xref: /openbmc/linux/drivers/mmc/host/jz4740_mmc.c (revision 588b48ca)
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 
34 #include <asm/mach-jz4740/jz4740_mmc.h>
35 
36 #define JZ_REG_MMC_STRPCL	0x00
37 #define JZ_REG_MMC_STATUS	0x04
38 #define JZ_REG_MMC_CLKRT	0x08
39 #define JZ_REG_MMC_CMDAT	0x0C
40 #define JZ_REG_MMC_RESTO	0x10
41 #define JZ_REG_MMC_RDTO		0x14
42 #define JZ_REG_MMC_BLKLEN	0x18
43 #define JZ_REG_MMC_NOB		0x1C
44 #define JZ_REG_MMC_SNOB		0x20
45 #define JZ_REG_MMC_IMASK	0x24
46 #define JZ_REG_MMC_IREG		0x28
47 #define JZ_REG_MMC_CMD		0x2C
48 #define JZ_REG_MMC_ARG		0x30
49 #define JZ_REG_MMC_RESP_FIFO	0x34
50 #define JZ_REG_MMC_RXFIFO	0x38
51 #define JZ_REG_MMC_TXFIFO	0x3C
52 
53 #define JZ_MMC_STRPCL_EXIT_MULTIPLE BIT(7)
54 #define JZ_MMC_STRPCL_EXIT_TRANSFER BIT(6)
55 #define JZ_MMC_STRPCL_START_READWAIT BIT(5)
56 #define JZ_MMC_STRPCL_STOP_READWAIT BIT(4)
57 #define JZ_MMC_STRPCL_RESET BIT(3)
58 #define JZ_MMC_STRPCL_START_OP BIT(2)
59 #define JZ_MMC_STRPCL_CLOCK_CONTROL (BIT(1) | BIT(0))
60 #define JZ_MMC_STRPCL_CLOCK_STOP BIT(0)
61 #define JZ_MMC_STRPCL_CLOCK_START BIT(1)
62 
63 
64 #define JZ_MMC_STATUS_IS_RESETTING BIT(15)
65 #define JZ_MMC_STATUS_SDIO_INT_ACTIVE BIT(14)
66 #define JZ_MMC_STATUS_PRG_DONE BIT(13)
67 #define JZ_MMC_STATUS_DATA_TRAN_DONE BIT(12)
68 #define JZ_MMC_STATUS_END_CMD_RES BIT(11)
69 #define JZ_MMC_STATUS_DATA_FIFO_AFULL BIT(10)
70 #define JZ_MMC_STATUS_IS_READWAIT BIT(9)
71 #define JZ_MMC_STATUS_CLK_EN BIT(8)
72 #define JZ_MMC_STATUS_DATA_FIFO_FULL BIT(7)
73 #define JZ_MMC_STATUS_DATA_FIFO_EMPTY BIT(6)
74 #define JZ_MMC_STATUS_CRC_RES_ERR BIT(5)
75 #define JZ_MMC_STATUS_CRC_READ_ERROR BIT(4)
76 #define JZ_MMC_STATUS_TIMEOUT_WRITE BIT(3)
77 #define JZ_MMC_STATUS_CRC_WRITE_ERROR BIT(2)
78 #define JZ_MMC_STATUS_TIMEOUT_RES BIT(1)
79 #define JZ_MMC_STATUS_TIMEOUT_READ BIT(0)
80 
81 #define JZ_MMC_STATUS_READ_ERROR_MASK (BIT(4) | BIT(0))
82 #define JZ_MMC_STATUS_WRITE_ERROR_MASK (BIT(3) | BIT(2))
83 
84 
85 #define JZ_MMC_CMDAT_IO_ABORT BIT(11)
86 #define JZ_MMC_CMDAT_BUS_WIDTH_4BIT BIT(10)
87 #define JZ_MMC_CMDAT_DMA_EN BIT(8)
88 #define JZ_MMC_CMDAT_INIT BIT(7)
89 #define JZ_MMC_CMDAT_BUSY BIT(6)
90 #define JZ_MMC_CMDAT_STREAM BIT(5)
91 #define JZ_MMC_CMDAT_WRITE BIT(4)
92 #define JZ_MMC_CMDAT_DATA_EN BIT(3)
93 #define JZ_MMC_CMDAT_RESPONSE_FORMAT (BIT(2) | BIT(1) | BIT(0))
94 #define JZ_MMC_CMDAT_RSP_R1 1
95 #define JZ_MMC_CMDAT_RSP_R2 2
96 #define JZ_MMC_CMDAT_RSP_R3 3
97 
98 #define JZ_MMC_IRQ_SDIO BIT(7)
99 #define JZ_MMC_IRQ_TXFIFO_WR_REQ BIT(6)
100 #define JZ_MMC_IRQ_RXFIFO_RD_REQ BIT(5)
101 #define JZ_MMC_IRQ_END_CMD_RES BIT(2)
102 #define JZ_MMC_IRQ_PRG_DONE BIT(1)
103 #define JZ_MMC_IRQ_DATA_TRAN_DONE BIT(0)
104 
105 
106 #define JZ_MMC_CLK_RATE 24000000
107 
108 enum jz4740_mmc_state {
109 	JZ4740_MMC_STATE_READ_RESPONSE,
110 	JZ4740_MMC_STATE_TRANSFER_DATA,
111 	JZ4740_MMC_STATE_SEND_STOP,
112 	JZ4740_MMC_STATE_DONE,
113 };
114 
115 struct jz4740_mmc_host {
116 	struct mmc_host *mmc;
117 	struct platform_device *pdev;
118 	struct jz4740_mmc_platform_data *pdata;
119 	struct clk *clk;
120 
121 	int irq;
122 	int card_detect_irq;
123 
124 	void __iomem *base;
125 	struct mmc_request *req;
126 	struct mmc_command *cmd;
127 
128 	unsigned long waiting;
129 
130 	uint32_t cmdat;
131 
132 	uint16_t irq_mask;
133 
134 	spinlock_t lock;
135 
136 	struct timer_list timeout_timer;
137 	struct sg_mapping_iter miter;
138 	enum jz4740_mmc_state state;
139 };
140 
141 static void jz4740_mmc_set_irq_enabled(struct jz4740_mmc_host *host,
142 	unsigned int irq, bool enabled)
143 {
144 	unsigned long flags;
145 
146 	spin_lock_irqsave(&host->lock, flags);
147 	if (enabled)
148 		host->irq_mask &= ~irq;
149 	else
150 		host->irq_mask |= irq;
151 	spin_unlock_irqrestore(&host->lock, flags);
152 
153 	writew(host->irq_mask, host->base + JZ_REG_MMC_IMASK);
154 }
155 
156 static void jz4740_mmc_clock_enable(struct jz4740_mmc_host *host,
157 	bool start_transfer)
158 {
159 	uint16_t val = JZ_MMC_STRPCL_CLOCK_START;
160 
161 	if (start_transfer)
162 		val |= JZ_MMC_STRPCL_START_OP;
163 
164 	writew(val, host->base + JZ_REG_MMC_STRPCL);
165 }
166 
167 static void jz4740_mmc_clock_disable(struct jz4740_mmc_host *host)
168 {
169 	uint32_t status;
170 	unsigned int timeout = 1000;
171 
172 	writew(JZ_MMC_STRPCL_CLOCK_STOP, host->base + JZ_REG_MMC_STRPCL);
173 	do {
174 		status = readl(host->base + JZ_REG_MMC_STATUS);
175 	} while (status & JZ_MMC_STATUS_CLK_EN && --timeout);
176 }
177 
178 static void jz4740_mmc_reset(struct jz4740_mmc_host *host)
179 {
180 	uint32_t status;
181 	unsigned int timeout = 1000;
182 
183 	writew(JZ_MMC_STRPCL_RESET, host->base + JZ_REG_MMC_STRPCL);
184 	udelay(10);
185 	do {
186 		status = readl(host->base + JZ_REG_MMC_STATUS);
187 	} while (status & JZ_MMC_STATUS_IS_RESETTING && --timeout);
188 }
189 
190 static void jz4740_mmc_request_done(struct jz4740_mmc_host *host)
191 {
192 	struct mmc_request *req;
193 
194 	req = host->req;
195 	host->req = NULL;
196 
197 	mmc_request_done(host->mmc, req);
198 }
199 
200 static unsigned int jz4740_mmc_poll_irq(struct jz4740_mmc_host *host,
201 	unsigned int irq)
202 {
203 	unsigned int timeout = 0x800;
204 	uint16_t status;
205 
206 	do {
207 		status = readw(host->base + JZ_REG_MMC_IREG);
208 	} while (!(status & irq) && --timeout);
209 
210 	if (timeout == 0) {
211 		set_bit(0, &host->waiting);
212 		mod_timer(&host->timeout_timer, jiffies + 5*HZ);
213 		jz4740_mmc_set_irq_enabled(host, irq, true);
214 		return true;
215 	}
216 
217 	return false;
218 }
219 
220 static void jz4740_mmc_transfer_check_state(struct jz4740_mmc_host *host,
221 	struct mmc_data *data)
222 {
223 	int status;
224 
225 	status = readl(host->base + JZ_REG_MMC_STATUS);
226 	if (status & JZ_MMC_STATUS_WRITE_ERROR_MASK) {
227 		if (status & (JZ_MMC_STATUS_TIMEOUT_WRITE)) {
228 			host->req->cmd->error = -ETIMEDOUT;
229 			data->error = -ETIMEDOUT;
230 		} else {
231 			host->req->cmd->error = -EIO;
232 			data->error = -EIO;
233 		}
234 	} else if (status & JZ_MMC_STATUS_READ_ERROR_MASK) {
235 		if (status & (JZ_MMC_STATUS_TIMEOUT_READ)) {
236 			host->req->cmd->error = -ETIMEDOUT;
237 			data->error = -ETIMEDOUT;
238 		} else {
239 			host->req->cmd->error = -EIO;
240 			data->error = -EIO;
241 		}
242 	}
243 }
244 
245 static bool jz4740_mmc_write_data(struct jz4740_mmc_host *host,
246 	struct mmc_data *data)
247 {
248 	struct sg_mapping_iter *miter = &host->miter;
249 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_TXFIFO;
250 	uint32_t *buf;
251 	bool timeout;
252 	size_t i, j;
253 
254 	while (sg_miter_next(miter)) {
255 		buf = miter->addr;
256 		i = miter->length / 4;
257 		j = i / 8;
258 		i = i & 0x7;
259 		while (j) {
260 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
261 			if (unlikely(timeout))
262 				goto poll_timeout;
263 
264 			writel(buf[0], fifo_addr);
265 			writel(buf[1], fifo_addr);
266 			writel(buf[2], fifo_addr);
267 			writel(buf[3], fifo_addr);
268 			writel(buf[4], fifo_addr);
269 			writel(buf[5], fifo_addr);
270 			writel(buf[6], fifo_addr);
271 			writel(buf[7], fifo_addr);
272 			buf += 8;
273 			--j;
274 		}
275 		if (unlikely(i)) {
276 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
277 			if (unlikely(timeout))
278 				goto poll_timeout;
279 
280 			while (i) {
281 				writel(*buf, fifo_addr);
282 				++buf;
283 				--i;
284 			}
285 		}
286 		data->bytes_xfered += miter->length;
287 	}
288 	sg_miter_stop(miter);
289 
290 	return false;
291 
292 poll_timeout:
293 	miter->consumed = (void *)buf - miter->addr;
294 	data->bytes_xfered += miter->consumed;
295 	sg_miter_stop(miter);
296 
297 	return true;
298 }
299 
300 static bool jz4740_mmc_read_data(struct jz4740_mmc_host *host,
301 				struct mmc_data *data)
302 {
303 	struct sg_mapping_iter *miter = &host->miter;
304 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_RXFIFO;
305 	uint32_t *buf;
306 	uint32_t d;
307 	uint16_t status;
308 	size_t i, j;
309 	unsigned int timeout;
310 
311 	while (sg_miter_next(miter)) {
312 		buf = miter->addr;
313 		i = miter->length;
314 		j = i / 32;
315 		i = i & 0x1f;
316 		while (j) {
317 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
318 			if (unlikely(timeout))
319 				goto poll_timeout;
320 
321 			buf[0] = readl(fifo_addr);
322 			buf[1] = readl(fifo_addr);
323 			buf[2] = readl(fifo_addr);
324 			buf[3] = readl(fifo_addr);
325 			buf[4] = readl(fifo_addr);
326 			buf[5] = readl(fifo_addr);
327 			buf[6] = readl(fifo_addr);
328 			buf[7] = readl(fifo_addr);
329 
330 			buf += 8;
331 			--j;
332 		}
333 
334 		if (unlikely(i)) {
335 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
336 			if (unlikely(timeout))
337 				goto poll_timeout;
338 
339 			while (i >= 4) {
340 				*buf++ = readl(fifo_addr);
341 				i -= 4;
342 			}
343 			if (unlikely(i > 0)) {
344 				d = readl(fifo_addr);
345 				memcpy(buf, &d, i);
346 			}
347 		}
348 		data->bytes_xfered += miter->length;
349 
350 		/* This can go away once MIPS implements
351 		 * flush_kernel_dcache_page */
352 		flush_dcache_page(miter->page);
353 	}
354 	sg_miter_stop(miter);
355 
356 	/* For whatever reason there is sometime one word more in the fifo then
357 	 * requested */
358 	timeout = 1000;
359 	status = readl(host->base + JZ_REG_MMC_STATUS);
360 	while (!(status & JZ_MMC_STATUS_DATA_FIFO_EMPTY) && --timeout) {
361 		d = readl(fifo_addr);
362 		status = readl(host->base + JZ_REG_MMC_STATUS);
363 	}
364 
365 	return false;
366 
367 poll_timeout:
368 	miter->consumed = (void *)buf - miter->addr;
369 	data->bytes_xfered += miter->consumed;
370 	sg_miter_stop(miter);
371 
372 	return true;
373 }
374 
375 static void jz4740_mmc_timeout(unsigned long data)
376 {
377 	struct jz4740_mmc_host *host = (struct jz4740_mmc_host *)data;
378 
379 	if (!test_and_clear_bit(0, &host->waiting))
380 		return;
381 
382 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, false);
383 
384 	host->req->cmd->error = -ETIMEDOUT;
385 	jz4740_mmc_request_done(host);
386 }
387 
388 static void jz4740_mmc_read_response(struct jz4740_mmc_host *host,
389 	struct mmc_command *cmd)
390 {
391 	int i;
392 	uint16_t tmp;
393 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_RESP_FIFO;
394 
395 	if (cmd->flags & MMC_RSP_136) {
396 		tmp = readw(fifo_addr);
397 		for (i = 0; i < 4; ++i) {
398 			cmd->resp[i] = tmp << 24;
399 			tmp = readw(fifo_addr);
400 			cmd->resp[i] |= tmp << 8;
401 			tmp = readw(fifo_addr);
402 			cmd->resp[i] |= tmp >> 8;
403 		}
404 	} else {
405 		cmd->resp[0] = readw(fifo_addr) << 24;
406 		cmd->resp[0] |= readw(fifo_addr) << 8;
407 		cmd->resp[0] |= readw(fifo_addr) & 0xff;
408 	}
409 }
410 
411 static void jz4740_mmc_send_command(struct jz4740_mmc_host *host,
412 	struct mmc_command *cmd)
413 {
414 	uint32_t cmdat = host->cmdat;
415 
416 	host->cmdat &= ~JZ_MMC_CMDAT_INIT;
417 	jz4740_mmc_clock_disable(host);
418 
419 	host->cmd = cmd;
420 
421 	if (cmd->flags & MMC_RSP_BUSY)
422 		cmdat |= JZ_MMC_CMDAT_BUSY;
423 
424 	switch (mmc_resp_type(cmd)) {
425 	case MMC_RSP_R1B:
426 	case MMC_RSP_R1:
427 		cmdat |= JZ_MMC_CMDAT_RSP_R1;
428 		break;
429 	case MMC_RSP_R2:
430 		cmdat |= JZ_MMC_CMDAT_RSP_R2;
431 		break;
432 	case MMC_RSP_R3:
433 		cmdat |= JZ_MMC_CMDAT_RSP_R3;
434 		break;
435 	default:
436 		break;
437 	}
438 
439 	if (cmd->data) {
440 		cmdat |= JZ_MMC_CMDAT_DATA_EN;
441 		if (cmd->data->flags & MMC_DATA_WRITE)
442 			cmdat |= JZ_MMC_CMDAT_WRITE;
443 		if (cmd->data->flags & MMC_DATA_STREAM)
444 			cmdat |= JZ_MMC_CMDAT_STREAM;
445 
446 		writew(cmd->data->blksz, host->base + JZ_REG_MMC_BLKLEN);
447 		writew(cmd->data->blocks, host->base + JZ_REG_MMC_NOB);
448 	}
449 
450 	writeb(cmd->opcode, host->base + JZ_REG_MMC_CMD);
451 	writel(cmd->arg, host->base + JZ_REG_MMC_ARG);
452 	writel(cmdat, host->base + JZ_REG_MMC_CMDAT);
453 
454 	jz4740_mmc_clock_enable(host, 1);
455 }
456 
457 static void jz_mmc_prepare_data_transfer(struct jz4740_mmc_host *host)
458 {
459 	struct mmc_command *cmd = host->req->cmd;
460 	struct mmc_data *data = cmd->data;
461 	int direction;
462 
463 	if (data->flags & MMC_DATA_READ)
464 		direction = SG_MITER_TO_SG;
465 	else
466 		direction = SG_MITER_FROM_SG;
467 
468 	sg_miter_start(&host->miter, data->sg, data->sg_len, direction);
469 }
470 
471 
472 static irqreturn_t jz_mmc_irq_worker(int irq, void *devid)
473 {
474 	struct jz4740_mmc_host *host = (struct jz4740_mmc_host *)devid;
475 	struct mmc_command *cmd = host->req->cmd;
476 	struct mmc_request *req = host->req;
477 	bool timeout = false;
478 
479 	if (cmd->error)
480 		host->state = JZ4740_MMC_STATE_DONE;
481 
482 	switch (host->state) {
483 	case JZ4740_MMC_STATE_READ_RESPONSE:
484 		if (cmd->flags & MMC_RSP_PRESENT)
485 			jz4740_mmc_read_response(host, cmd);
486 
487 		if (!cmd->data)
488 			break;
489 
490 		jz_mmc_prepare_data_transfer(host);
491 
492 	case JZ4740_MMC_STATE_TRANSFER_DATA:
493 		if (cmd->data->flags & MMC_DATA_READ)
494 			timeout = jz4740_mmc_read_data(host, cmd->data);
495 		else
496 			timeout = jz4740_mmc_write_data(host, cmd->data);
497 
498 		if (unlikely(timeout)) {
499 			host->state = JZ4740_MMC_STATE_TRANSFER_DATA;
500 			break;
501 		}
502 
503 		jz4740_mmc_transfer_check_state(host, cmd->data);
504 
505 		timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_DATA_TRAN_DONE);
506 		if (unlikely(timeout)) {
507 			host->state = JZ4740_MMC_STATE_SEND_STOP;
508 			break;
509 		}
510 		writew(JZ_MMC_IRQ_DATA_TRAN_DONE, host->base + JZ_REG_MMC_IREG);
511 
512 	case JZ4740_MMC_STATE_SEND_STOP:
513 		if (!req->stop)
514 			break;
515 
516 		jz4740_mmc_send_command(host, req->stop);
517 
518 		if (mmc_resp_type(req->stop) & MMC_RSP_BUSY) {
519 			timeout = jz4740_mmc_poll_irq(host,
520 						      JZ_MMC_IRQ_PRG_DONE);
521 			if (timeout) {
522 				host->state = JZ4740_MMC_STATE_DONE;
523 				break;
524 			}
525 		}
526 	case JZ4740_MMC_STATE_DONE:
527 		break;
528 	}
529 
530 	if (!timeout)
531 		jz4740_mmc_request_done(host);
532 
533 	return IRQ_HANDLED;
534 }
535 
536 static irqreturn_t jz_mmc_irq(int irq, void *devid)
537 {
538 	struct jz4740_mmc_host *host = devid;
539 	struct mmc_command *cmd = host->cmd;
540 	uint16_t irq_reg, status, tmp;
541 
542 	irq_reg = readw(host->base + JZ_REG_MMC_IREG);
543 
544 	tmp = irq_reg;
545 	irq_reg &= ~host->irq_mask;
546 
547 	tmp &= ~(JZ_MMC_IRQ_TXFIFO_WR_REQ | JZ_MMC_IRQ_RXFIFO_RD_REQ |
548 		JZ_MMC_IRQ_PRG_DONE | JZ_MMC_IRQ_DATA_TRAN_DONE);
549 
550 	if (tmp != irq_reg)
551 		writew(tmp & ~irq_reg, host->base + JZ_REG_MMC_IREG);
552 
553 	if (irq_reg & JZ_MMC_IRQ_SDIO) {
554 		writew(JZ_MMC_IRQ_SDIO, host->base + JZ_REG_MMC_IREG);
555 		mmc_signal_sdio_irq(host->mmc);
556 		irq_reg &= ~JZ_MMC_IRQ_SDIO;
557 	}
558 
559 	if (host->req && cmd && irq_reg) {
560 		if (test_and_clear_bit(0, &host->waiting)) {
561 			del_timer(&host->timeout_timer);
562 
563 			status = readl(host->base + JZ_REG_MMC_STATUS);
564 
565 			if (status & JZ_MMC_STATUS_TIMEOUT_RES) {
566 					cmd->error = -ETIMEDOUT;
567 			} else if (status & JZ_MMC_STATUS_CRC_RES_ERR) {
568 					cmd->error = -EIO;
569 			} else if (status & (JZ_MMC_STATUS_CRC_READ_ERROR |
570 				    JZ_MMC_STATUS_CRC_WRITE_ERROR)) {
571 					if (cmd->data)
572 							cmd->data->error = -EIO;
573 					cmd->error = -EIO;
574 			}
575 
576 			jz4740_mmc_set_irq_enabled(host, irq_reg, false);
577 			writew(irq_reg, host->base + JZ_REG_MMC_IREG);
578 
579 			return IRQ_WAKE_THREAD;
580 		}
581 	}
582 
583 	return IRQ_HANDLED;
584 }
585 
586 static int jz4740_mmc_set_clock_rate(struct jz4740_mmc_host *host, int rate)
587 {
588 	int div = 0;
589 	int real_rate;
590 
591 	jz4740_mmc_clock_disable(host);
592 	clk_set_rate(host->clk, JZ_MMC_CLK_RATE);
593 
594 	real_rate = clk_get_rate(host->clk);
595 
596 	while (real_rate > rate && div < 7) {
597 		++div;
598 		real_rate >>= 1;
599 	}
600 
601 	writew(div, host->base + JZ_REG_MMC_CLKRT);
602 	return real_rate;
603 }
604 
605 static void jz4740_mmc_request(struct mmc_host *mmc, struct mmc_request *req)
606 {
607 	struct jz4740_mmc_host *host = mmc_priv(mmc);
608 
609 	host->req = req;
610 
611 	writew(0xffff, host->base + JZ_REG_MMC_IREG);
612 
613 	writew(JZ_MMC_IRQ_END_CMD_RES, host->base + JZ_REG_MMC_IREG);
614 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, true);
615 
616 	host->state = JZ4740_MMC_STATE_READ_RESPONSE;
617 	set_bit(0, &host->waiting);
618 	mod_timer(&host->timeout_timer, jiffies + 5*HZ);
619 	jz4740_mmc_send_command(host, req->cmd);
620 }
621 
622 static void jz4740_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
623 {
624 	struct jz4740_mmc_host *host = mmc_priv(mmc);
625 	if (ios->clock)
626 		jz4740_mmc_set_clock_rate(host, ios->clock);
627 
628 	switch (ios->power_mode) {
629 	case MMC_POWER_UP:
630 		jz4740_mmc_reset(host);
631 		if (gpio_is_valid(host->pdata->gpio_power))
632 			gpio_set_value(host->pdata->gpio_power,
633 					!host->pdata->power_active_low);
634 		host->cmdat |= JZ_MMC_CMDAT_INIT;
635 		clk_prepare_enable(host->clk);
636 		break;
637 	case MMC_POWER_ON:
638 		break;
639 	default:
640 		if (gpio_is_valid(host->pdata->gpio_power))
641 			gpio_set_value(host->pdata->gpio_power,
642 					host->pdata->power_active_low);
643 		clk_disable_unprepare(host->clk);
644 		break;
645 	}
646 
647 	switch (ios->bus_width) {
648 	case MMC_BUS_WIDTH_1:
649 		host->cmdat &= ~JZ_MMC_CMDAT_BUS_WIDTH_4BIT;
650 		break;
651 	case MMC_BUS_WIDTH_4:
652 		host->cmdat |= JZ_MMC_CMDAT_BUS_WIDTH_4BIT;
653 		break;
654 	default:
655 		break;
656 	}
657 }
658 
659 static void jz4740_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
660 {
661 	struct jz4740_mmc_host *host = mmc_priv(mmc);
662 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_SDIO, enable);
663 }
664 
665 static const struct mmc_host_ops jz4740_mmc_ops = {
666 	.request	= jz4740_mmc_request,
667 	.set_ios	= jz4740_mmc_set_ios,
668 	.get_ro		= mmc_gpio_get_ro,
669 	.get_cd		= mmc_gpio_get_cd,
670 	.enable_sdio_irq = jz4740_mmc_enable_sdio_irq,
671 };
672 
673 static const struct jz_gpio_bulk_request jz4740_mmc_pins[] = {
674 	JZ_GPIO_BULK_PIN(MSC_CMD),
675 	JZ_GPIO_BULK_PIN(MSC_CLK),
676 	JZ_GPIO_BULK_PIN(MSC_DATA0),
677 	JZ_GPIO_BULK_PIN(MSC_DATA1),
678 	JZ_GPIO_BULK_PIN(MSC_DATA2),
679 	JZ_GPIO_BULK_PIN(MSC_DATA3),
680 };
681 
682 static int jz4740_mmc_request_gpio(struct device *dev, int gpio,
683 	const char *name, bool output, int value)
684 {
685 	int ret;
686 
687 	if (!gpio_is_valid(gpio))
688 		return 0;
689 
690 	ret = gpio_request(gpio, name);
691 	if (ret) {
692 		dev_err(dev, "Failed to request %s gpio: %d\n", name, ret);
693 		return ret;
694 	}
695 
696 	if (output)
697 		gpio_direction_output(gpio, value);
698 	else
699 		gpio_direction_input(gpio);
700 
701 	return 0;
702 }
703 
704 static int jz4740_mmc_request_gpios(struct mmc_host *mmc,
705 	struct platform_device *pdev)
706 {
707 	struct jz4740_mmc_platform_data *pdata = pdev->dev.platform_data;
708 	int ret = 0;
709 
710 	if (!pdata)
711 		return 0;
712 
713 	if (!pdata->card_detect_active_low)
714 		mmc->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
715 	if (!pdata->read_only_active_low)
716 		mmc->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
717 
718 	if (gpio_is_valid(pdata->gpio_card_detect)) {
719 		ret = mmc_gpio_request_cd(mmc, pdata->gpio_card_detect, 0);
720 		if (ret)
721 			return ret;
722 	}
723 
724 	if (gpio_is_valid(pdata->gpio_read_only)) {
725 		ret = mmc_gpio_request_ro(mmc, pdata->gpio_read_only);
726 		if (ret)
727 			return ret;
728 	}
729 
730 	return jz4740_mmc_request_gpio(&pdev->dev, pdata->gpio_power,
731 			"MMC read only", true, pdata->power_active_low);
732 }
733 
734 static void jz4740_mmc_free_gpios(struct platform_device *pdev)
735 {
736 	struct jz4740_mmc_platform_data *pdata = pdev->dev.platform_data;
737 
738 	if (!pdata)
739 		return;
740 
741 	if (gpio_is_valid(pdata->gpio_power))
742 		gpio_free(pdata->gpio_power);
743 }
744 
745 static inline size_t jz4740_mmc_num_pins(struct jz4740_mmc_host *host)
746 {
747 	size_t num_pins = ARRAY_SIZE(jz4740_mmc_pins);
748 	if (host->pdata && host->pdata->data_1bit)
749 		num_pins -= 3;
750 
751 	return num_pins;
752 }
753 
754 static int jz4740_mmc_probe(struct platform_device* pdev)
755 {
756 	int ret;
757 	struct mmc_host *mmc;
758 	struct jz4740_mmc_host *host;
759 	struct jz4740_mmc_platform_data *pdata;
760 	struct resource *res;
761 
762 	pdata = pdev->dev.platform_data;
763 
764 	mmc = mmc_alloc_host(sizeof(struct jz4740_mmc_host), &pdev->dev);
765 	if (!mmc) {
766 		dev_err(&pdev->dev, "Failed to alloc mmc host structure\n");
767 		return -ENOMEM;
768 	}
769 
770 	host = mmc_priv(mmc);
771 	host->pdata = pdata;
772 
773 	host->irq = platform_get_irq(pdev, 0);
774 	if (host->irq < 0) {
775 		ret = host->irq;
776 		dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
777 		goto err_free_host;
778 	}
779 
780 	host->clk = devm_clk_get(&pdev->dev, "mmc");
781 	if (IS_ERR(host->clk)) {
782 		ret = PTR_ERR(host->clk);
783 		dev_err(&pdev->dev, "Failed to get mmc clock\n");
784 		goto err_free_host;
785 	}
786 
787 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
788 	host->base = devm_ioremap_resource(&pdev->dev, res);
789 	if (IS_ERR(host->base)) {
790 		ret = PTR_ERR(host->base);
791 		goto err_free_host;
792 	}
793 
794 	ret = jz_gpio_bulk_request(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
795 	if (ret) {
796 		dev_err(&pdev->dev, "Failed to request mmc pins: %d\n", ret);
797 		goto err_free_host;
798 	}
799 
800 	ret = jz4740_mmc_request_gpios(mmc, pdev);
801 	if (ret)
802 		goto err_gpio_bulk_free;
803 
804 	mmc->ops = &jz4740_mmc_ops;
805 	mmc->f_min = JZ_MMC_CLK_RATE / 128;
806 	mmc->f_max = JZ_MMC_CLK_RATE;
807 	mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
808 	mmc->caps = (pdata && pdata->data_1bit) ? 0 : MMC_CAP_4_BIT_DATA;
809 	mmc->caps |= MMC_CAP_SDIO_IRQ;
810 
811 	mmc->max_blk_size = (1 << 10) - 1;
812 	mmc->max_blk_count = (1 << 15) - 1;
813 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
814 
815 	mmc->max_segs = 128;
816 	mmc->max_seg_size = mmc->max_req_size;
817 
818 	host->mmc = mmc;
819 	host->pdev = pdev;
820 	spin_lock_init(&host->lock);
821 	host->irq_mask = 0xffff;
822 
823 	ret = request_threaded_irq(host->irq, jz_mmc_irq, jz_mmc_irq_worker, 0,
824 			dev_name(&pdev->dev), host);
825 	if (ret) {
826 		dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
827 		goto err_free_gpios;
828 	}
829 
830 	jz4740_mmc_reset(host);
831 	jz4740_mmc_clock_disable(host);
832 	setup_timer(&host->timeout_timer, jz4740_mmc_timeout,
833 			(unsigned long)host);
834 	/* It is not important when it times out, it just needs to timeout. */
835 	set_timer_slack(&host->timeout_timer, HZ);
836 
837 	platform_set_drvdata(pdev, host);
838 	ret = mmc_add_host(mmc);
839 
840 	if (ret) {
841 		dev_err(&pdev->dev, "Failed to add mmc host: %d\n", ret);
842 		goto err_free_irq;
843 	}
844 	dev_info(&pdev->dev, "JZ SD/MMC card driver registered\n");
845 
846 	return 0;
847 
848 err_free_irq:
849 	free_irq(host->irq, host);
850 err_free_gpios:
851 	jz4740_mmc_free_gpios(pdev);
852 err_gpio_bulk_free:
853 	jz_gpio_bulk_free(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
854 err_free_host:
855 	mmc_free_host(mmc);
856 
857 	return ret;
858 }
859 
860 static int jz4740_mmc_remove(struct platform_device *pdev)
861 {
862 	struct jz4740_mmc_host *host = platform_get_drvdata(pdev);
863 
864 	del_timer_sync(&host->timeout_timer);
865 	jz4740_mmc_set_irq_enabled(host, 0xff, false);
866 	jz4740_mmc_reset(host);
867 
868 	mmc_remove_host(host->mmc);
869 
870 	free_irq(host->irq, host);
871 
872 	jz4740_mmc_free_gpios(pdev);
873 	jz_gpio_bulk_free(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
874 
875 	mmc_free_host(host->mmc);
876 
877 	return 0;
878 }
879 
880 #ifdef CONFIG_PM_SLEEP
881 
882 static int jz4740_mmc_suspend(struct device *dev)
883 {
884 	struct jz4740_mmc_host *host = dev_get_drvdata(dev);
885 
886 	jz_gpio_bulk_suspend(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
887 
888 	return 0;
889 }
890 
891 static int jz4740_mmc_resume(struct device *dev)
892 {
893 	struct jz4740_mmc_host *host = dev_get_drvdata(dev);
894 
895 	jz_gpio_bulk_resume(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
896 
897 	return 0;
898 }
899 
900 static SIMPLE_DEV_PM_OPS(jz4740_mmc_pm_ops, jz4740_mmc_suspend,
901 	jz4740_mmc_resume);
902 #define JZ4740_MMC_PM_OPS (&jz4740_mmc_pm_ops)
903 #else
904 #define JZ4740_MMC_PM_OPS NULL
905 #endif
906 
907 static struct platform_driver jz4740_mmc_driver = {
908 	.probe = jz4740_mmc_probe,
909 	.remove = jz4740_mmc_remove,
910 	.driver = {
911 		.name = "jz4740-mmc",
912 		.owner = THIS_MODULE,
913 		.pm = JZ4740_MMC_PM_OPS,
914 	},
915 };
916 
917 module_platform_driver(jz4740_mmc_driver);
918 
919 MODULE_DESCRIPTION("JZ4740 SD/MMC controller driver");
920 MODULE_LICENSE("GPL");
921 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
922