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/gpio.h>
16#include <linux/interrupt.h>
17#include <linux/io.h>
18#include <linux/irq.h>
19#include <linux/module.h>
20#include <linux/of.h>
21#include <linux/platform_device.h>
22#include <linux/pm_runtime.h>
23#include <linux/scatterlist.h>
24#include <linux/slab.h>
25#include <linux/spi/spi.h>
26#include <linux/spinlock.h>
27
28#define SPFI_DEVICE_PARAMETER(x)		(0x00 + 0x4 * (x))
29#define SPFI_DEVICE_PARAMETER_BITCLK_SHIFT	24
30#define SPFI_DEVICE_PARAMETER_BITCLK_MASK	0xff
31#define SPFI_DEVICE_PARAMETER_CSSETUP_SHIFT	16
32#define SPFI_DEVICE_PARAMETER_CSSETUP_MASK	0xff
33#define SPFI_DEVICE_PARAMETER_CSHOLD_SHIFT	8
34#define SPFI_DEVICE_PARAMETER_CSHOLD_MASK	0xff
35#define SPFI_DEVICE_PARAMETER_CSDELAY_SHIFT	0
36#define SPFI_DEVICE_PARAMETER_CSDELAY_MASK	0xff
37
38#define SPFI_CONTROL				0x14
39#define SPFI_CONTROL_CONTINUE			BIT(12)
40#define SPFI_CONTROL_SOFT_RESET			BIT(11)
41#define SPFI_CONTROL_SEND_DMA			BIT(10)
42#define SPFI_CONTROL_GET_DMA			BIT(9)
43#define SPFI_CONTROL_SE			BIT(8)
44#define SPFI_CONTROL_TMODE_SHIFT		5
45#define SPFI_CONTROL_TMODE_MASK			0x7
46#define SPFI_CONTROL_TMODE_SINGLE		0
47#define SPFI_CONTROL_TMODE_DUAL			1
48#define SPFI_CONTROL_TMODE_QUAD			2
49#define SPFI_CONTROL_SPFI_EN			BIT(0)
50
51#define SPFI_TRANSACTION			0x18
52#define SPFI_TRANSACTION_TSIZE_SHIFT		16
53#define SPFI_TRANSACTION_TSIZE_MASK		0xffff
54
55#define SPFI_PORT_STATE				0x1c
56#define SPFI_PORT_STATE_DEV_SEL_SHIFT		20
57#define SPFI_PORT_STATE_DEV_SEL_MASK		0x7
58#define SPFI_PORT_STATE_CK_POL(x)		BIT(19 - (x))
59#define SPFI_PORT_STATE_CK_PHASE(x)		BIT(14 - (x))
60
61#define SPFI_TX_32BIT_VALID_DATA		0x20
62#define SPFI_TX_8BIT_VALID_DATA			0x24
63#define SPFI_RX_32BIT_VALID_DATA		0x28
64#define SPFI_RX_8BIT_VALID_DATA			0x2c
65
66#define SPFI_INTERRUPT_STATUS			0x30
67#define SPFI_INTERRUPT_ENABLE			0x34
68#define SPFI_INTERRUPT_CLEAR			0x38
69#define SPFI_INTERRUPT_IACCESS			BIT(12)
70#define SPFI_INTERRUPT_GDEX8BIT			BIT(11)
71#define SPFI_INTERRUPT_ALLDONETRIG		BIT(9)
72#define SPFI_INTERRUPT_GDFUL			BIT(8)
73#define SPFI_INTERRUPT_GDHF			BIT(7)
74#define SPFI_INTERRUPT_GDEX32BIT		BIT(6)
75#define SPFI_INTERRUPT_GDTRIG			BIT(5)
76#define SPFI_INTERRUPT_SDFUL			BIT(3)
77#define SPFI_INTERRUPT_SDHF			BIT(2)
78#define SPFI_INTERRUPT_SDE			BIT(1)
79#define SPFI_INTERRUPT_SDTRIG			BIT(0)
80
81/*
82 * There are four parallel FIFOs of 16 bytes each.  The word buffer
83 * (*_32BIT_VALID_DATA) accesses all four FIFOs at once, resulting in an
84 * effective FIFO size of 64 bytes.  The byte buffer (*_8BIT_VALID_DATA)
85 * accesses only a single FIFO, resulting in an effective FIFO size of
86 * 16 bytes.
87 */
88#define SPFI_32BIT_FIFO_SIZE			64
89#define SPFI_8BIT_FIFO_SIZE			16
90
91struct img_spfi {
92	struct device *dev;
93	struct spi_master *master;
94	spinlock_t lock;
95
96	void __iomem *regs;
97	phys_addr_t phys;
98	int irq;
99	struct clk *spfi_clk;
100	struct clk *sys_clk;
101
102	struct dma_chan *rx_ch;
103	struct dma_chan *tx_ch;
104	bool tx_dma_busy;
105	bool rx_dma_busy;
106};
107
108struct img_spfi_device_data {
109	bool gpio_requested;
110};
111
112static inline u32 spfi_readl(struct img_spfi *spfi, u32 reg)
113{
114	return readl(spfi->regs + reg);
115}
116
117static inline void spfi_writel(struct img_spfi *spfi, u32 val, u32 reg)
118{
119	writel(val, spfi->regs + reg);
120}
121
122static inline void spfi_start(struct img_spfi *spfi)
123{
124	u32 val;
125
126	val = spfi_readl(spfi, SPFI_CONTROL);
127	val |= SPFI_CONTROL_SPFI_EN;
128	spfi_writel(spfi, val, SPFI_CONTROL);
129}
130
131static inline void spfi_reset(struct img_spfi *spfi)
132{
133	spfi_writel(spfi, SPFI_CONTROL_SOFT_RESET, SPFI_CONTROL);
134	spfi_writel(spfi, 0, SPFI_CONTROL);
135}
136
137static int spfi_wait_all_done(struct img_spfi *spfi)
138{
139	unsigned long timeout = jiffies + msecs_to_jiffies(50);
140
141	while (time_before(jiffies, timeout)) {
142		u32 status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
143
144		if (status & SPFI_INTERRUPT_ALLDONETRIG) {
145			spfi_writel(spfi, SPFI_INTERRUPT_ALLDONETRIG,
146				    SPFI_INTERRUPT_CLEAR);
147			return 0;
148		}
149		cpu_relax();
150	}
151
152	dev_err(spfi->dev, "Timed out waiting for transaction to complete\n");
153	spfi_reset(spfi);
154
155	return -ETIMEDOUT;
156}
157
158static unsigned int spfi_pio_write32(struct img_spfi *spfi, const u32 *buf,
159				     unsigned int max)
160{
161	unsigned int count = 0;
162	u32 status;
163
164	while (count < max / 4) {
165		spfi_writel(spfi, SPFI_INTERRUPT_SDFUL, SPFI_INTERRUPT_CLEAR);
166		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
167		if (status & SPFI_INTERRUPT_SDFUL)
168			break;
169		spfi_writel(spfi, buf[count], SPFI_TX_32BIT_VALID_DATA);
170		count++;
171	}
172
173	return count * 4;
174}
175
176static unsigned int spfi_pio_write8(struct img_spfi *spfi, const u8 *buf,
177				    unsigned int max)
178{
179	unsigned int count = 0;
180	u32 status;
181
182	while (count < max) {
183		spfi_writel(spfi, SPFI_INTERRUPT_SDFUL, SPFI_INTERRUPT_CLEAR);
184		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
185		if (status & SPFI_INTERRUPT_SDFUL)
186			break;
187		spfi_writel(spfi, buf[count], SPFI_TX_8BIT_VALID_DATA);
188		count++;
189	}
190
191	return count;
192}
193
194static unsigned int spfi_pio_read32(struct img_spfi *spfi, u32 *buf,
195				    unsigned int max)
196{
197	unsigned int count = 0;
198	u32 status;
199
200	while (count < max / 4) {
201		spfi_writel(spfi, SPFI_INTERRUPT_GDEX32BIT,
202			    SPFI_INTERRUPT_CLEAR);
203		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
204		if (!(status & SPFI_INTERRUPT_GDEX32BIT))
205			break;
206		buf[count] = spfi_readl(spfi, SPFI_RX_32BIT_VALID_DATA);
207		count++;
208	}
209
210	return count * 4;
211}
212
213static unsigned int spfi_pio_read8(struct img_spfi *spfi, u8 *buf,
214				   unsigned int max)
215{
216	unsigned int count = 0;
217	u32 status;
218
219	while (count < max) {
220		spfi_writel(spfi, SPFI_INTERRUPT_GDEX8BIT,
221			    SPFI_INTERRUPT_CLEAR);
222		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
223		if (!(status & SPFI_INTERRUPT_GDEX8BIT))
224			break;
225		buf[count] = spfi_readl(spfi, SPFI_RX_8BIT_VALID_DATA);
226		count++;
227	}
228
229	return count;
230}
231
232static int img_spfi_start_pio(struct spi_master *master,
233			       struct spi_device *spi,
234			       struct spi_transfer *xfer)
235{
236	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
237	unsigned int tx_bytes = 0, rx_bytes = 0;
238	const void *tx_buf = xfer->tx_buf;
239	void *rx_buf = xfer->rx_buf;
240	unsigned long timeout;
241	int ret;
242
243	if (tx_buf)
244		tx_bytes = xfer->len;
245	if (rx_buf)
246		rx_bytes = xfer->len;
247
248	spfi_start(spfi);
249
250	timeout = jiffies +
251		msecs_to_jiffies(xfer->len * 8 * 1000 / xfer->speed_hz + 100);
252	while ((tx_bytes > 0 || rx_bytes > 0) &&
253	       time_before(jiffies, timeout)) {
254		unsigned int tx_count, rx_count;
255
256		if (tx_bytes >= 4)
257			tx_count = spfi_pio_write32(spfi, tx_buf, tx_bytes);
258		else
259			tx_count = spfi_pio_write8(spfi, tx_buf, tx_bytes);
260
261		if (rx_bytes >= 4)
262			rx_count = spfi_pio_read32(spfi, rx_buf, rx_bytes);
263		else
264			rx_count = spfi_pio_read8(spfi, rx_buf, rx_bytes);
265
266		tx_buf += tx_count;
267		rx_buf += rx_count;
268		tx_bytes -= tx_count;
269		rx_bytes -= rx_count;
270
271		cpu_relax();
272	}
273
274	if (rx_bytes > 0 || tx_bytes > 0) {
275		dev_err(spfi->dev, "PIO transfer timed out\n");
276		return -ETIMEDOUT;
277	}
278
279	ret = spfi_wait_all_done(spfi);
280	if (ret < 0)
281		return ret;
282
283	return 0;
284}
285
286static void img_spfi_dma_rx_cb(void *data)
287{
288	struct img_spfi *spfi = data;
289	unsigned long flags;
290
291	spfi_wait_all_done(spfi);
292
293	spin_lock_irqsave(&spfi->lock, flags);
294	spfi->rx_dma_busy = false;
295	if (!spfi->tx_dma_busy)
296		spi_finalize_current_transfer(spfi->master);
297	spin_unlock_irqrestore(&spfi->lock, flags);
298}
299
300static void img_spfi_dma_tx_cb(void *data)
301{
302	struct img_spfi *spfi = data;
303	unsigned long flags;
304
305	spfi_wait_all_done(spfi);
306
307	spin_lock_irqsave(&spfi->lock, flags);
308	spfi->tx_dma_busy = false;
309	if (!spfi->rx_dma_busy)
310		spi_finalize_current_transfer(spfi->master);
311	spin_unlock_irqrestore(&spfi->lock, flags);
312}
313
314static int img_spfi_start_dma(struct spi_master *master,
315			      struct spi_device *spi,
316			      struct spi_transfer *xfer)
317{
318	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
319	struct dma_async_tx_descriptor *rxdesc = NULL, *txdesc = NULL;
320	struct dma_slave_config rxconf, txconf;
321
322	spfi->rx_dma_busy = false;
323	spfi->tx_dma_busy = false;
324
325	if (xfer->rx_buf) {
326		rxconf.direction = DMA_DEV_TO_MEM;
327		if (xfer->len % 4 == 0) {
328			rxconf.src_addr = spfi->phys + SPFI_RX_32BIT_VALID_DATA;
329			rxconf.src_addr_width = 4;
330			rxconf.src_maxburst = 4;
331		} else {
332			rxconf.src_addr = spfi->phys + SPFI_RX_8BIT_VALID_DATA;
333			rxconf.src_addr_width = 1;
334			rxconf.src_maxburst = 4;
335		}
336		dmaengine_slave_config(spfi->rx_ch, &rxconf);
337
338		rxdesc = dmaengine_prep_slave_sg(spfi->rx_ch, xfer->rx_sg.sgl,
339						 xfer->rx_sg.nents,
340						 DMA_DEV_TO_MEM,
341						 DMA_PREP_INTERRUPT);
342		if (!rxdesc)
343			goto stop_dma;
344
345		rxdesc->callback = img_spfi_dma_rx_cb;
346		rxdesc->callback_param = spfi;
347	}
348
349	if (xfer->tx_buf) {
350		txconf.direction = DMA_MEM_TO_DEV;
351		if (xfer->len % 4 == 0) {
352			txconf.dst_addr = spfi->phys + SPFI_TX_32BIT_VALID_DATA;
353			txconf.dst_addr_width = 4;
354			txconf.dst_maxburst = 4;
355		} else {
356			txconf.dst_addr = spfi->phys + SPFI_TX_8BIT_VALID_DATA;
357			txconf.dst_addr_width = 1;
358			txconf.dst_maxburst = 4;
359		}
360		dmaengine_slave_config(spfi->tx_ch, &txconf);
361
362		txdesc = dmaengine_prep_slave_sg(spfi->tx_ch, xfer->tx_sg.sgl,
363						 xfer->tx_sg.nents,
364						 DMA_MEM_TO_DEV,
365						 DMA_PREP_INTERRUPT);
366		if (!txdesc)
367			goto stop_dma;
368
369		txdesc->callback = img_spfi_dma_tx_cb;
370		txdesc->callback_param = spfi;
371	}
372
373	if (xfer->rx_buf) {
374		spfi->rx_dma_busy = true;
375		dmaengine_submit(rxdesc);
376		dma_async_issue_pending(spfi->rx_ch);
377	}
378
379	spfi_start(spfi);
380
381	if (xfer->tx_buf) {
382		spfi->tx_dma_busy = true;
383		dmaengine_submit(txdesc);
384		dma_async_issue_pending(spfi->tx_ch);
385	}
386
387	return 1;
388
389stop_dma:
390	dmaengine_terminate_all(spfi->rx_ch);
391	dmaengine_terminate_all(spfi->tx_ch);
392	return -EIO;
393}
394
395static void img_spfi_handle_err(struct spi_master *master,
396				struct spi_message *msg)
397{
398	struct img_spfi *spfi = spi_master_get_devdata(master);
399	unsigned long flags;
400
401	/*
402	 * Stop all DMA and reset the controller if the previous transaction
403	 * timed-out and never completed it's DMA.
404	 */
405	spin_lock_irqsave(&spfi->lock, flags);
406	if (spfi->tx_dma_busy || spfi->rx_dma_busy) {
407		spfi->tx_dma_busy = false;
408		spfi->rx_dma_busy = false;
409
410		dmaengine_terminate_all(spfi->tx_ch);
411		dmaengine_terminate_all(spfi->rx_ch);
412	}
413	spin_unlock_irqrestore(&spfi->lock, flags);
414}
415
416static int img_spfi_prepare(struct spi_master *master, struct spi_message *msg)
417{
418	struct img_spfi *spfi = spi_master_get_devdata(master);
419	u32 val;
420
421	val = spfi_readl(spfi, SPFI_PORT_STATE);
422	if (msg->spi->mode & SPI_CPHA)
423		val |= SPFI_PORT_STATE_CK_PHASE(msg->spi->chip_select);
424	else
425		val &= ~SPFI_PORT_STATE_CK_PHASE(msg->spi->chip_select);
426	if (msg->spi->mode & SPI_CPOL)
427		val |= SPFI_PORT_STATE_CK_POL(msg->spi->chip_select);
428	else
429		val &= ~SPFI_PORT_STATE_CK_POL(msg->spi->chip_select);
430	spfi_writel(spfi, val, SPFI_PORT_STATE);
431
432	return 0;
433}
434
435static int img_spfi_unprepare(struct spi_master *master,
436			      struct spi_message *msg)
437{
438	struct img_spfi *spfi = spi_master_get_devdata(master);
439
440	spfi_reset(spfi);
441
442	return 0;
443}
444
445static int img_spfi_setup(struct spi_device *spi)
446{
447	int ret = -EINVAL;
448	struct img_spfi_device_data *spfi_data = spi_get_ctldata(spi);
449
450	if (!spfi_data) {
451		spfi_data = kzalloc(sizeof(*spfi_data), GFP_KERNEL);
452		if (!spfi_data)
453			return -ENOMEM;
454		spfi_data->gpio_requested = false;
455		spi_set_ctldata(spi, spfi_data);
456	}
457	if (!spfi_data->gpio_requested) {
458		ret = gpio_request_one(spi->cs_gpio,
459				       (spi->mode & SPI_CS_HIGH) ?
460				       GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH,
461				       dev_name(&spi->dev));
462		if (ret)
463			dev_err(&spi->dev, "can't request chipselect gpio %d\n",
464				spi->cs_gpio);
465		else
466			spfi_data->gpio_requested = true;
467	} else {
468		if (gpio_is_valid(spi->cs_gpio)) {
469			int mode = ((spi->mode & SPI_CS_HIGH) ?
470				    GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH);
471
472			ret = gpio_direction_output(spi->cs_gpio, mode);
473			if (ret)
474				dev_err(&spi->dev, "chipselect gpio %d setup failed (%d)\n",
475					spi->cs_gpio, ret);
476		}
477	}
478	return ret;
479}
480
481static void img_spfi_cleanup(struct spi_device *spi)
482{
483	struct img_spfi_device_data *spfi_data = spi_get_ctldata(spi);
484
485	if (spfi_data) {
486		if (spfi_data->gpio_requested)
487			gpio_free(spi->cs_gpio);
488		kfree(spfi_data);
489		spi_set_ctldata(spi, NULL);
490	}
491}
492
493static void img_spfi_config(struct spi_master *master, struct spi_device *spi,
494			    struct spi_transfer *xfer)
495{
496	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
497	u32 val, div;
498
499	/*
500	 * output = spfi_clk * (BITCLK / 512), where BITCLK must be a
501	 * power of 2 up to 128
502	 */
503	div = DIV_ROUND_UP(clk_get_rate(spfi->spfi_clk), xfer->speed_hz);
504	div = clamp(512 / (1 << get_count_order(div)), 1, 128);
505
506	val = spfi_readl(spfi, SPFI_DEVICE_PARAMETER(spi->chip_select));
507	val &= ~(SPFI_DEVICE_PARAMETER_BITCLK_MASK <<
508		 SPFI_DEVICE_PARAMETER_BITCLK_SHIFT);
509	val |= div << SPFI_DEVICE_PARAMETER_BITCLK_SHIFT;
510	spfi_writel(spfi, val, SPFI_DEVICE_PARAMETER(spi->chip_select));
511
512	spfi_writel(spfi, xfer->len << SPFI_TRANSACTION_TSIZE_SHIFT,
513		    SPFI_TRANSACTION);
514
515	val = spfi_readl(spfi, SPFI_CONTROL);
516	val &= ~(SPFI_CONTROL_SEND_DMA | SPFI_CONTROL_GET_DMA);
517	if (xfer->tx_buf)
518		val |= SPFI_CONTROL_SEND_DMA;
519	if (xfer->rx_buf)
520		val |= SPFI_CONTROL_GET_DMA;
521	val &= ~(SPFI_CONTROL_TMODE_MASK << SPFI_CONTROL_TMODE_SHIFT);
522	if (xfer->tx_nbits == SPI_NBITS_DUAL &&
523	    xfer->rx_nbits == SPI_NBITS_DUAL)
524		val |= SPFI_CONTROL_TMODE_DUAL << SPFI_CONTROL_TMODE_SHIFT;
525	else if (xfer->tx_nbits == SPI_NBITS_QUAD &&
526		 xfer->rx_nbits == SPI_NBITS_QUAD)
527		val |= SPFI_CONTROL_TMODE_QUAD << SPFI_CONTROL_TMODE_SHIFT;
528	val |= SPFI_CONTROL_SE;
529	spfi_writel(spfi, val, SPFI_CONTROL);
530}
531
532static int img_spfi_transfer_one(struct spi_master *master,
533				 struct spi_device *spi,
534				 struct spi_transfer *xfer)
535{
536	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
537	int ret;
538
539	if (xfer->len > SPFI_TRANSACTION_TSIZE_MASK) {
540		dev_err(spfi->dev,
541			"Transfer length (%d) is greater than the max supported (%d)",
542			xfer->len, SPFI_TRANSACTION_TSIZE_MASK);
543		return -EINVAL;
544	}
545
546	img_spfi_config(master, spi, xfer);
547	if (master->can_dma && master->can_dma(master, spi, xfer))
548		ret = img_spfi_start_dma(master, spi, xfer);
549	else
550		ret = img_spfi_start_pio(master, spi, xfer);
551
552	return ret;
553}
554
555static bool img_spfi_can_dma(struct spi_master *master, struct spi_device *spi,
556			     struct spi_transfer *xfer)
557{
558	if (xfer->len > SPFI_32BIT_FIFO_SIZE)
559		return true;
560	return false;
561}
562
563static irqreturn_t img_spfi_irq(int irq, void *dev_id)
564{
565	struct img_spfi *spfi = (struct img_spfi *)dev_id;
566	u32 status;
567
568	status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
569	if (status & SPFI_INTERRUPT_IACCESS) {
570		spfi_writel(spfi, SPFI_INTERRUPT_IACCESS, SPFI_INTERRUPT_CLEAR);
571		dev_err(spfi->dev, "Illegal access interrupt");
572		return IRQ_HANDLED;
573	}
574
575	return IRQ_NONE;
576}
577
578static int img_spfi_probe(struct platform_device *pdev)
579{
580	struct spi_master *master;
581	struct img_spfi *spfi;
582	struct resource *res;
583	int ret;
584
585	master = spi_alloc_master(&pdev->dev, sizeof(*spfi));
586	if (!master)
587		return -ENOMEM;
588	platform_set_drvdata(pdev, master);
589
590	spfi = spi_master_get_devdata(master);
591	spfi->dev = &pdev->dev;
592	spfi->master = master;
593	spin_lock_init(&spfi->lock);
594
595	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
596	spfi->regs = devm_ioremap_resource(spfi->dev, res);
597	if (IS_ERR(spfi->regs)) {
598		ret = PTR_ERR(spfi->regs);
599		goto put_spi;
600	}
601	spfi->phys = res->start;
602
603	spfi->irq = platform_get_irq(pdev, 0);
604	if (spfi->irq < 0) {
605		ret = spfi->irq;
606		goto put_spi;
607	}
608	ret = devm_request_irq(spfi->dev, spfi->irq, img_spfi_irq,
609			       IRQ_TYPE_LEVEL_HIGH, dev_name(spfi->dev), spfi);
610	if (ret)
611		goto put_spi;
612
613	spfi->sys_clk = devm_clk_get(spfi->dev, "sys");
614	if (IS_ERR(spfi->sys_clk)) {
615		ret = PTR_ERR(spfi->sys_clk);
616		goto put_spi;
617	}
618	spfi->spfi_clk = devm_clk_get(spfi->dev, "spfi");
619	if (IS_ERR(spfi->spfi_clk)) {
620		ret = PTR_ERR(spfi->spfi_clk);
621		goto put_spi;
622	}
623
624	ret = clk_prepare_enable(spfi->sys_clk);
625	if (ret)
626		goto put_spi;
627	ret = clk_prepare_enable(spfi->spfi_clk);
628	if (ret)
629		goto disable_pclk;
630
631	spfi_reset(spfi);
632	/*
633	 * Only enable the error (IACCESS) interrupt.  In PIO mode we'll
634	 * poll the status of the FIFOs.
635	 */
636	spfi_writel(spfi, SPFI_INTERRUPT_IACCESS, SPFI_INTERRUPT_ENABLE);
637
638	master->auto_runtime_pm = true;
639	master->bus_num = pdev->id;
640	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_TX_DUAL | SPI_RX_DUAL;
641	if (of_property_read_bool(spfi->dev->of_node, "img,supports-quad-mode"))
642		master->mode_bits |= SPI_TX_QUAD | SPI_RX_QUAD;
643	master->dev.of_node = pdev->dev.of_node;
644	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(8);
645	master->max_speed_hz = clk_get_rate(spfi->spfi_clk) / 4;
646	master->min_speed_hz = clk_get_rate(spfi->spfi_clk) / 512;
647
648	master->setup = img_spfi_setup;
649	master->cleanup = img_spfi_cleanup;
650	master->transfer_one = img_spfi_transfer_one;
651	master->prepare_message = img_spfi_prepare;
652	master->unprepare_message = img_spfi_unprepare;
653	master->handle_err = img_spfi_handle_err;
654
655	spfi->tx_ch = dma_request_slave_channel(spfi->dev, "tx");
656	spfi->rx_ch = dma_request_slave_channel(spfi->dev, "rx");
657	if (!spfi->tx_ch || !spfi->rx_ch) {
658		if (spfi->tx_ch)
659			dma_release_channel(spfi->tx_ch);
660		if (spfi->rx_ch)
661			dma_release_channel(spfi->rx_ch);
662		dev_warn(spfi->dev, "Failed to get DMA channels, falling back to PIO mode\n");
663	} else {
664		master->dma_tx = spfi->tx_ch;
665		master->dma_rx = spfi->rx_ch;
666		master->can_dma = img_spfi_can_dma;
667	}
668
669	pm_runtime_set_active(spfi->dev);
670	pm_runtime_enable(spfi->dev);
671
672	ret = devm_spi_register_master(spfi->dev, master);
673	if (ret)
674		goto disable_pm;
675
676	return 0;
677
678disable_pm:
679	pm_runtime_disable(spfi->dev);
680	if (spfi->rx_ch)
681		dma_release_channel(spfi->rx_ch);
682	if (spfi->tx_ch)
683		dma_release_channel(spfi->tx_ch);
684	clk_disable_unprepare(spfi->spfi_clk);
685disable_pclk:
686	clk_disable_unprepare(spfi->sys_clk);
687put_spi:
688	spi_master_put(master);
689
690	return ret;
691}
692
693static int img_spfi_remove(struct platform_device *pdev)
694{
695	struct spi_master *master = platform_get_drvdata(pdev);
696	struct img_spfi *spfi = spi_master_get_devdata(master);
697
698	if (spfi->tx_ch)
699		dma_release_channel(spfi->tx_ch);
700	if (spfi->rx_ch)
701		dma_release_channel(spfi->rx_ch);
702
703	pm_runtime_disable(spfi->dev);
704	if (!pm_runtime_status_suspended(spfi->dev)) {
705		clk_disable_unprepare(spfi->spfi_clk);
706		clk_disable_unprepare(spfi->sys_clk);
707	}
708
709	spi_master_put(master);
710
711	return 0;
712}
713
714#ifdef CONFIG_PM
715static int img_spfi_runtime_suspend(struct device *dev)
716{
717	struct spi_master *master = dev_get_drvdata(dev);
718	struct img_spfi *spfi = spi_master_get_devdata(master);
719
720	clk_disable_unprepare(spfi->spfi_clk);
721	clk_disable_unprepare(spfi->sys_clk);
722
723	return 0;
724}
725
726static int img_spfi_runtime_resume(struct device *dev)
727{
728	struct spi_master *master = dev_get_drvdata(dev);
729	struct img_spfi *spfi = spi_master_get_devdata(master);
730	int ret;
731
732	ret = clk_prepare_enable(spfi->sys_clk);
733	if (ret)
734		return ret;
735	ret = clk_prepare_enable(spfi->spfi_clk);
736	if (ret) {
737		clk_disable_unprepare(spfi->sys_clk);
738		return ret;
739	}
740
741	return 0;
742}
743#endif /* CONFIG_PM */
744
745#ifdef CONFIG_PM_SLEEP
746static int img_spfi_suspend(struct device *dev)
747{
748	struct spi_master *master = dev_get_drvdata(dev);
749
750	return spi_master_suspend(master);
751}
752
753static int img_spfi_resume(struct device *dev)
754{
755	struct spi_master *master = dev_get_drvdata(dev);
756	struct img_spfi *spfi = spi_master_get_devdata(master);
757	int ret;
758
759	ret = pm_runtime_get_sync(dev);
760	if (ret)
761		return ret;
762	spfi_reset(spfi);
763	pm_runtime_put(dev);
764
765	return spi_master_resume(master);
766}
767#endif /* CONFIG_PM_SLEEP */
768
769static const struct dev_pm_ops img_spfi_pm_ops = {
770	SET_RUNTIME_PM_OPS(img_spfi_runtime_suspend, img_spfi_runtime_resume,
771			   NULL)
772	SET_SYSTEM_SLEEP_PM_OPS(img_spfi_suspend, img_spfi_resume)
773};
774
775static const struct of_device_id img_spfi_of_match[] = {
776	{ .compatible = "img,spfi", },
777	{ },
778};
779MODULE_DEVICE_TABLE(of, img_spfi_of_match);
780
781static struct platform_driver img_spfi_driver = {
782	.driver = {
783		.name = "img-spfi",
784		.pm = &img_spfi_pm_ops,
785		.of_match_table = of_match_ptr(img_spfi_of_match),
786	},
787	.probe = img_spfi_probe,
788	.remove = img_spfi_remove,
789};
790module_platform_driver(img_spfi_driver);
791
792MODULE_DESCRIPTION("IMG SPFI controller driver");
793MODULE_AUTHOR("Andrew Bresticker <abrestic@chromium.org>");
794MODULE_LICENSE("GPL v2");
795