xref: /linux/drivers/mmc/host/omap.c (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
1 /*
2  *  linux/drivers/mmc/host/omap.c
3  *
4  *  Copyright (C) 2004 Nokia Corporation
5  *  Written by Tuukka Tikkanen and Juha Yrjölä<juha.yrjola@nokia.com>
6  *  Misc hacks here and there by Tony Lindgren <tony@atomide.com>
7  *  Other hacks (DMA, SD, etc) by David Brownell
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 
14 #include <linux/module.h>
15 #include <linux/moduleparam.h>
16 #include <linux/init.h>
17 #include <linux/ioport.h>
18 #include <linux/platform_device.h>
19 #include <linux/interrupt.h>
20 #include <linux/dmaengine.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/delay.h>
23 #include <linux/spinlock.h>
24 #include <linux/timer.h>
25 #include <linux/of.h>
26 #include <linux/omap-dma.h>
27 #include <linux/mmc/host.h>
28 #include <linux/mmc/card.h>
29 #include <linux/mmc/mmc.h>
30 #include <linux/clk.h>
31 #include <linux/scatterlist.h>
32 #include <linux/slab.h>
33 #include <linux/platform_data/mmc-omap.h>
34 
35 
36 #define	OMAP_MMC_REG_CMD	0x00
37 #define	OMAP_MMC_REG_ARGL	0x01
38 #define	OMAP_MMC_REG_ARGH	0x02
39 #define	OMAP_MMC_REG_CON	0x03
40 #define	OMAP_MMC_REG_STAT	0x04
41 #define	OMAP_MMC_REG_IE		0x05
42 #define	OMAP_MMC_REG_CTO	0x06
43 #define	OMAP_MMC_REG_DTO	0x07
44 #define	OMAP_MMC_REG_DATA	0x08
45 #define	OMAP_MMC_REG_BLEN	0x09
46 #define	OMAP_MMC_REG_NBLK	0x0a
47 #define	OMAP_MMC_REG_BUF	0x0b
48 #define	OMAP_MMC_REG_SDIO	0x0d
49 #define	OMAP_MMC_REG_REV	0x0f
50 #define	OMAP_MMC_REG_RSP0	0x10
51 #define	OMAP_MMC_REG_RSP1	0x11
52 #define	OMAP_MMC_REG_RSP2	0x12
53 #define	OMAP_MMC_REG_RSP3	0x13
54 #define	OMAP_MMC_REG_RSP4	0x14
55 #define	OMAP_MMC_REG_RSP5	0x15
56 #define	OMAP_MMC_REG_RSP6	0x16
57 #define	OMAP_MMC_REG_RSP7	0x17
58 #define	OMAP_MMC_REG_IOSR	0x18
59 #define	OMAP_MMC_REG_SYSC	0x19
60 #define	OMAP_MMC_REG_SYSS	0x1a
61 
62 #define	OMAP_MMC_STAT_CARD_ERR		(1 << 14)
63 #define	OMAP_MMC_STAT_CARD_IRQ		(1 << 13)
64 #define	OMAP_MMC_STAT_OCR_BUSY		(1 << 12)
65 #define	OMAP_MMC_STAT_A_EMPTY		(1 << 11)
66 #define	OMAP_MMC_STAT_A_FULL		(1 << 10)
67 #define	OMAP_MMC_STAT_CMD_CRC		(1 <<  8)
68 #define	OMAP_MMC_STAT_CMD_TOUT		(1 <<  7)
69 #define	OMAP_MMC_STAT_DATA_CRC		(1 <<  6)
70 #define	OMAP_MMC_STAT_DATA_TOUT		(1 <<  5)
71 #define	OMAP_MMC_STAT_END_BUSY		(1 <<  4)
72 #define	OMAP_MMC_STAT_END_OF_DATA	(1 <<  3)
73 #define	OMAP_MMC_STAT_CARD_BUSY		(1 <<  2)
74 #define	OMAP_MMC_STAT_END_OF_CMD	(1 <<  0)
75 
76 #define mmc_omap7xx()	(host->features & MMC_OMAP7XX)
77 #define mmc_omap15xx()	(host->features & MMC_OMAP15XX)
78 #define mmc_omap16xx()	(host->features & MMC_OMAP16XX)
79 #define MMC_OMAP1_MASK	(MMC_OMAP7XX | MMC_OMAP15XX | MMC_OMAP16XX)
80 #define mmc_omap1()	(host->features & MMC_OMAP1_MASK)
81 #define mmc_omap2()	(!mmc_omap1())
82 
83 #define OMAP_MMC_REG(host, reg)		(OMAP_MMC_REG_##reg << (host)->reg_shift)
84 #define OMAP_MMC_READ(host, reg)	__raw_readw((host)->virt_base + OMAP_MMC_REG(host, reg))
85 #define OMAP_MMC_WRITE(host, reg, val)	__raw_writew((val), (host)->virt_base + OMAP_MMC_REG(host, reg))
86 
87 /*
88  * Command types
89  */
90 #define OMAP_MMC_CMDTYPE_BC	0
91 #define OMAP_MMC_CMDTYPE_BCR	1
92 #define OMAP_MMC_CMDTYPE_AC	2
93 #define OMAP_MMC_CMDTYPE_ADTC	3
94 
95 #define DRIVER_NAME "mmci-omap"
96 
97 /* Specifies how often in millisecs to poll for card status changes
98  * when the cover switch is open */
99 #define OMAP_MMC_COVER_POLL_DELAY	500
100 
101 struct mmc_omap_host;
102 
103 struct mmc_omap_slot {
104 	int			id;
105 	unsigned int		vdd;
106 	u16			saved_con;
107 	u16			bus_mode;
108 	unsigned int		fclk_freq;
109 
110 	struct tasklet_struct	cover_tasklet;
111 	struct timer_list       cover_timer;
112 	unsigned		cover_open;
113 
114 	struct mmc_request      *mrq;
115 	struct mmc_omap_host    *host;
116 	struct mmc_host		*mmc;
117 	struct omap_mmc_slot_data *pdata;
118 };
119 
120 struct mmc_omap_host {
121 	int			initialized;
122 	struct mmc_request *	mrq;
123 	struct mmc_command *	cmd;
124 	struct mmc_data *	data;
125 	struct mmc_host *	mmc;
126 	struct device *		dev;
127 	unsigned char		id; /* 16xx chips have 2 MMC blocks */
128 	struct clk *		iclk;
129 	struct clk *		fclk;
130 	struct dma_chan		*dma_rx;
131 	u32			dma_rx_burst;
132 	struct dma_chan		*dma_tx;
133 	u32			dma_tx_burst;
134 	void __iomem		*virt_base;
135 	unsigned int		phys_base;
136 	int			irq;
137 	unsigned char		bus_mode;
138 	unsigned int		reg_shift;
139 
140 	struct work_struct	cmd_abort_work;
141 	unsigned		abort:1;
142 	struct timer_list	cmd_abort_timer;
143 
144 	struct work_struct      slot_release_work;
145 	struct mmc_omap_slot    *next_slot;
146 	struct work_struct      send_stop_work;
147 	struct mmc_data		*stop_data;
148 
149 	unsigned int		sg_len;
150 	int			sg_idx;
151 	u16 *			buffer;
152 	u32			buffer_bytes_left;
153 	u32			total_bytes_left;
154 
155 	unsigned		features;
156 	unsigned		brs_received:1, dma_done:1;
157 	unsigned		dma_in_use:1;
158 	spinlock_t		dma_lock;
159 
160 	struct mmc_omap_slot    *slots[OMAP_MMC_MAX_SLOTS];
161 	struct mmc_omap_slot    *current_slot;
162 	spinlock_t              slot_lock;
163 	wait_queue_head_t       slot_wq;
164 	int                     nr_slots;
165 
166 	struct timer_list       clk_timer;
167 	spinlock_t		clk_lock;     /* for changing enabled state */
168 	unsigned int            fclk_enabled:1;
169 	struct workqueue_struct *mmc_omap_wq;
170 
171 	struct omap_mmc_platform_data *pdata;
172 };
173 
174 
175 static void mmc_omap_fclk_offdelay(struct mmc_omap_slot *slot)
176 {
177 	unsigned long tick_ns;
178 
179 	if (slot != NULL && slot->host->fclk_enabled && slot->fclk_freq > 0) {
180 		tick_ns = DIV_ROUND_UP(NSEC_PER_SEC, slot->fclk_freq);
181 		ndelay(8 * tick_ns);
182 	}
183 }
184 
185 static void mmc_omap_fclk_enable(struct mmc_omap_host *host, unsigned int enable)
186 {
187 	unsigned long flags;
188 
189 	spin_lock_irqsave(&host->clk_lock, flags);
190 	if (host->fclk_enabled != enable) {
191 		host->fclk_enabled = enable;
192 		if (enable)
193 			clk_enable(host->fclk);
194 		else
195 			clk_disable(host->fclk);
196 	}
197 	spin_unlock_irqrestore(&host->clk_lock, flags);
198 }
199 
200 static void mmc_omap_select_slot(struct mmc_omap_slot *slot, int claimed)
201 {
202 	struct mmc_omap_host *host = slot->host;
203 	unsigned long flags;
204 
205 	if (claimed)
206 		goto no_claim;
207 	spin_lock_irqsave(&host->slot_lock, flags);
208 	while (host->mmc != NULL) {
209 		spin_unlock_irqrestore(&host->slot_lock, flags);
210 		wait_event(host->slot_wq, host->mmc == NULL);
211 		spin_lock_irqsave(&host->slot_lock, flags);
212 	}
213 	host->mmc = slot->mmc;
214 	spin_unlock_irqrestore(&host->slot_lock, flags);
215 no_claim:
216 	del_timer(&host->clk_timer);
217 	if (host->current_slot != slot || !claimed)
218 		mmc_omap_fclk_offdelay(host->current_slot);
219 
220 	if (host->current_slot != slot) {
221 		OMAP_MMC_WRITE(host, CON, slot->saved_con & 0xFC00);
222 		if (host->pdata->switch_slot != NULL)
223 			host->pdata->switch_slot(mmc_dev(slot->mmc), slot->id);
224 		host->current_slot = slot;
225 	}
226 
227 	if (claimed) {
228 		mmc_omap_fclk_enable(host, 1);
229 
230 		/* Doing the dummy read here seems to work around some bug
231 		 * at least in OMAP24xx silicon where the command would not
232 		 * start after writing the CMD register. Sigh. */
233 		OMAP_MMC_READ(host, CON);
234 
235 		OMAP_MMC_WRITE(host, CON, slot->saved_con);
236 	} else
237 		mmc_omap_fclk_enable(host, 0);
238 }
239 
240 static void mmc_omap_start_request(struct mmc_omap_host *host,
241 				   struct mmc_request *req);
242 
243 static void mmc_omap_slot_release_work(struct work_struct *work)
244 {
245 	struct mmc_omap_host *host = container_of(work, struct mmc_omap_host,
246 						  slot_release_work);
247 	struct mmc_omap_slot *next_slot = host->next_slot;
248 	struct mmc_request *rq;
249 
250 	host->next_slot = NULL;
251 	mmc_omap_select_slot(next_slot, 1);
252 
253 	rq = next_slot->mrq;
254 	next_slot->mrq = NULL;
255 	mmc_omap_start_request(host, rq);
256 }
257 
258 static void mmc_omap_release_slot(struct mmc_omap_slot *slot, int clk_enabled)
259 {
260 	struct mmc_omap_host *host = slot->host;
261 	unsigned long flags;
262 	int i;
263 
264 	BUG_ON(slot == NULL || host->mmc == NULL);
265 
266 	if (clk_enabled)
267 		/* Keeps clock running for at least 8 cycles on valid freq */
268 		mod_timer(&host->clk_timer, jiffies  + HZ/10);
269 	else {
270 		del_timer(&host->clk_timer);
271 		mmc_omap_fclk_offdelay(slot);
272 		mmc_omap_fclk_enable(host, 0);
273 	}
274 
275 	spin_lock_irqsave(&host->slot_lock, flags);
276 	/* Check for any pending requests */
277 	for (i = 0; i < host->nr_slots; i++) {
278 		struct mmc_omap_slot *new_slot;
279 
280 		if (host->slots[i] == NULL || host->slots[i]->mrq == NULL)
281 			continue;
282 
283 		BUG_ON(host->next_slot != NULL);
284 		new_slot = host->slots[i];
285 		/* The current slot should not have a request in queue */
286 		BUG_ON(new_slot == host->current_slot);
287 
288 		host->next_slot = new_slot;
289 		host->mmc = new_slot->mmc;
290 		spin_unlock_irqrestore(&host->slot_lock, flags);
291 		queue_work(host->mmc_omap_wq, &host->slot_release_work);
292 		return;
293 	}
294 
295 	host->mmc = NULL;
296 	wake_up(&host->slot_wq);
297 	spin_unlock_irqrestore(&host->slot_lock, flags);
298 }
299 
300 static inline
301 int mmc_omap_cover_is_open(struct mmc_omap_slot *slot)
302 {
303 	if (slot->pdata->get_cover_state)
304 		return slot->pdata->get_cover_state(mmc_dev(slot->mmc),
305 						    slot->id);
306 	return 0;
307 }
308 
309 static ssize_t
310 mmc_omap_show_cover_switch(struct device *dev, struct device_attribute *attr,
311 			   char *buf)
312 {
313 	struct mmc_host *mmc = container_of(dev, struct mmc_host, class_dev);
314 	struct mmc_omap_slot *slot = mmc_priv(mmc);
315 
316 	return sprintf(buf, "%s\n", mmc_omap_cover_is_open(slot) ? "open" :
317 		       "closed");
318 }
319 
320 static DEVICE_ATTR(cover_switch, S_IRUGO, mmc_omap_show_cover_switch, NULL);
321 
322 static ssize_t
323 mmc_omap_show_slot_name(struct device *dev, struct device_attribute *attr,
324 			char *buf)
325 {
326 	struct mmc_host *mmc = container_of(dev, struct mmc_host, class_dev);
327 	struct mmc_omap_slot *slot = mmc_priv(mmc);
328 
329 	return sprintf(buf, "%s\n", slot->pdata->name);
330 }
331 
332 static DEVICE_ATTR(slot_name, S_IRUGO, mmc_omap_show_slot_name, NULL);
333 
334 static void
335 mmc_omap_start_command(struct mmc_omap_host *host, struct mmc_command *cmd)
336 {
337 	u32 cmdreg;
338 	u32 resptype;
339 	u32 cmdtype;
340 	u16 irq_mask;
341 
342 	host->cmd = cmd;
343 
344 	resptype = 0;
345 	cmdtype = 0;
346 
347 	/* Our hardware needs to know exact type */
348 	switch (mmc_resp_type(cmd)) {
349 	case MMC_RSP_NONE:
350 		break;
351 	case MMC_RSP_R1:
352 	case MMC_RSP_R1B:
353 		/* resp 1, 1b, 6, 7 */
354 		resptype = 1;
355 		break;
356 	case MMC_RSP_R2:
357 		resptype = 2;
358 		break;
359 	case MMC_RSP_R3:
360 		resptype = 3;
361 		break;
362 	default:
363 		dev_err(mmc_dev(host->mmc), "Invalid response type: %04x\n", mmc_resp_type(cmd));
364 		break;
365 	}
366 
367 	if (mmc_cmd_type(cmd) == MMC_CMD_ADTC) {
368 		cmdtype = OMAP_MMC_CMDTYPE_ADTC;
369 	} else if (mmc_cmd_type(cmd) == MMC_CMD_BC) {
370 		cmdtype = OMAP_MMC_CMDTYPE_BC;
371 	} else if (mmc_cmd_type(cmd) == MMC_CMD_BCR) {
372 		cmdtype = OMAP_MMC_CMDTYPE_BCR;
373 	} else {
374 		cmdtype = OMAP_MMC_CMDTYPE_AC;
375 	}
376 
377 	cmdreg = cmd->opcode | (resptype << 8) | (cmdtype << 12);
378 
379 	if (host->current_slot->bus_mode == MMC_BUSMODE_OPENDRAIN)
380 		cmdreg |= 1 << 6;
381 
382 	if (cmd->flags & MMC_RSP_BUSY)
383 		cmdreg |= 1 << 11;
384 
385 	if (host->data && !(host->data->flags & MMC_DATA_WRITE))
386 		cmdreg |= 1 << 15;
387 
388 	mod_timer(&host->cmd_abort_timer, jiffies + HZ/2);
389 
390 	OMAP_MMC_WRITE(host, CTO, 200);
391 	OMAP_MMC_WRITE(host, ARGL, cmd->arg & 0xffff);
392 	OMAP_MMC_WRITE(host, ARGH, cmd->arg >> 16);
393 	irq_mask = OMAP_MMC_STAT_A_EMPTY    | OMAP_MMC_STAT_A_FULL    |
394 		   OMAP_MMC_STAT_CMD_CRC    | OMAP_MMC_STAT_CMD_TOUT  |
395 		   OMAP_MMC_STAT_DATA_CRC   | OMAP_MMC_STAT_DATA_TOUT |
396 		   OMAP_MMC_STAT_END_OF_CMD | OMAP_MMC_STAT_CARD_ERR  |
397 		   OMAP_MMC_STAT_END_OF_DATA;
398 	if (cmd->opcode == MMC_ERASE)
399 		irq_mask &= ~OMAP_MMC_STAT_DATA_TOUT;
400 	OMAP_MMC_WRITE(host, IE, irq_mask);
401 	OMAP_MMC_WRITE(host, CMD, cmdreg);
402 }
403 
404 static void
405 mmc_omap_release_dma(struct mmc_omap_host *host, struct mmc_data *data,
406 		     int abort)
407 {
408 	enum dma_data_direction dma_data_dir;
409 	struct device *dev = mmc_dev(host->mmc);
410 	struct dma_chan *c;
411 
412 	if (data->flags & MMC_DATA_WRITE) {
413 		dma_data_dir = DMA_TO_DEVICE;
414 		c = host->dma_tx;
415 	} else {
416 		dma_data_dir = DMA_FROM_DEVICE;
417 		c = host->dma_rx;
418 	}
419 	if (c) {
420 		if (data->error) {
421 			dmaengine_terminate_all(c);
422 			/* Claim nothing transferred on error... */
423 			data->bytes_xfered = 0;
424 		}
425 		dev = c->device->dev;
426 	}
427 	dma_unmap_sg(dev, data->sg, host->sg_len, dma_data_dir);
428 }
429 
430 static void mmc_omap_send_stop_work(struct work_struct *work)
431 {
432 	struct mmc_omap_host *host = container_of(work, struct mmc_omap_host,
433 						  send_stop_work);
434 	struct mmc_omap_slot *slot = host->current_slot;
435 	struct mmc_data *data = host->stop_data;
436 	unsigned long tick_ns;
437 
438 	tick_ns = DIV_ROUND_UP(NSEC_PER_SEC, slot->fclk_freq);
439 	ndelay(8*tick_ns);
440 
441 	mmc_omap_start_command(host, data->stop);
442 }
443 
444 static void
445 mmc_omap_xfer_done(struct mmc_omap_host *host, struct mmc_data *data)
446 {
447 	if (host->dma_in_use)
448 		mmc_omap_release_dma(host, data, data->error);
449 
450 	host->data = NULL;
451 	host->sg_len = 0;
452 
453 	/* NOTE:  MMC layer will sometimes poll-wait CMD13 next, issuing
454 	 * dozens of requests until the card finishes writing data.
455 	 * It'd be cheaper to just wait till an EOFB interrupt arrives...
456 	 */
457 
458 	if (!data->stop) {
459 		struct mmc_host *mmc;
460 
461 		host->mrq = NULL;
462 		mmc = host->mmc;
463 		mmc_omap_release_slot(host->current_slot, 1);
464 		mmc_request_done(mmc, data->mrq);
465 		return;
466 	}
467 
468 	host->stop_data = data;
469 	queue_work(host->mmc_omap_wq, &host->send_stop_work);
470 }
471 
472 static void
473 mmc_omap_send_abort(struct mmc_omap_host *host, int maxloops)
474 {
475 	struct mmc_omap_slot *slot = host->current_slot;
476 	unsigned int restarts, passes, timeout;
477 	u16 stat = 0;
478 
479 	/* Sending abort takes 80 clocks. Have some extra and round up */
480 	timeout = DIV_ROUND_UP(120 * USEC_PER_SEC, slot->fclk_freq);
481 	restarts = 0;
482 	while (restarts < maxloops) {
483 		OMAP_MMC_WRITE(host, STAT, 0xFFFF);
484 		OMAP_MMC_WRITE(host, CMD, (3 << 12) | (1 << 7));
485 
486 		passes = 0;
487 		while (passes < timeout) {
488 			stat = OMAP_MMC_READ(host, STAT);
489 			if (stat & OMAP_MMC_STAT_END_OF_CMD)
490 				goto out;
491 			udelay(1);
492 			passes++;
493 		}
494 
495 		restarts++;
496 	}
497 out:
498 	OMAP_MMC_WRITE(host, STAT, stat);
499 }
500 
501 static void
502 mmc_omap_abort_xfer(struct mmc_omap_host *host, struct mmc_data *data)
503 {
504 	if (host->dma_in_use)
505 		mmc_omap_release_dma(host, data, 1);
506 
507 	host->data = NULL;
508 	host->sg_len = 0;
509 
510 	mmc_omap_send_abort(host, 10000);
511 }
512 
513 static void
514 mmc_omap_end_of_data(struct mmc_omap_host *host, struct mmc_data *data)
515 {
516 	unsigned long flags;
517 	int done;
518 
519 	if (!host->dma_in_use) {
520 		mmc_omap_xfer_done(host, data);
521 		return;
522 	}
523 	done = 0;
524 	spin_lock_irqsave(&host->dma_lock, flags);
525 	if (host->dma_done)
526 		done = 1;
527 	else
528 		host->brs_received = 1;
529 	spin_unlock_irqrestore(&host->dma_lock, flags);
530 	if (done)
531 		mmc_omap_xfer_done(host, data);
532 }
533 
534 static void
535 mmc_omap_dma_done(struct mmc_omap_host *host, struct mmc_data *data)
536 {
537 	unsigned long flags;
538 	int done;
539 
540 	done = 0;
541 	spin_lock_irqsave(&host->dma_lock, flags);
542 	if (host->brs_received)
543 		done = 1;
544 	else
545 		host->dma_done = 1;
546 	spin_unlock_irqrestore(&host->dma_lock, flags);
547 	if (done)
548 		mmc_omap_xfer_done(host, data);
549 }
550 
551 static void
552 mmc_omap_cmd_done(struct mmc_omap_host *host, struct mmc_command *cmd)
553 {
554 	host->cmd = NULL;
555 
556 	del_timer(&host->cmd_abort_timer);
557 
558 	if (cmd->flags & MMC_RSP_PRESENT) {
559 		if (cmd->flags & MMC_RSP_136) {
560 			/* response type 2 */
561 			cmd->resp[3] =
562 				OMAP_MMC_READ(host, RSP0) |
563 				(OMAP_MMC_READ(host, RSP1) << 16);
564 			cmd->resp[2] =
565 				OMAP_MMC_READ(host, RSP2) |
566 				(OMAP_MMC_READ(host, RSP3) << 16);
567 			cmd->resp[1] =
568 				OMAP_MMC_READ(host, RSP4) |
569 				(OMAP_MMC_READ(host, RSP5) << 16);
570 			cmd->resp[0] =
571 				OMAP_MMC_READ(host, RSP6) |
572 				(OMAP_MMC_READ(host, RSP7) << 16);
573 		} else {
574 			/* response types 1, 1b, 3, 4, 5, 6 */
575 			cmd->resp[0] =
576 				OMAP_MMC_READ(host, RSP6) |
577 				(OMAP_MMC_READ(host, RSP7) << 16);
578 		}
579 	}
580 
581 	if (host->data == NULL || cmd->error) {
582 		struct mmc_host *mmc;
583 
584 		if (host->data != NULL)
585 			mmc_omap_abort_xfer(host, host->data);
586 		host->mrq = NULL;
587 		mmc = host->mmc;
588 		mmc_omap_release_slot(host->current_slot, 1);
589 		mmc_request_done(mmc, cmd->mrq);
590 	}
591 }
592 
593 /*
594  * Abort stuck command. Can occur when card is removed while it is being
595  * read.
596  */
597 static void mmc_omap_abort_command(struct work_struct *work)
598 {
599 	struct mmc_omap_host *host = container_of(work, struct mmc_omap_host,
600 						  cmd_abort_work);
601 	BUG_ON(!host->cmd);
602 
603 	dev_dbg(mmc_dev(host->mmc), "Aborting stuck command CMD%d\n",
604 		host->cmd->opcode);
605 
606 	if (host->cmd->error == 0)
607 		host->cmd->error = -ETIMEDOUT;
608 
609 	if (host->data == NULL) {
610 		struct mmc_command *cmd;
611 		struct mmc_host    *mmc;
612 
613 		cmd = host->cmd;
614 		host->cmd = NULL;
615 		mmc_omap_send_abort(host, 10000);
616 
617 		host->mrq = NULL;
618 		mmc = host->mmc;
619 		mmc_omap_release_slot(host->current_slot, 1);
620 		mmc_request_done(mmc, cmd->mrq);
621 	} else
622 		mmc_omap_cmd_done(host, host->cmd);
623 
624 	host->abort = 0;
625 	enable_irq(host->irq);
626 }
627 
628 static void
629 mmc_omap_cmd_timer(unsigned long data)
630 {
631 	struct mmc_omap_host *host = (struct mmc_omap_host *) data;
632 	unsigned long flags;
633 
634 	spin_lock_irqsave(&host->slot_lock, flags);
635 	if (host->cmd != NULL && !host->abort) {
636 		OMAP_MMC_WRITE(host, IE, 0);
637 		disable_irq(host->irq);
638 		host->abort = 1;
639 		queue_work(host->mmc_omap_wq, &host->cmd_abort_work);
640 	}
641 	spin_unlock_irqrestore(&host->slot_lock, flags);
642 }
643 
644 /* PIO only */
645 static void
646 mmc_omap_sg_to_buf(struct mmc_omap_host *host)
647 {
648 	struct scatterlist *sg;
649 
650 	sg = host->data->sg + host->sg_idx;
651 	host->buffer_bytes_left = sg->length;
652 	host->buffer = sg_virt(sg);
653 	if (host->buffer_bytes_left > host->total_bytes_left)
654 		host->buffer_bytes_left = host->total_bytes_left;
655 }
656 
657 static void
658 mmc_omap_clk_timer(unsigned long data)
659 {
660 	struct mmc_omap_host *host = (struct mmc_omap_host *) data;
661 
662 	mmc_omap_fclk_enable(host, 0);
663 }
664 
665 /* PIO only */
666 static void
667 mmc_omap_xfer_data(struct mmc_omap_host *host, int write)
668 {
669 	int n, nwords;
670 
671 	if (host->buffer_bytes_left == 0) {
672 		host->sg_idx++;
673 		BUG_ON(host->sg_idx == host->sg_len);
674 		mmc_omap_sg_to_buf(host);
675 	}
676 	n = 64;
677 	if (n > host->buffer_bytes_left)
678 		n = host->buffer_bytes_left;
679 
680 	/* Round up to handle odd number of bytes to transfer */
681 	nwords = DIV_ROUND_UP(n, 2);
682 
683 	host->buffer_bytes_left -= n;
684 	host->total_bytes_left -= n;
685 	host->data->bytes_xfered += n;
686 
687 	if (write) {
688 		__raw_writesw(host->virt_base + OMAP_MMC_REG(host, DATA),
689 			      host->buffer, nwords);
690 	} else {
691 		__raw_readsw(host->virt_base + OMAP_MMC_REG(host, DATA),
692 			     host->buffer, nwords);
693 	}
694 
695 	host->buffer += nwords;
696 }
697 
698 #ifdef CONFIG_MMC_DEBUG
699 static void mmc_omap_report_irq(struct mmc_omap_host *host, u16 status)
700 {
701 	static const char *mmc_omap_status_bits[] = {
702 		"EOC", "CD", "CB", "BRS", "EOFB", "DTO", "DCRC", "CTO",
703 		"CCRC", "CRW", "AF", "AE", "OCRB", "CIRQ", "CERR"
704 	};
705 	int i;
706 	char res[64], *buf = res;
707 
708 	buf += sprintf(buf, "MMC IRQ 0x%x:", status);
709 
710 	for (i = 0; i < ARRAY_SIZE(mmc_omap_status_bits); i++)
711 		if (status & (1 << i))
712 			buf += sprintf(buf, " %s", mmc_omap_status_bits[i]);
713 	dev_vdbg(mmc_dev(host->mmc), "%s\n", res);
714 }
715 #else
716 static void mmc_omap_report_irq(struct mmc_omap_host *host, u16 status)
717 {
718 }
719 #endif
720 
721 
722 static irqreturn_t mmc_omap_irq(int irq, void *dev_id)
723 {
724 	struct mmc_omap_host * host = (struct mmc_omap_host *)dev_id;
725 	u16 status;
726 	int end_command;
727 	int end_transfer;
728 	int transfer_error, cmd_error;
729 
730 	if (host->cmd == NULL && host->data == NULL) {
731 		status = OMAP_MMC_READ(host, STAT);
732 		dev_info(mmc_dev(host->slots[0]->mmc),
733 			 "Spurious IRQ 0x%04x\n", status);
734 		if (status != 0) {
735 			OMAP_MMC_WRITE(host, STAT, status);
736 			OMAP_MMC_WRITE(host, IE, 0);
737 		}
738 		return IRQ_HANDLED;
739 	}
740 
741 	end_command = 0;
742 	end_transfer = 0;
743 	transfer_error = 0;
744 	cmd_error = 0;
745 
746 	while ((status = OMAP_MMC_READ(host, STAT)) != 0) {
747 		int cmd;
748 
749 		OMAP_MMC_WRITE(host, STAT, status);
750 		if (host->cmd != NULL)
751 			cmd = host->cmd->opcode;
752 		else
753 			cmd = -1;
754 		dev_dbg(mmc_dev(host->mmc), "MMC IRQ %04x (CMD %d): ",
755 			status, cmd);
756 		mmc_omap_report_irq(host, status);
757 
758 		if (host->total_bytes_left) {
759 			if ((status & OMAP_MMC_STAT_A_FULL) ||
760 			    (status & OMAP_MMC_STAT_END_OF_DATA))
761 				mmc_omap_xfer_data(host, 0);
762 			if (status & OMAP_MMC_STAT_A_EMPTY)
763 				mmc_omap_xfer_data(host, 1);
764 		}
765 
766 		if (status & OMAP_MMC_STAT_END_OF_DATA)
767 			end_transfer = 1;
768 
769 		if (status & OMAP_MMC_STAT_DATA_TOUT) {
770 			dev_dbg(mmc_dev(host->mmc), "data timeout (CMD%d)\n",
771 				cmd);
772 			if (host->data) {
773 				host->data->error = -ETIMEDOUT;
774 				transfer_error = 1;
775 			}
776 		}
777 
778 		if (status & OMAP_MMC_STAT_DATA_CRC) {
779 			if (host->data) {
780 				host->data->error = -EILSEQ;
781 				dev_dbg(mmc_dev(host->mmc),
782 					 "data CRC error, bytes left %d\n",
783 					host->total_bytes_left);
784 				transfer_error = 1;
785 			} else {
786 				dev_dbg(mmc_dev(host->mmc), "data CRC error\n");
787 			}
788 		}
789 
790 		if (status & OMAP_MMC_STAT_CMD_TOUT) {
791 			/* Timeouts are routine with some commands */
792 			if (host->cmd) {
793 				struct mmc_omap_slot *slot =
794 					host->current_slot;
795 				if (slot == NULL ||
796 				    !mmc_omap_cover_is_open(slot))
797 					dev_err(mmc_dev(host->mmc),
798 						"command timeout (CMD%d)\n",
799 						cmd);
800 				host->cmd->error = -ETIMEDOUT;
801 				end_command = 1;
802 				cmd_error = 1;
803 			}
804 		}
805 
806 		if (status & OMAP_MMC_STAT_CMD_CRC) {
807 			if (host->cmd) {
808 				dev_err(mmc_dev(host->mmc),
809 					"command CRC error (CMD%d, arg 0x%08x)\n",
810 					cmd, host->cmd->arg);
811 				host->cmd->error = -EILSEQ;
812 				end_command = 1;
813 				cmd_error = 1;
814 			} else
815 				dev_err(mmc_dev(host->mmc),
816 					"command CRC error without cmd?\n");
817 		}
818 
819 		if (status & OMAP_MMC_STAT_CARD_ERR) {
820 			dev_dbg(mmc_dev(host->mmc),
821 				"ignoring card status error (CMD%d)\n",
822 				cmd);
823 			end_command = 1;
824 		}
825 
826 		/*
827 		 * NOTE: On 1610 the END_OF_CMD may come too early when
828 		 * starting a write
829 		 */
830 		if ((status & OMAP_MMC_STAT_END_OF_CMD) &&
831 		    (!(status & OMAP_MMC_STAT_A_EMPTY))) {
832 			end_command = 1;
833 		}
834 	}
835 
836 	if (cmd_error && host->data) {
837 		del_timer(&host->cmd_abort_timer);
838 		host->abort = 1;
839 		OMAP_MMC_WRITE(host, IE, 0);
840 		disable_irq_nosync(host->irq);
841 		queue_work(host->mmc_omap_wq, &host->cmd_abort_work);
842 		return IRQ_HANDLED;
843 	}
844 
845 	if (end_command && host->cmd)
846 		mmc_omap_cmd_done(host, host->cmd);
847 	if (host->data != NULL) {
848 		if (transfer_error)
849 			mmc_omap_xfer_done(host, host->data);
850 		else if (end_transfer)
851 			mmc_omap_end_of_data(host, host->data);
852 	}
853 
854 	return IRQ_HANDLED;
855 }
856 
857 void omap_mmc_notify_cover_event(struct device *dev, int num, int is_closed)
858 {
859 	int cover_open;
860 	struct mmc_omap_host *host = dev_get_drvdata(dev);
861 	struct mmc_omap_slot *slot = host->slots[num];
862 
863 	BUG_ON(num >= host->nr_slots);
864 
865 	/* Other subsystems can call in here before we're initialised. */
866 	if (host->nr_slots == 0 || !host->slots[num])
867 		return;
868 
869 	cover_open = mmc_omap_cover_is_open(slot);
870 	if (cover_open != slot->cover_open) {
871 		slot->cover_open = cover_open;
872 		sysfs_notify(&slot->mmc->class_dev.kobj, NULL, "cover_switch");
873 	}
874 
875 	tasklet_hi_schedule(&slot->cover_tasklet);
876 }
877 
878 static void mmc_omap_cover_timer(unsigned long arg)
879 {
880 	struct mmc_omap_slot *slot = (struct mmc_omap_slot *) arg;
881 	tasklet_schedule(&slot->cover_tasklet);
882 }
883 
884 static void mmc_omap_cover_handler(unsigned long param)
885 {
886 	struct mmc_omap_slot *slot = (struct mmc_omap_slot *)param;
887 	int cover_open = mmc_omap_cover_is_open(slot);
888 
889 	mmc_detect_change(slot->mmc, 0);
890 	if (!cover_open)
891 		return;
892 
893 	/*
894 	 * If no card is inserted, we postpone polling until
895 	 * the cover has been closed.
896 	 */
897 	if (slot->mmc->card == NULL || !mmc_card_present(slot->mmc->card))
898 		return;
899 
900 	mod_timer(&slot->cover_timer,
901 		  jiffies + msecs_to_jiffies(OMAP_MMC_COVER_POLL_DELAY));
902 }
903 
904 static void mmc_omap_dma_callback(void *priv)
905 {
906 	struct mmc_omap_host *host = priv;
907 	struct mmc_data *data = host->data;
908 
909 	/* If we got to the end of DMA, assume everything went well */
910 	data->bytes_xfered += data->blocks * data->blksz;
911 
912 	mmc_omap_dma_done(host, data);
913 }
914 
915 static inline void set_cmd_timeout(struct mmc_omap_host *host, struct mmc_request *req)
916 {
917 	u16 reg;
918 
919 	reg = OMAP_MMC_READ(host, SDIO);
920 	reg &= ~(1 << 5);
921 	OMAP_MMC_WRITE(host, SDIO, reg);
922 	/* Set maximum timeout */
923 	OMAP_MMC_WRITE(host, CTO, 0xff);
924 }
925 
926 static inline void set_data_timeout(struct mmc_omap_host *host, struct mmc_request *req)
927 {
928 	unsigned int timeout, cycle_ns;
929 	u16 reg;
930 
931 	cycle_ns = 1000000000 / host->current_slot->fclk_freq;
932 	timeout = req->data->timeout_ns / cycle_ns;
933 	timeout += req->data->timeout_clks;
934 
935 	/* Check if we need to use timeout multiplier register */
936 	reg = OMAP_MMC_READ(host, SDIO);
937 	if (timeout > 0xffff) {
938 		reg |= (1 << 5);
939 		timeout /= 1024;
940 	} else
941 		reg &= ~(1 << 5);
942 	OMAP_MMC_WRITE(host, SDIO, reg);
943 	OMAP_MMC_WRITE(host, DTO, timeout);
944 }
945 
946 static void
947 mmc_omap_prepare_data(struct mmc_omap_host *host, struct mmc_request *req)
948 {
949 	struct mmc_data *data = req->data;
950 	int i, use_dma = 1, block_size;
951 	unsigned sg_len;
952 
953 	host->data = data;
954 	if (data == NULL) {
955 		OMAP_MMC_WRITE(host, BLEN, 0);
956 		OMAP_MMC_WRITE(host, NBLK, 0);
957 		OMAP_MMC_WRITE(host, BUF, 0);
958 		host->dma_in_use = 0;
959 		set_cmd_timeout(host, req);
960 		return;
961 	}
962 
963 	block_size = data->blksz;
964 
965 	OMAP_MMC_WRITE(host, NBLK, data->blocks - 1);
966 	OMAP_MMC_WRITE(host, BLEN, block_size - 1);
967 	set_data_timeout(host, req);
968 
969 	/* cope with calling layer confusion; it issues "single
970 	 * block" writes using multi-block scatterlists.
971 	 */
972 	sg_len = (data->blocks == 1) ? 1 : data->sg_len;
973 
974 	/* Only do DMA for entire blocks */
975 	for (i = 0; i < sg_len; i++) {
976 		if ((data->sg[i].length % block_size) != 0) {
977 			use_dma = 0;
978 			break;
979 		}
980 	}
981 
982 	host->sg_idx = 0;
983 	if (use_dma) {
984 		enum dma_data_direction dma_data_dir;
985 		struct dma_async_tx_descriptor *tx;
986 		struct dma_chan *c;
987 		u32 burst, *bp;
988 		u16 buf;
989 
990 		/*
991 		 * FIFO is 16x2 bytes on 15xx, and 32x2 bytes on 16xx
992 		 * and 24xx. Use 16 or 32 word frames when the
993 		 * blocksize is at least that large. Blocksize is
994 		 * usually 512 bytes; but not for some SD reads.
995 		 */
996 		burst = mmc_omap15xx() ? 32 : 64;
997 		if (burst > data->blksz)
998 			burst = data->blksz;
999 
1000 		burst >>= 1;
1001 
1002 		if (data->flags & MMC_DATA_WRITE) {
1003 			c = host->dma_tx;
1004 			bp = &host->dma_tx_burst;
1005 			buf = 0x0f80 | (burst - 1) << 0;
1006 			dma_data_dir = DMA_TO_DEVICE;
1007 		} else {
1008 			c = host->dma_rx;
1009 			bp = &host->dma_rx_burst;
1010 			buf = 0x800f | (burst - 1) << 8;
1011 			dma_data_dir = DMA_FROM_DEVICE;
1012 		}
1013 
1014 		if (!c)
1015 			goto use_pio;
1016 
1017 		/* Only reconfigure if we have a different burst size */
1018 		if (*bp != burst) {
1019 			struct dma_slave_config cfg;
1020 
1021 			cfg.src_addr = host->phys_base + OMAP_MMC_REG(host, DATA);
1022 			cfg.dst_addr = host->phys_base + OMAP_MMC_REG(host, DATA);
1023 			cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1024 			cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1025 			cfg.src_maxburst = burst;
1026 			cfg.dst_maxburst = burst;
1027 
1028 			if (dmaengine_slave_config(c, &cfg))
1029 				goto use_pio;
1030 
1031 			*bp = burst;
1032 		}
1033 
1034 		host->sg_len = dma_map_sg(c->device->dev, data->sg, sg_len,
1035 					  dma_data_dir);
1036 		if (host->sg_len == 0)
1037 			goto use_pio;
1038 
1039 		tx = dmaengine_prep_slave_sg(c, data->sg, host->sg_len,
1040 			data->flags & MMC_DATA_WRITE ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
1041 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1042 		if (!tx)
1043 			goto use_pio;
1044 
1045 		OMAP_MMC_WRITE(host, BUF, buf);
1046 
1047 		tx->callback = mmc_omap_dma_callback;
1048 		tx->callback_param = host;
1049 		dmaengine_submit(tx);
1050 		host->brs_received = 0;
1051 		host->dma_done = 0;
1052 		host->dma_in_use = 1;
1053 		return;
1054 	}
1055  use_pio:
1056 
1057 	/* Revert to PIO? */
1058 	OMAP_MMC_WRITE(host, BUF, 0x1f1f);
1059 	host->total_bytes_left = data->blocks * block_size;
1060 	host->sg_len = sg_len;
1061 	mmc_omap_sg_to_buf(host);
1062 	host->dma_in_use = 0;
1063 }
1064 
1065 static void mmc_omap_start_request(struct mmc_omap_host *host,
1066 				   struct mmc_request *req)
1067 {
1068 	BUG_ON(host->mrq != NULL);
1069 
1070 	host->mrq = req;
1071 
1072 	/* only touch fifo AFTER the controller readies it */
1073 	mmc_omap_prepare_data(host, req);
1074 	mmc_omap_start_command(host, req->cmd);
1075 	if (host->dma_in_use) {
1076 		struct dma_chan *c = host->data->flags & MMC_DATA_WRITE ?
1077 				host->dma_tx : host->dma_rx;
1078 
1079 		dma_async_issue_pending(c);
1080 	}
1081 }
1082 
1083 static void mmc_omap_request(struct mmc_host *mmc, struct mmc_request *req)
1084 {
1085 	struct mmc_omap_slot *slot = mmc_priv(mmc);
1086 	struct mmc_omap_host *host = slot->host;
1087 	unsigned long flags;
1088 
1089 	spin_lock_irqsave(&host->slot_lock, flags);
1090 	if (host->mmc != NULL) {
1091 		BUG_ON(slot->mrq != NULL);
1092 		slot->mrq = req;
1093 		spin_unlock_irqrestore(&host->slot_lock, flags);
1094 		return;
1095 	} else
1096 		host->mmc = mmc;
1097 	spin_unlock_irqrestore(&host->slot_lock, flags);
1098 	mmc_omap_select_slot(slot, 1);
1099 	mmc_omap_start_request(host, req);
1100 }
1101 
1102 static void mmc_omap_set_power(struct mmc_omap_slot *slot, int power_on,
1103 				int vdd)
1104 {
1105 	struct mmc_omap_host *host;
1106 
1107 	host = slot->host;
1108 
1109 	if (slot->pdata->set_power != NULL)
1110 		slot->pdata->set_power(mmc_dev(slot->mmc), slot->id, power_on,
1111 					vdd);
1112 	if (mmc_omap2()) {
1113 		u16 w;
1114 
1115 		if (power_on) {
1116 			w = OMAP_MMC_READ(host, CON);
1117 			OMAP_MMC_WRITE(host, CON, w | (1 << 11));
1118 		} else {
1119 			w = OMAP_MMC_READ(host, CON);
1120 			OMAP_MMC_WRITE(host, CON, w & ~(1 << 11));
1121 		}
1122 	}
1123 }
1124 
1125 static int mmc_omap_calc_divisor(struct mmc_host *mmc, struct mmc_ios *ios)
1126 {
1127 	struct mmc_omap_slot *slot = mmc_priv(mmc);
1128 	struct mmc_omap_host *host = slot->host;
1129 	int func_clk_rate = clk_get_rate(host->fclk);
1130 	int dsor;
1131 
1132 	if (ios->clock == 0)
1133 		return 0;
1134 
1135 	dsor = func_clk_rate / ios->clock;
1136 	if (dsor < 1)
1137 		dsor = 1;
1138 
1139 	if (func_clk_rate / dsor > ios->clock)
1140 		dsor++;
1141 
1142 	if (dsor > 250)
1143 		dsor = 250;
1144 
1145 	slot->fclk_freq = func_clk_rate / dsor;
1146 
1147 	if (ios->bus_width == MMC_BUS_WIDTH_4)
1148 		dsor |= 1 << 15;
1149 
1150 	return dsor;
1151 }
1152 
1153 static void mmc_omap_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
1154 {
1155 	struct mmc_omap_slot *slot = mmc_priv(mmc);
1156 	struct mmc_omap_host *host = slot->host;
1157 	int i, dsor;
1158 	int clk_enabled;
1159 
1160 	mmc_omap_select_slot(slot, 0);
1161 
1162 	dsor = mmc_omap_calc_divisor(mmc, ios);
1163 
1164 	if (ios->vdd != slot->vdd)
1165 		slot->vdd = ios->vdd;
1166 
1167 	clk_enabled = 0;
1168 	switch (ios->power_mode) {
1169 	case MMC_POWER_OFF:
1170 		mmc_omap_set_power(slot, 0, ios->vdd);
1171 		break;
1172 	case MMC_POWER_UP:
1173 		/* Cannot touch dsor yet, just power up MMC */
1174 		mmc_omap_set_power(slot, 1, ios->vdd);
1175 		goto exit;
1176 	case MMC_POWER_ON:
1177 		mmc_omap_fclk_enable(host, 1);
1178 		clk_enabled = 1;
1179 		dsor |= 1 << 11;
1180 		break;
1181 	}
1182 
1183 	if (slot->bus_mode != ios->bus_mode) {
1184 		if (slot->pdata->set_bus_mode != NULL)
1185 			slot->pdata->set_bus_mode(mmc_dev(mmc), slot->id,
1186 						  ios->bus_mode);
1187 		slot->bus_mode = ios->bus_mode;
1188 	}
1189 
1190 	/* On insanely high arm_per frequencies something sometimes
1191 	 * goes somehow out of sync, and the POW bit is not being set,
1192 	 * which results in the while loop below getting stuck.
1193 	 * Writing to the CON register twice seems to do the trick. */
1194 	for (i = 0; i < 2; i++)
1195 		OMAP_MMC_WRITE(host, CON, dsor);
1196 	slot->saved_con = dsor;
1197 	if (ios->power_mode == MMC_POWER_ON) {
1198 		/* worst case at 400kHz, 80 cycles makes 200 microsecs */
1199 		int usecs = 250;
1200 
1201 		/* Send clock cycles, poll completion */
1202 		OMAP_MMC_WRITE(host, IE, 0);
1203 		OMAP_MMC_WRITE(host, STAT, 0xffff);
1204 		OMAP_MMC_WRITE(host, CMD, 1 << 7);
1205 		while (usecs > 0 && (OMAP_MMC_READ(host, STAT) & 1) == 0) {
1206 			udelay(1);
1207 			usecs--;
1208 		}
1209 		OMAP_MMC_WRITE(host, STAT, 1);
1210 	}
1211 
1212 exit:
1213 	mmc_omap_release_slot(slot, clk_enabled);
1214 }
1215 
1216 static const struct mmc_host_ops mmc_omap_ops = {
1217 	.request	= mmc_omap_request,
1218 	.set_ios	= mmc_omap_set_ios,
1219 };
1220 
1221 static int mmc_omap_new_slot(struct mmc_omap_host *host, int id)
1222 {
1223 	struct mmc_omap_slot *slot = NULL;
1224 	struct mmc_host *mmc;
1225 	int r;
1226 
1227 	mmc = mmc_alloc_host(sizeof(struct mmc_omap_slot), host->dev);
1228 	if (mmc == NULL)
1229 		return -ENOMEM;
1230 
1231 	slot = mmc_priv(mmc);
1232 	slot->host = host;
1233 	slot->mmc = mmc;
1234 	slot->id = id;
1235 	slot->pdata = &host->pdata->slots[id];
1236 
1237 	host->slots[id] = slot;
1238 
1239 	mmc->caps = 0;
1240 	if (host->pdata->slots[id].wires >= 4)
1241 		mmc->caps |= MMC_CAP_4_BIT_DATA | MMC_CAP_ERASE;
1242 
1243 	mmc->ops = &mmc_omap_ops;
1244 	mmc->f_min = 400000;
1245 
1246 	if (mmc_omap2())
1247 		mmc->f_max = 48000000;
1248 	else
1249 		mmc->f_max = 24000000;
1250 	if (host->pdata->max_freq)
1251 		mmc->f_max = min(host->pdata->max_freq, mmc->f_max);
1252 	mmc->ocr_avail = slot->pdata->ocr_mask;
1253 
1254 	/* Use scatterlist DMA to reduce per-transfer costs.
1255 	 * NOTE max_seg_size assumption that small blocks aren't
1256 	 * normally used (except e.g. for reading SD registers).
1257 	 */
1258 	mmc->max_segs = 32;
1259 	mmc->max_blk_size = 2048;	/* BLEN is 11 bits (+1) */
1260 	mmc->max_blk_count = 2048;	/* NBLK is 11 bits (+1) */
1261 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
1262 	mmc->max_seg_size = mmc->max_req_size;
1263 
1264 	if (slot->pdata->get_cover_state != NULL) {
1265 		setup_timer(&slot->cover_timer, mmc_omap_cover_timer,
1266 			    (unsigned long)slot);
1267 		tasklet_init(&slot->cover_tasklet, mmc_omap_cover_handler,
1268 			     (unsigned long)slot);
1269 	}
1270 
1271 	r = mmc_add_host(mmc);
1272 	if (r < 0)
1273 		goto err_remove_host;
1274 
1275 	if (slot->pdata->name != NULL) {
1276 		r = device_create_file(&mmc->class_dev,
1277 					&dev_attr_slot_name);
1278 		if (r < 0)
1279 			goto err_remove_host;
1280 	}
1281 
1282 	if (slot->pdata->get_cover_state != NULL) {
1283 		r = device_create_file(&mmc->class_dev,
1284 					&dev_attr_cover_switch);
1285 		if (r < 0)
1286 			goto err_remove_slot_name;
1287 		tasklet_schedule(&slot->cover_tasklet);
1288 	}
1289 
1290 	return 0;
1291 
1292 err_remove_slot_name:
1293 	if (slot->pdata->name != NULL)
1294 		device_remove_file(&mmc->class_dev, &dev_attr_slot_name);
1295 err_remove_host:
1296 	mmc_remove_host(mmc);
1297 	mmc_free_host(mmc);
1298 	return r;
1299 }
1300 
1301 static void mmc_omap_remove_slot(struct mmc_omap_slot *slot)
1302 {
1303 	struct mmc_host *mmc = slot->mmc;
1304 
1305 	if (slot->pdata->name != NULL)
1306 		device_remove_file(&mmc->class_dev, &dev_attr_slot_name);
1307 	if (slot->pdata->get_cover_state != NULL)
1308 		device_remove_file(&mmc->class_dev, &dev_attr_cover_switch);
1309 
1310 	tasklet_kill(&slot->cover_tasklet);
1311 	del_timer_sync(&slot->cover_timer);
1312 	flush_workqueue(slot->host->mmc_omap_wq);
1313 
1314 	mmc_remove_host(mmc);
1315 	mmc_free_host(mmc);
1316 }
1317 
1318 static int mmc_omap_probe(struct platform_device *pdev)
1319 {
1320 	struct omap_mmc_platform_data *pdata = pdev->dev.platform_data;
1321 	struct mmc_omap_host *host = NULL;
1322 	struct resource *res;
1323 	dma_cap_mask_t mask;
1324 	unsigned sig = 0;
1325 	int i, ret = 0;
1326 	int irq;
1327 
1328 	if (pdata == NULL) {
1329 		dev_err(&pdev->dev, "platform data missing\n");
1330 		return -ENXIO;
1331 	}
1332 	if (pdata->nr_slots == 0) {
1333 		dev_err(&pdev->dev, "no slots\n");
1334 		return -EPROBE_DEFER;
1335 	}
1336 
1337 	host = devm_kzalloc(&pdev->dev, sizeof(struct mmc_omap_host),
1338 			    GFP_KERNEL);
1339 	if (host == NULL)
1340 		return -ENOMEM;
1341 
1342 	irq = platform_get_irq(pdev, 0);
1343 	if (irq < 0)
1344 		return -ENXIO;
1345 
1346 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1347 	host->virt_base = devm_ioremap_resource(&pdev->dev, res);
1348 	if (IS_ERR(host->virt_base))
1349 		return PTR_ERR(host->virt_base);
1350 
1351 	INIT_WORK(&host->slot_release_work, mmc_omap_slot_release_work);
1352 	INIT_WORK(&host->send_stop_work, mmc_omap_send_stop_work);
1353 
1354 	INIT_WORK(&host->cmd_abort_work, mmc_omap_abort_command);
1355 	setup_timer(&host->cmd_abort_timer, mmc_omap_cmd_timer,
1356 		    (unsigned long) host);
1357 
1358 	spin_lock_init(&host->clk_lock);
1359 	setup_timer(&host->clk_timer, mmc_omap_clk_timer, (unsigned long) host);
1360 
1361 	spin_lock_init(&host->dma_lock);
1362 	spin_lock_init(&host->slot_lock);
1363 	init_waitqueue_head(&host->slot_wq);
1364 
1365 	host->pdata = pdata;
1366 	host->features = host->pdata->slots[0].features;
1367 	host->dev = &pdev->dev;
1368 	platform_set_drvdata(pdev, host);
1369 
1370 	host->id = pdev->id;
1371 	host->irq = irq;
1372 	host->phys_base = res->start;
1373 	host->iclk = clk_get(&pdev->dev, "ick");
1374 	if (IS_ERR(host->iclk))
1375 		return PTR_ERR(host->iclk);
1376 	clk_enable(host->iclk);
1377 
1378 	host->fclk = clk_get(&pdev->dev, "fck");
1379 	if (IS_ERR(host->fclk)) {
1380 		ret = PTR_ERR(host->fclk);
1381 		goto err_free_iclk;
1382 	}
1383 
1384 	dma_cap_zero(mask);
1385 	dma_cap_set(DMA_SLAVE, mask);
1386 
1387 	host->dma_tx_burst = -1;
1388 	host->dma_rx_burst = -1;
1389 
1390 	res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "tx");
1391 	if (res)
1392 		sig = res->start;
1393 	host->dma_tx = dma_request_slave_channel_compat(mask,
1394 				omap_dma_filter_fn, &sig, &pdev->dev, "tx");
1395 	if (!host->dma_tx)
1396 		dev_warn(host->dev, "unable to obtain TX DMA engine channel %u\n",
1397 			sig);
1398 
1399 	res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "rx");
1400 	if (res)
1401 		sig = res->start;
1402 	host->dma_rx = dma_request_slave_channel_compat(mask,
1403 				omap_dma_filter_fn, &sig, &pdev->dev, "rx");
1404 	if (!host->dma_rx)
1405 		dev_warn(host->dev, "unable to obtain RX DMA engine channel %u\n",
1406 			sig);
1407 
1408 	ret = request_irq(host->irq, mmc_omap_irq, 0, DRIVER_NAME, host);
1409 	if (ret)
1410 		goto err_free_dma;
1411 
1412 	if (pdata->init != NULL) {
1413 		ret = pdata->init(&pdev->dev);
1414 		if (ret < 0)
1415 			goto err_free_irq;
1416 	}
1417 
1418 	host->nr_slots = pdata->nr_slots;
1419 	host->reg_shift = (mmc_omap7xx() ? 1 : 2);
1420 
1421 	host->mmc_omap_wq = alloc_workqueue("mmc_omap", 0, 0);
1422 	if (!host->mmc_omap_wq)
1423 		goto err_plat_cleanup;
1424 
1425 	for (i = 0; i < pdata->nr_slots; i++) {
1426 		ret = mmc_omap_new_slot(host, i);
1427 		if (ret < 0) {
1428 			while (--i >= 0)
1429 				mmc_omap_remove_slot(host->slots[i]);
1430 
1431 			goto err_destroy_wq;
1432 		}
1433 	}
1434 
1435 	return 0;
1436 
1437 err_destroy_wq:
1438 	destroy_workqueue(host->mmc_omap_wq);
1439 err_plat_cleanup:
1440 	if (pdata->cleanup)
1441 		pdata->cleanup(&pdev->dev);
1442 err_free_irq:
1443 	free_irq(host->irq, host);
1444 err_free_dma:
1445 	if (host->dma_tx)
1446 		dma_release_channel(host->dma_tx);
1447 	if (host->dma_rx)
1448 		dma_release_channel(host->dma_rx);
1449 	clk_put(host->fclk);
1450 err_free_iclk:
1451 	clk_disable(host->iclk);
1452 	clk_put(host->iclk);
1453 	return ret;
1454 }
1455 
1456 static int mmc_omap_remove(struct platform_device *pdev)
1457 {
1458 	struct mmc_omap_host *host = platform_get_drvdata(pdev);
1459 	int i;
1460 
1461 	BUG_ON(host == NULL);
1462 
1463 	for (i = 0; i < host->nr_slots; i++)
1464 		mmc_omap_remove_slot(host->slots[i]);
1465 
1466 	if (host->pdata->cleanup)
1467 		host->pdata->cleanup(&pdev->dev);
1468 
1469 	mmc_omap_fclk_enable(host, 0);
1470 	free_irq(host->irq, host);
1471 	clk_put(host->fclk);
1472 	clk_disable(host->iclk);
1473 	clk_put(host->iclk);
1474 
1475 	if (host->dma_tx)
1476 		dma_release_channel(host->dma_tx);
1477 	if (host->dma_rx)
1478 		dma_release_channel(host->dma_rx);
1479 
1480 	destroy_workqueue(host->mmc_omap_wq);
1481 
1482 	return 0;
1483 }
1484 
1485 #if IS_BUILTIN(CONFIG_OF)
1486 static const struct of_device_id mmc_omap_match[] = {
1487 	{ .compatible = "ti,omap2420-mmc", },
1488 	{ },
1489 };
1490 #endif
1491 
1492 static struct platform_driver mmc_omap_driver = {
1493 	.probe		= mmc_omap_probe,
1494 	.remove		= mmc_omap_remove,
1495 	.driver		= {
1496 		.name	= DRIVER_NAME,
1497 		.of_match_table = of_match_ptr(mmc_omap_match),
1498 	},
1499 };
1500 
1501 module_platform_driver(mmc_omap_driver);
1502 MODULE_DESCRIPTION("OMAP Multimedia Card driver");
1503 MODULE_LICENSE("GPL");
1504 MODULE_ALIAS("platform:" DRIVER_NAME);
1505 MODULE_AUTHOR("Juha Yrjölä");
1506