xref: /openbmc/linux/drivers/mmc/host/mxcmmc.c (revision 80483c3a)
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 	void __iomem		*base;
128 	dma_addr_t		phys_base;
129 	int			detect_irq;
130 	struct dma_chan		*dma;
131 	struct dma_async_tx_descriptor *desc;
132 	int			do_dma;
133 	int			default_irq_mask;
134 	int			use_sdio;
135 	unsigned int		power_mode;
136 	struct imxmmc_platform_data *pdata;
137 
138 	struct mmc_request	*req;
139 	struct mmc_command	*cmd;
140 	struct mmc_data		*data;
141 
142 	unsigned int		datasize;
143 	unsigned int		dma_dir;
144 
145 	u16			rev_no;
146 	unsigned int		cmdat;
147 
148 	struct clk		*clk_ipg;
149 	struct clk		*clk_per;
150 
151 	int			clock;
152 
153 	struct work_struct	datawork;
154 	spinlock_t		lock;
155 
156 	int			burstlen;
157 	int			dmareq;
158 	struct dma_slave_config dma_slave_config;
159 	struct imx_dma_data	dma_data;
160 
161 	struct timer_list	watchdog;
162 	enum mxcmci_type	devtype;
163 };
164 
165 static const struct platform_device_id mxcmci_devtype[] = {
166 	{
167 		.name = "imx21-mmc",
168 		.driver_data = IMX21_MMC,
169 	}, {
170 		.name = "imx31-mmc",
171 		.driver_data = IMX31_MMC,
172 	}, {
173 		.name = "mpc512x-sdhc",
174 		.driver_data = MPC512X_MMC,
175 	}, {
176 		/* sentinel */
177 	}
178 };
179 MODULE_DEVICE_TABLE(platform, mxcmci_devtype);
180 
181 static const struct of_device_id mxcmci_of_match[] = {
182 	{
183 		.compatible = "fsl,imx21-mmc",
184 		.data = &mxcmci_devtype[IMX21_MMC],
185 	}, {
186 		.compatible = "fsl,imx31-mmc",
187 		.data = &mxcmci_devtype[IMX31_MMC],
188 	}, {
189 		.compatible = "fsl,mpc5121-sdhc",
190 		.data = &mxcmci_devtype[MPC512X_MMC],
191 	}, {
192 		/* sentinel */
193 	}
194 };
195 MODULE_DEVICE_TABLE(of, mxcmci_of_match);
196 
197 static inline int is_imx31_mmc(struct mxcmci_host *host)
198 {
199 	return host->devtype == IMX31_MMC;
200 }
201 
202 static inline int is_mpc512x_mmc(struct mxcmci_host *host)
203 {
204 	return host->devtype == MPC512X_MMC;
205 }
206 
207 static inline u32 mxcmci_readl(struct mxcmci_host *host, int reg)
208 {
209 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
210 		return ioread32be(host->base + reg);
211 	else
212 		return readl(host->base + reg);
213 }
214 
215 static inline void mxcmci_writel(struct mxcmci_host *host, u32 val, int reg)
216 {
217 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
218 		iowrite32be(val, host->base + reg);
219 	else
220 		writel(val, host->base + reg);
221 }
222 
223 static inline u16 mxcmci_readw(struct mxcmci_host *host, int reg)
224 {
225 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
226 		return ioread32be(host->base + reg);
227 	else
228 		return readw(host->base + reg);
229 }
230 
231 static inline void mxcmci_writew(struct mxcmci_host *host, u16 val, int reg)
232 {
233 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
234 		iowrite32be(val, host->base + reg);
235 	else
236 		writew(val, host->base + reg);
237 }
238 
239 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios);
240 
241 static void mxcmci_set_power(struct mxcmci_host *host, unsigned int vdd)
242 {
243 	if (!IS_ERR(host->mmc->supply.vmmc)) {
244 		if (host->power_mode == MMC_POWER_UP)
245 			mmc_regulator_set_ocr(host->mmc,
246 					      host->mmc->supply.vmmc, vdd);
247 		else if (host->power_mode == MMC_POWER_OFF)
248 			mmc_regulator_set_ocr(host->mmc,
249 					      host->mmc->supply.vmmc, 0);
250 	}
251 
252 	if (host->pdata && host->pdata->setpower)
253 		host->pdata->setpower(mmc_dev(host->mmc), vdd);
254 }
255 
256 static inline int mxcmci_use_dma(struct mxcmci_host *host)
257 {
258 	return host->do_dma;
259 }
260 
261 static void mxcmci_softreset(struct mxcmci_host *host)
262 {
263 	int i;
264 
265 	dev_dbg(mmc_dev(host->mmc), "mxcmci_softreset\n");
266 
267 	/* reset sequence */
268 	mxcmci_writew(host, STR_STP_CLK_RESET, MMC_REG_STR_STP_CLK);
269 	mxcmci_writew(host, STR_STP_CLK_RESET | STR_STP_CLK_START_CLK,
270 			MMC_REG_STR_STP_CLK);
271 
272 	for (i = 0; i < 8; i++)
273 		mxcmci_writew(host, STR_STP_CLK_START_CLK, MMC_REG_STR_STP_CLK);
274 
275 	mxcmci_writew(host, 0xff, MMC_REG_RES_TO);
276 }
277 
278 #if IS_ENABLED(CONFIG_PPC_MPC512x)
279 static inline void buffer_swap32(u32 *buf, int len)
280 {
281 	int i;
282 
283 	for (i = 0; i < ((len + 3) / 4); i++) {
284 		*buf = swab32(*buf);
285 		buf++;
286 	}
287 }
288 
289 static void mxcmci_swap_buffers(struct mmc_data *data)
290 {
291 	struct scatterlist *sg;
292 	int i;
293 
294 	for_each_sg(data->sg, sg, data->sg_len, i)
295 		buffer_swap32(sg_virt(sg), sg->length);
296 }
297 #else
298 static inline void mxcmci_swap_buffers(struct mmc_data *data) {}
299 #endif
300 
301 static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
302 {
303 	unsigned int nob = data->blocks;
304 	unsigned int blksz = data->blksz;
305 	unsigned int datasize = nob * blksz;
306 	struct scatterlist *sg;
307 	enum dma_transfer_direction slave_dirn;
308 	int i, nents;
309 
310 	host->data = data;
311 	data->bytes_xfered = 0;
312 
313 	mxcmci_writew(host, nob, MMC_REG_NOB);
314 	mxcmci_writew(host, blksz, MMC_REG_BLK_LEN);
315 	host->datasize = datasize;
316 
317 	if (!mxcmci_use_dma(host))
318 		return 0;
319 
320 	for_each_sg(data->sg, sg, data->sg_len, i) {
321 		if (sg->offset & 3 || sg->length & 3 || sg->length < 512) {
322 			host->do_dma = 0;
323 			return 0;
324 		}
325 	}
326 
327 	if (data->flags & MMC_DATA_READ) {
328 		host->dma_dir = DMA_FROM_DEVICE;
329 		slave_dirn = DMA_DEV_TO_MEM;
330 	} else {
331 		host->dma_dir = DMA_TO_DEVICE;
332 		slave_dirn = DMA_MEM_TO_DEV;
333 
334 		mxcmci_swap_buffers(data);
335 	}
336 
337 	nents = dma_map_sg(host->dma->device->dev, data->sg,
338 				     data->sg_len,  host->dma_dir);
339 	if (nents != data->sg_len)
340 		return -EINVAL;
341 
342 	host->desc = dmaengine_prep_slave_sg(host->dma,
343 		data->sg, data->sg_len, slave_dirn,
344 		DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
345 
346 	if (!host->desc) {
347 		dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
348 				host->dma_dir);
349 		host->do_dma = 0;
350 		return 0; /* Fall back to PIO */
351 	}
352 	wmb();
353 
354 	dmaengine_submit(host->desc);
355 	dma_async_issue_pending(host->dma);
356 
357 	mod_timer(&host->watchdog, jiffies + msecs_to_jiffies(MXCMCI_TIMEOUT_MS));
358 
359 	return 0;
360 }
361 
362 static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat);
363 static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat);
364 
365 static void mxcmci_dma_callback(void *data)
366 {
367 	struct mxcmci_host *host = data;
368 	u32 stat;
369 
370 	del_timer(&host->watchdog);
371 
372 	stat = mxcmci_readl(host, MMC_REG_STATUS);
373 
374 	dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
375 
376 	mxcmci_data_done(host, stat);
377 }
378 
379 static int mxcmci_start_cmd(struct mxcmci_host *host, struct mmc_command *cmd,
380 		unsigned int cmdat)
381 {
382 	u32 int_cntr = host->default_irq_mask;
383 	unsigned long flags;
384 
385 	WARN_ON(host->cmd != NULL);
386 	host->cmd = cmd;
387 
388 	switch (mmc_resp_type(cmd)) {
389 	case MMC_RSP_R1: /* short CRC, OPCODE */
390 	case MMC_RSP_R1B:/* short CRC, OPCODE, BUSY */
391 		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT_CRC;
392 		break;
393 	case MMC_RSP_R2: /* long 136 bit + CRC */
394 		cmdat |= CMD_DAT_CONT_RESPONSE_136BIT;
395 		break;
396 	case MMC_RSP_R3: /* short */
397 		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT;
398 		break;
399 	case MMC_RSP_NONE:
400 		break;
401 	default:
402 		dev_err(mmc_dev(host->mmc), "unhandled response type 0x%x\n",
403 				mmc_resp_type(cmd));
404 		cmd->error = -EINVAL;
405 		return -EINVAL;
406 	}
407 
408 	int_cntr = INT_END_CMD_RES_EN;
409 
410 	if (mxcmci_use_dma(host)) {
411 		if (host->dma_dir == DMA_FROM_DEVICE) {
412 			host->desc->callback = mxcmci_dma_callback;
413 			host->desc->callback_param = host;
414 		} else {
415 			int_cntr |= INT_WRITE_OP_DONE_EN;
416 		}
417 	}
418 
419 	spin_lock_irqsave(&host->lock, flags);
420 	if (host->use_sdio)
421 		int_cntr |= INT_SDIO_IRQ_EN;
422 	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
423 	spin_unlock_irqrestore(&host->lock, flags);
424 
425 	mxcmci_writew(host, cmd->opcode, MMC_REG_CMD);
426 	mxcmci_writel(host, cmd->arg, MMC_REG_ARG);
427 	mxcmci_writew(host, cmdat, MMC_REG_CMD_DAT_CONT);
428 
429 	return 0;
430 }
431 
432 static void mxcmci_finish_request(struct mxcmci_host *host,
433 		struct mmc_request *req)
434 {
435 	u32 int_cntr = host->default_irq_mask;
436 	unsigned long flags;
437 
438 	spin_lock_irqsave(&host->lock, flags);
439 	if (host->use_sdio)
440 		int_cntr |= INT_SDIO_IRQ_EN;
441 	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
442 	spin_unlock_irqrestore(&host->lock, flags);
443 
444 	host->req = NULL;
445 	host->cmd = NULL;
446 	host->data = NULL;
447 
448 	mmc_request_done(host->mmc, req);
449 }
450 
451 static int mxcmci_finish_data(struct mxcmci_host *host, unsigned int stat)
452 {
453 	struct mmc_data *data = host->data;
454 	int data_error;
455 
456 	if (mxcmci_use_dma(host)) {
457 		dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
458 				host->dma_dir);
459 		mxcmci_swap_buffers(data);
460 	}
461 
462 	if (stat & STATUS_ERR_MASK) {
463 		dev_dbg(mmc_dev(host->mmc), "request failed. status: 0x%08x\n",
464 				stat);
465 		if (stat & STATUS_CRC_READ_ERR) {
466 			dev_err(mmc_dev(host->mmc), "%s: -EILSEQ\n", __func__);
467 			data->error = -EILSEQ;
468 		} else if (stat & STATUS_CRC_WRITE_ERR) {
469 			u32 err_code = (stat >> 9) & 0x3;
470 			if (err_code == 2) { /* No CRC response */
471 				dev_err(mmc_dev(host->mmc),
472 					"%s: No CRC -ETIMEDOUT\n", __func__);
473 				data->error = -ETIMEDOUT;
474 			} else {
475 				dev_err(mmc_dev(host->mmc),
476 					"%s: -EILSEQ\n", __func__);
477 				data->error = -EILSEQ;
478 			}
479 		} else if (stat & STATUS_TIME_OUT_READ) {
480 			dev_err(mmc_dev(host->mmc),
481 				"%s: read -ETIMEDOUT\n", __func__);
482 			data->error = -ETIMEDOUT;
483 		} else {
484 			dev_err(mmc_dev(host->mmc), "%s: -EIO\n", __func__);
485 			data->error = -EIO;
486 		}
487 	} else {
488 		data->bytes_xfered = host->datasize;
489 	}
490 
491 	data_error = data->error;
492 
493 	host->data = NULL;
494 
495 	return data_error;
496 }
497 
498 static void mxcmci_read_response(struct mxcmci_host *host, unsigned int stat)
499 {
500 	struct mmc_command *cmd = host->cmd;
501 	int i;
502 	u32 a, b, c;
503 
504 	if (!cmd)
505 		return;
506 
507 	if (stat & STATUS_TIME_OUT_RESP) {
508 		dev_dbg(mmc_dev(host->mmc), "CMD TIMEOUT\n");
509 		cmd->error = -ETIMEDOUT;
510 	} else if (stat & STATUS_RESP_CRC_ERR && cmd->flags & MMC_RSP_CRC) {
511 		dev_dbg(mmc_dev(host->mmc), "cmd crc error\n");
512 		cmd->error = -EILSEQ;
513 	}
514 
515 	if (cmd->flags & MMC_RSP_PRESENT) {
516 		if (cmd->flags & MMC_RSP_136) {
517 			for (i = 0; i < 4; i++) {
518 				a = mxcmci_readw(host, MMC_REG_RES_FIFO);
519 				b = mxcmci_readw(host, MMC_REG_RES_FIFO);
520 				cmd->resp[i] = a << 16 | b;
521 			}
522 		} else {
523 			a = mxcmci_readw(host, MMC_REG_RES_FIFO);
524 			b = mxcmci_readw(host, MMC_REG_RES_FIFO);
525 			c = mxcmci_readw(host, MMC_REG_RES_FIFO);
526 			cmd->resp[0] = a << 24 | b << 8 | c >> 8;
527 		}
528 	}
529 }
530 
531 static int mxcmci_poll_status(struct mxcmci_host *host, u32 mask)
532 {
533 	u32 stat;
534 	unsigned long timeout = jiffies + HZ;
535 
536 	do {
537 		stat = mxcmci_readl(host, MMC_REG_STATUS);
538 		if (stat & STATUS_ERR_MASK)
539 			return stat;
540 		if (time_after(jiffies, timeout)) {
541 			mxcmci_softreset(host);
542 			mxcmci_set_clk_rate(host, host->clock);
543 			return STATUS_TIME_OUT_READ;
544 		}
545 		if (stat & mask)
546 			return 0;
547 		cpu_relax();
548 	} while (1);
549 }
550 
551 static int mxcmci_pull(struct mxcmci_host *host, void *_buf, int bytes)
552 {
553 	unsigned int stat;
554 	u32 *buf = _buf;
555 
556 	while (bytes > 3) {
557 		stat = mxcmci_poll_status(host,
558 				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
559 		if (stat)
560 			return stat;
561 		*buf++ = cpu_to_le32(mxcmci_readl(host, MMC_REG_BUFFER_ACCESS));
562 		bytes -= 4;
563 	}
564 
565 	if (bytes) {
566 		u8 *b = (u8 *)buf;
567 		u32 tmp;
568 
569 		stat = mxcmci_poll_status(host,
570 				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
571 		if (stat)
572 			return stat;
573 		tmp = cpu_to_le32(mxcmci_readl(host, MMC_REG_BUFFER_ACCESS));
574 		memcpy(b, &tmp, bytes);
575 	}
576 
577 	return 0;
578 }
579 
580 static int mxcmci_push(struct mxcmci_host *host, void *_buf, int bytes)
581 {
582 	unsigned int stat;
583 	u32 *buf = _buf;
584 
585 	while (bytes > 3) {
586 		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
587 		if (stat)
588 			return stat;
589 		mxcmci_writel(host, cpu_to_le32(*buf++), MMC_REG_BUFFER_ACCESS);
590 		bytes -= 4;
591 	}
592 
593 	if (bytes) {
594 		u8 *b = (u8 *)buf;
595 		u32 tmp;
596 
597 		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
598 		if (stat)
599 			return stat;
600 
601 		memcpy(&tmp, b, bytes);
602 		mxcmci_writel(host, cpu_to_le32(tmp), MMC_REG_BUFFER_ACCESS);
603 	}
604 
605 	return mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
606 }
607 
608 static int mxcmci_transfer_data(struct mxcmci_host *host)
609 {
610 	struct mmc_data *data = host->req->data;
611 	struct scatterlist *sg;
612 	int stat, i;
613 
614 	host->data = data;
615 	host->datasize = 0;
616 
617 	if (data->flags & MMC_DATA_READ) {
618 		for_each_sg(data->sg, sg, data->sg_len, i) {
619 			stat = mxcmci_pull(host, sg_virt(sg), sg->length);
620 			if (stat)
621 				return stat;
622 			host->datasize += sg->length;
623 		}
624 	} else {
625 		for_each_sg(data->sg, sg, data->sg_len, i) {
626 			stat = mxcmci_push(host, sg_virt(sg), sg->length);
627 			if (stat)
628 				return stat;
629 			host->datasize += sg->length;
630 		}
631 		stat = mxcmci_poll_status(host, STATUS_WRITE_OP_DONE);
632 		if (stat)
633 			return stat;
634 	}
635 	return 0;
636 }
637 
638 static void mxcmci_datawork(struct work_struct *work)
639 {
640 	struct mxcmci_host *host = container_of(work, struct mxcmci_host,
641 						  datawork);
642 	int datastat = mxcmci_transfer_data(host);
643 
644 	mxcmci_writel(host, STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
645 		MMC_REG_STATUS);
646 	mxcmci_finish_data(host, datastat);
647 
648 	if (host->req->stop) {
649 		if (mxcmci_start_cmd(host, host->req->stop, 0)) {
650 			mxcmci_finish_request(host, host->req);
651 			return;
652 		}
653 	} else {
654 		mxcmci_finish_request(host, host->req);
655 	}
656 }
657 
658 static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat)
659 {
660 	struct mmc_request *req;
661 	int data_error;
662 	unsigned long flags;
663 
664 	spin_lock_irqsave(&host->lock, flags);
665 
666 	if (!host->data) {
667 		spin_unlock_irqrestore(&host->lock, flags);
668 		return;
669 	}
670 
671 	if (!host->req) {
672 		spin_unlock_irqrestore(&host->lock, flags);
673 		return;
674 	}
675 
676 	req = host->req;
677 	if (!req->stop)
678 		host->req = NULL; /* we will handle finish req below */
679 
680 	data_error = mxcmci_finish_data(host, stat);
681 
682 	spin_unlock_irqrestore(&host->lock, flags);
683 
684 	mxcmci_read_response(host, stat);
685 	host->cmd = NULL;
686 
687 	if (req->stop) {
688 		if (mxcmci_start_cmd(host, req->stop, 0)) {
689 			mxcmci_finish_request(host, req);
690 			return;
691 		}
692 	} else {
693 		mxcmci_finish_request(host, req);
694 	}
695 }
696 
697 static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat)
698 {
699 	mxcmci_read_response(host, stat);
700 	host->cmd = NULL;
701 
702 	if (!host->data && host->req) {
703 		mxcmci_finish_request(host, host->req);
704 		return;
705 	}
706 
707 	/* For the DMA case the DMA engine handles the data transfer
708 	 * automatically. For non DMA we have to do it ourselves.
709 	 * Don't do it in interrupt context though.
710 	 */
711 	if (!mxcmci_use_dma(host) && host->data)
712 		schedule_work(&host->datawork);
713 
714 }
715 
716 static irqreturn_t mxcmci_irq(int irq, void *devid)
717 {
718 	struct mxcmci_host *host = devid;
719 	unsigned long flags;
720 	bool sdio_irq;
721 	u32 stat;
722 
723 	stat = mxcmci_readl(host, MMC_REG_STATUS);
724 	mxcmci_writel(host,
725 		stat & ~(STATUS_SDIO_INT_ACTIVE | STATUS_DATA_TRANS_DONE |
726 			 STATUS_WRITE_OP_DONE),
727 		MMC_REG_STATUS);
728 
729 	dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
730 
731 	spin_lock_irqsave(&host->lock, flags);
732 	sdio_irq = (stat & STATUS_SDIO_INT_ACTIVE) && host->use_sdio;
733 	spin_unlock_irqrestore(&host->lock, flags);
734 
735 	if (mxcmci_use_dma(host) && (stat & (STATUS_WRITE_OP_DONE)))
736 		mxcmci_writel(host, STATUS_WRITE_OP_DONE, MMC_REG_STATUS);
737 
738 	if (sdio_irq) {
739 		mxcmci_writel(host, STATUS_SDIO_INT_ACTIVE, MMC_REG_STATUS);
740 		mmc_signal_sdio_irq(host->mmc);
741 	}
742 
743 	if (stat & STATUS_END_CMD_RESP)
744 		mxcmci_cmd_done(host, stat);
745 
746 	if (mxcmci_use_dma(host) && (stat & STATUS_WRITE_OP_DONE)) {
747 		del_timer(&host->watchdog);
748 		mxcmci_data_done(host, stat);
749 	}
750 
751 	if (host->default_irq_mask &&
752 		  (stat & (STATUS_CARD_INSERTION | STATUS_CARD_REMOVAL)))
753 		mmc_detect_change(host->mmc, msecs_to_jiffies(200));
754 
755 	return IRQ_HANDLED;
756 }
757 
758 static void mxcmci_request(struct mmc_host *mmc, struct mmc_request *req)
759 {
760 	struct mxcmci_host *host = mmc_priv(mmc);
761 	unsigned int cmdat = host->cmdat;
762 	int error;
763 
764 	WARN_ON(host->req != NULL);
765 
766 	host->req = req;
767 	host->cmdat &= ~CMD_DAT_CONT_INIT;
768 
769 	if (host->dma)
770 		host->do_dma = 1;
771 
772 	if (req->data) {
773 		error = mxcmci_setup_data(host, req->data);
774 		if (error) {
775 			req->cmd->error = error;
776 			goto out;
777 		}
778 
779 
780 		cmdat |= CMD_DAT_CONT_DATA_ENABLE;
781 
782 		if (req->data->flags & MMC_DATA_WRITE)
783 			cmdat |= CMD_DAT_CONT_WRITE;
784 	}
785 
786 	error = mxcmci_start_cmd(host, req->cmd, cmdat);
787 
788 out:
789 	if (error)
790 		mxcmci_finish_request(host, req);
791 }
792 
793 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios)
794 {
795 	unsigned int divider;
796 	int prescaler = 0;
797 	unsigned int clk_in = clk_get_rate(host->clk_per);
798 
799 	while (prescaler <= 0x800) {
800 		for (divider = 1; divider <= 0xF; divider++) {
801 			int x;
802 
803 			x = (clk_in / (divider + 1));
804 
805 			if (prescaler)
806 				x /= (prescaler * 2);
807 
808 			if (x <= clk_ios)
809 				break;
810 		}
811 		if (divider < 0x10)
812 			break;
813 
814 		if (prescaler == 0)
815 			prescaler = 1;
816 		else
817 			prescaler <<= 1;
818 	}
819 
820 	mxcmci_writew(host, (prescaler << 4) | divider, MMC_REG_CLK_RATE);
821 
822 	dev_dbg(mmc_dev(host->mmc), "scaler: %d divider: %d in: %d out: %d\n",
823 			prescaler, divider, clk_in, clk_ios);
824 }
825 
826 static int mxcmci_setup_dma(struct mmc_host *mmc)
827 {
828 	struct mxcmci_host *host = mmc_priv(mmc);
829 	struct dma_slave_config *config = &host->dma_slave_config;
830 
831 	config->dst_addr = host->phys_base + MMC_REG_BUFFER_ACCESS;
832 	config->src_addr = host->phys_base + MMC_REG_BUFFER_ACCESS;
833 	config->dst_addr_width = 4;
834 	config->src_addr_width = 4;
835 	config->dst_maxburst = host->burstlen;
836 	config->src_maxburst = host->burstlen;
837 	config->device_fc = false;
838 
839 	return dmaengine_slave_config(host->dma, config);
840 }
841 
842 static void mxcmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
843 {
844 	struct mxcmci_host *host = mmc_priv(mmc);
845 	int burstlen, ret;
846 
847 	/*
848 	 * use burstlen of 64 (16 words) in 4 bit mode (--> reg value  0)
849 	 * use burstlen of 16 (4 words) in 1 bit mode (--> reg value 16)
850 	 */
851 	if (ios->bus_width == MMC_BUS_WIDTH_4)
852 		burstlen = 16;
853 	else
854 		burstlen = 4;
855 
856 	if (mxcmci_use_dma(host) && burstlen != host->burstlen) {
857 		host->burstlen = burstlen;
858 		ret = mxcmci_setup_dma(mmc);
859 		if (ret) {
860 			dev_err(mmc_dev(host->mmc),
861 				"failed to config DMA channel. Falling back to PIO\n");
862 			dma_release_channel(host->dma);
863 			host->do_dma = 0;
864 			host->dma = NULL;
865 		}
866 	}
867 
868 	if (ios->bus_width == MMC_BUS_WIDTH_4)
869 		host->cmdat |= CMD_DAT_CONT_BUS_WIDTH_4;
870 	else
871 		host->cmdat &= ~CMD_DAT_CONT_BUS_WIDTH_4;
872 
873 	if (host->power_mode != ios->power_mode) {
874 		host->power_mode = ios->power_mode;
875 		mxcmci_set_power(host, ios->vdd);
876 
877 		if (ios->power_mode == MMC_POWER_ON)
878 			host->cmdat |= CMD_DAT_CONT_INIT;
879 	}
880 
881 	if (ios->clock) {
882 		mxcmci_set_clk_rate(host, ios->clock);
883 		mxcmci_writew(host, STR_STP_CLK_START_CLK, MMC_REG_STR_STP_CLK);
884 	} else {
885 		mxcmci_writew(host, STR_STP_CLK_STOP_CLK, MMC_REG_STR_STP_CLK);
886 	}
887 
888 	host->clock = ios->clock;
889 }
890 
891 static irqreturn_t mxcmci_detect_irq(int irq, void *data)
892 {
893 	struct mmc_host *mmc = data;
894 
895 	dev_dbg(mmc_dev(mmc), "%s\n", __func__);
896 
897 	mmc_detect_change(mmc, msecs_to_jiffies(250));
898 	return IRQ_HANDLED;
899 }
900 
901 static int mxcmci_get_ro(struct mmc_host *mmc)
902 {
903 	struct mxcmci_host *host = mmc_priv(mmc);
904 
905 	if (host->pdata && host->pdata->get_ro)
906 		return !!host->pdata->get_ro(mmc_dev(mmc));
907 	/*
908 	 * If board doesn't support read only detection (no mmc_gpio
909 	 * context or gpio is invalid), then let the mmc core decide
910 	 * what to do.
911 	 */
912 	return mmc_gpio_get_ro(mmc);
913 }
914 
915 static void mxcmci_enable_sdio_irq(struct mmc_host *mmc, int enable)
916 {
917 	struct mxcmci_host *host = mmc_priv(mmc);
918 	unsigned long flags;
919 	u32 int_cntr;
920 
921 	spin_lock_irqsave(&host->lock, flags);
922 	host->use_sdio = enable;
923 	int_cntr = mxcmci_readl(host, MMC_REG_INT_CNTR);
924 
925 	if (enable)
926 		int_cntr |= INT_SDIO_IRQ_EN;
927 	else
928 		int_cntr &= ~INT_SDIO_IRQ_EN;
929 
930 	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
931 	spin_unlock_irqrestore(&host->lock, flags);
932 }
933 
934 static void mxcmci_init_card(struct mmc_host *host, struct mmc_card *card)
935 {
936 	struct mxcmci_host *mxcmci = mmc_priv(host);
937 
938 	/*
939 	 * MX3 SoCs have a silicon bug which corrupts CRC calculation of
940 	 * multi-block transfers when connected SDIO peripheral doesn't
941 	 * drive the BUSY line as required by the specs.
942 	 * One way to prevent this is to only allow 1-bit transfers.
943 	 */
944 
945 	if (is_imx31_mmc(mxcmci) && card->type == MMC_TYPE_SDIO)
946 		host->caps &= ~MMC_CAP_4_BIT_DATA;
947 	else
948 		host->caps |= MMC_CAP_4_BIT_DATA;
949 }
950 
951 static bool filter(struct dma_chan *chan, void *param)
952 {
953 	struct mxcmci_host *host = param;
954 
955 	if (!imx_dma_is_general_purpose(chan))
956 		return false;
957 
958 	chan->private = &host->dma_data;
959 
960 	return true;
961 }
962 
963 static void mxcmci_watchdog(unsigned long data)
964 {
965 	struct mmc_host *mmc = (struct mmc_host *)data;
966 	struct mxcmci_host *host = mmc_priv(mmc);
967 	struct mmc_request *req = host->req;
968 	unsigned int stat = mxcmci_readl(host, MMC_REG_STATUS);
969 
970 	if (host->dma_dir == DMA_FROM_DEVICE) {
971 		dmaengine_terminate_all(host->dma);
972 		dev_err(mmc_dev(host->mmc),
973 			"%s: read time out (status = 0x%08x)\n",
974 			__func__, stat);
975 	} else {
976 		dev_err(mmc_dev(host->mmc),
977 			"%s: write time out (status = 0x%08x)\n",
978 			__func__, stat);
979 		mxcmci_softreset(host);
980 	}
981 
982 	/* Mark transfer as erroneus and inform the upper layers */
983 
984 	if (host->data)
985 		host->data->error = -ETIMEDOUT;
986 	host->req = NULL;
987 	host->cmd = NULL;
988 	host->data = NULL;
989 	mmc_request_done(host->mmc, req);
990 }
991 
992 static const struct mmc_host_ops mxcmci_ops = {
993 	.request		= mxcmci_request,
994 	.set_ios		= mxcmci_set_ios,
995 	.get_ro			= mxcmci_get_ro,
996 	.enable_sdio_irq	= mxcmci_enable_sdio_irq,
997 	.init_card		= mxcmci_init_card,
998 };
999 
1000 static int mxcmci_probe(struct platform_device *pdev)
1001 {
1002 	struct mmc_host *mmc;
1003 	struct mxcmci_host *host;
1004 	struct resource *res;
1005 	int ret = 0, irq;
1006 	bool dat3_card_detect = false;
1007 	dma_cap_mask_t mask;
1008 	const struct of_device_id *of_id;
1009 	struct imxmmc_platform_data *pdata = pdev->dev.platform_data;
1010 
1011 	pr_info("i.MX/MPC512x SDHC driver\n");
1012 
1013 	of_id = of_match_device(mxcmci_of_match, &pdev->dev);
1014 
1015 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1016 	irq = platform_get_irq(pdev, 0);
1017 	if (irq < 0)
1018 		return -EINVAL;
1019 
1020 	mmc = mmc_alloc_host(sizeof(*host), &pdev->dev);
1021 	if (!mmc)
1022 		return -ENOMEM;
1023 
1024 	host = mmc_priv(mmc);
1025 
1026 	host->base = devm_ioremap_resource(&pdev->dev, res);
1027 	if (IS_ERR(host->base)) {
1028 		ret = PTR_ERR(host->base);
1029 		goto out_free;
1030 	}
1031 
1032 	host->phys_base = res->start;
1033 
1034 	ret = mmc_of_parse(mmc);
1035 	if (ret)
1036 		goto out_free;
1037 	mmc->ops = &mxcmci_ops;
1038 
1039 	/* For devicetree parsing, the bus width is read from devicetree */
1040 	if (pdata)
1041 		mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
1042 	else
1043 		mmc->caps |= MMC_CAP_SDIO_IRQ;
1044 
1045 	/* MMC core transfer sizes tunable parameters */
1046 	mmc->max_blk_size = 2048;
1047 	mmc->max_blk_count = 65535;
1048 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
1049 	mmc->max_seg_size = mmc->max_req_size;
1050 
1051 	if (of_id) {
1052 		const struct platform_device_id *id_entry = of_id->data;
1053 		host->devtype = id_entry->driver_data;
1054 	} else {
1055 		host->devtype = pdev->id_entry->driver_data;
1056 	}
1057 
1058 	/* adjust max_segs after devtype detection */
1059 	if (!is_mpc512x_mmc(host))
1060 		mmc->max_segs = 64;
1061 
1062 	host->mmc = mmc;
1063 	host->pdata = pdata;
1064 	spin_lock_init(&host->lock);
1065 
1066 	if (pdata)
1067 		dat3_card_detect = pdata->dat3_card_detect;
1068 	else if (mmc_card_is_removable(mmc)
1069 			&& !of_property_read_bool(pdev->dev.of_node, "cd-gpios"))
1070 		dat3_card_detect = true;
1071 
1072 	ret = mmc_regulator_get_supply(mmc);
1073 	if (ret == -EPROBE_DEFER)
1074 		goto out_free;
1075 
1076 	if (!mmc->ocr_avail) {
1077 		if (pdata && pdata->ocr_avail)
1078 			mmc->ocr_avail = pdata->ocr_avail;
1079 		else
1080 			mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
1081 	}
1082 
1083 	if (dat3_card_detect)
1084 		host->default_irq_mask =
1085 			INT_CARD_INSERTION_EN | INT_CARD_REMOVAL_EN;
1086 	else
1087 		host->default_irq_mask = 0;
1088 
1089 	host->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1090 	if (IS_ERR(host->clk_ipg)) {
1091 		ret = PTR_ERR(host->clk_ipg);
1092 		goto out_free;
1093 	}
1094 
1095 	host->clk_per = devm_clk_get(&pdev->dev, "per");
1096 	if (IS_ERR(host->clk_per)) {
1097 		ret = PTR_ERR(host->clk_per);
1098 		goto out_free;
1099 	}
1100 
1101 	clk_prepare_enable(host->clk_per);
1102 	clk_prepare_enable(host->clk_ipg);
1103 
1104 	mxcmci_softreset(host);
1105 
1106 	host->rev_no = mxcmci_readw(host, MMC_REG_REV_NO);
1107 	if (host->rev_no != 0x400) {
1108 		ret = -ENODEV;
1109 		dev_err(mmc_dev(host->mmc), "wrong rev.no. 0x%08x. aborting.\n",
1110 			host->rev_no);
1111 		goto out_clk_put;
1112 	}
1113 
1114 	mmc->f_min = clk_get_rate(host->clk_per) >> 16;
1115 	mmc->f_max = clk_get_rate(host->clk_per) >> 1;
1116 
1117 	/* recommended in data sheet */
1118 	mxcmci_writew(host, 0x2db4, MMC_REG_READ_TO);
1119 
1120 	mxcmci_writel(host, host->default_irq_mask, MMC_REG_INT_CNTR);
1121 
1122 	if (!host->pdata) {
1123 		host->dma = dma_request_slave_channel(&pdev->dev, "rx-tx");
1124 	} else {
1125 		res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
1126 		if (res) {
1127 			host->dmareq = res->start;
1128 			host->dma_data.peripheral_type = IMX_DMATYPE_SDHC;
1129 			host->dma_data.priority = DMA_PRIO_LOW;
1130 			host->dma_data.dma_request = host->dmareq;
1131 			dma_cap_zero(mask);
1132 			dma_cap_set(DMA_SLAVE, mask);
1133 			host->dma = dma_request_channel(mask, filter, host);
1134 		}
1135 	}
1136 	if (host->dma)
1137 		mmc->max_seg_size = dma_get_max_seg_size(
1138 				host->dma->device->dev);
1139 	else
1140 		dev_info(mmc_dev(host->mmc), "dma not available. Using PIO\n");
1141 
1142 	INIT_WORK(&host->datawork, mxcmci_datawork);
1143 
1144 	ret = devm_request_irq(&pdev->dev, irq, mxcmci_irq, 0,
1145 			       dev_name(&pdev->dev), host);
1146 	if (ret)
1147 		goto out_free_dma;
1148 
1149 	platform_set_drvdata(pdev, mmc);
1150 
1151 	if (host->pdata && host->pdata->init) {
1152 		ret = host->pdata->init(&pdev->dev, mxcmci_detect_irq,
1153 				host->mmc);
1154 		if (ret)
1155 			goto out_free_dma;
1156 	}
1157 
1158 	init_timer(&host->watchdog);
1159 	host->watchdog.function = &mxcmci_watchdog;
1160 	host->watchdog.data = (unsigned long)mmc;
1161 
1162 	mmc_add_host(mmc);
1163 
1164 	return 0;
1165 
1166 out_free_dma:
1167 	if (host->dma)
1168 		dma_release_channel(host->dma);
1169 
1170 out_clk_put:
1171 	clk_disable_unprepare(host->clk_per);
1172 	clk_disable_unprepare(host->clk_ipg);
1173 
1174 out_free:
1175 	mmc_free_host(mmc);
1176 
1177 	return ret;
1178 }
1179 
1180 static int mxcmci_remove(struct platform_device *pdev)
1181 {
1182 	struct mmc_host *mmc = platform_get_drvdata(pdev);
1183 	struct mxcmci_host *host = mmc_priv(mmc);
1184 
1185 	mmc_remove_host(mmc);
1186 
1187 	if (host->pdata && host->pdata->exit)
1188 		host->pdata->exit(&pdev->dev, mmc);
1189 
1190 	if (host->dma)
1191 		dma_release_channel(host->dma);
1192 
1193 	clk_disable_unprepare(host->clk_per);
1194 	clk_disable_unprepare(host->clk_ipg);
1195 
1196 	mmc_free_host(mmc);
1197 
1198 	return 0;
1199 }
1200 
1201 static int __maybe_unused mxcmci_suspend(struct device *dev)
1202 {
1203 	struct mmc_host *mmc = dev_get_drvdata(dev);
1204 	struct mxcmci_host *host = mmc_priv(mmc);
1205 
1206 	clk_disable_unprepare(host->clk_per);
1207 	clk_disable_unprepare(host->clk_ipg);
1208 	return 0;
1209 }
1210 
1211 static int __maybe_unused mxcmci_resume(struct device *dev)
1212 {
1213 	struct mmc_host *mmc = dev_get_drvdata(dev);
1214 	struct mxcmci_host *host = mmc_priv(mmc);
1215 
1216 	clk_prepare_enable(host->clk_per);
1217 	clk_prepare_enable(host->clk_ipg);
1218 	return 0;
1219 }
1220 
1221 static SIMPLE_DEV_PM_OPS(mxcmci_pm_ops, mxcmci_suspend, mxcmci_resume);
1222 
1223 static struct platform_driver mxcmci_driver = {
1224 	.probe		= mxcmci_probe,
1225 	.remove		= mxcmci_remove,
1226 	.id_table	= mxcmci_devtype,
1227 	.driver		= {
1228 		.name		= DRIVER_NAME,
1229 		.pm	= &mxcmci_pm_ops,
1230 		.of_match_table	= mxcmci_of_match,
1231 	}
1232 };
1233 
1234 module_platform_driver(mxcmci_driver);
1235 
1236 MODULE_DESCRIPTION("i.MX Multimedia Card Interface Driver");
1237 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
1238 MODULE_LICENSE("GPL");
1239 MODULE_ALIAS("platform:mxc-mmc");
1240