summaryrefslogtreecommitdiff
path: root/drivers/mmc/host/pxamci.c
blob: 28a057fae0a196092c113af946bc5ef32629f28a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
/*
 *  linux/drivers/mmc/host/pxa.c - PXA MMCI driver
 *
 *  Copyright (C) 2003 Russell King, All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *  This hardware is really sick:
 *   - No way to clear interrupts.
 *   - Have to turn off the clock whenever we touch the device.
 *   - Doesn't tell you how many data blocks were transferred.
 *  Yuck!
 *
 *	1 and 3 byte data transfers not supported
 *	max block length up to 1023
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/dma/pxa-dma.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/mmc/host.h>
#include <linux/mmc/slot-gpio.h>
#include <linux/io.h>
#include <linux/regulator/consumer.h>
#include <linux/gpio.h>
#include <linux/gfp.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/of_device.h>

#include <asm/sizes.h>

#include <mach/hardware.h>
#include <linux/platform_data/mmc-pxamci.h>

#include "pxamci.h"

#define DRIVER_NAME	"pxa2xx-mci"

#define NR_SG	1
#define CLKRT_OFF	(~0)

#define mmc_has_26MHz()		(cpu_is_pxa300() || cpu_is_pxa310() \
				|| cpu_is_pxa935())

struct pxamci_host {
	struct mmc_host		*mmc;
	spinlock_t		lock;
	struct resource		*res;
	void __iomem		*base;
	struct clk		*clk;
	unsigned long		clkrate;
	int			irq;
	unsigned int		clkrt;
	unsigned int		cmdat;
	unsigned int		imask;
	unsigned int		power_mode;
	struct pxamci_platform_data *pdata;

	struct mmc_request	*mrq;
	struct mmc_command	*cmd;
	struct mmc_data		*data;

	struct dma_chan		*dma_chan_rx;
	struct dma_chan		*dma_chan_tx;
	dma_cookie_t		dma_cookie;
	dma_addr_t		sg_dma;
	unsigned int		dma_len;

	unsigned int		dma_dir;
	unsigned int		dma_drcmrrx;
	unsigned int		dma_drcmrtx;

	struct regulator	*vcc;
};

static inline void pxamci_init_ocr(struct pxamci_host *host)
{
#ifdef CONFIG_REGULATOR
	host->vcc = regulator_get_optional(mmc_dev(host->mmc), "vmmc");

	if (IS_ERR(host->vcc))
		host->vcc = NULL;
	else {
		host->mmc->ocr_avail = mmc_regulator_get_ocrmask(host->vcc);
		if (host->pdata && host->pdata->ocr_mask)
			dev_warn(mmc_dev(host->mmc),
				"ocr_mask/setpower will not be used\n");
	}
#endif
	if (host->vcc == NULL) {
		/* fall-back to platform data */
		host->mmc->ocr_avail = host->pdata ?
			host->pdata->ocr_mask :
			MMC_VDD_32_33 | MMC_VDD_33_34;
	}
}

static inline int pxamci_set_power(struct pxamci_host *host,
				    unsigned char power_mode,
				    unsigned int vdd)
{
	int on;

	if (host->vcc) {
		int ret;

		if (power_mode == MMC_POWER_UP) {
			ret = mmc_regulator_set_ocr(host->mmc, host->vcc, vdd);
			if (ret)
				return ret;
		} else if (power_mode == MMC_POWER_OFF) {
			ret = mmc_regulator_set_ocr(host->mmc, host->vcc, 0);
			if (ret)
				return ret;
		}
	}
	if (!host->vcc && host->pdata &&
	    gpio_is_valid(host->pdata->gpio_power)) {
		on = ((1 << vdd) & host->pdata->ocr_mask);
		gpio_set_value(host->pdata->gpio_power,
			       !!on ^ host->pdata->gpio_power_invert);
	}
	if (!host->vcc && host->pdata && host->pdata->setpower)
		return host->pdata->setpower(mmc_dev(host->mmc), vdd);

	return 0;
}

static void pxamci_stop_clock(struct pxamci_host *host)
{
	if (readl(host->base + MMC_STAT) & STAT_CLK_EN) {
		unsigned long timeout = 10000;
		unsigned int v;

		writel(STOP_CLOCK, host->base + MMC_STRPCL);

		do {
			v = readl(host->base + MMC_STAT);
			if (!(v & STAT_CLK_EN))
				break;
			udelay(1);
		} while (timeout--);

		if (v & STAT_CLK_EN)
			dev_err(mmc_dev(host->mmc), "unable to stop clock\n");
	}
}

static void pxamci_enable_irq(struct pxamci_host *host, unsigned int mask)
{
	unsigned long flags;

	spin_lock_irqsave(&host->lock, flags);
	host->imask &= ~mask;
	writel(host->imask, host->base + MMC_I_MASK);
	spin_unlock_irqrestore(&host->lock, flags);
}

static void pxamci_disable_irq(struct pxamci_host *host, unsigned int mask)
{
	unsigned long flags;

	spin_lock_irqsave(&host->lock, flags);
	host->imask |= mask;
	writel(host->imask, host->base + MMC_I_MASK);
	spin_unlock_irqrestore(&host->lock, flags);
}

static void pxamci_dma_irq(void *param);

static void pxamci_setup_data(struct pxamci_host *host, struct mmc_data *data)
{
	struct dma_async_tx_descriptor *tx;
	enum dma_data_direction direction;
	struct dma_slave_config	config;
	struct dma_chan *chan;
	unsigned int nob = data->blocks;
	unsigned long long clks;
	unsigned int timeout;
	int ret;

	host->data = data;

	if (data->flags & MMC_DATA_STREAM)
		nob = 0xffff;

	writel(nob, host->base + MMC_NOB);
	writel(data->blksz, host->base + MMC_BLKLEN);

	clks = (unsigned long long)data->timeout_ns * host->clkrate;
	do_div(clks, 1000000000UL);
	timeout = (unsigned int)clks + (data->timeout_clks << host->clkrt);
	writel((timeout + 255) / 256, host->base + MMC_RDTO);

	memset(&config, 0, sizeof(config));
	config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
	config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
	config.src_addr = host->res->start + MMC_RXFIFO;
	config.dst_addr = host->res->start + MMC_TXFIFO;
	config.src_maxburst = 32;
	config.dst_maxburst = 32;

	if (data->flags & MMC_DATA_READ) {
		host->dma_dir = DMA_FROM_DEVICE;
		direction = DMA_DEV_TO_MEM;
		chan = host->dma_chan_rx;
	} else {
		host->dma_dir = DMA_TO_DEVICE;
		direction = DMA_MEM_TO_DEV;
		chan = host->dma_chan_tx;
	}

	config.direction = direction;

	ret = dmaengine_slave_config(chan, &config);
	if (ret < 0) {
		dev_err(mmc_dev(host->mmc), "dma slave config failed\n");
		return;
	}

	host->dma_len = dma_map_sg(chan->device->dev, data->sg, data->sg_len,
				   host->dma_dir);

	tx = dmaengine_prep_slave_sg(chan, data->sg, host->dma_len, direction,
				     DMA_PREP_INTERRUPT);
	if (!tx) {
		dev_err(mmc_dev(host->mmc), "prep_slave_sg() failed\n");
		return;
	}

	if (!(data->flags & MMC_DATA_READ)) {
		tx->callback = pxamci_dma_irq;
		tx->callback_param = host;
	}

	host->dma_cookie = dmaengine_submit(tx);

	/*
	 * workaround for erratum #91:
	 * only start DMA now if we are doing a read,
	 * otherwise we wait until CMD/RESP has finished
	 * before starting DMA.
	 */
	if (!cpu_is_pxa27x() || data->flags & MMC_DATA_READ)
		dma_async_issue_pending(chan);
}

static void pxamci_start_cmd(struct pxamci_host *host, struct mmc_command *cmd, unsigned int cmdat)
{
	WARN_ON(host->cmd != NULL);
	host->cmd = cmd;

	if (cmd->flags & MMC_RSP_BUSY)
		cmdat |= CMDAT_BUSY;

#define RSP_TYPE(x)	((x) & ~(MMC_RSP_BUSY|MMC_RSP_OPCODE))
	switch (RSP_TYPE(mmc_resp_type(cmd))) {
	case RSP_TYPE(MMC_RSP_R1): /* r1, r1b, r6, r7 */
		cmdat |= CMDAT_RESP_SHORT;
		break;
	case RSP_TYPE(MMC_RSP_R3):
		cmdat |= CMDAT_RESP_R3;
		break;
	case RSP_TYPE(MMC_RSP_R2):
		cmdat |= CMDAT_RESP_R2;
		break;
	default:
		break;
	}

	writel(cmd->opcode, host->base + MMC_CMD);
	writel(cmd->arg >> 16, host->base + MMC_ARGH);
	writel(cmd->arg & 0xffff, host->base + MMC_ARGL);
	writel(cmdat, host->base + MMC_CMDAT);
	writel(host->clkrt, host->base + MMC_CLKRT);

	writel(START_CLOCK, host->base + MMC_STRPCL);

	pxamci_enable_irq(host, END_CMD_RES);
}

static void pxamci_finish_request(struct pxamci_host *host, struct mmc_request *mrq)
{
	host->mrq = NULL;
	host->cmd = NULL;
	host->data = NULL;
	mmc_request_done(host->mmc, mrq);
}

static int pxamci_cmd_done(struct pxamci_host *host, unsigned int stat)
{
	struct mmc_command *cmd = host->cmd;
	int i;
	u32 v;

	if (!cmd)
		return 0;

	host->cmd = NULL;

	/*
	 * Did I mention this is Sick.  We always need to
	 * discard the upper 8 bits of the first 16-bit word.
	 */
	v = readl(host->base + MMC_RES) & 0xffff;
	for (i = 0; i < 4; i++) {
		u32 w1 = readl(host->base + MMC_RES) & 0xffff;
		u32 w2 = readl(host->base + MMC_RES) & 0xffff;
		cmd->resp[i] = v << 24 | w1 << 8 | w2 >> 8;
		v = w2;
	}

	if (stat & STAT_TIME_OUT_RESPONSE) {
		cmd->error = -ETIMEDOUT;
	} else if (stat & STAT_RES_CRC_ERR && cmd->flags & MMC_RSP_CRC) {
		/*
		 * workaround for erratum #42:
		 * Intel PXA27x Family Processor Specification Update Rev 001
		 * A bogus CRC error can appear if the msb of a 136 bit
		 * response is a one.
		 */
		if (cpu_is_pxa27x() &&
		    (cmd->flags & MMC_RSP_136 && cmd->resp[0] & 0x80000000))
			pr_debug("ignoring CRC from command %d - *risky*\n", cmd->opcode);
		else
			cmd->error = -EILSEQ;
	}

	pxamci_disable_irq(host, END_CMD_RES);
	if (host->data && !cmd->error) {
		pxamci_enable_irq(host, DATA_TRAN_DONE);
		/*
		 * workaround for erratum #91, if doing write
		 * enable DMA late
		 */
		if (cpu_is_pxa27x() && host->data->flags & MMC_DATA_WRITE)
			dma_async_issue_pending(host->dma_chan_tx);
	} else {
		pxamci_finish_request(host, host->mrq);
	}

	return 1;
}

static int pxamci_data_done(struct pxamci_host *host, unsigned int stat)
{
	struct mmc_data *data = host->data;
	struct dma_chan *chan;

	if (!data)
		return 0;

	if (data->flags & MMC_DATA_READ)
		chan = host->dma_chan_rx;
	else
		chan = host->dma_chan_tx;
	dma_unmap_sg(chan->device->dev,
		     data->sg, data->sg_len, host->dma_dir);

	if (stat & STAT_READ_TIME_OUT)
		data->error = -ETIMEDOUT;
	else if (stat & (STAT_CRC_READ_ERROR|STAT_CRC_WRITE_ERROR))
		data->error = -EILSEQ;

	/*
	 * There appears to be a hardware design bug here.  There seems to
	 * be no way to find out how much data was transferred to the card.
	 * This means that if there was an error on any block, we mark all
	 * data blocks as being in error.
	 */
	if (!data->error)
		data->bytes_xfered = data->blocks * data->blksz;
	else
		data->bytes_xfered = 0;

	pxamci_disable_irq(host, DATA_TRAN_DONE);

	host->data = NULL;
	if (host->mrq->stop) {
		pxamci_stop_clock(host);
		pxamci_start_cmd(host, host->mrq->stop, host->cmdat);
	} else {
		pxamci_finish_request(host, host->mrq);
	}

	return 1;
}

static irqreturn_t pxamci_irq(int irq, void *devid)
{
	struct pxamci_host *host = devid;
	unsigned int ireg;
	int handled = 0;

	ireg = readl(host->base + MMC_I_REG) & ~readl(host->base + MMC_I_MASK);

	if (ireg) {
		unsigned stat = readl(host->base + MMC_STAT);

		pr_debug("PXAMCI: irq %08x stat %08x\n", ireg, stat);

		if (ireg & END_CMD_RES)
			handled |= pxamci_cmd_done(host, stat);
		if (ireg & DATA_TRAN_DONE)
			handled |= pxamci_data_done(host, stat);
		if (ireg & SDIO_INT) {
			mmc_signal_sdio_irq(host->mmc);
			handled = 1;
		}
	}

	return IRQ_RETVAL(handled);
}

static void pxamci_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
	struct pxamci_host *host = mmc_priv(mmc);
	unsigned int cmdat;

	WARN_ON(host->mrq != NULL);

	host->mrq = mrq;

	pxamci_stop_clock(host);

	cmdat = host->cmdat;
	host->cmdat &= ~CMDAT_INIT;

	if (mrq->data) {
		pxamci_setup_data(host, mrq->data);

		cmdat &= ~CMDAT_BUSY;
		cmdat |= CMDAT_DATAEN | CMDAT_DMAEN;
		if (mrq->data->flags & MMC_DATA_WRITE)
			cmdat |= CMDAT_WRITE;

		if (mrq->data->flags & MMC_DATA_STREAM)
			cmdat |= CMDAT_STREAM;
	}

	pxamci_start_cmd(host, mrq->cmd, cmdat);
}

static int pxamci_get_ro(struct mmc_host *mmc)
{
	struct pxamci_host *host = mmc_priv(mmc);

	if (host->pdata && gpio_is_valid(host->pdata->gpio_card_ro))
		return mmc_gpio_get_ro(mmc);
	if (host->pdata && host->pdata->get_ro)
		return !!host->pdata->get_ro(mmc_dev(mmc));
	/*
	 * Board doesn't support read only detection; let the mmc core
	 * decide what to do.
	 */
	return -ENOSYS;
}

static void pxamci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
	struct pxamci_host *host = mmc_priv(mmc);

	if (ios->clock) {
		unsigned long rate = host->clkrate;
		unsigned int clk = rate / ios->clock;

		if (host->clkrt == CLKRT_OFF)
			clk_prepare_enable(host->clk);

		if (ios->clock == 26000000) {
			/* to support 26MHz */
			host->clkrt = 7;
		} else {
			/* to handle (19.5MHz, 26MHz) */
			if (!clk)
				clk = 1;

			/*
			 * clk might result in a lower divisor than we
			 * desire.  check for that condition and adjust
			 * as appropriate.
			 */
			if (rate / clk > ios->clock)
				clk <<= 1;
			host->clkrt = fls(clk) - 1;
		}

		/*
		 * we write clkrt on the next command
		 */
	} else {
		pxamci_stop_clock(host);
		if (host->clkrt != CLKRT_OFF) {
			host->clkrt = CLKRT_OFF;
			clk_disable_unprepare(host->clk);
		}
	}

	if (host->power_mode != ios->power_mode) {
		int ret;

		host->power_mode = ios->power_mode;

		ret = pxamci_set_power(host, ios->power_mode, ios->vdd);
		if (ret) {
			dev_err(mmc_dev(mmc), "unable to set power\n");
			/*
			 * The .set_ios() function in the mmc_host_ops
			 * struct return void, and failing to set the
			 * power should be rare so we print an error and
			 * return here.
			 */
			return;
		}

		if (ios->power_mode == MMC_POWER_ON)
			host->cmdat |= CMDAT_INIT;
	}

	if (ios->bus_width == MMC_BUS_WIDTH_4)
		host->cmdat |= CMDAT_SD_4DAT;
	else
		host->cmdat &= ~CMDAT_SD_4DAT;

	dev_dbg(mmc_dev(mmc), "PXAMCI: clkrt = %x cmdat = %x\n",
		host->clkrt, host->cmdat);
}

static void pxamci_enable_sdio_irq(struct mmc_host *host, int enable)
{
	struct pxamci_host *pxa_host = mmc_priv(host);

	if (enable)
		pxamci_enable_irq(pxa_host, SDIO_INT);
	else
		pxamci_disable_irq(pxa_host, SDIO_INT);
}

static const struct mmc_host_ops pxamci_ops = {
	.request		= pxamci_request,
	.get_cd			= mmc_gpio_get_cd,
	.get_ro			= pxamci_get_ro,
	.set_ios		= pxamci_set_ios,
	.enable_sdio_irq	= pxamci_enable_sdio_irq,
};

static void pxamci_dma_irq(void *param)
{
	struct pxamci_host *host = param;
	struct dma_tx_state state;
	enum dma_status status;
	struct dma_chan *chan;
	unsigned long flags;

	spin_lock_irqsave(&host->lock, flags);

	if (!host->data)
		goto out_unlock;

	if (host->data->flags & MMC_DATA_READ)
		chan = host->dma_chan_rx;
	else
		chan = host->dma_chan_tx;

	status = dmaengine_tx_status(chan, host->dma_cookie, &state);

	if (likely(status == DMA_COMPLETE)) {
		writel(BUF_PART_FULL, host->base + MMC_PRTBUF);
	} else {
		pr_err("%s: DMA error on %s channel\n", mmc_hostname(host->mmc),
			host->data->flags & MMC_DATA_READ ? "rx" : "tx");
		host->data->error = -EIO;
		pxamci_data_done(host, 0);
	}

out_unlock:
	spin_unlock_irqrestore(&host->lock, flags);
}

static irqreturn_t pxamci_detect_irq(int irq, void *devid)
{
	struct pxamci_host *host = mmc_priv(devid);

	mmc_detect_change(devid, msecs_to_jiffies(host->pdata->detect_delay_ms));
	return IRQ_HANDLED;
}

#ifdef CONFIG_OF
static const struct of_device_id pxa_mmc_dt_ids[] = {
        { .compatible = "marvell,pxa-mmc" },
        { }
};

MODULE_DEVICE_TABLE(of, pxa_mmc_dt_ids);

static int pxamci_of_init(struct platform_device *pdev)
{
        struct device_node *np = pdev->dev.of_node;
        struct pxamci_platform_data *pdata;
        u32 tmp;

        if (!np)
                return 0;

        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return -ENOMEM;

	pdata->gpio_card_detect =
		of_get_named_gpio(np, "cd-gpios", 0);
	pdata->gpio_card_ro =
		of_get_named_gpio(np, "wp-gpios", 0);

	/* pxa-mmc specific */
	pdata->gpio_power =
		of_get_named_gpio(np, "pxa-mmc,gpio-power", 0);

	if (of_property_read_u32(np, "pxa-mmc,detect-delay-ms", &tmp) == 0)
		pdata->detect_delay_ms = tmp;

        pdev->dev.platform_data = pdata;

        return 0;
}
#else
static int pxamci_of_init(struct platform_device *pdev)
{
        return 0;
}
#endif

static int pxamci_probe(struct platform_device *pdev)
{
	struct mmc_host *mmc;
	struct pxamci_host *host = NULL;
	struct resource *r, *dmarx, *dmatx;
	struct pxad_param param_rx, param_tx;
	int ret, irq, gpio_cd = -1, gpio_ro = -1, gpio_power = -1;
	dma_cap_mask_t mask;

	ret = pxamci_of_init(pdev);
	if (ret)
		return ret;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	irq = platform_get_irq(pdev, 0);
	if (!r || irq < 0)
		return -ENXIO;

	r = request_mem_region(r->start, SZ_4K, DRIVER_NAME);
	if (!r)
		return -EBUSY;

	mmc = mmc_alloc_host(sizeof(struct pxamci_host), &pdev->dev);
	if (!mmc) {
		ret = -ENOMEM;
		goto out;
	}

	mmc->ops = &pxamci_ops;

	/*
	 * We can do SG-DMA, but we don't because we never know how much
	 * data we successfully wrote to the card.
	 */
	mmc->max_segs = NR_SG;

	/*
	 * Our hardware DMA can handle a maximum of one page per SG entry.
	 */
	mmc->max_seg_size = PAGE_SIZE;

	/*
	 * Block length register is only 10 bits before PXA27x.
	 */
	mmc->max_blk_size = cpu_is_pxa25x() ? 1023 : 2048;

	/*
	 * Block count register is 16 bits.
	 */
	mmc->max_blk_count = 65535;

	host = mmc_priv(mmc);
	host->mmc = mmc;
	host->pdata = pdev->dev.platform_data;
	host->clkrt = CLKRT_OFF;

	host->clk = clk_get(&pdev->dev, NULL);
	if (IS_ERR(host->clk)) {
		ret = PTR_ERR(host->clk);
		host->clk = NULL;
		goto out;
	}

	host->clkrate = clk_get_rate(host->clk);

	/*
	 * Calculate minimum clock rate, rounding up.
	 */
	mmc->f_min = (host->clkrate + 63) / 64;
	mmc->f_max = (mmc_has_26MHz()) ? 26000000 : host->clkrate;

	pxamci_init_ocr(host);

	mmc->caps = 0;
	host->cmdat = 0;
	if (!cpu_is_pxa25x()) {
		mmc->caps |= MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
		host->cmdat |= CMDAT_SDIO_INT_EN;
		if (mmc_has_26MHz())
			mmc->caps |= MMC_CAP_MMC_HIGHSPEED |
				     MMC_CAP_SD_HIGHSPEED;
	}

	spin_lock_init(&host->lock);
	host->res = r;
	host->irq = irq;
	host->imask = MMC_I_MASK_ALL;

	host->base = ioremap(r->start, SZ_4K);
	if (!host->base) {
		ret = -ENOMEM;
		goto out;
	}

	/*
	 * Ensure that the host controller is shut down, and setup
	 * with our defaults.
	 */
	pxamci_stop_clock(host);
	writel(0, host->base + MMC_SPI);
	writel(64, host->base + MMC_RESTO);
	writel(host->imask, host->base + MMC_I_MASK);

	ret = request_irq(host->irq, pxamci_irq, 0, DRIVER_NAME, host);
	if (ret)
		goto out;

	platform_set_drvdata(pdev, mmc);

	if (!pdev->dev.of_node) {
		dmarx = platform_get_resource(pdev, IORESOURCE_DMA, 0);
		dmatx = platform_get_resource(pdev, IORESOURCE_DMA, 1);
		if (!dmarx || !dmatx) {
			ret = -ENXIO;
			goto out;
		}
		param_rx.prio = PXAD_PRIO_LOWEST;
		param_rx.drcmr = dmarx->start;
		param_tx.prio = PXAD_PRIO_LOWEST;
		param_tx.drcmr = dmatx->start;
	}

	dma_cap_zero(mask);
	dma_cap_set(DMA_SLAVE, mask);

	host->dma_chan_rx =
		dma_request_slave_channel_compat(mask, pxad_filter_fn,
						 &param_rx, &pdev->dev, "rx");
	if (host->dma_chan_rx == NULL) {
		dev_err(&pdev->dev, "unable to request rx dma channel\n");
		ret = -ENODEV;
		goto out;
	}

	host->dma_chan_tx =
		dma_request_slave_channel_compat(mask, pxad_filter_fn,
						 &param_tx,  &pdev->dev, "tx");
	if (host->dma_chan_tx == NULL) {
		dev_err(&pdev->dev, "unable to request tx dma channel\n");
		ret = -ENODEV;
		goto out;
	}

	if (host->pdata) {
		gpio_cd = host->pdata->gpio_card_detect;
		gpio_ro = host->pdata->gpio_card_ro;
		gpio_power = host->pdata->gpio_power;
	}
	if (gpio_is_valid(gpio_power)) {
		ret = devm_gpio_request(&pdev->dev, gpio_power,
					"mmc card power");
		if (ret) {
			dev_err(&pdev->dev, "Failed requesting gpio_power %d\n",
				gpio_power);
			goto out;
		}
		gpio_direction_output(gpio_power,
				      host->pdata->gpio_power_invert);
	}
	if (gpio_is_valid(gpio_ro))
		ret = mmc_gpio_request_ro(mmc, gpio_ro);
	if (ret) {
		dev_err(&pdev->dev, "Failed requesting gpio_ro %d\n", gpio_ro);
		goto out;
	} else {
		mmc->caps2 |= host->pdata->gpio_card_ro_invert ?
			0 : MMC_CAP2_RO_ACTIVE_HIGH;
	}

	if (gpio_is_valid(gpio_cd))
		ret = mmc_gpio_request_cd(mmc, gpio_cd, 0);
	if (ret) {
		dev_err(&pdev->dev, "Failed requesting gpio_cd %d\n", gpio_cd);
		goto out;
	}

	if (host->pdata && host->pdata->init)
		host->pdata->init(&pdev->dev, pxamci_detect_irq, mmc);

	if (gpio_is_valid(gpio_power) && host->pdata->setpower)
		dev_warn(&pdev->dev, "gpio_power and setpower() both defined\n");
	if (gpio_is_valid(gpio_ro) && host->pdata->get_ro)
		dev_warn(&pdev->dev, "gpio_ro and get_ro() both defined\n");

	mmc_add_host(mmc);

	return 0;

out:
	if (host) {
		if (host->dma_chan_rx)
			dma_release_channel(host->dma_chan_rx);
		if (host->dma_chan_tx)
			dma_release_channel(host->dma_chan_tx);
		if (host->base)
			iounmap(host->base);
		if (host->clk)
			clk_put(host->clk);
	}
	if (mmc)
		mmc_free_host(mmc);
	release_resource(r);
	return ret;
}

static int pxamci_remove(struct platform_device *pdev)
{
	struct mmc_host *mmc = platform_get_drvdata(pdev);
	int gpio_cd = -1, gpio_ro = -1, gpio_power = -1;

	if (mmc) {
		struct pxamci_host *host = mmc_priv(mmc);

		mmc_remove_host(mmc);

		if (host->pdata) {
			gpio_cd = host->pdata->gpio_card_detect;
			gpio_ro = host->pdata->gpio_card_ro;
			gpio_power = host->pdata->gpio_power;
		}
		if (host->vcc)
			regulator_put(host->vcc);

		if (host->pdata && host->pdata->exit)
			host->pdata->exit(&pdev->dev, mmc);

		pxamci_stop_clock(host);
		writel(TXFIFO_WR_REQ|RXFIFO_RD_REQ|CLK_IS_OFF|STOP_CMD|
		       END_CMD_RES|PRG_DONE|DATA_TRAN_DONE,
		       host->base + MMC_I_MASK);

		free_irq(host->irq, host);
		dmaengine_terminate_all(host->dma_chan_rx);
		dmaengine_terminate_all(host->dma_chan_tx);
		dma_release_channel(host->dma_chan_rx);
		dma_release_channel(host->dma_chan_tx);
		iounmap(host->base);

		clk_put(host->clk);

		release_resource(host->res);

		mmc_free_host(mmc);
	}
	return 0;
}

static struct platform_driver pxamci_driver = {
	.probe		= pxamci_probe,
	.remove		= pxamci_remove,
	.driver		= {
		.name	= DRIVER_NAME,
		.of_match_table = of_match_ptr(pxa_mmc_dt_ids),
	},
};

module_platform_driver(pxamci_driver);

MODULE_DESCRIPTION("PXA Multimedia Card Interface Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pxa2xx-mci");