xref: /linux/drivers/mmc/host/jz4740_mmc.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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 {
325 	struct jz4740_mmc_host *host = mmc_priv(mmc);
326 	struct mmc_data *data = mrq->data;
327 	struct jz4740_mmc_host_next *next_data = &host->next_data;
328 
329 	BUG_ON(data->host_cookie);
330 
331 	if (host->use_dma) {
332 		struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
333 
334 		if (jz4740_mmc_prepare_dma_data(host, data, next_data, chan))
335 			data->host_cookie = 0;
336 	}
337 }
338 
339 static void jz4740_mmc_post_request(struct mmc_host *mmc,
340 				    struct mmc_request *mrq,
341 				    int err)
342 {
343 	struct jz4740_mmc_host *host = mmc_priv(mmc);
344 	struct mmc_data *data = mrq->data;
345 
346 	if (host->use_dma && data->host_cookie) {
347 		jz4740_mmc_dma_unmap(host, data);
348 		data->host_cookie = 0;
349 	}
350 
351 	if (err) {
352 		struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
353 
354 		dmaengine_terminate_all(chan);
355 	}
356 }
357 
358 /*----------------------------------------------------------------------------*/
359 
360 static void jz4740_mmc_set_irq_enabled(struct jz4740_mmc_host *host,
361 	unsigned int irq, bool enabled)
362 {
363 	unsigned long flags;
364 
365 	spin_lock_irqsave(&host->lock, flags);
366 	if (enabled)
367 		host->irq_mask &= ~irq;
368 	else
369 		host->irq_mask |= irq;
370 	spin_unlock_irqrestore(&host->lock, flags);
371 
372 	writew(host->irq_mask, host->base + JZ_REG_MMC_IMASK);
373 }
374 
375 static void jz4740_mmc_clock_enable(struct jz4740_mmc_host *host,
376 	bool start_transfer)
377 {
378 	uint16_t val = JZ_MMC_STRPCL_CLOCK_START;
379 
380 	if (start_transfer)
381 		val |= JZ_MMC_STRPCL_START_OP;
382 
383 	writew(val, host->base + JZ_REG_MMC_STRPCL);
384 }
385 
386 static void jz4740_mmc_clock_disable(struct jz4740_mmc_host *host)
387 {
388 	uint32_t status;
389 	unsigned int timeout = 1000;
390 
391 	writew(JZ_MMC_STRPCL_CLOCK_STOP, host->base + JZ_REG_MMC_STRPCL);
392 	do {
393 		status = readl(host->base + JZ_REG_MMC_STATUS);
394 	} while (status & JZ_MMC_STATUS_CLK_EN && --timeout);
395 }
396 
397 static void jz4740_mmc_reset(struct jz4740_mmc_host *host)
398 {
399 	uint32_t status;
400 	unsigned int timeout = 1000;
401 
402 	writew(JZ_MMC_STRPCL_RESET, host->base + JZ_REG_MMC_STRPCL);
403 	udelay(10);
404 	do {
405 		status = readl(host->base + JZ_REG_MMC_STATUS);
406 	} while (status & JZ_MMC_STATUS_IS_RESETTING && --timeout);
407 }
408 
409 static void jz4740_mmc_request_done(struct jz4740_mmc_host *host)
410 {
411 	struct mmc_request *req;
412 
413 	req = host->req;
414 	host->req = NULL;
415 
416 	mmc_request_done(host->mmc, req);
417 }
418 
419 static unsigned int jz4740_mmc_poll_irq(struct jz4740_mmc_host *host,
420 	unsigned int irq)
421 {
422 	unsigned int timeout = 0x800;
423 	uint16_t status;
424 
425 	do {
426 		status = readw(host->base + JZ_REG_MMC_IREG);
427 	} while (!(status & irq) && --timeout);
428 
429 	if (timeout == 0) {
430 		set_bit(0, &host->waiting);
431 		mod_timer(&host->timeout_timer, jiffies + 5*HZ);
432 		jz4740_mmc_set_irq_enabled(host, irq, true);
433 		return true;
434 	}
435 
436 	return false;
437 }
438 
439 static void jz4740_mmc_transfer_check_state(struct jz4740_mmc_host *host,
440 	struct mmc_data *data)
441 {
442 	int status;
443 
444 	status = readl(host->base + JZ_REG_MMC_STATUS);
445 	if (status & JZ_MMC_STATUS_WRITE_ERROR_MASK) {
446 		if (status & (JZ_MMC_STATUS_TIMEOUT_WRITE)) {
447 			host->req->cmd->error = -ETIMEDOUT;
448 			data->error = -ETIMEDOUT;
449 		} else {
450 			host->req->cmd->error = -EIO;
451 			data->error = -EIO;
452 		}
453 	} else if (status & JZ_MMC_STATUS_READ_ERROR_MASK) {
454 		if (status & (JZ_MMC_STATUS_TIMEOUT_READ)) {
455 			host->req->cmd->error = -ETIMEDOUT;
456 			data->error = -ETIMEDOUT;
457 		} else {
458 			host->req->cmd->error = -EIO;
459 			data->error = -EIO;
460 		}
461 	}
462 }
463 
464 static bool jz4740_mmc_write_data(struct jz4740_mmc_host *host,
465 	struct mmc_data *data)
466 {
467 	struct sg_mapping_iter *miter = &host->miter;
468 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_TXFIFO;
469 	uint32_t *buf;
470 	bool timeout;
471 	size_t i, j;
472 
473 	while (sg_miter_next(miter)) {
474 		buf = miter->addr;
475 		i = miter->length / 4;
476 		j = i / 8;
477 		i = i & 0x7;
478 		while (j) {
479 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
480 			if (unlikely(timeout))
481 				goto poll_timeout;
482 
483 			writel(buf[0], fifo_addr);
484 			writel(buf[1], fifo_addr);
485 			writel(buf[2], fifo_addr);
486 			writel(buf[3], fifo_addr);
487 			writel(buf[4], fifo_addr);
488 			writel(buf[5], fifo_addr);
489 			writel(buf[6], fifo_addr);
490 			writel(buf[7], fifo_addr);
491 			buf += 8;
492 			--j;
493 		}
494 		if (unlikely(i)) {
495 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
496 			if (unlikely(timeout))
497 				goto poll_timeout;
498 
499 			while (i) {
500 				writel(*buf, fifo_addr);
501 				++buf;
502 				--i;
503 			}
504 		}
505 		data->bytes_xfered += miter->length;
506 	}
507 	sg_miter_stop(miter);
508 
509 	return false;
510 
511 poll_timeout:
512 	miter->consumed = (void *)buf - miter->addr;
513 	data->bytes_xfered += miter->consumed;
514 	sg_miter_stop(miter);
515 
516 	return true;
517 }
518 
519 static bool jz4740_mmc_read_data(struct jz4740_mmc_host *host,
520 				struct mmc_data *data)
521 {
522 	struct sg_mapping_iter *miter = &host->miter;
523 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_RXFIFO;
524 	uint32_t *buf;
525 	uint32_t d;
526 	uint16_t status;
527 	size_t i, j;
528 	unsigned int timeout;
529 
530 	while (sg_miter_next(miter)) {
531 		buf = miter->addr;
532 		i = miter->length;
533 		j = i / 32;
534 		i = i & 0x1f;
535 		while (j) {
536 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
537 			if (unlikely(timeout))
538 				goto poll_timeout;
539 
540 			buf[0] = readl(fifo_addr);
541 			buf[1] = readl(fifo_addr);
542 			buf[2] = readl(fifo_addr);
543 			buf[3] = readl(fifo_addr);
544 			buf[4] = readl(fifo_addr);
545 			buf[5] = readl(fifo_addr);
546 			buf[6] = readl(fifo_addr);
547 			buf[7] = readl(fifo_addr);
548 
549 			buf += 8;
550 			--j;
551 		}
552 
553 		if (unlikely(i)) {
554 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
555 			if (unlikely(timeout))
556 				goto poll_timeout;
557 
558 			while (i >= 4) {
559 				*buf++ = readl(fifo_addr);
560 				i -= 4;
561 			}
562 			if (unlikely(i > 0)) {
563 				d = readl(fifo_addr);
564 				memcpy(buf, &d, i);
565 			}
566 		}
567 		data->bytes_xfered += miter->length;
568 
569 		/* This can go away once MIPS implements
570 		 * flush_kernel_dcache_page */
571 		flush_dcache_page(miter->page);
572 	}
573 	sg_miter_stop(miter);
574 
575 	/* For whatever reason there is sometime one word more in the fifo then
576 	 * requested */
577 	timeout = 1000;
578 	status = readl(host->base + JZ_REG_MMC_STATUS);
579 	while (!(status & JZ_MMC_STATUS_DATA_FIFO_EMPTY) && --timeout) {
580 		d = readl(fifo_addr);
581 		status = readl(host->base + JZ_REG_MMC_STATUS);
582 	}
583 
584 	return false;
585 
586 poll_timeout:
587 	miter->consumed = (void *)buf - miter->addr;
588 	data->bytes_xfered += miter->consumed;
589 	sg_miter_stop(miter);
590 
591 	return true;
592 }
593 
594 static void jz4740_mmc_timeout(unsigned long data)
595 {
596 	struct jz4740_mmc_host *host = (struct jz4740_mmc_host *)data;
597 
598 	if (!test_and_clear_bit(0, &host->waiting))
599 		return;
600 
601 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, false);
602 
603 	host->req->cmd->error = -ETIMEDOUT;
604 	jz4740_mmc_request_done(host);
605 }
606 
607 static void jz4740_mmc_read_response(struct jz4740_mmc_host *host,
608 	struct mmc_command *cmd)
609 {
610 	int i;
611 	uint16_t tmp;
612 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_RESP_FIFO;
613 
614 	if (cmd->flags & MMC_RSP_136) {
615 		tmp = readw(fifo_addr);
616 		for (i = 0; i < 4; ++i) {
617 			cmd->resp[i] = tmp << 24;
618 			tmp = readw(fifo_addr);
619 			cmd->resp[i] |= tmp << 8;
620 			tmp = readw(fifo_addr);
621 			cmd->resp[i] |= tmp >> 8;
622 		}
623 	} else {
624 		cmd->resp[0] = readw(fifo_addr) << 24;
625 		cmd->resp[0] |= readw(fifo_addr) << 8;
626 		cmd->resp[0] |= readw(fifo_addr) & 0xff;
627 	}
628 }
629 
630 static void jz4740_mmc_send_command(struct jz4740_mmc_host *host,
631 	struct mmc_command *cmd)
632 {
633 	uint32_t cmdat = host->cmdat;
634 
635 	host->cmdat &= ~JZ_MMC_CMDAT_INIT;
636 	jz4740_mmc_clock_disable(host);
637 
638 	host->cmd = cmd;
639 
640 	if (cmd->flags & MMC_RSP_BUSY)
641 		cmdat |= JZ_MMC_CMDAT_BUSY;
642 
643 	switch (mmc_resp_type(cmd)) {
644 	case MMC_RSP_R1B:
645 	case MMC_RSP_R1:
646 		cmdat |= JZ_MMC_CMDAT_RSP_R1;
647 		break;
648 	case MMC_RSP_R2:
649 		cmdat |= JZ_MMC_CMDAT_RSP_R2;
650 		break;
651 	case MMC_RSP_R3:
652 		cmdat |= JZ_MMC_CMDAT_RSP_R3;
653 		break;
654 	default:
655 		break;
656 	}
657 
658 	if (cmd->data) {
659 		cmdat |= JZ_MMC_CMDAT_DATA_EN;
660 		if (cmd->data->flags & MMC_DATA_WRITE)
661 			cmdat |= JZ_MMC_CMDAT_WRITE;
662 		if (host->use_dma)
663 			cmdat |= JZ_MMC_CMDAT_DMA_EN;
664 
665 		writew(cmd->data->blksz, host->base + JZ_REG_MMC_BLKLEN);
666 		writew(cmd->data->blocks, host->base + JZ_REG_MMC_NOB);
667 	}
668 
669 	writeb(cmd->opcode, host->base + JZ_REG_MMC_CMD);
670 	writel(cmd->arg, host->base + JZ_REG_MMC_ARG);
671 	writel(cmdat, host->base + JZ_REG_MMC_CMDAT);
672 
673 	jz4740_mmc_clock_enable(host, 1);
674 }
675 
676 static void jz_mmc_prepare_data_transfer(struct jz4740_mmc_host *host)
677 {
678 	struct mmc_command *cmd = host->req->cmd;
679 	struct mmc_data *data = cmd->data;
680 	int direction;
681 
682 	if (data->flags & MMC_DATA_READ)
683 		direction = SG_MITER_TO_SG;
684 	else
685 		direction = SG_MITER_FROM_SG;
686 
687 	sg_miter_start(&host->miter, data->sg, data->sg_len, direction);
688 }
689 
690 
691 static irqreturn_t jz_mmc_irq_worker(int irq, void *devid)
692 {
693 	struct jz4740_mmc_host *host = (struct jz4740_mmc_host *)devid;
694 	struct mmc_command *cmd = host->req->cmd;
695 	struct mmc_request *req = host->req;
696 	struct mmc_data *data = cmd->data;
697 	bool timeout = false;
698 
699 	if (cmd->error)
700 		host->state = JZ4740_MMC_STATE_DONE;
701 
702 	switch (host->state) {
703 	case JZ4740_MMC_STATE_READ_RESPONSE:
704 		if (cmd->flags & MMC_RSP_PRESENT)
705 			jz4740_mmc_read_response(host, cmd);
706 
707 		if (!data)
708 			break;
709 
710 		jz_mmc_prepare_data_transfer(host);
711 
712 	case JZ4740_MMC_STATE_TRANSFER_DATA:
713 		if (host->use_dma) {
714 			/* Use DMA if enabled.
715 			 * Data transfer direction is defined later by
716 			 * relying on data flags in
717 			 * jz4740_mmc_prepare_dma_data() and
718 			 * jz4740_mmc_start_dma_transfer().
719 			 */
720 			timeout = jz4740_mmc_start_dma_transfer(host, data);
721 			data->bytes_xfered = data->blocks * data->blksz;
722 		} else if (data->flags & MMC_DATA_READ)
723 			/* Use PIO if DMA is not enabled.
724 			 * Data transfer direction was defined before
725 			 * by relying on data flags in
726 			 * jz_mmc_prepare_data_transfer().
727 			 */
728 			timeout = jz4740_mmc_read_data(host, data);
729 		else
730 			timeout = jz4740_mmc_write_data(host, data);
731 
732 		if (unlikely(timeout)) {
733 			host->state = JZ4740_MMC_STATE_TRANSFER_DATA;
734 			break;
735 		}
736 
737 		jz4740_mmc_transfer_check_state(host, data);
738 
739 		timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_DATA_TRAN_DONE);
740 		if (unlikely(timeout)) {
741 			host->state = JZ4740_MMC_STATE_SEND_STOP;
742 			break;
743 		}
744 		writew(JZ_MMC_IRQ_DATA_TRAN_DONE, host->base + JZ_REG_MMC_IREG);
745 
746 	case JZ4740_MMC_STATE_SEND_STOP:
747 		if (!req->stop)
748 			break;
749 
750 		jz4740_mmc_send_command(host, req->stop);
751 
752 		if (mmc_resp_type(req->stop) & MMC_RSP_BUSY) {
753 			timeout = jz4740_mmc_poll_irq(host,
754 						      JZ_MMC_IRQ_PRG_DONE);
755 			if (timeout) {
756 				host->state = JZ4740_MMC_STATE_DONE;
757 				break;
758 			}
759 		}
760 	case JZ4740_MMC_STATE_DONE:
761 		break;
762 	}
763 
764 	if (!timeout)
765 		jz4740_mmc_request_done(host);
766 
767 	return IRQ_HANDLED;
768 }
769 
770 static irqreturn_t jz_mmc_irq(int irq, void *devid)
771 {
772 	struct jz4740_mmc_host *host = devid;
773 	struct mmc_command *cmd = host->cmd;
774 	uint16_t irq_reg, status, tmp;
775 
776 	irq_reg = readw(host->base + JZ_REG_MMC_IREG);
777 
778 	tmp = irq_reg;
779 	irq_reg &= ~host->irq_mask;
780 
781 	tmp &= ~(JZ_MMC_IRQ_TXFIFO_WR_REQ | JZ_MMC_IRQ_RXFIFO_RD_REQ |
782 		JZ_MMC_IRQ_PRG_DONE | JZ_MMC_IRQ_DATA_TRAN_DONE);
783 
784 	if (tmp != irq_reg)
785 		writew(tmp & ~irq_reg, host->base + JZ_REG_MMC_IREG);
786 
787 	if (irq_reg & JZ_MMC_IRQ_SDIO) {
788 		writew(JZ_MMC_IRQ_SDIO, host->base + JZ_REG_MMC_IREG);
789 		mmc_signal_sdio_irq(host->mmc);
790 		irq_reg &= ~JZ_MMC_IRQ_SDIO;
791 	}
792 
793 	if (host->req && cmd && irq_reg) {
794 		if (test_and_clear_bit(0, &host->waiting)) {
795 			del_timer(&host->timeout_timer);
796 
797 			status = readl(host->base + JZ_REG_MMC_STATUS);
798 
799 			if (status & JZ_MMC_STATUS_TIMEOUT_RES) {
800 					cmd->error = -ETIMEDOUT;
801 			} else if (status & JZ_MMC_STATUS_CRC_RES_ERR) {
802 					cmd->error = -EIO;
803 			} else if (status & (JZ_MMC_STATUS_CRC_READ_ERROR |
804 				    JZ_MMC_STATUS_CRC_WRITE_ERROR)) {
805 					if (cmd->data)
806 							cmd->data->error = -EIO;
807 					cmd->error = -EIO;
808 			}
809 
810 			jz4740_mmc_set_irq_enabled(host, irq_reg, false);
811 			writew(irq_reg, host->base + JZ_REG_MMC_IREG);
812 
813 			return IRQ_WAKE_THREAD;
814 		}
815 	}
816 
817 	return IRQ_HANDLED;
818 }
819 
820 static int jz4740_mmc_set_clock_rate(struct jz4740_mmc_host *host, int rate)
821 {
822 	int div = 0;
823 	int real_rate;
824 
825 	jz4740_mmc_clock_disable(host);
826 	clk_set_rate(host->clk, JZ_MMC_CLK_RATE);
827 
828 	real_rate = clk_get_rate(host->clk);
829 
830 	while (real_rate > rate && div < 7) {
831 		++div;
832 		real_rate >>= 1;
833 	}
834 
835 	writew(div, host->base + JZ_REG_MMC_CLKRT);
836 	return real_rate;
837 }
838 
839 static void jz4740_mmc_request(struct mmc_host *mmc, struct mmc_request *req)
840 {
841 	struct jz4740_mmc_host *host = mmc_priv(mmc);
842 
843 	host->req = req;
844 
845 	writew(0xffff, host->base + JZ_REG_MMC_IREG);
846 
847 	writew(JZ_MMC_IRQ_END_CMD_RES, host->base + JZ_REG_MMC_IREG);
848 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, true);
849 
850 	host->state = JZ4740_MMC_STATE_READ_RESPONSE;
851 	set_bit(0, &host->waiting);
852 	mod_timer(&host->timeout_timer, jiffies + 5*HZ);
853 	jz4740_mmc_send_command(host, req->cmd);
854 }
855 
856 static void jz4740_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
857 {
858 	struct jz4740_mmc_host *host = mmc_priv(mmc);
859 	if (ios->clock)
860 		jz4740_mmc_set_clock_rate(host, ios->clock);
861 
862 	switch (ios->power_mode) {
863 	case MMC_POWER_UP:
864 		jz4740_mmc_reset(host);
865 		if (gpio_is_valid(host->pdata->gpio_power))
866 			gpio_set_value(host->pdata->gpio_power,
867 					!host->pdata->power_active_low);
868 		host->cmdat |= JZ_MMC_CMDAT_INIT;
869 		clk_prepare_enable(host->clk);
870 		break;
871 	case MMC_POWER_ON:
872 		break;
873 	default:
874 		if (gpio_is_valid(host->pdata->gpio_power))
875 			gpio_set_value(host->pdata->gpio_power,
876 					host->pdata->power_active_low);
877 		clk_disable_unprepare(host->clk);
878 		break;
879 	}
880 
881 	switch (ios->bus_width) {
882 	case MMC_BUS_WIDTH_1:
883 		host->cmdat &= ~JZ_MMC_CMDAT_BUS_WIDTH_4BIT;
884 		break;
885 	case MMC_BUS_WIDTH_4:
886 		host->cmdat |= JZ_MMC_CMDAT_BUS_WIDTH_4BIT;
887 		break;
888 	default:
889 		break;
890 	}
891 }
892 
893 static void jz4740_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
894 {
895 	struct jz4740_mmc_host *host = mmc_priv(mmc);
896 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_SDIO, enable);
897 }
898 
899 static const struct mmc_host_ops jz4740_mmc_ops = {
900 	.request	= jz4740_mmc_request,
901 	.pre_req	= jz4740_mmc_pre_request,
902 	.post_req	= jz4740_mmc_post_request,
903 	.set_ios	= jz4740_mmc_set_ios,
904 	.get_ro		= mmc_gpio_get_ro,
905 	.get_cd		= mmc_gpio_get_cd,
906 	.enable_sdio_irq = jz4740_mmc_enable_sdio_irq,
907 };
908 
909 static const struct jz_gpio_bulk_request jz4740_mmc_pins[] = {
910 	JZ_GPIO_BULK_PIN(MSC_CMD),
911 	JZ_GPIO_BULK_PIN(MSC_CLK),
912 	JZ_GPIO_BULK_PIN(MSC_DATA0),
913 	JZ_GPIO_BULK_PIN(MSC_DATA1),
914 	JZ_GPIO_BULK_PIN(MSC_DATA2),
915 	JZ_GPIO_BULK_PIN(MSC_DATA3),
916 };
917 
918 static int jz4740_mmc_request_gpio(struct device *dev, int gpio,
919 	const char *name, bool output, int value)
920 {
921 	int ret;
922 
923 	if (!gpio_is_valid(gpio))
924 		return 0;
925 
926 	ret = gpio_request(gpio, name);
927 	if (ret) {
928 		dev_err(dev, "Failed to request %s gpio: %d\n", name, ret);
929 		return ret;
930 	}
931 
932 	if (output)
933 		gpio_direction_output(gpio, value);
934 	else
935 		gpio_direction_input(gpio);
936 
937 	return 0;
938 }
939 
940 static int jz4740_mmc_request_gpios(struct mmc_host *mmc,
941 	struct platform_device *pdev)
942 {
943 	struct jz4740_mmc_platform_data *pdata = pdev->dev.platform_data;
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 	if (gpio_is_valid(pdata->gpio_card_detect)) {
955 		ret = mmc_gpio_request_cd(mmc, pdata->gpio_card_detect, 0);
956 		if (ret)
957 			return ret;
958 	}
959 
960 	if (gpio_is_valid(pdata->gpio_read_only)) {
961 		ret = mmc_gpio_request_ro(mmc, pdata->gpio_read_only);
962 		if (ret)
963 			return ret;
964 	}
965 
966 	return jz4740_mmc_request_gpio(&pdev->dev, pdata->gpio_power,
967 			"MMC read only", true, pdata->power_active_low);
968 }
969 
970 static void jz4740_mmc_free_gpios(struct platform_device *pdev)
971 {
972 	struct jz4740_mmc_platform_data *pdata = pdev->dev.platform_data;
973 
974 	if (!pdata)
975 		return;
976 
977 	if (gpio_is_valid(pdata->gpio_power))
978 		gpio_free(pdata->gpio_power);
979 }
980 
981 static inline size_t jz4740_mmc_num_pins(struct jz4740_mmc_host *host)
982 {
983 	size_t num_pins = ARRAY_SIZE(jz4740_mmc_pins);
984 	if (host->pdata && host->pdata->data_1bit)
985 		num_pins -= 3;
986 
987 	return num_pins;
988 }
989 
990 static int jz4740_mmc_probe(struct platform_device* pdev)
991 {
992 	int ret;
993 	struct mmc_host *mmc;
994 	struct jz4740_mmc_host *host;
995 	struct jz4740_mmc_platform_data *pdata;
996 
997 	pdata = pdev->dev.platform_data;
998 
999 	mmc = mmc_alloc_host(sizeof(struct jz4740_mmc_host), &pdev->dev);
1000 	if (!mmc) {
1001 		dev_err(&pdev->dev, "Failed to alloc mmc host structure\n");
1002 		return -ENOMEM;
1003 	}
1004 
1005 	host = mmc_priv(mmc);
1006 	host->pdata = pdata;
1007 
1008 	host->irq = platform_get_irq(pdev, 0);
1009 	if (host->irq < 0) {
1010 		ret = host->irq;
1011 		dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
1012 		goto err_free_host;
1013 	}
1014 
1015 	host->clk = devm_clk_get(&pdev->dev, "mmc");
1016 	if (IS_ERR(host->clk)) {
1017 		ret = PTR_ERR(host->clk);
1018 		dev_err(&pdev->dev, "Failed to get mmc clock\n");
1019 		goto err_free_host;
1020 	}
1021 
1022 	host->mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1023 	host->base = devm_ioremap_resource(&pdev->dev, host->mem_res);
1024 	if (IS_ERR(host->base)) {
1025 		ret = PTR_ERR(host->base);
1026 		dev_err(&pdev->dev, "Failed to ioremap base memory\n");
1027 		goto err_free_host;
1028 	}
1029 
1030 	ret = jz_gpio_bulk_request(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
1031 	if (ret) {
1032 		dev_err(&pdev->dev, "Failed to request mmc pins: %d\n", ret);
1033 		goto err_free_host;
1034 	}
1035 
1036 	ret = jz4740_mmc_request_gpios(mmc, pdev);
1037 	if (ret)
1038 		goto err_gpio_bulk_free;
1039 
1040 	mmc->ops = &jz4740_mmc_ops;
1041 	mmc->f_min = JZ_MMC_CLK_RATE / 128;
1042 	mmc->f_max = JZ_MMC_CLK_RATE;
1043 	mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
1044 	mmc->caps = (pdata && pdata->data_1bit) ? 0 : MMC_CAP_4_BIT_DATA;
1045 	mmc->caps |= MMC_CAP_SDIO_IRQ;
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 = 0xffff;
1058 
1059 	ret = request_threaded_irq(host->irq, jz_mmc_irq, jz_mmc_irq_worker, 0,
1060 			dev_name(&pdev->dev), host);
1061 	if (ret) {
1062 		dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
1063 		goto err_free_gpios;
1064 	}
1065 
1066 	jz4740_mmc_reset(host);
1067 	jz4740_mmc_clock_disable(host);
1068 	setup_timer(&host->timeout_timer, jz4740_mmc_timeout,
1069 			(unsigned long)host);
1070 
1071 	host->use_dma = true;
1072 	if (host->use_dma && jz4740_mmc_acquire_dma_channels(host) != 0)
1073 		host->use_dma = false;
1074 
1075 	platform_set_drvdata(pdev, host);
1076 	ret = mmc_add_host(mmc);
1077 
1078 	if (ret) {
1079 		dev_err(&pdev->dev, "Failed to add mmc host: %d\n", ret);
1080 		goto err_free_irq;
1081 	}
1082 	dev_info(&pdev->dev, "JZ SD/MMC card driver registered\n");
1083 
1084 	dev_info(&pdev->dev, "Using %s, %d-bit mode\n",
1085 		 host->use_dma ? "DMA" : "PIO",
1086 		 (mmc->caps & MMC_CAP_4_BIT_DATA) ? 4 : 1);
1087 
1088 	return 0;
1089 
1090 err_free_irq:
1091 	free_irq(host->irq, host);
1092 err_free_gpios:
1093 	jz4740_mmc_free_gpios(pdev);
1094 err_gpio_bulk_free:
1095 	if (host->use_dma)
1096 		jz4740_mmc_release_dma_channels(host);
1097 	jz_gpio_bulk_free(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
1098 err_free_host:
1099 	mmc_free_host(mmc);
1100 
1101 	return ret;
1102 }
1103 
1104 static int jz4740_mmc_remove(struct platform_device *pdev)
1105 {
1106 	struct jz4740_mmc_host *host = platform_get_drvdata(pdev);
1107 
1108 	del_timer_sync(&host->timeout_timer);
1109 	jz4740_mmc_set_irq_enabled(host, 0xff, false);
1110 	jz4740_mmc_reset(host);
1111 
1112 	mmc_remove_host(host->mmc);
1113 
1114 	free_irq(host->irq, host);
1115 
1116 	jz4740_mmc_free_gpios(pdev);
1117 	jz_gpio_bulk_free(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
1118 
1119 	if (host->use_dma)
1120 		jz4740_mmc_release_dma_channels(host);
1121 
1122 	mmc_free_host(host->mmc);
1123 
1124 	return 0;
1125 }
1126 
1127 #ifdef CONFIG_PM_SLEEP
1128 
1129 static int jz4740_mmc_suspend(struct device *dev)
1130 {
1131 	struct jz4740_mmc_host *host = dev_get_drvdata(dev);
1132 
1133 	jz_gpio_bulk_suspend(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
1134 
1135 	return 0;
1136 }
1137 
1138 static int jz4740_mmc_resume(struct device *dev)
1139 {
1140 	struct jz4740_mmc_host *host = dev_get_drvdata(dev);
1141 
1142 	jz_gpio_bulk_resume(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
1143 
1144 	return 0;
1145 }
1146 
1147 static SIMPLE_DEV_PM_OPS(jz4740_mmc_pm_ops, jz4740_mmc_suspend,
1148 	jz4740_mmc_resume);
1149 #define JZ4740_MMC_PM_OPS (&jz4740_mmc_pm_ops)
1150 #else
1151 #define JZ4740_MMC_PM_OPS NULL
1152 #endif
1153 
1154 static struct platform_driver jz4740_mmc_driver = {
1155 	.probe = jz4740_mmc_probe,
1156 	.remove = jz4740_mmc_remove,
1157 	.driver = {
1158 		.name = "jz4740-mmc",
1159 		.pm = JZ4740_MMC_PM_OPS,
1160 	},
1161 };
1162 
1163 module_platform_driver(jz4740_mmc_driver);
1164 
1165 MODULE_DESCRIPTION("JZ4740 SD/MMC controller driver");
1166 MODULE_LICENSE("GPL");
1167 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
1168