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_HOST				0x0
108#define CR0_OPM_TARGET				0x1
109
110#define CR0_SOI_OFFSET				23
111
112#define CR0_MTM_OFFSET				0x21
113
114/* Bit fields in SER, 2bit */
115#define SER_MASK					0x3
116
117/* Bit fields in BAUDR */
118#define BAUDR_SCKDV_MIN				2
119#define BAUDR_SCKDV_MAX				65534
120
121/* Bit fields in SR, 6bit */
122#define SR_MASK						0x3f
123#define SR_BUSY						(1 << 0)
124#define SR_TF_FULL					(1 << 1)
125#define SR_TF_EMPTY					(1 << 2)
126#define SR_RF_EMPTY					(1 << 3)
127#define SR_RF_FULL					(1 << 4)
128#define SR_TARGET_TX_BUSY				(1 << 5)
129
130/* Bit fields in ISR, IMR, ISR, RISR, 5bit */
131#define INT_MASK					0x1f
132#define INT_TF_EMPTY				(1 << 0)
133#define INT_TF_OVERFLOW				(1 << 1)
134#define INT_RF_UNDERFLOW			(1 << 2)
135#define INT_RF_OVERFLOW				(1 << 3)
136#define INT_RF_FULL				(1 << 4)
137#define INT_CS_INACTIVE				(1 << 6)
138
139/* Bit fields in ICR, 4bit */
140#define ICR_MASK					0x0f
141#define ICR_ALL						(1 << 0)
142#define ICR_RF_UNDERFLOW			(1 << 1)
143#define ICR_RF_OVERFLOW				(1 << 2)
144#define ICR_TF_OVERFLOW				(1 << 3)
145
146/* Bit fields in DMACR */
147#define RF_DMA_EN					(1 << 0)
148#define TF_DMA_EN					(1 << 1)
149
150/* Driver state flags */
151#define RXDMA					(1 << 0)
152#define TXDMA					(1 << 1)
153
154/* sclk_out: spi host internal logic in rk3x can support 50Mhz */
155#define MAX_SCLK_OUT				50000000U
156
157/*
158 * SPI_CTRLR1 is 16-bits, so we should support lengths of 0xffff + 1. However,
159 * the controller seems to hang when given 0x10000, so stick with this for now.
160 */
161#define ROCKCHIP_SPI_MAX_TRANLEN		0xffff
162
163/* 2 for native cs, 2 for cs-gpio */
164#define ROCKCHIP_SPI_MAX_CS_NUM			4
165#define ROCKCHIP_SPI_VER2_TYPE1			0x05EC0002
166#define ROCKCHIP_SPI_VER2_TYPE2			0x00110002
167
168#define ROCKCHIP_AUTOSUSPEND_TIMEOUT		2000
169
170struct rockchip_spi {
171	struct device *dev;
172
173	struct clk *spiclk;
174	struct clk *apb_pclk;
175
176	void __iomem *regs;
177	dma_addr_t dma_addr_rx;
178	dma_addr_t dma_addr_tx;
179
180	const void *tx;
181	void *rx;
182	unsigned int tx_left;
183	unsigned int rx_left;
184
185	atomic_t state;
186
187	/*depth of the FIFO buffer */
188	u32 fifo_len;
189	/* frequency of spiclk */
190	u32 freq;
191
192	u8 n_bytes;
193	u8 rsd;
194
195	bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
196
197	bool target_abort;
198	bool cs_inactive; /* spi target tansmition stop when cs inactive */
199	bool cs_high_supported; /* native CS supports active-high polarity */
200
201	struct spi_transfer *xfer; /* Store xfer temporarily */
202};
203
204static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
205{
206	writel_relaxed((enable ? 1U : 0U), rs->regs + ROCKCHIP_SPI_SSIENR);
207}
208
209static inline void wait_for_tx_idle(struct rockchip_spi *rs, bool target_mode)
210{
211	unsigned long timeout = jiffies + msecs_to_jiffies(5);
212
213	do {
214		if (target_mode) {
215			if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_TARGET_TX_BUSY) &&
216			    !((readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY)))
217				return;
218		} else {
219			if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
220				return;
221		}
222	} while (!time_after(jiffies, timeout));
223
224	dev_warn(rs->dev, "spi controller is in busy state!\n");
225}
226
227static u32 get_fifo_len(struct rockchip_spi *rs)
228{
229	u32 ver;
230
231	ver = readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION);
232
233	switch (ver) {
234	case ROCKCHIP_SPI_VER2_TYPE1:
235	case ROCKCHIP_SPI_VER2_TYPE2:
236		return 64;
237	default:
238		return 32;
239	}
240}
241
242static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
243{
244	struct spi_controller *ctlr = spi->controller;
245	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
246	bool cs_asserted = spi->mode & SPI_CS_HIGH ? enable : !enable;
247
248	/* Return immediately for no-op */
249	if (cs_asserted == rs->cs_asserted[spi_get_chipselect(spi, 0)])
250		return;
251
252	if (cs_asserted) {
253		/* Keep things powered as long as CS is asserted */
254		pm_runtime_get_sync(rs->dev);
255
256		if (spi_get_csgpiod(spi, 0))
257			ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
258		else
259			ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER,
260					      BIT(spi_get_chipselect(spi, 0)));
261	} else {
262		if (spi_get_csgpiod(spi, 0))
263			ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
264		else
265			ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER,
266					      BIT(spi_get_chipselect(spi, 0)));
267
268		/* Drop reference from when we first asserted CS */
269		pm_runtime_put(rs->dev);
270	}
271
272	rs->cs_asserted[spi_get_chipselect(spi, 0)] = cs_asserted;
273}
274
275static void rockchip_spi_handle_err(struct spi_controller *ctlr,
276				    struct spi_message *msg)
277{
278	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
279
280	/* stop running spi transfer
281	 * this also flushes both rx and tx fifos
282	 */
283	spi_enable_chip(rs, false);
284
285	/* make sure all interrupts are masked and status cleared */
286	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
287	writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
288
289	if (atomic_read(&rs->state) & TXDMA)
290		dmaengine_terminate_async(ctlr->dma_tx);
291
292	if (atomic_read(&rs->state) & RXDMA)
293		dmaengine_terminate_async(ctlr->dma_rx);
294}
295
296static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
297{
298	u32 tx_free = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
299	u32 words = min(rs->tx_left, tx_free);
300
301	rs->tx_left -= words;
302	for (; words; words--) {
303		u32 txw;
304
305		if (rs->n_bytes == 1)
306			txw = *(u8 *)rs->tx;
307		else
308			txw = *(u16 *)rs->tx;
309
310		writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
311		rs->tx += rs->n_bytes;
312	}
313}
314
315static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
316{
317	u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
318	u32 rx_left = (rs->rx_left > words) ? rs->rx_left - words : 0;
319
320	/* the hardware doesn't allow us to change fifo threshold
321	 * level while spi is enabled, so instead make sure to leave
322	 * enough words in the rx fifo to get the last interrupt
323	 * exactly when all words have been received
324	 */
325	if (rx_left) {
326		u32 ftl = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFTLR) + 1;
327
328		if (rx_left < ftl) {
329			rx_left = ftl;
330			words = rs->rx_left - rx_left;
331		}
332	}
333
334	rs->rx_left = rx_left;
335	for (; words; words--) {
336		u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
337
338		if (!rs->rx)
339			continue;
340
341		if (rs->n_bytes == 1)
342			*(u8 *)rs->rx = (u8)rxw;
343		else
344			*(u16 *)rs->rx = (u16)rxw;
345		rs->rx += rs->n_bytes;
346	}
347}
348
349static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
350{
351	struct spi_controller *ctlr = dev_id;
352	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
353
354	/* When int_cs_inactive comes, spi target abort */
355	if (rs->cs_inactive && readl_relaxed(rs->regs + ROCKCHIP_SPI_IMR) & INT_CS_INACTIVE) {
356		ctlr->target_abort(ctlr);
357		writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
358		writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
359
360		return IRQ_HANDLED;
361	}
362
363	if (rs->tx_left)
364		rockchip_spi_pio_writer(rs);
365
366	rockchip_spi_pio_reader(rs);
367	if (!rs->rx_left) {
368		spi_enable_chip(rs, false);
369		writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
370		writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
371		spi_finalize_current_transfer(ctlr);
372	}
373
374	return IRQ_HANDLED;
375}
376
377static int rockchip_spi_prepare_irq(struct rockchip_spi *rs,
378				    struct spi_controller *ctlr,
379				    struct spi_transfer *xfer)
380{
381	rs->tx = xfer->tx_buf;
382	rs->rx = xfer->rx_buf;
383	rs->tx_left = rs->tx ? xfer->len / rs->n_bytes : 0;
384	rs->rx_left = xfer->len / rs->n_bytes;
385
386	writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
387
388	spi_enable_chip(rs, true);
389
390	if (rs->tx_left)
391		rockchip_spi_pio_writer(rs);
392
393	if (rs->cs_inactive)
394		writel_relaxed(INT_RF_FULL | INT_CS_INACTIVE, rs->regs + ROCKCHIP_SPI_IMR);
395	else
396		writel_relaxed(INT_RF_FULL, rs->regs + ROCKCHIP_SPI_IMR);
397
398	/* 1 means the transfer is in progress */
399	return 1;
400}
401
402static void rockchip_spi_dma_rxcb(void *data)
403{
404	struct spi_controller *ctlr = data;
405	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
406	int state = atomic_fetch_andnot(RXDMA, &rs->state);
407
408	if (state & TXDMA && !rs->target_abort)
409		return;
410
411	if (rs->cs_inactive)
412		writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
413
414	spi_enable_chip(rs, false);
415	spi_finalize_current_transfer(ctlr);
416}
417
418static void rockchip_spi_dma_txcb(void *data)
419{
420	struct spi_controller *ctlr = data;
421	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
422	int state = atomic_fetch_andnot(TXDMA, &rs->state);
423
424	if (state & RXDMA && !rs->target_abort)
425		return;
426
427	/* Wait until the FIFO data completely. */
428	wait_for_tx_idle(rs, ctlr->target);
429
430	spi_enable_chip(rs, false);
431	spi_finalize_current_transfer(ctlr);
432}
433
434static u32 rockchip_spi_calc_burst_size(u32 data_len)
435{
436	u32 i;
437
438	/* burst size: 1, 2, 4, 8 */
439	for (i = 1; i < 8; i <<= 1) {
440		if (data_len & i)
441			break;
442	}
443
444	return i;
445}
446
447static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
448		struct spi_controller *ctlr, struct spi_transfer *xfer)
449{
450	struct dma_async_tx_descriptor *rxdesc, *txdesc;
451
452	atomic_set(&rs->state, 0);
453
454	rs->tx = xfer->tx_buf;
455	rs->rx = xfer->rx_buf;
456
457	rxdesc = NULL;
458	if (xfer->rx_buf) {
459		struct dma_slave_config rxconf = {
460			.direction = DMA_DEV_TO_MEM,
461			.src_addr = rs->dma_addr_rx,
462			.src_addr_width = rs->n_bytes,
463			.src_maxburst = rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes),
464		};
465
466		dmaengine_slave_config(ctlr->dma_rx, &rxconf);
467
468		rxdesc = dmaengine_prep_slave_sg(
469				ctlr->dma_rx,
470				xfer->rx_sg.sgl, xfer->rx_sg.nents,
471				DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
472		if (!rxdesc)
473			return -EINVAL;
474
475		rxdesc->callback = rockchip_spi_dma_rxcb;
476		rxdesc->callback_param = ctlr;
477	}
478
479	txdesc = NULL;
480	if (xfer->tx_buf) {
481		struct dma_slave_config txconf = {
482			.direction = DMA_MEM_TO_DEV,
483			.dst_addr = rs->dma_addr_tx,
484			.dst_addr_width = rs->n_bytes,
485			.dst_maxburst = rs->fifo_len / 4,
486		};
487
488		dmaengine_slave_config(ctlr->dma_tx, &txconf);
489
490		txdesc = dmaengine_prep_slave_sg(
491				ctlr->dma_tx,
492				xfer->tx_sg.sgl, xfer->tx_sg.nents,
493				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
494		if (!txdesc) {
495			if (rxdesc)
496				dmaengine_terminate_sync(ctlr->dma_rx);
497			return -EINVAL;
498		}
499
500		txdesc->callback = rockchip_spi_dma_txcb;
501		txdesc->callback_param = ctlr;
502	}
503
504	/* rx must be started before tx due to spi instinct */
505	if (rxdesc) {
506		atomic_or(RXDMA, &rs->state);
507		ctlr->dma_rx->cookie = dmaengine_submit(rxdesc);
508		dma_async_issue_pending(ctlr->dma_rx);
509	}
510
511	if (rs->cs_inactive)
512		writel_relaxed(INT_CS_INACTIVE, rs->regs + ROCKCHIP_SPI_IMR);
513
514	spi_enable_chip(rs, true);
515
516	if (txdesc) {
517		atomic_or(TXDMA, &rs->state);
518		dmaengine_submit(txdesc);
519		dma_async_issue_pending(ctlr->dma_tx);
520	}
521
522	/* 1 means the transfer is in progress */
523	return 1;
524}
525
526static int rockchip_spi_config(struct rockchip_spi *rs,
527		struct spi_device *spi, struct spi_transfer *xfer,
528		bool use_dma, bool target_mode)
529{
530	u32 cr0 = CR0_FRF_SPI  << CR0_FRF_OFFSET
531		| CR0_BHT_8BIT << CR0_BHT_OFFSET
532		| CR0_SSD_ONE  << CR0_SSD_OFFSET
533		| CR0_EM_BIG   << CR0_EM_OFFSET;
534	u32 cr1;
535	u32 dmacr = 0;
536
537	if (target_mode)
538		cr0 |= CR0_OPM_TARGET << CR0_OPM_OFFSET;
539	rs->target_abort = false;
540
541	cr0 |= rs->rsd << CR0_RSD_OFFSET;
542	cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
543	if (spi->mode & SPI_LSB_FIRST)
544		cr0 |= CR0_FBM_LSB << CR0_FBM_OFFSET;
545	if (spi->mode & SPI_CS_HIGH)
546		cr0 |= BIT(spi_get_chipselect(spi, 0)) << CR0_SOI_OFFSET;
547
548	if (xfer->rx_buf && xfer->tx_buf)
549		cr0 |= CR0_XFM_TR << CR0_XFM_OFFSET;
550	else if (xfer->rx_buf)
551		cr0 |= CR0_XFM_RO << CR0_XFM_OFFSET;
552	else if (use_dma)
553		cr0 |= CR0_XFM_TO << CR0_XFM_OFFSET;
554
555	switch (xfer->bits_per_word) {
556	case 4:
557		cr0 |= CR0_DFS_4BIT << CR0_DFS_OFFSET;
558		cr1 = xfer->len - 1;
559		break;
560	case 8:
561		cr0 |= CR0_DFS_8BIT << CR0_DFS_OFFSET;
562		cr1 = xfer->len - 1;
563		break;
564	case 16:
565		cr0 |= CR0_DFS_16BIT << CR0_DFS_OFFSET;
566		cr1 = xfer->len / 2 - 1;
567		break;
568	default:
569		/* we only whitelist 4, 8 and 16 bit words in
570		 * ctlr->bits_per_word_mask, so this shouldn't
571		 * happen
572		 */
573		dev_err(rs->dev, "unknown bits per word: %d\n",
574			xfer->bits_per_word);
575		return -EINVAL;
576	}
577
578	if (use_dma) {
579		if (xfer->tx_buf)
580			dmacr |= TF_DMA_EN;
581		if (xfer->rx_buf)
582			dmacr |= RF_DMA_EN;
583	}
584
585	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
586	writel_relaxed(cr1, rs->regs + ROCKCHIP_SPI_CTRLR1);
587
588	/* unfortunately setting the fifo threshold level to generate an
589	 * interrupt exactly when the fifo is full doesn't seem to work,
590	 * so we need the strict inequality here
591	 */
592	if ((xfer->len / rs->n_bytes) < rs->fifo_len)
593		writel_relaxed(xfer->len / rs->n_bytes - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
594	else
595		writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
596
597	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_DMATDLR);
598	writel_relaxed(rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes) - 1,
599		       rs->regs + ROCKCHIP_SPI_DMARDLR);
600	writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
601
602	/* the hardware only supports an even clock divisor, so
603	 * round divisor = spiclk / speed up to nearest even number
604	 * so that the resulting speed is <= the requested speed
605	 */
606	writel_relaxed(2 * DIV_ROUND_UP(rs->freq, 2 * xfer->speed_hz),
607			rs->regs + ROCKCHIP_SPI_BAUDR);
608
609	return 0;
610}
611
612static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
613{
614	return ROCKCHIP_SPI_MAX_TRANLEN;
615}
616
617static int rockchip_spi_target_abort(struct spi_controller *ctlr)
618{
619	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
620	u32 rx_fifo_left;
621	struct dma_tx_state state;
622	enum dma_status status;
623
624	/* Get current dma rx point */
625	if (atomic_read(&rs->state) & RXDMA) {
626		dmaengine_pause(ctlr->dma_rx);
627		status = dmaengine_tx_status(ctlr->dma_rx, ctlr->dma_rx->cookie, &state);
628		if (status == DMA_ERROR) {
629			rs->rx = rs->xfer->rx_buf;
630			rs->xfer->len = 0;
631			rx_fifo_left = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
632			for (; rx_fifo_left; rx_fifo_left--)
633				readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
634			goto out;
635		} else {
636			rs->rx += rs->xfer->len - rs->n_bytes * state.residue;
637		}
638	}
639
640	/* Get the valid data left in rx fifo and set rs->xfer->len real rx size */
641	if (rs->rx) {
642		rx_fifo_left = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
643		for (; rx_fifo_left; rx_fifo_left--) {
644			u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
645
646			if (rs->n_bytes == 1)
647				*(u8 *)rs->rx = (u8)rxw;
648			else
649				*(u16 *)rs->rx = (u16)rxw;
650			rs->rx += rs->n_bytes;
651		}
652		rs->xfer->len = (unsigned int)(rs->rx - rs->xfer->rx_buf);
653	}
654
655out:
656	if (atomic_read(&rs->state) & RXDMA)
657		dmaengine_terminate_sync(ctlr->dma_rx);
658	if (atomic_read(&rs->state) & TXDMA)
659		dmaengine_terminate_sync(ctlr->dma_tx);
660	atomic_set(&rs->state, 0);
661	spi_enable_chip(rs, false);
662	rs->target_abort = true;
663	spi_finalize_current_transfer(ctlr);
664
665	return 0;
666}
667
668static int rockchip_spi_transfer_one(
669		struct spi_controller *ctlr,
670		struct spi_device *spi,
671		struct spi_transfer *xfer)
672{
673	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
674	int ret;
675	bool use_dma;
676
677	/* Zero length transfers won't trigger an interrupt on completion */
678	if (!xfer->len) {
679		spi_finalize_current_transfer(ctlr);
680		return 1;
681	}
682
683	WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
684		(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
685
686	if (!xfer->tx_buf && !xfer->rx_buf) {
687		dev_err(rs->dev, "No buffer for transfer\n");
688		return -EINVAL;
689	}
690
691	if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
692		dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
693		return -EINVAL;
694	}
695
696	rs->n_bytes = xfer->bits_per_word <= 8 ? 1 : 2;
697	rs->xfer = xfer;
698	use_dma = ctlr->can_dma ? ctlr->can_dma(ctlr, spi, xfer) : false;
699
700	ret = rockchip_spi_config(rs, spi, xfer, use_dma, ctlr->target);
701	if (ret)
702		return ret;
703
704	if (use_dma)
705		return rockchip_spi_prepare_dma(rs, ctlr, xfer);
706
707	return rockchip_spi_prepare_irq(rs, ctlr, xfer);
708}
709
710static bool rockchip_spi_can_dma(struct spi_controller *ctlr,
711				 struct spi_device *spi,
712				 struct spi_transfer *xfer)
713{
714	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
715	unsigned int bytes_per_word = xfer->bits_per_word <= 8 ? 1 : 2;
716
717	/* if the numbor of spi words to transfer is less than the fifo
718	 * length we can just fill the fifo and wait for a single irq,
719	 * so don't bother setting up dma
720	 */
721	return xfer->len / bytes_per_word >= rs->fifo_len;
722}
723
724static int rockchip_spi_setup(struct spi_device *spi)
725{
726	struct rockchip_spi *rs = spi_controller_get_devdata(spi->controller);
727	u32 cr0;
728
729	if (!spi_get_csgpiod(spi, 0) && (spi->mode & SPI_CS_HIGH) && !rs->cs_high_supported) {
730		dev_warn(&spi->dev, "setup: non GPIO CS can't be active-high\n");
731		return -EINVAL;
732	}
733
734	pm_runtime_get_sync(rs->dev);
735
736	cr0 = readl_relaxed(rs->regs + ROCKCHIP_SPI_CTRLR0);
737
738	cr0 &= ~(0x3 << CR0_SCPH_OFFSET);
739	cr0 |= ((spi->mode & 0x3) << CR0_SCPH_OFFSET);
740	if (spi->mode & SPI_CS_HIGH && spi_get_chipselect(spi, 0) <= 1)
741		cr0 |= BIT(spi_get_chipselect(spi, 0)) << CR0_SOI_OFFSET;
742	else if (spi_get_chipselect(spi, 0) <= 1)
743		cr0 &= ~(BIT(spi_get_chipselect(spi, 0)) << CR0_SOI_OFFSET);
744
745	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
746
747	pm_runtime_put(rs->dev);
748
749	return 0;
750}
751
752static int rockchip_spi_probe(struct platform_device *pdev)
753{
754	int ret;
755	struct rockchip_spi *rs;
756	struct spi_controller *ctlr;
757	struct resource *mem;
758	struct device_node *np = pdev->dev.of_node;
759	u32 rsd_nsecs, num_cs;
760	bool target_mode;
761
762	target_mode = of_property_read_bool(np, "spi-slave");
763
764	if (target_mode)
765		ctlr = spi_alloc_target(&pdev->dev,
766				sizeof(struct rockchip_spi));
767	else
768		ctlr = spi_alloc_host(&pdev->dev,
769				sizeof(struct rockchip_spi));
770
771	if (!ctlr)
772		return -ENOMEM;
773
774	platform_set_drvdata(pdev, ctlr);
775
776	rs = spi_controller_get_devdata(ctlr);
777
778	/* Get basic io resource and map it */
779	rs->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
780	if (IS_ERR(rs->regs)) {
781		ret =  PTR_ERR(rs->regs);
782		goto err_put_ctlr;
783	}
784
785	rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
786	if (IS_ERR(rs->apb_pclk)) {
787		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
788		ret = PTR_ERR(rs->apb_pclk);
789		goto err_put_ctlr;
790	}
791
792	rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
793	if (IS_ERR(rs->spiclk)) {
794		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
795		ret = PTR_ERR(rs->spiclk);
796		goto err_put_ctlr;
797	}
798
799	ret = clk_prepare_enable(rs->apb_pclk);
800	if (ret < 0) {
801		dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
802		goto err_put_ctlr;
803	}
804
805	ret = clk_prepare_enable(rs->spiclk);
806	if (ret < 0) {
807		dev_err(&pdev->dev, "Failed to enable spi_clk\n");
808		goto err_disable_apbclk;
809	}
810
811	spi_enable_chip(rs, false);
812
813	ret = platform_get_irq(pdev, 0);
814	if (ret < 0)
815		goto err_disable_spiclk;
816
817	ret = devm_request_threaded_irq(&pdev->dev, ret, rockchip_spi_isr, NULL,
818			IRQF_ONESHOT, dev_name(&pdev->dev), ctlr);
819	if (ret)
820		goto err_disable_spiclk;
821
822	rs->dev = &pdev->dev;
823	rs->freq = clk_get_rate(rs->spiclk);
824
825	if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
826				  &rsd_nsecs)) {
827		/* rx sample delay is expressed in parent clock cycles (max 3) */
828		u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8),
829				1000000000 >> 8);
830		if (!rsd) {
831			dev_warn(rs->dev, "%u Hz are too slow to express %u ns delay\n",
832					rs->freq, rsd_nsecs);
833		} else if (rsd > CR0_RSD_MAX) {
834			rsd = CR0_RSD_MAX;
835			dev_warn(rs->dev, "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
836					rs->freq, rsd_nsecs,
837					CR0_RSD_MAX * 1000000000U / rs->freq);
838		}
839		rs->rsd = rsd;
840	}
841
842	rs->fifo_len = get_fifo_len(rs);
843	if (!rs->fifo_len) {
844		dev_err(&pdev->dev, "Failed to get fifo length\n");
845		ret = -EINVAL;
846		goto err_disable_spiclk;
847	}
848
849	pm_runtime_set_autosuspend_delay(&pdev->dev, ROCKCHIP_AUTOSUSPEND_TIMEOUT);
850	pm_runtime_use_autosuspend(&pdev->dev);
851	pm_runtime_set_active(&pdev->dev);
852	pm_runtime_enable(&pdev->dev);
853
854	ctlr->auto_runtime_pm = true;
855	ctlr->bus_num = pdev->id;
856	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
857	if (target_mode) {
858		ctlr->mode_bits |= SPI_NO_CS;
859		ctlr->target_abort = rockchip_spi_target_abort;
860	} else {
861		ctlr->flags = SPI_CONTROLLER_GPIO_SS;
862		ctlr->max_native_cs = ROCKCHIP_SPI_MAX_CS_NUM;
863		/*
864		 * rk spi0 has two native cs, spi1..5 one cs only
865		 * if num-cs is missing in the dts, default to 1
866		 */
867		if (of_property_read_u32(np, "num-cs", &num_cs))
868			num_cs = 1;
869		ctlr->num_chipselect = num_cs;
870		ctlr->use_gpio_descriptors = true;
871	}
872	ctlr->dev.of_node = pdev->dev.of_node;
873	ctlr->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
874	ctlr->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
875	ctlr->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);
876
877	ctlr->setup = rockchip_spi_setup;
878	ctlr->set_cs = rockchip_spi_set_cs;
879	ctlr->transfer_one = rockchip_spi_transfer_one;
880	ctlr->max_transfer_size = rockchip_spi_max_transfer_size;
881	ctlr->handle_err = rockchip_spi_handle_err;
882
883	ctlr->dma_tx = dma_request_chan(rs->dev, "tx");
884	if (IS_ERR(ctlr->dma_tx)) {
885		/* Check tx to see if we need defer probing driver */
886		if (PTR_ERR(ctlr->dma_tx) == -EPROBE_DEFER) {
887			ret = -EPROBE_DEFER;
888			goto err_disable_pm_runtime;
889		}
890		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
891		ctlr->dma_tx = NULL;
892	}
893
894	ctlr->dma_rx = dma_request_chan(rs->dev, "rx");
895	if (IS_ERR(ctlr->dma_rx)) {
896		if (PTR_ERR(ctlr->dma_rx) == -EPROBE_DEFER) {
897			ret = -EPROBE_DEFER;
898			goto err_free_dma_tx;
899		}
900		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
901		ctlr->dma_rx = NULL;
902	}
903
904	if (ctlr->dma_tx && ctlr->dma_rx) {
905		rs->dma_addr_tx = mem->start + ROCKCHIP_SPI_TXDR;
906		rs->dma_addr_rx = mem->start + ROCKCHIP_SPI_RXDR;
907		ctlr->can_dma = rockchip_spi_can_dma;
908	}
909
910	switch (readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION)) {
911	case ROCKCHIP_SPI_VER2_TYPE2:
912		rs->cs_high_supported = true;
913		ctlr->mode_bits |= SPI_CS_HIGH;
914		if (ctlr->can_dma && target_mode)
915			rs->cs_inactive = true;
916		else
917			rs->cs_inactive = false;
918		break;
919	default:
920		rs->cs_inactive = false;
921		break;
922	}
923
924	ret = devm_spi_register_controller(&pdev->dev, ctlr);
925	if (ret < 0) {
926		dev_err(&pdev->dev, "Failed to register controller\n");
927		goto err_free_dma_rx;
928	}
929
930	return 0;
931
932err_free_dma_rx:
933	if (ctlr->dma_rx)
934		dma_release_channel(ctlr->dma_rx);
935err_free_dma_tx:
936	if (ctlr->dma_tx)
937		dma_release_channel(ctlr->dma_tx);
938err_disable_pm_runtime:
939	pm_runtime_disable(&pdev->dev);
940err_disable_spiclk:
941	clk_disable_unprepare(rs->spiclk);
942err_disable_apbclk:
943	clk_disable_unprepare(rs->apb_pclk);
944err_put_ctlr:
945	spi_controller_put(ctlr);
946
947	return ret;
948}
949
950static void rockchip_spi_remove(struct platform_device *pdev)
951{
952	struct spi_controller *ctlr = spi_controller_get(platform_get_drvdata(pdev));
953	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
954
955	pm_runtime_get_sync(&pdev->dev);
956
957	clk_disable_unprepare(rs->spiclk);
958	clk_disable_unprepare(rs->apb_pclk);
959
960	pm_runtime_put_noidle(&pdev->dev);
961	pm_runtime_disable(&pdev->dev);
962	pm_runtime_set_suspended(&pdev->dev);
963
964	if (ctlr->dma_tx)
965		dma_release_channel(ctlr->dma_tx);
966	if (ctlr->dma_rx)
967		dma_release_channel(ctlr->dma_rx);
968
969	spi_controller_put(ctlr);
970}
971
972#ifdef CONFIG_PM_SLEEP
973static int rockchip_spi_suspend(struct device *dev)
974{
975	int ret;
976	struct spi_controller *ctlr = dev_get_drvdata(dev);
977	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
978
979	ret = spi_controller_suspend(ctlr);
980	if (ret < 0)
981		return ret;
982
983	clk_disable_unprepare(rs->spiclk);
984	clk_disable_unprepare(rs->apb_pclk);
985
986	pinctrl_pm_select_sleep_state(dev);
987
988	return 0;
989}
990
991static int rockchip_spi_resume(struct device *dev)
992{
993	int ret;
994	struct spi_controller *ctlr = dev_get_drvdata(dev);
995	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
996
997	pinctrl_pm_select_default_state(dev);
998
999	ret = clk_prepare_enable(rs->apb_pclk);
1000	if (ret < 0)
1001		return ret;
1002
1003	ret = clk_prepare_enable(rs->spiclk);
1004	if (ret < 0)
1005		clk_disable_unprepare(rs->apb_pclk);
1006
1007	ret = spi_controller_resume(ctlr);
1008	if (ret < 0) {
1009		clk_disable_unprepare(rs->spiclk);
1010		clk_disable_unprepare(rs->apb_pclk);
1011	}
1012
1013	return 0;
1014}
1015#endif /* CONFIG_PM_SLEEP */
1016
1017#ifdef CONFIG_PM
1018static int rockchip_spi_runtime_suspend(struct device *dev)
1019{
1020	struct spi_controller *ctlr = dev_get_drvdata(dev);
1021	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
1022
1023	clk_disable_unprepare(rs->spiclk);
1024	clk_disable_unprepare(rs->apb_pclk);
1025
1026	return 0;
1027}
1028
1029static int rockchip_spi_runtime_resume(struct device *dev)
1030{
1031	int ret;
1032	struct spi_controller *ctlr = dev_get_drvdata(dev);
1033	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
1034
1035	ret = clk_prepare_enable(rs->apb_pclk);
1036	if (ret < 0)
1037		return ret;
1038
1039	ret = clk_prepare_enable(rs->spiclk);
1040	if (ret < 0)
1041		clk_disable_unprepare(rs->apb_pclk);
1042
1043	return 0;
1044}
1045#endif /* CONFIG_PM */
1046
1047static const struct dev_pm_ops rockchip_spi_pm = {
1048	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
1049	SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
1050			   rockchip_spi_runtime_resume, NULL)
1051};
1052
1053static const struct of_device_id rockchip_spi_dt_match[] = {
1054	{ .compatible = "rockchip,px30-spi", },
1055	{ .compatible = "rockchip,rk3036-spi", },
1056	{ .compatible = "rockchip,rk3066-spi", },
1057	{ .compatible = "rockchip,rk3188-spi", },
1058	{ .compatible = "rockchip,rk3228-spi", },
1059	{ .compatible = "rockchip,rk3288-spi", },
1060	{ .compatible = "rockchip,rk3308-spi", },
1061	{ .compatible = "rockchip,rk3328-spi", },
1062	{ .compatible = "rockchip,rk3368-spi", },
1063	{ .compatible = "rockchip,rk3399-spi", },
1064	{ .compatible = "rockchip,rv1108-spi", },
1065	{ .compatible = "rockchip,rv1126-spi", },
1066	{ },
1067};
1068MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
1069
1070static struct platform_driver rockchip_spi_driver = {
1071	.driver = {
1072		.name	= DRIVER_NAME,
1073		.pm = &rockchip_spi_pm,
1074		.of_match_table = of_match_ptr(rockchip_spi_dt_match),
1075	},
1076	.probe = rockchip_spi_probe,
1077	.remove_new = rockchip_spi_remove,
1078};
1079
1080module_platform_driver(rockchip_spi_driver);
1081
1082MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
1083MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
1084MODULE_LICENSE("GPL v2");
1085