xref: /openbmc/linux/drivers/mmc/host/omap.c (revision 483eb062)
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/clk.h>
30 #include <linux/scatterlist.h>
31 #include <linux/slab.h>
32 #include <linux/platform_data/mmc-omap.h>
33 
34 
35 #define	OMAP_MMC_REG_CMD	0x00
36 #define	OMAP_MMC_REG_ARGL	0x01
37 #define	OMAP_MMC_REG_ARGH	0x02
38 #define	OMAP_MMC_REG_CON	0x03
39 #define	OMAP_MMC_REG_STAT	0x04
40 #define	OMAP_MMC_REG_IE		0x05
41 #define	OMAP_MMC_REG_CTO	0x06
42 #define	OMAP_MMC_REG_DTO	0x07
43 #define	OMAP_MMC_REG_DATA	0x08
44 #define	OMAP_MMC_REG_BLEN	0x09
45 #define	OMAP_MMC_REG_NBLK	0x0a
46 #define	OMAP_MMC_REG_BUF	0x0b
47 #define	OMAP_MMC_REG_SDIO	0x0d
48 #define	OMAP_MMC_REG_REV	0x0f
49 #define	OMAP_MMC_REG_RSP0	0x10
50 #define	OMAP_MMC_REG_RSP1	0x11
51 #define	OMAP_MMC_REG_RSP2	0x12
52 #define	OMAP_MMC_REG_RSP3	0x13
53 #define	OMAP_MMC_REG_RSP4	0x14
54 #define	OMAP_MMC_REG_RSP5	0x15
55 #define	OMAP_MMC_REG_RSP6	0x16
56 #define	OMAP_MMC_REG_RSP7	0x17
57 #define	OMAP_MMC_REG_IOSR	0x18
58 #define	OMAP_MMC_REG_SYSC	0x19
59 #define	OMAP_MMC_REG_SYSS	0x1a
60 
61 #define	OMAP_MMC_STAT_CARD_ERR		(1 << 14)
62 #define	OMAP_MMC_STAT_CARD_IRQ		(1 << 13)
63 #define	OMAP_MMC_STAT_OCR_BUSY		(1 << 12)
64 #define	OMAP_MMC_STAT_A_EMPTY		(1 << 11)
65 #define	OMAP_MMC_STAT_A_FULL		(1 << 10)
66 #define	OMAP_MMC_STAT_CMD_CRC		(1 <<  8)
67 #define	OMAP_MMC_STAT_CMD_TOUT		(1 <<  7)
68 #define	OMAP_MMC_STAT_DATA_CRC		(1 <<  6)
69 #define	OMAP_MMC_STAT_DATA_TOUT		(1 <<  5)
70 #define	OMAP_MMC_STAT_END_BUSY		(1 <<  4)
71 #define	OMAP_MMC_STAT_END_OF_DATA	(1 <<  3)
72 #define	OMAP_MMC_STAT_CARD_BUSY		(1 <<  2)
73 #define	OMAP_MMC_STAT_END_OF_CMD	(1 <<  0)
74 
75 #define mmc_omap7xx()	(host->features & MMC_OMAP7XX)
76 #define mmc_omap15xx()	(host->features & MMC_OMAP15XX)
77 #define mmc_omap16xx()	(host->features & MMC_OMAP16XX)
78 #define MMC_OMAP1_MASK	(MMC_OMAP7XX | MMC_OMAP15XX | MMC_OMAP16XX)
79 #define mmc_omap1()	(host->features & MMC_OMAP1_MASK)
80 #define mmc_omap2()	(!mmc_omap1())
81 
82 #define OMAP_MMC_REG(host, reg)		(OMAP_MMC_REG_##reg << (host)->reg_shift)
83 #define OMAP_MMC_READ(host, reg)	__raw_readw((host)->virt_base + OMAP_MMC_REG(host, reg))
84 #define OMAP_MMC_WRITE(host, reg, val)	__raw_writew((val), (host)->virt_base + OMAP_MMC_REG(host, reg))
85 
86 /*
87  * Command types
88  */
89 #define OMAP_MMC_CMDTYPE_BC	0
90 #define OMAP_MMC_CMDTYPE_BCR	1
91 #define OMAP_MMC_CMDTYPE_AC	2
92 #define OMAP_MMC_CMDTYPE_ADTC	3
93 
94 #define DRIVER_NAME "mmci-omap"
95 
96 /* Specifies how often in millisecs to poll for card status changes
97  * when the cover switch is open */
98 #define OMAP_MMC_COVER_POLL_DELAY	500
99 
100 struct mmc_omap_host;
101 
102 struct mmc_omap_slot {
103 	int			id;
104 	unsigned int		vdd;
105 	u16			saved_con;
106 	u16			bus_mode;
107 	unsigned int		fclk_freq;
108 
109 	struct tasklet_struct	cover_tasklet;
110 	struct timer_list       cover_timer;
111 	unsigned		cover_open;
112 
113 	struct mmc_request      *mrq;
114 	struct mmc_omap_host    *host;
115 	struct mmc_host		*mmc;
116 	struct omap_mmc_slot_data *pdata;
117 };
118 
119 struct mmc_omap_host {
120 	int			initialized;
121 	struct mmc_request *	mrq;
122 	struct mmc_command *	cmd;
123 	struct mmc_data *	data;
124 	struct mmc_host *	mmc;
125 	struct device *		dev;
126 	unsigned char		id; /* 16xx chips have 2 MMC blocks */
127 	struct clk *		iclk;
128 	struct clk *		fclk;
129 	struct dma_chan		*dma_rx;
130 	u32			dma_rx_burst;
131 	struct dma_chan		*dma_tx;
132 	u32			dma_tx_burst;
133 	struct resource		*mem_res;
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		use_dma:1;
157 	unsigned		brs_received:1, dma_done:1;
158 	unsigned		dma_in_use:1;
159 	spinlock_t		dma_lock;
160 
161 	struct mmc_omap_slot    *slots[OMAP_MMC_MAX_SLOTS];
162 	struct mmc_omap_slot    *current_slot;
163 	spinlock_t              slot_lock;
164 	wait_queue_head_t       slot_wq;
165 	int                     nr_slots;
166 
167 	struct timer_list       clk_timer;
168 	spinlock_t		clk_lock;     /* for changing enabled state */
169 	unsigned int            fclk_enabled:1;
170 	struct workqueue_struct *mmc_omap_wq;
171 
172 	struct omap_mmc_platform_data *pdata;
173 };
174 
175 
176 static void mmc_omap_fclk_offdelay(struct mmc_omap_slot *slot)
177 {
178 	unsigned long tick_ns;
179 
180 	if (slot != NULL && slot->host->fclk_enabled && slot->fclk_freq > 0) {
181 		tick_ns = (1000000000 + slot->fclk_freq - 1) / slot->fclk_freq;
182 		ndelay(8 * tick_ns);
183 	}
184 }
185 
186 static void mmc_omap_fclk_enable(struct mmc_omap_host *host, unsigned int enable)
187 {
188 	unsigned long flags;
189 
190 	spin_lock_irqsave(&host->clk_lock, flags);
191 	if (host->fclk_enabled != enable) {
192 		host->fclk_enabled = enable;
193 		if (enable)
194 			clk_enable(host->fclk);
195 		else
196 			clk_disable(host->fclk);
197 	}
198 	spin_unlock_irqrestore(&host->clk_lock, flags);
199 }
200 
201 static void mmc_omap_select_slot(struct mmc_omap_slot *slot, int claimed)
202 {
203 	struct mmc_omap_host *host = slot->host;
204 	unsigned long flags;
205 
206 	if (claimed)
207 		goto no_claim;
208 	spin_lock_irqsave(&host->slot_lock, flags);
209 	while (host->mmc != NULL) {
210 		spin_unlock_irqrestore(&host->slot_lock, flags);
211 		wait_event(host->slot_wq, host->mmc == NULL);
212 		spin_lock_irqsave(&host->slot_lock, flags);
213 	}
214 	host->mmc = slot->mmc;
215 	spin_unlock_irqrestore(&host->slot_lock, flags);
216 no_claim:
217 	del_timer(&host->clk_timer);
218 	if (host->current_slot != slot || !claimed)
219 		mmc_omap_fclk_offdelay(host->current_slot);
220 
221 	if (host->current_slot != slot) {
222 		OMAP_MMC_WRITE(host, CON, slot->saved_con & 0xFC00);
223 		if (host->pdata->switch_slot != NULL)
224 			host->pdata->switch_slot(mmc_dev(slot->mmc), slot->id);
225 		host->current_slot = slot;
226 	}
227 
228 	if (claimed) {
229 		mmc_omap_fclk_enable(host, 1);
230 
231 		/* Doing the dummy read here seems to work around some bug
232 		 * at least in OMAP24xx silicon where the command would not
233 		 * start after writing the CMD register. Sigh. */
234 		OMAP_MMC_READ(host, CON);
235 
236 		OMAP_MMC_WRITE(host, CON, slot->saved_con);
237 	} else
238 		mmc_omap_fclk_enable(host, 0);
239 }
240 
241 static void mmc_omap_start_request(struct mmc_omap_host *host,
242 				   struct mmc_request *req);
243 
244 static void mmc_omap_slot_release_work(struct work_struct *work)
245 {
246 	struct mmc_omap_host *host = container_of(work, struct mmc_omap_host,
247 						  slot_release_work);
248 	struct mmc_omap_slot *next_slot = host->next_slot;
249 	struct mmc_request *rq;
250 
251 	host->next_slot = NULL;
252 	mmc_omap_select_slot(next_slot, 1);
253 
254 	rq = next_slot->mrq;
255 	next_slot->mrq = NULL;
256 	mmc_omap_start_request(host, rq);
257 }
258 
259 static void mmc_omap_release_slot(struct mmc_omap_slot *slot, int clk_enabled)
260 {
261 	struct mmc_omap_host *host = slot->host;
262 	unsigned long flags;
263 	int i;
264 
265 	BUG_ON(slot == NULL || host->mmc == NULL);
266 
267 	if (clk_enabled)
268 		/* Keeps clock running for at least 8 cycles on valid freq */
269 		mod_timer(&host->clk_timer, jiffies  + HZ/10);
270 	else {
271 		del_timer(&host->clk_timer);
272 		mmc_omap_fclk_offdelay(slot);
273 		mmc_omap_fclk_enable(host, 0);
274 	}
275 
276 	spin_lock_irqsave(&host->slot_lock, flags);
277 	/* Check for any pending requests */
278 	for (i = 0; i < host->nr_slots; i++) {
279 		struct mmc_omap_slot *new_slot;
280 
281 		if (host->slots[i] == NULL || host->slots[i]->mrq == NULL)
282 			continue;
283 
284 		BUG_ON(host->next_slot != NULL);
285 		new_slot = host->slots[i];
286 		/* The current slot should not have a request in queue */
287 		BUG_ON(new_slot == host->current_slot);
288 
289 		host->next_slot = new_slot;
290 		host->mmc = new_slot->mmc;
291 		spin_unlock_irqrestore(&host->slot_lock, flags);
292 		queue_work(host->mmc_omap_wq, &host->slot_release_work);
293 		return;
294 	}
295 
296 	host->mmc = NULL;
297 	wake_up(&host->slot_wq);
298 	spin_unlock_irqrestore(&host->slot_lock, flags);
299 }
300 
301 static inline
302 int mmc_omap_cover_is_open(struct mmc_omap_slot *slot)
303 {
304 	if (slot->pdata->get_cover_state)
305 		return slot->pdata->get_cover_state(mmc_dev(slot->mmc),
306 						    slot->id);
307 	return 0;
308 }
309 
310 static ssize_t
311 mmc_omap_show_cover_switch(struct device *dev, struct device_attribute *attr,
312 			   char *buf)
313 {
314 	struct mmc_host *mmc = container_of(dev, struct mmc_host, class_dev);
315 	struct mmc_omap_slot *slot = mmc_priv(mmc);
316 
317 	return sprintf(buf, "%s\n", mmc_omap_cover_is_open(slot) ? "open" :
318 		       "closed");
319 }
320 
321 static DEVICE_ATTR(cover_switch, S_IRUGO, mmc_omap_show_cover_switch, NULL);
322 
323 static ssize_t
324 mmc_omap_show_slot_name(struct device *dev, struct device_attribute *attr,
325 			char *buf)
326 {
327 	struct mmc_host *mmc = container_of(dev, struct mmc_host, class_dev);
328 	struct mmc_omap_slot *slot = mmc_priv(mmc);
329 
330 	return sprintf(buf, "%s\n", slot->pdata->name);
331 }
332 
333 static DEVICE_ATTR(slot_name, S_IRUGO, mmc_omap_show_slot_name, NULL);
334 
335 static void
336 mmc_omap_start_command(struct mmc_omap_host *host, struct mmc_command *cmd)
337 {
338 	u32 cmdreg;
339 	u32 resptype;
340 	u32 cmdtype;
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 	OMAP_MMC_WRITE(host, IE,
394 		       OMAP_MMC_STAT_A_EMPTY    | OMAP_MMC_STAT_A_FULL    |
395 		       OMAP_MMC_STAT_CMD_CRC    | OMAP_MMC_STAT_CMD_TOUT  |
396 		       OMAP_MMC_STAT_DATA_CRC   | OMAP_MMC_STAT_DATA_TOUT |
397 		       OMAP_MMC_STAT_END_OF_CMD | OMAP_MMC_STAT_CARD_ERR  |
398 		       OMAP_MMC_STAT_END_OF_DATA);
399 	OMAP_MMC_WRITE(host, CMD, cmdreg);
400 }
401 
402 static void
403 mmc_omap_release_dma(struct mmc_omap_host *host, struct mmc_data *data,
404 		     int abort)
405 {
406 	enum dma_data_direction dma_data_dir;
407 	struct device *dev = mmc_dev(host->mmc);
408 	struct dma_chan *c;
409 
410 	if (data->flags & MMC_DATA_WRITE) {
411 		dma_data_dir = DMA_TO_DEVICE;
412 		c = host->dma_tx;
413 	} else {
414 		dma_data_dir = DMA_FROM_DEVICE;
415 		c = host->dma_rx;
416 	}
417 	if (c) {
418 		if (data->error) {
419 			dmaengine_terminate_all(c);
420 			/* Claim nothing transferred on error... */
421 			data->bytes_xfered = 0;
422 		}
423 		dev = c->device->dev;
424 	}
425 	dma_unmap_sg(dev, data->sg, host->sg_len, dma_data_dir);
426 }
427 
428 static void mmc_omap_send_stop_work(struct work_struct *work)
429 {
430 	struct mmc_omap_host *host = container_of(work, struct mmc_omap_host,
431 						  send_stop_work);
432 	struct mmc_omap_slot *slot = host->current_slot;
433 	struct mmc_data *data = host->stop_data;
434 	unsigned long tick_ns;
435 
436 	tick_ns = (1000000000 + slot->fclk_freq - 1)/slot->fclk_freq;
437 	ndelay(8*tick_ns);
438 
439 	mmc_omap_start_command(host, data->stop);
440 }
441 
442 static void
443 mmc_omap_xfer_done(struct mmc_omap_host *host, struct mmc_data *data)
444 {
445 	if (host->dma_in_use)
446 		mmc_omap_release_dma(host, data, data->error);
447 
448 	host->data = NULL;
449 	host->sg_len = 0;
450 
451 	/* NOTE:  MMC layer will sometimes poll-wait CMD13 next, issuing
452 	 * dozens of requests until the card finishes writing data.
453 	 * It'd be cheaper to just wait till an EOFB interrupt arrives...
454 	 */
455 
456 	if (!data->stop) {
457 		struct mmc_host *mmc;
458 
459 		host->mrq = NULL;
460 		mmc = host->mmc;
461 		mmc_omap_release_slot(host->current_slot, 1);
462 		mmc_request_done(mmc, data->mrq);
463 		return;
464 	}
465 
466 	host->stop_data = data;
467 	queue_work(host->mmc_omap_wq, &host->send_stop_work);
468 }
469 
470 static void
471 mmc_omap_send_abort(struct mmc_omap_host *host, int maxloops)
472 {
473 	struct mmc_omap_slot *slot = host->current_slot;
474 	unsigned int restarts, passes, timeout;
475 	u16 stat = 0;
476 
477 	/* Sending abort takes 80 clocks. Have some extra and round up */
478 	timeout = (120*1000000 + slot->fclk_freq - 1)/slot->fclk_freq;
479 	restarts = 0;
480 	while (restarts < maxloops) {
481 		OMAP_MMC_WRITE(host, STAT, 0xFFFF);
482 		OMAP_MMC_WRITE(host, CMD, (3 << 12) | (1 << 7));
483 
484 		passes = 0;
485 		while (passes < timeout) {
486 			stat = OMAP_MMC_READ(host, STAT);
487 			if (stat & OMAP_MMC_STAT_END_OF_CMD)
488 				goto out;
489 			udelay(1);
490 			passes++;
491 		}
492 
493 		restarts++;
494 	}
495 out:
496 	OMAP_MMC_WRITE(host, STAT, stat);
497 }
498 
499 static void
500 mmc_omap_abort_xfer(struct mmc_omap_host *host, struct mmc_data *data)
501 {
502 	if (host->dma_in_use)
503 		mmc_omap_release_dma(host, data, 1);
504 
505 	host->data = NULL;
506 	host->sg_len = 0;
507 
508 	mmc_omap_send_abort(host, 10000);
509 }
510 
511 static void
512 mmc_omap_end_of_data(struct mmc_omap_host *host, struct mmc_data *data)
513 {
514 	unsigned long flags;
515 	int done;
516 
517 	if (!host->dma_in_use) {
518 		mmc_omap_xfer_done(host, data);
519 		return;
520 	}
521 	done = 0;
522 	spin_lock_irqsave(&host->dma_lock, flags);
523 	if (host->dma_done)
524 		done = 1;
525 	else
526 		host->brs_received = 1;
527 	spin_unlock_irqrestore(&host->dma_lock, flags);
528 	if (done)
529 		mmc_omap_xfer_done(host, data);
530 }
531 
532 static void
533 mmc_omap_dma_done(struct mmc_omap_host *host, struct mmc_data *data)
534 {
535 	unsigned long flags;
536 	int done;
537 
538 	done = 0;
539 	spin_lock_irqsave(&host->dma_lock, flags);
540 	if (host->brs_received)
541 		done = 1;
542 	else
543 		host->dma_done = 1;
544 	spin_unlock_irqrestore(&host->dma_lock, flags);
545 	if (done)
546 		mmc_omap_xfer_done(host, data);
547 }
548 
549 static void
550 mmc_omap_cmd_done(struct mmc_omap_host *host, struct mmc_command *cmd)
551 {
552 	host->cmd = NULL;
553 
554 	del_timer(&host->cmd_abort_timer);
555 
556 	if (cmd->flags & MMC_RSP_PRESENT) {
557 		if (cmd->flags & MMC_RSP_136) {
558 			/* response type 2 */
559 			cmd->resp[3] =
560 				OMAP_MMC_READ(host, RSP0) |
561 				(OMAP_MMC_READ(host, RSP1) << 16);
562 			cmd->resp[2] =
563 				OMAP_MMC_READ(host, RSP2) |
564 				(OMAP_MMC_READ(host, RSP3) << 16);
565 			cmd->resp[1] =
566 				OMAP_MMC_READ(host, RSP4) |
567 				(OMAP_MMC_READ(host, RSP5) << 16);
568 			cmd->resp[0] =
569 				OMAP_MMC_READ(host, RSP6) |
570 				(OMAP_MMC_READ(host, RSP7) << 16);
571 		} else {
572 			/* response types 1, 1b, 3, 4, 5, 6 */
573 			cmd->resp[0] =
574 				OMAP_MMC_READ(host, RSP6) |
575 				(OMAP_MMC_READ(host, RSP7) << 16);
576 		}
577 	}
578 
579 	if (host->data == NULL || cmd->error) {
580 		struct mmc_host *mmc;
581 
582 		if (host->data != NULL)
583 			mmc_omap_abort_xfer(host, host->data);
584 		host->mrq = NULL;
585 		mmc = host->mmc;
586 		mmc_omap_release_slot(host->current_slot, 1);
587 		mmc_request_done(mmc, cmd->mrq);
588 	}
589 }
590 
591 /*
592  * Abort stuck command. Can occur when card is removed while it is being
593  * read.
594  */
595 static void mmc_omap_abort_command(struct work_struct *work)
596 {
597 	struct mmc_omap_host *host = container_of(work, struct mmc_omap_host,
598 						  cmd_abort_work);
599 	BUG_ON(!host->cmd);
600 
601 	dev_dbg(mmc_dev(host->mmc), "Aborting stuck command CMD%d\n",
602 		host->cmd->opcode);
603 
604 	if (host->cmd->error == 0)
605 		host->cmd->error = -ETIMEDOUT;
606 
607 	if (host->data == NULL) {
608 		struct mmc_command *cmd;
609 		struct mmc_host    *mmc;
610 
611 		cmd = host->cmd;
612 		host->cmd = NULL;
613 		mmc_omap_send_abort(host, 10000);
614 
615 		host->mrq = NULL;
616 		mmc = host->mmc;
617 		mmc_omap_release_slot(host->current_slot, 1);
618 		mmc_request_done(mmc, cmd->mrq);
619 	} else
620 		mmc_omap_cmd_done(host, host->cmd);
621 
622 	host->abort = 0;
623 	enable_irq(host->irq);
624 }
625 
626 static void
627 mmc_omap_cmd_timer(unsigned long data)
628 {
629 	struct mmc_omap_host *host = (struct mmc_omap_host *) data;
630 	unsigned long flags;
631 
632 	spin_lock_irqsave(&host->slot_lock, flags);
633 	if (host->cmd != NULL && !host->abort) {
634 		OMAP_MMC_WRITE(host, IE, 0);
635 		disable_irq(host->irq);
636 		host->abort = 1;
637 		queue_work(host->mmc_omap_wq, &host->cmd_abort_work);
638 	}
639 	spin_unlock_irqrestore(&host->slot_lock, flags);
640 }
641 
642 /* PIO only */
643 static void
644 mmc_omap_sg_to_buf(struct mmc_omap_host *host)
645 {
646 	struct scatterlist *sg;
647 
648 	sg = host->data->sg + host->sg_idx;
649 	host->buffer_bytes_left = sg->length;
650 	host->buffer = sg_virt(sg);
651 	if (host->buffer_bytes_left > host->total_bytes_left)
652 		host->buffer_bytes_left = host->total_bytes_left;
653 }
654 
655 static void
656 mmc_omap_clk_timer(unsigned long data)
657 {
658 	struct mmc_omap_host *host = (struct mmc_omap_host *) data;
659 
660 	mmc_omap_fclk_enable(host, 0);
661 }
662 
663 /* PIO only */
664 static void
665 mmc_omap_xfer_data(struct mmc_omap_host *host, int write)
666 {
667 	int n, nwords;
668 
669 	if (host->buffer_bytes_left == 0) {
670 		host->sg_idx++;
671 		BUG_ON(host->sg_idx == host->sg_len);
672 		mmc_omap_sg_to_buf(host);
673 	}
674 	n = 64;
675 	if (n > host->buffer_bytes_left)
676 		n = host->buffer_bytes_left;
677 
678 	nwords = n / 2;
679 	nwords += n & 1; /* handle odd number of bytes to transfer */
680 
681 	host->buffer_bytes_left -= n;
682 	host->total_bytes_left -= n;
683 	host->data->bytes_xfered += n;
684 
685 	if (write) {
686 		__raw_writesw(host->virt_base + OMAP_MMC_REG(host, DATA),
687 			      host->buffer, nwords);
688 	} else {
689 		__raw_readsw(host->virt_base + OMAP_MMC_REG(host, DATA),
690 			     host->buffer, nwords);
691 	}
692 
693 	host->buffer += nwords;
694 }
695 
696 #ifdef CONFIG_MMC_DEBUG
697 static void mmc_omap_report_irq(struct mmc_omap_host *host, u16 status)
698 {
699 	static const char *mmc_omap_status_bits[] = {
700 		"EOC", "CD", "CB", "BRS", "EOFB", "DTO", "DCRC", "CTO",
701 		"CCRC", "CRW", "AF", "AE", "OCRB", "CIRQ", "CERR"
702 	};
703 	int i;
704 	char res[64], *buf = res;
705 
706 	buf += sprintf(buf, "MMC IRQ 0x%x:", status);
707 
708 	for (i = 0; i < ARRAY_SIZE(mmc_omap_status_bits); i++)
709 		if (status & (1 << i))
710 			buf += sprintf(buf, " %s", mmc_omap_status_bits[i]);
711 	dev_vdbg(mmc_dev(host->mmc), "%s\n", res);
712 }
713 #else
714 static void mmc_omap_report_irq(struct mmc_omap_host *host, u16 status)
715 {
716 }
717 #endif
718 
719 
720 static irqreturn_t mmc_omap_irq(int irq, void *dev_id)
721 {
722 	struct mmc_omap_host * host = (struct mmc_omap_host *)dev_id;
723 	u16 status;
724 	int end_command;
725 	int end_transfer;
726 	int transfer_error, cmd_error;
727 
728 	if (host->cmd == NULL && host->data == NULL) {
729 		status = OMAP_MMC_READ(host, STAT);
730 		dev_info(mmc_dev(host->slots[0]->mmc),
731 			 "Spurious IRQ 0x%04x\n", status);
732 		if (status != 0) {
733 			OMAP_MMC_WRITE(host, STAT, status);
734 			OMAP_MMC_WRITE(host, IE, 0);
735 		}
736 		return IRQ_HANDLED;
737 	}
738 
739 	end_command = 0;
740 	end_transfer = 0;
741 	transfer_error = 0;
742 	cmd_error = 0;
743 
744 	while ((status = OMAP_MMC_READ(host, STAT)) != 0) {
745 		int cmd;
746 
747 		OMAP_MMC_WRITE(host, STAT, status);
748 		if (host->cmd != NULL)
749 			cmd = host->cmd->opcode;
750 		else
751 			cmd = -1;
752 		dev_dbg(mmc_dev(host->mmc), "MMC IRQ %04x (CMD %d): ",
753 			status, cmd);
754 		mmc_omap_report_irq(host, status);
755 
756 		if (host->total_bytes_left) {
757 			if ((status & OMAP_MMC_STAT_A_FULL) ||
758 			    (status & OMAP_MMC_STAT_END_OF_DATA))
759 				mmc_omap_xfer_data(host, 0);
760 			if (status & OMAP_MMC_STAT_A_EMPTY)
761 				mmc_omap_xfer_data(host, 1);
762 		}
763 
764 		if (status & OMAP_MMC_STAT_END_OF_DATA)
765 			end_transfer = 1;
766 
767 		if (status & OMAP_MMC_STAT_DATA_TOUT) {
768 			dev_dbg(mmc_dev(host->mmc), "data timeout (CMD%d)\n",
769 				cmd);
770 			if (host->data) {
771 				host->data->error = -ETIMEDOUT;
772 				transfer_error = 1;
773 			}
774 		}
775 
776 		if (status & OMAP_MMC_STAT_DATA_CRC) {
777 			if (host->data) {
778 				host->data->error = -EILSEQ;
779 				dev_dbg(mmc_dev(host->mmc),
780 					 "data CRC error, bytes left %d\n",
781 					host->total_bytes_left);
782 				transfer_error = 1;
783 			} else {
784 				dev_dbg(mmc_dev(host->mmc), "data CRC error\n");
785 			}
786 		}
787 
788 		if (status & OMAP_MMC_STAT_CMD_TOUT) {
789 			/* Timeouts are routine with some commands */
790 			if (host->cmd) {
791 				struct mmc_omap_slot *slot =
792 					host->current_slot;
793 				if (slot == NULL ||
794 				    !mmc_omap_cover_is_open(slot))
795 					dev_err(mmc_dev(host->mmc),
796 						"command timeout (CMD%d)\n",
797 						cmd);
798 				host->cmd->error = -ETIMEDOUT;
799 				end_command = 1;
800 				cmd_error = 1;
801 			}
802 		}
803 
804 		if (status & OMAP_MMC_STAT_CMD_CRC) {
805 			if (host->cmd) {
806 				dev_err(mmc_dev(host->mmc),
807 					"command CRC error (CMD%d, arg 0x%08x)\n",
808 					cmd, host->cmd->arg);
809 				host->cmd->error = -EILSEQ;
810 				end_command = 1;
811 				cmd_error = 1;
812 			} else
813 				dev_err(mmc_dev(host->mmc),
814 					"command CRC error without cmd?\n");
815 		}
816 
817 		if (status & OMAP_MMC_STAT_CARD_ERR) {
818 			dev_dbg(mmc_dev(host->mmc),
819 				"ignoring card status error (CMD%d)\n",
820 				cmd);
821 			end_command = 1;
822 		}
823 
824 		/*
825 		 * NOTE: On 1610 the END_OF_CMD may come too early when
826 		 * starting a write
827 		 */
828 		if ((status & OMAP_MMC_STAT_END_OF_CMD) &&
829 		    (!(status & OMAP_MMC_STAT_A_EMPTY))) {
830 			end_command = 1;
831 		}
832 	}
833 
834 	if (cmd_error && host->data) {
835 		del_timer(&host->cmd_abort_timer);
836 		host->abort = 1;
837 		OMAP_MMC_WRITE(host, IE, 0);
838 		disable_irq_nosync(host->irq);
839 		queue_work(host->mmc_omap_wq, &host->cmd_abort_work);
840 		return IRQ_HANDLED;
841 	}
842 
843 	if (end_command && host->cmd)
844 		mmc_omap_cmd_done(host, host->cmd);
845 	if (host->data != NULL) {
846 		if (transfer_error)
847 			mmc_omap_xfer_done(host, host->data);
848 		else if (end_transfer)
849 			mmc_omap_end_of_data(host, host->data);
850 	}
851 
852 	return IRQ_HANDLED;
853 }
854 
855 void omap_mmc_notify_cover_event(struct device *dev, int num, int is_closed)
856 {
857 	int cover_open;
858 	struct mmc_omap_host *host = dev_get_drvdata(dev);
859 	struct mmc_omap_slot *slot = host->slots[num];
860 
861 	BUG_ON(num >= host->nr_slots);
862 
863 	/* Other subsystems can call in here before we're initialised. */
864 	if (host->nr_slots == 0 || !host->slots[num])
865 		return;
866 
867 	cover_open = mmc_omap_cover_is_open(slot);
868 	if (cover_open != slot->cover_open) {
869 		slot->cover_open = cover_open;
870 		sysfs_notify(&slot->mmc->class_dev.kobj, NULL, "cover_switch");
871 	}
872 
873 	tasklet_hi_schedule(&slot->cover_tasklet);
874 }
875 
876 static void mmc_omap_cover_timer(unsigned long arg)
877 {
878 	struct mmc_omap_slot *slot = (struct mmc_omap_slot *) arg;
879 	tasklet_schedule(&slot->cover_tasklet);
880 }
881 
882 static void mmc_omap_cover_handler(unsigned long param)
883 {
884 	struct mmc_omap_slot *slot = (struct mmc_omap_slot *)param;
885 	int cover_open = mmc_omap_cover_is_open(slot);
886 
887 	mmc_detect_change(slot->mmc, 0);
888 	if (!cover_open)
889 		return;
890 
891 	/*
892 	 * If no card is inserted, we postpone polling until
893 	 * the cover has been closed.
894 	 */
895 	if (slot->mmc->card == NULL || !mmc_card_present(slot->mmc->card))
896 		return;
897 
898 	mod_timer(&slot->cover_timer,
899 		  jiffies + msecs_to_jiffies(OMAP_MMC_COVER_POLL_DELAY));
900 }
901 
902 static void mmc_omap_dma_callback(void *priv)
903 {
904 	struct mmc_omap_host *host = priv;
905 	struct mmc_data *data = host->data;
906 
907 	/* If we got to the end of DMA, assume everything went well */
908 	data->bytes_xfered += data->blocks * data->blksz;
909 
910 	mmc_omap_dma_done(host, data);
911 }
912 
913 static inline void set_cmd_timeout(struct mmc_omap_host *host, struct mmc_request *req)
914 {
915 	u16 reg;
916 
917 	reg = OMAP_MMC_READ(host, SDIO);
918 	reg &= ~(1 << 5);
919 	OMAP_MMC_WRITE(host, SDIO, reg);
920 	/* Set maximum timeout */
921 	OMAP_MMC_WRITE(host, CTO, 0xff);
922 }
923 
924 static inline void set_data_timeout(struct mmc_omap_host *host, struct mmc_request *req)
925 {
926 	unsigned int timeout, cycle_ns;
927 	u16 reg;
928 
929 	cycle_ns = 1000000000 / host->current_slot->fclk_freq;
930 	timeout = req->data->timeout_ns / cycle_ns;
931 	timeout += req->data->timeout_clks;
932 
933 	/* Check if we need to use timeout multiplier register */
934 	reg = OMAP_MMC_READ(host, SDIO);
935 	if (timeout > 0xffff) {
936 		reg |= (1 << 5);
937 		timeout /= 1024;
938 	} else
939 		reg &= ~(1 << 5);
940 	OMAP_MMC_WRITE(host, SDIO, reg);
941 	OMAP_MMC_WRITE(host, DTO, timeout);
942 }
943 
944 static void
945 mmc_omap_prepare_data(struct mmc_omap_host *host, struct mmc_request *req)
946 {
947 	struct mmc_data *data = req->data;
948 	int i, use_dma, block_size;
949 	unsigned sg_len;
950 
951 	host->data = data;
952 	if (data == NULL) {
953 		OMAP_MMC_WRITE(host, BLEN, 0);
954 		OMAP_MMC_WRITE(host, NBLK, 0);
955 		OMAP_MMC_WRITE(host, BUF, 0);
956 		host->dma_in_use = 0;
957 		set_cmd_timeout(host, req);
958 		return;
959 	}
960 
961 	block_size = data->blksz;
962 
963 	OMAP_MMC_WRITE(host, NBLK, data->blocks - 1);
964 	OMAP_MMC_WRITE(host, BLEN, block_size - 1);
965 	set_data_timeout(host, req);
966 
967 	/* cope with calling layer confusion; it issues "single
968 	 * block" writes using multi-block scatterlists.
969 	 */
970 	sg_len = (data->blocks == 1) ? 1 : data->sg_len;
971 
972 	/* Only do DMA for entire blocks */
973 	use_dma = host->use_dma;
974 	if (use_dma) {
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 
983 	host->sg_idx = 0;
984 	if (use_dma) {
985 		enum dma_data_direction dma_data_dir;
986 		struct dma_async_tx_descriptor *tx;
987 		struct dma_chan *c;
988 		u32 burst, *bp;
989 		u16 buf;
990 
991 		/*
992 		 * FIFO is 16x2 bytes on 15xx, and 32x2 bytes on 16xx
993 		 * and 24xx. Use 16 or 32 word frames when the
994 		 * blocksize is at least that large. Blocksize is
995 		 * usually 512 bytes; but not for some SD reads.
996 		 */
997 		burst = mmc_omap15xx() ? 32 : 64;
998 		if (burst > data->blksz)
999 			burst = data->blksz;
1000 
1001 		burst >>= 1;
1002 
1003 		if (data->flags & MMC_DATA_WRITE) {
1004 			c = host->dma_tx;
1005 			bp = &host->dma_tx_burst;
1006 			buf = 0x0f80 | (burst - 1) << 0;
1007 			dma_data_dir = DMA_TO_DEVICE;
1008 		} else {
1009 			c = host->dma_rx;
1010 			bp = &host->dma_rx_burst;
1011 			buf = 0x800f | (burst - 1) << 8;
1012 			dma_data_dir = DMA_FROM_DEVICE;
1013 		}
1014 
1015 		if (!c)
1016 			goto use_pio;
1017 
1018 		/* Only reconfigure if we have a different burst size */
1019 		if (*bp != burst) {
1020 			struct dma_slave_config cfg;
1021 
1022 			cfg.src_addr = host->phys_base + OMAP_MMC_REG(host, DATA);
1023 			cfg.dst_addr = host->phys_base + OMAP_MMC_REG(host, DATA);
1024 			cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1025 			cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1026 			cfg.src_maxburst = burst;
1027 			cfg.dst_maxburst = burst;
1028 
1029 			if (dmaengine_slave_config(c, &cfg))
1030 				goto use_pio;
1031 
1032 			*bp = burst;
1033 		}
1034 
1035 		host->sg_len = dma_map_sg(c->device->dev, data->sg, sg_len,
1036 					  dma_data_dir);
1037 		if (host->sg_len == 0)
1038 			goto use_pio;
1039 
1040 		tx = dmaengine_prep_slave_sg(c, data->sg, host->sg_len,
1041 			data->flags & MMC_DATA_WRITE ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
1042 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1043 		if (!tx)
1044 			goto use_pio;
1045 
1046 		OMAP_MMC_WRITE(host, BUF, buf);
1047 
1048 		tx->callback = mmc_omap_dma_callback;
1049 		tx->callback_param = host;
1050 		dmaengine_submit(tx);
1051 		host->brs_received = 0;
1052 		host->dma_done = 0;
1053 		host->dma_in_use = 1;
1054 		return;
1055 	}
1056  use_pio:
1057 
1058 	/* Revert to PIO? */
1059 	OMAP_MMC_WRITE(host, BUF, 0x1f1f);
1060 	host->total_bytes_left = data->blocks * block_size;
1061 	host->sg_len = sg_len;
1062 	mmc_omap_sg_to_buf(host);
1063 	host->dma_in_use = 0;
1064 }
1065 
1066 static void mmc_omap_start_request(struct mmc_omap_host *host,
1067 				   struct mmc_request *req)
1068 {
1069 	BUG_ON(host->mrq != NULL);
1070 
1071 	host->mrq = req;
1072 
1073 	/* only touch fifo AFTER the controller readies it */
1074 	mmc_omap_prepare_data(host, req);
1075 	mmc_omap_start_command(host, req->cmd);
1076 	if (host->dma_in_use) {
1077 		struct dma_chan *c = host->data->flags & MMC_DATA_WRITE ?
1078 				host->dma_tx : host->dma_rx;
1079 
1080 		dma_async_issue_pending(c);
1081 	}
1082 }
1083 
1084 static void mmc_omap_request(struct mmc_host *mmc, struct mmc_request *req)
1085 {
1086 	struct mmc_omap_slot *slot = mmc_priv(mmc);
1087 	struct mmc_omap_host *host = slot->host;
1088 	unsigned long flags;
1089 
1090 	spin_lock_irqsave(&host->slot_lock, flags);
1091 	if (host->mmc != NULL) {
1092 		BUG_ON(slot->mrq != NULL);
1093 		slot->mrq = req;
1094 		spin_unlock_irqrestore(&host->slot_lock, flags);
1095 		return;
1096 	} else
1097 		host->mmc = mmc;
1098 	spin_unlock_irqrestore(&host->slot_lock, flags);
1099 	mmc_omap_select_slot(slot, 1);
1100 	mmc_omap_start_request(host, req);
1101 }
1102 
1103 static void mmc_omap_set_power(struct mmc_omap_slot *slot, int power_on,
1104 				int vdd)
1105 {
1106 	struct mmc_omap_host *host;
1107 
1108 	host = slot->host;
1109 
1110 	if (slot->pdata->set_power != NULL)
1111 		slot->pdata->set_power(mmc_dev(slot->mmc), slot->id, power_on,
1112 					vdd);
1113 	if (mmc_omap2()) {
1114 		u16 w;
1115 
1116 		if (power_on) {
1117 			w = OMAP_MMC_READ(host, CON);
1118 			OMAP_MMC_WRITE(host, CON, w | (1 << 11));
1119 		} else {
1120 			w = OMAP_MMC_READ(host, CON);
1121 			OMAP_MMC_WRITE(host, CON, w & ~(1 << 11));
1122 		}
1123 	}
1124 }
1125 
1126 static int mmc_omap_calc_divisor(struct mmc_host *mmc, struct mmc_ios *ios)
1127 {
1128 	struct mmc_omap_slot *slot = mmc_priv(mmc);
1129 	struct mmc_omap_host *host = slot->host;
1130 	int func_clk_rate = clk_get_rate(host->fclk);
1131 	int dsor;
1132 
1133 	if (ios->clock == 0)
1134 		return 0;
1135 
1136 	dsor = func_clk_rate / ios->clock;
1137 	if (dsor < 1)
1138 		dsor = 1;
1139 
1140 	if (func_clk_rate / dsor > ios->clock)
1141 		dsor++;
1142 
1143 	if (dsor > 250)
1144 		dsor = 250;
1145 
1146 	slot->fclk_freq = func_clk_rate / dsor;
1147 
1148 	if (ios->bus_width == MMC_BUS_WIDTH_4)
1149 		dsor |= 1 << 15;
1150 
1151 	return dsor;
1152 }
1153 
1154 static void mmc_omap_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
1155 {
1156 	struct mmc_omap_slot *slot = mmc_priv(mmc);
1157 	struct mmc_omap_host *host = slot->host;
1158 	int i, dsor;
1159 	int clk_enabled;
1160 
1161 	mmc_omap_select_slot(slot, 0);
1162 
1163 	dsor = mmc_omap_calc_divisor(mmc, ios);
1164 
1165 	if (ios->vdd != slot->vdd)
1166 		slot->vdd = ios->vdd;
1167 
1168 	clk_enabled = 0;
1169 	switch (ios->power_mode) {
1170 	case MMC_POWER_OFF:
1171 		mmc_omap_set_power(slot, 0, ios->vdd);
1172 		break;
1173 	case MMC_POWER_UP:
1174 		/* Cannot touch dsor yet, just power up MMC */
1175 		mmc_omap_set_power(slot, 1, ios->vdd);
1176 		goto exit;
1177 	case MMC_POWER_ON:
1178 		mmc_omap_fclk_enable(host, 1);
1179 		clk_enabled = 1;
1180 		dsor |= 1 << 11;
1181 		break;
1182 	}
1183 
1184 	if (slot->bus_mode != ios->bus_mode) {
1185 		if (slot->pdata->set_bus_mode != NULL)
1186 			slot->pdata->set_bus_mode(mmc_dev(mmc), slot->id,
1187 						  ios->bus_mode);
1188 		slot->bus_mode = ios->bus_mode;
1189 	}
1190 
1191 	/* On insanely high arm_per frequencies something sometimes
1192 	 * goes somehow out of sync, and the POW bit is not being set,
1193 	 * which results in the while loop below getting stuck.
1194 	 * Writing to the CON register twice seems to do the trick. */
1195 	for (i = 0; i < 2; i++)
1196 		OMAP_MMC_WRITE(host, CON, dsor);
1197 	slot->saved_con = dsor;
1198 	if (ios->power_mode == MMC_POWER_ON) {
1199 		/* worst case at 400kHz, 80 cycles makes 200 microsecs */
1200 		int usecs = 250;
1201 
1202 		/* Send clock cycles, poll completion */
1203 		OMAP_MMC_WRITE(host, IE, 0);
1204 		OMAP_MMC_WRITE(host, STAT, 0xffff);
1205 		OMAP_MMC_WRITE(host, CMD, 1 << 7);
1206 		while (usecs > 0 && (OMAP_MMC_READ(host, STAT) & 1) == 0) {
1207 			udelay(1);
1208 			usecs--;
1209 		}
1210 		OMAP_MMC_WRITE(host, STAT, 1);
1211 	}
1212 
1213 exit:
1214 	mmc_omap_release_slot(slot, clk_enabled);
1215 }
1216 
1217 static const struct mmc_host_ops mmc_omap_ops = {
1218 	.request	= mmc_omap_request,
1219 	.set_ios	= mmc_omap_set_ios,
1220 };
1221 
1222 static int mmc_omap_new_slot(struct mmc_omap_host *host, int id)
1223 {
1224 	struct mmc_omap_slot *slot = NULL;
1225 	struct mmc_host *mmc;
1226 	int r;
1227 
1228 	mmc = mmc_alloc_host(sizeof(struct mmc_omap_slot), host->dev);
1229 	if (mmc == NULL)
1230 		return -ENOMEM;
1231 
1232 	slot = mmc_priv(mmc);
1233 	slot->host = host;
1234 	slot->mmc = mmc;
1235 	slot->id = id;
1236 	slot->pdata = &host->pdata->slots[id];
1237 
1238 	host->slots[id] = slot;
1239 
1240 	mmc->caps = 0;
1241 	if (host->pdata->slots[id].wires >= 4)
1242 		mmc->caps |= MMC_CAP_4_BIT_DATA;
1243 
1244 	mmc->ops = &mmc_omap_ops;
1245 	mmc->f_min = 400000;
1246 
1247 	if (mmc_omap2())
1248 		mmc->f_max = 48000000;
1249 	else
1250 		mmc->f_max = 24000000;
1251 	if (host->pdata->max_freq)
1252 		mmc->f_max = min(host->pdata->max_freq, mmc->f_max);
1253 	mmc->ocr_avail = slot->pdata->ocr_mask;
1254 
1255 	/* Use scatterlist DMA to reduce per-transfer costs.
1256 	 * NOTE max_seg_size assumption that small blocks aren't
1257 	 * normally used (except e.g. for reading SD registers).
1258 	 */
1259 	mmc->max_segs = 32;
1260 	mmc->max_blk_size = 2048;	/* BLEN is 11 bits (+1) */
1261 	mmc->max_blk_count = 2048;	/* NBLK is 11 bits (+1) */
1262 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
1263 	mmc->max_seg_size = mmc->max_req_size;
1264 
1265 	r = mmc_add_host(mmc);
1266 	if (r < 0)
1267 		goto err_remove_host;
1268 
1269 	if (slot->pdata->name != NULL) {
1270 		r = device_create_file(&mmc->class_dev,
1271 					&dev_attr_slot_name);
1272 		if (r < 0)
1273 			goto err_remove_host;
1274 	}
1275 
1276 	if (slot->pdata->get_cover_state != NULL) {
1277 		r = device_create_file(&mmc->class_dev,
1278 					&dev_attr_cover_switch);
1279 		if (r < 0)
1280 			goto err_remove_slot_name;
1281 
1282 		setup_timer(&slot->cover_timer, mmc_omap_cover_timer,
1283 			    (unsigned long)slot);
1284 		tasklet_init(&slot->cover_tasklet, mmc_omap_cover_handler,
1285 			     (unsigned long)slot);
1286 		tasklet_schedule(&slot->cover_tasklet);
1287 	}
1288 
1289 	return 0;
1290 
1291 err_remove_slot_name:
1292 	if (slot->pdata->name != NULL)
1293 		device_remove_file(&mmc->class_dev, &dev_attr_slot_name);
1294 err_remove_host:
1295 	mmc_remove_host(mmc);
1296 	mmc_free_host(mmc);
1297 	return r;
1298 }
1299 
1300 static void mmc_omap_remove_slot(struct mmc_omap_slot *slot)
1301 {
1302 	struct mmc_host *mmc = slot->mmc;
1303 
1304 	if (slot->pdata->name != NULL)
1305 		device_remove_file(&mmc->class_dev, &dev_attr_slot_name);
1306 	if (slot->pdata->get_cover_state != NULL)
1307 		device_remove_file(&mmc->class_dev, &dev_attr_cover_switch);
1308 
1309 	tasklet_kill(&slot->cover_tasklet);
1310 	del_timer_sync(&slot->cover_timer);
1311 	flush_workqueue(slot->host->mmc_omap_wq);
1312 
1313 	mmc_remove_host(mmc);
1314 	mmc_free_host(mmc);
1315 }
1316 
1317 static int mmc_omap_probe(struct platform_device *pdev)
1318 {
1319 	struct omap_mmc_platform_data *pdata = pdev->dev.platform_data;
1320 	struct mmc_omap_host *host = NULL;
1321 	struct resource *res;
1322 	dma_cap_mask_t mask;
1323 	unsigned sig = 0;
1324 	int i, ret = 0;
1325 	int irq;
1326 
1327 	if (pdata == NULL) {
1328 		dev_err(&pdev->dev, "platform data missing\n");
1329 		return -ENXIO;
1330 	}
1331 	if (pdata->nr_slots == 0) {
1332 		dev_err(&pdev->dev, "no slots\n");
1333 		return -EPROBE_DEFER;
1334 	}
1335 
1336 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1337 	irq = platform_get_irq(pdev, 0);
1338 	if (res == NULL || irq < 0)
1339 		return -ENXIO;
1340 
1341 	res = request_mem_region(res->start, resource_size(res),
1342 				 pdev->name);
1343 	if (res == NULL)
1344 		return -EBUSY;
1345 
1346 	host = kzalloc(sizeof(struct mmc_omap_host), GFP_KERNEL);
1347 	if (host == NULL) {
1348 		ret = -ENOMEM;
1349 		goto err_free_mem_region;
1350 	}
1351 
1352 	INIT_WORK(&host->slot_release_work, mmc_omap_slot_release_work);
1353 	INIT_WORK(&host->send_stop_work, mmc_omap_send_stop_work);
1354 
1355 	INIT_WORK(&host->cmd_abort_work, mmc_omap_abort_command);
1356 	setup_timer(&host->cmd_abort_timer, mmc_omap_cmd_timer,
1357 		    (unsigned long) host);
1358 
1359 	spin_lock_init(&host->clk_lock);
1360 	setup_timer(&host->clk_timer, mmc_omap_clk_timer, (unsigned long) host);
1361 
1362 	spin_lock_init(&host->dma_lock);
1363 	spin_lock_init(&host->slot_lock);
1364 	init_waitqueue_head(&host->slot_wq);
1365 
1366 	host->pdata = pdata;
1367 	host->features = host->pdata->slots[0].features;
1368 	host->dev = &pdev->dev;
1369 	platform_set_drvdata(pdev, host);
1370 
1371 	host->id = pdev->id;
1372 	host->mem_res = res;
1373 	host->irq = irq;
1374 	host->use_dma = 1;
1375 	host->irq = irq;
1376 	host->phys_base = host->mem_res->start;
1377 	host->virt_base = ioremap(res->start, resource_size(res));
1378 	if (!host->virt_base)
1379 		goto err_ioremap;
1380 
1381 	host->iclk = clk_get(&pdev->dev, "ick");
1382 	if (IS_ERR(host->iclk)) {
1383 		ret = PTR_ERR(host->iclk);
1384 		goto err_free_mmc_host;
1385 	}
1386 	clk_enable(host->iclk);
1387 
1388 	host->fclk = clk_get(&pdev->dev, "fck");
1389 	if (IS_ERR(host->fclk)) {
1390 		ret = PTR_ERR(host->fclk);
1391 		goto err_free_iclk;
1392 	}
1393 
1394 	dma_cap_zero(mask);
1395 	dma_cap_set(DMA_SLAVE, mask);
1396 
1397 	host->dma_tx_burst = -1;
1398 	host->dma_rx_burst = -1;
1399 
1400 	res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "tx");
1401 	if (res)
1402 		sig = res->start;
1403 	host->dma_tx = dma_request_slave_channel_compat(mask,
1404 				omap_dma_filter_fn, &sig, &pdev->dev, "tx");
1405 	if (!host->dma_tx)
1406 		dev_warn(host->dev, "unable to obtain TX DMA engine channel %u\n",
1407 			sig);
1408 
1409 	res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "rx");
1410 	if (res)
1411 		sig = res->start;
1412 	host->dma_rx = dma_request_slave_channel_compat(mask,
1413 				omap_dma_filter_fn, &sig, &pdev->dev, "rx");
1414 	if (!host->dma_rx)
1415 		dev_warn(host->dev, "unable to obtain RX DMA engine channel %u\n",
1416 			sig);
1417 
1418 	ret = request_irq(host->irq, mmc_omap_irq, 0, DRIVER_NAME, host);
1419 	if (ret)
1420 		goto err_free_dma;
1421 
1422 	if (pdata->init != NULL) {
1423 		ret = pdata->init(&pdev->dev);
1424 		if (ret < 0)
1425 			goto err_free_irq;
1426 	}
1427 
1428 	host->nr_slots = pdata->nr_slots;
1429 	host->reg_shift = (mmc_omap7xx() ? 1 : 2);
1430 
1431 	host->mmc_omap_wq = alloc_workqueue("mmc_omap", 0, 0);
1432 	if (!host->mmc_omap_wq)
1433 		goto err_plat_cleanup;
1434 
1435 	for (i = 0; i < pdata->nr_slots; i++) {
1436 		ret = mmc_omap_new_slot(host, i);
1437 		if (ret < 0) {
1438 			while (--i >= 0)
1439 				mmc_omap_remove_slot(host->slots[i]);
1440 
1441 			goto err_destroy_wq;
1442 		}
1443 	}
1444 
1445 	return 0;
1446 
1447 err_destroy_wq:
1448 	destroy_workqueue(host->mmc_omap_wq);
1449 err_plat_cleanup:
1450 	if (pdata->cleanup)
1451 		pdata->cleanup(&pdev->dev);
1452 err_free_irq:
1453 	free_irq(host->irq, host);
1454 err_free_dma:
1455 	if (host->dma_tx)
1456 		dma_release_channel(host->dma_tx);
1457 	if (host->dma_rx)
1458 		dma_release_channel(host->dma_rx);
1459 	clk_put(host->fclk);
1460 err_free_iclk:
1461 	clk_disable(host->iclk);
1462 	clk_put(host->iclk);
1463 err_free_mmc_host:
1464 	iounmap(host->virt_base);
1465 err_ioremap:
1466 	kfree(host);
1467 err_free_mem_region:
1468 	release_mem_region(res->start, resource_size(res));
1469 	return ret;
1470 }
1471 
1472 static int mmc_omap_remove(struct platform_device *pdev)
1473 {
1474 	struct mmc_omap_host *host = platform_get_drvdata(pdev);
1475 	int i;
1476 
1477 	BUG_ON(host == NULL);
1478 
1479 	for (i = 0; i < host->nr_slots; i++)
1480 		mmc_omap_remove_slot(host->slots[i]);
1481 
1482 	if (host->pdata->cleanup)
1483 		host->pdata->cleanup(&pdev->dev);
1484 
1485 	mmc_omap_fclk_enable(host, 0);
1486 	free_irq(host->irq, host);
1487 	clk_put(host->fclk);
1488 	clk_disable(host->iclk);
1489 	clk_put(host->iclk);
1490 
1491 	if (host->dma_tx)
1492 		dma_release_channel(host->dma_tx);
1493 	if (host->dma_rx)
1494 		dma_release_channel(host->dma_rx);
1495 
1496 	iounmap(host->virt_base);
1497 	release_mem_region(pdev->resource[0].start,
1498 			   pdev->resource[0].end - pdev->resource[0].start + 1);
1499 	destroy_workqueue(host->mmc_omap_wq);
1500 
1501 	kfree(host);
1502 
1503 	return 0;
1504 }
1505 
1506 #if IS_BUILTIN(CONFIG_OF)
1507 static const struct of_device_id mmc_omap_match[] = {
1508 	{ .compatible = "ti,omap2420-mmc", },
1509 	{ },
1510 };
1511 #endif
1512 
1513 static struct platform_driver mmc_omap_driver = {
1514 	.probe		= mmc_omap_probe,
1515 	.remove		= mmc_omap_remove,
1516 	.driver		= {
1517 		.name	= DRIVER_NAME,
1518 		.owner	= THIS_MODULE,
1519 		.of_match_table = of_match_ptr(mmc_omap_match),
1520 	},
1521 };
1522 
1523 module_platform_driver(mmc_omap_driver);
1524 MODULE_DESCRIPTION("OMAP Multimedia Card driver");
1525 MODULE_LICENSE("GPL");
1526 MODULE_ALIAS("platform:" DRIVER_NAME);
1527 MODULE_AUTHOR("Juha Yrjölä");
1528