xref: /linux/drivers/mmc/host/mxcmmc.c (revision 78c3925c048c752334873f56c3a3d1c9d53e0416)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/drivers/mmc/host/mxcmmc.c - Freescale i.MX MMCI driver
4  *
5  *  This is a driver for the SDHC controller found in Freescale MX2/MX3
6  *  SoCs. It is basically the same hardware as found on MX1 (imxmmc.c).
7  *  Unlike the hardware found on MX1, this hardware just works and does
8  *  not need all the quirks found in imxmmc.c, hence the separate driver.
9  *
10  *  Copyright (C) 2008 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
11  *  Copyright (C) 2006 Pavel Pisa, PiKRON <ppisa@pikron.com>
12  *
13  *  derived from pxamci.c by Russell King
14  */
15 
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/ioport.h>
19 #include <linux/platform_device.h>
20 #include <linux/highmem.h>
21 #include <linux/interrupt.h>
22 #include <linux/irq.h>
23 #include <linux/blkdev.h>
24 #include <linux/dma-mapping.h>
25 #include <linux/mmc/host.h>
26 #include <linux/mmc/card.h>
27 #include <linux/delay.h>
28 #include <linux/clk.h>
29 #include <linux/io.h>
30 #include <linux/regulator/consumer.h>
31 #include <linux/dmaengine.h>
32 #include <linux/types.h>
33 #include <linux/of.h>
34 #include <linux/of_dma.h>
35 #include <linux/mmc/slot-gpio.h>
36 
37 #include <asm/dma.h>
38 #include <asm/irq.h>
39 #include <linux/platform_data/mmc-mxcmmc.h>
40 
41 #include <linux/dma/imx-dma.h>
42 
43 #define DRIVER_NAME "mxc-mmc"
44 #define MXCMCI_TIMEOUT_MS 10000
45 
46 #define MMC_REG_STR_STP_CLK		0x00
47 #define MMC_REG_STATUS			0x04
48 #define MMC_REG_CLK_RATE		0x08
49 #define MMC_REG_CMD_DAT_CONT		0x0C
50 #define MMC_REG_RES_TO			0x10
51 #define MMC_REG_READ_TO			0x14
52 #define MMC_REG_BLK_LEN			0x18
53 #define MMC_REG_NOB			0x1C
54 #define MMC_REG_REV_NO			0x20
55 #define MMC_REG_INT_CNTR		0x24
56 #define MMC_REG_CMD			0x28
57 #define MMC_REG_ARG			0x2C
58 #define MMC_REG_RES_FIFO		0x34
59 #define MMC_REG_BUFFER_ACCESS		0x38
60 
61 #define STR_STP_CLK_RESET               (1 << 3)
62 #define STR_STP_CLK_START_CLK           (1 << 1)
63 #define STR_STP_CLK_STOP_CLK            (1 << 0)
64 
65 #define STATUS_CARD_INSERTION		(1 << 31)
66 #define STATUS_CARD_REMOVAL		(1 << 30)
67 #define STATUS_YBUF_EMPTY		(1 << 29)
68 #define STATUS_XBUF_EMPTY		(1 << 28)
69 #define STATUS_YBUF_FULL		(1 << 27)
70 #define STATUS_XBUF_FULL		(1 << 26)
71 #define STATUS_BUF_UND_RUN		(1 << 25)
72 #define STATUS_BUF_OVFL			(1 << 24)
73 #define STATUS_SDIO_INT_ACTIVE		(1 << 14)
74 #define STATUS_END_CMD_RESP		(1 << 13)
75 #define STATUS_WRITE_OP_DONE		(1 << 12)
76 #define STATUS_DATA_TRANS_DONE		(1 << 11)
77 #define STATUS_READ_OP_DONE		(1 << 11)
78 #define STATUS_WR_CRC_ERROR_CODE_MASK	(3 << 10)
79 #define STATUS_CARD_BUS_CLK_RUN		(1 << 8)
80 #define STATUS_BUF_READ_RDY		(1 << 7)
81 #define STATUS_BUF_WRITE_RDY		(1 << 6)
82 #define STATUS_RESP_CRC_ERR		(1 << 5)
83 #define STATUS_CRC_READ_ERR		(1 << 3)
84 #define STATUS_CRC_WRITE_ERR		(1 << 2)
85 #define STATUS_TIME_OUT_RESP		(1 << 1)
86 #define STATUS_TIME_OUT_READ		(1 << 0)
87 #define STATUS_ERR_MASK			0x2f
88 
89 #define CMD_DAT_CONT_CMD_RESP_LONG_OFF	(1 << 12)
90 #define CMD_DAT_CONT_STOP_READWAIT	(1 << 11)
91 #define CMD_DAT_CONT_START_READWAIT	(1 << 10)
92 #define CMD_DAT_CONT_BUS_WIDTH_4	(2 << 8)
93 #define CMD_DAT_CONT_INIT		(1 << 7)
94 #define CMD_DAT_CONT_WRITE		(1 << 4)
95 #define CMD_DAT_CONT_DATA_ENABLE	(1 << 3)
96 #define CMD_DAT_CONT_RESPONSE_48BIT_CRC	(1 << 0)
97 #define CMD_DAT_CONT_RESPONSE_136BIT	(2 << 0)
98 #define CMD_DAT_CONT_RESPONSE_48BIT	(3 << 0)
99 
100 #define INT_SDIO_INT_WKP_EN		(1 << 18)
101 #define INT_CARD_INSERTION_WKP_EN	(1 << 17)
102 #define INT_CARD_REMOVAL_WKP_EN		(1 << 16)
103 #define INT_CARD_INSERTION_EN		(1 << 15)
104 #define INT_CARD_REMOVAL_EN		(1 << 14)
105 #define INT_SDIO_IRQ_EN			(1 << 13)
106 #define INT_DAT0_EN			(1 << 12)
107 #define INT_BUF_READ_EN			(1 << 4)
108 #define INT_BUF_WRITE_EN		(1 << 3)
109 #define INT_END_CMD_RES_EN		(1 << 2)
110 #define INT_WRITE_OP_DONE_EN		(1 << 1)
111 #define INT_READ_OP_EN			(1 << 0)
112 
113 enum mxcmci_type {
114 	IMX21_MMC,
115 	IMX31_MMC,
116 	MPC512X_MMC,
117 };
118 
119 struct mxcmci_host {
120 	struct mmc_host		*mmc;
121 	void __iomem		*base;
122 	dma_addr_t		phys_base;
123 	int			detect_irq;
124 	struct dma_chan		*dma;
125 	struct dma_async_tx_descriptor *desc;
126 	int			do_dma;
127 	int			default_irq_mask;
128 	int			use_sdio;
129 	unsigned int		power_mode;
130 	struct imxmmc_platform_data *pdata;
131 
132 	struct mmc_request	*req;
133 	struct mmc_command	*cmd;
134 	struct mmc_data		*data;
135 
136 	unsigned int		datasize;
137 	unsigned int		dma_dir;
138 
139 	u16			rev_no;
140 	unsigned int		cmdat;
141 
142 	struct clk		*clk_ipg;
143 	struct clk		*clk_per;
144 
145 	int			clock;
146 
147 	struct work_struct	datawork;
148 	spinlock_t		lock;
149 
150 	int			burstlen;
151 	int			dmareq;
152 	struct dma_slave_config dma_slave_config;
153 	struct imx_dma_data	dma_data;
154 
155 	struct timer_list	watchdog;
156 	enum mxcmci_type	devtype;
157 };
158 
159 static const struct of_device_id mxcmci_of_match[] = {
160 	{
161 		.compatible = "fsl,imx21-mmc",
162 		.data = (void *) IMX21_MMC,
163 	}, {
164 		.compatible = "fsl,imx31-mmc",
165 		.data = (void *) IMX31_MMC,
166 	}, {
167 		.compatible = "fsl,mpc5121-sdhc",
168 		.data = (void *) MPC512X_MMC,
169 	}, {
170 		/* sentinel */
171 	}
172 };
173 MODULE_DEVICE_TABLE(of, mxcmci_of_match);
174 
175 static inline int is_imx31_mmc(struct mxcmci_host *host)
176 {
177 	return host->devtype == IMX31_MMC;
178 }
179 
180 static inline int is_mpc512x_mmc(struct mxcmci_host *host)
181 {
182 	return host->devtype == MPC512X_MMC;
183 }
184 
185 static inline u32 mxcmci_readl(struct mxcmci_host *host, int reg)
186 {
187 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
188 		return ioread32be(host->base + reg);
189 	else
190 		return readl(host->base + reg);
191 }
192 
193 static inline void mxcmci_writel(struct mxcmci_host *host, u32 val, int reg)
194 {
195 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
196 		iowrite32be(val, host->base + reg);
197 	else
198 		writel(val, host->base + reg);
199 }
200 
201 static inline u16 mxcmci_readw(struct mxcmci_host *host, int reg)
202 {
203 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
204 		return ioread32be(host->base + reg);
205 	else
206 		return readw(host->base + reg);
207 }
208 
209 static inline void mxcmci_writew(struct mxcmci_host *host, u16 val, int reg)
210 {
211 	if (IS_ENABLED(CONFIG_PPC_MPC512x))
212 		iowrite32be(val, host->base + reg);
213 	else
214 		writew(val, host->base + reg);
215 }
216 
217 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios);
218 
219 static void mxcmci_set_power(struct mxcmci_host *host, unsigned int vdd)
220 {
221 	if (!IS_ERR(host->mmc->supply.vmmc)) {
222 		if (host->power_mode == MMC_POWER_UP)
223 			mmc_regulator_set_ocr(host->mmc,
224 					      host->mmc->supply.vmmc, vdd);
225 		else if (host->power_mode == MMC_POWER_OFF)
226 			mmc_regulator_set_ocr(host->mmc,
227 					      host->mmc->supply.vmmc, 0);
228 	}
229 
230 	if (host->pdata && host->pdata->setpower)
231 		host->pdata->setpower(mmc_dev(host->mmc), vdd);
232 }
233 
234 static inline int mxcmci_use_dma(struct mxcmci_host *host)
235 {
236 	return host->do_dma;
237 }
238 
239 static void mxcmci_softreset(struct mxcmci_host *host)
240 {
241 	int i;
242 
243 	dev_dbg(mmc_dev(host->mmc), "mxcmci_softreset\n");
244 
245 	/* reset sequence */
246 	mxcmci_writew(host, STR_STP_CLK_RESET, MMC_REG_STR_STP_CLK);
247 	mxcmci_writew(host, STR_STP_CLK_RESET | STR_STP_CLK_START_CLK,
248 			MMC_REG_STR_STP_CLK);
249 
250 	for (i = 0; i < 8; i++)
251 		mxcmci_writew(host, STR_STP_CLK_START_CLK, MMC_REG_STR_STP_CLK);
252 
253 	mxcmci_writew(host, 0xff, MMC_REG_RES_TO);
254 }
255 
256 #if IS_ENABLED(CONFIG_PPC_MPC512x)
257 static inline void buffer_swap32(u32 *buf, int len)
258 {
259 	int i;
260 
261 	for (i = 0; i < ((len + 3) / 4); i++) {
262 		*buf = swab32(*buf);
263 		buf++;
264 	}
265 }
266 
267 static void mxcmci_swap_buffers(struct mmc_data *data)
268 {
269 	struct sg_mapping_iter sgm;
270 	u32 *buf;
271 
272 	sg_miter_start(&sgm, data->sg, data->sg_len,
273 		       SG_MITER_TO_SG | SG_MITER_FROM_SG);
274 
275 	while (sg_miter_next(&sgm)) {
276 		buf = sgm.addr;
277 		buffer_swap32(buf, sgm.length);
278 	}
279 
280 	sg_miter_stop(&sgm);
281 }
282 #else
283 static inline void mxcmci_swap_buffers(struct mmc_data *data) {}
284 #endif
285 
286 static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
287 {
288 	unsigned int nob = data->blocks;
289 	unsigned int blksz = data->blksz;
290 	unsigned int datasize = nob * blksz;
291 	struct scatterlist *sg;
292 	enum dma_transfer_direction slave_dirn;
293 	int i, nents;
294 
295 	host->data = data;
296 	data->bytes_xfered = 0;
297 
298 	mxcmci_writew(host, nob, MMC_REG_NOB);
299 	mxcmci_writew(host, blksz, MMC_REG_BLK_LEN);
300 	host->datasize = datasize;
301 
302 	if (!mxcmci_use_dma(host))
303 		return 0;
304 
305 	for_each_sg(data->sg, sg, data->sg_len, i) {
306 		if (sg->offset & 3 || sg->length & 3 || sg->length < 512) {
307 			host->do_dma = 0;
308 			return 0;
309 		}
310 	}
311 
312 	if (data->flags & MMC_DATA_READ) {
313 		host->dma_dir = DMA_FROM_DEVICE;
314 		slave_dirn = DMA_DEV_TO_MEM;
315 	} else {
316 		host->dma_dir = DMA_TO_DEVICE;
317 		slave_dirn = DMA_MEM_TO_DEV;
318 
319 		mxcmci_swap_buffers(data);
320 	}
321 
322 	nents = dma_map_sg(host->dma->device->dev, data->sg,
323 				     data->sg_len,  host->dma_dir);
324 	if (nents != data->sg_len)
325 		return -EINVAL;
326 
327 	host->desc = dmaengine_prep_slave_sg(host->dma,
328 		data->sg, data->sg_len, slave_dirn,
329 		DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
330 
331 	if (!host->desc) {
332 		dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
333 				host->dma_dir);
334 		host->do_dma = 0;
335 		return 0; /* Fall back to PIO */
336 	}
337 	wmb();
338 
339 	dmaengine_submit(host->desc);
340 	dma_async_issue_pending(host->dma);
341 
342 	mod_timer(&host->watchdog, jiffies + msecs_to_jiffies(MXCMCI_TIMEOUT_MS));
343 
344 	return 0;
345 }
346 
347 static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat);
348 static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat);
349 
350 static void mxcmci_dma_callback(void *data)
351 {
352 	struct mxcmci_host *host = data;
353 	u32 stat;
354 
355 	del_timer(&host->watchdog);
356 
357 	stat = mxcmci_readl(host, MMC_REG_STATUS);
358 
359 	dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
360 
361 	mxcmci_data_done(host, stat);
362 }
363 
364 static int mxcmci_start_cmd(struct mxcmci_host *host, struct mmc_command *cmd,
365 		unsigned int cmdat)
366 {
367 	u32 int_cntr = host->default_irq_mask;
368 	unsigned long flags;
369 
370 	WARN_ON(host->cmd != NULL);
371 	host->cmd = cmd;
372 
373 	switch (mmc_resp_type(cmd)) {
374 	case MMC_RSP_R1: /* short CRC, OPCODE */
375 	case MMC_RSP_R1B:/* short CRC, OPCODE, BUSY */
376 		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT_CRC;
377 		break;
378 	case MMC_RSP_R2: /* long 136 bit + CRC */
379 		cmdat |= CMD_DAT_CONT_RESPONSE_136BIT;
380 		break;
381 	case MMC_RSP_R3: /* short */
382 		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT;
383 		break;
384 	case MMC_RSP_NONE:
385 		break;
386 	default:
387 		dev_err(mmc_dev(host->mmc), "unhandled response type 0x%x\n",
388 				mmc_resp_type(cmd));
389 		cmd->error = -EINVAL;
390 		return -EINVAL;
391 	}
392 
393 	int_cntr = INT_END_CMD_RES_EN;
394 
395 	if (mxcmci_use_dma(host)) {
396 		if (host->dma_dir == DMA_FROM_DEVICE) {
397 			host->desc->callback = mxcmci_dma_callback;
398 			host->desc->callback_param = host;
399 		} else {
400 			int_cntr |= INT_WRITE_OP_DONE_EN;
401 		}
402 	}
403 
404 	spin_lock_irqsave(&host->lock, flags);
405 	if (host->use_sdio)
406 		int_cntr |= INT_SDIO_IRQ_EN;
407 	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
408 	spin_unlock_irqrestore(&host->lock, flags);
409 
410 	mxcmci_writew(host, cmd->opcode, MMC_REG_CMD);
411 	mxcmci_writel(host, cmd->arg, MMC_REG_ARG);
412 	mxcmci_writew(host, cmdat, MMC_REG_CMD_DAT_CONT);
413 
414 	return 0;
415 }
416 
417 static void mxcmci_finish_request(struct mxcmci_host *host,
418 		struct mmc_request *req)
419 {
420 	u32 int_cntr = host->default_irq_mask;
421 	unsigned long flags;
422 
423 	spin_lock_irqsave(&host->lock, flags);
424 	if (host->use_sdio)
425 		int_cntr |= INT_SDIO_IRQ_EN;
426 	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
427 	spin_unlock_irqrestore(&host->lock, flags);
428 
429 	host->req = NULL;
430 	host->cmd = NULL;
431 	host->data = NULL;
432 
433 	mmc_request_done(host->mmc, req);
434 }
435 
436 static int mxcmci_finish_data(struct mxcmci_host *host, unsigned int stat)
437 {
438 	struct mmc_data *data = host->data;
439 	int data_error;
440 
441 	if (mxcmci_use_dma(host)) {
442 		dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
443 				host->dma_dir);
444 		mxcmci_swap_buffers(data);
445 	}
446 
447 	if (stat & STATUS_ERR_MASK) {
448 		dev_dbg(mmc_dev(host->mmc), "request failed. status: 0x%08x\n",
449 				stat);
450 		if (stat & STATUS_CRC_READ_ERR) {
451 			dev_err(mmc_dev(host->mmc), "%s: -EILSEQ\n", __func__);
452 			data->error = -EILSEQ;
453 		} else if (stat & STATUS_CRC_WRITE_ERR) {
454 			u32 err_code = (stat >> 9) & 0x3;
455 			if (err_code == 2) { /* No CRC response */
456 				dev_err(mmc_dev(host->mmc),
457 					"%s: No CRC -ETIMEDOUT\n", __func__);
458 				data->error = -ETIMEDOUT;
459 			} else {
460 				dev_err(mmc_dev(host->mmc),
461 					"%s: -EILSEQ\n", __func__);
462 				data->error = -EILSEQ;
463 			}
464 		} else if (stat & STATUS_TIME_OUT_READ) {
465 			dev_err(mmc_dev(host->mmc),
466 				"%s: read -ETIMEDOUT\n", __func__);
467 			data->error = -ETIMEDOUT;
468 		} else {
469 			dev_err(mmc_dev(host->mmc), "%s: -EIO\n", __func__);
470 			data->error = -EIO;
471 		}
472 	} else {
473 		data->bytes_xfered = host->datasize;
474 	}
475 
476 	data_error = data->error;
477 
478 	host->data = NULL;
479 
480 	return data_error;
481 }
482 
483 static void mxcmci_read_response(struct mxcmci_host *host, unsigned int stat)
484 {
485 	struct mmc_command *cmd = host->cmd;
486 	int i;
487 	u32 a, b, c;
488 
489 	if (!cmd)
490 		return;
491 
492 	if (stat & STATUS_TIME_OUT_RESP) {
493 		dev_dbg(mmc_dev(host->mmc), "CMD TIMEOUT\n");
494 		cmd->error = -ETIMEDOUT;
495 	} else if (stat & STATUS_RESP_CRC_ERR && cmd->flags & MMC_RSP_CRC) {
496 		dev_dbg(mmc_dev(host->mmc), "cmd crc error\n");
497 		cmd->error = -EILSEQ;
498 	}
499 
500 	if (cmd->flags & MMC_RSP_PRESENT) {
501 		if (cmd->flags & MMC_RSP_136) {
502 			for (i = 0; i < 4; i++) {
503 				a = mxcmci_readw(host, MMC_REG_RES_FIFO);
504 				b = mxcmci_readw(host, MMC_REG_RES_FIFO);
505 				cmd->resp[i] = a << 16 | b;
506 			}
507 		} else {
508 			a = mxcmci_readw(host, MMC_REG_RES_FIFO);
509 			b = mxcmci_readw(host, MMC_REG_RES_FIFO);
510 			c = mxcmci_readw(host, MMC_REG_RES_FIFO);
511 			cmd->resp[0] = a << 24 | b << 8 | c >> 8;
512 		}
513 	}
514 }
515 
516 static int mxcmci_poll_status(struct mxcmci_host *host, u32 mask)
517 {
518 	u32 stat;
519 	unsigned long timeout = jiffies + HZ;
520 
521 	do {
522 		stat = mxcmci_readl(host, MMC_REG_STATUS);
523 		if (stat & STATUS_ERR_MASK)
524 			return stat;
525 		if (time_after(jiffies, timeout)) {
526 			mxcmci_softreset(host);
527 			mxcmci_set_clk_rate(host, host->clock);
528 			return STATUS_TIME_OUT_READ;
529 		}
530 		if (stat & mask)
531 			return 0;
532 		cpu_relax();
533 	} while (1);
534 }
535 
536 static int mxcmci_pull(struct mxcmci_host *host, u32 *buf, int bytes)
537 {
538 	unsigned int stat;
539 
540 	while (bytes > 3) {
541 		stat = mxcmci_poll_status(host,
542 				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
543 		if (stat)
544 			return stat;
545 		*buf++ = cpu_to_le32(mxcmci_readl(host, MMC_REG_BUFFER_ACCESS));
546 		bytes -= 4;
547 	}
548 
549 	if (bytes) {
550 		u8 *b = (u8 *)buf;
551 		u32 tmp;
552 
553 		stat = mxcmci_poll_status(host,
554 				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
555 		if (stat)
556 			return stat;
557 		tmp = cpu_to_le32(mxcmci_readl(host, MMC_REG_BUFFER_ACCESS));
558 		memcpy(b, &tmp, bytes);
559 	}
560 
561 	return 0;
562 }
563 
564 static int mxcmci_push(struct mxcmci_host *host, u32 *buf, int bytes)
565 {
566 	unsigned int stat;
567 
568 	while (bytes > 3) {
569 		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
570 		if (stat)
571 			return stat;
572 		mxcmci_writel(host, cpu_to_le32(*buf++), MMC_REG_BUFFER_ACCESS);
573 		bytes -= 4;
574 	}
575 
576 	if (bytes) {
577 		u8 *b = (u8 *)buf;
578 		u32 tmp;
579 
580 		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
581 		if (stat)
582 			return stat;
583 
584 		memcpy(&tmp, b, bytes);
585 		mxcmci_writel(host, cpu_to_le32(tmp), MMC_REG_BUFFER_ACCESS);
586 	}
587 
588 	return mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
589 }
590 
591 static int mxcmci_transfer_data(struct mxcmci_host *host)
592 {
593 	struct mmc_data *data = host->req->data;
594 	struct sg_mapping_iter sgm;
595 	int stat;
596 	u32 *buf;
597 
598 	host->data = data;
599 	host->datasize = 0;
600 	sg_miter_start(&sgm, data->sg, data->sg_len,
601 		       (data->flags & MMC_DATA_READ) ? SG_MITER_TO_SG : SG_MITER_FROM_SG);
602 
603 	if (data->flags & MMC_DATA_READ) {
604 		while (sg_miter_next(&sgm)) {
605 			buf = sgm.addr;
606 			stat = mxcmci_pull(host, buf, sgm.length);
607 			if (stat)
608 				goto transfer_error;
609 			host->datasize += sgm.length;
610 		}
611 	} else {
612 		while (sg_miter_next(&sgm)) {
613 			buf = sgm.addr;
614 			stat = mxcmci_push(host, buf, sgm.length);
615 			if (stat)
616 				goto transfer_error;
617 			host->datasize += sgm.length;
618 		}
619 		stat = mxcmci_poll_status(host, STATUS_WRITE_OP_DONE);
620 		if (stat)
621 			goto transfer_error;
622 	}
623 
624 transfer_error:
625 	sg_miter_stop(&sgm);
626 	return stat;
627 }
628 
629 static void mxcmci_datawork(struct work_struct *work)
630 {
631 	struct mxcmci_host *host = container_of(work, struct mxcmci_host,
632 						  datawork);
633 	int datastat = mxcmci_transfer_data(host);
634 
635 	mxcmci_writel(host, STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
636 		MMC_REG_STATUS);
637 	mxcmci_finish_data(host, datastat);
638 
639 	if (host->req->stop) {
640 		if (mxcmci_start_cmd(host, host->req->stop, 0)) {
641 			mxcmci_finish_request(host, host->req);
642 			return;
643 		}
644 	} else {
645 		mxcmci_finish_request(host, host->req);
646 	}
647 }
648 
649 static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat)
650 {
651 	struct mmc_request *req;
652 	int data_error;
653 	unsigned long flags;
654 
655 	spin_lock_irqsave(&host->lock, flags);
656 
657 	if (!host->data) {
658 		spin_unlock_irqrestore(&host->lock, flags);
659 		return;
660 	}
661 
662 	if (!host->req) {
663 		spin_unlock_irqrestore(&host->lock, flags);
664 		return;
665 	}
666 
667 	req = host->req;
668 	if (!req->stop)
669 		host->req = NULL; /* we will handle finish req below */
670 
671 	data_error = mxcmci_finish_data(host, stat);
672 
673 	spin_unlock_irqrestore(&host->lock, flags);
674 
675 	if (data_error)
676 		return;
677 
678 	mxcmci_read_response(host, stat);
679 	host->cmd = NULL;
680 
681 	if (req->stop) {
682 		if (mxcmci_start_cmd(host, req->stop, 0)) {
683 			mxcmci_finish_request(host, req);
684 			return;
685 		}
686 	} else {
687 		mxcmci_finish_request(host, req);
688 	}
689 }
690 
691 static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat)
692 {
693 	mxcmci_read_response(host, stat);
694 	host->cmd = NULL;
695 
696 	if (!host->data && host->req) {
697 		mxcmci_finish_request(host, host->req);
698 		return;
699 	}
700 
701 	/* For the DMA case the DMA engine handles the data transfer
702 	 * automatically. For non DMA we have to do it ourselves.
703 	 * Don't do it in interrupt context though.
704 	 */
705 	if (!mxcmci_use_dma(host) && host->data)
706 		schedule_work(&host->datawork);
707 
708 }
709 
710 static irqreturn_t mxcmci_irq(int irq, void *devid)
711 {
712 	struct mxcmci_host *host = devid;
713 	bool sdio_irq;
714 	u32 stat;
715 
716 	stat = mxcmci_readl(host, MMC_REG_STATUS);
717 	mxcmci_writel(host,
718 		stat & ~(STATUS_SDIO_INT_ACTIVE | STATUS_DATA_TRANS_DONE |
719 			 STATUS_WRITE_OP_DONE),
720 		MMC_REG_STATUS);
721 
722 	dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
723 
724 	spin_lock(&host->lock);
725 	sdio_irq = (stat & STATUS_SDIO_INT_ACTIVE) && host->use_sdio;
726 	spin_unlock(&host->lock);
727 
728 	if (mxcmci_use_dma(host) && (stat & (STATUS_WRITE_OP_DONE)))
729 		mxcmci_writel(host, STATUS_WRITE_OP_DONE, MMC_REG_STATUS);
730 
731 	if (sdio_irq) {
732 		mxcmci_writel(host, STATUS_SDIO_INT_ACTIVE, MMC_REG_STATUS);
733 		mmc_signal_sdio_irq(host->mmc);
734 	}
735 
736 	if (stat & STATUS_END_CMD_RESP)
737 		mxcmci_cmd_done(host, stat);
738 
739 	if (mxcmci_use_dma(host) && (stat & STATUS_WRITE_OP_DONE)) {
740 		del_timer(&host->watchdog);
741 		mxcmci_data_done(host, stat);
742 	}
743 
744 	if (host->default_irq_mask &&
745 		  (stat & (STATUS_CARD_INSERTION | STATUS_CARD_REMOVAL)))
746 		mmc_detect_change(host->mmc, msecs_to_jiffies(200));
747 
748 	return IRQ_HANDLED;
749 }
750 
751 static void mxcmci_request(struct mmc_host *mmc, struct mmc_request *req)
752 {
753 	struct mxcmci_host *host = mmc_priv(mmc);
754 	unsigned int cmdat = host->cmdat;
755 	int error;
756 
757 	WARN_ON(host->req != NULL);
758 
759 	host->req = req;
760 	host->cmdat &= ~CMD_DAT_CONT_INIT;
761 
762 	if (host->dma)
763 		host->do_dma = 1;
764 
765 	if (req->data) {
766 		error = mxcmci_setup_data(host, req->data);
767 		if (error) {
768 			req->cmd->error = error;
769 			goto out;
770 		}
771 
772 
773 		cmdat |= CMD_DAT_CONT_DATA_ENABLE;
774 
775 		if (req->data->flags & MMC_DATA_WRITE)
776 			cmdat |= CMD_DAT_CONT_WRITE;
777 	}
778 
779 	error = mxcmci_start_cmd(host, req->cmd, cmdat);
780 
781 out:
782 	if (error)
783 		mxcmci_finish_request(host, req);
784 }
785 
786 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios)
787 {
788 	unsigned int divider;
789 	int prescaler = 0;
790 	unsigned int clk_in = clk_get_rate(host->clk_per);
791 
792 	while (prescaler <= 0x800) {
793 		for (divider = 1; divider <= 0xF; divider++) {
794 			int x;
795 
796 			x = (clk_in / (divider + 1));
797 
798 			if (prescaler)
799 				x /= (prescaler * 2);
800 
801 			if (x <= clk_ios)
802 				break;
803 		}
804 		if (divider < 0x10)
805 			break;
806 
807 		if (prescaler == 0)
808 			prescaler = 1;
809 		else
810 			prescaler <<= 1;
811 	}
812 
813 	mxcmci_writew(host, (prescaler << 4) | divider, MMC_REG_CLK_RATE);
814 
815 	dev_dbg(mmc_dev(host->mmc), "scaler: %d divider: %d in: %d out: %d\n",
816 			prescaler, divider, clk_in, clk_ios);
817 }
818 
819 static int mxcmci_setup_dma(struct mmc_host *mmc)
820 {
821 	struct mxcmci_host *host = mmc_priv(mmc);
822 	struct dma_slave_config *config = &host->dma_slave_config;
823 
824 	config->dst_addr = host->phys_base + MMC_REG_BUFFER_ACCESS;
825 	config->src_addr = host->phys_base + MMC_REG_BUFFER_ACCESS;
826 	config->dst_addr_width = 4;
827 	config->src_addr_width = 4;
828 	config->dst_maxburst = host->burstlen;
829 	config->src_maxburst = host->burstlen;
830 	config->device_fc = false;
831 
832 	return dmaengine_slave_config(host->dma, config);
833 }
834 
835 static void mxcmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
836 {
837 	struct mxcmci_host *host = mmc_priv(mmc);
838 	int burstlen, ret;
839 
840 	/*
841 	 * use burstlen of 64 (16 words) in 4 bit mode (--> reg value  0)
842 	 * use burstlen of 16 (4 words) in 1 bit mode (--> reg value 16)
843 	 */
844 	if (ios->bus_width == MMC_BUS_WIDTH_4)
845 		burstlen = 16;
846 	else
847 		burstlen = 4;
848 
849 	if (mxcmci_use_dma(host) && burstlen != host->burstlen) {
850 		host->burstlen = burstlen;
851 		ret = mxcmci_setup_dma(mmc);
852 		if (ret) {
853 			dev_err(mmc_dev(host->mmc),
854 				"failed to config DMA channel. Falling back to PIO\n");
855 			dma_release_channel(host->dma);
856 			host->do_dma = 0;
857 			host->dma = NULL;
858 		}
859 	}
860 
861 	if (ios->bus_width == MMC_BUS_WIDTH_4)
862 		host->cmdat |= CMD_DAT_CONT_BUS_WIDTH_4;
863 	else
864 		host->cmdat &= ~CMD_DAT_CONT_BUS_WIDTH_4;
865 
866 	if (host->power_mode != ios->power_mode) {
867 		host->power_mode = ios->power_mode;
868 		mxcmci_set_power(host, ios->vdd);
869 
870 		if (ios->power_mode == MMC_POWER_ON)
871 			host->cmdat |= CMD_DAT_CONT_INIT;
872 	}
873 
874 	if (ios->clock) {
875 		mxcmci_set_clk_rate(host, ios->clock);
876 		mxcmci_writew(host, STR_STP_CLK_START_CLK, MMC_REG_STR_STP_CLK);
877 	} else {
878 		mxcmci_writew(host, STR_STP_CLK_STOP_CLK, MMC_REG_STR_STP_CLK);
879 	}
880 
881 	host->clock = ios->clock;
882 }
883 
884 static irqreturn_t mxcmci_detect_irq(int irq, void *data)
885 {
886 	struct mmc_host *mmc = data;
887 
888 	dev_dbg(mmc_dev(mmc), "%s\n", __func__);
889 
890 	mmc_detect_change(mmc, msecs_to_jiffies(250));
891 	return IRQ_HANDLED;
892 }
893 
894 static int mxcmci_get_ro(struct mmc_host *mmc)
895 {
896 	struct mxcmci_host *host = mmc_priv(mmc);
897 
898 	if (host->pdata && host->pdata->get_ro)
899 		return !!host->pdata->get_ro(mmc_dev(mmc));
900 	/*
901 	 * If board doesn't support read only detection (no mmc_gpio
902 	 * context or gpio is invalid), then let the mmc core decide
903 	 * what to do.
904 	 */
905 	return mmc_gpio_get_ro(mmc);
906 }
907 
908 static void mxcmci_enable_sdio_irq(struct mmc_host *mmc, int enable)
909 {
910 	struct mxcmci_host *host = mmc_priv(mmc);
911 	unsigned long flags;
912 	u32 int_cntr;
913 
914 	spin_lock_irqsave(&host->lock, flags);
915 	host->use_sdio = enable;
916 	int_cntr = mxcmci_readl(host, MMC_REG_INT_CNTR);
917 
918 	if (enable)
919 		int_cntr |= INT_SDIO_IRQ_EN;
920 	else
921 		int_cntr &= ~INT_SDIO_IRQ_EN;
922 
923 	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
924 	spin_unlock_irqrestore(&host->lock, flags);
925 }
926 
927 static void mxcmci_init_card(struct mmc_host *host, struct mmc_card *card)
928 {
929 	struct mxcmci_host *mxcmci = mmc_priv(host);
930 
931 	/*
932 	 * MX3 SoCs have a silicon bug which corrupts CRC calculation of
933 	 * multi-block transfers when connected SDIO peripheral doesn't
934 	 * drive the BUSY line as required by the specs.
935 	 * One way to prevent this is to only allow 1-bit transfers.
936 	 */
937 
938 	if (is_imx31_mmc(mxcmci) && mmc_card_sdio(card))
939 		host->caps &= ~MMC_CAP_4_BIT_DATA;
940 	else
941 		host->caps |= MMC_CAP_4_BIT_DATA;
942 }
943 
944 static bool filter(struct dma_chan *chan, void *param)
945 {
946 	struct mxcmci_host *host = param;
947 
948 	if (!imx_dma_is_general_purpose(chan))
949 		return false;
950 
951 	chan->private = &host->dma_data;
952 
953 	return true;
954 }
955 
956 static void mxcmci_watchdog(struct timer_list *t)
957 {
958 	struct mxcmci_host *host = from_timer(host, t, watchdog);
959 	struct mmc_request *req = host->req;
960 	unsigned int stat = mxcmci_readl(host, MMC_REG_STATUS);
961 
962 	if (host->dma_dir == DMA_FROM_DEVICE) {
963 		dmaengine_terminate_all(host->dma);
964 		dev_err(mmc_dev(host->mmc),
965 			"%s: read time out (status = 0x%08x)\n",
966 			__func__, stat);
967 	} else {
968 		dev_err(mmc_dev(host->mmc),
969 			"%s: write time out (status = 0x%08x)\n",
970 			__func__, stat);
971 		mxcmci_softreset(host);
972 	}
973 
974 	/* Mark transfer as erroneus and inform the upper layers */
975 
976 	if (host->data)
977 		host->data->error = -ETIMEDOUT;
978 	host->req = NULL;
979 	host->cmd = NULL;
980 	host->data = NULL;
981 	mmc_request_done(host->mmc, req);
982 }
983 
984 static const struct mmc_host_ops mxcmci_ops = {
985 	.request		= mxcmci_request,
986 	.set_ios		= mxcmci_set_ios,
987 	.get_ro			= mxcmci_get_ro,
988 	.enable_sdio_irq	= mxcmci_enable_sdio_irq,
989 	.init_card		= mxcmci_init_card,
990 };
991 
992 static int mxcmci_probe(struct platform_device *pdev)
993 {
994 	struct mmc_host *mmc;
995 	struct mxcmci_host *host;
996 	struct resource *res;
997 	int ret = 0, irq;
998 	bool dat3_card_detect = false;
999 	dma_cap_mask_t mask;
1000 	struct imxmmc_platform_data *pdata = pdev->dev.platform_data;
1001 
1002 	pr_info("i.MX/MPC512x SDHC driver\n");
1003 
1004 	irq = platform_get_irq(pdev, 0);
1005 	if (irq < 0)
1006 		return irq;
1007 
1008 	mmc = mmc_alloc_host(sizeof(*host), &pdev->dev);
1009 	if (!mmc)
1010 		return -ENOMEM;
1011 
1012 	host = mmc_priv(mmc);
1013 
1014 	host->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
1015 	if (IS_ERR(host->base)) {
1016 		ret = PTR_ERR(host->base);
1017 		goto out_free;
1018 	}
1019 
1020 	host->phys_base = res->start;
1021 
1022 	ret = mmc_of_parse(mmc);
1023 	if (ret)
1024 		goto out_free;
1025 	mmc->ops = &mxcmci_ops;
1026 
1027 	/* For devicetree parsing, the bus width is read from devicetree */
1028 	if (pdata)
1029 		mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
1030 	else
1031 		mmc->caps |= MMC_CAP_SDIO_IRQ;
1032 
1033 	/* MMC core transfer sizes tunable parameters */
1034 	mmc->max_blk_size = 2048;
1035 	mmc->max_blk_count = 65535;
1036 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
1037 	mmc->max_seg_size = mmc->max_req_size;
1038 
1039 	host->devtype = (uintptr_t)of_device_get_match_data(&pdev->dev);
1040 
1041 	/* adjust max_segs after devtype detection */
1042 	if (!is_mpc512x_mmc(host))
1043 		mmc->max_segs = 64;
1044 
1045 	host->mmc = mmc;
1046 	host->pdata = pdata;
1047 	spin_lock_init(&host->lock);
1048 
1049 	if (pdata)
1050 		dat3_card_detect = pdata->dat3_card_detect;
1051 	else if (mmc_card_is_removable(mmc)
1052 			&& !of_property_read_bool(pdev->dev.of_node, "cd-gpios"))
1053 		dat3_card_detect = true;
1054 
1055 	ret = mmc_regulator_get_supply(mmc);
1056 	if (ret)
1057 		goto out_free;
1058 
1059 	if (!mmc->ocr_avail) {
1060 		if (pdata && pdata->ocr_avail)
1061 			mmc->ocr_avail = pdata->ocr_avail;
1062 		else
1063 			mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
1064 	}
1065 
1066 	if (dat3_card_detect)
1067 		host->default_irq_mask =
1068 			INT_CARD_INSERTION_EN | INT_CARD_REMOVAL_EN;
1069 	else
1070 		host->default_irq_mask = 0;
1071 
1072 	host->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1073 	if (IS_ERR(host->clk_ipg)) {
1074 		ret = PTR_ERR(host->clk_ipg);
1075 		goto out_free;
1076 	}
1077 
1078 	host->clk_per = devm_clk_get(&pdev->dev, "per");
1079 	if (IS_ERR(host->clk_per)) {
1080 		ret = PTR_ERR(host->clk_per);
1081 		goto out_free;
1082 	}
1083 
1084 	ret = clk_prepare_enable(host->clk_per);
1085 	if (ret)
1086 		goto out_free;
1087 
1088 	ret = clk_prepare_enable(host->clk_ipg);
1089 	if (ret)
1090 		goto out_clk_per_put;
1091 
1092 	mxcmci_softreset(host);
1093 
1094 	host->rev_no = mxcmci_readw(host, MMC_REG_REV_NO);
1095 	if (host->rev_no != 0x400) {
1096 		ret = -ENODEV;
1097 		dev_err(mmc_dev(host->mmc), "wrong rev.no. 0x%08x. aborting.\n",
1098 			host->rev_no);
1099 		goto out_clk_put;
1100 	}
1101 
1102 	mmc->f_min = clk_get_rate(host->clk_per) >> 16;
1103 	mmc->f_max = clk_get_rate(host->clk_per) >> 1;
1104 
1105 	/* recommended in data sheet */
1106 	mxcmci_writew(host, 0x2db4, MMC_REG_READ_TO);
1107 
1108 	mxcmci_writel(host, host->default_irq_mask, MMC_REG_INT_CNTR);
1109 
1110 	if (!host->pdata) {
1111 		host->dma = dma_request_chan(&pdev->dev, "rx-tx");
1112 		if (IS_ERR(host->dma)) {
1113 			if (PTR_ERR(host->dma) == -EPROBE_DEFER) {
1114 				ret = -EPROBE_DEFER;
1115 				goto out_clk_put;
1116 			}
1117 
1118 			/* Ignore errors to fall back to PIO mode */
1119 			host->dma = NULL;
1120 		}
1121 	} else {
1122 		res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
1123 		if (res) {
1124 			host->dmareq = res->start;
1125 			host->dma_data.peripheral_type = IMX_DMATYPE_SDHC;
1126 			host->dma_data.priority = DMA_PRIO_LOW;
1127 			host->dma_data.dma_request = host->dmareq;
1128 			dma_cap_zero(mask);
1129 			dma_cap_set(DMA_SLAVE, mask);
1130 			host->dma = dma_request_channel(mask, filter, host);
1131 		}
1132 	}
1133 	if (host->dma)
1134 		mmc->max_seg_size = dma_get_max_seg_size(
1135 				host->dma->device->dev);
1136 	else
1137 		dev_info(mmc_dev(host->mmc), "dma not available. Using PIO\n");
1138 
1139 	INIT_WORK(&host->datawork, mxcmci_datawork);
1140 
1141 	ret = devm_request_irq(&pdev->dev, irq, mxcmci_irq, 0,
1142 			       dev_name(&pdev->dev), host);
1143 	if (ret)
1144 		goto out_free_dma;
1145 
1146 	platform_set_drvdata(pdev, mmc);
1147 
1148 	if (host->pdata && host->pdata->init) {
1149 		ret = host->pdata->init(&pdev->dev, mxcmci_detect_irq,
1150 				host->mmc);
1151 		if (ret)
1152 			goto out_free_dma;
1153 	}
1154 
1155 	timer_setup(&host->watchdog, mxcmci_watchdog, 0);
1156 
1157 	ret = mmc_add_host(mmc);
1158 	if (ret)
1159 		goto out_free_dma;
1160 
1161 	return 0;
1162 
1163 out_free_dma:
1164 	if (host->dma)
1165 		dma_release_channel(host->dma);
1166 
1167 out_clk_put:
1168 	clk_disable_unprepare(host->clk_ipg);
1169 out_clk_per_put:
1170 	clk_disable_unprepare(host->clk_per);
1171 
1172 out_free:
1173 	mmc_free_host(mmc);
1174 
1175 	return ret;
1176 }
1177 
1178 static void mxcmci_remove(struct platform_device *pdev)
1179 {
1180 	struct mmc_host *mmc = platform_get_drvdata(pdev);
1181 	struct mxcmci_host *host = mmc_priv(mmc);
1182 
1183 	mmc_remove_host(mmc);
1184 
1185 	if (host->pdata && host->pdata->exit)
1186 		host->pdata->exit(&pdev->dev, mmc);
1187 
1188 	if (host->dma)
1189 		dma_release_channel(host->dma);
1190 
1191 	clk_disable_unprepare(host->clk_per);
1192 	clk_disable_unprepare(host->clk_ipg);
1193 
1194 	mmc_free_host(mmc);
1195 }
1196 
1197 static int mxcmci_suspend(struct device *dev)
1198 {
1199 	struct mmc_host *mmc = dev_get_drvdata(dev);
1200 	struct mxcmci_host *host = mmc_priv(mmc);
1201 
1202 	clk_disable_unprepare(host->clk_per);
1203 	clk_disable_unprepare(host->clk_ipg);
1204 	return 0;
1205 }
1206 
1207 static int mxcmci_resume(struct device *dev)
1208 {
1209 	struct mmc_host *mmc = dev_get_drvdata(dev);
1210 	struct mxcmci_host *host = mmc_priv(mmc);
1211 	int ret;
1212 
1213 	ret = clk_prepare_enable(host->clk_per);
1214 	if (ret)
1215 		return ret;
1216 
1217 	ret = clk_prepare_enable(host->clk_ipg);
1218 	if (ret)
1219 		clk_disable_unprepare(host->clk_per);
1220 
1221 	return ret;
1222 }
1223 
1224 static DEFINE_SIMPLE_DEV_PM_OPS(mxcmci_pm_ops, mxcmci_suspend, mxcmci_resume);
1225 
1226 static struct platform_driver mxcmci_driver = {
1227 	.probe		= mxcmci_probe,
1228 	.remove_new	= mxcmci_remove,
1229 	.driver		= {
1230 		.name		= DRIVER_NAME,
1231 		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
1232 		.pm	= pm_sleep_ptr(&mxcmci_pm_ops),
1233 		.of_match_table	= mxcmci_of_match,
1234 	}
1235 };
1236 
1237 module_platform_driver(mxcmci_driver);
1238 
1239 MODULE_DESCRIPTION("i.MX Multimedia Card Interface Driver");
1240 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
1241 MODULE_LICENSE("GPL");
1242 MODULE_ALIAS("platform:mxc-mmc");
1243