xref: /openbmc/linux/drivers/spi/spi-rspi.c (revision afb46f79)
1 /*
2  * SH RSPI driver
3  *
4  * Copyright (C) 2012, 2013  Renesas Solutions Corp.
5  * Copyright (C) 2014 Glider bvba
6  *
7  * Based on spi-sh.c:
8  * Copyright (C) 2011 Renesas Solutions Corp.
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; version 2 of the License.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
22  *
23  */
24 
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/sched.h>
28 #include <linux/errno.h>
29 #include <linux/interrupt.h>
30 #include <linux/platform_device.h>
31 #include <linux/io.h>
32 #include <linux/clk.h>
33 #include <linux/dmaengine.h>
34 #include <linux/dma-mapping.h>
35 #include <linux/of_device.h>
36 #include <linux/pm_runtime.h>
37 #include <linux/sh_dma.h>
38 #include <linux/spi/spi.h>
39 #include <linux/spi/rspi.h>
40 
41 #define RSPI_SPCR		0x00	/* Control Register */
42 #define RSPI_SSLP		0x01	/* Slave Select Polarity Register */
43 #define RSPI_SPPCR		0x02	/* Pin Control Register */
44 #define RSPI_SPSR		0x03	/* Status Register */
45 #define RSPI_SPDR		0x04	/* Data Register */
46 #define RSPI_SPSCR		0x08	/* Sequence Control Register */
47 #define RSPI_SPSSR		0x09	/* Sequence Status Register */
48 #define RSPI_SPBR		0x0a	/* Bit Rate Register */
49 #define RSPI_SPDCR		0x0b	/* Data Control Register */
50 #define RSPI_SPCKD		0x0c	/* Clock Delay Register */
51 #define RSPI_SSLND		0x0d	/* Slave Select Negation Delay Register */
52 #define RSPI_SPND		0x0e	/* Next-Access Delay Register */
53 #define RSPI_SPCR2		0x0f	/* Control Register 2 (SH only) */
54 #define RSPI_SPCMD0		0x10	/* Command Register 0 */
55 #define RSPI_SPCMD1		0x12	/* Command Register 1 */
56 #define RSPI_SPCMD2		0x14	/* Command Register 2 */
57 #define RSPI_SPCMD3		0x16	/* Command Register 3 */
58 #define RSPI_SPCMD4		0x18	/* Command Register 4 */
59 #define RSPI_SPCMD5		0x1a	/* Command Register 5 */
60 #define RSPI_SPCMD6		0x1c	/* Command Register 6 */
61 #define RSPI_SPCMD7		0x1e	/* Command Register 7 */
62 #define RSPI_SPCMD(i)		(RSPI_SPCMD0 + (i) * 2)
63 #define RSPI_NUM_SPCMD		8
64 #define RSPI_RZ_NUM_SPCMD	4
65 #define QSPI_NUM_SPCMD		4
66 
67 /* RSPI on RZ only */
68 #define RSPI_SPBFCR		0x20	/* Buffer Control Register */
69 #define RSPI_SPBFDR		0x22	/* Buffer Data Count Setting Register */
70 
71 /* QSPI only */
72 #define QSPI_SPBFCR		0x18	/* Buffer Control Register */
73 #define QSPI_SPBDCR		0x1a	/* Buffer Data Count Register */
74 #define QSPI_SPBMUL0		0x1c	/* Transfer Data Length Multiplier Setting Register 0 */
75 #define QSPI_SPBMUL1		0x20	/* Transfer Data Length Multiplier Setting Register 1 */
76 #define QSPI_SPBMUL2		0x24	/* Transfer Data Length Multiplier Setting Register 2 */
77 #define QSPI_SPBMUL3		0x28	/* Transfer Data Length Multiplier Setting Register 3 */
78 #define QSPI_SPBMUL(i)		(QSPI_SPBMUL0 + (i) * 4)
79 
80 /* SPCR - Control Register */
81 #define SPCR_SPRIE		0x80	/* Receive Interrupt Enable */
82 #define SPCR_SPE		0x40	/* Function Enable */
83 #define SPCR_SPTIE		0x20	/* Transmit Interrupt Enable */
84 #define SPCR_SPEIE		0x10	/* Error Interrupt Enable */
85 #define SPCR_MSTR		0x08	/* Master/Slave Mode Select */
86 #define SPCR_MODFEN		0x04	/* Mode Fault Error Detection Enable */
87 /* RSPI on SH only */
88 #define SPCR_TXMD		0x02	/* TX Only Mode (vs. Full Duplex) */
89 #define SPCR_SPMS		0x01	/* 3-wire Mode (vs. 4-wire) */
90 /* QSPI on R-Car M2 only */
91 #define SPCR_WSWAP		0x02	/* Word Swap of read-data for DMAC */
92 #define SPCR_BSWAP		0x01	/* Byte Swap of read-data for DMAC */
93 
94 /* SSLP - Slave Select Polarity Register */
95 #define SSLP_SSL1P		0x02	/* SSL1 Signal Polarity Setting */
96 #define SSLP_SSL0P		0x01	/* SSL0 Signal Polarity Setting */
97 
98 /* SPPCR - Pin Control Register */
99 #define SPPCR_MOIFE		0x20	/* MOSI Idle Value Fixing Enable */
100 #define SPPCR_MOIFV		0x10	/* MOSI Idle Fixed Value */
101 #define SPPCR_SPOM		0x04
102 #define SPPCR_SPLP2		0x02	/* Loopback Mode 2 (non-inverting) */
103 #define SPPCR_SPLP		0x01	/* Loopback Mode (inverting) */
104 
105 #define SPPCR_IO3FV		0x04	/* Single-/Dual-SPI Mode IO3 Output Fixed Value */
106 #define SPPCR_IO2FV		0x04	/* Single-/Dual-SPI Mode IO2 Output Fixed Value */
107 
108 /* SPSR - Status Register */
109 #define SPSR_SPRF		0x80	/* Receive Buffer Full Flag */
110 #define SPSR_TEND		0x40	/* Transmit End */
111 #define SPSR_SPTEF		0x20	/* Transmit Buffer Empty Flag */
112 #define SPSR_PERF		0x08	/* Parity Error Flag */
113 #define SPSR_MODF		0x04	/* Mode Fault Error Flag */
114 #define SPSR_IDLNF		0x02	/* RSPI Idle Flag */
115 #define SPSR_OVRF		0x01	/* Overrun Error Flag (RSPI only) */
116 
117 /* SPSCR - Sequence Control Register */
118 #define SPSCR_SPSLN_MASK	0x07	/* Sequence Length Specification */
119 
120 /* SPSSR - Sequence Status Register */
121 #define SPSSR_SPECM_MASK	0x70	/* Command Error Mask */
122 #define SPSSR_SPCP_MASK		0x07	/* Command Pointer Mask */
123 
124 /* SPDCR - Data Control Register */
125 #define SPDCR_TXDMY		0x80	/* Dummy Data Transmission Enable */
126 #define SPDCR_SPLW1		0x40	/* Access Width Specification (RZ) */
127 #define SPDCR_SPLW0		0x20	/* Access Width Specification (RZ) */
128 #define SPDCR_SPLLWORD		(SPDCR_SPLW1 | SPDCR_SPLW0)
129 #define SPDCR_SPLWORD		SPDCR_SPLW1
130 #define SPDCR_SPLBYTE		SPDCR_SPLW0
131 #define SPDCR_SPLW		0x20	/* Access Width Specification (SH) */
132 #define SPDCR_SPRDTD		0x10	/* Receive Transmit Data Select (SH) */
133 #define SPDCR_SLSEL1		0x08
134 #define SPDCR_SLSEL0		0x04
135 #define SPDCR_SLSEL_MASK	0x0c	/* SSL1 Output Select (SH) */
136 #define SPDCR_SPFC1		0x02
137 #define SPDCR_SPFC0		0x01
138 #define SPDCR_SPFC_MASK		0x03	/* Frame Count Setting (1-4) (SH) */
139 
140 /* SPCKD - Clock Delay Register */
141 #define SPCKD_SCKDL_MASK	0x07	/* Clock Delay Setting (1-8) */
142 
143 /* SSLND - Slave Select Negation Delay Register */
144 #define SSLND_SLNDL_MASK	0x07	/* SSL Negation Delay Setting (1-8) */
145 
146 /* SPND - Next-Access Delay Register */
147 #define SPND_SPNDL_MASK		0x07	/* Next-Access Delay Setting (1-8) */
148 
149 /* SPCR2 - Control Register 2 */
150 #define SPCR2_PTE		0x08	/* Parity Self-Test Enable */
151 #define SPCR2_SPIE		0x04	/* Idle Interrupt Enable */
152 #define SPCR2_SPOE		0x02	/* Odd Parity Enable (vs. Even) */
153 #define SPCR2_SPPE		0x01	/* Parity Enable */
154 
155 /* SPCMDn - Command Registers */
156 #define SPCMD_SCKDEN		0x8000	/* Clock Delay Setting Enable */
157 #define SPCMD_SLNDEN		0x4000	/* SSL Negation Delay Setting Enable */
158 #define SPCMD_SPNDEN		0x2000	/* Next-Access Delay Enable */
159 #define SPCMD_LSBF		0x1000	/* LSB First */
160 #define SPCMD_SPB_MASK		0x0f00	/* Data Length Setting */
161 #define SPCMD_SPB_8_TO_16(bit)	(((bit - 1) << 8) & SPCMD_SPB_MASK)
162 #define SPCMD_SPB_8BIT		0x0000	/* QSPI only */
163 #define SPCMD_SPB_16BIT		0x0100
164 #define SPCMD_SPB_20BIT		0x0000
165 #define SPCMD_SPB_24BIT		0x0100
166 #define SPCMD_SPB_32BIT		0x0200
167 #define SPCMD_SSLKP		0x0080	/* SSL Signal Level Keeping */
168 #define SPCMD_SPIMOD_MASK	0x0060	/* SPI Operating Mode (QSPI only) */
169 #define SPCMD_SPIMOD1		0x0040
170 #define SPCMD_SPIMOD0		0x0020
171 #define SPCMD_SPIMOD_SINGLE	0
172 #define SPCMD_SPIMOD_DUAL	SPCMD_SPIMOD0
173 #define SPCMD_SPIMOD_QUAD	SPCMD_SPIMOD1
174 #define SPCMD_SPRW		0x0010	/* SPI Read/Write Access (Dual/Quad) */
175 #define SPCMD_SSLA_MASK		0x0030	/* SSL Assert Signal Setting (RSPI) */
176 #define SPCMD_BRDV_MASK		0x000c	/* Bit Rate Division Setting */
177 #define SPCMD_CPOL		0x0002	/* Clock Polarity Setting */
178 #define SPCMD_CPHA		0x0001	/* Clock Phase Setting */
179 
180 /* SPBFCR - Buffer Control Register */
181 #define SPBFCR_TXRST		0x80	/* Transmit Buffer Data Reset */
182 #define SPBFCR_RXRST		0x40	/* Receive Buffer Data Reset */
183 #define SPBFCR_TXTRG_MASK	0x30	/* Transmit Buffer Data Triggering Number */
184 #define SPBFCR_RXTRG_MASK	0x07	/* Receive Buffer Data Triggering Number */
185 
186 #define DUMMY_DATA		0x00
187 
188 struct rspi_data {
189 	void __iomem *addr;
190 	u32 max_speed_hz;
191 	struct spi_master *master;
192 	wait_queue_head_t wait;
193 	struct clk *clk;
194 	u16 spcmd;
195 	u8 spsr;
196 	u8 sppcr;
197 	int rx_irq, tx_irq;
198 	const struct spi_ops *ops;
199 
200 	/* for dmaengine */
201 	struct dma_chan *chan_tx;
202 	struct dma_chan *chan_rx;
203 
204 	unsigned dma_width_16bit:1;
205 	unsigned dma_callbacked:1;
206 	unsigned byte_access:1;
207 };
208 
209 static void rspi_write8(const struct rspi_data *rspi, u8 data, u16 offset)
210 {
211 	iowrite8(data, rspi->addr + offset);
212 }
213 
214 static void rspi_write16(const struct rspi_data *rspi, u16 data, u16 offset)
215 {
216 	iowrite16(data, rspi->addr + offset);
217 }
218 
219 static void rspi_write32(const struct rspi_data *rspi, u32 data, u16 offset)
220 {
221 	iowrite32(data, rspi->addr + offset);
222 }
223 
224 static u8 rspi_read8(const struct rspi_data *rspi, u16 offset)
225 {
226 	return ioread8(rspi->addr + offset);
227 }
228 
229 static u16 rspi_read16(const struct rspi_data *rspi, u16 offset)
230 {
231 	return ioread16(rspi->addr + offset);
232 }
233 
234 static void rspi_write_data(const struct rspi_data *rspi, u16 data)
235 {
236 	if (rspi->byte_access)
237 		rspi_write8(rspi, data, RSPI_SPDR);
238 	else /* 16 bit */
239 		rspi_write16(rspi, data, RSPI_SPDR);
240 }
241 
242 static u16 rspi_read_data(const struct rspi_data *rspi)
243 {
244 	if (rspi->byte_access)
245 		return rspi_read8(rspi, RSPI_SPDR);
246 	else /* 16 bit */
247 		return rspi_read16(rspi, RSPI_SPDR);
248 }
249 
250 /* optional functions */
251 struct spi_ops {
252 	int (*set_config_register)(struct rspi_data *rspi, int access_size);
253 	int (*transfer_one)(struct spi_master *master, struct spi_device *spi,
254 			    struct spi_transfer *xfer);
255 	u16 mode_bits;
256 };
257 
258 /*
259  * functions for RSPI on legacy SH
260  */
261 static int rspi_set_config_register(struct rspi_data *rspi, int access_size)
262 {
263 	int spbr;
264 
265 	/* Sets output mode, MOSI signal, and (optionally) loopback */
266 	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
267 
268 	/* Sets transfer bit rate */
269 	spbr = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz) - 1;
270 	rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
271 
272 	/* Disable dummy transmission, set 16-bit word access, 1 frame */
273 	rspi_write8(rspi, 0, RSPI_SPDCR);
274 	rspi->byte_access = 0;
275 
276 	/* Sets RSPCK, SSL, next-access delay value */
277 	rspi_write8(rspi, 0x00, RSPI_SPCKD);
278 	rspi_write8(rspi, 0x00, RSPI_SSLND);
279 	rspi_write8(rspi, 0x00, RSPI_SPND);
280 
281 	/* Sets parity, interrupt mask */
282 	rspi_write8(rspi, 0x00, RSPI_SPCR2);
283 
284 	/* Sets SPCMD */
285 	rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
286 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
287 
288 	/* Sets RSPI mode */
289 	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
290 
291 	return 0;
292 }
293 
294 /*
295  * functions for RSPI on RZ
296  */
297 static int rspi_rz_set_config_register(struct rspi_data *rspi, int access_size)
298 {
299 	int spbr;
300 
301 	/* Sets output mode, MOSI signal, and (optionally) loopback */
302 	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
303 
304 	/* Sets transfer bit rate */
305 	spbr = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz) - 1;
306 	rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
307 
308 	/* Disable dummy transmission, set byte access */
309 	rspi_write8(rspi, SPDCR_SPLBYTE, RSPI_SPDCR);
310 	rspi->byte_access = 1;
311 
312 	/* Sets RSPCK, SSL, next-access delay value */
313 	rspi_write8(rspi, 0x00, RSPI_SPCKD);
314 	rspi_write8(rspi, 0x00, RSPI_SSLND);
315 	rspi_write8(rspi, 0x00, RSPI_SPND);
316 
317 	/* Sets SPCMD */
318 	rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
319 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
320 
321 	/* Sets RSPI mode */
322 	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
323 
324 	return 0;
325 }
326 
327 /*
328  * functions for QSPI
329  */
330 static int qspi_set_config_register(struct rspi_data *rspi, int access_size)
331 {
332 	int spbr;
333 
334 	/* Sets output mode, MOSI signal, and (optionally) loopback */
335 	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
336 
337 	/* Sets transfer bit rate */
338 	spbr = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz);
339 	rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
340 
341 	/* Disable dummy transmission, set byte access */
342 	rspi_write8(rspi, 0, RSPI_SPDCR);
343 	rspi->byte_access = 1;
344 
345 	/* Sets RSPCK, SSL, next-access delay value */
346 	rspi_write8(rspi, 0x00, RSPI_SPCKD);
347 	rspi_write8(rspi, 0x00, RSPI_SSLND);
348 	rspi_write8(rspi, 0x00, RSPI_SPND);
349 
350 	/* Data Length Setting */
351 	if (access_size == 8)
352 		rspi->spcmd |= SPCMD_SPB_8BIT;
353 	else if (access_size == 16)
354 		rspi->spcmd |= SPCMD_SPB_16BIT;
355 	else
356 		rspi->spcmd |= SPCMD_SPB_32BIT;
357 
358 	rspi->spcmd |= SPCMD_SCKDEN | SPCMD_SLNDEN | SPCMD_SPNDEN;
359 
360 	/* Resets transfer data length */
361 	rspi_write32(rspi, 0, QSPI_SPBMUL0);
362 
363 	/* Resets transmit and receive buffer */
364 	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
365 	/* Sets buffer to allow normal operation */
366 	rspi_write8(rspi, 0x00, QSPI_SPBFCR);
367 
368 	/* Sets SPCMD */
369 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
370 
371 	/* Enables SPI function in master mode */
372 	rspi_write8(rspi, SPCR_SPE | SPCR_MSTR, RSPI_SPCR);
373 
374 	return 0;
375 }
376 
377 #define set_config_register(spi, n) spi->ops->set_config_register(spi, n)
378 
379 static void rspi_enable_irq(const struct rspi_data *rspi, u8 enable)
380 {
381 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | enable, RSPI_SPCR);
382 }
383 
384 static void rspi_disable_irq(const struct rspi_data *rspi, u8 disable)
385 {
386 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~disable, RSPI_SPCR);
387 }
388 
389 static int rspi_wait_for_interrupt(struct rspi_data *rspi, u8 wait_mask,
390 				   u8 enable_bit)
391 {
392 	int ret;
393 
394 	rspi->spsr = rspi_read8(rspi, RSPI_SPSR);
395 	if (rspi->spsr & wait_mask)
396 		return 0;
397 
398 	rspi_enable_irq(rspi, enable_bit);
399 	ret = wait_event_timeout(rspi->wait, rspi->spsr & wait_mask, HZ);
400 	if (ret == 0 && !(rspi->spsr & wait_mask))
401 		return -ETIMEDOUT;
402 
403 	return 0;
404 }
405 
406 static int rspi_data_out(struct rspi_data *rspi, u8 data)
407 {
408 	if (rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE) < 0) {
409 		dev_err(&rspi->master->dev, "transmit timeout\n");
410 		return -ETIMEDOUT;
411 	}
412 	rspi_write_data(rspi, data);
413 	return 0;
414 }
415 
416 static int rspi_data_in(struct rspi_data *rspi)
417 {
418 	u8 data;
419 
420 	if (rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE) < 0) {
421 		dev_err(&rspi->master->dev, "receive timeout\n");
422 		return -ETIMEDOUT;
423 	}
424 	data = rspi_read_data(rspi);
425 	return data;
426 }
427 
428 static int rspi_data_out_in(struct rspi_data *rspi, u8 data)
429 {
430 	int ret;
431 
432 	ret = rspi_data_out(rspi, data);
433 	if (ret < 0)
434 		return ret;
435 
436 	return rspi_data_in(rspi);
437 }
438 
439 static void rspi_dma_complete(void *arg)
440 {
441 	struct rspi_data *rspi = arg;
442 
443 	rspi->dma_callbacked = 1;
444 	wake_up_interruptible(&rspi->wait);
445 }
446 
447 static int rspi_dma_map_sg(struct scatterlist *sg, const void *buf,
448 			   unsigned len, struct dma_chan *chan,
449 			   enum dma_transfer_direction dir)
450 {
451 	sg_init_table(sg, 1);
452 	sg_set_buf(sg, buf, len);
453 	sg_dma_len(sg) = len;
454 	return dma_map_sg(chan->device->dev, sg, 1, dir);
455 }
456 
457 static void rspi_dma_unmap_sg(struct scatterlist *sg, struct dma_chan *chan,
458 			      enum dma_transfer_direction dir)
459 {
460 	dma_unmap_sg(chan->device->dev, sg, 1, dir);
461 }
462 
463 static void rspi_memory_to_8bit(void *buf, const void *data, unsigned len)
464 {
465 	u16 *dst = buf;
466 	const u8 *src = data;
467 
468 	while (len) {
469 		*dst++ = (u16)(*src++);
470 		len--;
471 	}
472 }
473 
474 static void rspi_memory_from_8bit(void *buf, const void *data, unsigned len)
475 {
476 	u8 *dst = buf;
477 	const u16 *src = data;
478 
479 	while (len) {
480 		*dst++ = (u8)*src++;
481 		len--;
482 	}
483 }
484 
485 static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t)
486 {
487 	struct scatterlist sg;
488 	const void *buf = NULL;
489 	struct dma_async_tx_descriptor *desc;
490 	unsigned int len;
491 	int ret = 0;
492 
493 	if (rspi->dma_width_16bit) {
494 		void *tmp;
495 		/*
496 		 * If DMAC bus width is 16-bit, the driver allocates a dummy
497 		 * buffer. And, the driver converts original data into the
498 		 * DMAC data as the following format:
499 		 *  original data: 1st byte, 2nd byte ...
500 		 *  DMAC data:     1st byte, dummy, 2nd byte, dummy ...
501 		 */
502 		len = t->len * 2;
503 		tmp = kmalloc(len, GFP_KERNEL);
504 		if (!tmp)
505 			return -ENOMEM;
506 		rspi_memory_to_8bit(tmp, t->tx_buf, t->len);
507 		buf = tmp;
508 	} else {
509 		len = t->len;
510 		buf = t->tx_buf;
511 	}
512 
513 	if (!rspi_dma_map_sg(&sg, buf, len, rspi->chan_tx, DMA_TO_DEVICE)) {
514 		ret = -EFAULT;
515 		goto end_nomap;
516 	}
517 	desc = dmaengine_prep_slave_sg(rspi->chan_tx, &sg, 1, DMA_TO_DEVICE,
518 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
519 	if (!desc) {
520 		ret = -EIO;
521 		goto end;
522 	}
523 
524 	/*
525 	 * DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be
526 	 * called. So, this driver disables the IRQ while DMA transfer.
527 	 */
528 	disable_irq(rspi->tx_irq);
529 
530 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_TXMD, RSPI_SPCR);
531 	rspi_enable_irq(rspi, SPCR_SPTIE);
532 	rspi->dma_callbacked = 0;
533 
534 	desc->callback = rspi_dma_complete;
535 	desc->callback_param = rspi;
536 	dmaengine_submit(desc);
537 	dma_async_issue_pending(rspi->chan_tx);
538 
539 	ret = wait_event_interruptible_timeout(rspi->wait,
540 					       rspi->dma_callbacked, HZ);
541 	if (ret > 0 && rspi->dma_callbacked)
542 		ret = 0;
543 	else if (!ret)
544 		ret = -ETIMEDOUT;
545 	rspi_disable_irq(rspi, SPCR_SPTIE);
546 
547 	enable_irq(rspi->tx_irq);
548 
549 end:
550 	rspi_dma_unmap_sg(&sg, rspi->chan_tx, DMA_TO_DEVICE);
551 end_nomap:
552 	if (rspi->dma_width_16bit)
553 		kfree(buf);
554 
555 	return ret;
556 }
557 
558 static void rspi_receive_init(const struct rspi_data *rspi)
559 {
560 	u8 spsr;
561 
562 	spsr = rspi_read8(rspi, RSPI_SPSR);
563 	if (spsr & SPSR_SPRF)
564 		rspi_read_data(rspi);	/* dummy read */
565 	if (spsr & SPSR_OVRF)
566 		rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF,
567 			    RSPI_SPSR);
568 }
569 
570 static void rspi_rz_receive_init(const struct rspi_data *rspi)
571 {
572 	rspi_receive_init(rspi);
573 	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, RSPI_SPBFCR);
574 	rspi_write8(rspi, 0, RSPI_SPBFCR);
575 }
576 
577 static void qspi_receive_init(const struct rspi_data *rspi)
578 {
579 	u8 spsr;
580 
581 	spsr = rspi_read8(rspi, RSPI_SPSR);
582 	if (spsr & SPSR_SPRF)
583 		rspi_read_data(rspi);   /* dummy read */
584 	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
585 	rspi_write8(rspi, 0, QSPI_SPBFCR);
586 }
587 
588 static int rspi_receive_dma(struct rspi_data *rspi, struct spi_transfer *t)
589 {
590 	struct scatterlist sg, sg_dummy;
591 	void *dummy = NULL, *rx_buf = NULL;
592 	struct dma_async_tx_descriptor *desc, *desc_dummy;
593 	unsigned int len;
594 	int ret = 0;
595 
596 	if (rspi->dma_width_16bit) {
597 		/*
598 		 * If DMAC bus width is 16-bit, the driver allocates a dummy
599 		 * buffer. And, finally the driver converts the DMAC data into
600 		 * actual data as the following format:
601 		 *  DMAC data:   1st byte, dummy, 2nd byte, dummy ...
602 		 *  actual data: 1st byte, 2nd byte ...
603 		 */
604 		len = t->len * 2;
605 		rx_buf = kmalloc(len, GFP_KERNEL);
606 		if (!rx_buf)
607 			return -ENOMEM;
608 	 } else {
609 		len = t->len;
610 		rx_buf = t->rx_buf;
611 	}
612 
613 	/* prepare dummy transfer to generate SPI clocks */
614 	dummy = kzalloc(len, GFP_KERNEL);
615 	if (!dummy) {
616 		ret = -ENOMEM;
617 		goto end_nomap;
618 	}
619 	if (!rspi_dma_map_sg(&sg_dummy, dummy, len, rspi->chan_tx,
620 			     DMA_TO_DEVICE)) {
621 		ret = -EFAULT;
622 		goto end_nomap;
623 	}
624 	desc_dummy = dmaengine_prep_slave_sg(rspi->chan_tx, &sg_dummy, 1,
625 			DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
626 	if (!desc_dummy) {
627 		ret = -EIO;
628 		goto end_dummy_mapped;
629 	}
630 
631 	/* prepare receive transfer */
632 	if (!rspi_dma_map_sg(&sg, rx_buf, len, rspi->chan_rx,
633 			     DMA_FROM_DEVICE)) {
634 		ret = -EFAULT;
635 		goto end_dummy_mapped;
636 
637 	}
638 	desc = dmaengine_prep_slave_sg(rspi->chan_rx, &sg, 1, DMA_FROM_DEVICE,
639 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
640 	if (!desc) {
641 		ret = -EIO;
642 		goto end;
643 	}
644 
645 	rspi_receive_init(rspi);
646 
647 	/*
648 	 * DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be
649 	 * called. So, this driver disables the IRQ while DMA transfer.
650 	 */
651 	disable_irq(rspi->tx_irq);
652 	if (rspi->rx_irq != rspi->tx_irq)
653 		disable_irq(rspi->rx_irq);
654 
655 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_TXMD, RSPI_SPCR);
656 	rspi_enable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE);
657 	rspi->dma_callbacked = 0;
658 
659 	desc->callback = rspi_dma_complete;
660 	desc->callback_param = rspi;
661 	dmaengine_submit(desc);
662 	dma_async_issue_pending(rspi->chan_rx);
663 
664 	desc_dummy->callback = NULL;	/* No callback */
665 	dmaengine_submit(desc_dummy);
666 	dma_async_issue_pending(rspi->chan_tx);
667 
668 	ret = wait_event_interruptible_timeout(rspi->wait,
669 					       rspi->dma_callbacked, HZ);
670 	if (ret > 0 && rspi->dma_callbacked)
671 		ret = 0;
672 	else if (!ret)
673 		ret = -ETIMEDOUT;
674 	rspi_disable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE);
675 
676 	enable_irq(rspi->tx_irq);
677 	if (rspi->rx_irq != rspi->tx_irq)
678 		enable_irq(rspi->rx_irq);
679 
680 end:
681 	rspi_dma_unmap_sg(&sg, rspi->chan_rx, DMA_FROM_DEVICE);
682 end_dummy_mapped:
683 	rspi_dma_unmap_sg(&sg_dummy, rspi->chan_tx, DMA_TO_DEVICE);
684 end_nomap:
685 	if (rspi->dma_width_16bit) {
686 		if (!ret)
687 			rspi_memory_from_8bit(t->rx_buf, rx_buf, t->len);
688 		kfree(rx_buf);
689 	}
690 	kfree(dummy);
691 
692 	return ret;
693 }
694 
695 static int rspi_is_dma(const struct rspi_data *rspi, struct spi_transfer *t)
696 {
697 	if (t->tx_buf && rspi->chan_tx)
698 		return 1;
699 	/* If the module receives data by DMAC, it also needs TX DMAC */
700 	if (t->rx_buf && rspi->chan_tx && rspi->chan_rx)
701 		return 1;
702 
703 	return 0;
704 }
705 
706 static int rspi_transfer_out_in(struct rspi_data *rspi,
707 				struct spi_transfer *xfer)
708 {
709 	int remain = xfer->len, ret;
710 	const u8 *tx_buf = xfer->tx_buf;
711 	u8 *rx_buf = xfer->rx_buf;
712 	u8 spcr, data;
713 
714 	rspi_receive_init(rspi);
715 
716 	spcr = rspi_read8(rspi, RSPI_SPCR);
717 	if (rx_buf)
718 		spcr &= ~SPCR_TXMD;
719 	else
720 		spcr |= SPCR_TXMD;
721 	rspi_write8(rspi, spcr, RSPI_SPCR);
722 
723 	while (remain > 0) {
724 		data = tx_buf ? *tx_buf++ : DUMMY_DATA;
725 		ret = rspi_data_out(rspi, data);
726 		if (ret < 0)
727 			return ret;
728 		if (rx_buf) {
729 			ret = rspi_data_in(rspi);
730 			if (ret < 0)
731 				return ret;
732 			*rx_buf++ = ret;
733 		}
734 		remain--;
735 	}
736 
737 	/* Wait for the last transmission */
738 	rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
739 
740 	return 0;
741 }
742 
743 static int rspi_transfer_one(struct spi_master *master, struct spi_device *spi,
744 			     struct spi_transfer *xfer)
745 {
746 	struct rspi_data *rspi = spi_master_get_devdata(master);
747 	int ret;
748 
749 	if (!rspi_is_dma(rspi, xfer))
750 		return rspi_transfer_out_in(rspi, xfer);
751 
752 	if (xfer->tx_buf) {
753 		ret = rspi_send_dma(rspi, xfer);
754 		if (ret < 0)
755 			return ret;
756 	}
757 	if (xfer->rx_buf)
758 		return rspi_receive_dma(rspi, xfer);
759 
760 	return 0;
761 }
762 
763 static int rspi_rz_transfer_out_in(struct rspi_data *rspi,
764 				   struct spi_transfer *xfer)
765 {
766 	int remain = xfer->len, ret;
767 	const u8 *tx_buf = xfer->tx_buf;
768 	u8 *rx_buf = xfer->rx_buf;
769 	u8 data;
770 
771 	rspi_rz_receive_init(rspi);
772 
773 	while (remain > 0) {
774 		data = tx_buf ? *tx_buf++ : DUMMY_DATA;
775 		ret = rspi_data_out_in(rspi, data);
776 		if (ret < 0)
777 			return ret;
778 		if (rx_buf)
779 			*rx_buf++ = ret;
780 		remain--;
781 	}
782 
783 	/* Wait for the last transmission */
784 	rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
785 
786 	return 0;
787 }
788 
789 static int rspi_rz_transfer_one(struct spi_master *master,
790 				struct spi_device *spi,
791 				struct spi_transfer *xfer)
792 {
793 	struct rspi_data *rspi = spi_master_get_devdata(master);
794 
795 	return rspi_rz_transfer_out_in(rspi, xfer);
796 }
797 
798 static int qspi_transfer_out_in(struct rspi_data *rspi,
799 				struct spi_transfer *xfer)
800 {
801 	int remain = xfer->len, ret;
802 	const u8 *tx_buf = xfer->tx_buf;
803 	u8 *rx_buf = xfer->rx_buf;
804 	u8 data;
805 
806 	qspi_receive_init(rspi);
807 
808 	while (remain > 0) {
809 		data = tx_buf ? *tx_buf++ : DUMMY_DATA;
810 		ret = rspi_data_out_in(rspi, data);
811 		if (ret < 0)
812 			return ret;
813 		if (rx_buf)
814 			*rx_buf++ = ret;
815 		remain--;
816 	}
817 
818 	/* Wait for the last transmission */
819 	rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
820 
821 	return 0;
822 }
823 
824 static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)
825 {
826 	const u8 *buf = xfer->tx_buf;
827 	unsigned int i;
828 	int ret;
829 
830 	for (i = 0; i < xfer->len; i++) {
831 		ret = rspi_data_out(rspi, *buf++);
832 		if (ret < 0)
833 			return ret;
834 	}
835 
836 	/* Wait for the last transmission */
837 	rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
838 
839 	return 0;
840 }
841 
842 static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)
843 {
844 	u8 *buf = xfer->rx_buf;
845 	unsigned int i;
846 	int ret;
847 
848 	for (i = 0; i < xfer->len; i++) {
849 		ret = rspi_data_in(rspi);
850 		if (ret < 0)
851 			return ret;
852 		*buf++ = ret;
853 	}
854 
855 	return 0;
856 }
857 
858 static int qspi_transfer_one(struct spi_master *master, struct spi_device *spi,
859 			     struct spi_transfer *xfer)
860 {
861 	struct rspi_data *rspi = spi_master_get_devdata(master);
862 
863 	if (spi->mode & SPI_LOOP) {
864 		return qspi_transfer_out_in(rspi, xfer);
865 	} else if (xfer->tx_buf && xfer->tx_nbits > SPI_NBITS_SINGLE) {
866 		/* Quad or Dual SPI Write */
867 		return qspi_transfer_out(rspi, xfer);
868 	} else if (xfer->rx_buf && xfer->rx_nbits > SPI_NBITS_SINGLE) {
869 		/* Quad or Dual SPI Read */
870 		return qspi_transfer_in(rspi, xfer);
871 	} else {
872 		/* Single SPI Transfer */
873 		return qspi_transfer_out_in(rspi, xfer);
874 	}
875 }
876 
877 static int rspi_setup(struct spi_device *spi)
878 {
879 	struct rspi_data *rspi = spi_master_get_devdata(spi->master);
880 
881 	rspi->max_speed_hz = spi->max_speed_hz;
882 
883 	rspi->spcmd = SPCMD_SSLKP;
884 	if (spi->mode & SPI_CPOL)
885 		rspi->spcmd |= SPCMD_CPOL;
886 	if (spi->mode & SPI_CPHA)
887 		rspi->spcmd |= SPCMD_CPHA;
888 
889 	/* CMOS output mode and MOSI signal from previous transfer */
890 	rspi->sppcr = 0;
891 	if (spi->mode & SPI_LOOP)
892 		rspi->sppcr |= SPPCR_SPLP;
893 
894 	set_config_register(rspi, 8);
895 
896 	return 0;
897 }
898 
899 static u16 qspi_transfer_mode(const struct spi_transfer *xfer)
900 {
901 	if (xfer->tx_buf)
902 		switch (xfer->tx_nbits) {
903 		case SPI_NBITS_QUAD:
904 			return SPCMD_SPIMOD_QUAD;
905 		case SPI_NBITS_DUAL:
906 			return SPCMD_SPIMOD_DUAL;
907 		default:
908 			return 0;
909 		}
910 	if (xfer->rx_buf)
911 		switch (xfer->rx_nbits) {
912 		case SPI_NBITS_QUAD:
913 			return SPCMD_SPIMOD_QUAD | SPCMD_SPRW;
914 		case SPI_NBITS_DUAL:
915 			return SPCMD_SPIMOD_DUAL | SPCMD_SPRW;
916 		default:
917 			return 0;
918 		}
919 
920 	return 0;
921 }
922 
923 static int qspi_setup_sequencer(struct rspi_data *rspi,
924 				const struct spi_message *msg)
925 {
926 	const struct spi_transfer *xfer;
927 	unsigned int i = 0, len = 0;
928 	u16 current_mode = 0xffff, mode;
929 
930 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
931 		mode = qspi_transfer_mode(xfer);
932 		if (mode == current_mode) {
933 			len += xfer->len;
934 			continue;
935 		}
936 
937 		/* Transfer mode change */
938 		if (i) {
939 			/* Set transfer data length of previous transfer */
940 			rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
941 		}
942 
943 		if (i >= QSPI_NUM_SPCMD) {
944 			dev_err(&msg->spi->dev,
945 				"Too many different transfer modes");
946 			return -EINVAL;
947 		}
948 
949 		/* Program transfer mode for this transfer */
950 		rspi_write16(rspi, rspi->spcmd | mode, RSPI_SPCMD(i));
951 		current_mode = mode;
952 		len = xfer->len;
953 		i++;
954 	}
955 	if (i) {
956 		/* Set final transfer data length and sequence length */
957 		rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
958 		rspi_write8(rspi, i - 1, RSPI_SPSCR);
959 	}
960 
961 	return 0;
962 }
963 
964 static int rspi_prepare_message(struct spi_master *master,
965 				struct spi_message *msg)
966 {
967 	struct rspi_data *rspi = spi_master_get_devdata(master);
968 	int ret;
969 
970 	if (msg->spi->mode &
971 	    (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)) {
972 		/* Setup sequencer for messages with multiple transfer modes */
973 		ret = qspi_setup_sequencer(rspi, msg);
974 		if (ret < 0)
975 			return ret;
976 	}
977 
978 	/* Enable SPI function in master mode */
979 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_SPE, RSPI_SPCR);
980 	return 0;
981 }
982 
983 static int rspi_unprepare_message(struct spi_master *master,
984 				  struct spi_message *msg)
985 {
986 	struct rspi_data *rspi = spi_master_get_devdata(master);
987 
988 	/* Disable SPI function */
989 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_SPE, RSPI_SPCR);
990 
991 	/* Reset sequencer for Single SPI Transfers */
992 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
993 	rspi_write8(rspi, 0, RSPI_SPSCR);
994 	return 0;
995 }
996 
997 static irqreturn_t rspi_irq_mux(int irq, void *_sr)
998 {
999 	struct rspi_data *rspi = _sr;
1000 	u8 spsr;
1001 	irqreturn_t ret = IRQ_NONE;
1002 	u8 disable_irq = 0;
1003 
1004 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1005 	if (spsr & SPSR_SPRF)
1006 		disable_irq |= SPCR_SPRIE;
1007 	if (spsr & SPSR_SPTEF)
1008 		disable_irq |= SPCR_SPTIE;
1009 
1010 	if (disable_irq) {
1011 		ret = IRQ_HANDLED;
1012 		rspi_disable_irq(rspi, disable_irq);
1013 		wake_up(&rspi->wait);
1014 	}
1015 
1016 	return ret;
1017 }
1018 
1019 static irqreturn_t rspi_irq_rx(int irq, void *_sr)
1020 {
1021 	struct rspi_data *rspi = _sr;
1022 	u8 spsr;
1023 
1024 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1025 	if (spsr & SPSR_SPRF) {
1026 		rspi_disable_irq(rspi, SPCR_SPRIE);
1027 		wake_up(&rspi->wait);
1028 		return IRQ_HANDLED;
1029 	}
1030 
1031 	return 0;
1032 }
1033 
1034 static irqreturn_t rspi_irq_tx(int irq, void *_sr)
1035 {
1036 	struct rspi_data *rspi = _sr;
1037 	u8 spsr;
1038 
1039 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1040 	if (spsr & SPSR_SPTEF) {
1041 		rspi_disable_irq(rspi, SPCR_SPTIE);
1042 		wake_up(&rspi->wait);
1043 		return IRQ_HANDLED;
1044 	}
1045 
1046 	return 0;
1047 }
1048 
1049 static int rspi_request_dma(struct rspi_data *rspi,
1050 				      struct platform_device *pdev)
1051 {
1052 	const struct rspi_plat_data *rspi_pd = dev_get_platdata(&pdev->dev);
1053 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1054 	dma_cap_mask_t mask;
1055 	struct dma_slave_config cfg;
1056 	int ret;
1057 
1058 	if (!res || !rspi_pd)
1059 		return 0;	/* The driver assumes no error. */
1060 
1061 	rspi->dma_width_16bit = rspi_pd->dma_width_16bit;
1062 
1063 	/* If the module receives data by DMAC, it also needs TX DMAC */
1064 	if (rspi_pd->dma_rx_id && rspi_pd->dma_tx_id) {
1065 		dma_cap_zero(mask);
1066 		dma_cap_set(DMA_SLAVE, mask);
1067 		rspi->chan_rx = dma_request_channel(mask, shdma_chan_filter,
1068 						    (void *)rspi_pd->dma_rx_id);
1069 		if (rspi->chan_rx) {
1070 			cfg.slave_id = rspi_pd->dma_rx_id;
1071 			cfg.direction = DMA_DEV_TO_MEM;
1072 			cfg.dst_addr = 0;
1073 			cfg.src_addr = res->start + RSPI_SPDR;
1074 			ret = dmaengine_slave_config(rspi->chan_rx, &cfg);
1075 			if (!ret)
1076 				dev_info(&pdev->dev, "Use DMA when rx.\n");
1077 			else
1078 				return ret;
1079 		}
1080 	}
1081 	if (rspi_pd->dma_tx_id) {
1082 		dma_cap_zero(mask);
1083 		dma_cap_set(DMA_SLAVE, mask);
1084 		rspi->chan_tx = dma_request_channel(mask, shdma_chan_filter,
1085 						    (void *)rspi_pd->dma_tx_id);
1086 		if (rspi->chan_tx) {
1087 			cfg.slave_id = rspi_pd->dma_tx_id;
1088 			cfg.direction = DMA_MEM_TO_DEV;
1089 			cfg.dst_addr = res->start + RSPI_SPDR;
1090 			cfg.src_addr = 0;
1091 			ret = dmaengine_slave_config(rspi->chan_tx, &cfg);
1092 			if (!ret)
1093 				dev_info(&pdev->dev, "Use DMA when tx\n");
1094 			else
1095 				return ret;
1096 		}
1097 	}
1098 
1099 	return 0;
1100 }
1101 
1102 static void rspi_release_dma(struct rspi_data *rspi)
1103 {
1104 	if (rspi->chan_tx)
1105 		dma_release_channel(rspi->chan_tx);
1106 	if (rspi->chan_rx)
1107 		dma_release_channel(rspi->chan_rx);
1108 }
1109 
1110 static int rspi_remove(struct platform_device *pdev)
1111 {
1112 	struct rspi_data *rspi = platform_get_drvdata(pdev);
1113 
1114 	rspi_release_dma(rspi);
1115 	pm_runtime_disable(&pdev->dev);
1116 
1117 	return 0;
1118 }
1119 
1120 static const struct spi_ops rspi_ops = {
1121 	.set_config_register =		rspi_set_config_register,
1122 	.transfer_one =			rspi_transfer_one,
1123 	.mode_bits =			SPI_CPHA | SPI_CPOL | SPI_LOOP,
1124 };
1125 
1126 static const struct spi_ops rspi_rz_ops = {
1127 	.set_config_register =		rspi_rz_set_config_register,
1128 	.transfer_one =			rspi_rz_transfer_one,
1129 	.mode_bits =			SPI_CPHA | SPI_CPOL | SPI_LOOP,
1130 };
1131 
1132 static const struct spi_ops qspi_ops = {
1133 	.set_config_register =		qspi_set_config_register,
1134 	.transfer_one =			qspi_transfer_one,
1135 	.mode_bits =			SPI_CPHA | SPI_CPOL | SPI_LOOP |
1136 					SPI_TX_DUAL | SPI_TX_QUAD |
1137 					SPI_RX_DUAL | SPI_RX_QUAD,
1138 };
1139 
1140 #ifdef CONFIG_OF
1141 static const struct of_device_id rspi_of_match[] = {
1142 	/* RSPI on legacy SH */
1143 	{ .compatible = "renesas,rspi", .data = &rspi_ops },
1144 	/* RSPI on RZ/A1H */
1145 	{ .compatible = "renesas,rspi-rz", .data = &rspi_rz_ops },
1146 	/* QSPI on R-Car Gen2 */
1147 	{ .compatible = "renesas,qspi", .data = &qspi_ops },
1148 	{ /* sentinel */ }
1149 };
1150 
1151 MODULE_DEVICE_TABLE(of, rspi_of_match);
1152 
1153 static int rspi_parse_dt(struct device *dev, struct spi_master *master)
1154 {
1155 	u32 num_cs;
1156 	int error;
1157 
1158 	/* Parse DT properties */
1159 	error = of_property_read_u32(dev->of_node, "num-cs", &num_cs);
1160 	if (error) {
1161 		dev_err(dev, "of_property_read_u32 num-cs failed %d\n", error);
1162 		return error;
1163 	}
1164 
1165 	master->num_chipselect = num_cs;
1166 	return 0;
1167 }
1168 #else
1169 #define rspi_of_match	NULL
1170 static inline int rspi_parse_dt(struct device *dev, struct spi_master *master)
1171 {
1172 	return -EINVAL;
1173 }
1174 #endif /* CONFIG_OF */
1175 
1176 static int rspi_request_irq(struct device *dev, unsigned int irq,
1177 			    irq_handler_t handler, const char *suffix,
1178 			    void *dev_id)
1179 {
1180 	const char *base = dev_name(dev);
1181 	size_t len = strlen(base) + strlen(suffix) + 2;
1182 	char *name = devm_kzalloc(dev, len, GFP_KERNEL);
1183 	if (!name)
1184 		return -ENOMEM;
1185 	snprintf(name, len, "%s:%s", base, suffix);
1186 	return devm_request_irq(dev, irq, handler, 0, name, dev_id);
1187 }
1188 
1189 static int rspi_probe(struct platform_device *pdev)
1190 {
1191 	struct resource *res;
1192 	struct spi_master *master;
1193 	struct rspi_data *rspi;
1194 	int ret;
1195 	const struct of_device_id *of_id;
1196 	const struct rspi_plat_data *rspi_pd;
1197 	const struct spi_ops *ops;
1198 
1199 	master = spi_alloc_master(&pdev->dev, sizeof(struct rspi_data));
1200 	if (master == NULL) {
1201 		dev_err(&pdev->dev, "spi_alloc_master error.\n");
1202 		return -ENOMEM;
1203 	}
1204 
1205 	of_id = of_match_device(rspi_of_match, &pdev->dev);
1206 	if (of_id) {
1207 		ops = of_id->data;
1208 		ret = rspi_parse_dt(&pdev->dev, master);
1209 		if (ret)
1210 			goto error1;
1211 	} else {
1212 		ops = (struct spi_ops *)pdev->id_entry->driver_data;
1213 		rspi_pd = dev_get_platdata(&pdev->dev);
1214 		if (rspi_pd && rspi_pd->num_chipselect)
1215 			master->num_chipselect = rspi_pd->num_chipselect;
1216 		else
1217 			master->num_chipselect = 2; /* default */
1218 	};
1219 
1220 	/* ops parameter check */
1221 	if (!ops->set_config_register) {
1222 		dev_err(&pdev->dev, "there is no set_config_register\n");
1223 		ret = -ENODEV;
1224 		goto error1;
1225 	}
1226 
1227 	rspi = spi_master_get_devdata(master);
1228 	platform_set_drvdata(pdev, rspi);
1229 	rspi->ops = ops;
1230 	rspi->master = master;
1231 
1232 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1233 	rspi->addr = devm_ioremap_resource(&pdev->dev, res);
1234 	if (IS_ERR(rspi->addr)) {
1235 		ret = PTR_ERR(rspi->addr);
1236 		goto error1;
1237 	}
1238 
1239 	rspi->clk = devm_clk_get(&pdev->dev, NULL);
1240 	if (IS_ERR(rspi->clk)) {
1241 		dev_err(&pdev->dev, "cannot get clock\n");
1242 		ret = PTR_ERR(rspi->clk);
1243 		goto error1;
1244 	}
1245 
1246 	pm_runtime_enable(&pdev->dev);
1247 
1248 	init_waitqueue_head(&rspi->wait);
1249 
1250 	master->bus_num = pdev->id;
1251 	master->setup = rspi_setup;
1252 	master->auto_runtime_pm = true;
1253 	master->transfer_one = ops->transfer_one;
1254 	master->prepare_message = rspi_prepare_message;
1255 	master->unprepare_message = rspi_unprepare_message;
1256 	master->mode_bits = ops->mode_bits;
1257 	master->dev.of_node = pdev->dev.of_node;
1258 
1259 	ret = platform_get_irq_byname(pdev, "rx");
1260 	if (ret < 0) {
1261 		ret = platform_get_irq_byname(pdev, "mux");
1262 		if (ret < 0)
1263 			ret = platform_get_irq(pdev, 0);
1264 		if (ret >= 0)
1265 			rspi->rx_irq = rspi->tx_irq = ret;
1266 	} else {
1267 		rspi->rx_irq = ret;
1268 		ret = platform_get_irq_byname(pdev, "tx");
1269 		if (ret >= 0)
1270 			rspi->tx_irq = ret;
1271 	}
1272 	if (ret < 0) {
1273 		dev_err(&pdev->dev, "platform_get_irq error\n");
1274 		goto error2;
1275 	}
1276 
1277 	if (rspi->rx_irq == rspi->tx_irq) {
1278 		/* Single multiplexed interrupt */
1279 		ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_mux,
1280 				       "mux", rspi);
1281 	} else {
1282 		/* Multi-interrupt mode, only SPRI and SPTI are used */
1283 		ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_rx,
1284 				       "rx", rspi);
1285 		if (!ret)
1286 			ret = rspi_request_irq(&pdev->dev, rspi->tx_irq,
1287 					       rspi_irq_tx, "tx", rspi);
1288 	}
1289 	if (ret < 0) {
1290 		dev_err(&pdev->dev, "request_irq error\n");
1291 		goto error2;
1292 	}
1293 
1294 	ret = rspi_request_dma(rspi, pdev);
1295 	if (ret < 0) {
1296 		dev_err(&pdev->dev, "rspi_request_dma failed.\n");
1297 		goto error3;
1298 	}
1299 
1300 	ret = devm_spi_register_master(&pdev->dev, master);
1301 	if (ret < 0) {
1302 		dev_err(&pdev->dev, "spi_register_master error.\n");
1303 		goto error3;
1304 	}
1305 
1306 	dev_info(&pdev->dev, "probed\n");
1307 
1308 	return 0;
1309 
1310 error3:
1311 	rspi_release_dma(rspi);
1312 error2:
1313 	pm_runtime_disable(&pdev->dev);
1314 error1:
1315 	spi_master_put(master);
1316 
1317 	return ret;
1318 }
1319 
1320 static struct platform_device_id spi_driver_ids[] = {
1321 	{ "rspi",	(kernel_ulong_t)&rspi_ops },
1322 	{ "rspi-rz",	(kernel_ulong_t)&rspi_rz_ops },
1323 	{ "qspi",	(kernel_ulong_t)&qspi_ops },
1324 	{},
1325 };
1326 
1327 MODULE_DEVICE_TABLE(platform, spi_driver_ids);
1328 
1329 static struct platform_driver rspi_driver = {
1330 	.probe =	rspi_probe,
1331 	.remove =	rspi_remove,
1332 	.id_table =	spi_driver_ids,
1333 	.driver		= {
1334 		.name = "renesas_spi",
1335 		.owner	= THIS_MODULE,
1336 		.of_match_table = of_match_ptr(rspi_of_match),
1337 	},
1338 };
1339 module_platform_driver(rspi_driver);
1340 
1341 MODULE_DESCRIPTION("Renesas RSPI bus driver");
1342 MODULE_LICENSE("GPL v2");
1343 MODULE_AUTHOR("Yoshihiro Shimoda");
1344 MODULE_ALIAS("platform:rspi");
1345