xref: /openbmc/linux/drivers/spi/spi-rockchip.c (revision 8ec90bfd)
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_VERSION			0x0048
45 #define ROCKCHIP_SPI_TXDR			0x0400
46 #define ROCKCHIP_SPI_RXDR			0x0800
47 
48 /* Bit fields in CTRLR0 */
49 #define CR0_DFS_OFFSET				0
50 #define CR0_DFS_4BIT				0x0
51 #define CR0_DFS_8BIT				0x1
52 #define CR0_DFS_16BIT				0x2
53 
54 #define CR0_CFS_OFFSET				2
55 
56 #define CR0_SCPH_OFFSET				6
57 
58 #define CR0_SCPOL_OFFSET			7
59 
60 #define CR0_CSM_OFFSET				8
61 #define CR0_CSM_KEEP				0x0
62 /* ss_n be high for half sclk_out cycles */
63 #define CR0_CSM_HALF				0X1
64 /* ss_n be high for one sclk_out cycle */
65 #define CR0_CSM_ONE					0x2
66 
67 /* ss_n to sclk_out delay */
68 #define CR0_SSD_OFFSET				10
69 /*
70  * The period between ss_n active and
71  * sclk_out active is half sclk_out cycles
72  */
73 #define CR0_SSD_HALF				0x0
74 /*
75  * The period between ss_n active and
76  * sclk_out active is one sclk_out cycle
77  */
78 #define CR0_SSD_ONE					0x1
79 
80 #define CR0_EM_OFFSET				11
81 #define CR0_EM_LITTLE				0x0
82 #define CR0_EM_BIG					0x1
83 
84 #define CR0_FBM_OFFSET				12
85 #define CR0_FBM_MSB					0x0
86 #define CR0_FBM_LSB					0x1
87 
88 #define CR0_BHT_OFFSET				13
89 #define CR0_BHT_16BIT				0x0
90 #define CR0_BHT_8BIT				0x1
91 
92 #define CR0_RSD_OFFSET				14
93 #define CR0_RSD_MAX				0x3
94 
95 #define CR0_FRF_OFFSET				16
96 #define CR0_FRF_SPI					0x0
97 #define CR0_FRF_SSP					0x1
98 #define CR0_FRF_MICROWIRE			0x2
99 
100 #define CR0_XFM_OFFSET				18
101 #define CR0_XFM_MASK				(0x03 << SPI_XFM_OFFSET)
102 #define CR0_XFM_TR					0x0
103 #define CR0_XFM_TO					0x1
104 #define CR0_XFM_RO					0x2
105 
106 #define CR0_OPM_OFFSET				20
107 #define CR0_OPM_MASTER				0x0
108 #define CR0_OPM_SLAVE				0x1
109 
110 #define CR0_MTM_OFFSET				0x21
111 
112 /* Bit fields in SER, 2bit */
113 #define SER_MASK					0x3
114 
115 /* Bit fields in BAUDR */
116 #define BAUDR_SCKDV_MIN				2
117 #define BAUDR_SCKDV_MAX				65534
118 
119 /* Bit fields in SR, 5bit */
120 #define SR_MASK						0x1f
121 #define SR_BUSY						(1 << 0)
122 #define SR_TF_FULL					(1 << 1)
123 #define SR_TF_EMPTY					(1 << 2)
124 #define SR_RF_EMPTY					(1 << 3)
125 #define SR_RF_FULL					(1 << 4)
126 
127 /* Bit fields in ISR, IMR, ISR, RISR, 5bit */
128 #define INT_MASK					0x1f
129 #define INT_TF_EMPTY				(1 << 0)
130 #define INT_TF_OVERFLOW				(1 << 1)
131 #define INT_RF_UNDERFLOW			(1 << 2)
132 #define INT_RF_OVERFLOW				(1 << 3)
133 #define INT_RF_FULL					(1 << 4)
134 
135 /* Bit fields in ICR, 4bit */
136 #define ICR_MASK					0x0f
137 #define ICR_ALL						(1 << 0)
138 #define ICR_RF_UNDERFLOW			(1 << 1)
139 #define ICR_RF_OVERFLOW				(1 << 2)
140 #define ICR_TF_OVERFLOW				(1 << 3)
141 
142 /* Bit fields in DMACR */
143 #define RF_DMA_EN					(1 << 0)
144 #define TF_DMA_EN					(1 << 1)
145 
146 /* Driver state flags */
147 #define RXDMA					(1 << 0)
148 #define TXDMA					(1 << 1)
149 
150 /* sclk_out: spi master internal logic in rk3x can support 50Mhz */
151 #define MAX_SCLK_OUT				50000000U
152 
153 /*
154  * SPI_CTRLR1 is 16-bits, so we should support lengths of 0xffff + 1. However,
155  * the controller seems to hang when given 0x10000, so stick with this for now.
156  */
157 #define ROCKCHIP_SPI_MAX_TRANLEN		0xffff
158 
159 #define ROCKCHIP_SPI_MAX_CS_NUM			2
160 #define ROCKCHIP_SPI_VER2_TYPE1			0x05EC0002
161 #define ROCKCHIP_SPI_VER2_TYPE2			0x00110002
162 
163 struct rockchip_spi {
164 	struct device *dev;
165 
166 	struct clk *spiclk;
167 	struct clk *apb_pclk;
168 
169 	void __iomem *regs;
170 	dma_addr_t dma_addr_rx;
171 	dma_addr_t dma_addr_tx;
172 
173 	const void *tx;
174 	void *rx;
175 	unsigned int tx_left;
176 	unsigned int rx_left;
177 
178 	atomic_t state;
179 
180 	/*depth of the FIFO buffer */
181 	u32 fifo_len;
182 	/* frequency of spiclk */
183 	u32 freq;
184 
185 	u8 n_bytes;
186 	u8 rsd;
187 
188 	bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
189 
190 	bool slave_abort;
191 };
192 
193 static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
194 {
195 	writel_relaxed((enable ? 1U : 0U), rs->regs + ROCKCHIP_SPI_SSIENR);
196 }
197 
198 static inline void wait_for_idle(struct rockchip_spi *rs)
199 {
200 	unsigned long timeout = jiffies + msecs_to_jiffies(5);
201 
202 	do {
203 		if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
204 			return;
205 	} while (!time_after(jiffies, timeout));
206 
207 	dev_warn(rs->dev, "spi controller is in busy state!\n");
208 }
209 
210 static u32 get_fifo_len(struct rockchip_spi *rs)
211 {
212 	u32 ver;
213 
214 	ver = readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION);
215 
216 	switch (ver) {
217 	case ROCKCHIP_SPI_VER2_TYPE1:
218 	case ROCKCHIP_SPI_VER2_TYPE2:
219 		return 64;
220 	default:
221 		return 32;
222 	}
223 }
224 
225 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
226 {
227 	struct spi_controller *ctlr = spi->controller;
228 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
229 	bool cs_asserted = !enable;
230 
231 	/* Return immediately for no-op */
232 	if (cs_asserted == rs->cs_asserted[spi->chip_select])
233 		return;
234 
235 	if (cs_asserted) {
236 		/* Keep things powered as long as CS is asserted */
237 		pm_runtime_get_sync(rs->dev);
238 
239 		ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER,
240 				      BIT(spi->chip_select));
241 	} else {
242 		ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER,
243 				      BIT(spi->chip_select));
244 
245 		/* Drop reference from when we first asserted CS */
246 		pm_runtime_put(rs->dev);
247 	}
248 
249 	rs->cs_asserted[spi->chip_select] = cs_asserted;
250 }
251 
252 static void rockchip_spi_handle_err(struct spi_controller *ctlr,
253 				    struct spi_message *msg)
254 {
255 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
256 
257 	/* stop running spi transfer
258 	 * this also flushes both rx and tx fifos
259 	 */
260 	spi_enable_chip(rs, false);
261 
262 	/* make sure all interrupts are masked */
263 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
264 
265 	if (atomic_read(&rs->state) & TXDMA)
266 		dmaengine_terminate_async(ctlr->dma_tx);
267 
268 	if (atomic_read(&rs->state) & RXDMA)
269 		dmaengine_terminate_async(ctlr->dma_rx);
270 }
271 
272 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
273 {
274 	u32 tx_free = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
275 	u32 words = min(rs->tx_left, tx_free);
276 
277 	rs->tx_left -= words;
278 	for (; words; words--) {
279 		u32 txw;
280 
281 		if (rs->n_bytes == 1)
282 			txw = *(u8 *)rs->tx;
283 		else
284 			txw = *(u16 *)rs->tx;
285 
286 		writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
287 		rs->tx += rs->n_bytes;
288 	}
289 }
290 
291 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
292 {
293 	u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
294 	u32 rx_left = (rs->rx_left > words) ? rs->rx_left - words : 0;
295 
296 	/* the hardware doesn't allow us to change fifo threshold
297 	 * level while spi is enabled, so instead make sure to leave
298 	 * enough words in the rx fifo to get the last interrupt
299 	 * exactly when all words have been received
300 	 */
301 	if (rx_left) {
302 		u32 ftl = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFTLR) + 1;
303 
304 		if (rx_left < ftl) {
305 			rx_left = ftl;
306 			words = rs->rx_left - rx_left;
307 		}
308 	}
309 
310 	rs->rx_left = rx_left;
311 	for (; words; words--) {
312 		u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
313 
314 		if (!rs->rx)
315 			continue;
316 
317 		if (rs->n_bytes == 1)
318 			*(u8 *)rs->rx = (u8)rxw;
319 		else
320 			*(u16 *)rs->rx = (u16)rxw;
321 		rs->rx += rs->n_bytes;
322 	}
323 }
324 
325 static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
326 {
327 	struct spi_controller *ctlr = dev_id;
328 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
329 
330 	if (rs->tx_left)
331 		rockchip_spi_pio_writer(rs);
332 
333 	rockchip_spi_pio_reader(rs);
334 	if (!rs->rx_left) {
335 		spi_enable_chip(rs, false);
336 		writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
337 		spi_finalize_current_transfer(ctlr);
338 	}
339 
340 	return IRQ_HANDLED;
341 }
342 
343 static int rockchip_spi_prepare_irq(struct rockchip_spi *rs,
344 		struct spi_transfer *xfer)
345 {
346 	rs->tx = xfer->tx_buf;
347 	rs->rx = xfer->rx_buf;
348 	rs->tx_left = rs->tx ? xfer->len / rs->n_bytes : 0;
349 	rs->rx_left = xfer->len / rs->n_bytes;
350 
351 	writel_relaxed(INT_RF_FULL, rs->regs + ROCKCHIP_SPI_IMR);
352 	spi_enable_chip(rs, true);
353 
354 	if (rs->tx_left)
355 		rockchip_spi_pio_writer(rs);
356 
357 	/* 1 means the transfer is in progress */
358 	return 1;
359 }
360 
361 static void rockchip_spi_dma_rxcb(void *data)
362 {
363 	struct spi_controller *ctlr = data;
364 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
365 	int state = atomic_fetch_andnot(RXDMA, &rs->state);
366 
367 	if (state & TXDMA && !rs->slave_abort)
368 		return;
369 
370 	spi_enable_chip(rs, false);
371 	spi_finalize_current_transfer(ctlr);
372 }
373 
374 static void rockchip_spi_dma_txcb(void *data)
375 {
376 	struct spi_controller *ctlr = data;
377 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
378 	int state = atomic_fetch_andnot(TXDMA, &rs->state);
379 
380 	if (state & RXDMA && !rs->slave_abort)
381 		return;
382 
383 	/* Wait until the FIFO data completely. */
384 	wait_for_idle(rs);
385 
386 	spi_enable_chip(rs, false);
387 	spi_finalize_current_transfer(ctlr);
388 }
389 
390 static u32 rockchip_spi_calc_burst_size(u32 data_len)
391 {
392 	u32 i;
393 
394 	/* burst size: 1, 2, 4, 8 */
395 	for (i = 1; i < 8; i <<= 1) {
396 		if (data_len & i)
397 			break;
398 	}
399 
400 	return i;
401 }
402 
403 static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
404 		struct spi_controller *ctlr, struct spi_transfer *xfer)
405 {
406 	struct dma_async_tx_descriptor *rxdesc, *txdesc;
407 
408 	atomic_set(&rs->state, 0);
409 
410 	rxdesc = NULL;
411 	if (xfer->rx_buf) {
412 		struct dma_slave_config rxconf = {
413 			.direction = DMA_DEV_TO_MEM,
414 			.src_addr = rs->dma_addr_rx,
415 			.src_addr_width = rs->n_bytes,
416 			.src_maxburst = rockchip_spi_calc_burst_size(xfer->len /
417 								     rs->n_bytes),
418 		};
419 
420 		dmaengine_slave_config(ctlr->dma_rx, &rxconf);
421 
422 		rxdesc = dmaengine_prep_slave_sg(
423 				ctlr->dma_rx,
424 				xfer->rx_sg.sgl, xfer->rx_sg.nents,
425 				DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
426 		if (!rxdesc)
427 			return -EINVAL;
428 
429 		rxdesc->callback = rockchip_spi_dma_rxcb;
430 		rxdesc->callback_param = ctlr;
431 	}
432 
433 	txdesc = NULL;
434 	if (xfer->tx_buf) {
435 		struct dma_slave_config txconf = {
436 			.direction = DMA_MEM_TO_DEV,
437 			.dst_addr = rs->dma_addr_tx,
438 			.dst_addr_width = rs->n_bytes,
439 			.dst_maxburst = rs->fifo_len / 4,
440 		};
441 
442 		dmaengine_slave_config(ctlr->dma_tx, &txconf);
443 
444 		txdesc = dmaengine_prep_slave_sg(
445 				ctlr->dma_tx,
446 				xfer->tx_sg.sgl, xfer->tx_sg.nents,
447 				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
448 		if (!txdesc) {
449 			if (rxdesc)
450 				dmaengine_terminate_sync(ctlr->dma_rx);
451 			return -EINVAL;
452 		}
453 
454 		txdesc->callback = rockchip_spi_dma_txcb;
455 		txdesc->callback_param = ctlr;
456 	}
457 
458 	/* rx must be started before tx due to spi instinct */
459 	if (rxdesc) {
460 		atomic_or(RXDMA, &rs->state);
461 		dmaengine_submit(rxdesc);
462 		dma_async_issue_pending(ctlr->dma_rx);
463 	}
464 
465 	spi_enable_chip(rs, true);
466 
467 	if (txdesc) {
468 		atomic_or(TXDMA, &rs->state);
469 		dmaengine_submit(txdesc);
470 		dma_async_issue_pending(ctlr->dma_tx);
471 	}
472 
473 	/* 1 means the transfer is in progress */
474 	return 1;
475 }
476 
477 static void rockchip_spi_config(struct rockchip_spi *rs,
478 		struct spi_device *spi, struct spi_transfer *xfer,
479 		bool use_dma, bool slave_mode)
480 {
481 	u32 cr0 = CR0_FRF_SPI  << CR0_FRF_OFFSET
482 	        | CR0_BHT_8BIT << CR0_BHT_OFFSET
483 	        | CR0_SSD_ONE  << CR0_SSD_OFFSET
484 	        | CR0_EM_BIG   << CR0_EM_OFFSET;
485 	u32 cr1;
486 	u32 dmacr = 0;
487 
488 	if (slave_mode)
489 		cr0 |= CR0_OPM_SLAVE << CR0_OPM_OFFSET;
490 	rs->slave_abort = false;
491 
492 	cr0 |= rs->rsd << CR0_RSD_OFFSET;
493 	cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
494 	if (spi->mode & SPI_LSB_FIRST)
495 		cr0 |= CR0_FBM_LSB << CR0_FBM_OFFSET;
496 
497 	if (xfer->rx_buf && xfer->tx_buf)
498 		cr0 |= CR0_XFM_TR << CR0_XFM_OFFSET;
499 	else if (xfer->rx_buf)
500 		cr0 |= CR0_XFM_RO << CR0_XFM_OFFSET;
501 	else if (use_dma)
502 		cr0 |= CR0_XFM_TO << CR0_XFM_OFFSET;
503 
504 	switch (xfer->bits_per_word) {
505 	case 4:
506 		cr0 |= CR0_DFS_4BIT << CR0_DFS_OFFSET;
507 		cr1 = xfer->len - 1;
508 		break;
509 	case 8:
510 		cr0 |= CR0_DFS_8BIT << CR0_DFS_OFFSET;
511 		cr1 = xfer->len - 1;
512 		break;
513 	case 16:
514 		cr0 |= CR0_DFS_16BIT << CR0_DFS_OFFSET;
515 		cr1 = xfer->len / 2 - 1;
516 		break;
517 	default:
518 		/* we only whitelist 4, 8 and 16 bit words in
519 		 * ctlr->bits_per_word_mask, so this shouldn't
520 		 * happen
521 		 */
522 		unreachable();
523 	}
524 
525 	if (use_dma) {
526 		if (xfer->tx_buf)
527 			dmacr |= TF_DMA_EN;
528 		if (xfer->rx_buf)
529 			dmacr |= RF_DMA_EN;
530 	}
531 
532 	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
533 	writel_relaxed(cr1, rs->regs + ROCKCHIP_SPI_CTRLR1);
534 
535 	/* unfortunately setting the fifo threshold level to generate an
536 	 * interrupt exactly when the fifo is full doesn't seem to work,
537 	 * so we need the strict inequality here
538 	 */
539 	if (xfer->len < rs->fifo_len)
540 		writel_relaxed(xfer->len - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
541 	else
542 		writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
543 
544 	writel_relaxed(rs->fifo_len / 2, rs->regs + ROCKCHIP_SPI_DMATDLR);
545 	writel_relaxed(rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes) - 1,
546 		       rs->regs + ROCKCHIP_SPI_DMARDLR);
547 	writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
548 
549 	/* the hardware only supports an even clock divisor, so
550 	 * round divisor = spiclk / speed up to nearest even number
551 	 * so that the resulting speed is <= the requested speed
552 	 */
553 	writel_relaxed(2 * DIV_ROUND_UP(rs->freq, 2 * xfer->speed_hz),
554 			rs->regs + ROCKCHIP_SPI_BAUDR);
555 }
556 
557 static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
558 {
559 	return ROCKCHIP_SPI_MAX_TRANLEN;
560 }
561 
562 static int rockchip_spi_slave_abort(struct spi_controller *ctlr)
563 {
564 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
565 
566 	rs->slave_abort = true;
567 	complete(&ctlr->xfer_completion);
568 
569 	return 0;
570 }
571 
572 static int rockchip_spi_transfer_one(
573 		struct spi_controller *ctlr,
574 		struct spi_device *spi,
575 		struct spi_transfer *xfer)
576 {
577 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
578 	bool use_dma;
579 
580 	WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
581 		(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
582 
583 	if (!xfer->tx_buf && !xfer->rx_buf) {
584 		dev_err(rs->dev, "No buffer for transfer\n");
585 		return -EINVAL;
586 	}
587 
588 	if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
589 		dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
590 		return -EINVAL;
591 	}
592 
593 	rs->n_bytes = xfer->bits_per_word <= 8 ? 1 : 2;
594 
595 	use_dma = ctlr->can_dma ? ctlr->can_dma(ctlr, spi, xfer) : false;
596 
597 	rockchip_spi_config(rs, spi, xfer, use_dma, ctlr->slave);
598 
599 	if (use_dma)
600 		return rockchip_spi_prepare_dma(rs, ctlr, xfer);
601 
602 	return rockchip_spi_prepare_irq(rs, xfer);
603 }
604 
605 static bool rockchip_spi_can_dma(struct spi_controller *ctlr,
606 				 struct spi_device *spi,
607 				 struct spi_transfer *xfer)
608 {
609 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
610 	unsigned int bytes_per_word = xfer->bits_per_word <= 8 ? 1 : 2;
611 
612 	/* if the numbor of spi words to transfer is less than the fifo
613 	 * length we can just fill the fifo and wait for a single irq,
614 	 * so don't bother setting up dma
615 	 */
616 	return xfer->len / bytes_per_word >= rs->fifo_len;
617 }
618 
619 static int rockchip_spi_probe(struct platform_device *pdev)
620 {
621 	int ret;
622 	struct rockchip_spi *rs;
623 	struct spi_controller *ctlr;
624 	struct resource *mem;
625 	struct device_node *np = pdev->dev.of_node;
626 	u32 rsd_nsecs;
627 	bool slave_mode;
628 
629 	slave_mode = of_property_read_bool(np, "spi-slave");
630 
631 	if (slave_mode)
632 		ctlr = spi_alloc_slave(&pdev->dev,
633 				sizeof(struct rockchip_spi));
634 	else
635 		ctlr = spi_alloc_master(&pdev->dev,
636 				sizeof(struct rockchip_spi));
637 
638 	if (!ctlr)
639 		return -ENOMEM;
640 
641 	platform_set_drvdata(pdev, ctlr);
642 
643 	rs = spi_controller_get_devdata(ctlr);
644 	ctlr->slave = slave_mode;
645 
646 	/* Get basic io resource and map it */
647 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
648 	rs->regs = devm_ioremap_resource(&pdev->dev, mem);
649 	if (IS_ERR(rs->regs)) {
650 		ret =  PTR_ERR(rs->regs);
651 		goto err_put_ctlr;
652 	}
653 
654 	rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
655 	if (IS_ERR(rs->apb_pclk)) {
656 		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
657 		ret = PTR_ERR(rs->apb_pclk);
658 		goto err_put_ctlr;
659 	}
660 
661 	rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
662 	if (IS_ERR(rs->spiclk)) {
663 		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
664 		ret = PTR_ERR(rs->spiclk);
665 		goto err_put_ctlr;
666 	}
667 
668 	ret = clk_prepare_enable(rs->apb_pclk);
669 	if (ret < 0) {
670 		dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
671 		goto err_put_ctlr;
672 	}
673 
674 	ret = clk_prepare_enable(rs->spiclk);
675 	if (ret < 0) {
676 		dev_err(&pdev->dev, "Failed to enable spi_clk\n");
677 		goto err_disable_apbclk;
678 	}
679 
680 	spi_enable_chip(rs, false);
681 
682 	ret = platform_get_irq(pdev, 0);
683 	if (ret < 0)
684 		goto err_disable_spiclk;
685 
686 	ret = devm_request_threaded_irq(&pdev->dev, ret, rockchip_spi_isr, NULL,
687 			IRQF_ONESHOT, dev_name(&pdev->dev), ctlr);
688 	if (ret)
689 		goto err_disable_spiclk;
690 
691 	rs->dev = &pdev->dev;
692 	rs->freq = clk_get_rate(rs->spiclk);
693 
694 	if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
695 				  &rsd_nsecs)) {
696 		/* rx sample delay is expressed in parent clock cycles (max 3) */
697 		u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8),
698 				1000000000 >> 8);
699 		if (!rsd) {
700 			dev_warn(rs->dev, "%u Hz are too slow to express %u ns delay\n",
701 					rs->freq, rsd_nsecs);
702 		} else if (rsd > CR0_RSD_MAX) {
703 			rsd = CR0_RSD_MAX;
704 			dev_warn(rs->dev, "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
705 					rs->freq, rsd_nsecs,
706 					CR0_RSD_MAX * 1000000000U / rs->freq);
707 		}
708 		rs->rsd = rsd;
709 	}
710 
711 	rs->fifo_len = get_fifo_len(rs);
712 	if (!rs->fifo_len) {
713 		dev_err(&pdev->dev, "Failed to get fifo length\n");
714 		ret = -EINVAL;
715 		goto err_disable_spiclk;
716 	}
717 
718 	pm_runtime_set_active(&pdev->dev);
719 	pm_runtime_enable(&pdev->dev);
720 
721 	ctlr->auto_runtime_pm = true;
722 	ctlr->bus_num = pdev->id;
723 	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
724 	if (slave_mode) {
725 		ctlr->mode_bits |= SPI_NO_CS;
726 		ctlr->slave_abort = rockchip_spi_slave_abort;
727 	} else {
728 		ctlr->flags = SPI_MASTER_GPIO_SS;
729 		ctlr->max_native_cs = ROCKCHIP_SPI_MAX_CS_NUM;
730 		/*
731 		 * rk spi0 has two native cs, spi1..5 one cs only
732 		 * if num-cs is missing in the dts, default to 1
733 		 */
734 		if (of_property_read_u16(np, "num-cs", &ctlr->num_chipselect))
735 			ctlr->num_chipselect = 1;
736 		ctlr->use_gpio_descriptors = true;
737 	}
738 	ctlr->dev.of_node = pdev->dev.of_node;
739 	ctlr->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
740 	ctlr->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
741 	ctlr->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);
742 
743 	ctlr->set_cs = rockchip_spi_set_cs;
744 	ctlr->transfer_one = rockchip_spi_transfer_one;
745 	ctlr->max_transfer_size = rockchip_spi_max_transfer_size;
746 	ctlr->handle_err = rockchip_spi_handle_err;
747 
748 	ctlr->dma_tx = dma_request_chan(rs->dev, "tx");
749 	if (IS_ERR(ctlr->dma_tx)) {
750 		/* Check tx to see if we need defer probing driver */
751 		if (PTR_ERR(ctlr->dma_tx) == -EPROBE_DEFER) {
752 			ret = -EPROBE_DEFER;
753 			goto err_disable_pm_runtime;
754 		}
755 		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
756 		ctlr->dma_tx = NULL;
757 	}
758 
759 	ctlr->dma_rx = dma_request_chan(rs->dev, "rx");
760 	if (IS_ERR(ctlr->dma_rx)) {
761 		if (PTR_ERR(ctlr->dma_rx) == -EPROBE_DEFER) {
762 			ret = -EPROBE_DEFER;
763 			goto err_free_dma_tx;
764 		}
765 		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
766 		ctlr->dma_rx = NULL;
767 	}
768 
769 	if (ctlr->dma_tx && ctlr->dma_rx) {
770 		rs->dma_addr_tx = mem->start + ROCKCHIP_SPI_TXDR;
771 		rs->dma_addr_rx = mem->start + ROCKCHIP_SPI_RXDR;
772 		ctlr->can_dma = rockchip_spi_can_dma;
773 	}
774 
775 	ret = devm_spi_register_controller(&pdev->dev, ctlr);
776 	if (ret < 0) {
777 		dev_err(&pdev->dev, "Failed to register controller\n");
778 		goto err_free_dma_rx;
779 	}
780 
781 	return 0;
782 
783 err_free_dma_rx:
784 	if (ctlr->dma_rx)
785 		dma_release_channel(ctlr->dma_rx);
786 err_free_dma_tx:
787 	if (ctlr->dma_tx)
788 		dma_release_channel(ctlr->dma_tx);
789 err_disable_pm_runtime:
790 	pm_runtime_disable(&pdev->dev);
791 err_disable_spiclk:
792 	clk_disable_unprepare(rs->spiclk);
793 err_disable_apbclk:
794 	clk_disable_unprepare(rs->apb_pclk);
795 err_put_ctlr:
796 	spi_controller_put(ctlr);
797 
798 	return ret;
799 }
800 
801 static int rockchip_spi_remove(struct platform_device *pdev)
802 {
803 	struct spi_controller *ctlr = spi_controller_get(platform_get_drvdata(pdev));
804 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
805 
806 	pm_runtime_get_sync(&pdev->dev);
807 
808 	clk_disable_unprepare(rs->spiclk);
809 	clk_disable_unprepare(rs->apb_pclk);
810 
811 	pm_runtime_put_noidle(&pdev->dev);
812 	pm_runtime_disable(&pdev->dev);
813 	pm_runtime_set_suspended(&pdev->dev);
814 
815 	if (ctlr->dma_tx)
816 		dma_release_channel(ctlr->dma_tx);
817 	if (ctlr->dma_rx)
818 		dma_release_channel(ctlr->dma_rx);
819 
820 	spi_controller_put(ctlr);
821 
822 	return 0;
823 }
824 
825 #ifdef CONFIG_PM_SLEEP
826 static int rockchip_spi_suspend(struct device *dev)
827 {
828 	int ret;
829 	struct spi_controller *ctlr = dev_get_drvdata(dev);
830 
831 	ret = spi_controller_suspend(ctlr);
832 	if (ret < 0)
833 		return ret;
834 
835 	ret = pm_runtime_force_suspend(dev);
836 	if (ret < 0)
837 		return ret;
838 
839 	pinctrl_pm_select_sleep_state(dev);
840 
841 	return 0;
842 }
843 
844 static int rockchip_spi_resume(struct device *dev)
845 {
846 	int ret;
847 	struct spi_controller *ctlr = dev_get_drvdata(dev);
848 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
849 
850 	pinctrl_pm_select_default_state(dev);
851 
852 	ret = pm_runtime_force_resume(dev);
853 	if (ret < 0)
854 		return ret;
855 
856 	ret = spi_controller_resume(ctlr);
857 	if (ret < 0) {
858 		clk_disable_unprepare(rs->spiclk);
859 		clk_disable_unprepare(rs->apb_pclk);
860 	}
861 
862 	return 0;
863 }
864 #endif /* CONFIG_PM_SLEEP */
865 
866 #ifdef CONFIG_PM
867 static int rockchip_spi_runtime_suspend(struct device *dev)
868 {
869 	struct spi_controller *ctlr = dev_get_drvdata(dev);
870 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
871 
872 	clk_disable_unprepare(rs->spiclk);
873 	clk_disable_unprepare(rs->apb_pclk);
874 
875 	return 0;
876 }
877 
878 static int rockchip_spi_runtime_resume(struct device *dev)
879 {
880 	int ret;
881 	struct spi_controller *ctlr = dev_get_drvdata(dev);
882 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
883 
884 	ret = clk_prepare_enable(rs->apb_pclk);
885 	if (ret < 0)
886 		return ret;
887 
888 	ret = clk_prepare_enable(rs->spiclk);
889 	if (ret < 0)
890 		clk_disable_unprepare(rs->apb_pclk);
891 
892 	return 0;
893 }
894 #endif /* CONFIG_PM */
895 
896 static const struct dev_pm_ops rockchip_spi_pm = {
897 	SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
898 	SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
899 			   rockchip_spi_runtime_resume, NULL)
900 };
901 
902 static const struct of_device_id rockchip_spi_dt_match[] = {
903 	{ .compatible = "rockchip,px30-spi", },
904 	{ .compatible = "rockchip,rk3036-spi", },
905 	{ .compatible = "rockchip,rk3066-spi", },
906 	{ .compatible = "rockchip,rk3188-spi", },
907 	{ .compatible = "rockchip,rk3228-spi", },
908 	{ .compatible = "rockchip,rk3288-spi", },
909 	{ .compatible = "rockchip,rk3308-spi", },
910 	{ .compatible = "rockchip,rk3328-spi", },
911 	{ .compatible = "rockchip,rk3368-spi", },
912 	{ .compatible = "rockchip,rk3399-spi", },
913 	{ .compatible = "rockchip,rv1108-spi", },
914 	{ },
915 };
916 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
917 
918 static struct platform_driver rockchip_spi_driver = {
919 	.driver = {
920 		.name	= DRIVER_NAME,
921 		.pm = &rockchip_spi_pm,
922 		.of_match_table = of_match_ptr(rockchip_spi_dt_match),
923 	},
924 	.probe = rockchip_spi_probe,
925 	.remove = rockchip_spi_remove,
926 };
927 
928 module_platform_driver(rockchip_spi_driver);
929 
930 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
931 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
932 MODULE_LICENSE("GPL v2");
933