_DMA_BLK);
546 
547 	if (tspi->is_packed)
548 		len = DIV_ROUND_UP(tspi->curr_dma_words * tspi->bytes_per_word,
549 					4) * 4;
550 	else
551 		len = tspi->curr_dma_words * 4;
552 
553 	/* Set attention level based on length of transfer */
554 	if (len & 0xF) {
555 		val |= SPI_TX_TRIG_1 | SPI_RX_TRIG_1;
556 		dma_burst = 1;
557 	} else if (((len) >> 4) & 0x1) {
558 		val |= SPI_TX_TRIG_4 | SPI_RX_TRIG_4;
559 		dma_burst = 4;
560 	} else {
561 		val |= SPI_TX_TRIG_8 | SPI_RX_TRIG_8;
562 		dma_burst = 8;
563 	}
564 
565 	if (!tspi->soc_data->has_intr_mask_reg) {
566 		if (tspi->cur_direction & DATA_DIR_TX)
567 			val |= SPI_IE_TX;
568 
569 		if (tspi->cur_direction & DATA_DIR_RX)
570 			val |= SPI_IE_RX;
571 	}
572 
573 	tegra_spi_writel(tspi, val, SPI_DMA_CTL);
574 	tspi->dma_control_reg = val;
575 
576 	dma_sconfig.device_fc = true;
577 	if (tspi->cur_direction & DATA_DIR_TX) {
578 		dma_sconfig.dst_addr = tspi->phys + SPI_TX_FIFO;
579 		dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
580 		dma_sconfig.dst_maxburst = dma_burst;
581 		ret = dmaengine_slave_config(tspi->tx_dma_chan, &dma_sconfig);
582 		if (ret < 0) {
583 			dev_err(tspi->dev,
584 				"DMA slave config failed: %d\n", ret);
585 			return ret;
586 		}
587 
588 		tegra_spi_copy_client_txbuf_to_spi_txbuf(tspi, t);
589 		ret = tegra_spi_start_tx_dma(tspi, len);
590 		if (ret < 0) {
591 			dev_err(tspi->dev,
592 				"Starting tx dma failed, err %d\n", ret);
593 			return ret;
594 		}
595 	}
596 
597 	if (tspi->cur_direction & DATA_DIR_RX) {
598 		dma_sconfig.src_addr = tspi->phys + SPI_RX_FIFO;
599 		dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
600 		dma_sconfig.src_maxburst = dma_burst;
601 		ret = dmaengine_slave_config(tspi->rx_dma_chan, &dma_sconfig);
602 		if (ret < 0) {
603 			dev_err(tspi->dev,
604 				"DMA slave config failed: %d\n", ret);
605 			return ret;
606 		}
607 
608 		/* Make the dma buffer to read by dma */
609 		dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
610 				tspi->dma_buf_size, DMA_FROM_DEVICE);
611 
612 		ret = tegra_spi_start_rx_dma(tspi, len);
613 		if (ret < 0) {
614 			dev_err(tspi->dev,
615 				"Starting rx dma failed, err %d\n", ret);
616 			if (tspi->cur_direction & DATA_DIR_TX)
617 				dmaengine_terminate_all(tspi->tx_dma_chan);
618 			return ret;
619 		}
620 	}
621 	tspi->is_curr_dma_xfer = true;
622 	tspi->dma_control_reg = val;
623 
624 	val |= SPI_DMA_EN;
625 	tegra_spi_writel(tspi, val, SPI_DMA_CTL);
626 	return ret;
627 }
628 
629 static int tegra_spi_start_cpu_based_transfer(
630 		struct tegra_spi_data *tspi, struct spi_transfer *t)
631 {
632 	u32 val;
633 	unsigned cur_words;
634 
635 	if (tspi->cur_direction & DATA_DIR_TX)
636 		cur_words = tegra_spi_fill_tx_fifo_from_client_txbuf(tspi, t);
637 	else
638 		cur_words = tspi->curr_dma_words;
639 
640 	val = SPI_DMA_BLK_SET(cur_words - 1);
641 	tegra_spi_writel(tspi, val, SPI_DMA_BLK);
642 
643 	val = 0;
644 	if (tspi->cur_direction & DATA_DIR_TX)
645 		val |= SPI_IE_TX;
646 
647 	if (tspi->cur_direction & DATA_DIR_RX)
648 		val |= SPI_IE_RX;
649 
650 	tegra_spi_writel(tspi, val, SPI_DMA_CTL);
651 	tspi->dma_control_reg = val;
652 
653 	tspi->is_curr_dma_xfer = false;
654 
655 	val = tspi->command1_reg;
656 	val |= SPI_PIO;
657 	tegra_spi_writel(tspi, val, SPI_COMMAND1);
658 	return 0;
659 }
660 
661 static int tegra_spi_init_dma_param(struct tegra_spi_data *tspi,
662 			bool dma_to_memory)
663 {
664 	struct dma_chan *dma_chan;
665 	u32 *dma_buf;
666 	dma_addr_t dma_phys;
667 	int ret;
668 
669 	dma_chan = dma_request_chan(tspi->dev, dma_to_memory ? "rx" : "tx");
670 	if (IS_ERR(dma_chan)) {
671 		ret = PTR_ERR(dma_chan);
672 		if (ret != -EPROBE_DEFER)
673 			dev_err(tspi->dev,
674 				"Dma channel is not available: %d\n", ret);
675 		return ret;
676 	}
677 
678 	dma_buf = dma_alloc_coherent(tspi->dev, tspi->dma_buf_size,
679 				&dma_phys, GFP_KERNEL);
680 	if (!dma_buf) {
681 		dev_err(tspi->dev, " Not able to allocate the dma buffer\n");
682 		dma_release_channel(dma_chan);
683 		return -ENOMEM;
684 	}
685 
686 	if (dma_to_memory) {
687 		tspi->rx_dma_chan = dma_chan;
688 		tspi->rx_dma_buf = dma_buf;
689 		tspi->rx_dma_phys = dma_phys;
690 	} else {
691 		tspi->tx_dma_chan = dma_chan;
692 		tspi->tx_dma_buf = dma_buf;
693 		tspi->tx_dma_phys = dma_phys;
694 	}
695 	return 0;
696 }
697 
698 static void tegra_spi_deinit_dma_param(struct tegra_spi_data *tspi,
699 	bool dma_to_memory)
700 {
701 	u32 *dma_buf;
702 	dma_addr_t dma_phys;
703 	struct dma_chan *dma_chan;
704 
705 	if (dma_to_memory) {
706 		dma_buf = tspi->rx_dma_buf;
707 		dma_chan = tspi->rx_dma_chan;
708 		dma_phys = tspi->rx_dma_phys;
709 		tspi->rx_dma_chan = NULL;
710 		tspi->rx_dma_buf = NULL;
711 	} else {
712 		dma_buf = tspi->tx_dma_buf;
713 		dma_chan = tspi->tx_dma_chan;
714 		dma_phys = tspi->tx_dma_phys;
715 		tspi->tx_dma_buf = NULL;
716 		tspi->tx_dma_chan = NULL;
717 	}
718 	if (!dma_chan)
719 		return;
720 
721 	dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
722 	dma_release_channel(dma_chan);
723 }
724 
725 static int tegra_spi_set_hw_cs_timing(struct spi_device *spi,
726 				      struct spi_delay *setup,
727 				      struct spi_delay *hold,
728 				      struct spi_delay *inactive)
729 {
730 	struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
731 	u8 setup_dly, hold_dly, inactive_dly;
732 	u32 setup_hold;
733 	u32 spi_cs_timing;
734 	u32 inactive_cycles;
735 	u8 cs_state;
736 
737 	if ((setup && setup->unit != SPI_DELAY_UNIT_SCK) ||
738 	    (hold && hold->unit != SPI_DELAY_UNIT_SCK) ||
739 	    (inactive && inactive->unit != SPI_DELAY_UNIT_SCK)) {
740 		dev_err(&spi->dev,
741 			"Invalid delay unit %d, should be SPI_DELAY_UNIT_SCK\n",
742 			SPI_DELAY_UNIT_SCK);
743 		return -EINVAL;
744 	}
745 
746 	setup_dly = setup ? setup->value : 0;
747 	hold_dly = hold ? hold->value : 0;
748 	inactive_dly = inactive ? inactive->value : 0;
749 
750 	setup_dly = min_t(u8, setup_dly, MAX_SETUP_HOLD_CYCLES);
751 	hold_dly = min_t(u8, hold_dly, MAX_SETUP_HOLD_CYCLES);
752 	if (setup_dly && hold_dly) {
753 		setup_hold = SPI_SETUP_HOLD(setup_dly - 1, hold_dly - 1);
754 		spi_cs_timing = SPI_CS_SETUP_HOLD(tspi->spi_cs_timing1,
755 						  spi->chip_select,
756 						  setup_hold);
757 		if (tspi->spi_cs_timing1 != spi_cs_timing) {
758 			tspi->spi_cs_timing1 = spi_cs_timing;
759 			tegra_spi_writel(tspi, spi_cs_timing, SPI_CS_TIMING1);
760 		}
761 	}
762 
763 	inactive_cycles = min_t(u8, inactive_dly, MAX_INACTIVE_CYCLES);
764 	if (inactive_cycles)
765 		inactive_cycles--;
766 	cs_state = inactive_cycles ? 0 : 1;
767 	spi_cs_timing = tspi->spi_cs_timing2;
768 	SPI_SET_CS_ACTIVE_BETWEEN_PACKETS(spi_cs_timing, spi->chip_select,
769 					  cs_state);
770 	SPI_SET_CYCLES_BETWEEN_PACKETS(spi_cs_timing, spi->chip_select,
771 				       inactive_cycles);
772 	if (tspi->spi_cs_timing2 != spi_cs_timing) {
773 		tspi->spi_cs_timing2 = spi_cs_timing;
774 		tegra_spi_writel(tspi, spi_cs_timing, SPI_CS_TIMING2);
775 	}
776 
777 	return 0;
778 }
779 
780 static u32 tegra_spi_setup_transfer_one(struct spi_device *spi,
781 					struct spi_transfer *t,
782 					bool is_first_of_msg,
783 					bool is_single_xfer)
784 {
785 	struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
786 	struct tegra_spi_client_data *cdata = spi->controller_data;
787 	u32 speed = t->speed_hz;
788 	u8 bits_per_word = t->bits_per_word;
789 	u32 command1, command2;
790 	int req_mode;
791 	u32 tx_tap = 0, rx_tap = 0;
792 
793 	if (speed != tspi->cur_speed) {
794 		clk_set_rate(tspi->clk, speed);
795 		tspi->cur_speed = speed;
796 	}
797 
798 	tspi->cur_spi = spi;
799 	tspi->cur_pos = 0;
800 	tspi->cur_rx_pos = 0;
801 	tspi->cur_tx_pos = 0;
802 	tspi->curr_xfer = t;
803 
804 	if (is_first_of_msg) {
805 		tegra_spi_clear_status(tspi);
806 
807 		command1 = tspi->def_command1_reg;
808 		command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
809 
810 		command1 &= ~SPI_CONTROL_MODE_MASK;
811 		req_mode = spi->mode & 0x3;
812 		if (req_mode == SPI_MODE_0)
813 			command1 |= SPI_CONTROL_MODE_0;
814 		else if (req_mode == SPI_MODE_1)
815 			command1 |= SPI_CONTROL_MODE_1;
816 		else if (req_mode == SPI_MODE_2)
817 			command1 |= SPI_CONTROL_MODE_2;
818 		else if (req_mode == SPI_MODE_3)
819 			command1 |= SPI_CONTROL_MODE_3;
820 
821 		if (spi->mode & SPI_LSB_FIRST)
822 			command1 |= SPI_LSBIT_FE;
823 		else
824 			command1 &= ~SPI_LSBIT_FE;
825 
826 		if (spi->mode & SPI_3WIRE)
827 			command1 |= SPI_BIDIROE;
828 		else
829 			command1 &= ~SPI_BIDIROE;
830 
831 		if (tspi->cs_control) {
832 			if (tspi->cs_control != spi)
833 				tegra_spi_writel(tspi, command1, SPI_COMMAND1);
834 			tspi->cs_control = NULL;
835 		} else
836 			tegra_spi_writel(tspi, command1, SPI_COMMAND1);
837 
838 		/* GPIO based chip select control */
839 		if (spi->cs_gpiod)
840 			gpiod_set_value(spi->cs_gpiod, 1);
841 
842 		if (is_single_xfer && !(t->cs_change)) {
843 			tspi->use_hw_based_cs = true;
844 			command1 &= ~(SPI_CS_SW_HW | SPI_CS_SW_VAL);
845 		} else {
846 			tspi->use_hw_based_cs = false;
847 			command1 |= SPI_CS_SW_HW;
848 			if (spi->mode & SPI_CS_HIGH)
849 				command1 |= SPI_CS_SW_VAL;
850 			else
851 				command1 &= ~SPI_CS_SW_VAL;
852 		}
853 
854 		if (tspi->last_used_cs != spi->chip_select) {
855 			if (cdata && cdata->tx_clk_tap_delay)
856 				tx_tap = cdata->tx_clk_tap_delay;
857 			if (cdata && cdata->rx_clk_tap_delay)
858 				rx_tap = cdata->rx_clk_tap_delay;
859 			command2 = SPI_TX_TAP_DELAY(tx_tap) |
860 				   SPI_RX_TAP_DELAY(rx_tap);
861 			if (command2 != tspi->def_command2_reg)
862 				tegra_spi_writel(tspi, command2, SPI_COMMAND2);
863 			tspi->last_used_cs = spi->chip_select;
864 		}
865 
866 	} else {
867 		command1 = tspi->command1_reg;
868 		command1 &= ~SPI_BIT_LENGTH(~0);
869 		command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
870 	}
871 
872 	return command1;
873 }
874 
875 static int tegra_spi_start_transfer_one(struct spi_device *spi,
876 		struct spi_transfer *t, u32 command1)
877 {
878 	struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
879 	unsigned total_fifo_words;
880 	int ret;
881 
882 	total_fifo_words = tegra_spi_calculate_curr_xfer_param(spi, tspi, t);
883 
884 	if (t->rx_nbits == SPI_NBITS_DUAL || t->tx_nbits == SPI_NBITS_DUAL)
885 		command1 |= SPI_BOTH_EN_BIT;
886 	else
887 		command1 &= ~SPI_BOTH_EN_BIT;
888 
889 	if (tspi->is_packed)
890 		command1 |= SPI_PACKED;
891 	else
892 		command1 &= ~SPI_PACKED;
893 
894 	command1 &= ~(SPI_CS_SEL_MASK | SPI_TX_EN | SPI_RX_EN);
895 	tspi->cur_direction = 0;
896 	if (t->rx_buf) {
897 		command1 |= SPI_RX_EN;
898 		tspi->cur_direction |= DATA_DIR_RX;
899 	}
900 	if (t->tx_buf) {
901 		command1 |= SPI_TX_EN;
902 		tspi->cur_direction |= DATA_DIR_TX;
903 	}
904 	command1 |= SPI_CS_SEL(spi->chip_select);
905 	tegra_spi_writel(tspi, command1, SPI_COMMAND1);
906 	tspi->command1_reg = command1;
907 
908 	dev_dbg(tspi->dev, "The def 0x%x and written 0x%x\n",
909 		tspi->def_command1_reg, (unsigned)command1);
910 
911 	ret = tegra_spi_flush_fifos(tspi);
912 	if (ret < 0)
913 		return ret;
914 	if (total_fifo_words > SPI_FIFO_DEPTH)
915 		ret = tegra_spi_start_dma_based_transfer(tspi, t);
916 	else
917 		ret = tegra_spi_start_cpu_based_transfer(tspi, t);
918 	return ret;
919 }
920 
921 static struct tegra_spi_client_data
922 	*tegra_spi_parse_cdata_dt(struct spi_device *spi)
923 {
924 	struct tegra_spi_client_data *cdata;
925 	struct device_node *slave_np;
926 
927 	slave_np = spi->dev.of_node;
928 	if (!slave_np) {
929 		dev_dbg(&spi->dev, "device node not found\n");
930 		return NULL;
931 	}
932 
933 	cdata = kzalloc(sizeof(*cdata), GFP_KERNEL);
934 	if (!cdata)
935 		return NULL;
936 
937 	of_property_read_u32(slave_np, "nvidia,tx-clk-tap-delay",
938 			     &cdata->tx_clk_tap_delay);
939 	of_property_read_u32(slave_np, "nvidia,rx-clk-tap-delay",
940 			     &cdata->rx_clk_tap_delay);
941 	return cdata;
942 }
943 
944 static void tegra_spi_cleanup(struct spi_device *spi)
945 {
946 	struct tegra_spi_client_data *cdata = spi->controller_data;
947 
948 	spi->controller_data = NULL;
949 	if (spi->dev.of_node)
950 		kfree(cdata);
951 }
952 
953 static int tegra_spi_setup(struct spi_device *spi)
954 {
955 	struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
956 	struct tegra_spi_client_data *cdata = spi->controller_data;
957 	u32 val;
958 	unsigned long flags;
959 	int ret;
960 
961 	dev_dbg(&spi->dev, "setup %d bpw, %scpol, %scpha, %dHz\n",
962 		spi->bits_per_word,
963 		spi->mode & SPI_CPOL ? "" : "~",
964 		spi->mode & SPI_CPHA ? "" : "~",
965 		spi->max_speed_hz);
966 
967 	if (!cdata) {
968 		cdata = tegra_spi_parse_cdata_dt(spi);
969 		spi->controller_data = cdata;
970 	}
971 
972 	ret = pm_runtime_get_sync(tspi->dev);
973 	if (ret < 0) {
974 		dev_err(tspi->dev, "pm runtime failed, e = %d\n", ret);
975 		if (cdata)
976 			tegra_spi_cleanup(spi);
977 		return ret;
978 	}
979 
980 	if (tspi->soc_data->has_intr_mask_reg) {
981 		val = tegra_spi_readl(tspi, SPI_INTR_MASK);
982 		val &= ~SPI_INTR_ALL_MASK;
983 		tegra_spi_writel(tspi, val, SPI_INTR_MASK);
984 	}
985 
986 	spin_lock_irqsave(&tspi->lock, flags);
987 	/* GPIO based chip select control */
988 	if (spi->cs_gpiod)
989 		gpiod_set_value(spi->cs_gpiod, 0);
990 
991 	val = tspi->def_command1_reg;
992 	if (spi->mode & SPI_CS_HIGH)
993 		val &= ~SPI_CS_POL_INACTIVE(spi->chip_select);
994 	else
995 		val |= SPI_CS_POL_INACTIVE(spi->chip_select);
996 	tspi->def_command1_reg = val;
997 	tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
998 	spin_unlock_irqrestore(&tspi->lock, flags);
999 
1000 	pm_runtime_put(tspi->dev);
1001 	return 0;
1002 }
1003 
1004 static void tegra_spi_transfer_end(struct spi_device *spi)
1005 {
1006 	struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
1007 	int cs_val = (spi->mode & SPI_CS_HIGH) ? 0 : 1;
1008 
1009 	/* GPIO based chip select control */
1010 	if (spi->cs_gpiod)
1011 		gpiod_set_value(spi->cs_gpiod, 0);
1012 
1013 	if (!tspi->use_hw_based_cs) {
1014 		if (cs_val)
1015 			tspi->command1_reg |= SPI_CS_SW_VAL;
1016 		else
1017 			tspi->command1_reg &= ~SPI_CS_SW_VAL;
1018 		tegra_spi_writel(tspi, tspi->command1_reg, SPI_COMMAND1);
1019 	}
1020 
1021 	tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
1022 }
1023 
1024 static void tegra_spi_dump_regs(struct tegra_spi_data *tspi)
1025 {
1026 	dev_dbg(tspi->dev, "============ SPI REGISTER DUMP ============\n");
1027 	dev_dbg(tspi->dev, "Command1:    0x%08x | Command2:    0x%08x\n",
1028 		tegra_spi_readl(tspi, SPI_COMMAND1),
1029 		tegra_spi_readl(tspi, SPI_COMMAND2));
1030 	dev_dbg(tspi->dev, "DMA_CTL:     0x%08x | DMA_BLK:     0x%08x\n",
1031 		tegra_spi_readl(tspi, SPI_DMA_CTL),
1032 		tegra_spi_readl(tspi, SPI_DMA_BLK));
1033 	dev_dbg(tspi->dev, "TRANS_STAT:  0x%08x | FIFO_STATUS: 0x%08x\n",
1034 		tegra_spi_readl(tspi, SPI_TRANS_STATUS),
1035 		tegra_spi_readl(tspi, SPI_FIFO_STATUS));
1036 }
1037 
1038 static int tegra_spi_transfer_one_message(struct spi_master *master,
1039 			struct spi_message *msg)
1040 {
1041 	bool is_first_msg = true;
1042 	struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1043 	struct spi_transfer *xfer;
1044 	struct spi_device *spi = msg->spi;
1045 	int ret;
1046 	bool skip = false;
1047 	int single_xfer;
1048 
1049 	msg->status = 0;
1050 	msg->actual_length = 0;
1051 
1052 	single_xfer = list_is_singular(&msg->transfers);
1053 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1054 		u32 cmd1;
1055 
1056 		reinit_completion(&tspi->xfer_completion);
1057 
1058 		cmd1 = tegra_spi_setup_transfer_one(spi, xfer, is_first_msg,
1059 						    single_xfer);
1060 
1061 		if (!xfer->len) {
1062 			ret = 0;
1063 			skip = true;
1064 			goto complete_xfer;
1065 		}
1066 
1067 		ret = tegra_spi_start_transfer_one(spi, xfer, cmd1);
1068 		if (ret < 0) {
1069 			dev_err(tspi->dev,
1070 				"spi can not start transfer, err %d\n", ret);
1071 			goto complete_xfer;
1072 		}
1073 
1074 		is_first_msg = false;
1075 		ret = wait_for_completion_timeout(&tspi->xfer_completion,
1076 						SPI_DMA_TIMEOUT);
1077 		if (WARN_ON(ret == 0)) {
1078 			dev_err(tspi->dev,
1079 				"spi transfer timeout, err %d\n", ret);
1080 			if (tspi->is_curr_dma_xfer &&
1081 			    (tspi->cur_direction & DATA_DIR_TX))
1082 				dmaengine_terminate_all(tspi->tx_dma_chan);
1083 			if (tspi->is_curr_dma_xfer &&
1084 			    (tspi->cur_direction & DATA_DIR_RX))
1085 				dmaengine_terminate_all(tspi->rx_dma_chan);
1086 			ret = -EIO;
1087 			tegra_spi_dump_regs(tspi);
1088 			tegra_spi_flush_fifos(tspi);
1089 			reset_control_assert(tspi->rst);
1090 			udelay(2);
1091 			reset_control_deassert(tspi->rst);
1092 			tspi->last_used_cs = master->num_chipselect + 1;
1093 			goto complete_xfer;
1094 		}
1095 
1096 		if (tspi->tx_status ||  tspi->rx_status) {
1097 			dev_err(tspi->dev, "Error in Transfer\n");
1098 			ret = -EIO;
1099 			tegra_spi_dump_regs(tspi);
1100 			goto complete_xfer;
1101 		}
1102 		msg->actual_length += xfer->len;
1103 
1104 complete_xfer:
1105 		if (ret < 0 || skip) {
1106 			tegra_spi_transfer_end(spi);
1107 			spi_transfer_delay_exec(xfer);
1108 			goto exit;
1109 		} else if (list_is_last(&xfer->transfer_list,
1110 					&msg->transfers)) {
1111 			if (xfer->cs_change)
1112 				tspi->cs_control = spi;
1113 			else {
1114 				tegra_spi_transfer_end(spi);
1115 				spi_transfer_delay_exec(xfer);
1116 			}
1117 		} else if (xfer->cs_change) {
1118 			tegra_spi_transfer_end(spi);
1119 			spi_transfer_delay_exec(xfer);
1120 		}
1121 
1122 	}
1123 	ret = 0;
1124 exit:
1125 	msg->status = ret;
1126 	spi_finalize_current_message(master);
1127 	return ret;
1128 }
1129 
1130 static irqreturn_t handle_cpu_based_xfer(struct tegra_spi_data *tspi)
1131 {
1132 	struct spi_transfer *t = tspi->curr_xfer;
1133 	unsigned long flags;
1134 
1135 	spin_lock_irqsave(&tspi->lock, flags);
1136 	if (tspi->tx_status ||  tspi->rx_status) {
1137 		dev_err(tspi->dev, "CpuXfer ERROR bit set 0x%x\n",
1138 			tspi->status_reg);
1139 		dev_err(tspi->dev, "CpuXfer 0x%08x:0x%08x\n",
1140 			tspi->command1_reg, tspi->dma_control_reg);
1141 		tegra_spi_dump_regs(tspi);
1142 		tegra_spi_flush_fifos(tspi);
1143 		complete(&tspi->xfer_completion);
1144 		spin_unlock_irqrestore(&tspi->lock, flags);
1145 		reset_control_assert(tspi->rst);
1146 		udelay(2);
1147 		reset_control_deassert(tspi->rst);
1148 		return IRQ_HANDLED;
1149 	}
1150 
1151 	if (tspi->cur_direction & DATA_DIR_RX)
1152 		tegra_spi_read_rx_fifo_to_client_rxbuf(tspi, t);
1153 
1154 	if (tspi->cur_direction & DATA_DIR_TX)
1155 		tspi->cur_pos = tspi->cur_tx_pos;
1156 	else
1157 		tspi->cur_pos = tspi->cur_rx_pos;
1158 
1159 	if (tspi->cur_pos == t->len) {
1160 		complete(&tspi->xfer_completion);
1161 		goto exit;
1162 	}
1163 
1164 	tegra_spi_calculate_curr_xfer_param(tspi->cur_spi, tspi, t);
1165 	tegra_spi_start_cpu_based_transfer(tspi, t);
1166 exit:
1167 	spin_unlock_irqrestore(&tspi->lock, flags);
1168 	return IRQ_HANDLED;
1169 }
1170 
1171 static irqreturn_t handle_dma_based_xfer(struct tegra_spi_data *tspi)
1172 {
1173 	struct spi_transfer *t = tspi->curr_xfer;
1174 	long wait_status;
1175 	int err = 0;
1176 	unsigned total_fifo_words;
1177 	unsigned long flags;
1178 
1179 	/* Abort dmas if any error */
1180 	if (tspi->cur_direction & DATA_DIR_TX) {
1181 		if (tspi->tx_status) {
1182 			dmaengine_terminate_all(tspi->tx_dma_chan);
1183 			err += 1;
1184 		} else {
1185 			wait_status = wait_for_completion_interruptible_timeout(
1186 				&tspi->tx_dma_complete, SPI_DMA_TIMEOUT);
1187 			if (wait_status <= 0) {
1188 				dmaengine_terminate_all(tspi->tx_dma_chan);
1189 				dev_err(tspi->dev, "TxDma Xfer failed\n");
1190 				err += 1;
1191 			}
1192 		}
1193 	}
1194 
1195 	if (tspi->cur_direction & DATA_DIR_RX) {
1196 		if (tspi->rx_status) {
1197 			dmaengine_terminate_all(tspi->rx_dma_chan);
1198 			err += 2;
1199 		} else {
1200 			wait_status = wait_for_completion_interruptible_timeout(
1201 				&tspi->rx_dma_complete, SPI_DMA_TIMEOUT);
1202 			if (wait_status <= 0) {
1203 				dmaengine_terminate_all(tspi->rx_dma_chan);
1204 				dev_err(tspi->dev, "RxDma Xfer failed\n");
1205 				err += 2;
1206 			}
1207 		}
1208 	}
1209 
1210 	spin_lock_irqsave(&tspi->lock, flags);
1211 	if (err) {
1212 		dev_err(tspi->dev, "DmaXfer: ERROR bit set 0x%x\n",
1213 			tspi->status_reg);
1214 		dev_err(tspi->dev, "DmaXfer 0x%08x:0x%08x\n",
1215 			tspi->command1_reg, tspi->dma_control_reg);
1216 		tegra_spi_dump_regs(tspi);
1217 		tegra_spi_flush_fifos(tspi);
1218 		complete(&tspi->xfer_completion);
1219 		spin_unlock_irqrestore(&tspi->lock, flags);
1220 		reset_control_assert(tspi->rst);
1221 		udelay(2);
1222 		reset_control_deassert(tspi->rst);
1223 		return IRQ_HANDLED;
1224 	}
1225 
1226 	if (tspi->cur_direction & DATA_DIR_RX)
1227 		tegra_spi_copy_spi_rxbuf_to_client_rxbuf(tspi, t);
1228 
1229 	if (tspi->cur_direction & DATA_DIR_TX)
1230 		tspi->cur_pos = tspi->cur_tx_pos;
1231 	else
1232 		tspi->cur_pos = tspi->cur_rx_pos;
1233 
1234 	if (tspi->cur_pos == t->len) {
1235 		complete(&tspi->xfer_completion);
1236 		goto exit;
1237 	}
1238 
1239 	/* Continue transfer in current message */
1240 	total_fifo_words = tegra_spi_calculate_curr_xfer_param(tspi->cur_spi,
1241 							tspi, t);
1242 	if (total_fifo_words > SPI_FIFO_DEPTH)
1243 		err = tegra_spi_start_dma_based_transfer(tspi, t);
1244 	else
1245 		err = tegra_spi_start_cpu_based_transfer(tspi, t);
1246 
1247 exit:
1248 	spin_unlock_irqrestore(&tspi->lock, flags);
1249 	return IRQ_HANDLED;
1250 }
1251 
1252 static irqreturn_t tegra_spi_isr_thread(int irq, void *context_data)
1253 {
1254 	struct tegra_spi_data *tspi = context_data;
1255 
1256 	if (!tspi->is_curr_dma_xfer)
1257 		return handle_cpu_based_xfer(tspi);
1258 	return handle_dma_based_xfer(tspi);
1259 }
1260 
1261 static irqreturn_t tegra_spi_isr(int irq, void *context_data)
1262 {
1263 	struct tegra_spi_data *tspi = context_data;
1264 
1265 	tspi->status_reg = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
1266 	if (tspi->cur_direction & DATA_DIR_TX)
1267 		tspi->tx_status = tspi->status_reg &
1268 					(SPI_TX_FIFO_UNF | SPI_TX_FIFO_OVF);
1269 
1270 	if (tspi->cur_direction & DATA_DIR_RX)
1271 		tspi->rx_status = tspi->status_reg &
1272 					(SPI_RX_FIFO_OVF | SPI_RX_FIFO_UNF);
1273 	tegra_spi_clear_status(tspi);
1274 
1275 	return IRQ_WAKE_THREAD;
1276 }
1277 
1278 static struct tegra_spi_soc_data tegra114_spi_soc_data = {
1279 	.has_intr_mask_reg = false,
1280 };
1281 
1282 static struct tegra_spi_soc_data tegra124_spi_soc_data = {
1283 	.has_intr_mask_reg = false,
1284 };
1285 
1286 static struct tegra_spi_soc_data tegra210_spi_soc_data = {
1287 	.has_intr_mask_reg = true,
1288 };
1289 
1290 static const struct of_device_id tegra_spi_of_match[] = {
1291 	{
1292 		.compatible = "nvidia,tegra114-spi",
1293 		.data	    = &tegra114_spi_soc_data,
1294 	}, {
1295 		.compatible = "nvidia,tegra124-spi",
1296 		.data	    = &tegra124_spi_soc_data,
1297 	}, {
1298 		.compatible = "nvidia,tegra210-spi",
1299 		.data	    = &tegra210_spi_soc_data,
1300 	},
1301 	{}
1302 };
1303 MODULE_DEVICE_TABLE(of, tegra_spi_of_match);
1304 
1305 static int tegra_spi_probe(struct platform_device *pdev)
1306 {
1307 	struct spi_master	*master;
1308 	struct tegra_spi_data	*tspi;
1309 	struct resource		*r;
1310 	int ret, spi_irq;
1311 	int bus_num;
1312 
1313 	master = spi_alloc_master(&pdev->dev, sizeof(*tspi));
1314 	if (!master) {
1315 		dev_err(&pdev->dev, "master allocation failed\n");
1316 		return -ENOMEM;
1317 	}
1318 	platform_set_drvdata(pdev, master);
1319 	tspi = spi_master_get_devdata(master);
1320 
1321 	if (of_property_read_u32(pdev->dev.of_node, "spi-max-frequency",
1322 				 &master->max_speed_hz))
1323 		master->max_speed_hz = 25000000; /* 25MHz */
1324 
1325 	/* the spi->mode bits understood by this driver: */
1326 	master->use_gpio_descriptors = true;
1327 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST |
1328 			    SPI_TX_DUAL | SPI_RX_DUAL | SPI_3WIRE;
1329 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1330 	master->setup = tegra_spi_setup;
1331 	master->cleanup = tegra_spi_cleanup;
1332 	master->transfer_one_message = tegra_spi_transfer_one_message;
1333 	master->set_cs_timing = tegra_spi_set_hw_cs_timing;
1334 	master->num_chipselect = MAX_CHIP_SELECT;
1335 	master->auto_runtime_pm = true;
1336 	bus_num = of_alias_get_id(pdev->dev.of_node, "spi");
1337 	if (bus_num >= 0)
1338 		master->bus_num = bus_num;
1339 
1340 	tspi->master = master;
1341 	tspi->dev = &pdev->dev;
1342 	spin_lock_init(&tspi->lock);
1343 
1344 	tspi->soc_data = of_device_get_match_data(&pdev->dev);
1345 	if (!tspi->soc_data) {
1346 		dev_err(&pdev->dev, "unsupported tegra\n");
1347 		ret = -ENODEV;
1348 		goto exit_free_master;
1349 	}
1350 
1351 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1352 	tspi->base = devm_ioremap_resource(&pdev->dev, r);
1353 	if (IS_ERR(tspi->base)) {
1354 		ret = PTR_ERR(tspi->base);
1355 		goto exit_free_master;
1356 	}
1357 	tspi->phys = r->start;
1358 
1359 	spi_irq = platform_get_irq(pdev, 0);
1360 	tspi->irq = spi_irq;
1361 
1362 	tspi->clk = devm_clk_get(&pdev->dev, "spi");
1363 	if (IS_ERR(tspi->clk)) {
1364 		dev_err(&pdev->dev, "can not get clock\n");
1365 		ret = PTR_ERR(tspi->clk);
1366 		goto exit_free_master;
1367 	}
1368 
1369 	tspi->rst = devm_reset_control_get_exclusive(&pdev->dev, "spi");
1370 	if (IS_ERR(tspi->rst)) {
1371 		dev_err(&pdev->dev, "can not get reset\n");
1372 		ret = PTR_ERR(tspi->rst);
1373 		goto exit_free_master;
1374 	}
1375 
1376 	tspi->max_buf_size = SPI_FIFO_DEPTH << 2;
1377 	tspi->dma_buf_size = DEFAULT_SPI_DMA_BUF_LEN;
1378 
1379 	ret = tegra_spi_init_dma_param(tspi, true);
1380 	if (ret < 0)
1381 		goto exit_free_master;
1382 	ret = tegra_spi_init_dma_param(tspi, false);
1383 	if (ret < 0)
1384 		goto exit_rx_dma_free;
1385 	tspi->max_buf_size = tspi->dma_buf_size;
1386 	init_completion(&tspi->tx_dma_complete);
1387 	init_completion(&tspi->rx_dma_complete);
1388 
1389 	init_completion(&tspi->xfer_completion);
1390 
1391 	pm_runtime_enable(&pdev->dev);
1392 	if (!pm_runtime_enabled(&pdev->dev)) {
1393 		ret = tegra_spi_runtime_resume(&pdev->dev);
1394 		if (ret)
1395 			goto exit_pm_disable;
1396 	}
1397 
1398 	ret = pm_runtime_get_sync(&pdev->dev);
1399 	if (ret < 0) {
1400 		dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret);
1401 		goto exit_pm_disable;
1402 	}
1403 
1404 	reset_control_assert(tspi->rst);
1405 	udelay(2);
1406 	reset_control_deassert(tspi->rst);
1407 	tspi->def_command1_reg  = SPI_M_S;
1408 	tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
1409 	tspi->spi_cs_timing1 = tegra_spi_readl(tspi, SPI_CS_TIMING1);
1410 	tspi->spi_cs_timing2 = tegra_spi_readl(tspi, SPI_CS_TIMING2);
1411 	tspi->def_command2_reg = tegra_spi_readl(tspi, SPI_COMMAND2);
1412 	tspi->last_used_cs = master->num_chipselect + 1;
1413 	pm_runtime_put(&pdev->dev);
1414 	ret = request_threaded_irq(tspi->irq, tegra_spi_isr,
1415 				   tegra_spi_isr_thread, IRQF_ONESHOT,
1416 				   dev_name(&pdev->dev), tspi);
1417 	if (ret < 0) {
1418 		dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
1419 			tspi->irq);
1420 		goto exit_pm_disable;
1421 	}
1422 
1423 	master->dev.of_node = pdev->dev.of_node;
1424 	ret = devm_spi_register_master(&pdev->dev, master);
1425 	if (ret < 0) {
1426 		dev_err(&pdev->dev, "can not register to master err %d\n", ret);
1427 		goto exit_free_irq;
1428 	}
1429 	return ret;
1430 
1431 exit_free_irq:
1432 	free_irq(spi_irq, tspi);
1433 exit_pm_disable:
1434 	pm_runtime_disable(&pdev->dev);
1435 	if (!pm_runtime_status_suspended(&pdev->dev))
1436 		tegra_spi_runtime_suspend(&pdev->dev);
1437 	tegra_spi_deinit_dma_param(tspi, false);
1438 exit_rx_dma_free:
1439 	tegra_spi_deinit_dma_param(tspi, true);
1440 exit_free_master:
1441 	spi_master_put(master);
1442 	return ret;
1443 }
1444 
1445 static int tegra_spi_remove(struct platform_device *pdev)
1446 {
1447 	struct spi_master *master = platform_get_drvdata(pdev);
1448 	struct tegra_spi_data	*tspi = spi_master_get_devdata(master);
1449 
1450 	free_irq(tspi->irq, tspi);
1451 
1452 	if (tspi->tx_dma_chan)
1453 		tegra_spi_deinit_dma_param(tspi, false);
1454 
1455 	if (tspi->rx_dma_chan)
1456 		tegra_spi_deinit_dma_param(tspi, true);
1457 
1458 	pm_runtime_disable(&pdev->dev);
1459 	if (!pm_runtime_status_suspended(&pdev->dev))
1460 		tegra_spi_runtime_suspend(&pdev->dev);
1461 
1462 	return 0;
1463 }
1464 
1465 #ifdef CONFIG_PM_SLEEP
1466 static int tegra_spi_suspend(struct device *dev)
1467 {
1468 	struct spi_master *master = dev_get_drvdata(dev);
1469 
1470 	return spi_master_suspend(master);
1471 }
1472 
1473 static int tegra_spi_resume(struct device *dev)
1474 {
1475 	struct spi_master *master = dev_get_drvdata(dev);
1476 	struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1477 	int ret;
1478 
1479 	ret = pm_runtime_get_sync(dev);
1480 	if (ret < 0) {
1481 		dev_err(dev, "pm runtime failed, e = %d\n", ret);
1482 		return ret;
1483 	}
1484 	tegra_spi_writel(tspi, tspi->command1_reg, SPI_COMMAND1);
1485 	tegra_spi_writel(tspi, tspi->def_command2_reg, SPI_COMMAND2);
1486 	tspi->last_used_cs = master->num_chipselect + 1;
1487 	pm_runtime_put(dev);
1488 
1489 	return spi_master_resume(master);
1490 }
1491 #endif
1492 
1493 static int tegra_spi_runtime_suspend(struct device *dev)
1494 {
1495 	struct spi_master *master = dev_get_drvdata(dev);
1496 	struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1497 
1498 	/* Flush all write which are in PPSB queue by reading back */
1499 	tegra_spi_readl(tspi, SPI_COMMAND1);
1500 
1501 	clk_disable_unprepare(tspi->clk);
1502 	return 0;
1503 }
1504 
1505 static int tegra_spi_runtime_resume(struct device *dev)
1506 {
1507 	struct spi_master *master = dev_get_drvdata(dev);
1508 	struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1509 	int ret;
1510 
1511 	ret = clk_prepare_enable(tspi->clk);
1512 	if (ret < 0) {
1513 		dev_err(tspi->dev, "clk_prepare failed: %d\n", ret);
1514 		return ret;
1515 	}
1516 	return 0;
1517 }
1518 
1519 static const struct dev_pm_ops tegra_spi_pm_ops = {
1520 	SET_RUNTIME_PM_OPS(tegra_spi_runtime_suspend,
1521 		tegra_spi_runtime_resume, NULL)
1522 	SET_SYSTEM_SLEEP_PM_OPS(tegra_spi_suspend, tegra_spi_resume)
1523 };
1524 static struct platform_driver tegra_spi_driver = {
1525 	.driver = {
1526 		.name		= "spi-tegra114",
1527 		.pm		= &tegra_spi_pm_ops,
1528 		.of_match_table	= tegra_spi_of_match,
1529 	},
1530 	.probe =	tegra_spi_probe,
1531 	.remove =	tegra_spi_remove,
1532 };
1533 module_platform_driver(tegra_spi_driver);
1534 
1535 MODULE_ALIAS("platform:spi-tegra114");
1536 MODULE_DESCRIPTION("NVIDIA Tegra114 SPI Controller Driver");
1537 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1538 MODULE_LICENSE("GPL v2");
1539