xref: /linux/drivers/spi/spi-rockchip.c (revision f3539c12d8196ce0a1993364d30b3a18908470d1)
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/clk.h>
17 #include <linux/dmaengine.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/platform_device.h>
21 #include <linux/spi/spi.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/scatterlist.h>
24 
25 #define DRIVER_NAME "rockchip-spi"
26 
27 /* SPI register offsets */
28 #define ROCKCHIP_SPI_CTRLR0			0x0000
29 #define ROCKCHIP_SPI_CTRLR1			0x0004
30 #define ROCKCHIP_SPI_SSIENR			0x0008
31 #define ROCKCHIP_SPI_SER			0x000c
32 #define ROCKCHIP_SPI_BAUDR			0x0010
33 #define ROCKCHIP_SPI_TXFTLR			0x0014
34 #define ROCKCHIP_SPI_RXFTLR			0x0018
35 #define ROCKCHIP_SPI_TXFLR			0x001c
36 #define ROCKCHIP_SPI_RXFLR			0x0020
37 #define ROCKCHIP_SPI_SR				0x0024
38 #define ROCKCHIP_SPI_IPR			0x0028
39 #define ROCKCHIP_SPI_IMR			0x002c
40 #define ROCKCHIP_SPI_ISR			0x0030
41 #define ROCKCHIP_SPI_RISR			0x0034
42 #define ROCKCHIP_SPI_ICR			0x0038
43 #define ROCKCHIP_SPI_DMACR			0x003c
44 #define ROCKCHIP_SPI_DMATDLR		0x0040
45 #define ROCKCHIP_SPI_DMARDLR		0x0044
46 #define ROCKCHIP_SPI_TXDR			0x0400
47 #define ROCKCHIP_SPI_RXDR			0x0800
48 
49 /* Bit fields in CTRLR0 */
50 #define CR0_DFS_OFFSET				0
51 
52 #define CR0_CFS_OFFSET				2
53 
54 #define CR0_SCPH_OFFSET				6
55 
56 #define CR0_SCPOL_OFFSET			7
57 
58 #define CR0_CSM_OFFSET				8
59 #define CR0_CSM_KEEP				0x0
60 /* ss_n be high for half sclk_out cycles */
61 #define CR0_CSM_HALF				0X1
62 /* ss_n be high for one sclk_out cycle */
63 #define CR0_CSM_ONE					0x2
64 
65 /* ss_n to sclk_out delay */
66 #define CR0_SSD_OFFSET				10
67 /*
68  * The period between ss_n active and
69  * sclk_out active is half sclk_out cycles
70  */
71 #define CR0_SSD_HALF				0x0
72 /*
73  * The period between ss_n active and
74  * sclk_out active is one sclk_out cycle
75  */
76 #define CR0_SSD_ONE					0x1
77 
78 #define CR0_EM_OFFSET				11
79 #define CR0_EM_LITTLE				0x0
80 #define CR0_EM_BIG					0x1
81 
82 #define CR0_FBM_OFFSET				12
83 #define CR0_FBM_MSB					0x0
84 #define CR0_FBM_LSB					0x1
85 
86 #define CR0_BHT_OFFSET				13
87 #define CR0_BHT_16BIT				0x0
88 #define CR0_BHT_8BIT				0x1
89 
90 #define CR0_RSD_OFFSET				14
91 
92 #define CR0_FRF_OFFSET				16
93 #define CR0_FRF_SPI					0x0
94 #define CR0_FRF_SSP					0x1
95 #define CR0_FRF_MICROWIRE			0x2
96 
97 #define CR0_XFM_OFFSET				18
98 #define CR0_XFM_MASK				(0x03 << SPI_XFM_OFFSET)
99 #define CR0_XFM_TR					0x0
100 #define CR0_XFM_TO					0x1
101 #define CR0_XFM_RO					0x2
102 
103 #define CR0_OPM_OFFSET				20
104 #define CR0_OPM_MASTER				0x0
105 #define CR0_OPM_SLAVE				0x1
106 
107 #define CR0_MTM_OFFSET				0x21
108 
109 /* Bit fields in SER, 2bit */
110 #define SER_MASK					0x3
111 
112 /* Bit fields in SR, 5bit */
113 #define SR_MASK						0x1f
114 #define SR_BUSY						(1 << 0)
115 #define SR_TF_FULL					(1 << 1)
116 #define SR_TF_EMPTY					(1 << 2)
117 #define SR_RF_EMPTY					(1 << 3)
118 #define SR_RF_FULL					(1 << 4)
119 
120 /* Bit fields in ISR, IMR, ISR, RISR, 5bit */
121 #define INT_MASK					0x1f
122 #define INT_TF_EMPTY				(1 << 0)
123 #define INT_TF_OVERFLOW				(1 << 1)
124 #define INT_RF_UNDERFLOW			(1 << 2)
125 #define INT_RF_OVERFLOW				(1 << 3)
126 #define INT_RF_FULL					(1 << 4)
127 
128 /* Bit fields in ICR, 4bit */
129 #define ICR_MASK					0x0f
130 #define ICR_ALL						(1 << 0)
131 #define ICR_RF_UNDERFLOW			(1 << 1)
132 #define ICR_RF_OVERFLOW				(1 << 2)
133 #define ICR_TF_OVERFLOW				(1 << 3)
134 
135 /* Bit fields in DMACR */
136 #define RF_DMA_EN					(1 << 0)
137 #define TF_DMA_EN					(1 << 1)
138 
139 #define RXBUSY						(1 << 0)
140 #define TXBUSY						(1 << 1)
141 
142 /* sclk_out: spi master internal logic in rk3x can support 50Mhz */
143 #define MAX_SCLK_OUT		50000000
144 
145 /*
146  * SPI_CTRLR1 is 16-bits, so we should support lengths of 0xffff + 1. However,
147  * the controller seems to hang when given 0x10000, so stick with this for now.
148  */
149 #define ROCKCHIP_SPI_MAX_TRANLEN		0xffff
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 	u32 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 	u32 use_dma;
196 	struct sg_table tx_sg;
197 	struct sg_table rx_sg;
198 	struct rockchip_spi_dma_data dma_rx;
199 	struct rockchip_spi_dma_data dma_tx;
200 	struct dma_slave_caps dma_caps;
201 };
202 
203 static inline void spi_enable_chip(struct rockchip_spi *rs, int enable)
204 {
205 	writel_relaxed((enable ? 1 : 0), rs->regs + ROCKCHIP_SPI_SSIENR);
206 }
207 
208 static inline void spi_set_clk(struct rockchip_spi *rs, u16 div)
209 {
210 	writel_relaxed(div, rs->regs + ROCKCHIP_SPI_BAUDR);
211 }
212 
213 static inline void flush_fifo(struct rockchip_spi *rs)
214 {
215 	while (readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR))
216 		readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
217 }
218 
219 static inline void wait_for_idle(struct rockchip_spi *rs)
220 {
221 	unsigned long timeout = jiffies + msecs_to_jiffies(5);
222 
223 	do {
224 		if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
225 			return;
226 	} while (!time_after(jiffies, timeout));
227 
228 	dev_warn(rs->dev, "spi controller is in busy state!\n");
229 }
230 
231 static u32 get_fifo_len(struct rockchip_spi *rs)
232 {
233 	u32 fifo;
234 
235 	for (fifo = 2; fifo < 32; fifo++) {
236 		writel_relaxed(fifo, rs->regs + ROCKCHIP_SPI_TXFTLR);
237 		if (fifo != readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFTLR))
238 			break;
239 	}
240 
241 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_TXFTLR);
242 
243 	return (fifo == 31) ? 0 : fifo;
244 }
245 
246 static inline u32 tx_max(struct rockchip_spi *rs)
247 {
248 	u32 tx_left, tx_room;
249 
250 	tx_left = (rs->tx_end - rs->tx) / rs->n_bytes;
251 	tx_room = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
252 
253 	return min(tx_left, tx_room);
254 }
255 
256 static inline u32 rx_max(struct rockchip_spi *rs)
257 {
258 	u32 rx_left = (rs->rx_end - rs->rx) / rs->n_bytes;
259 	u32 rx_room = (u32)readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
260 
261 	return min(rx_left, rx_room);
262 }
263 
264 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
265 {
266 	u32 ser;
267 	struct spi_master *master = spi->master;
268 	struct rockchip_spi *rs = spi_master_get_devdata(master);
269 
270 	pm_runtime_get_sync(rs->dev);
271 
272 	ser = readl_relaxed(rs->regs + ROCKCHIP_SPI_SER) & SER_MASK;
273 
274 	/*
275 	 * drivers/spi/spi.c:
276 	 * static void spi_set_cs(struct spi_device *spi, bool enable)
277 	 * {
278 	 *		if (spi->mode & SPI_CS_HIGH)
279 	 *			enable = !enable;
280 	 *
281 	 *		if (spi->cs_gpio >= 0)
282 	 *			gpio_set_value(spi->cs_gpio, !enable);
283 	 *		else if (spi->master->set_cs)
284 	 *		spi->master->set_cs(spi, !enable);
285 	 * }
286 	 *
287 	 * Note: enable(rockchip_spi_set_cs) = !enable(spi_set_cs)
288 	 */
289 	if (!enable)
290 		ser |= 1 << spi->chip_select;
291 	else
292 		ser &= ~(1 << spi->chip_select);
293 
294 	writel_relaxed(ser, rs->regs + ROCKCHIP_SPI_SER);
295 
296 	pm_runtime_put_sync(rs->dev);
297 }
298 
299 static int rockchip_spi_prepare_message(struct spi_master *master,
300 					struct spi_message *msg)
301 {
302 	struct rockchip_spi *rs = spi_master_get_devdata(master);
303 	struct spi_device *spi = msg->spi;
304 
305 	rs->mode = spi->mode;
306 
307 	return 0;
308 }
309 
310 static void rockchip_spi_handle_err(struct spi_master *master,
311 				    struct spi_message *msg)
312 {
313 	unsigned long flags;
314 	struct rockchip_spi *rs = spi_master_get_devdata(master);
315 
316 	spin_lock_irqsave(&rs->lock, flags);
317 
318 	/*
319 	 * For DMA mode, we need terminate DMA channel and flush
320 	 * fifo for the next transfer if DMA thansfer timeout.
321 	 * handle_err() was called by core if transfer failed.
322 	 * Maybe it is reasonable for error handling here.
323 	 */
324 	if (rs->use_dma) {
325 		if (rs->state & RXBUSY) {
326 			dmaengine_terminate_async(rs->dma_rx.ch);
327 			flush_fifo(rs);
328 		}
329 
330 		if (rs->state & TXBUSY)
331 			dmaengine_terminate_async(rs->dma_tx.ch);
332 	}
333 
334 	spin_unlock_irqrestore(&rs->lock, flags);
335 }
336 
337 static int rockchip_spi_unprepare_message(struct spi_master *master,
338 					  struct spi_message *msg)
339 {
340 	struct rockchip_spi *rs = spi_master_get_devdata(master);
341 
342 	spi_enable_chip(rs, 0);
343 
344 	return 0;
345 }
346 
347 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
348 {
349 	u32 max = tx_max(rs);
350 	u32 txw = 0;
351 
352 	while (max--) {
353 		if (rs->n_bytes == 1)
354 			txw = *(u8 *)(rs->tx);
355 		else
356 			txw = *(u16 *)(rs->tx);
357 
358 		writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
359 		rs->tx += rs->n_bytes;
360 	}
361 }
362 
363 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
364 {
365 	u32 max = rx_max(rs);
366 	u32 rxw;
367 
368 	while (max--) {
369 		rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
370 		if (rs->n_bytes == 1)
371 			*(u8 *)(rs->rx) = (u8)rxw;
372 		else
373 			*(u16 *)(rs->rx) = (u16)rxw;
374 		rs->rx += rs->n_bytes;
375 	}
376 }
377 
378 static int rockchip_spi_pio_transfer(struct rockchip_spi *rs)
379 {
380 	int remain = 0;
381 
382 	do {
383 		if (rs->tx) {
384 			remain = rs->tx_end - rs->tx;
385 			rockchip_spi_pio_writer(rs);
386 		}
387 
388 		if (rs->rx) {
389 			remain = rs->rx_end - rs->rx;
390 			rockchip_spi_pio_reader(rs);
391 		}
392 
393 		cpu_relax();
394 	} while (remain);
395 
396 	/* If tx, wait until the FIFO data completely. */
397 	if (rs->tx)
398 		wait_for_idle(rs);
399 
400 	spi_enable_chip(rs, 0);
401 
402 	return 0;
403 }
404 
405 static void rockchip_spi_dma_rxcb(void *data)
406 {
407 	unsigned long flags;
408 	struct rockchip_spi *rs = data;
409 
410 	spin_lock_irqsave(&rs->lock, flags);
411 
412 	rs->state &= ~RXBUSY;
413 	if (!(rs->state & TXBUSY)) {
414 		spi_enable_chip(rs, 0);
415 		spi_finalize_current_transfer(rs->master);
416 	}
417 
418 	spin_unlock_irqrestore(&rs->lock, flags);
419 }
420 
421 static void rockchip_spi_dma_txcb(void *data)
422 {
423 	unsigned long flags;
424 	struct rockchip_spi *rs = data;
425 
426 	/* Wait until the FIFO data completely. */
427 	wait_for_idle(rs);
428 
429 	spin_lock_irqsave(&rs->lock, flags);
430 
431 	rs->state &= ~TXBUSY;
432 	if (!(rs->state & RXBUSY)) {
433 		spi_enable_chip(rs, 0);
434 		spi_finalize_current_transfer(rs->master);
435 	}
436 
437 	spin_unlock_irqrestore(&rs->lock, flags);
438 }
439 
440 static int rockchip_spi_prepare_dma(struct rockchip_spi *rs)
441 {
442 	unsigned long flags;
443 	struct dma_slave_config rxconf, txconf;
444 	struct dma_async_tx_descriptor *rxdesc, *txdesc;
445 
446 	spin_lock_irqsave(&rs->lock, flags);
447 	rs->state &= ~RXBUSY;
448 	rs->state &= ~TXBUSY;
449 	spin_unlock_irqrestore(&rs->lock, flags);
450 
451 	rxdesc = NULL;
452 	if (rs->rx) {
453 		rxconf.direction = rs->dma_rx.direction;
454 		rxconf.src_addr = rs->dma_rx.addr;
455 		rxconf.src_addr_width = rs->n_bytes;
456 		if (rs->dma_caps.max_burst > 4)
457 			rxconf.src_maxburst = 4;
458 		else
459 			rxconf.src_maxburst = 1;
460 		dmaengine_slave_config(rs->dma_rx.ch, &rxconf);
461 
462 		rxdesc = dmaengine_prep_slave_sg(
463 				rs->dma_rx.ch,
464 				rs->rx_sg.sgl, rs->rx_sg.nents,
465 				rs->dma_rx.direction, DMA_PREP_INTERRUPT);
466 		if (!rxdesc)
467 			return -EINVAL;
468 
469 		rxdesc->callback = rockchip_spi_dma_rxcb;
470 		rxdesc->callback_param = rs;
471 	}
472 
473 	txdesc = NULL;
474 	if (rs->tx) {
475 		txconf.direction = rs->dma_tx.direction;
476 		txconf.dst_addr = rs->dma_tx.addr;
477 		txconf.dst_addr_width = rs->n_bytes;
478 		if (rs->dma_caps.max_burst > 4)
479 			txconf.dst_maxburst = 4;
480 		else
481 			txconf.dst_maxburst = 1;
482 		dmaengine_slave_config(rs->dma_tx.ch, &txconf);
483 
484 		txdesc = dmaengine_prep_slave_sg(
485 				rs->dma_tx.ch,
486 				rs->tx_sg.sgl, rs->tx_sg.nents,
487 				rs->dma_tx.direction, DMA_PREP_INTERRUPT);
488 		if (!txdesc) {
489 			if (rxdesc)
490 				dmaengine_terminate_sync(rs->dma_rx.ch);
491 			return -EINVAL;
492 		}
493 
494 		txdesc->callback = rockchip_spi_dma_txcb;
495 		txdesc->callback_param = rs;
496 	}
497 
498 	/* rx must be started before tx due to spi instinct */
499 	if (rxdesc) {
500 		spin_lock_irqsave(&rs->lock, flags);
501 		rs->state |= RXBUSY;
502 		spin_unlock_irqrestore(&rs->lock, flags);
503 		dmaengine_submit(rxdesc);
504 		dma_async_issue_pending(rs->dma_rx.ch);
505 	}
506 
507 	if (txdesc) {
508 		spin_lock_irqsave(&rs->lock, flags);
509 		rs->state |= TXBUSY;
510 		spin_unlock_irqrestore(&rs->lock, flags);
511 		dmaengine_submit(txdesc);
512 		dma_async_issue_pending(rs->dma_tx.ch);
513 	}
514 
515 	return 0;
516 }
517 
518 static void rockchip_spi_config(struct rockchip_spi *rs)
519 {
520 	u32 div = 0;
521 	u32 dmacr = 0;
522 	int rsd = 0;
523 
524 	u32 cr0 = (CR0_BHT_8BIT << CR0_BHT_OFFSET)
525 		| (CR0_SSD_ONE << CR0_SSD_OFFSET)
526 		| (CR0_EM_BIG << CR0_EM_OFFSET);
527 
528 	cr0 |= (rs->n_bytes << CR0_DFS_OFFSET);
529 	cr0 |= ((rs->mode & 0x3) << CR0_SCPH_OFFSET);
530 	cr0 |= (rs->tmode << CR0_XFM_OFFSET);
531 	cr0 |= (rs->type << CR0_FRF_OFFSET);
532 
533 	if (rs->use_dma) {
534 		if (rs->tx)
535 			dmacr |= TF_DMA_EN;
536 		if (rs->rx)
537 			dmacr |= RF_DMA_EN;
538 	}
539 
540 	if (WARN_ON(rs->speed > MAX_SCLK_OUT))
541 		rs->speed = MAX_SCLK_OUT;
542 
543 	/* the minimum divisor is 2 */
544 	if (rs->max_freq < 2 * rs->speed) {
545 		clk_set_rate(rs->spiclk, 2 * rs->speed);
546 		rs->max_freq = clk_get_rate(rs->spiclk);
547 	}
548 
549 	/* div doesn't support odd number */
550 	div = DIV_ROUND_UP(rs->max_freq, rs->speed);
551 	div = (div + 1) & 0xfffe;
552 
553 	/* Rx sample delay is expressed in parent clock cycles (max 3) */
554 	rsd = DIV_ROUND_CLOSEST(rs->rsd_nsecs * (rs->max_freq >> 8),
555 				1000000000 >> 8);
556 	if (!rsd && rs->rsd_nsecs) {
557 		pr_warn_once("rockchip-spi: %u Hz are too slow to express %u ns delay\n",
558 			     rs->max_freq, rs->rsd_nsecs);
559 	} else if (rsd > 3) {
560 		rsd = 3;
561 		pr_warn_once("rockchip-spi: %u Hz are too fast to express %u ns delay, clamping at %u ns\n",
562 			     rs->max_freq, rs->rsd_nsecs,
563 			     rsd * 1000000000U / rs->max_freq);
564 	}
565 	cr0 |= rsd << CR0_RSD_OFFSET;
566 
567 	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
568 
569 	writel_relaxed(rs->len - 1, rs->regs + ROCKCHIP_SPI_CTRLR1);
570 	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_TXFTLR);
571 	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
572 
573 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMATDLR);
574 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMARDLR);
575 	writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
576 
577 	spi_set_clk(rs, div);
578 
579 	dev_dbg(rs->dev, "cr0 0x%x, div %d\n", cr0, div);
580 }
581 
582 static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
583 {
584 	return ROCKCHIP_SPI_MAX_TRANLEN;
585 }
586 
587 static int rockchip_spi_transfer_one(
588 		struct spi_master *master,
589 		struct spi_device *spi,
590 		struct spi_transfer *xfer)
591 {
592 	int ret = 0;
593 	struct rockchip_spi *rs = spi_master_get_devdata(master);
594 
595 	WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
596 		(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
597 
598 	if (!xfer->tx_buf && !xfer->rx_buf) {
599 		dev_err(rs->dev, "No buffer for transfer\n");
600 		return -EINVAL;
601 	}
602 
603 	if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
604 		dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
605 		return -EINVAL;
606 	}
607 
608 	rs->speed = xfer->speed_hz;
609 	rs->bpw = xfer->bits_per_word;
610 	rs->n_bytes = rs->bpw >> 3;
611 
612 	rs->tx = xfer->tx_buf;
613 	rs->tx_end = rs->tx + xfer->len;
614 	rs->rx = xfer->rx_buf;
615 	rs->rx_end = rs->rx + xfer->len;
616 	rs->len = xfer->len;
617 
618 	rs->tx_sg = xfer->tx_sg;
619 	rs->rx_sg = xfer->rx_sg;
620 
621 	if (rs->tx && rs->rx)
622 		rs->tmode = CR0_XFM_TR;
623 	else if (rs->tx)
624 		rs->tmode = CR0_XFM_TO;
625 	else if (rs->rx)
626 		rs->tmode = CR0_XFM_RO;
627 
628 	/* we need prepare dma before spi was enabled */
629 	if (master->can_dma && master->can_dma(master, spi, xfer))
630 		rs->use_dma = 1;
631 	else
632 		rs->use_dma = 0;
633 
634 	rockchip_spi_config(rs);
635 
636 	if (rs->use_dma) {
637 		if (rs->tmode == CR0_XFM_RO) {
638 			/* rx: dma must be prepared first */
639 			ret = rockchip_spi_prepare_dma(rs);
640 			spi_enable_chip(rs, 1);
641 		} else {
642 			/* tx or tr: spi must be enabled first */
643 			spi_enable_chip(rs, 1);
644 			ret = rockchip_spi_prepare_dma(rs);
645 		}
646 		/* successful DMA prepare means the transfer is in progress */
647 		ret = ret ? ret : 1;
648 	} else {
649 		spi_enable_chip(rs, 1);
650 		ret = rockchip_spi_pio_transfer(rs);
651 	}
652 
653 	return ret;
654 }
655 
656 static bool rockchip_spi_can_dma(struct spi_master *master,
657 				 struct spi_device *spi,
658 				 struct spi_transfer *xfer)
659 {
660 	struct rockchip_spi *rs = spi_master_get_devdata(master);
661 
662 	return (xfer->len > rs->fifo_len);
663 }
664 
665 static int rockchip_spi_probe(struct platform_device *pdev)
666 {
667 	int ret = 0;
668 	struct rockchip_spi *rs;
669 	struct spi_master *master;
670 	struct resource *mem;
671 	u32 rsd_nsecs;
672 
673 	master = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi));
674 	if (!master)
675 		return -ENOMEM;
676 
677 	platform_set_drvdata(pdev, master);
678 
679 	rs = spi_master_get_devdata(master);
680 
681 	/* Get basic io resource and map it */
682 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
683 	rs->regs = devm_ioremap_resource(&pdev->dev, mem);
684 	if (IS_ERR(rs->regs)) {
685 		ret =  PTR_ERR(rs->regs);
686 		goto err_ioremap_resource;
687 	}
688 
689 	rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
690 	if (IS_ERR(rs->apb_pclk)) {
691 		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
692 		ret = PTR_ERR(rs->apb_pclk);
693 		goto err_ioremap_resource;
694 	}
695 
696 	rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
697 	if (IS_ERR(rs->spiclk)) {
698 		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
699 		ret = PTR_ERR(rs->spiclk);
700 		goto err_ioremap_resource;
701 	}
702 
703 	ret = clk_prepare_enable(rs->apb_pclk);
704 	if (ret) {
705 		dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
706 		goto err_ioremap_resource;
707 	}
708 
709 	ret = clk_prepare_enable(rs->spiclk);
710 	if (ret) {
711 		dev_err(&pdev->dev, "Failed to enable spi_clk\n");
712 		goto err_spiclk_enable;
713 	}
714 
715 	spi_enable_chip(rs, 0);
716 
717 	rs->type = SSI_MOTO_SPI;
718 	rs->master = master;
719 	rs->dev = &pdev->dev;
720 	rs->max_freq = clk_get_rate(rs->spiclk);
721 
722 	if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
723 				  &rsd_nsecs))
724 		rs->rsd_nsecs = rsd_nsecs;
725 
726 	rs->fifo_len = get_fifo_len(rs);
727 	if (!rs->fifo_len) {
728 		dev_err(&pdev->dev, "Failed to get fifo length\n");
729 		ret = -EINVAL;
730 		goto err_get_fifo_len;
731 	}
732 
733 	spin_lock_init(&rs->lock);
734 
735 	pm_runtime_set_active(&pdev->dev);
736 	pm_runtime_enable(&pdev->dev);
737 
738 	master->auto_runtime_pm = true;
739 	master->bus_num = pdev->id;
740 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
741 	master->num_chipselect = 2;
742 	master->dev.of_node = pdev->dev.of_node;
743 	master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8);
744 
745 	master->set_cs = rockchip_spi_set_cs;
746 	master->prepare_message = rockchip_spi_prepare_message;
747 	master->unprepare_message = rockchip_spi_unprepare_message;
748 	master->transfer_one = rockchip_spi_transfer_one;
749 	master->max_transfer_size = rockchip_spi_max_transfer_size;
750 	master->handle_err = rockchip_spi_handle_err;
751 
752 	rs->dma_tx.ch = dma_request_chan(rs->dev, "tx");
753 	if (IS_ERR(rs->dma_tx.ch)) {
754 		/* Check tx to see if we need defer probing driver */
755 		if (PTR_ERR(rs->dma_tx.ch) == -EPROBE_DEFER) {
756 			ret = -EPROBE_DEFER;
757 			goto err_get_fifo_len;
758 		}
759 		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
760 		rs->dma_tx.ch = NULL;
761 	}
762 
763 	rs->dma_rx.ch = dma_request_chan(rs->dev, "rx");
764 	if (IS_ERR(rs->dma_rx.ch)) {
765 		if (PTR_ERR(rs->dma_rx.ch) == -EPROBE_DEFER) {
766 			ret = -EPROBE_DEFER;
767 			goto err_free_dma_tx;
768 		}
769 		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
770 		rs->dma_rx.ch = NULL;
771 	}
772 
773 	if (rs->dma_tx.ch && rs->dma_rx.ch) {
774 		dma_get_slave_caps(rs->dma_rx.ch, &(rs->dma_caps));
775 		rs->dma_tx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_TXDR);
776 		rs->dma_rx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_RXDR);
777 		rs->dma_tx.direction = DMA_MEM_TO_DEV;
778 		rs->dma_rx.direction = DMA_DEV_TO_MEM;
779 
780 		master->can_dma = rockchip_spi_can_dma;
781 		master->dma_tx = rs->dma_tx.ch;
782 		master->dma_rx = rs->dma_rx.ch;
783 	}
784 
785 	ret = devm_spi_register_master(&pdev->dev, master);
786 	if (ret) {
787 		dev_err(&pdev->dev, "Failed to register master\n");
788 		goto err_register_master;
789 	}
790 
791 	return 0;
792 
793 err_register_master:
794 	pm_runtime_disable(&pdev->dev);
795 	if (rs->dma_rx.ch)
796 		dma_release_channel(rs->dma_rx.ch);
797 err_free_dma_tx:
798 	if (rs->dma_tx.ch)
799 		dma_release_channel(rs->dma_tx.ch);
800 err_get_fifo_len:
801 	clk_disable_unprepare(rs->spiclk);
802 err_spiclk_enable:
803 	clk_disable_unprepare(rs->apb_pclk);
804 err_ioremap_resource:
805 	spi_master_put(master);
806 
807 	return ret;
808 }
809 
810 static int rockchip_spi_remove(struct platform_device *pdev)
811 {
812 	struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
813 	struct rockchip_spi *rs = spi_master_get_devdata(master);
814 
815 	pm_runtime_disable(&pdev->dev);
816 
817 	clk_disable_unprepare(rs->spiclk);
818 	clk_disable_unprepare(rs->apb_pclk);
819 
820 	if (rs->dma_tx.ch)
821 		dma_release_channel(rs->dma_tx.ch);
822 	if (rs->dma_rx.ch)
823 		dma_release_channel(rs->dma_rx.ch);
824 
825 	spi_master_put(master);
826 
827 	return 0;
828 }
829 
830 #ifdef CONFIG_PM_SLEEP
831 static int rockchip_spi_suspend(struct device *dev)
832 {
833 	int ret = 0;
834 	struct spi_master *master = dev_get_drvdata(dev);
835 	struct rockchip_spi *rs = spi_master_get_devdata(master);
836 
837 	ret = spi_master_suspend(rs->master);
838 	if (ret)
839 		return ret;
840 
841 	if (!pm_runtime_suspended(dev)) {
842 		clk_disable_unprepare(rs->spiclk);
843 		clk_disable_unprepare(rs->apb_pclk);
844 	}
845 
846 	return ret;
847 }
848 
849 static int rockchip_spi_resume(struct device *dev)
850 {
851 	int ret = 0;
852 	struct spi_master *master = dev_get_drvdata(dev);
853 	struct rockchip_spi *rs = spi_master_get_devdata(master);
854 
855 	if (!pm_runtime_suspended(dev)) {
856 		ret = clk_prepare_enable(rs->apb_pclk);
857 		if (ret < 0)
858 			return ret;
859 
860 		ret = clk_prepare_enable(rs->spiclk);
861 		if (ret < 0) {
862 			clk_disable_unprepare(rs->apb_pclk);
863 			return ret;
864 		}
865 	}
866 
867 	ret = spi_master_resume(rs->master);
868 	if (ret < 0) {
869 		clk_disable_unprepare(rs->spiclk);
870 		clk_disable_unprepare(rs->apb_pclk);
871 	}
872 
873 	return ret;
874 }
875 #endif /* CONFIG_PM_SLEEP */
876 
877 #ifdef CONFIG_PM
878 static int rockchip_spi_runtime_suspend(struct device *dev)
879 {
880 	struct spi_master *master = dev_get_drvdata(dev);
881 	struct rockchip_spi *rs = spi_master_get_devdata(master);
882 
883 	clk_disable_unprepare(rs->spiclk);
884 	clk_disable_unprepare(rs->apb_pclk);
885 
886 	return 0;
887 }
888 
889 static int rockchip_spi_runtime_resume(struct device *dev)
890 {
891 	int ret;
892 	struct spi_master *master = dev_get_drvdata(dev);
893 	struct rockchip_spi *rs = spi_master_get_devdata(master);
894 
895 	ret = clk_prepare_enable(rs->apb_pclk);
896 	if (ret)
897 		return ret;
898 
899 	ret = clk_prepare_enable(rs->spiclk);
900 	if (ret)
901 		clk_disable_unprepare(rs->apb_pclk);
902 
903 	return ret;
904 }
905 #endif /* CONFIG_PM */
906 
907 static const struct dev_pm_ops rockchip_spi_pm = {
908 	SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
909 	SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
910 			   rockchip_spi_runtime_resume, NULL)
911 };
912 
913 static const struct of_device_id rockchip_spi_dt_match[] = {
914 	{ .compatible = "rockchip,rk3036-spi", },
915 	{ .compatible = "rockchip,rk3066-spi", },
916 	{ .compatible = "rockchip,rk3188-spi", },
917 	{ .compatible = "rockchip,rk3228-spi", },
918 	{ .compatible = "rockchip,rk3288-spi", },
919 	{ .compatible = "rockchip,rk3368-spi", },
920 	{ .compatible = "rockchip,rk3399-spi", },
921 	{ },
922 };
923 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
924 
925 static struct platform_driver rockchip_spi_driver = {
926 	.driver = {
927 		.name	= DRIVER_NAME,
928 		.pm = &rockchip_spi_pm,
929 		.of_match_table = of_match_ptr(rockchip_spi_dt_match),
930 	},
931 	.probe = rockchip_spi_probe,
932 	.remove = rockchip_spi_remove,
933 };
934 
935 module_platform_driver(rockchip_spi_driver);
936 
937 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
938 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
939 MODULE_LICENSE("GPL v2");
940