xref: /linux/drivers/spi/spi-rockchip.c (revision b8d312aa075f33282565467662c4628dae0a2aff)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
4  * Author: Addy Ke <addy.ke@rock-chips.com>
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/dmaengine.h>
9 #include <linux/interrupt.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/pinctrl/consumer.h>
13 #include <linux/platform_device.h>
14 #include <linux/spi/spi.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/scatterlist.h>
17 
18 #define DRIVER_NAME "rockchip-spi"
19 
20 #define ROCKCHIP_SPI_CLR_BITS(reg, bits) \
21 		writel_relaxed(readl_relaxed(reg) & ~(bits), reg)
22 #define ROCKCHIP_SPI_SET_BITS(reg, bits) \
23 		writel_relaxed(readl_relaxed(reg) | (bits), reg)
24 
25 /* SPI register offsets */
26 #define ROCKCHIP_SPI_CTRLR0			0x0000
27 #define ROCKCHIP_SPI_CTRLR1			0x0004
28 #define ROCKCHIP_SPI_SSIENR			0x0008
29 #define ROCKCHIP_SPI_SER			0x000c
30 #define ROCKCHIP_SPI_BAUDR			0x0010
31 #define ROCKCHIP_SPI_TXFTLR			0x0014
32 #define ROCKCHIP_SPI_RXFTLR			0x0018
33 #define ROCKCHIP_SPI_TXFLR			0x001c
34 #define ROCKCHIP_SPI_RXFLR			0x0020
35 #define ROCKCHIP_SPI_SR				0x0024
36 #define ROCKCHIP_SPI_IPR			0x0028
37 #define ROCKCHIP_SPI_IMR			0x002c
38 #define ROCKCHIP_SPI_ISR			0x0030
39 #define ROCKCHIP_SPI_RISR			0x0034
40 #define ROCKCHIP_SPI_ICR			0x0038
41 #define ROCKCHIP_SPI_DMACR			0x003c
42 #define ROCKCHIP_SPI_DMATDLR		0x0040
43 #define ROCKCHIP_SPI_DMARDLR		0x0044
44 #define ROCKCHIP_SPI_TXDR			0x0400
45 #define ROCKCHIP_SPI_RXDR			0x0800
46 
47 /* Bit fields in CTRLR0 */
48 #define CR0_DFS_OFFSET				0
49 #define CR0_DFS_4BIT				0x0
50 #define CR0_DFS_8BIT				0x1
51 #define CR0_DFS_16BIT				0x2
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 #define CR0_RSD_MAX				0x3
93 
94 #define CR0_FRF_OFFSET				16
95 #define CR0_FRF_SPI					0x0
96 #define CR0_FRF_SSP					0x1
97 #define CR0_FRF_MICROWIRE			0x2
98 
99 #define CR0_XFM_OFFSET				18
100 #define CR0_XFM_MASK				(0x03 << SPI_XFM_OFFSET)
101 #define CR0_XFM_TR					0x0
102 #define CR0_XFM_TO					0x1
103 #define CR0_XFM_RO					0x2
104 
105 #define CR0_OPM_OFFSET				20
106 #define CR0_OPM_MASTER				0x0
107 #define CR0_OPM_SLAVE				0x1
108 
109 #define CR0_MTM_OFFSET				0x21
110 
111 /* Bit fields in SER, 2bit */
112 #define SER_MASK					0x3
113 
114 /* Bit fields in BAUDR */
115 #define BAUDR_SCKDV_MIN				2
116 #define BAUDR_SCKDV_MAX				65534
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 /* Driver state flags */
146 #define RXDMA					(1 << 0)
147 #define TXDMA					(1 << 1)
148 
149 /* sclk_out: spi master internal logic in rk3x can support 50Mhz */
150 #define MAX_SCLK_OUT				50000000U
151 
152 /*
153  * SPI_CTRLR1 is 16-bits, so we should support lengths of 0xffff + 1. However,
154  * the controller seems to hang when given 0x10000, so stick with this for now.
155  */
156 #define ROCKCHIP_SPI_MAX_TRANLEN		0xffff
157 
158 #define ROCKCHIP_SPI_MAX_CS_NUM			2
159 
160 struct rockchip_spi {
161 	struct device *dev;
162 
163 	struct clk *spiclk;
164 	struct clk *apb_pclk;
165 
166 	void __iomem *regs;
167 	dma_addr_t dma_addr_rx;
168 	dma_addr_t dma_addr_tx;
169 
170 	const void *tx;
171 	void *rx;
172 	unsigned int tx_left;
173 	unsigned int rx_left;
174 
175 	atomic_t state;
176 
177 	/*depth of the FIFO buffer */
178 	u32 fifo_len;
179 	/* frequency of spiclk */
180 	u32 freq;
181 
182 	u8 n_bytes;
183 	u8 rsd;
184 
185 	bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
186 };
187 
188 static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
189 {
190 	writel_relaxed((enable ? 1U : 0U), rs->regs + ROCKCHIP_SPI_SSIENR);
191 }
192 
193 static inline void wait_for_idle(struct rockchip_spi *rs)
194 {
195 	unsigned long timeout = jiffies + msecs_to_jiffies(5);
196 
197 	do {
198 		if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
199 			return;
200 	} while (!time_after(jiffies, timeout));
201 
202 	dev_warn(rs->dev, "spi controller is in busy state!\n");
203 }
204 
205 static u32 get_fifo_len(struct rockchip_spi *rs)
206 {
207 	u32 fifo;
208 
209 	for (fifo = 2; fifo < 32; fifo++) {
210 		writel_relaxed(fifo, rs->regs + ROCKCHIP_SPI_TXFTLR);
211 		if (fifo != readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFTLR))
212 			break;
213 	}
214 
215 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_TXFTLR);
216 
217 	return (fifo == 31) ? 0 : fifo;
218 }
219 
220 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
221 {
222 	struct spi_master *master = spi->master;
223 	struct rockchip_spi *rs = spi_master_get_devdata(master);
224 	bool cs_asserted = !enable;
225 
226 	/* Return immediately for no-op */
227 	if (cs_asserted == rs->cs_asserted[spi->chip_select])
228 		return;
229 
230 	if (cs_asserted) {
231 		/* Keep things powered as long as CS is asserted */
232 		pm_runtime_get_sync(rs->dev);
233 
234 		ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER,
235 				      BIT(spi->chip_select));
236 	} else {
237 		ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER,
238 				      BIT(spi->chip_select));
239 
240 		/* Drop reference from when we first asserted CS */
241 		pm_runtime_put(rs->dev);
242 	}
243 
244 	rs->cs_asserted[spi->chip_select] = cs_asserted;
245 }
246 
247 static void rockchip_spi_handle_err(struct spi_master *master,
248 				    struct spi_message *msg)
249 {
250 	struct rockchip_spi *rs = spi_master_get_devdata(master);
251 
252 	/* stop running spi transfer
253 	 * this also flushes both rx and tx fifos
254 	 */
255 	spi_enable_chip(rs, false);
256 
257 	/* make sure all interrupts are masked */
258 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
259 
260 	if (atomic_read(&rs->state) & TXDMA)
261 		dmaengine_terminate_async(master->dma_tx);
262 
263 	if (atomic_read(&rs->state) & RXDMA)
264 		dmaengine_terminate_async(master->dma_rx);
265 }
266 
267 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
268 {
269 	u32 tx_free = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
270 	u32 words = min(rs->tx_left, tx_free);
271 
272 	rs->tx_left -= words;
273 	for (; words; words--) {
274 		u32 txw;
275 
276 		if (rs->n_bytes == 1)
277 			txw = *(u8 *)rs->tx;
278 		else
279 			txw = *(u16 *)rs->tx;
280 
281 		writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
282 		rs->tx += rs->n_bytes;
283 	}
284 }
285 
286 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
287 {
288 	u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
289 	u32 rx_left = rs->rx_left - words;
290 
291 	/* the hardware doesn't allow us to change fifo threshold
292 	 * level while spi is enabled, so instead make sure to leave
293 	 * enough words in the rx fifo to get the last interrupt
294 	 * exactly when all words have been received
295 	 */
296 	if (rx_left) {
297 		u32 ftl = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFTLR) + 1;
298 
299 		if (rx_left < ftl) {
300 			rx_left = ftl;
301 			words = rs->rx_left - rx_left;
302 		}
303 	}
304 
305 	rs->rx_left = rx_left;
306 	for (; words; words--) {
307 		u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
308 
309 		if (!rs->rx)
310 			continue;
311 
312 		if (rs->n_bytes == 1)
313 			*(u8 *)rs->rx = (u8)rxw;
314 		else
315 			*(u16 *)rs->rx = (u16)rxw;
316 		rs->rx += rs->n_bytes;
317 	}
318 }
319 
320 static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
321 {
322 	struct spi_master *master = dev_id;
323 	struct rockchip_spi *rs = spi_master_get_devdata(master);
324 
325 	if (rs->tx_left)
326 		rockchip_spi_pio_writer(rs);
327 
328 	rockchip_spi_pio_reader(rs);
329 	if (!rs->rx_left) {
330 		spi_enable_chip(rs, false);
331 		writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
332 		spi_finalize_current_transfer(master);
333 	}
334 
335 	return IRQ_HANDLED;
336 }
337 
338 static int rockchip_spi_prepare_irq(struct rockchip_spi *rs,
339 		struct spi_transfer *xfer)
340 {
341 	rs->tx = xfer->tx_buf;
342 	rs->rx = xfer->rx_buf;
343 	rs->tx_left = rs->tx ? xfer->len / rs->n_bytes : 0;
344 	rs->rx_left = xfer->len / rs->n_bytes;
345 
346 	writel_relaxed(INT_RF_FULL, rs->regs + ROCKCHIP_SPI_IMR);
347 	spi_enable_chip(rs, true);
348 
349 	if (rs->tx_left)
350 		rockchip_spi_pio_writer(rs);
351 
352 	/* 1 means the transfer is in progress */
353 	return 1;
354 }
355 
356 static void rockchip_spi_dma_rxcb(void *data)
357 {
358 	struct spi_master *master = data;
359 	struct rockchip_spi *rs = spi_master_get_devdata(master);
360 	int state = atomic_fetch_andnot(RXDMA, &rs->state);
361 
362 	if (state & TXDMA)
363 		return;
364 
365 	spi_enable_chip(rs, false);
366 	spi_finalize_current_transfer(master);
367 }
368 
369 static void rockchip_spi_dma_txcb(void *data)
370 {
371 	struct spi_master *master = data;
372 	struct rockchip_spi *rs = spi_master_get_devdata(master);
373 	int state = atomic_fetch_andnot(TXDMA, &rs->state);
374 
375 	if (state & RXDMA)
376 		return;
377 
378 	/* Wait until the FIFO data completely. */
379 	wait_for_idle(rs);
380 
381 	spi_enable_chip(rs, false);
382 	spi_finalize_current_transfer(master);
383 }
384 
385 static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
386 		struct spi_master *master, struct spi_transfer *xfer)
387 {
388 	struct dma_async_tx_descriptor *rxdesc, *txdesc;
389 
390 	atomic_set(&rs->state, 0);
391 
392 	rxdesc = NULL;
393 	if (xfer->rx_buf) {
394 		struct dma_slave_config rxconf = {
395 			.direction = DMA_DEV_TO_MEM,
396 			.src_addr = rs->dma_addr_rx,
397 			.src_addr_width = rs->n_bytes,
398 			.src_maxburst = 1,
399 		};
400 
401 		dmaengine_slave_config(master->dma_rx, &rxconf);
402 
403 		rxdesc = dmaengine_prep_slave_sg(
404 				master->dma_rx,
405 				xfer->rx_sg.sgl, xfer->rx_sg.nents,
406 				DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
407 		if (!rxdesc)
408 			return -EINVAL;
409 
410 		rxdesc->callback = rockchip_spi_dma_rxcb;
411 		rxdesc->callback_param = master;
412 	}
413 
414 	txdesc = NULL;
415 	if (xfer->tx_buf) {
416 		struct dma_slave_config txconf = {
417 			.direction = DMA_MEM_TO_DEV,
418 			.dst_addr = rs->dma_addr_tx,
419 			.dst_addr_width = rs->n_bytes,
420 			.dst_maxburst = rs->fifo_len / 4,
421 		};
422 
423 		dmaengine_slave_config(master->dma_tx, &txconf);
424 
425 		txdesc = dmaengine_prep_slave_sg(
426 				master->dma_tx,
427 				xfer->tx_sg.sgl, xfer->tx_sg.nents,
428 				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
429 		if (!txdesc) {
430 			if (rxdesc)
431 				dmaengine_terminate_sync(master->dma_rx);
432 			return -EINVAL;
433 		}
434 
435 		txdesc->callback = rockchip_spi_dma_txcb;
436 		txdesc->callback_param = master;
437 	}
438 
439 	/* rx must be started before tx due to spi instinct */
440 	if (rxdesc) {
441 		atomic_or(RXDMA, &rs->state);
442 		dmaengine_submit(rxdesc);
443 		dma_async_issue_pending(master->dma_rx);
444 	}
445 
446 	spi_enable_chip(rs, true);
447 
448 	if (txdesc) {
449 		atomic_or(TXDMA, &rs->state);
450 		dmaengine_submit(txdesc);
451 		dma_async_issue_pending(master->dma_tx);
452 	}
453 
454 	/* 1 means the transfer is in progress */
455 	return 1;
456 }
457 
458 static void rockchip_spi_config(struct rockchip_spi *rs,
459 		struct spi_device *spi, struct spi_transfer *xfer,
460 		bool use_dma)
461 {
462 	u32 cr0 = CR0_FRF_SPI  << CR0_FRF_OFFSET
463 	        | CR0_BHT_8BIT << CR0_BHT_OFFSET
464 	        | CR0_SSD_ONE  << CR0_SSD_OFFSET
465 	        | CR0_EM_BIG   << CR0_EM_OFFSET;
466 	u32 cr1;
467 	u32 dmacr = 0;
468 
469 	cr0 |= rs->rsd << CR0_RSD_OFFSET;
470 	cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
471 	if (spi->mode & SPI_LSB_FIRST)
472 		cr0 |= CR0_FBM_LSB << CR0_FBM_OFFSET;
473 
474 	if (xfer->rx_buf && xfer->tx_buf)
475 		cr0 |= CR0_XFM_TR << CR0_XFM_OFFSET;
476 	else if (xfer->rx_buf)
477 		cr0 |= CR0_XFM_RO << CR0_XFM_OFFSET;
478 	else if (use_dma)
479 		cr0 |= CR0_XFM_TO << CR0_XFM_OFFSET;
480 
481 	switch (xfer->bits_per_word) {
482 	case 4:
483 		cr0 |= CR0_DFS_4BIT << CR0_DFS_OFFSET;
484 		cr1 = xfer->len - 1;
485 		break;
486 	case 8:
487 		cr0 |= CR0_DFS_8BIT << CR0_DFS_OFFSET;
488 		cr1 = xfer->len - 1;
489 		break;
490 	case 16:
491 		cr0 |= CR0_DFS_16BIT << CR0_DFS_OFFSET;
492 		cr1 = xfer->len / 2 - 1;
493 		break;
494 	default:
495 		/* we only whitelist 4, 8 and 16 bit words in
496 		 * master->bits_per_word_mask, so this shouldn't
497 		 * happen
498 		 */
499 		unreachable();
500 	}
501 
502 	if (use_dma) {
503 		if (xfer->tx_buf)
504 			dmacr |= TF_DMA_EN;
505 		if (xfer->rx_buf)
506 			dmacr |= RF_DMA_EN;
507 	}
508 
509 	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
510 	writel_relaxed(cr1, rs->regs + ROCKCHIP_SPI_CTRLR1);
511 
512 	/* unfortunately setting the fifo threshold level to generate an
513 	 * interrupt exactly when the fifo is full doesn't seem to work,
514 	 * so we need the strict inequality here
515 	 */
516 	if (xfer->len < rs->fifo_len)
517 		writel_relaxed(xfer->len - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
518 	else
519 		writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
520 
521 	writel_relaxed(rs->fifo_len / 2, rs->regs + ROCKCHIP_SPI_DMATDLR);
522 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMARDLR);
523 	writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
524 
525 	/* the hardware only supports an even clock divisor, so
526 	 * round divisor = spiclk / speed up to nearest even number
527 	 * so that the resulting speed is <= the requested speed
528 	 */
529 	writel_relaxed(2 * DIV_ROUND_UP(rs->freq, 2 * xfer->speed_hz),
530 			rs->regs + ROCKCHIP_SPI_BAUDR);
531 }
532 
533 static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
534 {
535 	return ROCKCHIP_SPI_MAX_TRANLEN;
536 }
537 
538 static int rockchip_spi_transfer_one(
539 		struct spi_master *master,
540 		struct spi_device *spi,
541 		struct spi_transfer *xfer)
542 {
543 	struct rockchip_spi *rs = spi_master_get_devdata(master);
544 	bool use_dma;
545 
546 	WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
547 		(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
548 
549 	if (!xfer->tx_buf && !xfer->rx_buf) {
550 		dev_err(rs->dev, "No buffer for transfer\n");
551 		return -EINVAL;
552 	}
553 
554 	if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
555 		dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
556 		return -EINVAL;
557 	}
558 
559 	rs->n_bytes = xfer->bits_per_word <= 8 ? 1 : 2;
560 
561 	use_dma = master->can_dma ? master->can_dma(master, spi, xfer) : false;
562 
563 	rockchip_spi_config(rs, spi, xfer, use_dma);
564 
565 	if (use_dma)
566 		return rockchip_spi_prepare_dma(rs, master, xfer);
567 
568 	return rockchip_spi_prepare_irq(rs, xfer);
569 }
570 
571 static bool rockchip_spi_can_dma(struct spi_master *master,
572 				 struct spi_device *spi,
573 				 struct spi_transfer *xfer)
574 {
575 	struct rockchip_spi *rs = spi_master_get_devdata(master);
576 	unsigned int bytes_per_word = xfer->bits_per_word <= 8 ? 1 : 2;
577 
578 	/* if the numbor of spi words to transfer is less than the fifo
579 	 * length we can just fill the fifo and wait for a single irq,
580 	 * so don't bother setting up dma
581 	 */
582 	return xfer->len / bytes_per_word >= rs->fifo_len;
583 }
584 
585 static int rockchip_spi_probe(struct platform_device *pdev)
586 {
587 	int ret;
588 	struct rockchip_spi *rs;
589 	struct spi_master *master;
590 	struct resource *mem;
591 	u32 rsd_nsecs;
592 
593 	master = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi));
594 	if (!master)
595 		return -ENOMEM;
596 
597 	platform_set_drvdata(pdev, master);
598 
599 	rs = spi_master_get_devdata(master);
600 
601 	/* Get basic io resource and map it */
602 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
603 	rs->regs = devm_ioremap_resource(&pdev->dev, mem);
604 	if (IS_ERR(rs->regs)) {
605 		ret =  PTR_ERR(rs->regs);
606 		goto err_put_master;
607 	}
608 
609 	rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
610 	if (IS_ERR(rs->apb_pclk)) {
611 		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
612 		ret = PTR_ERR(rs->apb_pclk);
613 		goto err_put_master;
614 	}
615 
616 	rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
617 	if (IS_ERR(rs->spiclk)) {
618 		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
619 		ret = PTR_ERR(rs->spiclk);
620 		goto err_put_master;
621 	}
622 
623 	ret = clk_prepare_enable(rs->apb_pclk);
624 	if (ret < 0) {
625 		dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
626 		goto err_put_master;
627 	}
628 
629 	ret = clk_prepare_enable(rs->spiclk);
630 	if (ret < 0) {
631 		dev_err(&pdev->dev, "Failed to enable spi_clk\n");
632 		goto err_disable_apbclk;
633 	}
634 
635 	spi_enable_chip(rs, false);
636 
637 	ret = platform_get_irq(pdev, 0);
638 	if (ret < 0)
639 		goto err_disable_spiclk;
640 
641 	ret = devm_request_threaded_irq(&pdev->dev, ret, rockchip_spi_isr, NULL,
642 			IRQF_ONESHOT, dev_name(&pdev->dev), master);
643 	if (ret)
644 		goto err_disable_spiclk;
645 
646 	rs->dev = &pdev->dev;
647 	rs->freq = clk_get_rate(rs->spiclk);
648 
649 	if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
650 				  &rsd_nsecs)) {
651 		/* rx sample delay is expressed in parent clock cycles (max 3) */
652 		u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8),
653 				1000000000 >> 8);
654 		if (!rsd) {
655 			dev_warn(rs->dev, "%u Hz are too slow to express %u ns delay\n",
656 					rs->freq, rsd_nsecs);
657 		} else if (rsd > CR0_RSD_MAX) {
658 			rsd = CR0_RSD_MAX;
659 			dev_warn(rs->dev, "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
660 					rs->freq, rsd_nsecs,
661 					CR0_RSD_MAX * 1000000000U / rs->freq);
662 		}
663 		rs->rsd = rsd;
664 	}
665 
666 	rs->fifo_len = get_fifo_len(rs);
667 	if (!rs->fifo_len) {
668 		dev_err(&pdev->dev, "Failed to get fifo length\n");
669 		ret = -EINVAL;
670 		goto err_disable_spiclk;
671 	}
672 
673 	pm_runtime_set_active(&pdev->dev);
674 	pm_runtime_enable(&pdev->dev);
675 
676 	master->auto_runtime_pm = true;
677 	master->bus_num = pdev->id;
678 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
679 	master->num_chipselect = ROCKCHIP_SPI_MAX_CS_NUM;
680 	master->dev.of_node = pdev->dev.of_node;
681 	master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
682 	master->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
683 	master->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);
684 
685 	master->set_cs = rockchip_spi_set_cs;
686 	master->transfer_one = rockchip_spi_transfer_one;
687 	master->max_transfer_size = rockchip_spi_max_transfer_size;
688 	master->handle_err = rockchip_spi_handle_err;
689 	master->flags = SPI_MASTER_GPIO_SS;
690 
691 	master->dma_tx = dma_request_chan(rs->dev, "tx");
692 	if (IS_ERR(master->dma_tx)) {
693 		/* Check tx to see if we need defer probing driver */
694 		if (PTR_ERR(master->dma_tx) == -EPROBE_DEFER) {
695 			ret = -EPROBE_DEFER;
696 			goto err_disable_pm_runtime;
697 		}
698 		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
699 		master->dma_tx = NULL;
700 	}
701 
702 	master->dma_rx = dma_request_chan(rs->dev, "rx");
703 	if (IS_ERR(master->dma_rx)) {
704 		if (PTR_ERR(master->dma_rx) == -EPROBE_DEFER) {
705 			ret = -EPROBE_DEFER;
706 			goto err_free_dma_tx;
707 		}
708 		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
709 		master->dma_rx = NULL;
710 	}
711 
712 	if (master->dma_tx && master->dma_rx) {
713 		rs->dma_addr_tx = mem->start + ROCKCHIP_SPI_TXDR;
714 		rs->dma_addr_rx = mem->start + ROCKCHIP_SPI_RXDR;
715 		master->can_dma = rockchip_spi_can_dma;
716 	}
717 
718 	ret = devm_spi_register_master(&pdev->dev, master);
719 	if (ret < 0) {
720 		dev_err(&pdev->dev, "Failed to register master\n");
721 		goto err_free_dma_rx;
722 	}
723 
724 	return 0;
725 
726 err_free_dma_rx:
727 	if (master->dma_rx)
728 		dma_release_channel(master->dma_rx);
729 err_free_dma_tx:
730 	if (master->dma_tx)
731 		dma_release_channel(master->dma_tx);
732 err_disable_pm_runtime:
733 	pm_runtime_disable(&pdev->dev);
734 err_disable_spiclk:
735 	clk_disable_unprepare(rs->spiclk);
736 err_disable_apbclk:
737 	clk_disable_unprepare(rs->apb_pclk);
738 err_put_master:
739 	spi_master_put(master);
740 
741 	return ret;
742 }
743 
744 static int rockchip_spi_remove(struct platform_device *pdev)
745 {
746 	struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
747 	struct rockchip_spi *rs = spi_master_get_devdata(master);
748 
749 	pm_runtime_get_sync(&pdev->dev);
750 
751 	clk_disable_unprepare(rs->spiclk);
752 	clk_disable_unprepare(rs->apb_pclk);
753 
754 	pm_runtime_put_noidle(&pdev->dev);
755 	pm_runtime_disable(&pdev->dev);
756 	pm_runtime_set_suspended(&pdev->dev);
757 
758 	if (master->dma_tx)
759 		dma_release_channel(master->dma_tx);
760 	if (master->dma_rx)
761 		dma_release_channel(master->dma_rx);
762 
763 	spi_master_put(master);
764 
765 	return 0;
766 }
767 
768 #ifdef CONFIG_PM_SLEEP
769 static int rockchip_spi_suspend(struct device *dev)
770 {
771 	int ret;
772 	struct spi_master *master = dev_get_drvdata(dev);
773 
774 	ret = spi_master_suspend(master);
775 	if (ret < 0)
776 		return ret;
777 
778 	ret = pm_runtime_force_suspend(dev);
779 	if (ret < 0)
780 		return ret;
781 
782 	pinctrl_pm_select_sleep_state(dev);
783 
784 	return 0;
785 }
786 
787 static int rockchip_spi_resume(struct device *dev)
788 {
789 	int ret;
790 	struct spi_master *master = dev_get_drvdata(dev);
791 	struct rockchip_spi *rs = spi_master_get_devdata(master);
792 
793 	pinctrl_pm_select_default_state(dev);
794 
795 	ret = pm_runtime_force_resume(dev);
796 	if (ret < 0)
797 		return ret;
798 
799 	ret = spi_master_resume(master);
800 	if (ret < 0) {
801 		clk_disable_unprepare(rs->spiclk);
802 		clk_disable_unprepare(rs->apb_pclk);
803 	}
804 
805 	return 0;
806 }
807 #endif /* CONFIG_PM_SLEEP */
808 
809 #ifdef CONFIG_PM
810 static int rockchip_spi_runtime_suspend(struct device *dev)
811 {
812 	struct spi_master *master = dev_get_drvdata(dev);
813 	struct rockchip_spi *rs = spi_master_get_devdata(master);
814 
815 	clk_disable_unprepare(rs->spiclk);
816 	clk_disable_unprepare(rs->apb_pclk);
817 
818 	return 0;
819 }
820 
821 static int rockchip_spi_runtime_resume(struct device *dev)
822 {
823 	int ret;
824 	struct spi_master *master = dev_get_drvdata(dev);
825 	struct rockchip_spi *rs = spi_master_get_devdata(master);
826 
827 	ret = clk_prepare_enable(rs->apb_pclk);
828 	if (ret < 0)
829 		return ret;
830 
831 	ret = clk_prepare_enable(rs->spiclk);
832 	if (ret < 0)
833 		clk_disable_unprepare(rs->apb_pclk);
834 
835 	return 0;
836 }
837 #endif /* CONFIG_PM */
838 
839 static const struct dev_pm_ops rockchip_spi_pm = {
840 	SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
841 	SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
842 			   rockchip_spi_runtime_resume, NULL)
843 };
844 
845 static const struct of_device_id rockchip_spi_dt_match[] = {
846 	{ .compatible = "rockchip,rv1108-spi", },
847 	{ .compatible = "rockchip,rk3036-spi", },
848 	{ .compatible = "rockchip,rk3066-spi", },
849 	{ .compatible = "rockchip,rk3188-spi", },
850 	{ .compatible = "rockchip,rk3228-spi", },
851 	{ .compatible = "rockchip,rk3288-spi", },
852 	{ .compatible = "rockchip,rk3368-spi", },
853 	{ .compatible = "rockchip,rk3399-spi", },
854 	{ },
855 };
856 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
857 
858 static struct platform_driver rockchip_spi_driver = {
859 	.driver = {
860 		.name	= DRIVER_NAME,
861 		.pm = &rockchip_spi_pm,
862 		.of_match_table = of_match_ptr(rockchip_spi_dt_match),
863 	},
864 	.probe = rockchip_spi_probe,
865 	.remove = rockchip_spi_remove,
866 };
867 
868 module_platform_driver(rockchip_spi_driver);
869 
870 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
871 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
872 MODULE_LICENSE("GPL v2");
873