xref: /openbmc/linux/drivers/spi/spi-rockchip.c (revision df687341)
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 #define ROCKCHIP_SPI_CLR_BITS(reg, bits) \
29 		writel_relaxed(readl_relaxed(reg) & ~(bits), reg)
30 #define ROCKCHIP_SPI_SET_BITS(reg, bits) \
31 		writel_relaxed(readl_relaxed(reg) | (bits), reg)
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 #define CR0_DFS_4BIT				0x0
58 #define CR0_DFS_8BIT				0x1
59 #define CR0_DFS_16BIT				0x2
60 
61 #define CR0_CFS_OFFSET				2
62 
63 #define CR0_SCPH_OFFSET				6
64 
65 #define CR0_SCPOL_OFFSET			7
66 
67 #define CR0_CSM_OFFSET				8
68 #define CR0_CSM_KEEP				0x0
69 /* ss_n be high for half sclk_out cycles */
70 #define CR0_CSM_HALF				0X1
71 /* ss_n be high for one sclk_out cycle */
72 #define CR0_CSM_ONE					0x2
73 
74 /* ss_n to sclk_out delay */
75 #define CR0_SSD_OFFSET				10
76 /*
77  * The period between ss_n active and
78  * sclk_out active is half sclk_out cycles
79  */
80 #define CR0_SSD_HALF				0x0
81 /*
82  * The period between ss_n active and
83  * sclk_out active is one sclk_out cycle
84  */
85 #define CR0_SSD_ONE					0x1
86 
87 #define CR0_EM_OFFSET				11
88 #define CR0_EM_LITTLE				0x0
89 #define CR0_EM_BIG					0x1
90 
91 #define CR0_FBM_OFFSET				12
92 #define CR0_FBM_MSB					0x0
93 #define CR0_FBM_LSB					0x1
94 
95 #define CR0_BHT_OFFSET				13
96 #define CR0_BHT_16BIT				0x0
97 #define CR0_BHT_8BIT				0x1
98 
99 #define CR0_RSD_OFFSET				14
100 #define CR0_RSD_MAX				0x3
101 
102 #define CR0_FRF_OFFSET				16
103 #define CR0_FRF_SPI					0x0
104 #define CR0_FRF_SSP					0x1
105 #define CR0_FRF_MICROWIRE			0x2
106 
107 #define CR0_XFM_OFFSET				18
108 #define CR0_XFM_MASK				(0x03 << SPI_XFM_OFFSET)
109 #define CR0_XFM_TR					0x0
110 #define CR0_XFM_TO					0x1
111 #define CR0_XFM_RO					0x2
112 
113 #define CR0_OPM_OFFSET				20
114 #define CR0_OPM_MASTER				0x0
115 #define CR0_OPM_SLAVE				0x1
116 
117 #define CR0_MTM_OFFSET				0x21
118 
119 /* Bit fields in SER, 2bit */
120 #define SER_MASK					0x3
121 
122 /* Bit fields in BAUDR */
123 #define BAUDR_SCKDV_MIN				2
124 #define BAUDR_SCKDV_MAX				65534
125 
126 /* Bit fields in SR, 5bit */
127 #define SR_MASK						0x1f
128 #define SR_BUSY						(1 << 0)
129 #define SR_TF_FULL					(1 << 1)
130 #define SR_TF_EMPTY					(1 << 2)
131 #define SR_RF_EMPTY					(1 << 3)
132 #define SR_RF_FULL					(1 << 4)
133 
134 /* Bit fields in ISR, IMR, ISR, RISR, 5bit */
135 #define INT_MASK					0x1f
136 #define INT_TF_EMPTY				(1 << 0)
137 #define INT_TF_OVERFLOW				(1 << 1)
138 #define INT_RF_UNDERFLOW			(1 << 2)
139 #define INT_RF_OVERFLOW				(1 << 3)
140 #define INT_RF_FULL					(1 << 4)
141 
142 /* Bit fields in ICR, 4bit */
143 #define ICR_MASK					0x0f
144 #define ICR_ALL						(1 << 0)
145 #define ICR_RF_UNDERFLOW			(1 << 1)
146 #define ICR_RF_OVERFLOW				(1 << 2)
147 #define ICR_TF_OVERFLOW				(1 << 3)
148 
149 /* Bit fields in DMACR */
150 #define RF_DMA_EN					(1 << 0)
151 #define TF_DMA_EN					(1 << 1)
152 
153 /* Driver state flags */
154 #define RXDMA					(1 << 0)
155 #define TXDMA					(1 << 1)
156 
157 /* sclk_out: spi master internal logic in rk3x can support 50Mhz */
158 #define MAX_SCLK_OUT				50000000U
159 
160 /*
161  * SPI_CTRLR1 is 16-bits, so we should support lengths of 0xffff + 1. However,
162  * the controller seems to hang when given 0x10000, so stick with this for now.
163  */
164 #define ROCKCHIP_SPI_MAX_TRANLEN		0xffff
165 
166 #define ROCKCHIP_SPI_MAX_CS_NUM			2
167 
168 struct rockchip_spi {
169 	struct device *dev;
170 
171 	struct clk *spiclk;
172 	struct clk *apb_pclk;
173 
174 	void __iomem *regs;
175 	dma_addr_t dma_addr_rx;
176 	dma_addr_t dma_addr_tx;
177 
178 	const void *tx;
179 	void *rx;
180 	unsigned int tx_left;
181 	unsigned int rx_left;
182 
183 	atomic_t state;
184 
185 	/*depth of the FIFO buffer */
186 	u32 fifo_len;
187 	/* frequency of spiclk */
188 	u32 freq;
189 
190 	u8 n_bytes;
191 	u8 rsd;
192 
193 	bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
194 };
195 
196 static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
197 {
198 	writel_relaxed((enable ? 1U : 0U), rs->regs + ROCKCHIP_SPI_SSIENR);
199 }
200 
201 static inline void wait_for_idle(struct rockchip_spi *rs)
202 {
203 	unsigned long timeout = jiffies + msecs_to_jiffies(5);
204 
205 	do {
206 		if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
207 			return;
208 	} while (!time_after(jiffies, timeout));
209 
210 	dev_warn(rs->dev, "spi controller is in busy state!\n");
211 }
212 
213 static u32 get_fifo_len(struct rockchip_spi *rs)
214 {
215 	u32 fifo;
216 
217 	for (fifo = 2; fifo < 32; fifo++) {
218 		writel_relaxed(fifo, rs->regs + ROCKCHIP_SPI_TXFTLR);
219 		if (fifo != readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFTLR))
220 			break;
221 	}
222 
223 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_TXFTLR);
224 
225 	return (fifo == 31) ? 0 : fifo;
226 }
227 
228 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
229 {
230 	struct spi_master *master = spi->master;
231 	struct rockchip_spi *rs = spi_master_get_devdata(master);
232 	bool cs_asserted = !enable;
233 
234 	/* Return immediately for no-op */
235 	if (cs_asserted == rs->cs_asserted[spi->chip_select])
236 		return;
237 
238 	if (cs_asserted) {
239 		/* Keep things powered as long as CS is asserted */
240 		pm_runtime_get_sync(rs->dev);
241 
242 		ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER,
243 				      BIT(spi->chip_select));
244 	} else {
245 		ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER,
246 				      BIT(spi->chip_select));
247 
248 		/* Drop reference from when we first asserted CS */
249 		pm_runtime_put(rs->dev);
250 	}
251 
252 	rs->cs_asserted[spi->chip_select] = cs_asserted;
253 }
254 
255 static void rockchip_spi_handle_err(struct spi_master *master,
256 				    struct spi_message *msg)
257 {
258 	struct rockchip_spi *rs = spi_master_get_devdata(master);
259 
260 	/* stop running spi transfer
261 	 * this also flushes both rx and tx fifos
262 	 */
263 	spi_enable_chip(rs, false);
264 
265 	/* make sure all interrupts are masked */
266 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
267 
268 	if (atomic_read(&rs->state) & TXDMA)
269 		dmaengine_terminate_async(master->dma_tx);
270 
271 	if (atomic_read(&rs->state) & RXDMA)
272 		dmaengine_terminate_async(master->dma_rx);
273 }
274 
275 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
276 {
277 	u32 tx_free = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
278 	u32 words = min(rs->tx_left, tx_free);
279 
280 	rs->tx_left -= words;
281 	for (; words; words--) {
282 		u32 txw;
283 
284 		if (rs->n_bytes == 1)
285 			txw = *(u8 *)rs->tx;
286 		else
287 			txw = *(u16 *)rs->tx;
288 
289 		writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
290 		rs->tx += rs->n_bytes;
291 	}
292 }
293 
294 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
295 {
296 	u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
297 	u32 rx_left = rs->rx_left - words;
298 
299 	/* the hardware doesn't allow us to change fifo threshold
300 	 * level while spi is enabled, so instead make sure to leave
301 	 * enough words in the rx fifo to get the last interrupt
302 	 * exactly when all words have been received
303 	 */
304 	if (rx_left) {
305 		u32 ftl = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFTLR) + 1;
306 
307 		if (rx_left < ftl) {
308 			rx_left = ftl;
309 			words = rs->rx_left - rx_left;
310 		}
311 	}
312 
313 	rs->rx_left = rx_left;
314 	for (; words; words--) {
315 		u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
316 
317 		if (!rs->rx)
318 			continue;
319 
320 		if (rs->n_bytes == 1)
321 			*(u8 *)rs->rx = (u8)rxw;
322 		else
323 			*(u16 *)rs->rx = (u16)rxw;
324 		rs->rx += rs->n_bytes;
325 	}
326 }
327 
328 static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
329 {
330 	struct spi_master *master = dev_id;
331 	struct rockchip_spi *rs = spi_master_get_devdata(master);
332 
333 	if (rs->tx_left)
334 		rockchip_spi_pio_writer(rs);
335 
336 	rockchip_spi_pio_reader(rs);
337 	if (!rs->rx_left) {
338 		spi_enable_chip(rs, false);
339 		writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
340 		spi_finalize_current_transfer(master);
341 	}
342 
343 	return IRQ_HANDLED;
344 }
345 
346 static int rockchip_spi_prepare_irq(struct rockchip_spi *rs,
347 		struct spi_transfer *xfer)
348 {
349 	rs->tx = xfer->tx_buf;
350 	rs->rx = xfer->rx_buf;
351 	rs->tx_left = rs->tx ? xfer->len / rs->n_bytes : 0;
352 	rs->rx_left = xfer->len / rs->n_bytes;
353 
354 	writel_relaxed(INT_RF_FULL, rs->regs + ROCKCHIP_SPI_IMR);
355 	spi_enable_chip(rs, true);
356 
357 	if (rs->tx_left)
358 		rockchip_spi_pio_writer(rs);
359 
360 	/* 1 means the transfer is in progress */
361 	return 1;
362 }
363 
364 static void rockchip_spi_dma_rxcb(void *data)
365 {
366 	struct spi_master *master = data;
367 	struct rockchip_spi *rs = spi_master_get_devdata(master);
368 	int state = atomic_fetch_andnot(RXDMA, &rs->state);
369 
370 	if (state & TXDMA)
371 		return;
372 
373 	spi_enable_chip(rs, false);
374 	spi_finalize_current_transfer(master);
375 }
376 
377 static void rockchip_spi_dma_txcb(void *data)
378 {
379 	struct spi_master *master = data;
380 	struct rockchip_spi *rs = spi_master_get_devdata(master);
381 	int state = atomic_fetch_andnot(TXDMA, &rs->state);
382 
383 	if (state & RXDMA)
384 		return;
385 
386 	/* Wait until the FIFO data completely. */
387 	wait_for_idle(rs);
388 
389 	spi_enable_chip(rs, false);
390 	spi_finalize_current_transfer(master);
391 }
392 
393 static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
394 		struct spi_master *master, struct spi_transfer *xfer)
395 {
396 	struct dma_async_tx_descriptor *rxdesc, *txdesc;
397 
398 	atomic_set(&rs->state, 0);
399 
400 	rxdesc = NULL;
401 	if (xfer->rx_buf) {
402 		struct dma_slave_config rxconf = {
403 			.direction = DMA_DEV_TO_MEM,
404 			.src_addr = rs->dma_addr_rx,
405 			.src_addr_width = rs->n_bytes,
406 			.src_maxburst = 1,
407 		};
408 
409 		dmaengine_slave_config(master->dma_rx, &rxconf);
410 
411 		rxdesc = dmaengine_prep_slave_sg(
412 				master->dma_rx,
413 				xfer->rx_sg.sgl, xfer->rx_sg.nents,
414 				DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
415 		if (!rxdesc)
416 			return -EINVAL;
417 
418 		rxdesc->callback = rockchip_spi_dma_rxcb;
419 		rxdesc->callback_param = master;
420 	}
421 
422 	txdesc = NULL;
423 	if (xfer->tx_buf) {
424 		struct dma_slave_config txconf = {
425 			.direction = DMA_MEM_TO_DEV,
426 			.dst_addr = rs->dma_addr_tx,
427 			.dst_addr_width = rs->n_bytes,
428 			.dst_maxburst = rs->fifo_len / 2,
429 		};
430 
431 		dmaengine_slave_config(master->dma_tx, &txconf);
432 
433 		txdesc = dmaengine_prep_slave_sg(
434 				master->dma_tx,
435 				xfer->tx_sg.sgl, xfer->tx_sg.nents,
436 				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
437 		if (!txdesc) {
438 			if (rxdesc)
439 				dmaengine_terminate_sync(master->dma_rx);
440 			return -EINVAL;
441 		}
442 
443 		txdesc->callback = rockchip_spi_dma_txcb;
444 		txdesc->callback_param = master;
445 	}
446 
447 	/* rx must be started before tx due to spi instinct */
448 	if (rxdesc) {
449 		atomic_or(RXDMA, &rs->state);
450 		dmaengine_submit(rxdesc);
451 		dma_async_issue_pending(master->dma_rx);
452 	}
453 
454 	spi_enable_chip(rs, true);
455 
456 	if (txdesc) {
457 		atomic_or(TXDMA, &rs->state);
458 		dmaengine_submit(txdesc);
459 		dma_async_issue_pending(master->dma_tx);
460 	}
461 
462 	/* 1 means the transfer is in progress */
463 	return 1;
464 }
465 
466 static void rockchip_spi_config(struct rockchip_spi *rs,
467 		struct spi_device *spi, struct spi_transfer *xfer,
468 		bool use_dma)
469 {
470 	u32 cr0 = CR0_FRF_SPI  << CR0_FRF_OFFSET
471 	        | CR0_BHT_8BIT << CR0_BHT_OFFSET
472 	        | CR0_SSD_ONE  << CR0_SSD_OFFSET
473 	        | CR0_EM_BIG   << CR0_EM_OFFSET;
474 	u32 cr1;
475 	u32 dmacr = 0;
476 
477 	cr0 |= rs->rsd << CR0_RSD_OFFSET;
478 	cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
479 	if (spi->mode & SPI_LSB_FIRST)
480 		cr0 |= CR0_FBM_LSB << CR0_FBM_OFFSET;
481 
482 	if (xfer->rx_buf && xfer->tx_buf)
483 		cr0 |= CR0_XFM_TR << CR0_XFM_OFFSET;
484 	else if (xfer->rx_buf)
485 		cr0 |= CR0_XFM_RO << CR0_XFM_OFFSET;
486 	else if (use_dma)
487 		cr0 |= CR0_XFM_TO << CR0_XFM_OFFSET;
488 
489 	switch (xfer->bits_per_word) {
490 	case 4:
491 		cr0 |= CR0_DFS_4BIT << CR0_DFS_OFFSET;
492 		cr1 = xfer->len - 1;
493 		break;
494 	case 8:
495 		cr0 |= CR0_DFS_8BIT << CR0_DFS_OFFSET;
496 		cr1 = xfer->len - 1;
497 		break;
498 	case 16:
499 		cr0 |= CR0_DFS_16BIT << CR0_DFS_OFFSET;
500 		cr1 = xfer->len / 2 - 1;
501 		break;
502 	default:
503 		/* we only whitelist 4, 8 and 16 bit words in
504 		 * master->bits_per_word_mask, so this shouldn't
505 		 * happen
506 		 */
507 		unreachable();
508 	}
509 
510 	if (use_dma) {
511 		if (xfer->tx_buf)
512 			dmacr |= TF_DMA_EN;
513 		if (xfer->rx_buf)
514 			dmacr |= RF_DMA_EN;
515 	}
516 
517 	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
518 	writel_relaxed(cr1, rs->regs + ROCKCHIP_SPI_CTRLR1);
519 
520 	/* unfortunately setting the fifo threshold level to generate an
521 	 * interrupt exactly when the fifo is full doesn't seem to work,
522 	 * so we need the strict inequality here
523 	 */
524 	if (xfer->len < rs->fifo_len)
525 		writel_relaxed(xfer->len - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
526 	else
527 		writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
528 
529 	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_DMATDLR);
530 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMARDLR);
531 	writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
532 
533 	/* the hardware only supports an even clock divisor, so
534 	 * round divisor = spiclk / speed up to nearest even number
535 	 * so that the resulting speed is <= the requested speed
536 	 */
537 	writel_relaxed(2 * DIV_ROUND_UP(rs->freq, 2 * xfer->speed_hz),
538 			rs->regs + ROCKCHIP_SPI_BAUDR);
539 }
540 
541 static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
542 {
543 	return ROCKCHIP_SPI_MAX_TRANLEN;
544 }
545 
546 static int rockchip_spi_transfer_one(
547 		struct spi_master *master,
548 		struct spi_device *spi,
549 		struct spi_transfer *xfer)
550 {
551 	struct rockchip_spi *rs = spi_master_get_devdata(master);
552 	bool use_dma;
553 
554 	WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
555 		(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
556 
557 	if (!xfer->tx_buf && !xfer->rx_buf) {
558 		dev_err(rs->dev, "No buffer for transfer\n");
559 		return -EINVAL;
560 	}
561 
562 	if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
563 		dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
564 		return -EINVAL;
565 	}
566 
567 	rs->n_bytes = xfer->bits_per_word <= 8 ? 1 : 2;
568 
569 	use_dma = master->can_dma ? master->can_dma(master, spi, xfer) : false;
570 
571 	rockchip_spi_config(rs, spi, xfer, use_dma);
572 
573 	if (use_dma)
574 		return rockchip_spi_prepare_dma(rs, master, xfer);
575 
576 	return rockchip_spi_prepare_irq(rs, xfer);
577 }
578 
579 static bool rockchip_spi_can_dma(struct spi_master *master,
580 				 struct spi_device *spi,
581 				 struct spi_transfer *xfer)
582 {
583 	struct rockchip_spi *rs = spi_master_get_devdata(master);
584 	unsigned int bytes_per_word = xfer->bits_per_word <= 8 ? 1 : 2;
585 
586 	/* if the numbor of spi words to transfer is less than the fifo
587 	 * length we can just fill the fifo and wait for a single irq,
588 	 * so don't bother setting up dma
589 	 */
590 	return xfer->len / bytes_per_word >= rs->fifo_len;
591 }
592 
593 static int rockchip_spi_probe(struct platform_device *pdev)
594 {
595 	int ret;
596 	struct rockchip_spi *rs;
597 	struct spi_master *master;
598 	struct resource *mem;
599 	u32 rsd_nsecs;
600 
601 	master = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi));
602 	if (!master)
603 		return -ENOMEM;
604 
605 	platform_set_drvdata(pdev, master);
606 
607 	rs = spi_master_get_devdata(master);
608 
609 	/* Get basic io resource and map it */
610 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
611 	rs->regs = devm_ioremap_resource(&pdev->dev, mem);
612 	if (IS_ERR(rs->regs)) {
613 		ret =  PTR_ERR(rs->regs);
614 		goto err_put_master;
615 	}
616 
617 	rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
618 	if (IS_ERR(rs->apb_pclk)) {
619 		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
620 		ret = PTR_ERR(rs->apb_pclk);
621 		goto err_put_master;
622 	}
623 
624 	rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
625 	if (IS_ERR(rs->spiclk)) {
626 		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
627 		ret = PTR_ERR(rs->spiclk);
628 		goto err_put_master;
629 	}
630 
631 	ret = clk_prepare_enable(rs->apb_pclk);
632 	if (ret < 0) {
633 		dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
634 		goto err_put_master;
635 	}
636 
637 	ret = clk_prepare_enable(rs->spiclk);
638 	if (ret < 0) {
639 		dev_err(&pdev->dev, "Failed to enable spi_clk\n");
640 		goto err_disable_apbclk;
641 	}
642 
643 	spi_enable_chip(rs, false);
644 
645 	ret = platform_get_irq(pdev, 0);
646 	if (ret < 0)
647 		goto err_disable_spiclk;
648 
649 	ret = devm_request_threaded_irq(&pdev->dev, ret, rockchip_spi_isr, NULL,
650 			IRQF_ONESHOT, dev_name(&pdev->dev), master);
651 	if (ret)
652 		goto err_disable_spiclk;
653 
654 	rs->dev = &pdev->dev;
655 	rs->freq = clk_get_rate(rs->spiclk);
656 
657 	if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
658 				  &rsd_nsecs)) {
659 		/* rx sample delay is expressed in parent clock cycles (max 3) */
660 		u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8),
661 				1000000000 >> 8);
662 		if (!rsd) {
663 			dev_warn(rs->dev, "%u Hz are too slow to express %u ns delay\n",
664 					rs->freq, rsd_nsecs);
665 		} else if (rsd > CR0_RSD_MAX) {
666 			rsd = CR0_RSD_MAX;
667 			dev_warn(rs->dev, "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
668 					rs->freq, rsd_nsecs,
669 					CR0_RSD_MAX * 1000000000U / rs->freq);
670 		}
671 		rs->rsd = rsd;
672 	}
673 
674 	rs->fifo_len = get_fifo_len(rs);
675 	if (!rs->fifo_len) {
676 		dev_err(&pdev->dev, "Failed to get fifo length\n");
677 		ret = -EINVAL;
678 		goto err_disable_spiclk;
679 	}
680 
681 	pm_runtime_set_active(&pdev->dev);
682 	pm_runtime_enable(&pdev->dev);
683 
684 	master->auto_runtime_pm = true;
685 	master->bus_num = pdev->id;
686 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
687 	master->num_chipselect = ROCKCHIP_SPI_MAX_CS_NUM;
688 	master->dev.of_node = pdev->dev.of_node;
689 	master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
690 	master->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
691 	master->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);
692 
693 	master->set_cs = rockchip_spi_set_cs;
694 	master->transfer_one = rockchip_spi_transfer_one;
695 	master->max_transfer_size = rockchip_spi_max_transfer_size;
696 	master->handle_err = rockchip_spi_handle_err;
697 	master->flags = SPI_MASTER_GPIO_SS;
698 
699 	master->dma_tx = dma_request_chan(rs->dev, "tx");
700 	if (IS_ERR(master->dma_tx)) {
701 		/* Check tx to see if we need defer probing driver */
702 		if (PTR_ERR(master->dma_tx) == -EPROBE_DEFER) {
703 			ret = -EPROBE_DEFER;
704 			goto err_disable_pm_runtime;
705 		}
706 		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
707 		master->dma_tx = NULL;
708 	}
709 
710 	master->dma_rx = dma_request_chan(rs->dev, "rx");
711 	if (IS_ERR(master->dma_rx)) {
712 		if (PTR_ERR(master->dma_rx) == -EPROBE_DEFER) {
713 			ret = -EPROBE_DEFER;
714 			goto err_free_dma_tx;
715 		}
716 		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
717 		master->dma_rx = NULL;
718 	}
719 
720 	if (master->dma_tx && master->dma_rx) {
721 		rs->dma_addr_tx = mem->start + ROCKCHIP_SPI_TXDR;
722 		rs->dma_addr_rx = mem->start + ROCKCHIP_SPI_RXDR;
723 		master->can_dma = rockchip_spi_can_dma;
724 	}
725 
726 	ret = devm_spi_register_master(&pdev->dev, master);
727 	if (ret < 0) {
728 		dev_err(&pdev->dev, "Failed to register master\n");
729 		goto err_free_dma_rx;
730 	}
731 
732 	return 0;
733 
734 err_free_dma_rx:
735 	if (master->dma_rx)
736 		dma_release_channel(master->dma_rx);
737 err_free_dma_tx:
738 	if (master->dma_tx)
739 		dma_release_channel(master->dma_tx);
740 err_disable_pm_runtime:
741 	pm_runtime_disable(&pdev->dev);
742 err_disable_spiclk:
743 	clk_disable_unprepare(rs->spiclk);
744 err_disable_apbclk:
745 	clk_disable_unprepare(rs->apb_pclk);
746 err_put_master:
747 	spi_master_put(master);
748 
749 	return ret;
750 }
751 
752 static int rockchip_spi_remove(struct platform_device *pdev)
753 {
754 	struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
755 	struct rockchip_spi *rs = spi_master_get_devdata(master);
756 
757 	pm_runtime_get_sync(&pdev->dev);
758 
759 	clk_disable_unprepare(rs->spiclk);
760 	clk_disable_unprepare(rs->apb_pclk);
761 
762 	pm_runtime_put_noidle(&pdev->dev);
763 	pm_runtime_disable(&pdev->dev);
764 	pm_runtime_set_suspended(&pdev->dev);
765 
766 	if (master->dma_tx)
767 		dma_release_channel(master->dma_tx);
768 	if (master->dma_rx)
769 		dma_release_channel(master->dma_rx);
770 
771 	spi_master_put(master);
772 
773 	return 0;
774 }
775 
776 #ifdef CONFIG_PM_SLEEP
777 static int rockchip_spi_suspend(struct device *dev)
778 {
779 	int ret;
780 	struct spi_master *master = dev_get_drvdata(dev);
781 
782 	ret = spi_master_suspend(master);
783 	if (ret < 0)
784 		return ret;
785 
786 	ret = pm_runtime_force_suspend(dev);
787 	if (ret < 0)
788 		return ret;
789 
790 	pinctrl_pm_select_sleep_state(dev);
791 
792 	return 0;
793 }
794 
795 static int rockchip_spi_resume(struct device *dev)
796 {
797 	int ret;
798 	struct spi_master *master = dev_get_drvdata(dev);
799 	struct rockchip_spi *rs = spi_master_get_devdata(master);
800 
801 	pinctrl_pm_select_default_state(dev);
802 
803 	ret = pm_runtime_force_resume(dev);
804 	if (ret < 0)
805 		return ret;
806 
807 	ret = spi_master_resume(master);
808 	if (ret < 0) {
809 		clk_disable_unprepare(rs->spiclk);
810 		clk_disable_unprepare(rs->apb_pclk);
811 	}
812 
813 	return 0;
814 }
815 #endif /* CONFIG_PM_SLEEP */
816 
817 #ifdef CONFIG_PM
818 static int rockchip_spi_runtime_suspend(struct device *dev)
819 {
820 	struct spi_master *master = dev_get_drvdata(dev);
821 	struct rockchip_spi *rs = spi_master_get_devdata(master);
822 
823 	clk_disable_unprepare(rs->spiclk);
824 	clk_disable_unprepare(rs->apb_pclk);
825 
826 	return 0;
827 }
828 
829 static int rockchip_spi_runtime_resume(struct device *dev)
830 {
831 	int ret;
832 	struct spi_master *master = dev_get_drvdata(dev);
833 	struct rockchip_spi *rs = spi_master_get_devdata(master);
834 
835 	ret = clk_prepare_enable(rs->apb_pclk);
836 	if (ret < 0)
837 		return ret;
838 
839 	ret = clk_prepare_enable(rs->spiclk);
840 	if (ret < 0)
841 		clk_disable_unprepare(rs->apb_pclk);
842 
843 	return 0;
844 }
845 #endif /* CONFIG_PM */
846 
847 static const struct dev_pm_ops rockchip_spi_pm = {
848 	SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
849 	SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
850 			   rockchip_spi_runtime_resume, NULL)
851 };
852 
853 static const struct of_device_id rockchip_spi_dt_match[] = {
854 	{ .compatible = "rockchip,rv1108-spi", },
855 	{ .compatible = "rockchip,rk3036-spi", },
856 	{ .compatible = "rockchip,rk3066-spi", },
857 	{ .compatible = "rockchip,rk3188-spi", },
858 	{ .compatible = "rockchip,rk3228-spi", },
859 	{ .compatible = "rockchip,rk3288-spi", },
860 	{ .compatible = "rockchip,rk3368-spi", },
861 	{ .compatible = "rockchip,rk3399-spi", },
862 	{ },
863 };
864 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
865 
866 static struct platform_driver rockchip_spi_driver = {
867 	.driver = {
868 		.name	= DRIVER_NAME,
869 		.pm = &rockchip_spi_pm,
870 		.of_match_table = of_match_ptr(rockchip_spi_dt_match),
871 	},
872 	.probe = rockchip_spi_probe,
873 	.remove = rockchip_spi_remove,
874 };
875 
876 module_platform_driver(rockchip_spi_driver);
877 
878 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
879 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
880 MODULE_LICENSE("GPL v2");
881