xref: /openbmc/linux/drivers/spi/spi-imx.c (revision 2596e07a)
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 IMX_DMA_TIMEOUT (msecs_to_jiffies(3000))
60 struct spi_imx_config {
61 	unsigned int speed_hz;
62 	unsigned int bpw;
63 	unsigned int mode;
64 	u8 cs;
65 };
66 
67 enum spi_imx_devtype {
68 	IMX1_CSPI,
69 	IMX21_CSPI,
70 	IMX27_CSPI,
71 	IMX31_CSPI,
72 	IMX35_CSPI,	/* CSPI on all i.mx except above */
73 	IMX51_ECSPI,	/* ECSPI on i.mx51 and later */
74 };
75 
76 struct spi_imx_data;
77 
78 struct spi_imx_devtype_data {
79 	void (*intctrl)(struct spi_imx_data *, int);
80 	int (*config)(struct spi_imx_data *, struct spi_imx_config *);
81 	void (*trigger)(struct spi_imx_data *);
82 	int (*rx_available)(struct spi_imx_data *);
83 	void (*reset)(struct spi_imx_data *);
84 	enum spi_imx_devtype devtype;
85 };
86 
87 struct spi_imx_data {
88 	struct spi_bitbang bitbang;
89 
90 	struct completion xfer_done;
91 	void __iomem *base;
92 	struct clk *clk_per;
93 	struct clk *clk_ipg;
94 	unsigned long spi_clk;
95 
96 	unsigned int count;
97 	void (*tx)(struct spi_imx_data *);
98 	void (*rx)(struct spi_imx_data *);
99 	void *rx_buf;
100 	const void *tx_buf;
101 	unsigned int txfifo; /* number of words pushed in tx FIFO */
102 
103 	/* DMA */
104 	unsigned int dma_is_inited;
105 	unsigned int dma_finished;
106 	bool usedma;
107 	u32 wml;
108 	struct completion dma_rx_completion;
109 	struct completion dma_tx_completion;
110 
111 	const struct spi_imx_devtype_data *devtype_data;
112 	int chipselect[0];
113 };
114 
115 static inline int is_imx27_cspi(struct spi_imx_data *d)
116 {
117 	return d->devtype_data->devtype == IMX27_CSPI;
118 }
119 
120 static inline int is_imx35_cspi(struct spi_imx_data *d)
121 {
122 	return d->devtype_data->devtype == IMX35_CSPI;
123 }
124 
125 static inline int is_imx51_ecspi(struct spi_imx_data *d)
126 {
127 	return d->devtype_data->devtype == IMX51_ECSPI;
128 }
129 
130 static inline unsigned spi_imx_get_fifosize(struct spi_imx_data *d)
131 {
132 	return is_imx51_ecspi(d) ? 64 : 8;
133 }
134 
135 #define MXC_SPI_BUF_RX(type)						\
136 static void spi_imx_buf_rx_##type(struct spi_imx_data *spi_imx)		\
137 {									\
138 	unsigned int val = readl(spi_imx->base + MXC_CSPIRXDATA);	\
139 									\
140 	if (spi_imx->rx_buf) {						\
141 		*(type *)spi_imx->rx_buf = val;				\
142 		spi_imx->rx_buf += sizeof(type);			\
143 	}								\
144 }
145 
146 #define MXC_SPI_BUF_TX(type)						\
147 static void spi_imx_buf_tx_##type(struct spi_imx_data *spi_imx)		\
148 {									\
149 	type val = 0;							\
150 									\
151 	if (spi_imx->tx_buf) {						\
152 		val = *(type *)spi_imx->tx_buf;				\
153 		spi_imx->tx_buf += sizeof(type);			\
154 	}								\
155 									\
156 	spi_imx->count -= sizeof(type);					\
157 									\
158 	writel(val, spi_imx->base + MXC_CSPITXDATA);			\
159 }
160 
161 MXC_SPI_BUF_RX(u8)
162 MXC_SPI_BUF_TX(u8)
163 MXC_SPI_BUF_RX(u16)
164 MXC_SPI_BUF_TX(u16)
165 MXC_SPI_BUF_RX(u32)
166 MXC_SPI_BUF_TX(u32)
167 
168 /* First entry is reserved, second entry is valid only if SDHC_SPIEN is set
169  * (which is currently not the case in this driver)
170  */
171 static int mxc_clkdivs[] = {0, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192,
172 	256, 384, 512, 768, 1024};
173 
174 /* MX21, MX27 */
175 static unsigned int spi_imx_clkdiv_1(unsigned int fin,
176 		unsigned int fspi, unsigned int max)
177 {
178 	int i;
179 
180 	for (i = 2; i < max; i++)
181 		if (fspi * mxc_clkdivs[i] >= fin)
182 			return i;
183 
184 	return max;
185 }
186 
187 /* MX1, MX31, MX35, MX51 CSPI */
188 static unsigned int spi_imx_clkdiv_2(unsigned int fin,
189 		unsigned int fspi)
190 {
191 	int i, div = 4;
192 
193 	for (i = 0; i < 7; i++) {
194 		if (fspi * div >= fin)
195 			return i;
196 		div <<= 1;
197 	}
198 
199 	return 7;
200 }
201 
202 static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
203 			 struct spi_transfer *transfer)
204 {
205 	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
206 
207 	if (spi_imx->dma_is_inited &&
208 	    transfer->len > spi_imx->wml * sizeof(u32))
209 		return true;
210 	return false;
211 }
212 
213 #define MX51_ECSPI_CTRL		0x08
214 #define MX51_ECSPI_CTRL_ENABLE		(1 <<  0)
215 #define MX51_ECSPI_CTRL_XCH		(1 <<  2)
216 #define MX51_ECSPI_CTRL_SMC		(1 << 3)
217 #define MX51_ECSPI_CTRL_MODE_MASK	(0xf << 4)
218 #define MX51_ECSPI_CTRL_POSTDIV_OFFSET	8
219 #define MX51_ECSPI_CTRL_PREDIV_OFFSET	12
220 #define MX51_ECSPI_CTRL_CS(cs)		((cs) << 18)
221 #define MX51_ECSPI_CTRL_BL_OFFSET	20
222 
223 #define MX51_ECSPI_CONFIG	0x0c
224 #define MX51_ECSPI_CONFIG_SCLKPHA(cs)	(1 << ((cs) +  0))
225 #define MX51_ECSPI_CONFIG_SCLKPOL(cs)	(1 << ((cs) +  4))
226 #define MX51_ECSPI_CONFIG_SBBCTRL(cs)	(1 << ((cs) +  8))
227 #define MX51_ECSPI_CONFIG_SSBPOL(cs)	(1 << ((cs) + 12))
228 #define MX51_ECSPI_CONFIG_SCLKCTL(cs)	(1 << ((cs) + 20))
229 
230 #define MX51_ECSPI_INT		0x10
231 #define MX51_ECSPI_INT_TEEN		(1 <<  0)
232 #define MX51_ECSPI_INT_RREN		(1 <<  3)
233 
234 #define MX51_ECSPI_DMA      0x14
235 #define MX51_ECSPI_DMA_TX_WML_OFFSET	0
236 #define MX51_ECSPI_DMA_TX_WML_MASK	0x3F
237 #define MX51_ECSPI_DMA_RX_WML_OFFSET	16
238 #define MX51_ECSPI_DMA_RX_WML_MASK	(0x3F << 16)
239 #define MX51_ECSPI_DMA_RXT_WML_OFFSET	24
240 #define MX51_ECSPI_DMA_RXT_WML_MASK	(0x3F << 24)
241 
242 #define MX51_ECSPI_DMA_TEDEN_OFFSET	7
243 #define MX51_ECSPI_DMA_RXDEN_OFFSET	23
244 #define MX51_ECSPI_DMA_RXTDEN_OFFSET	31
245 
246 #define MX51_ECSPI_STAT		0x18
247 #define MX51_ECSPI_STAT_RR		(1 <<  3)
248 
249 #define MX51_ECSPI_TESTREG	0x20
250 #define MX51_ECSPI_TESTREG_LBC	BIT(31)
251 
252 /* MX51 eCSPI */
253 static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi,
254 				      unsigned int *fres)
255 {
256 	/*
257 	 * there are two 4-bit dividers, the pre-divider divides by
258 	 * $pre, the post-divider by 2^$post
259 	 */
260 	unsigned int pre, post;
261 
262 	if (unlikely(fspi > fin))
263 		return 0;
264 
265 	post = fls(fin) - fls(fspi);
266 	if (fin > fspi << post)
267 		post++;
268 
269 	/* now we have: (fin <= fspi << post) with post being minimal */
270 
271 	post = max(4U, post) - 4;
272 	if (unlikely(post > 0xf)) {
273 		pr_err("%s: cannot set clock freq: %u (base freq: %u)\n",
274 				__func__, fspi, fin);
275 		return 0xff;
276 	}
277 
278 	pre = DIV_ROUND_UP(fin, fspi << post) - 1;
279 
280 	pr_debug("%s: fin: %u, fspi: %u, post: %u, pre: %u\n",
281 			__func__, fin, fspi, post, pre);
282 
283 	/* Resulting frequency for the SCLK line. */
284 	*fres = (fin / (pre + 1)) >> post;
285 
286 	return (pre << MX51_ECSPI_CTRL_PREDIV_OFFSET) |
287 		(post << MX51_ECSPI_CTRL_POSTDIV_OFFSET);
288 }
289 
290 static void __maybe_unused mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int enable)
291 {
292 	unsigned val = 0;
293 
294 	if (enable & MXC_INT_TE)
295 		val |= MX51_ECSPI_INT_TEEN;
296 
297 	if (enable & MXC_INT_RR)
298 		val |= MX51_ECSPI_INT_RREN;
299 
300 	writel(val, spi_imx->base + MX51_ECSPI_INT);
301 }
302 
303 static void __maybe_unused mx51_ecspi_trigger(struct spi_imx_data *spi_imx)
304 {
305 	u32 reg = readl(spi_imx->base + MX51_ECSPI_CTRL);
306 
307 	if (!spi_imx->usedma)
308 		reg |= MX51_ECSPI_CTRL_XCH;
309 	else if (!spi_imx->dma_finished)
310 		reg |= MX51_ECSPI_CTRL_SMC;
311 	else
312 		reg &= ~MX51_ECSPI_CTRL_SMC;
313 	writel(reg, spi_imx->base + MX51_ECSPI_CTRL);
314 }
315 
316 static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
317 		struct spi_imx_config *config)
318 {
319 	u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0, dma = 0;
320 	u32 tx_wml_cfg, rx_wml_cfg, rxt_wml_cfg;
321 	u32 clk = config->speed_hz, delay, reg;
322 
323 	/*
324 	 * The hardware seems to have a race condition when changing modes. The
325 	 * current assumption is that the selection of the channel arrives
326 	 * earlier in the hardware than the mode bits when they are written at
327 	 * the same time.
328 	 * So set master mode for all channels as we do not support slave mode.
329 	 */
330 	ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
331 
332 	/* set clock speed */
333 	ctrl |= mx51_ecspi_clkdiv(spi_imx->spi_clk, config->speed_hz, &clk);
334 
335 	/* set chip select to use */
336 	ctrl |= MX51_ECSPI_CTRL_CS(config->cs);
337 
338 	ctrl |= (config->bpw - 1) << MX51_ECSPI_CTRL_BL_OFFSET;
339 
340 	cfg |= MX51_ECSPI_CONFIG_SBBCTRL(config->cs);
341 
342 	if (config->mode & SPI_CPHA)
343 		cfg |= MX51_ECSPI_CONFIG_SCLKPHA(config->cs);
344 	else
345 		cfg &= ~MX51_ECSPI_CONFIG_SCLKPHA(config->cs);
346 
347 	if (config->mode & SPI_CPOL) {
348 		cfg |= MX51_ECSPI_CONFIG_SCLKPOL(config->cs);
349 		cfg |= MX51_ECSPI_CONFIG_SCLKCTL(config->cs);
350 	} else {
351 		cfg &= ~MX51_ECSPI_CONFIG_SCLKPOL(config->cs);
352 		cfg &= ~MX51_ECSPI_CONFIG_SCLKCTL(config->cs);
353 	}
354 	if (config->mode & SPI_CS_HIGH)
355 		cfg |= MX51_ECSPI_CONFIG_SSBPOL(config->cs);
356 	else
357 		cfg &= ~MX51_ECSPI_CONFIG_SSBPOL(config->cs);
358 
359 	/* CTRL register always go first to bring out controller from reset */
360 	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
361 
362 	reg = readl(spi_imx->base + MX51_ECSPI_TESTREG);
363 	if (config->mode & SPI_LOOP)
364 		reg |= MX51_ECSPI_TESTREG_LBC;
365 	else
366 		reg &= ~MX51_ECSPI_TESTREG_LBC;
367 	writel(reg, spi_imx->base + MX51_ECSPI_TESTREG);
368 
369 	writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
370 
371 	/*
372 	 * Wait until the changes in the configuration register CONFIGREG
373 	 * propagate into the hardware. It takes exactly one tick of the
374 	 * SCLK clock, but we will wait two SCLK clock just to be sure. The
375 	 * effect of the delay it takes for the hardware to apply changes
376 	 * is noticable if the SCLK clock run very slow. In such a case, if
377 	 * the polarity of SCLK should be inverted, the GPIO ChipSelect might
378 	 * be asserted before the SCLK polarity changes, which would disrupt
379 	 * the SPI communication as the device on the other end would consider
380 	 * the change of SCLK polarity as a clock tick already.
381 	 */
382 	delay = (2 * 1000000) / clk;
383 	if (likely(delay < 10))	/* SCLK is faster than 100 kHz */
384 		udelay(delay);
385 	else			/* SCLK is _very_ slow */
386 		usleep_range(delay, delay + 10);
387 
388 	/*
389 	 * Configure the DMA register: setup the watermark
390 	 * and enable DMA request.
391 	 */
392 	if (spi_imx->dma_is_inited) {
393 		dma = readl(spi_imx->base + MX51_ECSPI_DMA);
394 
395 		rx_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_RX_WML_OFFSET;
396 		tx_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_TX_WML_OFFSET;
397 		rxt_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_RXT_WML_OFFSET;
398 		dma = (dma & ~MX51_ECSPI_DMA_TX_WML_MASK
399 			   & ~MX51_ECSPI_DMA_RX_WML_MASK
400 			   & ~MX51_ECSPI_DMA_RXT_WML_MASK)
401 			   | rx_wml_cfg | tx_wml_cfg | rxt_wml_cfg
402 			   |(1 << MX51_ECSPI_DMA_TEDEN_OFFSET)
403 			   |(1 << MX51_ECSPI_DMA_RXDEN_OFFSET)
404 			   |(1 << MX51_ECSPI_DMA_RXTDEN_OFFSET);
405 
406 		writel(dma, spi_imx->base + MX51_ECSPI_DMA);
407 	}
408 
409 	return 0;
410 }
411 
412 static int __maybe_unused mx51_ecspi_rx_available(struct spi_imx_data *spi_imx)
413 {
414 	return readl(spi_imx->base + MX51_ECSPI_STAT) & MX51_ECSPI_STAT_RR;
415 }
416 
417 static void __maybe_unused mx51_ecspi_reset(struct spi_imx_data *spi_imx)
418 {
419 	/* drain receive buffer */
420 	while (mx51_ecspi_rx_available(spi_imx))
421 		readl(spi_imx->base + MXC_CSPIRXDATA);
422 }
423 
424 #define MX31_INTREG_TEEN	(1 << 0)
425 #define MX31_INTREG_RREN	(1 << 3)
426 
427 #define MX31_CSPICTRL_ENABLE	(1 << 0)
428 #define MX31_CSPICTRL_MASTER	(1 << 1)
429 #define MX31_CSPICTRL_XCH	(1 << 2)
430 #define MX31_CSPICTRL_POL	(1 << 4)
431 #define MX31_CSPICTRL_PHA	(1 << 5)
432 #define MX31_CSPICTRL_SSCTL	(1 << 6)
433 #define MX31_CSPICTRL_SSPOL	(1 << 7)
434 #define MX31_CSPICTRL_BC_SHIFT	8
435 #define MX35_CSPICTRL_BL_SHIFT	20
436 #define MX31_CSPICTRL_CS_SHIFT	24
437 #define MX35_CSPICTRL_CS_SHIFT	12
438 #define MX31_CSPICTRL_DR_SHIFT	16
439 
440 #define MX31_CSPISTATUS		0x14
441 #define MX31_STATUS_RR		(1 << 3)
442 
443 /* These functions also work for the i.MX35, but be aware that
444  * the i.MX35 has a slightly different register layout for bits
445  * we do not use here.
446  */
447 static void __maybe_unused mx31_intctrl(struct spi_imx_data *spi_imx, int enable)
448 {
449 	unsigned int val = 0;
450 
451 	if (enable & MXC_INT_TE)
452 		val |= MX31_INTREG_TEEN;
453 	if (enable & MXC_INT_RR)
454 		val |= MX31_INTREG_RREN;
455 
456 	writel(val, spi_imx->base + MXC_CSPIINT);
457 }
458 
459 static void __maybe_unused mx31_trigger(struct spi_imx_data *spi_imx)
460 {
461 	unsigned int reg;
462 
463 	reg = readl(spi_imx->base + MXC_CSPICTRL);
464 	reg |= MX31_CSPICTRL_XCH;
465 	writel(reg, spi_imx->base + MXC_CSPICTRL);
466 }
467 
468 static int __maybe_unused mx31_config(struct spi_imx_data *spi_imx,
469 		struct spi_imx_config *config)
470 {
471 	unsigned int reg = MX31_CSPICTRL_ENABLE | MX31_CSPICTRL_MASTER;
472 	int cs = spi_imx->chipselect[config->cs];
473 
474 	reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
475 		MX31_CSPICTRL_DR_SHIFT;
476 
477 	if (is_imx35_cspi(spi_imx)) {
478 		reg |= (config->bpw - 1) << MX35_CSPICTRL_BL_SHIFT;
479 		reg |= MX31_CSPICTRL_SSCTL;
480 	} else {
481 		reg |= (config->bpw - 1) << MX31_CSPICTRL_BC_SHIFT;
482 	}
483 
484 	if (config->mode & SPI_CPHA)
485 		reg |= MX31_CSPICTRL_PHA;
486 	if (config->mode & SPI_CPOL)
487 		reg |= MX31_CSPICTRL_POL;
488 	if (config->mode & SPI_CS_HIGH)
489 		reg |= MX31_CSPICTRL_SSPOL;
490 	if (cs < 0)
491 		reg |= (cs + 32) <<
492 			(is_imx35_cspi(spi_imx) ? MX35_CSPICTRL_CS_SHIFT :
493 						  MX31_CSPICTRL_CS_SHIFT);
494 
495 	writel(reg, spi_imx->base + MXC_CSPICTRL);
496 
497 	return 0;
498 }
499 
500 static int __maybe_unused mx31_rx_available(struct spi_imx_data *spi_imx)
501 {
502 	return readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR;
503 }
504 
505 static void __maybe_unused mx31_reset(struct spi_imx_data *spi_imx)
506 {
507 	/* drain receive buffer */
508 	while (readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR)
509 		readl(spi_imx->base + MXC_CSPIRXDATA);
510 }
511 
512 #define MX21_INTREG_RR		(1 << 4)
513 #define MX21_INTREG_TEEN	(1 << 9)
514 #define MX21_INTREG_RREN	(1 << 13)
515 
516 #define MX21_CSPICTRL_POL	(1 << 5)
517 #define MX21_CSPICTRL_PHA	(1 << 6)
518 #define MX21_CSPICTRL_SSPOL	(1 << 8)
519 #define MX21_CSPICTRL_XCH	(1 << 9)
520 #define MX21_CSPICTRL_ENABLE	(1 << 10)
521 #define MX21_CSPICTRL_MASTER	(1 << 11)
522 #define MX21_CSPICTRL_DR_SHIFT	14
523 #define MX21_CSPICTRL_CS_SHIFT	19
524 
525 static void __maybe_unused mx21_intctrl(struct spi_imx_data *spi_imx, int enable)
526 {
527 	unsigned int val = 0;
528 
529 	if (enable & MXC_INT_TE)
530 		val |= MX21_INTREG_TEEN;
531 	if (enable & MXC_INT_RR)
532 		val |= MX21_INTREG_RREN;
533 
534 	writel(val, spi_imx->base + MXC_CSPIINT);
535 }
536 
537 static void __maybe_unused mx21_trigger(struct spi_imx_data *spi_imx)
538 {
539 	unsigned int reg;
540 
541 	reg = readl(spi_imx->base + MXC_CSPICTRL);
542 	reg |= MX21_CSPICTRL_XCH;
543 	writel(reg, spi_imx->base + MXC_CSPICTRL);
544 }
545 
546 static int __maybe_unused mx21_config(struct spi_imx_data *spi_imx,
547 		struct spi_imx_config *config)
548 {
549 	unsigned int reg = MX21_CSPICTRL_ENABLE | MX21_CSPICTRL_MASTER;
550 	int cs = spi_imx->chipselect[config->cs];
551 	unsigned int max = is_imx27_cspi(spi_imx) ? 16 : 18;
552 
553 	reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, config->speed_hz, max) <<
554 		MX21_CSPICTRL_DR_SHIFT;
555 	reg |= config->bpw - 1;
556 
557 	if (config->mode & SPI_CPHA)
558 		reg |= MX21_CSPICTRL_PHA;
559 	if (config->mode & SPI_CPOL)
560 		reg |= MX21_CSPICTRL_POL;
561 	if (config->mode & SPI_CS_HIGH)
562 		reg |= MX21_CSPICTRL_SSPOL;
563 	if (cs < 0)
564 		reg |= (cs + 32) << MX21_CSPICTRL_CS_SHIFT;
565 
566 	writel(reg, spi_imx->base + MXC_CSPICTRL);
567 
568 	return 0;
569 }
570 
571 static int __maybe_unused mx21_rx_available(struct spi_imx_data *spi_imx)
572 {
573 	return readl(spi_imx->base + MXC_CSPIINT) & MX21_INTREG_RR;
574 }
575 
576 static void __maybe_unused mx21_reset(struct spi_imx_data *spi_imx)
577 {
578 	writel(1, spi_imx->base + MXC_RESET);
579 }
580 
581 #define MX1_INTREG_RR		(1 << 3)
582 #define MX1_INTREG_TEEN		(1 << 8)
583 #define MX1_INTREG_RREN		(1 << 11)
584 
585 #define MX1_CSPICTRL_POL	(1 << 4)
586 #define MX1_CSPICTRL_PHA	(1 << 5)
587 #define MX1_CSPICTRL_XCH	(1 << 8)
588 #define MX1_CSPICTRL_ENABLE	(1 << 9)
589 #define MX1_CSPICTRL_MASTER	(1 << 10)
590 #define MX1_CSPICTRL_DR_SHIFT	13
591 
592 static void __maybe_unused mx1_intctrl(struct spi_imx_data *spi_imx, int enable)
593 {
594 	unsigned int val = 0;
595 
596 	if (enable & MXC_INT_TE)
597 		val |= MX1_INTREG_TEEN;
598 	if (enable & MXC_INT_RR)
599 		val |= MX1_INTREG_RREN;
600 
601 	writel(val, spi_imx->base + MXC_CSPIINT);
602 }
603 
604 static void __maybe_unused mx1_trigger(struct spi_imx_data *spi_imx)
605 {
606 	unsigned int reg;
607 
608 	reg = readl(spi_imx->base + MXC_CSPICTRL);
609 	reg |= MX1_CSPICTRL_XCH;
610 	writel(reg, spi_imx->base + MXC_CSPICTRL);
611 }
612 
613 static int __maybe_unused mx1_config(struct spi_imx_data *spi_imx,
614 		struct spi_imx_config *config)
615 {
616 	unsigned int reg = MX1_CSPICTRL_ENABLE | MX1_CSPICTRL_MASTER;
617 
618 	reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
619 		MX1_CSPICTRL_DR_SHIFT;
620 	reg |= config->bpw - 1;
621 
622 	if (config->mode & SPI_CPHA)
623 		reg |= MX1_CSPICTRL_PHA;
624 	if (config->mode & SPI_CPOL)
625 		reg |= MX1_CSPICTRL_POL;
626 
627 	writel(reg, spi_imx->base + MXC_CSPICTRL);
628 
629 	return 0;
630 }
631 
632 static int __maybe_unused mx1_rx_available(struct spi_imx_data *spi_imx)
633 {
634 	return readl(spi_imx->base + MXC_CSPIINT) & MX1_INTREG_RR;
635 }
636 
637 static void __maybe_unused mx1_reset(struct spi_imx_data *spi_imx)
638 {
639 	writel(1, spi_imx->base + MXC_RESET);
640 }
641 
642 static struct spi_imx_devtype_data imx1_cspi_devtype_data = {
643 	.intctrl = mx1_intctrl,
644 	.config = mx1_config,
645 	.trigger = mx1_trigger,
646 	.rx_available = mx1_rx_available,
647 	.reset = mx1_reset,
648 	.devtype = IMX1_CSPI,
649 };
650 
651 static struct spi_imx_devtype_data imx21_cspi_devtype_data = {
652 	.intctrl = mx21_intctrl,
653 	.config = mx21_config,
654 	.trigger = mx21_trigger,
655 	.rx_available = mx21_rx_available,
656 	.reset = mx21_reset,
657 	.devtype = IMX21_CSPI,
658 };
659 
660 static struct spi_imx_devtype_data imx27_cspi_devtype_data = {
661 	/* i.mx27 cspi shares the functions with i.mx21 one */
662 	.intctrl = mx21_intctrl,
663 	.config = mx21_config,
664 	.trigger = mx21_trigger,
665 	.rx_available = mx21_rx_available,
666 	.reset = mx21_reset,
667 	.devtype = IMX27_CSPI,
668 };
669 
670 static struct spi_imx_devtype_data imx31_cspi_devtype_data = {
671 	.intctrl = mx31_intctrl,
672 	.config = mx31_config,
673 	.trigger = mx31_trigger,
674 	.rx_available = mx31_rx_available,
675 	.reset = mx31_reset,
676 	.devtype = IMX31_CSPI,
677 };
678 
679 static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
680 	/* i.mx35 and later cspi shares the functions with i.mx31 one */
681 	.intctrl = mx31_intctrl,
682 	.config = mx31_config,
683 	.trigger = mx31_trigger,
684 	.rx_available = mx31_rx_available,
685 	.reset = mx31_reset,
686 	.devtype = IMX35_CSPI,
687 };
688 
689 static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
690 	.intctrl = mx51_ecspi_intctrl,
691 	.config = mx51_ecspi_config,
692 	.trigger = mx51_ecspi_trigger,
693 	.rx_available = mx51_ecspi_rx_available,
694 	.reset = mx51_ecspi_reset,
695 	.devtype = IMX51_ECSPI,
696 };
697 
698 static const struct platform_device_id spi_imx_devtype[] = {
699 	{
700 		.name = "imx1-cspi",
701 		.driver_data = (kernel_ulong_t) &imx1_cspi_devtype_data,
702 	}, {
703 		.name = "imx21-cspi",
704 		.driver_data = (kernel_ulong_t) &imx21_cspi_devtype_data,
705 	}, {
706 		.name = "imx27-cspi",
707 		.driver_data = (kernel_ulong_t) &imx27_cspi_devtype_data,
708 	}, {
709 		.name = "imx31-cspi",
710 		.driver_data = (kernel_ulong_t) &imx31_cspi_devtype_data,
711 	}, {
712 		.name = "imx35-cspi",
713 		.driver_data = (kernel_ulong_t) &imx35_cspi_devtype_data,
714 	}, {
715 		.name = "imx51-ecspi",
716 		.driver_data = (kernel_ulong_t) &imx51_ecspi_devtype_data,
717 	}, {
718 		/* sentinel */
719 	}
720 };
721 
722 static const struct of_device_id spi_imx_dt_ids[] = {
723 	{ .compatible = "fsl,imx1-cspi", .data = &imx1_cspi_devtype_data, },
724 	{ .compatible = "fsl,imx21-cspi", .data = &imx21_cspi_devtype_data, },
725 	{ .compatible = "fsl,imx27-cspi", .data = &imx27_cspi_devtype_data, },
726 	{ .compatible = "fsl,imx31-cspi", .data = &imx31_cspi_devtype_data, },
727 	{ .compatible = "fsl,imx35-cspi", .data = &imx35_cspi_devtype_data, },
728 	{ .compatible = "fsl,imx51-ecspi", .data = &imx51_ecspi_devtype_data, },
729 	{ /* sentinel */ }
730 };
731 MODULE_DEVICE_TABLE(of, spi_imx_dt_ids);
732 
733 static void spi_imx_chipselect(struct spi_device *spi, int is_active)
734 {
735 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
736 	int gpio = spi_imx->chipselect[spi->chip_select];
737 	int active = is_active != BITBANG_CS_INACTIVE;
738 	int dev_is_lowactive = !(spi->mode & SPI_CS_HIGH);
739 
740 	if (!gpio_is_valid(gpio))
741 		return;
742 
743 	gpio_set_value(gpio, dev_is_lowactive ^ active);
744 }
745 
746 static void spi_imx_push(struct spi_imx_data *spi_imx)
747 {
748 	while (spi_imx->txfifo < spi_imx_get_fifosize(spi_imx)) {
749 		if (!spi_imx->count)
750 			break;
751 		spi_imx->tx(spi_imx);
752 		spi_imx->txfifo++;
753 	}
754 
755 	spi_imx->devtype_data->trigger(spi_imx);
756 }
757 
758 static irqreturn_t spi_imx_isr(int irq, void *dev_id)
759 {
760 	struct spi_imx_data *spi_imx = dev_id;
761 
762 	while (spi_imx->devtype_data->rx_available(spi_imx)) {
763 		spi_imx->rx(spi_imx);
764 		spi_imx->txfifo--;
765 	}
766 
767 	if (spi_imx->count) {
768 		spi_imx_push(spi_imx);
769 		return IRQ_HANDLED;
770 	}
771 
772 	if (spi_imx->txfifo) {
773 		/* No data left to push, but still waiting for rx data,
774 		 * enable receive data available interrupt.
775 		 */
776 		spi_imx->devtype_data->intctrl(
777 				spi_imx, MXC_INT_RR);
778 		return IRQ_HANDLED;
779 	}
780 
781 	spi_imx->devtype_data->intctrl(spi_imx, 0);
782 	complete(&spi_imx->xfer_done);
783 
784 	return IRQ_HANDLED;
785 }
786 
787 static int spi_imx_setupxfer(struct spi_device *spi,
788 				 struct spi_transfer *t)
789 {
790 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
791 	struct spi_imx_config config;
792 
793 	config.bpw = t ? t->bits_per_word : spi->bits_per_word;
794 	config.speed_hz  = t ? t->speed_hz : spi->max_speed_hz;
795 	config.mode = spi->mode;
796 	config.cs = spi->chip_select;
797 
798 	if (!config.speed_hz)
799 		config.speed_hz = spi->max_speed_hz;
800 	if (!config.bpw)
801 		config.bpw = spi->bits_per_word;
802 
803 	/* Initialize the functions for transfer */
804 	if (config.bpw <= 8) {
805 		spi_imx->rx = spi_imx_buf_rx_u8;
806 		spi_imx->tx = spi_imx_buf_tx_u8;
807 	} else if (config.bpw <= 16) {
808 		spi_imx->rx = spi_imx_buf_rx_u16;
809 		spi_imx->tx = spi_imx_buf_tx_u16;
810 	} else {
811 		spi_imx->rx = spi_imx_buf_rx_u32;
812 		spi_imx->tx = spi_imx_buf_tx_u32;
813 	}
814 
815 	spi_imx->devtype_data->config(spi_imx, &config);
816 
817 	return 0;
818 }
819 
820 static void spi_imx_sdma_exit(struct spi_imx_data *spi_imx)
821 {
822 	struct spi_master *master = spi_imx->bitbang.master;
823 
824 	if (master->dma_rx) {
825 		dma_release_channel(master->dma_rx);
826 		master->dma_rx = NULL;
827 	}
828 
829 	if (master->dma_tx) {
830 		dma_release_channel(master->dma_tx);
831 		master->dma_tx = NULL;
832 	}
833 
834 	spi_imx->dma_is_inited = 0;
835 }
836 
837 static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
838 			     struct spi_master *master,
839 			     const struct resource *res)
840 {
841 	struct dma_slave_config slave_config = {};
842 	int ret;
843 
844 	/* use pio mode for i.mx6dl chip TKT238285 */
845 	if (of_machine_is_compatible("fsl,imx6dl"))
846 		return 0;
847 
848 	spi_imx->wml = spi_imx_get_fifosize(spi_imx) / 2;
849 
850 	/* Prepare for TX DMA: */
851 	master->dma_tx = dma_request_slave_channel_reason(dev, "tx");
852 	if (IS_ERR(master->dma_tx)) {
853 		ret = PTR_ERR(master->dma_tx);
854 		dev_dbg(dev, "can't get the TX DMA channel, error %d!\n", ret);
855 		master->dma_tx = NULL;
856 		goto err;
857 	}
858 
859 	slave_config.direction = DMA_MEM_TO_DEV;
860 	slave_config.dst_addr = res->start + MXC_CSPITXDATA;
861 	slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
862 	slave_config.dst_maxburst = spi_imx->wml;
863 	ret = dmaengine_slave_config(master->dma_tx, &slave_config);
864 	if (ret) {
865 		dev_err(dev, "error in TX dma configuration.\n");
866 		goto err;
867 	}
868 
869 	/* Prepare for RX : */
870 	master->dma_rx = dma_request_slave_channel_reason(dev, "rx");
871 	if (IS_ERR(master->dma_rx)) {
872 		ret = PTR_ERR(master->dma_rx);
873 		dev_dbg(dev, "can't get the RX DMA channel, error %d\n", ret);
874 		master->dma_rx = NULL;
875 		goto err;
876 	}
877 
878 	slave_config.direction = DMA_DEV_TO_MEM;
879 	slave_config.src_addr = res->start + MXC_CSPIRXDATA;
880 	slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
881 	slave_config.src_maxburst = spi_imx->wml;
882 	ret = dmaengine_slave_config(master->dma_rx, &slave_config);
883 	if (ret) {
884 		dev_err(dev, "error in RX dma configuration.\n");
885 		goto err;
886 	}
887 
888 	init_completion(&spi_imx->dma_rx_completion);
889 	init_completion(&spi_imx->dma_tx_completion);
890 	master->can_dma = spi_imx_can_dma;
891 	master->max_dma_len = MAX_SDMA_BD_BYTES;
892 	spi_imx->bitbang.master->flags = SPI_MASTER_MUST_RX |
893 					 SPI_MASTER_MUST_TX;
894 	spi_imx->dma_is_inited = 1;
895 
896 	return 0;
897 err:
898 	spi_imx_sdma_exit(spi_imx);
899 	return ret;
900 }
901 
902 static void spi_imx_dma_rx_callback(void *cookie)
903 {
904 	struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie;
905 
906 	complete(&spi_imx->dma_rx_completion);
907 }
908 
909 static void spi_imx_dma_tx_callback(void *cookie)
910 {
911 	struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie;
912 
913 	complete(&spi_imx->dma_tx_completion);
914 }
915 
916 static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
917 				struct spi_transfer *transfer)
918 {
919 	struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
920 	int ret;
921 	unsigned long timeout;
922 	u32 dma;
923 	int left;
924 	struct spi_master *master = spi_imx->bitbang.master;
925 	struct sg_table *tx = &transfer->tx_sg, *rx = &transfer->rx_sg;
926 
927 	if (tx) {
928 		desc_tx = dmaengine_prep_slave_sg(master->dma_tx,
929 					tx->sgl, tx->nents, DMA_MEM_TO_DEV,
930 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
931 		if (!desc_tx)
932 			goto tx_nodma;
933 
934 		desc_tx->callback = spi_imx_dma_tx_callback;
935 		desc_tx->callback_param = (void *)spi_imx;
936 		dmaengine_submit(desc_tx);
937 	}
938 
939 	if (rx) {
940 		desc_rx = dmaengine_prep_slave_sg(master->dma_rx,
941 					rx->sgl, rx->nents, DMA_DEV_TO_MEM,
942 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
943 		if (!desc_rx)
944 			goto rx_nodma;
945 
946 		desc_rx->callback = spi_imx_dma_rx_callback;
947 		desc_rx->callback_param = (void *)spi_imx;
948 		dmaengine_submit(desc_rx);
949 	}
950 
951 	reinit_completion(&spi_imx->dma_rx_completion);
952 	reinit_completion(&spi_imx->dma_tx_completion);
953 
954 	/* Trigger the cspi module. */
955 	spi_imx->dma_finished = 0;
956 
957 	dma = readl(spi_imx->base + MX51_ECSPI_DMA);
958 	dma = dma & (~MX51_ECSPI_DMA_RXT_WML_MASK);
959 	/* Change RX_DMA_LENGTH trigger dma fetch tail data */
960 	left = transfer->len % spi_imx->wml;
961 	if (left)
962 		writel(dma | (left << MX51_ECSPI_DMA_RXT_WML_OFFSET),
963 				spi_imx->base + MX51_ECSPI_DMA);
964 	/*
965 	 * Set these order to avoid potential RX overflow. The overflow may
966 	 * happen if we enable SPI HW before starting RX DMA due to rescheduling
967 	 * for another task and/or interrupt.
968 	 * So RX DMA enabled first to make sure data would be read out from FIFO
969 	 * ASAP. TX DMA enabled next to start filling TX FIFO with new data.
970 	 * And finaly SPI HW enabled to start actual data transfer.
971 	 */
972 	dma_async_issue_pending(master->dma_rx);
973 	dma_async_issue_pending(master->dma_tx);
974 	spi_imx->devtype_data->trigger(spi_imx);
975 
976 	/* Wait SDMA to finish the data transfer.*/
977 	timeout = wait_for_completion_timeout(&spi_imx->dma_tx_completion,
978 						IMX_DMA_TIMEOUT);
979 	if (!timeout) {
980 		pr_warn("%s %s: I/O Error in DMA TX\n",
981 			dev_driver_string(&master->dev),
982 			dev_name(&master->dev));
983 		dmaengine_terminate_all(master->dma_tx);
984 		dmaengine_terminate_all(master->dma_rx);
985 	} else {
986 		timeout = wait_for_completion_timeout(
987 				&spi_imx->dma_rx_completion, IMX_DMA_TIMEOUT);
988 		if (!timeout) {
989 			pr_warn("%s %s: I/O Error in DMA RX\n",
990 				dev_driver_string(&master->dev),
991 				dev_name(&master->dev));
992 			spi_imx->devtype_data->reset(spi_imx);
993 			dmaengine_terminate_all(master->dma_rx);
994 		}
995 		dma &= ~MX51_ECSPI_DMA_RXT_WML_MASK;
996 		writel(dma |
997 		       spi_imx->wml << MX51_ECSPI_DMA_RXT_WML_OFFSET,
998 		       spi_imx->base + MX51_ECSPI_DMA);
999 	}
1000 
1001 	spi_imx->dma_finished = 1;
1002 	spi_imx->devtype_data->trigger(spi_imx);
1003 
1004 	if (!timeout)
1005 		ret = -ETIMEDOUT;
1006 	else
1007 		ret = transfer->len;
1008 
1009 	return ret;
1010 
1011 rx_nodma:
1012 	dmaengine_terminate_all(master->dma_tx);
1013 tx_nodma:
1014 	pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
1015 		     dev_driver_string(&master->dev),
1016 		     dev_name(&master->dev));
1017 	return -EAGAIN;
1018 }
1019 
1020 static int spi_imx_pio_transfer(struct spi_device *spi,
1021 				struct spi_transfer *transfer)
1022 {
1023 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
1024 
1025 	spi_imx->tx_buf = transfer->tx_buf;
1026 	spi_imx->rx_buf = transfer->rx_buf;
1027 	spi_imx->count = transfer->len;
1028 	spi_imx->txfifo = 0;
1029 
1030 	reinit_completion(&spi_imx->xfer_done);
1031 
1032 	spi_imx_push(spi_imx);
1033 
1034 	spi_imx->devtype_data->intctrl(spi_imx, MXC_INT_TE);
1035 
1036 	wait_for_completion(&spi_imx->xfer_done);
1037 
1038 	return transfer->len;
1039 }
1040 
1041 static int spi_imx_transfer(struct spi_device *spi,
1042 				struct spi_transfer *transfer)
1043 {
1044 	int ret;
1045 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
1046 
1047 	if (spi_imx->bitbang.master->can_dma &&
1048 	    spi_imx_can_dma(spi_imx->bitbang.master, spi, transfer)) {
1049 		spi_imx->usedma = true;
1050 		ret = spi_imx_dma_transfer(spi_imx, transfer);
1051 		if (ret != -EAGAIN)
1052 			return ret;
1053 	}
1054 	spi_imx->usedma = false;
1055 
1056 	return spi_imx_pio_transfer(spi, transfer);
1057 }
1058 
1059 static int spi_imx_setup(struct spi_device *spi)
1060 {
1061 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
1062 	int gpio = spi_imx->chipselect[spi->chip_select];
1063 
1064 	dev_dbg(&spi->dev, "%s: mode %d, %u bpw, %d hz\n", __func__,
1065 		 spi->mode, spi->bits_per_word, spi->max_speed_hz);
1066 
1067 	if (gpio_is_valid(gpio))
1068 		gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
1069 
1070 	spi_imx_chipselect(spi, BITBANG_CS_INACTIVE);
1071 
1072 	return 0;
1073 }
1074 
1075 static void spi_imx_cleanup(struct spi_device *spi)
1076 {
1077 }
1078 
1079 static int
1080 spi_imx_prepare_message(struct spi_master *master, struct spi_message *msg)
1081 {
1082 	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
1083 	int ret;
1084 
1085 	ret = clk_enable(spi_imx->clk_per);
1086 	if (ret)
1087 		return ret;
1088 
1089 	ret = clk_enable(spi_imx->clk_ipg);
1090 	if (ret) {
1091 		clk_disable(spi_imx->clk_per);
1092 		return ret;
1093 	}
1094 
1095 	return 0;
1096 }
1097 
1098 static int
1099 spi_imx_unprepare_message(struct spi_master *master, struct spi_message *msg)
1100 {
1101 	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
1102 
1103 	clk_disable(spi_imx->clk_ipg);
1104 	clk_disable(spi_imx->clk_per);
1105 	return 0;
1106 }
1107 
1108 static int spi_imx_probe(struct platform_device *pdev)
1109 {
1110 	struct device_node *np = pdev->dev.of_node;
1111 	const struct of_device_id *of_id =
1112 			of_match_device(spi_imx_dt_ids, &pdev->dev);
1113 	struct spi_imx_master *mxc_platform_info =
1114 			dev_get_platdata(&pdev->dev);
1115 	struct spi_master *master;
1116 	struct spi_imx_data *spi_imx;
1117 	struct resource *res;
1118 	int i, ret, num_cs, irq;
1119 
1120 	if (!np && !mxc_platform_info) {
1121 		dev_err(&pdev->dev, "can't get the platform data\n");
1122 		return -EINVAL;
1123 	}
1124 
1125 	ret = of_property_read_u32(np, "fsl,spi-num-chipselects", &num_cs);
1126 	if (ret < 0) {
1127 		if (mxc_platform_info)
1128 			num_cs = mxc_platform_info->num_chipselect;
1129 		else
1130 			return ret;
1131 	}
1132 
1133 	master = spi_alloc_master(&pdev->dev,
1134 			sizeof(struct spi_imx_data) + sizeof(int) * num_cs);
1135 	if (!master)
1136 		return -ENOMEM;
1137 
1138 	platform_set_drvdata(pdev, master);
1139 
1140 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
1141 	master->bus_num = pdev->id;
1142 	master->num_chipselect = num_cs;
1143 
1144 	spi_imx = spi_master_get_devdata(master);
1145 	spi_imx->bitbang.master = master;
1146 
1147 	spi_imx->devtype_data = of_id ? of_id->data :
1148 		(struct spi_imx_devtype_data *)pdev->id_entry->driver_data;
1149 
1150 	for (i = 0; i < master->num_chipselect; i++) {
1151 		int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
1152 		if (!gpio_is_valid(cs_gpio) && mxc_platform_info)
1153 			cs_gpio = mxc_platform_info->chipselect[i];
1154 
1155 		spi_imx->chipselect[i] = cs_gpio;
1156 		if (!gpio_is_valid(cs_gpio))
1157 			continue;
1158 
1159 		ret = devm_gpio_request(&pdev->dev, spi_imx->chipselect[i],
1160 					DRIVER_NAME);
1161 		if (ret) {
1162 			dev_err(&pdev->dev, "can't get cs gpios\n");
1163 			goto out_master_put;
1164 		}
1165 	}
1166 
1167 	spi_imx->bitbang.chipselect = spi_imx_chipselect;
1168 	spi_imx->bitbang.setup_transfer = spi_imx_setupxfer;
1169 	spi_imx->bitbang.txrx_bufs = spi_imx_transfer;
1170 	spi_imx->bitbang.master->setup = spi_imx_setup;
1171 	spi_imx->bitbang.master->cleanup = spi_imx_cleanup;
1172 	spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message;
1173 	spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;
1174 	spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1175 	if (is_imx51_ecspi(spi_imx))
1176 		spi_imx->bitbang.master->mode_bits |= SPI_LOOP;
1177 
1178 	init_completion(&spi_imx->xfer_done);
1179 
1180 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1181 	spi_imx->base = devm_ioremap_resource(&pdev->dev, res);
1182 	if (IS_ERR(spi_imx->base)) {
1183 		ret = PTR_ERR(spi_imx->base);
1184 		goto out_master_put;
1185 	}
1186 
1187 	irq = platform_get_irq(pdev, 0);
1188 	if (irq < 0) {
1189 		ret = irq;
1190 		goto out_master_put;
1191 	}
1192 
1193 	ret = devm_request_irq(&pdev->dev, irq, spi_imx_isr, 0,
1194 			       dev_name(&pdev->dev), spi_imx);
1195 	if (ret) {
1196 		dev_err(&pdev->dev, "can't get irq%d: %d\n", irq, ret);
1197 		goto out_master_put;
1198 	}
1199 
1200 	spi_imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1201 	if (IS_ERR(spi_imx->clk_ipg)) {
1202 		ret = PTR_ERR(spi_imx->clk_ipg);
1203 		goto out_master_put;
1204 	}
1205 
1206 	spi_imx->clk_per = devm_clk_get(&pdev->dev, "per");
1207 	if (IS_ERR(spi_imx->clk_per)) {
1208 		ret = PTR_ERR(spi_imx->clk_per);
1209 		goto out_master_put;
1210 	}
1211 
1212 	ret = clk_prepare_enable(spi_imx->clk_per);
1213 	if (ret)
1214 		goto out_master_put;
1215 
1216 	ret = clk_prepare_enable(spi_imx->clk_ipg);
1217 	if (ret)
1218 		goto out_put_per;
1219 
1220 	spi_imx->spi_clk = clk_get_rate(spi_imx->clk_per);
1221 	/*
1222 	 * Only validated on i.mx6 now, can remove the constrain if validated on
1223 	 * other chips.
1224 	 */
1225 	if (is_imx51_ecspi(spi_imx)) {
1226 		ret = spi_imx_sdma_init(&pdev->dev, spi_imx, master, res);
1227 		if (ret == -EPROBE_DEFER)
1228 			goto out_clk_put;
1229 
1230 		if (ret < 0)
1231 			dev_err(&pdev->dev, "dma setup error %d, use pio\n",
1232 				ret);
1233 	}
1234 
1235 	spi_imx->devtype_data->reset(spi_imx);
1236 
1237 	spi_imx->devtype_data->intctrl(spi_imx, 0);
1238 
1239 	master->dev.of_node = pdev->dev.of_node;
1240 	ret = spi_bitbang_start(&spi_imx->bitbang);
1241 	if (ret) {
1242 		dev_err(&pdev->dev, "bitbang start failed with %d\n", ret);
1243 		goto out_clk_put;
1244 	}
1245 
1246 	dev_info(&pdev->dev, "probed\n");
1247 
1248 	clk_disable(spi_imx->clk_ipg);
1249 	clk_disable(spi_imx->clk_per);
1250 	return ret;
1251 
1252 out_clk_put:
1253 	clk_disable_unprepare(spi_imx->clk_ipg);
1254 out_put_per:
1255 	clk_disable_unprepare(spi_imx->clk_per);
1256 out_master_put:
1257 	spi_master_put(master);
1258 
1259 	return ret;
1260 }
1261 
1262 static int spi_imx_remove(struct platform_device *pdev)
1263 {
1264 	struct spi_master *master = platform_get_drvdata(pdev);
1265 	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
1266 
1267 	spi_bitbang_stop(&spi_imx->bitbang);
1268 
1269 	writel(0, spi_imx->base + MXC_CSPICTRL);
1270 	clk_unprepare(spi_imx->clk_ipg);
1271 	clk_unprepare(spi_imx->clk_per);
1272 	spi_imx_sdma_exit(spi_imx);
1273 	spi_master_put(master);
1274 
1275 	return 0;
1276 }
1277 
1278 static struct platform_driver spi_imx_driver = {
1279 	.driver = {
1280 		   .name = DRIVER_NAME,
1281 		   .of_match_table = spi_imx_dt_ids,
1282 		   },
1283 	.id_table = spi_imx_devtype,
1284 	.probe = spi_imx_probe,
1285 	.remove = spi_imx_remove,
1286 };
1287 module_platform_driver(spi_imx_driver);
1288 
1289 MODULE_DESCRIPTION("SPI Master Controller driver");
1290 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
1291 MODULE_LICENSE("GPL");
1292 MODULE_ALIAS("platform:" DRIVER_NAME);
1293