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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
[linux-2.6/btrfs-unstable.git] / drivers / spi / spi-coldfire-qspi.c
blobcabed8f9119e1af30d80766420d548b94567c91c
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 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 */
21
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/interrupt.h>
25 #include <linux/errno.h>
26 #include <linux/platform_device.h>
27 #include <linux/sched.h>
28 #include <linux/delay.h>
29 #include <linux/io.h>
30 #include <linux/clk.h>
31 #include <linux/err.h>
32 #include <linux/spi/spi.h>
33 #include <linux/pm_runtime.h>
34
35 #include <asm/coldfire.h>
36 #include <asm/mcfsim.h>
37 #include <asm/mcfqspi.h>
38
39 #define DRIVER_NAME "mcfqspi"
40
41 #define MCFQSPI_BUSCLK (MCF_BUSCLK / 2)
42
43 #define MCFQSPI_QMR 0x00
44 #define MCFQSPI_QMR_MSTR 0x8000
45 #define MCFQSPI_QMR_CPOL 0x0200
46 #define MCFQSPI_QMR_CPHA 0x0100
47 #define MCFQSPI_QDLYR 0x04
48 #define MCFQSPI_QDLYR_SPE 0x8000
49 #define MCFQSPI_QWR 0x08
50 #define MCFQSPI_QWR_HALT 0x8000
51 #define MCFQSPI_QWR_WREN 0x4000
52 #define MCFQSPI_QWR_CSIV 0x1000
53 #define MCFQSPI_QIR 0x0C
54 #define MCFQSPI_QIR_WCEFB 0x8000
55 #define MCFQSPI_QIR_ABRTB 0x4000
56 #define MCFQSPI_QIR_ABRTL 0x1000
57 #define MCFQSPI_QIR_WCEFE 0x0800
58 #define MCFQSPI_QIR_ABRTE 0x0400
59 #define MCFQSPI_QIR_SPIFE 0x0100
60 #define MCFQSPI_QIR_WCEF 0x0008
61 #define MCFQSPI_QIR_ABRT 0x0004
62 #define MCFQSPI_QIR_SPIF 0x0001
63 #define MCFQSPI_QAR 0x010
64 #define MCFQSPI_QAR_TXBUF 0x00
65 #define MCFQSPI_QAR_RXBUF 0x10
66 #define MCFQSPI_QAR_CMDBUF 0x20
67 #define MCFQSPI_QDR 0x014
68 #define MCFQSPI_QCR 0x014
69 #define MCFQSPI_QCR_CONT 0x8000
70 #define MCFQSPI_QCR_BITSE 0x4000
71 #define MCFQSPI_QCR_DT 0x2000
72
73 struct mcfqspi {
74 void __iomem *iobase;
75 int irq;
76 struct clk *clk;
77 struct mcfqspi_cs_control *cs_control;
78
79 wait_queue_head_t waitq;
80
81 struct device *dev;
82 };
83
84 static void mcfqspi_wr_qmr(struct mcfqspi *mcfqspi, u16 val)
85 {
86 writew(val, mcfqspi->iobase + MCFQSPI_QMR);
87 }
88
89 static void mcfqspi_wr_qdlyr(struct mcfqspi *mcfqspi, u16 val)
90 {
91 writew(val, mcfqspi->iobase + MCFQSPI_QDLYR);
92 }
93
94 static u16 mcfqspi_rd_qdlyr(struct mcfqspi *mcfqspi)
95 {
96 return readw(mcfqspi->iobase + MCFQSPI_QDLYR);
97 }
98
99 static void mcfqspi_wr_qwr(struct mcfqspi *mcfqspi, u16 val)
100 {
101 writew(val, mcfqspi->iobase + MCFQSPI_QWR);
102 }
103
104 static void mcfqspi_wr_qir(struct mcfqspi *mcfqspi, u16 val)
105 {
106 writew(val, mcfqspi->iobase + MCFQSPI_QIR);
107 }
108
109 static void mcfqspi_wr_qar(struct mcfqspi *mcfqspi, u16 val)
110 {
111 writew(val, mcfqspi->iobase + MCFQSPI_QAR);
112 }
113
114 static void mcfqspi_wr_qdr(struct mcfqspi *mcfqspi, u16 val)
115 {
116 writew(val, mcfqspi->iobase + MCFQSPI_QDR);
117 }
118
119 static u16 mcfqspi_rd_qdr(struct mcfqspi *mcfqspi)
120 {
121 return readw(mcfqspi->iobase + MCFQSPI_QDR);
122 }
123
124 static void mcfqspi_cs_select(struct mcfqspi *mcfqspi, u8 chip_select,
125 bool cs_high)
126 {
127 mcfqspi->cs_control->select(mcfqspi->cs_control, chip_select, cs_high);
128 }
129
130 static void mcfqspi_cs_deselect(struct mcfqspi *mcfqspi, u8 chip_select,
131 bool cs_high)
132 {
133 mcfqspi->cs_control->deselect(mcfqspi->cs_control, chip_select, cs_high);
134 }
135
136 static int mcfqspi_cs_setup(struct mcfqspi *mcfqspi)
137 {
138 return (mcfqspi->cs_control && mcfqspi->cs_control->setup) ?
139 mcfqspi->cs_control->setup(mcfqspi->cs_control) : 0;
140 }
141
142 static void mcfqspi_cs_teardown(struct mcfqspi *mcfqspi)
143 {
144 if (mcfqspi->cs_control && mcfqspi->cs_control->teardown)
145 mcfqspi->cs_control->teardown(mcfqspi->cs_control);
146 }
147
148 static u8 mcfqspi_qmr_baud(u32 speed_hz)
149 {
150 return clamp((MCFQSPI_BUSCLK + speed_hz - 1) / speed_hz, 2u, 255u);
151 }
152
153 static bool mcfqspi_qdlyr_spe(struct mcfqspi *mcfqspi)
154 {
155 return mcfqspi_rd_qdlyr(mcfqspi) & MCFQSPI_QDLYR_SPE;
156 }
157
158 static irqreturn_t mcfqspi_irq_handler(int this_irq, void *dev_id)
159 {
160 struct mcfqspi *mcfqspi = dev_id;
161
162 /* clear interrupt */
163 mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE | MCFQSPI_QIR_SPIF);
164 wake_up(&mcfqspi->waitq);
165
166 return IRQ_HANDLED;
167 }
168
169 static void mcfqspi_transfer_msg8(struct mcfqspi *mcfqspi, unsigned count,
170 const u8 *txbuf, u8 *rxbuf)
171 {
172 unsigned i, n, offset = 0;
173
174 n = min(count, 16u);
175
176 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF);
177 for (i = 0; i < n; ++i)
178 mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE);
179
180 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF);
181 if (txbuf)
182 for (i = 0; i < n; ++i)
183 mcfqspi_wr_qdr(mcfqspi, *txbuf++);
184 else
185 for (i = 0; i < count; ++i)
186 mcfqspi_wr_qdr(mcfqspi, 0);
187
188 count -= n;
189 if (count) {
190 u16 qwr = 0xf08;
191 mcfqspi_wr_qwr(mcfqspi, 0x700);
192 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
193
194 do {
195 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
196 mcfqspi_wr_qwr(mcfqspi, qwr);
197 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
198 if (rxbuf) {
199 mcfqspi_wr_qar(mcfqspi,
200 MCFQSPI_QAR_RXBUF + offset);
201 for (i = 0; i < 8; ++i)
202 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
203 }
204 n = min(count, 8u);
205 if (txbuf) {
206 mcfqspi_wr_qar(mcfqspi,
207 MCFQSPI_QAR_TXBUF + offset);
208 for (i = 0; i < n; ++i)
209 mcfqspi_wr_qdr(mcfqspi, *txbuf++);
210 }
211 qwr = (offset ? 0x808 : 0) + ((n - 1) << 8);
212 offset ^= 8;
213 count -= n;
214 } while (count);
215 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
216 mcfqspi_wr_qwr(mcfqspi, qwr);
217 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
218 if (rxbuf) {
219 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
220 for (i = 0; i < 8; ++i)
221 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
222 offset ^= 8;
223 }
224 } else {
225 mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8);
226 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
227 }
228 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
229 if (rxbuf) {
230 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
231 for (i = 0; i < n; ++i)
232 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
233 }
234 }
235
236 static void mcfqspi_transfer_msg16(struct mcfqspi *mcfqspi, unsigned count,
237 const u16 *txbuf, u16 *rxbuf)
238 {
239 unsigned i, n, offset = 0;
240
241 n = min(count, 16u);
242
243 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF);
244 for (i = 0; i < n; ++i)
245 mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE);
246
247 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF);
248 if (txbuf)
249 for (i = 0; i < n; ++i)
250 mcfqspi_wr_qdr(mcfqspi, *txbuf++);
251 else
252 for (i = 0; i < count; ++i)
253 mcfqspi_wr_qdr(mcfqspi, 0);
254
255 count -= n;
256 if (count) {
257 u16 qwr = 0xf08;
258 mcfqspi_wr_qwr(mcfqspi, 0x700);
259 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
260
261 do {
262 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
263 mcfqspi_wr_qwr(mcfqspi, qwr);
264 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
265 if (rxbuf) {
266 mcfqspi_wr_qar(mcfqspi,
267 MCFQSPI_QAR_RXBUF + offset);
268 for (i = 0; i < 8; ++i)
269 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
270 }
271 n = min(count, 8u);
272 if (txbuf) {
273 mcfqspi_wr_qar(mcfqspi,
274 MCFQSPI_QAR_TXBUF + offset);
275 for (i = 0; i < n; ++i)
276 mcfqspi_wr_qdr(mcfqspi, *txbuf++);
277 }
278 qwr = (offset ? 0x808 : 0x000) + ((n - 1) << 8);
279 offset ^= 8;
280 count -= n;
281 } while (count);
282 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
283 mcfqspi_wr_qwr(mcfqspi, qwr);
284 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
285 if (rxbuf) {
286 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
287 for (i = 0; i < 8; ++i)
288 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
289 offset ^= 8;
290 }
291 } else {
292 mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8);
293 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
294 }
295 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
296 if (rxbuf) {
297 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
298 for (i = 0; i < n; ++i)
299 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
300 }
301 }
302
303 static int mcfqspi_transfer_one_message(struct spi_master *master,
304 struct spi_message *msg)
305 {
306 struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
307 struct spi_device *spi = msg->spi;
308 struct spi_transfer *t;
309 int status = 0;
310
311 list_for_each_entry(t, &msg->transfers, transfer_list) {
312 bool cs_high = spi->mode & SPI_CS_HIGH;
313 u16 qmr = MCFQSPI_QMR_MSTR;
314
315 qmr |= t->bits_per_word << 10;
316 if (spi->mode & SPI_CPHA)
317 qmr |= MCFQSPI_QMR_CPHA;
318 if (spi->mode & SPI_CPOL)
319 qmr |= MCFQSPI_QMR_CPOL;
320 if (t->speed_hz)
321 qmr |= mcfqspi_qmr_baud(t->speed_hz);
322 else
323 qmr |= mcfqspi_qmr_baud(spi->max_speed_hz);
324 mcfqspi_wr_qmr(mcfqspi, qmr);
325
326 mcfqspi_cs_select(mcfqspi, spi->chip_select, cs_high);
327
328 mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE);
329 if (t->bits_per_word == 8)
330 mcfqspi_transfer_msg8(mcfqspi, t->len, t->tx_buf,
331 t->rx_buf);
332 else
333 mcfqspi_transfer_msg16(mcfqspi, t->len / 2, t->tx_buf,
334 t->rx_buf);
335 mcfqspi_wr_qir(mcfqspi, 0);
336
337 if (t->delay_usecs)
338 udelay(t->delay_usecs);
339 if (t->cs_change) {
340 if (!list_is_last(&t->transfer_list, &msg->transfers))
341 mcfqspi_cs_deselect(mcfqspi, spi->chip_select,
342 cs_high);
343 } else {
344 if (list_is_last(&t->transfer_list, &msg->transfers))
345 mcfqspi_cs_deselect(mcfqspi, spi->chip_select,
346 cs_high);
347 }
348 msg->actual_length += t->len;
349 }
350 msg->status = status;
351 spi_finalize_current_message(master);
352
353 return status;
354
355 }
356
357 static int mcfqspi_setup(struct spi_device *spi)
358 {
359 if (spi->chip_select >= spi->master->num_chipselect) {
360 dev_dbg(&spi->dev, "%d chip select is out of range\n",
361 spi->chip_select);
362 return -EINVAL;
363 }
364
365 mcfqspi_cs_deselect(spi_master_get_devdata(spi->master),
366 spi->chip_select, spi->mode & SPI_CS_HIGH);
367
368 dev_dbg(&spi->dev,
369 "bits per word %d, chip select %d, speed %d KHz\n",
370 spi->bits_per_word, spi->chip_select,
371 (MCFQSPI_BUSCLK / mcfqspi_qmr_baud(spi->max_speed_hz))
372 / 1000);
373
374 return 0;
375 }
376
377 static int mcfqspi_probe(struct platform_device *pdev)
378 {
379 struct spi_master *master;
380 struct mcfqspi *mcfqspi;
381 struct resource *res;
382 struct mcfqspi_platform_data *pdata;
383 int status;
384
385 pdata = dev_get_platdata(&pdev->dev);
386 if (!pdata) {
387 dev_dbg(&pdev->dev, "platform data is missing\n");
388 return -ENOENT;
389 }
390
391 master = spi_alloc_master(&pdev->dev, sizeof(*mcfqspi));
392 if (master == NULL) {
393 dev_dbg(&pdev->dev, "spi_alloc_master failed\n");
394 return -ENOMEM;
395 }
396
397 mcfqspi = spi_master_get_devdata(master);
398
399 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
400 mcfqspi->iobase = devm_ioremap_resource(&pdev->dev, res);
401 if (IS_ERR(mcfqspi->iobase)) {
402 status = PTR_ERR(mcfqspi->iobase);
403 goto fail0;
404 }
405
406 mcfqspi->irq = platform_get_irq(pdev, 0);
407 if (mcfqspi->irq < 0) {
408 dev_dbg(&pdev->dev, "platform_get_irq failed\n");
409 status = -ENXIO;
410 goto fail0;
411 }
412
413 status = devm_request_irq(&pdev->dev, mcfqspi->irq, mcfqspi_irq_handler,
414 0, pdev->name, mcfqspi);
415 if (status) {
416 dev_dbg(&pdev->dev, "request_irq failed\n");
417 goto fail0;
418 }
419
420 mcfqspi->clk = devm_clk_get(&pdev->dev, "qspi_clk");
421 if (IS_ERR(mcfqspi->clk)) {
422 dev_dbg(&pdev->dev, "clk_get failed\n");
423 status = PTR_ERR(mcfqspi->clk);
424 goto fail0;
425 }
426 clk_enable(mcfqspi->clk);
427
428 master->bus_num = pdata->bus_num;
429 master->num_chipselect = pdata->num_chipselect;
430
431 mcfqspi->cs_control = pdata->cs_control;
432 status = mcfqspi_cs_setup(mcfqspi);
433 if (status) {
434 dev_dbg(&pdev->dev, "error initializing cs_control\n");
435 goto fail1;
436 }
437
438 init_waitqueue_head(&mcfqspi->waitq);
439 mcfqspi->dev = &pdev->dev;
440
441 master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA;
442 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16);
443 master->setup = mcfqspi_setup;
444 master->transfer_one_message = mcfqspi_transfer_one_message;
445 master->auto_runtime_pm = true;
446
447 platform_set_drvdata(pdev, master);
448
449 status = devm_spi_register_master(&pdev->dev, master);
450 if (status) {
451 dev_dbg(&pdev->dev, "spi_register_master failed\n");
452 goto fail2;
453 }
454 pm_runtime_enable(mcfqspi->dev);
455
456 dev_info(&pdev->dev, "Coldfire QSPI bus driver\n");
457
458 return 0;
459
460 fail2:
461 mcfqspi_cs_teardown(mcfqspi);
462 fail1:
463 clk_disable(mcfqspi->clk);
464 fail0:
465 spi_master_put(master);
466
467 dev_dbg(&pdev->dev, "Coldfire QSPI probe failed\n");
468
469 return status;
470 }
471
472 static int mcfqspi_remove(struct platform_device *pdev)
473 {
474 struct spi_master *master = platform_get_drvdata(pdev);
475 struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
476 struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
477
478 pm_runtime_disable(mcfqspi->dev);
479 /* disable the hardware (set the baud rate to 0) */
480 mcfqspi_wr_qmr(mcfqspi, MCFQSPI_QMR_MSTR);
481
482 mcfqspi_cs_teardown(mcfqspi);
483 clk_disable(mcfqspi->clk);
484
485 return 0;
486 }
487
488 #ifdef CONFIG_PM_SLEEP
489 static int mcfqspi_suspend(struct device *dev)
490 {
491 struct spi_master *master = dev_get_drvdata(dev);
492 struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
493
494 spi_master_suspend(master);
495
496 clk_disable(mcfqspi->clk);
497
498 return 0;
499 }
500
501 static int mcfqspi_resume(struct device *dev)
502 {
503 struct spi_master *master = dev_get_drvdata(dev);
504 struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
505
506 spi_master_resume(master);
507
508 clk_enable(mcfqspi->clk);
509
510 return 0;
511 }
512 #endif
513
514 #ifdef CONFIG_PM_RUNTIME
515 static int mcfqspi_runtime_suspend(struct device *dev)
516 {
517 struct mcfqspi *mcfqspi = dev_get_drvdata(dev);
518
519 clk_disable(mcfqspi->clk);
520
521 return 0;
522 }
523
524 static int mcfqspi_runtime_resume(struct device *dev)
525 {
526 struct mcfqspi *mcfqspi = dev_get_drvdata(dev);
527
528 clk_enable(mcfqspi->clk);
529
530 return 0;
531 }
532 #endif
533
534 static const struct dev_pm_ops mcfqspi_pm = {
535 SET_SYSTEM_SLEEP_PM_OPS(mcfqspi_suspend, mcfqspi_resume)
536 SET_RUNTIME_PM_OPS(mcfqspi_runtime_suspend, mcfqspi_runtime_resume,
537 NULL)
538 };
539
540 static struct platform_driver mcfqspi_driver = {
541 .driver.name = DRIVER_NAME,
542 .driver.owner = THIS_MODULE,
543 .driver.pm = &mcfqspi_pm,
544 .probe = mcfqspi_probe,
545 .remove = mcfqspi_remove,
546 };
547 module_platform_driver(mcfqspi_driver);
548
549 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
550 MODULE_DESCRIPTION("Coldfire QSPI Controller Driver");
551 MODULE_LICENSE("GPL");
552 MODULE_ALIAS("platform:" DRIVER_NAME);
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