xref: /openbmc/linux/drivers/spi/spi-imx.c (revision 7211ec63)
1 /*
2  * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
3  * Copyright (C) 2008 Juergen Beisert
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License
7  * as published by the Free Software Foundation; either version 2
8  * of the License, or (at your option) any later version.
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the
16  * Free Software Foundation
17  * 51 Franklin Street, Fifth Floor
18  * Boston, MA  02110-1301, USA.
19  */
20 
21 #include <linux/clk.h>
22 #include <linux/completion.h>
23 #include <linux/delay.h>
24 #include <linux/dmaengine.h>
25 #include <linux/dma-mapping.h>
26 #include <linux/err.h>
27 #include <linux/gpio.h>
28 #include <linux/interrupt.h>
29 #include <linux/io.h>
30 #include <linux/irq.h>
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/platform_device.h>
34 #include <linux/slab.h>
35 #include <linux/spi/spi.h>
36 #include <linux/spi/spi_bitbang.h>
37 #include <linux/types.h>
38 #include <linux/of.h>
39 #include <linux/of_device.h>
40 #include <linux/of_gpio.h>
41 
42 #include <linux/platform_data/dma-imx.h>
43 #include <linux/platform_data/spi-imx.h>
44 
45 #define DRIVER_NAME "spi_imx"
46 
47 #define MXC_CSPIRXDATA		0x00
48 #define MXC_CSPITXDATA		0x04
49 #define MXC_CSPICTRL		0x08
50 #define MXC_CSPIINT		0x0c
51 #define MXC_RESET		0x1c
52 
53 /* generic defines to abstract from the different register layouts */
54 #define MXC_INT_RR	(1 << 0) /* Receive data ready interrupt */
55 #define MXC_INT_TE	(1 << 1) /* Transmit FIFO empty interrupt */
56 
57 /* The maximum  bytes that a sdma BD can transfer.*/
58 #define MAX_SDMA_BD_BYTES  (1 << 15)
59 #define MX51_ECSPI_CTRL_MAX_BURST	512
60 
61 enum spi_imx_devtype {
62 	IMX1_CSPI,
63 	IMX21_CSPI,
64 	IMX27_CSPI,
65 	IMX31_CSPI,
66 	IMX35_CSPI,	/* CSPI on all i.mx except above */
67 	IMX51_ECSPI,	/* ECSPI on i.mx51 */
68 	IMX53_ECSPI,	/* ECSPI on i.mx53 and later */
69 };
70 
71 struct spi_imx_data;
72 
73 struct spi_imx_devtype_data {
74 	void (*intctrl)(struct spi_imx_data *, int);
75 	int (*config)(struct spi_device *);
76 	void (*trigger)(struct spi_imx_data *);
77 	int (*rx_available)(struct spi_imx_data *);
78 	void (*reset)(struct spi_imx_data *);
79 	bool has_dmamode;
80 	unsigned int fifo_size;
81 	bool dynamic_burst;
82 	enum spi_imx_devtype devtype;
83 };
84 
85 struct spi_imx_data {
86 	struct spi_bitbang bitbang;
87 	struct device *dev;
88 
89 	struct completion xfer_done;
90 	void __iomem *base;
91 	unsigned long base_phys;
92 
93 	struct clk *clk_per;
94 	struct clk *clk_ipg;
95 	unsigned long spi_clk;
96 	unsigned int spi_bus_clk;
97 
98 	unsigned int speed_hz;
99 	unsigned int bits_per_word;
100 	unsigned int spi_drctl;
101 
102 	unsigned int count, remainder;
103 	void (*tx)(struct spi_imx_data *);
104 	void (*rx)(struct spi_imx_data *);
105 	void *rx_buf;
106 	const void *tx_buf;
107 	unsigned int txfifo; /* number of words pushed in tx FIFO */
108 	unsigned int dynamic_burst, read_u32;
109 	unsigned int word_mask;
110 
111 	/* DMA */
112 	bool usedma;
113 	u32 wml;
114 	struct completion dma_rx_completion;
115 	struct completion dma_tx_completion;
116 
117 	const struct spi_imx_devtype_data *devtype_data;
118 };
119 
120 static inline int is_imx27_cspi(struct spi_imx_data *d)
121 {
122 	return d->devtype_data->devtype == IMX27_CSPI;
123 }
124 
125 static inline int is_imx35_cspi(struct spi_imx_data *d)
126 {
127 	return d->devtype_data->devtype == IMX35_CSPI;
128 }
129 
130 static inline int is_imx51_ecspi(struct spi_imx_data *d)
131 {
132 	return d->devtype_data->devtype == IMX51_ECSPI;
133 }
134 
135 static inline int is_imx53_ecspi(struct spi_imx_data *d)
136 {
137 	return d->devtype_data->devtype == IMX53_ECSPI;
138 }
139 
140 #define MXC_SPI_BUF_RX(type)						\
141 static void spi_imx_buf_rx_##type(struct spi_imx_data *spi_imx)		\
142 {									\
143 	unsigned int val = readl(spi_imx->base + MXC_CSPIRXDATA);	\
144 									\
145 	if (spi_imx->rx_buf) {						\
146 		*(type *)spi_imx->rx_buf = val;				\
147 		spi_imx->rx_buf += sizeof(type);			\
148 	}								\
149 }
150 
151 #define MXC_SPI_BUF_TX(type)						\
152 static void spi_imx_buf_tx_##type(struct spi_imx_data *spi_imx)		\
153 {									\
154 	type val = 0;							\
155 									\
156 	if (spi_imx->tx_buf) {						\
157 		val = *(type *)spi_imx->tx_buf;				\
158 		spi_imx->tx_buf += sizeof(type);			\
159 	}								\
160 									\
161 	spi_imx->count -= sizeof(type);					\
162 									\
163 	writel(val, spi_imx->base + MXC_CSPITXDATA);			\
164 }
165 
166 MXC_SPI_BUF_RX(u8)
167 MXC_SPI_BUF_TX(u8)
168 MXC_SPI_BUF_RX(u16)
169 MXC_SPI_BUF_TX(u16)
170 MXC_SPI_BUF_RX(u32)
171 MXC_SPI_BUF_TX(u32)
172 
173 /* First entry is reserved, second entry is valid only if SDHC_SPIEN is set
174  * (which is currently not the case in this driver)
175  */
176 static int mxc_clkdivs[] = {0, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192,
177 	256, 384, 512, 768, 1024};
178 
179 /* MX21, MX27 */
180 static unsigned int spi_imx_clkdiv_1(unsigned int fin,
181 		unsigned int fspi, unsigned int max, unsigned int *fres)
182 {
183 	int i;
184 
185 	for (i = 2; i < max; i++)
186 		if (fspi * mxc_clkdivs[i] >= fin)
187 			break;
188 
189 	*fres = fin / mxc_clkdivs[i];
190 	return i;
191 }
192 
193 /* MX1, MX31, MX35, MX51 CSPI */
194 static unsigned int spi_imx_clkdiv_2(unsigned int fin,
195 		unsigned int fspi, unsigned int *fres)
196 {
197 	int i, div = 4;
198 
199 	for (i = 0; i < 7; i++) {
200 		if (fspi * div >= fin)
201 			goto out;
202 		div <<= 1;
203 	}
204 
205 out:
206 	*fres = fin / div;
207 	return i;
208 }
209 
210 static int spi_imx_bytes_per_word(const int bits_per_word)
211 {
212 	return DIV_ROUND_UP(bits_per_word, BITS_PER_BYTE);
213 }
214 
215 static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
216 			 struct spi_transfer *transfer)
217 {
218 	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
219 	unsigned int bytes_per_word, i;
220 
221 	if (!master->dma_rx)
222 		return false;
223 
224 	bytes_per_word = spi_imx_bytes_per_word(transfer->bits_per_word);
225 
226 	if (bytes_per_word != 1 && bytes_per_word != 2 && bytes_per_word != 4)
227 		return false;
228 
229 	for (i = spi_imx->devtype_data->fifo_size / 2; i > 0; i--) {
230 		if (!(transfer->len % (i * bytes_per_word)))
231 			break;
232 	}
233 
234 	if (i == 0)
235 		return false;
236 
237 	spi_imx->wml = i;
238 	spi_imx->dynamic_burst = 0;
239 
240 	return true;
241 }
242 
243 #define MX51_ECSPI_CTRL		0x08
244 #define MX51_ECSPI_CTRL_ENABLE		(1 <<  0)
245 #define MX51_ECSPI_CTRL_XCH		(1 <<  2)
246 #define MX51_ECSPI_CTRL_SMC		(1 << 3)
247 #define MX51_ECSPI_CTRL_MODE_MASK	(0xf << 4)
248 #define MX51_ECSPI_CTRL_DRCTL(drctl)	((drctl) << 16)
249 #define MX51_ECSPI_CTRL_POSTDIV_OFFSET	8
250 #define MX51_ECSPI_CTRL_PREDIV_OFFSET	12
251 #define MX51_ECSPI_CTRL_CS(cs)		((cs) << 18)
252 #define MX51_ECSPI_CTRL_BL_OFFSET	20
253 #define MX51_ECSPI_CTRL_BL_MASK		(0xfff << 20)
254 
255 #define MX51_ECSPI_CONFIG	0x0c
256 #define MX51_ECSPI_CONFIG_SCLKPHA(cs)	(1 << ((cs) +  0))
257 #define MX51_ECSPI_CONFIG_SCLKPOL(cs)	(1 << ((cs) +  4))
258 #define MX51_ECSPI_CONFIG_SBBCTRL(cs)	(1 << ((cs) +  8))
259 #define MX51_ECSPI_CONFIG_SSBPOL(cs)	(1 << ((cs) + 12))
260 #define MX51_ECSPI_CONFIG_SCLKCTL(cs)	(1 << ((cs) + 20))
261 
262 #define MX51_ECSPI_INT		0x10
263 #define MX51_ECSPI_INT_TEEN		(1 <<  0)
264 #define MX51_ECSPI_INT_RREN		(1 <<  3)
265 
266 #define MX51_ECSPI_DMA      0x14
267 #define MX51_ECSPI_DMA_TX_WML(wml)	((wml) & 0x3f)
268 #define MX51_ECSPI_DMA_RX_WML(wml)	(((wml) & 0x3f) << 16)
269 #define MX51_ECSPI_DMA_RXT_WML(wml)	(((wml) & 0x3f) << 24)
270 
271 #define MX51_ECSPI_DMA_TEDEN		(1 << 7)
272 #define MX51_ECSPI_DMA_RXDEN		(1 << 23)
273 #define MX51_ECSPI_DMA_RXTDEN		(1 << 31)
274 
275 #define MX51_ECSPI_STAT		0x18
276 #define MX51_ECSPI_STAT_RR		(1 <<  3)
277 
278 #define MX51_ECSPI_TESTREG	0x20
279 #define MX51_ECSPI_TESTREG_LBC	BIT(31)
280 
281 static void spi_imx_buf_rx_swap_u32(struct spi_imx_data *spi_imx)
282 {
283 	unsigned int val = readl(spi_imx->base + MXC_CSPIRXDATA);
284 #ifdef __LITTLE_ENDIAN
285 	unsigned int bytes_per_word;
286 #endif
287 
288 	if (spi_imx->rx_buf) {
289 #ifdef __LITTLE_ENDIAN
290 		bytes_per_word = spi_imx_bytes_per_word(spi_imx->bits_per_word);
291 		if (bytes_per_word == 1)
292 			val = cpu_to_be32(val);
293 		else if (bytes_per_word == 2)
294 			val = (val << 16) | (val >> 16);
295 #endif
296 		val &= spi_imx->word_mask;
297 		*(u32 *)spi_imx->rx_buf = val;
298 		spi_imx->rx_buf += sizeof(u32);
299 	}
300 }
301 
302 static void spi_imx_buf_rx_swap(struct spi_imx_data *spi_imx)
303 {
304 	unsigned int bytes_per_word;
305 
306 	bytes_per_word = spi_imx_bytes_per_word(spi_imx->bits_per_word);
307 	if (spi_imx->read_u32) {
308 		spi_imx_buf_rx_swap_u32(spi_imx);
309 		return;
310 	}
311 
312 	if (bytes_per_word == 1)
313 		spi_imx_buf_rx_u8(spi_imx);
314 	else if (bytes_per_word == 2)
315 		spi_imx_buf_rx_u16(spi_imx);
316 }
317 
318 static void spi_imx_buf_tx_swap_u32(struct spi_imx_data *spi_imx)
319 {
320 	u32 val = 0;
321 #ifdef __LITTLE_ENDIAN
322 	unsigned int bytes_per_word;
323 #endif
324 
325 	if (spi_imx->tx_buf) {
326 		val = *(u32 *)spi_imx->tx_buf;
327 		val &= spi_imx->word_mask;
328 		spi_imx->tx_buf += sizeof(u32);
329 	}
330 
331 	spi_imx->count -= sizeof(u32);
332 #ifdef __LITTLE_ENDIAN
333 	bytes_per_word = spi_imx_bytes_per_word(spi_imx->bits_per_word);
334 
335 	if (bytes_per_word == 1)
336 		val = cpu_to_be32(val);
337 	else if (bytes_per_word == 2)
338 		val = (val << 16) | (val >> 16);
339 #endif
340 	writel(val, spi_imx->base + MXC_CSPITXDATA);
341 }
342 
343 static void spi_imx_buf_tx_swap(struct spi_imx_data *spi_imx)
344 {
345 	u32 ctrl, val;
346 	unsigned int bytes_per_word;
347 
348 	if (spi_imx->count == spi_imx->remainder) {
349 		ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL);
350 		ctrl &= ~MX51_ECSPI_CTRL_BL_MASK;
351 		if (spi_imx->count > MX51_ECSPI_CTRL_MAX_BURST) {
352 			spi_imx->remainder = spi_imx->count %
353 					     MX51_ECSPI_CTRL_MAX_BURST;
354 			val = MX51_ECSPI_CTRL_MAX_BURST * 8 - 1;
355 		} else if (spi_imx->count >= sizeof(u32)) {
356 			spi_imx->remainder = spi_imx->count % sizeof(u32);
357 			val = (spi_imx->count - spi_imx->remainder) * 8 - 1;
358 		} else {
359 			spi_imx->remainder = 0;
360 			val = spi_imx->bits_per_word - 1;
361 			spi_imx->read_u32 = 0;
362 		}
363 
364 		ctrl |= (val << MX51_ECSPI_CTRL_BL_OFFSET);
365 		writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
366 	}
367 
368 	if (spi_imx->count >= sizeof(u32)) {
369 		spi_imx_buf_tx_swap_u32(spi_imx);
370 		return;
371 	}
372 
373 	bytes_per_word = spi_imx_bytes_per_word(spi_imx->bits_per_word);
374 
375 	if (bytes_per_word == 1)
376 		spi_imx_buf_tx_u8(spi_imx);
377 	else if (bytes_per_word == 2)
378 		spi_imx_buf_tx_u16(spi_imx);
379 }
380 
381 /* MX51 eCSPI */
382 static unsigned int mx51_ecspi_clkdiv(struct spi_imx_data *spi_imx,
383 				      unsigned int fspi, unsigned int *fres)
384 {
385 	/*
386 	 * there are two 4-bit dividers, the pre-divider divides by
387 	 * $pre, the post-divider by 2^$post
388 	 */
389 	unsigned int pre, post;
390 	unsigned int fin = spi_imx->spi_clk;
391 
392 	if (unlikely(fspi > fin))
393 		return 0;
394 
395 	post = fls(fin) - fls(fspi);
396 	if (fin > fspi << post)
397 		post++;
398 
399 	/* now we have: (fin <= fspi << post) with post being minimal */
400 
401 	post = max(4U, post) - 4;
402 	if (unlikely(post > 0xf)) {
403 		dev_err(spi_imx->dev, "cannot set clock freq: %u (base freq: %u)\n",
404 				fspi, fin);
405 		return 0xff;
406 	}
407 
408 	pre = DIV_ROUND_UP(fin, fspi << post) - 1;
409 
410 	dev_dbg(spi_imx->dev, "%s: fin: %u, fspi: %u, post: %u, pre: %u\n",
411 			__func__, fin, fspi, post, pre);
412 
413 	/* Resulting frequency for the SCLK line. */
414 	*fres = (fin / (pre + 1)) >> post;
415 
416 	return (pre << MX51_ECSPI_CTRL_PREDIV_OFFSET) |
417 		(post << MX51_ECSPI_CTRL_POSTDIV_OFFSET);
418 }
419 
420 static void mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int enable)
421 {
422 	unsigned val = 0;
423 
424 	if (enable & MXC_INT_TE)
425 		val |= MX51_ECSPI_INT_TEEN;
426 
427 	if (enable & MXC_INT_RR)
428 		val |= MX51_ECSPI_INT_RREN;
429 
430 	writel(val, spi_imx->base + MX51_ECSPI_INT);
431 }
432 
433 static void mx51_ecspi_trigger(struct spi_imx_data *spi_imx)
434 {
435 	u32 reg;
436 
437 	reg = readl(spi_imx->base + MX51_ECSPI_CTRL);
438 	reg |= MX51_ECSPI_CTRL_XCH;
439 	writel(reg, spi_imx->base + MX51_ECSPI_CTRL);
440 }
441 
442 static int mx51_ecspi_config(struct spi_device *spi)
443 {
444 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
445 	u32 ctrl = MX51_ECSPI_CTRL_ENABLE;
446 	u32 clk = spi_imx->speed_hz, delay, reg;
447 	u32 cfg = readl(spi_imx->base + MX51_ECSPI_CONFIG);
448 
449 	/*
450 	 * The hardware seems to have a race condition when changing modes. The
451 	 * current assumption is that the selection of the channel arrives
452 	 * earlier in the hardware than the mode bits when they are written at
453 	 * the same time.
454 	 * So set master mode for all channels as we do not support slave mode.
455 	 */
456 	ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
457 
458 	/*
459 	 * Enable SPI_RDY handling (falling edge/level triggered).
460 	 */
461 	if (spi->mode & SPI_READY)
462 		ctrl |= MX51_ECSPI_CTRL_DRCTL(spi_imx->spi_drctl);
463 
464 	/* set clock speed */
465 	ctrl |= mx51_ecspi_clkdiv(spi_imx, spi_imx->speed_hz, &clk);
466 	spi_imx->spi_bus_clk = clk;
467 
468 	/* set chip select to use */
469 	ctrl |= MX51_ECSPI_CTRL_CS(spi->chip_select);
470 
471 	ctrl |= (spi_imx->bits_per_word - 1) << MX51_ECSPI_CTRL_BL_OFFSET;
472 
473 	cfg |= MX51_ECSPI_CONFIG_SBBCTRL(spi->chip_select);
474 
475 	if (spi->mode & SPI_CPHA)
476 		cfg |= MX51_ECSPI_CONFIG_SCLKPHA(spi->chip_select);
477 	else
478 		cfg &= ~MX51_ECSPI_CONFIG_SCLKPHA(spi->chip_select);
479 
480 	if (spi->mode & SPI_CPOL) {
481 		cfg |= MX51_ECSPI_CONFIG_SCLKPOL(spi->chip_select);
482 		cfg |= MX51_ECSPI_CONFIG_SCLKCTL(spi->chip_select);
483 	} else {
484 		cfg &= ~MX51_ECSPI_CONFIG_SCLKPOL(spi->chip_select);
485 		cfg &= ~MX51_ECSPI_CONFIG_SCLKCTL(spi->chip_select);
486 	}
487 	if (spi->mode & SPI_CS_HIGH)
488 		cfg |= MX51_ECSPI_CONFIG_SSBPOL(spi->chip_select);
489 	else
490 		cfg &= ~MX51_ECSPI_CONFIG_SSBPOL(spi->chip_select);
491 
492 	if (spi_imx->usedma)
493 		ctrl |= MX51_ECSPI_CTRL_SMC;
494 
495 	/* CTRL register always go first to bring out controller from reset */
496 	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
497 
498 	reg = readl(spi_imx->base + MX51_ECSPI_TESTREG);
499 	if (spi->mode & SPI_LOOP)
500 		reg |= MX51_ECSPI_TESTREG_LBC;
501 	else
502 		reg &= ~MX51_ECSPI_TESTREG_LBC;
503 	writel(reg, spi_imx->base + MX51_ECSPI_TESTREG);
504 
505 	writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
506 
507 	/*
508 	 * Wait until the changes in the configuration register CONFIGREG
509 	 * propagate into the hardware. It takes exactly one tick of the
510 	 * SCLK clock, but we will wait two SCLK clock just to be sure. The
511 	 * effect of the delay it takes for the hardware to apply changes
512 	 * is noticable if the SCLK clock run very slow. In such a case, if
513 	 * the polarity of SCLK should be inverted, the GPIO ChipSelect might
514 	 * be asserted before the SCLK polarity changes, which would disrupt
515 	 * the SPI communication as the device on the other end would consider
516 	 * the change of SCLK polarity as a clock tick already.
517 	 */
518 	delay = (2 * 1000000) / clk;
519 	if (likely(delay < 10))	/* SCLK is faster than 100 kHz */
520 		udelay(delay);
521 	else			/* SCLK is _very_ slow */
522 		usleep_range(delay, delay + 10);
523 
524 	/*
525 	 * Configure the DMA register: setup the watermark
526 	 * and enable DMA request.
527 	 */
528 
529 	writel(MX51_ECSPI_DMA_RX_WML(spi_imx->wml) |
530 		MX51_ECSPI_DMA_TX_WML(spi_imx->wml) |
531 		MX51_ECSPI_DMA_RXT_WML(spi_imx->wml) |
532 		MX51_ECSPI_DMA_TEDEN | MX51_ECSPI_DMA_RXDEN |
533 		MX51_ECSPI_DMA_RXTDEN, spi_imx->base + MX51_ECSPI_DMA);
534 
535 	return 0;
536 }
537 
538 static int mx51_ecspi_rx_available(struct spi_imx_data *spi_imx)
539 {
540 	return readl(spi_imx->base + MX51_ECSPI_STAT) & MX51_ECSPI_STAT_RR;
541 }
542 
543 static void mx51_ecspi_reset(struct spi_imx_data *spi_imx)
544 {
545 	/* drain receive buffer */
546 	while (mx51_ecspi_rx_available(spi_imx))
547 		readl(spi_imx->base + MXC_CSPIRXDATA);
548 }
549 
550 #define MX31_INTREG_TEEN	(1 << 0)
551 #define MX31_INTREG_RREN	(1 << 3)
552 
553 #define MX31_CSPICTRL_ENABLE	(1 << 0)
554 #define MX31_CSPICTRL_MASTER	(1 << 1)
555 #define MX31_CSPICTRL_XCH	(1 << 2)
556 #define MX31_CSPICTRL_SMC	(1 << 3)
557 #define MX31_CSPICTRL_POL	(1 << 4)
558 #define MX31_CSPICTRL_PHA	(1 << 5)
559 #define MX31_CSPICTRL_SSCTL	(1 << 6)
560 #define MX31_CSPICTRL_SSPOL	(1 << 7)
561 #define MX31_CSPICTRL_BC_SHIFT	8
562 #define MX35_CSPICTRL_BL_SHIFT	20
563 #define MX31_CSPICTRL_CS_SHIFT	24
564 #define MX35_CSPICTRL_CS_SHIFT	12
565 #define MX31_CSPICTRL_DR_SHIFT	16
566 
567 #define MX31_CSPI_DMAREG	0x10
568 #define MX31_DMAREG_RH_DEN	(1<<4)
569 #define MX31_DMAREG_TH_DEN	(1<<1)
570 
571 #define MX31_CSPISTATUS		0x14
572 #define MX31_STATUS_RR		(1 << 3)
573 
574 #define MX31_CSPI_TESTREG	0x1C
575 #define MX31_TEST_LBC		(1 << 14)
576 
577 /* These functions also work for the i.MX35, but be aware that
578  * the i.MX35 has a slightly different register layout for bits
579  * we do not use here.
580  */
581 static void mx31_intctrl(struct spi_imx_data *spi_imx, int enable)
582 {
583 	unsigned int val = 0;
584 
585 	if (enable & MXC_INT_TE)
586 		val |= MX31_INTREG_TEEN;
587 	if (enable & MXC_INT_RR)
588 		val |= MX31_INTREG_RREN;
589 
590 	writel(val, spi_imx->base + MXC_CSPIINT);
591 }
592 
593 static void mx31_trigger(struct spi_imx_data *spi_imx)
594 {
595 	unsigned int reg;
596 
597 	reg = readl(spi_imx->base + MXC_CSPICTRL);
598 	reg |= MX31_CSPICTRL_XCH;
599 	writel(reg, spi_imx->base + MXC_CSPICTRL);
600 }
601 
602 static int mx31_config(struct spi_device *spi)
603 {
604 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
605 	unsigned int reg = MX31_CSPICTRL_ENABLE | MX31_CSPICTRL_MASTER;
606 	unsigned int clk;
607 
608 	reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, spi_imx->speed_hz, &clk) <<
609 		MX31_CSPICTRL_DR_SHIFT;
610 	spi_imx->spi_bus_clk = clk;
611 
612 	if (is_imx35_cspi(spi_imx)) {
613 		reg |= (spi_imx->bits_per_word - 1) << MX35_CSPICTRL_BL_SHIFT;
614 		reg |= MX31_CSPICTRL_SSCTL;
615 	} else {
616 		reg |= (spi_imx->bits_per_word - 1) << MX31_CSPICTRL_BC_SHIFT;
617 	}
618 
619 	if (spi->mode & SPI_CPHA)
620 		reg |= MX31_CSPICTRL_PHA;
621 	if (spi->mode & SPI_CPOL)
622 		reg |= MX31_CSPICTRL_POL;
623 	if (spi->mode & SPI_CS_HIGH)
624 		reg |= MX31_CSPICTRL_SSPOL;
625 	if (!gpio_is_valid(spi->cs_gpio))
626 		reg |= (spi->chip_select) <<
627 			(is_imx35_cspi(spi_imx) ? MX35_CSPICTRL_CS_SHIFT :
628 						  MX31_CSPICTRL_CS_SHIFT);
629 
630 	if (spi_imx->usedma)
631 		reg |= MX31_CSPICTRL_SMC;
632 
633 	writel(reg, spi_imx->base + MXC_CSPICTRL);
634 
635 	reg = readl(spi_imx->base + MX31_CSPI_TESTREG);
636 	if (spi->mode & SPI_LOOP)
637 		reg |= MX31_TEST_LBC;
638 	else
639 		reg &= ~MX31_TEST_LBC;
640 	writel(reg, spi_imx->base + MX31_CSPI_TESTREG);
641 
642 	if (spi_imx->usedma) {
643 		/* configure DMA requests when RXFIFO is half full and
644 		   when TXFIFO is half empty */
645 		writel(MX31_DMAREG_RH_DEN | MX31_DMAREG_TH_DEN,
646 			spi_imx->base + MX31_CSPI_DMAREG);
647 	}
648 
649 	return 0;
650 }
651 
652 static int mx31_rx_available(struct spi_imx_data *spi_imx)
653 {
654 	return readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR;
655 }
656 
657 static void mx31_reset(struct spi_imx_data *spi_imx)
658 {
659 	/* drain receive buffer */
660 	while (readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR)
661 		readl(spi_imx->base + MXC_CSPIRXDATA);
662 }
663 
664 #define MX21_INTREG_RR		(1 << 4)
665 #define MX21_INTREG_TEEN	(1 << 9)
666 #define MX21_INTREG_RREN	(1 << 13)
667 
668 #define MX21_CSPICTRL_POL	(1 << 5)
669 #define MX21_CSPICTRL_PHA	(1 << 6)
670 #define MX21_CSPICTRL_SSPOL	(1 << 8)
671 #define MX21_CSPICTRL_XCH	(1 << 9)
672 #define MX21_CSPICTRL_ENABLE	(1 << 10)
673 #define MX21_CSPICTRL_MASTER	(1 << 11)
674 #define MX21_CSPICTRL_DR_SHIFT	14
675 #define MX21_CSPICTRL_CS_SHIFT	19
676 
677 static void mx21_intctrl(struct spi_imx_data *spi_imx, int enable)
678 {
679 	unsigned int val = 0;
680 
681 	if (enable & MXC_INT_TE)
682 		val |= MX21_INTREG_TEEN;
683 	if (enable & MXC_INT_RR)
684 		val |= MX21_INTREG_RREN;
685 
686 	writel(val, spi_imx->base + MXC_CSPIINT);
687 }
688 
689 static void mx21_trigger(struct spi_imx_data *spi_imx)
690 {
691 	unsigned int reg;
692 
693 	reg = readl(spi_imx->base + MXC_CSPICTRL);
694 	reg |= MX21_CSPICTRL_XCH;
695 	writel(reg, spi_imx->base + MXC_CSPICTRL);
696 }
697 
698 static int mx21_config(struct spi_device *spi)
699 {
700 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
701 	unsigned int reg = MX21_CSPICTRL_ENABLE | MX21_CSPICTRL_MASTER;
702 	unsigned int max = is_imx27_cspi(spi_imx) ? 16 : 18;
703 	unsigned int clk;
704 
705 	reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, spi_imx->speed_hz, max, &clk)
706 		<< MX21_CSPICTRL_DR_SHIFT;
707 	spi_imx->spi_bus_clk = clk;
708 
709 	reg |= spi_imx->bits_per_word - 1;
710 
711 	if (spi->mode & SPI_CPHA)
712 		reg |= MX21_CSPICTRL_PHA;
713 	if (spi->mode & SPI_CPOL)
714 		reg |= MX21_CSPICTRL_POL;
715 	if (spi->mode & SPI_CS_HIGH)
716 		reg |= MX21_CSPICTRL_SSPOL;
717 	if (!gpio_is_valid(spi->cs_gpio))
718 		reg |= spi->chip_select << MX21_CSPICTRL_CS_SHIFT;
719 
720 	writel(reg, spi_imx->base + MXC_CSPICTRL);
721 
722 	return 0;
723 }
724 
725 static int mx21_rx_available(struct spi_imx_data *spi_imx)
726 {
727 	return readl(spi_imx->base + MXC_CSPIINT) & MX21_INTREG_RR;
728 }
729 
730 static void mx21_reset(struct spi_imx_data *spi_imx)
731 {
732 	writel(1, spi_imx->base + MXC_RESET);
733 }
734 
735 #define MX1_INTREG_RR		(1 << 3)
736 #define MX1_INTREG_TEEN		(1 << 8)
737 #define MX1_INTREG_RREN		(1 << 11)
738 
739 #define MX1_CSPICTRL_POL	(1 << 4)
740 #define MX1_CSPICTRL_PHA	(1 << 5)
741 #define MX1_CSPICTRL_XCH	(1 << 8)
742 #define MX1_CSPICTRL_ENABLE	(1 << 9)
743 #define MX1_CSPICTRL_MASTER	(1 << 10)
744 #define MX1_CSPICTRL_DR_SHIFT	13
745 
746 static void mx1_intctrl(struct spi_imx_data *spi_imx, int enable)
747 {
748 	unsigned int val = 0;
749 
750 	if (enable & MXC_INT_TE)
751 		val |= MX1_INTREG_TEEN;
752 	if (enable & MXC_INT_RR)
753 		val |= MX1_INTREG_RREN;
754 
755 	writel(val, spi_imx->base + MXC_CSPIINT);
756 }
757 
758 static void mx1_trigger(struct spi_imx_data *spi_imx)
759 {
760 	unsigned int reg;
761 
762 	reg = readl(spi_imx->base + MXC_CSPICTRL);
763 	reg |= MX1_CSPICTRL_XCH;
764 	writel(reg, spi_imx->base + MXC_CSPICTRL);
765 }
766 
767 static int mx1_config(struct spi_device *spi)
768 {
769 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
770 	unsigned int reg = MX1_CSPICTRL_ENABLE | MX1_CSPICTRL_MASTER;
771 	unsigned int clk;
772 
773 	reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, spi_imx->speed_hz, &clk) <<
774 		MX1_CSPICTRL_DR_SHIFT;
775 	spi_imx->spi_bus_clk = clk;
776 
777 	reg |= spi_imx->bits_per_word - 1;
778 
779 	if (spi->mode & SPI_CPHA)
780 		reg |= MX1_CSPICTRL_PHA;
781 	if (spi->mode & SPI_CPOL)
782 		reg |= MX1_CSPICTRL_POL;
783 
784 	writel(reg, spi_imx->base + MXC_CSPICTRL);
785 
786 	return 0;
787 }
788 
789 static int mx1_rx_available(struct spi_imx_data *spi_imx)
790 {
791 	return readl(spi_imx->base + MXC_CSPIINT) & MX1_INTREG_RR;
792 }
793 
794 static void mx1_reset(struct spi_imx_data *spi_imx)
795 {
796 	writel(1, spi_imx->base + MXC_RESET);
797 }
798 
799 static struct spi_imx_devtype_data imx1_cspi_devtype_data = {
800 	.intctrl = mx1_intctrl,
801 	.config = mx1_config,
802 	.trigger = mx1_trigger,
803 	.rx_available = mx1_rx_available,
804 	.reset = mx1_reset,
805 	.fifo_size = 8,
806 	.has_dmamode = false,
807 	.dynamic_burst = false,
808 	.devtype = IMX1_CSPI,
809 };
810 
811 static struct spi_imx_devtype_data imx21_cspi_devtype_data = {
812 	.intctrl = mx21_intctrl,
813 	.config = mx21_config,
814 	.trigger = mx21_trigger,
815 	.rx_available = mx21_rx_available,
816 	.reset = mx21_reset,
817 	.fifo_size = 8,
818 	.has_dmamode = false,
819 	.dynamic_burst = false,
820 	.devtype = IMX21_CSPI,
821 };
822 
823 static struct spi_imx_devtype_data imx27_cspi_devtype_data = {
824 	/* i.mx27 cspi shares the functions with i.mx21 one */
825 	.intctrl = mx21_intctrl,
826 	.config = mx21_config,
827 	.trigger = mx21_trigger,
828 	.rx_available = mx21_rx_available,
829 	.reset = mx21_reset,
830 	.fifo_size = 8,
831 	.has_dmamode = false,
832 	.dynamic_burst = false,
833 	.devtype = IMX27_CSPI,
834 };
835 
836 static struct spi_imx_devtype_data imx31_cspi_devtype_data = {
837 	.intctrl = mx31_intctrl,
838 	.config = mx31_config,
839 	.trigger = mx31_trigger,
840 	.rx_available = mx31_rx_available,
841 	.reset = mx31_reset,
842 	.fifo_size = 8,
843 	.has_dmamode = false,
844 	.dynamic_burst = false,
845 	.devtype = IMX31_CSPI,
846 };
847 
848 static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
849 	/* i.mx35 and later cspi shares the functions with i.mx31 one */
850 	.intctrl = mx31_intctrl,
851 	.config = mx31_config,
852 	.trigger = mx31_trigger,
853 	.rx_available = mx31_rx_available,
854 	.reset = mx31_reset,
855 	.fifo_size = 8,
856 	.has_dmamode = true,
857 	.dynamic_burst = false,
858 	.devtype = IMX35_CSPI,
859 };
860 
861 static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
862 	.intctrl = mx51_ecspi_intctrl,
863 	.config = mx51_ecspi_config,
864 	.trigger = mx51_ecspi_trigger,
865 	.rx_available = mx51_ecspi_rx_available,
866 	.reset = mx51_ecspi_reset,
867 	.fifo_size = 64,
868 	.has_dmamode = true,
869 	.dynamic_burst = true,
870 	.devtype = IMX51_ECSPI,
871 };
872 
873 static struct spi_imx_devtype_data imx53_ecspi_devtype_data = {
874 	.intctrl = mx51_ecspi_intctrl,
875 	.config = mx51_ecspi_config,
876 	.trigger = mx51_ecspi_trigger,
877 	.rx_available = mx51_ecspi_rx_available,
878 	.reset = mx51_ecspi_reset,
879 	.fifo_size = 64,
880 	.has_dmamode = true,
881 	.devtype = IMX53_ECSPI,
882 };
883 
884 static const struct platform_device_id spi_imx_devtype[] = {
885 	{
886 		.name = "imx1-cspi",
887 		.driver_data = (kernel_ulong_t) &imx1_cspi_devtype_data,
888 	}, {
889 		.name = "imx21-cspi",
890 		.driver_data = (kernel_ulong_t) &imx21_cspi_devtype_data,
891 	}, {
892 		.name = "imx27-cspi",
893 		.driver_data = (kernel_ulong_t) &imx27_cspi_devtype_data,
894 	}, {
895 		.name = "imx31-cspi",
896 		.driver_data = (kernel_ulong_t) &imx31_cspi_devtype_data,
897 	}, {
898 		.name = "imx35-cspi",
899 		.driver_data = (kernel_ulong_t) &imx35_cspi_devtype_data,
900 	}, {
901 		.name = "imx51-ecspi",
902 		.driver_data = (kernel_ulong_t) &imx51_ecspi_devtype_data,
903 	}, {
904 		.name = "imx53-ecspi",
905 		.driver_data = (kernel_ulong_t) &imx53_ecspi_devtype_data,
906 	}, {
907 		/* sentinel */
908 	}
909 };
910 
911 static const struct of_device_id spi_imx_dt_ids[] = {
912 	{ .compatible = "fsl,imx1-cspi", .data = &imx1_cspi_devtype_data, },
913 	{ .compatible = "fsl,imx21-cspi", .data = &imx21_cspi_devtype_data, },
914 	{ .compatible = "fsl,imx27-cspi", .data = &imx27_cspi_devtype_data, },
915 	{ .compatible = "fsl,imx31-cspi", .data = &imx31_cspi_devtype_data, },
916 	{ .compatible = "fsl,imx35-cspi", .data = &imx35_cspi_devtype_data, },
917 	{ .compatible = "fsl,imx51-ecspi", .data = &imx51_ecspi_devtype_data, },
918 	{ .compatible = "fsl,imx53-ecspi", .data = &imx53_ecspi_devtype_data, },
919 	{ /* sentinel */ }
920 };
921 MODULE_DEVICE_TABLE(of, spi_imx_dt_ids);
922 
923 static void spi_imx_chipselect(struct spi_device *spi, int is_active)
924 {
925 	int active = is_active != BITBANG_CS_INACTIVE;
926 	int dev_is_lowactive = !(spi->mode & SPI_CS_HIGH);
927 
928 	if (spi->mode & SPI_NO_CS)
929 		return;
930 
931 	if (!gpio_is_valid(spi->cs_gpio))
932 		return;
933 
934 	gpio_set_value(spi->cs_gpio, dev_is_lowactive ^ active);
935 }
936 
937 static void spi_imx_push(struct spi_imx_data *spi_imx)
938 {
939 	while (spi_imx->txfifo < spi_imx->devtype_data->fifo_size) {
940 		if (!spi_imx->count)
941 			break;
942 		if (spi_imx->txfifo && (spi_imx->count == spi_imx->remainder))
943 			break;
944 		spi_imx->tx(spi_imx);
945 		spi_imx->txfifo++;
946 	}
947 
948 	spi_imx->devtype_data->trigger(spi_imx);
949 }
950 
951 static irqreturn_t spi_imx_isr(int irq, void *dev_id)
952 {
953 	struct spi_imx_data *spi_imx = dev_id;
954 
955 	while (spi_imx->devtype_data->rx_available(spi_imx)) {
956 		spi_imx->rx(spi_imx);
957 		spi_imx->txfifo--;
958 	}
959 
960 	if (spi_imx->count) {
961 		spi_imx_push(spi_imx);
962 		return IRQ_HANDLED;
963 	}
964 
965 	if (spi_imx->txfifo) {
966 		/* No data left to push, but still waiting for rx data,
967 		 * enable receive data available interrupt.
968 		 */
969 		spi_imx->devtype_data->intctrl(
970 				spi_imx, MXC_INT_RR);
971 		return IRQ_HANDLED;
972 	}
973 
974 	spi_imx->devtype_data->intctrl(spi_imx, 0);
975 	complete(&spi_imx->xfer_done);
976 
977 	return IRQ_HANDLED;
978 }
979 
980 static int spi_imx_dma_configure(struct spi_master *master)
981 {
982 	int ret;
983 	enum dma_slave_buswidth buswidth;
984 	struct dma_slave_config rx = {}, tx = {};
985 	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
986 
987 	switch (spi_imx_bytes_per_word(spi_imx->bits_per_word)) {
988 	case 4:
989 		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
990 		break;
991 	case 2:
992 		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
993 		break;
994 	case 1:
995 		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
996 		break;
997 	default:
998 		return -EINVAL;
999 	}
1000 
1001 	tx.direction = DMA_MEM_TO_DEV;
1002 	tx.dst_addr = spi_imx->base_phys + MXC_CSPITXDATA;
1003 	tx.dst_addr_width = buswidth;
1004 	tx.dst_maxburst = spi_imx->wml;
1005 	ret = dmaengine_slave_config(master->dma_tx, &tx);
1006 	if (ret) {
1007 		dev_err(spi_imx->dev, "TX dma configuration failed with %d\n", ret);
1008 		return ret;
1009 	}
1010 
1011 	rx.direction = DMA_DEV_TO_MEM;
1012 	rx.src_addr = spi_imx->base_phys + MXC_CSPIRXDATA;
1013 	rx.src_addr_width = buswidth;
1014 	rx.src_maxburst = spi_imx->wml;
1015 	ret = dmaengine_slave_config(master->dma_rx, &rx);
1016 	if (ret) {
1017 		dev_err(spi_imx->dev, "RX dma configuration failed with %d\n", ret);
1018 		return ret;
1019 	}
1020 
1021 	return 0;
1022 }
1023 
1024 static int spi_imx_setupxfer(struct spi_device *spi,
1025 				 struct spi_transfer *t)
1026 {
1027 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
1028 	int ret;
1029 
1030 	if (!t)
1031 		return 0;
1032 
1033 	spi_imx->bits_per_word = t->bits_per_word;
1034 	spi_imx->speed_hz  = t->speed_hz;
1035 
1036 	/* Initialize the functions for transfer */
1037 	if (spi_imx->devtype_data->dynamic_burst) {
1038 		u32 mask;
1039 
1040 		spi_imx->dynamic_burst = 0;
1041 		spi_imx->remainder = 0;
1042 		spi_imx->read_u32  = 1;
1043 
1044 		mask = (1 << spi_imx->bits_per_word) - 1;
1045 		spi_imx->rx = spi_imx_buf_rx_swap;
1046 		spi_imx->tx = spi_imx_buf_tx_swap;
1047 		spi_imx->dynamic_burst = 1;
1048 		spi_imx->remainder = t->len;
1049 
1050 		if (spi_imx->bits_per_word <= 8)
1051 			spi_imx->word_mask = mask << 24 | mask << 16
1052 					     | mask << 8 | mask;
1053 		else if (spi_imx->bits_per_word <= 16)
1054 			spi_imx->word_mask = mask << 16 | mask;
1055 		else
1056 			spi_imx->word_mask = mask;
1057 	} else {
1058 		if (spi_imx->bits_per_word <= 8) {
1059 			spi_imx->rx = spi_imx_buf_rx_u8;
1060 			spi_imx->tx = spi_imx_buf_tx_u8;
1061 		} else if (spi_imx->bits_per_word <= 16) {
1062 			spi_imx->rx = spi_imx_buf_rx_u16;
1063 			spi_imx->tx = spi_imx_buf_tx_u16;
1064 		} else {
1065 			spi_imx->rx = spi_imx_buf_rx_u32;
1066 			spi_imx->tx = spi_imx_buf_tx_u32;
1067 		}
1068 	}
1069 
1070 	if (spi_imx_can_dma(spi_imx->bitbang.master, spi, t))
1071 		spi_imx->usedma = 1;
1072 	else
1073 		spi_imx->usedma = 0;
1074 
1075 	if (spi_imx->usedma) {
1076 		ret = spi_imx_dma_configure(spi->master);
1077 		if (ret)
1078 			return ret;
1079 	}
1080 
1081 	spi_imx->devtype_data->config(spi);
1082 
1083 	return 0;
1084 }
1085 
1086 static void spi_imx_sdma_exit(struct spi_imx_data *spi_imx)
1087 {
1088 	struct spi_master *master = spi_imx->bitbang.master;
1089 
1090 	if (master->dma_rx) {
1091 		dma_release_channel(master->dma_rx);
1092 		master->dma_rx = NULL;
1093 	}
1094 
1095 	if (master->dma_tx) {
1096 		dma_release_channel(master->dma_tx);
1097 		master->dma_tx = NULL;
1098 	}
1099 }
1100 
1101 static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
1102 			     struct spi_master *master)
1103 {
1104 	int ret;
1105 
1106 	/* use pio mode for i.mx6dl chip TKT238285 */
1107 	if (of_machine_is_compatible("fsl,imx6dl"))
1108 		return 0;
1109 
1110 	spi_imx->wml = spi_imx->devtype_data->fifo_size / 2;
1111 
1112 	/* Prepare for TX DMA: */
1113 	master->dma_tx = dma_request_slave_channel_reason(dev, "tx");
1114 	if (IS_ERR(master->dma_tx)) {
1115 		ret = PTR_ERR(master->dma_tx);
1116 		dev_dbg(dev, "can't get the TX DMA channel, error %d!\n", ret);
1117 		master->dma_tx = NULL;
1118 		goto err;
1119 	}
1120 
1121 	/* Prepare for RX : */
1122 	master->dma_rx = dma_request_slave_channel_reason(dev, "rx");
1123 	if (IS_ERR(master->dma_rx)) {
1124 		ret = PTR_ERR(master->dma_rx);
1125 		dev_dbg(dev, "can't get the RX DMA channel, error %d\n", ret);
1126 		master->dma_rx = NULL;
1127 		goto err;
1128 	}
1129 
1130 	init_completion(&spi_imx->dma_rx_completion);
1131 	init_completion(&spi_imx->dma_tx_completion);
1132 	master->can_dma = spi_imx_can_dma;
1133 	master->max_dma_len = MAX_SDMA_BD_BYTES;
1134 	spi_imx->bitbang.master->flags = SPI_MASTER_MUST_RX |
1135 					 SPI_MASTER_MUST_TX;
1136 
1137 	return 0;
1138 err:
1139 	spi_imx_sdma_exit(spi_imx);
1140 	return ret;
1141 }
1142 
1143 static void spi_imx_dma_rx_callback(void *cookie)
1144 {
1145 	struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie;
1146 
1147 	complete(&spi_imx->dma_rx_completion);
1148 }
1149 
1150 static void spi_imx_dma_tx_callback(void *cookie)
1151 {
1152 	struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie;
1153 
1154 	complete(&spi_imx->dma_tx_completion);
1155 }
1156 
1157 static int spi_imx_calculate_timeout(struct spi_imx_data *spi_imx, int size)
1158 {
1159 	unsigned long timeout = 0;
1160 
1161 	/* Time with actual data transfer and CS change delay related to HW */
1162 	timeout = (8 + 4) * size / spi_imx->spi_bus_clk;
1163 
1164 	/* Add extra second for scheduler related activities */
1165 	timeout += 1;
1166 
1167 	/* Double calculated timeout */
1168 	return msecs_to_jiffies(2 * timeout * MSEC_PER_SEC);
1169 }
1170 
1171 static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
1172 				struct spi_transfer *transfer)
1173 {
1174 	struct dma_async_tx_descriptor *desc_tx, *desc_rx;
1175 	unsigned long transfer_timeout;
1176 	unsigned long timeout;
1177 	struct spi_master *master = spi_imx->bitbang.master;
1178 	struct sg_table *tx = &transfer->tx_sg, *rx = &transfer->rx_sg;
1179 
1180 	/*
1181 	 * The TX DMA setup starts the transfer, so make sure RX is configured
1182 	 * before TX.
1183 	 */
1184 	desc_rx = dmaengine_prep_slave_sg(master->dma_rx,
1185 				rx->sgl, rx->nents, DMA_DEV_TO_MEM,
1186 				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1187 	if (!desc_rx)
1188 		return -EINVAL;
1189 
1190 	desc_rx->callback = spi_imx_dma_rx_callback;
1191 	desc_rx->callback_param = (void *)spi_imx;
1192 	dmaengine_submit(desc_rx);
1193 	reinit_completion(&spi_imx->dma_rx_completion);
1194 	dma_async_issue_pending(master->dma_rx);
1195 
1196 	desc_tx = dmaengine_prep_slave_sg(master->dma_tx,
1197 				tx->sgl, tx->nents, DMA_MEM_TO_DEV,
1198 				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1199 	if (!desc_tx) {
1200 		dmaengine_terminate_all(master->dma_tx);
1201 		return -EINVAL;
1202 	}
1203 
1204 	desc_tx->callback = spi_imx_dma_tx_callback;
1205 	desc_tx->callback_param = (void *)spi_imx;
1206 	dmaengine_submit(desc_tx);
1207 	reinit_completion(&spi_imx->dma_tx_completion);
1208 	dma_async_issue_pending(master->dma_tx);
1209 
1210 	transfer_timeout = spi_imx_calculate_timeout(spi_imx, transfer->len);
1211 
1212 	/* Wait SDMA to finish the data transfer.*/
1213 	timeout = wait_for_completion_timeout(&spi_imx->dma_tx_completion,
1214 						transfer_timeout);
1215 	if (!timeout) {
1216 		dev_err(spi_imx->dev, "I/O Error in DMA TX\n");
1217 		dmaengine_terminate_all(master->dma_tx);
1218 		dmaengine_terminate_all(master->dma_rx);
1219 		return -ETIMEDOUT;
1220 	}
1221 
1222 	timeout = wait_for_completion_timeout(&spi_imx->dma_rx_completion,
1223 					      transfer_timeout);
1224 	if (!timeout) {
1225 		dev_err(&master->dev, "I/O Error in DMA RX\n");
1226 		spi_imx->devtype_data->reset(spi_imx);
1227 		dmaengine_terminate_all(master->dma_rx);
1228 		return -ETIMEDOUT;
1229 	}
1230 
1231 	return transfer->len;
1232 }
1233 
1234 static int spi_imx_pio_transfer(struct spi_device *spi,
1235 				struct spi_transfer *transfer)
1236 {
1237 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
1238 	unsigned long transfer_timeout;
1239 	unsigned long timeout;
1240 
1241 	spi_imx->tx_buf = transfer->tx_buf;
1242 	spi_imx->rx_buf = transfer->rx_buf;
1243 	spi_imx->count = transfer->len;
1244 	spi_imx->txfifo = 0;
1245 
1246 	reinit_completion(&spi_imx->xfer_done);
1247 
1248 	spi_imx_push(spi_imx);
1249 
1250 	spi_imx->devtype_data->intctrl(spi_imx, MXC_INT_TE);
1251 
1252 	transfer_timeout = spi_imx_calculate_timeout(spi_imx, transfer->len);
1253 
1254 	timeout = wait_for_completion_timeout(&spi_imx->xfer_done,
1255 					      transfer_timeout);
1256 	if (!timeout) {
1257 		dev_err(&spi->dev, "I/O Error in PIO\n");
1258 		spi_imx->devtype_data->reset(spi_imx);
1259 		return -ETIMEDOUT;
1260 	}
1261 
1262 	return transfer->len;
1263 }
1264 
1265 static int spi_imx_transfer(struct spi_device *spi,
1266 				struct spi_transfer *transfer)
1267 {
1268 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
1269 
1270 	if (spi_imx->usedma)
1271 		return spi_imx_dma_transfer(spi_imx, transfer);
1272 	else
1273 		return spi_imx_pio_transfer(spi, transfer);
1274 }
1275 
1276 static int spi_imx_setup(struct spi_device *spi)
1277 {
1278 	dev_dbg(&spi->dev, "%s: mode %d, %u bpw, %d hz\n", __func__,
1279 		 spi->mode, spi->bits_per_word, spi->max_speed_hz);
1280 
1281 	if (spi->mode & SPI_NO_CS)
1282 		return 0;
1283 
1284 	if (gpio_is_valid(spi->cs_gpio))
1285 		gpio_direction_output(spi->cs_gpio,
1286 				      spi->mode & SPI_CS_HIGH ? 0 : 1);
1287 
1288 	spi_imx_chipselect(spi, BITBANG_CS_INACTIVE);
1289 
1290 	return 0;
1291 }
1292 
1293 static void spi_imx_cleanup(struct spi_device *spi)
1294 {
1295 }
1296 
1297 static int
1298 spi_imx_prepare_message(struct spi_master *master, struct spi_message *msg)
1299 {
1300 	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
1301 	int ret;
1302 
1303 	ret = clk_enable(spi_imx->clk_per);
1304 	if (ret)
1305 		return ret;
1306 
1307 	ret = clk_enable(spi_imx->clk_ipg);
1308 	if (ret) {
1309 		clk_disable(spi_imx->clk_per);
1310 		return ret;
1311 	}
1312 
1313 	return 0;
1314 }
1315 
1316 static int
1317 spi_imx_unprepare_message(struct spi_master *master, struct spi_message *msg)
1318 {
1319 	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
1320 
1321 	clk_disable(spi_imx->clk_ipg);
1322 	clk_disable(spi_imx->clk_per);
1323 	return 0;
1324 }
1325 
1326 static int spi_imx_probe(struct platform_device *pdev)
1327 {
1328 	struct device_node *np = pdev->dev.of_node;
1329 	const struct of_device_id *of_id =
1330 			of_match_device(spi_imx_dt_ids, &pdev->dev);
1331 	struct spi_imx_master *mxc_platform_info =
1332 			dev_get_platdata(&pdev->dev);
1333 	struct spi_master *master;
1334 	struct spi_imx_data *spi_imx;
1335 	struct resource *res;
1336 	int i, ret, irq, spi_drctl;
1337 
1338 	if (!np && !mxc_platform_info) {
1339 		dev_err(&pdev->dev, "can't get the platform data\n");
1340 		return -EINVAL;
1341 	}
1342 
1343 	master = spi_alloc_master(&pdev->dev, sizeof(struct spi_imx_data));
1344 	if (!master)
1345 		return -ENOMEM;
1346 
1347 	ret = of_property_read_u32(np, "fsl,spi-rdy-drctl", &spi_drctl);
1348 	if ((ret < 0) || (spi_drctl >= 0x3)) {
1349 		/* '11' is reserved */
1350 		spi_drctl = 0;
1351 	}
1352 
1353 	platform_set_drvdata(pdev, master);
1354 
1355 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
1356 	master->bus_num = np ? -1 : pdev->id;
1357 
1358 	spi_imx = spi_master_get_devdata(master);
1359 	spi_imx->bitbang.master = master;
1360 	spi_imx->dev = &pdev->dev;
1361 
1362 	spi_imx->devtype_data = of_id ? of_id->data :
1363 		(struct spi_imx_devtype_data *)pdev->id_entry->driver_data;
1364 
1365 	if (mxc_platform_info) {
1366 		master->num_chipselect = mxc_platform_info->num_chipselect;
1367 		master->cs_gpios = devm_kzalloc(&master->dev,
1368 			sizeof(int) * master->num_chipselect, GFP_KERNEL);
1369 		if (!master->cs_gpios)
1370 			return -ENOMEM;
1371 
1372 		for (i = 0; i < master->num_chipselect; i++)
1373 			master->cs_gpios[i] = mxc_platform_info->chipselect[i];
1374  	}
1375 
1376 	spi_imx->bitbang.chipselect = spi_imx_chipselect;
1377 	spi_imx->bitbang.setup_transfer = spi_imx_setupxfer;
1378 	spi_imx->bitbang.txrx_bufs = spi_imx_transfer;
1379 	spi_imx->bitbang.master->setup = spi_imx_setup;
1380 	spi_imx->bitbang.master->cleanup = spi_imx_cleanup;
1381 	spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message;
1382 	spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;
1383 	spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \
1384 					     | SPI_NO_CS;
1385 	if (is_imx35_cspi(spi_imx) || is_imx51_ecspi(spi_imx) ||
1386 	    is_imx53_ecspi(spi_imx))
1387 		spi_imx->bitbang.master->mode_bits |= SPI_LOOP | SPI_READY;
1388 
1389 	spi_imx->spi_drctl = spi_drctl;
1390 
1391 	init_completion(&spi_imx->xfer_done);
1392 
1393 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1394 	spi_imx->base = devm_ioremap_resource(&pdev->dev, res);
1395 	if (IS_ERR(spi_imx->base)) {
1396 		ret = PTR_ERR(spi_imx->base);
1397 		goto out_master_put;
1398 	}
1399 	spi_imx->base_phys = res->start;
1400 
1401 	irq = platform_get_irq(pdev, 0);
1402 	if (irq < 0) {
1403 		ret = irq;
1404 		goto out_master_put;
1405 	}
1406 
1407 	ret = devm_request_irq(&pdev->dev, irq, spi_imx_isr, 0,
1408 			       dev_name(&pdev->dev), spi_imx);
1409 	if (ret) {
1410 		dev_err(&pdev->dev, "can't get irq%d: %d\n", irq, ret);
1411 		goto out_master_put;
1412 	}
1413 
1414 	spi_imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1415 	if (IS_ERR(spi_imx->clk_ipg)) {
1416 		ret = PTR_ERR(spi_imx->clk_ipg);
1417 		goto out_master_put;
1418 	}
1419 
1420 	spi_imx->clk_per = devm_clk_get(&pdev->dev, "per");
1421 	if (IS_ERR(spi_imx->clk_per)) {
1422 		ret = PTR_ERR(spi_imx->clk_per);
1423 		goto out_master_put;
1424 	}
1425 
1426 	ret = clk_prepare_enable(spi_imx->clk_per);
1427 	if (ret)
1428 		goto out_master_put;
1429 
1430 	ret = clk_prepare_enable(spi_imx->clk_ipg);
1431 	if (ret)
1432 		goto out_put_per;
1433 
1434 	spi_imx->spi_clk = clk_get_rate(spi_imx->clk_per);
1435 	/*
1436 	 * Only validated on i.mx35 and i.mx6 now, can remove the constraint
1437 	 * if validated on other chips.
1438 	 */
1439 	if (spi_imx->devtype_data->has_dmamode) {
1440 		ret = spi_imx_sdma_init(&pdev->dev, spi_imx, master);
1441 		if (ret == -EPROBE_DEFER)
1442 			goto out_clk_put;
1443 
1444 		if (ret < 0)
1445 			dev_err(&pdev->dev, "dma setup error %d, use pio\n",
1446 				ret);
1447 	}
1448 
1449 	spi_imx->devtype_data->reset(spi_imx);
1450 
1451 	spi_imx->devtype_data->intctrl(spi_imx, 0);
1452 
1453 	master->dev.of_node = pdev->dev.of_node;
1454 	ret = spi_bitbang_start(&spi_imx->bitbang);
1455 	if (ret) {
1456 		dev_err(&pdev->dev, "bitbang start failed with %d\n", ret);
1457 		goto out_clk_put;
1458 	}
1459 
1460 	if (!master->cs_gpios) {
1461 		dev_err(&pdev->dev, "No CS GPIOs available\n");
1462 		ret = -EINVAL;
1463 		goto out_clk_put;
1464 	}
1465 
1466 	for (i = 0; i < master->num_chipselect; i++) {
1467 		if (!gpio_is_valid(master->cs_gpios[i]))
1468 			continue;
1469 
1470 		ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i],
1471 					DRIVER_NAME);
1472 		if (ret) {
1473 			dev_err(&pdev->dev, "Can't get CS GPIO %i\n",
1474 				master->cs_gpios[i]);
1475 			goto out_clk_put;
1476 		}
1477 	}
1478 
1479 	dev_info(&pdev->dev, "probed\n");
1480 
1481 	clk_disable(spi_imx->clk_ipg);
1482 	clk_disable(spi_imx->clk_per);
1483 	return ret;
1484 
1485 out_clk_put:
1486 	clk_disable_unprepare(spi_imx->clk_ipg);
1487 out_put_per:
1488 	clk_disable_unprepare(spi_imx->clk_per);
1489 out_master_put:
1490 	spi_master_put(master);
1491 
1492 	return ret;
1493 }
1494 
1495 static int spi_imx_remove(struct platform_device *pdev)
1496 {
1497 	struct spi_master *master = platform_get_drvdata(pdev);
1498 	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
1499 
1500 	spi_bitbang_stop(&spi_imx->bitbang);
1501 
1502 	writel(0, spi_imx->base + MXC_CSPICTRL);
1503 	clk_unprepare(spi_imx->clk_ipg);
1504 	clk_unprepare(spi_imx->clk_per);
1505 	spi_imx_sdma_exit(spi_imx);
1506 	spi_master_put(master);
1507 
1508 	return 0;
1509 }
1510 
1511 static struct platform_driver spi_imx_driver = {
1512 	.driver = {
1513 		   .name = DRIVER_NAME,
1514 		   .of_match_table = spi_imx_dt_ids,
1515 		   },
1516 	.id_table = spi_imx_devtype,
1517 	.probe = spi_imx_probe,
1518 	.remove = spi_imx_remove,
1519 };
1520 module_platform_driver(spi_imx_driver);
1521 
1522 MODULE_DESCRIPTION("SPI Master Controller driver");
1523 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
1524 MODULE_LICENSE("GPL");
1525 MODULE_ALIAS("platform:" DRIVER_NAME);
1526