xref: /openbmc/linux/drivers/mmc/host/mxcmmc.c (revision 89e33ea7)
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/highmem.h>
25 #include <linux/interrupt.h>
26 #include <linux/irq.h>
27 #include <linux/blkdev.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/mmc/host.h>
30 #include <linux/mmc/card.h>
31 #include <linux/delay.h>
32 #include <linux/clk.h>
33 #include <linux/io.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/mmc/slot-gpio.h>
41 
42 #include <asm/dma.h>
43 #include <asm/irq.h>
44 #include <linux/platform_data/mmc-mxcmmc.h>
45 
46 #include <linux/platform_data/dma-imx.h>
47 
48 #define DRIVER_NAME "mxc-mmc"
49 #define MXCMCI_TIMEOUT_MS 10000
50 
51 #define MMC_REG_STR_STP_CLK		0x00
52 #define MMC_REG_STATUS			0x04
53 #define MMC_REG_CLK_RATE		0x08
54 #define MMC_REG_CMD_DAT_CONT		0x0C
55 #define MMC_REG_RES_TO			0x10
56 #define MMC_REG_READ_TO			0x14
57 #define MMC_REG_BLK_LEN			0x18
58 #define MMC_REG_NOB			0x1C
59 #define MMC_REG_REV_NO			0x20
60 #define MMC_REG_INT_CNTR		0x24
61 #define MMC_REG_CMD			0x28
62 #define MMC_REG_ARG			0x2C
63 #define MMC_REG_RES_FIFO		0x34
64 #define MMC_REG_BUFFER_ACCESS		0x38
65 
66 #define STR_STP_CLK_RESET               (1 << 3)
67 #define STR_STP_CLK_START_CLK           (1 << 1)
68 #define STR_STP_CLK_STOP_CLK            (1 << 0)
69 
70 #define STATUS_CARD_INSERTION		(1 << 31)
71 #define STATUS_CARD_REMOVAL		(1 << 30)
72 #define STATUS_YBUF_EMPTY		(1 << 29)
73 #define STATUS_XBUF_EMPTY		(1 << 28)
74 #define STATUS_YBUF_FULL		(1 << 27)
75 #define STATUS_XBUF_FULL		(1 << 26)
76 #define STATUS_BUF_UND_RUN		(1 << 25)
77 #define STATUS_BUF_OVFL			(1 << 24)
78 #define STATUS_SDIO_INT_ACTIVE		(1 << 14)
79 #define STATUS_END_CMD_RESP		(1 << 13)
80 #define STATUS_WRITE_OP_DONE		(1 << 12)
81 #define STATUS_DATA_TRANS_DONE		(1 << 11)
82 #define STATUS_READ_OP_DONE		(1 << 11)
83 #define STATUS_WR_CRC_ERROR_CODE_MASK	(3 << 10)
84 #define STATUS_CARD_BUS_CLK_RUN		(1 << 8)
85 #define STATUS_BUF_READ_RDY		(1 << 7)
86 #define STATUS_BUF_WRITE_RDY		(1 << 6)
87 #define STATUS_RESP_CRC_ERR		(1 << 5)
88 #define STATUS_CRC_READ_ERR		(1 << 3)
89 #define STATUS_CRC_WRITE_ERR		(1 << 2)
90 #define STATUS_TIME_OUT_RESP		(1 << 1)
91 #define STATUS_TIME_OUT_READ		(1 << 0)
92 #define STATUS_ERR_MASK			0x2f
93 
94 #define CMD_DAT_CONT_CMD_RESP_LONG_OFF	(1 << 12)
95 #define CMD_DAT_CONT_STOP_READWAIT	(1 << 11)
96 #define CMD_DAT_CONT_START_READWAIT	(1 << 10)
97 #define CMD_DAT_CONT_BUS_WIDTH_4	(2 << 8)
98 #define CMD_DAT_CONT_INIT		(1 << 7)
99 #define CMD_DAT_CONT_WRITE		(1 << 4)
100 #define CMD_DAT_CONT_DATA_ENABLE	(1 << 3)
101 #define CMD_DAT_CONT_RESPONSE_48BIT_CRC	(1 << 0)
102 #define CMD_DAT_CONT_RESPONSE_136BIT	(2 << 0)
103 #define CMD_DAT_CONT_RESPONSE_48BIT	(3 << 0)
104 
105 #define INT_SDIO_INT_WKP_EN		(1 << 18)
106 #define INT_CARD_INSERTION_WKP_EN	(1 << 17)
107 #define INT_CARD_REMOVAL_WKP_EN		(1 << 16)
108 #define INT_CARD_INSERTION_EN		(1 << 15)
109 #define INT_CARD_REMOVAL_EN		(1 << 14)
110 #define INT_SDIO_IRQ_EN			(1 << 13)
111 #define INT_DAT0_EN			(1 << 12)
112 #define INT_BUF_READ_EN			(1 << 4)
113 #define INT_BUF_WRITE_EN		(1 << 3)
114 #define INT_END_CMD_RES_EN		(1 << 2)
115 #define INT_WRITE_OP_DONE_EN		(1 << 1)
116 #define INT_READ_OP_EN			(1 << 0)
117 
118 enum mxcmci_type {
119 	IMX21_MMC,
120 	IMX31_MMC,
121 	MPC512X_MMC,
122 };
123 
124 struct mxcmci_host {
125 	struct mmc_host		*mmc;
126 	void __iomem		*base;
127 	dma_addr_t		phys_base;
128 	int			detect_irq;
129 	struct dma_chan		*dma;
130 	struct dma_async_tx_descriptor *desc;
131 	int			do_dma;
132 	int			default_irq_mask;
133 	int			use_sdio;
134 	unsigned int		power_mode;
135 	struct imxmmc_platform_data *pdata;
136 
137 	struct mmc_request	*req;
138 	struct mmc_command	*cmd;
139 	struct mmc_data		*data;
140 
141 	unsigned int		datasize;
142 	unsigned int		dma_dir;
143 
144 	u16			rev_no;
145 	unsigned int		cmdat;
146 
147 	struct clk		*clk_ipg;
148 	struct clk		*clk_per;
149 
150 	int			clock;
151 
152 	struct work_struct	datawork;
153 	spinlock_t		lock;
154 
155 	int			burstlen;
156 	int			dmareq;
157 	struct dma_slave_config dma_slave_config;
158 	struct imx_dma_data	dma_data;
159 
160 	struct timer_list	watchdog;
161 	enum mxcmci_type	devtype;
162 };
163 
164 static const struct platform_device_id mxcmci_devtype[] = {
165 	{
166 		.name = "imx21-mmc",
167 		.driver_data = IMX21_MMC,
168 	}, {
169 		.name = "imx31-mmc",
170 		.driver_data = IMX31_MMC,
171 	}, {
172 		.name = "mpc512x-sdhc",
173 		.driver_data = MPC512X_MMC,
174 	}, {
175 		/* sentinel */
176 	}
177 };
178 MODULE_DEVICE_TABLE(platform, mxcmci_devtype);
179 
180 static const struct of_device_id mxcmci_of_match[] = {
181 	{
182 		.compatible = "fsl,imx21-mmc",
183 		.data = &mxcmci_devtype[IMX21_MMC],
184 	}, {
185 		.compatible = "fsl,imx31-mmc",
186 		.data = &mxcmci_devtype[IMX31_MMC],
187 	}, {
188 		.compatible = "fsl,mpc5121-sdhc",
189 		.data = &mxcmci_devtype[MPC512X_MMC],
190 	}, {
191 		/* sentinel */
192 	}
193 };
194 MODULE_DEVICE_TABLE(of, mxcmci_of_match);
195 
196 static inline int is_imx31_mmc(struct mxcmci_host *host)
197 {
198 	return host->devtype == IMX31_MMC;
199 }
200 
201 static inline int is_mpc512x_mmc(struct mxcmci_host *host)
202 {
203 	return host->devtype == MPC512X_MMC;
204 }
205 
206 static inline u32 mxcmci_readl(struct mxcmci_host *host, int reg)
207 {
208 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
209 		return ioread32be(host->base + reg);
210 	else
211 		return readl(host->base + reg);
212 }
213 
214 static inline void mxcmci_writel(struct mxcmci_host *host, u32 val, int reg)
215 {
216 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
217 		iowrite32be(val, host->base + reg);
218 	else
219 		writel(val, host->base + reg);
220 }
221 
222 static inline u16 mxcmci_readw(struct mxcmci_host *host, int reg)
223 {
224 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
225 		return ioread32be(host->base + reg);
226 	else
227 		return readw(host->base + reg);
228 }
229 
230 static inline void mxcmci_writew(struct mxcmci_host *host, u16 val, int reg)
231 {
232 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
233 		iowrite32be(val, host->base + reg);
234 	else
235 		writew(val, host->base + reg);
236 }
237 
238 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios);
239 
240 static void mxcmci_set_power(struct mxcmci_host *host, unsigned int vdd)
241 {
242 	if (!IS_ERR(host->mmc->supply.vmmc)) {
243 		if (host->power_mode == MMC_POWER_UP)
244 			mmc_regulator_set_ocr(host->mmc,
245 					      host->mmc->supply.vmmc, vdd);
246 		else if (host->power_mode == MMC_POWER_OFF)
247 			mmc_regulator_set_ocr(host->mmc,
248 					      host->mmc->supply.vmmc, 0);
249 	}
250 
251 	if (host->pdata && host->pdata->setpower)
252 		host->pdata->setpower(mmc_dev(host->mmc), vdd);
253 }
254 
255 static inline int mxcmci_use_dma(struct mxcmci_host *host)
256 {
257 	return host->do_dma;
258 }
259 
260 static void mxcmci_softreset(struct mxcmci_host *host)
261 {
262 	int i;
263 
264 	dev_dbg(mmc_dev(host->mmc), "mxcmci_softreset\n");
265 
266 	/* reset sequence */
267 	mxcmci_writew(host, STR_STP_CLK_RESET, MMC_REG_STR_STP_CLK);
268 	mxcmci_writew(host, STR_STP_CLK_RESET | STR_STP_CLK_START_CLK,
269 			MMC_REG_STR_STP_CLK);
270 
271 	for (i = 0; i < 8; i++)
272 		mxcmci_writew(host, STR_STP_CLK_START_CLK, MMC_REG_STR_STP_CLK);
273 
274 	mxcmci_writew(host, 0xff, MMC_REG_RES_TO);
275 }
276 
277 #if IS_ENABLED(CONFIG_PPC_MPC512x)
278 static inline void buffer_swap32(u32 *buf, int len)
279 {
280 	int i;
281 
282 	for (i = 0; i < ((len + 3) / 4); i++) {
283 		*buf = swab32(*buf);
284 		buf++;
285 	}
286 }
287 
288 static void mxcmci_swap_buffers(struct mmc_data *data)
289 {
290 	struct scatterlist *sg;
291 	int i;
292 
293 	for_each_sg(data->sg, sg, data->sg_len, i) {
294 		void *buf = kmap_atomic(sg_page(sg) + sg->offset);
295 		buffer_swap32(buf, sg->length);
296 		kunmap_atomic(buf);
297 	}
298 }
299 #else
300 static inline void mxcmci_swap_buffers(struct mmc_data *data) {}
301 #endif
302 
303 static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
304 {
305 	unsigned int nob = data->blocks;
306 	unsigned int blksz = data->blksz;
307 	unsigned int datasize = nob * blksz;
308 	struct scatterlist *sg;
309 	enum dma_transfer_direction slave_dirn;
310 	int i, nents;
311 
312 	host->data = data;
313 	data->bytes_xfered = 0;
314 
315 	mxcmci_writew(host, nob, MMC_REG_NOB);
316 	mxcmci_writew(host, blksz, MMC_REG_BLK_LEN);
317 	host->datasize = datasize;
318 
319 	if (!mxcmci_use_dma(host))
320 		return 0;
321 
322 	for_each_sg(data->sg, sg, data->sg_len, i) {
323 		if (sg->offset & 3 || sg->length & 3 || sg->length < 512) {
324 			host->do_dma = 0;
325 			return 0;
326 		}
327 	}
328 
329 	if (data->flags & MMC_DATA_READ) {
330 		host->dma_dir = DMA_FROM_DEVICE;
331 		slave_dirn = DMA_DEV_TO_MEM;
332 	} else {
333 		host->dma_dir = DMA_TO_DEVICE;
334 		slave_dirn = DMA_MEM_TO_DEV;
335 
336 		mxcmci_swap_buffers(data);
337 	}
338 
339 	nents = dma_map_sg(host->dma->device->dev, data->sg,
340 				     data->sg_len,  host->dma_dir);
341 	if (nents != data->sg_len)
342 		return -EINVAL;
343 
344 	host->desc = dmaengine_prep_slave_sg(host->dma,
345 		data->sg, data->sg_len, slave_dirn,
346 		DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
347 
348 	if (!host->desc) {
349 		dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
350 				host->dma_dir);
351 		host->do_dma = 0;
352 		return 0; /* Fall back to PIO */
353 	}
354 	wmb();
355 
356 	dmaengine_submit(host->desc);
357 	dma_async_issue_pending(host->dma);
358 
359 	mod_timer(&host->watchdog, jiffies + msecs_to_jiffies(MXCMCI_TIMEOUT_MS));
360 
361 	return 0;
362 }
363 
364 static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat);
365 static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat);
366 
367 static void mxcmci_dma_callback(void *data)
368 {
369 	struct mxcmci_host *host = data;
370 	u32 stat;
371 
372 	del_timer(&host->watchdog);
373 
374 	stat = mxcmci_readl(host, MMC_REG_STATUS);
375 
376 	dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
377 
378 	mxcmci_data_done(host, stat);
379 }
380 
381 static int mxcmci_start_cmd(struct mxcmci_host *host, struct mmc_command *cmd,
382 		unsigned int cmdat)
383 {
384 	u32 int_cntr = host->default_irq_mask;
385 	unsigned long flags;
386 
387 	WARN_ON(host->cmd != NULL);
388 	host->cmd = cmd;
389 
390 	switch (mmc_resp_type(cmd)) {
391 	case MMC_RSP_R1: /* short CRC, OPCODE */
392 	case MMC_RSP_R1B:/* short CRC, OPCODE, BUSY */
393 		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT_CRC;
394 		break;
395 	case MMC_RSP_R2: /* long 136 bit + CRC */
396 		cmdat |= CMD_DAT_CONT_RESPONSE_136BIT;
397 		break;
398 	case MMC_RSP_R3: /* short */
399 		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT;
400 		break;
401 	case MMC_RSP_NONE:
402 		break;
403 	default:
404 		dev_err(mmc_dev(host->mmc), "unhandled response type 0x%x\n",
405 				mmc_resp_type(cmd));
406 		cmd->error = -EINVAL;
407 		return -EINVAL;
408 	}
409 
410 	int_cntr = INT_END_CMD_RES_EN;
411 
412 	if (mxcmci_use_dma(host)) {
413 		if (host->dma_dir == DMA_FROM_DEVICE) {
414 			host->desc->callback = mxcmci_dma_callback;
415 			host->desc->callback_param = host;
416 		} else {
417 			int_cntr |= INT_WRITE_OP_DONE_EN;
418 		}
419 	}
420 
421 	spin_lock_irqsave(&host->lock, flags);
422 	if (host->use_sdio)
423 		int_cntr |= INT_SDIO_IRQ_EN;
424 	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
425 	spin_unlock_irqrestore(&host->lock, flags);
426 
427 	mxcmci_writew(host, cmd->opcode, MMC_REG_CMD);
428 	mxcmci_writel(host, cmd->arg, MMC_REG_ARG);
429 	mxcmci_writew(host, cmdat, MMC_REG_CMD_DAT_CONT);
430 
431 	return 0;
432 }
433 
434 static void mxcmci_finish_request(struct mxcmci_host *host,
435 		struct mmc_request *req)
436 {
437 	u32 int_cntr = host->default_irq_mask;
438 	unsigned long flags;
439 
440 	spin_lock_irqsave(&host->lock, flags);
441 	if (host->use_sdio)
442 		int_cntr |= INT_SDIO_IRQ_EN;
443 	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
444 	spin_unlock_irqrestore(&host->lock, flags);
445 
446 	host->req = NULL;
447 	host->cmd = NULL;
448 	host->data = NULL;
449 
450 	mmc_request_done(host->mmc, req);
451 }
452 
453 static int mxcmci_finish_data(struct mxcmci_host *host, unsigned int stat)
454 {
455 	struct mmc_data *data = host->data;
456 	int data_error;
457 
458 	if (mxcmci_use_dma(host)) {
459 		dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
460 				host->dma_dir);
461 		mxcmci_swap_buffers(data);
462 	}
463 
464 	if (stat & STATUS_ERR_MASK) {
465 		dev_dbg(mmc_dev(host->mmc), "request failed. status: 0x%08x\n",
466 				stat);
467 		if (stat & STATUS_CRC_READ_ERR) {
468 			dev_err(mmc_dev(host->mmc), "%s: -EILSEQ\n", __func__);
469 			data->error = -EILSEQ;
470 		} else if (stat & STATUS_CRC_WRITE_ERR) {
471 			u32 err_code = (stat >> 9) & 0x3;
472 			if (err_code == 2) { /* No CRC response */
473 				dev_err(mmc_dev(host->mmc),
474 					"%s: No CRC -ETIMEDOUT\n", __func__);
475 				data->error = -ETIMEDOUT;
476 			} else {
477 				dev_err(mmc_dev(host->mmc),
478 					"%s: -EILSEQ\n", __func__);
479 				data->error = -EILSEQ;
480 			}
481 		} else if (stat & STATUS_TIME_OUT_READ) {
482 			dev_err(mmc_dev(host->mmc),
483 				"%s: read -ETIMEDOUT\n", __func__);
484 			data->error = -ETIMEDOUT;
485 		} else {
486 			dev_err(mmc_dev(host->mmc), "%s: -EIO\n", __func__);
487 			data->error = -EIO;
488 		}
489 	} else {
490 		data->bytes_xfered = host->datasize;
491 	}
492 
493 	data_error = data->error;
494 
495 	host->data = NULL;
496 
497 	return data_error;
498 }
499 
500 static void mxcmci_read_response(struct mxcmci_host *host, unsigned int stat)
501 {
502 	struct mmc_command *cmd = host->cmd;
503 	int i;
504 	u32 a, b, c;
505 
506 	if (!cmd)
507 		return;
508 
509 	if (stat & STATUS_TIME_OUT_RESP) {
510 		dev_dbg(mmc_dev(host->mmc), "CMD TIMEOUT\n");
511 		cmd->error = -ETIMEDOUT;
512 	} else if (stat & STATUS_RESP_CRC_ERR && cmd->flags & MMC_RSP_CRC) {
513 		dev_dbg(mmc_dev(host->mmc), "cmd crc error\n");
514 		cmd->error = -EILSEQ;
515 	}
516 
517 	if (cmd->flags & MMC_RSP_PRESENT) {
518 		if (cmd->flags & MMC_RSP_136) {
519 			for (i = 0; i < 4; i++) {
520 				a = mxcmci_readw(host, MMC_REG_RES_FIFO);
521 				b = mxcmci_readw(host, MMC_REG_RES_FIFO);
522 				cmd->resp[i] = a << 16 | b;
523 			}
524 		} else {
525 			a = mxcmci_readw(host, MMC_REG_RES_FIFO);
526 			b = mxcmci_readw(host, MMC_REG_RES_FIFO);
527 			c = mxcmci_readw(host, MMC_REG_RES_FIFO);
528 			cmd->resp[0] = a << 24 | b << 8 | c >> 8;
529 		}
530 	}
531 }
532 
533 static int mxcmci_poll_status(struct mxcmci_host *host, u32 mask)
534 {
535 	u32 stat;
536 	unsigned long timeout = jiffies + HZ;
537 
538 	do {
539 		stat = mxcmci_readl(host, MMC_REG_STATUS);
540 		if (stat & STATUS_ERR_MASK)
541 			return stat;
542 		if (time_after(jiffies, timeout)) {
543 			mxcmci_softreset(host);
544 			mxcmci_set_clk_rate(host, host->clock);
545 			return STATUS_TIME_OUT_READ;
546 		}
547 		if (stat & mask)
548 			return 0;
549 		cpu_relax();
550 	} while (1);
551 }
552 
553 static int mxcmci_pull(struct mxcmci_host *host, void *_buf, int bytes)
554 {
555 	unsigned int stat;
556 	u32 *buf = _buf;
557 
558 	while (bytes > 3) {
559 		stat = mxcmci_poll_status(host,
560 				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
561 		if (stat)
562 			return stat;
563 		*buf++ = cpu_to_le32(mxcmci_readl(host, MMC_REG_BUFFER_ACCESS));
564 		bytes -= 4;
565 	}
566 
567 	if (bytes) {
568 		u8 *b = (u8 *)buf;
569 		u32 tmp;
570 
571 		stat = mxcmci_poll_status(host,
572 				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
573 		if (stat)
574 			return stat;
575 		tmp = cpu_to_le32(mxcmci_readl(host, MMC_REG_BUFFER_ACCESS));
576 		memcpy(b, &tmp, bytes);
577 	}
578 
579 	return 0;
580 }
581 
582 static int mxcmci_push(struct mxcmci_host *host, void *_buf, int bytes)
583 {
584 	unsigned int stat;
585 	u32 *buf = _buf;
586 
587 	while (bytes > 3) {
588 		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
589 		if (stat)
590 			return stat;
591 		mxcmci_writel(host, cpu_to_le32(*buf++), MMC_REG_BUFFER_ACCESS);
592 		bytes -= 4;
593 	}
594 
595 	if (bytes) {
596 		u8 *b = (u8 *)buf;
597 		u32 tmp;
598 
599 		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
600 		if (stat)
601 			return stat;
602 
603 		memcpy(&tmp, b, bytes);
604 		mxcmci_writel(host, cpu_to_le32(tmp), MMC_REG_BUFFER_ACCESS);
605 	}
606 
607 	return mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
608 }
609 
610 static int mxcmci_transfer_data(struct mxcmci_host *host)
611 {
612 	struct mmc_data *data = host->req->data;
613 	struct scatterlist *sg;
614 	void *buf;
615 	int stat, i;
616 
617 	host->data = data;
618 	host->datasize = 0;
619 
620 	if (data->flags & MMC_DATA_READ) {
621 		for_each_sg(data->sg, sg, data->sg_len, i) {
622 			buf = kmap_atomic(sg_page(sg) + sg->offset);
623 			stat = mxcmci_pull(host, buf, sg->length);
624 			kunmap(buf);
625 			if (stat)
626 				return stat;
627 			host->datasize += sg->length;
628 		}
629 	} else {
630 		for_each_sg(data->sg, sg, data->sg_len, i) {
631 			buf = kmap_atomic(sg_page(sg) + sg->offset);
632 			stat = mxcmci_push(host, buf, sg->length);
633 			kunmap(buf);
634 			if (stat)
635 				return stat;
636 			host->datasize += sg->length;
637 		}
638 		stat = mxcmci_poll_status(host, STATUS_WRITE_OP_DONE);
639 		if (stat)
640 			return stat;
641 	}
642 	return 0;
643 }
644 
645 static void mxcmci_datawork(struct work_struct *work)
646 {
647 	struct mxcmci_host *host = container_of(work, struct mxcmci_host,
648 						  datawork);
649 	int datastat = mxcmci_transfer_data(host);
650 
651 	mxcmci_writel(host, STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
652 		MMC_REG_STATUS);
653 	mxcmci_finish_data(host, datastat);
654 
655 	if (host->req->stop) {
656 		if (mxcmci_start_cmd(host, host->req->stop, 0)) {
657 			mxcmci_finish_request(host, host->req);
658 			return;
659 		}
660 	} else {
661 		mxcmci_finish_request(host, host->req);
662 	}
663 }
664 
665 static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat)
666 {
667 	struct mmc_request *req;
668 	int data_error;
669 	unsigned long flags;
670 
671 	spin_lock_irqsave(&host->lock, flags);
672 
673 	if (!host->data) {
674 		spin_unlock_irqrestore(&host->lock, flags);
675 		return;
676 	}
677 
678 	if (!host->req) {
679 		spin_unlock_irqrestore(&host->lock, flags);
680 		return;
681 	}
682 
683 	req = host->req;
684 	if (!req->stop)
685 		host->req = NULL; /* we will handle finish req below */
686 
687 	data_error = mxcmci_finish_data(host, stat);
688 
689 	spin_unlock_irqrestore(&host->lock, flags);
690 
691 	if (data_error)
692 		return;
693 
694 	mxcmci_read_response(host, stat);
695 	host->cmd = NULL;
696 
697 	if (req->stop) {
698 		if (mxcmci_start_cmd(host, req->stop, 0)) {
699 			mxcmci_finish_request(host, req);
700 			return;
701 		}
702 	} else {
703 		mxcmci_finish_request(host, req);
704 	}
705 }
706 
707 static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat)
708 {
709 	mxcmci_read_response(host, stat);
710 	host->cmd = NULL;
711 
712 	if (!host->data && host->req) {
713 		mxcmci_finish_request(host, host->req);
714 		return;
715 	}
716 
717 	/* For the DMA case the DMA engine handles the data transfer
718 	 * automatically. For non DMA we have to do it ourselves.
719 	 * Don't do it in interrupt context though.
720 	 */
721 	if (!mxcmci_use_dma(host) && host->data)
722 		schedule_work(&host->datawork);
723 
724 }
725 
726 static irqreturn_t mxcmci_irq(int irq, void *devid)
727 {
728 	struct mxcmci_host *host = devid;
729 	bool sdio_irq;
730 	u32 stat;
731 
732 	stat = mxcmci_readl(host, MMC_REG_STATUS);
733 	mxcmci_writel(host,
734 		stat & ~(STATUS_SDIO_INT_ACTIVE | STATUS_DATA_TRANS_DONE |
735 			 STATUS_WRITE_OP_DONE),
736 		MMC_REG_STATUS);
737 
738 	dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
739 
740 	spin_lock(&host->lock);
741 	sdio_irq = (stat & STATUS_SDIO_INT_ACTIVE) && host->use_sdio;
742 	spin_unlock(&host->lock);
743 
744 	if (mxcmci_use_dma(host) && (stat & (STATUS_WRITE_OP_DONE)))
745 		mxcmci_writel(host, STATUS_WRITE_OP_DONE, MMC_REG_STATUS);
746 
747 	if (sdio_irq) {
748 		mxcmci_writel(host, STATUS_SDIO_INT_ACTIVE, MMC_REG_STATUS);
749 		mmc_signal_sdio_irq(host->mmc);
750 	}
751 
752 	if (stat & STATUS_END_CMD_RESP)
753 		mxcmci_cmd_done(host, stat);
754 
755 	if (mxcmci_use_dma(host) && (stat & STATUS_WRITE_OP_DONE)) {
756 		del_timer(&host->watchdog);
757 		mxcmci_data_done(host, stat);
758 	}
759 
760 	if (host->default_irq_mask &&
761 		  (stat & (STATUS_CARD_INSERTION | STATUS_CARD_REMOVAL)))
762 		mmc_detect_change(host->mmc, msecs_to_jiffies(200));
763 
764 	return IRQ_HANDLED;
765 }
766 
767 static void mxcmci_request(struct mmc_host *mmc, struct mmc_request *req)
768 {
769 	struct mxcmci_host *host = mmc_priv(mmc);
770 	unsigned int cmdat = host->cmdat;
771 	int error;
772 
773 	WARN_ON(host->req != NULL);
774 
775 	host->req = req;
776 	host->cmdat &= ~CMD_DAT_CONT_INIT;
777 
778 	if (host->dma)
779 		host->do_dma = 1;
780 
781 	if (req->data) {
782 		error = mxcmci_setup_data(host, req->data);
783 		if (error) {
784 			req->cmd->error = error;
785 			goto out;
786 		}
787 
788 
789 		cmdat |= CMD_DAT_CONT_DATA_ENABLE;
790 
791 		if (req->data->flags & MMC_DATA_WRITE)
792 			cmdat |= CMD_DAT_CONT_WRITE;
793 	}
794 
795 	error = mxcmci_start_cmd(host, req->cmd, cmdat);
796 
797 out:
798 	if (error)
799 		mxcmci_finish_request(host, req);
800 }
801 
802 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios)
803 {
804 	unsigned int divider;
805 	int prescaler = 0;
806 	unsigned int clk_in = clk_get_rate(host->clk_per);
807 
808 	while (prescaler <= 0x800) {
809 		for (divider = 1; divider <= 0xF; divider++) {
810 			int x;
811 
812 			x = (clk_in / (divider + 1));
813 
814 			if (prescaler)
815 				x /= (prescaler * 2);
816 
817 			if (x <= clk_ios)
818 				break;
819 		}
820 		if (divider < 0x10)
821 			break;
822 
823 		if (prescaler == 0)
824 			prescaler = 1;
825 		else
826 			prescaler <<= 1;
827 	}
828 
829 	mxcmci_writew(host, (prescaler << 4) | divider, MMC_REG_CLK_RATE);
830 
831 	dev_dbg(mmc_dev(host->mmc), "scaler: %d divider: %d in: %d out: %d\n",
832 			prescaler, divider, clk_in, clk_ios);
833 }
834 
835 static int mxcmci_setup_dma(struct mmc_host *mmc)
836 {
837 	struct mxcmci_host *host = mmc_priv(mmc);
838 	struct dma_slave_config *config = &host->dma_slave_config;
839 
840 	config->dst_addr = host->phys_base + MMC_REG_BUFFER_ACCESS;
841 	config->src_addr = host->phys_base + MMC_REG_BUFFER_ACCESS;
842 	config->dst_addr_width = 4;
843 	config->src_addr_width = 4;
844 	config->dst_maxburst = host->burstlen;
845 	config->src_maxburst = host->burstlen;
846 	config->device_fc = false;
847 
848 	return dmaengine_slave_config(host->dma, config);
849 }
850 
851 static void mxcmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
852 {
853 	struct mxcmci_host *host = mmc_priv(mmc);
854 	int burstlen, ret;
855 
856 	/*
857 	 * use burstlen of 64 (16 words) in 4 bit mode (--> reg value  0)
858 	 * use burstlen of 16 (4 words) in 1 bit mode (--> reg value 16)
859 	 */
860 	if (ios->bus_width == MMC_BUS_WIDTH_4)
861 		burstlen = 16;
862 	else
863 		burstlen = 4;
864 
865 	if (mxcmci_use_dma(host) && burstlen != host->burstlen) {
866 		host->burstlen = burstlen;
867 		ret = mxcmci_setup_dma(mmc);
868 		if (ret) {
869 			dev_err(mmc_dev(host->mmc),
870 				"failed to config DMA channel. Falling back to PIO\n");
871 			dma_release_channel(host->dma);
872 			host->do_dma = 0;
873 			host->dma = NULL;
874 		}
875 	}
876 
877 	if (ios->bus_width == MMC_BUS_WIDTH_4)
878 		host->cmdat |= CMD_DAT_CONT_BUS_WIDTH_4;
879 	else
880 		host->cmdat &= ~CMD_DAT_CONT_BUS_WIDTH_4;
881 
882 	if (host->power_mode != ios->power_mode) {
883 		host->power_mode = ios->power_mode;
884 		mxcmci_set_power(host, ios->vdd);
885 
886 		if (ios->power_mode == MMC_POWER_ON)
887 			host->cmdat |= CMD_DAT_CONT_INIT;
888 	}
889 
890 	if (ios->clock) {
891 		mxcmci_set_clk_rate(host, ios->clock);
892 		mxcmci_writew(host, STR_STP_CLK_START_CLK, MMC_REG_STR_STP_CLK);
893 	} else {
894 		mxcmci_writew(host, STR_STP_CLK_STOP_CLK, MMC_REG_STR_STP_CLK);
895 	}
896 
897 	host->clock = ios->clock;
898 }
899 
900 static irqreturn_t mxcmci_detect_irq(int irq, void *data)
901 {
902 	struct mmc_host *mmc = data;
903 
904 	dev_dbg(mmc_dev(mmc), "%s\n", __func__);
905 
906 	mmc_detect_change(mmc, msecs_to_jiffies(250));
907 	return IRQ_HANDLED;
908 }
909 
910 static int mxcmci_get_ro(struct mmc_host *mmc)
911 {
912 	struct mxcmci_host *host = mmc_priv(mmc);
913 
914 	if (host->pdata && host->pdata->get_ro)
915 		return !!host->pdata->get_ro(mmc_dev(mmc));
916 	/*
917 	 * If board doesn't support read only detection (no mmc_gpio
918 	 * context or gpio is invalid), then let the mmc core decide
919 	 * what to do.
920 	 */
921 	return mmc_gpio_get_ro(mmc);
922 }
923 
924 static void mxcmci_enable_sdio_irq(struct mmc_host *mmc, int enable)
925 {
926 	struct mxcmci_host *host = mmc_priv(mmc);
927 	unsigned long flags;
928 	u32 int_cntr;
929 
930 	spin_lock_irqsave(&host->lock, flags);
931 	host->use_sdio = enable;
932 	int_cntr = mxcmci_readl(host, MMC_REG_INT_CNTR);
933 
934 	if (enable)
935 		int_cntr |= INT_SDIO_IRQ_EN;
936 	else
937 		int_cntr &= ~INT_SDIO_IRQ_EN;
938 
939 	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
940 	spin_unlock_irqrestore(&host->lock, flags);
941 }
942 
943 static void mxcmci_init_card(struct mmc_host *host, struct mmc_card *card)
944 {
945 	struct mxcmci_host *mxcmci = mmc_priv(host);
946 
947 	/*
948 	 * MX3 SoCs have a silicon bug which corrupts CRC calculation of
949 	 * multi-block transfers when connected SDIO peripheral doesn't
950 	 * drive the BUSY line as required by the specs.
951 	 * One way to prevent this is to only allow 1-bit transfers.
952 	 */
953 
954 	if (is_imx31_mmc(mxcmci) && card->type == MMC_TYPE_SDIO)
955 		host->caps &= ~MMC_CAP_4_BIT_DATA;
956 	else
957 		host->caps |= MMC_CAP_4_BIT_DATA;
958 }
959 
960 static bool filter(struct dma_chan *chan, void *param)
961 {
962 	struct mxcmci_host *host = param;
963 
964 	if (!imx_dma_is_general_purpose(chan))
965 		return false;
966 
967 	chan->private = &host->dma_data;
968 
969 	return true;
970 }
971 
972 static void mxcmci_watchdog(struct timer_list *t)
973 {
974 	struct mxcmci_host *host = from_timer(host, t, watchdog);
975 	struct mmc_request *req = host->req;
976 	unsigned int stat = mxcmci_readl(host, MMC_REG_STATUS);
977 
978 	if (host->dma_dir == DMA_FROM_DEVICE) {
979 		dmaengine_terminate_all(host->dma);
980 		dev_err(mmc_dev(host->mmc),
981 			"%s: read time out (status = 0x%08x)\n",
982 			__func__, stat);
983 	} else {
984 		dev_err(mmc_dev(host->mmc),
985 			"%s: write time out (status = 0x%08x)\n",
986 			__func__, stat);
987 		mxcmci_softreset(host);
988 	}
989 
990 	/* Mark transfer as erroneus and inform the upper layers */
991 
992 	if (host->data)
993 		host->data->error = -ETIMEDOUT;
994 	host->req = NULL;
995 	host->cmd = NULL;
996 	host->data = NULL;
997 	mmc_request_done(host->mmc, req);
998 }
999 
1000 static const struct mmc_host_ops mxcmci_ops = {
1001 	.request		= mxcmci_request,
1002 	.set_ios		= mxcmci_set_ios,
1003 	.get_ro			= mxcmci_get_ro,
1004 	.enable_sdio_irq	= mxcmci_enable_sdio_irq,
1005 	.init_card		= mxcmci_init_card,
1006 };
1007 
1008 static int mxcmci_probe(struct platform_device *pdev)
1009 {
1010 	struct mmc_host *mmc;
1011 	struct mxcmci_host *host;
1012 	struct resource *res;
1013 	int ret = 0, irq;
1014 	bool dat3_card_detect = false;
1015 	dma_cap_mask_t mask;
1016 	const struct of_device_id *of_id;
1017 	struct imxmmc_platform_data *pdata = pdev->dev.platform_data;
1018 
1019 	pr_info("i.MX/MPC512x SDHC driver\n");
1020 
1021 	of_id = of_match_device(mxcmci_of_match, &pdev->dev);
1022 
1023 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1024 	irq = platform_get_irq(pdev, 0);
1025 	if (irq < 0) {
1026 		dev_err(&pdev->dev, "failed to get IRQ: %d\n", irq);
1027 		return irq;
1028 	}
1029 
1030 	mmc = mmc_alloc_host(sizeof(*host), &pdev->dev);
1031 	if (!mmc)
1032 		return -ENOMEM;
1033 
1034 	host = mmc_priv(mmc);
1035 
1036 	host->base = devm_ioremap_resource(&pdev->dev, res);
1037 	if (IS_ERR(host->base)) {
1038 		ret = PTR_ERR(host->base);
1039 		goto out_free;
1040 	}
1041 
1042 	host->phys_base = res->start;
1043 
1044 	ret = mmc_of_parse(mmc);
1045 	if (ret)
1046 		goto out_free;
1047 	mmc->ops = &mxcmci_ops;
1048 
1049 	/* For devicetree parsing, the bus width is read from devicetree */
1050 	if (pdata)
1051 		mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
1052 	else
1053 		mmc->caps |= MMC_CAP_SDIO_IRQ;
1054 
1055 	/* MMC core transfer sizes tunable parameters */
1056 	mmc->max_blk_size = 2048;
1057 	mmc->max_blk_count = 65535;
1058 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
1059 	mmc->max_seg_size = mmc->max_req_size;
1060 
1061 	if (of_id) {
1062 		const struct platform_device_id *id_entry = of_id->data;
1063 		host->devtype = id_entry->driver_data;
1064 	} else {
1065 		host->devtype = pdev->id_entry->driver_data;
1066 	}
1067 
1068 	/* adjust max_segs after devtype detection */
1069 	if (!is_mpc512x_mmc(host))
1070 		mmc->max_segs = 64;
1071 
1072 	host->mmc = mmc;
1073 	host->pdata = pdata;
1074 	spin_lock_init(&host->lock);
1075 
1076 	if (pdata)
1077 		dat3_card_detect = pdata->dat3_card_detect;
1078 	else if (mmc_card_is_removable(mmc)
1079 			&& !of_property_read_bool(pdev->dev.of_node, "cd-gpios"))
1080 		dat3_card_detect = true;
1081 
1082 	ret = mmc_regulator_get_supply(mmc);
1083 	if (ret)
1084 		goto out_free;
1085 
1086 	if (!mmc->ocr_avail) {
1087 		if (pdata && pdata->ocr_avail)
1088 			mmc->ocr_avail = pdata->ocr_avail;
1089 		else
1090 			mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
1091 	}
1092 
1093 	if (dat3_card_detect)
1094 		host->default_irq_mask =
1095 			INT_CARD_INSERTION_EN | INT_CARD_REMOVAL_EN;
1096 	else
1097 		host->default_irq_mask = 0;
1098 
1099 	host->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1100 	if (IS_ERR(host->clk_ipg)) {
1101 		ret = PTR_ERR(host->clk_ipg);
1102 		goto out_free;
1103 	}
1104 
1105 	host->clk_per = devm_clk_get(&pdev->dev, "per");
1106 	if (IS_ERR(host->clk_per)) {
1107 		ret = PTR_ERR(host->clk_per);
1108 		goto out_free;
1109 	}
1110 
1111 	ret = clk_prepare_enable(host->clk_per);
1112 	if (ret)
1113 		goto out_free;
1114 
1115 	ret = clk_prepare_enable(host->clk_ipg);
1116 	if (ret)
1117 		goto out_clk_per_put;
1118 
1119 	mxcmci_softreset(host);
1120 
1121 	host->rev_no = mxcmci_readw(host, MMC_REG_REV_NO);
1122 	if (host->rev_no != 0x400) {
1123 		ret = -ENODEV;
1124 		dev_err(mmc_dev(host->mmc), "wrong rev.no. 0x%08x. aborting.\n",
1125 			host->rev_no);
1126 		goto out_clk_put;
1127 	}
1128 
1129 	mmc->f_min = clk_get_rate(host->clk_per) >> 16;
1130 	mmc->f_max = clk_get_rate(host->clk_per) >> 1;
1131 
1132 	/* recommended in data sheet */
1133 	mxcmci_writew(host, 0x2db4, MMC_REG_READ_TO);
1134 
1135 	mxcmci_writel(host, host->default_irq_mask, MMC_REG_INT_CNTR);
1136 
1137 	if (!host->pdata) {
1138 		host->dma = dma_request_slave_channel(&pdev->dev, "rx-tx");
1139 	} else {
1140 		res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
1141 		if (res) {
1142 			host->dmareq = res->start;
1143 			host->dma_data.peripheral_type = IMX_DMATYPE_SDHC;
1144 			host->dma_data.priority = DMA_PRIO_LOW;
1145 			host->dma_data.dma_request = host->dmareq;
1146 			dma_cap_zero(mask);
1147 			dma_cap_set(DMA_SLAVE, mask);
1148 			host->dma = dma_request_channel(mask, filter, host);
1149 		}
1150 	}
1151 	if (host->dma)
1152 		mmc->max_seg_size = dma_get_max_seg_size(
1153 				host->dma->device->dev);
1154 	else
1155 		dev_info(mmc_dev(host->mmc), "dma not available. Using PIO\n");
1156 
1157 	INIT_WORK(&host->datawork, mxcmci_datawork);
1158 
1159 	ret = devm_request_irq(&pdev->dev, irq, mxcmci_irq, 0,
1160 			       dev_name(&pdev->dev), host);
1161 	if (ret)
1162 		goto out_free_dma;
1163 
1164 	platform_set_drvdata(pdev, mmc);
1165 
1166 	if (host->pdata && host->pdata->init) {
1167 		ret = host->pdata->init(&pdev->dev, mxcmci_detect_irq,
1168 				host->mmc);
1169 		if (ret)
1170 			goto out_free_dma;
1171 	}
1172 
1173 	timer_setup(&host->watchdog, mxcmci_watchdog, 0);
1174 
1175 	mmc_add_host(mmc);
1176 
1177 	return 0;
1178 
1179 out_free_dma:
1180 	if (host->dma)
1181 		dma_release_channel(host->dma);
1182 
1183 out_clk_put:
1184 	clk_disable_unprepare(host->clk_ipg);
1185 out_clk_per_put:
1186 	clk_disable_unprepare(host->clk_per);
1187 
1188 out_free:
1189 	mmc_free_host(mmc);
1190 
1191 	return ret;
1192 }
1193 
1194 static int mxcmci_remove(struct platform_device *pdev)
1195 {
1196 	struct mmc_host *mmc = platform_get_drvdata(pdev);
1197 	struct mxcmci_host *host = mmc_priv(mmc);
1198 
1199 	mmc_remove_host(mmc);
1200 
1201 	if (host->pdata && host->pdata->exit)
1202 		host->pdata->exit(&pdev->dev, mmc);
1203 
1204 	if (host->dma)
1205 		dma_release_channel(host->dma);
1206 
1207 	clk_disable_unprepare(host->clk_per);
1208 	clk_disable_unprepare(host->clk_ipg);
1209 
1210 	mmc_free_host(mmc);
1211 
1212 	return 0;
1213 }
1214 
1215 #ifdef CONFIG_PM_SLEEP
1216 static int mxcmci_suspend(struct device *dev)
1217 {
1218 	struct mmc_host *mmc = dev_get_drvdata(dev);
1219 	struct mxcmci_host *host = mmc_priv(mmc);
1220 
1221 	clk_disable_unprepare(host->clk_per);
1222 	clk_disable_unprepare(host->clk_ipg);
1223 	return 0;
1224 }
1225 
1226 static int mxcmci_resume(struct device *dev)
1227 {
1228 	struct mmc_host *mmc = dev_get_drvdata(dev);
1229 	struct mxcmci_host *host = mmc_priv(mmc);
1230 	int ret;
1231 
1232 	ret = clk_prepare_enable(host->clk_per);
1233 	if (ret)
1234 		return ret;
1235 
1236 	ret = clk_prepare_enable(host->clk_ipg);
1237 	if (ret)
1238 		clk_disable_unprepare(host->clk_per);
1239 
1240 	return ret;
1241 }
1242 #endif
1243 
1244 static SIMPLE_DEV_PM_OPS(mxcmci_pm_ops, mxcmci_suspend, mxcmci_resume);
1245 
1246 static struct platform_driver mxcmci_driver = {
1247 	.probe		= mxcmci_probe,
1248 	.remove		= mxcmci_remove,
1249 	.id_table	= mxcmci_devtype,
1250 	.driver		= {
1251 		.name		= DRIVER_NAME,
1252 		.pm	= &mxcmci_pm_ops,
1253 		.of_match_table	= mxcmci_of_match,
1254 	}
1255 };
1256 
1257 module_platform_driver(mxcmci_driver);
1258 
1259 MODULE_DESCRIPTION("i.MX Multimedia Card Interface Driver");
1260 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
1261 MODULE_LICENSE("GPL");
1262 MODULE_ALIAS("platform:mxc-mmc");
1263