xref: /linux/drivers/spi/spi-imx.c (revision de90cc610eb61341662fc23919dd823573ef9a41)
1 // SPDX-License-Identifier: GPL-2.0+
2 // Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
3 // Copyright (C) 2008 Juergen Beisert
4 
5 #include <linux/bits.h>
6 #include <linux/bitfield.h>
7 #include <linux/clk.h>
8 #include <linux/completion.h>
9 #include <linux/delay.h>
10 #include <linux/dmaengine.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/err.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/irq.h>
16 #include <linux/kernel.h>
17 #include <linux/math.h>
18 #include <linux/math64.h>
19 #include <linux/module.h>
20 #include <linux/overflow.h>
21 #include <linux/pinctrl/consumer.h>
22 #include <linux/platform_device.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/slab.h>
25 #include <linux/spi/spi.h>
26 #include <linux/types.h>
27 #include <linux/of.h>
28 #include <linux/property.h>
29 
30 #include <linux/dma/imx-dma.h>
31 
32 #define DRIVER_NAME "spi_imx"
33 
34 static bool use_dma = true;
35 module_param(use_dma, bool, 0644);
36 MODULE_PARM_DESC(use_dma, "Enable usage of DMA when available (default)");
37 
38 /* define polling limits */
39 static unsigned int polling_limit_us = 30;
40 module_param(polling_limit_us, uint, 0664);
41 MODULE_PARM_DESC(polling_limit_us,
42 		 "time in us to run a transfer in polling mode\n");
43 
44 #define MXC_RPM_TIMEOUT		2000 /* 2000ms */
45 
46 #define MXC_CSPIRXDATA		0x00
47 #define MXC_CSPITXDATA		0x04
48 #define MXC_CSPICTRL		0x08
49 #define MXC_CSPIINT		0x0c
50 #define MXC_RESET		0x1c
51 
52 /* generic defines to abstract from the different register layouts */
53 #define MXC_INT_RR	(1 << 0) /* Receive data ready interrupt */
54 #define MXC_INT_TE	(1 << 1) /* Transmit FIFO empty interrupt */
55 #define MXC_INT_RDR	BIT(4) /* Receive date threshold 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 /* The maximum bytes that IMX53_ECSPI can transfer in target mode.*/
61 #define MX53_MAX_TRANSFER_BYTES		512
62 
63 enum spi_imx_devtype {
64 	IMX1_CSPI,
65 	IMX21_CSPI,
66 	IMX27_CSPI,
67 	IMX31_CSPI,
68 	IMX35_CSPI,	/* CSPI on all i.mx except above */
69 	IMX51_ECSPI,	/* ECSPI on i.mx51 */
70 	IMX53_ECSPI,	/* ECSPI on i.mx53 and later */
71 };
72 
73 struct spi_imx_data;
74 
75 struct spi_imx_devtype_data {
76 	void (*intctrl)(struct spi_imx_data *spi_imx, int enable);
77 	int (*prepare_message)(struct spi_imx_data *spi_imx, struct spi_message *msg);
78 	int (*prepare_transfer)(struct spi_imx_data *spi_imx, struct spi_device *spi,
79 				struct spi_transfer *t);
80 	void (*trigger)(struct spi_imx_data *spi_imx);
81 	int (*rx_available)(struct spi_imx_data *spi_imx);
82 	void (*reset)(struct spi_imx_data *spi_imx);
83 	void (*setup_wml)(struct spi_imx_data *spi_imx);
84 	void (*disable)(struct spi_imx_data *spi_imx);
85 	bool has_dmamode;
86 	bool has_targetmode;
87 	unsigned int fifo_size;
88 	bool dynamic_burst;
89 	/*
90 	 * ERR009165 fixed or not:
91 	 * https://www.nxp.com/docs/en/errata/IMX6DQCE.pdf
92 	 */
93 	bool tx_glitch_fixed;
94 	enum spi_imx_devtype devtype;
95 };
96 
97 struct spi_imx_data {
98 	struct spi_controller *controller;
99 	struct device *dev;
100 
101 	struct completion xfer_done;
102 	void __iomem *base;
103 	unsigned long base_phys;
104 
105 	struct clk *clk_per;
106 	struct clk *clk_ipg;
107 	unsigned long spi_clk;
108 	unsigned int spi_bus_clk;
109 
110 	unsigned int bits_per_word;
111 	unsigned int spi_drctl;
112 
113 	unsigned int count, remainder;
114 	void (*tx)(struct spi_imx_data *spi_imx);
115 	void (*rx)(struct spi_imx_data *spi_imx);
116 	void *rx_buf;
117 	const void *tx_buf;
118 	unsigned int txfifo; /* number of words pushed in tx FIFO */
119 	unsigned int dynamic_burst;
120 	bool rx_only;
121 
122 	/* Target mode */
123 	bool target_mode;
124 	bool target_aborted;
125 	unsigned int target_burst;
126 
127 	/* DMA */
128 	bool usedma;
129 	u32 wml;
130 	struct completion dma_rx_completion;
131 	struct completion dma_tx_completion;
132 
133 	const struct spi_imx_devtype_data *devtype_data;
134 };
135 
is_imx27_cspi(struct spi_imx_data * d)136 static inline int is_imx27_cspi(struct spi_imx_data *d)
137 {
138 	return d->devtype_data->devtype == IMX27_CSPI;
139 }
140 
is_imx35_cspi(struct spi_imx_data * d)141 static inline int is_imx35_cspi(struct spi_imx_data *d)
142 {
143 	return d->devtype_data->devtype == IMX35_CSPI;
144 }
145 
is_imx51_ecspi(struct spi_imx_data * d)146 static inline int is_imx51_ecspi(struct spi_imx_data *d)
147 {
148 	return d->devtype_data->devtype == IMX51_ECSPI;
149 }
150 
is_imx53_ecspi(struct spi_imx_data * d)151 static inline int is_imx53_ecspi(struct spi_imx_data *d)
152 {
153 	return d->devtype_data->devtype == IMX53_ECSPI;
154 }
155 
156 #define MXC_SPI_BUF_RX(type)						\
157 static void spi_imx_buf_rx_##type(struct spi_imx_data *spi_imx)		\
158 {									\
159 	unsigned int val = readl(spi_imx->base + MXC_CSPIRXDATA);	\
160 									\
161 	if (spi_imx->rx_buf) {						\
162 		*(type *)spi_imx->rx_buf = val;				\
163 		spi_imx->rx_buf += sizeof(type);			\
164 	}								\
165 									\
166 	spi_imx->remainder -= sizeof(type);				\
167 }
168 
169 #define MXC_SPI_BUF_TX(type)						\
170 static void spi_imx_buf_tx_##type(struct spi_imx_data *spi_imx)		\
171 {									\
172 	type val = 0;							\
173 									\
174 	if (spi_imx->tx_buf) {						\
175 		val = *(type *)spi_imx->tx_buf;				\
176 		spi_imx->tx_buf += sizeof(type);			\
177 	}								\
178 									\
179 	spi_imx->count -= sizeof(type);					\
180 									\
181 	writel(val, spi_imx->base + MXC_CSPITXDATA);			\
182 }
183 
184 MXC_SPI_BUF_RX(u8)
185 MXC_SPI_BUF_TX(u8)
186 MXC_SPI_BUF_RX(u16)
187 MXC_SPI_BUF_TX(u16)
188 MXC_SPI_BUF_RX(u32)
189 MXC_SPI_BUF_TX(u32)
190 
191 /* First entry is reserved, second entry is valid only if SDHC_SPIEN is set
192  * (which is currently not the case in this driver)
193  */
194 static int mxc_clkdivs[] = {0, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192,
195 	256, 384, 512, 768, 1024};
196 
197 /* MX21, MX27 */
spi_imx_clkdiv_1(unsigned int fin,unsigned int fspi,unsigned int max,unsigned int * fres)198 static unsigned int spi_imx_clkdiv_1(unsigned int fin,
199 		unsigned int fspi, unsigned int max, unsigned int *fres)
200 {
201 	int i;
202 
203 	for (i = 2; i < max; i++)
204 		if (fspi * mxc_clkdivs[i] >= fin)
205 			break;
206 
207 	*fres = fin / mxc_clkdivs[i];
208 	return i;
209 }
210 
211 /* MX1, MX31, MX35, MX51 CSPI */
spi_imx_clkdiv_2(unsigned int fin,unsigned int fspi,unsigned int * fres)212 static unsigned int spi_imx_clkdiv_2(unsigned int fin,
213 		unsigned int fspi, unsigned int *fres)
214 {
215 	int i, div = 4;
216 
217 	for (i = 0; i < 7; i++) {
218 		if (fspi * div >= fin)
219 			goto out;
220 		div <<= 1;
221 	}
222 
223 out:
224 	*fres = fin / div;
225 	return i;
226 }
227 
spi_imx_bytes_per_word(const int bits_per_word)228 static int spi_imx_bytes_per_word(const int bits_per_word)
229 {
230 	if (bits_per_word <= 8)
231 		return 1;
232 	else if (bits_per_word <= 16)
233 		return 2;
234 	else
235 		return 4;
236 }
237 
spi_imx_can_dma(struct spi_controller * controller,struct spi_device * spi,struct spi_transfer * transfer)238 static bool spi_imx_can_dma(struct spi_controller *controller, struct spi_device *spi,
239 			 struct spi_transfer *transfer)
240 {
241 	struct spi_imx_data *spi_imx = spi_controller_get_devdata(controller);
242 
243 	if (!use_dma || controller->fallback)
244 		return false;
245 
246 	if (!controller->dma_rx)
247 		return false;
248 
249 	if (spi_imx->target_mode)
250 		return false;
251 
252 	if (transfer->len < spi_imx->devtype_data->fifo_size)
253 		return false;
254 
255 	spi_imx->dynamic_burst = 0;
256 
257 	return true;
258 }
259 
260 /*
261  * Note the number of natively supported chip selects for MX51 is 4. Some
262  * devices may have less actual SS pins but the register map supports 4. When
263  * using gpio chip selects the cs values passed into the macros below can go
264  * outside the range 0 - 3. We therefore need to limit the cs value to avoid
265  * corrupting bits outside the allocated locations.
266  *
267  * The simplest way to do this is to just mask the cs bits to 2 bits. This
268  * still allows all 4 native chip selects to work as well as gpio chip selects
269  * (which can use any of the 4 chip select configurations).
270  */
271 
272 #define MX51_ECSPI_CTRL		0x08
273 #define MX51_ECSPI_CTRL_ENABLE		(1 <<  0)
274 #define MX51_ECSPI_CTRL_XCH		(1 <<  2)
275 #define MX51_ECSPI_CTRL_SMC		(1 << 3)
276 #define MX51_ECSPI_CTRL_MODE_MASK	(0xf << 4)
277 #define MX51_ECSPI_CTRL_DRCTL(drctl)	((drctl) << 16)
278 #define MX51_ECSPI_CTRL_POSTDIV_OFFSET	8
279 #define MX51_ECSPI_CTRL_PREDIV_OFFSET	12
280 #define MX51_ECSPI_CTRL_CS(cs)		((cs & 3) << 18)
281 #define MX51_ECSPI_CTRL_BL_OFFSET	20
282 #define MX51_ECSPI_CTRL_BL_MASK		(0xfff << 20)
283 
284 #define MX51_ECSPI_CONFIG	0x0c
285 #define MX51_ECSPI_CONFIG_SCLKPHA(cs)	(1 << ((cs & 3) +  0))
286 #define MX51_ECSPI_CONFIG_SCLKPOL(cs)	(1 << ((cs & 3) +  4))
287 #define MX51_ECSPI_CONFIG_SBBCTRL(cs)	(1 << ((cs & 3) +  8))
288 #define MX51_ECSPI_CONFIG_SSBPOL(cs)	(1 << ((cs & 3) + 12))
289 #define MX51_ECSPI_CONFIG_DATACTL(cs)	(1 << ((cs & 3) + 16))
290 #define MX51_ECSPI_CONFIG_SCLKCTL(cs)	(1 << ((cs & 3) + 20))
291 
292 #define MX51_ECSPI_INT		0x10
293 #define MX51_ECSPI_INT_TEEN		(1 <<  0)
294 #define MX51_ECSPI_INT_RREN		(1 <<  3)
295 #define MX51_ECSPI_INT_RDREN		(1 <<  4)
296 
297 #define MX51_ECSPI_DMA		0x14
298 #define MX51_ECSPI_DMA_TX_WML(wml)	((wml) & 0x3f)
299 #define MX51_ECSPI_DMA_RX_WML(wml)	(((wml) & 0x3f) << 16)
300 #define MX51_ECSPI_DMA_RXT_WML(wml)	(((wml) & 0x3f) << 24)
301 
302 #define MX51_ECSPI_DMA_TEDEN		(1 << 7)
303 #define MX51_ECSPI_DMA_RXDEN		(1 << 23)
304 #define MX51_ECSPI_DMA_RXTDEN		(1 << 31)
305 
306 #define MX51_ECSPI_STAT		0x18
307 #define MX51_ECSPI_STAT_RR		(1 <<  3)
308 
309 #define MX51_ECSPI_PERIOD	0x1c
310 #define MX51_ECSPI_PERIOD_MASK		0x7fff
311 /*
312  * As measured on the i.MX6, the SPI host controller inserts a 4 SPI-Clock
313  * (SCLK) delay after each burst if the PERIOD reg is 0x0. This value will be
314  * called MX51_ECSPI_PERIOD_MIN_DELAY_SCK.
315  *
316  * If the PERIOD register is != 0, the controller inserts a delay of
317  * MX51_ECSPI_PERIOD_MIN_DELAY_SCK + register value + 1 SCLK after each burst.
318  */
319 #define MX51_ECSPI_PERIOD_MIN_DELAY_SCK 4
320 
321 #define MX51_ECSPI_TESTREG	0x20
322 #define MX51_ECSPI_TESTREG_LBC	BIT(31)
323 
spi_imx_buf_rx_swap_u32(struct spi_imx_data * spi_imx)324 static void spi_imx_buf_rx_swap_u32(struct spi_imx_data *spi_imx)
325 {
326 	unsigned int val = readl(spi_imx->base + MXC_CSPIRXDATA);
327 
328 	if (spi_imx->rx_buf) {
329 #ifdef __LITTLE_ENDIAN
330 		unsigned int bytes_per_word;
331 
332 		bytes_per_word = spi_imx_bytes_per_word(spi_imx->bits_per_word);
333 		if (bytes_per_word == 1)
334 			swab32s(&val);
335 		else if (bytes_per_word == 2)
336 			swahw32s(&val);
337 #endif
338 		*(u32 *)spi_imx->rx_buf = val;
339 		spi_imx->rx_buf += sizeof(u32);
340 	}
341 
342 	spi_imx->remainder -= sizeof(u32);
343 }
344 
spi_imx_buf_rx_swap(struct spi_imx_data * spi_imx)345 static void spi_imx_buf_rx_swap(struct spi_imx_data *spi_imx)
346 {
347 	int unaligned;
348 	u32 val;
349 
350 	unaligned = spi_imx->remainder % 4;
351 
352 	if (!unaligned) {
353 		spi_imx_buf_rx_swap_u32(spi_imx);
354 		return;
355 	}
356 
357 	if (spi_imx_bytes_per_word(spi_imx->bits_per_word) == 2) {
358 		spi_imx_buf_rx_u16(spi_imx);
359 		return;
360 	}
361 
362 	val = readl(spi_imx->base + MXC_CSPIRXDATA);
363 
364 	while (unaligned--) {
365 		if (spi_imx->rx_buf) {
366 			*(u8 *)spi_imx->rx_buf = (val >> (8 * unaligned)) & 0xff;
367 			spi_imx->rx_buf++;
368 		}
369 		spi_imx->remainder--;
370 	}
371 }
372 
spi_imx_buf_tx_swap_u32(struct spi_imx_data * spi_imx)373 static void spi_imx_buf_tx_swap_u32(struct spi_imx_data *spi_imx)
374 {
375 	u32 val = 0;
376 #ifdef __LITTLE_ENDIAN
377 	unsigned int bytes_per_word;
378 #endif
379 
380 	if (spi_imx->tx_buf) {
381 		val = *(u32 *)spi_imx->tx_buf;
382 		spi_imx->tx_buf += sizeof(u32);
383 	}
384 
385 	spi_imx->count -= sizeof(u32);
386 #ifdef __LITTLE_ENDIAN
387 	bytes_per_word = spi_imx_bytes_per_word(spi_imx->bits_per_word);
388 
389 	if (bytes_per_word == 1)
390 		swab32s(&val);
391 	else if (bytes_per_word == 2)
392 		swahw32s(&val);
393 #endif
394 	writel(val, spi_imx->base + MXC_CSPITXDATA);
395 }
396 
spi_imx_buf_tx_swap(struct spi_imx_data * spi_imx)397 static void spi_imx_buf_tx_swap(struct spi_imx_data *spi_imx)
398 {
399 	int unaligned;
400 	u32 val = 0;
401 
402 	unaligned = spi_imx->count % 4;
403 
404 	if (!unaligned) {
405 		spi_imx_buf_tx_swap_u32(spi_imx);
406 		return;
407 	}
408 
409 	if (spi_imx_bytes_per_word(spi_imx->bits_per_word) == 2) {
410 		spi_imx_buf_tx_u16(spi_imx);
411 		return;
412 	}
413 
414 	while (unaligned--) {
415 		if (spi_imx->tx_buf) {
416 			val |= *(u8 *)spi_imx->tx_buf << (8 * unaligned);
417 			spi_imx->tx_buf++;
418 		}
419 		spi_imx->count--;
420 	}
421 
422 	writel(val, spi_imx->base + MXC_CSPITXDATA);
423 }
424 
mx53_ecspi_rx_target(struct spi_imx_data * spi_imx)425 static void mx53_ecspi_rx_target(struct spi_imx_data *spi_imx)
426 {
427 	u32 val = ioread32be(spi_imx->base + MXC_CSPIRXDATA);
428 
429 	if (spi_imx->rx_buf) {
430 		int n_bytes = spi_imx->target_burst % sizeof(val);
431 
432 		if (!n_bytes)
433 			n_bytes = sizeof(val);
434 
435 		memcpy(spi_imx->rx_buf,
436 		       ((u8 *)&val) + sizeof(val) - n_bytes, n_bytes);
437 
438 		spi_imx->rx_buf += n_bytes;
439 		spi_imx->target_burst -= n_bytes;
440 	}
441 
442 	spi_imx->remainder -= sizeof(u32);
443 }
444 
mx53_ecspi_tx_target(struct spi_imx_data * spi_imx)445 static void mx53_ecspi_tx_target(struct spi_imx_data *spi_imx)
446 {
447 	u32 val = 0;
448 	int n_bytes = spi_imx->count % sizeof(val);
449 
450 	if (!n_bytes)
451 		n_bytes = sizeof(val);
452 
453 	if (spi_imx->tx_buf) {
454 		memcpy(((u8 *)&val) + sizeof(val) - n_bytes,
455 		       spi_imx->tx_buf, n_bytes);
456 		spi_imx->tx_buf += n_bytes;
457 	}
458 
459 	spi_imx->count -= n_bytes;
460 
461 	iowrite32be(val, spi_imx->base + MXC_CSPITXDATA);
462 }
463 
464 /* MX51 eCSPI */
mx51_ecspi_clkdiv(struct spi_imx_data * spi_imx,unsigned int fspi,unsigned int * fres)465 static unsigned int mx51_ecspi_clkdiv(struct spi_imx_data *spi_imx,
466 				      unsigned int fspi, unsigned int *fres)
467 {
468 	/*
469 	 * there are two 4-bit dividers, the pre-divider divides by
470 	 * $pre, the post-divider by 2^$post
471 	 */
472 	unsigned int pre, post;
473 	unsigned int fin = spi_imx->spi_clk;
474 
475 	fspi = min(fspi, fin);
476 
477 	post = fls(fin) - fls(fspi);
478 	if (fin > fspi << post)
479 		post++;
480 
481 	/* now we have: (fin <= fspi << post) with post being minimal */
482 
483 	post = max(4U, post) - 4;
484 	if (unlikely(post > 0xf)) {
485 		dev_err(spi_imx->dev, "cannot set clock freq: %u (base freq: %u)\n",
486 				fspi, fin);
487 		return 0xff;
488 	}
489 
490 	pre = DIV_ROUND_UP(fin, fspi << post) - 1;
491 
492 	dev_dbg(spi_imx->dev, "%s: fin: %u, fspi: %u, post: %u, pre: %u\n",
493 			__func__, fin, fspi, post, pre);
494 
495 	/* Resulting frequency for the SCLK line. */
496 	*fres = (fin / (pre + 1)) >> post;
497 
498 	return (pre << MX51_ECSPI_CTRL_PREDIV_OFFSET) |
499 		(post << MX51_ECSPI_CTRL_POSTDIV_OFFSET);
500 }
501 
mx51_ecspi_intctrl(struct spi_imx_data * spi_imx,int enable)502 static void mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int enable)
503 {
504 	unsigned int val = 0;
505 
506 	if (enable & MXC_INT_TE)
507 		val |= MX51_ECSPI_INT_TEEN;
508 
509 	if (enable & MXC_INT_RR)
510 		val |= MX51_ECSPI_INT_RREN;
511 
512 	if (enable & MXC_INT_RDR)
513 		val |= MX51_ECSPI_INT_RDREN;
514 
515 	writel(val, spi_imx->base + MX51_ECSPI_INT);
516 }
517 
mx51_ecspi_trigger(struct spi_imx_data * spi_imx)518 static void mx51_ecspi_trigger(struct spi_imx_data *spi_imx)
519 {
520 	u32 reg;
521 
522 	if (spi_imx->usedma) {
523 		reg = readl(spi_imx->base + MX51_ECSPI_DMA);
524 		reg |= MX51_ECSPI_DMA_TEDEN | MX51_ECSPI_DMA_RXDEN;
525 		writel(reg, spi_imx->base + MX51_ECSPI_DMA);
526 	} else {
527 		reg = readl(spi_imx->base + MX51_ECSPI_CTRL);
528 		reg |= MX51_ECSPI_CTRL_XCH;
529 		writel(reg, spi_imx->base + MX51_ECSPI_CTRL);
530 	}
531 }
532 
mx51_ecspi_disable(struct spi_imx_data * spi_imx)533 static void mx51_ecspi_disable(struct spi_imx_data *spi_imx)
534 {
535 	u32 ctrl;
536 
537 	ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL);
538 	ctrl &= ~MX51_ECSPI_CTRL_ENABLE;
539 	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
540 }
541 
mx51_ecspi_channel(const struct spi_device * spi)542 static int mx51_ecspi_channel(const struct spi_device *spi)
543 {
544 	if (!spi_get_csgpiod(spi, 0))
545 		return spi_get_chipselect(spi, 0);
546 	return spi->controller->unused_native_cs;
547 }
548 
mx51_ecspi_prepare_message(struct spi_imx_data * spi_imx,struct spi_message * msg)549 static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx,
550 				      struct spi_message *msg)
551 {
552 	struct spi_device *spi = msg->spi;
553 	struct spi_transfer *xfer;
554 	u32 ctrl = MX51_ECSPI_CTRL_ENABLE;
555 	u32 min_speed_hz = ~0U;
556 	u32 testreg, delay;
557 	u32 cfg = readl(spi_imx->base + MX51_ECSPI_CONFIG);
558 	u32 current_cfg = cfg;
559 	int channel = mx51_ecspi_channel(spi);
560 
561 	/* set Host or Target mode */
562 	if (spi_imx->target_mode)
563 		ctrl &= ~MX51_ECSPI_CTRL_MODE_MASK;
564 	else
565 		ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
566 
567 	/*
568 	 * Enable SPI_RDY handling (falling edge/level triggered).
569 	 */
570 	if (spi->mode & SPI_READY)
571 		ctrl |= MX51_ECSPI_CTRL_DRCTL(spi_imx->spi_drctl);
572 
573 	/* set chip select to use */
574 	ctrl |= MX51_ECSPI_CTRL_CS(channel);
575 
576 	/*
577 	 * The ctrl register must be written first, with the EN bit set other
578 	 * registers must not be written to.
579 	 */
580 	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
581 
582 	testreg = readl(spi_imx->base + MX51_ECSPI_TESTREG);
583 	if (spi->mode & SPI_LOOP)
584 		testreg |= MX51_ECSPI_TESTREG_LBC;
585 	else
586 		testreg &= ~MX51_ECSPI_TESTREG_LBC;
587 	writel(testreg, spi_imx->base + MX51_ECSPI_TESTREG);
588 
589 	/*
590 	 * eCSPI burst completion by Chip Select signal in Target mode
591 	 * is not functional for imx53 Soc, config SPI burst completed when
592 	 * BURST_LENGTH + 1 bits are received
593 	 */
594 	if (spi_imx->target_mode && is_imx53_ecspi(spi_imx))
595 		cfg &= ~MX51_ECSPI_CONFIG_SBBCTRL(channel);
596 	else
597 		cfg |= MX51_ECSPI_CONFIG_SBBCTRL(channel);
598 
599 	if (spi->mode & SPI_CPOL) {
600 		cfg |= MX51_ECSPI_CONFIG_SCLKPOL(channel);
601 		cfg |= MX51_ECSPI_CONFIG_SCLKCTL(channel);
602 	} else {
603 		cfg &= ~MX51_ECSPI_CONFIG_SCLKPOL(channel);
604 		cfg &= ~MX51_ECSPI_CONFIG_SCLKCTL(channel);
605 	}
606 
607 	if (spi->mode & SPI_MOSI_IDLE_LOW)
608 		cfg |= MX51_ECSPI_CONFIG_DATACTL(channel);
609 	else
610 		cfg &= ~MX51_ECSPI_CONFIG_DATACTL(channel);
611 
612 	if (spi->mode & SPI_CS_HIGH)
613 		cfg |= MX51_ECSPI_CONFIG_SSBPOL(channel);
614 	else
615 		cfg &= ~MX51_ECSPI_CONFIG_SSBPOL(channel);
616 
617 	if (cfg == current_cfg)
618 		return 0;
619 
620 	writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
621 
622 	/*
623 	 * Wait until the changes in the configuration register CONFIGREG
624 	 * propagate into the hardware. It takes exactly one tick of the
625 	 * SCLK clock, but we will wait two SCLK clock just to be sure. The
626 	 * effect of the delay it takes for the hardware to apply changes
627 	 * is noticable if the SCLK clock run very slow. In such a case, if
628 	 * the polarity of SCLK should be inverted, the GPIO ChipSelect might
629 	 * be asserted before the SCLK polarity changes, which would disrupt
630 	 * the SPI communication as the device on the other end would consider
631 	 * the change of SCLK polarity as a clock tick already.
632 	 *
633 	 * Because spi_imx->spi_bus_clk is only set in prepare_message
634 	 * callback, iterate over all the transfers in spi_message, find the
635 	 * one with lowest bus frequency, and use that bus frequency for the
636 	 * delay calculation. In case all transfers have speed_hz == 0, then
637 	 * min_speed_hz is ~0 and the resulting delay is zero.
638 	 */
639 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
640 		if (!xfer->speed_hz)
641 			continue;
642 		min_speed_hz = min(xfer->speed_hz, min_speed_hz);
643 	}
644 
645 	delay = (2 * 1000000) / min_speed_hz;
646 	if (likely(delay < 10))	/* SCLK is faster than 200 kHz */
647 		udelay(delay);
648 	else			/* SCLK is _very_ slow */
649 		usleep_range(delay, delay + 10);
650 
651 	return 0;
652 }
653 
mx51_configure_cpha(struct spi_imx_data * spi_imx,struct spi_device * spi)654 static void mx51_configure_cpha(struct spi_imx_data *spi_imx,
655 				struct spi_device *spi)
656 {
657 	bool cpha = (spi->mode & SPI_CPHA);
658 	bool flip_cpha = (spi->mode & SPI_RX_CPHA_FLIP) && spi_imx->rx_only;
659 	u32 cfg = readl(spi_imx->base + MX51_ECSPI_CONFIG);
660 	int channel = mx51_ecspi_channel(spi);
661 
662 	/* Flip cpha logical value iff flip_cpha */
663 	cpha ^= flip_cpha;
664 
665 	if (cpha)
666 		cfg |= MX51_ECSPI_CONFIG_SCLKPHA(channel);
667 	else
668 		cfg &= ~MX51_ECSPI_CONFIG_SCLKPHA(channel);
669 
670 	writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
671 }
672 
mx51_ecspi_prepare_transfer(struct spi_imx_data * spi_imx,struct spi_device * spi,struct spi_transfer * t)673 static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
674 				       struct spi_device *spi, struct spi_transfer *t)
675 {
676 	u32 ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL);
677 	u64 word_delay_sck;
678 	u32 clk;
679 
680 	/* Clear BL field and set the right value */
681 	ctrl &= ~MX51_ECSPI_CTRL_BL_MASK;
682 	if (spi_imx->target_mode && is_imx53_ecspi(spi_imx))
683 		ctrl |= (spi_imx->target_burst * 8 - 1)
684 			<< MX51_ECSPI_CTRL_BL_OFFSET;
685 	else {
686 		ctrl |= (spi_imx->bits_per_word - 1)
687 			<< MX51_ECSPI_CTRL_BL_OFFSET;
688 	}
689 
690 	/* set clock speed */
691 	ctrl &= ~(0xf << MX51_ECSPI_CTRL_POSTDIV_OFFSET |
692 		  0xf << MX51_ECSPI_CTRL_PREDIV_OFFSET);
693 	ctrl |= mx51_ecspi_clkdiv(spi_imx, spi_imx->spi_bus_clk, &clk);
694 	spi_imx->spi_bus_clk = clk;
695 
696 	mx51_configure_cpha(spi_imx, spi);
697 
698 	/*
699 	 * ERR009165: work in XHC mode instead of SMC as PIO on the chips
700 	 * before i.mx6ul.
701 	 */
702 	if (spi_imx->usedma && spi_imx->devtype_data->tx_glitch_fixed)
703 		ctrl |= MX51_ECSPI_CTRL_SMC;
704 	else
705 		ctrl &= ~MX51_ECSPI_CTRL_SMC;
706 
707 	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
708 
709 	/* calculate word delay in SPI Clock (SCLK) cycles */
710 	if (t->word_delay.value == 0) {
711 		word_delay_sck = 0;
712 	} else if (t->word_delay.unit == SPI_DELAY_UNIT_SCK) {
713 		word_delay_sck = t->word_delay.value;
714 
715 		if (word_delay_sck <= MX51_ECSPI_PERIOD_MIN_DELAY_SCK)
716 			word_delay_sck = 0;
717 		else if (word_delay_sck <= MX51_ECSPI_PERIOD_MIN_DELAY_SCK + 1)
718 			word_delay_sck = 1;
719 		else
720 			word_delay_sck -= MX51_ECSPI_PERIOD_MIN_DELAY_SCK + 1;
721 	} else {
722 		int word_delay_ns;
723 
724 		word_delay_ns = spi_delay_to_ns(&t->word_delay, t);
725 		if (word_delay_ns < 0)
726 			return word_delay_ns;
727 
728 		if (word_delay_ns <= mul_u64_u32_div(NSEC_PER_SEC,
729 						     MX51_ECSPI_PERIOD_MIN_DELAY_SCK,
730 						     spi_imx->spi_bus_clk)) {
731 			word_delay_sck = 0;
732 		} else if (word_delay_ns <= mul_u64_u32_div(NSEC_PER_SEC,
733 							    MX51_ECSPI_PERIOD_MIN_DELAY_SCK + 1,
734 							    spi_imx->spi_bus_clk)) {
735 			word_delay_sck = 1;
736 		} else {
737 			word_delay_ns -= mul_u64_u32_div(NSEC_PER_SEC,
738 							 MX51_ECSPI_PERIOD_MIN_DELAY_SCK + 1,
739 							 spi_imx->spi_bus_clk);
740 
741 			word_delay_sck = DIV_U64_ROUND_UP((u64)word_delay_ns * spi_imx->spi_bus_clk,
742 							  NSEC_PER_SEC);
743 		}
744 	}
745 
746 	if (!FIELD_FIT(MX51_ECSPI_PERIOD_MASK, word_delay_sck))
747 		return -EINVAL;
748 
749 	writel(FIELD_PREP(MX51_ECSPI_PERIOD_MASK, word_delay_sck),
750 	       spi_imx->base + MX51_ECSPI_PERIOD);
751 
752 	return 0;
753 }
754 
mx51_setup_wml(struct spi_imx_data * spi_imx)755 static void mx51_setup_wml(struct spi_imx_data *spi_imx)
756 {
757 	u32 tx_wml = 0;
758 
759 	if (spi_imx->devtype_data->tx_glitch_fixed)
760 		tx_wml = spi_imx->wml;
761 	/*
762 	 * Configure the DMA register: setup the watermark
763 	 * and enable DMA request.
764 	 */
765 	writel(MX51_ECSPI_DMA_RX_WML(spi_imx->wml - 1) |
766 		MX51_ECSPI_DMA_TX_WML(tx_wml) |
767 		MX51_ECSPI_DMA_RXT_WML(spi_imx->wml) |
768 		MX51_ECSPI_DMA_RXTDEN, spi_imx->base + MX51_ECSPI_DMA);
769 }
770 
mx51_ecspi_rx_available(struct spi_imx_data * spi_imx)771 static int mx51_ecspi_rx_available(struct spi_imx_data *spi_imx)
772 {
773 	return readl(spi_imx->base + MX51_ECSPI_STAT) & MX51_ECSPI_STAT_RR;
774 }
775 
mx51_ecspi_reset(struct spi_imx_data * spi_imx)776 static void mx51_ecspi_reset(struct spi_imx_data *spi_imx)
777 {
778 	/* drain receive buffer */
779 	while (mx51_ecspi_rx_available(spi_imx))
780 		readl(spi_imx->base + MXC_CSPIRXDATA);
781 }
782 
783 #define MX31_INTREG_TEEN	(1 << 0)
784 #define MX31_INTREG_RREN	(1 << 3)
785 
786 #define MX31_CSPICTRL_ENABLE	(1 << 0)
787 #define MX31_CSPICTRL_HOST	(1 << 1)
788 #define MX31_CSPICTRL_XCH	(1 << 2)
789 #define MX31_CSPICTRL_SMC	(1 << 3)
790 #define MX31_CSPICTRL_POL	(1 << 4)
791 #define MX31_CSPICTRL_PHA	(1 << 5)
792 #define MX31_CSPICTRL_SSCTL	(1 << 6)
793 #define MX31_CSPICTRL_SSPOL	(1 << 7)
794 #define MX31_CSPICTRL_BC_SHIFT	8
795 #define MX35_CSPICTRL_BL_SHIFT	20
796 #define MX31_CSPICTRL_CS_SHIFT	24
797 #define MX35_CSPICTRL_CS_SHIFT	12
798 #define MX31_CSPICTRL_DR_SHIFT	16
799 
800 #define MX31_CSPI_DMAREG	0x10
801 #define MX31_DMAREG_RH_DEN	(1<<4)
802 #define MX31_DMAREG_TH_DEN	(1<<1)
803 
804 #define MX31_CSPISTATUS		0x14
805 #define MX31_STATUS_RR		(1 << 3)
806 
807 #define MX31_CSPI_TESTREG	0x1C
808 #define MX31_TEST_LBC		(1 << 14)
809 
810 /* These functions also work for the i.MX35, but be aware that
811  * the i.MX35 has a slightly different register layout for bits
812  * we do not use here.
813  */
mx31_intctrl(struct spi_imx_data * spi_imx,int enable)814 static void mx31_intctrl(struct spi_imx_data *spi_imx, int enable)
815 {
816 	unsigned int val = 0;
817 
818 	if (enable & MXC_INT_TE)
819 		val |= MX31_INTREG_TEEN;
820 	if (enable & MXC_INT_RR)
821 		val |= MX31_INTREG_RREN;
822 
823 	writel(val, spi_imx->base + MXC_CSPIINT);
824 }
825 
mx31_trigger(struct spi_imx_data * spi_imx)826 static void mx31_trigger(struct spi_imx_data *spi_imx)
827 {
828 	unsigned int reg;
829 
830 	reg = readl(spi_imx->base + MXC_CSPICTRL);
831 	reg |= MX31_CSPICTRL_XCH;
832 	writel(reg, spi_imx->base + MXC_CSPICTRL);
833 }
834 
mx31_prepare_message(struct spi_imx_data * spi_imx,struct spi_message * msg)835 static int mx31_prepare_message(struct spi_imx_data *spi_imx,
836 				struct spi_message *msg)
837 {
838 	return 0;
839 }
840 
mx31_prepare_transfer(struct spi_imx_data * spi_imx,struct spi_device * spi,struct spi_transfer * t)841 static int mx31_prepare_transfer(struct spi_imx_data *spi_imx,
842 				 struct spi_device *spi, struct spi_transfer *t)
843 {
844 	unsigned int reg = MX31_CSPICTRL_ENABLE | MX31_CSPICTRL_HOST;
845 	unsigned int clk;
846 
847 	reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, spi_imx->spi_bus_clk, &clk) <<
848 		MX31_CSPICTRL_DR_SHIFT;
849 	spi_imx->spi_bus_clk = clk;
850 
851 	if (is_imx35_cspi(spi_imx)) {
852 		reg |= (spi_imx->bits_per_word - 1) << MX35_CSPICTRL_BL_SHIFT;
853 		reg |= MX31_CSPICTRL_SSCTL;
854 	} else {
855 		reg |= (spi_imx->bits_per_word - 1) << MX31_CSPICTRL_BC_SHIFT;
856 	}
857 
858 	if (spi->mode & SPI_CPHA)
859 		reg |= MX31_CSPICTRL_PHA;
860 	if (spi->mode & SPI_CPOL)
861 		reg |= MX31_CSPICTRL_POL;
862 	if (spi->mode & SPI_CS_HIGH)
863 		reg |= MX31_CSPICTRL_SSPOL;
864 	if (!spi_get_csgpiod(spi, 0))
865 		reg |= (spi_get_chipselect(spi, 0)) <<
866 			(is_imx35_cspi(spi_imx) ? MX35_CSPICTRL_CS_SHIFT :
867 						  MX31_CSPICTRL_CS_SHIFT);
868 
869 	if (spi_imx->usedma)
870 		reg |= MX31_CSPICTRL_SMC;
871 
872 	writel(reg, spi_imx->base + MXC_CSPICTRL);
873 
874 	reg = readl(spi_imx->base + MX31_CSPI_TESTREG);
875 	if (spi->mode & SPI_LOOP)
876 		reg |= MX31_TEST_LBC;
877 	else
878 		reg &= ~MX31_TEST_LBC;
879 	writel(reg, spi_imx->base + MX31_CSPI_TESTREG);
880 
881 	if (spi_imx->usedma) {
882 		/*
883 		 * configure DMA requests when RXFIFO is half full and
884 		 * when TXFIFO is half empty
885 		 */
886 		writel(MX31_DMAREG_RH_DEN | MX31_DMAREG_TH_DEN,
887 			spi_imx->base + MX31_CSPI_DMAREG);
888 	}
889 
890 	return 0;
891 }
892 
mx31_rx_available(struct spi_imx_data * spi_imx)893 static int mx31_rx_available(struct spi_imx_data *spi_imx)
894 {
895 	return readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR;
896 }
897 
mx31_reset(struct spi_imx_data * spi_imx)898 static void mx31_reset(struct spi_imx_data *spi_imx)
899 {
900 	/* drain receive buffer */
901 	while (readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR)
902 		readl(spi_imx->base + MXC_CSPIRXDATA);
903 }
904 
905 #define MX21_INTREG_RR		(1 << 4)
906 #define MX21_INTREG_TEEN	(1 << 9)
907 #define MX21_INTREG_RREN	(1 << 13)
908 
909 #define MX21_CSPICTRL_POL	(1 << 5)
910 #define MX21_CSPICTRL_PHA	(1 << 6)
911 #define MX21_CSPICTRL_SSPOL	(1 << 8)
912 #define MX21_CSPICTRL_XCH	(1 << 9)
913 #define MX21_CSPICTRL_ENABLE	(1 << 10)
914 #define MX21_CSPICTRL_HOST	(1 << 11)
915 #define MX21_CSPICTRL_DR_SHIFT	14
916 #define MX21_CSPICTRL_CS_SHIFT	19
917 
mx21_intctrl(struct spi_imx_data * spi_imx,int enable)918 static void mx21_intctrl(struct spi_imx_data *spi_imx, int enable)
919 {
920 	unsigned int val = 0;
921 
922 	if (enable & MXC_INT_TE)
923 		val |= MX21_INTREG_TEEN;
924 	if (enable & MXC_INT_RR)
925 		val |= MX21_INTREG_RREN;
926 
927 	writel(val, spi_imx->base + MXC_CSPIINT);
928 }
929 
mx21_trigger(struct spi_imx_data * spi_imx)930 static void mx21_trigger(struct spi_imx_data *spi_imx)
931 {
932 	unsigned int reg;
933 
934 	reg = readl(spi_imx->base + MXC_CSPICTRL);
935 	reg |= MX21_CSPICTRL_XCH;
936 	writel(reg, spi_imx->base + MXC_CSPICTRL);
937 }
938 
mx21_prepare_message(struct spi_imx_data * spi_imx,struct spi_message * msg)939 static int mx21_prepare_message(struct spi_imx_data *spi_imx,
940 				struct spi_message *msg)
941 {
942 	return 0;
943 }
944 
mx21_prepare_transfer(struct spi_imx_data * spi_imx,struct spi_device * spi,struct spi_transfer * t)945 static int mx21_prepare_transfer(struct spi_imx_data *spi_imx,
946 				 struct spi_device *spi, struct spi_transfer *t)
947 {
948 	unsigned int reg = MX21_CSPICTRL_ENABLE | MX21_CSPICTRL_HOST;
949 	unsigned int max = is_imx27_cspi(spi_imx) ? 16 : 18;
950 	unsigned int clk;
951 
952 	reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, spi_imx->spi_bus_clk, max, &clk)
953 		<< MX21_CSPICTRL_DR_SHIFT;
954 	spi_imx->spi_bus_clk = clk;
955 
956 	reg |= spi_imx->bits_per_word - 1;
957 
958 	if (spi->mode & SPI_CPHA)
959 		reg |= MX21_CSPICTRL_PHA;
960 	if (spi->mode & SPI_CPOL)
961 		reg |= MX21_CSPICTRL_POL;
962 	if (spi->mode & SPI_CS_HIGH)
963 		reg |= MX21_CSPICTRL_SSPOL;
964 	if (!spi_get_csgpiod(spi, 0))
965 		reg |= spi_get_chipselect(spi, 0) << MX21_CSPICTRL_CS_SHIFT;
966 
967 	writel(reg, spi_imx->base + MXC_CSPICTRL);
968 
969 	return 0;
970 }
971 
mx21_rx_available(struct spi_imx_data * spi_imx)972 static int mx21_rx_available(struct spi_imx_data *spi_imx)
973 {
974 	return readl(spi_imx->base + MXC_CSPIINT) & MX21_INTREG_RR;
975 }
976 
mx21_reset(struct spi_imx_data * spi_imx)977 static void mx21_reset(struct spi_imx_data *spi_imx)
978 {
979 	writel(1, spi_imx->base + MXC_RESET);
980 }
981 
982 #define MX1_INTREG_RR		(1 << 3)
983 #define MX1_INTREG_TEEN		(1 << 8)
984 #define MX1_INTREG_RREN		(1 << 11)
985 
986 #define MX1_CSPICTRL_POL	(1 << 4)
987 #define MX1_CSPICTRL_PHA	(1 << 5)
988 #define MX1_CSPICTRL_XCH	(1 << 8)
989 #define MX1_CSPICTRL_ENABLE	(1 << 9)
990 #define MX1_CSPICTRL_HOST	(1 << 10)
991 #define MX1_CSPICTRL_DR_SHIFT	13
992 
mx1_intctrl(struct spi_imx_data * spi_imx,int enable)993 static void mx1_intctrl(struct spi_imx_data *spi_imx, int enable)
994 {
995 	unsigned int val = 0;
996 
997 	if (enable & MXC_INT_TE)
998 		val |= MX1_INTREG_TEEN;
999 	if (enable & MXC_INT_RR)
1000 		val |= MX1_INTREG_RREN;
1001 
1002 	writel(val, spi_imx->base + MXC_CSPIINT);
1003 }
1004 
mx1_trigger(struct spi_imx_data * spi_imx)1005 static void mx1_trigger(struct spi_imx_data *spi_imx)
1006 {
1007 	unsigned int reg;
1008 
1009 	reg = readl(spi_imx->base + MXC_CSPICTRL);
1010 	reg |= MX1_CSPICTRL_XCH;
1011 	writel(reg, spi_imx->base + MXC_CSPICTRL);
1012 }
1013 
mx1_prepare_message(struct spi_imx_data * spi_imx,struct spi_message * msg)1014 static int mx1_prepare_message(struct spi_imx_data *spi_imx,
1015 			       struct spi_message *msg)
1016 {
1017 	return 0;
1018 }
1019 
mx1_prepare_transfer(struct spi_imx_data * spi_imx,struct spi_device * spi,struct spi_transfer * t)1020 static int mx1_prepare_transfer(struct spi_imx_data *spi_imx,
1021 				struct spi_device *spi, struct spi_transfer *t)
1022 {
1023 	unsigned int reg = MX1_CSPICTRL_ENABLE | MX1_CSPICTRL_HOST;
1024 	unsigned int clk;
1025 
1026 	reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, spi_imx->spi_bus_clk, &clk) <<
1027 		MX1_CSPICTRL_DR_SHIFT;
1028 	spi_imx->spi_bus_clk = clk;
1029 
1030 	reg |= spi_imx->bits_per_word - 1;
1031 
1032 	if (spi->mode & SPI_CPHA)
1033 		reg |= MX1_CSPICTRL_PHA;
1034 	if (spi->mode & SPI_CPOL)
1035 		reg |= MX1_CSPICTRL_POL;
1036 
1037 	writel(reg, spi_imx->base + MXC_CSPICTRL);
1038 
1039 	return 0;
1040 }
1041 
mx1_rx_available(struct spi_imx_data * spi_imx)1042 static int mx1_rx_available(struct spi_imx_data *spi_imx)
1043 {
1044 	return readl(spi_imx->base + MXC_CSPIINT) & MX1_INTREG_RR;
1045 }
1046 
mx1_reset(struct spi_imx_data * spi_imx)1047 static void mx1_reset(struct spi_imx_data *spi_imx)
1048 {
1049 	writel(1, spi_imx->base + MXC_RESET);
1050 }
1051 
1052 static struct spi_imx_devtype_data imx1_cspi_devtype_data = {
1053 	.intctrl = mx1_intctrl,
1054 	.prepare_message = mx1_prepare_message,
1055 	.prepare_transfer = mx1_prepare_transfer,
1056 	.trigger = mx1_trigger,
1057 	.rx_available = mx1_rx_available,
1058 	.reset = mx1_reset,
1059 	.fifo_size = 8,
1060 	.has_dmamode = false,
1061 	.dynamic_burst = false,
1062 	.has_targetmode = false,
1063 	.devtype = IMX1_CSPI,
1064 };
1065 
1066 static struct spi_imx_devtype_data imx21_cspi_devtype_data = {
1067 	.intctrl = mx21_intctrl,
1068 	.prepare_message = mx21_prepare_message,
1069 	.prepare_transfer = mx21_prepare_transfer,
1070 	.trigger = mx21_trigger,
1071 	.rx_available = mx21_rx_available,
1072 	.reset = mx21_reset,
1073 	.fifo_size = 8,
1074 	.has_dmamode = false,
1075 	.dynamic_burst = false,
1076 	.has_targetmode = false,
1077 	.devtype = IMX21_CSPI,
1078 };
1079 
1080 static struct spi_imx_devtype_data imx27_cspi_devtype_data = {
1081 	/* i.mx27 cspi shares the functions with i.mx21 one */
1082 	.intctrl = mx21_intctrl,
1083 	.prepare_message = mx21_prepare_message,
1084 	.prepare_transfer = mx21_prepare_transfer,
1085 	.trigger = mx21_trigger,
1086 	.rx_available = mx21_rx_available,
1087 	.reset = mx21_reset,
1088 	.fifo_size = 8,
1089 	.has_dmamode = false,
1090 	.dynamic_burst = false,
1091 	.has_targetmode = false,
1092 	.devtype = IMX27_CSPI,
1093 };
1094 
1095 static struct spi_imx_devtype_data imx31_cspi_devtype_data = {
1096 	.intctrl = mx31_intctrl,
1097 	.prepare_message = mx31_prepare_message,
1098 	.prepare_transfer = mx31_prepare_transfer,
1099 	.trigger = mx31_trigger,
1100 	.rx_available = mx31_rx_available,
1101 	.reset = mx31_reset,
1102 	.fifo_size = 8,
1103 	.has_dmamode = false,
1104 	.dynamic_burst = false,
1105 	.has_targetmode = false,
1106 	.devtype = IMX31_CSPI,
1107 };
1108 
1109 static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
1110 	/* i.mx35 and later cspi shares the functions with i.mx31 one */
1111 	.intctrl = mx31_intctrl,
1112 	.prepare_message = mx31_prepare_message,
1113 	.prepare_transfer = mx31_prepare_transfer,
1114 	.trigger = mx31_trigger,
1115 	.rx_available = mx31_rx_available,
1116 	.reset = mx31_reset,
1117 	.fifo_size = 8,
1118 	.has_dmamode = false,
1119 	.dynamic_burst = false,
1120 	.has_targetmode = false,
1121 	.devtype = IMX35_CSPI,
1122 };
1123 
1124 static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
1125 	.intctrl = mx51_ecspi_intctrl,
1126 	.prepare_message = mx51_ecspi_prepare_message,
1127 	.prepare_transfer = mx51_ecspi_prepare_transfer,
1128 	.trigger = mx51_ecspi_trigger,
1129 	.rx_available = mx51_ecspi_rx_available,
1130 	.reset = mx51_ecspi_reset,
1131 	.setup_wml = mx51_setup_wml,
1132 	.fifo_size = 64,
1133 	.has_dmamode = true,
1134 	.dynamic_burst = true,
1135 	.has_targetmode = true,
1136 	.disable = mx51_ecspi_disable,
1137 	.devtype = IMX51_ECSPI,
1138 };
1139 
1140 static struct spi_imx_devtype_data imx53_ecspi_devtype_data = {
1141 	.intctrl = mx51_ecspi_intctrl,
1142 	.prepare_message = mx51_ecspi_prepare_message,
1143 	.prepare_transfer = mx51_ecspi_prepare_transfer,
1144 	.trigger = mx51_ecspi_trigger,
1145 	.rx_available = mx51_ecspi_rx_available,
1146 	.reset = mx51_ecspi_reset,
1147 	.fifo_size = 64,
1148 	.has_dmamode = true,
1149 	.has_targetmode = true,
1150 	.disable = mx51_ecspi_disable,
1151 	.devtype = IMX53_ECSPI,
1152 };
1153 
1154 static struct spi_imx_devtype_data imx6ul_ecspi_devtype_data = {
1155 	.intctrl = mx51_ecspi_intctrl,
1156 	.prepare_message = mx51_ecspi_prepare_message,
1157 	.prepare_transfer = mx51_ecspi_prepare_transfer,
1158 	.trigger = mx51_ecspi_trigger,
1159 	.rx_available = mx51_ecspi_rx_available,
1160 	.reset = mx51_ecspi_reset,
1161 	.setup_wml = mx51_setup_wml,
1162 	.fifo_size = 64,
1163 	.has_dmamode = true,
1164 	.dynamic_burst = true,
1165 	.has_targetmode = true,
1166 	.tx_glitch_fixed = true,
1167 	.disable = mx51_ecspi_disable,
1168 	.devtype = IMX51_ECSPI,
1169 };
1170 
1171 static const struct of_device_id spi_imx_dt_ids[] = {
1172 	{ .compatible = "fsl,imx1-cspi", .data = &imx1_cspi_devtype_data, },
1173 	{ .compatible = "fsl,imx21-cspi", .data = &imx21_cspi_devtype_data, },
1174 	{ .compatible = "fsl,imx27-cspi", .data = &imx27_cspi_devtype_data, },
1175 	{ .compatible = "fsl,imx31-cspi", .data = &imx31_cspi_devtype_data, },
1176 	{ .compatible = "fsl,imx35-cspi", .data = &imx35_cspi_devtype_data, },
1177 	{ .compatible = "fsl,imx51-ecspi", .data = &imx51_ecspi_devtype_data, },
1178 	{ .compatible = "fsl,imx53-ecspi", .data = &imx53_ecspi_devtype_data, },
1179 	{ .compatible = "fsl,imx6ul-ecspi", .data = &imx6ul_ecspi_devtype_data, },
1180 	{ /* sentinel */ }
1181 };
1182 MODULE_DEVICE_TABLE(of, spi_imx_dt_ids);
1183 
spi_imx_set_burst_len(struct spi_imx_data * spi_imx,int n_bits)1184 static void spi_imx_set_burst_len(struct spi_imx_data *spi_imx, int n_bits)
1185 {
1186 	u32 ctrl;
1187 
1188 	ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL);
1189 	ctrl &= ~MX51_ECSPI_CTRL_BL_MASK;
1190 	ctrl |= ((n_bits - 1) << MX51_ECSPI_CTRL_BL_OFFSET);
1191 	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
1192 }
1193 
spi_imx_push(struct spi_imx_data * spi_imx)1194 static void spi_imx_push(struct spi_imx_data *spi_imx)
1195 {
1196 	unsigned int burst_len;
1197 
1198 	/*
1199 	 * Reload the FIFO when the remaining bytes to be transferred in the
1200 	 * current burst is 0. This only applies when bits_per_word is a
1201 	 * multiple of 8.
1202 	 */
1203 	if (!spi_imx->remainder) {
1204 		if (spi_imx->dynamic_burst) {
1205 
1206 			/* We need to deal unaligned data first */
1207 			burst_len = spi_imx->count % MX51_ECSPI_CTRL_MAX_BURST;
1208 
1209 			if (!burst_len)
1210 				burst_len = MX51_ECSPI_CTRL_MAX_BURST;
1211 
1212 			spi_imx_set_burst_len(spi_imx, burst_len * 8);
1213 
1214 			spi_imx->remainder = burst_len;
1215 		} else {
1216 			spi_imx->remainder = spi_imx_bytes_per_word(spi_imx->bits_per_word);
1217 		}
1218 	}
1219 
1220 	while (spi_imx->txfifo < spi_imx->devtype_data->fifo_size) {
1221 		if (!spi_imx->count)
1222 			break;
1223 		if (spi_imx->dynamic_burst &&
1224 		    spi_imx->txfifo >= DIV_ROUND_UP(spi_imx->remainder, 4))
1225 			break;
1226 		spi_imx->tx(spi_imx);
1227 		spi_imx->txfifo++;
1228 	}
1229 
1230 	if (!spi_imx->target_mode)
1231 		spi_imx->devtype_data->trigger(spi_imx);
1232 }
1233 
spi_imx_isr(int irq,void * dev_id)1234 static irqreturn_t spi_imx_isr(int irq, void *dev_id)
1235 {
1236 	struct spi_imx_data *spi_imx = dev_id;
1237 
1238 	while (spi_imx->txfifo &&
1239 	       spi_imx->devtype_data->rx_available(spi_imx)) {
1240 		spi_imx->rx(spi_imx);
1241 		spi_imx->txfifo--;
1242 	}
1243 
1244 	if (spi_imx->count) {
1245 		spi_imx_push(spi_imx);
1246 		return IRQ_HANDLED;
1247 	}
1248 
1249 	if (spi_imx->txfifo) {
1250 		/* No data left to push, but still waiting for rx data,
1251 		 * enable receive data available interrupt.
1252 		 */
1253 		spi_imx->devtype_data->intctrl(
1254 				spi_imx, MXC_INT_RR);
1255 		return IRQ_HANDLED;
1256 	}
1257 
1258 	spi_imx->devtype_data->intctrl(spi_imx, 0);
1259 	complete(&spi_imx->xfer_done);
1260 
1261 	return IRQ_HANDLED;
1262 }
1263 
spi_imx_dma_configure(struct spi_controller * controller)1264 static int spi_imx_dma_configure(struct spi_controller *controller)
1265 {
1266 	int ret;
1267 	enum dma_slave_buswidth buswidth;
1268 	struct dma_slave_config rx = {}, tx = {};
1269 	struct spi_imx_data *spi_imx = spi_controller_get_devdata(controller);
1270 
1271 	switch (spi_imx_bytes_per_word(spi_imx->bits_per_word)) {
1272 	case 4:
1273 		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
1274 		break;
1275 	case 2:
1276 		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
1277 		break;
1278 	case 1:
1279 		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
1280 		break;
1281 	default:
1282 		return -EINVAL;
1283 	}
1284 
1285 	tx.direction = DMA_MEM_TO_DEV;
1286 	tx.dst_addr = spi_imx->base_phys + MXC_CSPITXDATA;
1287 	tx.dst_addr_width = buswidth;
1288 	tx.dst_maxburst = spi_imx->wml;
1289 	ret = dmaengine_slave_config(controller->dma_tx, &tx);
1290 	if (ret) {
1291 		dev_err(spi_imx->dev, "TX dma configuration failed with %d\n", ret);
1292 		return ret;
1293 	}
1294 
1295 	rx.direction = DMA_DEV_TO_MEM;
1296 	rx.src_addr = spi_imx->base_phys + MXC_CSPIRXDATA;
1297 	rx.src_addr_width = buswidth;
1298 	rx.src_maxburst = spi_imx->wml;
1299 	ret = dmaengine_slave_config(controller->dma_rx, &rx);
1300 	if (ret) {
1301 		dev_err(spi_imx->dev, "RX dma configuration failed with %d\n", ret);
1302 		return ret;
1303 	}
1304 
1305 	return 0;
1306 }
1307 
spi_imx_setupxfer(struct spi_device * spi,struct spi_transfer * t)1308 static int spi_imx_setupxfer(struct spi_device *spi,
1309 				 struct spi_transfer *t)
1310 {
1311 	struct spi_imx_data *spi_imx = spi_controller_get_devdata(spi->controller);
1312 
1313 	if (!t)
1314 		return 0;
1315 
1316 	if (!t->speed_hz) {
1317 		if (!spi->max_speed_hz) {
1318 			dev_err(&spi->dev, "no speed_hz provided!\n");
1319 			return -EINVAL;
1320 		}
1321 		dev_dbg(&spi->dev, "using spi->max_speed_hz!\n");
1322 		spi_imx->spi_bus_clk = spi->max_speed_hz;
1323 	} else
1324 		spi_imx->spi_bus_clk = t->speed_hz;
1325 
1326 	spi_imx->bits_per_word = t->bits_per_word;
1327 	spi_imx->count = t->len;
1328 
1329 	/*
1330 	 * Initialize the functions for transfer. To transfer non byte-aligned
1331 	 * words, we have to use multiple word-size bursts. To insert word
1332 	 * delay, the burst size has to equal the word size. We can't use
1333 	 * dynamic_burst in these cases.
1334 	 */
1335 	if (spi_imx->devtype_data->dynamic_burst && !spi_imx->target_mode &&
1336 	    !(spi->mode & SPI_CS_WORD) &&
1337 	    !(t->word_delay.value) &&
1338 	    (spi_imx->bits_per_word == 8 ||
1339 	    spi_imx->bits_per_word == 16 ||
1340 	    spi_imx->bits_per_word == 32)) {
1341 
1342 		spi_imx->rx = spi_imx_buf_rx_swap;
1343 		spi_imx->tx = spi_imx_buf_tx_swap;
1344 		spi_imx->dynamic_burst = 1;
1345 
1346 	} else {
1347 		if (spi_imx->bits_per_word <= 8) {
1348 			spi_imx->rx = spi_imx_buf_rx_u8;
1349 			spi_imx->tx = spi_imx_buf_tx_u8;
1350 		} else if (spi_imx->bits_per_word <= 16) {
1351 			spi_imx->rx = spi_imx_buf_rx_u16;
1352 			spi_imx->tx = spi_imx_buf_tx_u16;
1353 		} else {
1354 			spi_imx->rx = spi_imx_buf_rx_u32;
1355 			spi_imx->tx = spi_imx_buf_tx_u32;
1356 		}
1357 		spi_imx->dynamic_burst = 0;
1358 	}
1359 
1360 	if (spi_imx_can_dma(spi_imx->controller, spi, t))
1361 		spi_imx->usedma = true;
1362 	else
1363 		spi_imx->usedma = false;
1364 
1365 	spi_imx->rx_only = ((t->tx_buf == NULL)
1366 			|| (t->tx_buf == spi->controller->dummy_tx));
1367 
1368 	if (is_imx53_ecspi(spi_imx) && spi_imx->target_mode) {
1369 		spi_imx->rx = mx53_ecspi_rx_target;
1370 		spi_imx->tx = mx53_ecspi_tx_target;
1371 		spi_imx->target_burst = t->len;
1372 	}
1373 
1374 	spi_imx->devtype_data->prepare_transfer(spi_imx, spi, t);
1375 
1376 	return 0;
1377 }
1378 
spi_imx_sdma_exit(struct spi_imx_data * spi_imx)1379 static void spi_imx_sdma_exit(struct spi_imx_data *spi_imx)
1380 {
1381 	struct spi_controller *controller = spi_imx->controller;
1382 
1383 	if (controller->dma_rx) {
1384 		dma_release_channel(controller->dma_rx);
1385 		controller->dma_rx = NULL;
1386 	}
1387 
1388 	if (controller->dma_tx) {
1389 		dma_release_channel(controller->dma_tx);
1390 		controller->dma_tx = NULL;
1391 	}
1392 }
1393 
spi_imx_sdma_init(struct device * dev,struct spi_imx_data * spi_imx,struct spi_controller * controller)1394 static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
1395 			     struct spi_controller *controller)
1396 {
1397 	int ret;
1398 
1399 	spi_imx->wml = spi_imx->devtype_data->fifo_size / 2;
1400 
1401 	/* Prepare for TX DMA: */
1402 	controller->dma_tx = dma_request_chan(dev, "tx");
1403 	if (IS_ERR(controller->dma_tx)) {
1404 		ret = PTR_ERR(controller->dma_tx);
1405 		dev_err_probe(dev, ret, "can't get the TX DMA channel!\n");
1406 		controller->dma_tx = NULL;
1407 		goto err;
1408 	}
1409 
1410 	/* Prepare for RX : */
1411 	controller->dma_rx = dma_request_chan(dev, "rx");
1412 	if (IS_ERR(controller->dma_rx)) {
1413 		ret = PTR_ERR(controller->dma_rx);
1414 		dev_err_probe(dev, ret, "can't get the RX DMA channel!\n");
1415 		controller->dma_rx = NULL;
1416 		goto err;
1417 	}
1418 
1419 	init_completion(&spi_imx->dma_rx_completion);
1420 	init_completion(&spi_imx->dma_tx_completion);
1421 	controller->can_dma = spi_imx_can_dma;
1422 	controller->max_dma_len = MAX_SDMA_BD_BYTES;
1423 	spi_imx->controller->flags = SPI_CONTROLLER_MUST_RX |
1424 					 SPI_CONTROLLER_MUST_TX;
1425 
1426 	return 0;
1427 err:
1428 	spi_imx_sdma_exit(spi_imx);
1429 	return ret;
1430 }
1431 
spi_imx_dma_rx_callback(void * cookie)1432 static void spi_imx_dma_rx_callback(void *cookie)
1433 {
1434 	struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie;
1435 
1436 	complete(&spi_imx->dma_rx_completion);
1437 }
1438 
spi_imx_dma_tx_callback(void * cookie)1439 static void spi_imx_dma_tx_callback(void *cookie)
1440 {
1441 	struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie;
1442 
1443 	complete(&spi_imx->dma_tx_completion);
1444 }
1445 
spi_imx_calculate_timeout(struct spi_imx_data * spi_imx,int size)1446 static int spi_imx_calculate_timeout(struct spi_imx_data *spi_imx, int size)
1447 {
1448 	unsigned long timeout = 0;
1449 
1450 	/* Time with actual data transfer and CS change delay related to HW */
1451 	timeout = (8 + 4) * size / spi_imx->spi_bus_clk;
1452 
1453 	/* Add extra second for scheduler related activities */
1454 	timeout += 1;
1455 
1456 	/* Double calculated timeout */
1457 	return secs_to_jiffies(2 * timeout);
1458 }
1459 
spi_imx_dma_transfer(struct spi_imx_data * spi_imx,struct spi_transfer * transfer)1460 static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
1461 				struct spi_transfer *transfer)
1462 {
1463 	struct dma_async_tx_descriptor *desc_tx, *desc_rx;
1464 	unsigned long transfer_timeout;
1465 	unsigned long time_left;
1466 	struct spi_controller *controller = spi_imx->controller;
1467 	struct sg_table *tx = &transfer->tx_sg, *rx = &transfer->rx_sg;
1468 	struct scatterlist *last_sg = sg_last(rx->sgl, rx->nents);
1469 	unsigned int bytes_per_word, i;
1470 	int ret;
1471 
1472 	/* Get the right burst length from the last sg to ensure no tail data */
1473 	bytes_per_word = spi_imx_bytes_per_word(transfer->bits_per_word);
1474 	for (i = spi_imx->devtype_data->fifo_size / 2; i > 0; i--) {
1475 		if (!(sg_dma_len(last_sg) % (i * bytes_per_word)))
1476 			break;
1477 	}
1478 	/* Use 1 as wml in case no available burst length got */
1479 	if (i == 0)
1480 		i = 1;
1481 
1482 	spi_imx->wml =  i;
1483 
1484 	ret = spi_imx_dma_configure(controller);
1485 	if (ret)
1486 		goto dma_failure_no_start;
1487 
1488 	if (!spi_imx->devtype_data->setup_wml) {
1489 		dev_err(spi_imx->dev, "No setup_wml()?\n");
1490 		ret = -EINVAL;
1491 		goto dma_failure_no_start;
1492 	}
1493 	spi_imx->devtype_data->setup_wml(spi_imx);
1494 
1495 	/*
1496 	 * The TX DMA setup starts the transfer, so make sure RX is configured
1497 	 * before TX.
1498 	 */
1499 	desc_rx = dmaengine_prep_slave_sg(controller->dma_rx,
1500 				rx->sgl, rx->nents, DMA_DEV_TO_MEM,
1501 				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1502 	if (!desc_rx) {
1503 		ret = -EINVAL;
1504 		goto dma_failure_no_start;
1505 	}
1506 
1507 	desc_rx->callback = spi_imx_dma_rx_callback;
1508 	desc_rx->callback_param = (void *)spi_imx;
1509 	dmaengine_submit(desc_rx);
1510 	reinit_completion(&spi_imx->dma_rx_completion);
1511 	dma_async_issue_pending(controller->dma_rx);
1512 
1513 	desc_tx = dmaengine_prep_slave_sg(controller->dma_tx,
1514 				tx->sgl, tx->nents, DMA_MEM_TO_DEV,
1515 				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1516 	if (!desc_tx) {
1517 		dmaengine_terminate_all(controller->dma_tx);
1518 		dmaengine_terminate_all(controller->dma_rx);
1519 		return -EINVAL;
1520 	}
1521 
1522 	desc_tx->callback = spi_imx_dma_tx_callback;
1523 	desc_tx->callback_param = (void *)spi_imx;
1524 	dmaengine_submit(desc_tx);
1525 	reinit_completion(&spi_imx->dma_tx_completion);
1526 	dma_async_issue_pending(controller->dma_tx);
1527 
1528 	spi_imx->devtype_data->trigger(spi_imx);
1529 
1530 	transfer_timeout = spi_imx_calculate_timeout(spi_imx, transfer->len);
1531 
1532 	/* Wait SDMA to finish the data transfer.*/
1533 	time_left = wait_for_completion_timeout(&spi_imx->dma_tx_completion,
1534 						transfer_timeout);
1535 	if (!time_left) {
1536 		dev_err(spi_imx->dev, "I/O Error in DMA TX\n");
1537 		dmaengine_terminate_all(controller->dma_tx);
1538 		dmaengine_terminate_all(controller->dma_rx);
1539 		return -ETIMEDOUT;
1540 	}
1541 
1542 	time_left = wait_for_completion_timeout(&spi_imx->dma_rx_completion,
1543 						transfer_timeout);
1544 	if (!time_left) {
1545 		dev_err(&controller->dev, "I/O Error in DMA RX\n");
1546 		spi_imx->devtype_data->reset(spi_imx);
1547 		dmaengine_terminate_all(controller->dma_rx);
1548 		return -ETIMEDOUT;
1549 	}
1550 
1551 	return 0;
1552 /* fallback to pio */
1553 dma_failure_no_start:
1554 	transfer->error |= SPI_TRANS_FAIL_NO_START;
1555 	return ret;
1556 }
1557 
spi_imx_pio_transfer(struct spi_device * spi,struct spi_transfer * transfer)1558 static int spi_imx_pio_transfer(struct spi_device *spi,
1559 				struct spi_transfer *transfer)
1560 {
1561 	struct spi_imx_data *spi_imx = spi_controller_get_devdata(spi->controller);
1562 	unsigned long transfer_timeout;
1563 	unsigned long time_left;
1564 
1565 	spi_imx->tx_buf = transfer->tx_buf;
1566 	spi_imx->rx_buf = transfer->rx_buf;
1567 	spi_imx->count = transfer->len;
1568 	spi_imx->txfifo = 0;
1569 	spi_imx->remainder = 0;
1570 
1571 	reinit_completion(&spi_imx->xfer_done);
1572 
1573 	spi_imx_push(spi_imx);
1574 
1575 	spi_imx->devtype_data->intctrl(spi_imx, MXC_INT_TE);
1576 
1577 	transfer_timeout = spi_imx_calculate_timeout(spi_imx, transfer->len);
1578 
1579 	time_left = wait_for_completion_timeout(&spi_imx->xfer_done,
1580 						transfer_timeout);
1581 	if (!time_left) {
1582 		dev_err(&spi->dev, "I/O Error in PIO\n");
1583 		spi_imx->devtype_data->reset(spi_imx);
1584 		return -ETIMEDOUT;
1585 	}
1586 
1587 	return 0;
1588 }
1589 
spi_imx_poll_transfer(struct spi_device * spi,struct spi_transfer * transfer)1590 static int spi_imx_poll_transfer(struct spi_device *spi,
1591 				 struct spi_transfer *transfer)
1592 {
1593 	struct spi_imx_data *spi_imx = spi_controller_get_devdata(spi->controller);
1594 	unsigned long timeout;
1595 
1596 	spi_imx->tx_buf = transfer->tx_buf;
1597 	spi_imx->rx_buf = transfer->rx_buf;
1598 	spi_imx->count = transfer->len;
1599 	spi_imx->txfifo = 0;
1600 	spi_imx->remainder = 0;
1601 
1602 	/* fill in the fifo before timeout calculations if we are
1603 	 * interrupted here, then the data is getting transferred by
1604 	 * the HW while we are interrupted
1605 	 */
1606 	spi_imx_push(spi_imx);
1607 
1608 	timeout = spi_imx_calculate_timeout(spi_imx, transfer->len) + jiffies;
1609 	while (spi_imx->txfifo) {
1610 		/* RX */
1611 		while (spi_imx->txfifo &&
1612 		       spi_imx->devtype_data->rx_available(spi_imx)) {
1613 			spi_imx->rx(spi_imx);
1614 			spi_imx->txfifo--;
1615 		}
1616 
1617 		/* TX */
1618 		if (spi_imx->count) {
1619 			spi_imx_push(spi_imx);
1620 			continue;
1621 		}
1622 
1623 		if (spi_imx->txfifo &&
1624 		    time_after(jiffies, timeout)) {
1625 
1626 			dev_err_ratelimited(&spi->dev,
1627 					    "timeout period reached: jiffies: %lu- falling back to interrupt mode\n",
1628 					    jiffies - timeout);
1629 
1630 			/* fall back to interrupt mode */
1631 			return spi_imx_pio_transfer(spi, transfer);
1632 		}
1633 	}
1634 
1635 	return 0;
1636 }
1637 
spi_imx_pio_transfer_target(struct spi_device * spi,struct spi_transfer * transfer)1638 static int spi_imx_pio_transfer_target(struct spi_device *spi,
1639 				       struct spi_transfer *transfer)
1640 {
1641 	struct spi_imx_data *spi_imx = spi_controller_get_devdata(spi->controller);
1642 	int ret = 0;
1643 
1644 	if (is_imx53_ecspi(spi_imx) &&
1645 	    transfer->len > MX53_MAX_TRANSFER_BYTES) {
1646 		dev_err(&spi->dev, "Transaction too big, max size is %d bytes\n",
1647 			MX53_MAX_TRANSFER_BYTES);
1648 		return -EMSGSIZE;
1649 	}
1650 
1651 	spi_imx->tx_buf = transfer->tx_buf;
1652 	spi_imx->rx_buf = transfer->rx_buf;
1653 	spi_imx->count = transfer->len;
1654 	spi_imx->txfifo = 0;
1655 	spi_imx->remainder = 0;
1656 
1657 	reinit_completion(&spi_imx->xfer_done);
1658 	spi_imx->target_aborted = false;
1659 
1660 	spi_imx_push(spi_imx);
1661 
1662 	spi_imx->devtype_data->intctrl(spi_imx, MXC_INT_TE | MXC_INT_RDR);
1663 
1664 	if (wait_for_completion_interruptible(&spi_imx->xfer_done) ||
1665 	    spi_imx->target_aborted) {
1666 		dev_dbg(&spi->dev, "interrupted\n");
1667 		ret = -EINTR;
1668 	}
1669 
1670 	/* ecspi has a HW issue when works in Target mode,
1671 	 * after 64 words writtern to TXFIFO, even TXFIFO becomes empty,
1672 	 * ECSPI_TXDATA keeps shift out the last word data,
1673 	 * so we have to disable ECSPI when in target mode after the
1674 	 * transfer completes
1675 	 */
1676 	if (spi_imx->devtype_data->disable)
1677 		spi_imx->devtype_data->disable(spi_imx);
1678 
1679 	return ret;
1680 }
1681 
spi_imx_transfer_estimate_time_us(struct spi_transfer * transfer)1682 static unsigned int spi_imx_transfer_estimate_time_us(struct spi_transfer *transfer)
1683 {
1684 	u64 result;
1685 
1686 	result = DIV_U64_ROUND_CLOSEST((u64)USEC_PER_SEC * transfer->len * BITS_PER_BYTE,
1687 				       transfer->effective_speed_hz);
1688 	if (transfer->word_delay.value) {
1689 		unsigned int word_delay_us;
1690 		unsigned int words;
1691 
1692 		words = DIV_ROUND_UP(transfer->len * BITS_PER_BYTE, transfer->bits_per_word);
1693 		word_delay_us = DIV_ROUND_CLOSEST(spi_delay_to_ns(&transfer->word_delay, transfer),
1694 						  NSEC_PER_USEC);
1695 		result += (u64)words * word_delay_us;
1696 	}
1697 
1698 	return min(result, U32_MAX);
1699 }
1700 
spi_imx_transfer_one(struct spi_controller * controller,struct spi_device * spi,struct spi_transfer * transfer)1701 static int spi_imx_transfer_one(struct spi_controller *controller,
1702 				struct spi_device *spi,
1703 				struct spi_transfer *transfer)
1704 {
1705 	int ret;
1706 	struct spi_imx_data *spi_imx = spi_controller_get_devdata(spi->controller);
1707 
1708 	ret = spi_imx_setupxfer(spi, transfer);
1709 	if (ret < 0)
1710 		return ret;
1711 	transfer->effective_speed_hz = spi_imx->spi_bus_clk;
1712 
1713 	/* flush rxfifo before transfer */
1714 	while (spi_imx->devtype_data->rx_available(spi_imx))
1715 		readl(spi_imx->base + MXC_CSPIRXDATA);
1716 
1717 	if (spi_imx->target_mode)
1718 		return spi_imx_pio_transfer_target(spi, transfer);
1719 
1720 	/*
1721 	 * If we decided in spi_imx_can_dma() that we want to do a DMA
1722 	 * transfer, the SPI transfer has already been mapped, so we
1723 	 * have to do the DMA transfer here.
1724 	 */
1725 	if (spi_imx->usedma)
1726 		return spi_imx_dma_transfer(spi_imx, transfer);
1727 
1728 	/* run in polling mode for short transfers */
1729 	if (transfer->len == 1 || (polling_limit_us &&
1730 				   spi_imx_transfer_estimate_time_us(transfer) < polling_limit_us))
1731 		return spi_imx_poll_transfer(spi, transfer);
1732 
1733 	return spi_imx_pio_transfer(spi, transfer);
1734 }
1735 
spi_imx_setup(struct spi_device * spi)1736 static int spi_imx_setup(struct spi_device *spi)
1737 {
1738 	dev_dbg(&spi->dev, "%s: mode %d, %u bpw, %d hz\n", __func__,
1739 		 spi->mode, spi->bits_per_word, spi->max_speed_hz);
1740 
1741 	return 0;
1742 }
1743 
1744 static int
spi_imx_prepare_message(struct spi_controller * controller,struct spi_message * msg)1745 spi_imx_prepare_message(struct spi_controller *controller, struct spi_message *msg)
1746 {
1747 	struct spi_imx_data *spi_imx = spi_controller_get_devdata(controller);
1748 	int ret;
1749 
1750 	ret = pm_runtime_resume_and_get(spi_imx->dev);
1751 	if (ret < 0) {
1752 		dev_err(spi_imx->dev, "failed to enable clock\n");
1753 		return ret;
1754 	}
1755 
1756 	ret = spi_imx->devtype_data->prepare_message(spi_imx, msg);
1757 	if (ret) {
1758 		pm_runtime_put_autosuspend(spi_imx->dev);
1759 	}
1760 
1761 	return ret;
1762 }
1763 
1764 static int
spi_imx_unprepare_message(struct spi_controller * controller,struct spi_message * msg)1765 spi_imx_unprepare_message(struct spi_controller *controller, struct spi_message *msg)
1766 {
1767 	struct spi_imx_data *spi_imx = spi_controller_get_devdata(controller);
1768 
1769 	pm_runtime_put_autosuspend(spi_imx->dev);
1770 	return 0;
1771 }
1772 
spi_imx_target_abort(struct spi_controller * controller)1773 static int spi_imx_target_abort(struct spi_controller *controller)
1774 {
1775 	struct spi_imx_data *spi_imx = spi_controller_get_devdata(controller);
1776 
1777 	spi_imx->target_aborted = true;
1778 	complete(&spi_imx->xfer_done);
1779 
1780 	return 0;
1781 }
1782 
spi_imx_probe(struct platform_device * pdev)1783 static int spi_imx_probe(struct platform_device *pdev)
1784 {
1785 	struct device_node *np = pdev->dev.of_node;
1786 	struct spi_controller *controller;
1787 	struct spi_imx_data *spi_imx;
1788 	struct resource *res;
1789 	int ret, irq, spi_drctl;
1790 	const struct spi_imx_devtype_data *devtype_data =
1791 			of_device_get_match_data(&pdev->dev);
1792 	bool target_mode;
1793 	u32 val;
1794 
1795 	target_mode = devtype_data->has_targetmode &&
1796 		      of_property_read_bool(np, "spi-slave");
1797 	if (target_mode)
1798 		controller = spi_alloc_target(&pdev->dev,
1799 					      sizeof(struct spi_imx_data));
1800 	else
1801 		controller = spi_alloc_host(&pdev->dev,
1802 					    sizeof(struct spi_imx_data));
1803 	if (!controller)
1804 		return -ENOMEM;
1805 
1806 	ret = of_property_read_u32(np, "fsl,spi-rdy-drctl", &spi_drctl);
1807 	if ((ret < 0) || (spi_drctl >= 0x3)) {
1808 		/* '11' is reserved */
1809 		spi_drctl = 0;
1810 	}
1811 
1812 	platform_set_drvdata(pdev, controller);
1813 
1814 	controller->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
1815 	controller->bus_num = np ? -1 : pdev->id;
1816 	controller->use_gpio_descriptors = true;
1817 
1818 	spi_imx = spi_controller_get_devdata(controller);
1819 	spi_imx->controller = controller;
1820 	spi_imx->dev = &pdev->dev;
1821 	spi_imx->target_mode = target_mode;
1822 
1823 	spi_imx->devtype_data = devtype_data;
1824 
1825 	/*
1826 	 * Get number of chip selects from device properties. This can be
1827 	 * coming from device tree or boardfiles, if it is not defined,
1828 	 * a default value of 3 chip selects will be used, as all the legacy
1829 	 * board files have <= 3 chip selects.
1830 	 */
1831 	if (!device_property_read_u32(&pdev->dev, "num-cs", &val))
1832 		controller->num_chipselect = val;
1833 	else
1834 		controller->num_chipselect = 3;
1835 
1836 	controller->transfer_one = spi_imx_transfer_one;
1837 	controller->setup = spi_imx_setup;
1838 	controller->prepare_message = spi_imx_prepare_message;
1839 	controller->unprepare_message = spi_imx_unprepare_message;
1840 	controller->target_abort = spi_imx_target_abort;
1841 	controller->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_NO_CS |
1842 				SPI_MOSI_IDLE_LOW;
1843 
1844 	if (is_imx35_cspi(spi_imx) || is_imx51_ecspi(spi_imx) ||
1845 	    is_imx53_ecspi(spi_imx))
1846 		controller->mode_bits |= SPI_LOOP | SPI_READY;
1847 
1848 	if (is_imx51_ecspi(spi_imx) || is_imx53_ecspi(spi_imx))
1849 		controller->mode_bits |= SPI_RX_CPHA_FLIP;
1850 
1851 	if (is_imx51_ecspi(spi_imx) &&
1852 	    device_property_read_u32(&pdev->dev, "cs-gpios", NULL))
1853 		/*
1854 		 * When using HW-CS implementing SPI_CS_WORD can be done by just
1855 		 * setting the burst length to the word size. This is
1856 		 * considerably faster than manually controlling the CS.
1857 		 */
1858 		controller->mode_bits |= SPI_CS_WORD;
1859 
1860 	if (is_imx51_ecspi(spi_imx) || is_imx53_ecspi(spi_imx)) {
1861 		controller->max_native_cs = 4;
1862 		controller->flags |= SPI_CONTROLLER_GPIO_SS;
1863 	}
1864 
1865 	spi_imx->spi_drctl = spi_drctl;
1866 
1867 	init_completion(&spi_imx->xfer_done);
1868 
1869 	spi_imx->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
1870 	if (IS_ERR(spi_imx->base)) {
1871 		ret = PTR_ERR(spi_imx->base);
1872 		goto out_controller_put;
1873 	}
1874 	spi_imx->base_phys = res->start;
1875 
1876 	irq = platform_get_irq(pdev, 0);
1877 	if (irq < 0) {
1878 		ret = irq;
1879 		goto out_controller_put;
1880 	}
1881 
1882 	ret = devm_request_irq(&pdev->dev, irq, spi_imx_isr, 0,
1883 			       dev_name(&pdev->dev), spi_imx);
1884 	if (ret) {
1885 		dev_err(&pdev->dev, "can't get irq%d: %d\n", irq, ret);
1886 		goto out_controller_put;
1887 	}
1888 
1889 	spi_imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1890 	if (IS_ERR(spi_imx->clk_ipg)) {
1891 		ret = PTR_ERR(spi_imx->clk_ipg);
1892 		goto out_controller_put;
1893 	}
1894 
1895 	spi_imx->clk_per = devm_clk_get(&pdev->dev, "per");
1896 	if (IS_ERR(spi_imx->clk_per)) {
1897 		ret = PTR_ERR(spi_imx->clk_per);
1898 		goto out_controller_put;
1899 	}
1900 
1901 	ret = clk_prepare_enable(spi_imx->clk_per);
1902 	if (ret)
1903 		goto out_controller_put;
1904 
1905 	ret = clk_prepare_enable(spi_imx->clk_ipg);
1906 	if (ret)
1907 		goto out_put_per;
1908 
1909 	pm_runtime_set_autosuspend_delay(spi_imx->dev, MXC_RPM_TIMEOUT);
1910 	pm_runtime_use_autosuspend(spi_imx->dev);
1911 	pm_runtime_get_noresume(spi_imx->dev);
1912 	pm_runtime_set_active(spi_imx->dev);
1913 	pm_runtime_enable(spi_imx->dev);
1914 
1915 	spi_imx->spi_clk = clk_get_rate(spi_imx->clk_per);
1916 	/*
1917 	 * Only validated on i.mx35 and i.mx6 now, can remove the constraint
1918 	 * if validated on other chips.
1919 	 */
1920 	if (spi_imx->devtype_data->has_dmamode) {
1921 		ret = spi_imx_sdma_init(&pdev->dev, spi_imx, controller);
1922 		if (ret == -EPROBE_DEFER)
1923 			goto out_runtime_pm_put;
1924 
1925 		if (ret < 0)
1926 			dev_dbg(&pdev->dev, "dma setup error %d, use pio\n",
1927 				ret);
1928 	}
1929 
1930 	spi_imx->devtype_data->reset(spi_imx);
1931 
1932 	spi_imx->devtype_data->intctrl(spi_imx, 0);
1933 
1934 	controller->dev.of_node = pdev->dev.of_node;
1935 	ret = spi_register_controller(controller);
1936 	if (ret) {
1937 		dev_err_probe(&pdev->dev, ret, "register controller failed\n");
1938 		goto out_register_controller;
1939 	}
1940 
1941 	pm_runtime_put_autosuspend(spi_imx->dev);
1942 
1943 	return ret;
1944 
1945 out_register_controller:
1946 	if (spi_imx->devtype_data->has_dmamode)
1947 		spi_imx_sdma_exit(spi_imx);
1948 out_runtime_pm_put:
1949 	pm_runtime_dont_use_autosuspend(spi_imx->dev);
1950 	pm_runtime_disable(spi_imx->dev);
1951 	pm_runtime_set_suspended(&pdev->dev);
1952 
1953 	clk_disable_unprepare(spi_imx->clk_ipg);
1954 out_put_per:
1955 	clk_disable_unprepare(spi_imx->clk_per);
1956 out_controller_put:
1957 	spi_controller_put(controller);
1958 
1959 	return ret;
1960 }
1961 
spi_imx_remove(struct platform_device * pdev)1962 static void spi_imx_remove(struct platform_device *pdev)
1963 {
1964 	struct spi_controller *controller = platform_get_drvdata(pdev);
1965 	struct spi_imx_data *spi_imx = spi_controller_get_devdata(controller);
1966 	int ret;
1967 
1968 	spi_unregister_controller(controller);
1969 
1970 	ret = pm_runtime_get_sync(spi_imx->dev);
1971 	if (ret >= 0)
1972 		writel(0, spi_imx->base + MXC_CSPICTRL);
1973 	else
1974 		dev_warn(spi_imx->dev, "failed to enable clock, skip hw disable\n");
1975 
1976 	pm_runtime_dont_use_autosuspend(spi_imx->dev);
1977 	pm_runtime_put_sync(spi_imx->dev);
1978 	pm_runtime_disable(spi_imx->dev);
1979 
1980 	spi_imx_sdma_exit(spi_imx);
1981 }
1982 
spi_imx_runtime_resume(struct device * dev)1983 static int spi_imx_runtime_resume(struct device *dev)
1984 {
1985 	struct spi_controller *controller = dev_get_drvdata(dev);
1986 	struct spi_imx_data *spi_imx;
1987 	int ret;
1988 
1989 	spi_imx = spi_controller_get_devdata(controller);
1990 
1991 	ret = clk_prepare_enable(spi_imx->clk_per);
1992 	if (ret)
1993 		return ret;
1994 
1995 	ret = clk_prepare_enable(spi_imx->clk_ipg);
1996 	if (ret) {
1997 		clk_disable_unprepare(spi_imx->clk_per);
1998 		return ret;
1999 	}
2000 
2001 	return 0;
2002 }
2003 
spi_imx_runtime_suspend(struct device * dev)2004 static int spi_imx_runtime_suspend(struct device *dev)
2005 {
2006 	struct spi_controller *controller = dev_get_drvdata(dev);
2007 	struct spi_imx_data *spi_imx;
2008 
2009 	spi_imx = spi_controller_get_devdata(controller);
2010 
2011 	clk_disable_unprepare(spi_imx->clk_per);
2012 	clk_disable_unprepare(spi_imx->clk_ipg);
2013 
2014 	return 0;
2015 }
2016 
spi_imx_suspend(struct device * dev)2017 static int spi_imx_suspend(struct device *dev)
2018 {
2019 	pinctrl_pm_select_sleep_state(dev);
2020 	return 0;
2021 }
2022 
spi_imx_resume(struct device * dev)2023 static int spi_imx_resume(struct device *dev)
2024 {
2025 	pinctrl_pm_select_default_state(dev);
2026 	return 0;
2027 }
2028 
2029 static const struct dev_pm_ops imx_spi_pm = {
2030 	RUNTIME_PM_OPS(spi_imx_runtime_suspend,	spi_imx_runtime_resume, NULL)
2031 	SYSTEM_SLEEP_PM_OPS(spi_imx_suspend, spi_imx_resume)
2032 };
2033 
2034 static struct platform_driver spi_imx_driver = {
2035 	.driver = {
2036 		   .name = DRIVER_NAME,
2037 		   .of_match_table = spi_imx_dt_ids,
2038 		   .pm = pm_ptr(&imx_spi_pm),
2039 	},
2040 	.probe = spi_imx_probe,
2041 	.remove = spi_imx_remove,
2042 };
2043 module_platform_driver(spi_imx_driver);
2044 
2045 MODULE_DESCRIPTION("i.MX SPI Controller driver");
2046 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
2047 MODULE_LICENSE("GPL");
2048 MODULE_ALIAS("platform:" DRIVER_NAME);
2049