xref: /linux/drivers/spi/spi-rockchip.c (revision 2a6b6c9a226279b4f6668450ddb21ae655558087)
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 #define ROCKCHIP_SPI_MAX_NATIVE_CS_NUM		2
164 #define ROCKCHIP_SPI_VER2_TYPE1			0x05EC0002
165 #define ROCKCHIP_SPI_VER2_TYPE2			0x00110002
166 
167 #define ROCKCHIP_AUTOSUSPEND_TIMEOUT		2000
168 
169 struct rockchip_spi {
170 	struct device *dev;
171 
172 	struct clk *spiclk;
173 	struct clk *apb_pclk;
174 
175 	void __iomem *regs;
176 	dma_addr_t dma_addr_rx;
177 	dma_addr_t dma_addr_tx;
178 
179 	const void *tx;
180 	void *rx;
181 	unsigned int tx_left;
182 	unsigned int rx_left;
183 
184 	atomic_t state;
185 
186 	/*depth of the FIFO buffer */
187 	u32 fifo_len;
188 	/* frequency of spiclk */
189 	u32 freq;
190 
191 	u8 n_bytes;
192 	u8 rsd;
193 
194 	bool target_abort;
195 	bool cs_inactive; /* spi target tansmition stop when cs inactive */
196 	bool cs_high_supported; /* native CS supports active-high polarity */
197 
198 	struct spi_transfer *xfer; /* Store xfer temporarily */
199 };
200 
201 static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
202 {
203 	writel_relaxed((enable ? 1U : 0U), rs->regs + ROCKCHIP_SPI_SSIENR);
204 }
205 
206 static inline void wait_for_tx_idle(struct rockchip_spi *rs, bool target_mode)
207 {
208 	unsigned long timeout = jiffies + msecs_to_jiffies(5);
209 
210 	do {
211 		if (target_mode) {
212 			if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_TARGET_TX_BUSY) &&
213 			    !((readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY)))
214 				return;
215 		} else {
216 			if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
217 				return;
218 		}
219 	} while (!time_after(jiffies, timeout));
220 
221 	dev_warn(rs->dev, "spi controller is in busy state!\n");
222 }
223 
224 static u32 get_fifo_len(struct rockchip_spi *rs)
225 {
226 	u32 ver;
227 
228 	ver = readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION);
229 
230 	switch (ver) {
231 	case ROCKCHIP_SPI_VER2_TYPE1:
232 	case ROCKCHIP_SPI_VER2_TYPE2:
233 		return 64;
234 	default:
235 		return 32;
236 	}
237 }
238 
239 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
240 {
241 	struct spi_controller *ctlr = spi->controller;
242 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
243 	bool cs_asserted = spi->mode & SPI_CS_HIGH ? enable : !enable;
244 
245 	if (cs_asserted) {
246 		/* Keep things powered as long as CS is asserted */
247 		pm_runtime_get_sync(rs->dev);
248 
249 		if (spi_get_csgpiod(spi, 0))
250 			ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
251 		else
252 			ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER,
253 					      BIT(spi_get_chipselect(spi, 0)));
254 	} else {
255 		if (spi_get_csgpiod(spi, 0))
256 			ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
257 		else
258 			ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER,
259 					      BIT(spi_get_chipselect(spi, 0)));
260 
261 		/* Drop reference from when we first asserted CS */
262 		pm_runtime_put(rs->dev);
263 	}
264 }
265 
266 static void rockchip_spi_handle_err(struct spi_controller *ctlr,
267 				    struct spi_message *msg)
268 {
269 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
270 
271 	/* stop running spi transfer
272 	 * this also flushes both rx and tx fifos
273 	 */
274 	spi_enable_chip(rs, false);
275 
276 	/* make sure all interrupts are masked and status cleared */
277 	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
278 	writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
279 
280 	if (atomic_read(&rs->state) & TXDMA)
281 		dmaengine_terminate_async(ctlr->dma_tx);
282 
283 	if (atomic_read(&rs->state) & RXDMA)
284 		dmaengine_terminate_async(ctlr->dma_rx);
285 }
286 
287 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
288 {
289 	u32 tx_free = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
290 	u32 words = min(rs->tx_left, tx_free);
291 
292 	rs->tx_left -= words;
293 	for (; words; words--) {
294 		u32 txw;
295 
296 		if (rs->n_bytes == 1)
297 			txw = *(u8 *)rs->tx;
298 		else
299 			txw = *(u16 *)rs->tx;
300 
301 		writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
302 		rs->tx += rs->n_bytes;
303 	}
304 }
305 
306 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
307 {
308 	u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
309 	u32 rx_left = (rs->rx_left > words) ? rs->rx_left - words : 0;
310 
311 	/* the hardware doesn't allow us to change fifo threshold
312 	 * level while spi is enabled, so instead make sure to leave
313 	 * enough words in the rx fifo to get the last interrupt
314 	 * exactly when all words have been received
315 	 */
316 	if (rx_left) {
317 		u32 ftl = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFTLR) + 1;
318 
319 		if (rx_left < ftl) {
320 			rx_left = ftl;
321 			words = rs->rx_left - rx_left;
322 		}
323 	}
324 
325 	rs->rx_left = rx_left;
326 	for (; words; words--) {
327 		u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
328 
329 		if (!rs->rx)
330 			continue;
331 
332 		if (rs->n_bytes == 1)
333 			*(u8 *)rs->rx = (u8)rxw;
334 		else
335 			*(u16 *)rs->rx = (u16)rxw;
336 		rs->rx += rs->n_bytes;
337 	}
338 }
339 
340 static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
341 {
342 	struct spi_controller *ctlr = dev_id;
343 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
344 
345 	/* When int_cs_inactive comes, spi target abort */
346 	if (rs->cs_inactive && readl_relaxed(rs->regs + ROCKCHIP_SPI_IMR) & INT_CS_INACTIVE) {
347 		ctlr->target_abort(ctlr);
348 		writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
349 		writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
350 
351 		return IRQ_HANDLED;
352 	}
353 
354 	if (rs->tx_left)
355 		rockchip_spi_pio_writer(rs);
356 
357 	rockchip_spi_pio_reader(rs);
358 	if (!rs->rx_left) {
359 		spi_enable_chip(rs, false);
360 		writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
361 		writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
362 		spi_finalize_current_transfer(ctlr);
363 	}
364 
365 	return IRQ_HANDLED;
366 }
367 
368 static int rockchip_spi_prepare_irq(struct rockchip_spi *rs,
369 				    struct spi_controller *ctlr,
370 				    struct spi_transfer *xfer)
371 {
372 	rs->tx = xfer->tx_buf;
373 	rs->rx = xfer->rx_buf;
374 	rs->tx_left = rs->tx ? xfer->len / rs->n_bytes : 0;
375 	rs->rx_left = xfer->len / rs->n_bytes;
376 
377 	writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
378 
379 	spi_enable_chip(rs, true);
380 
381 	if (rs->tx_left)
382 		rockchip_spi_pio_writer(rs);
383 
384 	if (rs->cs_inactive)
385 		writel_relaxed(INT_RF_FULL | INT_CS_INACTIVE, rs->regs + ROCKCHIP_SPI_IMR);
386 	else
387 		writel_relaxed(INT_RF_FULL, rs->regs + ROCKCHIP_SPI_IMR);
388 
389 	/* 1 means the transfer is in progress */
390 	return 1;
391 }
392 
393 static void rockchip_spi_dma_rxcb(void *data)
394 {
395 	struct spi_controller *ctlr = data;
396 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
397 	int state = atomic_fetch_andnot(RXDMA, &rs->state);
398 
399 	if (state & TXDMA && !rs->target_abort)
400 		return;
401 
402 	if (rs->cs_inactive)
403 		writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
404 
405 	spi_enable_chip(rs, false);
406 	spi_finalize_current_transfer(ctlr);
407 }
408 
409 static void rockchip_spi_dma_txcb(void *data)
410 {
411 	struct spi_controller *ctlr = data;
412 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
413 	int state = atomic_fetch_andnot(TXDMA, &rs->state);
414 
415 	if (state & RXDMA && !rs->target_abort)
416 		return;
417 
418 	/* Wait until the FIFO data completely. */
419 	wait_for_tx_idle(rs, ctlr->target);
420 
421 	spi_enable_chip(rs, false);
422 	spi_finalize_current_transfer(ctlr);
423 }
424 
425 static u32 rockchip_spi_calc_burst_size(u32 data_len)
426 {
427 	u32 i;
428 
429 	/* burst size: 1, 2, 4, 8 */
430 	for (i = 1; i < 8; i <<= 1) {
431 		if (data_len & i)
432 			break;
433 	}
434 
435 	return i;
436 }
437 
438 static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
439 		struct spi_controller *ctlr, struct spi_transfer *xfer)
440 {
441 	struct dma_async_tx_descriptor *rxdesc, *txdesc;
442 
443 	atomic_set(&rs->state, 0);
444 
445 	rs->tx = xfer->tx_buf;
446 	rs->rx = xfer->rx_buf;
447 
448 	rxdesc = NULL;
449 	if (xfer->rx_buf) {
450 		struct dma_slave_config rxconf = {
451 			.direction = DMA_DEV_TO_MEM,
452 			.src_addr = rs->dma_addr_rx,
453 			.src_addr_width = rs->n_bytes,
454 			.src_maxburst = rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes),
455 		};
456 
457 		dmaengine_slave_config(ctlr->dma_rx, &rxconf);
458 
459 		rxdesc = dmaengine_prep_slave_sg(
460 				ctlr->dma_rx,
461 				xfer->rx_sg.sgl, xfer->rx_sg.nents,
462 				DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
463 		if (!rxdesc)
464 			return -EINVAL;
465 
466 		rxdesc->callback = rockchip_spi_dma_rxcb;
467 		rxdesc->callback_param = ctlr;
468 	}
469 
470 	txdesc = NULL;
471 	if (xfer->tx_buf) {
472 		struct dma_slave_config txconf = {
473 			.direction = DMA_MEM_TO_DEV,
474 			.dst_addr = rs->dma_addr_tx,
475 			.dst_addr_width = rs->n_bytes,
476 			.dst_maxburst = rs->fifo_len / 4,
477 		};
478 
479 		dmaengine_slave_config(ctlr->dma_tx, &txconf);
480 
481 		txdesc = dmaengine_prep_slave_sg(
482 				ctlr->dma_tx,
483 				xfer->tx_sg.sgl, xfer->tx_sg.nents,
484 				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
485 		if (!txdesc) {
486 			if (rxdesc)
487 				dmaengine_terminate_sync(ctlr->dma_rx);
488 			return -EINVAL;
489 		}
490 
491 		txdesc->callback = rockchip_spi_dma_txcb;
492 		txdesc->callback_param = ctlr;
493 	}
494 
495 	/* rx must be started before tx due to spi instinct */
496 	if (rxdesc) {
497 		atomic_or(RXDMA, &rs->state);
498 		ctlr->dma_rx->cookie = dmaengine_submit(rxdesc);
499 		dma_async_issue_pending(ctlr->dma_rx);
500 	}
501 
502 	if (rs->cs_inactive)
503 		writel_relaxed(INT_CS_INACTIVE, rs->regs + ROCKCHIP_SPI_IMR);
504 
505 	spi_enable_chip(rs, true);
506 
507 	if (txdesc) {
508 		atomic_or(TXDMA, &rs->state);
509 		dmaengine_submit(txdesc);
510 		dma_async_issue_pending(ctlr->dma_tx);
511 	}
512 
513 	/* 1 means the transfer is in progress */
514 	return 1;
515 }
516 
517 static int rockchip_spi_config(struct rockchip_spi *rs,
518 		struct spi_device *spi, struct spi_transfer *xfer,
519 		bool use_dma, bool target_mode)
520 {
521 	u32 cr0 = CR0_FRF_SPI  << CR0_FRF_OFFSET
522 		| CR0_BHT_8BIT << CR0_BHT_OFFSET
523 		| CR0_SSD_ONE  << CR0_SSD_OFFSET
524 		| CR0_EM_BIG   << CR0_EM_OFFSET;
525 	u32 cr1;
526 	u32 dmacr = 0;
527 
528 	if (target_mode)
529 		cr0 |= CR0_OPM_TARGET << CR0_OPM_OFFSET;
530 	rs->target_abort = false;
531 
532 	cr0 |= rs->rsd << CR0_RSD_OFFSET;
533 	cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
534 	if (spi->mode & SPI_LSB_FIRST)
535 		cr0 |= CR0_FBM_LSB << CR0_FBM_OFFSET;
536 	if (spi->mode & SPI_CS_HIGH)
537 		cr0 |= BIT(spi_get_chipselect(spi, 0)) << CR0_SOI_OFFSET;
538 
539 	if (xfer->rx_buf && xfer->tx_buf)
540 		cr0 |= CR0_XFM_TR << CR0_XFM_OFFSET;
541 	else if (xfer->rx_buf)
542 		cr0 |= CR0_XFM_RO << CR0_XFM_OFFSET;
543 	else if (use_dma)
544 		cr0 |= CR0_XFM_TO << CR0_XFM_OFFSET;
545 
546 	switch (xfer->bits_per_word) {
547 	case 4:
548 		cr0 |= CR0_DFS_4BIT << CR0_DFS_OFFSET;
549 		cr1 = xfer->len - 1;
550 		break;
551 	case 8:
552 		cr0 |= CR0_DFS_8BIT << CR0_DFS_OFFSET;
553 		cr1 = xfer->len - 1;
554 		break;
555 	case 16:
556 		cr0 |= CR0_DFS_16BIT << CR0_DFS_OFFSET;
557 		cr1 = xfer->len / 2 - 1;
558 		break;
559 	default:
560 		/* we only whitelist 4, 8 and 16 bit words in
561 		 * ctlr->bits_per_word_mask, so this shouldn't
562 		 * happen
563 		 */
564 		dev_err(rs->dev, "unknown bits per word: %d\n",
565 			xfer->bits_per_word);
566 		return -EINVAL;
567 	}
568 
569 	if (use_dma) {
570 		if (xfer->tx_buf)
571 			dmacr |= TF_DMA_EN;
572 		if (xfer->rx_buf)
573 			dmacr |= RF_DMA_EN;
574 	}
575 
576 	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
577 	writel_relaxed(cr1, rs->regs + ROCKCHIP_SPI_CTRLR1);
578 
579 	/* unfortunately setting the fifo threshold level to generate an
580 	 * interrupt exactly when the fifo is full doesn't seem to work,
581 	 * so we need the strict inequality here
582 	 */
583 	if ((xfer->len / rs->n_bytes) < rs->fifo_len)
584 		writel_relaxed(xfer->len / rs->n_bytes - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
585 	else
586 		writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
587 
588 	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_DMATDLR);
589 	writel_relaxed(rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes) - 1,
590 		       rs->regs + ROCKCHIP_SPI_DMARDLR);
591 	writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
592 
593 	/* the hardware only supports an even clock divisor, so
594 	 * round divisor = spiclk / speed up to nearest even number
595 	 * so that the resulting speed is <= the requested speed
596 	 */
597 	writel_relaxed(2 * DIV_ROUND_UP(rs->freq, 2 * xfer->speed_hz),
598 			rs->regs + ROCKCHIP_SPI_BAUDR);
599 
600 	return 0;
601 }
602 
603 static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
604 {
605 	return ROCKCHIP_SPI_MAX_TRANLEN;
606 }
607 
608 static int rockchip_spi_target_abort(struct spi_controller *ctlr)
609 {
610 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
611 	u32 rx_fifo_left;
612 	struct dma_tx_state state;
613 	enum dma_status status;
614 
615 	/* Get current dma rx point */
616 	if (atomic_read(&rs->state) & RXDMA) {
617 		dmaengine_pause(ctlr->dma_rx);
618 		status = dmaengine_tx_status(ctlr->dma_rx, ctlr->dma_rx->cookie, &state);
619 		if (status == DMA_ERROR) {
620 			rs->rx = rs->xfer->rx_buf;
621 			rs->xfer->len = 0;
622 			rx_fifo_left = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
623 			for (; rx_fifo_left; rx_fifo_left--)
624 				readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
625 			goto out;
626 		} else {
627 			rs->rx += rs->xfer->len - rs->n_bytes * state.residue;
628 		}
629 	}
630 
631 	/* Get the valid data left in rx fifo and set rs->xfer->len real rx size */
632 	if (rs->rx) {
633 		rx_fifo_left = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
634 		for (; rx_fifo_left; rx_fifo_left--) {
635 			u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
636 
637 			if (rs->n_bytes == 1)
638 				*(u8 *)rs->rx = (u8)rxw;
639 			else
640 				*(u16 *)rs->rx = (u16)rxw;
641 			rs->rx += rs->n_bytes;
642 		}
643 		rs->xfer->len = (unsigned int)(rs->rx - rs->xfer->rx_buf);
644 	}
645 
646 out:
647 	if (atomic_read(&rs->state) & RXDMA)
648 		dmaengine_terminate_sync(ctlr->dma_rx);
649 	if (atomic_read(&rs->state) & TXDMA)
650 		dmaengine_terminate_sync(ctlr->dma_tx);
651 	atomic_set(&rs->state, 0);
652 	spi_enable_chip(rs, false);
653 	rs->target_abort = true;
654 	spi_finalize_current_transfer(ctlr);
655 
656 	return 0;
657 }
658 
659 static int rockchip_spi_transfer_one(
660 		struct spi_controller *ctlr,
661 		struct spi_device *spi,
662 		struct spi_transfer *xfer)
663 {
664 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
665 	int ret;
666 	bool use_dma;
667 
668 	/* Zero length transfers won't trigger an interrupt on completion */
669 	if (!xfer->len) {
670 		spi_finalize_current_transfer(ctlr);
671 		return 1;
672 	}
673 
674 	WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
675 		(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
676 
677 	if (!xfer->tx_buf && !xfer->rx_buf) {
678 		dev_err(rs->dev, "No buffer for transfer\n");
679 		return -EINVAL;
680 	}
681 
682 	if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
683 		dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
684 		return -EINVAL;
685 	}
686 
687 	rs->n_bytes = xfer->bits_per_word <= 8 ? 1 : 2;
688 	rs->xfer = xfer;
689 	use_dma = ctlr->can_dma ? ctlr->can_dma(ctlr, spi, xfer) : false;
690 
691 	ret = rockchip_spi_config(rs, spi, xfer, use_dma, ctlr->target);
692 	if (ret)
693 		return ret;
694 
695 	if (use_dma)
696 		return rockchip_spi_prepare_dma(rs, ctlr, xfer);
697 
698 	return rockchip_spi_prepare_irq(rs, ctlr, xfer);
699 }
700 
701 static bool rockchip_spi_can_dma(struct spi_controller *ctlr,
702 				 struct spi_device *spi,
703 				 struct spi_transfer *xfer)
704 {
705 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
706 	unsigned int bytes_per_word = xfer->bits_per_word <= 8 ? 1 : 2;
707 
708 	/* if the numbor of spi words to transfer is less than the fifo
709 	 * length we can just fill the fifo and wait for a single irq,
710 	 * so don't bother setting up dma
711 	 */
712 	return xfer->len / bytes_per_word >= rs->fifo_len;
713 }
714 
715 static int rockchip_spi_setup(struct spi_device *spi)
716 {
717 	struct rockchip_spi *rs = spi_controller_get_devdata(spi->controller);
718 	u32 cr0;
719 
720 	if (!spi_get_csgpiod(spi, 0) && (spi->mode & SPI_CS_HIGH) && !rs->cs_high_supported) {
721 		dev_warn(&spi->dev, "setup: non GPIO CS can't be active-high\n");
722 		return -EINVAL;
723 	}
724 
725 	pm_runtime_get_sync(rs->dev);
726 
727 	cr0 = readl_relaxed(rs->regs + ROCKCHIP_SPI_CTRLR0);
728 
729 	cr0 &= ~(0x3 << CR0_SCPH_OFFSET);
730 	cr0 |= ((spi->mode & 0x3) << CR0_SCPH_OFFSET);
731 	if (spi->mode & SPI_CS_HIGH && spi_get_chipselect(spi, 0) <= 1)
732 		cr0 |= BIT(spi_get_chipselect(spi, 0)) << CR0_SOI_OFFSET;
733 	else if (spi_get_chipselect(spi, 0) <= 1)
734 		cr0 &= ~(BIT(spi_get_chipselect(spi, 0)) << CR0_SOI_OFFSET);
735 
736 	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
737 
738 	pm_runtime_put(rs->dev);
739 
740 	return 0;
741 }
742 
743 static int rockchip_spi_probe(struct platform_device *pdev)
744 {
745 	int ret;
746 	struct rockchip_spi *rs;
747 	struct spi_controller *ctlr;
748 	struct resource *mem;
749 	struct device_node *np = pdev->dev.of_node;
750 	u32 rsd_nsecs, num_cs;
751 	bool target_mode;
752 
753 	target_mode = of_property_read_bool(np, "spi-slave");
754 
755 	if (target_mode)
756 		ctlr = spi_alloc_target(&pdev->dev,
757 				sizeof(struct rockchip_spi));
758 	else
759 		ctlr = spi_alloc_host(&pdev->dev,
760 				sizeof(struct rockchip_spi));
761 
762 	if (!ctlr)
763 		return -ENOMEM;
764 
765 	platform_set_drvdata(pdev, ctlr);
766 
767 	rs = spi_controller_get_devdata(ctlr);
768 
769 	/* Get basic io resource and map it */
770 	rs->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
771 	if (IS_ERR(rs->regs)) {
772 		ret =  PTR_ERR(rs->regs);
773 		goto err_put_ctlr;
774 	}
775 
776 	rs->apb_pclk = devm_clk_get_enabled(&pdev->dev, "apb_pclk");
777 	if (IS_ERR(rs->apb_pclk)) {
778 		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
779 		ret = PTR_ERR(rs->apb_pclk);
780 		goto err_put_ctlr;
781 	}
782 
783 	rs->spiclk = devm_clk_get_enabled(&pdev->dev, "spiclk");
784 	if (IS_ERR(rs->spiclk)) {
785 		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
786 		ret = PTR_ERR(rs->spiclk);
787 		goto err_put_ctlr;
788 	}
789 
790 	spi_enable_chip(rs, false);
791 
792 	ret = platform_get_irq(pdev, 0);
793 	if (ret < 0)
794 		goto err_put_ctlr;
795 
796 	ret = devm_request_threaded_irq(&pdev->dev, ret, rockchip_spi_isr, NULL,
797 			IRQF_ONESHOT, dev_name(&pdev->dev), ctlr);
798 	if (ret)
799 		goto err_put_ctlr;
800 
801 	rs->dev = &pdev->dev;
802 	rs->freq = clk_get_rate(rs->spiclk);
803 
804 	if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
805 				  &rsd_nsecs)) {
806 		/* rx sample delay is expressed in parent clock cycles (max 3) */
807 		u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8),
808 				1000000000 >> 8);
809 		if (!rsd) {
810 			dev_warn(rs->dev, "%u Hz are too slow to express %u ns delay\n",
811 					rs->freq, rsd_nsecs);
812 		} else if (rsd > CR0_RSD_MAX) {
813 			rsd = CR0_RSD_MAX;
814 			dev_warn(rs->dev, "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
815 					rs->freq, rsd_nsecs,
816 					CR0_RSD_MAX * 1000000000U / rs->freq);
817 		}
818 		rs->rsd = rsd;
819 	}
820 
821 	rs->fifo_len = get_fifo_len(rs);
822 	if (!rs->fifo_len) {
823 		dev_err(&pdev->dev, "Failed to get fifo length\n");
824 		ret = -EINVAL;
825 		goto err_put_ctlr;
826 	}
827 
828 	pm_runtime_set_autosuspend_delay(&pdev->dev, ROCKCHIP_AUTOSUSPEND_TIMEOUT);
829 	pm_runtime_use_autosuspend(&pdev->dev);
830 	pm_runtime_set_active(&pdev->dev);
831 	pm_runtime_enable(&pdev->dev);
832 
833 	ctlr->auto_runtime_pm = true;
834 	ctlr->bus_num = pdev->id;
835 	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
836 	if (target_mode) {
837 		ctlr->mode_bits |= SPI_NO_CS;
838 		ctlr->target_abort = rockchip_spi_target_abort;
839 	} else {
840 		ctlr->flags = SPI_CONTROLLER_GPIO_SS;
841 		ctlr->max_native_cs = ROCKCHIP_SPI_MAX_NATIVE_CS_NUM;
842 		/*
843 		 * rk spi0 has two native cs, spi1..5 one cs only
844 		 * if num-cs is missing in the dts, default to 1
845 		 */
846 		if (of_property_read_u32(np, "num-cs", &num_cs))
847 			num_cs = 1;
848 		ctlr->num_chipselect = num_cs;
849 		ctlr->use_gpio_descriptors = true;
850 	}
851 	ctlr->dev.of_node = pdev->dev.of_node;
852 	ctlr->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
853 	ctlr->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
854 	ctlr->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);
855 
856 	ctlr->setup = rockchip_spi_setup;
857 	ctlr->set_cs = rockchip_spi_set_cs;
858 	ctlr->transfer_one = rockchip_spi_transfer_one;
859 	ctlr->max_transfer_size = rockchip_spi_max_transfer_size;
860 	ctlr->handle_err = rockchip_spi_handle_err;
861 
862 	ctlr->dma_tx = dma_request_chan(rs->dev, "tx");
863 	if (IS_ERR(ctlr->dma_tx)) {
864 		/* Check tx to see if we need defer probing driver */
865 		if (PTR_ERR(ctlr->dma_tx) == -EPROBE_DEFER) {
866 			ret = -EPROBE_DEFER;
867 			goto err_disable_pm_runtime;
868 		}
869 		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
870 		ctlr->dma_tx = NULL;
871 	}
872 
873 	ctlr->dma_rx = dma_request_chan(rs->dev, "rx");
874 	if (IS_ERR(ctlr->dma_rx)) {
875 		if (PTR_ERR(ctlr->dma_rx) == -EPROBE_DEFER) {
876 			ret = -EPROBE_DEFER;
877 			goto err_free_dma_tx;
878 		}
879 		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
880 		ctlr->dma_rx = NULL;
881 	}
882 
883 	if (ctlr->dma_tx && ctlr->dma_rx) {
884 		rs->dma_addr_tx = mem->start + ROCKCHIP_SPI_TXDR;
885 		rs->dma_addr_rx = mem->start + ROCKCHIP_SPI_RXDR;
886 		ctlr->can_dma = rockchip_spi_can_dma;
887 	}
888 
889 	switch (readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION)) {
890 	case ROCKCHIP_SPI_VER2_TYPE2:
891 		rs->cs_high_supported = true;
892 		ctlr->mode_bits |= SPI_CS_HIGH;
893 		if (ctlr->can_dma && target_mode)
894 			rs->cs_inactive = true;
895 		else
896 			rs->cs_inactive = false;
897 		break;
898 	default:
899 		rs->cs_inactive = false;
900 		break;
901 	}
902 
903 	ret = devm_spi_register_controller(&pdev->dev, ctlr);
904 	if (ret < 0) {
905 		dev_err(&pdev->dev, "Failed to register controller\n");
906 		goto err_free_dma_rx;
907 	}
908 
909 	return 0;
910 
911 err_free_dma_rx:
912 	if (ctlr->dma_rx)
913 		dma_release_channel(ctlr->dma_rx);
914 err_free_dma_tx:
915 	if (ctlr->dma_tx)
916 		dma_release_channel(ctlr->dma_tx);
917 err_disable_pm_runtime:
918 	pm_runtime_disable(&pdev->dev);
919 err_put_ctlr:
920 	spi_controller_put(ctlr);
921 
922 	return ret;
923 }
924 
925 static void rockchip_spi_remove(struct platform_device *pdev)
926 {
927 	struct spi_controller *ctlr = spi_controller_get(platform_get_drvdata(pdev));
928 
929 	pm_runtime_get_sync(&pdev->dev);
930 
931 	pm_runtime_put_noidle(&pdev->dev);
932 	pm_runtime_disable(&pdev->dev);
933 	pm_runtime_set_suspended(&pdev->dev);
934 
935 	if (ctlr->dma_tx)
936 		dma_release_channel(ctlr->dma_tx);
937 	if (ctlr->dma_rx)
938 		dma_release_channel(ctlr->dma_rx);
939 
940 	spi_controller_put(ctlr);
941 }
942 
943 #ifdef CONFIG_PM_SLEEP
944 static int rockchip_spi_suspend(struct device *dev)
945 {
946 	int ret;
947 	struct spi_controller *ctlr = dev_get_drvdata(dev);
948 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
949 
950 	ret = spi_controller_suspend(ctlr);
951 	if (ret < 0)
952 		return ret;
953 
954 	clk_disable_unprepare(rs->spiclk);
955 	clk_disable_unprepare(rs->apb_pclk);
956 
957 	pinctrl_pm_select_sleep_state(dev);
958 
959 	return 0;
960 }
961 
962 static int rockchip_spi_resume(struct device *dev)
963 {
964 	int ret;
965 	struct spi_controller *ctlr = dev_get_drvdata(dev);
966 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
967 
968 	pinctrl_pm_select_default_state(dev);
969 
970 	ret = clk_prepare_enable(rs->apb_pclk);
971 	if (ret < 0)
972 		return ret;
973 
974 	ret = clk_prepare_enable(rs->spiclk);
975 	if (ret < 0)
976 		clk_disable_unprepare(rs->apb_pclk);
977 
978 	ret = spi_controller_resume(ctlr);
979 	if (ret < 0) {
980 		clk_disable_unprepare(rs->spiclk);
981 		clk_disable_unprepare(rs->apb_pclk);
982 	}
983 
984 	return 0;
985 }
986 #endif /* CONFIG_PM_SLEEP */
987 
988 #ifdef CONFIG_PM
989 static int rockchip_spi_runtime_suspend(struct device *dev)
990 {
991 	struct spi_controller *ctlr = dev_get_drvdata(dev);
992 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
993 
994 	clk_disable_unprepare(rs->spiclk);
995 	clk_disable_unprepare(rs->apb_pclk);
996 
997 	return 0;
998 }
999 
1000 static int rockchip_spi_runtime_resume(struct device *dev)
1001 {
1002 	int ret;
1003 	struct spi_controller *ctlr = dev_get_drvdata(dev);
1004 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
1005 
1006 	ret = clk_prepare_enable(rs->apb_pclk);
1007 	if (ret < 0)
1008 		return ret;
1009 
1010 	ret = clk_prepare_enable(rs->spiclk);
1011 	if (ret < 0)
1012 		clk_disable_unprepare(rs->apb_pclk);
1013 
1014 	return 0;
1015 }
1016 #endif /* CONFIG_PM */
1017 
1018 static const struct dev_pm_ops rockchip_spi_pm = {
1019 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
1020 	SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
1021 			   rockchip_spi_runtime_resume, NULL)
1022 };
1023 
1024 static const struct of_device_id rockchip_spi_dt_match[] = {
1025 	{ .compatible = "rockchip,px30-spi", },
1026 	{ .compatible = "rockchip,rk3036-spi", },
1027 	{ .compatible = "rockchip,rk3066-spi", },
1028 	{ .compatible = "rockchip,rk3188-spi", },
1029 	{ .compatible = "rockchip,rk3228-spi", },
1030 	{ .compatible = "rockchip,rk3288-spi", },
1031 	{ .compatible = "rockchip,rk3308-spi", },
1032 	{ .compatible = "rockchip,rk3328-spi", },
1033 	{ .compatible = "rockchip,rk3368-spi", },
1034 	{ .compatible = "rockchip,rk3399-spi", },
1035 	{ .compatible = "rockchip,rv1108-spi", },
1036 	{ .compatible = "rockchip,rv1126-spi", },
1037 	{ },
1038 };
1039 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
1040 
1041 static struct platform_driver rockchip_spi_driver = {
1042 	.driver = {
1043 		.name	= DRIVER_NAME,
1044 		.pm = &rockchip_spi_pm,
1045 		.of_match_table = of_match_ptr(rockchip_spi_dt_match),
1046 	},
1047 	.probe = rockchip_spi_probe,
1048 	.remove_new = rockchip_spi_remove,
1049 };
1050 
1051 module_platform_driver(rockchip_spi_driver);
1052 
1053 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
1054 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
1055 MODULE_LICENSE("GPL v2");
1056