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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 
20 #include <linux/module.h>
21 #include <linux/kernel.h>
22 #include <linux/sched.h>
23 #include <linux/errno.h>
24 #include <linux/interrupt.h>
25 #include <linux/platform_device.h>
26 #include <linux/io.h>
27 #include <linux/clk.h>
28 #include <linux/dmaengine.h>
29 #include <linux/dma-mapping.h>
30 #include <linux/of_device.h>
31 #include <linux/pm_runtime.h>
32 #include <linux/sh_dma.h>
33 #include <linux/spi/spi.h>
34 #include <linux/spi/rspi.h>
35 
36 #define RSPI_SPCR		0x00	/* Control Register */
37 #define RSPI_SSLP		0x01	/* Slave Select Polarity Register */
38 #define RSPI_SPPCR		0x02	/* Pin Control Register */
39 #define RSPI_SPSR		0x03	/* Status Register */
40 #define RSPI_SPDR		0x04	/* Data Register */
41 #define RSPI_SPSCR		0x08	/* Sequence Control Register */
42 #define RSPI_SPSSR		0x09	/* Sequence Status Register */
43 #define RSPI_SPBR		0x0a	/* Bit Rate Register */
44 #define RSPI_SPDCR		0x0b	/* Data Control Register */
45 #define RSPI_SPCKD		0x0c	/* Clock Delay Register */
46 #define RSPI_SSLND		0x0d	/* Slave Select Negation Delay Register */
47 #define RSPI_SPND		0x0e	/* Next-Access Delay Register */
48 #define RSPI_SPCR2		0x0f	/* Control Register 2 (SH only) */
49 #define RSPI_SPCMD0		0x10	/* Command Register 0 */
50 #define RSPI_SPCMD1		0x12	/* Command Register 1 */
51 #define RSPI_SPCMD2		0x14	/* Command Register 2 */
52 #define RSPI_SPCMD3		0x16	/* Command Register 3 */
53 #define RSPI_SPCMD4		0x18	/* Command Register 4 */
54 #define RSPI_SPCMD5		0x1a	/* Command Register 5 */
55 #define RSPI_SPCMD6		0x1c	/* Command Register 6 */
56 #define RSPI_SPCMD7		0x1e	/* Command Register 7 */
57 #define RSPI_SPCMD(i)		(RSPI_SPCMD0 + (i) * 2)
58 #define RSPI_NUM_SPCMD		8
59 #define RSPI_RZ_NUM_SPCMD	4
60 #define QSPI_NUM_SPCMD		4
61 
62 /* RSPI on RZ only */
63 #define RSPI_SPBFCR		0x20	/* Buffer Control Register */
64 #define RSPI_SPBFDR		0x22	/* Buffer Data Count Setting Register */
65 
66 /* QSPI only */
67 #define QSPI_SPBFCR		0x18	/* Buffer Control Register */
68 #define QSPI_SPBDCR		0x1a	/* Buffer Data Count Register */
69 #define QSPI_SPBMUL0		0x1c	/* Transfer Data Length Multiplier Setting Register 0 */
70 #define QSPI_SPBMUL1		0x20	/* Transfer Data Length Multiplier Setting Register 1 */
71 #define QSPI_SPBMUL2		0x24	/* Transfer Data Length Multiplier Setting Register 2 */
72 #define QSPI_SPBMUL3		0x28	/* Transfer Data Length Multiplier Setting Register 3 */
73 #define QSPI_SPBMUL(i)		(QSPI_SPBMUL0 + (i) * 4)
74 
75 /* SPCR - Control Register */
76 #define SPCR_SPRIE		0x80	/* Receive Interrupt Enable */
77 #define SPCR_SPE		0x40	/* Function Enable */
78 #define SPCR_SPTIE		0x20	/* Transmit Interrupt Enable */
79 #define SPCR_SPEIE		0x10	/* Error Interrupt Enable */
80 #define SPCR_MSTR		0x08	/* Master/Slave Mode Select */
81 #define SPCR_MODFEN		0x04	/* Mode Fault Error Detection Enable */
82 /* RSPI on SH only */
83 #define SPCR_TXMD		0x02	/* TX Only Mode (vs. Full Duplex) */
84 #define SPCR_SPMS		0x01	/* 3-wire Mode (vs. 4-wire) */
85 /* QSPI on R-Car Gen2 only */
86 #define SPCR_WSWAP		0x02	/* Word Swap of read-data for DMAC */
87 #define SPCR_BSWAP		0x01	/* Byte Swap of read-data for DMAC */
88 
89 /* SSLP - Slave Select Polarity Register */
90 #define SSLP_SSL1P		0x02	/* SSL1 Signal Polarity Setting */
91 #define SSLP_SSL0P		0x01	/* SSL0 Signal Polarity Setting */
92 
93 /* SPPCR - Pin Control Register */
94 #define SPPCR_MOIFE		0x20	/* MOSI Idle Value Fixing Enable */
95 #define SPPCR_MOIFV		0x10	/* MOSI Idle Fixed Value */
96 #define SPPCR_SPOM		0x04
97 #define SPPCR_SPLP2		0x02	/* Loopback Mode 2 (non-inverting) */
98 #define SPPCR_SPLP		0x01	/* Loopback Mode (inverting) */
99 
100 #define SPPCR_IO3FV		0x04	/* Single-/Dual-SPI Mode IO3 Output Fixed Value */
101 #define SPPCR_IO2FV		0x04	/* Single-/Dual-SPI Mode IO2 Output Fixed Value */
102 
103 /* SPSR - Status Register */
104 #define SPSR_SPRF		0x80	/* Receive Buffer Full Flag */
105 #define SPSR_TEND		0x40	/* Transmit End */
106 #define SPSR_SPTEF		0x20	/* Transmit Buffer Empty Flag */
107 #define SPSR_PERF		0x08	/* Parity Error Flag */
108 #define SPSR_MODF		0x04	/* Mode Fault Error Flag */
109 #define SPSR_IDLNF		0x02	/* RSPI Idle Flag */
110 #define SPSR_OVRF		0x01	/* Overrun Error Flag (RSPI only) */
111 
112 /* SPSCR - Sequence Control Register */
113 #define SPSCR_SPSLN_MASK	0x07	/* Sequence Length Specification */
114 
115 /* SPSSR - Sequence Status Register */
116 #define SPSSR_SPECM_MASK	0x70	/* Command Error Mask */
117 #define SPSSR_SPCP_MASK		0x07	/* Command Pointer Mask */
118 
119 /* SPDCR - Data Control Register */
120 #define SPDCR_TXDMY		0x80	/* Dummy Data Transmission Enable */
121 #define SPDCR_SPLW1		0x40	/* Access Width Specification (RZ) */
122 #define SPDCR_SPLW0		0x20	/* Access Width Specification (RZ) */
123 #define SPDCR_SPLLWORD		(SPDCR_SPLW1 | SPDCR_SPLW0)
124 #define SPDCR_SPLWORD		SPDCR_SPLW1
125 #define SPDCR_SPLBYTE		SPDCR_SPLW0
126 #define SPDCR_SPLW		0x20	/* Access Width Specification (SH) */
127 #define SPDCR_SPRDTD		0x10	/* Receive Transmit Data Select (SH) */
128 #define SPDCR_SLSEL1		0x08
129 #define SPDCR_SLSEL0		0x04
130 #define SPDCR_SLSEL_MASK	0x0c	/* SSL1 Output Select (SH) */
131 #define SPDCR_SPFC1		0x02
132 #define SPDCR_SPFC0		0x01
133 #define SPDCR_SPFC_MASK		0x03	/* Frame Count Setting (1-4) (SH) */
134 
135 /* SPCKD - Clock Delay Register */
136 #define SPCKD_SCKDL_MASK	0x07	/* Clock Delay Setting (1-8) */
137 
138 /* SSLND - Slave Select Negation Delay Register */
139 #define SSLND_SLNDL_MASK	0x07	/* SSL Negation Delay Setting (1-8) */
140 
141 /* SPND - Next-Access Delay Register */
142 #define SPND_SPNDL_MASK		0x07	/* Next-Access Delay Setting (1-8) */
143 
144 /* SPCR2 - Control Register 2 */
145 #define SPCR2_PTE		0x08	/* Parity Self-Test Enable */
146 #define SPCR2_SPIE		0x04	/* Idle Interrupt Enable */
147 #define SPCR2_SPOE		0x02	/* Odd Parity Enable (vs. Even) */
148 #define SPCR2_SPPE		0x01	/* Parity Enable */
149 
150 /* SPCMDn - Command Registers */
151 #define SPCMD_SCKDEN		0x8000	/* Clock Delay Setting Enable */
152 #define SPCMD_SLNDEN		0x4000	/* SSL Negation Delay Setting Enable */
153 #define SPCMD_SPNDEN		0x2000	/* Next-Access Delay Enable */
154 #define SPCMD_LSBF		0x1000	/* LSB First */
155 #define SPCMD_SPB_MASK		0x0f00	/* Data Length Setting */
156 #define SPCMD_SPB_8_TO_16(bit)	(((bit - 1) << 8) & SPCMD_SPB_MASK)
157 #define SPCMD_SPB_8BIT		0x0000	/* QSPI only */
158 #define SPCMD_SPB_16BIT		0x0100
159 #define SPCMD_SPB_20BIT		0x0000
160 #define SPCMD_SPB_24BIT		0x0100
161 #define SPCMD_SPB_32BIT		0x0200
162 #define SPCMD_SSLKP		0x0080	/* SSL Signal Level Keeping */
163 #define SPCMD_SPIMOD_MASK	0x0060	/* SPI Operating Mode (QSPI only) */
164 #define SPCMD_SPIMOD1		0x0040
165 #define SPCMD_SPIMOD0		0x0020
166 #define SPCMD_SPIMOD_SINGLE	0
167 #define SPCMD_SPIMOD_DUAL	SPCMD_SPIMOD0
168 #define SPCMD_SPIMOD_QUAD	SPCMD_SPIMOD1
169 #define SPCMD_SPRW		0x0010	/* SPI Read/Write Access (Dual/Quad) */
170 #define SPCMD_SSLA_MASK		0x0030	/* SSL Assert Signal Setting (RSPI) */
171 #define SPCMD_BRDV_MASK		0x000c	/* Bit Rate Division Setting */
172 #define SPCMD_CPOL		0x0002	/* Clock Polarity Setting */
173 #define SPCMD_CPHA		0x0001	/* Clock Phase Setting */
174 
175 /* SPBFCR - Buffer Control Register */
176 #define SPBFCR_TXRST		0x80	/* Transmit Buffer Data Reset */
177 #define SPBFCR_RXRST		0x40	/* Receive Buffer Data Reset */
178 #define SPBFCR_TXTRG_MASK	0x30	/* Transmit Buffer Data Triggering Number */
179 #define SPBFCR_RXTRG_MASK	0x07	/* Receive Buffer Data Triggering Number */
180 /* QSPI on R-Car Gen2 */
181 #define SPBFCR_TXTRG_1B		0x00	/* 31 bytes (1 byte available) */
182 #define SPBFCR_TXTRG_32B	0x30	/* 0 byte (32 bytes available) */
183 #define SPBFCR_RXTRG_1B		0x00	/* 1 byte (31 bytes available) */
184 #define SPBFCR_RXTRG_32B	0x07	/* 32 bytes (0 byte available) */
185 
186 #define QSPI_BUFFER_SIZE        32u
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 	unsigned dma_callbacked:1;
201 	unsigned byte_access:1;
202 };
203 
rspi_write8(const struct rspi_data * rspi,u8 data,u16 offset)204 static void rspi_write8(const struct rspi_data *rspi, u8 data, u16 offset)
205 {
206 	iowrite8(data, rspi->addr + offset);
207 }
208 
rspi_write16(const struct rspi_data * rspi,u16 data,u16 offset)209 static void rspi_write16(const struct rspi_data *rspi, u16 data, u16 offset)
210 {
211 	iowrite16(data, rspi->addr + offset);
212 }
213 
rspi_write32(const struct rspi_data * rspi,u32 data,u16 offset)214 static void rspi_write32(const struct rspi_data *rspi, u32 data, u16 offset)
215 {
216 	iowrite32(data, rspi->addr + offset);
217 }
218 
rspi_read8(const struct rspi_data * rspi,u16 offset)219 static u8 rspi_read8(const struct rspi_data *rspi, u16 offset)
220 {
221 	return ioread8(rspi->addr + offset);
222 }
223 
rspi_read16(const struct rspi_data * rspi,u16 offset)224 static u16 rspi_read16(const struct rspi_data *rspi, u16 offset)
225 {
226 	return ioread16(rspi->addr + offset);
227 }
228 
rspi_write_data(const struct rspi_data * rspi,u16 data)229 static void rspi_write_data(const struct rspi_data *rspi, u16 data)
230 {
231 	if (rspi->byte_access)
232 		rspi_write8(rspi, data, RSPI_SPDR);
233 	else /* 16 bit */
234 		rspi_write16(rspi, data, RSPI_SPDR);
235 }
236 
rspi_read_data(const struct rspi_data * rspi)237 static u16 rspi_read_data(const struct rspi_data *rspi)
238 {
239 	if (rspi->byte_access)
240 		return rspi_read8(rspi, RSPI_SPDR);
241 	else /* 16 bit */
242 		return rspi_read16(rspi, RSPI_SPDR);
243 }
244 
245 /* optional functions */
246 struct spi_ops {
247 	int (*set_config_register)(struct rspi_data *rspi, int access_size);
248 	int (*transfer_one)(struct spi_master *master, struct spi_device *spi,
249 			    struct spi_transfer *xfer);
250 	u16 mode_bits;
251 	u16 flags;
252 	u16 fifo_size;
253 };
254 
255 /*
256  * functions for RSPI on legacy SH
257  */
rspi_set_config_register(struct rspi_data * rspi,int access_size)258 static int rspi_set_config_register(struct rspi_data *rspi, int access_size)
259 {
260 	int spbr;
261 
262 	/* Sets output mode, MOSI signal, and (optionally) loopback */
263 	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
264 
265 	/* Sets transfer bit rate */
266 	spbr = DIV_ROUND_UP(clk_get_rate(rspi->clk),
267 			    2 * rspi->max_speed_hz) - 1;
268 	rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
269 
270 	/* Disable dummy transmission, set 16-bit word access, 1 frame */
271 	rspi_write8(rspi, 0, RSPI_SPDCR);
272 	rspi->byte_access = 0;
273 
274 	/* Sets RSPCK, SSL, next-access delay value */
275 	rspi_write8(rspi, 0x00, RSPI_SPCKD);
276 	rspi_write8(rspi, 0x00, RSPI_SSLND);
277 	rspi_write8(rspi, 0x00, RSPI_SPND);
278 
279 	/* Sets parity, interrupt mask */
280 	rspi_write8(rspi, 0x00, RSPI_SPCR2);
281 
282 	/* Resets sequencer */
283 	rspi_write8(rspi, 0, RSPI_SPSCR);
284 	rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
285 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
286 
287 	/* Sets RSPI mode */
288 	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
289 
290 	return 0;
291 }
292 
293 /*
294  * functions for RSPI on RZ
295  */
rspi_rz_set_config_register(struct rspi_data * rspi,int access_size)296 static int rspi_rz_set_config_register(struct rspi_data *rspi, int access_size)
297 {
298 	int spbr;
299 	int div = 0;
300 	unsigned long clksrc;
301 
302 	/* Sets output mode, MOSI signal, and (optionally) loopback */
303 	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
304 
305 	clksrc = clk_get_rate(rspi->clk);
306 	while (div < 3) {
307 		if (rspi->max_speed_hz >= clksrc/4) /* 4=(CLK/2)/2 */
308 			break;
309 		div++;
310 		clksrc /= 2;
311 	}
312 
313 	/* Sets transfer bit rate */
314 	spbr = DIV_ROUND_UP(clksrc, 2 * rspi->max_speed_hz) - 1;
315 	rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
316 	rspi->spcmd |= div << 2;
317 
318 	/* Disable dummy transmission, set byte access */
319 	rspi_write8(rspi, SPDCR_SPLBYTE, RSPI_SPDCR);
320 	rspi->byte_access = 1;
321 
322 	/* Sets RSPCK, SSL, next-access delay value */
323 	rspi_write8(rspi, 0x00, RSPI_SPCKD);
324 	rspi_write8(rspi, 0x00, RSPI_SSLND);
325 	rspi_write8(rspi, 0x00, RSPI_SPND);
326 
327 	/* Resets sequencer */
328 	rspi_write8(rspi, 0, RSPI_SPSCR);
329 	rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
330 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
331 
332 	/* Sets RSPI mode */
333 	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
334 
335 	return 0;
336 }
337 
338 /*
339  * functions for QSPI
340  */
qspi_set_config_register(struct rspi_data * rspi,int access_size)341 static int qspi_set_config_register(struct rspi_data *rspi, int access_size)
342 {
343 	int spbr;
344 
345 	/* Sets output mode, MOSI signal, and (optionally) loopback */
346 	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
347 
348 	/* Sets transfer bit rate */
349 	spbr = DIV_ROUND_UP(clk_get_rate(rspi->clk), 2 * rspi->max_speed_hz);
350 	rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
351 
352 	/* Disable dummy transmission, set byte access */
353 	rspi_write8(rspi, 0, RSPI_SPDCR);
354 	rspi->byte_access = 1;
355 
356 	/* Sets RSPCK, SSL, next-access delay value */
357 	rspi_write8(rspi, 0x00, RSPI_SPCKD);
358 	rspi_write8(rspi, 0x00, RSPI_SSLND);
359 	rspi_write8(rspi, 0x00, RSPI_SPND);
360 
361 	/* Data Length Setting */
362 	if (access_size == 8)
363 		rspi->spcmd |= SPCMD_SPB_8BIT;
364 	else if (access_size == 16)
365 		rspi->spcmd |= SPCMD_SPB_16BIT;
366 	else
367 		rspi->spcmd |= SPCMD_SPB_32BIT;
368 
369 	rspi->spcmd |= SPCMD_SCKDEN | SPCMD_SLNDEN | SPCMD_SPNDEN;
370 
371 	/* Resets transfer data length */
372 	rspi_write32(rspi, 0, QSPI_SPBMUL0);
373 
374 	/* Resets transmit and receive buffer */
375 	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
376 	/* Sets buffer to allow normal operation */
377 	rspi_write8(rspi, 0x00, QSPI_SPBFCR);
378 
379 	/* Resets sequencer */
380 	rspi_write8(rspi, 0, RSPI_SPSCR);
381 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
382 
383 	/* Enables SPI function in master mode */
384 	rspi_write8(rspi, SPCR_SPE | SPCR_MSTR, RSPI_SPCR);
385 
386 	return 0;
387 }
388 
qspi_update(const struct rspi_data * rspi,u8 mask,u8 val,u8 reg)389 static void qspi_update(const struct rspi_data *rspi, u8 mask, u8 val, u8 reg)
390 {
391 	u8 data;
392 
393 	data = rspi_read8(rspi, reg);
394 	data &= ~mask;
395 	data |= (val & mask);
396 	rspi_write8(rspi, data, reg);
397 }
398 
qspi_set_send_trigger(struct rspi_data * rspi,unsigned int len)399 static unsigned int qspi_set_send_trigger(struct rspi_data *rspi,
400 					  unsigned int len)
401 {
402 	unsigned int n;
403 
404 	n = min(len, QSPI_BUFFER_SIZE);
405 
406 	if (len >= QSPI_BUFFER_SIZE) {
407 		/* sets triggering number to 32 bytes */
408 		qspi_update(rspi, SPBFCR_TXTRG_MASK,
409 			     SPBFCR_TXTRG_32B, QSPI_SPBFCR);
410 	} else {
411 		/* sets triggering number to 1 byte */
412 		qspi_update(rspi, SPBFCR_TXTRG_MASK,
413 			     SPBFCR_TXTRG_1B, QSPI_SPBFCR);
414 	}
415 
416 	return n;
417 }
418 
qspi_set_receive_trigger(struct rspi_data * rspi,unsigned int len)419 static int qspi_set_receive_trigger(struct rspi_data *rspi, unsigned int len)
420 {
421 	unsigned int n;
422 
423 	n = min(len, QSPI_BUFFER_SIZE);
424 
425 	if (len >= QSPI_BUFFER_SIZE) {
426 		/* sets triggering number to 32 bytes */
427 		qspi_update(rspi, SPBFCR_RXTRG_MASK,
428 			     SPBFCR_RXTRG_32B, QSPI_SPBFCR);
429 	} else {
430 		/* sets triggering number to 1 byte */
431 		qspi_update(rspi, SPBFCR_RXTRG_MASK,
432 			     SPBFCR_RXTRG_1B, QSPI_SPBFCR);
433 	}
434 	return n;
435 }
436 
437 #define set_config_register(spi, n) spi->ops->set_config_register(spi, n)
438 
rspi_enable_irq(const struct rspi_data * rspi,u8 enable)439 static void rspi_enable_irq(const struct rspi_data *rspi, u8 enable)
440 {
441 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | enable, RSPI_SPCR);
442 }
443 
rspi_disable_irq(const struct rspi_data * rspi,u8 disable)444 static void rspi_disable_irq(const struct rspi_data *rspi, u8 disable)
445 {
446 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~disable, RSPI_SPCR);
447 }
448 
rspi_wait_for_interrupt(struct rspi_data * rspi,u8 wait_mask,u8 enable_bit)449 static int rspi_wait_for_interrupt(struct rspi_data *rspi, u8 wait_mask,
450 				   u8 enable_bit)
451 {
452 	int ret;
453 
454 	rspi->spsr = rspi_read8(rspi, RSPI_SPSR);
455 	if (rspi->spsr & wait_mask)
456 		return 0;
457 
458 	rspi_enable_irq(rspi, enable_bit);
459 	ret = wait_event_timeout(rspi->wait, rspi->spsr & wait_mask, HZ);
460 	if (ret == 0 && !(rspi->spsr & wait_mask))
461 		return -ETIMEDOUT;
462 
463 	return 0;
464 }
465 
rspi_wait_for_tx_empty(struct rspi_data * rspi)466 static inline int rspi_wait_for_tx_empty(struct rspi_data *rspi)
467 {
468 	return rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
469 }
470 
rspi_wait_for_rx_full(struct rspi_data * rspi)471 static inline int rspi_wait_for_rx_full(struct rspi_data *rspi)
472 {
473 	return rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE);
474 }
475 
rspi_data_out(struct rspi_data * rspi,u8 data)476 static int rspi_data_out(struct rspi_data *rspi, u8 data)
477 {
478 	int error = rspi_wait_for_tx_empty(rspi);
479 	if (error < 0) {
480 		dev_err(&rspi->master->dev, "transmit timeout\n");
481 		return error;
482 	}
483 	rspi_write_data(rspi, data);
484 	return 0;
485 }
486 
rspi_data_in(struct rspi_data * rspi)487 static int rspi_data_in(struct rspi_data *rspi)
488 {
489 	int error;
490 	u8 data;
491 
492 	error = rspi_wait_for_rx_full(rspi);
493 	if (error < 0) {
494 		dev_err(&rspi->master->dev, "receive timeout\n");
495 		return error;
496 	}
497 	data = rspi_read_data(rspi);
498 	return data;
499 }
500 
rspi_pio_transfer(struct rspi_data * rspi,const u8 * tx,u8 * rx,unsigned int n)501 static int rspi_pio_transfer(struct rspi_data *rspi, const u8 *tx, u8 *rx,
502 			     unsigned int n)
503 {
504 	while (n-- > 0) {
505 		if (tx) {
506 			int ret = rspi_data_out(rspi, *tx++);
507 			if (ret < 0)
508 				return ret;
509 		}
510 		if (rx) {
511 			int ret = rspi_data_in(rspi);
512 			if (ret < 0)
513 				return ret;
514 			*rx++ = ret;
515 		}
516 	}
517 
518 	return 0;
519 }
520 
rspi_dma_complete(void * arg)521 static void rspi_dma_complete(void *arg)
522 {
523 	struct rspi_data *rspi = arg;
524 
525 	rspi->dma_callbacked = 1;
526 	wake_up_interruptible(&rspi->wait);
527 }
528 
rspi_dma_transfer(struct rspi_data * rspi,struct sg_table * tx,struct sg_table * rx)529 static int rspi_dma_transfer(struct rspi_data *rspi, struct sg_table *tx,
530 			     struct sg_table *rx)
531 {
532 	struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
533 	u8 irq_mask = 0;
534 	unsigned int other_irq = 0;
535 	dma_cookie_t cookie;
536 	int ret;
537 
538 	/* First prepare and submit the DMA request(s), as this may fail */
539 	if (rx) {
540 		desc_rx = dmaengine_prep_slave_sg(rspi->master->dma_rx,
541 					rx->sgl, rx->nents, DMA_FROM_DEVICE,
542 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
543 		if (!desc_rx) {
544 			ret = -EAGAIN;
545 			goto no_dma_rx;
546 		}
547 
548 		desc_rx->callback = rspi_dma_complete;
549 		desc_rx->callback_param = rspi;
550 		cookie = dmaengine_submit(desc_rx);
551 		if (dma_submit_error(cookie)) {
552 			ret = cookie;
553 			goto no_dma_rx;
554 		}
555 
556 		irq_mask |= SPCR_SPRIE;
557 	}
558 
559 	if (tx) {
560 		desc_tx = dmaengine_prep_slave_sg(rspi->master->dma_tx,
561 					tx->sgl, tx->nents, DMA_TO_DEVICE,
562 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
563 		if (!desc_tx) {
564 			ret = -EAGAIN;
565 			goto no_dma_tx;
566 		}
567 
568 		if (rx) {
569 			/* No callback */
570 			desc_tx->callback = NULL;
571 		} else {
572 			desc_tx->callback = rspi_dma_complete;
573 			desc_tx->callback_param = rspi;
574 		}
575 		cookie = dmaengine_submit(desc_tx);
576 		if (dma_submit_error(cookie)) {
577 			ret = cookie;
578 			goto no_dma_tx;
579 		}
580 
581 		irq_mask |= SPCR_SPTIE;
582 	}
583 
584 	/*
585 	 * DMAC needs SPxIE, but if SPxIE is set, the IRQ routine will be
586 	 * called. So, this driver disables the IRQ while DMA transfer.
587 	 */
588 	if (tx)
589 		disable_irq(other_irq = rspi->tx_irq);
590 	if (rx && rspi->rx_irq != other_irq)
591 		disable_irq(rspi->rx_irq);
592 
593 	rspi_enable_irq(rspi, irq_mask);
594 	rspi->dma_callbacked = 0;
595 
596 	/* Now start DMA */
597 	if (rx)
598 		dma_async_issue_pending(rspi->master->dma_rx);
599 	if (tx)
600 		dma_async_issue_pending(rspi->master->dma_tx);
601 
602 	ret = wait_event_interruptible_timeout(rspi->wait,
603 					       rspi->dma_callbacked, HZ);
604 	if (ret > 0 && rspi->dma_callbacked) {
605 		ret = 0;
606 	} else {
607 		if (!ret) {
608 			dev_err(&rspi->master->dev, "DMA timeout\n");
609 			ret = -ETIMEDOUT;
610 		}
611 		if (tx)
612 			dmaengine_terminate_all(rspi->master->dma_tx);
613 		if (rx)
614 			dmaengine_terminate_all(rspi->master->dma_rx);
615 	}
616 
617 	rspi_disable_irq(rspi, irq_mask);
618 
619 	if (tx)
620 		enable_irq(rspi->tx_irq);
621 	if (rx && rspi->rx_irq != other_irq)
622 		enable_irq(rspi->rx_irq);
623 
624 	return ret;
625 
626 no_dma_tx:
627 	if (rx)
628 		dmaengine_terminate_all(rspi->master->dma_rx);
629 no_dma_rx:
630 	if (ret == -EAGAIN) {
631 		pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
632 			     dev_driver_string(&rspi->master->dev),
633 			     dev_name(&rspi->master->dev));
634 	}
635 	return ret;
636 }
637 
rspi_receive_init(const struct rspi_data * rspi)638 static void rspi_receive_init(const struct rspi_data *rspi)
639 {
640 	u8 spsr;
641 
642 	spsr = rspi_read8(rspi, RSPI_SPSR);
643 	if (spsr & SPSR_SPRF)
644 		rspi_read_data(rspi);	/* dummy read */
645 	if (spsr & SPSR_OVRF)
646 		rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF,
647 			    RSPI_SPSR);
648 }
649 
rspi_rz_receive_init(const struct rspi_data * rspi)650 static void rspi_rz_receive_init(const struct rspi_data *rspi)
651 {
652 	rspi_receive_init(rspi);
653 	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, RSPI_SPBFCR);
654 	rspi_write8(rspi, 0, RSPI_SPBFCR);
655 }
656 
qspi_receive_init(const struct rspi_data * rspi)657 static void qspi_receive_init(const struct rspi_data *rspi)
658 {
659 	u8 spsr;
660 
661 	spsr = rspi_read8(rspi, RSPI_SPSR);
662 	if (spsr & SPSR_SPRF)
663 		rspi_read_data(rspi);   /* dummy read */
664 	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
665 	rspi_write8(rspi, 0, QSPI_SPBFCR);
666 }
667 
__rspi_can_dma(const struct rspi_data * rspi,const struct spi_transfer * xfer)668 static bool __rspi_can_dma(const struct rspi_data *rspi,
669 			   const struct spi_transfer *xfer)
670 {
671 	return xfer->len > rspi->ops->fifo_size;
672 }
673 
rspi_can_dma(struct spi_master * master,struct spi_device * spi,struct spi_transfer * xfer)674 static bool rspi_can_dma(struct spi_master *master, struct spi_device *spi,
675 			 struct spi_transfer *xfer)
676 {
677 	struct rspi_data *rspi = spi_master_get_devdata(master);
678 
679 	return __rspi_can_dma(rspi, xfer);
680 }
681 
rspi_dma_check_then_transfer(struct rspi_data * rspi,struct spi_transfer * xfer)682 static int rspi_dma_check_then_transfer(struct rspi_data *rspi,
683 					 struct spi_transfer *xfer)
684 {
685 	if (!rspi->master->can_dma || !__rspi_can_dma(rspi, xfer))
686 		return -EAGAIN;
687 
688 	/* rx_buf can be NULL on RSPI on SH in TX-only Mode */
689 	return rspi_dma_transfer(rspi, &xfer->tx_sg,
690 				xfer->rx_buf ? &xfer->rx_sg : NULL);
691 }
692 
rspi_common_transfer(struct rspi_data * rspi,struct spi_transfer * xfer)693 static int rspi_common_transfer(struct rspi_data *rspi,
694 				struct spi_transfer *xfer)
695 {
696 	int ret;
697 
698 	ret = rspi_dma_check_then_transfer(rspi, xfer);
699 	if (ret != -EAGAIN)
700 		return ret;
701 
702 	ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);
703 	if (ret < 0)
704 		return ret;
705 
706 	/* Wait for the last transmission */
707 	rspi_wait_for_tx_empty(rspi);
708 
709 	return 0;
710 }
711 
rspi_transfer_one(struct spi_master * master,struct spi_device * spi,struct spi_transfer * xfer)712 static int rspi_transfer_one(struct spi_master *master, struct spi_device *spi,
713 			     struct spi_transfer *xfer)
714 {
715 	struct rspi_data *rspi = spi_master_get_devdata(master);
716 	u8 spcr;
717 
718 	spcr = rspi_read8(rspi, RSPI_SPCR);
719 	if (xfer->rx_buf) {
720 		rspi_receive_init(rspi);
721 		spcr &= ~SPCR_TXMD;
722 	} else {
723 		spcr |= SPCR_TXMD;
724 	}
725 	rspi_write8(rspi, spcr, RSPI_SPCR);
726 
727 	return rspi_common_transfer(rspi, xfer);
728 }
729 
rspi_rz_transfer_one(struct spi_master * master,struct spi_device * spi,struct spi_transfer * xfer)730 static int rspi_rz_transfer_one(struct spi_master *master,
731 				struct spi_device *spi,
732 				struct spi_transfer *xfer)
733 {
734 	struct rspi_data *rspi = spi_master_get_devdata(master);
735 
736 	rspi_rz_receive_init(rspi);
737 
738 	return rspi_common_transfer(rspi, xfer);
739 }
740 
qspi_trigger_transfer_out_in(struct rspi_data * rspi,const u8 * tx,u8 * rx,unsigned int len)741 static int qspi_trigger_transfer_out_in(struct rspi_data *rspi, const u8 *tx,
742 					u8 *rx, unsigned int len)
743 {
744 	unsigned int i, n;
745 	int ret;
746 
747 	while (len > 0) {
748 		n = qspi_set_send_trigger(rspi, len);
749 		qspi_set_receive_trigger(rspi, len);
750 		if (n == QSPI_BUFFER_SIZE) {
751 			ret = rspi_wait_for_tx_empty(rspi);
752 			if (ret < 0) {
753 				dev_err(&rspi->master->dev, "transmit timeout\n");
754 				return ret;
755 			}
756 			for (i = 0; i < n; i++)
757 				rspi_write_data(rspi, *tx++);
758 
759 			ret = rspi_wait_for_rx_full(rspi);
760 			if (ret < 0) {
761 				dev_err(&rspi->master->dev, "receive timeout\n");
762 				return ret;
763 			}
764 			for (i = 0; i < n; i++)
765 				*rx++ = rspi_read_data(rspi);
766 		} else {
767 			ret = rspi_pio_transfer(rspi, tx, rx, n);
768 			if (ret < 0)
769 				return ret;
770 		}
771 		len -= n;
772 	}
773 
774 	return 0;
775 }
776 
qspi_transfer_out_in(struct rspi_data * rspi,struct spi_transfer * xfer)777 static int qspi_transfer_out_in(struct rspi_data *rspi,
778 				struct spi_transfer *xfer)
779 {
780 	int ret;
781 
782 	qspi_receive_init(rspi);
783 
784 	ret = rspi_dma_check_then_transfer(rspi, xfer);
785 	if (ret != -EAGAIN)
786 		return ret;
787 
788 	return qspi_trigger_transfer_out_in(rspi, xfer->tx_buf,
789 					    xfer->rx_buf, xfer->len);
790 }
791 
qspi_transfer_out(struct rspi_data * rspi,struct spi_transfer * xfer)792 static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)
793 {
794 	const u8 *tx = xfer->tx_buf;
795 	unsigned int n = xfer->len;
796 	unsigned int i, len;
797 	int ret;
798 
799 	if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) {
800 		ret = rspi_dma_transfer(rspi, &xfer->tx_sg, NULL);
801 		if (ret != -EAGAIN)
802 			return ret;
803 	}
804 
805 	while (n > 0) {
806 		len = qspi_set_send_trigger(rspi, n);
807 		if (len == QSPI_BUFFER_SIZE) {
808 			ret = rspi_wait_for_tx_empty(rspi);
809 			if (ret < 0) {
810 				dev_err(&rspi->master->dev, "transmit timeout\n");
811 				return ret;
812 			}
813 			for (i = 0; i < len; i++)
814 				rspi_write_data(rspi, *tx++);
815 		} else {
816 			ret = rspi_pio_transfer(rspi, tx, NULL, len);
817 			if (ret < 0)
818 				return ret;
819 		}
820 		n -= len;
821 	}
822 
823 	/* Wait for the last transmission */
824 	rspi_wait_for_tx_empty(rspi);
825 
826 	return 0;
827 }
828 
qspi_transfer_in(struct rspi_data * rspi,struct spi_transfer * xfer)829 static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)
830 {
831 	u8 *rx = xfer->rx_buf;
832 	unsigned int n = xfer->len;
833 	unsigned int i, len;
834 	int ret;
835 
836 	if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) {
837 		int ret = rspi_dma_transfer(rspi, NULL, &xfer->rx_sg);
838 		if (ret != -EAGAIN)
839 			return ret;
840 	}
841 
842 	while (n > 0) {
843 		len = qspi_set_receive_trigger(rspi, n);
844 		if (len == QSPI_BUFFER_SIZE) {
845 			ret = rspi_wait_for_rx_full(rspi);
846 			if (ret < 0) {
847 				dev_err(&rspi->master->dev, "receive timeout\n");
848 				return ret;
849 			}
850 			for (i = 0; i < len; i++)
851 				*rx++ = rspi_read_data(rspi);
852 		} else {
853 			ret = rspi_pio_transfer(rspi, NULL, rx, len);
854 			if (ret < 0)
855 				return ret;
856 		}
857 		n -= len;
858 	}
859 
860 	return 0;
861 }
862 
qspi_transfer_one(struct spi_master * master,struct spi_device * spi,struct spi_transfer * xfer)863 static int qspi_transfer_one(struct spi_master *master, struct spi_device *spi,
864 			     struct spi_transfer *xfer)
865 {
866 	struct rspi_data *rspi = spi_master_get_devdata(master);
867 
868 	if (spi->mode & SPI_LOOP) {
869 		return qspi_transfer_out_in(rspi, xfer);
870 	} else if (xfer->tx_nbits > SPI_NBITS_SINGLE) {
871 		/* Quad or Dual SPI Write */
872 		return qspi_transfer_out(rspi, xfer);
873 	} else if (xfer->rx_nbits > SPI_NBITS_SINGLE) {
874 		/* Quad or Dual SPI Read */
875 		return qspi_transfer_in(rspi, xfer);
876 	} else {
877 		/* Single SPI Transfer */
878 		return qspi_transfer_out_in(rspi, xfer);
879 	}
880 }
881 
rspi_setup(struct spi_device * spi)882 static int rspi_setup(struct spi_device *spi)
883 {
884 	struct rspi_data *rspi = spi_master_get_devdata(spi->master);
885 
886 	rspi->max_speed_hz = spi->max_speed_hz;
887 
888 	rspi->spcmd = SPCMD_SSLKP;
889 	if (spi->mode & SPI_CPOL)
890 		rspi->spcmd |= SPCMD_CPOL;
891 	if (spi->mode & SPI_CPHA)
892 		rspi->spcmd |= SPCMD_CPHA;
893 
894 	/* CMOS output mode and MOSI signal from previous transfer */
895 	rspi->sppcr = 0;
896 	if (spi->mode & SPI_LOOP)
897 		rspi->sppcr |= SPPCR_SPLP;
898 
899 	set_config_register(rspi, 8);
900 
901 	return 0;
902 }
903 
qspi_transfer_mode(const struct spi_transfer * xfer)904 static u16 qspi_transfer_mode(const struct spi_transfer *xfer)
905 {
906 	if (xfer->tx_buf)
907 		switch (xfer->tx_nbits) {
908 		case SPI_NBITS_QUAD:
909 			return SPCMD_SPIMOD_QUAD;
910 		case SPI_NBITS_DUAL:
911 			return SPCMD_SPIMOD_DUAL;
912 		default:
913 			return 0;
914 		}
915 	if (xfer->rx_buf)
916 		switch (xfer->rx_nbits) {
917 		case SPI_NBITS_QUAD:
918 			return SPCMD_SPIMOD_QUAD | SPCMD_SPRW;
919 		case SPI_NBITS_DUAL:
920 			return SPCMD_SPIMOD_DUAL | SPCMD_SPRW;
921 		default:
922 			return 0;
923 		}
924 
925 	return 0;
926 }
927 
qspi_setup_sequencer(struct rspi_data * rspi,const struct spi_message * msg)928 static int qspi_setup_sequencer(struct rspi_data *rspi,
929 				const struct spi_message *msg)
930 {
931 	const struct spi_transfer *xfer;
932 	unsigned int i = 0, len = 0;
933 	u16 current_mode = 0xffff, mode;
934 
935 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
936 		mode = qspi_transfer_mode(xfer);
937 		if (mode == current_mode) {
938 			len += xfer->len;
939 			continue;
940 		}
941 
942 		/* Transfer mode change */
943 		if (i) {
944 			/* Set transfer data length of previous transfer */
945 			rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
946 		}
947 
948 		if (i >= QSPI_NUM_SPCMD) {
949 			dev_err(&msg->spi->dev,
950 				"Too many different transfer modes");
951 			return -EINVAL;
952 		}
953 
954 		/* Program transfer mode for this transfer */
955 		rspi_write16(rspi, rspi->spcmd | mode, RSPI_SPCMD(i));
956 		current_mode = mode;
957 		len = xfer->len;
958 		i++;
959 	}
960 	if (i) {
961 		/* Set final transfer data length and sequence length */
962 		rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
963 		rspi_write8(rspi, i - 1, RSPI_SPSCR);
964 	}
965 
966 	return 0;
967 }
968 
rspi_prepare_message(struct spi_master * master,struct spi_message * msg)969 static int rspi_prepare_message(struct spi_master *master,
970 				struct spi_message *msg)
971 {
972 	struct rspi_data *rspi = spi_master_get_devdata(master);
973 	int ret;
974 
975 	if (msg->spi->mode &
976 	    (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)) {
977 		/* Setup sequencer for messages with multiple transfer modes */
978 		ret = qspi_setup_sequencer(rspi, msg);
979 		if (ret < 0)
980 			return ret;
981 	}
982 
983 	/* Enable SPI function in master mode */
984 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_SPE, RSPI_SPCR);
985 	return 0;
986 }
987 
rspi_unprepare_message(struct spi_master * master,struct spi_message * msg)988 static int rspi_unprepare_message(struct spi_master *master,
989 				  struct spi_message *msg)
990 {
991 	struct rspi_data *rspi = spi_master_get_devdata(master);
992 
993 	/* Disable SPI function */
994 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_SPE, RSPI_SPCR);
995 
996 	/* Reset sequencer for Single SPI Transfers */
997 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
998 	rspi_write8(rspi, 0, RSPI_SPSCR);
999 	return 0;
1000 }
1001 
rspi_irq_mux(int irq,void * _sr)1002 static irqreturn_t rspi_irq_mux(int irq, void *_sr)
1003 {
1004 	struct rspi_data *rspi = _sr;
1005 	u8 spsr;
1006 	irqreturn_t ret = IRQ_NONE;
1007 	u8 disable_irq = 0;
1008 
1009 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1010 	if (spsr & SPSR_SPRF)
1011 		disable_irq |= SPCR_SPRIE;
1012 	if (spsr & SPSR_SPTEF)
1013 		disable_irq |= SPCR_SPTIE;
1014 
1015 	if (disable_irq) {
1016 		ret = IRQ_HANDLED;
1017 		rspi_disable_irq(rspi, disable_irq);
1018 		wake_up(&rspi->wait);
1019 	}
1020 
1021 	return ret;
1022 }
1023 
rspi_irq_rx(int irq,void * _sr)1024 static irqreturn_t rspi_irq_rx(int irq, void *_sr)
1025 {
1026 	struct rspi_data *rspi = _sr;
1027 	u8 spsr;
1028 
1029 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1030 	if (spsr & SPSR_SPRF) {
1031 		rspi_disable_irq(rspi, SPCR_SPRIE);
1032 		wake_up(&rspi->wait);
1033 		return IRQ_HANDLED;
1034 	}
1035 
1036 	return 0;
1037 }
1038 
rspi_irq_tx(int irq,void * _sr)1039 static irqreturn_t rspi_irq_tx(int irq, void *_sr)
1040 {
1041 	struct rspi_data *rspi = _sr;
1042 	u8 spsr;
1043 
1044 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1045 	if (spsr & SPSR_SPTEF) {
1046 		rspi_disable_irq(rspi, SPCR_SPTIE);
1047 		wake_up(&rspi->wait);
1048 		return IRQ_HANDLED;
1049 	}
1050 
1051 	return 0;
1052 }
1053 
rspi_request_dma_chan(struct device * dev,enum dma_transfer_direction dir,unsigned int id,dma_addr_t port_addr)1054 static struct dma_chan *rspi_request_dma_chan(struct device *dev,
1055 					      enum dma_transfer_direction dir,
1056 					      unsigned int id,
1057 					      dma_addr_t port_addr)
1058 {
1059 	dma_cap_mask_t mask;
1060 	struct dma_chan *chan;
1061 	struct dma_slave_config cfg;
1062 	int ret;
1063 
1064 	dma_cap_zero(mask);
1065 	dma_cap_set(DMA_SLAVE, mask);
1066 
1067 	chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
1068 				(void *)(unsigned long)id, dev,
1069 				dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1070 	if (!chan) {
1071 		dev_warn(dev, "dma_request_slave_channel_compat failed\n");
1072 		return NULL;
1073 	}
1074 
1075 	memset(&cfg, 0, sizeof(cfg));
1076 	cfg.direction = dir;
1077 	if (dir == DMA_MEM_TO_DEV) {
1078 		cfg.dst_addr = port_addr;
1079 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1080 	} else {
1081 		cfg.src_addr = port_addr;
1082 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1083 	}
1084 
1085 	ret = dmaengine_slave_config(chan, &cfg);
1086 	if (ret) {
1087 		dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
1088 		dma_release_channel(chan);
1089 		return NULL;
1090 	}
1091 
1092 	return chan;
1093 }
1094 
rspi_request_dma(struct device * dev,struct spi_master * master,const struct resource * res)1095 static int rspi_request_dma(struct device *dev, struct spi_master *master,
1096 			    const struct resource *res)
1097 {
1098 	const struct rspi_plat_data *rspi_pd = dev_get_platdata(dev);
1099 	unsigned int dma_tx_id, dma_rx_id;
1100 
1101 	if (dev->of_node) {
1102 		/* In the OF case we will get the slave IDs from the DT */
1103 		dma_tx_id = 0;
1104 		dma_rx_id = 0;
1105 	} else if (rspi_pd && rspi_pd->dma_tx_id && rspi_pd->dma_rx_id) {
1106 		dma_tx_id = rspi_pd->dma_tx_id;
1107 		dma_rx_id = rspi_pd->dma_rx_id;
1108 	} else {
1109 		/* The driver assumes no error. */
1110 		return 0;
1111 	}
1112 
1113 	master->dma_tx = rspi_request_dma_chan(dev, DMA_MEM_TO_DEV, dma_tx_id,
1114 					       res->start + RSPI_SPDR);
1115 	if (!master->dma_tx)
1116 		return -ENODEV;
1117 
1118 	master->dma_rx = rspi_request_dma_chan(dev, DMA_DEV_TO_MEM, dma_rx_id,
1119 					       res->start + RSPI_SPDR);
1120 	if (!master->dma_rx) {
1121 		dma_release_channel(master->dma_tx);
1122 		master->dma_tx = NULL;
1123 		return -ENODEV;
1124 	}
1125 
1126 	master->can_dma = rspi_can_dma;
1127 	dev_info(dev, "DMA available");
1128 	return 0;
1129 }
1130 
rspi_release_dma(struct spi_master * master)1131 static void rspi_release_dma(struct spi_master *master)
1132 {
1133 	if (master->dma_tx)
1134 		dma_release_channel(master->dma_tx);
1135 	if (master->dma_rx)
1136 		dma_release_channel(master->dma_rx);
1137 }
1138 
rspi_remove(struct platform_device * pdev)1139 static int rspi_remove(struct platform_device *pdev)
1140 {
1141 	struct rspi_data *rspi = platform_get_drvdata(pdev);
1142 
1143 	rspi_release_dma(rspi->master);
1144 	pm_runtime_disable(&pdev->dev);
1145 
1146 	return 0;
1147 }
1148 
1149 static const struct spi_ops rspi_ops = {
1150 	.set_config_register =	rspi_set_config_register,
1151 	.transfer_one =		rspi_transfer_one,
1152 	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP,
1153 	.flags =		SPI_MASTER_MUST_TX,
1154 	.fifo_size =		8,
1155 };
1156 
1157 static const struct spi_ops rspi_rz_ops = {
1158 	.set_config_register =	rspi_rz_set_config_register,
1159 	.transfer_one =		rspi_rz_transfer_one,
1160 	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP,
1161 	.flags =		SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX,
1162 	.fifo_size =		8,	/* 8 for TX, 32 for RX */
1163 };
1164 
1165 static const struct spi_ops qspi_ops = {
1166 	.set_config_register =	qspi_set_config_register,
1167 	.transfer_one =		qspi_transfer_one,
1168 	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP |
1169 				SPI_TX_DUAL | SPI_TX_QUAD |
1170 				SPI_RX_DUAL | SPI_RX_QUAD,
1171 	.flags =		SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX,
1172 	.fifo_size =		32,
1173 };
1174 
1175 #ifdef CONFIG_OF
1176 static const struct of_device_id rspi_of_match[] = {
1177 	/* RSPI on legacy SH */
1178 	{ .compatible = "renesas,rspi", .data = &rspi_ops },
1179 	/* RSPI on RZ/A1H */
1180 	{ .compatible = "renesas,rspi-rz", .data = &rspi_rz_ops },
1181 	/* QSPI on R-Car Gen2 */
1182 	{ .compatible = "renesas,qspi", .data = &qspi_ops },
1183 	{ /* sentinel */ }
1184 };
1185 
1186 MODULE_DEVICE_TABLE(of, rspi_of_match);
1187 
rspi_parse_dt(struct device * dev,struct spi_master * master)1188 static int rspi_parse_dt(struct device *dev, struct spi_master *master)
1189 {
1190 	u32 num_cs;
1191 	int error;
1192 
1193 	/* Parse DT properties */
1194 	error = of_property_read_u32(dev->of_node, "num-cs", &num_cs);
1195 	if (error) {
1196 		dev_err(dev, "of_property_read_u32 num-cs failed %d\n", error);
1197 		return error;
1198 	}
1199 
1200 	master->num_chipselect = num_cs;
1201 	return 0;
1202 }
1203 #else
1204 #define rspi_of_match	NULL
rspi_parse_dt(struct device * dev,struct spi_master * master)1205 static inline int rspi_parse_dt(struct device *dev, struct spi_master *master)
1206 {
1207 	return -EINVAL;
1208 }
1209 #endif /* CONFIG_OF */
1210 
rspi_request_irq(struct device * dev,unsigned int irq,irq_handler_t handler,const char * suffix,void * dev_id)1211 static int rspi_request_irq(struct device *dev, unsigned int irq,
1212 			    irq_handler_t handler, const char *suffix,
1213 			    void *dev_id)
1214 {
1215 	const char *name = devm_kasprintf(dev, GFP_KERNEL, "%s:%s",
1216 					  dev_name(dev), suffix);
1217 	if (!name)
1218 		return -ENOMEM;
1219 
1220 	return devm_request_irq(dev, irq, handler, 0, name, dev_id);
1221 }
1222 
rspi_probe(struct platform_device * pdev)1223 static int rspi_probe(struct platform_device *pdev)
1224 {
1225 	struct resource *res;
1226 	struct spi_master *master;
1227 	struct rspi_data *rspi;
1228 	int ret;
1229 	const struct of_device_id *of_id;
1230 	const struct rspi_plat_data *rspi_pd;
1231 	const struct spi_ops *ops;
1232 
1233 	master = spi_alloc_master(&pdev->dev, sizeof(struct rspi_data));
1234 	if (master == NULL)
1235 		return -ENOMEM;
1236 
1237 	of_id = of_match_device(rspi_of_match, &pdev->dev);
1238 	if (of_id) {
1239 		ops = of_id->data;
1240 		ret = rspi_parse_dt(&pdev->dev, master);
1241 		if (ret)
1242 			goto error1;
1243 	} else {
1244 		ops = (struct spi_ops *)pdev->id_entry->driver_data;
1245 		rspi_pd = dev_get_platdata(&pdev->dev);
1246 		if (rspi_pd && rspi_pd->num_chipselect)
1247 			master->num_chipselect = rspi_pd->num_chipselect;
1248 		else
1249 			master->num_chipselect = 2; /* default */
1250 	}
1251 
1252 	/* ops parameter check */
1253 	if (!ops->set_config_register) {
1254 		dev_err(&pdev->dev, "there is no set_config_register\n");
1255 		ret = -ENODEV;
1256 		goto error1;
1257 	}
1258 
1259 	rspi = spi_master_get_devdata(master);
1260 	platform_set_drvdata(pdev, rspi);
1261 	rspi->ops = ops;
1262 	rspi->master = master;
1263 
1264 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1265 	rspi->addr = devm_ioremap_resource(&pdev->dev, res);
1266 	if (IS_ERR(rspi->addr)) {
1267 		ret = PTR_ERR(rspi->addr);
1268 		goto error1;
1269 	}
1270 
1271 	rspi->clk = devm_clk_get(&pdev->dev, NULL);
1272 	if (IS_ERR(rspi->clk)) {
1273 		dev_err(&pdev->dev, "cannot get clock\n");
1274 		ret = PTR_ERR(rspi->clk);
1275 		goto error1;
1276 	}
1277 
1278 	pm_runtime_enable(&pdev->dev);
1279 
1280 	init_waitqueue_head(&rspi->wait);
1281 
1282 	master->bus_num = pdev->id;
1283 	master->setup = rspi_setup;
1284 	master->auto_runtime_pm = true;
1285 	master->transfer_one = ops->transfer_one;
1286 	master->prepare_message = rspi_prepare_message;
1287 	master->unprepare_message = rspi_unprepare_message;
1288 	master->mode_bits = ops->mode_bits;
1289 	master->flags = ops->flags;
1290 	master->dev.of_node = pdev->dev.of_node;
1291 
1292 	ret = platform_get_irq_byname(pdev, "rx");
1293 	if (ret < 0) {
1294 		ret = platform_get_irq_byname(pdev, "mux");
1295 		if (ret < 0)
1296 			ret = platform_get_irq(pdev, 0);
1297 		if (ret >= 0)
1298 			rspi->rx_irq = rspi->tx_irq = ret;
1299 	} else {
1300 		rspi->rx_irq = ret;
1301 		ret = platform_get_irq_byname(pdev, "tx");
1302 		if (ret >= 0)
1303 			rspi->tx_irq = ret;
1304 	}
1305 	if (ret < 0) {
1306 		dev_err(&pdev->dev, "platform_get_irq error\n");
1307 		goto error2;
1308 	}
1309 
1310 	if (rspi->rx_irq == rspi->tx_irq) {
1311 		/* Single multiplexed interrupt */
1312 		ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_mux,
1313 				       "mux", rspi);
1314 	} else {
1315 		/* Multi-interrupt mode, only SPRI and SPTI are used */
1316 		ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_rx,
1317 				       "rx", rspi);
1318 		if (!ret)
1319 			ret = rspi_request_irq(&pdev->dev, rspi->tx_irq,
1320 					       rspi_irq_tx, "tx", rspi);
1321 	}
1322 	if (ret < 0) {
1323 		dev_err(&pdev->dev, "request_irq error\n");
1324 		goto error2;
1325 	}
1326 
1327 	ret = rspi_request_dma(&pdev->dev, master, res);
1328 	if (ret < 0)
1329 		dev_warn(&pdev->dev, "DMA not available, using PIO\n");
1330 
1331 	ret = devm_spi_register_master(&pdev->dev, master);
1332 	if (ret < 0) {
1333 		dev_err(&pdev->dev, "spi_register_master error.\n");
1334 		goto error3;
1335 	}
1336 
1337 	dev_info(&pdev->dev, "probed\n");
1338 
1339 	return 0;
1340 
1341 error3:
1342 	rspi_release_dma(master);
1343 error2:
1344 	pm_runtime_disable(&pdev->dev);
1345 error1:
1346 	spi_master_put(master);
1347 
1348 	return ret;
1349 }
1350 
1351 static const struct platform_device_id spi_driver_ids[] = {
1352 	{ "rspi",	(kernel_ulong_t)&rspi_ops },
1353 	{ "rspi-rz",	(kernel_ulong_t)&rspi_rz_ops },
1354 	{ "qspi",	(kernel_ulong_t)&qspi_ops },
1355 	{},
1356 };
1357 
1358 MODULE_DEVICE_TABLE(platform, spi_driver_ids);
1359 
1360 #ifdef CONFIG_PM_SLEEP
rspi_suspend(struct device * dev)1361 static int rspi_suspend(struct device *dev)
1362 {
1363 	struct platform_device *pdev = to_platform_device(dev);
1364 	struct rspi_data *rspi = platform_get_drvdata(pdev);
1365 
1366 	return spi_master_suspend(rspi->master);
1367 }
1368 
rspi_resume(struct device * dev)1369 static int rspi_resume(struct device *dev)
1370 {
1371 	struct platform_device *pdev = to_platform_device(dev);
1372 	struct rspi_data *rspi = platform_get_drvdata(pdev);
1373 
1374 	return spi_master_resume(rspi->master);
1375 }
1376 
1377 static SIMPLE_DEV_PM_OPS(rspi_pm_ops, rspi_suspend, rspi_resume);
1378 #define DEV_PM_OPS	&rspi_pm_ops
1379 #else
1380 #define DEV_PM_OPS	NULL
1381 #endif /* CONFIG_PM_SLEEP */
1382 
1383 static struct platform_driver rspi_driver = {
1384 	.probe =	rspi_probe,
1385 	.remove =	rspi_remove,
1386 	.id_table =	spi_driver_ids,
1387 	.driver		= {
1388 		.name = "renesas_spi",
1389 		.pm = DEV_PM_OPS,
1390 		.of_match_table = of_match_ptr(rspi_of_match),
1391 	},
1392 };
1393 module_platform_driver(rspi_driver);
1394 
1395 MODULE_DESCRIPTION("Renesas RSPI bus driver");
1396 MODULE_LICENSE("GPL v2");
1397 MODULE_AUTHOR("Yoshihiro Shimoda");
1398 MODULE_ALIAS("platform:rspi");
1399