xref: /openbmc/linux/drivers/mmc/host/jz4740_mmc.c (revision 8fdf9062)
1 /*
2  *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
3  *  Copyright (C) 2013, Imagination Technologies
4  *
5  *  JZ4740 SD/MMC controller driver
6  *
7  *  This program is free software; you can redistribute  it and/or modify it
8  *  under  the terms of  the GNU General  Public License as published by the
9  *  Free Software Foundation;  either version 2 of the  License, or (at your
10  *  option) any later version.
11  *
12  *  You should have received a copy of the  GNU General Public License along
13  *  with this program; if not, write  to the Free Software Foundation, Inc.,
14  *  675 Mass Ave, Cambridge, MA 02139, USA.
15  *
16  */
17 
18 #include <linux/bitops.h>
19 #include <linux/clk.h>
20 #include <linux/delay.h>
21 #include <linux/dmaengine.h>
22 #include <linux/dma-mapping.h>
23 #include <linux/err.h>
24 #include <linux/gpio/consumer.h>
25 #include <linux/interrupt.h>
26 #include <linux/io.h>
27 #include <linux/irq.h>
28 #include <linux/mmc/host.h>
29 #include <linux/mmc/slot-gpio.h>
30 #include <linux/module.h>
31 #include <linux/of_device.h>
32 #include <linux/pinctrl/consumer.h>
33 #include <linux/platform_device.h>
34 #include <linux/scatterlist.h>
35 
36 #include <asm/cacheflush.h>
37 
38 #include <asm/mach-jz4740/dma.h>
39 #include <asm/mach-jz4740/jz4740_mmc.h>
40 
41 #define JZ_REG_MMC_STRPCL	0x00
42 #define JZ_REG_MMC_STATUS	0x04
43 #define JZ_REG_MMC_CLKRT	0x08
44 #define JZ_REG_MMC_CMDAT	0x0C
45 #define JZ_REG_MMC_RESTO	0x10
46 #define JZ_REG_MMC_RDTO		0x14
47 #define JZ_REG_MMC_BLKLEN	0x18
48 #define JZ_REG_MMC_NOB		0x1C
49 #define JZ_REG_MMC_SNOB		0x20
50 #define JZ_REG_MMC_IMASK	0x24
51 #define JZ_REG_MMC_IREG		0x28
52 #define JZ_REG_MMC_CMD		0x2C
53 #define JZ_REG_MMC_ARG		0x30
54 #define JZ_REG_MMC_RESP_FIFO	0x34
55 #define JZ_REG_MMC_RXFIFO	0x38
56 #define JZ_REG_MMC_TXFIFO	0x3C
57 #define JZ_REG_MMC_DMAC		0x44
58 
59 #define JZ_MMC_STRPCL_EXIT_MULTIPLE BIT(7)
60 #define JZ_MMC_STRPCL_EXIT_TRANSFER BIT(6)
61 #define JZ_MMC_STRPCL_START_READWAIT BIT(5)
62 #define JZ_MMC_STRPCL_STOP_READWAIT BIT(4)
63 #define JZ_MMC_STRPCL_RESET BIT(3)
64 #define JZ_MMC_STRPCL_START_OP BIT(2)
65 #define JZ_MMC_STRPCL_CLOCK_CONTROL (BIT(1) | BIT(0))
66 #define JZ_MMC_STRPCL_CLOCK_STOP BIT(0)
67 #define JZ_MMC_STRPCL_CLOCK_START BIT(1)
68 
69 
70 #define JZ_MMC_STATUS_IS_RESETTING BIT(15)
71 #define JZ_MMC_STATUS_SDIO_INT_ACTIVE BIT(14)
72 #define JZ_MMC_STATUS_PRG_DONE BIT(13)
73 #define JZ_MMC_STATUS_DATA_TRAN_DONE BIT(12)
74 #define JZ_MMC_STATUS_END_CMD_RES BIT(11)
75 #define JZ_MMC_STATUS_DATA_FIFO_AFULL BIT(10)
76 #define JZ_MMC_STATUS_IS_READWAIT BIT(9)
77 #define JZ_MMC_STATUS_CLK_EN BIT(8)
78 #define JZ_MMC_STATUS_DATA_FIFO_FULL BIT(7)
79 #define JZ_MMC_STATUS_DATA_FIFO_EMPTY BIT(6)
80 #define JZ_MMC_STATUS_CRC_RES_ERR BIT(5)
81 #define JZ_MMC_STATUS_CRC_READ_ERROR BIT(4)
82 #define JZ_MMC_STATUS_TIMEOUT_WRITE BIT(3)
83 #define JZ_MMC_STATUS_CRC_WRITE_ERROR BIT(2)
84 #define JZ_MMC_STATUS_TIMEOUT_RES BIT(1)
85 #define JZ_MMC_STATUS_TIMEOUT_READ BIT(0)
86 
87 #define JZ_MMC_STATUS_READ_ERROR_MASK (BIT(4) | BIT(0))
88 #define JZ_MMC_STATUS_WRITE_ERROR_MASK (BIT(3) | BIT(2))
89 
90 
91 #define JZ_MMC_CMDAT_IO_ABORT BIT(11)
92 #define JZ_MMC_CMDAT_BUS_WIDTH_4BIT BIT(10)
93 #define JZ_MMC_CMDAT_DMA_EN BIT(8)
94 #define JZ_MMC_CMDAT_INIT BIT(7)
95 #define JZ_MMC_CMDAT_BUSY BIT(6)
96 #define JZ_MMC_CMDAT_STREAM BIT(5)
97 #define JZ_MMC_CMDAT_WRITE BIT(4)
98 #define JZ_MMC_CMDAT_DATA_EN BIT(3)
99 #define JZ_MMC_CMDAT_RESPONSE_FORMAT (BIT(2) | BIT(1) | BIT(0))
100 #define JZ_MMC_CMDAT_RSP_R1 1
101 #define JZ_MMC_CMDAT_RSP_R2 2
102 #define JZ_MMC_CMDAT_RSP_R3 3
103 
104 #define JZ_MMC_IRQ_SDIO BIT(7)
105 #define JZ_MMC_IRQ_TXFIFO_WR_REQ BIT(6)
106 #define JZ_MMC_IRQ_RXFIFO_RD_REQ BIT(5)
107 #define JZ_MMC_IRQ_END_CMD_RES BIT(2)
108 #define JZ_MMC_IRQ_PRG_DONE BIT(1)
109 #define JZ_MMC_IRQ_DATA_TRAN_DONE BIT(0)
110 
111 #define JZ_MMC_DMAC_DMA_SEL BIT(1)
112 #define JZ_MMC_DMAC_DMA_EN BIT(0)
113 
114 #define JZ_MMC_CLK_RATE 24000000
115 
116 enum jz4740_mmc_version {
117 	JZ_MMC_JZ4740,
118 	JZ_MMC_JZ4725B,
119 	JZ_MMC_JZ4780,
120 };
121 
122 enum jz4740_mmc_state {
123 	JZ4740_MMC_STATE_READ_RESPONSE,
124 	JZ4740_MMC_STATE_TRANSFER_DATA,
125 	JZ4740_MMC_STATE_SEND_STOP,
126 	JZ4740_MMC_STATE_DONE,
127 };
128 
129 /*
130  * The MMC core allows to prepare a mmc_request while another mmc_request
131  * is in-flight. This is used via the pre_req/post_req hooks.
132  * This driver uses the pre_req/post_req hooks to map/unmap the mmc_request.
133  * Following what other drivers do (sdhci, dw_mmc) we use the following cookie
134  * flags to keep track of the mmc_request mapping state.
135  *
136  * COOKIE_UNMAPPED: the request is not mapped.
137  * COOKIE_PREMAPPED: the request was mapped in pre_req,
138  * and should be unmapped in post_req.
139  * COOKIE_MAPPED: the request was mapped in the irq handler,
140  * and should be unmapped before mmc_request_done is called..
141  */
142 enum jz4780_cookie {
143 	COOKIE_UNMAPPED = 0,
144 	COOKIE_PREMAPPED,
145 	COOKIE_MAPPED,
146 };
147 
148 struct jz4740_mmc_host {
149 	struct mmc_host *mmc;
150 	struct platform_device *pdev;
151 	struct jz4740_mmc_platform_data *pdata;
152 	struct clk *clk;
153 	struct gpio_desc *power;
154 
155 	enum jz4740_mmc_version version;
156 
157 	int irq;
158 	int card_detect_irq;
159 
160 	void __iomem *base;
161 	struct resource *mem_res;
162 	struct mmc_request *req;
163 	struct mmc_command *cmd;
164 
165 	unsigned long waiting;
166 
167 	uint32_t cmdat;
168 
169 	uint32_t irq_mask;
170 
171 	spinlock_t lock;
172 
173 	struct timer_list timeout_timer;
174 	struct sg_mapping_iter miter;
175 	enum jz4740_mmc_state state;
176 
177 	/* DMA support */
178 	struct dma_chan *dma_rx;
179 	struct dma_chan *dma_tx;
180 	bool use_dma;
181 
182 /* The DMA trigger level is 8 words, that is to say, the DMA read
183  * trigger is when data words in MSC_RXFIFO is >= 8 and the DMA write
184  * trigger is when data words in MSC_TXFIFO is < 8.
185  */
186 #define JZ4740_MMC_FIFO_HALF_SIZE 8
187 };
188 
189 static void jz4740_mmc_write_irq_mask(struct jz4740_mmc_host *host,
190 				      uint32_t val)
191 {
192 	if (host->version >= JZ_MMC_JZ4725B)
193 		return writel(val, host->base + JZ_REG_MMC_IMASK);
194 	else
195 		return writew(val, host->base + JZ_REG_MMC_IMASK);
196 }
197 
198 static void jz4740_mmc_write_irq_reg(struct jz4740_mmc_host *host,
199 				     uint32_t val)
200 {
201 	if (host->version >= JZ_MMC_JZ4780)
202 		return writel(val, host->base + JZ_REG_MMC_IREG);
203 	else
204 		return writew(val, host->base + JZ_REG_MMC_IREG);
205 }
206 
207 static uint32_t jz4740_mmc_read_irq_reg(struct jz4740_mmc_host *host)
208 {
209 	if (host->version >= JZ_MMC_JZ4780)
210 		return readl(host->base + JZ_REG_MMC_IREG);
211 	else
212 		return readw(host->base + JZ_REG_MMC_IREG);
213 }
214 
215 /*----------------------------------------------------------------------------*/
216 /* DMA infrastructure */
217 
218 static void jz4740_mmc_release_dma_channels(struct jz4740_mmc_host *host)
219 {
220 	if (!host->use_dma)
221 		return;
222 
223 	dma_release_channel(host->dma_tx);
224 	dma_release_channel(host->dma_rx);
225 }
226 
227 static int jz4740_mmc_acquire_dma_channels(struct jz4740_mmc_host *host)
228 {
229 	host->dma_tx = dma_request_chan(mmc_dev(host->mmc), "tx");
230 	if (IS_ERR(host->dma_tx)) {
231 		dev_err(mmc_dev(host->mmc), "Failed to get dma_tx channel\n");
232 		return PTR_ERR(host->dma_tx);
233 	}
234 
235 	host->dma_rx = dma_request_chan(mmc_dev(host->mmc), "rx");
236 	if (IS_ERR(host->dma_rx)) {
237 		dev_err(mmc_dev(host->mmc), "Failed to get dma_rx channel\n");
238 		dma_release_channel(host->dma_tx);
239 		return PTR_ERR(host->dma_rx);
240 	}
241 
242 	return 0;
243 }
244 
245 static inline struct dma_chan *jz4740_mmc_get_dma_chan(struct jz4740_mmc_host *host,
246 						       struct mmc_data *data)
247 {
248 	return (data->flags & MMC_DATA_READ) ? host->dma_rx : host->dma_tx;
249 }
250 
251 static void jz4740_mmc_dma_unmap(struct jz4740_mmc_host *host,
252 				 struct mmc_data *data)
253 {
254 	struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
255 	enum dma_data_direction dir = mmc_get_dma_dir(data);
256 
257 	dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
258 	data->host_cookie = COOKIE_UNMAPPED;
259 }
260 
261 /* Prepares DMA data for current or next transfer.
262  * A request can be in-flight when this is called.
263  */
264 static int jz4740_mmc_prepare_dma_data(struct jz4740_mmc_host *host,
265 				       struct mmc_data *data,
266 				       int cookie)
267 {
268 	struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
269 	enum dma_data_direction dir = mmc_get_dma_dir(data);
270 	int sg_count;
271 
272 	if (data->host_cookie == COOKIE_PREMAPPED)
273 		return data->sg_count;
274 
275 	sg_count = dma_map_sg(chan->device->dev,
276 			data->sg,
277 			data->sg_len,
278 			dir);
279 
280 	if (sg_count <= 0) {
281 		dev_err(mmc_dev(host->mmc),
282 			"Failed to map scatterlist for DMA operation\n");
283 		return -EINVAL;
284 	}
285 
286 	data->sg_count = sg_count;
287 	data->host_cookie = cookie;
288 
289 	return data->sg_count;
290 }
291 
292 static int jz4740_mmc_start_dma_transfer(struct jz4740_mmc_host *host,
293 					 struct mmc_data *data)
294 {
295 	struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
296 	struct dma_async_tx_descriptor *desc;
297 	struct dma_slave_config conf = {
298 		.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
299 		.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
300 		.src_maxburst = JZ4740_MMC_FIFO_HALF_SIZE,
301 		.dst_maxburst = JZ4740_MMC_FIFO_HALF_SIZE,
302 	};
303 	int sg_count;
304 
305 	if (data->flags & MMC_DATA_WRITE) {
306 		conf.direction = DMA_MEM_TO_DEV;
307 		conf.dst_addr = host->mem_res->start + JZ_REG_MMC_TXFIFO;
308 		conf.slave_id = JZ4740_DMA_TYPE_MMC_TRANSMIT;
309 	} else {
310 		conf.direction = DMA_DEV_TO_MEM;
311 		conf.src_addr = host->mem_res->start + JZ_REG_MMC_RXFIFO;
312 		conf.slave_id = JZ4740_DMA_TYPE_MMC_RECEIVE;
313 	}
314 
315 	sg_count = jz4740_mmc_prepare_dma_data(host, data, COOKIE_MAPPED);
316 	if (sg_count < 0)
317 		return sg_count;
318 
319 	dmaengine_slave_config(chan, &conf);
320 	desc = dmaengine_prep_slave_sg(chan, data->sg, sg_count,
321 			conf.direction,
322 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
323 	if (!desc) {
324 		dev_err(mmc_dev(host->mmc),
325 			"Failed to allocate DMA %s descriptor",
326 			 conf.direction == DMA_MEM_TO_DEV ? "TX" : "RX");
327 		goto dma_unmap;
328 	}
329 
330 	dmaengine_submit(desc);
331 	dma_async_issue_pending(chan);
332 
333 	return 0;
334 
335 dma_unmap:
336 	if (data->host_cookie == COOKIE_MAPPED)
337 		jz4740_mmc_dma_unmap(host, data);
338 	return -ENOMEM;
339 }
340 
341 static void jz4740_mmc_pre_request(struct mmc_host *mmc,
342 				   struct mmc_request *mrq)
343 {
344 	struct jz4740_mmc_host *host = mmc_priv(mmc);
345 	struct mmc_data *data = mrq->data;
346 
347 	if (!host->use_dma)
348 		return;
349 
350 	data->host_cookie = COOKIE_UNMAPPED;
351 	if (jz4740_mmc_prepare_dma_data(host, data, COOKIE_PREMAPPED) < 0)
352 		data->host_cookie = COOKIE_UNMAPPED;
353 }
354 
355 static void jz4740_mmc_post_request(struct mmc_host *mmc,
356 				    struct mmc_request *mrq,
357 				    int err)
358 {
359 	struct jz4740_mmc_host *host = mmc_priv(mmc);
360 	struct mmc_data *data = mrq->data;
361 
362 	if (data && data->host_cookie != COOKIE_UNMAPPED)
363 		jz4740_mmc_dma_unmap(host, data);
364 
365 	if (err) {
366 		struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
367 
368 		dmaengine_terminate_all(chan);
369 	}
370 }
371 
372 /*----------------------------------------------------------------------------*/
373 
374 static void jz4740_mmc_set_irq_enabled(struct jz4740_mmc_host *host,
375 	unsigned int irq, bool enabled)
376 {
377 	unsigned long flags;
378 
379 	spin_lock_irqsave(&host->lock, flags);
380 	if (enabled)
381 		host->irq_mask &= ~irq;
382 	else
383 		host->irq_mask |= irq;
384 
385 	jz4740_mmc_write_irq_mask(host, host->irq_mask);
386 	spin_unlock_irqrestore(&host->lock, flags);
387 }
388 
389 static void jz4740_mmc_clock_enable(struct jz4740_mmc_host *host,
390 	bool start_transfer)
391 {
392 	uint16_t val = JZ_MMC_STRPCL_CLOCK_START;
393 
394 	if (start_transfer)
395 		val |= JZ_MMC_STRPCL_START_OP;
396 
397 	writew(val, host->base + JZ_REG_MMC_STRPCL);
398 }
399 
400 static void jz4740_mmc_clock_disable(struct jz4740_mmc_host *host)
401 {
402 	uint32_t status;
403 	unsigned int timeout = 1000;
404 
405 	writew(JZ_MMC_STRPCL_CLOCK_STOP, host->base + JZ_REG_MMC_STRPCL);
406 	do {
407 		status = readl(host->base + JZ_REG_MMC_STATUS);
408 	} while (status & JZ_MMC_STATUS_CLK_EN && --timeout);
409 }
410 
411 static void jz4740_mmc_reset(struct jz4740_mmc_host *host)
412 {
413 	uint32_t status;
414 	unsigned int timeout = 1000;
415 
416 	writew(JZ_MMC_STRPCL_RESET, host->base + JZ_REG_MMC_STRPCL);
417 	udelay(10);
418 	do {
419 		status = readl(host->base + JZ_REG_MMC_STATUS);
420 	} while (status & JZ_MMC_STATUS_IS_RESETTING && --timeout);
421 }
422 
423 static void jz4740_mmc_request_done(struct jz4740_mmc_host *host)
424 {
425 	struct mmc_request *req;
426 	struct mmc_data *data;
427 
428 	req = host->req;
429 	data = req->data;
430 	host->req = NULL;
431 
432 	if (data && data->host_cookie == COOKIE_MAPPED)
433 		jz4740_mmc_dma_unmap(host, data);
434 	mmc_request_done(host->mmc, req);
435 }
436 
437 static unsigned int jz4740_mmc_poll_irq(struct jz4740_mmc_host *host,
438 	unsigned int irq)
439 {
440 	unsigned int timeout = 0x800;
441 	uint32_t status;
442 
443 	do {
444 		status = jz4740_mmc_read_irq_reg(host);
445 	} while (!(status & irq) && --timeout);
446 
447 	if (timeout == 0) {
448 		set_bit(0, &host->waiting);
449 		mod_timer(&host->timeout_timer, jiffies + 5*HZ);
450 		jz4740_mmc_set_irq_enabled(host, irq, true);
451 		return true;
452 	}
453 
454 	return false;
455 }
456 
457 static void jz4740_mmc_transfer_check_state(struct jz4740_mmc_host *host,
458 	struct mmc_data *data)
459 {
460 	int status;
461 
462 	status = readl(host->base + JZ_REG_MMC_STATUS);
463 	if (status & JZ_MMC_STATUS_WRITE_ERROR_MASK) {
464 		if (status & (JZ_MMC_STATUS_TIMEOUT_WRITE)) {
465 			host->req->cmd->error = -ETIMEDOUT;
466 			data->error = -ETIMEDOUT;
467 		} else {
468 			host->req->cmd->error = -EIO;
469 			data->error = -EIO;
470 		}
471 	} else if (status & JZ_MMC_STATUS_READ_ERROR_MASK) {
472 		if (status & (JZ_MMC_STATUS_TIMEOUT_READ)) {
473 			host->req->cmd->error = -ETIMEDOUT;
474 			data->error = -ETIMEDOUT;
475 		} else {
476 			host->req->cmd->error = -EIO;
477 			data->error = -EIO;
478 		}
479 	}
480 }
481 
482 static bool jz4740_mmc_write_data(struct jz4740_mmc_host *host,
483 	struct mmc_data *data)
484 {
485 	struct sg_mapping_iter *miter = &host->miter;
486 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_TXFIFO;
487 	uint32_t *buf;
488 	bool timeout;
489 	size_t i, j;
490 
491 	while (sg_miter_next(miter)) {
492 		buf = miter->addr;
493 		i = miter->length / 4;
494 		j = i / 8;
495 		i = i & 0x7;
496 		while (j) {
497 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
498 			if (unlikely(timeout))
499 				goto poll_timeout;
500 
501 			writel(buf[0], fifo_addr);
502 			writel(buf[1], fifo_addr);
503 			writel(buf[2], fifo_addr);
504 			writel(buf[3], fifo_addr);
505 			writel(buf[4], fifo_addr);
506 			writel(buf[5], fifo_addr);
507 			writel(buf[6], fifo_addr);
508 			writel(buf[7], fifo_addr);
509 			buf += 8;
510 			--j;
511 		}
512 		if (unlikely(i)) {
513 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
514 			if (unlikely(timeout))
515 				goto poll_timeout;
516 
517 			while (i) {
518 				writel(*buf, fifo_addr);
519 				++buf;
520 				--i;
521 			}
522 		}
523 		data->bytes_xfered += miter->length;
524 	}
525 	sg_miter_stop(miter);
526 
527 	return false;
528 
529 poll_timeout:
530 	miter->consumed = (void *)buf - miter->addr;
531 	data->bytes_xfered += miter->consumed;
532 	sg_miter_stop(miter);
533 
534 	return true;
535 }
536 
537 static bool jz4740_mmc_read_data(struct jz4740_mmc_host *host,
538 				struct mmc_data *data)
539 {
540 	struct sg_mapping_iter *miter = &host->miter;
541 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_RXFIFO;
542 	uint32_t *buf;
543 	uint32_t d;
544 	uint32_t status;
545 	size_t i, j;
546 	unsigned int timeout;
547 
548 	while (sg_miter_next(miter)) {
549 		buf = miter->addr;
550 		i = miter->length;
551 		j = i / 32;
552 		i = i & 0x1f;
553 		while (j) {
554 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
555 			if (unlikely(timeout))
556 				goto poll_timeout;
557 
558 			buf[0] = readl(fifo_addr);
559 			buf[1] = readl(fifo_addr);
560 			buf[2] = readl(fifo_addr);
561 			buf[3] = readl(fifo_addr);
562 			buf[4] = readl(fifo_addr);
563 			buf[5] = readl(fifo_addr);
564 			buf[6] = readl(fifo_addr);
565 			buf[7] = readl(fifo_addr);
566 
567 			buf += 8;
568 			--j;
569 		}
570 
571 		if (unlikely(i)) {
572 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
573 			if (unlikely(timeout))
574 				goto poll_timeout;
575 
576 			while (i >= 4) {
577 				*buf++ = readl(fifo_addr);
578 				i -= 4;
579 			}
580 			if (unlikely(i > 0)) {
581 				d = readl(fifo_addr);
582 				memcpy(buf, &d, i);
583 			}
584 		}
585 		data->bytes_xfered += miter->length;
586 
587 		/* This can go away once MIPS implements
588 		 * flush_kernel_dcache_page */
589 		flush_dcache_page(miter->page);
590 	}
591 	sg_miter_stop(miter);
592 
593 	/* For whatever reason there is sometime one word more in the fifo then
594 	 * requested */
595 	timeout = 1000;
596 	status = readl(host->base + JZ_REG_MMC_STATUS);
597 	while (!(status & JZ_MMC_STATUS_DATA_FIFO_EMPTY) && --timeout) {
598 		d = readl(fifo_addr);
599 		status = readl(host->base + JZ_REG_MMC_STATUS);
600 	}
601 
602 	return false;
603 
604 poll_timeout:
605 	miter->consumed = (void *)buf - miter->addr;
606 	data->bytes_xfered += miter->consumed;
607 	sg_miter_stop(miter);
608 
609 	return true;
610 }
611 
612 static void jz4740_mmc_timeout(struct timer_list *t)
613 {
614 	struct jz4740_mmc_host *host = from_timer(host, t, timeout_timer);
615 
616 	if (!test_and_clear_bit(0, &host->waiting))
617 		return;
618 
619 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, false);
620 
621 	host->req->cmd->error = -ETIMEDOUT;
622 	jz4740_mmc_request_done(host);
623 }
624 
625 static void jz4740_mmc_read_response(struct jz4740_mmc_host *host,
626 	struct mmc_command *cmd)
627 {
628 	int i;
629 	uint16_t tmp;
630 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_RESP_FIFO;
631 
632 	if (cmd->flags & MMC_RSP_136) {
633 		tmp = readw(fifo_addr);
634 		for (i = 0; i < 4; ++i) {
635 			cmd->resp[i] = tmp << 24;
636 			tmp = readw(fifo_addr);
637 			cmd->resp[i] |= tmp << 8;
638 			tmp = readw(fifo_addr);
639 			cmd->resp[i] |= tmp >> 8;
640 		}
641 	} else {
642 		cmd->resp[0] = readw(fifo_addr) << 24;
643 		cmd->resp[0] |= readw(fifo_addr) << 8;
644 		cmd->resp[0] |= readw(fifo_addr) & 0xff;
645 	}
646 }
647 
648 static void jz4740_mmc_send_command(struct jz4740_mmc_host *host,
649 	struct mmc_command *cmd)
650 {
651 	uint32_t cmdat = host->cmdat;
652 
653 	host->cmdat &= ~JZ_MMC_CMDAT_INIT;
654 	jz4740_mmc_clock_disable(host);
655 
656 	host->cmd = cmd;
657 
658 	if (cmd->flags & MMC_RSP_BUSY)
659 		cmdat |= JZ_MMC_CMDAT_BUSY;
660 
661 	switch (mmc_resp_type(cmd)) {
662 	case MMC_RSP_R1B:
663 	case MMC_RSP_R1:
664 		cmdat |= JZ_MMC_CMDAT_RSP_R1;
665 		break;
666 	case MMC_RSP_R2:
667 		cmdat |= JZ_MMC_CMDAT_RSP_R2;
668 		break;
669 	case MMC_RSP_R3:
670 		cmdat |= JZ_MMC_CMDAT_RSP_R3;
671 		break;
672 	default:
673 		break;
674 	}
675 
676 	if (cmd->data) {
677 		cmdat |= JZ_MMC_CMDAT_DATA_EN;
678 		if (cmd->data->flags & MMC_DATA_WRITE)
679 			cmdat |= JZ_MMC_CMDAT_WRITE;
680 		if (host->use_dma) {
681 			/*
682 			 * The 4780's MMC controller has integrated DMA ability
683 			 * in addition to being able to use the external DMA
684 			 * controller. It moves DMA control bits to a separate
685 			 * register. The DMA_SEL bit chooses the external
686 			 * controller over the integrated one. Earlier SoCs
687 			 * can only use the external controller, and have a
688 			 * single DMA enable bit in CMDAT.
689 			 */
690 			if (host->version >= JZ_MMC_JZ4780) {
691 				writel(JZ_MMC_DMAC_DMA_EN | JZ_MMC_DMAC_DMA_SEL,
692 				       host->base + JZ_REG_MMC_DMAC);
693 			} else {
694 				cmdat |= JZ_MMC_CMDAT_DMA_EN;
695 			}
696 		} else if (host->version >= JZ_MMC_JZ4780) {
697 			writel(0, host->base + JZ_REG_MMC_DMAC);
698 		}
699 
700 		writew(cmd->data->blksz, host->base + JZ_REG_MMC_BLKLEN);
701 		writew(cmd->data->blocks, host->base + JZ_REG_MMC_NOB);
702 	}
703 
704 	writeb(cmd->opcode, host->base + JZ_REG_MMC_CMD);
705 	writel(cmd->arg, host->base + JZ_REG_MMC_ARG);
706 	writel(cmdat, host->base + JZ_REG_MMC_CMDAT);
707 
708 	jz4740_mmc_clock_enable(host, 1);
709 }
710 
711 static void jz_mmc_prepare_data_transfer(struct jz4740_mmc_host *host)
712 {
713 	struct mmc_command *cmd = host->req->cmd;
714 	struct mmc_data *data = cmd->data;
715 	int direction;
716 
717 	if (data->flags & MMC_DATA_READ)
718 		direction = SG_MITER_TO_SG;
719 	else
720 		direction = SG_MITER_FROM_SG;
721 
722 	sg_miter_start(&host->miter, data->sg, data->sg_len, direction);
723 }
724 
725 
726 static irqreturn_t jz_mmc_irq_worker(int irq, void *devid)
727 {
728 	struct jz4740_mmc_host *host = (struct jz4740_mmc_host *)devid;
729 	struct mmc_command *cmd = host->req->cmd;
730 	struct mmc_request *req = host->req;
731 	struct mmc_data *data = cmd->data;
732 	bool timeout = false;
733 
734 	if (cmd->error)
735 		host->state = JZ4740_MMC_STATE_DONE;
736 
737 	switch (host->state) {
738 	case JZ4740_MMC_STATE_READ_RESPONSE:
739 		if (cmd->flags & MMC_RSP_PRESENT)
740 			jz4740_mmc_read_response(host, cmd);
741 
742 		if (!data)
743 			break;
744 
745 		jz_mmc_prepare_data_transfer(host);
746 
747 	case JZ4740_MMC_STATE_TRANSFER_DATA:
748 		if (host->use_dma) {
749 			/* Use DMA if enabled.
750 			 * Data transfer direction is defined later by
751 			 * relying on data flags in
752 			 * jz4740_mmc_prepare_dma_data() and
753 			 * jz4740_mmc_start_dma_transfer().
754 			 */
755 			timeout = jz4740_mmc_start_dma_transfer(host, data);
756 			data->bytes_xfered = data->blocks * data->blksz;
757 		} else if (data->flags & MMC_DATA_READ)
758 			/* Use PIO if DMA is not enabled.
759 			 * Data transfer direction was defined before
760 			 * by relying on data flags in
761 			 * jz_mmc_prepare_data_transfer().
762 			 */
763 			timeout = jz4740_mmc_read_data(host, data);
764 		else
765 			timeout = jz4740_mmc_write_data(host, data);
766 
767 		if (unlikely(timeout)) {
768 			host->state = JZ4740_MMC_STATE_TRANSFER_DATA;
769 			break;
770 		}
771 
772 		jz4740_mmc_transfer_check_state(host, data);
773 
774 		timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_DATA_TRAN_DONE);
775 		if (unlikely(timeout)) {
776 			host->state = JZ4740_MMC_STATE_SEND_STOP;
777 			break;
778 		}
779 		jz4740_mmc_write_irq_reg(host, JZ_MMC_IRQ_DATA_TRAN_DONE);
780 
781 	case JZ4740_MMC_STATE_SEND_STOP:
782 		if (!req->stop)
783 			break;
784 
785 		jz4740_mmc_send_command(host, req->stop);
786 
787 		if (mmc_resp_type(req->stop) & MMC_RSP_BUSY) {
788 			timeout = jz4740_mmc_poll_irq(host,
789 						      JZ_MMC_IRQ_PRG_DONE);
790 			if (timeout) {
791 				host->state = JZ4740_MMC_STATE_DONE;
792 				break;
793 			}
794 		}
795 	case JZ4740_MMC_STATE_DONE:
796 		break;
797 	}
798 
799 	if (!timeout)
800 		jz4740_mmc_request_done(host);
801 
802 	return IRQ_HANDLED;
803 }
804 
805 static irqreturn_t jz_mmc_irq(int irq, void *devid)
806 {
807 	struct jz4740_mmc_host *host = devid;
808 	struct mmc_command *cmd = host->cmd;
809 	uint32_t irq_reg, status, tmp;
810 
811 	status = readl(host->base + JZ_REG_MMC_STATUS);
812 	irq_reg = jz4740_mmc_read_irq_reg(host);
813 
814 	tmp = irq_reg;
815 	irq_reg &= ~host->irq_mask;
816 
817 	tmp &= ~(JZ_MMC_IRQ_TXFIFO_WR_REQ | JZ_MMC_IRQ_RXFIFO_RD_REQ |
818 		JZ_MMC_IRQ_PRG_DONE | JZ_MMC_IRQ_DATA_TRAN_DONE);
819 
820 	if (tmp != irq_reg)
821 		jz4740_mmc_write_irq_reg(host, tmp & ~irq_reg);
822 
823 	if (irq_reg & JZ_MMC_IRQ_SDIO) {
824 		jz4740_mmc_write_irq_reg(host, JZ_MMC_IRQ_SDIO);
825 		mmc_signal_sdio_irq(host->mmc);
826 		irq_reg &= ~JZ_MMC_IRQ_SDIO;
827 	}
828 
829 	if (host->req && cmd && irq_reg) {
830 		if (test_and_clear_bit(0, &host->waiting)) {
831 			del_timer(&host->timeout_timer);
832 
833 			if (status & JZ_MMC_STATUS_TIMEOUT_RES) {
834 					cmd->error = -ETIMEDOUT;
835 			} else if (status & JZ_MMC_STATUS_CRC_RES_ERR) {
836 					cmd->error = -EIO;
837 			} else if (status & (JZ_MMC_STATUS_CRC_READ_ERROR |
838 				    JZ_MMC_STATUS_CRC_WRITE_ERROR)) {
839 					if (cmd->data)
840 							cmd->data->error = -EIO;
841 					cmd->error = -EIO;
842 			}
843 
844 			jz4740_mmc_set_irq_enabled(host, irq_reg, false);
845 			jz4740_mmc_write_irq_reg(host, irq_reg);
846 
847 			return IRQ_WAKE_THREAD;
848 		}
849 	}
850 
851 	return IRQ_HANDLED;
852 }
853 
854 static int jz4740_mmc_set_clock_rate(struct jz4740_mmc_host *host, int rate)
855 {
856 	int div = 0;
857 	int real_rate;
858 
859 	jz4740_mmc_clock_disable(host);
860 	clk_set_rate(host->clk, host->mmc->f_max);
861 
862 	real_rate = clk_get_rate(host->clk);
863 
864 	while (real_rate > rate && div < 7) {
865 		++div;
866 		real_rate >>= 1;
867 	}
868 
869 	writew(div, host->base + JZ_REG_MMC_CLKRT);
870 	return real_rate;
871 }
872 
873 static void jz4740_mmc_request(struct mmc_host *mmc, struct mmc_request *req)
874 {
875 	struct jz4740_mmc_host *host = mmc_priv(mmc);
876 
877 	host->req = req;
878 
879 	jz4740_mmc_write_irq_reg(host, ~0);
880 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, true);
881 
882 	host->state = JZ4740_MMC_STATE_READ_RESPONSE;
883 	set_bit(0, &host->waiting);
884 	mod_timer(&host->timeout_timer, jiffies + 5*HZ);
885 	jz4740_mmc_send_command(host, req->cmd);
886 }
887 
888 static void jz4740_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
889 {
890 	struct jz4740_mmc_host *host = mmc_priv(mmc);
891 	if (ios->clock)
892 		jz4740_mmc_set_clock_rate(host, ios->clock);
893 
894 	switch (ios->power_mode) {
895 	case MMC_POWER_UP:
896 		jz4740_mmc_reset(host);
897 		if (host->power)
898 			gpiod_set_value(host->power, 1);
899 		host->cmdat |= JZ_MMC_CMDAT_INIT;
900 		clk_prepare_enable(host->clk);
901 		break;
902 	case MMC_POWER_ON:
903 		break;
904 	default:
905 		if (host->power)
906 			gpiod_set_value(host->power, 0);
907 		clk_disable_unprepare(host->clk);
908 		break;
909 	}
910 
911 	switch (ios->bus_width) {
912 	case MMC_BUS_WIDTH_1:
913 		host->cmdat &= ~JZ_MMC_CMDAT_BUS_WIDTH_4BIT;
914 		break;
915 	case MMC_BUS_WIDTH_4:
916 		host->cmdat |= JZ_MMC_CMDAT_BUS_WIDTH_4BIT;
917 		break;
918 	default:
919 		break;
920 	}
921 }
922 
923 static void jz4740_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
924 {
925 	struct jz4740_mmc_host *host = mmc_priv(mmc);
926 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_SDIO, enable);
927 }
928 
929 static const struct mmc_host_ops jz4740_mmc_ops = {
930 	.request	= jz4740_mmc_request,
931 	.pre_req	= jz4740_mmc_pre_request,
932 	.post_req	= jz4740_mmc_post_request,
933 	.set_ios	= jz4740_mmc_set_ios,
934 	.get_ro		= mmc_gpio_get_ro,
935 	.get_cd		= mmc_gpio_get_cd,
936 	.enable_sdio_irq = jz4740_mmc_enable_sdio_irq,
937 };
938 
939 static int jz4740_mmc_request_gpios(struct jz4740_mmc_host *host,
940 				    struct mmc_host *mmc,
941 				    struct platform_device *pdev)
942 {
943 	struct jz4740_mmc_platform_data *pdata = dev_get_platdata(&pdev->dev);
944 	int ret = 0;
945 
946 	if (!pdata)
947 		return 0;
948 
949 	if (!pdata->card_detect_active_low)
950 		mmc->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
951 	if (!pdata->read_only_active_low)
952 		mmc->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
953 
954 	/*
955 	 * Get optional card detect and write protect GPIOs,
956 	 * only back out on probe deferral.
957 	 */
958 	ret = mmc_gpiod_request_cd(mmc, "cd", 0, false, 0, NULL);
959 	if (ret == -EPROBE_DEFER)
960 		return ret;
961 
962 	ret = mmc_gpiod_request_ro(mmc, "wp", 0, false, 0, NULL);
963 	if (ret == -EPROBE_DEFER)
964 		return ret;
965 
966 	host->power = devm_gpiod_get_optional(&pdev->dev, "power",
967 					      GPIOD_OUT_HIGH);
968 	return PTR_ERR_OR_ZERO(host->power);
969 }
970 
971 static const struct of_device_id jz4740_mmc_of_match[] = {
972 	{ .compatible = "ingenic,jz4740-mmc", .data = (void *) JZ_MMC_JZ4740 },
973 	{ .compatible = "ingenic,jz4725b-mmc", .data = (void *)JZ_MMC_JZ4725B },
974 	{ .compatible = "ingenic,jz4780-mmc", .data = (void *) JZ_MMC_JZ4780 },
975 	{},
976 };
977 MODULE_DEVICE_TABLE(of, jz4740_mmc_of_match);
978 
979 static int jz4740_mmc_probe(struct platform_device* pdev)
980 {
981 	int ret;
982 	struct mmc_host *mmc;
983 	struct jz4740_mmc_host *host;
984 	const struct of_device_id *match;
985 	struct jz4740_mmc_platform_data *pdata;
986 
987 	pdata = dev_get_platdata(&pdev->dev);
988 
989 	mmc = mmc_alloc_host(sizeof(struct jz4740_mmc_host), &pdev->dev);
990 	if (!mmc) {
991 		dev_err(&pdev->dev, "Failed to alloc mmc host structure\n");
992 		return -ENOMEM;
993 	}
994 
995 	host = mmc_priv(mmc);
996 	host->pdata = pdata;
997 
998 	match = of_match_device(jz4740_mmc_of_match, &pdev->dev);
999 	if (match) {
1000 		host->version = (enum jz4740_mmc_version)match->data;
1001 		ret = mmc_of_parse(mmc);
1002 		if (ret) {
1003 			if (ret != -EPROBE_DEFER)
1004 				dev_err(&pdev->dev,
1005 					"could not parse of data: %d\n", ret);
1006 			goto err_free_host;
1007 		}
1008 	} else {
1009 		/* JZ4740 should be the only one using legacy probe */
1010 		host->version = JZ_MMC_JZ4740;
1011 		mmc->caps |= MMC_CAP_SDIO_IRQ;
1012 		if (!(pdata && pdata->data_1bit))
1013 			mmc->caps |= MMC_CAP_4_BIT_DATA;
1014 		ret = jz4740_mmc_request_gpios(host, mmc, pdev);
1015 		if (ret)
1016 			goto err_free_host;
1017 	}
1018 
1019 	host->irq = platform_get_irq(pdev, 0);
1020 	if (host->irq < 0) {
1021 		ret = host->irq;
1022 		dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
1023 		goto err_free_host;
1024 	}
1025 
1026 	host->clk = devm_clk_get(&pdev->dev, "mmc");
1027 	if (IS_ERR(host->clk)) {
1028 		ret = PTR_ERR(host->clk);
1029 		dev_err(&pdev->dev, "Failed to get mmc clock\n");
1030 		goto err_free_host;
1031 	}
1032 
1033 	host->mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1034 	host->base = devm_ioremap_resource(&pdev->dev, host->mem_res);
1035 	if (IS_ERR(host->base)) {
1036 		ret = PTR_ERR(host->base);
1037 		dev_err(&pdev->dev, "Failed to ioremap base memory\n");
1038 		goto err_free_host;
1039 	}
1040 
1041 	mmc->ops = &jz4740_mmc_ops;
1042 	if (!mmc->f_max)
1043 		mmc->f_max = JZ_MMC_CLK_RATE;
1044 	mmc->f_min = mmc->f_max / 128;
1045 	mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
1046 
1047 	mmc->max_blk_size = (1 << 10) - 1;
1048 	mmc->max_blk_count = (1 << 15) - 1;
1049 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
1050 
1051 	mmc->max_segs = 128;
1052 	mmc->max_seg_size = mmc->max_req_size;
1053 
1054 	host->mmc = mmc;
1055 	host->pdev = pdev;
1056 	spin_lock_init(&host->lock);
1057 	host->irq_mask = ~0;
1058 
1059 	jz4740_mmc_reset(host);
1060 
1061 	ret = request_threaded_irq(host->irq, jz_mmc_irq, jz_mmc_irq_worker, 0,
1062 			dev_name(&pdev->dev), host);
1063 	if (ret) {
1064 		dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
1065 		goto err_free_host;
1066 	}
1067 
1068 	jz4740_mmc_clock_disable(host);
1069 	timer_setup(&host->timeout_timer, jz4740_mmc_timeout, 0);
1070 
1071 	ret = jz4740_mmc_acquire_dma_channels(host);
1072 	if (ret == -EPROBE_DEFER)
1073 		goto err_free_irq;
1074 	host->use_dma = !ret;
1075 
1076 	platform_set_drvdata(pdev, host);
1077 	ret = mmc_add_host(mmc);
1078 
1079 	if (ret) {
1080 		dev_err(&pdev->dev, "Failed to add mmc host: %d\n", ret);
1081 		goto err_release_dma;
1082 	}
1083 	dev_info(&pdev->dev, "JZ SD/MMC card driver registered\n");
1084 
1085 	dev_info(&pdev->dev, "Using %s, %d-bit mode\n",
1086 		 host->use_dma ? "DMA" : "PIO",
1087 		 (mmc->caps & MMC_CAP_4_BIT_DATA) ? 4 : 1);
1088 
1089 	return 0;
1090 
1091 err_release_dma:
1092 	if (host->use_dma)
1093 		jz4740_mmc_release_dma_channels(host);
1094 err_free_irq:
1095 	free_irq(host->irq, host);
1096 err_free_host:
1097 	mmc_free_host(mmc);
1098 
1099 	return ret;
1100 }
1101 
1102 static int jz4740_mmc_remove(struct platform_device *pdev)
1103 {
1104 	struct jz4740_mmc_host *host = platform_get_drvdata(pdev);
1105 
1106 	del_timer_sync(&host->timeout_timer);
1107 	jz4740_mmc_set_irq_enabled(host, 0xff, false);
1108 	jz4740_mmc_reset(host);
1109 
1110 	mmc_remove_host(host->mmc);
1111 
1112 	free_irq(host->irq, host);
1113 
1114 	if (host->use_dma)
1115 		jz4740_mmc_release_dma_channels(host);
1116 
1117 	mmc_free_host(host->mmc);
1118 
1119 	return 0;
1120 }
1121 
1122 #ifdef CONFIG_PM_SLEEP
1123 
1124 static int jz4740_mmc_suspend(struct device *dev)
1125 {
1126 	return pinctrl_pm_select_sleep_state(dev);
1127 }
1128 
1129 static int jz4740_mmc_resume(struct device *dev)
1130 {
1131 	return pinctrl_pm_select_default_state(dev);
1132 }
1133 
1134 static SIMPLE_DEV_PM_OPS(jz4740_mmc_pm_ops, jz4740_mmc_suspend,
1135 	jz4740_mmc_resume);
1136 #define JZ4740_MMC_PM_OPS (&jz4740_mmc_pm_ops)
1137 #else
1138 #define JZ4740_MMC_PM_OPS NULL
1139 #endif
1140 
1141 static struct platform_driver jz4740_mmc_driver = {
1142 	.probe = jz4740_mmc_probe,
1143 	.remove = jz4740_mmc_remove,
1144 	.driver = {
1145 		.name = "jz4740-mmc",
1146 		.of_match_table = of_match_ptr(jz4740_mmc_of_match),
1147 		.pm = JZ4740_MMC_PM_OPS,
1148 	},
1149 };
1150 
1151 module_platform_driver(jz4740_mmc_driver);
1152 
1153 MODULE_DESCRIPTION("JZ4740 SD/MMC controller driver");
1154 MODULE_LICENSE("GPL");
1155 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
1156