xref: /openbmc/linux/drivers/mmc/host/mxcmmc.c (revision 78c99ba1)
1 /*
2  *  linux/drivers/mmc/host/mxcmmc.c - Freescale i.MX MMCI driver
3  *
4  *  This is a driver for the SDHC controller found in Freescale MX2/MX3
5  *  SoCs. It is basically the same hardware as found on MX1 (imxmmc.c).
6  *  Unlike the hardware found on MX1, this hardware just works and does
7  *  not need all the quirks found in imxmmc.c, hence the seperate driver.
8  *
9  *  Copyright (C) 2008 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
10  *  Copyright (C) 2006 Pavel Pisa, PiKRON <ppisa@pikron.com>
11  *
12  *  derived from pxamci.c by Russell King
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License version 2 as
16  * published by the Free Software Foundation.
17  *
18  */
19 
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/ioport.h>
23 #include <linux/platform_device.h>
24 #include <linux/interrupt.h>
25 #include <linux/irq.h>
26 #include <linux/blkdev.h>
27 #include <linux/dma-mapping.h>
28 #include <linux/mmc/host.h>
29 #include <linux/mmc/card.h>
30 #include <linux/delay.h>
31 #include <linux/clk.h>
32 #include <linux/io.h>
33 #include <linux/gpio.h>
34 
35 #include <asm/dma.h>
36 #include <asm/irq.h>
37 #include <asm/sizes.h>
38 #include <mach/mmc.h>
39 
40 #ifdef CONFIG_ARCH_MX2
41 #include <mach/dma-mx1-mx2.h>
42 #define HAS_DMA
43 #endif
44 
45 #define DRIVER_NAME "mxc-mmc"
46 
47 #define MMC_REG_STR_STP_CLK		0x00
48 #define MMC_REG_STATUS			0x04
49 #define MMC_REG_CLK_RATE		0x08
50 #define MMC_REG_CMD_DAT_CONT		0x0C
51 #define MMC_REG_RES_TO			0x10
52 #define MMC_REG_READ_TO			0x14
53 #define MMC_REG_BLK_LEN			0x18
54 #define MMC_REG_NOB			0x1C
55 #define MMC_REG_REV_NO			0x20
56 #define MMC_REG_INT_CNTR		0x24
57 #define MMC_REG_CMD			0x28
58 #define MMC_REG_ARG			0x2C
59 #define MMC_REG_RES_FIFO		0x34
60 #define MMC_REG_BUFFER_ACCESS		0x38
61 
62 #define STR_STP_CLK_RESET               (1 << 3)
63 #define STR_STP_CLK_START_CLK           (1 << 1)
64 #define STR_STP_CLK_STOP_CLK            (1 << 0)
65 
66 #define STATUS_CARD_INSERTION		(1 << 31)
67 #define STATUS_CARD_REMOVAL		(1 << 30)
68 #define STATUS_YBUF_EMPTY		(1 << 29)
69 #define STATUS_XBUF_EMPTY		(1 << 28)
70 #define STATUS_YBUF_FULL		(1 << 27)
71 #define STATUS_XBUF_FULL		(1 << 26)
72 #define STATUS_BUF_UND_RUN		(1 << 25)
73 #define STATUS_BUF_OVFL			(1 << 24)
74 #define STATUS_SDIO_INT_ACTIVE		(1 << 14)
75 #define STATUS_END_CMD_RESP		(1 << 13)
76 #define STATUS_WRITE_OP_DONE		(1 << 12)
77 #define STATUS_DATA_TRANS_DONE		(1 << 11)
78 #define STATUS_READ_OP_DONE		(1 << 11)
79 #define STATUS_WR_CRC_ERROR_CODE_MASK	(3 << 10)
80 #define STATUS_CARD_BUS_CLK_RUN		(1 << 8)
81 #define STATUS_BUF_READ_RDY		(1 << 7)
82 #define STATUS_BUF_WRITE_RDY		(1 << 6)
83 #define STATUS_RESP_CRC_ERR		(1 << 5)
84 #define STATUS_CRC_READ_ERR		(1 << 3)
85 #define STATUS_CRC_WRITE_ERR		(1 << 2)
86 #define STATUS_TIME_OUT_RESP		(1 << 1)
87 #define STATUS_TIME_OUT_READ		(1 << 0)
88 #define STATUS_ERR_MASK			0x2f
89 
90 #define CMD_DAT_CONT_CMD_RESP_LONG_OFF	(1 << 12)
91 #define CMD_DAT_CONT_STOP_READWAIT	(1 << 11)
92 #define CMD_DAT_CONT_START_READWAIT	(1 << 10)
93 #define CMD_DAT_CONT_BUS_WIDTH_4	(2 << 8)
94 #define CMD_DAT_CONT_INIT		(1 << 7)
95 #define CMD_DAT_CONT_WRITE		(1 << 4)
96 #define CMD_DAT_CONT_DATA_ENABLE	(1 << 3)
97 #define CMD_DAT_CONT_RESPONSE_48BIT_CRC	(1 << 0)
98 #define CMD_DAT_CONT_RESPONSE_136BIT	(2 << 0)
99 #define CMD_DAT_CONT_RESPONSE_48BIT	(3 << 0)
100 
101 #define INT_SDIO_INT_WKP_EN		(1 << 18)
102 #define INT_CARD_INSERTION_WKP_EN	(1 << 17)
103 #define INT_CARD_REMOVAL_WKP_EN		(1 << 16)
104 #define INT_CARD_INSERTION_EN		(1 << 15)
105 #define INT_CARD_REMOVAL_EN		(1 << 14)
106 #define INT_SDIO_IRQ_EN			(1 << 13)
107 #define INT_DAT0_EN			(1 << 12)
108 #define INT_BUF_READ_EN			(1 << 4)
109 #define INT_BUF_WRITE_EN		(1 << 3)
110 #define INT_END_CMD_RES_EN		(1 << 2)
111 #define INT_WRITE_OP_DONE_EN		(1 << 1)
112 #define INT_READ_OP_EN			(1 << 0)
113 
114 struct mxcmci_host {
115 	struct mmc_host		*mmc;
116 	struct resource		*res;
117 	void __iomem		*base;
118 	int			irq;
119 	int			detect_irq;
120 	int			dma;
121 	int			do_dma;
122 	unsigned int		power_mode;
123 	struct imxmmc_platform_data *pdata;
124 
125 	struct mmc_request	*req;
126 	struct mmc_command	*cmd;
127 	struct mmc_data		*data;
128 
129 	unsigned int		dma_nents;
130 	unsigned int		datasize;
131 	unsigned int		dma_dir;
132 
133 	u16			rev_no;
134 	unsigned int		cmdat;
135 
136 	struct clk		*clk;
137 
138 	int			clock;
139 
140 	struct work_struct	datawork;
141 };
142 
143 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios);
144 
145 static inline int mxcmci_use_dma(struct mxcmci_host *host)
146 {
147 	return host->do_dma;
148 }
149 
150 static void mxcmci_softreset(struct mxcmci_host *host)
151 {
152 	int i;
153 
154 	/* reset sequence */
155 	writew(STR_STP_CLK_RESET, host->base + MMC_REG_STR_STP_CLK);
156 	writew(STR_STP_CLK_RESET | STR_STP_CLK_START_CLK,
157 			host->base + MMC_REG_STR_STP_CLK);
158 
159 	for (i = 0; i < 8; i++)
160 		writew(STR_STP_CLK_START_CLK, host->base + MMC_REG_STR_STP_CLK);
161 
162 	writew(0xff, host->base + MMC_REG_RES_TO);
163 }
164 
165 static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
166 {
167 	unsigned int nob = data->blocks;
168 	unsigned int blksz = data->blksz;
169 	unsigned int datasize = nob * blksz;
170 #ifdef HAS_DMA
171 	struct scatterlist *sg;
172 	int i;
173 	int ret;
174 #endif
175 	if (data->flags & MMC_DATA_STREAM)
176 		nob = 0xffff;
177 
178 	host->data = data;
179 	data->bytes_xfered = 0;
180 
181 	writew(nob, host->base + MMC_REG_NOB);
182 	writew(blksz, host->base + MMC_REG_BLK_LEN);
183 	host->datasize = datasize;
184 
185 #ifdef HAS_DMA
186 	for_each_sg(data->sg, sg, data->sg_len, i) {
187 		if (sg->offset & 3 || sg->length & 3) {
188 			host->do_dma = 0;
189 			return 0;
190 		}
191 	}
192 
193 	if (data->flags & MMC_DATA_READ) {
194 		host->dma_dir = DMA_FROM_DEVICE;
195 		host->dma_nents = dma_map_sg(mmc_dev(host->mmc), data->sg,
196 					     data->sg_len,  host->dma_dir);
197 
198 		ret = imx_dma_setup_sg(host->dma, data->sg, host->dma_nents,
199 				datasize,
200 				host->res->start + MMC_REG_BUFFER_ACCESS,
201 				DMA_MODE_READ);
202 	} else {
203 		host->dma_dir = DMA_TO_DEVICE;
204 		host->dma_nents = dma_map_sg(mmc_dev(host->mmc), data->sg,
205 					     data->sg_len,  host->dma_dir);
206 
207 		ret = imx_dma_setup_sg(host->dma, data->sg, host->dma_nents,
208 				datasize,
209 				host->res->start + MMC_REG_BUFFER_ACCESS,
210 				DMA_MODE_WRITE);
211 	}
212 
213 	if (ret) {
214 		dev_err(mmc_dev(host->mmc), "failed to setup DMA : %d\n", ret);
215 		return ret;
216 	}
217 	wmb();
218 
219 	imx_dma_enable(host->dma);
220 #endif /* HAS_DMA */
221 	return 0;
222 }
223 
224 static int mxcmci_start_cmd(struct mxcmci_host *host, struct mmc_command *cmd,
225 		unsigned int cmdat)
226 {
227 	WARN_ON(host->cmd != NULL);
228 	host->cmd = cmd;
229 
230 	switch (mmc_resp_type(cmd)) {
231 	case MMC_RSP_R1: /* short CRC, OPCODE */
232 	case MMC_RSP_R1B:/* short CRC, OPCODE, BUSY */
233 		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT_CRC;
234 		break;
235 	case MMC_RSP_R2: /* long 136 bit + CRC */
236 		cmdat |= CMD_DAT_CONT_RESPONSE_136BIT;
237 		break;
238 	case MMC_RSP_R3: /* short */
239 		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT;
240 		break;
241 	case MMC_RSP_NONE:
242 		break;
243 	default:
244 		dev_err(mmc_dev(host->mmc), "unhandled response type 0x%x\n",
245 				mmc_resp_type(cmd));
246 		cmd->error = -EINVAL;
247 		return -EINVAL;
248 	}
249 
250 	if (mxcmci_use_dma(host))
251 		writel(INT_READ_OP_EN | INT_WRITE_OP_DONE_EN |
252 				INT_END_CMD_RES_EN,
253 				host->base + MMC_REG_INT_CNTR);
254 	else
255 		writel(INT_END_CMD_RES_EN, host->base + MMC_REG_INT_CNTR);
256 
257 	writew(cmd->opcode, host->base + MMC_REG_CMD);
258 	writel(cmd->arg, host->base + MMC_REG_ARG);
259 	writew(cmdat, host->base + MMC_REG_CMD_DAT_CONT);
260 
261 	return 0;
262 }
263 
264 static void mxcmci_finish_request(struct mxcmci_host *host,
265 		struct mmc_request *req)
266 {
267 	writel(0, host->base + MMC_REG_INT_CNTR);
268 
269 	host->req = NULL;
270 	host->cmd = NULL;
271 	host->data = NULL;
272 
273 	mmc_request_done(host->mmc, req);
274 }
275 
276 static int mxcmci_finish_data(struct mxcmci_host *host, unsigned int stat)
277 {
278 	struct mmc_data *data = host->data;
279 	int data_error;
280 
281 #ifdef HAS_DMA
282 	if (mxcmci_use_dma(host)) {
283 		imx_dma_disable(host->dma);
284 		dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->dma_nents,
285 				host->dma_dir);
286 	}
287 #endif
288 
289 	if (stat & STATUS_ERR_MASK) {
290 		dev_dbg(mmc_dev(host->mmc), "request failed. status: 0x%08x\n",
291 				stat);
292 		if (stat & STATUS_CRC_READ_ERR) {
293 			data->error = -EILSEQ;
294 		} else if (stat & STATUS_CRC_WRITE_ERR) {
295 			u32 err_code = (stat >> 9) & 0x3;
296 			if (err_code == 2) /* No CRC response */
297 				data->error = -ETIMEDOUT;
298 			else
299 				data->error = -EILSEQ;
300 		} else if (stat & STATUS_TIME_OUT_READ) {
301 			data->error = -ETIMEDOUT;
302 		} else {
303 			data->error = -EIO;
304 		}
305 	} else {
306 		data->bytes_xfered = host->datasize;
307 	}
308 
309 	data_error = data->error;
310 
311 	host->data = NULL;
312 
313 	return data_error;
314 }
315 
316 static void mxcmci_read_response(struct mxcmci_host *host, unsigned int stat)
317 {
318 	struct mmc_command *cmd = host->cmd;
319 	int i;
320 	u32 a, b, c;
321 
322 	if (!cmd)
323 		return;
324 
325 	if (stat & STATUS_TIME_OUT_RESP) {
326 		dev_dbg(mmc_dev(host->mmc), "CMD TIMEOUT\n");
327 		cmd->error = -ETIMEDOUT;
328 	} else if (stat & STATUS_RESP_CRC_ERR && cmd->flags & MMC_RSP_CRC) {
329 		dev_dbg(mmc_dev(host->mmc), "cmd crc error\n");
330 		cmd->error = -EILSEQ;
331 	}
332 
333 	if (cmd->flags & MMC_RSP_PRESENT) {
334 		if (cmd->flags & MMC_RSP_136) {
335 			for (i = 0; i < 4; i++) {
336 				a = readw(host->base + MMC_REG_RES_FIFO);
337 				b = readw(host->base + MMC_REG_RES_FIFO);
338 				cmd->resp[i] = a << 16 | b;
339 			}
340 		} else {
341 			a = readw(host->base + MMC_REG_RES_FIFO);
342 			b = readw(host->base + MMC_REG_RES_FIFO);
343 			c = readw(host->base + MMC_REG_RES_FIFO);
344 			cmd->resp[0] = a << 24 | b << 8 | c >> 8;
345 		}
346 	}
347 }
348 
349 static int mxcmci_poll_status(struct mxcmci_host *host, u32 mask)
350 {
351 	u32 stat;
352 	unsigned long timeout = jiffies + HZ;
353 
354 	do {
355 		stat = readl(host->base + MMC_REG_STATUS);
356 		if (stat & STATUS_ERR_MASK)
357 			return stat;
358 		if (time_after(jiffies, timeout)) {
359 			mxcmci_softreset(host);
360 			mxcmci_set_clk_rate(host, host->clock);
361 			return STATUS_TIME_OUT_READ;
362 		}
363 		if (stat & mask)
364 			return 0;
365 		cpu_relax();
366 	} while (1);
367 }
368 
369 static int mxcmci_pull(struct mxcmci_host *host, void *_buf, int bytes)
370 {
371 	unsigned int stat;
372 	u32 *buf = _buf;
373 
374 	while (bytes > 3) {
375 		stat = mxcmci_poll_status(host,
376 				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
377 		if (stat)
378 			return stat;
379 		*buf++ = readl(host->base + MMC_REG_BUFFER_ACCESS);
380 		bytes -= 4;
381 	}
382 
383 	if (bytes) {
384 		u8 *b = (u8 *)buf;
385 		u32 tmp;
386 
387 		stat = mxcmci_poll_status(host,
388 				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
389 		if (stat)
390 			return stat;
391 		tmp = readl(host->base + MMC_REG_BUFFER_ACCESS);
392 		memcpy(b, &tmp, bytes);
393 	}
394 
395 	return 0;
396 }
397 
398 static int mxcmci_push(struct mxcmci_host *host, void *_buf, int bytes)
399 {
400 	unsigned int stat;
401 	u32 *buf = _buf;
402 
403 	while (bytes > 3) {
404 		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
405 		if (stat)
406 			return stat;
407 		writel(*buf++, host->base + MMC_REG_BUFFER_ACCESS);
408 		bytes -= 4;
409 	}
410 
411 	if (bytes) {
412 		u8 *b = (u8 *)buf;
413 		u32 tmp;
414 
415 		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
416 		if (stat)
417 			return stat;
418 
419 		memcpy(&tmp, b, bytes);
420 		writel(tmp, host->base + MMC_REG_BUFFER_ACCESS);
421 	}
422 
423 	stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
424 	if (stat)
425 		return stat;
426 
427 	return 0;
428 }
429 
430 static int mxcmci_transfer_data(struct mxcmci_host *host)
431 {
432 	struct mmc_data *data = host->req->data;
433 	struct scatterlist *sg;
434 	int stat, i;
435 
436 	host->datasize = 0;
437 
438 	host->data = data;
439 	host->datasize = 0;
440 
441 	if (data->flags & MMC_DATA_READ) {
442 		for_each_sg(data->sg, sg, data->sg_len, i) {
443 			stat = mxcmci_pull(host, sg_virt(sg), sg->length);
444 			if (stat)
445 				return stat;
446 			host->datasize += sg->length;
447 		}
448 	} else {
449 		for_each_sg(data->sg, sg, data->sg_len, i) {
450 			stat = mxcmci_push(host, sg_virt(sg), sg->length);
451 			if (stat)
452 				return stat;
453 			host->datasize += sg->length;
454 		}
455 		stat = mxcmci_poll_status(host, STATUS_WRITE_OP_DONE);
456 		if (stat)
457 			return stat;
458 	}
459 	return 0;
460 }
461 
462 static void mxcmci_datawork(struct work_struct *work)
463 {
464 	struct mxcmci_host *host = container_of(work, struct mxcmci_host,
465 						  datawork);
466 	int datastat = mxcmci_transfer_data(host);
467 	mxcmci_finish_data(host, datastat);
468 
469 	if (host->req->stop) {
470 		if (mxcmci_start_cmd(host, host->req->stop, 0)) {
471 			mxcmci_finish_request(host, host->req);
472 			return;
473 		}
474 	} else {
475 		mxcmci_finish_request(host, host->req);
476 	}
477 }
478 
479 #ifdef HAS_DMA
480 static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat)
481 {
482 	struct mmc_data *data = host->data;
483 	int data_error;
484 
485 	if (!data)
486 		return;
487 
488 	data_error = mxcmci_finish_data(host, stat);
489 
490 	mxcmci_read_response(host, stat);
491 	host->cmd = NULL;
492 
493 	if (host->req->stop) {
494 		if (mxcmci_start_cmd(host, host->req->stop, 0)) {
495 			mxcmci_finish_request(host, host->req);
496 			return;
497 		}
498 	} else {
499 		mxcmci_finish_request(host, host->req);
500 	}
501 }
502 #endif /* HAS_DMA */
503 
504 static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat)
505 {
506 	mxcmci_read_response(host, stat);
507 	host->cmd = NULL;
508 
509 	if (!host->data && host->req) {
510 		mxcmci_finish_request(host, host->req);
511 		return;
512 	}
513 
514 	/* For the DMA case the DMA engine handles the data transfer
515 	 * automatically. For non DMA we have to to it ourselves.
516 	 * Don't do it in interrupt context though.
517 	 */
518 	if (!mxcmci_use_dma(host) && host->data)
519 		schedule_work(&host->datawork);
520 
521 }
522 
523 static irqreturn_t mxcmci_irq(int irq, void *devid)
524 {
525 	struct mxcmci_host *host = devid;
526 	u32 stat;
527 
528 	stat = readl(host->base + MMC_REG_STATUS);
529 	writel(stat, host->base + MMC_REG_STATUS);
530 
531 	dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
532 
533 	if (stat & STATUS_END_CMD_RESP)
534 		mxcmci_cmd_done(host, stat);
535 #ifdef HAS_DMA
536 	if (mxcmci_use_dma(host) &&
537 		  (stat & (STATUS_DATA_TRANS_DONE | STATUS_WRITE_OP_DONE)))
538 		mxcmci_data_done(host, stat);
539 #endif
540 	return IRQ_HANDLED;
541 }
542 
543 static void mxcmci_request(struct mmc_host *mmc, struct mmc_request *req)
544 {
545 	struct mxcmci_host *host = mmc_priv(mmc);
546 	unsigned int cmdat = host->cmdat;
547 	int error;
548 
549 	WARN_ON(host->req != NULL);
550 
551 	host->req = req;
552 	host->cmdat &= ~CMD_DAT_CONT_INIT;
553 #ifdef HAS_DMA
554 	host->do_dma = 1;
555 #endif
556 	if (req->data) {
557 		error = mxcmci_setup_data(host, req->data);
558 		if (error) {
559 			req->cmd->error = error;
560 			goto out;
561 		}
562 
563 
564 		cmdat |= CMD_DAT_CONT_DATA_ENABLE;
565 
566 		if (req->data->flags & MMC_DATA_WRITE)
567 			cmdat |= CMD_DAT_CONT_WRITE;
568 	}
569 
570 	error = mxcmci_start_cmd(host, req->cmd, cmdat);
571 out:
572 	if (error)
573 		mxcmci_finish_request(host, req);
574 }
575 
576 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios)
577 {
578 	unsigned int divider;
579 	int prescaler = 0;
580 	unsigned int clk_in = clk_get_rate(host->clk);
581 
582 	while (prescaler <= 0x800) {
583 		for (divider = 1; divider <= 0xF; divider++) {
584 			int x;
585 
586 			x = (clk_in / (divider + 1));
587 
588 			if (prescaler)
589 				x /= (prescaler * 2);
590 
591 			if (x <= clk_ios)
592 				break;
593 		}
594 		if (divider < 0x10)
595 			break;
596 
597 		if (prescaler == 0)
598 			prescaler = 1;
599 		else
600 			prescaler <<= 1;
601 	}
602 
603 	writew((prescaler << 4) | divider, host->base + MMC_REG_CLK_RATE);
604 
605 	dev_dbg(mmc_dev(host->mmc), "scaler: %d divider: %d in: %d out: %d\n",
606 			prescaler, divider, clk_in, clk_ios);
607 }
608 
609 static void mxcmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
610 {
611 	struct mxcmci_host *host = mmc_priv(mmc);
612 #ifdef HAS_DMA
613 	unsigned int blen;
614 	/*
615 	 * use burstlen of 64 in 4 bit mode (--> reg value  0)
616 	 * use burstlen of 16 in 1 bit mode (--> reg value 16)
617 	 */
618 	if (ios->bus_width == MMC_BUS_WIDTH_4)
619 		blen = 0;
620 	else
621 		blen = 16;
622 
623 	imx_dma_config_burstlen(host->dma, blen);
624 #endif
625 	if (ios->bus_width == MMC_BUS_WIDTH_4)
626 		host->cmdat |= CMD_DAT_CONT_BUS_WIDTH_4;
627 	else
628 		host->cmdat &= ~CMD_DAT_CONT_BUS_WIDTH_4;
629 
630 	if (host->power_mode != ios->power_mode) {
631 		if (host->pdata && host->pdata->setpower)
632 			host->pdata->setpower(mmc_dev(mmc), ios->vdd);
633 		host->power_mode = ios->power_mode;
634 		if (ios->power_mode == MMC_POWER_ON)
635 			host->cmdat |= CMD_DAT_CONT_INIT;
636 	}
637 
638 	if (ios->clock) {
639 		mxcmci_set_clk_rate(host, ios->clock);
640 		writew(STR_STP_CLK_START_CLK, host->base + MMC_REG_STR_STP_CLK);
641 	} else {
642 		writew(STR_STP_CLK_STOP_CLK, host->base + MMC_REG_STR_STP_CLK);
643 	}
644 
645 	host->clock = ios->clock;
646 }
647 
648 static irqreturn_t mxcmci_detect_irq(int irq, void *data)
649 {
650 	struct mmc_host *mmc = data;
651 
652 	dev_dbg(mmc_dev(mmc), "%s\n", __func__);
653 
654 	mmc_detect_change(mmc, msecs_to_jiffies(250));
655 	return IRQ_HANDLED;
656 }
657 
658 static int mxcmci_get_ro(struct mmc_host *mmc)
659 {
660 	struct mxcmci_host *host = mmc_priv(mmc);
661 
662 	if (host->pdata && host->pdata->get_ro)
663 		return !!host->pdata->get_ro(mmc_dev(mmc));
664 	/*
665 	 * Board doesn't support read only detection; let the mmc core
666 	 * decide what to do.
667 	 */
668 	return -ENOSYS;
669 }
670 
671 
672 static const struct mmc_host_ops mxcmci_ops = {
673 	.request	= mxcmci_request,
674 	.set_ios	= mxcmci_set_ios,
675 	.get_ro		= mxcmci_get_ro,
676 };
677 
678 static int mxcmci_probe(struct platform_device *pdev)
679 {
680 	struct mmc_host *mmc;
681 	struct mxcmci_host *host = NULL;
682 	struct resource *r;
683 	int ret = 0, irq;
684 
685 	printk(KERN_INFO "i.MX SDHC driver\n");
686 
687 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
688 	irq = platform_get_irq(pdev, 0);
689 	if (!r || irq < 0)
690 		return -EINVAL;
691 
692 	r = request_mem_region(r->start, resource_size(r), pdev->name);
693 	if (!r)
694 		return -EBUSY;
695 
696 	mmc = mmc_alloc_host(sizeof(struct mxcmci_host), &pdev->dev);
697 	if (!mmc) {
698 		ret = -ENOMEM;
699 		goto out_release_mem;
700 	}
701 
702 	mmc->ops = &mxcmci_ops;
703 	mmc->caps = MMC_CAP_4_BIT_DATA;
704 
705 	/* MMC core transfer sizes tunable parameters */
706 	mmc->max_hw_segs = 64;
707 	mmc->max_phys_segs = 64;
708 	mmc->max_blk_size = 2048;
709 	mmc->max_blk_count = 65535;
710 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
711 	mmc->max_seg_size = mmc->max_seg_size;
712 
713 	host = mmc_priv(mmc);
714 	host->base = ioremap(r->start, resource_size(r));
715 	if (!host->base) {
716 		ret = -ENOMEM;
717 		goto out_free;
718 	}
719 
720 	host->mmc = mmc;
721 	host->pdata = pdev->dev.platform_data;
722 
723 	if (host->pdata && host->pdata->ocr_avail)
724 		mmc->ocr_avail = host->pdata->ocr_avail;
725 	else
726 		mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
727 
728 	host->res = r;
729 	host->irq = irq;
730 
731 	host->clk = clk_get(&pdev->dev, NULL);
732 	if (IS_ERR(host->clk)) {
733 		ret = PTR_ERR(host->clk);
734 		goto out_iounmap;
735 	}
736 	clk_enable(host->clk);
737 
738 	mxcmci_softreset(host);
739 
740 	host->rev_no = readw(host->base + MMC_REG_REV_NO);
741 	if (host->rev_no != 0x400) {
742 		ret = -ENODEV;
743 		dev_err(mmc_dev(host->mmc), "wrong rev.no. 0x%08x. aborting.\n",
744 			host->rev_no);
745 		goto out_clk_put;
746 	}
747 
748 	mmc->f_min = clk_get_rate(host->clk) >> 16;
749 	if (mmc->f_min < 400000)
750 		mmc->f_min = 400000;
751 	mmc->f_max = clk_get_rate(host->clk) >> 1;
752 
753 	/* recommended in data sheet */
754 	writew(0x2db4, host->base + MMC_REG_READ_TO);
755 
756 	writel(0, host->base + MMC_REG_INT_CNTR);
757 
758 #ifdef HAS_DMA
759 	host->dma = imx_dma_request_by_prio(DRIVER_NAME, DMA_PRIO_LOW);
760 	if (host->dma < 0) {
761 		dev_err(mmc_dev(host->mmc), "imx_dma_request_by_prio failed\n");
762 		ret = -EBUSY;
763 		goto out_clk_put;
764 	}
765 
766 	r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
767 	if (!r) {
768 		ret = -EINVAL;
769 		goto out_free_dma;
770 	}
771 
772 	ret = imx_dma_config_channel(host->dma,
773 				     IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_FIFO,
774 				     IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR,
775 				     r->start, 0);
776 	if (ret) {
777 		dev_err(mmc_dev(host->mmc), "failed to config DMA channel\n");
778 		goto out_free_dma;
779 	}
780 #endif
781 	INIT_WORK(&host->datawork, mxcmci_datawork);
782 
783 	ret = request_irq(host->irq, mxcmci_irq, 0, DRIVER_NAME, host);
784 	if (ret)
785 		goto out_free_dma;
786 
787 	platform_set_drvdata(pdev, mmc);
788 
789 	if (host->pdata && host->pdata->init) {
790 		ret = host->pdata->init(&pdev->dev, mxcmci_detect_irq,
791 				host->mmc);
792 		if (ret)
793 			goto out_free_irq;
794 	}
795 
796 	mmc_add_host(mmc);
797 
798 	return 0;
799 
800 out_free_irq:
801 	free_irq(host->irq, host);
802 out_free_dma:
803 #ifdef HAS_DMA
804 	imx_dma_free(host->dma);
805 #endif
806 out_clk_put:
807 	clk_disable(host->clk);
808 	clk_put(host->clk);
809 out_iounmap:
810 	iounmap(host->base);
811 out_free:
812 	mmc_free_host(mmc);
813 out_release_mem:
814 	release_mem_region(host->res->start, resource_size(host->res));
815 	return ret;
816 }
817 
818 static int mxcmci_remove(struct platform_device *pdev)
819 {
820 	struct mmc_host *mmc = platform_get_drvdata(pdev);
821 	struct mxcmci_host *host = mmc_priv(mmc);
822 
823 	platform_set_drvdata(pdev, NULL);
824 
825 	mmc_remove_host(mmc);
826 
827 	if (host->pdata && host->pdata->exit)
828 		host->pdata->exit(&pdev->dev, mmc);
829 
830 	free_irq(host->irq, host);
831 	iounmap(host->base);
832 #ifdef HAS_DMA
833 	imx_dma_free(host->dma);
834 #endif
835 	clk_disable(host->clk);
836 	clk_put(host->clk);
837 
838 	release_mem_region(host->res->start, resource_size(host->res));
839 	release_resource(host->res);
840 
841 	mmc_free_host(mmc);
842 
843 	return 0;
844 }
845 
846 #ifdef CONFIG_PM
847 static int mxcmci_suspend(struct platform_device *dev, pm_message_t state)
848 {
849 	struct mmc_host *mmc = platform_get_drvdata(dev);
850 	int ret = 0;
851 
852 	if (mmc)
853 		ret = mmc_suspend_host(mmc, state);
854 
855 	return ret;
856 }
857 
858 static int mxcmci_resume(struct platform_device *dev)
859 {
860 	struct mmc_host *mmc = platform_get_drvdata(dev);
861 	struct mxcmci_host *host;
862 	int ret = 0;
863 
864 	if (mmc) {
865 		host = mmc_priv(mmc);
866 		ret = mmc_resume_host(mmc);
867 	}
868 
869 	return ret;
870 }
871 #else
872 #define mxcmci_suspend  NULL
873 #define mxcmci_resume   NULL
874 #endif /* CONFIG_PM */
875 
876 static struct platform_driver mxcmci_driver = {
877 	.probe		= mxcmci_probe,
878 	.remove		= mxcmci_remove,
879 	.suspend	= mxcmci_suspend,
880 	.resume		= mxcmci_resume,
881 	.driver		= {
882 		.name		= DRIVER_NAME,
883 		.owner		= THIS_MODULE,
884 	}
885 };
886 
887 static int __init mxcmci_init(void)
888 {
889 	return platform_driver_register(&mxcmci_driver);
890 }
891 
892 static void __exit mxcmci_exit(void)
893 {
894 	platform_driver_unregister(&mxcmci_driver);
895 }
896 
897 module_init(mxcmci_init);
898 module_exit(mxcmci_exit);
899 
900 MODULE_DESCRIPTION("i.MX Multimedia Card Interface Driver");
901 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
902 MODULE_LICENSE("GPL");
903 MODULE_ALIAS("platform:imx-mmc");
904