xref: /linux/drivers/spi/spi-img-spfi.c (revision 2ba9268dd603d23e17643437b2246acb6844953b)
1 /*
2  * IMG SPFI controller driver
3  *
4  * Copyright (C) 2007,2008,2013 Imagination Technologies Ltd.
5  * Copyright (C) 2014 Google, Inc.
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2, as published by the Free Software Foundation.
10  */
11 
12 #include <linux/clk.h>
13 #include <linux/delay.h>
14 #include <linux/dmaengine.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/irq.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/platform_device.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/scatterlist.h>
23 #include <linux/slab.h>
24 #include <linux/spi/spi.h>
25 #include <linux/spinlock.h>
26 
27 #define SPFI_DEVICE_PARAMETER(x)		(0x00 + 0x4 * (x))
28 #define SPFI_DEVICE_PARAMETER_BITCLK_SHIFT	24
29 #define SPFI_DEVICE_PARAMETER_BITCLK_MASK	0xff
30 #define SPFI_DEVICE_PARAMETER_CSSETUP_SHIFT	16
31 #define SPFI_DEVICE_PARAMETER_CSSETUP_MASK	0xff
32 #define SPFI_DEVICE_PARAMETER_CSHOLD_SHIFT	8
33 #define SPFI_DEVICE_PARAMETER_CSHOLD_MASK	0xff
34 #define SPFI_DEVICE_PARAMETER_CSDELAY_SHIFT	0
35 #define SPFI_DEVICE_PARAMETER_CSDELAY_MASK	0xff
36 
37 #define SPFI_CONTROL				0x14
38 #define SPFI_CONTROL_CONTINUE			BIT(12)
39 #define SPFI_CONTROL_SOFT_RESET			BIT(11)
40 #define SPFI_CONTROL_SEND_DMA			BIT(10)
41 #define SPFI_CONTROL_GET_DMA			BIT(9)
42 #define SPFI_CONTROL_TMODE_SHIFT		5
43 #define SPFI_CONTROL_TMODE_MASK			0x7
44 #define SPFI_CONTROL_TMODE_SINGLE		0
45 #define SPFI_CONTROL_TMODE_DUAL			1
46 #define SPFI_CONTROL_TMODE_QUAD			2
47 #define SPFI_CONTROL_SPFI_EN			BIT(0)
48 
49 #define SPFI_TRANSACTION			0x18
50 #define SPFI_TRANSACTION_TSIZE_SHIFT		16
51 #define SPFI_TRANSACTION_TSIZE_MASK		0xffff
52 
53 #define SPFI_PORT_STATE				0x1c
54 #define SPFI_PORT_STATE_DEV_SEL_SHIFT		20
55 #define SPFI_PORT_STATE_DEV_SEL_MASK		0x7
56 #define SPFI_PORT_STATE_CK_POL(x)		BIT(19 - (x))
57 #define SPFI_PORT_STATE_CK_PHASE(x)		BIT(14 - (x))
58 
59 #define SPFI_TX_32BIT_VALID_DATA		0x20
60 #define SPFI_TX_8BIT_VALID_DATA			0x24
61 #define SPFI_RX_32BIT_VALID_DATA		0x28
62 #define SPFI_RX_8BIT_VALID_DATA			0x2c
63 
64 #define SPFI_INTERRUPT_STATUS			0x30
65 #define SPFI_INTERRUPT_ENABLE			0x34
66 #define SPFI_INTERRUPT_CLEAR			0x38
67 #define SPFI_INTERRUPT_IACCESS			BIT(12)
68 #define SPFI_INTERRUPT_GDEX8BIT			BIT(11)
69 #define SPFI_INTERRUPT_ALLDONETRIG		BIT(9)
70 #define SPFI_INTERRUPT_GDFUL			BIT(8)
71 #define SPFI_INTERRUPT_GDHF			BIT(7)
72 #define SPFI_INTERRUPT_GDEX32BIT		BIT(6)
73 #define SPFI_INTERRUPT_GDTRIG			BIT(5)
74 #define SPFI_INTERRUPT_SDFUL			BIT(3)
75 #define SPFI_INTERRUPT_SDHF			BIT(2)
76 #define SPFI_INTERRUPT_SDE			BIT(1)
77 #define SPFI_INTERRUPT_SDTRIG			BIT(0)
78 
79 /*
80  * There are four parallel FIFOs of 16 bytes each.  The word buffer
81  * (*_32BIT_VALID_DATA) accesses all four FIFOs at once, resulting in an
82  * effective FIFO size of 64 bytes.  The byte buffer (*_8BIT_VALID_DATA)
83  * accesses only a single FIFO, resulting in an effective FIFO size of
84  * 16 bytes.
85  */
86 #define SPFI_32BIT_FIFO_SIZE			64
87 #define SPFI_8BIT_FIFO_SIZE			16
88 
89 struct img_spfi {
90 	struct device *dev;
91 	struct spi_master *master;
92 	spinlock_t lock;
93 
94 	void __iomem *regs;
95 	phys_addr_t phys;
96 	int irq;
97 	struct clk *spfi_clk;
98 	struct clk *sys_clk;
99 
100 	struct dma_chan *rx_ch;
101 	struct dma_chan *tx_ch;
102 	bool tx_dma_busy;
103 	bool rx_dma_busy;
104 };
105 
106 static inline u32 spfi_readl(struct img_spfi *spfi, u32 reg)
107 {
108 	return readl(spfi->regs + reg);
109 }
110 
111 static inline void spfi_writel(struct img_spfi *spfi, u32 val, u32 reg)
112 {
113 	writel(val, spfi->regs + reg);
114 }
115 
116 static inline void spfi_start(struct img_spfi *spfi)
117 {
118 	u32 val;
119 
120 	val = spfi_readl(spfi, SPFI_CONTROL);
121 	val |= SPFI_CONTROL_SPFI_EN;
122 	spfi_writel(spfi, val, SPFI_CONTROL);
123 }
124 
125 static inline void spfi_stop(struct img_spfi *spfi)
126 {
127 	u32 val;
128 
129 	val = spfi_readl(spfi, SPFI_CONTROL);
130 	val &= ~SPFI_CONTROL_SPFI_EN;
131 	spfi_writel(spfi, val, SPFI_CONTROL);
132 }
133 
134 static inline void spfi_reset(struct img_spfi *spfi)
135 {
136 	spfi_writel(spfi, SPFI_CONTROL_SOFT_RESET, SPFI_CONTROL);
137 	udelay(1);
138 	spfi_writel(spfi, 0, SPFI_CONTROL);
139 }
140 
141 static void spfi_flush_tx_fifo(struct img_spfi *spfi)
142 {
143 	unsigned long timeout = jiffies + msecs_to_jiffies(10);
144 
145 	spfi_writel(spfi, SPFI_INTERRUPT_SDE, SPFI_INTERRUPT_CLEAR);
146 	while (time_before(jiffies, timeout)) {
147 		if (spfi_readl(spfi, SPFI_INTERRUPT_STATUS) &
148 		    SPFI_INTERRUPT_SDE)
149 			return;
150 		cpu_relax();
151 	}
152 
153 	dev_err(spfi->dev, "Timed out waiting for FIFO to drain\n");
154 	spfi_reset(spfi);
155 }
156 
157 static unsigned int spfi_pio_write32(struct img_spfi *spfi, const u32 *buf,
158 				     unsigned int max)
159 {
160 	unsigned int count = 0;
161 	u32 status;
162 
163 	while (count < max / 4) {
164 		spfi_writel(spfi, SPFI_INTERRUPT_SDFUL, SPFI_INTERRUPT_CLEAR);
165 		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
166 		if (status & SPFI_INTERRUPT_SDFUL)
167 			break;
168 		spfi_writel(spfi, buf[count], SPFI_TX_32BIT_VALID_DATA);
169 		count++;
170 	}
171 
172 	return count * 4;
173 }
174 
175 static unsigned int spfi_pio_write8(struct img_spfi *spfi, const u8 *buf,
176 				    unsigned int max)
177 {
178 	unsigned int count = 0;
179 	u32 status;
180 
181 	while (count < max) {
182 		spfi_writel(spfi, SPFI_INTERRUPT_SDFUL, SPFI_INTERRUPT_CLEAR);
183 		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
184 		if (status & SPFI_INTERRUPT_SDFUL)
185 			break;
186 		spfi_writel(spfi, buf[count], SPFI_TX_8BIT_VALID_DATA);
187 		count++;
188 	}
189 
190 	return count;
191 }
192 
193 static unsigned int spfi_pio_read32(struct img_spfi *spfi, u32 *buf,
194 				    unsigned int max)
195 {
196 	unsigned int count = 0;
197 	u32 status;
198 
199 	while (count < max / 4) {
200 		spfi_writel(spfi, SPFI_INTERRUPT_GDEX32BIT,
201 			    SPFI_INTERRUPT_CLEAR);
202 		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
203 		if (!(status & SPFI_INTERRUPT_GDEX32BIT))
204 			break;
205 		buf[count] = spfi_readl(spfi, SPFI_RX_32BIT_VALID_DATA);
206 		count++;
207 	}
208 
209 	return count * 4;
210 }
211 
212 static unsigned int spfi_pio_read8(struct img_spfi *spfi, u8 *buf,
213 				   unsigned int max)
214 {
215 	unsigned int count = 0;
216 	u32 status;
217 
218 	while (count < max) {
219 		spfi_writel(spfi, SPFI_INTERRUPT_GDEX8BIT,
220 			    SPFI_INTERRUPT_CLEAR);
221 		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
222 		if (!(status & SPFI_INTERRUPT_GDEX8BIT))
223 			break;
224 		buf[count] = spfi_readl(spfi, SPFI_RX_8BIT_VALID_DATA);
225 		count++;
226 	}
227 
228 	return count;
229 }
230 
231 static int img_spfi_start_pio(struct spi_master *master,
232 			       struct spi_device *spi,
233 			       struct spi_transfer *xfer)
234 {
235 	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
236 	unsigned int tx_bytes = 0, rx_bytes = 0;
237 	const void *tx_buf = xfer->tx_buf;
238 	void *rx_buf = xfer->rx_buf;
239 	unsigned long timeout;
240 
241 	if (tx_buf)
242 		tx_bytes = xfer->len;
243 	if (rx_buf)
244 		rx_bytes = xfer->len;
245 
246 	spfi_start(spfi);
247 
248 	timeout = jiffies +
249 		msecs_to_jiffies(xfer->len * 8 * 1000 / xfer->speed_hz + 100);
250 	while ((tx_bytes > 0 || rx_bytes > 0) &&
251 	       time_before(jiffies, timeout)) {
252 		unsigned int tx_count, rx_count;
253 
254 		if (tx_bytes >= 4)
255 			tx_count = spfi_pio_write32(spfi, tx_buf, tx_bytes);
256 		else
257 			tx_count = spfi_pio_write8(spfi, tx_buf, tx_bytes);
258 
259 		if (rx_bytes >= 4)
260 			rx_count = spfi_pio_read32(spfi, rx_buf, rx_bytes);
261 		else
262 			rx_count = spfi_pio_read8(spfi, rx_buf, rx_bytes);
263 
264 		tx_buf += tx_count;
265 		rx_buf += rx_count;
266 		tx_bytes -= tx_count;
267 		rx_bytes -= rx_count;
268 
269 		cpu_relax();
270 	}
271 
272 	if (rx_bytes > 0 || tx_bytes > 0) {
273 		dev_err(spfi->dev, "PIO transfer timed out\n");
274 		spfi_reset(spfi);
275 		return -ETIMEDOUT;
276 	}
277 
278 	if (tx_buf)
279 		spfi_flush_tx_fifo(spfi);
280 	spfi_stop(spfi);
281 
282 	return 0;
283 }
284 
285 static void img_spfi_dma_rx_cb(void *data)
286 {
287 	struct img_spfi *spfi = data;
288 	unsigned long flags;
289 
290 	spin_lock_irqsave(&spfi->lock, flags);
291 
292 	spfi->rx_dma_busy = false;
293 	if (!spfi->tx_dma_busy) {
294 		spfi_stop(spfi);
295 		spi_finalize_current_transfer(spfi->master);
296 	}
297 
298 	spin_unlock_irqrestore(&spfi->lock, flags);
299 }
300 
301 static void img_spfi_dma_tx_cb(void *data)
302 {
303 	struct img_spfi *spfi = data;
304 	unsigned long flags;
305 
306 	spfi_flush_tx_fifo(spfi);
307 
308 	spin_lock_irqsave(&spfi->lock, flags);
309 
310 	spfi->tx_dma_busy = false;
311 	if (!spfi->rx_dma_busy) {
312 		spfi_stop(spfi);
313 		spi_finalize_current_transfer(spfi->master);
314 	}
315 
316 	spin_unlock_irqrestore(&spfi->lock, flags);
317 }
318 
319 static int img_spfi_start_dma(struct spi_master *master,
320 			      struct spi_device *spi,
321 			      struct spi_transfer *xfer)
322 {
323 	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
324 	struct dma_async_tx_descriptor *rxdesc = NULL, *txdesc = NULL;
325 	struct dma_slave_config rxconf, txconf;
326 
327 	spfi->rx_dma_busy = false;
328 	spfi->tx_dma_busy = false;
329 
330 	if (xfer->rx_buf) {
331 		rxconf.direction = DMA_DEV_TO_MEM;
332 		if (xfer->len % 4 == 0) {
333 			rxconf.src_addr = spfi->phys + SPFI_RX_32BIT_VALID_DATA;
334 			rxconf.src_addr_width = 4;
335 			rxconf.src_maxburst = 4;
336 		} else {
337 			rxconf.src_addr = spfi->phys + SPFI_RX_8BIT_VALID_DATA;
338 			rxconf.src_addr_width = 1;
339 			rxconf.src_maxburst = 4;
340 		}
341 		dmaengine_slave_config(spfi->rx_ch, &rxconf);
342 
343 		rxdesc = dmaengine_prep_slave_sg(spfi->rx_ch, xfer->rx_sg.sgl,
344 						 xfer->rx_sg.nents,
345 						 DMA_DEV_TO_MEM,
346 						 DMA_PREP_INTERRUPT);
347 		if (!rxdesc)
348 			goto stop_dma;
349 
350 		rxdesc->callback = img_spfi_dma_rx_cb;
351 		rxdesc->callback_param = spfi;
352 	}
353 
354 	if (xfer->tx_buf) {
355 		txconf.direction = DMA_MEM_TO_DEV;
356 		if (xfer->len % 4 == 0) {
357 			txconf.dst_addr = spfi->phys + SPFI_TX_32BIT_VALID_DATA;
358 			txconf.dst_addr_width = 4;
359 			txconf.dst_maxburst = 4;
360 		} else {
361 			txconf.dst_addr = spfi->phys + SPFI_TX_8BIT_VALID_DATA;
362 			txconf.dst_addr_width = 1;
363 			txconf.dst_maxburst = 4;
364 		}
365 		dmaengine_slave_config(spfi->tx_ch, &txconf);
366 
367 		txdesc = dmaengine_prep_slave_sg(spfi->tx_ch, xfer->tx_sg.sgl,
368 						 xfer->tx_sg.nents,
369 						 DMA_MEM_TO_DEV,
370 						 DMA_PREP_INTERRUPT);
371 		if (!txdesc)
372 			goto stop_dma;
373 
374 		txdesc->callback = img_spfi_dma_tx_cb;
375 		txdesc->callback_param = spfi;
376 	}
377 
378 	if (xfer->rx_buf) {
379 		spfi->rx_dma_busy = true;
380 		dmaengine_submit(rxdesc);
381 		dma_async_issue_pending(spfi->rx_ch);
382 	}
383 
384 	spfi_start(spfi);
385 
386 	if (xfer->tx_buf) {
387 		spfi->tx_dma_busy = true;
388 		dmaengine_submit(txdesc);
389 		dma_async_issue_pending(spfi->tx_ch);
390 	}
391 
392 	return 1;
393 
394 stop_dma:
395 	dmaengine_terminate_all(spfi->rx_ch);
396 	dmaengine_terminate_all(spfi->tx_ch);
397 	return -EIO;
398 }
399 
400 static void img_spfi_config(struct spi_master *master, struct spi_device *spi,
401 			    struct spi_transfer *xfer)
402 {
403 	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
404 	u32 val, div;
405 
406 	/*
407 	 * output = spfi_clk * (BITCLK / 512), where BITCLK must be a
408 	 * power of 2 up to 256 (where 255 == 256 since BITCLK is 8 bits)
409 	 */
410 	div = DIV_ROUND_UP(master->max_speed_hz, xfer->speed_hz);
411 	div = clamp(512 / (1 << get_count_order(div)), 1, 255);
412 
413 	val = spfi_readl(spfi, SPFI_DEVICE_PARAMETER(spi->chip_select));
414 	val &= ~(SPFI_DEVICE_PARAMETER_BITCLK_MASK <<
415 		 SPFI_DEVICE_PARAMETER_BITCLK_SHIFT);
416 	val |= div << SPFI_DEVICE_PARAMETER_BITCLK_SHIFT;
417 	spfi_writel(spfi, val, SPFI_DEVICE_PARAMETER(spi->chip_select));
418 
419 	val = spfi_readl(spfi, SPFI_CONTROL);
420 	val &= ~(SPFI_CONTROL_SEND_DMA | SPFI_CONTROL_GET_DMA);
421 	if (xfer->tx_buf)
422 		val |= SPFI_CONTROL_SEND_DMA;
423 	if (xfer->rx_buf)
424 		val |= SPFI_CONTROL_GET_DMA;
425 	val &= ~(SPFI_CONTROL_TMODE_MASK << SPFI_CONTROL_TMODE_SHIFT);
426 	if (xfer->tx_nbits == SPI_NBITS_DUAL &&
427 	    xfer->rx_nbits == SPI_NBITS_DUAL)
428 		val |= SPFI_CONTROL_TMODE_DUAL << SPFI_CONTROL_TMODE_SHIFT;
429 	else if (xfer->tx_nbits == SPI_NBITS_QUAD &&
430 		 xfer->rx_nbits == SPI_NBITS_QUAD)
431 		val |= SPFI_CONTROL_TMODE_QUAD << SPFI_CONTROL_TMODE_SHIFT;
432 	val &= ~SPFI_CONTROL_CONTINUE;
433 	if (!xfer->cs_change && !list_is_last(&xfer->transfer_list,
434 					      &master->cur_msg->transfers))
435 		val |= SPFI_CONTROL_CONTINUE;
436 	spfi_writel(spfi, val, SPFI_CONTROL);
437 
438 	val = spfi_readl(spfi, SPFI_PORT_STATE);
439 	if (spi->mode & SPI_CPHA)
440 		val |= SPFI_PORT_STATE_CK_PHASE(spi->chip_select);
441 	else
442 		val &= ~SPFI_PORT_STATE_CK_PHASE(spi->chip_select);
443 	if (spi->mode & SPI_CPOL)
444 		val |= SPFI_PORT_STATE_CK_POL(spi->chip_select);
445 	else
446 		val &= ~SPFI_PORT_STATE_CK_POL(spi->chip_select);
447 	spfi_writel(spfi, val, SPFI_PORT_STATE);
448 
449 	spfi_writel(spfi, xfer->len << SPFI_TRANSACTION_TSIZE_SHIFT,
450 		    SPFI_TRANSACTION);
451 }
452 
453 static int img_spfi_transfer_one(struct spi_master *master,
454 				 struct spi_device *spi,
455 				 struct spi_transfer *xfer)
456 {
457 	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
458 	bool dma_reset = false;
459 	unsigned long flags;
460 	int ret;
461 
462 	if (xfer->len > SPFI_TRANSACTION_TSIZE_MASK) {
463 		dev_err(spfi->dev,
464 			"Transfer length (%d) is greater than the max supported (%d)",
465 			xfer->len, SPFI_TRANSACTION_TSIZE_MASK);
466 		return -EINVAL;
467 	}
468 
469 	/*
470 	 * Stop all DMA and reset the controller if the previous transaction
471 	 * timed-out and never completed it's DMA.
472 	 */
473 	spin_lock_irqsave(&spfi->lock, flags);
474 	if (spfi->tx_dma_busy || spfi->rx_dma_busy) {
475 		dev_err(spfi->dev, "SPI DMA still busy\n");
476 		dma_reset = true;
477 	}
478 	spin_unlock_irqrestore(&spfi->lock, flags);
479 
480 	if (dma_reset) {
481 		dmaengine_terminate_all(spfi->tx_ch);
482 		dmaengine_terminate_all(spfi->rx_ch);
483 		spfi_reset(spfi);
484 	}
485 
486 	img_spfi_config(master, spi, xfer);
487 	if (master->can_dma && master->can_dma(master, spi, xfer))
488 		ret = img_spfi_start_dma(master, spi, xfer);
489 	else
490 		ret = img_spfi_start_pio(master, spi, xfer);
491 
492 	return ret;
493 }
494 
495 static void img_spfi_set_cs(struct spi_device *spi, bool enable)
496 {
497 	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
498 	u32 val;
499 
500 	val = spfi_readl(spfi, SPFI_PORT_STATE);
501 	val &= ~(SPFI_PORT_STATE_DEV_SEL_MASK << SPFI_PORT_STATE_DEV_SEL_SHIFT);
502 	val |= spi->chip_select << SPFI_PORT_STATE_DEV_SEL_SHIFT;
503 	spfi_writel(spfi, val, SPFI_PORT_STATE);
504 }
505 
506 static bool img_spfi_can_dma(struct spi_master *master, struct spi_device *spi,
507 			     struct spi_transfer *xfer)
508 {
509 	if (xfer->len > SPFI_32BIT_FIFO_SIZE)
510 		return true;
511 	return false;
512 }
513 
514 static irqreturn_t img_spfi_irq(int irq, void *dev_id)
515 {
516 	struct img_spfi *spfi = (struct img_spfi *)dev_id;
517 	u32 status;
518 
519 	status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
520 	if (status & SPFI_INTERRUPT_IACCESS) {
521 		spfi_writel(spfi, SPFI_INTERRUPT_IACCESS, SPFI_INTERRUPT_CLEAR);
522 		dev_err(spfi->dev, "Illegal access interrupt");
523 		return IRQ_HANDLED;
524 	}
525 
526 	return IRQ_NONE;
527 }
528 
529 static int img_spfi_probe(struct platform_device *pdev)
530 {
531 	struct spi_master *master;
532 	struct img_spfi *spfi;
533 	struct resource *res;
534 	int ret;
535 
536 	master = spi_alloc_master(&pdev->dev, sizeof(*spfi));
537 	if (!master)
538 		return -ENOMEM;
539 	platform_set_drvdata(pdev, master);
540 
541 	spfi = spi_master_get_devdata(master);
542 	spfi->dev = &pdev->dev;
543 	spfi->master = master;
544 	spin_lock_init(&spfi->lock);
545 
546 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
547 	spfi->regs = devm_ioremap_resource(spfi->dev, res);
548 	if (IS_ERR(spfi->regs)) {
549 		ret = PTR_ERR(spfi->regs);
550 		goto put_spi;
551 	}
552 	spfi->phys = res->start;
553 
554 	spfi->irq = platform_get_irq(pdev, 0);
555 	if (spfi->irq < 0) {
556 		ret = spfi->irq;
557 		goto put_spi;
558 	}
559 	ret = devm_request_irq(spfi->dev, spfi->irq, img_spfi_irq,
560 			       IRQ_TYPE_LEVEL_HIGH, dev_name(spfi->dev), spfi);
561 	if (ret)
562 		goto put_spi;
563 
564 	spfi->sys_clk = devm_clk_get(spfi->dev, "sys");
565 	if (IS_ERR(spfi->sys_clk)) {
566 		ret = PTR_ERR(spfi->sys_clk);
567 		goto put_spi;
568 	}
569 	spfi->spfi_clk = devm_clk_get(spfi->dev, "spfi");
570 	if (IS_ERR(spfi->spfi_clk)) {
571 		ret = PTR_ERR(spfi->spfi_clk);
572 		goto put_spi;
573 	}
574 
575 	ret = clk_prepare_enable(spfi->sys_clk);
576 	if (ret)
577 		goto put_spi;
578 	ret = clk_prepare_enable(spfi->spfi_clk);
579 	if (ret)
580 		goto disable_pclk;
581 
582 	spfi_reset(spfi);
583 	/*
584 	 * Only enable the error (IACCESS) interrupt.  In PIO mode we'll
585 	 * poll the status of the FIFOs.
586 	 */
587 	spfi_writel(spfi, SPFI_INTERRUPT_IACCESS, SPFI_INTERRUPT_ENABLE);
588 
589 	master->auto_runtime_pm = true;
590 	master->bus_num = pdev->id;
591 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_TX_DUAL | SPI_RX_DUAL;
592 	if (of_property_read_bool(spfi->dev->of_node, "img,supports-quad-mode"))
593 		master->mode_bits |= SPI_TX_QUAD | SPI_RX_QUAD;
594 	master->num_chipselect = 5;
595 	master->dev.of_node = pdev->dev.of_node;
596 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(8);
597 	master->max_speed_hz = clk_get_rate(spfi->spfi_clk);
598 	master->min_speed_hz = master->max_speed_hz / 512;
599 
600 	master->set_cs = img_spfi_set_cs;
601 	master->transfer_one = img_spfi_transfer_one;
602 
603 	spfi->tx_ch = dma_request_slave_channel(spfi->dev, "tx");
604 	spfi->rx_ch = dma_request_slave_channel(spfi->dev, "rx");
605 	if (!spfi->tx_ch || !spfi->rx_ch) {
606 		if (spfi->tx_ch)
607 			dma_release_channel(spfi->tx_ch);
608 		if (spfi->rx_ch)
609 			dma_release_channel(spfi->rx_ch);
610 		dev_warn(spfi->dev, "Failed to get DMA channels, falling back to PIO mode\n");
611 	} else {
612 		master->dma_tx = spfi->tx_ch;
613 		master->dma_rx = spfi->rx_ch;
614 		master->can_dma = img_spfi_can_dma;
615 	}
616 
617 	pm_runtime_set_active(spfi->dev);
618 	pm_runtime_enable(spfi->dev);
619 
620 	ret = devm_spi_register_master(spfi->dev, master);
621 	if (ret)
622 		goto disable_pm;
623 
624 	return 0;
625 
626 disable_pm:
627 	pm_runtime_disable(spfi->dev);
628 	if (spfi->rx_ch)
629 		dma_release_channel(spfi->rx_ch);
630 	if (spfi->tx_ch)
631 		dma_release_channel(spfi->tx_ch);
632 	clk_disable_unprepare(spfi->spfi_clk);
633 disable_pclk:
634 	clk_disable_unprepare(spfi->sys_clk);
635 put_spi:
636 	spi_master_put(master);
637 
638 	return ret;
639 }
640 
641 static int img_spfi_remove(struct platform_device *pdev)
642 {
643 	struct spi_master *master = platform_get_drvdata(pdev);
644 	struct img_spfi *spfi = spi_master_get_devdata(master);
645 
646 	if (spfi->tx_ch)
647 		dma_release_channel(spfi->tx_ch);
648 	if (spfi->rx_ch)
649 		dma_release_channel(spfi->rx_ch);
650 
651 	pm_runtime_disable(spfi->dev);
652 	if (!pm_runtime_status_suspended(spfi->dev)) {
653 		clk_disable_unprepare(spfi->spfi_clk);
654 		clk_disable_unprepare(spfi->sys_clk);
655 	}
656 
657 	spi_master_put(master);
658 
659 	return 0;
660 }
661 
662 #ifdef CONFIG_PM
663 static int img_spfi_runtime_suspend(struct device *dev)
664 {
665 	struct spi_master *master = dev_get_drvdata(dev);
666 	struct img_spfi *spfi = spi_master_get_devdata(master);
667 
668 	clk_disable_unprepare(spfi->spfi_clk);
669 	clk_disable_unprepare(spfi->sys_clk);
670 
671 	return 0;
672 }
673 
674 static int img_spfi_runtime_resume(struct device *dev)
675 {
676 	struct spi_master *master = dev_get_drvdata(dev);
677 	struct img_spfi *spfi = spi_master_get_devdata(master);
678 	int ret;
679 
680 	ret = clk_prepare_enable(spfi->sys_clk);
681 	if (ret)
682 		return ret;
683 	ret = clk_prepare_enable(spfi->spfi_clk);
684 	if (ret) {
685 		clk_disable_unprepare(spfi->sys_clk);
686 		return ret;
687 	}
688 
689 	return 0;
690 }
691 #endif /* CONFIG_PM */
692 
693 #ifdef CONFIG_PM_SLEEP
694 static int img_spfi_suspend(struct device *dev)
695 {
696 	struct spi_master *master = dev_get_drvdata(dev);
697 
698 	return spi_master_suspend(master);
699 }
700 
701 static int img_spfi_resume(struct device *dev)
702 {
703 	struct spi_master *master = dev_get_drvdata(dev);
704 	struct img_spfi *spfi = spi_master_get_devdata(master);
705 	int ret;
706 
707 	ret = pm_runtime_get_sync(dev);
708 	if (ret)
709 		return ret;
710 	spfi_reset(spfi);
711 	pm_runtime_put(dev);
712 
713 	return spi_master_resume(master);
714 }
715 #endif /* CONFIG_PM_SLEEP */
716 
717 static const struct dev_pm_ops img_spfi_pm_ops = {
718 	SET_RUNTIME_PM_OPS(img_spfi_runtime_suspend, img_spfi_runtime_resume,
719 			   NULL)
720 	SET_SYSTEM_SLEEP_PM_OPS(img_spfi_suspend, img_spfi_resume)
721 };
722 
723 static const struct of_device_id img_spfi_of_match[] = {
724 	{ .compatible = "img,spfi", },
725 	{ },
726 };
727 MODULE_DEVICE_TABLE(of, img_spfi_of_match);
728 
729 static struct platform_driver img_spfi_driver = {
730 	.driver = {
731 		.name = "img-spfi",
732 		.pm = &img_spfi_pm_ops,
733 		.of_match_table = of_match_ptr(img_spfi_of_match),
734 	},
735 	.probe = img_spfi_probe,
736 	.remove = img_spfi_remove,
737 };
738 module_platform_driver(img_spfi_driver);
739 
740 MODULE_DESCRIPTION("IMG SPFI controller driver");
741 MODULE_AUTHOR("Andrew Bresticker <abrestic@chromium.org>");
742 MODULE_LICENSE("GPL v2");
743