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Add copy_to_iter(), copy_from_iter() and iov_iter_zero()
[deliverable/linux.git] / drivers / spi / spi-rspi.c
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 struct rspi_data {
187 void __iomem *addr;
188 u32 max_speed_hz;
189 struct spi_master *master;
190 wait_queue_head_t wait;
191 struct clk *clk;
192 u16 spcmd;
193 u8 spsr;
194 u8 sppcr;
195 int rx_irq, tx_irq;
196 const struct spi_ops *ops;
197
198 unsigned dma_callbacked:1;
199 unsigned byte_access:1;
200 };
201
202 static void rspi_write8(const struct rspi_data *rspi, u8 data, u16 offset)
203 {
204 iowrite8(data, rspi->addr + offset);
205 }
206
207 static void rspi_write16(const struct rspi_data *rspi, u16 data, u16 offset)
208 {
209 iowrite16(data, rspi->addr + offset);
210 }
211
212 static void rspi_write32(const struct rspi_data *rspi, u32 data, u16 offset)
213 {
214 iowrite32(data, rspi->addr + offset);
215 }
216
217 static u8 rspi_read8(const struct rspi_data *rspi, u16 offset)
218 {
219 return ioread8(rspi->addr + offset);
220 }
221
222 static u16 rspi_read16(const struct rspi_data *rspi, u16 offset)
223 {
224 return ioread16(rspi->addr + offset);
225 }
226
227 static void rspi_write_data(const struct rspi_data *rspi, u16 data)
228 {
229 if (rspi->byte_access)
230 rspi_write8(rspi, data, RSPI_SPDR);
231 else /* 16 bit */
232 rspi_write16(rspi, data, RSPI_SPDR);
233 }
234
235 static u16 rspi_read_data(const struct rspi_data *rspi)
236 {
237 if (rspi->byte_access)
238 return rspi_read8(rspi, RSPI_SPDR);
239 else /* 16 bit */
240 return rspi_read16(rspi, RSPI_SPDR);
241 }
242
243 /* optional functions */
244 struct spi_ops {
245 int (*set_config_register)(struct rspi_data *rspi, int access_size);
246 int (*transfer_one)(struct spi_master *master, struct spi_device *spi,
247 struct spi_transfer *xfer);
248 u16 mode_bits;
249 u16 flags;
250 u16 fifo_size;
251 };
252
253 /*
254 * functions for RSPI on legacy SH
255 */
256 static int rspi_set_config_register(struct rspi_data *rspi, int access_size)
257 {
258 int spbr;
259
260 /* Sets output mode, MOSI signal, and (optionally) loopback */
261 rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
262
263 /* Sets transfer bit rate */
264 spbr = DIV_ROUND_UP(clk_get_rate(rspi->clk),
265 2 * rspi->max_speed_hz) - 1;
266 rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
267
268 /* Disable dummy transmission, set 16-bit word access, 1 frame */
269 rspi_write8(rspi, 0, RSPI_SPDCR);
270 rspi->byte_access = 0;
271
272 /* Sets RSPCK, SSL, next-access delay value */
273 rspi_write8(rspi, 0x00, RSPI_SPCKD);
274 rspi_write8(rspi, 0x00, RSPI_SSLND);
275 rspi_write8(rspi, 0x00, RSPI_SPND);
276
277 /* Sets parity, interrupt mask */
278 rspi_write8(rspi, 0x00, RSPI_SPCR2);
279
280 /* Sets SPCMD */
281 rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
282 rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
283
284 /* Sets RSPI mode */
285 rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
286
287 return 0;
288 }
289
290 /*
291 * functions for RSPI on RZ
292 */
293 static int rspi_rz_set_config_register(struct rspi_data *rspi, int access_size)
294 {
295 int spbr;
296
297 /* Sets output mode, MOSI signal, and (optionally) loopback */
298 rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
299
300 /* Sets transfer bit rate */
301 spbr = DIV_ROUND_UP(clk_get_rate(rspi->clk),
302 2 * rspi->max_speed_hz) - 1;
303 rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
304
305 /* Disable dummy transmission, set byte access */
306 rspi_write8(rspi, SPDCR_SPLBYTE, RSPI_SPDCR);
307 rspi->byte_access = 1;
308
309 /* Sets RSPCK, SSL, next-access delay value */
310 rspi_write8(rspi, 0x00, RSPI_SPCKD);
311 rspi_write8(rspi, 0x00, RSPI_SSLND);
312 rspi_write8(rspi, 0x00, RSPI_SPND);
313
314 /* Sets SPCMD */
315 rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
316 rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
317
318 /* Sets RSPI mode */
319 rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
320
321 return 0;
322 }
323
324 /*
325 * functions for QSPI
326 */
327 static int qspi_set_config_register(struct rspi_data *rspi, int access_size)
328 {
329 int spbr;
330
331 /* Sets output mode, MOSI signal, and (optionally) loopback */
332 rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
333
334 /* Sets transfer bit rate */
335 spbr = DIV_ROUND_UP(clk_get_rate(rspi->clk), 2 * rspi->max_speed_hz);
336 rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
337
338 /* Disable dummy transmission, set byte access */
339 rspi_write8(rspi, 0, RSPI_SPDCR);
340 rspi->byte_access = 1;
341
342 /* Sets RSPCK, SSL, next-access delay value */
343 rspi_write8(rspi, 0x00, RSPI_SPCKD);
344 rspi_write8(rspi, 0x00, RSPI_SSLND);
345 rspi_write8(rspi, 0x00, RSPI_SPND);
346
347 /* Data Length Setting */
348 if (access_size == 8)
349 rspi->spcmd |= SPCMD_SPB_8BIT;
350 else if (access_size == 16)
351 rspi->spcmd |= SPCMD_SPB_16BIT;
352 else
353 rspi->spcmd |= SPCMD_SPB_32BIT;
354
355 rspi->spcmd |= SPCMD_SCKDEN | SPCMD_SLNDEN | SPCMD_SPNDEN;
356
357 /* Resets transfer data length */
358 rspi_write32(rspi, 0, QSPI_SPBMUL0);
359
360 /* Resets transmit and receive buffer */
361 rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
362 /* Sets buffer to allow normal operation */
363 rspi_write8(rspi, 0x00, QSPI_SPBFCR);
364
365 /* Sets SPCMD */
366 rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
367
368 /* Enables SPI function in master mode */
369 rspi_write8(rspi, SPCR_SPE | SPCR_MSTR, RSPI_SPCR);
370
371 return 0;
372 }
373
374 #define set_config_register(spi, n) spi->ops->set_config_register(spi, n)
375
376 static void rspi_enable_irq(const struct rspi_data *rspi, u8 enable)
377 {
378 rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | enable, RSPI_SPCR);
379 }
380
381 static void rspi_disable_irq(const struct rspi_data *rspi, u8 disable)
382 {
383 rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~disable, RSPI_SPCR);
384 }
385
386 static int rspi_wait_for_interrupt(struct rspi_data *rspi, u8 wait_mask,
387 u8 enable_bit)
388 {
389 int ret;
390
391 rspi->spsr = rspi_read8(rspi, RSPI_SPSR);
392 if (rspi->spsr & wait_mask)
393 return 0;
394
395 rspi_enable_irq(rspi, enable_bit);
396 ret = wait_event_timeout(rspi->wait, rspi->spsr & wait_mask, HZ);
397 if (ret == 0 && !(rspi->spsr & wait_mask))
398 return -ETIMEDOUT;
399
400 return 0;
401 }
402
403 static inline int rspi_wait_for_tx_empty(struct rspi_data *rspi)
404 {
405 return rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
406 }
407
408 static inline int rspi_wait_for_rx_full(struct rspi_data *rspi)
409 {
410 return rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE);
411 }
412
413 static int rspi_data_out(struct rspi_data *rspi, u8 data)
414 {
415 int error = rspi_wait_for_tx_empty(rspi);
416 if (error < 0) {
417 dev_err(&rspi->master->dev, "transmit timeout\n");
418 return error;
419 }
420 rspi_write_data(rspi, data);
421 return 0;
422 }
423
424 static int rspi_data_in(struct rspi_data *rspi)
425 {
426 int error;
427 u8 data;
428
429 error = rspi_wait_for_rx_full(rspi);
430 if (error < 0) {
431 dev_err(&rspi->master->dev, "receive timeout\n");
432 return error;
433 }
434 data = rspi_read_data(rspi);
435 return data;
436 }
437
438 static int rspi_pio_transfer(struct rspi_data *rspi, const u8 *tx, u8 *rx,
439 unsigned int n)
440 {
441 while (n-- > 0) {
442 if (tx) {
443 int ret = rspi_data_out(rspi, *tx++);
444 if (ret < 0)
445 return ret;
446 }
447 if (rx) {
448 int ret = rspi_data_in(rspi);
449 if (ret < 0)
450 return ret;
451 *rx++ = ret;
452 }
453 }
454
455 return 0;
456 }
457
458 static void rspi_dma_complete(void *arg)
459 {
460 struct rspi_data *rspi = arg;
461
462 rspi->dma_callbacked = 1;
463 wake_up_interruptible(&rspi->wait);
464 }
465
466 static int rspi_dma_transfer(struct rspi_data *rspi, struct sg_table *tx,
467 struct sg_table *rx)
468 {
469 struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
470 u8 irq_mask = 0;
471 unsigned int other_irq = 0;
472 dma_cookie_t cookie;
473 int ret;
474
475 /* First prepare and submit the DMA request(s), as this may fail */
476 if (rx) {
477 desc_rx = dmaengine_prep_slave_sg(rspi->master->dma_rx,
478 rx->sgl, rx->nents, DMA_FROM_DEVICE,
479 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
480 if (!desc_rx) {
481 ret = -EAGAIN;
482 goto no_dma_rx;
483 }
484
485 desc_rx->callback = rspi_dma_complete;
486 desc_rx->callback_param = rspi;
487 cookie = dmaengine_submit(desc_rx);
488 if (dma_submit_error(cookie)) {
489 ret = cookie;
490 goto no_dma_rx;
491 }
492
493 irq_mask |= SPCR_SPRIE;
494 }
495
496 if (tx) {
497 desc_tx = dmaengine_prep_slave_sg(rspi->master->dma_tx,
498 tx->sgl, tx->nents, DMA_TO_DEVICE,
499 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
500 if (!desc_tx) {
501 ret = -EAGAIN;
502 goto no_dma_tx;
503 }
504
505 if (rx) {
506 /* No callback */
507 desc_tx->callback = NULL;
508 } else {
509 desc_tx->callback = rspi_dma_complete;
510 desc_tx->callback_param = rspi;
511 }
512 cookie = dmaengine_submit(desc_tx);
513 if (dma_submit_error(cookie)) {
514 ret = cookie;
515 goto no_dma_tx;
516 }
517
518 irq_mask |= SPCR_SPTIE;
519 }
520
521 /*
522 * DMAC needs SPxIE, but if SPxIE is set, the IRQ routine will be
523 * called. So, this driver disables the IRQ while DMA transfer.
524 */
525 if (tx)
526 disable_irq(other_irq = rspi->tx_irq);
527 if (rx && rspi->rx_irq != other_irq)
528 disable_irq(rspi->rx_irq);
529
530 rspi_enable_irq(rspi, irq_mask);
531 rspi->dma_callbacked = 0;
532
533 /* Now start DMA */
534 if (rx)
535 dma_async_issue_pending(rspi->master->dma_rx);
536 if (tx)
537 dma_async_issue_pending(rspi->master->dma_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 dev_err(&rspi->master->dev, "DMA timeout\n");
545 ret = -ETIMEDOUT;
546 if (tx)
547 dmaengine_terminate_all(rspi->master->dma_tx);
548 if (rx)
549 dmaengine_terminate_all(rspi->master->dma_rx);
550 }
551
552 rspi_disable_irq(rspi, irq_mask);
553
554 if (tx)
555 enable_irq(rspi->tx_irq);
556 if (rx && rspi->rx_irq != other_irq)
557 enable_irq(rspi->rx_irq);
558
559 return ret;
560
561 no_dma_tx:
562 if (rx)
563 dmaengine_terminate_all(rspi->master->dma_rx);
564 no_dma_rx:
565 if (ret == -EAGAIN) {
566 pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
567 dev_driver_string(&rspi->master->dev),
568 dev_name(&rspi->master->dev));
569 }
570 return ret;
571 }
572
573 static void rspi_receive_init(const struct rspi_data *rspi)
574 {
575 u8 spsr;
576
577 spsr = rspi_read8(rspi, RSPI_SPSR);
578 if (spsr & SPSR_SPRF)
579 rspi_read_data(rspi); /* dummy read */
580 if (spsr & SPSR_OVRF)
581 rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF,
582 RSPI_SPSR);
583 }
584
585 static void rspi_rz_receive_init(const struct rspi_data *rspi)
586 {
587 rspi_receive_init(rspi);
588 rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, RSPI_SPBFCR);
589 rspi_write8(rspi, 0, RSPI_SPBFCR);
590 }
591
592 static void qspi_receive_init(const struct rspi_data *rspi)
593 {
594 u8 spsr;
595
596 spsr = rspi_read8(rspi, RSPI_SPSR);
597 if (spsr & SPSR_SPRF)
598 rspi_read_data(rspi); /* dummy read */
599 rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
600 rspi_write8(rspi, 0, QSPI_SPBFCR);
601 }
602
603 static bool __rspi_can_dma(const struct rspi_data *rspi,
604 const struct spi_transfer *xfer)
605 {
606 return xfer->len > rspi->ops->fifo_size;
607 }
608
609 static bool rspi_can_dma(struct spi_master *master, struct spi_device *spi,
610 struct spi_transfer *xfer)
611 {
612 struct rspi_data *rspi = spi_master_get_devdata(master);
613
614 return __rspi_can_dma(rspi, xfer);
615 }
616
617 static int rspi_common_transfer(struct rspi_data *rspi,
618 struct spi_transfer *xfer)
619 {
620 int ret;
621
622 if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) {
623 /* rx_buf can be NULL on RSPI on SH in TX-only Mode */
624 ret = rspi_dma_transfer(rspi, &xfer->tx_sg,
625 xfer->rx_buf ? &xfer->rx_sg : NULL);
626 if (ret != -EAGAIN)
627 return ret;
628 }
629
630 ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);
631 if (ret < 0)
632 return ret;
633
634 /* Wait for the last transmission */
635 rspi_wait_for_tx_empty(rspi);
636
637 return 0;
638 }
639
640 static int rspi_transfer_one(struct spi_master *master, struct spi_device *spi,
641 struct spi_transfer *xfer)
642 {
643 struct rspi_data *rspi = spi_master_get_devdata(master);
644 u8 spcr;
645
646 spcr = rspi_read8(rspi, RSPI_SPCR);
647 if (xfer->rx_buf) {
648 rspi_receive_init(rspi);
649 spcr &= ~SPCR_TXMD;
650 } else {
651 spcr |= SPCR_TXMD;
652 }
653 rspi_write8(rspi, spcr, RSPI_SPCR);
654
655 return rspi_common_transfer(rspi, xfer);
656 }
657
658 static int rspi_rz_transfer_one(struct spi_master *master,
659 struct spi_device *spi,
660 struct spi_transfer *xfer)
661 {
662 struct rspi_data *rspi = spi_master_get_devdata(master);
663
664 rspi_rz_receive_init(rspi);
665
666 return rspi_common_transfer(rspi, xfer);
667 }
668
669 static int qspi_transfer_out_in(struct rspi_data *rspi,
670 struct spi_transfer *xfer)
671 {
672 qspi_receive_init(rspi);
673
674 return rspi_common_transfer(rspi, xfer);
675 }
676
677 static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)
678 {
679 int ret;
680
681 if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) {
682 ret = rspi_dma_transfer(rspi, &xfer->tx_sg, NULL);
683 if (ret != -EAGAIN)
684 return ret;
685 }
686
687 ret = rspi_pio_transfer(rspi, xfer->tx_buf, NULL, xfer->len);
688 if (ret < 0)
689 return ret;
690
691 /* Wait for the last transmission */
692 rspi_wait_for_tx_empty(rspi);
693
694 return 0;
695 }
696
697 static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)
698 {
699 if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) {
700 int ret = rspi_dma_transfer(rspi, NULL, &xfer->rx_sg);
701 if (ret != -EAGAIN)
702 return ret;
703 }
704
705 return rspi_pio_transfer(rspi, NULL, xfer->rx_buf, xfer->len);
706 }
707
708 static int qspi_transfer_one(struct spi_master *master, struct spi_device *spi,
709 struct spi_transfer *xfer)
710 {
711 struct rspi_data *rspi = spi_master_get_devdata(master);
712
713 if (spi->mode & SPI_LOOP) {
714 return qspi_transfer_out_in(rspi, xfer);
715 } else if (xfer->tx_nbits > SPI_NBITS_SINGLE) {
716 /* Quad or Dual SPI Write */
717 return qspi_transfer_out(rspi, xfer);
718 } else if (xfer->rx_nbits > SPI_NBITS_SINGLE) {
719 /* Quad or Dual SPI Read */
720 return qspi_transfer_in(rspi, xfer);
721 } else {
722 /* Single SPI Transfer */
723 return qspi_transfer_out_in(rspi, xfer);
724 }
725 }
726
727 static int rspi_setup(struct spi_device *spi)
728 {
729 struct rspi_data *rspi = spi_master_get_devdata(spi->master);
730
731 rspi->max_speed_hz = spi->max_speed_hz;
732
733 rspi->spcmd = SPCMD_SSLKP;
734 if (spi->mode & SPI_CPOL)
735 rspi->spcmd |= SPCMD_CPOL;
736 if (spi->mode & SPI_CPHA)
737 rspi->spcmd |= SPCMD_CPHA;
738
739 /* CMOS output mode and MOSI signal from previous transfer */
740 rspi->sppcr = 0;
741 if (spi->mode & SPI_LOOP)
742 rspi->sppcr |= SPPCR_SPLP;
743
744 set_config_register(rspi, 8);
745
746 return 0;
747 }
748
749 static u16 qspi_transfer_mode(const struct spi_transfer *xfer)
750 {
751 if (xfer->tx_buf)
752 switch (xfer->tx_nbits) {
753 case SPI_NBITS_QUAD:
754 return SPCMD_SPIMOD_QUAD;
755 case SPI_NBITS_DUAL:
756 return SPCMD_SPIMOD_DUAL;
757 default:
758 return 0;
759 }
760 if (xfer->rx_buf)
761 switch (xfer->rx_nbits) {
762 case SPI_NBITS_QUAD:
763 return SPCMD_SPIMOD_QUAD | SPCMD_SPRW;
764 case SPI_NBITS_DUAL:
765 return SPCMD_SPIMOD_DUAL | SPCMD_SPRW;
766 default:
767 return 0;
768 }
769
770 return 0;
771 }
772
773 static int qspi_setup_sequencer(struct rspi_data *rspi,
774 const struct spi_message *msg)
775 {
776 const struct spi_transfer *xfer;
777 unsigned int i = 0, len = 0;
778 u16 current_mode = 0xffff, mode;
779
780 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
781 mode = qspi_transfer_mode(xfer);
782 if (mode == current_mode) {
783 len += xfer->len;
784 continue;
785 }
786
787 /* Transfer mode change */
788 if (i) {
789 /* Set transfer data length of previous transfer */
790 rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
791 }
792
793 if (i >= QSPI_NUM_SPCMD) {
794 dev_err(&msg->spi->dev,
795 "Too many different transfer modes");
796 return -EINVAL;
797 }
798
799 /* Program transfer mode for this transfer */
800 rspi_write16(rspi, rspi->spcmd | mode, RSPI_SPCMD(i));
801 current_mode = mode;
802 len = xfer->len;
803 i++;
804 }
805 if (i) {
806 /* Set final transfer data length and sequence length */
807 rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
808 rspi_write8(rspi, i - 1, RSPI_SPSCR);
809 }
810
811 return 0;
812 }
813
814 static int rspi_prepare_message(struct spi_master *master,
815 struct spi_message *msg)
816 {
817 struct rspi_data *rspi = spi_master_get_devdata(master);
818 int ret;
819
820 if (msg->spi->mode &
821 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)) {
822 /* Setup sequencer for messages with multiple transfer modes */
823 ret = qspi_setup_sequencer(rspi, msg);
824 if (ret < 0)
825 return ret;
826 }
827
828 /* Enable SPI function in master mode */
829 rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_SPE, RSPI_SPCR);
830 return 0;
831 }
832
833 static int rspi_unprepare_message(struct spi_master *master,
834 struct spi_message *msg)
835 {
836 struct rspi_data *rspi = spi_master_get_devdata(master);
837
838 /* Disable SPI function */
839 rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_SPE, RSPI_SPCR);
840
841 /* Reset sequencer for Single SPI Transfers */
842 rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
843 rspi_write8(rspi, 0, RSPI_SPSCR);
844 return 0;
845 }
846
847 static irqreturn_t rspi_irq_mux(int irq, void *_sr)
848 {
849 struct rspi_data *rspi = _sr;
850 u8 spsr;
851 irqreturn_t ret = IRQ_NONE;
852 u8 disable_irq = 0;
853
854 rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
855 if (spsr & SPSR_SPRF)
856 disable_irq |= SPCR_SPRIE;
857 if (spsr & SPSR_SPTEF)
858 disable_irq |= SPCR_SPTIE;
859
860 if (disable_irq) {
861 ret = IRQ_HANDLED;
862 rspi_disable_irq(rspi, disable_irq);
863 wake_up(&rspi->wait);
864 }
865
866 return ret;
867 }
868
869 static irqreturn_t rspi_irq_rx(int irq, void *_sr)
870 {
871 struct rspi_data *rspi = _sr;
872 u8 spsr;
873
874 rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
875 if (spsr & SPSR_SPRF) {
876 rspi_disable_irq(rspi, SPCR_SPRIE);
877 wake_up(&rspi->wait);
878 return IRQ_HANDLED;
879 }
880
881 return 0;
882 }
883
884 static irqreturn_t rspi_irq_tx(int irq, void *_sr)
885 {
886 struct rspi_data *rspi = _sr;
887 u8 spsr;
888
889 rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
890 if (spsr & SPSR_SPTEF) {
891 rspi_disable_irq(rspi, SPCR_SPTIE);
892 wake_up(&rspi->wait);
893 return IRQ_HANDLED;
894 }
895
896 return 0;
897 }
898
899 static struct dma_chan *rspi_request_dma_chan(struct device *dev,
900 enum dma_transfer_direction dir,
901 unsigned int id,
902 dma_addr_t port_addr)
903 {
904 dma_cap_mask_t mask;
905 struct dma_chan *chan;
906 struct dma_slave_config cfg;
907 int ret;
908
909 dma_cap_zero(mask);
910 dma_cap_set(DMA_SLAVE, mask);
911
912 chan = dma_request_channel(mask, shdma_chan_filter,
913 (void *)(unsigned long)id);
914 if (!chan) {
915 dev_warn(dev, "dma_request_channel failed\n");
916 return NULL;
917 }
918
919 memset(&cfg, 0, sizeof(cfg));
920 cfg.slave_id = id;
921 cfg.direction = dir;
922 if (dir == DMA_MEM_TO_DEV)
923 cfg.dst_addr = port_addr;
924 else
925 cfg.src_addr = port_addr;
926
927 ret = dmaengine_slave_config(chan, &cfg);
928 if (ret) {
929 dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
930 dma_release_channel(chan);
931 return NULL;
932 }
933
934 return chan;
935 }
936
937 static int rspi_request_dma(struct device *dev, struct spi_master *master,
938 const struct resource *res)
939 {
940 const struct rspi_plat_data *rspi_pd = dev_get_platdata(dev);
941
942 if (!rspi_pd || !rspi_pd->dma_rx_id || !rspi_pd->dma_tx_id)
943 return 0; /* The driver assumes no error. */
944
945 master->dma_rx = rspi_request_dma_chan(dev, DMA_DEV_TO_MEM,
946 rspi_pd->dma_rx_id,
947 res->start + RSPI_SPDR);
948 if (!master->dma_rx)
949 return -ENODEV;
950
951 master->dma_tx = rspi_request_dma_chan(dev, DMA_MEM_TO_DEV,
952 rspi_pd->dma_tx_id,
953 res->start + RSPI_SPDR);
954 if (!master->dma_tx) {
955 dma_release_channel(master->dma_rx);
956 master->dma_rx = NULL;
957 return -ENODEV;
958 }
959
960 master->can_dma = rspi_can_dma;
961 dev_info(dev, "DMA available");
962 return 0;
963 }
964
965 static void rspi_release_dma(struct spi_master *master)
966 {
967 if (master->dma_tx)
968 dma_release_channel(master->dma_tx);
969 if (master->dma_rx)
970 dma_release_channel(master->dma_rx);
971 }
972
973 static int rspi_remove(struct platform_device *pdev)
974 {
975 struct rspi_data *rspi = platform_get_drvdata(pdev);
976
977 rspi_release_dma(rspi->master);
978 pm_runtime_disable(&pdev->dev);
979
980 return 0;
981 }
982
983 static const struct spi_ops rspi_ops = {
984 .set_config_register = rspi_set_config_register,
985 .transfer_one = rspi_transfer_one,
986 .mode_bits = SPI_CPHA | SPI_CPOL | SPI_LOOP,
987 .flags = SPI_MASTER_MUST_TX,
988 .fifo_size = 8,
989 };
990
991 static const struct spi_ops rspi_rz_ops = {
992 .set_config_register = rspi_rz_set_config_register,
993 .transfer_one = rspi_rz_transfer_one,
994 .mode_bits = SPI_CPHA | SPI_CPOL | SPI_LOOP,
995 .flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX,
996 .fifo_size = 8, /* 8 for TX, 32 for RX */
997 };
998
999 static const struct spi_ops qspi_ops = {
1000 .set_config_register = qspi_set_config_register,
1001 .transfer_one = qspi_transfer_one,
1002 .mode_bits = SPI_CPHA | SPI_CPOL | SPI_LOOP |
1003 SPI_TX_DUAL | SPI_TX_QUAD |
1004 SPI_RX_DUAL | SPI_RX_QUAD,
1005 .flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX,
1006 .fifo_size = 32,
1007 };
1008
1009 #ifdef CONFIG_OF
1010 static const struct of_device_id rspi_of_match[] = {
1011 /* RSPI on legacy SH */
1012 { .compatible = "renesas,rspi", .data = &rspi_ops },
1013 /* RSPI on RZ/A1H */
1014 { .compatible = "renesas,rspi-rz", .data = &rspi_rz_ops },
1015 /* QSPI on R-Car Gen2 */
1016 { .compatible = "renesas,qspi", .data = &qspi_ops },
1017 { /* sentinel */ }
1018 };
1019
1020 MODULE_DEVICE_TABLE(of, rspi_of_match);
1021
1022 static int rspi_parse_dt(struct device *dev, struct spi_master *master)
1023 {
1024 u32 num_cs;
1025 int error;
1026
1027 /* Parse DT properties */
1028 error = of_property_read_u32(dev->of_node, "num-cs", &num_cs);
1029 if (error) {
1030 dev_err(dev, "of_property_read_u32 num-cs failed %d\n", error);
1031 return error;
1032 }
1033
1034 master->num_chipselect = num_cs;
1035 return 0;
1036 }
1037 #else
1038 #define rspi_of_match NULL
1039 static inline int rspi_parse_dt(struct device *dev, struct spi_master *master)
1040 {
1041 return -EINVAL;
1042 }
1043 #endif /* CONFIG_OF */
1044
1045 static int rspi_request_irq(struct device *dev, unsigned int irq,
1046 irq_handler_t handler, const char *suffix,
1047 void *dev_id)
1048 {
1049 const char *base = dev_name(dev);
1050 size_t len = strlen(base) + strlen(suffix) + 2;
1051 char *name = devm_kzalloc(dev, len, GFP_KERNEL);
1052 if (!name)
1053 return -ENOMEM;
1054 snprintf(name, len, "%s:%s", base, suffix);
1055 return devm_request_irq(dev, irq, handler, 0, name, dev_id);
1056 }
1057
1058 static int rspi_probe(struct platform_device *pdev)
1059 {
1060 struct resource *res;
1061 struct spi_master *master;
1062 struct rspi_data *rspi;
1063 int ret;
1064 const struct of_device_id *of_id;
1065 const struct rspi_plat_data *rspi_pd;
1066 const struct spi_ops *ops;
1067
1068 master = spi_alloc_master(&pdev->dev, sizeof(struct rspi_data));
1069 if (master == NULL) {
1070 dev_err(&pdev->dev, "spi_alloc_master error.\n");
1071 return -ENOMEM;
1072 }
1073
1074 of_id = of_match_device(rspi_of_match, &pdev->dev);
1075 if (of_id) {
1076 ops = of_id->data;
1077 ret = rspi_parse_dt(&pdev->dev, master);
1078 if (ret)
1079 goto error1;
1080 } else {
1081 ops = (struct spi_ops *)pdev->id_entry->driver_data;
1082 rspi_pd = dev_get_platdata(&pdev->dev);
1083 if (rspi_pd && rspi_pd->num_chipselect)
1084 master->num_chipselect = rspi_pd->num_chipselect;
1085 else
1086 master->num_chipselect = 2; /* default */
1087 };
1088
1089 /* ops parameter check */
1090 if (!ops->set_config_register) {
1091 dev_err(&pdev->dev, "there is no set_config_register\n");
1092 ret = -ENODEV;
1093 goto error1;
1094 }
1095
1096 rspi = spi_master_get_devdata(master);
1097 platform_set_drvdata(pdev, rspi);
1098 rspi->ops = ops;
1099 rspi->master = master;
1100
1101 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1102 rspi->addr = devm_ioremap_resource(&pdev->dev, res);
1103 if (IS_ERR(rspi->addr)) {
1104 ret = PTR_ERR(rspi->addr);
1105 goto error1;
1106 }
1107
1108 rspi->clk = devm_clk_get(&pdev->dev, NULL);
1109 if (IS_ERR(rspi->clk)) {
1110 dev_err(&pdev->dev, "cannot get clock\n");
1111 ret = PTR_ERR(rspi->clk);
1112 goto error1;
1113 }
1114
1115 pm_runtime_enable(&pdev->dev);
1116
1117 init_waitqueue_head(&rspi->wait);
1118
1119 master->bus_num = pdev->id;
1120 master->setup = rspi_setup;
1121 master->auto_runtime_pm = true;
1122 master->transfer_one = ops->transfer_one;
1123 master->prepare_message = rspi_prepare_message;
1124 master->unprepare_message = rspi_unprepare_message;
1125 master->mode_bits = ops->mode_bits;
1126 master->flags = ops->flags;
1127 master->dev.of_node = pdev->dev.of_node;
1128
1129 ret = platform_get_irq_byname(pdev, "rx");
1130 if (ret < 0) {
1131 ret = platform_get_irq_byname(pdev, "mux");
1132 if (ret < 0)
1133 ret = platform_get_irq(pdev, 0);
1134 if (ret >= 0)
1135 rspi->rx_irq = rspi->tx_irq = ret;
1136 } else {
1137 rspi->rx_irq = ret;
1138 ret = platform_get_irq_byname(pdev, "tx");
1139 if (ret >= 0)
1140 rspi->tx_irq = ret;
1141 }
1142 if (ret < 0) {
1143 dev_err(&pdev->dev, "platform_get_irq error\n");
1144 goto error2;
1145 }
1146
1147 if (rspi->rx_irq == rspi->tx_irq) {
1148 /* Single multiplexed interrupt */
1149 ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_mux,
1150 "mux", rspi);
1151 } else {
1152 /* Multi-interrupt mode, only SPRI and SPTI are used */
1153 ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_rx,
1154 "rx", rspi);
1155 if (!ret)
1156 ret = rspi_request_irq(&pdev->dev, rspi->tx_irq,
1157 rspi_irq_tx, "tx", rspi);
1158 }
1159 if (ret < 0) {
1160 dev_err(&pdev->dev, "request_irq error\n");
1161 goto error2;
1162 }
1163
1164 ret = rspi_request_dma(&pdev->dev, master, res);
1165 if (ret < 0)
1166 dev_warn(&pdev->dev, "DMA not available, using PIO\n");
1167
1168 ret = devm_spi_register_master(&pdev->dev, master);
1169 if (ret < 0) {
1170 dev_err(&pdev->dev, "spi_register_master error.\n");
1171 goto error3;
1172 }
1173
1174 dev_info(&pdev->dev, "probed\n");
1175
1176 return 0;
1177
1178 error3:
1179 rspi_release_dma(master);
1180 error2:
1181 pm_runtime_disable(&pdev->dev);
1182 error1:
1183 spi_master_put(master);
1184
1185 return ret;
1186 }
1187
1188 static struct platform_device_id spi_driver_ids[] = {
1189 { "rspi", (kernel_ulong_t)&rspi_ops },
1190 { "rspi-rz", (kernel_ulong_t)&rspi_rz_ops },
1191 { "qspi", (kernel_ulong_t)&qspi_ops },
1192 {},
1193 };
1194
1195 MODULE_DEVICE_TABLE(platform, spi_driver_ids);
1196
1197 static struct platform_driver rspi_driver = {
1198 .probe = rspi_probe,
1199 .remove = rspi_remove,
1200 .id_table = spi_driver_ids,
1201 .driver = {
1202 .name = "renesas_spi",
1203 .owner = THIS_MODULE,
1204 .of_match_table = of_match_ptr(rspi_of_match),
1205 },
1206 };
1207 module_platform_driver(rspi_driver);
1208
1209 MODULE_DESCRIPTION("Renesas RSPI bus driver");
1210 MODULE_LICENSE("GPL v2");
1211 MODULE_AUTHOR("Yoshihiro Shimoda");
1212 MODULE_ALIAS("platform:rspi");
Linux kernel - Deliverables
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