xref: /openbmc/linux/drivers/spi/spi-img-spfi.c (revision 547840bd)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * IMG SPFI controller driver
4  *
5  * Copyright (C) 2007,2008,2013 Imagination Technologies Ltd.
6  * Copyright (C) 2014 Google, Inc.
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/delay.h>
11 #include <linux/dmaengine.h>
12 #include <linux/gpio.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/irq.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/platform_device.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/scatterlist.h>
21 #include <linux/slab.h>
22 #include <linux/spi/spi.h>
23 #include <linux/spinlock.h>
24 
25 #define SPFI_DEVICE_PARAMETER(x)		(0x00 + 0x4 * (x))
26 #define SPFI_DEVICE_PARAMETER_BITCLK_SHIFT	24
27 #define SPFI_DEVICE_PARAMETER_BITCLK_MASK	0xff
28 #define SPFI_DEVICE_PARAMETER_CSSETUP_SHIFT	16
29 #define SPFI_DEVICE_PARAMETER_CSSETUP_MASK	0xff
30 #define SPFI_DEVICE_PARAMETER_CSHOLD_SHIFT	8
31 #define SPFI_DEVICE_PARAMETER_CSHOLD_MASK	0xff
32 #define SPFI_DEVICE_PARAMETER_CSDELAY_SHIFT	0
33 #define SPFI_DEVICE_PARAMETER_CSDELAY_MASK	0xff
34 
35 #define SPFI_CONTROL				0x14
36 #define SPFI_CONTROL_CONTINUE			BIT(12)
37 #define SPFI_CONTROL_SOFT_RESET			BIT(11)
38 #define SPFI_CONTROL_SEND_DMA			BIT(10)
39 #define SPFI_CONTROL_GET_DMA			BIT(9)
40 #define SPFI_CONTROL_SE			BIT(8)
41 #define SPFI_CONTROL_TMODE_SHIFT		5
42 #define SPFI_CONTROL_TMODE_MASK			0x7
43 #define SPFI_CONTROL_TMODE_SINGLE		0
44 #define SPFI_CONTROL_TMODE_DUAL			1
45 #define SPFI_CONTROL_TMODE_QUAD			2
46 #define SPFI_CONTROL_SPFI_EN			BIT(0)
47 
48 #define SPFI_TRANSACTION			0x18
49 #define SPFI_TRANSACTION_TSIZE_SHIFT		16
50 #define SPFI_TRANSACTION_TSIZE_MASK		0xffff
51 
52 #define SPFI_PORT_STATE				0x1c
53 #define SPFI_PORT_STATE_DEV_SEL_SHIFT		20
54 #define SPFI_PORT_STATE_DEV_SEL_MASK		0x7
55 #define SPFI_PORT_STATE_CK_POL(x)		BIT(19 - (x))
56 #define SPFI_PORT_STATE_CK_PHASE(x)		BIT(14 - (x))
57 
58 #define SPFI_TX_32BIT_VALID_DATA		0x20
59 #define SPFI_TX_8BIT_VALID_DATA			0x24
60 #define SPFI_RX_32BIT_VALID_DATA		0x28
61 #define SPFI_RX_8BIT_VALID_DATA			0x2c
62 
63 #define SPFI_INTERRUPT_STATUS			0x30
64 #define SPFI_INTERRUPT_ENABLE			0x34
65 #define SPFI_INTERRUPT_CLEAR			0x38
66 #define SPFI_INTERRUPT_IACCESS			BIT(12)
67 #define SPFI_INTERRUPT_GDEX8BIT			BIT(11)
68 #define SPFI_INTERRUPT_ALLDONETRIG		BIT(9)
69 #define SPFI_INTERRUPT_GDFUL			BIT(8)
70 #define SPFI_INTERRUPT_GDHF			BIT(7)
71 #define SPFI_INTERRUPT_GDEX32BIT		BIT(6)
72 #define SPFI_INTERRUPT_GDTRIG			BIT(5)
73 #define SPFI_INTERRUPT_SDFUL			BIT(3)
74 #define SPFI_INTERRUPT_SDHF			BIT(2)
75 #define SPFI_INTERRUPT_SDE			BIT(1)
76 #define SPFI_INTERRUPT_SDTRIG			BIT(0)
77 
78 /*
79  * There are four parallel FIFOs of 16 bytes each.  The word buffer
80  * (*_32BIT_VALID_DATA) accesses all four FIFOs at once, resulting in an
81  * effective FIFO size of 64 bytes.  The byte buffer (*_8BIT_VALID_DATA)
82  * accesses only a single FIFO, resulting in an effective FIFO size of
83  * 16 bytes.
84  */
85 #define SPFI_32BIT_FIFO_SIZE			64
86 #define SPFI_8BIT_FIFO_SIZE			16
87 
88 struct img_spfi {
89 	struct device *dev;
90 	struct spi_master *master;
91 	spinlock_t lock;
92 
93 	void __iomem *regs;
94 	phys_addr_t phys;
95 	int irq;
96 	struct clk *spfi_clk;
97 	struct clk *sys_clk;
98 
99 	struct dma_chan *rx_ch;
100 	struct dma_chan *tx_ch;
101 	bool tx_dma_busy;
102 	bool rx_dma_busy;
103 };
104 
105 struct img_spfi_device_data {
106 	bool gpio_requested;
107 };
108 
109 static inline u32 spfi_readl(struct img_spfi *spfi, u32 reg)
110 {
111 	return readl(spfi->regs + reg);
112 }
113 
114 static inline void spfi_writel(struct img_spfi *spfi, u32 val, u32 reg)
115 {
116 	writel(val, spfi->regs + reg);
117 }
118 
119 static inline void spfi_start(struct img_spfi *spfi)
120 {
121 	u32 val;
122 
123 	val = spfi_readl(spfi, SPFI_CONTROL);
124 	val |= SPFI_CONTROL_SPFI_EN;
125 	spfi_writel(spfi, val, SPFI_CONTROL);
126 }
127 
128 static inline void spfi_reset(struct img_spfi *spfi)
129 {
130 	spfi_writel(spfi, SPFI_CONTROL_SOFT_RESET, SPFI_CONTROL);
131 	spfi_writel(spfi, 0, SPFI_CONTROL);
132 }
133 
134 static int spfi_wait_all_done(struct img_spfi *spfi)
135 {
136 	unsigned long timeout = jiffies + msecs_to_jiffies(50);
137 
138 	while (time_before(jiffies, timeout)) {
139 		u32 status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
140 
141 		if (status & SPFI_INTERRUPT_ALLDONETRIG) {
142 			spfi_writel(spfi, SPFI_INTERRUPT_ALLDONETRIG,
143 				    SPFI_INTERRUPT_CLEAR);
144 			return 0;
145 		}
146 		cpu_relax();
147 	}
148 
149 	dev_err(spfi->dev, "Timed out waiting for transaction to complete\n");
150 	spfi_reset(spfi);
151 
152 	return -ETIMEDOUT;
153 }
154 
155 static unsigned int spfi_pio_write32(struct img_spfi *spfi, const u32 *buf,
156 				     unsigned int max)
157 {
158 	unsigned int count = 0;
159 	u32 status;
160 
161 	while (count < max / 4) {
162 		spfi_writel(spfi, SPFI_INTERRUPT_SDFUL, SPFI_INTERRUPT_CLEAR);
163 		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
164 		if (status & SPFI_INTERRUPT_SDFUL)
165 			break;
166 		spfi_writel(spfi, buf[count], SPFI_TX_32BIT_VALID_DATA);
167 		count++;
168 	}
169 
170 	return count * 4;
171 }
172 
173 static unsigned int spfi_pio_write8(struct img_spfi *spfi, const u8 *buf,
174 				    unsigned int max)
175 {
176 	unsigned int count = 0;
177 	u32 status;
178 
179 	while (count < max) {
180 		spfi_writel(spfi, SPFI_INTERRUPT_SDFUL, SPFI_INTERRUPT_CLEAR);
181 		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
182 		if (status & SPFI_INTERRUPT_SDFUL)
183 			break;
184 		spfi_writel(spfi, buf[count], SPFI_TX_8BIT_VALID_DATA);
185 		count++;
186 	}
187 
188 	return count;
189 }
190 
191 static unsigned int spfi_pio_read32(struct img_spfi *spfi, u32 *buf,
192 				    unsigned int max)
193 {
194 	unsigned int count = 0;
195 	u32 status;
196 
197 	while (count < max / 4) {
198 		spfi_writel(spfi, SPFI_INTERRUPT_GDEX32BIT,
199 			    SPFI_INTERRUPT_CLEAR);
200 		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
201 		if (!(status & SPFI_INTERRUPT_GDEX32BIT))
202 			break;
203 		buf[count] = spfi_readl(spfi, SPFI_RX_32BIT_VALID_DATA);
204 		count++;
205 	}
206 
207 	return count * 4;
208 }
209 
210 static unsigned int spfi_pio_read8(struct img_spfi *spfi, u8 *buf,
211 				   unsigned int max)
212 {
213 	unsigned int count = 0;
214 	u32 status;
215 
216 	while (count < max) {
217 		spfi_writel(spfi, SPFI_INTERRUPT_GDEX8BIT,
218 			    SPFI_INTERRUPT_CLEAR);
219 		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
220 		if (!(status & SPFI_INTERRUPT_GDEX8BIT))
221 			break;
222 		buf[count] = spfi_readl(spfi, SPFI_RX_8BIT_VALID_DATA);
223 		count++;
224 	}
225 
226 	return count;
227 }
228 
229 static int img_spfi_start_pio(struct spi_master *master,
230 			       struct spi_device *spi,
231 			       struct spi_transfer *xfer)
232 {
233 	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
234 	unsigned int tx_bytes = 0, rx_bytes = 0;
235 	const void *tx_buf = xfer->tx_buf;
236 	void *rx_buf = xfer->rx_buf;
237 	unsigned long timeout;
238 	int ret;
239 
240 	if (tx_buf)
241 		tx_bytes = xfer->len;
242 	if (rx_buf)
243 		rx_bytes = xfer->len;
244 
245 	spfi_start(spfi);
246 
247 	timeout = jiffies +
248 		msecs_to_jiffies(xfer->len * 8 * 1000 / xfer->speed_hz + 100);
249 	while ((tx_bytes > 0 || rx_bytes > 0) &&
250 	       time_before(jiffies, timeout)) {
251 		unsigned int tx_count, rx_count;
252 
253 		if (tx_bytes >= 4)
254 			tx_count = spfi_pio_write32(spfi, tx_buf, tx_bytes);
255 		else
256 			tx_count = spfi_pio_write8(spfi, tx_buf, tx_bytes);
257 
258 		if (rx_bytes >= 4)
259 			rx_count = spfi_pio_read32(spfi, rx_buf, rx_bytes);
260 		else
261 			rx_count = spfi_pio_read8(spfi, rx_buf, rx_bytes);
262 
263 		tx_buf += tx_count;
264 		rx_buf += rx_count;
265 		tx_bytes -= tx_count;
266 		rx_bytes -= rx_count;
267 
268 		cpu_relax();
269 	}
270 
271 	if (rx_bytes > 0 || tx_bytes > 0) {
272 		dev_err(spfi->dev, "PIO transfer timed out\n");
273 		return -ETIMEDOUT;
274 	}
275 
276 	ret = spfi_wait_all_done(spfi);
277 	if (ret < 0)
278 		return ret;
279 
280 	return 0;
281 }
282 
283 static void img_spfi_dma_rx_cb(void *data)
284 {
285 	struct img_spfi *spfi = data;
286 	unsigned long flags;
287 
288 	spfi_wait_all_done(spfi);
289 
290 	spin_lock_irqsave(&spfi->lock, flags);
291 	spfi->rx_dma_busy = false;
292 	if (!spfi->tx_dma_busy)
293 		spi_finalize_current_transfer(spfi->master);
294 	spin_unlock_irqrestore(&spfi->lock, flags);
295 }
296 
297 static void img_spfi_dma_tx_cb(void *data)
298 {
299 	struct img_spfi *spfi = data;
300 	unsigned long flags;
301 
302 	spfi_wait_all_done(spfi);
303 
304 	spin_lock_irqsave(&spfi->lock, flags);
305 	spfi->tx_dma_busy = false;
306 	if (!spfi->rx_dma_busy)
307 		spi_finalize_current_transfer(spfi->master);
308 	spin_unlock_irqrestore(&spfi->lock, flags);
309 }
310 
311 static int img_spfi_start_dma(struct spi_master *master,
312 			      struct spi_device *spi,
313 			      struct spi_transfer *xfer)
314 {
315 	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
316 	struct dma_async_tx_descriptor *rxdesc = NULL, *txdesc = NULL;
317 	struct dma_slave_config rxconf, txconf;
318 
319 	spfi->rx_dma_busy = false;
320 	spfi->tx_dma_busy = false;
321 
322 	if (xfer->rx_buf) {
323 		rxconf.direction = DMA_DEV_TO_MEM;
324 		if (xfer->len % 4 == 0) {
325 			rxconf.src_addr = spfi->phys + SPFI_RX_32BIT_VALID_DATA;
326 			rxconf.src_addr_width = 4;
327 			rxconf.src_maxburst = 4;
328 		} else {
329 			rxconf.src_addr = spfi->phys + SPFI_RX_8BIT_VALID_DATA;
330 			rxconf.src_addr_width = 1;
331 			rxconf.src_maxburst = 4;
332 		}
333 		dmaengine_slave_config(spfi->rx_ch, &rxconf);
334 
335 		rxdesc = dmaengine_prep_slave_sg(spfi->rx_ch, xfer->rx_sg.sgl,
336 						 xfer->rx_sg.nents,
337 						 DMA_DEV_TO_MEM,
338 						 DMA_PREP_INTERRUPT);
339 		if (!rxdesc)
340 			goto stop_dma;
341 
342 		rxdesc->callback = img_spfi_dma_rx_cb;
343 		rxdesc->callback_param = spfi;
344 	}
345 
346 	if (xfer->tx_buf) {
347 		txconf.direction = DMA_MEM_TO_DEV;
348 		if (xfer->len % 4 == 0) {
349 			txconf.dst_addr = spfi->phys + SPFI_TX_32BIT_VALID_DATA;
350 			txconf.dst_addr_width = 4;
351 			txconf.dst_maxburst = 4;
352 		} else {
353 			txconf.dst_addr = spfi->phys + SPFI_TX_8BIT_VALID_DATA;
354 			txconf.dst_addr_width = 1;
355 			txconf.dst_maxburst = 4;
356 		}
357 		dmaengine_slave_config(spfi->tx_ch, &txconf);
358 
359 		txdesc = dmaengine_prep_slave_sg(spfi->tx_ch, xfer->tx_sg.sgl,
360 						 xfer->tx_sg.nents,
361 						 DMA_MEM_TO_DEV,
362 						 DMA_PREP_INTERRUPT);
363 		if (!txdesc)
364 			goto stop_dma;
365 
366 		txdesc->callback = img_spfi_dma_tx_cb;
367 		txdesc->callback_param = spfi;
368 	}
369 
370 	if (xfer->rx_buf) {
371 		spfi->rx_dma_busy = true;
372 		dmaengine_submit(rxdesc);
373 		dma_async_issue_pending(spfi->rx_ch);
374 	}
375 
376 	spfi_start(spfi);
377 
378 	if (xfer->tx_buf) {
379 		spfi->tx_dma_busy = true;
380 		dmaengine_submit(txdesc);
381 		dma_async_issue_pending(spfi->tx_ch);
382 	}
383 
384 	return 1;
385 
386 stop_dma:
387 	dmaengine_terminate_all(spfi->rx_ch);
388 	dmaengine_terminate_all(spfi->tx_ch);
389 	return -EIO;
390 }
391 
392 static void img_spfi_handle_err(struct spi_master *master,
393 				struct spi_message *msg)
394 {
395 	struct img_spfi *spfi = spi_master_get_devdata(master);
396 	unsigned long flags;
397 
398 	/*
399 	 * Stop all DMA and reset the controller if the previous transaction
400 	 * timed-out and never completed it's DMA.
401 	 */
402 	spin_lock_irqsave(&spfi->lock, flags);
403 	if (spfi->tx_dma_busy || spfi->rx_dma_busy) {
404 		spfi->tx_dma_busy = false;
405 		spfi->rx_dma_busy = false;
406 
407 		dmaengine_terminate_all(spfi->tx_ch);
408 		dmaengine_terminate_all(spfi->rx_ch);
409 	}
410 	spin_unlock_irqrestore(&spfi->lock, flags);
411 }
412 
413 static int img_spfi_prepare(struct spi_master *master, struct spi_message *msg)
414 {
415 	struct img_spfi *spfi = spi_master_get_devdata(master);
416 	u32 val;
417 
418 	val = spfi_readl(spfi, SPFI_PORT_STATE);
419 	val &= ~(SPFI_PORT_STATE_DEV_SEL_MASK <<
420 		 SPFI_PORT_STATE_DEV_SEL_SHIFT);
421 	val |= msg->spi->chip_select << SPFI_PORT_STATE_DEV_SEL_SHIFT;
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 
435 static 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 
445 static 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 
481 static 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 
493 static 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 
532 static 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 
555 static 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 
563 static 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 
578 static 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 	u32 max_speed_hz;
585 
586 	master = spi_alloc_master(&pdev->dev, sizeof(*spfi));
587 	if (!master)
588 		return -ENOMEM;
589 	platform_set_drvdata(pdev, master);
590 
591 	spfi = spi_master_get_devdata(master);
592 	spfi->dev = &pdev->dev;
593 	spfi->master = master;
594 	spin_lock_init(&spfi->lock);
595 
596 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
597 	spfi->regs = devm_ioremap_resource(spfi->dev, res);
598 	if (IS_ERR(spfi->regs)) {
599 		ret = PTR_ERR(spfi->regs);
600 		goto put_spi;
601 	}
602 	spfi->phys = res->start;
603 
604 	spfi->irq = platform_get_irq(pdev, 0);
605 	if (spfi->irq < 0) {
606 		ret = spfi->irq;
607 		goto put_spi;
608 	}
609 	ret = devm_request_irq(spfi->dev, spfi->irq, img_spfi_irq,
610 			       IRQ_TYPE_LEVEL_HIGH, dev_name(spfi->dev), spfi);
611 	if (ret)
612 		goto put_spi;
613 
614 	spfi->sys_clk = devm_clk_get(spfi->dev, "sys");
615 	if (IS_ERR(spfi->sys_clk)) {
616 		ret = PTR_ERR(spfi->sys_clk);
617 		goto put_spi;
618 	}
619 	spfi->spfi_clk = devm_clk_get(spfi->dev, "spfi");
620 	if (IS_ERR(spfi->spfi_clk)) {
621 		ret = PTR_ERR(spfi->spfi_clk);
622 		goto put_spi;
623 	}
624 
625 	ret = clk_prepare_enable(spfi->sys_clk);
626 	if (ret)
627 		goto put_spi;
628 	ret = clk_prepare_enable(spfi->spfi_clk);
629 	if (ret)
630 		goto disable_pclk;
631 
632 	spfi_reset(spfi);
633 	/*
634 	 * Only enable the error (IACCESS) interrupt.  In PIO mode we'll
635 	 * poll the status of the FIFOs.
636 	 */
637 	spfi_writel(spfi, SPFI_INTERRUPT_IACCESS, SPFI_INTERRUPT_ENABLE);
638 
639 	master->auto_runtime_pm = true;
640 	master->bus_num = pdev->id;
641 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_TX_DUAL | SPI_RX_DUAL;
642 	if (of_property_read_bool(spfi->dev->of_node, "img,supports-quad-mode"))
643 		master->mode_bits |= SPI_TX_QUAD | SPI_RX_QUAD;
644 	master->dev.of_node = pdev->dev.of_node;
645 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(8);
646 	master->max_speed_hz = clk_get_rate(spfi->spfi_clk) / 4;
647 	master->min_speed_hz = clk_get_rate(spfi->spfi_clk) / 512;
648 
649 	/*
650 	 * Maximum speed supported by spfi is limited to the lower value
651 	 * between 1/4 of the SPFI clock or to "spfi-max-frequency"
652 	 * defined in the device tree.
653 	 * If no value is defined in the device tree assume the maximum
654 	 * speed supported to be 1/4 of the SPFI clock.
655 	 */
656 	if (!of_property_read_u32(spfi->dev->of_node, "spfi-max-frequency",
657 				  &max_speed_hz)) {
658 		if (master->max_speed_hz > max_speed_hz)
659 			master->max_speed_hz = max_speed_hz;
660 	}
661 
662 	master->setup = img_spfi_setup;
663 	master->cleanup = img_spfi_cleanup;
664 	master->transfer_one = img_spfi_transfer_one;
665 	master->prepare_message = img_spfi_prepare;
666 	master->unprepare_message = img_spfi_unprepare;
667 	master->handle_err = img_spfi_handle_err;
668 
669 	spfi->tx_ch = dma_request_chan(spfi->dev, "tx");
670 	if (IS_ERR(spfi->tx_ch)) {
671 		ret = PTR_ERR(spfi->tx_ch);
672 		spfi->tx_ch = NULL;
673 		if (ret == -EPROBE_DEFER)
674 			goto disable_pm;
675 	}
676 
677 	spfi->rx_ch = dma_request_chan(spfi->dev, "rx");
678 	if (IS_ERR(spfi->rx_ch)) {
679 		ret = PTR_ERR(spfi->rx_ch);
680 		spfi->rx_ch = NULL;
681 		if (ret == -EPROBE_DEFER)
682 			goto disable_pm;
683 	}
684 
685 	if (!spfi->tx_ch || !spfi->rx_ch) {
686 		if (spfi->tx_ch)
687 			dma_release_channel(spfi->tx_ch);
688 		if (spfi->rx_ch)
689 			dma_release_channel(spfi->rx_ch);
690 		spfi->tx_ch = NULL;
691 		spfi->rx_ch = NULL;
692 		dev_warn(spfi->dev, "Failed to get DMA channels, falling back to PIO mode\n");
693 	} else {
694 		master->dma_tx = spfi->tx_ch;
695 		master->dma_rx = spfi->rx_ch;
696 		master->can_dma = img_spfi_can_dma;
697 	}
698 
699 	pm_runtime_set_active(spfi->dev);
700 	pm_runtime_enable(spfi->dev);
701 
702 	ret = devm_spi_register_master(spfi->dev, master);
703 	if (ret)
704 		goto disable_pm;
705 
706 	return 0;
707 
708 disable_pm:
709 	pm_runtime_disable(spfi->dev);
710 	if (spfi->rx_ch)
711 		dma_release_channel(spfi->rx_ch);
712 	if (spfi->tx_ch)
713 		dma_release_channel(spfi->tx_ch);
714 	clk_disable_unprepare(spfi->spfi_clk);
715 disable_pclk:
716 	clk_disable_unprepare(spfi->sys_clk);
717 put_spi:
718 	spi_master_put(master);
719 
720 	return ret;
721 }
722 
723 static int img_spfi_remove(struct platform_device *pdev)
724 {
725 	struct spi_master *master = platform_get_drvdata(pdev);
726 	struct img_spfi *spfi = spi_master_get_devdata(master);
727 
728 	if (spfi->tx_ch)
729 		dma_release_channel(spfi->tx_ch);
730 	if (spfi->rx_ch)
731 		dma_release_channel(spfi->rx_ch);
732 
733 	pm_runtime_disable(spfi->dev);
734 	if (!pm_runtime_status_suspended(spfi->dev)) {
735 		clk_disable_unprepare(spfi->spfi_clk);
736 		clk_disable_unprepare(spfi->sys_clk);
737 	}
738 
739 	return 0;
740 }
741 
742 #ifdef CONFIG_PM
743 static int img_spfi_runtime_suspend(struct device *dev)
744 {
745 	struct spi_master *master = dev_get_drvdata(dev);
746 	struct img_spfi *spfi = spi_master_get_devdata(master);
747 
748 	clk_disable_unprepare(spfi->spfi_clk);
749 	clk_disable_unprepare(spfi->sys_clk);
750 
751 	return 0;
752 }
753 
754 static int img_spfi_runtime_resume(struct device *dev)
755 {
756 	struct spi_master *master = dev_get_drvdata(dev);
757 	struct img_spfi *spfi = spi_master_get_devdata(master);
758 	int ret;
759 
760 	ret = clk_prepare_enable(spfi->sys_clk);
761 	if (ret)
762 		return ret;
763 	ret = clk_prepare_enable(spfi->spfi_clk);
764 	if (ret) {
765 		clk_disable_unprepare(spfi->sys_clk);
766 		return ret;
767 	}
768 
769 	return 0;
770 }
771 #endif /* CONFIG_PM */
772 
773 #ifdef CONFIG_PM_SLEEP
774 static int img_spfi_suspend(struct device *dev)
775 {
776 	struct spi_master *master = dev_get_drvdata(dev);
777 
778 	return spi_master_suspend(master);
779 }
780 
781 static int img_spfi_resume(struct device *dev)
782 {
783 	struct spi_master *master = dev_get_drvdata(dev);
784 	struct img_spfi *spfi = spi_master_get_devdata(master);
785 	int ret;
786 
787 	ret = pm_runtime_get_sync(dev);
788 	if (ret)
789 		return ret;
790 	spfi_reset(spfi);
791 	pm_runtime_put(dev);
792 
793 	return spi_master_resume(master);
794 }
795 #endif /* CONFIG_PM_SLEEP */
796 
797 static const struct dev_pm_ops img_spfi_pm_ops = {
798 	SET_RUNTIME_PM_OPS(img_spfi_runtime_suspend, img_spfi_runtime_resume,
799 			   NULL)
800 	SET_SYSTEM_SLEEP_PM_OPS(img_spfi_suspend, img_spfi_resume)
801 };
802 
803 static const struct of_device_id img_spfi_of_match[] = {
804 	{ .compatible = "img,spfi", },
805 	{ },
806 };
807 MODULE_DEVICE_TABLE(of, img_spfi_of_match);
808 
809 static struct platform_driver img_spfi_driver = {
810 	.driver = {
811 		.name = "img-spfi",
812 		.pm = &img_spfi_pm_ops,
813 		.of_match_table = of_match_ptr(img_spfi_of_match),
814 	},
815 	.probe = img_spfi_probe,
816 	.remove = img_spfi_remove,
817 };
818 module_platform_driver(img_spfi_driver);
819 
820 MODULE_DESCRIPTION("IMG SPFI controller driver");
821 MODULE_AUTHOR("Andrew Bresticker <abrestic@chromium.org>");
822 MODULE_LICENSE("GPL v2");
823