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Linux 4.2.1
[linux/fpc-iii.git] / drivers / spi / spi-coldfire-qspi.c
blob688956ff5095c26a8c1101dc4740b310627ed294
1 /*
2 * Freescale/Motorola Coldfire Queued SPI driver
3 *
4 * Copyright 2010 Steven King <sfking@fdwdc.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 */
16
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/interrupt.h>
20 #include <linux/errno.h>
21 #include <linux/platform_device.h>
22 #include <linux/sched.h>
23 #include <linux/delay.h>
24 #include <linux/io.h>
25 #include <linux/clk.h>
26 #include <linux/err.h>
27 #include <linux/spi/spi.h>
28 #include <linux/pm_runtime.h>
29
30 #include <asm/coldfire.h>
31 #include <asm/mcfsim.h>
32 #include <asm/mcfqspi.h>
33
34 #define DRIVER_NAME "mcfqspi"
35
36 #define MCFQSPI_BUSCLK (MCF_BUSCLK / 2)
37
38 #define MCFQSPI_QMR 0x00
39 #define MCFQSPI_QMR_MSTR 0x8000
40 #define MCFQSPI_QMR_CPOL 0x0200
41 #define MCFQSPI_QMR_CPHA 0x0100
42 #define MCFQSPI_QDLYR 0x04
43 #define MCFQSPI_QDLYR_SPE 0x8000
44 #define MCFQSPI_QWR 0x08
45 #define MCFQSPI_QWR_HALT 0x8000
46 #define MCFQSPI_QWR_WREN 0x4000
47 #define MCFQSPI_QWR_CSIV 0x1000
48 #define MCFQSPI_QIR 0x0C
49 #define MCFQSPI_QIR_WCEFB 0x8000
50 #define MCFQSPI_QIR_ABRTB 0x4000
51 #define MCFQSPI_QIR_ABRTL 0x1000
52 #define MCFQSPI_QIR_WCEFE 0x0800
53 #define MCFQSPI_QIR_ABRTE 0x0400
54 #define MCFQSPI_QIR_SPIFE 0x0100
55 #define MCFQSPI_QIR_WCEF 0x0008
56 #define MCFQSPI_QIR_ABRT 0x0004
57 #define MCFQSPI_QIR_SPIF 0x0001
58 #define MCFQSPI_QAR 0x010
59 #define MCFQSPI_QAR_TXBUF 0x00
60 #define MCFQSPI_QAR_RXBUF 0x10
61 #define MCFQSPI_QAR_CMDBUF 0x20
62 #define MCFQSPI_QDR 0x014
63 #define MCFQSPI_QCR 0x014
64 #define MCFQSPI_QCR_CONT 0x8000
65 #define MCFQSPI_QCR_BITSE 0x4000
66 #define MCFQSPI_QCR_DT 0x2000
67
68 struct mcfqspi {
69 void __iomem *iobase;
70 int irq;
71 struct clk *clk;
72 struct mcfqspi_cs_control *cs_control;
73
74 wait_queue_head_t waitq;
75 };
76
77 static void mcfqspi_wr_qmr(struct mcfqspi *mcfqspi, u16 val)
78 {
79 writew(val, mcfqspi->iobase + MCFQSPI_QMR);
80 }
81
82 static void mcfqspi_wr_qdlyr(struct mcfqspi *mcfqspi, u16 val)
83 {
84 writew(val, mcfqspi->iobase + MCFQSPI_QDLYR);
85 }
86
87 static u16 mcfqspi_rd_qdlyr(struct mcfqspi *mcfqspi)
88 {
89 return readw(mcfqspi->iobase + MCFQSPI_QDLYR);
90 }
91
92 static void mcfqspi_wr_qwr(struct mcfqspi *mcfqspi, u16 val)
93 {
94 writew(val, mcfqspi->iobase + MCFQSPI_QWR);
95 }
96
97 static void mcfqspi_wr_qir(struct mcfqspi *mcfqspi, u16 val)
98 {
99 writew(val, mcfqspi->iobase + MCFQSPI_QIR);
100 }
101
102 static void mcfqspi_wr_qar(struct mcfqspi *mcfqspi, u16 val)
103 {
104 writew(val, mcfqspi->iobase + MCFQSPI_QAR);
105 }
106
107 static void mcfqspi_wr_qdr(struct mcfqspi *mcfqspi, u16 val)
108 {
109 writew(val, mcfqspi->iobase + MCFQSPI_QDR);
110 }
111
112 static u16 mcfqspi_rd_qdr(struct mcfqspi *mcfqspi)
113 {
114 return readw(mcfqspi->iobase + MCFQSPI_QDR);
115 }
116
117 static void mcfqspi_cs_select(struct mcfqspi *mcfqspi, u8 chip_select,
118 bool cs_high)
119 {
120 mcfqspi->cs_control->select(mcfqspi->cs_control, chip_select, cs_high);
121 }
122
123 static void mcfqspi_cs_deselect(struct mcfqspi *mcfqspi, u8 chip_select,
124 bool cs_high)
125 {
126 mcfqspi->cs_control->deselect(mcfqspi->cs_control, chip_select, cs_high);
127 }
128
129 static int mcfqspi_cs_setup(struct mcfqspi *mcfqspi)
130 {
131 return (mcfqspi->cs_control->setup) ?
132 mcfqspi->cs_control->setup(mcfqspi->cs_control) : 0;
133 }
134
135 static void mcfqspi_cs_teardown(struct mcfqspi *mcfqspi)
136 {
137 if (mcfqspi->cs_control->teardown)
138 mcfqspi->cs_control->teardown(mcfqspi->cs_control);
139 }
140
141 static u8 mcfqspi_qmr_baud(u32 speed_hz)
142 {
143 return clamp((MCFQSPI_BUSCLK + speed_hz - 1) / speed_hz, 2u, 255u);
144 }
145
146 static bool mcfqspi_qdlyr_spe(struct mcfqspi *mcfqspi)
147 {
148 return mcfqspi_rd_qdlyr(mcfqspi) & MCFQSPI_QDLYR_SPE;
149 }
150
151 static irqreturn_t mcfqspi_irq_handler(int this_irq, void *dev_id)
152 {
153 struct mcfqspi *mcfqspi = dev_id;
154
155 /* clear interrupt */
156 mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE | MCFQSPI_QIR_SPIF);
157 wake_up(&mcfqspi->waitq);
158
159 return IRQ_HANDLED;
160 }
161
162 static void mcfqspi_transfer_msg8(struct mcfqspi *mcfqspi, unsigned count,
163 const u8 *txbuf, u8 *rxbuf)
164 {
165 unsigned i, n, offset = 0;
166
167 n = min(count, 16u);
168
169 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF);
170 for (i = 0; i < n; ++i)
171 mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE);
172
173 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF);
174 if (txbuf)
175 for (i = 0; i < n; ++i)
176 mcfqspi_wr_qdr(mcfqspi, *txbuf++);
177 else
178 for (i = 0; i < count; ++i)
179 mcfqspi_wr_qdr(mcfqspi, 0);
180
181 count -= n;
182 if (count) {
183 u16 qwr = 0xf08;
184 mcfqspi_wr_qwr(mcfqspi, 0x700);
185 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
186
187 do {
188 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
189 mcfqspi_wr_qwr(mcfqspi, qwr);
190 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
191 if (rxbuf) {
192 mcfqspi_wr_qar(mcfqspi,
193 MCFQSPI_QAR_RXBUF + offset);
194 for (i = 0; i < 8; ++i)
195 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
196 }
197 n = min(count, 8u);
198 if (txbuf) {
199 mcfqspi_wr_qar(mcfqspi,
200 MCFQSPI_QAR_TXBUF + offset);
201 for (i = 0; i < n; ++i)
202 mcfqspi_wr_qdr(mcfqspi, *txbuf++);
203 }
204 qwr = (offset ? 0x808 : 0) + ((n - 1) << 8);
205 offset ^= 8;
206 count -= n;
207 } while (count);
208 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
209 mcfqspi_wr_qwr(mcfqspi, qwr);
210 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
211 if (rxbuf) {
212 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
213 for (i = 0; i < 8; ++i)
214 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
215 offset ^= 8;
216 }
217 } else {
218 mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8);
219 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
220 }
221 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
222 if (rxbuf) {
223 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
224 for (i = 0; i < n; ++i)
225 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
226 }
227 }
228
229 static void mcfqspi_transfer_msg16(struct mcfqspi *mcfqspi, unsigned count,
230 const u16 *txbuf, u16 *rxbuf)
231 {
232 unsigned i, n, offset = 0;
233
234 n = min(count, 16u);
235
236 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF);
237 for (i = 0; i < n; ++i)
238 mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE);
239
240 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF);
241 if (txbuf)
242 for (i = 0; i < n; ++i)
243 mcfqspi_wr_qdr(mcfqspi, *txbuf++);
244 else
245 for (i = 0; i < count; ++i)
246 mcfqspi_wr_qdr(mcfqspi, 0);
247
248 count -= n;
249 if (count) {
250 u16 qwr = 0xf08;
251 mcfqspi_wr_qwr(mcfqspi, 0x700);
252 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
253
254 do {
255 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
256 mcfqspi_wr_qwr(mcfqspi, qwr);
257 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
258 if (rxbuf) {
259 mcfqspi_wr_qar(mcfqspi,
260 MCFQSPI_QAR_RXBUF + offset);
261 for (i = 0; i < 8; ++i)
262 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
263 }
264 n = min(count, 8u);
265 if (txbuf) {
266 mcfqspi_wr_qar(mcfqspi,
267 MCFQSPI_QAR_TXBUF + offset);
268 for (i = 0; i < n; ++i)
269 mcfqspi_wr_qdr(mcfqspi, *txbuf++);
270 }
271 qwr = (offset ? 0x808 : 0x000) + ((n - 1) << 8);
272 offset ^= 8;
273 count -= n;
274 } while (count);
275 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
276 mcfqspi_wr_qwr(mcfqspi, qwr);
277 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
278 if (rxbuf) {
279 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
280 for (i = 0; i < 8; ++i)
281 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
282 offset ^= 8;
283 }
284 } else {
285 mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8);
286 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
287 }
288 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
289 if (rxbuf) {
290 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
291 for (i = 0; i < n; ++i)
292 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
293 }
294 }
295
296 static void mcfqspi_set_cs(struct spi_device *spi, bool enable)
297 {
298 struct mcfqspi *mcfqspi = spi_master_get_devdata(spi->master);
299 bool cs_high = spi->mode & SPI_CS_HIGH;
300
301 if (enable)
302 mcfqspi_cs_select(mcfqspi, spi->chip_select, cs_high);
303 else
304 mcfqspi_cs_deselect(mcfqspi, spi->chip_select, cs_high);
305 }
306
307 static int mcfqspi_transfer_one(struct spi_master *master,
308 struct spi_device *spi,
309 struct spi_transfer *t)
310 {
311 struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
312 u16 qmr = MCFQSPI_QMR_MSTR;
313
314 qmr |= t->bits_per_word << 10;
315 if (spi->mode & SPI_CPHA)
316 qmr |= MCFQSPI_QMR_CPHA;
317 if (spi->mode & SPI_CPOL)
318 qmr |= MCFQSPI_QMR_CPOL;
319 qmr |= mcfqspi_qmr_baud(t->speed_hz);
320 mcfqspi_wr_qmr(mcfqspi, qmr);
321
322 mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE);
323 if (t->bits_per_word == 8)
324 mcfqspi_transfer_msg8(mcfqspi, t->len, t->tx_buf, t->rx_buf);
325 else
326 mcfqspi_transfer_msg16(mcfqspi, t->len / 2, t->tx_buf,
327 t->rx_buf);
328 mcfqspi_wr_qir(mcfqspi, 0);
329
330 return 0;
331 }
332
333 static int mcfqspi_setup(struct spi_device *spi)
334 {
335 mcfqspi_cs_deselect(spi_master_get_devdata(spi->master),
336 spi->chip_select, spi->mode & SPI_CS_HIGH);
337
338 dev_dbg(&spi->dev,
339 "bits per word %d, chip select %d, speed %d KHz\n",
340 spi->bits_per_word, spi->chip_select,
341 (MCFQSPI_BUSCLK / mcfqspi_qmr_baud(spi->max_speed_hz))
342 / 1000);
343
344 return 0;
345 }
346
347 static int mcfqspi_probe(struct platform_device *pdev)
348 {
349 struct spi_master *master;
350 struct mcfqspi *mcfqspi;
351 struct resource *res;
352 struct mcfqspi_platform_data *pdata;
353 int status;
354
355 pdata = dev_get_platdata(&pdev->dev);
356 if (!pdata) {
357 dev_dbg(&pdev->dev, "platform data is missing\n");
358 return -ENOENT;
359 }
360
361 if (!pdata->cs_control) {
362 dev_dbg(&pdev->dev, "pdata->cs_control is NULL\n");
363 return -EINVAL;
364 }
365
366 master = spi_alloc_master(&pdev->dev, sizeof(*mcfqspi));
367 if (master == NULL) {
368 dev_dbg(&pdev->dev, "spi_alloc_master failed\n");
369 return -ENOMEM;
370 }
371
372 mcfqspi = spi_master_get_devdata(master);
373
374 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
375 mcfqspi->iobase = devm_ioremap_resource(&pdev->dev, res);
376 if (IS_ERR(mcfqspi->iobase)) {
377 status = PTR_ERR(mcfqspi->iobase);
378 goto fail0;
379 }
380
381 mcfqspi->irq = platform_get_irq(pdev, 0);
382 if (mcfqspi->irq < 0) {
383 dev_dbg(&pdev->dev, "platform_get_irq failed\n");
384 status = -ENXIO;
385 goto fail0;
386 }
387
388 status = devm_request_irq(&pdev->dev, mcfqspi->irq, mcfqspi_irq_handler,
389 0, pdev->name, mcfqspi);
390 if (status) {
391 dev_dbg(&pdev->dev, "request_irq failed\n");
392 goto fail0;
393 }
394
395 mcfqspi->clk = devm_clk_get(&pdev->dev, "qspi_clk");
396 if (IS_ERR(mcfqspi->clk)) {
397 dev_dbg(&pdev->dev, "clk_get failed\n");
398 status = PTR_ERR(mcfqspi->clk);
399 goto fail0;
400 }
401 clk_enable(mcfqspi->clk);
402
403 master->bus_num = pdata->bus_num;
404 master->num_chipselect = pdata->num_chipselect;
405
406 mcfqspi->cs_control = pdata->cs_control;
407 status = mcfqspi_cs_setup(mcfqspi);
408 if (status) {
409 dev_dbg(&pdev->dev, "error initializing cs_control\n");
410 goto fail1;
411 }
412
413 init_waitqueue_head(&mcfqspi->waitq);
414
415 master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA;
416 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16);
417 master->setup = mcfqspi_setup;
418 master->set_cs = mcfqspi_set_cs;
419 master->transfer_one = mcfqspi_transfer_one;
420 master->auto_runtime_pm = true;
421
422 platform_set_drvdata(pdev, master);
423
424 status = devm_spi_register_master(&pdev->dev, master);
425 if (status) {
426 dev_dbg(&pdev->dev, "spi_register_master failed\n");
427 goto fail2;
428 }
429 pm_runtime_enable(&pdev->dev);
430
431 dev_info(&pdev->dev, "Coldfire QSPI bus driver\n");
432
433 return 0;
434
435 fail2:
436 mcfqspi_cs_teardown(mcfqspi);
437 fail1:
438 clk_disable(mcfqspi->clk);
439 fail0:
440 spi_master_put(master);
441
442 dev_dbg(&pdev->dev, "Coldfire QSPI probe failed\n");
443
444 return status;
445 }
446
447 static int mcfqspi_remove(struct platform_device *pdev)
448 {
449 struct spi_master *master = platform_get_drvdata(pdev);
450 struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
451
452 pm_runtime_disable(&pdev->dev);
453 /* disable the hardware (set the baud rate to 0) */
454 mcfqspi_wr_qmr(mcfqspi, MCFQSPI_QMR_MSTR);
455
456 mcfqspi_cs_teardown(mcfqspi);
457 clk_disable(mcfqspi->clk);
458
459 return 0;
460 }
461
462 #ifdef CONFIG_PM_SLEEP
463 static int mcfqspi_suspend(struct device *dev)
464 {
465 struct spi_master *master = dev_get_drvdata(dev);
466 struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
467 int ret;
468
469 ret = spi_master_suspend(master);
470 if (ret)
471 return ret;
472
473 clk_disable(mcfqspi->clk);
474
475 return 0;
476 }
477
478 static int mcfqspi_resume(struct device *dev)
479 {
480 struct spi_master *master = dev_get_drvdata(dev);
481 struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
482
483 clk_enable(mcfqspi->clk);
484
485 return spi_master_resume(master);
486 }
487 #endif
488
489 #ifdef CONFIG_PM
490 static int mcfqspi_runtime_suspend(struct device *dev)
491 {
492 struct spi_master *master = dev_get_drvdata(dev);
493 struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
494
495 clk_disable(mcfqspi->clk);
496
497 return 0;
498 }
499
500 static int mcfqspi_runtime_resume(struct device *dev)
501 {
502 struct spi_master *master = dev_get_drvdata(dev);
503 struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
504
505 clk_enable(mcfqspi->clk);
506
507 return 0;
508 }
509 #endif
510
511 static const struct dev_pm_ops mcfqspi_pm = {
512 SET_SYSTEM_SLEEP_PM_OPS(mcfqspi_suspend, mcfqspi_resume)
513 SET_RUNTIME_PM_OPS(mcfqspi_runtime_suspend, mcfqspi_runtime_resume,
514 NULL)
515 };
516
517 static struct platform_driver mcfqspi_driver = {
518 .driver.name = DRIVER_NAME,
519 .driver.owner = THIS_MODULE,
520 .driver.pm = &mcfqspi_pm,
521 .probe = mcfqspi_probe,
522 .remove = mcfqspi_remove,
523 };
524 module_platform_driver(mcfqspi_driver);
525
526 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
527 MODULE_DESCRIPTION("Coldfire QSPI Controller Driver");
528 MODULE_LICENSE("GPL");
529 MODULE_ALIAS("platform:" DRIVER_NAME);
Linux with added FPC-III support