xref: /openbmc/linux/drivers/spi/spi-rockchip.c (revision a06c488d)
1 /*
2  * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
3  * Author: Addy Ke <addy.ke@rock-chips.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  */
15 
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/clk.h>
19 #include <linux/err.h>
20 #include <linux/delay.h>
21 #include <linux/interrupt.h>
22 #include <linux/platform_device.h>
23 #include <linux/slab.h>
24 #include <linux/spi/spi.h>
25 #include <linux/scatterlist.h>
26 #include <linux/of.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/io.h>
29 #include <linux/dmaengine.h>
30 
31 #define DRIVER_NAME "rockchip-spi"
32 
33 /* SPI register offsets */
34 #define ROCKCHIP_SPI_CTRLR0			0x0000
35 #define ROCKCHIP_SPI_CTRLR1			0x0004
36 #define ROCKCHIP_SPI_SSIENR			0x0008
37 #define ROCKCHIP_SPI_SER			0x000c
38 #define ROCKCHIP_SPI_BAUDR			0x0010
39 #define ROCKCHIP_SPI_TXFTLR			0x0014
40 #define ROCKCHIP_SPI_RXFTLR			0x0018
41 #define ROCKCHIP_SPI_TXFLR			0x001c
42 #define ROCKCHIP_SPI_RXFLR			0x0020
43 #define ROCKCHIP_SPI_SR				0x0024
44 #define ROCKCHIP_SPI_IPR			0x0028
45 #define ROCKCHIP_SPI_IMR			0x002c
46 #define ROCKCHIP_SPI_ISR			0x0030
47 #define ROCKCHIP_SPI_RISR			0x0034
48 #define ROCKCHIP_SPI_ICR			0x0038
49 #define ROCKCHIP_SPI_DMACR			0x003c
50 #define ROCKCHIP_SPI_DMATDLR		0x0040
51 #define ROCKCHIP_SPI_DMARDLR		0x0044
52 #define ROCKCHIP_SPI_TXDR			0x0400
53 #define ROCKCHIP_SPI_RXDR			0x0800
54 
55 /* Bit fields in CTRLR0 */
56 #define CR0_DFS_OFFSET				0
57 
58 #define CR0_CFS_OFFSET				2
59 
60 #define CR0_SCPH_OFFSET				6
61 
62 #define CR0_SCPOL_OFFSET			7
63 
64 #define CR0_CSM_OFFSET				8
65 #define CR0_CSM_KEEP				0x0
66 /* ss_n be high for half sclk_out cycles */
67 #define CR0_CSM_HALF				0X1
68 /* ss_n be high for one sclk_out cycle */
69 #define CR0_CSM_ONE					0x2
70 
71 /* ss_n to sclk_out delay */
72 #define CR0_SSD_OFFSET				10
73 /*
74  * The period between ss_n active and
75  * sclk_out active is half sclk_out cycles
76  */
77 #define CR0_SSD_HALF				0x0
78 /*
79  * The period between ss_n active and
80  * sclk_out active is one sclk_out cycle
81  */
82 #define CR0_SSD_ONE					0x1
83 
84 #define CR0_EM_OFFSET				11
85 #define CR0_EM_LITTLE				0x0
86 #define CR0_EM_BIG					0x1
87 
88 #define CR0_FBM_OFFSET				12
89 #define CR0_FBM_MSB					0x0
90 #define CR0_FBM_LSB					0x1
91 
92 #define CR0_BHT_OFFSET				13
93 #define CR0_BHT_16BIT				0x0
94 #define CR0_BHT_8BIT				0x1
95 
96 #define CR0_RSD_OFFSET				14
97 
98 #define CR0_FRF_OFFSET				16
99 #define CR0_FRF_SPI					0x0
100 #define CR0_FRF_SSP					0x1
101 #define CR0_FRF_MICROWIRE			0x2
102 
103 #define CR0_XFM_OFFSET				18
104 #define CR0_XFM_MASK				(0x03 << SPI_XFM_OFFSET)
105 #define CR0_XFM_TR					0x0
106 #define CR0_XFM_TO					0x1
107 #define CR0_XFM_RO					0x2
108 
109 #define CR0_OPM_OFFSET				20
110 #define CR0_OPM_MASTER				0x0
111 #define CR0_OPM_SLAVE				0x1
112 
113 #define CR0_MTM_OFFSET				0x21
114 
115 /* Bit fields in SER, 2bit */
116 #define SER_MASK					0x3
117 
118 /* Bit fields in SR, 5bit */
119 #define SR_MASK						0x1f
120 #define SR_BUSY						(1 << 0)
121 #define SR_TF_FULL					(1 << 1)
122 #define SR_TF_EMPTY					(1 << 2)
123 #define SR_RF_EMPTY					(1 << 3)
124 #define SR_RF_FULL					(1 << 4)
125 
126 /* Bit fields in ISR, IMR, ISR, RISR, 5bit */
127 #define INT_MASK					0x1f
128 #define INT_TF_EMPTY				(1 << 0)
129 #define INT_TF_OVERFLOW				(1 << 1)
130 #define INT_RF_UNDERFLOW			(1 << 2)
131 #define INT_RF_OVERFLOW				(1 << 3)
132 #define INT_RF_FULL					(1 << 4)
133 
134 /* Bit fields in ICR, 4bit */
135 #define ICR_MASK					0x0f
136 #define ICR_ALL						(1 << 0)
137 #define ICR_RF_UNDERFLOW			(1 << 1)
138 #define ICR_RF_OVERFLOW				(1 << 2)
139 #define ICR_TF_OVERFLOW				(1 << 3)
140 
141 /* Bit fields in DMACR */
142 #define RF_DMA_EN					(1 << 0)
143 #define TF_DMA_EN					(1 << 1)
144 
145 #define RXBUSY						(1 << 0)
146 #define TXBUSY						(1 << 1)
147 
148 /* sclk_out: spi master internal logic in rk3x can support 50Mhz */
149 #define MAX_SCLK_OUT		50000000
150 
151 enum rockchip_ssi_type {
152 	SSI_MOTO_SPI = 0,
153 	SSI_TI_SSP,
154 	SSI_NS_MICROWIRE,
155 };
156 
157 struct rockchip_spi_dma_data {
158 	struct dma_chan *ch;
159 	enum dma_transfer_direction direction;
160 	dma_addr_t addr;
161 };
162 
163 struct rockchip_spi {
164 	struct device *dev;
165 	struct spi_master *master;
166 
167 	struct clk *spiclk;
168 	struct clk *apb_pclk;
169 
170 	void __iomem *regs;
171 	/*depth of the FIFO buffer */
172 	u32 fifo_len;
173 	/* max bus freq supported */
174 	u32 max_freq;
175 	/* supported slave numbers */
176 	enum rockchip_ssi_type type;
177 
178 	u16 mode;
179 	u8 tmode;
180 	u8 bpw;
181 	u8 n_bytes;
182 	u8 rsd_nsecs;
183 	unsigned len;
184 	u32 speed;
185 
186 	const void *tx;
187 	const void *tx_end;
188 	void *rx;
189 	void *rx_end;
190 
191 	u32 state;
192 	/* protect state */
193 	spinlock_t lock;
194 
195 	struct completion xfer_completion;
196 
197 	u32 use_dma;
198 	struct sg_table tx_sg;
199 	struct sg_table rx_sg;
200 	struct rockchip_spi_dma_data dma_rx;
201 	struct rockchip_spi_dma_data dma_tx;
202 };
203 
204 static inline void spi_enable_chip(struct rockchip_spi *rs, int enable)
205 {
206 	writel_relaxed((enable ? 1 : 0), rs->regs + ROCKCHIP_SPI_SSIENR);
207 }
208 
209 static inline void spi_set_clk(struct rockchip_spi *rs, u16 div)
210 {
211 	writel_relaxed(div, rs->regs + ROCKCHIP_SPI_BAUDR);
212 }
213 
214 static inline void flush_fifo(struct rockchip_spi *rs)
215 {
216 	while (readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR))
217 		readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
218 }
219 
220 static inline void wait_for_idle(struct rockchip_spi *rs)
221 {
222 	unsigned long timeout = jiffies + msecs_to_jiffies(5);
223 
224 	do {
225 		if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
226 			return;
227 	} while (!time_after(jiffies, timeout));
228 
229 	dev_warn(rs->dev, "spi controller is in busy state!\n");
230 }
231 
232 static u32 get_fifo_len(struct rockchip_spi *rs)
233 {
234 	u32 fifo;
235 
236 	for (fifo = 2; fifo < 32; fifo++) {
237 		writel_relaxed(fifo, rs->regs + ROCKCHIP_SPI_TXFTLR);
238 		if (fifo != readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFTLR))
239 			break;
240 	}
241 
242 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_TXFTLR);
243 
244 	return (fifo == 31) ? 0 : fifo;
245 }
246 
247 static inline u32 tx_max(struct rockchip_spi *rs)
248 {
249 	u32 tx_left, tx_room;
250 
251 	tx_left = (rs->tx_end - rs->tx) / rs->n_bytes;
252 	tx_room = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
253 
254 	return min(tx_left, tx_room);
255 }
256 
257 static inline u32 rx_max(struct rockchip_spi *rs)
258 {
259 	u32 rx_left = (rs->rx_end - rs->rx) / rs->n_bytes;
260 	u32 rx_room = (u32)readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
261 
262 	return min(rx_left, rx_room);
263 }
264 
265 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
266 {
267 	u32 ser;
268 	struct rockchip_spi *rs = spi_master_get_devdata(spi->master);
269 
270 	ser = readl_relaxed(rs->regs + ROCKCHIP_SPI_SER) & SER_MASK;
271 
272 	/*
273 	 * drivers/spi/spi.c:
274 	 * static void spi_set_cs(struct spi_device *spi, bool enable)
275 	 * {
276 	 *		if (spi->mode & SPI_CS_HIGH)
277 	 *			enable = !enable;
278 	 *
279 	 *		if (spi->cs_gpio >= 0)
280 	 *			gpio_set_value(spi->cs_gpio, !enable);
281 	 *		else if (spi->master->set_cs)
282 	 *		spi->master->set_cs(spi, !enable);
283 	 * }
284 	 *
285 	 * Note: enable(rockchip_spi_set_cs) = !enable(spi_set_cs)
286 	 */
287 	if (!enable)
288 		ser |= 1 << spi->chip_select;
289 	else
290 		ser &= ~(1 << spi->chip_select);
291 
292 	writel_relaxed(ser, rs->regs + ROCKCHIP_SPI_SER);
293 }
294 
295 static int rockchip_spi_prepare_message(struct spi_master *master,
296 					struct spi_message *msg)
297 {
298 	struct rockchip_spi *rs = spi_master_get_devdata(master);
299 	struct spi_device *spi = msg->spi;
300 
301 	rs->mode = spi->mode;
302 
303 	return 0;
304 }
305 
306 static void rockchip_spi_handle_err(struct spi_master *master,
307 				    struct spi_message *msg)
308 {
309 	unsigned long flags;
310 	struct rockchip_spi *rs = spi_master_get_devdata(master);
311 
312 	spin_lock_irqsave(&rs->lock, flags);
313 
314 	/*
315 	 * For DMA mode, we need terminate DMA channel and flush
316 	 * fifo for the next transfer if DMA thansfer timeout.
317 	 * handle_err() was called by core if transfer failed.
318 	 * Maybe it is reasonable for error handling here.
319 	 */
320 	if (rs->use_dma) {
321 		if (rs->state & RXBUSY) {
322 			dmaengine_terminate_all(rs->dma_rx.ch);
323 			flush_fifo(rs);
324 		}
325 
326 		if (rs->state & TXBUSY)
327 			dmaengine_terminate_all(rs->dma_tx.ch);
328 	}
329 
330 	spin_unlock_irqrestore(&rs->lock, flags);
331 }
332 
333 static int rockchip_spi_unprepare_message(struct spi_master *master,
334 					  struct spi_message *msg)
335 {
336 	struct rockchip_spi *rs = spi_master_get_devdata(master);
337 
338 	spi_enable_chip(rs, 0);
339 
340 	return 0;
341 }
342 
343 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
344 {
345 	u32 max = tx_max(rs);
346 	u32 txw = 0;
347 
348 	while (max--) {
349 		if (rs->n_bytes == 1)
350 			txw = *(u8 *)(rs->tx);
351 		else
352 			txw = *(u16 *)(rs->tx);
353 
354 		writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
355 		rs->tx += rs->n_bytes;
356 	}
357 }
358 
359 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
360 {
361 	u32 max = rx_max(rs);
362 	u32 rxw;
363 
364 	while (max--) {
365 		rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
366 		if (rs->n_bytes == 1)
367 			*(u8 *)(rs->rx) = (u8)rxw;
368 		else
369 			*(u16 *)(rs->rx) = (u16)rxw;
370 		rs->rx += rs->n_bytes;
371 	}
372 }
373 
374 static int rockchip_spi_pio_transfer(struct rockchip_spi *rs)
375 {
376 	int remain = 0;
377 
378 	do {
379 		if (rs->tx) {
380 			remain = rs->tx_end - rs->tx;
381 			rockchip_spi_pio_writer(rs);
382 		}
383 
384 		if (rs->rx) {
385 			remain = rs->rx_end - rs->rx;
386 			rockchip_spi_pio_reader(rs);
387 		}
388 
389 		cpu_relax();
390 	} while (remain);
391 
392 	/* If tx, wait until the FIFO data completely. */
393 	if (rs->tx)
394 		wait_for_idle(rs);
395 
396 	spi_enable_chip(rs, 0);
397 
398 	return 0;
399 }
400 
401 static void rockchip_spi_dma_rxcb(void *data)
402 {
403 	unsigned long flags;
404 	struct rockchip_spi *rs = data;
405 
406 	spin_lock_irqsave(&rs->lock, flags);
407 
408 	rs->state &= ~RXBUSY;
409 	if (!(rs->state & TXBUSY)) {
410 		spi_enable_chip(rs, 0);
411 		spi_finalize_current_transfer(rs->master);
412 	}
413 
414 	spin_unlock_irqrestore(&rs->lock, flags);
415 }
416 
417 static void rockchip_spi_dma_txcb(void *data)
418 {
419 	unsigned long flags;
420 	struct rockchip_spi *rs = data;
421 
422 	/* Wait until the FIFO data completely. */
423 	wait_for_idle(rs);
424 
425 	spin_lock_irqsave(&rs->lock, flags);
426 
427 	rs->state &= ~TXBUSY;
428 	if (!(rs->state & RXBUSY)) {
429 		spi_enable_chip(rs, 0);
430 		spi_finalize_current_transfer(rs->master);
431 	}
432 
433 	spin_unlock_irqrestore(&rs->lock, flags);
434 }
435 
436 static void rockchip_spi_prepare_dma(struct rockchip_spi *rs)
437 {
438 	unsigned long flags;
439 	struct dma_slave_config rxconf, txconf;
440 	struct dma_async_tx_descriptor *rxdesc, *txdesc;
441 
442 	spin_lock_irqsave(&rs->lock, flags);
443 	rs->state &= ~RXBUSY;
444 	rs->state &= ~TXBUSY;
445 	spin_unlock_irqrestore(&rs->lock, flags);
446 
447 	rxdesc = NULL;
448 	if (rs->rx) {
449 		rxconf.direction = rs->dma_rx.direction;
450 		rxconf.src_addr = rs->dma_rx.addr;
451 		rxconf.src_addr_width = rs->n_bytes;
452 		rxconf.src_maxburst = rs->n_bytes;
453 		dmaengine_slave_config(rs->dma_rx.ch, &rxconf);
454 
455 		rxdesc = dmaengine_prep_slave_sg(
456 				rs->dma_rx.ch,
457 				rs->rx_sg.sgl, rs->rx_sg.nents,
458 				rs->dma_rx.direction, DMA_PREP_INTERRUPT);
459 
460 		rxdesc->callback = rockchip_spi_dma_rxcb;
461 		rxdesc->callback_param = rs;
462 	}
463 
464 	txdesc = NULL;
465 	if (rs->tx) {
466 		txconf.direction = rs->dma_tx.direction;
467 		txconf.dst_addr = rs->dma_tx.addr;
468 		txconf.dst_addr_width = rs->n_bytes;
469 		txconf.dst_maxburst = rs->n_bytes;
470 		dmaengine_slave_config(rs->dma_tx.ch, &txconf);
471 
472 		txdesc = dmaengine_prep_slave_sg(
473 				rs->dma_tx.ch,
474 				rs->tx_sg.sgl, rs->tx_sg.nents,
475 				rs->dma_tx.direction, DMA_PREP_INTERRUPT);
476 
477 		txdesc->callback = rockchip_spi_dma_txcb;
478 		txdesc->callback_param = rs;
479 	}
480 
481 	/* rx must be started before tx due to spi instinct */
482 	if (rxdesc) {
483 		spin_lock_irqsave(&rs->lock, flags);
484 		rs->state |= RXBUSY;
485 		spin_unlock_irqrestore(&rs->lock, flags);
486 		dmaengine_submit(rxdesc);
487 		dma_async_issue_pending(rs->dma_rx.ch);
488 	}
489 
490 	if (txdesc) {
491 		spin_lock_irqsave(&rs->lock, flags);
492 		rs->state |= TXBUSY;
493 		spin_unlock_irqrestore(&rs->lock, flags);
494 		dmaengine_submit(txdesc);
495 		dma_async_issue_pending(rs->dma_tx.ch);
496 	}
497 }
498 
499 static void rockchip_spi_config(struct rockchip_spi *rs)
500 {
501 	u32 div = 0;
502 	u32 dmacr = 0;
503 	int rsd = 0;
504 
505 	u32 cr0 = (CR0_BHT_8BIT << CR0_BHT_OFFSET)
506 		| (CR0_SSD_ONE << CR0_SSD_OFFSET);
507 
508 	cr0 |= (rs->n_bytes << CR0_DFS_OFFSET);
509 	cr0 |= ((rs->mode & 0x3) << CR0_SCPH_OFFSET);
510 	cr0 |= (rs->tmode << CR0_XFM_OFFSET);
511 	cr0 |= (rs->type << CR0_FRF_OFFSET);
512 
513 	if (rs->use_dma) {
514 		if (rs->tx)
515 			dmacr |= TF_DMA_EN;
516 		if (rs->rx)
517 			dmacr |= RF_DMA_EN;
518 	}
519 
520 	if (WARN_ON(rs->speed > MAX_SCLK_OUT))
521 		rs->speed = MAX_SCLK_OUT;
522 
523 	/* the minimum divsor is 2 */
524 	if (rs->max_freq < 2 * rs->speed) {
525 		clk_set_rate(rs->spiclk, 2 * rs->speed);
526 		rs->max_freq = clk_get_rate(rs->spiclk);
527 	}
528 
529 	/* div doesn't support odd number */
530 	div = DIV_ROUND_UP(rs->max_freq, rs->speed);
531 	div = (div + 1) & 0xfffe;
532 
533 	/* Rx sample delay is expressed in parent clock cycles (max 3) */
534 	rsd = DIV_ROUND_CLOSEST(rs->rsd_nsecs * (rs->max_freq >> 8),
535 				1000000000 >> 8);
536 	if (!rsd && rs->rsd_nsecs) {
537 		pr_warn_once("rockchip-spi: %u Hz are too slow to express %u ns delay\n",
538 			     rs->max_freq, rs->rsd_nsecs);
539 	} else if (rsd > 3) {
540 		rsd = 3;
541 		pr_warn_once("rockchip-spi: %u Hz are too fast to express %u ns delay, clamping at %u ns\n",
542 			     rs->max_freq, rs->rsd_nsecs,
543 			     rsd * 1000000000U / rs->max_freq);
544 	}
545 	cr0 |= rsd << CR0_RSD_OFFSET;
546 
547 	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
548 
549 	writel_relaxed(rs->len - 1, rs->regs + ROCKCHIP_SPI_CTRLR1);
550 	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_TXFTLR);
551 	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
552 
553 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMATDLR);
554 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMARDLR);
555 	writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
556 
557 	spi_set_clk(rs, div);
558 
559 	dev_dbg(rs->dev, "cr0 0x%x, div %d\n", cr0, div);
560 }
561 
562 static int rockchip_spi_transfer_one(
563 		struct spi_master *master,
564 		struct spi_device *spi,
565 		struct spi_transfer *xfer)
566 {
567 	int ret = 1;
568 	struct rockchip_spi *rs = spi_master_get_devdata(master);
569 
570 	WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
571 		(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
572 
573 	if (!xfer->tx_buf && !xfer->rx_buf) {
574 		dev_err(rs->dev, "No buffer for transfer\n");
575 		return -EINVAL;
576 	}
577 
578 	rs->speed = xfer->speed_hz;
579 	rs->bpw = xfer->bits_per_word;
580 	rs->n_bytes = rs->bpw >> 3;
581 
582 	rs->tx = xfer->tx_buf;
583 	rs->tx_end = rs->tx + xfer->len;
584 	rs->rx = xfer->rx_buf;
585 	rs->rx_end = rs->rx + xfer->len;
586 	rs->len = xfer->len;
587 
588 	rs->tx_sg = xfer->tx_sg;
589 	rs->rx_sg = xfer->rx_sg;
590 
591 	if (rs->tx && rs->rx)
592 		rs->tmode = CR0_XFM_TR;
593 	else if (rs->tx)
594 		rs->tmode = CR0_XFM_TO;
595 	else if (rs->rx)
596 		rs->tmode = CR0_XFM_RO;
597 
598 	/* we need prepare dma before spi was enabled */
599 	if (master->can_dma && master->can_dma(master, spi, xfer))
600 		rs->use_dma = 1;
601 	else
602 		rs->use_dma = 0;
603 
604 	rockchip_spi_config(rs);
605 
606 	if (rs->use_dma) {
607 		if (rs->tmode == CR0_XFM_RO) {
608 			/* rx: dma must be prepared first */
609 			rockchip_spi_prepare_dma(rs);
610 			spi_enable_chip(rs, 1);
611 		} else {
612 			/* tx or tr: spi must be enabled first */
613 			spi_enable_chip(rs, 1);
614 			rockchip_spi_prepare_dma(rs);
615 		}
616 	} else {
617 		spi_enable_chip(rs, 1);
618 		ret = rockchip_spi_pio_transfer(rs);
619 	}
620 
621 	return ret;
622 }
623 
624 static bool rockchip_spi_can_dma(struct spi_master *master,
625 				 struct spi_device *spi,
626 				 struct spi_transfer *xfer)
627 {
628 	struct rockchip_spi *rs = spi_master_get_devdata(master);
629 
630 	return (xfer->len > rs->fifo_len);
631 }
632 
633 static int rockchip_spi_probe(struct platform_device *pdev)
634 {
635 	int ret = 0;
636 	struct rockchip_spi *rs;
637 	struct spi_master *master;
638 	struct resource *mem;
639 	u32 rsd_nsecs;
640 
641 	master = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi));
642 	if (!master)
643 		return -ENOMEM;
644 
645 	platform_set_drvdata(pdev, master);
646 
647 	rs = spi_master_get_devdata(master);
648 
649 	/* Get basic io resource and map it */
650 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
651 	rs->regs = devm_ioremap_resource(&pdev->dev, mem);
652 	if (IS_ERR(rs->regs)) {
653 		ret =  PTR_ERR(rs->regs);
654 		goto err_ioremap_resource;
655 	}
656 
657 	rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
658 	if (IS_ERR(rs->apb_pclk)) {
659 		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
660 		ret = PTR_ERR(rs->apb_pclk);
661 		goto err_ioremap_resource;
662 	}
663 
664 	rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
665 	if (IS_ERR(rs->spiclk)) {
666 		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
667 		ret = PTR_ERR(rs->spiclk);
668 		goto err_ioremap_resource;
669 	}
670 
671 	ret = clk_prepare_enable(rs->apb_pclk);
672 	if (ret) {
673 		dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
674 		goto err_ioremap_resource;
675 	}
676 
677 	ret = clk_prepare_enable(rs->spiclk);
678 	if (ret) {
679 		dev_err(&pdev->dev, "Failed to enable spi_clk\n");
680 		goto err_spiclk_enable;
681 	}
682 
683 	spi_enable_chip(rs, 0);
684 
685 	rs->type = SSI_MOTO_SPI;
686 	rs->master = master;
687 	rs->dev = &pdev->dev;
688 	rs->max_freq = clk_get_rate(rs->spiclk);
689 
690 	if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
691 				  &rsd_nsecs))
692 		rs->rsd_nsecs = rsd_nsecs;
693 
694 	rs->fifo_len = get_fifo_len(rs);
695 	if (!rs->fifo_len) {
696 		dev_err(&pdev->dev, "Failed to get fifo length\n");
697 		ret = -EINVAL;
698 		goto err_get_fifo_len;
699 	}
700 
701 	spin_lock_init(&rs->lock);
702 
703 	pm_runtime_set_active(&pdev->dev);
704 	pm_runtime_enable(&pdev->dev);
705 
706 	master->auto_runtime_pm = true;
707 	master->bus_num = pdev->id;
708 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
709 	master->num_chipselect = 2;
710 	master->dev.of_node = pdev->dev.of_node;
711 	master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8);
712 
713 	master->set_cs = rockchip_spi_set_cs;
714 	master->prepare_message = rockchip_spi_prepare_message;
715 	master->unprepare_message = rockchip_spi_unprepare_message;
716 	master->transfer_one = rockchip_spi_transfer_one;
717 	master->handle_err = rockchip_spi_handle_err;
718 
719 	rs->dma_tx.ch = dma_request_slave_channel(rs->dev, "tx");
720 	if (!rs->dma_tx.ch)
721 		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
722 
723 	rs->dma_rx.ch = dma_request_slave_channel(rs->dev, "rx");
724 	if (!rs->dma_rx.ch) {
725 		if (rs->dma_tx.ch) {
726 			dma_release_channel(rs->dma_tx.ch);
727 			rs->dma_tx.ch = NULL;
728 		}
729 		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
730 	}
731 
732 	if (rs->dma_tx.ch && rs->dma_rx.ch) {
733 		rs->dma_tx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_TXDR);
734 		rs->dma_rx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_RXDR);
735 		rs->dma_tx.direction = DMA_MEM_TO_DEV;
736 		rs->dma_rx.direction = DMA_DEV_TO_MEM;
737 
738 		master->can_dma = rockchip_spi_can_dma;
739 		master->dma_tx = rs->dma_tx.ch;
740 		master->dma_rx = rs->dma_rx.ch;
741 	}
742 
743 	ret = devm_spi_register_master(&pdev->dev, master);
744 	if (ret) {
745 		dev_err(&pdev->dev, "Failed to register master\n");
746 		goto err_register_master;
747 	}
748 
749 	return 0;
750 
751 err_register_master:
752 	if (rs->dma_tx.ch)
753 		dma_release_channel(rs->dma_tx.ch);
754 	if (rs->dma_rx.ch)
755 		dma_release_channel(rs->dma_rx.ch);
756 err_get_fifo_len:
757 	clk_disable_unprepare(rs->spiclk);
758 err_spiclk_enable:
759 	clk_disable_unprepare(rs->apb_pclk);
760 err_ioremap_resource:
761 	spi_master_put(master);
762 
763 	return ret;
764 }
765 
766 static int rockchip_spi_remove(struct platform_device *pdev)
767 {
768 	struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
769 	struct rockchip_spi *rs = spi_master_get_devdata(master);
770 
771 	pm_runtime_disable(&pdev->dev);
772 
773 	clk_disable_unprepare(rs->spiclk);
774 	clk_disable_unprepare(rs->apb_pclk);
775 
776 	if (rs->dma_tx.ch)
777 		dma_release_channel(rs->dma_tx.ch);
778 	if (rs->dma_rx.ch)
779 		dma_release_channel(rs->dma_rx.ch);
780 
781 	return 0;
782 }
783 
784 #ifdef CONFIG_PM_SLEEP
785 static int rockchip_spi_suspend(struct device *dev)
786 {
787 	int ret = 0;
788 	struct spi_master *master = dev_get_drvdata(dev);
789 	struct rockchip_spi *rs = spi_master_get_devdata(master);
790 
791 	ret = spi_master_suspend(rs->master);
792 	if (ret)
793 		return ret;
794 
795 	if (!pm_runtime_suspended(dev)) {
796 		clk_disable_unprepare(rs->spiclk);
797 		clk_disable_unprepare(rs->apb_pclk);
798 	}
799 
800 	return ret;
801 }
802 
803 static int rockchip_spi_resume(struct device *dev)
804 {
805 	int ret = 0;
806 	struct spi_master *master = dev_get_drvdata(dev);
807 	struct rockchip_spi *rs = spi_master_get_devdata(master);
808 
809 	if (!pm_runtime_suspended(dev)) {
810 		ret = clk_prepare_enable(rs->apb_pclk);
811 		if (ret < 0)
812 			return ret;
813 
814 		ret = clk_prepare_enable(rs->spiclk);
815 		if (ret < 0) {
816 			clk_disable_unprepare(rs->apb_pclk);
817 			return ret;
818 		}
819 	}
820 
821 	ret = spi_master_resume(rs->master);
822 	if (ret < 0) {
823 		clk_disable_unprepare(rs->spiclk);
824 		clk_disable_unprepare(rs->apb_pclk);
825 	}
826 
827 	return ret;
828 }
829 #endif /* CONFIG_PM_SLEEP */
830 
831 #ifdef CONFIG_PM
832 static int rockchip_spi_runtime_suspend(struct device *dev)
833 {
834 	struct spi_master *master = dev_get_drvdata(dev);
835 	struct rockchip_spi *rs = spi_master_get_devdata(master);
836 
837 	clk_disable_unprepare(rs->spiclk);
838 	clk_disable_unprepare(rs->apb_pclk);
839 
840 	return 0;
841 }
842 
843 static int rockchip_spi_runtime_resume(struct device *dev)
844 {
845 	int ret;
846 	struct spi_master *master = dev_get_drvdata(dev);
847 	struct rockchip_spi *rs = spi_master_get_devdata(master);
848 
849 	ret = clk_prepare_enable(rs->apb_pclk);
850 	if (ret)
851 		return ret;
852 
853 	ret = clk_prepare_enable(rs->spiclk);
854 	if (ret)
855 		clk_disable_unprepare(rs->apb_pclk);
856 
857 	return ret;
858 }
859 #endif /* CONFIG_PM */
860 
861 static const struct dev_pm_ops rockchip_spi_pm = {
862 	SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
863 	SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
864 			   rockchip_spi_runtime_resume, NULL)
865 };
866 
867 static const struct of_device_id rockchip_spi_dt_match[] = {
868 	{ .compatible = "rockchip,rk3066-spi", },
869 	{ .compatible = "rockchip,rk3188-spi", },
870 	{ .compatible = "rockchip,rk3288-spi", },
871 	{ },
872 };
873 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
874 
875 static struct platform_driver rockchip_spi_driver = {
876 	.driver = {
877 		.name	= DRIVER_NAME,
878 		.pm = &rockchip_spi_pm,
879 		.of_match_table = of_match_ptr(rockchip_spi_dt_match),
880 	},
881 	.probe = rockchip_spi_probe,
882 	.remove = rockchip_spi_remove,
883 };
884 
885 module_platform_driver(rockchip_spi_driver);
886 
887 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
888 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
889 MODULE_LICENSE("GPL v2");
890