xref: /openbmc/linux/drivers/spi/spi-rockchip.c (revision af958a38)
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 enum rockchip_ssi_type {
149 	SSI_MOTO_SPI = 0,
150 	SSI_TI_SSP,
151 	SSI_NS_MICROWIRE,
152 };
153 
154 struct rockchip_spi_dma_data {
155 	struct dma_chan *ch;
156 	enum dma_transfer_direction direction;
157 	dma_addr_t addr;
158 };
159 
160 struct rockchip_spi {
161 	struct device *dev;
162 	struct spi_master *master;
163 
164 	struct clk *spiclk;
165 	struct clk *apb_pclk;
166 
167 	void __iomem *regs;
168 	/*depth of the FIFO buffer */
169 	u32 fifo_len;
170 	/* max bus freq supported */
171 	u32 max_freq;
172 	/* supported slave numbers */
173 	enum rockchip_ssi_type type;
174 
175 	u16 mode;
176 	u8 tmode;
177 	u8 bpw;
178 	u8 n_bytes;
179 	unsigned len;
180 	u32 speed;
181 
182 	const void *tx;
183 	const void *tx_end;
184 	void *rx;
185 	void *rx_end;
186 
187 	u32 state;
188 	/* protect state */
189 	spinlock_t lock;
190 
191 	struct completion xfer_completion;
192 
193 	u32 use_dma;
194 	struct sg_table tx_sg;
195 	struct sg_table rx_sg;
196 	struct rockchip_spi_dma_data dma_rx;
197 	struct rockchip_spi_dma_data dma_tx;
198 };
199 
200 static inline void spi_enable_chip(struct rockchip_spi *rs, int enable)
201 {
202 	writel_relaxed((enable ? 1 : 0), rs->regs + ROCKCHIP_SPI_SSIENR);
203 }
204 
205 static inline void spi_set_clk(struct rockchip_spi *rs, u16 div)
206 {
207 	writel_relaxed(div, rs->regs + ROCKCHIP_SPI_BAUDR);
208 }
209 
210 static inline void flush_fifo(struct rockchip_spi *rs)
211 {
212 	while (readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR))
213 		readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
214 }
215 
216 static inline void wait_for_idle(struct rockchip_spi *rs)
217 {
218 	unsigned long timeout = jiffies + msecs_to_jiffies(5);
219 
220 	do {
221 		if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
222 			return;
223 	} while (time_before(jiffies, timeout));
224 
225 	dev_warn(rs->dev, "spi controller is in busy state!\n");
226 }
227 
228 static u32 get_fifo_len(struct rockchip_spi *rs)
229 {
230 	u32 fifo;
231 
232 	for (fifo = 2; fifo < 32; fifo++) {
233 		writel_relaxed(fifo, rs->regs + ROCKCHIP_SPI_TXFTLR);
234 		if (fifo != readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFTLR))
235 			break;
236 	}
237 
238 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_TXFTLR);
239 
240 	return (fifo == 31) ? 0 : fifo;
241 }
242 
243 static inline u32 tx_max(struct rockchip_spi *rs)
244 {
245 	u32 tx_left, tx_room;
246 
247 	tx_left = (rs->tx_end - rs->tx) / rs->n_bytes;
248 	tx_room = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
249 
250 	return min(tx_left, tx_room);
251 }
252 
253 static inline u32 rx_max(struct rockchip_spi *rs)
254 {
255 	u32 rx_left = (rs->rx_end - rs->rx) / rs->n_bytes;
256 	u32 rx_room = (u32)readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
257 
258 	return min(rx_left, rx_room);
259 }
260 
261 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
262 {
263 	u32 ser;
264 	struct rockchip_spi *rs = spi_master_get_devdata(spi->master);
265 
266 	ser = readl_relaxed(rs->regs + ROCKCHIP_SPI_SER) & SER_MASK;
267 
268 	/*
269 	 * drivers/spi/spi.c:
270 	 * static void spi_set_cs(struct spi_device *spi, bool enable)
271 	 * {
272 	 *		if (spi->mode & SPI_CS_HIGH)
273 	 *			enable = !enable;
274 	 *
275 	 *		if (spi->cs_gpio >= 0)
276 	 *			gpio_set_value(spi->cs_gpio, !enable);
277 	 *		else if (spi->master->set_cs)
278 	 *		spi->master->set_cs(spi, !enable);
279 	 * }
280 	 *
281 	 * Note: enable(rockchip_spi_set_cs) = !enable(spi_set_cs)
282 	 */
283 	if (!enable)
284 		ser |= 1 << spi->chip_select;
285 	else
286 		ser &= ~(1 << spi->chip_select);
287 
288 	writel_relaxed(ser, rs->regs + ROCKCHIP_SPI_SER);
289 }
290 
291 static int rockchip_spi_prepare_message(struct spi_master *master,
292 					struct spi_message *msg)
293 {
294 	struct rockchip_spi *rs = spi_master_get_devdata(master);
295 	struct spi_device *spi = msg->spi;
296 
297 	rs->mode = spi->mode;
298 
299 	return 0;
300 }
301 
302 static int rockchip_spi_unprepare_message(struct spi_master *master,
303 					  struct spi_message *msg)
304 {
305 	unsigned long flags;
306 	struct rockchip_spi *rs = spi_master_get_devdata(master);
307 
308 	spin_lock_irqsave(&rs->lock, flags);
309 
310 	/*
311 	 * For DMA mode, we need terminate DMA channel and flush
312 	 * fifo for the next transfer if DMA thansfer timeout.
313 	 * unprepare_message() was called by core if transfer complete
314 	 * or timeout. Maybe it is reasonable for error handling here.
315 	 */
316 	if (rs->use_dma) {
317 		if (rs->state & RXBUSY) {
318 			dmaengine_terminate_all(rs->dma_rx.ch);
319 			flush_fifo(rs);
320 		}
321 
322 		if (rs->state & TXBUSY)
323 			dmaengine_terminate_all(rs->dma_tx.ch);
324 	}
325 
326 	spin_unlock_irqrestore(&rs->lock, flags);
327 
328 	return 0;
329 }
330 
331 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
332 {
333 	u32 max = tx_max(rs);
334 	u32 txw = 0;
335 
336 	while (max--) {
337 		if (rs->n_bytes == 1)
338 			txw = *(u8 *)(rs->tx);
339 		else
340 			txw = *(u16 *)(rs->tx);
341 
342 		writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
343 		rs->tx += rs->n_bytes;
344 	}
345 }
346 
347 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
348 {
349 	u32 max = rx_max(rs);
350 	u32 rxw;
351 
352 	while (max--) {
353 		rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
354 		if (rs->n_bytes == 1)
355 			*(u8 *)(rs->rx) = (u8)rxw;
356 		else
357 			*(u16 *)(rs->rx) = (u16)rxw;
358 		rs->rx += rs->n_bytes;
359 	}
360 }
361 
362 static int rockchip_spi_pio_transfer(struct rockchip_spi *rs)
363 {
364 	int remain = 0;
365 
366 	do {
367 		if (rs->tx) {
368 			remain = rs->tx_end - rs->tx;
369 			rockchip_spi_pio_writer(rs);
370 		}
371 
372 		if (rs->rx) {
373 			remain = rs->rx_end - rs->rx;
374 			rockchip_spi_pio_reader(rs);
375 		}
376 
377 		cpu_relax();
378 	} while (remain);
379 
380 	/* If tx, wait until the FIFO data completely. */
381 	if (rs->tx)
382 		wait_for_idle(rs);
383 
384 	return 0;
385 }
386 
387 static void rockchip_spi_dma_rxcb(void *data)
388 {
389 	unsigned long flags;
390 	struct rockchip_spi *rs = data;
391 
392 	spin_lock_irqsave(&rs->lock, flags);
393 
394 	rs->state &= ~RXBUSY;
395 	if (!(rs->state & TXBUSY))
396 		spi_finalize_current_transfer(rs->master);
397 
398 	spin_unlock_irqrestore(&rs->lock, flags);
399 }
400 
401 static void rockchip_spi_dma_txcb(void *data)
402 {
403 	unsigned long flags;
404 	struct rockchip_spi *rs = data;
405 
406 	/* Wait until the FIFO data completely. */
407 	wait_for_idle(rs);
408 
409 	spin_lock_irqsave(&rs->lock, flags);
410 
411 	rs->state &= ~TXBUSY;
412 	if (!(rs->state & RXBUSY))
413 		spi_finalize_current_transfer(rs->master);
414 
415 	spin_unlock_irqrestore(&rs->lock, flags);
416 }
417 
418 static int rockchip_spi_dma_transfer(struct rockchip_spi *rs)
419 {
420 	unsigned long flags;
421 	struct dma_slave_config rxconf, txconf;
422 	struct dma_async_tx_descriptor *rxdesc, *txdesc;
423 
424 	spin_lock_irqsave(&rs->lock, flags);
425 	rs->state &= ~RXBUSY;
426 	rs->state &= ~TXBUSY;
427 	spin_unlock_irqrestore(&rs->lock, flags);
428 
429 	if (rs->rx) {
430 		rxconf.direction = rs->dma_rx.direction;
431 		rxconf.src_addr = rs->dma_rx.addr;
432 		rxconf.src_addr_width = rs->n_bytes;
433 		rxconf.src_maxburst = rs->n_bytes;
434 		dmaengine_slave_config(rs->dma_rx.ch, &rxconf);
435 
436 		rxdesc = dmaengine_prep_slave_sg(
437 				rs->dma_rx.ch,
438 				rs->rx_sg.sgl, rs->rx_sg.nents,
439 				rs->dma_rx.direction, DMA_PREP_INTERRUPT);
440 
441 		rxdesc->callback = rockchip_spi_dma_rxcb;
442 		rxdesc->callback_param = rs;
443 	}
444 
445 	if (rs->tx) {
446 		txconf.direction = rs->dma_tx.direction;
447 		txconf.dst_addr = rs->dma_tx.addr;
448 		txconf.dst_addr_width = rs->n_bytes;
449 		txconf.dst_maxburst = rs->n_bytes;
450 		dmaengine_slave_config(rs->dma_tx.ch, &txconf);
451 
452 		txdesc = dmaengine_prep_slave_sg(
453 				rs->dma_tx.ch,
454 				rs->tx_sg.sgl, rs->tx_sg.nents,
455 				rs->dma_tx.direction, DMA_PREP_INTERRUPT);
456 
457 		txdesc->callback = rockchip_spi_dma_txcb;
458 		txdesc->callback_param = rs;
459 	}
460 
461 	/* rx must be started before tx due to spi instinct */
462 	if (rs->rx) {
463 		spin_lock_irqsave(&rs->lock, flags);
464 		rs->state |= RXBUSY;
465 		spin_unlock_irqrestore(&rs->lock, flags);
466 		dmaengine_submit(rxdesc);
467 		dma_async_issue_pending(rs->dma_rx.ch);
468 	}
469 
470 	if (rs->tx) {
471 		spin_lock_irqsave(&rs->lock, flags);
472 		rs->state |= TXBUSY;
473 		spin_unlock_irqrestore(&rs->lock, flags);
474 		dmaengine_submit(txdesc);
475 		dma_async_issue_pending(rs->dma_tx.ch);
476 	}
477 
478 	return 1;
479 }
480 
481 static void rockchip_spi_config(struct rockchip_spi *rs)
482 {
483 	u32 div = 0;
484 	u32 dmacr = 0;
485 
486 	u32 cr0 = (CR0_BHT_8BIT << CR0_BHT_OFFSET)
487 		| (CR0_SSD_ONE << CR0_SSD_OFFSET);
488 
489 	cr0 |= (rs->n_bytes << CR0_DFS_OFFSET);
490 	cr0 |= ((rs->mode & 0x3) << CR0_SCPH_OFFSET);
491 	cr0 |= (rs->tmode << CR0_XFM_OFFSET);
492 	cr0 |= (rs->type << CR0_FRF_OFFSET);
493 
494 	if (rs->use_dma) {
495 		if (rs->tx)
496 			dmacr |= TF_DMA_EN;
497 		if (rs->rx)
498 			dmacr |= RF_DMA_EN;
499 	}
500 
501 	/* div doesn't support odd number */
502 	div = max_t(u32, rs->max_freq / rs->speed, 1);
503 	div = (div + 1) & 0xfffe;
504 
505 	spi_enable_chip(rs, 0);
506 
507 	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
508 
509 	writel_relaxed(rs->len - 1, rs->regs + ROCKCHIP_SPI_CTRLR1);
510 	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_TXFTLR);
511 	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
512 
513 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMATDLR);
514 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMARDLR);
515 	writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
516 
517 	spi_set_clk(rs, div);
518 
519 	dev_dbg(rs->dev, "cr0 0x%x, div %d\n", cr0, div);
520 
521 	spi_enable_chip(rs, 1);
522 }
523 
524 static int rockchip_spi_transfer_one(
525 		struct spi_master *master,
526 		struct spi_device *spi,
527 		struct spi_transfer *xfer)
528 {
529 	int ret = 0;
530 	struct rockchip_spi *rs = spi_master_get_devdata(master);
531 
532 	WARN_ON((readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
533 
534 	if (!xfer->tx_buf && !xfer->rx_buf) {
535 		dev_err(rs->dev, "No buffer for transfer\n");
536 		return -EINVAL;
537 	}
538 
539 	rs->speed = xfer->speed_hz;
540 	rs->bpw = xfer->bits_per_word;
541 	rs->n_bytes = rs->bpw >> 3;
542 
543 	rs->tx = xfer->tx_buf;
544 	rs->tx_end = rs->tx + xfer->len;
545 	rs->rx = xfer->rx_buf;
546 	rs->rx_end = rs->rx + xfer->len;
547 	rs->len = xfer->len;
548 
549 	rs->tx_sg = xfer->tx_sg;
550 	rs->rx_sg = xfer->rx_sg;
551 
552 	if (rs->tx && rs->rx)
553 		rs->tmode = CR0_XFM_TR;
554 	else if (rs->tx)
555 		rs->tmode = CR0_XFM_TO;
556 	else if (rs->rx)
557 		rs->tmode = CR0_XFM_RO;
558 
559 	if (master->can_dma && master->can_dma(master, spi, xfer))
560 		rs->use_dma = 1;
561 	else
562 		rs->use_dma = 0;
563 
564 	rockchip_spi_config(rs);
565 
566 	if (rs->use_dma)
567 		ret = rockchip_spi_dma_transfer(rs);
568 	else
569 		ret = rockchip_spi_pio_transfer(rs);
570 
571 	return ret;
572 }
573 
574 static bool rockchip_spi_can_dma(struct spi_master *master,
575 				 struct spi_device *spi,
576 				 struct spi_transfer *xfer)
577 {
578 	struct rockchip_spi *rs = spi_master_get_devdata(master);
579 
580 	return (xfer->len > rs->fifo_len);
581 }
582 
583 static int rockchip_spi_probe(struct platform_device *pdev)
584 {
585 	int ret = 0;
586 	struct rockchip_spi *rs;
587 	struct spi_master *master;
588 	struct resource *mem;
589 
590 	master = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi));
591 	if (!master)
592 		return -ENOMEM;
593 
594 	platform_set_drvdata(pdev, master);
595 
596 	rs = spi_master_get_devdata(master);
597 	memset(rs, 0, sizeof(struct rockchip_spi));
598 
599 	/* Get basic io resource and map it */
600 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
601 	rs->regs = devm_ioremap_resource(&pdev->dev, mem);
602 	if (IS_ERR(rs->regs)) {
603 		ret =  PTR_ERR(rs->regs);
604 		goto err_ioremap_resource;
605 	}
606 
607 	rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
608 	if (IS_ERR(rs->apb_pclk)) {
609 		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
610 		ret = PTR_ERR(rs->apb_pclk);
611 		goto err_ioremap_resource;
612 	}
613 
614 	rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
615 	if (IS_ERR(rs->spiclk)) {
616 		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
617 		ret = PTR_ERR(rs->spiclk);
618 		goto err_ioremap_resource;
619 	}
620 
621 	ret = clk_prepare_enable(rs->apb_pclk);
622 	if (ret) {
623 		dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
624 		goto err_ioremap_resource;
625 	}
626 
627 	ret = clk_prepare_enable(rs->spiclk);
628 	if (ret) {
629 		dev_err(&pdev->dev, "Failed to enable spi_clk\n");
630 		goto err_spiclk_enable;
631 	}
632 
633 	spi_enable_chip(rs, 0);
634 
635 	rs->type = SSI_MOTO_SPI;
636 	rs->master = master;
637 	rs->dev = &pdev->dev;
638 	rs->max_freq = clk_get_rate(rs->spiclk);
639 
640 	rs->fifo_len = get_fifo_len(rs);
641 	if (!rs->fifo_len) {
642 		dev_err(&pdev->dev, "Failed to get fifo length\n");
643 		ret = -EINVAL;
644 		goto err_get_fifo_len;
645 	}
646 
647 	spin_lock_init(&rs->lock);
648 
649 	pm_runtime_set_active(&pdev->dev);
650 	pm_runtime_enable(&pdev->dev);
651 
652 	master->auto_runtime_pm = true;
653 	master->bus_num = pdev->id;
654 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
655 	master->num_chipselect = 2;
656 	master->dev.of_node = pdev->dev.of_node;
657 	master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8);
658 
659 	master->set_cs = rockchip_spi_set_cs;
660 	master->prepare_message = rockchip_spi_prepare_message;
661 	master->unprepare_message = rockchip_spi_unprepare_message;
662 	master->transfer_one = rockchip_spi_transfer_one;
663 
664 	rs->dma_tx.ch = dma_request_slave_channel(rs->dev, "tx");
665 	if (!rs->dma_tx.ch)
666 		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
667 
668 	rs->dma_rx.ch = dma_request_slave_channel(rs->dev, "rx");
669 	if (!rs->dma_rx.ch) {
670 		if (rs->dma_tx.ch) {
671 			dma_release_channel(rs->dma_tx.ch);
672 			rs->dma_tx.ch = NULL;
673 		}
674 		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
675 	}
676 
677 	if (rs->dma_tx.ch && rs->dma_rx.ch) {
678 		rs->dma_tx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_TXDR);
679 		rs->dma_rx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_RXDR);
680 		rs->dma_tx.direction = DMA_MEM_TO_DEV;
681 		rs->dma_rx.direction = DMA_DEV_TO_MEM;
682 
683 		master->can_dma = rockchip_spi_can_dma;
684 		master->dma_tx = rs->dma_tx.ch;
685 		master->dma_rx = rs->dma_rx.ch;
686 	}
687 
688 	ret = devm_spi_register_master(&pdev->dev, master);
689 	if (ret) {
690 		dev_err(&pdev->dev, "Failed to register master\n");
691 		goto err_register_master;
692 	}
693 
694 	return 0;
695 
696 err_register_master:
697 	if (rs->dma_tx.ch)
698 		dma_release_channel(rs->dma_tx.ch);
699 	if (rs->dma_rx.ch)
700 		dma_release_channel(rs->dma_rx.ch);
701 err_get_fifo_len:
702 	clk_disable_unprepare(rs->spiclk);
703 err_spiclk_enable:
704 	clk_disable_unprepare(rs->apb_pclk);
705 err_ioremap_resource:
706 	spi_master_put(master);
707 
708 	return ret;
709 }
710 
711 static int rockchip_spi_remove(struct platform_device *pdev)
712 {
713 	struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
714 	struct rockchip_spi *rs = spi_master_get_devdata(master);
715 
716 	pm_runtime_disable(&pdev->dev);
717 
718 	clk_disable_unprepare(rs->spiclk);
719 	clk_disable_unprepare(rs->apb_pclk);
720 
721 	if (rs->dma_tx.ch)
722 		dma_release_channel(rs->dma_tx.ch);
723 	if (rs->dma_rx.ch)
724 		dma_release_channel(rs->dma_rx.ch);
725 
726 	spi_master_put(master);
727 
728 	return 0;
729 }
730 
731 #ifdef CONFIG_PM_SLEEP
732 static int rockchip_spi_suspend(struct device *dev)
733 {
734 	int ret = 0;
735 	struct spi_master *master = dev_get_drvdata(dev);
736 	struct rockchip_spi *rs = spi_master_get_devdata(master);
737 
738 	ret = spi_master_suspend(rs->master);
739 	if (ret)
740 		return ret;
741 
742 	if (!pm_runtime_suspended(dev)) {
743 		clk_disable_unprepare(rs->spiclk);
744 		clk_disable_unprepare(rs->apb_pclk);
745 	}
746 
747 	return ret;
748 }
749 
750 static int rockchip_spi_resume(struct device *dev)
751 {
752 	int ret = 0;
753 	struct spi_master *master = dev_get_drvdata(dev);
754 	struct rockchip_spi *rs = spi_master_get_devdata(master);
755 
756 	if (!pm_runtime_suspended(dev)) {
757 		ret = clk_prepare_enable(rs->apb_pclk);
758 		if (ret < 0)
759 			return ret;
760 
761 		ret = clk_prepare_enable(rs->spiclk);
762 		if (ret < 0) {
763 			clk_disable_unprepare(rs->apb_pclk);
764 			return ret;
765 		}
766 	}
767 
768 	ret = spi_master_resume(rs->master);
769 	if (ret < 0) {
770 		clk_disable_unprepare(rs->spiclk);
771 		clk_disable_unprepare(rs->apb_pclk);
772 	}
773 
774 	return ret;
775 }
776 #endif /* CONFIG_PM_SLEEP */
777 
778 #ifdef CONFIG_PM_RUNTIME
779 static int rockchip_spi_runtime_suspend(struct device *dev)
780 {
781 	struct spi_master *master = dev_get_drvdata(dev);
782 	struct rockchip_spi *rs = spi_master_get_devdata(master);
783 
784 	clk_disable_unprepare(rs->spiclk);
785 	clk_disable_unprepare(rs->apb_pclk);
786 
787 	return 0;
788 }
789 
790 static int rockchip_spi_runtime_resume(struct device *dev)
791 {
792 	int ret;
793 	struct spi_master *master = dev_get_drvdata(dev);
794 	struct rockchip_spi *rs = spi_master_get_devdata(master);
795 
796 	ret = clk_prepare_enable(rs->apb_pclk);
797 	if (ret)
798 		return ret;
799 
800 	ret = clk_prepare_enable(rs->spiclk);
801 	if (ret)
802 		clk_disable_unprepare(rs->apb_pclk);
803 
804 	return ret;
805 }
806 #endif /* CONFIG_PM_RUNTIME */
807 
808 static const struct dev_pm_ops rockchip_spi_pm = {
809 	SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
810 	SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
811 			   rockchip_spi_runtime_resume, NULL)
812 };
813 
814 static const struct of_device_id rockchip_spi_dt_match[] = {
815 	{ .compatible = "rockchip,rk3066-spi", },
816 	{ .compatible = "rockchip,rk3188-spi", },
817 	{ .compatible = "rockchip,rk3288-spi", },
818 	{ },
819 };
820 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
821 
822 static struct platform_driver rockchip_spi_driver = {
823 	.driver = {
824 		.name	= DRIVER_NAME,
825 		.owner = THIS_MODULE,
826 		.pm = &rockchip_spi_pm,
827 		.of_match_table = of_match_ptr(rockchip_spi_dt_match),
828 	},
829 	.probe = rockchip_spi_probe,
830 	.remove = rockchip_spi_remove,
831 };
832 
833 module_platform_driver(rockchip_spi_driver);
834 
835 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
836 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
837 MODULE_LICENSE("GPL v2");
838