xref: /openbmc/linux/drivers/mmc/host/pxamci.c (revision 8b036556)
1 /*
2  *  linux/drivers/mmc/host/pxa.c - PXA MMCI driver
3  *
4  *  Copyright (C) 2003 Russell King, All Rights Reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  *  This hardware is really sick:
11  *   - No way to clear interrupts.
12  *   - Have to turn off the clock whenever we touch the device.
13  *   - Doesn't tell you how many data blocks were transferred.
14  *  Yuck!
15  *
16  *	1 and 3 byte data transfers not supported
17  *	max block length up to 1023
18  */
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/ioport.h>
22 #include <linux/platform_device.h>
23 #include <linux/delay.h>
24 #include <linux/interrupt.h>
25 #include <linux/dma-mapping.h>
26 #include <linux/clk.h>
27 #include <linux/err.h>
28 #include <linux/mmc/host.h>
29 #include <linux/io.h>
30 #include <linux/regulator/consumer.h>
31 #include <linux/gpio.h>
32 #include <linux/gfp.h>
33 #include <linux/of.h>
34 #include <linux/of_gpio.h>
35 #include <linux/of_device.h>
36 
37 #include <asm/sizes.h>
38 
39 #include <mach/hardware.h>
40 #include <mach/dma.h>
41 #include <linux/platform_data/mmc-pxamci.h>
42 
43 #include "pxamci.h"
44 
45 #define DRIVER_NAME	"pxa2xx-mci"
46 
47 #define NR_SG	1
48 #define CLKRT_OFF	(~0)
49 
50 #define mmc_has_26MHz()		(cpu_is_pxa300() || cpu_is_pxa310() \
51 				|| cpu_is_pxa935())
52 
53 struct pxamci_host {
54 	struct mmc_host		*mmc;
55 	spinlock_t		lock;
56 	struct resource		*res;
57 	void __iomem		*base;
58 	struct clk		*clk;
59 	unsigned long		clkrate;
60 	int			irq;
61 	int			dma;
62 	unsigned int		clkrt;
63 	unsigned int		cmdat;
64 	unsigned int		imask;
65 	unsigned int		power_mode;
66 	struct pxamci_platform_data *pdata;
67 
68 	struct mmc_request	*mrq;
69 	struct mmc_command	*cmd;
70 	struct mmc_data		*data;
71 
72 	dma_addr_t		sg_dma;
73 	struct pxa_dma_desc	*sg_cpu;
74 	unsigned int		dma_len;
75 
76 	unsigned int		dma_dir;
77 	unsigned int		dma_drcmrrx;
78 	unsigned int		dma_drcmrtx;
79 
80 	struct regulator	*vcc;
81 };
82 
83 static inline void pxamci_init_ocr(struct pxamci_host *host)
84 {
85 #ifdef CONFIG_REGULATOR
86 	host->vcc = regulator_get_optional(mmc_dev(host->mmc), "vmmc");
87 
88 	if (IS_ERR(host->vcc))
89 		host->vcc = NULL;
90 	else {
91 		host->mmc->ocr_avail = mmc_regulator_get_ocrmask(host->vcc);
92 		if (host->pdata && host->pdata->ocr_mask)
93 			dev_warn(mmc_dev(host->mmc),
94 				"ocr_mask/setpower will not be used\n");
95 	}
96 #endif
97 	if (host->vcc == NULL) {
98 		/* fall-back to platform data */
99 		host->mmc->ocr_avail = host->pdata ?
100 			host->pdata->ocr_mask :
101 			MMC_VDD_32_33 | MMC_VDD_33_34;
102 	}
103 }
104 
105 static inline int pxamci_set_power(struct pxamci_host *host,
106 				    unsigned char power_mode,
107 				    unsigned int vdd)
108 {
109 	int on;
110 
111 	if (host->vcc) {
112 		int ret;
113 
114 		if (power_mode == MMC_POWER_UP) {
115 			ret = mmc_regulator_set_ocr(host->mmc, host->vcc, vdd);
116 			if (ret)
117 				return ret;
118 		} else if (power_mode == MMC_POWER_OFF) {
119 			ret = mmc_regulator_set_ocr(host->mmc, host->vcc, 0);
120 			if (ret)
121 				return ret;
122 		}
123 	}
124 	if (!host->vcc && host->pdata &&
125 	    gpio_is_valid(host->pdata->gpio_power)) {
126 		on = ((1 << vdd) & host->pdata->ocr_mask);
127 		gpio_set_value(host->pdata->gpio_power,
128 			       !!on ^ host->pdata->gpio_power_invert);
129 	}
130 	if (!host->vcc && host->pdata && host->pdata->setpower)
131 		return host->pdata->setpower(mmc_dev(host->mmc), vdd);
132 
133 	return 0;
134 }
135 
136 static void pxamci_stop_clock(struct pxamci_host *host)
137 {
138 	if (readl(host->base + MMC_STAT) & STAT_CLK_EN) {
139 		unsigned long timeout = 10000;
140 		unsigned int v;
141 
142 		writel(STOP_CLOCK, host->base + MMC_STRPCL);
143 
144 		do {
145 			v = readl(host->base + MMC_STAT);
146 			if (!(v & STAT_CLK_EN))
147 				break;
148 			udelay(1);
149 		} while (timeout--);
150 
151 		if (v & STAT_CLK_EN)
152 			dev_err(mmc_dev(host->mmc), "unable to stop clock\n");
153 	}
154 }
155 
156 static void pxamci_enable_irq(struct pxamci_host *host, unsigned int mask)
157 {
158 	unsigned long flags;
159 
160 	spin_lock_irqsave(&host->lock, flags);
161 	host->imask &= ~mask;
162 	writel(host->imask, host->base + MMC_I_MASK);
163 	spin_unlock_irqrestore(&host->lock, flags);
164 }
165 
166 static void pxamci_disable_irq(struct pxamci_host *host, unsigned int mask)
167 {
168 	unsigned long flags;
169 
170 	spin_lock_irqsave(&host->lock, flags);
171 	host->imask |= mask;
172 	writel(host->imask, host->base + MMC_I_MASK);
173 	spin_unlock_irqrestore(&host->lock, flags);
174 }
175 
176 static void pxamci_setup_data(struct pxamci_host *host, struct mmc_data *data)
177 {
178 	unsigned int nob = data->blocks;
179 	unsigned long long clks;
180 	unsigned int timeout;
181 	bool dalgn = 0;
182 	u32 dcmd;
183 	int i;
184 
185 	host->data = data;
186 
187 	if (data->flags & MMC_DATA_STREAM)
188 		nob = 0xffff;
189 
190 	writel(nob, host->base + MMC_NOB);
191 	writel(data->blksz, host->base + MMC_BLKLEN);
192 
193 	clks = (unsigned long long)data->timeout_ns * host->clkrate;
194 	do_div(clks, 1000000000UL);
195 	timeout = (unsigned int)clks + (data->timeout_clks << host->clkrt);
196 	writel((timeout + 255) / 256, host->base + MMC_RDTO);
197 
198 	if (data->flags & MMC_DATA_READ) {
199 		host->dma_dir = DMA_FROM_DEVICE;
200 		dcmd = DCMD_INCTRGADDR | DCMD_FLOWSRC;
201 		DRCMR(host->dma_drcmrtx) = 0;
202 		DRCMR(host->dma_drcmrrx) = host->dma | DRCMR_MAPVLD;
203 	} else {
204 		host->dma_dir = DMA_TO_DEVICE;
205 		dcmd = DCMD_INCSRCADDR | DCMD_FLOWTRG;
206 		DRCMR(host->dma_drcmrrx) = 0;
207 		DRCMR(host->dma_drcmrtx) = host->dma | DRCMR_MAPVLD;
208 	}
209 
210 	dcmd |= DCMD_BURST32 | DCMD_WIDTH1;
211 
212 	host->dma_len = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
213 				   host->dma_dir);
214 
215 	for (i = 0; i < host->dma_len; i++) {
216 		unsigned int length = sg_dma_len(&data->sg[i]);
217 		host->sg_cpu[i].dcmd = dcmd | length;
218 		if (length & 31 && !(data->flags & MMC_DATA_READ))
219 			host->sg_cpu[i].dcmd |= DCMD_ENDIRQEN;
220 		/* Not aligned to 8-byte boundary? */
221 		if (sg_dma_address(&data->sg[i]) & 0x7)
222 			dalgn = 1;
223 		if (data->flags & MMC_DATA_READ) {
224 			host->sg_cpu[i].dsadr = host->res->start + MMC_RXFIFO;
225 			host->sg_cpu[i].dtadr = sg_dma_address(&data->sg[i]);
226 		} else {
227 			host->sg_cpu[i].dsadr = sg_dma_address(&data->sg[i]);
228 			host->sg_cpu[i].dtadr = host->res->start + MMC_TXFIFO;
229 		}
230 		host->sg_cpu[i].ddadr = host->sg_dma + (i + 1) *
231 					sizeof(struct pxa_dma_desc);
232 	}
233 	host->sg_cpu[host->dma_len - 1].ddadr = DDADR_STOP;
234 	wmb();
235 
236 	/*
237 	 * The PXA27x DMA controller encounters overhead when working with
238 	 * unaligned (to 8-byte boundaries) data, so switch on byte alignment
239 	 * mode only if we have unaligned data.
240 	 */
241 	if (dalgn)
242 		DALGN |= (1 << host->dma);
243 	else
244 		DALGN &= ~(1 << host->dma);
245 	DDADR(host->dma) = host->sg_dma;
246 
247 	/*
248 	 * workaround for erratum #91:
249 	 * only start DMA now if we are doing a read,
250 	 * otherwise we wait until CMD/RESP has finished
251 	 * before starting DMA.
252 	 */
253 	if (!cpu_is_pxa27x() || data->flags & MMC_DATA_READ)
254 		DCSR(host->dma) = DCSR_RUN;
255 }
256 
257 static void pxamci_start_cmd(struct pxamci_host *host, struct mmc_command *cmd, unsigned int cmdat)
258 {
259 	WARN_ON(host->cmd != NULL);
260 	host->cmd = cmd;
261 
262 	if (cmd->flags & MMC_RSP_BUSY)
263 		cmdat |= CMDAT_BUSY;
264 
265 #define RSP_TYPE(x)	((x) & ~(MMC_RSP_BUSY|MMC_RSP_OPCODE))
266 	switch (RSP_TYPE(mmc_resp_type(cmd))) {
267 	case RSP_TYPE(MMC_RSP_R1): /* r1, r1b, r6, r7 */
268 		cmdat |= CMDAT_RESP_SHORT;
269 		break;
270 	case RSP_TYPE(MMC_RSP_R3):
271 		cmdat |= CMDAT_RESP_R3;
272 		break;
273 	case RSP_TYPE(MMC_RSP_R2):
274 		cmdat |= CMDAT_RESP_R2;
275 		break;
276 	default:
277 		break;
278 	}
279 
280 	writel(cmd->opcode, host->base + MMC_CMD);
281 	writel(cmd->arg >> 16, host->base + MMC_ARGH);
282 	writel(cmd->arg & 0xffff, host->base + MMC_ARGL);
283 	writel(cmdat, host->base + MMC_CMDAT);
284 	writel(host->clkrt, host->base + MMC_CLKRT);
285 
286 	writel(START_CLOCK, host->base + MMC_STRPCL);
287 
288 	pxamci_enable_irq(host, END_CMD_RES);
289 }
290 
291 static void pxamci_finish_request(struct pxamci_host *host, struct mmc_request *mrq)
292 {
293 	host->mrq = NULL;
294 	host->cmd = NULL;
295 	host->data = NULL;
296 	mmc_request_done(host->mmc, mrq);
297 }
298 
299 static int pxamci_cmd_done(struct pxamci_host *host, unsigned int stat)
300 {
301 	struct mmc_command *cmd = host->cmd;
302 	int i;
303 	u32 v;
304 
305 	if (!cmd)
306 		return 0;
307 
308 	host->cmd = NULL;
309 
310 	/*
311 	 * Did I mention this is Sick.  We always need to
312 	 * discard the upper 8 bits of the first 16-bit word.
313 	 */
314 	v = readl(host->base + MMC_RES) & 0xffff;
315 	for (i = 0; i < 4; i++) {
316 		u32 w1 = readl(host->base + MMC_RES) & 0xffff;
317 		u32 w2 = readl(host->base + MMC_RES) & 0xffff;
318 		cmd->resp[i] = v << 24 | w1 << 8 | w2 >> 8;
319 		v = w2;
320 	}
321 
322 	if (stat & STAT_TIME_OUT_RESPONSE) {
323 		cmd->error = -ETIMEDOUT;
324 	} else if (stat & STAT_RES_CRC_ERR && cmd->flags & MMC_RSP_CRC) {
325 		/*
326 		 * workaround for erratum #42:
327 		 * Intel PXA27x Family Processor Specification Update Rev 001
328 		 * A bogus CRC error can appear if the msb of a 136 bit
329 		 * response is a one.
330 		 */
331 		if (cpu_is_pxa27x() &&
332 		    (cmd->flags & MMC_RSP_136 && cmd->resp[0] & 0x80000000))
333 			pr_debug("ignoring CRC from command %d - *risky*\n", cmd->opcode);
334 		else
335 			cmd->error = -EILSEQ;
336 	}
337 
338 	pxamci_disable_irq(host, END_CMD_RES);
339 	if (host->data && !cmd->error) {
340 		pxamci_enable_irq(host, DATA_TRAN_DONE);
341 		/*
342 		 * workaround for erratum #91, if doing write
343 		 * enable DMA late
344 		 */
345 		if (cpu_is_pxa27x() && host->data->flags & MMC_DATA_WRITE)
346 			DCSR(host->dma) = DCSR_RUN;
347 	} else {
348 		pxamci_finish_request(host, host->mrq);
349 	}
350 
351 	return 1;
352 }
353 
354 static int pxamci_data_done(struct pxamci_host *host, unsigned int stat)
355 {
356 	struct mmc_data *data = host->data;
357 
358 	if (!data)
359 		return 0;
360 
361 	DCSR(host->dma) = 0;
362 	dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
363 		     host->dma_dir);
364 
365 	if (stat & STAT_READ_TIME_OUT)
366 		data->error = -ETIMEDOUT;
367 	else if (stat & (STAT_CRC_READ_ERROR|STAT_CRC_WRITE_ERROR))
368 		data->error = -EILSEQ;
369 
370 	/*
371 	 * There appears to be a hardware design bug here.  There seems to
372 	 * be no way to find out how much data was transferred to the card.
373 	 * This means that if there was an error on any block, we mark all
374 	 * data blocks as being in error.
375 	 */
376 	if (!data->error)
377 		data->bytes_xfered = data->blocks * data->blksz;
378 	else
379 		data->bytes_xfered = 0;
380 
381 	pxamci_disable_irq(host, DATA_TRAN_DONE);
382 
383 	host->data = NULL;
384 	if (host->mrq->stop) {
385 		pxamci_stop_clock(host);
386 		pxamci_start_cmd(host, host->mrq->stop, host->cmdat);
387 	} else {
388 		pxamci_finish_request(host, host->mrq);
389 	}
390 
391 	return 1;
392 }
393 
394 static irqreturn_t pxamci_irq(int irq, void *devid)
395 {
396 	struct pxamci_host *host = devid;
397 	unsigned int ireg;
398 	int handled = 0;
399 
400 	ireg = readl(host->base + MMC_I_REG) & ~readl(host->base + MMC_I_MASK);
401 
402 	if (ireg) {
403 		unsigned stat = readl(host->base + MMC_STAT);
404 
405 		pr_debug("PXAMCI: irq %08x stat %08x\n", ireg, stat);
406 
407 		if (ireg & END_CMD_RES)
408 			handled |= pxamci_cmd_done(host, stat);
409 		if (ireg & DATA_TRAN_DONE)
410 			handled |= pxamci_data_done(host, stat);
411 		if (ireg & SDIO_INT) {
412 			mmc_signal_sdio_irq(host->mmc);
413 			handled = 1;
414 		}
415 	}
416 
417 	return IRQ_RETVAL(handled);
418 }
419 
420 static void pxamci_request(struct mmc_host *mmc, struct mmc_request *mrq)
421 {
422 	struct pxamci_host *host = mmc_priv(mmc);
423 	unsigned int cmdat;
424 
425 	WARN_ON(host->mrq != NULL);
426 
427 	host->mrq = mrq;
428 
429 	pxamci_stop_clock(host);
430 
431 	cmdat = host->cmdat;
432 	host->cmdat &= ~CMDAT_INIT;
433 
434 	if (mrq->data) {
435 		pxamci_setup_data(host, mrq->data);
436 
437 		cmdat &= ~CMDAT_BUSY;
438 		cmdat |= CMDAT_DATAEN | CMDAT_DMAEN;
439 		if (mrq->data->flags & MMC_DATA_WRITE)
440 			cmdat |= CMDAT_WRITE;
441 
442 		if (mrq->data->flags & MMC_DATA_STREAM)
443 			cmdat |= CMDAT_STREAM;
444 	}
445 
446 	pxamci_start_cmd(host, mrq->cmd, cmdat);
447 }
448 
449 static int pxamci_get_ro(struct mmc_host *mmc)
450 {
451 	struct pxamci_host *host = mmc_priv(mmc);
452 
453 	if (host->pdata && gpio_is_valid(host->pdata->gpio_card_ro)) {
454 		if (host->pdata->gpio_card_ro_invert)
455 			return !gpio_get_value(host->pdata->gpio_card_ro);
456 		else
457 			return gpio_get_value(host->pdata->gpio_card_ro);
458 	}
459 	if (host->pdata && host->pdata->get_ro)
460 		return !!host->pdata->get_ro(mmc_dev(mmc));
461 	/*
462 	 * Board doesn't support read only detection; let the mmc core
463 	 * decide what to do.
464 	 */
465 	return -ENOSYS;
466 }
467 
468 static void pxamci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
469 {
470 	struct pxamci_host *host = mmc_priv(mmc);
471 
472 	if (ios->clock) {
473 		unsigned long rate = host->clkrate;
474 		unsigned int clk = rate / ios->clock;
475 
476 		if (host->clkrt == CLKRT_OFF)
477 			clk_prepare_enable(host->clk);
478 
479 		if (ios->clock == 26000000) {
480 			/* to support 26MHz */
481 			host->clkrt = 7;
482 		} else {
483 			/* to handle (19.5MHz, 26MHz) */
484 			if (!clk)
485 				clk = 1;
486 
487 			/*
488 			 * clk might result in a lower divisor than we
489 			 * desire.  check for that condition and adjust
490 			 * as appropriate.
491 			 */
492 			if (rate / clk > ios->clock)
493 				clk <<= 1;
494 			host->clkrt = fls(clk) - 1;
495 		}
496 
497 		/*
498 		 * we write clkrt on the next command
499 		 */
500 	} else {
501 		pxamci_stop_clock(host);
502 		if (host->clkrt != CLKRT_OFF) {
503 			host->clkrt = CLKRT_OFF;
504 			clk_disable_unprepare(host->clk);
505 		}
506 	}
507 
508 	if (host->power_mode != ios->power_mode) {
509 		int ret;
510 
511 		host->power_mode = ios->power_mode;
512 
513 		ret = pxamci_set_power(host, ios->power_mode, ios->vdd);
514 		if (ret) {
515 			dev_err(mmc_dev(mmc), "unable to set power\n");
516 			/*
517 			 * The .set_ios() function in the mmc_host_ops
518 			 * struct return void, and failing to set the
519 			 * power should be rare so we print an error and
520 			 * return here.
521 			 */
522 			return;
523 		}
524 
525 		if (ios->power_mode == MMC_POWER_ON)
526 			host->cmdat |= CMDAT_INIT;
527 	}
528 
529 	if (ios->bus_width == MMC_BUS_WIDTH_4)
530 		host->cmdat |= CMDAT_SD_4DAT;
531 	else
532 		host->cmdat &= ~CMDAT_SD_4DAT;
533 
534 	dev_dbg(mmc_dev(mmc), "PXAMCI: clkrt = %x cmdat = %x\n",
535 		host->clkrt, host->cmdat);
536 }
537 
538 static void pxamci_enable_sdio_irq(struct mmc_host *host, int enable)
539 {
540 	struct pxamci_host *pxa_host = mmc_priv(host);
541 
542 	if (enable)
543 		pxamci_enable_irq(pxa_host, SDIO_INT);
544 	else
545 		pxamci_disable_irq(pxa_host, SDIO_INT);
546 }
547 
548 static const struct mmc_host_ops pxamci_ops = {
549 	.request		= pxamci_request,
550 	.get_ro			= pxamci_get_ro,
551 	.set_ios		= pxamci_set_ios,
552 	.enable_sdio_irq	= pxamci_enable_sdio_irq,
553 };
554 
555 static void pxamci_dma_irq(int dma, void *devid)
556 {
557 	struct pxamci_host *host = devid;
558 	int dcsr = DCSR(dma);
559 	DCSR(dma) = dcsr & ~DCSR_STOPIRQEN;
560 
561 	if (dcsr & DCSR_ENDINTR) {
562 		writel(BUF_PART_FULL, host->base + MMC_PRTBUF);
563 	} else {
564 		pr_err("%s: DMA error on channel %d (DCSR=%#x)\n",
565 		       mmc_hostname(host->mmc), dma, dcsr);
566 		host->data->error = -EIO;
567 		pxamci_data_done(host, 0);
568 	}
569 }
570 
571 static irqreturn_t pxamci_detect_irq(int irq, void *devid)
572 {
573 	struct pxamci_host *host = mmc_priv(devid);
574 
575 	mmc_detect_change(devid, msecs_to_jiffies(host->pdata->detect_delay_ms));
576 	return IRQ_HANDLED;
577 }
578 
579 #ifdef CONFIG_OF
580 static const struct of_device_id pxa_mmc_dt_ids[] = {
581         { .compatible = "marvell,pxa-mmc" },
582         { }
583 };
584 
585 MODULE_DEVICE_TABLE(of, pxa_mmc_dt_ids);
586 
587 static int pxamci_of_init(struct platform_device *pdev)
588 {
589         struct device_node *np = pdev->dev.of_node;
590         struct pxamci_platform_data *pdata;
591         u32 tmp;
592 
593         if (!np)
594                 return 0;
595 
596         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
597         if (!pdata)
598                 return -ENOMEM;
599 
600 	pdata->gpio_card_detect =
601 		of_get_named_gpio(np, "cd-gpios", 0);
602 	pdata->gpio_card_ro =
603 		of_get_named_gpio(np, "wp-gpios", 0);
604 
605 	/* pxa-mmc specific */
606 	pdata->gpio_power =
607 		of_get_named_gpio(np, "pxa-mmc,gpio-power", 0);
608 
609 	if (of_property_read_u32(np, "pxa-mmc,detect-delay-ms", &tmp) == 0)
610 		pdata->detect_delay_ms = tmp;
611 
612         pdev->dev.platform_data = pdata;
613 
614         return 0;
615 }
616 #else
617 static int pxamci_of_init(struct platform_device *pdev)
618 {
619         return 0;
620 }
621 #endif
622 
623 static int pxamci_probe(struct platform_device *pdev)
624 {
625 	struct mmc_host *mmc;
626 	struct pxamci_host *host = NULL;
627 	struct resource *r, *dmarx, *dmatx;
628 	int ret, irq, gpio_cd = -1, gpio_ro = -1, gpio_power = -1;
629 
630 	ret = pxamci_of_init(pdev);
631 	if (ret)
632 		return ret;
633 
634 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
635 	irq = platform_get_irq(pdev, 0);
636 	if (!r || irq < 0)
637 		return -ENXIO;
638 
639 	r = request_mem_region(r->start, SZ_4K, DRIVER_NAME);
640 	if (!r)
641 		return -EBUSY;
642 
643 	mmc = mmc_alloc_host(sizeof(struct pxamci_host), &pdev->dev);
644 	if (!mmc) {
645 		ret = -ENOMEM;
646 		goto out;
647 	}
648 
649 	mmc->ops = &pxamci_ops;
650 
651 	/*
652 	 * We can do SG-DMA, but we don't because we never know how much
653 	 * data we successfully wrote to the card.
654 	 */
655 	mmc->max_segs = NR_SG;
656 
657 	/*
658 	 * Our hardware DMA can handle a maximum of one page per SG entry.
659 	 */
660 	mmc->max_seg_size = PAGE_SIZE;
661 
662 	/*
663 	 * Block length register is only 10 bits before PXA27x.
664 	 */
665 	mmc->max_blk_size = cpu_is_pxa25x() ? 1023 : 2048;
666 
667 	/*
668 	 * Block count register is 16 bits.
669 	 */
670 	mmc->max_blk_count = 65535;
671 
672 	host = mmc_priv(mmc);
673 	host->mmc = mmc;
674 	host->dma = -1;
675 	host->pdata = pdev->dev.platform_data;
676 	host->clkrt = CLKRT_OFF;
677 
678 	host->clk = clk_get(&pdev->dev, NULL);
679 	if (IS_ERR(host->clk)) {
680 		ret = PTR_ERR(host->clk);
681 		host->clk = NULL;
682 		goto out;
683 	}
684 
685 	host->clkrate = clk_get_rate(host->clk);
686 
687 	/*
688 	 * Calculate minimum clock rate, rounding up.
689 	 */
690 	mmc->f_min = (host->clkrate + 63) / 64;
691 	mmc->f_max = (mmc_has_26MHz()) ? 26000000 : host->clkrate;
692 
693 	pxamci_init_ocr(host);
694 
695 	mmc->caps = 0;
696 	host->cmdat = 0;
697 	if (!cpu_is_pxa25x()) {
698 		mmc->caps |= MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
699 		host->cmdat |= CMDAT_SDIO_INT_EN;
700 		if (mmc_has_26MHz())
701 			mmc->caps |= MMC_CAP_MMC_HIGHSPEED |
702 				     MMC_CAP_SD_HIGHSPEED;
703 	}
704 
705 	host->sg_cpu = dma_alloc_coherent(&pdev->dev, PAGE_SIZE, &host->sg_dma, GFP_KERNEL);
706 	if (!host->sg_cpu) {
707 		ret = -ENOMEM;
708 		goto out;
709 	}
710 
711 	spin_lock_init(&host->lock);
712 	host->res = r;
713 	host->irq = irq;
714 	host->imask = MMC_I_MASK_ALL;
715 
716 	host->base = ioremap(r->start, SZ_4K);
717 	if (!host->base) {
718 		ret = -ENOMEM;
719 		goto out;
720 	}
721 
722 	/*
723 	 * Ensure that the host controller is shut down, and setup
724 	 * with our defaults.
725 	 */
726 	pxamci_stop_clock(host);
727 	writel(0, host->base + MMC_SPI);
728 	writel(64, host->base + MMC_RESTO);
729 	writel(host->imask, host->base + MMC_I_MASK);
730 
731 	host->dma = pxa_request_dma(DRIVER_NAME, DMA_PRIO_LOW,
732 				    pxamci_dma_irq, host);
733 	if (host->dma < 0) {
734 		ret = -EBUSY;
735 		goto out;
736 	}
737 
738 	ret = request_irq(host->irq, pxamci_irq, 0, DRIVER_NAME, host);
739 	if (ret)
740 		goto out;
741 
742 	platform_set_drvdata(pdev, mmc);
743 
744 	dmarx = platform_get_resource(pdev, IORESOURCE_DMA, 0);
745 	if (!dmarx) {
746 		ret = -ENXIO;
747 		goto out;
748 	}
749 	host->dma_drcmrrx = dmarx->start;
750 
751 	dmatx = platform_get_resource(pdev, IORESOURCE_DMA, 1);
752 	if (!dmatx) {
753 		ret = -ENXIO;
754 		goto out;
755 	}
756 	host->dma_drcmrtx = dmatx->start;
757 
758 	if (host->pdata) {
759 		gpio_cd = host->pdata->gpio_card_detect;
760 		gpio_ro = host->pdata->gpio_card_ro;
761 		gpio_power = host->pdata->gpio_power;
762 	}
763 	if (gpio_is_valid(gpio_power)) {
764 		ret = gpio_request(gpio_power, "mmc card power");
765 		if (ret) {
766 			dev_err(&pdev->dev, "Failed requesting gpio_power %d\n", gpio_power);
767 			goto out;
768 		}
769 		gpio_direction_output(gpio_power,
770 				      host->pdata->gpio_power_invert);
771 	}
772 	if (gpio_is_valid(gpio_ro)) {
773 		ret = gpio_request(gpio_ro, "mmc card read only");
774 		if (ret) {
775 			dev_err(&pdev->dev, "Failed requesting gpio_ro %d\n", gpio_ro);
776 			goto err_gpio_ro;
777 		}
778 		gpio_direction_input(gpio_ro);
779 	}
780 	if (gpio_is_valid(gpio_cd)) {
781 		ret = gpio_request(gpio_cd, "mmc card detect");
782 		if (ret) {
783 			dev_err(&pdev->dev, "Failed requesting gpio_cd %d\n", gpio_cd);
784 			goto err_gpio_cd;
785 		}
786 		gpio_direction_input(gpio_cd);
787 
788 		ret = request_irq(gpio_to_irq(gpio_cd), pxamci_detect_irq,
789 				  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
790 				  "mmc card detect", mmc);
791 		if (ret) {
792 			dev_err(&pdev->dev, "failed to request card detect IRQ\n");
793 			goto err_request_irq;
794 		}
795 	}
796 
797 	if (host->pdata && host->pdata->init)
798 		host->pdata->init(&pdev->dev, pxamci_detect_irq, mmc);
799 
800 	if (gpio_is_valid(gpio_power) && host->pdata->setpower)
801 		dev_warn(&pdev->dev, "gpio_power and setpower() both defined\n");
802 	if (gpio_is_valid(gpio_ro) && host->pdata->get_ro)
803 		dev_warn(&pdev->dev, "gpio_ro and get_ro() both defined\n");
804 
805 	mmc_add_host(mmc);
806 
807 	return 0;
808 
809 err_request_irq:
810 	gpio_free(gpio_cd);
811 err_gpio_cd:
812 	gpio_free(gpio_ro);
813 err_gpio_ro:
814 	gpio_free(gpio_power);
815  out:
816 	if (host) {
817 		if (host->dma >= 0)
818 			pxa_free_dma(host->dma);
819 		if (host->base)
820 			iounmap(host->base);
821 		if (host->sg_cpu)
822 			dma_free_coherent(&pdev->dev, PAGE_SIZE, host->sg_cpu, host->sg_dma);
823 		if (host->clk)
824 			clk_put(host->clk);
825 	}
826 	if (mmc)
827 		mmc_free_host(mmc);
828 	release_resource(r);
829 	return ret;
830 }
831 
832 static int pxamci_remove(struct platform_device *pdev)
833 {
834 	struct mmc_host *mmc = platform_get_drvdata(pdev);
835 	int gpio_cd = -1, gpio_ro = -1, gpio_power = -1;
836 
837 	if (mmc) {
838 		struct pxamci_host *host = mmc_priv(mmc);
839 
840 		mmc_remove_host(mmc);
841 
842 		if (host->pdata) {
843 			gpio_cd = host->pdata->gpio_card_detect;
844 			gpio_ro = host->pdata->gpio_card_ro;
845 			gpio_power = host->pdata->gpio_power;
846 		}
847 		if (gpio_is_valid(gpio_cd)) {
848 			free_irq(gpio_to_irq(gpio_cd), mmc);
849 			gpio_free(gpio_cd);
850 		}
851 		if (gpio_is_valid(gpio_ro))
852 			gpio_free(gpio_ro);
853 		if (gpio_is_valid(gpio_power))
854 			gpio_free(gpio_power);
855 		if (host->vcc)
856 			regulator_put(host->vcc);
857 
858 		if (host->pdata && host->pdata->exit)
859 			host->pdata->exit(&pdev->dev, mmc);
860 
861 		pxamci_stop_clock(host);
862 		writel(TXFIFO_WR_REQ|RXFIFO_RD_REQ|CLK_IS_OFF|STOP_CMD|
863 		       END_CMD_RES|PRG_DONE|DATA_TRAN_DONE,
864 		       host->base + MMC_I_MASK);
865 
866 		DRCMR(host->dma_drcmrrx) = 0;
867 		DRCMR(host->dma_drcmrtx) = 0;
868 
869 		free_irq(host->irq, host);
870 		pxa_free_dma(host->dma);
871 		iounmap(host->base);
872 		dma_free_coherent(&pdev->dev, PAGE_SIZE, host->sg_cpu, host->sg_dma);
873 
874 		clk_put(host->clk);
875 
876 		release_resource(host->res);
877 
878 		mmc_free_host(mmc);
879 	}
880 	return 0;
881 }
882 
883 static struct platform_driver pxamci_driver = {
884 	.probe		= pxamci_probe,
885 	.remove		= pxamci_remove,
886 	.driver		= {
887 		.name	= DRIVER_NAME,
888 		.of_match_table = of_match_ptr(pxa_mmc_dt_ids),
889 	},
890 };
891 
892 module_platform_driver(pxamci_driver);
893 
894 MODULE_DESCRIPTION("PXA Multimedia Card Interface Driver");
895 MODULE_LICENSE("GPL");
896 MODULE_ALIAS("platform:pxa2xx-mci");
897