xref: /openbmc/linux/drivers/mmc/host/mxcmmc.c (revision 08157984)
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 
38 #include <asm/dma.h>
39 #include <asm/irq.h>
40 #include <asm/sizes.h>
41 #include <mach/mmc.h>
42 
43 #include <mach/dma.h>
44 #include <mach/hardware.h>
45 
46 #define DRIVER_NAME "mxc-mmc"
47 
48 #define MMC_REG_STR_STP_CLK		0x00
49 #define MMC_REG_STATUS			0x04
50 #define MMC_REG_CLK_RATE		0x08
51 #define MMC_REG_CMD_DAT_CONT		0x0C
52 #define MMC_REG_RES_TO			0x10
53 #define MMC_REG_READ_TO			0x14
54 #define MMC_REG_BLK_LEN			0x18
55 #define MMC_REG_NOB			0x1C
56 #define MMC_REG_REV_NO			0x20
57 #define MMC_REG_INT_CNTR		0x24
58 #define MMC_REG_CMD			0x28
59 #define MMC_REG_ARG			0x2C
60 #define MMC_REG_RES_FIFO		0x34
61 #define MMC_REG_BUFFER_ACCESS		0x38
62 
63 #define STR_STP_CLK_RESET               (1 << 3)
64 #define STR_STP_CLK_START_CLK           (1 << 1)
65 #define STR_STP_CLK_STOP_CLK            (1 << 0)
66 
67 #define STATUS_CARD_INSERTION		(1 << 31)
68 #define STATUS_CARD_REMOVAL		(1 << 30)
69 #define STATUS_YBUF_EMPTY		(1 << 29)
70 #define STATUS_XBUF_EMPTY		(1 << 28)
71 #define STATUS_YBUF_FULL		(1 << 27)
72 #define STATUS_XBUF_FULL		(1 << 26)
73 #define STATUS_BUF_UND_RUN		(1 << 25)
74 #define STATUS_BUF_OVFL			(1 << 24)
75 #define STATUS_SDIO_INT_ACTIVE		(1 << 14)
76 #define STATUS_END_CMD_RESP		(1 << 13)
77 #define STATUS_WRITE_OP_DONE		(1 << 12)
78 #define STATUS_DATA_TRANS_DONE		(1 << 11)
79 #define STATUS_READ_OP_DONE		(1 << 11)
80 #define STATUS_WR_CRC_ERROR_CODE_MASK	(3 << 10)
81 #define STATUS_CARD_BUS_CLK_RUN		(1 << 8)
82 #define STATUS_BUF_READ_RDY		(1 << 7)
83 #define STATUS_BUF_WRITE_RDY		(1 << 6)
84 #define STATUS_RESP_CRC_ERR		(1 << 5)
85 #define STATUS_CRC_READ_ERR		(1 << 3)
86 #define STATUS_CRC_WRITE_ERR		(1 << 2)
87 #define STATUS_TIME_OUT_RESP		(1 << 1)
88 #define STATUS_TIME_OUT_READ		(1 << 0)
89 #define STATUS_ERR_MASK			0x2f
90 
91 #define CMD_DAT_CONT_CMD_RESP_LONG_OFF	(1 << 12)
92 #define CMD_DAT_CONT_STOP_READWAIT	(1 << 11)
93 #define CMD_DAT_CONT_START_READWAIT	(1 << 10)
94 #define CMD_DAT_CONT_BUS_WIDTH_4	(2 << 8)
95 #define CMD_DAT_CONT_INIT		(1 << 7)
96 #define CMD_DAT_CONT_WRITE		(1 << 4)
97 #define CMD_DAT_CONT_DATA_ENABLE	(1 << 3)
98 #define CMD_DAT_CONT_RESPONSE_48BIT_CRC	(1 << 0)
99 #define CMD_DAT_CONT_RESPONSE_136BIT	(2 << 0)
100 #define CMD_DAT_CONT_RESPONSE_48BIT	(3 << 0)
101 
102 #define INT_SDIO_INT_WKP_EN		(1 << 18)
103 #define INT_CARD_INSERTION_WKP_EN	(1 << 17)
104 #define INT_CARD_REMOVAL_WKP_EN		(1 << 16)
105 #define INT_CARD_INSERTION_EN		(1 << 15)
106 #define INT_CARD_REMOVAL_EN		(1 << 14)
107 #define INT_SDIO_IRQ_EN			(1 << 13)
108 #define INT_DAT0_EN			(1 << 12)
109 #define INT_BUF_READ_EN			(1 << 4)
110 #define INT_BUF_WRITE_EN		(1 << 3)
111 #define INT_END_CMD_RES_EN		(1 << 2)
112 #define INT_WRITE_OP_DONE_EN		(1 << 1)
113 #define INT_READ_OP_EN			(1 << 0)
114 
115 struct mxcmci_host {
116 	struct mmc_host		*mmc;
117 	struct resource		*res;
118 	void __iomem		*base;
119 	int			irq;
120 	int			detect_irq;
121 	struct dma_chan		*dma;
122 	struct dma_async_tx_descriptor *desc;
123 	int			do_dma;
124 	int			default_irq_mask;
125 	int			use_sdio;
126 	unsigned int		power_mode;
127 	struct imxmmc_platform_data *pdata;
128 
129 	struct mmc_request	*req;
130 	struct mmc_command	*cmd;
131 	struct mmc_data		*data;
132 
133 	unsigned int		datasize;
134 	unsigned int		dma_dir;
135 
136 	u16			rev_no;
137 	unsigned int		cmdat;
138 
139 	struct clk		*clk;
140 
141 	int			clock;
142 
143 	struct work_struct	datawork;
144 	spinlock_t		lock;
145 
146 	struct regulator	*vcc;
147 
148 	int			burstlen;
149 	int			dmareq;
150 	struct dma_slave_config dma_slave_config;
151 	struct imx_dma_data	dma_data;
152 };
153 
154 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios);
155 
156 static inline void mxcmci_init_ocr(struct mxcmci_host *host)
157 {
158 	host->vcc = regulator_get(mmc_dev(host->mmc), "vmmc");
159 
160 	if (IS_ERR(host->vcc)) {
161 		host->vcc = NULL;
162 	} else {
163 		host->mmc->ocr_avail = mmc_regulator_get_ocrmask(host->vcc);
164 		if (host->pdata && host->pdata->ocr_avail)
165 			dev_warn(mmc_dev(host->mmc),
166 				"pdata->ocr_avail will not be used\n");
167 	}
168 
169 	if (host->vcc == NULL) {
170 		/* fall-back to platform data */
171 		if (host->pdata && host->pdata->ocr_avail)
172 			host->mmc->ocr_avail = host->pdata->ocr_avail;
173 		else
174 			host->mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
175 	}
176 }
177 
178 static inline void mxcmci_set_power(struct mxcmci_host *host,
179 				    unsigned char power_mode,
180 				    unsigned int vdd)
181 {
182 	if (host->vcc) {
183 		if (power_mode == MMC_POWER_UP)
184 			mmc_regulator_set_ocr(host->mmc, host->vcc, vdd);
185 		else if (power_mode == MMC_POWER_OFF)
186 			mmc_regulator_set_ocr(host->mmc, host->vcc, 0);
187 	}
188 
189 	if (host->pdata && host->pdata->setpower)
190 		host->pdata->setpower(mmc_dev(host->mmc), vdd);
191 }
192 
193 static inline int mxcmci_use_dma(struct mxcmci_host *host)
194 {
195 	return host->do_dma;
196 }
197 
198 static void mxcmci_softreset(struct mxcmci_host *host)
199 {
200 	int i;
201 
202 	dev_dbg(mmc_dev(host->mmc), "mxcmci_softreset\n");
203 
204 	/* reset sequence */
205 	writew(STR_STP_CLK_RESET, host->base + MMC_REG_STR_STP_CLK);
206 	writew(STR_STP_CLK_RESET | STR_STP_CLK_START_CLK,
207 			host->base + MMC_REG_STR_STP_CLK);
208 
209 	for (i = 0; i < 8; i++)
210 		writew(STR_STP_CLK_START_CLK, host->base + MMC_REG_STR_STP_CLK);
211 
212 	writew(0xff, host->base + MMC_REG_RES_TO);
213 }
214 static int mxcmci_setup_dma(struct mmc_host *mmc);
215 
216 static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
217 {
218 	unsigned int nob = data->blocks;
219 	unsigned int blksz = data->blksz;
220 	unsigned int datasize = nob * blksz;
221 	struct scatterlist *sg;
222 	enum dma_transfer_direction slave_dirn;
223 	int i, nents;
224 
225 	if (data->flags & MMC_DATA_STREAM)
226 		nob = 0xffff;
227 
228 	host->data = data;
229 	data->bytes_xfered = 0;
230 
231 	writew(nob, host->base + MMC_REG_NOB);
232 	writew(blksz, host->base + MMC_REG_BLK_LEN);
233 	host->datasize = datasize;
234 
235 	if (!mxcmci_use_dma(host))
236 		return 0;
237 
238 	for_each_sg(data->sg, sg, data->sg_len, i) {
239 		if (sg->offset & 3 || sg->length & 3) {
240 			host->do_dma = 0;
241 			return 0;
242 		}
243 	}
244 
245 	if (data->flags & MMC_DATA_READ) {
246 		host->dma_dir = DMA_FROM_DEVICE;
247 		slave_dirn = DMA_DEV_TO_MEM;
248 	} else {
249 		host->dma_dir = DMA_TO_DEVICE;
250 		slave_dirn = DMA_MEM_TO_DEV;
251 	}
252 
253 	nents = dma_map_sg(host->dma->device->dev, data->sg,
254 				     data->sg_len,  host->dma_dir);
255 	if (nents != data->sg_len)
256 		return -EINVAL;
257 
258 	host->desc = dmaengine_prep_slave_sg(host->dma,
259 		data->sg, data->sg_len, slave_dirn,
260 		DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
261 
262 	if (!host->desc) {
263 		dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
264 				host->dma_dir);
265 		host->do_dma = 0;
266 		return 0; /* Fall back to PIO */
267 	}
268 	wmb();
269 
270 	dmaengine_submit(host->desc);
271 	dma_async_issue_pending(host->dma);
272 
273 	return 0;
274 }
275 
276 static int mxcmci_start_cmd(struct mxcmci_host *host, struct mmc_command *cmd,
277 		unsigned int cmdat)
278 {
279 	u32 int_cntr = host->default_irq_mask;
280 	unsigned long flags;
281 
282 	WARN_ON(host->cmd != NULL);
283 	host->cmd = cmd;
284 
285 	switch (mmc_resp_type(cmd)) {
286 	case MMC_RSP_R1: /* short CRC, OPCODE */
287 	case MMC_RSP_R1B:/* short CRC, OPCODE, BUSY */
288 		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT_CRC;
289 		break;
290 	case MMC_RSP_R2: /* long 136 bit + CRC */
291 		cmdat |= CMD_DAT_CONT_RESPONSE_136BIT;
292 		break;
293 	case MMC_RSP_R3: /* short */
294 		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT;
295 		break;
296 	case MMC_RSP_NONE:
297 		break;
298 	default:
299 		dev_err(mmc_dev(host->mmc), "unhandled response type 0x%x\n",
300 				mmc_resp_type(cmd));
301 		cmd->error = -EINVAL;
302 		return -EINVAL;
303 	}
304 
305 	int_cntr = INT_END_CMD_RES_EN;
306 
307 	if (mxcmci_use_dma(host))
308 		int_cntr |= INT_READ_OP_EN | INT_WRITE_OP_DONE_EN;
309 
310 	spin_lock_irqsave(&host->lock, flags);
311 	if (host->use_sdio)
312 		int_cntr |= INT_SDIO_IRQ_EN;
313 	writel(int_cntr, host->base + MMC_REG_INT_CNTR);
314 	spin_unlock_irqrestore(&host->lock, flags);
315 
316 	writew(cmd->opcode, host->base + MMC_REG_CMD);
317 	writel(cmd->arg, host->base + MMC_REG_ARG);
318 	writew(cmdat, host->base + MMC_REG_CMD_DAT_CONT);
319 
320 	return 0;
321 }
322 
323 static void mxcmci_finish_request(struct mxcmci_host *host,
324 		struct mmc_request *req)
325 {
326 	u32 int_cntr = host->default_irq_mask;
327 	unsigned long flags;
328 
329 	spin_lock_irqsave(&host->lock, flags);
330 	if (host->use_sdio)
331 		int_cntr |= INT_SDIO_IRQ_EN;
332 	writel(int_cntr, host->base + MMC_REG_INT_CNTR);
333 	spin_unlock_irqrestore(&host->lock, flags);
334 
335 	host->req = NULL;
336 	host->cmd = NULL;
337 	host->data = NULL;
338 
339 	mmc_request_done(host->mmc, req);
340 }
341 
342 static int mxcmci_finish_data(struct mxcmci_host *host, unsigned int stat)
343 {
344 	struct mmc_data *data = host->data;
345 	int data_error;
346 
347 	if (mxcmci_use_dma(host)) {
348 		dmaengine_terminate_all(host->dma);
349 		dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
350 				host->dma_dir);
351 	}
352 
353 	if (stat & STATUS_ERR_MASK) {
354 		dev_dbg(mmc_dev(host->mmc), "request failed. status: 0x%08x\n",
355 				stat);
356 		if (stat & STATUS_CRC_READ_ERR) {
357 			dev_err(mmc_dev(host->mmc), "%s: -EILSEQ\n", __func__);
358 			data->error = -EILSEQ;
359 		} else if (stat & STATUS_CRC_WRITE_ERR) {
360 			u32 err_code = (stat >> 9) & 0x3;
361 			if (err_code == 2) { /* No CRC response */
362 				dev_err(mmc_dev(host->mmc),
363 					"%s: No CRC -ETIMEDOUT\n", __func__);
364 				data->error = -ETIMEDOUT;
365 			} else {
366 				dev_err(mmc_dev(host->mmc),
367 					"%s: -EILSEQ\n", __func__);
368 				data->error = -EILSEQ;
369 			}
370 		} else if (stat & STATUS_TIME_OUT_READ) {
371 			dev_err(mmc_dev(host->mmc),
372 				"%s: read -ETIMEDOUT\n", __func__);
373 			data->error = -ETIMEDOUT;
374 		} else {
375 			dev_err(mmc_dev(host->mmc), "%s: -EIO\n", __func__);
376 			data->error = -EIO;
377 		}
378 	} else {
379 		data->bytes_xfered = host->datasize;
380 	}
381 
382 	data_error = data->error;
383 
384 	host->data = NULL;
385 
386 	return data_error;
387 }
388 
389 static void mxcmci_read_response(struct mxcmci_host *host, unsigned int stat)
390 {
391 	struct mmc_command *cmd = host->cmd;
392 	int i;
393 	u32 a, b, c;
394 
395 	if (!cmd)
396 		return;
397 
398 	if (stat & STATUS_TIME_OUT_RESP) {
399 		dev_dbg(mmc_dev(host->mmc), "CMD TIMEOUT\n");
400 		cmd->error = -ETIMEDOUT;
401 	} else if (stat & STATUS_RESP_CRC_ERR && cmd->flags & MMC_RSP_CRC) {
402 		dev_dbg(mmc_dev(host->mmc), "cmd crc error\n");
403 		cmd->error = -EILSEQ;
404 	}
405 
406 	if (cmd->flags & MMC_RSP_PRESENT) {
407 		if (cmd->flags & MMC_RSP_136) {
408 			for (i = 0; i < 4; i++) {
409 				a = readw(host->base + MMC_REG_RES_FIFO);
410 				b = readw(host->base + MMC_REG_RES_FIFO);
411 				cmd->resp[i] = a << 16 | b;
412 			}
413 		} else {
414 			a = readw(host->base + MMC_REG_RES_FIFO);
415 			b = readw(host->base + MMC_REG_RES_FIFO);
416 			c = readw(host->base + MMC_REG_RES_FIFO);
417 			cmd->resp[0] = a << 24 | b << 8 | c >> 8;
418 		}
419 	}
420 }
421 
422 static int mxcmci_poll_status(struct mxcmci_host *host, u32 mask)
423 {
424 	u32 stat;
425 	unsigned long timeout = jiffies + HZ;
426 
427 	do {
428 		stat = readl(host->base + MMC_REG_STATUS);
429 		if (stat & STATUS_ERR_MASK)
430 			return stat;
431 		if (time_after(jiffies, timeout)) {
432 			mxcmci_softreset(host);
433 			mxcmci_set_clk_rate(host, host->clock);
434 			return STATUS_TIME_OUT_READ;
435 		}
436 		if (stat & mask)
437 			return 0;
438 		cpu_relax();
439 	} while (1);
440 }
441 
442 static int mxcmci_pull(struct mxcmci_host *host, void *_buf, int bytes)
443 {
444 	unsigned int stat;
445 	u32 *buf = _buf;
446 
447 	while (bytes > 3) {
448 		stat = mxcmci_poll_status(host,
449 				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
450 		if (stat)
451 			return stat;
452 		*buf++ = readl(host->base + MMC_REG_BUFFER_ACCESS);
453 		bytes -= 4;
454 	}
455 
456 	if (bytes) {
457 		u8 *b = (u8 *)buf;
458 		u32 tmp;
459 
460 		stat = mxcmci_poll_status(host,
461 				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
462 		if (stat)
463 			return stat;
464 		tmp = readl(host->base + MMC_REG_BUFFER_ACCESS);
465 		memcpy(b, &tmp, bytes);
466 	}
467 
468 	return 0;
469 }
470 
471 static int mxcmci_push(struct mxcmci_host *host, void *_buf, int bytes)
472 {
473 	unsigned int stat;
474 	u32 *buf = _buf;
475 
476 	while (bytes > 3) {
477 		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
478 		if (stat)
479 			return stat;
480 		writel(*buf++, host->base + MMC_REG_BUFFER_ACCESS);
481 		bytes -= 4;
482 	}
483 
484 	if (bytes) {
485 		u8 *b = (u8 *)buf;
486 		u32 tmp;
487 
488 		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
489 		if (stat)
490 			return stat;
491 
492 		memcpy(&tmp, b, bytes);
493 		writel(tmp, host->base + MMC_REG_BUFFER_ACCESS);
494 	}
495 
496 	stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
497 	if (stat)
498 		return stat;
499 
500 	return 0;
501 }
502 
503 static int mxcmci_transfer_data(struct mxcmci_host *host)
504 {
505 	struct mmc_data *data = host->req->data;
506 	struct scatterlist *sg;
507 	int stat, i;
508 
509 	host->data = data;
510 	host->datasize = 0;
511 
512 	if (data->flags & MMC_DATA_READ) {
513 		for_each_sg(data->sg, sg, data->sg_len, i) {
514 			stat = mxcmci_pull(host, sg_virt(sg), sg->length);
515 			if (stat)
516 				return stat;
517 			host->datasize += sg->length;
518 		}
519 	} else {
520 		for_each_sg(data->sg, sg, data->sg_len, i) {
521 			stat = mxcmci_push(host, sg_virt(sg), sg->length);
522 			if (stat)
523 				return stat;
524 			host->datasize += sg->length;
525 		}
526 		stat = mxcmci_poll_status(host, STATUS_WRITE_OP_DONE);
527 		if (stat)
528 			return stat;
529 	}
530 	return 0;
531 }
532 
533 static void mxcmci_datawork(struct work_struct *work)
534 {
535 	struct mxcmci_host *host = container_of(work, struct mxcmci_host,
536 						  datawork);
537 	int datastat = mxcmci_transfer_data(host);
538 
539 	writel(STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
540 		host->base + MMC_REG_STATUS);
541 	mxcmci_finish_data(host, datastat);
542 
543 	if (host->req->stop) {
544 		if (mxcmci_start_cmd(host, host->req->stop, 0)) {
545 			mxcmci_finish_request(host, host->req);
546 			return;
547 		}
548 	} else {
549 		mxcmci_finish_request(host, host->req);
550 	}
551 }
552 
553 static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat)
554 {
555 	struct mmc_data *data = host->data;
556 	int data_error;
557 
558 	if (!data)
559 		return;
560 
561 	data_error = mxcmci_finish_data(host, stat);
562 
563 	mxcmci_read_response(host, stat);
564 	host->cmd = NULL;
565 
566 	if (host->req->stop) {
567 		if (mxcmci_start_cmd(host, host->req->stop, 0)) {
568 			mxcmci_finish_request(host, host->req);
569 			return;
570 		}
571 	} else {
572 		mxcmci_finish_request(host, host->req);
573 	}
574 }
575 
576 static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat)
577 {
578 	mxcmci_read_response(host, stat);
579 	host->cmd = NULL;
580 
581 	if (!host->data && host->req) {
582 		mxcmci_finish_request(host, host->req);
583 		return;
584 	}
585 
586 	/* For the DMA case the DMA engine handles the data transfer
587 	 * automatically. For non DMA we have to do it ourselves.
588 	 * Don't do it in interrupt context though.
589 	 */
590 	if (!mxcmci_use_dma(host) && host->data)
591 		schedule_work(&host->datawork);
592 
593 }
594 
595 static irqreturn_t mxcmci_irq(int irq, void *devid)
596 {
597 	struct mxcmci_host *host = devid;
598 	unsigned long flags;
599 	bool sdio_irq;
600 	u32 stat;
601 
602 	stat = readl(host->base + MMC_REG_STATUS);
603 	writel(stat & ~(STATUS_SDIO_INT_ACTIVE | STATUS_DATA_TRANS_DONE |
604 			STATUS_WRITE_OP_DONE), host->base + MMC_REG_STATUS);
605 
606 	dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
607 
608 	spin_lock_irqsave(&host->lock, flags);
609 	sdio_irq = (stat & STATUS_SDIO_INT_ACTIVE) && host->use_sdio;
610 	spin_unlock_irqrestore(&host->lock, flags);
611 
612 	if (mxcmci_use_dma(host) &&
613 	    (stat & (STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE)))
614 		writel(STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
615 			host->base + MMC_REG_STATUS);
616 
617 	if (sdio_irq) {
618 		writel(STATUS_SDIO_INT_ACTIVE, host->base + MMC_REG_STATUS);
619 		mmc_signal_sdio_irq(host->mmc);
620 	}
621 
622 	if (stat & STATUS_END_CMD_RESP)
623 		mxcmci_cmd_done(host, stat);
624 
625 	if (mxcmci_use_dma(host) &&
626 		  (stat & (STATUS_DATA_TRANS_DONE | STATUS_WRITE_OP_DONE)))
627 		mxcmci_data_done(host, stat);
628 
629 	if (host->default_irq_mask &&
630 		  (stat & (STATUS_CARD_INSERTION | STATUS_CARD_REMOVAL)))
631 		mmc_detect_change(host->mmc, msecs_to_jiffies(200));
632 
633 	return IRQ_HANDLED;
634 }
635 
636 static void mxcmci_request(struct mmc_host *mmc, struct mmc_request *req)
637 {
638 	struct mxcmci_host *host = mmc_priv(mmc);
639 	unsigned int cmdat = host->cmdat;
640 	int error;
641 
642 	WARN_ON(host->req != NULL);
643 
644 	host->req = req;
645 	host->cmdat &= ~CMD_DAT_CONT_INIT;
646 
647 	if (host->dma)
648 		host->do_dma = 1;
649 
650 	if (req->data) {
651 		error = mxcmci_setup_data(host, req->data);
652 		if (error) {
653 			req->cmd->error = error;
654 			goto out;
655 		}
656 
657 
658 		cmdat |= CMD_DAT_CONT_DATA_ENABLE;
659 
660 		if (req->data->flags & MMC_DATA_WRITE)
661 			cmdat |= CMD_DAT_CONT_WRITE;
662 	}
663 
664 	error = mxcmci_start_cmd(host, req->cmd, cmdat);
665 
666 out:
667 	if (error)
668 		mxcmci_finish_request(host, req);
669 }
670 
671 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios)
672 {
673 	unsigned int divider;
674 	int prescaler = 0;
675 	unsigned int clk_in = clk_get_rate(host->clk);
676 
677 	while (prescaler <= 0x800) {
678 		for (divider = 1; divider <= 0xF; divider++) {
679 			int x;
680 
681 			x = (clk_in / (divider + 1));
682 
683 			if (prescaler)
684 				x /= (prescaler * 2);
685 
686 			if (x <= clk_ios)
687 				break;
688 		}
689 		if (divider < 0x10)
690 			break;
691 
692 		if (prescaler == 0)
693 			prescaler = 1;
694 		else
695 			prescaler <<= 1;
696 	}
697 
698 	writew((prescaler << 4) | divider, host->base + MMC_REG_CLK_RATE);
699 
700 	dev_dbg(mmc_dev(host->mmc), "scaler: %d divider: %d in: %d out: %d\n",
701 			prescaler, divider, clk_in, clk_ios);
702 }
703 
704 static int mxcmci_setup_dma(struct mmc_host *mmc)
705 {
706 	struct mxcmci_host *host = mmc_priv(mmc);
707 	struct dma_slave_config *config = &host->dma_slave_config;
708 
709 	config->dst_addr = host->res->start + MMC_REG_BUFFER_ACCESS;
710 	config->src_addr = host->res->start + MMC_REG_BUFFER_ACCESS;
711 	config->dst_addr_width = 4;
712 	config->src_addr_width = 4;
713 	config->dst_maxburst = host->burstlen;
714 	config->src_maxburst = host->burstlen;
715 	config->device_fc = false;
716 
717 	return dmaengine_slave_config(host->dma, config);
718 }
719 
720 static void mxcmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
721 {
722 	struct mxcmci_host *host = mmc_priv(mmc);
723 	int burstlen, ret;
724 
725 	/*
726 	 * use burstlen of 64 (16 words) in 4 bit mode (--> reg value  0)
727 	 * use burstlen of 16 (4 words) in 1 bit mode (--> reg value 16)
728 	 */
729 	if (ios->bus_width == MMC_BUS_WIDTH_4)
730 		burstlen = 16;
731 	else
732 		burstlen = 4;
733 
734 	if (mxcmci_use_dma(host) && burstlen != host->burstlen) {
735 		host->burstlen = burstlen;
736 		ret = mxcmci_setup_dma(mmc);
737 		if (ret) {
738 			dev_err(mmc_dev(host->mmc),
739 				"failed to config DMA channel. Falling back to PIO\n");
740 			dma_release_channel(host->dma);
741 			host->do_dma = 0;
742 			host->dma = NULL;
743 		}
744 	}
745 
746 	if (ios->bus_width == MMC_BUS_WIDTH_4)
747 		host->cmdat |= CMD_DAT_CONT_BUS_WIDTH_4;
748 	else
749 		host->cmdat &= ~CMD_DAT_CONT_BUS_WIDTH_4;
750 
751 	if (host->power_mode != ios->power_mode) {
752 		mxcmci_set_power(host, ios->power_mode, ios->vdd);
753 		host->power_mode = ios->power_mode;
754 
755 		if (ios->power_mode == MMC_POWER_ON)
756 			host->cmdat |= CMD_DAT_CONT_INIT;
757 	}
758 
759 	if (ios->clock) {
760 		mxcmci_set_clk_rate(host, ios->clock);
761 		writew(STR_STP_CLK_START_CLK, host->base + MMC_REG_STR_STP_CLK);
762 	} else {
763 		writew(STR_STP_CLK_STOP_CLK, host->base + MMC_REG_STR_STP_CLK);
764 	}
765 
766 	host->clock = ios->clock;
767 }
768 
769 static irqreturn_t mxcmci_detect_irq(int irq, void *data)
770 {
771 	struct mmc_host *mmc = data;
772 
773 	dev_dbg(mmc_dev(mmc), "%s\n", __func__);
774 
775 	mmc_detect_change(mmc, msecs_to_jiffies(250));
776 	return IRQ_HANDLED;
777 }
778 
779 static int mxcmci_get_ro(struct mmc_host *mmc)
780 {
781 	struct mxcmci_host *host = mmc_priv(mmc);
782 
783 	if (host->pdata && host->pdata->get_ro)
784 		return !!host->pdata->get_ro(mmc_dev(mmc));
785 	/*
786 	 * Board doesn't support read only detection; let the mmc core
787 	 * decide what to do.
788 	 */
789 	return -ENOSYS;
790 }
791 
792 static void mxcmci_enable_sdio_irq(struct mmc_host *mmc, int enable)
793 {
794 	struct mxcmci_host *host = mmc_priv(mmc);
795 	unsigned long flags;
796 	u32 int_cntr;
797 
798 	spin_lock_irqsave(&host->lock, flags);
799 	host->use_sdio = enable;
800 	int_cntr = readl(host->base + MMC_REG_INT_CNTR);
801 
802 	if (enable)
803 		int_cntr |= INT_SDIO_IRQ_EN;
804 	else
805 		int_cntr &= ~INT_SDIO_IRQ_EN;
806 
807 	writel(int_cntr, host->base + MMC_REG_INT_CNTR);
808 	spin_unlock_irqrestore(&host->lock, flags);
809 }
810 
811 static void mxcmci_init_card(struct mmc_host *host, struct mmc_card *card)
812 {
813 	/*
814 	 * MX3 SoCs have a silicon bug which corrupts CRC calculation of
815 	 * multi-block transfers when connected SDIO peripheral doesn't
816 	 * drive the BUSY line as required by the specs.
817 	 * One way to prevent this is to only allow 1-bit transfers.
818 	 */
819 
820 	if (cpu_is_mx3() && card->type == MMC_TYPE_SDIO)
821 		host->caps &= ~MMC_CAP_4_BIT_DATA;
822 	else
823 		host->caps |= MMC_CAP_4_BIT_DATA;
824 }
825 
826 static bool filter(struct dma_chan *chan, void *param)
827 {
828 	struct mxcmci_host *host = param;
829 
830 	if (!imx_dma_is_general_purpose(chan))
831 		return false;
832 
833 	chan->private = &host->dma_data;
834 
835 	return true;
836 }
837 
838 static const struct mmc_host_ops mxcmci_ops = {
839 	.request		= mxcmci_request,
840 	.set_ios		= mxcmci_set_ios,
841 	.get_ro			= mxcmci_get_ro,
842 	.enable_sdio_irq	= mxcmci_enable_sdio_irq,
843 	.init_card		= mxcmci_init_card,
844 };
845 
846 static int mxcmci_probe(struct platform_device *pdev)
847 {
848 	struct mmc_host *mmc;
849 	struct mxcmci_host *host = NULL;
850 	struct resource *iores, *r;
851 	int ret = 0, irq;
852 	dma_cap_mask_t mask;
853 
854 	pr_info("i.MX SDHC driver\n");
855 
856 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
857 	irq = platform_get_irq(pdev, 0);
858 	if (!iores || irq < 0)
859 		return -EINVAL;
860 
861 	r = request_mem_region(iores->start, resource_size(iores), pdev->name);
862 	if (!r)
863 		return -EBUSY;
864 
865 	mmc = mmc_alloc_host(sizeof(struct mxcmci_host), &pdev->dev);
866 	if (!mmc) {
867 		ret = -ENOMEM;
868 		goto out_release_mem;
869 	}
870 
871 	mmc->ops = &mxcmci_ops;
872 	mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
873 
874 	/* MMC core transfer sizes tunable parameters */
875 	mmc->max_segs = 64;
876 	mmc->max_blk_size = 2048;
877 	mmc->max_blk_count = 65535;
878 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
879 	mmc->max_seg_size = mmc->max_req_size;
880 
881 	host = mmc_priv(mmc);
882 	host->base = ioremap(r->start, resource_size(r));
883 	if (!host->base) {
884 		ret = -ENOMEM;
885 		goto out_free;
886 	}
887 
888 	host->mmc = mmc;
889 	host->pdata = pdev->dev.platform_data;
890 	spin_lock_init(&host->lock);
891 
892 	mxcmci_init_ocr(host);
893 
894 	if (host->pdata && host->pdata->dat3_card_detect)
895 		host->default_irq_mask =
896 			INT_CARD_INSERTION_EN | INT_CARD_REMOVAL_EN;
897 	else
898 		host->default_irq_mask = 0;
899 
900 	host->res = r;
901 	host->irq = irq;
902 
903 	host->clk = clk_get(&pdev->dev, NULL);
904 	if (IS_ERR(host->clk)) {
905 		ret = PTR_ERR(host->clk);
906 		goto out_iounmap;
907 	}
908 	clk_enable(host->clk);
909 
910 	mxcmci_softreset(host);
911 
912 	host->rev_no = readw(host->base + MMC_REG_REV_NO);
913 	if (host->rev_no != 0x400) {
914 		ret = -ENODEV;
915 		dev_err(mmc_dev(host->mmc), "wrong rev.no. 0x%08x. aborting.\n",
916 			host->rev_no);
917 		goto out_clk_put;
918 	}
919 
920 	mmc->f_min = clk_get_rate(host->clk) >> 16;
921 	mmc->f_max = clk_get_rate(host->clk) >> 1;
922 
923 	/* recommended in data sheet */
924 	writew(0x2db4, host->base + MMC_REG_READ_TO);
925 
926 	writel(host->default_irq_mask, host->base + MMC_REG_INT_CNTR);
927 
928 	r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
929 	if (r) {
930 		host->dmareq = r->start;
931 		host->dma_data.peripheral_type = IMX_DMATYPE_SDHC;
932 		host->dma_data.priority = DMA_PRIO_LOW;
933 		host->dma_data.dma_request = host->dmareq;
934 		dma_cap_zero(mask);
935 		dma_cap_set(DMA_SLAVE, mask);
936 		host->dma = dma_request_channel(mask, filter, host);
937 		if (host->dma)
938 			mmc->max_seg_size = dma_get_max_seg_size(
939 					host->dma->device->dev);
940 	}
941 
942 	if (!host->dma)
943 		dev_info(mmc_dev(host->mmc), "dma not available. Using PIO\n");
944 
945 	INIT_WORK(&host->datawork, mxcmci_datawork);
946 
947 	ret = request_irq(host->irq, mxcmci_irq, 0, DRIVER_NAME, host);
948 	if (ret)
949 		goto out_free_dma;
950 
951 	platform_set_drvdata(pdev, mmc);
952 
953 	if (host->pdata && host->pdata->init) {
954 		ret = host->pdata->init(&pdev->dev, mxcmci_detect_irq,
955 				host->mmc);
956 		if (ret)
957 			goto out_free_irq;
958 	}
959 
960 	mmc_add_host(mmc);
961 
962 	return 0;
963 
964 out_free_irq:
965 	free_irq(host->irq, host);
966 out_free_dma:
967 	if (host->dma)
968 		dma_release_channel(host->dma);
969 out_clk_put:
970 	clk_disable(host->clk);
971 	clk_put(host->clk);
972 out_iounmap:
973 	iounmap(host->base);
974 out_free:
975 	mmc_free_host(mmc);
976 out_release_mem:
977 	release_mem_region(iores->start, resource_size(iores));
978 	return ret;
979 }
980 
981 static int mxcmci_remove(struct platform_device *pdev)
982 {
983 	struct mmc_host *mmc = platform_get_drvdata(pdev);
984 	struct mxcmci_host *host = mmc_priv(mmc);
985 
986 	platform_set_drvdata(pdev, NULL);
987 
988 	mmc_remove_host(mmc);
989 
990 	if (host->vcc)
991 		regulator_put(host->vcc);
992 
993 	if (host->pdata && host->pdata->exit)
994 		host->pdata->exit(&pdev->dev, mmc);
995 
996 	free_irq(host->irq, host);
997 	iounmap(host->base);
998 
999 	if (host->dma)
1000 		dma_release_channel(host->dma);
1001 
1002 	clk_disable(host->clk);
1003 	clk_put(host->clk);
1004 
1005 	release_mem_region(host->res->start, resource_size(host->res));
1006 
1007 	mmc_free_host(mmc);
1008 
1009 	return 0;
1010 }
1011 
1012 #ifdef CONFIG_PM
1013 static int mxcmci_suspend(struct device *dev)
1014 {
1015 	struct mmc_host *mmc = dev_get_drvdata(dev);
1016 	struct mxcmci_host *host = mmc_priv(mmc);
1017 	int ret = 0;
1018 
1019 	if (mmc)
1020 		ret = mmc_suspend_host(mmc);
1021 	clk_disable(host->clk);
1022 
1023 	return ret;
1024 }
1025 
1026 static int mxcmci_resume(struct device *dev)
1027 {
1028 	struct mmc_host *mmc = dev_get_drvdata(dev);
1029 	struct mxcmci_host *host = mmc_priv(mmc);
1030 	int ret = 0;
1031 
1032 	clk_enable(host->clk);
1033 	if (mmc)
1034 		ret = mmc_resume_host(mmc);
1035 
1036 	return ret;
1037 }
1038 
1039 static const struct dev_pm_ops mxcmci_pm_ops = {
1040 	.suspend	= mxcmci_suspend,
1041 	.resume		= mxcmci_resume,
1042 };
1043 #endif
1044 
1045 static struct platform_driver mxcmci_driver = {
1046 	.probe		= mxcmci_probe,
1047 	.remove		= mxcmci_remove,
1048 	.driver		= {
1049 		.name		= DRIVER_NAME,
1050 		.owner		= THIS_MODULE,
1051 #ifdef CONFIG_PM
1052 		.pm	= &mxcmci_pm_ops,
1053 #endif
1054 	}
1055 };
1056 
1057 module_platform_driver(mxcmci_driver);
1058 
1059 MODULE_DESCRIPTION("i.MX Multimedia Card Interface Driver");
1060 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
1061 MODULE_LICENSE("GPL");
1062 MODULE_ALIAS("platform:imx-mmc");
1063