xref: /openbmc/linux/drivers/mmc/host/mxcmmc.c (revision 39b6f3aa)
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 #include <linux/regulator/consumer.h>
35 #include <linux/dmaengine.h>
36 #include <linux/types.h>
37 #include <linux/of.h>
38 #include <linux/of_device.h>
39 #include <linux/of_dma.h>
40 #include <linux/of_gpio.h>
41 #include <linux/mmc/slot-gpio.h>
42 
43 #include <asm/dma.h>
44 #include <asm/irq.h>
45 #include <linux/platform_data/mmc-mxcmmc.h>
46 
47 #include <linux/platform_data/dma-imx.h>
48 
49 #define DRIVER_NAME "mxc-mmc"
50 #define MXCMCI_TIMEOUT_MS 10000
51 
52 #define MMC_REG_STR_STP_CLK		0x00
53 #define MMC_REG_STATUS			0x04
54 #define MMC_REG_CLK_RATE		0x08
55 #define MMC_REG_CMD_DAT_CONT		0x0C
56 #define MMC_REG_RES_TO			0x10
57 #define MMC_REG_READ_TO			0x14
58 #define MMC_REG_BLK_LEN			0x18
59 #define MMC_REG_NOB			0x1C
60 #define MMC_REG_REV_NO			0x20
61 #define MMC_REG_INT_CNTR		0x24
62 #define MMC_REG_CMD			0x28
63 #define MMC_REG_ARG			0x2C
64 #define MMC_REG_RES_FIFO		0x34
65 #define MMC_REG_BUFFER_ACCESS		0x38
66 
67 #define STR_STP_CLK_RESET               (1 << 3)
68 #define STR_STP_CLK_START_CLK           (1 << 1)
69 #define STR_STP_CLK_STOP_CLK            (1 << 0)
70 
71 #define STATUS_CARD_INSERTION		(1 << 31)
72 #define STATUS_CARD_REMOVAL		(1 << 30)
73 #define STATUS_YBUF_EMPTY		(1 << 29)
74 #define STATUS_XBUF_EMPTY		(1 << 28)
75 #define STATUS_YBUF_FULL		(1 << 27)
76 #define STATUS_XBUF_FULL		(1 << 26)
77 #define STATUS_BUF_UND_RUN		(1 << 25)
78 #define STATUS_BUF_OVFL			(1 << 24)
79 #define STATUS_SDIO_INT_ACTIVE		(1 << 14)
80 #define STATUS_END_CMD_RESP		(1 << 13)
81 #define STATUS_WRITE_OP_DONE		(1 << 12)
82 #define STATUS_DATA_TRANS_DONE		(1 << 11)
83 #define STATUS_READ_OP_DONE		(1 << 11)
84 #define STATUS_WR_CRC_ERROR_CODE_MASK	(3 << 10)
85 #define STATUS_CARD_BUS_CLK_RUN		(1 << 8)
86 #define STATUS_BUF_READ_RDY		(1 << 7)
87 #define STATUS_BUF_WRITE_RDY		(1 << 6)
88 #define STATUS_RESP_CRC_ERR		(1 << 5)
89 #define STATUS_CRC_READ_ERR		(1 << 3)
90 #define STATUS_CRC_WRITE_ERR		(1 << 2)
91 #define STATUS_TIME_OUT_RESP		(1 << 1)
92 #define STATUS_TIME_OUT_READ		(1 << 0)
93 #define STATUS_ERR_MASK			0x2f
94 
95 #define CMD_DAT_CONT_CMD_RESP_LONG_OFF	(1 << 12)
96 #define CMD_DAT_CONT_STOP_READWAIT	(1 << 11)
97 #define CMD_DAT_CONT_START_READWAIT	(1 << 10)
98 #define CMD_DAT_CONT_BUS_WIDTH_4	(2 << 8)
99 #define CMD_DAT_CONT_INIT		(1 << 7)
100 #define CMD_DAT_CONT_WRITE		(1 << 4)
101 #define CMD_DAT_CONT_DATA_ENABLE	(1 << 3)
102 #define CMD_DAT_CONT_RESPONSE_48BIT_CRC	(1 << 0)
103 #define CMD_DAT_CONT_RESPONSE_136BIT	(2 << 0)
104 #define CMD_DAT_CONT_RESPONSE_48BIT	(3 << 0)
105 
106 #define INT_SDIO_INT_WKP_EN		(1 << 18)
107 #define INT_CARD_INSERTION_WKP_EN	(1 << 17)
108 #define INT_CARD_REMOVAL_WKP_EN		(1 << 16)
109 #define INT_CARD_INSERTION_EN		(1 << 15)
110 #define INT_CARD_REMOVAL_EN		(1 << 14)
111 #define INT_SDIO_IRQ_EN			(1 << 13)
112 #define INT_DAT0_EN			(1 << 12)
113 #define INT_BUF_READ_EN			(1 << 4)
114 #define INT_BUF_WRITE_EN		(1 << 3)
115 #define INT_END_CMD_RES_EN		(1 << 2)
116 #define INT_WRITE_OP_DONE_EN		(1 << 1)
117 #define INT_READ_OP_EN			(1 << 0)
118 
119 enum mxcmci_type {
120 	IMX21_MMC,
121 	IMX31_MMC,
122 	MPC512X_MMC,
123 };
124 
125 struct mxcmci_host {
126 	struct mmc_host		*mmc;
127 	struct resource		*res;
128 	void __iomem		*base;
129 	int			irq;
130 	int			detect_irq;
131 	struct dma_chan		*dma;
132 	struct dma_async_tx_descriptor *desc;
133 	int			do_dma;
134 	int			default_irq_mask;
135 	int			use_sdio;
136 	unsigned int		power_mode;
137 	struct imxmmc_platform_data *pdata;
138 
139 	struct mmc_request	*req;
140 	struct mmc_command	*cmd;
141 	struct mmc_data		*data;
142 
143 	unsigned int		datasize;
144 	unsigned int		dma_dir;
145 
146 	u16			rev_no;
147 	unsigned int		cmdat;
148 
149 	struct clk		*clk_ipg;
150 	struct clk		*clk_per;
151 
152 	int			clock;
153 
154 	struct work_struct	datawork;
155 	spinlock_t		lock;
156 
157 	struct regulator	*vcc;
158 
159 	int			burstlen;
160 	int			dmareq;
161 	struct dma_slave_config dma_slave_config;
162 	struct imx_dma_data	dma_data;
163 
164 	struct timer_list	watchdog;
165 	enum mxcmci_type	devtype;
166 };
167 
168 static const struct platform_device_id mxcmci_devtype[] = {
169 	{
170 		.name = "imx21-mmc",
171 		.driver_data = IMX21_MMC,
172 	}, {
173 		.name = "imx31-mmc",
174 		.driver_data = IMX31_MMC,
175 	}, {
176 		.name = "mpc512x-sdhc",
177 		.driver_data = MPC512X_MMC,
178 	}, {
179 		/* sentinel */
180 	}
181 };
182 MODULE_DEVICE_TABLE(platform, mxcmci_devtype);
183 
184 static const struct of_device_id mxcmci_of_match[] = {
185 	{
186 		.compatible = "fsl,imx21-mmc",
187 		.data = &mxcmci_devtype[IMX21_MMC],
188 	}, {
189 		.compatible = "fsl,imx31-mmc",
190 		.data = &mxcmci_devtype[IMX31_MMC],
191 	}, {
192 		.compatible = "fsl,mpc5121-sdhc",
193 		.data = &mxcmci_devtype[MPC512X_MMC],
194 	}, {
195 		/* sentinel */
196 	}
197 };
198 MODULE_DEVICE_TABLE(of, mxcmci_of_match);
199 
200 static inline int is_imx31_mmc(struct mxcmci_host *host)
201 {
202 	return host->devtype == IMX31_MMC;
203 }
204 
205 static inline int is_mpc512x_mmc(struct mxcmci_host *host)
206 {
207 	return host->devtype == MPC512X_MMC;
208 }
209 
210 static inline u32 mxcmci_readl(struct mxcmci_host *host, int reg)
211 {
212 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
213 		return ioread32be(host->base + reg);
214 	else
215 		return readl(host->base + reg);
216 }
217 
218 static inline void mxcmci_writel(struct mxcmci_host *host, u32 val, int reg)
219 {
220 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
221 		iowrite32be(val, host->base + reg);
222 	else
223 		writel(val, host->base + reg);
224 }
225 
226 static inline u16 mxcmci_readw(struct mxcmci_host *host, int reg)
227 {
228 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
229 		return ioread32be(host->base + reg);
230 	else
231 		return readw(host->base + reg);
232 }
233 
234 static inline void mxcmci_writew(struct mxcmci_host *host, u16 val, int reg)
235 {
236 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
237 		iowrite32be(val, host->base + reg);
238 	else
239 		writew(val, host->base + reg);
240 }
241 
242 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios);
243 
244 static inline void mxcmci_init_ocr(struct mxcmci_host *host)
245 {
246 	host->vcc = regulator_get(mmc_dev(host->mmc), "vmmc");
247 
248 	if (IS_ERR(host->vcc)) {
249 		host->vcc = NULL;
250 	} else {
251 		host->mmc->ocr_avail = mmc_regulator_get_ocrmask(host->vcc);
252 		if (host->pdata && host->pdata->ocr_avail)
253 			dev_warn(mmc_dev(host->mmc),
254 				"pdata->ocr_avail will not be used\n");
255 	}
256 
257 	if (host->vcc == NULL) {
258 		/* fall-back to platform data */
259 		if (host->pdata && host->pdata->ocr_avail)
260 			host->mmc->ocr_avail = host->pdata->ocr_avail;
261 		else
262 			host->mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
263 	}
264 }
265 
266 static inline void mxcmci_set_power(struct mxcmci_host *host,
267 				    unsigned char power_mode,
268 				    unsigned int vdd)
269 {
270 	if (host->vcc) {
271 		if (power_mode == MMC_POWER_UP)
272 			mmc_regulator_set_ocr(host->mmc, host->vcc, vdd);
273 		else if (power_mode == MMC_POWER_OFF)
274 			mmc_regulator_set_ocr(host->mmc, host->vcc, 0);
275 	}
276 
277 	if (host->pdata && host->pdata->setpower)
278 		host->pdata->setpower(mmc_dev(host->mmc), vdd);
279 }
280 
281 static inline int mxcmci_use_dma(struct mxcmci_host *host)
282 {
283 	return host->do_dma;
284 }
285 
286 static void mxcmci_softreset(struct mxcmci_host *host)
287 {
288 	int i;
289 
290 	dev_dbg(mmc_dev(host->mmc), "mxcmci_softreset\n");
291 
292 	/* reset sequence */
293 	mxcmci_writew(host, STR_STP_CLK_RESET, MMC_REG_STR_STP_CLK);
294 	mxcmci_writew(host, STR_STP_CLK_RESET | STR_STP_CLK_START_CLK,
295 			MMC_REG_STR_STP_CLK);
296 
297 	for (i = 0; i < 8; i++)
298 		mxcmci_writew(host, STR_STP_CLK_START_CLK, MMC_REG_STR_STP_CLK);
299 
300 	mxcmci_writew(host, 0xff, MMC_REG_RES_TO);
301 }
302 static int mxcmci_setup_dma(struct mmc_host *mmc);
303 
304 #if IS_ENABLED(CONFIG_PPC_MPC512x)
305 static inline void buffer_swap32(u32 *buf, int len)
306 {
307 	int i;
308 
309 	for (i = 0; i < ((len + 3) / 4); i++) {
310 		st_le32(buf, *buf);
311 		buf++;
312 	}
313 }
314 
315 static void mxcmci_swap_buffers(struct mmc_data *data)
316 {
317 	struct scatterlist *sg;
318 	int i;
319 
320 	for_each_sg(data->sg, sg, data->sg_len, i)
321 		buffer_swap32(sg_virt(sg), sg->length);
322 }
323 #else
324 static inline void mxcmci_swap_buffers(struct mmc_data *data) {}
325 #endif
326 
327 static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
328 {
329 	unsigned int nob = data->blocks;
330 	unsigned int blksz = data->blksz;
331 	unsigned int datasize = nob * blksz;
332 	struct scatterlist *sg;
333 	enum dma_transfer_direction slave_dirn;
334 	int i, nents;
335 
336 	if (data->flags & MMC_DATA_STREAM)
337 		nob = 0xffff;
338 
339 	host->data = data;
340 	data->bytes_xfered = 0;
341 
342 	mxcmci_writew(host, nob, MMC_REG_NOB);
343 	mxcmci_writew(host, blksz, MMC_REG_BLK_LEN);
344 	host->datasize = datasize;
345 
346 	if (!mxcmci_use_dma(host))
347 		return 0;
348 
349 	for_each_sg(data->sg, sg, data->sg_len, i) {
350 		if (sg->offset & 3 || sg->length & 3 || sg->length < 512) {
351 			host->do_dma = 0;
352 			return 0;
353 		}
354 	}
355 
356 	if (data->flags & MMC_DATA_READ) {
357 		host->dma_dir = DMA_FROM_DEVICE;
358 		slave_dirn = DMA_DEV_TO_MEM;
359 	} else {
360 		host->dma_dir = DMA_TO_DEVICE;
361 		slave_dirn = DMA_MEM_TO_DEV;
362 
363 		mxcmci_swap_buffers(data);
364 	}
365 
366 	nents = dma_map_sg(host->dma->device->dev, data->sg,
367 				     data->sg_len,  host->dma_dir);
368 	if (nents != data->sg_len)
369 		return -EINVAL;
370 
371 	host->desc = dmaengine_prep_slave_sg(host->dma,
372 		data->sg, data->sg_len, slave_dirn,
373 		DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
374 
375 	if (!host->desc) {
376 		dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
377 				host->dma_dir);
378 		host->do_dma = 0;
379 		return 0; /* Fall back to PIO */
380 	}
381 	wmb();
382 
383 	dmaengine_submit(host->desc);
384 	dma_async_issue_pending(host->dma);
385 
386 	mod_timer(&host->watchdog, jiffies + msecs_to_jiffies(MXCMCI_TIMEOUT_MS));
387 
388 	return 0;
389 }
390 
391 static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat);
392 static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat);
393 
394 static void mxcmci_dma_callback(void *data)
395 {
396 	struct mxcmci_host *host = data;
397 	u32 stat;
398 
399 	del_timer(&host->watchdog);
400 
401 	stat = mxcmci_readl(host, MMC_REG_STATUS);
402 	mxcmci_writel(host, stat & ~STATUS_DATA_TRANS_DONE, MMC_REG_STATUS);
403 
404 	dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
405 
406 	if (stat & STATUS_READ_OP_DONE)
407 		mxcmci_writel(host, STATUS_READ_OP_DONE, MMC_REG_STATUS);
408 
409 	mxcmci_data_done(host, stat);
410 }
411 
412 static int mxcmci_start_cmd(struct mxcmci_host *host, struct mmc_command *cmd,
413 		unsigned int cmdat)
414 {
415 	u32 int_cntr = host->default_irq_mask;
416 	unsigned long flags;
417 
418 	WARN_ON(host->cmd != NULL);
419 	host->cmd = cmd;
420 
421 	switch (mmc_resp_type(cmd)) {
422 	case MMC_RSP_R1: /* short CRC, OPCODE */
423 	case MMC_RSP_R1B:/* short CRC, OPCODE, BUSY */
424 		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT_CRC;
425 		break;
426 	case MMC_RSP_R2: /* long 136 bit + CRC */
427 		cmdat |= CMD_DAT_CONT_RESPONSE_136BIT;
428 		break;
429 	case MMC_RSP_R3: /* short */
430 		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT;
431 		break;
432 	case MMC_RSP_NONE:
433 		break;
434 	default:
435 		dev_err(mmc_dev(host->mmc), "unhandled response type 0x%x\n",
436 				mmc_resp_type(cmd));
437 		cmd->error = -EINVAL;
438 		return -EINVAL;
439 	}
440 
441 	int_cntr = INT_END_CMD_RES_EN;
442 
443 	if (mxcmci_use_dma(host)) {
444 		if (host->dma_dir == DMA_FROM_DEVICE) {
445 			host->desc->callback = mxcmci_dma_callback;
446 			host->desc->callback_param = host;
447 		} else {
448 			int_cntr |= INT_WRITE_OP_DONE_EN;
449 		}
450 	}
451 
452 	spin_lock_irqsave(&host->lock, flags);
453 	if (host->use_sdio)
454 		int_cntr |= INT_SDIO_IRQ_EN;
455 	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
456 	spin_unlock_irqrestore(&host->lock, flags);
457 
458 	mxcmci_writew(host, cmd->opcode, MMC_REG_CMD);
459 	mxcmci_writel(host, cmd->arg, MMC_REG_ARG);
460 	mxcmci_writew(host, cmdat, MMC_REG_CMD_DAT_CONT);
461 
462 	return 0;
463 }
464 
465 static void mxcmci_finish_request(struct mxcmci_host *host,
466 		struct mmc_request *req)
467 {
468 	u32 int_cntr = host->default_irq_mask;
469 	unsigned long flags;
470 
471 	spin_lock_irqsave(&host->lock, flags);
472 	if (host->use_sdio)
473 		int_cntr |= INT_SDIO_IRQ_EN;
474 	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
475 	spin_unlock_irqrestore(&host->lock, flags);
476 
477 	host->req = NULL;
478 	host->cmd = NULL;
479 	host->data = NULL;
480 
481 	mmc_request_done(host->mmc, req);
482 }
483 
484 static int mxcmci_finish_data(struct mxcmci_host *host, unsigned int stat)
485 {
486 	struct mmc_data *data = host->data;
487 	int data_error;
488 
489 	if (mxcmci_use_dma(host)) {
490 		dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
491 				host->dma_dir);
492 		mxcmci_swap_buffers(data);
493 	}
494 
495 	if (stat & STATUS_ERR_MASK) {
496 		dev_dbg(mmc_dev(host->mmc), "request failed. status: 0x%08x\n",
497 				stat);
498 		if (stat & STATUS_CRC_READ_ERR) {
499 			dev_err(mmc_dev(host->mmc), "%s: -EILSEQ\n", __func__);
500 			data->error = -EILSEQ;
501 		} else if (stat & STATUS_CRC_WRITE_ERR) {
502 			u32 err_code = (stat >> 9) & 0x3;
503 			if (err_code == 2) { /* No CRC response */
504 				dev_err(mmc_dev(host->mmc),
505 					"%s: No CRC -ETIMEDOUT\n", __func__);
506 				data->error = -ETIMEDOUT;
507 			} else {
508 				dev_err(mmc_dev(host->mmc),
509 					"%s: -EILSEQ\n", __func__);
510 				data->error = -EILSEQ;
511 			}
512 		} else if (stat & STATUS_TIME_OUT_READ) {
513 			dev_err(mmc_dev(host->mmc),
514 				"%s: read -ETIMEDOUT\n", __func__);
515 			data->error = -ETIMEDOUT;
516 		} else {
517 			dev_err(mmc_dev(host->mmc), "%s: -EIO\n", __func__);
518 			data->error = -EIO;
519 		}
520 	} else {
521 		data->bytes_xfered = host->datasize;
522 	}
523 
524 	data_error = data->error;
525 
526 	host->data = NULL;
527 
528 	return data_error;
529 }
530 
531 static void mxcmci_read_response(struct mxcmci_host *host, unsigned int stat)
532 {
533 	struct mmc_command *cmd = host->cmd;
534 	int i;
535 	u32 a, b, c;
536 
537 	if (!cmd)
538 		return;
539 
540 	if (stat & STATUS_TIME_OUT_RESP) {
541 		dev_dbg(mmc_dev(host->mmc), "CMD TIMEOUT\n");
542 		cmd->error = -ETIMEDOUT;
543 	} else if (stat & STATUS_RESP_CRC_ERR && cmd->flags & MMC_RSP_CRC) {
544 		dev_dbg(mmc_dev(host->mmc), "cmd crc error\n");
545 		cmd->error = -EILSEQ;
546 	}
547 
548 	if (cmd->flags & MMC_RSP_PRESENT) {
549 		if (cmd->flags & MMC_RSP_136) {
550 			for (i = 0; i < 4; i++) {
551 				a = mxcmci_readw(host, MMC_REG_RES_FIFO);
552 				b = mxcmci_readw(host, MMC_REG_RES_FIFO);
553 				cmd->resp[i] = a << 16 | b;
554 			}
555 		} else {
556 			a = mxcmci_readw(host, MMC_REG_RES_FIFO);
557 			b = mxcmci_readw(host, MMC_REG_RES_FIFO);
558 			c = mxcmci_readw(host, MMC_REG_RES_FIFO);
559 			cmd->resp[0] = a << 24 | b << 8 | c >> 8;
560 		}
561 	}
562 }
563 
564 static int mxcmci_poll_status(struct mxcmci_host *host, u32 mask)
565 {
566 	u32 stat;
567 	unsigned long timeout = jiffies + HZ;
568 
569 	do {
570 		stat = mxcmci_readl(host, MMC_REG_STATUS);
571 		if (stat & STATUS_ERR_MASK)
572 			return stat;
573 		if (time_after(jiffies, timeout)) {
574 			mxcmci_softreset(host);
575 			mxcmci_set_clk_rate(host, host->clock);
576 			return STATUS_TIME_OUT_READ;
577 		}
578 		if (stat & mask)
579 			return 0;
580 		cpu_relax();
581 	} while (1);
582 }
583 
584 static int mxcmci_pull(struct mxcmci_host *host, void *_buf, int bytes)
585 {
586 	unsigned int stat;
587 	u32 *buf = _buf;
588 
589 	while (bytes > 3) {
590 		stat = mxcmci_poll_status(host,
591 				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
592 		if (stat)
593 			return stat;
594 		*buf++ = cpu_to_le32(mxcmci_readl(host, MMC_REG_BUFFER_ACCESS));
595 		bytes -= 4;
596 	}
597 
598 	if (bytes) {
599 		u8 *b = (u8 *)buf;
600 		u32 tmp;
601 
602 		stat = mxcmci_poll_status(host,
603 				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
604 		if (stat)
605 			return stat;
606 		tmp = cpu_to_le32(mxcmci_readl(host, MMC_REG_BUFFER_ACCESS));
607 		memcpy(b, &tmp, bytes);
608 	}
609 
610 	return 0;
611 }
612 
613 static int mxcmci_push(struct mxcmci_host *host, void *_buf, int bytes)
614 {
615 	unsigned int stat;
616 	u32 *buf = _buf;
617 
618 	while (bytes > 3) {
619 		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
620 		if (stat)
621 			return stat;
622 		mxcmci_writel(host, cpu_to_le32(*buf++), MMC_REG_BUFFER_ACCESS);
623 		bytes -= 4;
624 	}
625 
626 	if (bytes) {
627 		u8 *b = (u8 *)buf;
628 		u32 tmp;
629 
630 		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
631 		if (stat)
632 			return stat;
633 
634 		memcpy(&tmp, b, bytes);
635 		mxcmci_writel(host, cpu_to_le32(tmp), MMC_REG_BUFFER_ACCESS);
636 	}
637 
638 	stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
639 	if (stat)
640 		return stat;
641 
642 	return 0;
643 }
644 
645 static int mxcmci_transfer_data(struct mxcmci_host *host)
646 {
647 	struct mmc_data *data = host->req->data;
648 	struct scatterlist *sg;
649 	int stat, i;
650 
651 	host->data = data;
652 	host->datasize = 0;
653 
654 	if (data->flags & MMC_DATA_READ) {
655 		for_each_sg(data->sg, sg, data->sg_len, i) {
656 			stat = mxcmci_pull(host, sg_virt(sg), sg->length);
657 			if (stat)
658 				return stat;
659 			host->datasize += sg->length;
660 		}
661 	} else {
662 		for_each_sg(data->sg, sg, data->sg_len, i) {
663 			stat = mxcmci_push(host, sg_virt(sg), sg->length);
664 			if (stat)
665 				return stat;
666 			host->datasize += sg->length;
667 		}
668 		stat = mxcmci_poll_status(host, STATUS_WRITE_OP_DONE);
669 		if (stat)
670 			return stat;
671 	}
672 	return 0;
673 }
674 
675 static void mxcmci_datawork(struct work_struct *work)
676 {
677 	struct mxcmci_host *host = container_of(work, struct mxcmci_host,
678 						  datawork);
679 	int datastat = mxcmci_transfer_data(host);
680 
681 	mxcmci_writel(host, STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
682 		MMC_REG_STATUS);
683 	mxcmci_finish_data(host, datastat);
684 
685 	if (host->req->stop) {
686 		if (mxcmci_start_cmd(host, host->req->stop, 0)) {
687 			mxcmci_finish_request(host, host->req);
688 			return;
689 		}
690 	} else {
691 		mxcmci_finish_request(host, host->req);
692 	}
693 }
694 
695 static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat)
696 {
697 	struct mmc_request *req;
698 	int data_error;
699 	unsigned long flags;
700 
701 	spin_lock_irqsave(&host->lock, flags);
702 
703 	if (!host->data) {
704 		spin_unlock_irqrestore(&host->lock, flags);
705 		return;
706 	}
707 
708 	if (!host->req) {
709 		spin_unlock_irqrestore(&host->lock, flags);
710 		return;
711 	}
712 
713 	req = host->req;
714 	if (!req->stop)
715 		host->req = NULL; /* we will handle finish req below */
716 
717 	data_error = mxcmci_finish_data(host, stat);
718 
719 	spin_unlock_irqrestore(&host->lock, flags);
720 
721 	mxcmci_read_response(host, stat);
722 	host->cmd = NULL;
723 
724 	if (req->stop) {
725 		if (mxcmci_start_cmd(host, req->stop, 0)) {
726 			mxcmci_finish_request(host, req);
727 			return;
728 		}
729 	} else {
730 		mxcmci_finish_request(host, req);
731 	}
732 }
733 
734 static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat)
735 {
736 	mxcmci_read_response(host, stat);
737 	host->cmd = NULL;
738 
739 	if (!host->data && host->req) {
740 		mxcmci_finish_request(host, host->req);
741 		return;
742 	}
743 
744 	/* For the DMA case the DMA engine handles the data transfer
745 	 * automatically. For non DMA we have to do it ourselves.
746 	 * Don't do it in interrupt context though.
747 	 */
748 	if (!mxcmci_use_dma(host) && host->data)
749 		schedule_work(&host->datawork);
750 
751 }
752 
753 static irqreturn_t mxcmci_irq(int irq, void *devid)
754 {
755 	struct mxcmci_host *host = devid;
756 	unsigned long flags;
757 	bool sdio_irq;
758 	u32 stat;
759 
760 	stat = mxcmci_readl(host, MMC_REG_STATUS);
761 	mxcmci_writel(host,
762 		stat & ~(STATUS_SDIO_INT_ACTIVE | STATUS_DATA_TRANS_DONE |
763 			 STATUS_WRITE_OP_DONE),
764 		MMC_REG_STATUS);
765 
766 	dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
767 
768 	spin_lock_irqsave(&host->lock, flags);
769 	sdio_irq = (stat & STATUS_SDIO_INT_ACTIVE) && host->use_sdio;
770 	spin_unlock_irqrestore(&host->lock, flags);
771 
772 	if (mxcmci_use_dma(host) &&
773 	    (stat & (STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE)))
774 		mxcmci_writel(host, STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
775 			MMC_REG_STATUS);
776 
777 	if (sdio_irq) {
778 		mxcmci_writel(host, STATUS_SDIO_INT_ACTIVE, MMC_REG_STATUS);
779 		mmc_signal_sdio_irq(host->mmc);
780 	}
781 
782 	if (stat & STATUS_END_CMD_RESP)
783 		mxcmci_cmd_done(host, stat);
784 
785 	if (mxcmci_use_dma(host) &&
786 		  (stat & (STATUS_DATA_TRANS_DONE | STATUS_WRITE_OP_DONE))) {
787 		del_timer(&host->watchdog);
788 		mxcmci_data_done(host, stat);
789 	}
790 
791 	if (host->default_irq_mask &&
792 		  (stat & (STATUS_CARD_INSERTION | STATUS_CARD_REMOVAL)))
793 		mmc_detect_change(host->mmc, msecs_to_jiffies(200));
794 
795 	return IRQ_HANDLED;
796 }
797 
798 static void mxcmci_request(struct mmc_host *mmc, struct mmc_request *req)
799 {
800 	struct mxcmci_host *host = mmc_priv(mmc);
801 	unsigned int cmdat = host->cmdat;
802 	int error;
803 
804 	WARN_ON(host->req != NULL);
805 
806 	host->req = req;
807 	host->cmdat &= ~CMD_DAT_CONT_INIT;
808 
809 	if (host->dma)
810 		host->do_dma = 1;
811 
812 	if (req->data) {
813 		error = mxcmci_setup_data(host, req->data);
814 		if (error) {
815 			req->cmd->error = error;
816 			goto out;
817 		}
818 
819 
820 		cmdat |= CMD_DAT_CONT_DATA_ENABLE;
821 
822 		if (req->data->flags & MMC_DATA_WRITE)
823 			cmdat |= CMD_DAT_CONT_WRITE;
824 	}
825 
826 	error = mxcmci_start_cmd(host, req->cmd, cmdat);
827 
828 out:
829 	if (error)
830 		mxcmci_finish_request(host, req);
831 }
832 
833 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios)
834 {
835 	unsigned int divider;
836 	int prescaler = 0;
837 	unsigned int clk_in = clk_get_rate(host->clk_per);
838 
839 	while (prescaler <= 0x800) {
840 		for (divider = 1; divider <= 0xF; divider++) {
841 			int x;
842 
843 			x = (clk_in / (divider + 1));
844 
845 			if (prescaler)
846 				x /= (prescaler * 2);
847 
848 			if (x <= clk_ios)
849 				break;
850 		}
851 		if (divider < 0x10)
852 			break;
853 
854 		if (prescaler == 0)
855 			prescaler = 1;
856 		else
857 			prescaler <<= 1;
858 	}
859 
860 	mxcmci_writew(host, (prescaler << 4) | divider, MMC_REG_CLK_RATE);
861 
862 	dev_dbg(mmc_dev(host->mmc), "scaler: %d divider: %d in: %d out: %d\n",
863 			prescaler, divider, clk_in, clk_ios);
864 }
865 
866 static int mxcmci_setup_dma(struct mmc_host *mmc)
867 {
868 	struct mxcmci_host *host = mmc_priv(mmc);
869 	struct dma_slave_config *config = &host->dma_slave_config;
870 
871 	config->dst_addr = host->res->start + MMC_REG_BUFFER_ACCESS;
872 	config->src_addr = host->res->start + MMC_REG_BUFFER_ACCESS;
873 	config->dst_addr_width = 4;
874 	config->src_addr_width = 4;
875 	config->dst_maxburst = host->burstlen;
876 	config->src_maxburst = host->burstlen;
877 	config->device_fc = false;
878 
879 	return dmaengine_slave_config(host->dma, config);
880 }
881 
882 static void mxcmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
883 {
884 	struct mxcmci_host *host = mmc_priv(mmc);
885 	int burstlen, ret;
886 
887 	/*
888 	 * use burstlen of 64 (16 words) in 4 bit mode (--> reg value  0)
889 	 * use burstlen of 16 (4 words) in 1 bit mode (--> reg value 16)
890 	 */
891 	if (ios->bus_width == MMC_BUS_WIDTH_4)
892 		burstlen = 16;
893 	else
894 		burstlen = 4;
895 
896 	if (mxcmci_use_dma(host) && burstlen != host->burstlen) {
897 		host->burstlen = burstlen;
898 		ret = mxcmci_setup_dma(mmc);
899 		if (ret) {
900 			dev_err(mmc_dev(host->mmc),
901 				"failed to config DMA channel. Falling back to PIO\n");
902 			dma_release_channel(host->dma);
903 			host->do_dma = 0;
904 			host->dma = NULL;
905 		}
906 	}
907 
908 	if (ios->bus_width == MMC_BUS_WIDTH_4)
909 		host->cmdat |= CMD_DAT_CONT_BUS_WIDTH_4;
910 	else
911 		host->cmdat &= ~CMD_DAT_CONT_BUS_WIDTH_4;
912 
913 	if (host->power_mode != ios->power_mode) {
914 		mxcmci_set_power(host, ios->power_mode, ios->vdd);
915 		host->power_mode = ios->power_mode;
916 
917 		if (ios->power_mode == MMC_POWER_ON)
918 			host->cmdat |= CMD_DAT_CONT_INIT;
919 	}
920 
921 	if (ios->clock) {
922 		mxcmci_set_clk_rate(host, ios->clock);
923 		mxcmci_writew(host, STR_STP_CLK_START_CLK, MMC_REG_STR_STP_CLK);
924 	} else {
925 		mxcmci_writew(host, STR_STP_CLK_STOP_CLK, MMC_REG_STR_STP_CLK);
926 	}
927 
928 	host->clock = ios->clock;
929 }
930 
931 static irqreturn_t mxcmci_detect_irq(int irq, void *data)
932 {
933 	struct mmc_host *mmc = data;
934 
935 	dev_dbg(mmc_dev(mmc), "%s\n", __func__);
936 
937 	mmc_detect_change(mmc, msecs_to_jiffies(250));
938 	return IRQ_HANDLED;
939 }
940 
941 static int mxcmci_get_ro(struct mmc_host *mmc)
942 {
943 	struct mxcmci_host *host = mmc_priv(mmc);
944 
945 	if (host->pdata && host->pdata->get_ro)
946 		return !!host->pdata->get_ro(mmc_dev(mmc));
947 	/*
948 	 * If board doesn't support read only detection (no mmc_gpio
949 	 * context or gpio is invalid), then let the mmc core decide
950 	 * what to do.
951 	 */
952 	return mmc_gpio_get_ro(mmc);
953 }
954 
955 static void mxcmci_enable_sdio_irq(struct mmc_host *mmc, int enable)
956 {
957 	struct mxcmci_host *host = mmc_priv(mmc);
958 	unsigned long flags;
959 	u32 int_cntr;
960 
961 	spin_lock_irqsave(&host->lock, flags);
962 	host->use_sdio = enable;
963 	int_cntr = mxcmci_readl(host, MMC_REG_INT_CNTR);
964 
965 	if (enable)
966 		int_cntr |= INT_SDIO_IRQ_EN;
967 	else
968 		int_cntr &= ~INT_SDIO_IRQ_EN;
969 
970 	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
971 	spin_unlock_irqrestore(&host->lock, flags);
972 }
973 
974 static void mxcmci_init_card(struct mmc_host *host, struct mmc_card *card)
975 {
976 	struct mxcmci_host *mxcmci = mmc_priv(host);
977 
978 	/*
979 	 * MX3 SoCs have a silicon bug which corrupts CRC calculation of
980 	 * multi-block transfers when connected SDIO peripheral doesn't
981 	 * drive the BUSY line as required by the specs.
982 	 * One way to prevent this is to only allow 1-bit transfers.
983 	 */
984 
985 	if (is_imx31_mmc(mxcmci) && card->type == MMC_TYPE_SDIO)
986 		host->caps &= ~MMC_CAP_4_BIT_DATA;
987 	else
988 		host->caps |= MMC_CAP_4_BIT_DATA;
989 }
990 
991 static bool filter(struct dma_chan *chan, void *param)
992 {
993 	struct mxcmci_host *host = param;
994 
995 	if (!imx_dma_is_general_purpose(chan))
996 		return false;
997 
998 	chan->private = &host->dma_data;
999 
1000 	return true;
1001 }
1002 
1003 static void mxcmci_watchdog(unsigned long data)
1004 {
1005 	struct mmc_host *mmc = (struct mmc_host *)data;
1006 	struct mxcmci_host *host = mmc_priv(mmc);
1007 	struct mmc_request *req = host->req;
1008 	unsigned int stat = mxcmci_readl(host, MMC_REG_STATUS);
1009 
1010 	if (host->dma_dir == DMA_FROM_DEVICE) {
1011 		dmaengine_terminate_all(host->dma);
1012 		dev_err(mmc_dev(host->mmc),
1013 			"%s: read time out (status = 0x%08x)\n",
1014 			__func__, stat);
1015 	} else {
1016 		dev_err(mmc_dev(host->mmc),
1017 			"%s: write time out (status = 0x%08x)\n",
1018 			__func__, stat);
1019 		mxcmci_softreset(host);
1020 	}
1021 
1022 	/* Mark transfer as erroneus and inform the upper layers */
1023 
1024 	if (host->data)
1025 		host->data->error = -ETIMEDOUT;
1026 	host->req = NULL;
1027 	host->cmd = NULL;
1028 	host->data = NULL;
1029 	mmc_request_done(host->mmc, req);
1030 }
1031 
1032 static const struct mmc_host_ops mxcmci_ops = {
1033 	.request		= mxcmci_request,
1034 	.set_ios		= mxcmci_set_ios,
1035 	.get_ro			= mxcmci_get_ro,
1036 	.enable_sdio_irq	= mxcmci_enable_sdio_irq,
1037 	.init_card		= mxcmci_init_card,
1038 };
1039 
1040 static int mxcmci_probe(struct platform_device *pdev)
1041 {
1042 	struct mmc_host *mmc;
1043 	struct mxcmci_host *host = NULL;
1044 	struct resource *iores, *r;
1045 	int ret = 0, irq;
1046 	bool dat3_card_detect = false;
1047 	dma_cap_mask_t mask;
1048 	const struct of_device_id *of_id;
1049 	struct imxmmc_platform_data *pdata = pdev->dev.platform_data;
1050 
1051 	pr_info("i.MX/MPC512x SDHC driver\n");
1052 
1053 	of_id = of_match_device(mxcmci_of_match, &pdev->dev);
1054 
1055 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1056 	irq = platform_get_irq(pdev, 0);
1057 	if (!iores || irq < 0)
1058 		return -EINVAL;
1059 
1060 	r = request_mem_region(iores->start, resource_size(iores), pdev->name);
1061 	if (!r)
1062 		return -EBUSY;
1063 
1064 	mmc = mmc_alloc_host(sizeof(struct mxcmci_host), &pdev->dev);
1065 	if (!mmc) {
1066 		ret = -ENOMEM;
1067 		goto out_release_mem;
1068 	}
1069 
1070 	mmc_of_parse(mmc);
1071 	mmc->ops = &mxcmci_ops;
1072 
1073 	/* For devicetree parsing, the bus width is read from devicetree */
1074 	if (pdata)
1075 		mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
1076 	else
1077 		mmc->caps |= MMC_CAP_SDIO_IRQ;
1078 
1079 	/* MMC core transfer sizes tunable parameters */
1080 	mmc->max_blk_size = 2048;
1081 	mmc->max_blk_count = 65535;
1082 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
1083 	mmc->max_seg_size = mmc->max_req_size;
1084 
1085 	host = mmc_priv(mmc);
1086 	host->base = ioremap(r->start, resource_size(r));
1087 	if (!host->base) {
1088 		ret = -ENOMEM;
1089 		goto out_free;
1090 	}
1091 
1092 	if (of_id) {
1093 		const struct platform_device_id *id_entry = of_id->data;
1094 		host->devtype = id_entry->driver_data;
1095 	} else {
1096 		host->devtype = pdev->id_entry->driver_data;
1097 	}
1098 
1099 	/* adjust max_segs after devtype detection */
1100 	if (!is_mpc512x_mmc(host))
1101 		mmc->max_segs = 64;
1102 
1103 	host->mmc = mmc;
1104 	host->pdata = pdata;
1105 	spin_lock_init(&host->lock);
1106 
1107 	if (pdata)
1108 		dat3_card_detect = pdata->dat3_card_detect;
1109 	else if (!(mmc->caps & MMC_CAP_NONREMOVABLE)
1110 			&& !of_property_read_bool(pdev->dev.of_node, "cd-gpios"))
1111 		dat3_card_detect = true;
1112 
1113 	mxcmci_init_ocr(host);
1114 
1115 	if (dat3_card_detect)
1116 		host->default_irq_mask =
1117 			INT_CARD_INSERTION_EN | INT_CARD_REMOVAL_EN;
1118 	else
1119 		host->default_irq_mask = 0;
1120 
1121 	host->res = r;
1122 	host->irq = irq;
1123 
1124 	host->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1125 	if (IS_ERR(host->clk_ipg)) {
1126 		ret = PTR_ERR(host->clk_ipg);
1127 		goto out_iounmap;
1128 	}
1129 
1130 	host->clk_per = devm_clk_get(&pdev->dev, "per");
1131 	if (IS_ERR(host->clk_per)) {
1132 		ret = PTR_ERR(host->clk_per);
1133 		goto out_iounmap;
1134 	}
1135 
1136 	clk_prepare_enable(host->clk_per);
1137 	clk_prepare_enable(host->clk_ipg);
1138 
1139 	mxcmci_softreset(host);
1140 
1141 	host->rev_no = mxcmci_readw(host, MMC_REG_REV_NO);
1142 	if (host->rev_no != 0x400) {
1143 		ret = -ENODEV;
1144 		dev_err(mmc_dev(host->mmc), "wrong rev.no. 0x%08x. aborting.\n",
1145 			host->rev_no);
1146 		goto out_clk_put;
1147 	}
1148 
1149 	mmc->f_min = clk_get_rate(host->clk_per) >> 16;
1150 	mmc->f_max = clk_get_rate(host->clk_per) >> 1;
1151 
1152 	/* recommended in data sheet */
1153 	mxcmci_writew(host, 0x2db4, MMC_REG_READ_TO);
1154 
1155 	mxcmci_writel(host, host->default_irq_mask, MMC_REG_INT_CNTR);
1156 
1157 	if (!host->pdata) {
1158 		host->dma = dma_request_slave_channel(&pdev->dev, "rx-tx");
1159 	} else {
1160 		r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
1161 		if (r) {
1162 			host->dmareq = r->start;
1163 			host->dma_data.peripheral_type = IMX_DMATYPE_SDHC;
1164 			host->dma_data.priority = DMA_PRIO_LOW;
1165 			host->dma_data.dma_request = host->dmareq;
1166 			dma_cap_zero(mask);
1167 			dma_cap_set(DMA_SLAVE, mask);
1168 			host->dma = dma_request_channel(mask, filter, host);
1169 		}
1170 	}
1171 	if (host->dma)
1172 		mmc->max_seg_size = dma_get_max_seg_size(
1173 				host->dma->device->dev);
1174 	else
1175 		dev_info(mmc_dev(host->mmc), "dma not available. Using PIO\n");
1176 
1177 	INIT_WORK(&host->datawork, mxcmci_datawork);
1178 
1179 	ret = request_irq(host->irq, mxcmci_irq, 0, DRIVER_NAME, host);
1180 	if (ret)
1181 		goto out_free_dma;
1182 
1183 	platform_set_drvdata(pdev, mmc);
1184 
1185 	if (host->pdata && host->pdata->init) {
1186 		ret = host->pdata->init(&pdev->dev, mxcmci_detect_irq,
1187 				host->mmc);
1188 		if (ret)
1189 			goto out_free_irq;
1190 	}
1191 
1192 	init_timer(&host->watchdog);
1193 	host->watchdog.function = &mxcmci_watchdog;
1194 	host->watchdog.data = (unsigned long)mmc;
1195 
1196 	mmc_add_host(mmc);
1197 
1198 	return 0;
1199 
1200 out_free_irq:
1201 	free_irq(host->irq, host);
1202 out_free_dma:
1203 	if (host->dma)
1204 		dma_release_channel(host->dma);
1205 out_clk_put:
1206 	clk_disable_unprepare(host->clk_per);
1207 	clk_disable_unprepare(host->clk_ipg);
1208 out_iounmap:
1209 	iounmap(host->base);
1210 out_free:
1211 	mmc_free_host(mmc);
1212 out_release_mem:
1213 	release_mem_region(iores->start, resource_size(iores));
1214 	return ret;
1215 }
1216 
1217 static int mxcmci_remove(struct platform_device *pdev)
1218 {
1219 	struct mmc_host *mmc = platform_get_drvdata(pdev);
1220 	struct mxcmci_host *host = mmc_priv(mmc);
1221 
1222 	platform_set_drvdata(pdev, NULL);
1223 
1224 	mmc_remove_host(mmc);
1225 
1226 	if (host->vcc)
1227 		regulator_put(host->vcc);
1228 
1229 	if (host->pdata && host->pdata->exit)
1230 		host->pdata->exit(&pdev->dev, mmc);
1231 
1232 	free_irq(host->irq, host);
1233 	iounmap(host->base);
1234 
1235 	if (host->dma)
1236 		dma_release_channel(host->dma);
1237 
1238 	clk_disable_unprepare(host->clk_per);
1239 	clk_disable_unprepare(host->clk_ipg);
1240 
1241 	release_mem_region(host->res->start, resource_size(host->res));
1242 
1243 	mmc_free_host(mmc);
1244 
1245 	return 0;
1246 }
1247 
1248 #ifdef CONFIG_PM
1249 static int mxcmci_suspend(struct device *dev)
1250 {
1251 	struct mmc_host *mmc = dev_get_drvdata(dev);
1252 	struct mxcmci_host *host = mmc_priv(mmc);
1253 	int ret = 0;
1254 
1255 	if (mmc)
1256 		ret = mmc_suspend_host(mmc);
1257 	clk_disable_unprepare(host->clk_per);
1258 	clk_disable_unprepare(host->clk_ipg);
1259 
1260 	return ret;
1261 }
1262 
1263 static int mxcmci_resume(struct device *dev)
1264 {
1265 	struct mmc_host *mmc = dev_get_drvdata(dev);
1266 	struct mxcmci_host *host = mmc_priv(mmc);
1267 	int ret = 0;
1268 
1269 	clk_prepare_enable(host->clk_per);
1270 	clk_prepare_enable(host->clk_ipg);
1271 	if (mmc)
1272 		ret = mmc_resume_host(mmc);
1273 
1274 	return ret;
1275 }
1276 
1277 static const struct dev_pm_ops mxcmci_pm_ops = {
1278 	.suspend	= mxcmci_suspend,
1279 	.resume		= mxcmci_resume,
1280 };
1281 #endif
1282 
1283 static struct platform_driver mxcmci_driver = {
1284 	.probe		= mxcmci_probe,
1285 	.remove		= mxcmci_remove,
1286 	.id_table	= mxcmci_devtype,
1287 	.driver		= {
1288 		.name		= DRIVER_NAME,
1289 		.owner		= THIS_MODULE,
1290 #ifdef CONFIG_PM
1291 		.pm	= &mxcmci_pm_ops,
1292 #endif
1293 		.of_match_table	= mxcmci_of_match,
1294 	}
1295 };
1296 
1297 module_platform_driver(mxcmci_driver);
1298 
1299 MODULE_DESCRIPTION("i.MX Multimedia Card Interface Driver");
1300 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
1301 MODULE_LICENSE("GPL");
1302 MODULE_ALIAS("platform:mxc-mmc");
1303