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1// SPDX-License-Identifier: GPL-2.0+
2//
3// Freescale i.MX7ULP LPSPI driver
4//
5// Copyright 2016 Freescale Semiconductor, Inc.
6// Copyright 2018 NXP Semiconductors
7
8#include <linux/clk.h>
9#include <linux/completion.h>
10#include <linux/delay.h>
11#include <linux/dmaengine.h>
12#include <linux/dma-mapping.h>
13#include <linux/err.h>
14#include <linux/interrupt.h>
15#include <linux/io.h>
16#include <linux/irq.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/of.h>
20#include <linux/of_device.h>
21#include <linux/pinctrl/consumer.h>
22#include <linux/platform_device.h>
23#include <linux/dma/imx-dma.h>
24#include <linux/pm_runtime.h>
25#include <linux/slab.h>
26#include <linux/spi/spi.h>
27#include <linux/spi/spi_bitbang.h>
28#include <linux/types.h>
29
30#define DRIVER_NAME "fsl_lpspi"
31
32#define FSL_LPSPI_RPM_TIMEOUT 50 /* 50ms */
33
34/* The maximum bytes that edma can transfer once.*/
35#define FSL_LPSPI_MAX_EDMA_BYTES ((1 << 15) - 1)
36
37/* i.MX7ULP LPSPI registers */
38#define IMX7ULP_VERID 0x0
39#define IMX7ULP_PARAM 0x4
40#define IMX7ULP_CR 0x10
41#define IMX7ULP_SR 0x14
42#define IMX7ULP_IER 0x18
43#define IMX7ULP_DER 0x1c
44#define IMX7ULP_CFGR0 0x20
45#define IMX7ULP_CFGR1 0x24
46#define IMX7ULP_DMR0 0x30
47#define IMX7ULP_DMR1 0x34
48#define IMX7ULP_CCR 0x40
49#define IMX7ULP_FCR 0x58
50#define IMX7ULP_FSR 0x5c
51#define IMX7ULP_TCR 0x60
52#define IMX7ULP_TDR 0x64
53#define IMX7ULP_RSR 0x70
54#define IMX7ULP_RDR 0x74
55
56/* General control register field define */
57#define CR_RRF BIT(9)
58#define CR_RTF BIT(8)
59#define CR_RST BIT(1)
60#define CR_MEN BIT(0)
61#define SR_MBF BIT(24)
62#define SR_TCF BIT(10)
63#define SR_FCF BIT(9)
64#define SR_RDF BIT(1)
65#define SR_TDF BIT(0)
66#define IER_TCIE BIT(10)
67#define IER_FCIE BIT(9)
68#define IER_RDIE BIT(1)
69#define IER_TDIE BIT(0)
70#define DER_RDDE BIT(1)
71#define DER_TDDE BIT(0)
72#define CFGR1_PCSCFG BIT(27)
73#define CFGR1_PINCFG (BIT(24)|BIT(25))
74#define CFGR1_PCSPOL BIT(8)
75#define CFGR1_NOSTALL BIT(3)
76#define CFGR1_MASTER BIT(0)
77#define FSR_TXCOUNT (0xFF)
78#define RSR_RXEMPTY BIT(1)
79#define TCR_CPOL BIT(31)
80#define TCR_CPHA BIT(30)
81#define TCR_CONT BIT(21)
82#define TCR_CONTC BIT(20)
83#define TCR_RXMSK BIT(19)
84#define TCR_TXMSK BIT(18)
85
86struct lpspi_config {
87 u8 bpw;
88 u8 chip_select;
89 u8 prescale;
90 u16 mode;
91 u32 speed_hz;
92};
93
94struct fsl_lpspi_data {
95 struct device *dev;
96 void __iomem *base;
97 unsigned long base_phys;
98 struct clk *clk_ipg;
99 struct clk *clk_per;
100 bool is_slave;
101 u32 num_cs;
102 bool is_only_cs1;
103 bool is_first_byte;
104
105 void *rx_buf;
106 const void *tx_buf;
107 void (*tx)(struct fsl_lpspi_data *);
108 void (*rx)(struct fsl_lpspi_data *);
109
110 u32 remain;
111 u8 watermark;
112 u8 txfifosize;
113 u8 rxfifosize;
114
115 struct lpspi_config config;
116 struct completion xfer_done;
117
118 bool slave_aborted;
119
120 /* DMA */
121 bool usedma;
122 struct completion dma_rx_completion;
123 struct completion dma_tx_completion;
124};
125
126static const struct of_device_id fsl_lpspi_dt_ids[] = {
127 { .compatible = "fsl,imx7ulp-spi", },
128 { /* sentinel */ }
129};
130MODULE_DEVICE_TABLE(of, fsl_lpspi_dt_ids);
131
132#define LPSPI_BUF_RX(type) \
133static void fsl_lpspi_buf_rx_##type(struct fsl_lpspi_data *fsl_lpspi) \
134{ \
135 unsigned int val = readl(fsl_lpspi->base + IMX7ULP_RDR); \
136 \
137 if (fsl_lpspi->rx_buf) { \
138 *(type *)fsl_lpspi->rx_buf = val; \
139 fsl_lpspi->rx_buf += sizeof(type); \
140 } \
141}
142
143#define LPSPI_BUF_TX(type) \
144static void fsl_lpspi_buf_tx_##type(struct fsl_lpspi_data *fsl_lpspi) \
145{ \
146 type val = 0; \
147 \
148 if (fsl_lpspi->tx_buf) { \
149 val = *(type *)fsl_lpspi->tx_buf; \
150 fsl_lpspi->tx_buf += sizeof(type); \
151 } \
152 \
153 fsl_lpspi->remain -= sizeof(type); \
154 writel(val, fsl_lpspi->base + IMX7ULP_TDR); \
155}
156
157LPSPI_BUF_RX(u8)
158LPSPI_BUF_TX(u8)
159LPSPI_BUF_RX(u16)
160LPSPI_BUF_TX(u16)
161LPSPI_BUF_RX(u32)
162LPSPI_BUF_TX(u32)
163
164static void fsl_lpspi_intctrl(struct fsl_lpspi_data *fsl_lpspi,
165 unsigned int enable)
166{
167 writel(enable, fsl_lpspi->base + IMX7ULP_IER);
168}
169
170static int fsl_lpspi_bytes_per_word(const int bpw)
171{
172 return DIV_ROUND_UP(bpw, BITS_PER_BYTE);
173}
174
175static bool fsl_lpspi_can_dma(struct spi_controller *controller,
176 struct spi_device *spi,
177 struct spi_transfer *transfer)
178{
179 unsigned int bytes_per_word;
180
181 if (!controller->dma_rx)
182 return false;
183
184 bytes_per_word = fsl_lpspi_bytes_per_word(transfer->bits_per_word);
185
186 switch (bytes_per_word) {
187 case 1:
188 case 2:
189 case 4:
190 break;
191 default:
192 return false;
193 }
194
195 return true;
196}
197
198static int lpspi_prepare_xfer_hardware(struct spi_controller *controller)
199{
200 struct fsl_lpspi_data *fsl_lpspi =
201 spi_controller_get_devdata(controller);
202 int ret;
203
204 ret = pm_runtime_resume_and_get(fsl_lpspi->dev);
205 if (ret < 0) {
206 dev_err(fsl_lpspi->dev, "failed to enable clock\n");
207 return ret;
208 }
209
210 return 0;
211}
212
213static int lpspi_unprepare_xfer_hardware(struct spi_controller *controller)
214{
215 struct fsl_lpspi_data *fsl_lpspi =
216 spi_controller_get_devdata(controller);
217
218 pm_runtime_mark_last_busy(fsl_lpspi->dev);
219 pm_runtime_put_autosuspend(fsl_lpspi->dev);
220
221 return 0;
222}
223
224static void fsl_lpspi_write_tx_fifo(struct fsl_lpspi_data *fsl_lpspi)
225{
226 u8 txfifo_cnt;
227 u32 temp;
228
229 txfifo_cnt = readl(fsl_lpspi->base + IMX7ULP_FSR) & 0xff;
230
231 while (txfifo_cnt < fsl_lpspi->txfifosize) {
232 if (!fsl_lpspi->remain)
233 break;
234 fsl_lpspi->tx(fsl_lpspi);
235 txfifo_cnt++;
236 }
237
238 if (txfifo_cnt < fsl_lpspi->txfifosize) {
239 if (!fsl_lpspi->is_slave) {
240 temp = readl(fsl_lpspi->base + IMX7ULP_TCR);
241 temp &= ~TCR_CONTC;
242 writel(temp, fsl_lpspi->base + IMX7ULP_TCR);
243 }
244
245 fsl_lpspi_intctrl(fsl_lpspi, IER_FCIE);
246 } else
247 fsl_lpspi_intctrl(fsl_lpspi, IER_TDIE);
248}
249
250static void fsl_lpspi_read_rx_fifo(struct fsl_lpspi_data *fsl_lpspi)
251{
252 while (!(readl(fsl_lpspi->base + IMX7ULP_RSR) & RSR_RXEMPTY))
253 fsl_lpspi->rx(fsl_lpspi);
254}
255
256static void fsl_lpspi_set_cmd(struct fsl_lpspi_data *fsl_lpspi)
257{
258 u32 temp = 0;
259
260 temp |= fsl_lpspi->config.bpw - 1;
261 temp |= (fsl_lpspi->config.mode & 0x3) << 30;
262 temp |= (fsl_lpspi->config.chip_select & 0x3) << 24;
263 if (!fsl_lpspi->is_slave) {
264 temp |= fsl_lpspi->config.prescale << 27;
265 /*
266 * Set TCR_CONT will keep SS asserted after current transfer.
267 * For the first transfer, clear TCR_CONTC to assert SS.
268 * For subsequent transfer, set TCR_CONTC to keep SS asserted.
269 */
270 if (!fsl_lpspi->usedma) {
271 temp |= TCR_CONT;
272 if (fsl_lpspi->is_first_byte)
273 temp &= ~TCR_CONTC;
274 else
275 temp |= TCR_CONTC;
276 }
277 }
278 writel(temp, fsl_lpspi->base + IMX7ULP_TCR);
279
280 dev_dbg(fsl_lpspi->dev, "TCR=0x%x\n", temp);
281}
282
283static void fsl_lpspi_set_watermark(struct fsl_lpspi_data *fsl_lpspi)
284{
285 u32 temp;
286
287 if (!fsl_lpspi->usedma)
288 temp = fsl_lpspi->watermark >> 1 |
289 (fsl_lpspi->watermark >> 1) << 16;
290 else
291 temp = fsl_lpspi->watermark >> 1;
292
293 writel(temp, fsl_lpspi->base + IMX7ULP_FCR);
294
295 dev_dbg(fsl_lpspi->dev, "FCR=0x%x\n", temp);
296}
297
298static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data *fsl_lpspi)
299{
300 struct lpspi_config config = fsl_lpspi->config;
301 unsigned int perclk_rate, scldiv;
302 u8 prescale;
303
304 perclk_rate = clk_get_rate(fsl_lpspi->clk_per);
305
306 if (config.speed_hz > perclk_rate / 2) {
307 dev_err(fsl_lpspi->dev,
308 "per-clk should be at least two times of transfer speed");
309 return -EINVAL;
310 }
311
312 for (prescale = 0; prescale < 8; prescale++) {
313 scldiv = perclk_rate / config.speed_hz / (1 << prescale) - 2;
314 if (scldiv < 256) {
315 fsl_lpspi->config.prescale = prescale;
316 break;
317 }
318 }
319
320 if (scldiv >= 256)
321 return -EINVAL;
322
323 writel(scldiv | (scldiv << 8) | ((scldiv >> 1) << 16),
324 fsl_lpspi->base + IMX7ULP_CCR);
325
326 dev_dbg(fsl_lpspi->dev, "perclk=%d, speed=%d, prescale=%d, scldiv=%d\n",
327 perclk_rate, config.speed_hz, prescale, scldiv);
328
329 return 0;
330}
331
332static int fsl_lpspi_dma_configure(struct spi_controller *controller)
333{
334 int ret;
335 enum dma_slave_buswidth buswidth;
336 struct dma_slave_config rx = {}, tx = {};
337 struct fsl_lpspi_data *fsl_lpspi =
338 spi_controller_get_devdata(controller);
339
340 switch (fsl_lpspi_bytes_per_word(fsl_lpspi->config.bpw)) {
341 case 4:
342 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
343 break;
344 case 2:
345 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
346 break;
347 case 1:
348 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
349 break;
350 default:
351 return -EINVAL;
352 }
353
354 tx.direction = DMA_MEM_TO_DEV;
355 tx.dst_addr = fsl_lpspi->base_phys + IMX7ULP_TDR;
356 tx.dst_addr_width = buswidth;
357 tx.dst_maxburst = 1;
358 ret = dmaengine_slave_config(controller->dma_tx, &tx);
359 if (ret) {
360 dev_err(fsl_lpspi->dev, "TX dma configuration failed with %d\n",
361 ret);
362 return ret;
363 }
364
365 rx.direction = DMA_DEV_TO_MEM;
366 rx.src_addr = fsl_lpspi->base_phys + IMX7ULP_RDR;
367 rx.src_addr_width = buswidth;
368 rx.src_maxburst = 1;
369 ret = dmaengine_slave_config(controller->dma_rx, &rx);
370 if (ret) {
371 dev_err(fsl_lpspi->dev, "RX dma configuration failed with %d\n",
372 ret);
373 return ret;
374 }
375
376 return 0;
377}
378
379static int fsl_lpspi_config(struct fsl_lpspi_data *fsl_lpspi)
380{
381 u32 temp;
382 int ret;
383
384 if (!fsl_lpspi->is_slave) {
385 ret = fsl_lpspi_set_bitrate(fsl_lpspi);
386 if (ret)
387 return ret;
388 }
389
390 fsl_lpspi_set_watermark(fsl_lpspi);
391
392 if (!fsl_lpspi->is_slave)
393 temp = CFGR1_MASTER;
394 else
395 temp = CFGR1_PINCFG;
396 if (fsl_lpspi->config.mode & SPI_CS_HIGH)
397 temp |= CFGR1_PCSPOL;
398 writel(temp, fsl_lpspi->base + IMX7ULP_CFGR1);
399
400 temp = readl(fsl_lpspi->base + IMX7ULP_CR);
401 temp |= CR_RRF | CR_RTF | CR_MEN;
402 writel(temp, fsl_lpspi->base + IMX7ULP_CR);
403
404 temp = 0;
405 if (fsl_lpspi->usedma)
406 temp = DER_TDDE | DER_RDDE;
407 writel(temp, fsl_lpspi->base + IMX7ULP_DER);
408
409 return 0;
410}
411
412static int fsl_lpspi_setup_transfer(struct spi_controller *controller,
413 struct spi_device *spi,
414 struct spi_transfer *t)
415{
416 struct fsl_lpspi_data *fsl_lpspi =
417 spi_controller_get_devdata(spi->controller);
418
419 if (t == NULL)
420 return -EINVAL;
421
422 fsl_lpspi->config.mode = spi->mode;
423 fsl_lpspi->config.bpw = t->bits_per_word;
424 fsl_lpspi->config.speed_hz = t->speed_hz;
425 if (fsl_lpspi->is_only_cs1)
426 fsl_lpspi->config.chip_select = 1;
427 else
428 fsl_lpspi->config.chip_select = spi->chip_select;
429
430 if (!fsl_lpspi->config.speed_hz)
431 fsl_lpspi->config.speed_hz = spi->max_speed_hz;
432 if (!fsl_lpspi->config.bpw)
433 fsl_lpspi->config.bpw = spi->bits_per_word;
434
435 /* Initialize the functions for transfer */
436 if (fsl_lpspi->config.bpw <= 8) {
437 fsl_lpspi->rx = fsl_lpspi_buf_rx_u8;
438 fsl_lpspi->tx = fsl_lpspi_buf_tx_u8;
439 } else if (fsl_lpspi->config.bpw <= 16) {
440 fsl_lpspi->rx = fsl_lpspi_buf_rx_u16;
441 fsl_lpspi->tx = fsl_lpspi_buf_tx_u16;
442 } else {
443 fsl_lpspi->rx = fsl_lpspi_buf_rx_u32;
444 fsl_lpspi->tx = fsl_lpspi_buf_tx_u32;
445 }
446
447 if (t->len <= fsl_lpspi->txfifosize)
448 fsl_lpspi->watermark = t->len;
449 else
450 fsl_lpspi->watermark = fsl_lpspi->txfifosize;
451
452 if (fsl_lpspi_can_dma(controller, spi, t))
453 fsl_lpspi->usedma = true;
454 else
455 fsl_lpspi->usedma = false;
456
457 return fsl_lpspi_config(fsl_lpspi);
458}
459
460static int fsl_lpspi_slave_abort(struct spi_controller *controller)
461{
462 struct fsl_lpspi_data *fsl_lpspi =
463 spi_controller_get_devdata(controller);
464
465 fsl_lpspi->slave_aborted = true;
466 if (!fsl_lpspi->usedma)
467 complete(&fsl_lpspi->xfer_done);
468 else {
469 complete(&fsl_lpspi->dma_tx_completion);
470 complete(&fsl_lpspi->dma_rx_completion);
471 }
472
473 return 0;
474}
475
476static int fsl_lpspi_wait_for_completion(struct spi_controller *controller)
477{
478 struct fsl_lpspi_data *fsl_lpspi =
479 spi_controller_get_devdata(controller);
480
481 if (fsl_lpspi->is_slave) {
482 if (wait_for_completion_interruptible(&fsl_lpspi->xfer_done) ||
483 fsl_lpspi->slave_aborted) {
484 dev_dbg(fsl_lpspi->dev, "interrupted\n");
485 return -EINTR;
486 }
487 } else {
488 if (!wait_for_completion_timeout(&fsl_lpspi->xfer_done, HZ)) {
489 dev_dbg(fsl_lpspi->dev, "wait for completion timeout\n");
490 return -ETIMEDOUT;
491 }
492 }
493
494 return 0;
495}
496
497static int fsl_lpspi_reset(struct fsl_lpspi_data *fsl_lpspi)
498{
499 u32 temp;
500
501 if (!fsl_lpspi->usedma) {
502 /* Disable all interrupt */
503 fsl_lpspi_intctrl(fsl_lpspi, 0);
504 }
505
506 /* W1C for all flags in SR */
507 temp = 0x3F << 8;
508 writel(temp, fsl_lpspi->base + IMX7ULP_SR);
509
510 /* Clear FIFO and disable module */
511 temp = CR_RRF | CR_RTF;
512 writel(temp, fsl_lpspi->base + IMX7ULP_CR);
513
514 return 0;
515}
516
517static void fsl_lpspi_dma_rx_callback(void *cookie)
518{
519 struct fsl_lpspi_data *fsl_lpspi = (struct fsl_lpspi_data *)cookie;
520
521 complete(&fsl_lpspi->dma_rx_completion);
522}
523
524static void fsl_lpspi_dma_tx_callback(void *cookie)
525{
526 struct fsl_lpspi_data *fsl_lpspi = (struct fsl_lpspi_data *)cookie;
527
528 complete(&fsl_lpspi->dma_tx_completion);
529}
530
531static int fsl_lpspi_calculate_timeout(struct fsl_lpspi_data *fsl_lpspi,
532 int size)
533{
534 unsigned long timeout = 0;
535
536 /* Time with actual data transfer and CS change delay related to HW */
537 timeout = (8 + 4) * size / fsl_lpspi->config.speed_hz;
538
539 /* Add extra second for scheduler related activities */
540 timeout += 1;
541
542 /* Double calculated timeout */
543 return msecs_to_jiffies(2 * timeout * MSEC_PER_SEC);
544}
545
546static int fsl_lpspi_dma_transfer(struct spi_controller *controller,
547 struct fsl_lpspi_data *fsl_lpspi,
548 struct spi_transfer *transfer)
549{
550 struct dma_async_tx_descriptor *desc_tx, *desc_rx;
551 unsigned long transfer_timeout;
552 unsigned long timeout;
553 struct sg_table *tx = &transfer->tx_sg, *rx = &transfer->rx_sg;
554 int ret;
555
556 ret = fsl_lpspi_dma_configure(controller);
557 if (ret)
558 return ret;
559
560 desc_rx = dmaengine_prep_slave_sg(controller->dma_rx,
561 rx->sgl, rx->nents, DMA_DEV_TO_MEM,
562 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
563 if (!desc_rx)
564 return -EINVAL;
565
566 desc_rx->callback = fsl_lpspi_dma_rx_callback;
567 desc_rx->callback_param = (void *)fsl_lpspi;
568 dmaengine_submit(desc_rx);
569 reinit_completion(&fsl_lpspi->dma_rx_completion);
570 dma_async_issue_pending(controller->dma_rx);
571
572 desc_tx = dmaengine_prep_slave_sg(controller->dma_tx,
573 tx->sgl, tx->nents, DMA_MEM_TO_DEV,
574 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
575 if (!desc_tx) {
576 dmaengine_terminate_all(controller->dma_tx);
577 return -EINVAL;
578 }
579
580 desc_tx->callback = fsl_lpspi_dma_tx_callback;
581 desc_tx->callback_param = (void *)fsl_lpspi;
582 dmaengine_submit(desc_tx);
583 reinit_completion(&fsl_lpspi->dma_tx_completion);
584 dma_async_issue_pending(controller->dma_tx);
585
586 fsl_lpspi->slave_aborted = false;
587
588 if (!fsl_lpspi->is_slave) {
589 transfer_timeout = fsl_lpspi_calculate_timeout(fsl_lpspi,
590 transfer->len);
591
592 /* Wait eDMA to finish the data transfer.*/
593 timeout = wait_for_completion_timeout(&fsl_lpspi->dma_tx_completion,
594 transfer_timeout);
595 if (!timeout) {
596 dev_err(fsl_lpspi->dev, "I/O Error in DMA TX\n");
597 dmaengine_terminate_all(controller->dma_tx);
598 dmaengine_terminate_all(controller->dma_rx);
599 fsl_lpspi_reset(fsl_lpspi);
600 return -ETIMEDOUT;
601 }
602
603 timeout = wait_for_completion_timeout(&fsl_lpspi->dma_rx_completion,
604 transfer_timeout);
605 if (!timeout) {
606 dev_err(fsl_lpspi->dev, "I/O Error in DMA RX\n");
607 dmaengine_terminate_all(controller->dma_tx);
608 dmaengine_terminate_all(controller->dma_rx);
609 fsl_lpspi_reset(fsl_lpspi);
610 return -ETIMEDOUT;
611 }
612 } else {
613 if (wait_for_completion_interruptible(&fsl_lpspi->dma_tx_completion) ||
614 fsl_lpspi->slave_aborted) {
615 dev_dbg(fsl_lpspi->dev,
616 "I/O Error in DMA TX interrupted\n");
617 dmaengine_terminate_all(controller->dma_tx);
618 dmaengine_terminate_all(controller->dma_rx);
619 fsl_lpspi_reset(fsl_lpspi);
620 return -EINTR;
621 }
622
623 if (wait_for_completion_interruptible(&fsl_lpspi->dma_rx_completion) ||
624 fsl_lpspi->slave_aborted) {
625 dev_dbg(fsl_lpspi->dev,
626 "I/O Error in DMA RX interrupted\n");
627 dmaengine_terminate_all(controller->dma_tx);
628 dmaengine_terminate_all(controller->dma_rx);
629 fsl_lpspi_reset(fsl_lpspi);
630 return -EINTR;
631 }
632 }
633
634 fsl_lpspi_reset(fsl_lpspi);
635
636 return 0;
637}
638
639static void fsl_lpspi_dma_exit(struct spi_controller *controller)
640{
641 if (controller->dma_rx) {
642 dma_release_channel(controller->dma_rx);
643 controller->dma_rx = NULL;
644 }
645
646 if (controller->dma_tx) {
647 dma_release_channel(controller->dma_tx);
648 controller->dma_tx = NULL;
649 }
650}
651
652static int fsl_lpspi_dma_init(struct device *dev,
653 struct fsl_lpspi_data *fsl_lpspi,
654 struct spi_controller *controller)
655{
656 int ret;
657
658 /* Prepare for TX DMA: */
659 controller->dma_tx = dma_request_chan(dev, "tx");
660 if (IS_ERR(controller->dma_tx)) {
661 ret = PTR_ERR(controller->dma_tx);
662 dev_dbg(dev, "can't get the TX DMA channel, error %d!\n", ret);
663 controller->dma_tx = NULL;
664 goto err;
665 }
666
667 /* Prepare for RX DMA: */
668 controller->dma_rx = dma_request_chan(dev, "rx");
669 if (IS_ERR(controller->dma_rx)) {
670 ret = PTR_ERR(controller->dma_rx);
671 dev_dbg(dev, "can't get the RX DMA channel, error %d\n", ret);
672 controller->dma_rx = NULL;
673 goto err;
674 }
675
676 init_completion(&fsl_lpspi->dma_rx_completion);
677 init_completion(&fsl_lpspi->dma_tx_completion);
678 controller->can_dma = fsl_lpspi_can_dma;
679 controller->max_dma_len = FSL_LPSPI_MAX_EDMA_BYTES;
680
681 return 0;
682err:
683 fsl_lpspi_dma_exit(controller);
684 return ret;
685}
686
687static int fsl_lpspi_pio_transfer(struct spi_controller *controller,
688 struct spi_transfer *t)
689{
690 struct fsl_lpspi_data *fsl_lpspi =
691 spi_controller_get_devdata(controller);
692 int ret;
693
694 fsl_lpspi->tx_buf = t->tx_buf;
695 fsl_lpspi->rx_buf = t->rx_buf;
696 fsl_lpspi->remain = t->len;
697
698 reinit_completion(&fsl_lpspi->xfer_done);
699 fsl_lpspi->slave_aborted = false;
700
701 fsl_lpspi_write_tx_fifo(fsl_lpspi);
702
703 ret = fsl_lpspi_wait_for_completion(controller);
704 if (ret)
705 return ret;
706
707 fsl_lpspi_reset(fsl_lpspi);
708
709 return 0;
710}
711
712static int fsl_lpspi_transfer_one(struct spi_controller *controller,
713 struct spi_device *spi,
714 struct spi_transfer *t)
715{
716 struct fsl_lpspi_data *fsl_lpspi =
717 spi_controller_get_devdata(controller);
718 int ret;
719
720 fsl_lpspi->is_first_byte = true;
721 ret = fsl_lpspi_setup_transfer(controller, spi, t);
722 if (ret < 0)
723 return ret;
724
725 fsl_lpspi_set_cmd(fsl_lpspi);
726 fsl_lpspi->is_first_byte = false;
727
728 if (fsl_lpspi->usedma)
729 ret = fsl_lpspi_dma_transfer(controller, fsl_lpspi, t);
730 else
731 ret = fsl_lpspi_pio_transfer(controller, t);
732 if (ret < 0)
733 return ret;
734
735 return 0;
736}
737
738static irqreturn_t fsl_lpspi_isr(int irq, void *dev_id)
739{
740 u32 temp_SR, temp_IER;
741 struct fsl_lpspi_data *fsl_lpspi = dev_id;
742
743 temp_IER = readl(fsl_lpspi->base + IMX7ULP_IER);
744 fsl_lpspi_intctrl(fsl_lpspi, 0);
745 temp_SR = readl(fsl_lpspi->base + IMX7ULP_SR);
746
747 fsl_lpspi_read_rx_fifo(fsl_lpspi);
748
749 if ((temp_SR & SR_TDF) && (temp_IER & IER_TDIE)) {
750 fsl_lpspi_write_tx_fifo(fsl_lpspi);
751 return IRQ_HANDLED;
752 }
753
754 if (temp_SR & SR_MBF ||
755 readl(fsl_lpspi->base + IMX7ULP_FSR) & FSR_TXCOUNT) {
756 writel(SR_FCF, fsl_lpspi->base + IMX7ULP_SR);
757 fsl_lpspi_intctrl(fsl_lpspi, IER_FCIE);
758 return IRQ_HANDLED;
759 }
760
761 if (temp_SR & SR_FCF && (temp_IER & IER_FCIE)) {
762 writel(SR_FCF, fsl_lpspi->base + IMX7ULP_SR);
763 complete(&fsl_lpspi->xfer_done);
764 return IRQ_HANDLED;
765 }
766
767 return IRQ_NONE;
768}
769
770#ifdef CONFIG_PM
771static int fsl_lpspi_runtime_resume(struct device *dev)
772{
773 struct spi_controller *controller = dev_get_drvdata(dev);
774 struct fsl_lpspi_data *fsl_lpspi;
775 int ret;
776
777 fsl_lpspi = spi_controller_get_devdata(controller);
778
779 ret = clk_prepare_enable(fsl_lpspi->clk_per);
780 if (ret)
781 return ret;
782
783 ret = clk_prepare_enable(fsl_lpspi->clk_ipg);
784 if (ret) {
785 clk_disable_unprepare(fsl_lpspi->clk_per);
786 return ret;
787 }
788
789 return 0;
790}
791
792static int fsl_lpspi_runtime_suspend(struct device *dev)
793{
794 struct spi_controller *controller = dev_get_drvdata(dev);
795 struct fsl_lpspi_data *fsl_lpspi;
796
797 fsl_lpspi = spi_controller_get_devdata(controller);
798
799 clk_disable_unprepare(fsl_lpspi->clk_per);
800 clk_disable_unprepare(fsl_lpspi->clk_ipg);
801
802 return 0;
803}
804#endif
805
806static int fsl_lpspi_init_rpm(struct fsl_lpspi_data *fsl_lpspi)
807{
808 struct device *dev = fsl_lpspi->dev;
809
810 pm_runtime_enable(dev);
811 pm_runtime_set_autosuspend_delay(dev, FSL_LPSPI_RPM_TIMEOUT);
812 pm_runtime_use_autosuspend(dev);
813
814 return 0;
815}
816
817static int fsl_lpspi_probe(struct platform_device *pdev)
818{
819 struct fsl_lpspi_data *fsl_lpspi;
820 struct spi_controller *controller;
821 struct resource *res;
822 int ret, irq;
823 u32 temp;
824 bool is_slave;
825
826 is_slave = of_property_read_bool((&pdev->dev)->of_node, "spi-slave");
827 if (is_slave)
828 controller = spi_alloc_slave(&pdev->dev,
829 sizeof(struct fsl_lpspi_data));
830 else
831 controller = spi_alloc_master(&pdev->dev,
832 sizeof(struct fsl_lpspi_data));
833
834 if (!controller)
835 return -ENOMEM;
836
837 platform_set_drvdata(pdev, controller);
838
839 fsl_lpspi = spi_controller_get_devdata(controller);
840 fsl_lpspi->dev = &pdev->dev;
841 fsl_lpspi->is_slave = is_slave;
842 fsl_lpspi->is_only_cs1 = of_property_read_bool((&pdev->dev)->of_node,
843 "fsl,spi-only-use-cs1-sel");
844 if (of_property_read_u32((&pdev->dev)->of_node, "num-cs",
845 &fsl_lpspi->num_cs))
846 fsl_lpspi->num_cs = 1;
847
848 controller->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32);
849 controller->transfer_one = fsl_lpspi_transfer_one;
850 controller->prepare_transfer_hardware = lpspi_prepare_xfer_hardware;
851 controller->unprepare_transfer_hardware = lpspi_unprepare_xfer_hardware;
852 controller->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
853 controller->flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX;
854 controller->dev.of_node = pdev->dev.of_node;
855 controller->bus_num = pdev->id;
856 controller->num_chipselect = fsl_lpspi->num_cs;
857 controller->slave_abort = fsl_lpspi_slave_abort;
858 if (!fsl_lpspi->is_slave)
859 controller->use_gpio_descriptors = true;
860
861 init_completion(&fsl_lpspi->xfer_done);
862
863 fsl_lpspi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
864 if (IS_ERR(fsl_lpspi->base)) {
865 ret = PTR_ERR(fsl_lpspi->base);
866 goto out_controller_put;
867 }
868 fsl_lpspi->base_phys = res->start;
869
870 irq = platform_get_irq(pdev, 0);
871 if (irq < 0) {
872 ret = irq;
873 goto out_controller_put;
874 }
875
876 ret = devm_request_irq(&pdev->dev, irq, fsl_lpspi_isr, 0,
877 dev_name(&pdev->dev), fsl_lpspi);
878 if (ret) {
879 dev_err(&pdev->dev, "can't get irq%d: %d\n", irq, ret);
880 goto out_controller_put;
881 }
882
883 fsl_lpspi->clk_per = devm_clk_get(&pdev->dev, "per");
884 if (IS_ERR(fsl_lpspi->clk_per)) {
885 ret = PTR_ERR(fsl_lpspi->clk_per);
886 goto out_controller_put;
887 }
888
889 fsl_lpspi->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
890 if (IS_ERR(fsl_lpspi->clk_ipg)) {
891 ret = PTR_ERR(fsl_lpspi->clk_ipg);
892 goto out_controller_put;
893 }
894
895 /* enable the clock */
896 ret = fsl_lpspi_init_rpm(fsl_lpspi);
897 if (ret)
898 goto out_controller_put;
899
900 ret = pm_runtime_get_sync(fsl_lpspi->dev);
901 if (ret < 0) {
902 dev_err(fsl_lpspi->dev, "failed to enable clock\n");
903 goto out_pm_get;
904 }
905
906 temp = readl(fsl_lpspi->base + IMX7ULP_PARAM);
907 fsl_lpspi->txfifosize = 1 << (temp & 0x0f);
908 fsl_lpspi->rxfifosize = 1 << ((temp >> 8) & 0x0f);
909
910 ret = fsl_lpspi_dma_init(&pdev->dev, fsl_lpspi, controller);
911 if (ret == -EPROBE_DEFER)
912 goto out_pm_get;
913
914 if (ret < 0)
915 dev_err(&pdev->dev, "dma setup error %d, use pio\n", ret);
916
917 ret = devm_spi_register_controller(&pdev->dev, controller);
918 if (ret < 0) {
919 dev_err_probe(&pdev->dev, ret, "spi_register_controller error\n");
920 goto free_dma;
921 }
922
923 pm_runtime_mark_last_busy(fsl_lpspi->dev);
924 pm_runtime_put_autosuspend(fsl_lpspi->dev);
925
926 return 0;
927
928free_dma:
929 fsl_lpspi_dma_exit(controller);
930out_pm_get:
931 pm_runtime_dont_use_autosuspend(fsl_lpspi->dev);
932 pm_runtime_put_sync(fsl_lpspi->dev);
933 pm_runtime_disable(fsl_lpspi->dev);
934out_controller_put:
935 spi_controller_put(controller);
936
937 return ret;
938}
939
940static int fsl_lpspi_remove(struct platform_device *pdev)
941{
942 struct spi_controller *controller = platform_get_drvdata(pdev);
943 struct fsl_lpspi_data *fsl_lpspi =
944 spi_controller_get_devdata(controller);
945
946 fsl_lpspi_dma_exit(controller);
947
948 pm_runtime_disable(fsl_lpspi->dev);
949 return 0;
950}
951
952static int __maybe_unused fsl_lpspi_suspend(struct device *dev)
953{
954 pinctrl_pm_select_sleep_state(dev);
955 return pm_runtime_force_suspend(dev);
956}
957
958static int __maybe_unused fsl_lpspi_resume(struct device *dev)
959{
960 int ret;
961
962 ret = pm_runtime_force_resume(dev);
963 if (ret) {
964 dev_err(dev, "Error in resume: %d\n", ret);
965 return ret;
966 }
967
968 pinctrl_pm_select_default_state(dev);
969
970 return 0;
971}
972
973static const struct dev_pm_ops fsl_lpspi_pm_ops = {
974 SET_RUNTIME_PM_OPS(fsl_lpspi_runtime_suspend,
975 fsl_lpspi_runtime_resume, NULL)
976 SET_SYSTEM_SLEEP_PM_OPS(fsl_lpspi_suspend, fsl_lpspi_resume)
977};
978
979static struct platform_driver fsl_lpspi_driver = {
980 .driver = {
981 .name = DRIVER_NAME,
982 .of_match_table = fsl_lpspi_dt_ids,
983 .pm = &fsl_lpspi_pm_ops,
984 },
985 .probe = fsl_lpspi_probe,
986 .remove = fsl_lpspi_remove,
987};
988module_platform_driver(fsl_lpspi_driver);
989
990MODULE_DESCRIPTION("LPSPI Controller driver");
991MODULE_AUTHOR("Gao Pan <pandy.gao@nxp.com>");
992MODULE_LICENSE("GPL");