xref: /linux/drivers/mmc/host/mxcmmc.c (revision 5d4a2e29fba5b2bef95b96a46b338ec4d76fa4fd)
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 separate 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 	int			use_sdio;
123 	unsigned int		power_mode;
124 	struct imxmmc_platform_data *pdata;
125 
126 	struct mmc_request	*req;
127 	struct mmc_command	*cmd;
128 	struct mmc_data		*data;
129 
130 	unsigned int		dma_nents;
131 	unsigned int		datasize;
132 	unsigned int		dma_dir;
133 
134 	u16			rev_no;
135 	unsigned int		cmdat;
136 
137 	struct clk		*clk;
138 
139 	int			clock;
140 
141 	struct work_struct	datawork;
142 	spinlock_t		lock;
143 };
144 
145 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios);
146 
147 static inline int mxcmci_use_dma(struct mxcmci_host *host)
148 {
149 	return host->do_dma;
150 }
151 
152 static void mxcmci_softreset(struct mxcmci_host *host)
153 {
154 	int i;
155 
156 	dev_dbg(mmc_dev(host->mmc), "mxcmci_softreset\n");
157 
158 	/* reset sequence */
159 	writew(STR_STP_CLK_RESET, host->base + MMC_REG_STR_STP_CLK);
160 	writew(STR_STP_CLK_RESET | STR_STP_CLK_START_CLK,
161 			host->base + MMC_REG_STR_STP_CLK);
162 
163 	for (i = 0; i < 8; i++)
164 		writew(STR_STP_CLK_START_CLK, host->base + MMC_REG_STR_STP_CLK);
165 
166 	writew(0xff, host->base + MMC_REG_RES_TO);
167 }
168 
169 static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
170 {
171 	unsigned int nob = data->blocks;
172 	unsigned int blksz = data->blksz;
173 	unsigned int datasize = nob * blksz;
174 #ifdef HAS_DMA
175 	struct scatterlist *sg;
176 	int i;
177 	int ret;
178 #endif
179 	if (data->flags & MMC_DATA_STREAM)
180 		nob = 0xffff;
181 
182 	host->data = data;
183 	data->bytes_xfered = 0;
184 
185 	writew(nob, host->base + MMC_REG_NOB);
186 	writew(blksz, host->base + MMC_REG_BLK_LEN);
187 	host->datasize = datasize;
188 
189 #ifdef HAS_DMA
190 	for_each_sg(data->sg, sg, data->sg_len, i) {
191 		if (sg->offset & 3 || sg->length & 3) {
192 			host->do_dma = 0;
193 			return 0;
194 		}
195 	}
196 
197 	if (data->flags & MMC_DATA_READ) {
198 		host->dma_dir = DMA_FROM_DEVICE;
199 		host->dma_nents = dma_map_sg(mmc_dev(host->mmc), data->sg,
200 					     data->sg_len,  host->dma_dir);
201 
202 		ret = imx_dma_setup_sg(host->dma, data->sg, host->dma_nents,
203 				datasize,
204 				host->res->start + MMC_REG_BUFFER_ACCESS,
205 				DMA_MODE_READ);
206 	} else {
207 		host->dma_dir = DMA_TO_DEVICE;
208 		host->dma_nents = dma_map_sg(mmc_dev(host->mmc), data->sg,
209 					     data->sg_len,  host->dma_dir);
210 
211 		ret = imx_dma_setup_sg(host->dma, data->sg, host->dma_nents,
212 				datasize,
213 				host->res->start + MMC_REG_BUFFER_ACCESS,
214 				DMA_MODE_WRITE);
215 	}
216 
217 	if (ret) {
218 		dev_err(mmc_dev(host->mmc), "failed to setup DMA : %d\n", ret);
219 		return ret;
220 	}
221 	wmb();
222 
223 	imx_dma_enable(host->dma);
224 #endif /* HAS_DMA */
225 	return 0;
226 }
227 
228 static int mxcmci_start_cmd(struct mxcmci_host *host, struct mmc_command *cmd,
229 		unsigned int cmdat)
230 {
231 	u32 int_cntr;
232 	unsigned long flags;
233 
234 	WARN_ON(host->cmd != NULL);
235 	host->cmd = cmd;
236 
237 	switch (mmc_resp_type(cmd)) {
238 	case MMC_RSP_R1: /* short CRC, OPCODE */
239 	case MMC_RSP_R1B:/* short CRC, OPCODE, BUSY */
240 		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT_CRC;
241 		break;
242 	case MMC_RSP_R2: /* long 136 bit + CRC */
243 		cmdat |= CMD_DAT_CONT_RESPONSE_136BIT;
244 		break;
245 	case MMC_RSP_R3: /* short */
246 		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT;
247 		break;
248 	case MMC_RSP_NONE:
249 		break;
250 	default:
251 		dev_err(mmc_dev(host->mmc), "unhandled response type 0x%x\n",
252 				mmc_resp_type(cmd));
253 		cmd->error = -EINVAL;
254 		return -EINVAL;
255 	}
256 
257 	int_cntr = INT_END_CMD_RES_EN;
258 
259 	if (mxcmci_use_dma(host))
260 		int_cntr |= INT_READ_OP_EN | INT_WRITE_OP_DONE_EN;
261 
262 	spin_lock_irqsave(&host->lock, flags);
263 	if (host->use_sdio)
264 		int_cntr |= INT_SDIO_IRQ_EN;
265 	writel(int_cntr, host->base + MMC_REG_INT_CNTR);
266 	spin_unlock_irqrestore(&host->lock, flags);
267 
268 	writew(cmd->opcode, host->base + MMC_REG_CMD);
269 	writel(cmd->arg, host->base + MMC_REG_ARG);
270 	writew(cmdat, host->base + MMC_REG_CMD_DAT_CONT);
271 
272 	return 0;
273 }
274 
275 static void mxcmci_finish_request(struct mxcmci_host *host,
276 		struct mmc_request *req)
277 {
278 	u32 int_cntr = 0;
279 	unsigned long flags;
280 
281 	spin_lock_irqsave(&host->lock, flags);
282 	if (host->use_sdio)
283 		int_cntr |= INT_SDIO_IRQ_EN;
284 	writel(int_cntr, host->base + MMC_REG_INT_CNTR);
285 	spin_unlock_irqrestore(&host->lock, flags);
286 
287 	host->req = NULL;
288 	host->cmd = NULL;
289 	host->data = NULL;
290 
291 	mmc_request_done(host->mmc, req);
292 }
293 
294 static int mxcmci_finish_data(struct mxcmci_host *host, unsigned int stat)
295 {
296 	struct mmc_data *data = host->data;
297 	int data_error;
298 
299 #ifdef HAS_DMA
300 	if (mxcmci_use_dma(host)) {
301 		imx_dma_disable(host->dma);
302 		dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->dma_nents,
303 				host->dma_dir);
304 	}
305 #endif
306 
307 	if (stat & STATUS_ERR_MASK) {
308 		dev_dbg(mmc_dev(host->mmc), "request failed. status: 0x%08x\n",
309 				stat);
310 		if (stat & STATUS_CRC_READ_ERR) {
311 			dev_err(mmc_dev(host->mmc), "%s: -EILSEQ\n", __func__);
312 			data->error = -EILSEQ;
313 		} else if (stat & STATUS_CRC_WRITE_ERR) {
314 			u32 err_code = (stat >> 9) & 0x3;
315 			if (err_code == 2) { /* No CRC response */
316 				dev_err(mmc_dev(host->mmc),
317 					"%s: No CRC -ETIMEDOUT\n", __func__);
318 				data->error = -ETIMEDOUT;
319 			} else {
320 				dev_err(mmc_dev(host->mmc),
321 					"%s: -EILSEQ\n", __func__);
322 				data->error = -EILSEQ;
323 			}
324 		} else if (stat & STATUS_TIME_OUT_READ) {
325 			dev_err(mmc_dev(host->mmc),
326 				"%s: read -ETIMEDOUT\n", __func__);
327 			data->error = -ETIMEDOUT;
328 		} else {
329 			dev_err(mmc_dev(host->mmc), "%s: -EIO\n", __func__);
330 			data->error = -EIO;
331 		}
332 	} else {
333 		data->bytes_xfered = host->datasize;
334 	}
335 
336 	data_error = data->error;
337 
338 	host->data = NULL;
339 
340 	return data_error;
341 }
342 
343 static void mxcmci_read_response(struct mxcmci_host *host, unsigned int stat)
344 {
345 	struct mmc_command *cmd = host->cmd;
346 	int i;
347 	u32 a, b, c;
348 
349 	if (!cmd)
350 		return;
351 
352 	if (stat & STATUS_TIME_OUT_RESP) {
353 		dev_dbg(mmc_dev(host->mmc), "CMD TIMEOUT\n");
354 		cmd->error = -ETIMEDOUT;
355 	} else if (stat & STATUS_RESP_CRC_ERR && cmd->flags & MMC_RSP_CRC) {
356 		dev_dbg(mmc_dev(host->mmc), "cmd crc error\n");
357 		cmd->error = -EILSEQ;
358 	}
359 
360 	if (cmd->flags & MMC_RSP_PRESENT) {
361 		if (cmd->flags & MMC_RSP_136) {
362 			for (i = 0; i < 4; i++) {
363 				a = readw(host->base + MMC_REG_RES_FIFO);
364 				b = readw(host->base + MMC_REG_RES_FIFO);
365 				cmd->resp[i] = a << 16 | b;
366 			}
367 		} else {
368 			a = readw(host->base + MMC_REG_RES_FIFO);
369 			b = readw(host->base + MMC_REG_RES_FIFO);
370 			c = readw(host->base + MMC_REG_RES_FIFO);
371 			cmd->resp[0] = a << 24 | b << 8 | c >> 8;
372 		}
373 	}
374 }
375 
376 static int mxcmci_poll_status(struct mxcmci_host *host, u32 mask)
377 {
378 	u32 stat;
379 	unsigned long timeout = jiffies + HZ;
380 
381 	do {
382 		stat = readl(host->base + MMC_REG_STATUS);
383 		if (stat & STATUS_ERR_MASK)
384 			return stat;
385 		if (time_after(jiffies, timeout)) {
386 			mxcmci_softreset(host);
387 			mxcmci_set_clk_rate(host, host->clock);
388 			return STATUS_TIME_OUT_READ;
389 		}
390 		if (stat & mask)
391 			return 0;
392 		cpu_relax();
393 	} while (1);
394 }
395 
396 static int mxcmci_pull(struct mxcmci_host *host, void *_buf, int bytes)
397 {
398 	unsigned int stat;
399 	u32 *buf = _buf;
400 
401 	while (bytes > 3) {
402 		stat = mxcmci_poll_status(host,
403 				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
404 		if (stat)
405 			return stat;
406 		*buf++ = readl(host->base + MMC_REG_BUFFER_ACCESS);
407 		bytes -= 4;
408 	}
409 
410 	if (bytes) {
411 		u8 *b = (u8 *)buf;
412 		u32 tmp;
413 
414 		stat = mxcmci_poll_status(host,
415 				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
416 		if (stat)
417 			return stat;
418 		tmp = readl(host->base + MMC_REG_BUFFER_ACCESS);
419 		memcpy(b, &tmp, bytes);
420 	}
421 
422 	return 0;
423 }
424 
425 static int mxcmci_push(struct mxcmci_host *host, void *_buf, int bytes)
426 {
427 	unsigned int stat;
428 	u32 *buf = _buf;
429 
430 	while (bytes > 3) {
431 		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
432 		if (stat)
433 			return stat;
434 		writel(*buf++, host->base + MMC_REG_BUFFER_ACCESS);
435 		bytes -= 4;
436 	}
437 
438 	if (bytes) {
439 		u8 *b = (u8 *)buf;
440 		u32 tmp;
441 
442 		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
443 		if (stat)
444 			return stat;
445 
446 		memcpy(&tmp, b, bytes);
447 		writel(tmp, host->base + MMC_REG_BUFFER_ACCESS);
448 	}
449 
450 	stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
451 	if (stat)
452 		return stat;
453 
454 	return 0;
455 }
456 
457 static int mxcmci_transfer_data(struct mxcmci_host *host)
458 {
459 	struct mmc_data *data = host->req->data;
460 	struct scatterlist *sg;
461 	int stat, i;
462 
463 	host->data = data;
464 	host->datasize = 0;
465 
466 	if (data->flags & MMC_DATA_READ) {
467 		for_each_sg(data->sg, sg, data->sg_len, i) {
468 			stat = mxcmci_pull(host, sg_virt(sg), sg->length);
469 			if (stat)
470 				return stat;
471 			host->datasize += sg->length;
472 		}
473 	} else {
474 		for_each_sg(data->sg, sg, data->sg_len, i) {
475 			stat = mxcmci_push(host, sg_virt(sg), sg->length);
476 			if (stat)
477 				return stat;
478 			host->datasize += sg->length;
479 		}
480 		stat = mxcmci_poll_status(host, STATUS_WRITE_OP_DONE);
481 		if (stat)
482 			return stat;
483 	}
484 	return 0;
485 }
486 
487 static void mxcmci_datawork(struct work_struct *work)
488 {
489 	struct mxcmci_host *host = container_of(work, struct mxcmci_host,
490 						  datawork);
491 	int datastat = mxcmci_transfer_data(host);
492 
493 	writel(STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
494 		host->base + MMC_REG_STATUS);
495 	mxcmci_finish_data(host, datastat);
496 
497 	if (host->req->stop) {
498 		if (mxcmci_start_cmd(host, host->req->stop, 0)) {
499 			mxcmci_finish_request(host, host->req);
500 			return;
501 		}
502 	} else {
503 		mxcmci_finish_request(host, host->req);
504 	}
505 }
506 
507 #ifdef HAS_DMA
508 static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat)
509 {
510 	struct mmc_data *data = host->data;
511 	int data_error;
512 
513 	if (!data)
514 		return;
515 
516 	data_error = mxcmci_finish_data(host, stat);
517 
518 	mxcmci_read_response(host, stat);
519 	host->cmd = NULL;
520 
521 	if (host->req->stop) {
522 		if (mxcmci_start_cmd(host, host->req->stop, 0)) {
523 			mxcmci_finish_request(host, host->req);
524 			return;
525 		}
526 	} else {
527 		mxcmci_finish_request(host, host->req);
528 	}
529 }
530 #endif /* HAS_DMA */
531 
532 static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat)
533 {
534 	mxcmci_read_response(host, stat);
535 	host->cmd = NULL;
536 
537 	if (!host->data && host->req) {
538 		mxcmci_finish_request(host, host->req);
539 		return;
540 	}
541 
542 	/* For the DMA case the DMA engine handles the data transfer
543 	 * automatically. For non DMA we have to do it ourselves.
544 	 * Don't do it in interrupt context though.
545 	 */
546 	if (!mxcmci_use_dma(host) && host->data)
547 		schedule_work(&host->datawork);
548 
549 }
550 
551 static irqreturn_t mxcmci_irq(int irq, void *devid)
552 {
553 	struct mxcmci_host *host = devid;
554 	unsigned long flags;
555 	bool sdio_irq;
556 	u32 stat;
557 
558 	stat = readl(host->base + MMC_REG_STATUS);
559 	writel(stat & ~(STATUS_SDIO_INT_ACTIVE | STATUS_DATA_TRANS_DONE |
560 			STATUS_WRITE_OP_DONE), host->base + MMC_REG_STATUS);
561 
562 	dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
563 
564 	spin_lock_irqsave(&host->lock, flags);
565 	sdio_irq = (stat & STATUS_SDIO_INT_ACTIVE) && host->use_sdio;
566 	spin_unlock_irqrestore(&host->lock, flags);
567 
568 #ifdef HAS_DMA
569 	if (mxcmci_use_dma(host) &&
570 	    (stat & (STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE)))
571 		writel(STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
572 			host->base + MMC_REG_STATUS);
573 #endif
574 
575 	if (sdio_irq) {
576 		writel(STATUS_SDIO_INT_ACTIVE, host->base + MMC_REG_STATUS);
577 		mmc_signal_sdio_irq(host->mmc);
578 	}
579 
580 	if (stat & STATUS_END_CMD_RESP)
581 		mxcmci_cmd_done(host, stat);
582 
583 #ifdef HAS_DMA
584 	if (mxcmci_use_dma(host) &&
585 		  (stat & (STATUS_DATA_TRANS_DONE | STATUS_WRITE_OP_DONE)))
586 		mxcmci_data_done(host, stat);
587 #endif
588 	return IRQ_HANDLED;
589 }
590 
591 static void mxcmci_request(struct mmc_host *mmc, struct mmc_request *req)
592 {
593 	struct mxcmci_host *host = mmc_priv(mmc);
594 	unsigned int cmdat = host->cmdat;
595 	int error;
596 
597 	WARN_ON(host->req != NULL);
598 
599 	host->req = req;
600 	host->cmdat &= ~CMD_DAT_CONT_INIT;
601 #ifdef HAS_DMA
602 	host->do_dma = 1;
603 #endif
604 	if (req->data) {
605 		error = mxcmci_setup_data(host, req->data);
606 		if (error) {
607 			req->cmd->error = error;
608 			goto out;
609 		}
610 
611 
612 		cmdat |= CMD_DAT_CONT_DATA_ENABLE;
613 
614 		if (req->data->flags & MMC_DATA_WRITE)
615 			cmdat |= CMD_DAT_CONT_WRITE;
616 	}
617 
618 	error = mxcmci_start_cmd(host, req->cmd, cmdat);
619 out:
620 	if (error)
621 		mxcmci_finish_request(host, req);
622 }
623 
624 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios)
625 {
626 	unsigned int divider;
627 	int prescaler = 0;
628 	unsigned int clk_in = clk_get_rate(host->clk);
629 
630 	while (prescaler <= 0x800) {
631 		for (divider = 1; divider <= 0xF; divider++) {
632 			int x;
633 
634 			x = (clk_in / (divider + 1));
635 
636 			if (prescaler)
637 				x /= (prescaler * 2);
638 
639 			if (x <= clk_ios)
640 				break;
641 		}
642 		if (divider < 0x10)
643 			break;
644 
645 		if (prescaler == 0)
646 			prescaler = 1;
647 		else
648 			prescaler <<= 1;
649 	}
650 
651 	writew((prescaler << 4) | divider, host->base + MMC_REG_CLK_RATE);
652 
653 	dev_dbg(mmc_dev(host->mmc), "scaler: %d divider: %d in: %d out: %d\n",
654 			prescaler, divider, clk_in, clk_ios);
655 }
656 
657 static void mxcmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
658 {
659 	struct mxcmci_host *host = mmc_priv(mmc);
660 #ifdef HAS_DMA
661 	unsigned int blen;
662 	/*
663 	 * use burstlen of 64 in 4 bit mode (--> reg value  0)
664 	 * use burstlen of 16 in 1 bit mode (--> reg value 16)
665 	 */
666 	if (ios->bus_width == MMC_BUS_WIDTH_4)
667 		blen = 0;
668 	else
669 		blen = 16;
670 
671 	imx_dma_config_burstlen(host->dma, blen);
672 #endif
673 	if (ios->bus_width == MMC_BUS_WIDTH_4)
674 		host->cmdat |= CMD_DAT_CONT_BUS_WIDTH_4;
675 	else
676 		host->cmdat &= ~CMD_DAT_CONT_BUS_WIDTH_4;
677 
678 	if (host->power_mode != ios->power_mode) {
679 		if (host->pdata && host->pdata->setpower)
680 			host->pdata->setpower(mmc_dev(mmc), ios->vdd);
681 		host->power_mode = ios->power_mode;
682 		if (ios->power_mode == MMC_POWER_ON)
683 			host->cmdat |= CMD_DAT_CONT_INIT;
684 	}
685 
686 	if (ios->clock) {
687 		mxcmci_set_clk_rate(host, ios->clock);
688 		writew(STR_STP_CLK_START_CLK, host->base + MMC_REG_STR_STP_CLK);
689 	} else {
690 		writew(STR_STP_CLK_STOP_CLK, host->base + MMC_REG_STR_STP_CLK);
691 	}
692 
693 	host->clock = ios->clock;
694 }
695 
696 static irqreturn_t mxcmci_detect_irq(int irq, void *data)
697 {
698 	struct mmc_host *mmc = data;
699 
700 	dev_dbg(mmc_dev(mmc), "%s\n", __func__);
701 
702 	mmc_detect_change(mmc, msecs_to_jiffies(250));
703 	return IRQ_HANDLED;
704 }
705 
706 static int mxcmci_get_ro(struct mmc_host *mmc)
707 {
708 	struct mxcmci_host *host = mmc_priv(mmc);
709 
710 	if (host->pdata && host->pdata->get_ro)
711 		return !!host->pdata->get_ro(mmc_dev(mmc));
712 	/*
713 	 * Board doesn't support read only detection; let the mmc core
714 	 * decide what to do.
715 	 */
716 	return -ENOSYS;
717 }
718 
719 static void mxcmci_enable_sdio_irq(struct mmc_host *mmc, int enable)
720 {
721 	struct mxcmci_host *host = mmc_priv(mmc);
722 	unsigned long flags;
723 	u32 int_cntr;
724 
725 	spin_lock_irqsave(&host->lock, flags);
726 	host->use_sdio = enable;
727 	int_cntr = readl(host->base + MMC_REG_INT_CNTR);
728 
729 	if (enable)
730 		int_cntr |= INT_SDIO_IRQ_EN;
731 	else
732 		int_cntr &= ~INT_SDIO_IRQ_EN;
733 
734 	writel(int_cntr, host->base + MMC_REG_INT_CNTR);
735 	spin_unlock_irqrestore(&host->lock, flags);
736 }
737 
738 static void mxcmci_init_card(struct mmc_host *host, struct mmc_card *card)
739 {
740 	/*
741 	 * MX3 SoCs have a silicon bug which corrupts CRC calculation of
742 	 * multi-block transfers when connected SDIO peripheral doesn't
743 	 * drive the BUSY line as required by the specs.
744 	 * One way to prevent this is to only allow 1-bit transfers.
745 	 */
746 
747 	if (cpu_is_mx3() && card->type == MMC_TYPE_SDIO)
748 		host->caps &= ~MMC_CAP_4_BIT_DATA;
749 	else
750 		host->caps |= MMC_CAP_4_BIT_DATA;
751 }
752 
753 static const struct mmc_host_ops mxcmci_ops = {
754 	.request		= mxcmci_request,
755 	.set_ios		= mxcmci_set_ios,
756 	.get_ro			= mxcmci_get_ro,
757 	.enable_sdio_irq	= mxcmci_enable_sdio_irq,
758 	.init_card		= mxcmci_init_card,
759 };
760 
761 static int mxcmci_probe(struct platform_device *pdev)
762 {
763 	struct mmc_host *mmc;
764 	struct mxcmci_host *host = NULL;
765 	struct resource *iores, *r;
766 	int ret = 0, irq;
767 
768 	printk(KERN_INFO "i.MX SDHC driver\n");
769 
770 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
771 	irq = platform_get_irq(pdev, 0);
772 	if (!iores || irq < 0)
773 		return -EINVAL;
774 
775 	r = request_mem_region(iores->start, resource_size(iores), pdev->name);
776 	if (!r)
777 		return -EBUSY;
778 
779 	mmc = mmc_alloc_host(sizeof(struct mxcmci_host), &pdev->dev);
780 	if (!mmc) {
781 		ret = -ENOMEM;
782 		goto out_release_mem;
783 	}
784 
785 	mmc->ops = &mxcmci_ops;
786 	mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
787 
788 	/* MMC core transfer sizes tunable parameters */
789 	mmc->max_hw_segs = 64;
790 	mmc->max_phys_segs = 64;
791 	mmc->max_blk_size = 2048;
792 	mmc->max_blk_count = 65535;
793 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
794 	mmc->max_seg_size = mmc->max_req_size;
795 
796 	host = mmc_priv(mmc);
797 	host->base = ioremap(r->start, resource_size(r));
798 	if (!host->base) {
799 		ret = -ENOMEM;
800 		goto out_free;
801 	}
802 
803 	host->mmc = mmc;
804 	host->pdata = pdev->dev.platform_data;
805 	spin_lock_init(&host->lock);
806 
807 	if (host->pdata && host->pdata->ocr_avail)
808 		mmc->ocr_avail = host->pdata->ocr_avail;
809 	else
810 		mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
811 
812 	host->res = r;
813 	host->irq = irq;
814 
815 	host->clk = clk_get(&pdev->dev, NULL);
816 	if (IS_ERR(host->clk)) {
817 		ret = PTR_ERR(host->clk);
818 		goto out_iounmap;
819 	}
820 	clk_enable(host->clk);
821 
822 	mxcmci_softreset(host);
823 
824 	host->rev_no = readw(host->base + MMC_REG_REV_NO);
825 	if (host->rev_no != 0x400) {
826 		ret = -ENODEV;
827 		dev_err(mmc_dev(host->mmc), "wrong rev.no. 0x%08x. aborting.\n",
828 			host->rev_no);
829 		goto out_clk_put;
830 	}
831 
832 	mmc->f_min = clk_get_rate(host->clk) >> 16;
833 	mmc->f_max = clk_get_rate(host->clk) >> 1;
834 
835 	/* recommended in data sheet */
836 	writew(0x2db4, host->base + MMC_REG_READ_TO);
837 
838 	writel(0, host->base + MMC_REG_INT_CNTR);
839 
840 #ifdef HAS_DMA
841 	host->dma = imx_dma_request_by_prio(DRIVER_NAME, DMA_PRIO_LOW);
842 	if (host->dma < 0) {
843 		dev_err(mmc_dev(host->mmc), "imx_dma_request_by_prio failed\n");
844 		ret = -EBUSY;
845 		goto out_clk_put;
846 	}
847 
848 	r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
849 	if (!r) {
850 		ret = -EINVAL;
851 		goto out_free_dma;
852 	}
853 
854 	ret = imx_dma_config_channel(host->dma,
855 				     IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_FIFO,
856 				     IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR,
857 				     r->start, 0);
858 	if (ret) {
859 		dev_err(mmc_dev(host->mmc), "failed to config DMA channel\n");
860 		goto out_free_dma;
861 	}
862 #endif
863 	INIT_WORK(&host->datawork, mxcmci_datawork);
864 
865 	ret = request_irq(host->irq, mxcmci_irq, 0, DRIVER_NAME, host);
866 	if (ret)
867 		goto out_free_dma;
868 
869 	platform_set_drvdata(pdev, mmc);
870 
871 	if (host->pdata && host->pdata->init) {
872 		ret = host->pdata->init(&pdev->dev, mxcmci_detect_irq,
873 				host->mmc);
874 		if (ret)
875 			goto out_free_irq;
876 	}
877 
878 	mmc_add_host(mmc);
879 
880 	return 0;
881 
882 out_free_irq:
883 	free_irq(host->irq, host);
884 out_free_dma:
885 #ifdef HAS_DMA
886 	imx_dma_free(host->dma);
887 #endif
888 out_clk_put:
889 	clk_disable(host->clk);
890 	clk_put(host->clk);
891 out_iounmap:
892 	iounmap(host->base);
893 out_free:
894 	mmc_free_host(mmc);
895 out_release_mem:
896 	release_mem_region(iores->start, resource_size(iores));
897 	return ret;
898 }
899 
900 static int mxcmci_remove(struct platform_device *pdev)
901 {
902 	struct mmc_host *mmc = platform_get_drvdata(pdev);
903 	struct mxcmci_host *host = mmc_priv(mmc);
904 
905 	platform_set_drvdata(pdev, NULL);
906 
907 	mmc_remove_host(mmc);
908 
909 	if (host->pdata && host->pdata->exit)
910 		host->pdata->exit(&pdev->dev, mmc);
911 
912 	free_irq(host->irq, host);
913 	iounmap(host->base);
914 #ifdef HAS_DMA
915 	imx_dma_free(host->dma);
916 #endif
917 	clk_disable(host->clk);
918 	clk_put(host->clk);
919 
920 	release_mem_region(host->res->start, resource_size(host->res));
921 	release_resource(host->res);
922 
923 	mmc_free_host(mmc);
924 
925 	return 0;
926 }
927 
928 #ifdef CONFIG_PM
929 static int mxcmci_suspend(struct platform_device *dev, pm_message_t state)
930 {
931 	struct mmc_host *mmc = platform_get_drvdata(dev);
932 	int ret = 0;
933 
934 	if (mmc)
935 		ret = mmc_suspend_host(mmc);
936 
937 	return ret;
938 }
939 
940 static int mxcmci_resume(struct platform_device *dev)
941 {
942 	struct mmc_host *mmc = platform_get_drvdata(dev);
943 	struct mxcmci_host *host;
944 	int ret = 0;
945 
946 	if (mmc) {
947 		host = mmc_priv(mmc);
948 		ret = mmc_resume_host(mmc);
949 	}
950 
951 	return ret;
952 }
953 #else
954 #define mxcmci_suspend  NULL
955 #define mxcmci_resume   NULL
956 #endif /* CONFIG_PM */
957 
958 static struct platform_driver mxcmci_driver = {
959 	.probe		= mxcmci_probe,
960 	.remove		= mxcmci_remove,
961 	.suspend	= mxcmci_suspend,
962 	.resume		= mxcmci_resume,
963 	.driver		= {
964 		.name		= DRIVER_NAME,
965 		.owner		= THIS_MODULE,
966 	}
967 };
968 
969 static int __init mxcmci_init(void)
970 {
971 	return platform_driver_register(&mxcmci_driver);
972 }
973 
974 static void __exit mxcmci_exit(void)
975 {
976 	platform_driver_unregister(&mxcmci_driver);
977 }
978 
979 module_init(mxcmci_init);
980 module_exit(mxcmci_exit);
981 
982 MODULE_DESCRIPTION("i.MX Multimedia Card Interface Driver");
983 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
984 MODULE_LICENSE("GPL");
985 MODULE_ALIAS("platform:imx-mmc");
986