xref: /openbmc/linux/drivers/mmc/host/jz4740_mmc.c (revision 7587eb18)
1 /*
2  *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
3  *  JZ4740 SD/MMC controller driver
4  *
5  *  This program is free software; you can redistribute  it and/or modify it
6  *  under  the terms of  the GNU General  Public License as published by the
7  *  Free Software Foundation;  either version 2 of the  License, or (at your
8  *  option) any later version.
9  *
10  *  You should have received a copy of the  GNU General Public License along
11  *  with this program; if not, write  to the Free Software Foundation, Inc.,
12  *  675 Mass Ave, Cambridge, MA 02139, USA.
13  *
14  */
15 
16 #include <linux/mmc/host.h>
17 #include <linux/mmc/slot-gpio.h>
18 #include <linux/err.h>
19 #include <linux/io.h>
20 #include <linux/irq.h>
21 #include <linux/interrupt.h>
22 #include <linux/module.h>
23 #include <linux/platform_device.h>
24 #include <linux/delay.h>
25 #include <linux/scatterlist.h>
26 #include <linux/clk.h>
27 
28 #include <linux/bitops.h>
29 #include <linux/gpio.h>
30 #include <asm/mach-jz4740/gpio.h>
31 #include <asm/cacheflush.h>
32 #include <linux/dma-mapping.h>
33 #include <linux/dmaengine.h>
34 
35 #include <asm/mach-jz4740/dma.h>
36 #include <asm/mach-jz4740/jz4740_mmc.h>
37 
38 #define JZ_REG_MMC_STRPCL	0x00
39 #define JZ_REG_MMC_STATUS	0x04
40 #define JZ_REG_MMC_CLKRT	0x08
41 #define JZ_REG_MMC_CMDAT	0x0C
42 #define JZ_REG_MMC_RESTO	0x10
43 #define JZ_REG_MMC_RDTO		0x14
44 #define JZ_REG_MMC_BLKLEN	0x18
45 #define JZ_REG_MMC_NOB		0x1C
46 #define JZ_REG_MMC_SNOB		0x20
47 #define JZ_REG_MMC_IMASK	0x24
48 #define JZ_REG_MMC_IREG		0x28
49 #define JZ_REG_MMC_CMD		0x2C
50 #define JZ_REG_MMC_ARG		0x30
51 #define JZ_REG_MMC_RESP_FIFO	0x34
52 #define JZ_REG_MMC_RXFIFO	0x38
53 #define JZ_REG_MMC_TXFIFO	0x3C
54 
55 #define JZ_MMC_STRPCL_EXIT_MULTIPLE BIT(7)
56 #define JZ_MMC_STRPCL_EXIT_TRANSFER BIT(6)
57 #define JZ_MMC_STRPCL_START_READWAIT BIT(5)
58 #define JZ_MMC_STRPCL_STOP_READWAIT BIT(4)
59 #define JZ_MMC_STRPCL_RESET BIT(3)
60 #define JZ_MMC_STRPCL_START_OP BIT(2)
61 #define JZ_MMC_STRPCL_CLOCK_CONTROL (BIT(1) | BIT(0))
62 #define JZ_MMC_STRPCL_CLOCK_STOP BIT(0)
63 #define JZ_MMC_STRPCL_CLOCK_START BIT(1)
64 
65 
66 #define JZ_MMC_STATUS_IS_RESETTING BIT(15)
67 #define JZ_MMC_STATUS_SDIO_INT_ACTIVE BIT(14)
68 #define JZ_MMC_STATUS_PRG_DONE BIT(13)
69 #define JZ_MMC_STATUS_DATA_TRAN_DONE BIT(12)
70 #define JZ_MMC_STATUS_END_CMD_RES BIT(11)
71 #define JZ_MMC_STATUS_DATA_FIFO_AFULL BIT(10)
72 #define JZ_MMC_STATUS_IS_READWAIT BIT(9)
73 #define JZ_MMC_STATUS_CLK_EN BIT(8)
74 #define JZ_MMC_STATUS_DATA_FIFO_FULL BIT(7)
75 #define JZ_MMC_STATUS_DATA_FIFO_EMPTY BIT(6)
76 #define JZ_MMC_STATUS_CRC_RES_ERR BIT(5)
77 #define JZ_MMC_STATUS_CRC_READ_ERROR BIT(4)
78 #define JZ_MMC_STATUS_TIMEOUT_WRITE BIT(3)
79 #define JZ_MMC_STATUS_CRC_WRITE_ERROR BIT(2)
80 #define JZ_MMC_STATUS_TIMEOUT_RES BIT(1)
81 #define JZ_MMC_STATUS_TIMEOUT_READ BIT(0)
82 
83 #define JZ_MMC_STATUS_READ_ERROR_MASK (BIT(4) | BIT(0))
84 #define JZ_MMC_STATUS_WRITE_ERROR_MASK (BIT(3) | BIT(2))
85 
86 
87 #define JZ_MMC_CMDAT_IO_ABORT BIT(11)
88 #define JZ_MMC_CMDAT_BUS_WIDTH_4BIT BIT(10)
89 #define JZ_MMC_CMDAT_DMA_EN BIT(8)
90 #define JZ_MMC_CMDAT_INIT BIT(7)
91 #define JZ_MMC_CMDAT_BUSY BIT(6)
92 #define JZ_MMC_CMDAT_STREAM BIT(5)
93 #define JZ_MMC_CMDAT_WRITE BIT(4)
94 #define JZ_MMC_CMDAT_DATA_EN BIT(3)
95 #define JZ_MMC_CMDAT_RESPONSE_FORMAT (BIT(2) | BIT(1) | BIT(0))
96 #define JZ_MMC_CMDAT_RSP_R1 1
97 #define JZ_MMC_CMDAT_RSP_R2 2
98 #define JZ_MMC_CMDAT_RSP_R3 3
99 
100 #define JZ_MMC_IRQ_SDIO BIT(7)
101 #define JZ_MMC_IRQ_TXFIFO_WR_REQ BIT(6)
102 #define JZ_MMC_IRQ_RXFIFO_RD_REQ BIT(5)
103 #define JZ_MMC_IRQ_END_CMD_RES BIT(2)
104 #define JZ_MMC_IRQ_PRG_DONE BIT(1)
105 #define JZ_MMC_IRQ_DATA_TRAN_DONE BIT(0)
106 
107 
108 #define JZ_MMC_CLK_RATE 24000000
109 
110 enum jz4740_mmc_state {
111 	JZ4740_MMC_STATE_READ_RESPONSE,
112 	JZ4740_MMC_STATE_TRANSFER_DATA,
113 	JZ4740_MMC_STATE_SEND_STOP,
114 	JZ4740_MMC_STATE_DONE,
115 };
116 
117 struct jz4740_mmc_host_next {
118 	int sg_len;
119 	s32 cookie;
120 };
121 
122 struct jz4740_mmc_host {
123 	struct mmc_host *mmc;
124 	struct platform_device *pdev;
125 	struct jz4740_mmc_platform_data *pdata;
126 	struct clk *clk;
127 
128 	int irq;
129 	int card_detect_irq;
130 
131 	void __iomem *base;
132 	struct resource *mem_res;
133 	struct mmc_request *req;
134 	struct mmc_command *cmd;
135 
136 	unsigned long waiting;
137 
138 	uint32_t cmdat;
139 
140 	uint16_t irq_mask;
141 
142 	spinlock_t lock;
143 
144 	struct timer_list timeout_timer;
145 	struct sg_mapping_iter miter;
146 	enum jz4740_mmc_state state;
147 
148 	/* DMA support */
149 	struct dma_chan *dma_rx;
150 	struct dma_chan *dma_tx;
151 	struct jz4740_mmc_host_next next_data;
152 	bool use_dma;
153 	int sg_len;
154 
155 /* The DMA trigger level is 8 words, that is to say, the DMA read
156  * trigger is when data words in MSC_RXFIFO is >= 8 and the DMA write
157  * trigger is when data words in MSC_TXFIFO is < 8.
158  */
159 #define JZ4740_MMC_FIFO_HALF_SIZE 8
160 };
161 
162 /*----------------------------------------------------------------------------*/
163 /* DMA infrastructure */
164 
165 static void jz4740_mmc_release_dma_channels(struct jz4740_mmc_host *host)
166 {
167 	if (!host->use_dma)
168 		return;
169 
170 	dma_release_channel(host->dma_tx);
171 	dma_release_channel(host->dma_rx);
172 }
173 
174 static int jz4740_mmc_acquire_dma_channels(struct jz4740_mmc_host *host)
175 {
176 	dma_cap_mask_t mask;
177 
178 	dma_cap_zero(mask);
179 	dma_cap_set(DMA_SLAVE, mask);
180 
181 	host->dma_tx = dma_request_channel(mask, NULL, host);
182 	if (!host->dma_tx) {
183 		dev_err(mmc_dev(host->mmc), "Failed to get dma_tx channel\n");
184 		return -ENODEV;
185 	}
186 
187 	host->dma_rx = dma_request_channel(mask, NULL, host);
188 	if (!host->dma_rx) {
189 		dev_err(mmc_dev(host->mmc), "Failed to get dma_rx channel\n");
190 		goto free_master_write;
191 	}
192 
193 	/* Initialize DMA pre request cookie */
194 	host->next_data.cookie = 1;
195 
196 	return 0;
197 
198 free_master_write:
199 	dma_release_channel(host->dma_tx);
200 	return -ENODEV;
201 }
202 
203 static inline int jz4740_mmc_get_dma_dir(struct mmc_data *data)
204 {
205 	return (data->flags & MMC_DATA_READ) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
206 }
207 
208 static inline struct dma_chan *jz4740_mmc_get_dma_chan(struct jz4740_mmc_host *host,
209 						       struct mmc_data *data)
210 {
211 	return (data->flags & MMC_DATA_READ) ? host->dma_rx : host->dma_tx;
212 }
213 
214 static void jz4740_mmc_dma_unmap(struct jz4740_mmc_host *host,
215 				 struct mmc_data *data)
216 {
217 	struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
218 	enum dma_data_direction dir = jz4740_mmc_get_dma_dir(data);
219 
220 	dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
221 }
222 
223 /* Prepares DMA data for current/next transfer, returns non-zero on failure */
224 static int jz4740_mmc_prepare_dma_data(struct jz4740_mmc_host *host,
225 				       struct mmc_data *data,
226 				       struct jz4740_mmc_host_next *next,
227 				       struct dma_chan *chan)
228 {
229 	struct jz4740_mmc_host_next *next_data = &host->next_data;
230 	enum dma_data_direction dir = jz4740_mmc_get_dma_dir(data);
231 	int sg_len;
232 
233 	if (!next && data->host_cookie &&
234 	    data->host_cookie != host->next_data.cookie) {
235 		dev_warn(mmc_dev(host->mmc),
236 			 "[%s] invalid cookie: data->host_cookie %d host->next_data.cookie %d\n",
237 			 __func__,
238 			 data->host_cookie,
239 			 host->next_data.cookie);
240 		data->host_cookie = 0;
241 	}
242 
243 	/* Check if next job is already prepared */
244 	if (next || data->host_cookie != host->next_data.cookie) {
245 		sg_len = dma_map_sg(chan->device->dev,
246 				    data->sg,
247 				    data->sg_len,
248 				    dir);
249 
250 	} else {
251 		sg_len = next_data->sg_len;
252 		next_data->sg_len = 0;
253 	}
254 
255 	if (sg_len <= 0) {
256 		dev_err(mmc_dev(host->mmc),
257 			"Failed to map scatterlist for DMA operation\n");
258 		return -EINVAL;
259 	}
260 
261 	if (next) {
262 		next->sg_len = sg_len;
263 		data->host_cookie = ++next->cookie < 0 ? 1 : next->cookie;
264 	} else
265 		host->sg_len = sg_len;
266 
267 	return 0;
268 }
269 
270 static int jz4740_mmc_start_dma_transfer(struct jz4740_mmc_host *host,
271 					 struct mmc_data *data)
272 {
273 	int ret;
274 	struct dma_chan *chan;
275 	struct dma_async_tx_descriptor *desc;
276 	struct dma_slave_config conf = {
277 		.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
278 		.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
279 		.src_maxburst = JZ4740_MMC_FIFO_HALF_SIZE,
280 		.dst_maxburst = JZ4740_MMC_FIFO_HALF_SIZE,
281 	};
282 
283 	if (data->flags & MMC_DATA_WRITE) {
284 		conf.direction = DMA_MEM_TO_DEV;
285 		conf.dst_addr = host->mem_res->start + JZ_REG_MMC_TXFIFO;
286 		conf.slave_id = JZ4740_DMA_TYPE_MMC_TRANSMIT;
287 		chan = host->dma_tx;
288 	} else {
289 		conf.direction = DMA_DEV_TO_MEM;
290 		conf.src_addr = host->mem_res->start + JZ_REG_MMC_RXFIFO;
291 		conf.slave_id = JZ4740_DMA_TYPE_MMC_RECEIVE;
292 		chan = host->dma_rx;
293 	}
294 
295 	ret = jz4740_mmc_prepare_dma_data(host, data, NULL, chan);
296 	if (ret)
297 		return ret;
298 
299 	dmaengine_slave_config(chan, &conf);
300 	desc = dmaengine_prep_slave_sg(chan,
301 				       data->sg,
302 				       host->sg_len,
303 				       conf.direction,
304 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
305 	if (!desc) {
306 		dev_err(mmc_dev(host->mmc),
307 			"Failed to allocate DMA %s descriptor",
308 			 conf.direction == DMA_MEM_TO_DEV ? "TX" : "RX");
309 		goto dma_unmap;
310 	}
311 
312 	dmaengine_submit(desc);
313 	dma_async_issue_pending(chan);
314 
315 	return 0;
316 
317 dma_unmap:
318 	jz4740_mmc_dma_unmap(host, data);
319 	return -ENOMEM;
320 }
321 
322 static void jz4740_mmc_pre_request(struct mmc_host *mmc,
323 				   struct mmc_request *mrq,
324 				   bool is_first_req)
325 {
326 	struct jz4740_mmc_host *host = mmc_priv(mmc);
327 	struct mmc_data *data = mrq->data;
328 	struct jz4740_mmc_host_next *next_data = &host->next_data;
329 
330 	BUG_ON(data->host_cookie);
331 
332 	if (host->use_dma) {
333 		struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
334 
335 		if (jz4740_mmc_prepare_dma_data(host, data, next_data, chan))
336 			data->host_cookie = 0;
337 	}
338 }
339 
340 static void jz4740_mmc_post_request(struct mmc_host *mmc,
341 				    struct mmc_request *mrq,
342 				    int err)
343 {
344 	struct jz4740_mmc_host *host = mmc_priv(mmc);
345 	struct mmc_data *data = mrq->data;
346 
347 	if (host->use_dma && data->host_cookie) {
348 		jz4740_mmc_dma_unmap(host, data);
349 		data->host_cookie = 0;
350 	}
351 
352 	if (err) {
353 		struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
354 
355 		dmaengine_terminate_all(chan);
356 	}
357 }
358 
359 /*----------------------------------------------------------------------------*/
360 
361 static void jz4740_mmc_set_irq_enabled(struct jz4740_mmc_host *host,
362 	unsigned int irq, bool enabled)
363 {
364 	unsigned long flags;
365 
366 	spin_lock_irqsave(&host->lock, flags);
367 	if (enabled)
368 		host->irq_mask &= ~irq;
369 	else
370 		host->irq_mask |= irq;
371 	spin_unlock_irqrestore(&host->lock, flags);
372 
373 	writew(host->irq_mask, host->base + JZ_REG_MMC_IMASK);
374 }
375 
376 static void jz4740_mmc_clock_enable(struct jz4740_mmc_host *host,
377 	bool start_transfer)
378 {
379 	uint16_t val = JZ_MMC_STRPCL_CLOCK_START;
380 
381 	if (start_transfer)
382 		val |= JZ_MMC_STRPCL_START_OP;
383 
384 	writew(val, host->base + JZ_REG_MMC_STRPCL);
385 }
386 
387 static void jz4740_mmc_clock_disable(struct jz4740_mmc_host *host)
388 {
389 	uint32_t status;
390 	unsigned int timeout = 1000;
391 
392 	writew(JZ_MMC_STRPCL_CLOCK_STOP, host->base + JZ_REG_MMC_STRPCL);
393 	do {
394 		status = readl(host->base + JZ_REG_MMC_STATUS);
395 	} while (status & JZ_MMC_STATUS_CLK_EN && --timeout);
396 }
397 
398 static void jz4740_mmc_reset(struct jz4740_mmc_host *host)
399 {
400 	uint32_t status;
401 	unsigned int timeout = 1000;
402 
403 	writew(JZ_MMC_STRPCL_RESET, host->base + JZ_REG_MMC_STRPCL);
404 	udelay(10);
405 	do {
406 		status = readl(host->base + JZ_REG_MMC_STATUS);
407 	} while (status & JZ_MMC_STATUS_IS_RESETTING && --timeout);
408 }
409 
410 static void jz4740_mmc_request_done(struct jz4740_mmc_host *host)
411 {
412 	struct mmc_request *req;
413 
414 	req = host->req;
415 	host->req = NULL;
416 
417 	mmc_request_done(host->mmc, req);
418 }
419 
420 static unsigned int jz4740_mmc_poll_irq(struct jz4740_mmc_host *host,
421 	unsigned int irq)
422 {
423 	unsigned int timeout = 0x800;
424 	uint16_t status;
425 
426 	do {
427 		status = readw(host->base + JZ_REG_MMC_IREG);
428 	} while (!(status & irq) && --timeout);
429 
430 	if (timeout == 0) {
431 		set_bit(0, &host->waiting);
432 		mod_timer(&host->timeout_timer, jiffies + 5*HZ);
433 		jz4740_mmc_set_irq_enabled(host, irq, true);
434 		return true;
435 	}
436 
437 	return false;
438 }
439 
440 static void jz4740_mmc_transfer_check_state(struct jz4740_mmc_host *host,
441 	struct mmc_data *data)
442 {
443 	int status;
444 
445 	status = readl(host->base + JZ_REG_MMC_STATUS);
446 	if (status & JZ_MMC_STATUS_WRITE_ERROR_MASK) {
447 		if (status & (JZ_MMC_STATUS_TIMEOUT_WRITE)) {
448 			host->req->cmd->error = -ETIMEDOUT;
449 			data->error = -ETIMEDOUT;
450 		} else {
451 			host->req->cmd->error = -EIO;
452 			data->error = -EIO;
453 		}
454 	} else if (status & JZ_MMC_STATUS_READ_ERROR_MASK) {
455 		if (status & (JZ_MMC_STATUS_TIMEOUT_READ)) {
456 			host->req->cmd->error = -ETIMEDOUT;
457 			data->error = -ETIMEDOUT;
458 		} else {
459 			host->req->cmd->error = -EIO;
460 			data->error = -EIO;
461 		}
462 	}
463 }
464 
465 static bool jz4740_mmc_write_data(struct jz4740_mmc_host *host,
466 	struct mmc_data *data)
467 {
468 	struct sg_mapping_iter *miter = &host->miter;
469 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_TXFIFO;
470 	uint32_t *buf;
471 	bool timeout;
472 	size_t i, j;
473 
474 	while (sg_miter_next(miter)) {
475 		buf = miter->addr;
476 		i = miter->length / 4;
477 		j = i / 8;
478 		i = i & 0x7;
479 		while (j) {
480 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
481 			if (unlikely(timeout))
482 				goto poll_timeout;
483 
484 			writel(buf[0], fifo_addr);
485 			writel(buf[1], fifo_addr);
486 			writel(buf[2], fifo_addr);
487 			writel(buf[3], fifo_addr);
488 			writel(buf[4], fifo_addr);
489 			writel(buf[5], fifo_addr);
490 			writel(buf[6], fifo_addr);
491 			writel(buf[7], fifo_addr);
492 			buf += 8;
493 			--j;
494 		}
495 		if (unlikely(i)) {
496 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
497 			if (unlikely(timeout))
498 				goto poll_timeout;
499 
500 			while (i) {
501 				writel(*buf, fifo_addr);
502 				++buf;
503 				--i;
504 			}
505 		}
506 		data->bytes_xfered += miter->length;
507 	}
508 	sg_miter_stop(miter);
509 
510 	return false;
511 
512 poll_timeout:
513 	miter->consumed = (void *)buf - miter->addr;
514 	data->bytes_xfered += miter->consumed;
515 	sg_miter_stop(miter);
516 
517 	return true;
518 }
519 
520 static bool jz4740_mmc_read_data(struct jz4740_mmc_host *host,
521 				struct mmc_data *data)
522 {
523 	struct sg_mapping_iter *miter = &host->miter;
524 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_RXFIFO;
525 	uint32_t *buf;
526 	uint32_t d;
527 	uint16_t status;
528 	size_t i, j;
529 	unsigned int timeout;
530 
531 	while (sg_miter_next(miter)) {
532 		buf = miter->addr;
533 		i = miter->length;
534 		j = i / 32;
535 		i = i & 0x1f;
536 		while (j) {
537 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
538 			if (unlikely(timeout))
539 				goto poll_timeout;
540 
541 			buf[0] = readl(fifo_addr);
542 			buf[1] = readl(fifo_addr);
543 			buf[2] = readl(fifo_addr);
544 			buf[3] = readl(fifo_addr);
545 			buf[4] = readl(fifo_addr);
546 			buf[5] = readl(fifo_addr);
547 			buf[6] = readl(fifo_addr);
548 			buf[7] = readl(fifo_addr);
549 
550 			buf += 8;
551 			--j;
552 		}
553 
554 		if (unlikely(i)) {
555 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
556 			if (unlikely(timeout))
557 				goto poll_timeout;
558 
559 			while (i >= 4) {
560 				*buf++ = readl(fifo_addr);
561 				i -= 4;
562 			}
563 			if (unlikely(i > 0)) {
564 				d = readl(fifo_addr);
565 				memcpy(buf, &d, i);
566 			}
567 		}
568 		data->bytes_xfered += miter->length;
569 
570 		/* This can go away once MIPS implements
571 		 * flush_kernel_dcache_page */
572 		flush_dcache_page(miter->page);
573 	}
574 	sg_miter_stop(miter);
575 
576 	/* For whatever reason there is sometime one word more in the fifo then
577 	 * requested */
578 	timeout = 1000;
579 	status = readl(host->base + JZ_REG_MMC_STATUS);
580 	while (!(status & JZ_MMC_STATUS_DATA_FIFO_EMPTY) && --timeout) {
581 		d = readl(fifo_addr);
582 		status = readl(host->base + JZ_REG_MMC_STATUS);
583 	}
584 
585 	return false;
586 
587 poll_timeout:
588 	miter->consumed = (void *)buf - miter->addr;
589 	data->bytes_xfered += miter->consumed;
590 	sg_miter_stop(miter);
591 
592 	return true;
593 }
594 
595 static void jz4740_mmc_timeout(unsigned long data)
596 {
597 	struct jz4740_mmc_host *host = (struct jz4740_mmc_host *)data;
598 
599 	if (!test_and_clear_bit(0, &host->waiting))
600 		return;
601 
602 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, false);
603 
604 	host->req->cmd->error = -ETIMEDOUT;
605 	jz4740_mmc_request_done(host);
606 }
607 
608 static void jz4740_mmc_read_response(struct jz4740_mmc_host *host,
609 	struct mmc_command *cmd)
610 {
611 	int i;
612 	uint16_t tmp;
613 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_RESP_FIFO;
614 
615 	if (cmd->flags & MMC_RSP_136) {
616 		tmp = readw(fifo_addr);
617 		for (i = 0; i < 4; ++i) {
618 			cmd->resp[i] = tmp << 24;
619 			tmp = readw(fifo_addr);
620 			cmd->resp[i] |= tmp << 8;
621 			tmp = readw(fifo_addr);
622 			cmd->resp[i] |= tmp >> 8;
623 		}
624 	} else {
625 		cmd->resp[0] = readw(fifo_addr) << 24;
626 		cmd->resp[0] |= readw(fifo_addr) << 8;
627 		cmd->resp[0] |= readw(fifo_addr) & 0xff;
628 	}
629 }
630 
631 static void jz4740_mmc_send_command(struct jz4740_mmc_host *host,
632 	struct mmc_command *cmd)
633 {
634 	uint32_t cmdat = host->cmdat;
635 
636 	host->cmdat &= ~JZ_MMC_CMDAT_INIT;
637 	jz4740_mmc_clock_disable(host);
638 
639 	host->cmd = cmd;
640 
641 	if (cmd->flags & MMC_RSP_BUSY)
642 		cmdat |= JZ_MMC_CMDAT_BUSY;
643 
644 	switch (mmc_resp_type(cmd)) {
645 	case MMC_RSP_R1B:
646 	case MMC_RSP_R1:
647 		cmdat |= JZ_MMC_CMDAT_RSP_R1;
648 		break;
649 	case MMC_RSP_R2:
650 		cmdat |= JZ_MMC_CMDAT_RSP_R2;
651 		break;
652 	case MMC_RSP_R3:
653 		cmdat |= JZ_MMC_CMDAT_RSP_R3;
654 		break;
655 	default:
656 		break;
657 	}
658 
659 	if (cmd->data) {
660 		cmdat |= JZ_MMC_CMDAT_DATA_EN;
661 		if (cmd->data->flags & MMC_DATA_WRITE)
662 			cmdat |= JZ_MMC_CMDAT_WRITE;
663 		if (host->use_dma)
664 			cmdat |= JZ_MMC_CMDAT_DMA_EN;
665 
666 		writew(cmd->data->blksz, host->base + JZ_REG_MMC_BLKLEN);
667 		writew(cmd->data->blocks, host->base + JZ_REG_MMC_NOB);
668 	}
669 
670 	writeb(cmd->opcode, host->base + JZ_REG_MMC_CMD);
671 	writel(cmd->arg, host->base + JZ_REG_MMC_ARG);
672 	writel(cmdat, host->base + JZ_REG_MMC_CMDAT);
673 
674 	jz4740_mmc_clock_enable(host, 1);
675 }
676 
677 static void jz_mmc_prepare_data_transfer(struct jz4740_mmc_host *host)
678 {
679 	struct mmc_command *cmd = host->req->cmd;
680 	struct mmc_data *data = cmd->data;
681 	int direction;
682 
683 	if (data->flags & MMC_DATA_READ)
684 		direction = SG_MITER_TO_SG;
685 	else
686 		direction = SG_MITER_FROM_SG;
687 
688 	sg_miter_start(&host->miter, data->sg, data->sg_len, direction);
689 }
690 
691 
692 static irqreturn_t jz_mmc_irq_worker(int irq, void *devid)
693 {
694 	struct jz4740_mmc_host *host = (struct jz4740_mmc_host *)devid;
695 	struct mmc_command *cmd = host->req->cmd;
696 	struct mmc_request *req = host->req;
697 	struct mmc_data *data = cmd->data;
698 	bool timeout = false;
699 
700 	if (cmd->error)
701 		host->state = JZ4740_MMC_STATE_DONE;
702 
703 	switch (host->state) {
704 	case JZ4740_MMC_STATE_READ_RESPONSE:
705 		if (cmd->flags & MMC_RSP_PRESENT)
706 			jz4740_mmc_read_response(host, cmd);
707 
708 		if (!data)
709 			break;
710 
711 		jz_mmc_prepare_data_transfer(host);
712 
713 	case JZ4740_MMC_STATE_TRANSFER_DATA:
714 		if (host->use_dma) {
715 			/* Use DMA if enabled.
716 			 * Data transfer direction is defined later by
717 			 * relying on data flags in
718 			 * jz4740_mmc_prepare_dma_data() and
719 			 * jz4740_mmc_start_dma_transfer().
720 			 */
721 			timeout = jz4740_mmc_start_dma_transfer(host, data);
722 			data->bytes_xfered = data->blocks * data->blksz;
723 		} else if (data->flags & MMC_DATA_READ)
724 			/* Use PIO if DMA is not enabled.
725 			 * Data transfer direction was defined before
726 			 * by relying on data flags in
727 			 * jz_mmc_prepare_data_transfer().
728 			 */
729 			timeout = jz4740_mmc_read_data(host, data);
730 		else
731 			timeout = jz4740_mmc_write_data(host, data);
732 
733 		if (unlikely(timeout)) {
734 			host->state = JZ4740_MMC_STATE_TRANSFER_DATA;
735 			break;
736 		}
737 
738 		jz4740_mmc_transfer_check_state(host, data);
739 
740 		timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_DATA_TRAN_DONE);
741 		if (unlikely(timeout)) {
742 			host->state = JZ4740_MMC_STATE_SEND_STOP;
743 			break;
744 		}
745 		writew(JZ_MMC_IRQ_DATA_TRAN_DONE, host->base + JZ_REG_MMC_IREG);
746 
747 	case JZ4740_MMC_STATE_SEND_STOP:
748 		if (!req->stop)
749 			break;
750 
751 		jz4740_mmc_send_command(host, req->stop);
752 
753 		if (mmc_resp_type(req->stop) & MMC_RSP_BUSY) {
754 			timeout = jz4740_mmc_poll_irq(host,
755 						      JZ_MMC_IRQ_PRG_DONE);
756 			if (timeout) {
757 				host->state = JZ4740_MMC_STATE_DONE;
758 				break;
759 			}
760 		}
761 	case JZ4740_MMC_STATE_DONE:
762 		break;
763 	}
764 
765 	if (!timeout)
766 		jz4740_mmc_request_done(host);
767 
768 	return IRQ_HANDLED;
769 }
770 
771 static irqreturn_t jz_mmc_irq(int irq, void *devid)
772 {
773 	struct jz4740_mmc_host *host = devid;
774 	struct mmc_command *cmd = host->cmd;
775 	uint16_t irq_reg, status, tmp;
776 
777 	irq_reg = readw(host->base + JZ_REG_MMC_IREG);
778 
779 	tmp = irq_reg;
780 	irq_reg &= ~host->irq_mask;
781 
782 	tmp &= ~(JZ_MMC_IRQ_TXFIFO_WR_REQ | JZ_MMC_IRQ_RXFIFO_RD_REQ |
783 		JZ_MMC_IRQ_PRG_DONE | JZ_MMC_IRQ_DATA_TRAN_DONE);
784 
785 	if (tmp != irq_reg)
786 		writew(tmp & ~irq_reg, host->base + JZ_REG_MMC_IREG);
787 
788 	if (irq_reg & JZ_MMC_IRQ_SDIO) {
789 		writew(JZ_MMC_IRQ_SDIO, host->base + JZ_REG_MMC_IREG);
790 		mmc_signal_sdio_irq(host->mmc);
791 		irq_reg &= ~JZ_MMC_IRQ_SDIO;
792 	}
793 
794 	if (host->req && cmd && irq_reg) {
795 		if (test_and_clear_bit(0, &host->waiting)) {
796 			del_timer(&host->timeout_timer);
797 
798 			status = readl(host->base + JZ_REG_MMC_STATUS);
799 
800 			if (status & JZ_MMC_STATUS_TIMEOUT_RES) {
801 					cmd->error = -ETIMEDOUT;
802 			} else if (status & JZ_MMC_STATUS_CRC_RES_ERR) {
803 					cmd->error = -EIO;
804 			} else if (status & (JZ_MMC_STATUS_CRC_READ_ERROR |
805 				    JZ_MMC_STATUS_CRC_WRITE_ERROR)) {
806 					if (cmd->data)
807 							cmd->data->error = -EIO;
808 					cmd->error = -EIO;
809 			}
810 
811 			jz4740_mmc_set_irq_enabled(host, irq_reg, false);
812 			writew(irq_reg, host->base + JZ_REG_MMC_IREG);
813 
814 			return IRQ_WAKE_THREAD;
815 		}
816 	}
817 
818 	return IRQ_HANDLED;
819 }
820 
821 static int jz4740_mmc_set_clock_rate(struct jz4740_mmc_host *host, int rate)
822 {
823 	int div = 0;
824 	int real_rate;
825 
826 	jz4740_mmc_clock_disable(host);
827 	clk_set_rate(host->clk, JZ_MMC_CLK_RATE);
828 
829 	real_rate = clk_get_rate(host->clk);
830 
831 	while (real_rate > rate && div < 7) {
832 		++div;
833 		real_rate >>= 1;
834 	}
835 
836 	writew(div, host->base + JZ_REG_MMC_CLKRT);
837 	return real_rate;
838 }
839 
840 static void jz4740_mmc_request(struct mmc_host *mmc, struct mmc_request *req)
841 {
842 	struct jz4740_mmc_host *host = mmc_priv(mmc);
843 
844 	host->req = req;
845 
846 	writew(0xffff, host->base + JZ_REG_MMC_IREG);
847 
848 	writew(JZ_MMC_IRQ_END_CMD_RES, host->base + JZ_REG_MMC_IREG);
849 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, true);
850 
851 	host->state = JZ4740_MMC_STATE_READ_RESPONSE;
852 	set_bit(0, &host->waiting);
853 	mod_timer(&host->timeout_timer, jiffies + 5*HZ);
854 	jz4740_mmc_send_command(host, req->cmd);
855 }
856 
857 static void jz4740_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
858 {
859 	struct jz4740_mmc_host *host = mmc_priv(mmc);
860 	if (ios->clock)
861 		jz4740_mmc_set_clock_rate(host, ios->clock);
862 
863 	switch (ios->power_mode) {
864 	case MMC_POWER_UP:
865 		jz4740_mmc_reset(host);
866 		if (gpio_is_valid(host->pdata->gpio_power))
867 			gpio_set_value(host->pdata->gpio_power,
868 					!host->pdata->power_active_low);
869 		host->cmdat |= JZ_MMC_CMDAT_INIT;
870 		clk_prepare_enable(host->clk);
871 		break;
872 	case MMC_POWER_ON:
873 		break;
874 	default:
875 		if (gpio_is_valid(host->pdata->gpio_power))
876 			gpio_set_value(host->pdata->gpio_power,
877 					host->pdata->power_active_low);
878 		clk_disable_unprepare(host->clk);
879 		break;
880 	}
881 
882 	switch (ios->bus_width) {
883 	case MMC_BUS_WIDTH_1:
884 		host->cmdat &= ~JZ_MMC_CMDAT_BUS_WIDTH_4BIT;
885 		break;
886 	case MMC_BUS_WIDTH_4:
887 		host->cmdat |= JZ_MMC_CMDAT_BUS_WIDTH_4BIT;
888 		break;
889 	default:
890 		break;
891 	}
892 }
893 
894 static void jz4740_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
895 {
896 	struct jz4740_mmc_host *host = mmc_priv(mmc);
897 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_SDIO, enable);
898 }
899 
900 static const struct mmc_host_ops jz4740_mmc_ops = {
901 	.request	= jz4740_mmc_request,
902 	.pre_req	= jz4740_mmc_pre_request,
903 	.post_req	= jz4740_mmc_post_request,
904 	.set_ios	= jz4740_mmc_set_ios,
905 	.get_ro		= mmc_gpio_get_ro,
906 	.get_cd		= mmc_gpio_get_cd,
907 	.enable_sdio_irq = jz4740_mmc_enable_sdio_irq,
908 };
909 
910 static const struct jz_gpio_bulk_request jz4740_mmc_pins[] = {
911 	JZ_GPIO_BULK_PIN(MSC_CMD),
912 	JZ_GPIO_BULK_PIN(MSC_CLK),
913 	JZ_GPIO_BULK_PIN(MSC_DATA0),
914 	JZ_GPIO_BULK_PIN(MSC_DATA1),
915 	JZ_GPIO_BULK_PIN(MSC_DATA2),
916 	JZ_GPIO_BULK_PIN(MSC_DATA3),
917 };
918 
919 static int jz4740_mmc_request_gpio(struct device *dev, int gpio,
920 	const char *name, bool output, int value)
921 {
922 	int ret;
923 
924 	if (!gpio_is_valid(gpio))
925 		return 0;
926 
927 	ret = gpio_request(gpio, name);
928 	if (ret) {
929 		dev_err(dev, "Failed to request %s gpio: %d\n", name, ret);
930 		return ret;
931 	}
932 
933 	if (output)
934 		gpio_direction_output(gpio, value);
935 	else
936 		gpio_direction_input(gpio);
937 
938 	return 0;
939 }
940 
941 static int jz4740_mmc_request_gpios(struct mmc_host *mmc,
942 	struct platform_device *pdev)
943 {
944 	struct jz4740_mmc_platform_data *pdata = pdev->dev.platform_data;
945 	int ret = 0;
946 
947 	if (!pdata)
948 		return 0;
949 
950 	if (!pdata->card_detect_active_low)
951 		mmc->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
952 	if (!pdata->read_only_active_low)
953 		mmc->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
954 
955 	if (gpio_is_valid(pdata->gpio_card_detect)) {
956 		ret = mmc_gpio_request_cd(mmc, pdata->gpio_card_detect, 0);
957 		if (ret)
958 			return ret;
959 	}
960 
961 	if (gpio_is_valid(pdata->gpio_read_only)) {
962 		ret = mmc_gpio_request_ro(mmc, pdata->gpio_read_only);
963 		if (ret)
964 			return ret;
965 	}
966 
967 	return jz4740_mmc_request_gpio(&pdev->dev, pdata->gpio_power,
968 			"MMC read only", true, pdata->power_active_low);
969 }
970 
971 static void jz4740_mmc_free_gpios(struct platform_device *pdev)
972 {
973 	struct jz4740_mmc_platform_data *pdata = pdev->dev.platform_data;
974 
975 	if (!pdata)
976 		return;
977 
978 	if (gpio_is_valid(pdata->gpio_power))
979 		gpio_free(pdata->gpio_power);
980 }
981 
982 static inline size_t jz4740_mmc_num_pins(struct jz4740_mmc_host *host)
983 {
984 	size_t num_pins = ARRAY_SIZE(jz4740_mmc_pins);
985 	if (host->pdata && host->pdata->data_1bit)
986 		num_pins -= 3;
987 
988 	return num_pins;
989 }
990 
991 static int jz4740_mmc_probe(struct platform_device* pdev)
992 {
993 	int ret;
994 	struct mmc_host *mmc;
995 	struct jz4740_mmc_host *host;
996 	struct jz4740_mmc_platform_data *pdata;
997 
998 	pdata = pdev->dev.platform_data;
999 
1000 	mmc = mmc_alloc_host(sizeof(struct jz4740_mmc_host), &pdev->dev);
1001 	if (!mmc) {
1002 		dev_err(&pdev->dev, "Failed to alloc mmc host structure\n");
1003 		return -ENOMEM;
1004 	}
1005 
1006 	host = mmc_priv(mmc);
1007 	host->pdata = pdata;
1008 
1009 	host->irq = platform_get_irq(pdev, 0);
1010 	if (host->irq < 0) {
1011 		ret = host->irq;
1012 		dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
1013 		goto err_free_host;
1014 	}
1015 
1016 	host->clk = devm_clk_get(&pdev->dev, "mmc");
1017 	if (IS_ERR(host->clk)) {
1018 		ret = PTR_ERR(host->clk);
1019 		dev_err(&pdev->dev, "Failed to get mmc clock\n");
1020 		goto err_free_host;
1021 	}
1022 
1023 	host->mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1024 	host->base = devm_ioremap_resource(&pdev->dev, host->mem_res);
1025 	if (IS_ERR(host->base)) {
1026 		ret = PTR_ERR(host->base);
1027 		dev_err(&pdev->dev, "Failed to ioremap base memory\n");
1028 		goto err_free_host;
1029 	}
1030 
1031 	ret = jz_gpio_bulk_request(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
1032 	if (ret) {
1033 		dev_err(&pdev->dev, "Failed to request mmc pins: %d\n", ret);
1034 		goto err_free_host;
1035 	}
1036 
1037 	ret = jz4740_mmc_request_gpios(mmc, pdev);
1038 	if (ret)
1039 		goto err_gpio_bulk_free;
1040 
1041 	mmc->ops = &jz4740_mmc_ops;
1042 	mmc->f_min = JZ_MMC_CLK_RATE / 128;
1043 	mmc->f_max = JZ_MMC_CLK_RATE;
1044 	mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
1045 	mmc->caps = (pdata && pdata->data_1bit) ? 0 : MMC_CAP_4_BIT_DATA;
1046 	mmc->caps |= MMC_CAP_SDIO_IRQ;
1047 
1048 	mmc->max_blk_size = (1 << 10) - 1;
1049 	mmc->max_blk_count = (1 << 15) - 1;
1050 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
1051 
1052 	mmc->max_segs = 128;
1053 	mmc->max_seg_size = mmc->max_req_size;
1054 
1055 	host->mmc = mmc;
1056 	host->pdev = pdev;
1057 	spin_lock_init(&host->lock);
1058 	host->irq_mask = 0xffff;
1059 
1060 	ret = request_threaded_irq(host->irq, jz_mmc_irq, jz_mmc_irq_worker, 0,
1061 			dev_name(&pdev->dev), host);
1062 	if (ret) {
1063 		dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
1064 		goto err_free_gpios;
1065 	}
1066 
1067 	jz4740_mmc_reset(host);
1068 	jz4740_mmc_clock_disable(host);
1069 	setup_timer(&host->timeout_timer, jz4740_mmc_timeout,
1070 			(unsigned long)host);
1071 	/* It is not important when it times out, it just needs to timeout. */
1072 	set_timer_slack(&host->timeout_timer, HZ);
1073 
1074 	host->use_dma = true;
1075 	if (host->use_dma && jz4740_mmc_acquire_dma_channels(host) != 0)
1076 		host->use_dma = false;
1077 
1078 	platform_set_drvdata(pdev, host);
1079 	ret = mmc_add_host(mmc);
1080 
1081 	if (ret) {
1082 		dev_err(&pdev->dev, "Failed to add mmc host: %d\n", ret);
1083 		goto err_free_irq;
1084 	}
1085 	dev_info(&pdev->dev, "JZ SD/MMC card driver registered\n");
1086 
1087 	dev_info(&pdev->dev, "Using %s, %d-bit mode\n",
1088 		 host->use_dma ? "DMA" : "PIO",
1089 		 (mmc->caps & MMC_CAP_4_BIT_DATA) ? 4 : 1);
1090 
1091 	return 0;
1092 
1093 err_free_irq:
1094 	free_irq(host->irq, host);
1095 err_free_gpios:
1096 	jz4740_mmc_free_gpios(pdev);
1097 err_gpio_bulk_free:
1098 	if (host->use_dma)
1099 		jz4740_mmc_release_dma_channels(host);
1100 	jz_gpio_bulk_free(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
1101 err_free_host:
1102 	mmc_free_host(mmc);
1103 
1104 	return ret;
1105 }
1106 
1107 static int jz4740_mmc_remove(struct platform_device *pdev)
1108 {
1109 	struct jz4740_mmc_host *host = platform_get_drvdata(pdev);
1110 
1111 	del_timer_sync(&host->timeout_timer);
1112 	jz4740_mmc_set_irq_enabled(host, 0xff, false);
1113 	jz4740_mmc_reset(host);
1114 
1115 	mmc_remove_host(host->mmc);
1116 
1117 	free_irq(host->irq, host);
1118 
1119 	jz4740_mmc_free_gpios(pdev);
1120 	jz_gpio_bulk_free(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
1121 
1122 	if (host->use_dma)
1123 		jz4740_mmc_release_dma_channels(host);
1124 
1125 	mmc_free_host(host->mmc);
1126 
1127 	return 0;
1128 }
1129 
1130 #ifdef CONFIG_PM_SLEEP
1131 
1132 static int jz4740_mmc_suspend(struct device *dev)
1133 {
1134 	struct jz4740_mmc_host *host = dev_get_drvdata(dev);
1135 
1136 	jz_gpio_bulk_suspend(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
1137 
1138 	return 0;
1139 }
1140 
1141 static int jz4740_mmc_resume(struct device *dev)
1142 {
1143 	struct jz4740_mmc_host *host = dev_get_drvdata(dev);
1144 
1145 	jz_gpio_bulk_resume(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
1146 
1147 	return 0;
1148 }
1149 
1150 static SIMPLE_DEV_PM_OPS(jz4740_mmc_pm_ops, jz4740_mmc_suspend,
1151 	jz4740_mmc_resume);
1152 #define JZ4740_MMC_PM_OPS (&jz4740_mmc_pm_ops)
1153 #else
1154 #define JZ4740_MMC_PM_OPS NULL
1155 #endif
1156 
1157 static struct platform_driver jz4740_mmc_driver = {
1158 	.probe = jz4740_mmc_probe,
1159 	.remove = jz4740_mmc_remove,
1160 	.driver = {
1161 		.name = "jz4740-mmc",
1162 		.pm = JZ4740_MMC_PM_OPS,
1163 	},
1164 };
1165 
1166 module_platform_driver(jz4740_mmc_driver);
1167 
1168 MODULE_DESCRIPTION("JZ4740 SD/MMC controller driver");
1169 MODULE_LICENSE("GPL");
1170 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
1171