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