xref: /openbmc/linux/drivers/spi/spi-rockchip.c (revision 82df5b73)
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 	bool slave_abort;
188 };
189 
190 static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
191 {
192 	writel_relaxed((enable ? 1U : 0U), rs->regs + ROCKCHIP_SPI_SSIENR);
193 }
194 
195 static inline void wait_for_idle(struct rockchip_spi *rs)
196 {
197 	unsigned long timeout = jiffies + msecs_to_jiffies(5);
198 
199 	do {
200 		if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
201 			return;
202 	} while (!time_after(jiffies, timeout));
203 
204 	dev_warn(rs->dev, "spi controller is in busy state!\n");
205 }
206 
207 static u32 get_fifo_len(struct rockchip_spi *rs)
208 {
209 	u32 fifo;
210 
211 	for (fifo = 2; fifo < 32; fifo++) {
212 		writel_relaxed(fifo, rs->regs + ROCKCHIP_SPI_TXFTLR);
213 		if (fifo != readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFTLR))
214 			break;
215 	}
216 
217 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_TXFTLR);
218 
219 	return (fifo == 31) ? 0 : fifo;
220 }
221 
222 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
223 {
224 	struct spi_controller *ctlr = spi->controller;
225 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
226 	bool cs_asserted = !enable;
227 
228 	/* Return immediately for no-op */
229 	if (cs_asserted == rs->cs_asserted[spi->chip_select])
230 		return;
231 
232 	if (cs_asserted) {
233 		/* Keep things powered as long as CS is asserted */
234 		pm_runtime_get_sync(rs->dev);
235 
236 		ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER,
237 				      BIT(spi->chip_select));
238 	} else {
239 		ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER,
240 				      BIT(spi->chip_select));
241 
242 		/* Drop reference from when we first asserted CS */
243 		pm_runtime_put(rs->dev);
244 	}
245 
246 	rs->cs_asserted[spi->chip_select] = cs_asserted;
247 }
248 
249 static void rockchip_spi_handle_err(struct spi_controller *ctlr,
250 				    struct spi_message *msg)
251 {
252 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
253 
254 	/* stop running spi transfer
255 	 * this also flushes both rx and tx fifos
256 	 */
257 	spi_enable_chip(rs, false);
258 
259 	/* make sure all interrupts are masked */
260 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
261 
262 	if (atomic_read(&rs->state) & TXDMA)
263 		dmaengine_terminate_async(ctlr->dma_tx);
264 
265 	if (atomic_read(&rs->state) & RXDMA)
266 		dmaengine_terminate_async(ctlr->dma_rx);
267 }
268 
269 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
270 {
271 	u32 tx_free = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
272 	u32 words = min(rs->tx_left, tx_free);
273 
274 	rs->tx_left -= words;
275 	for (; words; words--) {
276 		u32 txw;
277 
278 		if (rs->n_bytes == 1)
279 			txw = *(u8 *)rs->tx;
280 		else
281 			txw = *(u16 *)rs->tx;
282 
283 		writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
284 		rs->tx += rs->n_bytes;
285 	}
286 }
287 
288 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
289 {
290 	u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
291 	u32 rx_left = rs->rx_left - words;
292 
293 	/* the hardware doesn't allow us to change fifo threshold
294 	 * level while spi is enabled, so instead make sure to leave
295 	 * enough words in the rx fifo to get the last interrupt
296 	 * exactly when all words have been received
297 	 */
298 	if (rx_left) {
299 		u32 ftl = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFTLR) + 1;
300 
301 		if (rx_left < ftl) {
302 			rx_left = ftl;
303 			words = rs->rx_left - rx_left;
304 		}
305 	}
306 
307 	rs->rx_left = rx_left;
308 	for (; words; words--) {
309 		u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
310 
311 		if (!rs->rx)
312 			continue;
313 
314 		if (rs->n_bytes == 1)
315 			*(u8 *)rs->rx = (u8)rxw;
316 		else
317 			*(u16 *)rs->rx = (u16)rxw;
318 		rs->rx += rs->n_bytes;
319 	}
320 }
321 
322 static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
323 {
324 	struct spi_controller *ctlr = dev_id;
325 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
326 
327 	if (rs->tx_left)
328 		rockchip_spi_pio_writer(rs);
329 
330 	rockchip_spi_pio_reader(rs);
331 	if (!rs->rx_left) {
332 		spi_enable_chip(rs, false);
333 		writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
334 		spi_finalize_current_transfer(ctlr);
335 	}
336 
337 	return IRQ_HANDLED;
338 }
339 
340 static int rockchip_spi_prepare_irq(struct rockchip_spi *rs,
341 		struct spi_transfer *xfer)
342 {
343 	rs->tx = xfer->tx_buf;
344 	rs->rx = xfer->rx_buf;
345 	rs->tx_left = rs->tx ? xfer->len / rs->n_bytes : 0;
346 	rs->rx_left = xfer->len / rs->n_bytes;
347 
348 	writel_relaxed(INT_RF_FULL, rs->regs + ROCKCHIP_SPI_IMR);
349 	spi_enable_chip(rs, true);
350 
351 	if (rs->tx_left)
352 		rockchip_spi_pio_writer(rs);
353 
354 	/* 1 means the transfer is in progress */
355 	return 1;
356 }
357 
358 static void rockchip_spi_dma_rxcb(void *data)
359 {
360 	struct spi_controller *ctlr = data;
361 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
362 	int state = atomic_fetch_andnot(RXDMA, &rs->state);
363 
364 	if (state & TXDMA && !rs->slave_abort)
365 		return;
366 
367 	spi_enable_chip(rs, false);
368 	spi_finalize_current_transfer(ctlr);
369 }
370 
371 static void rockchip_spi_dma_txcb(void *data)
372 {
373 	struct spi_controller *ctlr = data;
374 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
375 	int state = atomic_fetch_andnot(TXDMA, &rs->state);
376 
377 	if (state & RXDMA && !rs->slave_abort)
378 		return;
379 
380 	/* Wait until the FIFO data completely. */
381 	wait_for_idle(rs);
382 
383 	spi_enable_chip(rs, false);
384 	spi_finalize_current_transfer(ctlr);
385 }
386 
387 static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
388 		struct spi_controller *ctlr, struct spi_transfer *xfer)
389 {
390 	struct dma_async_tx_descriptor *rxdesc, *txdesc;
391 
392 	atomic_set(&rs->state, 0);
393 
394 	rxdesc = NULL;
395 	if (xfer->rx_buf) {
396 		struct dma_slave_config rxconf = {
397 			.direction = DMA_DEV_TO_MEM,
398 			.src_addr = rs->dma_addr_rx,
399 			.src_addr_width = rs->n_bytes,
400 			.src_maxburst = 1,
401 		};
402 
403 		dmaengine_slave_config(ctlr->dma_rx, &rxconf);
404 
405 		rxdesc = dmaengine_prep_slave_sg(
406 				ctlr->dma_rx,
407 				xfer->rx_sg.sgl, xfer->rx_sg.nents,
408 				DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
409 		if (!rxdesc)
410 			return -EINVAL;
411 
412 		rxdesc->callback = rockchip_spi_dma_rxcb;
413 		rxdesc->callback_param = ctlr;
414 	}
415 
416 	txdesc = NULL;
417 	if (xfer->tx_buf) {
418 		struct dma_slave_config txconf = {
419 			.direction = DMA_MEM_TO_DEV,
420 			.dst_addr = rs->dma_addr_tx,
421 			.dst_addr_width = rs->n_bytes,
422 			.dst_maxburst = rs->fifo_len / 4,
423 		};
424 
425 		dmaengine_slave_config(ctlr->dma_tx, &txconf);
426 
427 		txdesc = dmaengine_prep_slave_sg(
428 				ctlr->dma_tx,
429 				xfer->tx_sg.sgl, xfer->tx_sg.nents,
430 				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
431 		if (!txdesc) {
432 			if (rxdesc)
433 				dmaengine_terminate_sync(ctlr->dma_rx);
434 			return -EINVAL;
435 		}
436 
437 		txdesc->callback = rockchip_spi_dma_txcb;
438 		txdesc->callback_param = ctlr;
439 	}
440 
441 	/* rx must be started before tx due to spi instinct */
442 	if (rxdesc) {
443 		atomic_or(RXDMA, &rs->state);
444 		dmaengine_submit(rxdesc);
445 		dma_async_issue_pending(ctlr->dma_rx);
446 	}
447 
448 	spi_enable_chip(rs, true);
449 
450 	if (txdesc) {
451 		atomic_or(TXDMA, &rs->state);
452 		dmaengine_submit(txdesc);
453 		dma_async_issue_pending(ctlr->dma_tx);
454 	}
455 
456 	/* 1 means the transfer is in progress */
457 	return 1;
458 }
459 
460 static void rockchip_spi_config(struct rockchip_spi *rs,
461 		struct spi_device *spi, struct spi_transfer *xfer,
462 		bool use_dma, bool slave_mode)
463 {
464 	u32 cr0 = CR0_FRF_SPI  << CR0_FRF_OFFSET
465 	        | CR0_BHT_8BIT << CR0_BHT_OFFSET
466 	        | CR0_SSD_ONE  << CR0_SSD_OFFSET
467 	        | CR0_EM_BIG   << CR0_EM_OFFSET;
468 	u32 cr1;
469 	u32 dmacr = 0;
470 
471 	if (slave_mode)
472 		cr0 |= CR0_OPM_SLAVE << CR0_OPM_OFFSET;
473 	rs->slave_abort = false;
474 
475 	cr0 |= rs->rsd << CR0_RSD_OFFSET;
476 	cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
477 	if (spi->mode & SPI_LSB_FIRST)
478 		cr0 |= CR0_FBM_LSB << CR0_FBM_OFFSET;
479 
480 	if (xfer->rx_buf && xfer->tx_buf)
481 		cr0 |= CR0_XFM_TR << CR0_XFM_OFFSET;
482 	else if (xfer->rx_buf)
483 		cr0 |= CR0_XFM_RO << CR0_XFM_OFFSET;
484 	else if (use_dma)
485 		cr0 |= CR0_XFM_TO << CR0_XFM_OFFSET;
486 
487 	switch (xfer->bits_per_word) {
488 	case 4:
489 		cr0 |= CR0_DFS_4BIT << CR0_DFS_OFFSET;
490 		cr1 = xfer->len - 1;
491 		break;
492 	case 8:
493 		cr0 |= CR0_DFS_8BIT << CR0_DFS_OFFSET;
494 		cr1 = xfer->len - 1;
495 		break;
496 	case 16:
497 		cr0 |= CR0_DFS_16BIT << CR0_DFS_OFFSET;
498 		cr1 = xfer->len / 2 - 1;
499 		break;
500 	default:
501 		/* we only whitelist 4, 8 and 16 bit words in
502 		 * ctlr->bits_per_word_mask, so this shouldn't
503 		 * happen
504 		 */
505 		unreachable();
506 	}
507 
508 	if (use_dma) {
509 		if (xfer->tx_buf)
510 			dmacr |= TF_DMA_EN;
511 		if (xfer->rx_buf)
512 			dmacr |= RF_DMA_EN;
513 	}
514 
515 	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
516 	writel_relaxed(cr1, rs->regs + ROCKCHIP_SPI_CTRLR1);
517 
518 	/* unfortunately setting the fifo threshold level to generate an
519 	 * interrupt exactly when the fifo is full doesn't seem to work,
520 	 * so we need the strict inequality here
521 	 */
522 	if (xfer->len < rs->fifo_len)
523 		writel_relaxed(xfer->len - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
524 	else
525 		writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
526 
527 	writel_relaxed(rs->fifo_len / 2, rs->regs + ROCKCHIP_SPI_DMATDLR);
528 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMARDLR);
529 	writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
530 
531 	/* the hardware only supports an even clock divisor, so
532 	 * round divisor = spiclk / speed up to nearest even number
533 	 * so that the resulting speed is <= the requested speed
534 	 */
535 	writel_relaxed(2 * DIV_ROUND_UP(rs->freq, 2 * xfer->speed_hz),
536 			rs->regs + ROCKCHIP_SPI_BAUDR);
537 }
538 
539 static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
540 {
541 	return ROCKCHIP_SPI_MAX_TRANLEN;
542 }
543 
544 static int rockchip_spi_slave_abort(struct spi_controller *ctlr)
545 {
546 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
547 
548 	rs->slave_abort = true;
549 	complete(&ctlr->xfer_completion);
550 
551 	return 0;
552 }
553 
554 static int rockchip_spi_transfer_one(
555 		struct spi_controller *ctlr,
556 		struct spi_device *spi,
557 		struct spi_transfer *xfer)
558 {
559 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
560 	bool use_dma;
561 
562 	WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
563 		(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
564 
565 	if (!xfer->tx_buf && !xfer->rx_buf) {
566 		dev_err(rs->dev, "No buffer for transfer\n");
567 		return -EINVAL;
568 	}
569 
570 	if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
571 		dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
572 		return -EINVAL;
573 	}
574 
575 	rs->n_bytes = xfer->bits_per_word <= 8 ? 1 : 2;
576 
577 	use_dma = ctlr->can_dma ? ctlr->can_dma(ctlr, spi, xfer) : false;
578 
579 	rockchip_spi_config(rs, spi, xfer, use_dma, ctlr->slave);
580 
581 	if (use_dma)
582 		return rockchip_spi_prepare_dma(rs, ctlr, xfer);
583 
584 	return rockchip_spi_prepare_irq(rs, xfer);
585 }
586 
587 static bool rockchip_spi_can_dma(struct spi_controller *ctlr,
588 				 struct spi_device *spi,
589 				 struct spi_transfer *xfer)
590 {
591 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
592 	unsigned int bytes_per_word = xfer->bits_per_word <= 8 ? 1 : 2;
593 
594 	/* if the numbor of spi words to transfer is less than the fifo
595 	 * length we can just fill the fifo and wait for a single irq,
596 	 * so don't bother setting up dma
597 	 */
598 	return xfer->len / bytes_per_word >= rs->fifo_len;
599 }
600 
601 static int rockchip_spi_probe(struct platform_device *pdev)
602 {
603 	int ret;
604 	struct rockchip_spi *rs;
605 	struct spi_controller *ctlr;
606 	struct resource *mem;
607 	struct device_node *np = pdev->dev.of_node;
608 	u32 rsd_nsecs;
609 	bool slave_mode;
610 
611 	slave_mode = of_property_read_bool(np, "spi-slave");
612 
613 	if (slave_mode)
614 		ctlr = spi_alloc_slave(&pdev->dev,
615 				sizeof(struct rockchip_spi));
616 	else
617 		ctlr = spi_alloc_master(&pdev->dev,
618 				sizeof(struct rockchip_spi));
619 
620 	if (!ctlr)
621 		return -ENOMEM;
622 
623 	platform_set_drvdata(pdev, ctlr);
624 
625 	rs = spi_controller_get_devdata(ctlr);
626 	ctlr->slave = slave_mode;
627 
628 	/* Get basic io resource and map it */
629 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
630 	rs->regs = devm_ioremap_resource(&pdev->dev, mem);
631 	if (IS_ERR(rs->regs)) {
632 		ret =  PTR_ERR(rs->regs);
633 		goto err_put_ctlr;
634 	}
635 
636 	rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
637 	if (IS_ERR(rs->apb_pclk)) {
638 		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
639 		ret = PTR_ERR(rs->apb_pclk);
640 		goto err_put_ctlr;
641 	}
642 
643 	rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
644 	if (IS_ERR(rs->spiclk)) {
645 		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
646 		ret = PTR_ERR(rs->spiclk);
647 		goto err_put_ctlr;
648 	}
649 
650 	ret = clk_prepare_enable(rs->apb_pclk);
651 	if (ret < 0) {
652 		dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
653 		goto err_put_ctlr;
654 	}
655 
656 	ret = clk_prepare_enable(rs->spiclk);
657 	if (ret < 0) {
658 		dev_err(&pdev->dev, "Failed to enable spi_clk\n");
659 		goto err_disable_apbclk;
660 	}
661 
662 	spi_enable_chip(rs, false);
663 
664 	ret = platform_get_irq(pdev, 0);
665 	if (ret < 0)
666 		goto err_disable_spiclk;
667 
668 	ret = devm_request_threaded_irq(&pdev->dev, ret, rockchip_spi_isr, NULL,
669 			IRQF_ONESHOT, dev_name(&pdev->dev), ctlr);
670 	if (ret)
671 		goto err_disable_spiclk;
672 
673 	rs->dev = &pdev->dev;
674 	rs->freq = clk_get_rate(rs->spiclk);
675 
676 	if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
677 				  &rsd_nsecs)) {
678 		/* rx sample delay is expressed in parent clock cycles (max 3) */
679 		u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8),
680 				1000000000 >> 8);
681 		if (!rsd) {
682 			dev_warn(rs->dev, "%u Hz are too slow to express %u ns delay\n",
683 					rs->freq, rsd_nsecs);
684 		} else if (rsd > CR0_RSD_MAX) {
685 			rsd = CR0_RSD_MAX;
686 			dev_warn(rs->dev, "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
687 					rs->freq, rsd_nsecs,
688 					CR0_RSD_MAX * 1000000000U / rs->freq);
689 		}
690 		rs->rsd = rsd;
691 	}
692 
693 	rs->fifo_len = get_fifo_len(rs);
694 	if (!rs->fifo_len) {
695 		dev_err(&pdev->dev, "Failed to get fifo length\n");
696 		ret = -EINVAL;
697 		goto err_disable_spiclk;
698 	}
699 
700 	pm_runtime_set_active(&pdev->dev);
701 	pm_runtime_enable(&pdev->dev);
702 
703 	ctlr->auto_runtime_pm = true;
704 	ctlr->bus_num = pdev->id;
705 	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
706 	if (slave_mode) {
707 		ctlr->mode_bits |= SPI_NO_CS;
708 		ctlr->slave_abort = rockchip_spi_slave_abort;
709 	} else {
710 		ctlr->flags = SPI_MASTER_GPIO_SS;
711 		ctlr->max_native_cs = ROCKCHIP_SPI_MAX_CS_NUM;
712 		/*
713 		 * rk spi0 has two native cs, spi1..5 one cs only
714 		 * if num-cs is missing in the dts, default to 1
715 		 */
716 		if (of_property_read_u16(np, "num-cs", &ctlr->num_chipselect))
717 			ctlr->num_chipselect = 1;
718 		ctlr->use_gpio_descriptors = true;
719 	}
720 	ctlr->dev.of_node = pdev->dev.of_node;
721 	ctlr->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
722 	ctlr->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
723 	ctlr->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);
724 
725 	ctlr->set_cs = rockchip_spi_set_cs;
726 	ctlr->transfer_one = rockchip_spi_transfer_one;
727 	ctlr->max_transfer_size = rockchip_spi_max_transfer_size;
728 	ctlr->handle_err = rockchip_spi_handle_err;
729 
730 	ctlr->dma_tx = dma_request_chan(rs->dev, "tx");
731 	if (IS_ERR(ctlr->dma_tx)) {
732 		/* Check tx to see if we need defer probing driver */
733 		if (PTR_ERR(ctlr->dma_tx) == -EPROBE_DEFER) {
734 			ret = -EPROBE_DEFER;
735 			goto err_disable_pm_runtime;
736 		}
737 		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
738 		ctlr->dma_tx = NULL;
739 	}
740 
741 	ctlr->dma_rx = dma_request_chan(rs->dev, "rx");
742 	if (IS_ERR(ctlr->dma_rx)) {
743 		if (PTR_ERR(ctlr->dma_rx) == -EPROBE_DEFER) {
744 			ret = -EPROBE_DEFER;
745 			goto err_free_dma_tx;
746 		}
747 		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
748 		ctlr->dma_rx = NULL;
749 	}
750 
751 	if (ctlr->dma_tx && ctlr->dma_rx) {
752 		rs->dma_addr_tx = mem->start + ROCKCHIP_SPI_TXDR;
753 		rs->dma_addr_rx = mem->start + ROCKCHIP_SPI_RXDR;
754 		ctlr->can_dma = rockchip_spi_can_dma;
755 	}
756 
757 	ret = devm_spi_register_controller(&pdev->dev, ctlr);
758 	if (ret < 0) {
759 		dev_err(&pdev->dev, "Failed to register controller\n");
760 		goto err_free_dma_rx;
761 	}
762 
763 	return 0;
764 
765 err_free_dma_rx:
766 	if (ctlr->dma_rx)
767 		dma_release_channel(ctlr->dma_rx);
768 err_free_dma_tx:
769 	if (ctlr->dma_tx)
770 		dma_release_channel(ctlr->dma_tx);
771 err_disable_pm_runtime:
772 	pm_runtime_disable(&pdev->dev);
773 err_disable_spiclk:
774 	clk_disable_unprepare(rs->spiclk);
775 err_disable_apbclk:
776 	clk_disable_unprepare(rs->apb_pclk);
777 err_put_ctlr:
778 	spi_controller_put(ctlr);
779 
780 	return ret;
781 }
782 
783 static int rockchip_spi_remove(struct platform_device *pdev)
784 {
785 	struct spi_controller *ctlr = spi_controller_get(platform_get_drvdata(pdev));
786 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
787 
788 	pm_runtime_get_sync(&pdev->dev);
789 
790 	clk_disable_unprepare(rs->spiclk);
791 	clk_disable_unprepare(rs->apb_pclk);
792 
793 	pm_runtime_put_noidle(&pdev->dev);
794 	pm_runtime_disable(&pdev->dev);
795 	pm_runtime_set_suspended(&pdev->dev);
796 
797 	if (ctlr->dma_tx)
798 		dma_release_channel(ctlr->dma_tx);
799 	if (ctlr->dma_rx)
800 		dma_release_channel(ctlr->dma_rx);
801 
802 	spi_controller_put(ctlr);
803 
804 	return 0;
805 }
806 
807 #ifdef CONFIG_PM_SLEEP
808 static int rockchip_spi_suspend(struct device *dev)
809 {
810 	int ret;
811 	struct spi_controller *ctlr = dev_get_drvdata(dev);
812 
813 	ret = spi_controller_suspend(ctlr);
814 	if (ret < 0)
815 		return ret;
816 
817 	ret = pm_runtime_force_suspend(dev);
818 	if (ret < 0)
819 		return ret;
820 
821 	pinctrl_pm_select_sleep_state(dev);
822 
823 	return 0;
824 }
825 
826 static int rockchip_spi_resume(struct device *dev)
827 {
828 	int ret;
829 	struct spi_controller *ctlr = dev_get_drvdata(dev);
830 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
831 
832 	pinctrl_pm_select_default_state(dev);
833 
834 	ret = pm_runtime_force_resume(dev);
835 	if (ret < 0)
836 		return ret;
837 
838 	ret = spi_controller_resume(ctlr);
839 	if (ret < 0) {
840 		clk_disable_unprepare(rs->spiclk);
841 		clk_disable_unprepare(rs->apb_pclk);
842 	}
843 
844 	return 0;
845 }
846 #endif /* CONFIG_PM_SLEEP */
847 
848 #ifdef CONFIG_PM
849 static int rockchip_spi_runtime_suspend(struct device *dev)
850 {
851 	struct spi_controller *ctlr = dev_get_drvdata(dev);
852 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
853 
854 	clk_disable_unprepare(rs->spiclk);
855 	clk_disable_unprepare(rs->apb_pclk);
856 
857 	return 0;
858 }
859 
860 static int rockchip_spi_runtime_resume(struct device *dev)
861 {
862 	int ret;
863 	struct spi_controller *ctlr = dev_get_drvdata(dev);
864 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
865 
866 	ret = clk_prepare_enable(rs->apb_pclk);
867 	if (ret < 0)
868 		return ret;
869 
870 	ret = clk_prepare_enable(rs->spiclk);
871 	if (ret < 0)
872 		clk_disable_unprepare(rs->apb_pclk);
873 
874 	return 0;
875 }
876 #endif /* CONFIG_PM */
877 
878 static const struct dev_pm_ops rockchip_spi_pm = {
879 	SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
880 	SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
881 			   rockchip_spi_runtime_resume, NULL)
882 };
883 
884 static const struct of_device_id rockchip_spi_dt_match[] = {
885 	{ .compatible = "rockchip,px30-spi", },
886 	{ .compatible = "rockchip,rk3036-spi", },
887 	{ .compatible = "rockchip,rk3066-spi", },
888 	{ .compatible = "rockchip,rk3188-spi", },
889 	{ .compatible = "rockchip,rk3228-spi", },
890 	{ .compatible = "rockchip,rk3288-spi", },
891 	{ .compatible = "rockchip,rk3308-spi", },
892 	{ .compatible = "rockchip,rk3328-spi", },
893 	{ .compatible = "rockchip,rk3368-spi", },
894 	{ .compatible = "rockchip,rk3399-spi", },
895 	{ .compatible = "rockchip,rv1108-spi", },
896 	{ },
897 };
898 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
899 
900 static struct platform_driver rockchip_spi_driver = {
901 	.driver = {
902 		.name	= DRIVER_NAME,
903 		.pm = &rockchip_spi_pm,
904 		.of_match_table = of_match_ptr(rockchip_spi_dt_match),
905 	},
906 	.probe = rockchip_spi_probe,
907 	.remove = rockchip_spi_remove,
908 };
909 
910 module_platform_driver(rockchip_spi_driver);
911 
912 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
913 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
914 MODULE_LICENSE("GPL v2");
915