xref: /linux/drivers/spi/spi-rockchip.c (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
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/pinctrl/consumer.h>
21 #include <linux/platform_device.h>
22 #include <linux/spi/spi.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/scatterlist.h>
25 
26 #define DRIVER_NAME "rockchip-spi"
27 
28 /* SPI register offsets */
29 #define ROCKCHIP_SPI_CTRLR0			0x0000
30 #define ROCKCHIP_SPI_CTRLR1			0x0004
31 #define ROCKCHIP_SPI_SSIENR			0x0008
32 #define ROCKCHIP_SPI_SER			0x000c
33 #define ROCKCHIP_SPI_BAUDR			0x0010
34 #define ROCKCHIP_SPI_TXFTLR			0x0014
35 #define ROCKCHIP_SPI_RXFTLR			0x0018
36 #define ROCKCHIP_SPI_TXFLR			0x001c
37 #define ROCKCHIP_SPI_RXFLR			0x0020
38 #define ROCKCHIP_SPI_SR				0x0024
39 #define ROCKCHIP_SPI_IPR			0x0028
40 #define ROCKCHIP_SPI_IMR			0x002c
41 #define ROCKCHIP_SPI_ISR			0x0030
42 #define ROCKCHIP_SPI_RISR			0x0034
43 #define ROCKCHIP_SPI_ICR			0x0038
44 #define ROCKCHIP_SPI_DMACR			0x003c
45 #define ROCKCHIP_SPI_DMATDLR		0x0040
46 #define ROCKCHIP_SPI_DMARDLR		0x0044
47 #define ROCKCHIP_SPI_TXDR			0x0400
48 #define ROCKCHIP_SPI_RXDR			0x0800
49 
50 /* Bit fields in CTRLR0 */
51 #define CR0_DFS_OFFSET				0
52 
53 #define CR0_CFS_OFFSET				2
54 
55 #define CR0_SCPH_OFFSET				6
56 
57 #define CR0_SCPOL_OFFSET			7
58 
59 #define CR0_CSM_OFFSET				8
60 #define CR0_CSM_KEEP				0x0
61 /* ss_n be high for half sclk_out cycles */
62 #define CR0_CSM_HALF				0X1
63 /* ss_n be high for one sclk_out cycle */
64 #define CR0_CSM_ONE					0x2
65 
66 /* ss_n to sclk_out delay */
67 #define CR0_SSD_OFFSET				10
68 /*
69  * The period between ss_n active and
70  * sclk_out active is half sclk_out cycles
71  */
72 #define CR0_SSD_HALF				0x0
73 /*
74  * The period between ss_n active and
75  * sclk_out active is one sclk_out cycle
76  */
77 #define CR0_SSD_ONE					0x1
78 
79 #define CR0_EM_OFFSET				11
80 #define CR0_EM_LITTLE				0x0
81 #define CR0_EM_BIG					0x1
82 
83 #define CR0_FBM_OFFSET				12
84 #define CR0_FBM_MSB					0x0
85 #define CR0_FBM_LSB					0x1
86 
87 #define CR0_BHT_OFFSET				13
88 #define CR0_BHT_16BIT				0x0
89 #define CR0_BHT_8BIT				0x1
90 
91 #define CR0_RSD_OFFSET				14
92 
93 #define CR0_FRF_OFFSET				16
94 #define CR0_FRF_SPI					0x0
95 #define CR0_FRF_SSP					0x1
96 #define CR0_FRF_MICROWIRE			0x2
97 
98 #define CR0_XFM_OFFSET				18
99 #define CR0_XFM_MASK				(0x03 << SPI_XFM_OFFSET)
100 #define CR0_XFM_TR					0x0
101 #define CR0_XFM_TO					0x1
102 #define CR0_XFM_RO					0x2
103 
104 #define CR0_OPM_OFFSET				20
105 #define CR0_OPM_MASTER				0x0
106 #define CR0_OPM_SLAVE				0x1
107 
108 #define CR0_MTM_OFFSET				0x21
109 
110 /* Bit fields in SER, 2bit */
111 #define SER_MASK					0x3
112 
113 /* Bit fields in SR, 5bit */
114 #define SR_MASK						0x1f
115 #define SR_BUSY						(1 << 0)
116 #define SR_TF_FULL					(1 << 1)
117 #define SR_TF_EMPTY					(1 << 2)
118 #define SR_RF_EMPTY					(1 << 3)
119 #define SR_RF_FULL					(1 << 4)
120 
121 /* Bit fields in ISR, IMR, ISR, RISR, 5bit */
122 #define INT_MASK					0x1f
123 #define INT_TF_EMPTY				(1 << 0)
124 #define INT_TF_OVERFLOW				(1 << 1)
125 #define INT_RF_UNDERFLOW			(1 << 2)
126 #define INT_RF_OVERFLOW				(1 << 3)
127 #define INT_RF_FULL					(1 << 4)
128 
129 /* Bit fields in ICR, 4bit */
130 #define ICR_MASK					0x0f
131 #define ICR_ALL						(1 << 0)
132 #define ICR_RF_UNDERFLOW			(1 << 1)
133 #define ICR_RF_OVERFLOW				(1 << 2)
134 #define ICR_TF_OVERFLOW				(1 << 3)
135 
136 /* Bit fields in DMACR */
137 #define RF_DMA_EN					(1 << 0)
138 #define TF_DMA_EN					(1 << 1)
139 
140 #define RXBUSY						(1 << 0)
141 #define TXBUSY						(1 << 1)
142 
143 /* sclk_out: spi master internal logic in rk3x can support 50Mhz */
144 #define MAX_SCLK_OUT		50000000
145 
146 /*
147  * SPI_CTRLR1 is 16-bits, so we should support lengths of 0xffff + 1. However,
148  * the controller seems to hang when given 0x10000, so stick with this for now.
149  */
150 #define ROCKCHIP_SPI_MAX_TRANLEN		0xffff
151 
152 enum rockchip_ssi_type {
153 	SSI_MOTO_SPI = 0,
154 	SSI_TI_SSP,
155 	SSI_NS_MICROWIRE,
156 };
157 
158 struct rockchip_spi_dma_data {
159 	struct dma_chan *ch;
160 	enum dma_transfer_direction direction;
161 	dma_addr_t addr;
162 };
163 
164 struct rockchip_spi {
165 	struct device *dev;
166 	struct spi_master *master;
167 
168 	struct clk *spiclk;
169 	struct clk *apb_pclk;
170 
171 	void __iomem *regs;
172 	/*depth of the FIFO buffer */
173 	u32 fifo_len;
174 	/* max bus freq supported */
175 	u32 max_freq;
176 	/* supported slave numbers */
177 	enum rockchip_ssi_type type;
178 
179 	u16 mode;
180 	u8 tmode;
181 	u8 bpw;
182 	u8 n_bytes;
183 	u32 rsd_nsecs;
184 	unsigned len;
185 	u32 speed;
186 
187 	const void *tx;
188 	const void *tx_end;
189 	void *rx;
190 	void *rx_end;
191 
192 	u32 state;
193 	/* protect state */
194 	spinlock_t lock;
195 
196 	u32 use_dma;
197 	struct sg_table tx_sg;
198 	struct sg_table rx_sg;
199 	struct rockchip_spi_dma_data dma_rx;
200 	struct rockchip_spi_dma_data dma_tx;
201 	struct dma_slave_caps dma_caps;
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 spi_master *master = spi->master;
269 	struct rockchip_spi *rs = spi_master_get_devdata(master);
270 
271 	pm_runtime_get_sync(rs->dev);
272 
273 	ser = readl_relaxed(rs->regs + ROCKCHIP_SPI_SER) & SER_MASK;
274 
275 	/*
276 	 * drivers/spi/spi.c:
277 	 * static void spi_set_cs(struct spi_device *spi, bool enable)
278 	 * {
279 	 *		if (spi->mode & SPI_CS_HIGH)
280 	 *			enable = !enable;
281 	 *
282 	 *		if (spi->cs_gpio >= 0)
283 	 *			gpio_set_value(spi->cs_gpio, !enable);
284 	 *		else if (spi->master->set_cs)
285 	 *		spi->master->set_cs(spi, !enable);
286 	 * }
287 	 *
288 	 * Note: enable(rockchip_spi_set_cs) = !enable(spi_set_cs)
289 	 */
290 	if (!enable)
291 		ser |= 1 << spi->chip_select;
292 	else
293 		ser &= ~(1 << spi->chip_select);
294 
295 	writel_relaxed(ser, rs->regs + ROCKCHIP_SPI_SER);
296 
297 	pm_runtime_put_sync(rs->dev);
298 }
299 
300 static int rockchip_spi_prepare_message(struct spi_master *master,
301 					struct spi_message *msg)
302 {
303 	struct rockchip_spi *rs = spi_master_get_devdata(master);
304 	struct spi_device *spi = msg->spi;
305 
306 	rs->mode = spi->mode;
307 
308 	return 0;
309 }
310 
311 static void rockchip_spi_handle_err(struct spi_master *master,
312 				    struct spi_message *msg)
313 {
314 	unsigned long flags;
315 	struct rockchip_spi *rs = spi_master_get_devdata(master);
316 
317 	spin_lock_irqsave(&rs->lock, flags);
318 
319 	/*
320 	 * For DMA mode, we need terminate DMA channel and flush
321 	 * fifo for the next transfer if DMA thansfer timeout.
322 	 * handle_err() was called by core if transfer failed.
323 	 * Maybe it is reasonable for error handling here.
324 	 */
325 	if (rs->use_dma) {
326 		if (rs->state & RXBUSY) {
327 			dmaengine_terminate_async(rs->dma_rx.ch);
328 			flush_fifo(rs);
329 		}
330 
331 		if (rs->state & TXBUSY)
332 			dmaengine_terminate_async(rs->dma_tx.ch);
333 	}
334 
335 	spin_unlock_irqrestore(&rs->lock, flags);
336 }
337 
338 static int rockchip_spi_unprepare_message(struct spi_master *master,
339 					  struct spi_message *msg)
340 {
341 	struct rockchip_spi *rs = spi_master_get_devdata(master);
342 
343 	spi_enable_chip(rs, 0);
344 
345 	return 0;
346 }
347 
348 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
349 {
350 	u32 max = tx_max(rs);
351 	u32 txw = 0;
352 
353 	while (max--) {
354 		if (rs->n_bytes == 1)
355 			txw = *(u8 *)(rs->tx);
356 		else
357 			txw = *(u16 *)(rs->tx);
358 
359 		writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
360 		rs->tx += rs->n_bytes;
361 	}
362 }
363 
364 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
365 {
366 	u32 max = rx_max(rs);
367 	u32 rxw;
368 
369 	while (max--) {
370 		rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
371 		if (rs->n_bytes == 1)
372 			*(u8 *)(rs->rx) = (u8)rxw;
373 		else
374 			*(u16 *)(rs->rx) = (u16)rxw;
375 		rs->rx += rs->n_bytes;
376 	}
377 }
378 
379 static int rockchip_spi_pio_transfer(struct rockchip_spi *rs)
380 {
381 	int remain = 0;
382 
383 	do {
384 		if (rs->tx) {
385 			remain = rs->tx_end - rs->tx;
386 			rockchip_spi_pio_writer(rs);
387 		}
388 
389 		if (rs->rx) {
390 			remain = rs->rx_end - rs->rx;
391 			rockchip_spi_pio_reader(rs);
392 		}
393 
394 		cpu_relax();
395 	} while (remain);
396 
397 	/* If tx, wait until the FIFO data completely. */
398 	if (rs->tx)
399 		wait_for_idle(rs);
400 
401 	spi_enable_chip(rs, 0);
402 
403 	return 0;
404 }
405 
406 static void rockchip_spi_dma_rxcb(void *data)
407 {
408 	unsigned long flags;
409 	struct rockchip_spi *rs = data;
410 
411 	spin_lock_irqsave(&rs->lock, flags);
412 
413 	rs->state &= ~RXBUSY;
414 	if (!(rs->state & TXBUSY)) {
415 		spi_enable_chip(rs, 0);
416 		spi_finalize_current_transfer(rs->master);
417 	}
418 
419 	spin_unlock_irqrestore(&rs->lock, flags);
420 }
421 
422 static void rockchip_spi_dma_txcb(void *data)
423 {
424 	unsigned long flags;
425 	struct rockchip_spi *rs = data;
426 
427 	/* Wait until the FIFO data completely. */
428 	wait_for_idle(rs);
429 
430 	spin_lock_irqsave(&rs->lock, flags);
431 
432 	rs->state &= ~TXBUSY;
433 	if (!(rs->state & RXBUSY)) {
434 		spi_enable_chip(rs, 0);
435 		spi_finalize_current_transfer(rs->master);
436 	}
437 
438 	spin_unlock_irqrestore(&rs->lock, flags);
439 }
440 
441 static int rockchip_spi_prepare_dma(struct rockchip_spi *rs)
442 {
443 	unsigned long flags;
444 	struct dma_slave_config rxconf, txconf;
445 	struct dma_async_tx_descriptor *rxdesc, *txdesc;
446 
447 	spin_lock_irqsave(&rs->lock, flags);
448 	rs->state &= ~RXBUSY;
449 	rs->state &= ~TXBUSY;
450 	spin_unlock_irqrestore(&rs->lock, flags);
451 
452 	rxdesc = NULL;
453 	if (rs->rx) {
454 		rxconf.direction = rs->dma_rx.direction;
455 		rxconf.src_addr = rs->dma_rx.addr;
456 		rxconf.src_addr_width = rs->n_bytes;
457 		if (rs->dma_caps.max_burst > 4)
458 			rxconf.src_maxburst = 4;
459 		else
460 			rxconf.src_maxburst = 1;
461 		dmaengine_slave_config(rs->dma_rx.ch, &rxconf);
462 
463 		rxdesc = dmaengine_prep_slave_sg(
464 				rs->dma_rx.ch,
465 				rs->rx_sg.sgl, rs->rx_sg.nents,
466 				rs->dma_rx.direction, DMA_PREP_INTERRUPT);
467 		if (!rxdesc)
468 			return -EINVAL;
469 
470 		rxdesc->callback = rockchip_spi_dma_rxcb;
471 		rxdesc->callback_param = rs;
472 	}
473 
474 	txdesc = NULL;
475 	if (rs->tx) {
476 		txconf.direction = rs->dma_tx.direction;
477 		txconf.dst_addr = rs->dma_tx.addr;
478 		txconf.dst_addr_width = rs->n_bytes;
479 		if (rs->dma_caps.max_burst > 4)
480 			txconf.dst_maxburst = 4;
481 		else
482 			txconf.dst_maxburst = 1;
483 		dmaengine_slave_config(rs->dma_tx.ch, &txconf);
484 
485 		txdesc = dmaengine_prep_slave_sg(
486 				rs->dma_tx.ch,
487 				rs->tx_sg.sgl, rs->tx_sg.nents,
488 				rs->dma_tx.direction, DMA_PREP_INTERRUPT);
489 		if (!txdesc) {
490 			if (rxdesc)
491 				dmaengine_terminate_sync(rs->dma_rx.ch);
492 			return -EINVAL;
493 		}
494 
495 		txdesc->callback = rockchip_spi_dma_txcb;
496 		txdesc->callback_param = rs;
497 	}
498 
499 	/* rx must be started before tx due to spi instinct */
500 	if (rxdesc) {
501 		spin_lock_irqsave(&rs->lock, flags);
502 		rs->state |= RXBUSY;
503 		spin_unlock_irqrestore(&rs->lock, flags);
504 		dmaengine_submit(rxdesc);
505 		dma_async_issue_pending(rs->dma_rx.ch);
506 	}
507 
508 	if (txdesc) {
509 		spin_lock_irqsave(&rs->lock, flags);
510 		rs->state |= TXBUSY;
511 		spin_unlock_irqrestore(&rs->lock, flags);
512 		dmaengine_submit(txdesc);
513 		dma_async_issue_pending(rs->dma_tx.ch);
514 	}
515 
516 	return 0;
517 }
518 
519 static void rockchip_spi_config(struct rockchip_spi *rs)
520 {
521 	u32 div = 0;
522 	u32 dmacr = 0;
523 	int rsd = 0;
524 
525 	u32 cr0 = (CR0_BHT_8BIT << CR0_BHT_OFFSET)
526 		| (CR0_SSD_ONE << CR0_SSD_OFFSET)
527 		| (CR0_EM_BIG << CR0_EM_OFFSET);
528 
529 	cr0 |= (rs->n_bytes << CR0_DFS_OFFSET);
530 	cr0 |= ((rs->mode & 0x3) << CR0_SCPH_OFFSET);
531 	cr0 |= (rs->tmode << CR0_XFM_OFFSET);
532 	cr0 |= (rs->type << CR0_FRF_OFFSET);
533 
534 	if (rs->use_dma) {
535 		if (rs->tx)
536 			dmacr |= TF_DMA_EN;
537 		if (rs->rx)
538 			dmacr |= RF_DMA_EN;
539 	}
540 
541 	if (WARN_ON(rs->speed > MAX_SCLK_OUT))
542 		rs->speed = MAX_SCLK_OUT;
543 
544 	/* the minimum divisor is 2 */
545 	if (rs->max_freq < 2 * rs->speed) {
546 		clk_set_rate(rs->spiclk, 2 * rs->speed);
547 		rs->max_freq = clk_get_rate(rs->spiclk);
548 	}
549 
550 	/* div doesn't support odd number */
551 	div = DIV_ROUND_UP(rs->max_freq, rs->speed);
552 	div = (div + 1) & 0xfffe;
553 
554 	/* Rx sample delay is expressed in parent clock cycles (max 3) */
555 	rsd = DIV_ROUND_CLOSEST(rs->rsd_nsecs * (rs->max_freq >> 8),
556 				1000000000 >> 8);
557 	if (!rsd && rs->rsd_nsecs) {
558 		pr_warn_once("rockchip-spi: %u Hz are too slow to express %u ns delay\n",
559 			     rs->max_freq, rs->rsd_nsecs);
560 	} else if (rsd > 3) {
561 		rsd = 3;
562 		pr_warn_once("rockchip-spi: %u Hz are too fast to express %u ns delay, clamping at %u ns\n",
563 			     rs->max_freq, rs->rsd_nsecs,
564 			     rsd * 1000000000U / rs->max_freq);
565 	}
566 	cr0 |= rsd << CR0_RSD_OFFSET;
567 
568 	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
569 
570 	writel_relaxed(rs->len - 1, rs->regs + ROCKCHIP_SPI_CTRLR1);
571 	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_TXFTLR);
572 	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
573 
574 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMATDLR);
575 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMARDLR);
576 	writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
577 
578 	spi_set_clk(rs, div);
579 
580 	dev_dbg(rs->dev, "cr0 0x%x, div %d\n", cr0, div);
581 }
582 
583 static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
584 {
585 	return ROCKCHIP_SPI_MAX_TRANLEN;
586 }
587 
588 static int rockchip_spi_transfer_one(
589 		struct spi_master *master,
590 		struct spi_device *spi,
591 		struct spi_transfer *xfer)
592 {
593 	int ret = 0;
594 	struct rockchip_spi *rs = spi_master_get_devdata(master);
595 
596 	WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
597 		(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
598 
599 	if (!xfer->tx_buf && !xfer->rx_buf) {
600 		dev_err(rs->dev, "No buffer for transfer\n");
601 		return -EINVAL;
602 	}
603 
604 	if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
605 		dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
606 		return -EINVAL;
607 	}
608 
609 	rs->speed = xfer->speed_hz;
610 	rs->bpw = xfer->bits_per_word;
611 	rs->n_bytes = rs->bpw >> 3;
612 
613 	rs->tx = xfer->tx_buf;
614 	rs->tx_end = rs->tx + xfer->len;
615 	rs->rx = xfer->rx_buf;
616 	rs->rx_end = rs->rx + xfer->len;
617 	rs->len = xfer->len;
618 
619 	rs->tx_sg = xfer->tx_sg;
620 	rs->rx_sg = xfer->rx_sg;
621 
622 	if (rs->tx && rs->rx)
623 		rs->tmode = CR0_XFM_TR;
624 	else if (rs->tx)
625 		rs->tmode = CR0_XFM_TO;
626 	else if (rs->rx)
627 		rs->tmode = CR0_XFM_RO;
628 
629 	/* we need prepare dma before spi was enabled */
630 	if (master->can_dma && master->can_dma(master, spi, xfer))
631 		rs->use_dma = 1;
632 	else
633 		rs->use_dma = 0;
634 
635 	rockchip_spi_config(rs);
636 
637 	if (rs->use_dma) {
638 		if (rs->tmode == CR0_XFM_RO) {
639 			/* rx: dma must be prepared first */
640 			ret = rockchip_spi_prepare_dma(rs);
641 			spi_enable_chip(rs, 1);
642 		} else {
643 			/* tx or tr: spi must be enabled first */
644 			spi_enable_chip(rs, 1);
645 			ret = rockchip_spi_prepare_dma(rs);
646 		}
647 		/* successful DMA prepare means the transfer is in progress */
648 		ret = ret ? ret : 1;
649 	} else {
650 		spi_enable_chip(rs, 1);
651 		ret = rockchip_spi_pio_transfer(rs);
652 	}
653 
654 	return ret;
655 }
656 
657 static bool rockchip_spi_can_dma(struct spi_master *master,
658 				 struct spi_device *spi,
659 				 struct spi_transfer *xfer)
660 {
661 	struct rockchip_spi *rs = spi_master_get_devdata(master);
662 
663 	return (xfer->len > rs->fifo_len);
664 }
665 
666 static int rockchip_spi_probe(struct platform_device *pdev)
667 {
668 	int ret = 0;
669 	struct rockchip_spi *rs;
670 	struct spi_master *master;
671 	struct resource *mem;
672 	u32 rsd_nsecs;
673 
674 	master = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi));
675 	if (!master)
676 		return -ENOMEM;
677 
678 	platform_set_drvdata(pdev, master);
679 
680 	rs = spi_master_get_devdata(master);
681 
682 	/* Get basic io resource and map it */
683 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
684 	rs->regs = devm_ioremap_resource(&pdev->dev, mem);
685 	if (IS_ERR(rs->regs)) {
686 		ret =  PTR_ERR(rs->regs);
687 		goto err_ioremap_resource;
688 	}
689 
690 	rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
691 	if (IS_ERR(rs->apb_pclk)) {
692 		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
693 		ret = PTR_ERR(rs->apb_pclk);
694 		goto err_ioremap_resource;
695 	}
696 
697 	rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
698 	if (IS_ERR(rs->spiclk)) {
699 		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
700 		ret = PTR_ERR(rs->spiclk);
701 		goto err_ioremap_resource;
702 	}
703 
704 	ret = clk_prepare_enable(rs->apb_pclk);
705 	if (ret) {
706 		dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
707 		goto err_ioremap_resource;
708 	}
709 
710 	ret = clk_prepare_enable(rs->spiclk);
711 	if (ret) {
712 		dev_err(&pdev->dev, "Failed to enable spi_clk\n");
713 		goto err_spiclk_enable;
714 	}
715 
716 	spi_enable_chip(rs, 0);
717 
718 	rs->type = SSI_MOTO_SPI;
719 	rs->master = master;
720 	rs->dev = &pdev->dev;
721 	rs->max_freq = clk_get_rate(rs->spiclk);
722 
723 	if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
724 				  &rsd_nsecs))
725 		rs->rsd_nsecs = rsd_nsecs;
726 
727 	rs->fifo_len = get_fifo_len(rs);
728 	if (!rs->fifo_len) {
729 		dev_err(&pdev->dev, "Failed to get fifo length\n");
730 		ret = -EINVAL;
731 		goto err_get_fifo_len;
732 	}
733 
734 	spin_lock_init(&rs->lock);
735 
736 	pm_runtime_set_active(&pdev->dev);
737 	pm_runtime_enable(&pdev->dev);
738 
739 	master->auto_runtime_pm = true;
740 	master->bus_num = pdev->id;
741 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
742 	master->num_chipselect = 2;
743 	master->dev.of_node = pdev->dev.of_node;
744 	master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8);
745 
746 	master->set_cs = rockchip_spi_set_cs;
747 	master->prepare_message = rockchip_spi_prepare_message;
748 	master->unprepare_message = rockchip_spi_unprepare_message;
749 	master->transfer_one = rockchip_spi_transfer_one;
750 	master->max_transfer_size = rockchip_spi_max_transfer_size;
751 	master->handle_err = rockchip_spi_handle_err;
752 
753 	rs->dma_tx.ch = dma_request_chan(rs->dev, "tx");
754 	if (IS_ERR(rs->dma_tx.ch)) {
755 		/* Check tx to see if we need defer probing driver */
756 		if (PTR_ERR(rs->dma_tx.ch) == -EPROBE_DEFER) {
757 			ret = -EPROBE_DEFER;
758 			goto err_get_fifo_len;
759 		}
760 		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
761 		rs->dma_tx.ch = NULL;
762 	}
763 
764 	rs->dma_rx.ch = dma_request_chan(rs->dev, "rx");
765 	if (IS_ERR(rs->dma_rx.ch)) {
766 		if (PTR_ERR(rs->dma_rx.ch) == -EPROBE_DEFER) {
767 			ret = -EPROBE_DEFER;
768 			goto err_free_dma_tx;
769 		}
770 		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
771 		rs->dma_rx.ch = NULL;
772 	}
773 
774 	if (rs->dma_tx.ch && rs->dma_rx.ch) {
775 		dma_get_slave_caps(rs->dma_rx.ch, &(rs->dma_caps));
776 		rs->dma_tx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_TXDR);
777 		rs->dma_rx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_RXDR);
778 		rs->dma_tx.direction = DMA_MEM_TO_DEV;
779 		rs->dma_rx.direction = DMA_DEV_TO_MEM;
780 
781 		master->can_dma = rockchip_spi_can_dma;
782 		master->dma_tx = rs->dma_tx.ch;
783 		master->dma_rx = rs->dma_rx.ch;
784 	}
785 
786 	ret = devm_spi_register_master(&pdev->dev, master);
787 	if (ret) {
788 		dev_err(&pdev->dev, "Failed to register master\n");
789 		goto err_register_master;
790 	}
791 
792 	return 0;
793 
794 err_register_master:
795 	pm_runtime_disable(&pdev->dev);
796 	if (rs->dma_rx.ch)
797 		dma_release_channel(rs->dma_rx.ch);
798 err_free_dma_tx:
799 	if (rs->dma_tx.ch)
800 		dma_release_channel(rs->dma_tx.ch);
801 err_get_fifo_len:
802 	clk_disable_unprepare(rs->spiclk);
803 err_spiclk_enable:
804 	clk_disable_unprepare(rs->apb_pclk);
805 err_ioremap_resource:
806 	spi_master_put(master);
807 
808 	return ret;
809 }
810 
811 static int rockchip_spi_remove(struct platform_device *pdev)
812 {
813 	struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
814 	struct rockchip_spi *rs = spi_master_get_devdata(master);
815 
816 	pm_runtime_disable(&pdev->dev);
817 
818 	clk_disable_unprepare(rs->spiclk);
819 	clk_disable_unprepare(rs->apb_pclk);
820 
821 	if (rs->dma_tx.ch)
822 		dma_release_channel(rs->dma_tx.ch);
823 	if (rs->dma_rx.ch)
824 		dma_release_channel(rs->dma_rx.ch);
825 
826 	spi_master_put(master);
827 
828 	return 0;
829 }
830 
831 #ifdef CONFIG_PM_SLEEP
832 static int rockchip_spi_suspend(struct device *dev)
833 {
834 	int ret = 0;
835 	struct spi_master *master = dev_get_drvdata(dev);
836 	struct rockchip_spi *rs = spi_master_get_devdata(master);
837 
838 	ret = spi_master_suspend(rs->master);
839 	if (ret)
840 		return ret;
841 
842 	if (!pm_runtime_suspended(dev)) {
843 		clk_disable_unprepare(rs->spiclk);
844 		clk_disable_unprepare(rs->apb_pclk);
845 	}
846 
847 	pinctrl_pm_select_sleep_state(dev);
848 
849 	return ret;
850 }
851 
852 static int rockchip_spi_resume(struct device *dev)
853 {
854 	int ret = 0;
855 	struct spi_master *master = dev_get_drvdata(dev);
856 	struct rockchip_spi *rs = spi_master_get_devdata(master);
857 
858 	pinctrl_pm_select_default_state(dev);
859 
860 	if (!pm_runtime_suspended(dev)) {
861 		ret = clk_prepare_enable(rs->apb_pclk);
862 		if (ret < 0)
863 			return ret;
864 
865 		ret = clk_prepare_enable(rs->spiclk);
866 		if (ret < 0) {
867 			clk_disable_unprepare(rs->apb_pclk);
868 			return ret;
869 		}
870 	}
871 
872 	ret = spi_master_resume(rs->master);
873 	if (ret < 0) {
874 		clk_disable_unprepare(rs->spiclk);
875 		clk_disable_unprepare(rs->apb_pclk);
876 	}
877 
878 	return ret;
879 }
880 #endif /* CONFIG_PM_SLEEP */
881 
882 #ifdef CONFIG_PM
883 static int rockchip_spi_runtime_suspend(struct device *dev)
884 {
885 	struct spi_master *master = dev_get_drvdata(dev);
886 	struct rockchip_spi *rs = spi_master_get_devdata(master);
887 
888 	clk_disable_unprepare(rs->spiclk);
889 	clk_disable_unprepare(rs->apb_pclk);
890 
891 	return 0;
892 }
893 
894 static int rockchip_spi_runtime_resume(struct device *dev)
895 {
896 	int ret;
897 	struct spi_master *master = dev_get_drvdata(dev);
898 	struct rockchip_spi *rs = spi_master_get_devdata(master);
899 
900 	ret = clk_prepare_enable(rs->apb_pclk);
901 	if (ret)
902 		return ret;
903 
904 	ret = clk_prepare_enable(rs->spiclk);
905 	if (ret)
906 		clk_disable_unprepare(rs->apb_pclk);
907 
908 	return ret;
909 }
910 #endif /* CONFIG_PM */
911 
912 static const struct dev_pm_ops rockchip_spi_pm = {
913 	SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
914 	SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
915 			   rockchip_spi_runtime_resume, NULL)
916 };
917 
918 static const struct of_device_id rockchip_spi_dt_match[] = {
919 	{ .compatible = "rockchip,rk3036-spi", },
920 	{ .compatible = "rockchip,rk3066-spi", },
921 	{ .compatible = "rockchip,rk3188-spi", },
922 	{ .compatible = "rockchip,rk3228-spi", },
923 	{ .compatible = "rockchip,rk3288-spi", },
924 	{ .compatible = "rockchip,rk3368-spi", },
925 	{ .compatible = "rockchip,rk3399-spi", },
926 	{ },
927 };
928 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
929 
930 static struct platform_driver rockchip_spi_driver = {
931 	.driver = {
932 		.name	= DRIVER_NAME,
933 		.pm = &rockchip_spi_pm,
934 		.of_match_table = of_match_ptr(rockchip_spi_dt_match),
935 	},
936 	.probe = rockchip_spi_probe,
937 	.remove = rockchip_spi_remove,
938 };
939 
940 module_platform_driver(rockchip_spi_driver);
941 
942 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
943 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
944 MODULE_LICENSE("GPL v2");
945