1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21#include <linux/kernel.h>
22#include <linux/ioport.h>
23#include <linux/of.h>
24#include <linux/of_device.h>
25#include <linux/of_gpio.h>
26#include <linux/platform_device.h>
27#include <linux/delay.h>
28#include <linux/interrupt.h>
29#include <linux/dma-mapping.h>
30#include <linux/dmaengine.h>
31#include <linux/highmem.h>
32#include <linux/clk.h>
33#include <linux/err.h>
34#include <linux/completion.h>
35#include <linux/gpio.h>
36#include <linux/regulator/consumer.h>
37#include <linux/pm_runtime.h>
38#include <linux/module.h>
39#include <linux/stmp_device.h>
40#include <linux/spi/spi.h>
41#include <linux/spi/mxs-spi.h>
42
43#define DRIVER_NAME "mxs-spi"
44
45
46#define SSP_TIMEOUT 10000
47
48#define SG_MAXLEN 0xff00
49
50
51
52
53
54#define TXRX_WRITE (1<<0)
55#define TXRX_DEASSERT_CS (1<<1)
56
57struct mxs_spi {
58 struct mxs_ssp ssp;
59 struct completion c;
60 unsigned int sck;
61};
62
63static int mxs_spi_setup_transfer(struct spi_device *dev,
64 const struct spi_transfer *t)
65{
66 struct mxs_spi *spi = spi_master_get_devdata(dev->master);
67 struct mxs_ssp *ssp = &spi->ssp;
68 const unsigned int hz = min(dev->max_speed_hz, t->speed_hz);
69
70 if (hz == 0) {
71 dev_err(&dev->dev, "SPI clock rate of zero not allowed\n");
72 return -EINVAL;
73 }
74
75 if (hz != spi->sck) {
76 mxs_ssp_set_clk_rate(ssp, hz);
77
78
79
80
81
82 spi->sck = hz;
83
84
85
86
87 }
88
89 writel(BM_SSP_CTRL0_LOCK_CS,
90 ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
91
92 writel(BF_SSP_CTRL1_SSP_MODE(BV_SSP_CTRL1_SSP_MODE__SPI) |
93 BF_SSP_CTRL1_WORD_LENGTH(BV_SSP_CTRL1_WORD_LENGTH__EIGHT_BITS) |
94 ((dev->mode & SPI_CPOL) ? BM_SSP_CTRL1_POLARITY : 0) |
95 ((dev->mode & SPI_CPHA) ? BM_SSP_CTRL1_PHASE : 0),
96 ssp->base + HW_SSP_CTRL1(ssp));
97
98 writel(0x0, ssp->base + HW_SSP_CMD0);
99 writel(0x0, ssp->base + HW_SSP_CMD1);
100
101 return 0;
102}
103
104static u32 mxs_spi_cs_to_reg(unsigned cs)
105{
106 u32 select = 0;
107
108
109
110
111
112
113
114
115
116 if (cs & 1)
117 select |= BM_SSP_CTRL0_WAIT_FOR_CMD;
118 if (cs & 2)
119 select |= BM_SSP_CTRL0_WAIT_FOR_IRQ;
120
121 return select;
122}
123
124static int mxs_ssp_wait(struct mxs_spi *spi, int offset, int mask, bool set)
125{
126 const unsigned long timeout = jiffies + msecs_to_jiffies(SSP_TIMEOUT);
127 struct mxs_ssp *ssp = &spi->ssp;
128 u32 reg;
129
130 do {
131 reg = readl_relaxed(ssp->base + offset);
132
133 if (!set)
134 reg = ~reg;
135
136 reg &= mask;
137
138 if (reg == mask)
139 return 0;
140 } while (time_before(jiffies, timeout));
141
142 return -ETIMEDOUT;
143}
144
145static void mxs_ssp_dma_irq_callback(void *param)
146{
147 struct mxs_spi *spi = param;
148
149 complete(&spi->c);
150}
151
152static irqreturn_t mxs_ssp_irq_handler(int irq, void *dev_id)
153{
154 struct mxs_ssp *ssp = dev_id;
155
156 dev_err(ssp->dev, "%s[%i] CTRL1=%08x STATUS=%08x\n",
157 __func__, __LINE__,
158 readl(ssp->base + HW_SSP_CTRL1(ssp)),
159 readl(ssp->base + HW_SSP_STATUS(ssp)));
160 return IRQ_HANDLED;
161}
162
163static int mxs_spi_txrx_dma(struct mxs_spi *spi,
164 unsigned char *buf, int len,
165 unsigned int flags)
166{
167 struct mxs_ssp *ssp = &spi->ssp;
168 struct dma_async_tx_descriptor *desc = NULL;
169 const bool vmalloced_buf = is_vmalloc_addr(buf);
170 const int desc_len = vmalloced_buf ? PAGE_SIZE : SG_MAXLEN;
171 const int sgs = DIV_ROUND_UP(len, desc_len);
172 int sg_count;
173 int min, ret;
174 u32 ctrl0;
175 struct page *vm_page;
176 struct {
177 u32 pio[4];
178 struct scatterlist sg;
179 } *dma_xfer;
180
181 if (!len)
182 return -EINVAL;
183
184 dma_xfer = kcalloc(sgs, sizeof(*dma_xfer), GFP_KERNEL);
185 if (!dma_xfer)
186 return -ENOMEM;
187
188 reinit_completion(&spi->c);
189
190
191 ctrl0 = readl(ssp->base + HW_SSP_CTRL0);
192 ctrl0 &= ~(BM_SSP_CTRL0_XFER_COUNT | BM_SSP_CTRL0_IGNORE_CRC |
193 BM_SSP_CTRL0_READ);
194 ctrl0 |= BM_SSP_CTRL0_DATA_XFER;
195
196 if (!(flags & TXRX_WRITE))
197 ctrl0 |= BM_SSP_CTRL0_READ;
198
199
200 for (sg_count = 0; sg_count < sgs; sg_count++) {
201
202 min = min(len, desc_len);
203
204
205
206
207
208 if ((sg_count + 1 == sgs) && (flags & TXRX_DEASSERT_CS))
209 ctrl0 |= BM_SSP_CTRL0_IGNORE_CRC;
210
211 if (ssp->devid == IMX23_SSP) {
212 ctrl0 &= ~BM_SSP_CTRL0_XFER_COUNT;
213 ctrl0 |= min;
214 }
215
216 dma_xfer[sg_count].pio[0] = ctrl0;
217 dma_xfer[sg_count].pio[3] = min;
218
219 if (vmalloced_buf) {
220 vm_page = vmalloc_to_page(buf);
221 if (!vm_page) {
222 ret = -ENOMEM;
223 goto err_vmalloc;
224 }
225
226 sg_init_table(&dma_xfer[sg_count].sg, 1);
227 sg_set_page(&dma_xfer[sg_count].sg, vm_page,
228 min, offset_in_page(buf));
229 } else {
230 sg_init_one(&dma_xfer[sg_count].sg, buf, min);
231 }
232
233 ret = dma_map_sg(ssp->dev, &dma_xfer[sg_count].sg, 1,
234 (flags & TXRX_WRITE) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
235
236 len -= min;
237 buf += min;
238
239
240 desc = dmaengine_prep_slave_sg(ssp->dmach,
241 (struct scatterlist *)dma_xfer[sg_count].pio,
242 (ssp->devid == IMX23_SSP) ? 1 : 4,
243 DMA_TRANS_NONE,
244 sg_count ? DMA_PREP_INTERRUPT : 0);
245 if (!desc) {
246 dev_err(ssp->dev,
247 "Failed to get PIO reg. write descriptor.\n");
248 ret = -EINVAL;
249 goto err_mapped;
250 }
251
252 desc = dmaengine_prep_slave_sg(ssp->dmach,
253 &dma_xfer[sg_count].sg, 1,
254 (flags & TXRX_WRITE) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
255 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
256
257 if (!desc) {
258 dev_err(ssp->dev,
259 "Failed to get DMA data write descriptor.\n");
260 ret = -EINVAL;
261 goto err_mapped;
262 }
263 }
264
265
266
267
268
269 desc->callback = mxs_ssp_dma_irq_callback;
270 desc->callback_param = spi;
271
272
273 dmaengine_submit(desc);
274 dma_async_issue_pending(ssp->dmach);
275
276 if (!wait_for_completion_timeout(&spi->c,
277 msecs_to_jiffies(SSP_TIMEOUT))) {
278 dev_err(ssp->dev, "DMA transfer timeout\n");
279 ret = -ETIMEDOUT;
280 dmaengine_terminate_all(ssp->dmach);
281 goto err_vmalloc;
282 }
283
284 ret = 0;
285
286err_vmalloc:
287 while (--sg_count >= 0) {
288err_mapped:
289 dma_unmap_sg(ssp->dev, &dma_xfer[sg_count].sg, 1,
290 (flags & TXRX_WRITE) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
291 }
292
293 kfree(dma_xfer);
294
295 return ret;
296}
297
298static int mxs_spi_txrx_pio(struct mxs_spi *spi,
299 unsigned char *buf, int len,
300 unsigned int flags)
301{
302 struct mxs_ssp *ssp = &spi->ssp;
303
304 writel(BM_SSP_CTRL0_IGNORE_CRC,
305 ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR);
306
307 while (len--) {
308 if (len == 0 && (flags & TXRX_DEASSERT_CS))
309 writel(BM_SSP_CTRL0_IGNORE_CRC,
310 ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
311
312 if (ssp->devid == IMX23_SSP) {
313 writel(BM_SSP_CTRL0_XFER_COUNT,
314 ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR);
315 writel(1,
316 ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
317 } else {
318 writel(1, ssp->base + HW_SSP_XFER_SIZE);
319 }
320
321 if (flags & TXRX_WRITE)
322 writel(BM_SSP_CTRL0_READ,
323 ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR);
324 else
325 writel(BM_SSP_CTRL0_READ,
326 ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
327
328 writel(BM_SSP_CTRL0_RUN,
329 ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
330
331 if (mxs_ssp_wait(spi, HW_SSP_CTRL0, BM_SSP_CTRL0_RUN, 1))
332 return -ETIMEDOUT;
333
334 if (flags & TXRX_WRITE)
335 writel(*buf, ssp->base + HW_SSP_DATA(ssp));
336
337 writel(BM_SSP_CTRL0_DATA_XFER,
338 ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
339
340 if (!(flags & TXRX_WRITE)) {
341 if (mxs_ssp_wait(spi, HW_SSP_STATUS(ssp),
342 BM_SSP_STATUS_FIFO_EMPTY, 0))
343 return -ETIMEDOUT;
344
345 *buf = (readl(ssp->base + HW_SSP_DATA(ssp)) & 0xff);
346 }
347
348 if (mxs_ssp_wait(spi, HW_SSP_CTRL0, BM_SSP_CTRL0_RUN, 0))
349 return -ETIMEDOUT;
350
351 buf++;
352 }
353
354 if (len <= 0)
355 return 0;
356
357 return -ETIMEDOUT;
358}
359
360static int mxs_spi_transfer_one(struct spi_master *master,
361 struct spi_message *m)
362{
363 struct mxs_spi *spi = spi_master_get_devdata(master);
364 struct mxs_ssp *ssp = &spi->ssp;
365 struct spi_transfer *t;
366 unsigned int flag;
367 int status = 0;
368
369
370 writel(BM_SSP_CTRL0_WAIT_FOR_CMD | BM_SSP_CTRL0_WAIT_FOR_IRQ,
371 ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR);
372 writel(mxs_spi_cs_to_reg(m->spi->chip_select),
373 ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
374
375 list_for_each_entry(t, &m->transfers, transfer_list) {
376
377 status = mxs_spi_setup_transfer(m->spi, t);
378 if (status)
379 break;
380
381
382 flag = (&t->transfer_list == m->transfers.prev) ^ t->cs_change ?
383 TXRX_DEASSERT_CS : 0;
384
385
386
387
388
389
390
391
392
393
394 if (t->len < 32) {
395 writel(BM_SSP_CTRL1_DMA_ENABLE,
396 ssp->base + HW_SSP_CTRL1(ssp) +
397 STMP_OFFSET_REG_CLR);
398
399 if (t->tx_buf)
400 status = mxs_spi_txrx_pio(spi,
401 (void *)t->tx_buf,
402 t->len, flag | TXRX_WRITE);
403 if (t->rx_buf)
404 status = mxs_spi_txrx_pio(spi,
405 t->rx_buf, t->len,
406 flag);
407 } else {
408 writel(BM_SSP_CTRL1_DMA_ENABLE,
409 ssp->base + HW_SSP_CTRL1(ssp) +
410 STMP_OFFSET_REG_SET);
411
412 if (t->tx_buf)
413 status = mxs_spi_txrx_dma(spi,
414 (void *)t->tx_buf, t->len,
415 flag | TXRX_WRITE);
416 if (t->rx_buf)
417 status = mxs_spi_txrx_dma(spi,
418 t->rx_buf, t->len,
419 flag);
420 }
421
422 if (status) {
423 stmp_reset_block(ssp->base);
424 break;
425 }
426
427 m->actual_length += t->len;
428 }
429
430 m->status = status;
431 spi_finalize_current_message(master);
432
433 return status;
434}
435
436static int mxs_spi_runtime_suspend(struct device *dev)
437{
438 struct spi_master *master = dev_get_drvdata(dev);
439 struct mxs_spi *spi = spi_master_get_devdata(master);
440 struct mxs_ssp *ssp = &spi->ssp;
441 int ret;
442
443 clk_disable_unprepare(ssp->clk);
444
445 ret = pinctrl_pm_select_idle_state(dev);
446 if (ret) {
447 int ret2 = clk_prepare_enable(ssp->clk);
448
449 if (ret2)
450 dev_warn(dev, "Failed to reenable clock after failing pinctrl request (pinctrl: %d, clk: %d)\n",
451 ret, ret2);
452 }
453
454 return ret;
455}
456
457static int mxs_spi_runtime_resume(struct device *dev)
458{
459 struct spi_master *master = dev_get_drvdata(dev);
460 struct mxs_spi *spi = spi_master_get_devdata(master);
461 struct mxs_ssp *ssp = &spi->ssp;
462 int ret;
463
464 ret = pinctrl_pm_select_default_state(dev);
465 if (ret)
466 return ret;
467
468 ret = clk_prepare_enable(ssp->clk);
469 if (ret)
470 pinctrl_pm_select_idle_state(dev);
471
472 return ret;
473}
474
475static int __maybe_unused mxs_spi_suspend(struct device *dev)
476{
477 struct spi_master *master = dev_get_drvdata(dev);
478 int ret;
479
480 ret = spi_master_suspend(master);
481 if (ret)
482 return ret;
483
484 if (!pm_runtime_suspended(dev))
485 return mxs_spi_runtime_suspend(dev);
486 else
487 return 0;
488}
489
490static int __maybe_unused mxs_spi_resume(struct device *dev)
491{
492 struct spi_master *master = dev_get_drvdata(dev);
493 int ret;
494
495 if (!pm_runtime_suspended(dev))
496 ret = mxs_spi_runtime_resume(dev);
497 else
498 ret = 0;
499 if (ret)
500 return ret;
501
502 ret = spi_master_resume(master);
503 if (ret < 0 && !pm_runtime_suspended(dev))
504 mxs_spi_runtime_suspend(dev);
505
506 return ret;
507}
508
509static const struct dev_pm_ops mxs_spi_pm = {
510 SET_RUNTIME_PM_OPS(mxs_spi_runtime_suspend,
511 mxs_spi_runtime_resume, NULL)
512 SET_SYSTEM_SLEEP_PM_OPS(mxs_spi_suspend, mxs_spi_resume)
513};
514
515static const struct of_device_id mxs_spi_dt_ids[] = {
516 { .compatible = "fsl,imx23-spi", .data = (void *) IMX23_SSP, },
517 { .compatible = "fsl,imx28-spi", .data = (void *) IMX28_SSP, },
518 { }
519};
520MODULE_DEVICE_TABLE(of, mxs_spi_dt_ids);
521
522static int mxs_spi_probe(struct platform_device *pdev)
523{
524 const struct of_device_id *of_id =
525 of_match_device(mxs_spi_dt_ids, &pdev->dev);
526 struct device_node *np = pdev->dev.of_node;
527 struct spi_master *master;
528 struct mxs_spi *spi;
529 struct mxs_ssp *ssp;
530 struct resource *iores;
531 struct clk *clk;
532 void __iomem *base;
533 int devid, clk_freq;
534 int ret = 0, irq_err;
535
536
537
538
539
540
541 const int clk_freq_default = 160000000;
542
543 iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
544 irq_err = platform_get_irq(pdev, 0);
545 if (irq_err < 0)
546 return irq_err;
547
548 base = devm_ioremap_resource(&pdev->dev, iores);
549 if (IS_ERR(base))
550 return PTR_ERR(base);
551
552 clk = devm_clk_get(&pdev->dev, NULL);
553 if (IS_ERR(clk))
554 return PTR_ERR(clk);
555
556 devid = (enum mxs_ssp_id) of_id->data;
557 ret = of_property_read_u32(np, "clock-frequency",
558 &clk_freq);
559 if (ret)
560 clk_freq = clk_freq_default;
561
562 master = spi_alloc_master(&pdev->dev, sizeof(*spi));
563 if (!master)
564 return -ENOMEM;
565
566 platform_set_drvdata(pdev, master);
567
568 master->transfer_one_message = mxs_spi_transfer_one;
569 master->bits_per_word_mask = SPI_BPW_MASK(8);
570 master->mode_bits = SPI_CPOL | SPI_CPHA;
571 master->num_chipselect = 3;
572 master->dev.of_node = np;
573 master->flags = SPI_MASTER_HALF_DUPLEX;
574 master->auto_runtime_pm = true;
575
576 spi = spi_master_get_devdata(master);
577 ssp = &spi->ssp;
578 ssp->dev = &pdev->dev;
579 ssp->clk = clk;
580 ssp->base = base;
581 ssp->devid = devid;
582
583 init_completion(&spi->c);
584
585 ret = devm_request_irq(&pdev->dev, irq_err, mxs_ssp_irq_handler, 0,
586 dev_name(&pdev->dev), ssp);
587 if (ret)
588 goto out_master_free;
589
590 ssp->dmach = dma_request_slave_channel(&pdev->dev, "rx-tx");
591 if (!ssp->dmach) {
592 dev_err(ssp->dev, "Failed to request DMA\n");
593 ret = -ENODEV;
594 goto out_master_free;
595 }
596
597 pm_runtime_enable(ssp->dev);
598 if (!pm_runtime_enabled(ssp->dev)) {
599 ret = mxs_spi_runtime_resume(ssp->dev);
600 if (ret < 0) {
601 dev_err(ssp->dev, "runtime resume failed\n");
602 goto out_dma_release;
603 }
604 }
605
606 ret = pm_runtime_get_sync(ssp->dev);
607 if (ret < 0) {
608 dev_err(ssp->dev, "runtime_get_sync failed\n");
609 goto out_pm_runtime_disable;
610 }
611
612 clk_set_rate(ssp->clk, clk_freq);
613
614 ret = stmp_reset_block(ssp->base);
615 if (ret)
616 goto out_pm_runtime_put;
617
618 ret = devm_spi_register_master(&pdev->dev, master);
619 if (ret) {
620 dev_err(&pdev->dev, "Cannot register SPI master, %d\n", ret);
621 goto out_pm_runtime_put;
622 }
623
624 pm_runtime_put(ssp->dev);
625
626 return 0;
627
628out_pm_runtime_put:
629 pm_runtime_put(ssp->dev);
630out_pm_runtime_disable:
631 pm_runtime_disable(ssp->dev);
632out_dma_release:
633 dma_release_channel(ssp->dmach);
634out_master_free:
635 spi_master_put(master);
636 return ret;
637}
638
639static int mxs_spi_remove(struct platform_device *pdev)
640{
641 struct spi_master *master;
642 struct mxs_spi *spi;
643 struct mxs_ssp *ssp;
644
645 master = platform_get_drvdata(pdev);
646 spi = spi_master_get_devdata(master);
647 ssp = &spi->ssp;
648
649 pm_runtime_disable(&pdev->dev);
650 if (!pm_runtime_status_suspended(&pdev->dev))
651 mxs_spi_runtime_suspend(&pdev->dev);
652
653 dma_release_channel(ssp->dmach);
654
655 return 0;
656}
657
658static struct platform_driver mxs_spi_driver = {
659 .probe = mxs_spi_probe,
660 .remove = mxs_spi_remove,
661 .driver = {
662 .name = DRIVER_NAME,
663 .of_match_table = mxs_spi_dt_ids,
664 .pm = &mxs_spi_pm,
665 },
666};
667
668module_platform_driver(mxs_spi_driver);
669
670MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
671MODULE_DESCRIPTION("MXS SPI master driver");
672MODULE_LICENSE("GPL");
673MODULE_ALIAS("platform:mxs-spi");
674
