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