xref: /openbmc/linux/drivers/mmc/host/atmel-mci.c (revision 9cdb81c7)
1 /*
2  * Atmel MultiMedia Card Interface driver
3  *
4  * Copyright (C) 2004-2008 Atmel Corporation
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 #include <linux/blkdev.h>
11 #include <linux/clk.h>
12 #include <linux/debugfs.h>
13 #include <linux/device.h>
14 #include <linux/dmaengine.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/err.h>
17 #include <linux/gpio.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/ioport.h>
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 #include <linux/scatterlist.h>
24 #include <linux/seq_file.h>
25 #include <linux/slab.h>
26 #include <linux/stat.h>
27 
28 #include <linux/mmc/host.h>
29 #include <linux/mmc/sdio.h>
30 
31 #include <mach/atmel-mci.h>
32 #include <linux/atmel-mci.h>
33 #include <linux/atmel_pdc.h>
34 
35 #include <asm/io.h>
36 #include <asm/unaligned.h>
37 
38 #include <mach/cpu.h>
39 #include <mach/board.h>
40 
41 #include "atmel-mci-regs.h"
42 
43 #define ATMCI_DATA_ERROR_FLAGS	(ATMCI_DCRCE | ATMCI_DTOE | ATMCI_OVRE | ATMCI_UNRE)
44 #define ATMCI_DMA_THRESHOLD	16
45 
46 enum {
47 	EVENT_CMD_COMPLETE = 0,
48 	EVENT_XFER_COMPLETE,
49 	EVENT_DATA_COMPLETE,
50 	EVENT_DATA_ERROR,
51 };
52 
53 enum atmel_mci_state {
54 	STATE_IDLE = 0,
55 	STATE_SENDING_CMD,
56 	STATE_SENDING_DATA,
57 	STATE_DATA_BUSY,
58 	STATE_SENDING_STOP,
59 	STATE_DATA_ERROR,
60 };
61 
62 enum atmci_xfer_dir {
63 	XFER_RECEIVE = 0,
64 	XFER_TRANSMIT,
65 };
66 
67 enum atmci_pdc_buf {
68 	PDC_FIRST_BUF = 0,
69 	PDC_SECOND_BUF,
70 };
71 
72 struct atmel_mci_caps {
73 	bool    has_dma;
74 	bool    has_pdc;
75 	bool    has_cfg_reg;
76 	bool    has_cstor_reg;
77 	bool    has_highspeed;
78 	bool    has_rwproof;
79 };
80 
81 struct atmel_mci_dma {
82 	struct dma_chan			*chan;
83 	struct dma_async_tx_descriptor	*data_desc;
84 };
85 
86 /**
87  * struct atmel_mci - MMC controller state shared between all slots
88  * @lock: Spinlock protecting the queue and associated data.
89  * @regs: Pointer to MMIO registers.
90  * @sg: Scatterlist entry currently being processed by PIO or PDC code.
91  * @pio_offset: Offset into the current scatterlist entry.
92  * @cur_slot: The slot which is currently using the controller.
93  * @mrq: The request currently being processed on @cur_slot,
94  *	or NULL if the controller is idle.
95  * @cmd: The command currently being sent to the card, or NULL.
96  * @data: The data currently being transferred, or NULL if no data
97  *	transfer is in progress.
98  * @data_size: just data->blocks * data->blksz.
99  * @dma: DMA client state.
100  * @data_chan: DMA channel being used for the current data transfer.
101  * @cmd_status: Snapshot of SR taken upon completion of the current
102  *	command. Only valid when EVENT_CMD_COMPLETE is pending.
103  * @data_status: Snapshot of SR taken upon completion of the current
104  *	data transfer. Only valid when EVENT_DATA_COMPLETE or
105  *	EVENT_DATA_ERROR is pending.
106  * @stop_cmdr: Value to be loaded into CMDR when the stop command is
107  *	to be sent.
108  * @tasklet: Tasklet running the request state machine.
109  * @pending_events: Bitmask of events flagged by the interrupt handler
110  *	to be processed by the tasklet.
111  * @completed_events: Bitmask of events which the state machine has
112  *	processed.
113  * @state: Tasklet state.
114  * @queue: List of slots waiting for access to the controller.
115  * @need_clock_update: Update the clock rate before the next request.
116  * @need_reset: Reset controller before next request.
117  * @mode_reg: Value of the MR register.
118  * @cfg_reg: Value of the CFG register.
119  * @bus_hz: The rate of @mck in Hz. This forms the basis for MMC bus
120  *	rate and timeout calculations.
121  * @mapbase: Physical address of the MMIO registers.
122  * @mck: The peripheral bus clock hooked up to the MMC controller.
123  * @pdev: Platform device associated with the MMC controller.
124  * @slot: Slots sharing this MMC controller.
125  * @caps: MCI capabilities depending on MCI version.
126  * @prepare_data: function to setup MCI before data transfer which
127  * depends on MCI capabilities.
128  * @submit_data: function to start data transfer which depends on MCI
129  * capabilities.
130  * @stop_transfer: function to stop data transfer which depends on MCI
131  * capabilities.
132  *
133  * Locking
134  * =======
135  *
136  * @lock is a softirq-safe spinlock protecting @queue as well as
137  * @cur_slot, @mrq and @state. These must always be updated
138  * at the same time while holding @lock.
139  *
140  * @lock also protects mode_reg and need_clock_update since these are
141  * used to synchronize mode register updates with the queue
142  * processing.
143  *
144  * The @mrq field of struct atmel_mci_slot is also protected by @lock,
145  * and must always be written at the same time as the slot is added to
146  * @queue.
147  *
148  * @pending_events and @completed_events are accessed using atomic bit
149  * operations, so they don't need any locking.
150  *
151  * None of the fields touched by the interrupt handler need any
152  * locking. However, ordering is important: Before EVENT_DATA_ERROR or
153  * EVENT_DATA_COMPLETE is set in @pending_events, all data-related
154  * interrupts must be disabled and @data_status updated with a
155  * snapshot of SR. Similarly, before EVENT_CMD_COMPLETE is set, the
156  * CMDRDY interrupt must be disabled and @cmd_status updated with a
157  * snapshot of SR, and before EVENT_XFER_COMPLETE can be set, the
158  * bytes_xfered field of @data must be written. This is ensured by
159  * using barriers.
160  */
161 struct atmel_mci {
162 	spinlock_t		lock;
163 	void __iomem		*regs;
164 
165 	struct scatterlist	*sg;
166 	unsigned int		pio_offset;
167 
168 	struct atmel_mci_slot	*cur_slot;
169 	struct mmc_request	*mrq;
170 	struct mmc_command	*cmd;
171 	struct mmc_data		*data;
172 	unsigned int		data_size;
173 
174 	struct atmel_mci_dma	dma;
175 	struct dma_chan		*data_chan;
176 
177 	u32			cmd_status;
178 	u32			data_status;
179 	u32			stop_cmdr;
180 
181 	struct tasklet_struct	tasklet;
182 	unsigned long		pending_events;
183 	unsigned long		completed_events;
184 	enum atmel_mci_state	state;
185 	struct list_head	queue;
186 
187 	bool			need_clock_update;
188 	bool			need_reset;
189 	u32			mode_reg;
190 	u32			cfg_reg;
191 	unsigned long		bus_hz;
192 	unsigned long		mapbase;
193 	struct clk		*mck;
194 	struct platform_device	*pdev;
195 
196 	struct atmel_mci_slot	*slot[ATMCI_MAX_NR_SLOTS];
197 
198 	struct atmel_mci_caps   caps;
199 
200 	u32 (*prepare_data)(struct atmel_mci *host, struct mmc_data *data);
201 	void (*submit_data)(struct atmel_mci *host, struct mmc_data *data);
202 	void (*stop_transfer)(struct atmel_mci *host);
203 };
204 
205 /**
206  * struct atmel_mci_slot - MMC slot state
207  * @mmc: The mmc_host representing this slot.
208  * @host: The MMC controller this slot is using.
209  * @sdc_reg: Value of SDCR to be written before using this slot.
210  * @sdio_irq: SDIO irq mask for this slot.
211  * @mrq: mmc_request currently being processed or waiting to be
212  *	processed, or NULL when the slot is idle.
213  * @queue_node: List node for placing this node in the @queue list of
214  *	&struct atmel_mci.
215  * @clock: Clock rate configured by set_ios(). Protected by host->lock.
216  * @flags: Random state bits associated with the slot.
217  * @detect_pin: GPIO pin used for card detection, or negative if not
218  *	available.
219  * @wp_pin: GPIO pin used for card write protect sending, or negative
220  *	if not available.
221  * @detect_is_active_high: The state of the detect pin when it is active.
222  * @detect_timer: Timer used for debouncing @detect_pin interrupts.
223  */
224 struct atmel_mci_slot {
225 	struct mmc_host		*mmc;
226 	struct atmel_mci	*host;
227 
228 	u32			sdc_reg;
229 	u32			sdio_irq;
230 
231 	struct mmc_request	*mrq;
232 	struct list_head	queue_node;
233 
234 	unsigned int		clock;
235 	unsigned long		flags;
236 #define ATMCI_CARD_PRESENT	0
237 #define ATMCI_CARD_NEED_INIT	1
238 #define ATMCI_SHUTDOWN		2
239 #define ATMCI_SUSPENDED		3
240 
241 	int			detect_pin;
242 	int			wp_pin;
243 	bool			detect_is_active_high;
244 
245 	struct timer_list	detect_timer;
246 };
247 
248 #define atmci_test_and_clear_pending(host, event)		\
249 	test_and_clear_bit(event, &host->pending_events)
250 #define atmci_set_completed(host, event)			\
251 	set_bit(event, &host->completed_events)
252 #define atmci_set_pending(host, event)				\
253 	set_bit(event, &host->pending_events)
254 
255 /*
256  * The debugfs stuff below is mostly optimized away when
257  * CONFIG_DEBUG_FS is not set.
258  */
259 static int atmci_req_show(struct seq_file *s, void *v)
260 {
261 	struct atmel_mci_slot	*slot = s->private;
262 	struct mmc_request	*mrq;
263 	struct mmc_command	*cmd;
264 	struct mmc_command	*stop;
265 	struct mmc_data		*data;
266 
267 	/* Make sure we get a consistent snapshot */
268 	spin_lock_bh(&slot->host->lock);
269 	mrq = slot->mrq;
270 
271 	if (mrq) {
272 		cmd = mrq->cmd;
273 		data = mrq->data;
274 		stop = mrq->stop;
275 
276 		if (cmd)
277 			seq_printf(s,
278 				"CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
279 				cmd->opcode, cmd->arg, cmd->flags,
280 				cmd->resp[0], cmd->resp[1], cmd->resp[2],
281 				cmd->resp[3], cmd->error);
282 		if (data)
283 			seq_printf(s, "DATA %u / %u * %u flg %x err %d\n",
284 				data->bytes_xfered, data->blocks,
285 				data->blksz, data->flags, data->error);
286 		if (stop)
287 			seq_printf(s,
288 				"CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
289 				stop->opcode, stop->arg, stop->flags,
290 				stop->resp[0], stop->resp[1], stop->resp[2],
291 				stop->resp[3], stop->error);
292 	}
293 
294 	spin_unlock_bh(&slot->host->lock);
295 
296 	return 0;
297 }
298 
299 static int atmci_req_open(struct inode *inode, struct file *file)
300 {
301 	return single_open(file, atmci_req_show, inode->i_private);
302 }
303 
304 static const struct file_operations atmci_req_fops = {
305 	.owner		= THIS_MODULE,
306 	.open		= atmci_req_open,
307 	.read		= seq_read,
308 	.llseek		= seq_lseek,
309 	.release	= single_release,
310 };
311 
312 static void atmci_show_status_reg(struct seq_file *s,
313 		const char *regname, u32 value)
314 {
315 	static const char	*sr_bit[] = {
316 		[0]	= "CMDRDY",
317 		[1]	= "RXRDY",
318 		[2]	= "TXRDY",
319 		[3]	= "BLKE",
320 		[4]	= "DTIP",
321 		[5]	= "NOTBUSY",
322 		[6]	= "ENDRX",
323 		[7]	= "ENDTX",
324 		[8]	= "SDIOIRQA",
325 		[9]	= "SDIOIRQB",
326 		[12]	= "SDIOWAIT",
327 		[14]	= "RXBUFF",
328 		[15]	= "TXBUFE",
329 		[16]	= "RINDE",
330 		[17]	= "RDIRE",
331 		[18]	= "RCRCE",
332 		[19]	= "RENDE",
333 		[20]	= "RTOE",
334 		[21]	= "DCRCE",
335 		[22]	= "DTOE",
336 		[23]	= "CSTOE",
337 		[24]	= "BLKOVRE",
338 		[25]	= "DMADONE",
339 		[26]	= "FIFOEMPTY",
340 		[27]	= "XFRDONE",
341 		[30]	= "OVRE",
342 		[31]	= "UNRE",
343 	};
344 	unsigned int		i;
345 
346 	seq_printf(s, "%s:\t0x%08x", regname, value);
347 	for (i = 0; i < ARRAY_SIZE(sr_bit); i++) {
348 		if (value & (1 << i)) {
349 			if (sr_bit[i])
350 				seq_printf(s, " %s", sr_bit[i]);
351 			else
352 				seq_puts(s, " UNKNOWN");
353 		}
354 	}
355 	seq_putc(s, '\n');
356 }
357 
358 static int atmci_regs_show(struct seq_file *s, void *v)
359 {
360 	struct atmel_mci	*host = s->private;
361 	u32			*buf;
362 
363 	buf = kmalloc(ATMCI_REGS_SIZE, GFP_KERNEL);
364 	if (!buf)
365 		return -ENOMEM;
366 
367 	/*
368 	 * Grab a more or less consistent snapshot. Note that we're
369 	 * not disabling interrupts, so IMR and SR may not be
370 	 * consistent.
371 	 */
372 	spin_lock_bh(&host->lock);
373 	clk_enable(host->mck);
374 	memcpy_fromio(buf, host->regs, ATMCI_REGS_SIZE);
375 	clk_disable(host->mck);
376 	spin_unlock_bh(&host->lock);
377 
378 	seq_printf(s, "MR:\t0x%08x%s%s CLKDIV=%u\n",
379 			buf[ATMCI_MR / 4],
380 			buf[ATMCI_MR / 4] & ATMCI_MR_RDPROOF ? " RDPROOF" : "",
381 			buf[ATMCI_MR / 4] & ATMCI_MR_WRPROOF ? " WRPROOF" : "",
382 			buf[ATMCI_MR / 4] & 0xff);
383 	seq_printf(s, "DTOR:\t0x%08x\n", buf[ATMCI_DTOR / 4]);
384 	seq_printf(s, "SDCR:\t0x%08x\n", buf[ATMCI_SDCR / 4]);
385 	seq_printf(s, "ARGR:\t0x%08x\n", buf[ATMCI_ARGR / 4]);
386 	seq_printf(s, "BLKR:\t0x%08x BCNT=%u BLKLEN=%u\n",
387 			buf[ATMCI_BLKR / 4],
388 			buf[ATMCI_BLKR / 4] & 0xffff,
389 			(buf[ATMCI_BLKR / 4] >> 16) & 0xffff);
390 	if (host->caps.has_cstor_reg)
391 		seq_printf(s, "CSTOR:\t0x%08x\n", buf[ATMCI_CSTOR / 4]);
392 
393 	/* Don't read RSPR and RDR; it will consume the data there */
394 
395 	atmci_show_status_reg(s, "SR", buf[ATMCI_SR / 4]);
396 	atmci_show_status_reg(s, "IMR", buf[ATMCI_IMR / 4]);
397 
398 	if (host->caps.has_dma) {
399 		u32 val;
400 
401 		val = buf[ATMCI_DMA / 4];
402 		seq_printf(s, "DMA:\t0x%08x OFFSET=%u CHKSIZE=%u%s\n",
403 				val, val & 3,
404 				((val >> 4) & 3) ?
405 					1 << (((val >> 4) & 3) + 1) : 1,
406 				val & ATMCI_DMAEN ? " DMAEN" : "");
407 	}
408 	if (host->caps.has_cfg_reg) {
409 		u32 val;
410 
411 		val = buf[ATMCI_CFG / 4];
412 		seq_printf(s, "CFG:\t0x%08x%s%s%s%s\n",
413 				val,
414 				val & ATMCI_CFG_FIFOMODE_1DATA ? " FIFOMODE_ONE_DATA" : "",
415 				val & ATMCI_CFG_FERRCTRL_COR ? " FERRCTRL_CLEAR_ON_READ" : "",
416 				val & ATMCI_CFG_HSMODE ? " HSMODE" : "",
417 				val & ATMCI_CFG_LSYNC ? " LSYNC" : "");
418 	}
419 
420 	kfree(buf);
421 
422 	return 0;
423 }
424 
425 static int atmci_regs_open(struct inode *inode, struct file *file)
426 {
427 	return single_open(file, atmci_regs_show, inode->i_private);
428 }
429 
430 static const struct file_operations atmci_regs_fops = {
431 	.owner		= THIS_MODULE,
432 	.open		= atmci_regs_open,
433 	.read		= seq_read,
434 	.llseek		= seq_lseek,
435 	.release	= single_release,
436 };
437 
438 static void atmci_init_debugfs(struct atmel_mci_slot *slot)
439 {
440 	struct mmc_host		*mmc = slot->mmc;
441 	struct atmel_mci	*host = slot->host;
442 	struct dentry		*root;
443 	struct dentry		*node;
444 
445 	root = mmc->debugfs_root;
446 	if (!root)
447 		return;
448 
449 	node = debugfs_create_file("regs", S_IRUSR, root, host,
450 			&atmci_regs_fops);
451 	if (IS_ERR(node))
452 		return;
453 	if (!node)
454 		goto err;
455 
456 	node = debugfs_create_file("req", S_IRUSR, root, slot, &atmci_req_fops);
457 	if (!node)
458 		goto err;
459 
460 	node = debugfs_create_u32("state", S_IRUSR, root, (u32 *)&host->state);
461 	if (!node)
462 		goto err;
463 
464 	node = debugfs_create_x32("pending_events", S_IRUSR, root,
465 				     (u32 *)&host->pending_events);
466 	if (!node)
467 		goto err;
468 
469 	node = debugfs_create_x32("completed_events", S_IRUSR, root,
470 				     (u32 *)&host->completed_events);
471 	if (!node)
472 		goto err;
473 
474 	return;
475 
476 err:
477 	dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n");
478 }
479 
480 static inline unsigned int atmci_ns_to_clocks(struct atmel_mci *host,
481 					unsigned int ns)
482 {
483 	return (ns * (host->bus_hz / 1000000) + 999) / 1000;
484 }
485 
486 static void atmci_set_timeout(struct atmel_mci *host,
487 		struct atmel_mci_slot *slot, struct mmc_data *data)
488 {
489 	static unsigned	dtomul_to_shift[] = {
490 		0, 4, 7, 8, 10, 12, 16, 20
491 	};
492 	unsigned	timeout;
493 	unsigned	dtocyc;
494 	unsigned	dtomul;
495 
496 	timeout = atmci_ns_to_clocks(host, data->timeout_ns)
497 		+ data->timeout_clks;
498 
499 	for (dtomul = 0; dtomul < 8; dtomul++) {
500 		unsigned shift = dtomul_to_shift[dtomul];
501 		dtocyc = (timeout + (1 << shift) - 1) >> shift;
502 		if (dtocyc < 15)
503 			break;
504 	}
505 
506 	if (dtomul >= 8) {
507 		dtomul = 7;
508 		dtocyc = 15;
509 	}
510 
511 	dev_vdbg(&slot->mmc->class_dev, "setting timeout to %u cycles\n",
512 			dtocyc << dtomul_to_shift[dtomul]);
513 	atmci_writel(host, ATMCI_DTOR, (ATMCI_DTOMUL(dtomul) | ATMCI_DTOCYC(dtocyc)));
514 }
515 
516 /*
517  * Return mask with command flags to be enabled for this command.
518  */
519 static u32 atmci_prepare_command(struct mmc_host *mmc,
520 				 struct mmc_command *cmd)
521 {
522 	struct mmc_data	*data;
523 	u32		cmdr;
524 
525 	cmd->error = -EINPROGRESS;
526 
527 	cmdr = ATMCI_CMDR_CMDNB(cmd->opcode);
528 
529 	if (cmd->flags & MMC_RSP_PRESENT) {
530 		if (cmd->flags & MMC_RSP_136)
531 			cmdr |= ATMCI_CMDR_RSPTYP_136BIT;
532 		else
533 			cmdr |= ATMCI_CMDR_RSPTYP_48BIT;
534 	}
535 
536 	/*
537 	 * This should really be MAXLAT_5 for CMD2 and ACMD41, but
538 	 * it's too difficult to determine whether this is an ACMD or
539 	 * not. Better make it 64.
540 	 */
541 	cmdr |= ATMCI_CMDR_MAXLAT_64CYC;
542 
543 	if (mmc->ios.bus_mode == MMC_BUSMODE_OPENDRAIN)
544 		cmdr |= ATMCI_CMDR_OPDCMD;
545 
546 	data = cmd->data;
547 	if (data) {
548 		cmdr |= ATMCI_CMDR_START_XFER;
549 
550 		if (cmd->opcode == SD_IO_RW_EXTENDED) {
551 			cmdr |= ATMCI_CMDR_SDIO_BLOCK;
552 		} else {
553 			if (data->flags & MMC_DATA_STREAM)
554 				cmdr |= ATMCI_CMDR_STREAM;
555 			else if (data->blocks > 1)
556 				cmdr |= ATMCI_CMDR_MULTI_BLOCK;
557 			else
558 				cmdr |= ATMCI_CMDR_BLOCK;
559 		}
560 
561 		if (data->flags & MMC_DATA_READ)
562 			cmdr |= ATMCI_CMDR_TRDIR_READ;
563 	}
564 
565 	return cmdr;
566 }
567 
568 static void atmci_send_command(struct atmel_mci *host,
569 		struct mmc_command *cmd, u32 cmd_flags)
570 {
571 	WARN_ON(host->cmd);
572 	host->cmd = cmd;
573 
574 	dev_vdbg(&host->pdev->dev,
575 			"start command: ARGR=0x%08x CMDR=0x%08x\n",
576 			cmd->arg, cmd_flags);
577 
578 	atmci_writel(host, ATMCI_ARGR, cmd->arg);
579 	atmci_writel(host, ATMCI_CMDR, cmd_flags);
580 }
581 
582 static void atmci_send_stop_cmd(struct atmel_mci *host, struct mmc_data *data)
583 {
584 	atmci_send_command(host, data->stop, host->stop_cmdr);
585 	atmci_writel(host, ATMCI_IER, ATMCI_CMDRDY);
586 }
587 
588 /*
589  * Configure given PDC buffer taking care of alignement issues.
590  * Update host->data_size and host->sg.
591  */
592 static void atmci_pdc_set_single_buf(struct atmel_mci *host,
593 	enum atmci_xfer_dir dir, enum atmci_pdc_buf buf_nb)
594 {
595 	u32 pointer_reg, counter_reg;
596 
597 	if (dir == XFER_RECEIVE) {
598 		pointer_reg = ATMEL_PDC_RPR;
599 		counter_reg = ATMEL_PDC_RCR;
600 	} else {
601 		pointer_reg = ATMEL_PDC_TPR;
602 		counter_reg = ATMEL_PDC_TCR;
603 	}
604 
605 	if (buf_nb == PDC_SECOND_BUF) {
606 		pointer_reg += ATMEL_PDC_SCND_BUF_OFF;
607 		counter_reg += ATMEL_PDC_SCND_BUF_OFF;
608 	}
609 
610 	atmci_writel(host, pointer_reg, sg_dma_address(host->sg));
611 	if (host->data_size <= sg_dma_len(host->sg)) {
612 		if (host->data_size & 0x3) {
613 			/* If size is different from modulo 4, transfer bytes */
614 			atmci_writel(host, counter_reg, host->data_size);
615 			atmci_writel(host, ATMCI_MR, host->mode_reg | ATMCI_MR_PDCFBYTE);
616 		} else {
617 			/* Else transfer 32-bits words */
618 			atmci_writel(host, counter_reg, host->data_size / 4);
619 		}
620 		host->data_size = 0;
621 	} else {
622 		/* We assume the size of a page is 32-bits aligned */
623 		atmci_writel(host, counter_reg, sg_dma_len(host->sg) / 4);
624 		host->data_size -= sg_dma_len(host->sg);
625 		if (host->data_size)
626 			host->sg = sg_next(host->sg);
627 	}
628 }
629 
630 /*
631  * Configure PDC buffer according to the data size ie configuring one or two
632  * buffers. Don't use this function if you want to configure only the second
633  * buffer. In this case, use atmci_pdc_set_single_buf.
634  */
635 static void atmci_pdc_set_both_buf(struct atmel_mci *host, int dir)
636 {
637 	atmci_pdc_set_single_buf(host, dir, PDC_FIRST_BUF);
638 	if (host->data_size)
639 		atmci_pdc_set_single_buf(host, dir, PDC_SECOND_BUF);
640 }
641 
642 /*
643  * Unmap sg lists, called when transfer is finished.
644  */
645 static void atmci_pdc_cleanup(struct atmel_mci *host)
646 {
647 	struct mmc_data         *data = host->data;
648 
649 	if (data)
650 		dma_unmap_sg(&host->pdev->dev,
651 				data->sg, data->sg_len,
652 				((data->flags & MMC_DATA_WRITE)
653 				 ? DMA_TO_DEVICE : DMA_FROM_DEVICE));
654 }
655 
656 /*
657  * Disable PDC transfers. Update pending flags to EVENT_XFER_COMPLETE after
658  * having received ATMCI_TXBUFE or ATMCI_RXBUFF interrupt. Enable ATMCI_NOTBUSY
659  * interrupt needed for both transfer directions.
660  */
661 static void atmci_pdc_complete(struct atmel_mci *host)
662 {
663 	atmci_writel(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS | ATMEL_PDC_TXTDIS);
664 	atmci_pdc_cleanup(host);
665 
666 	/*
667 	 * If the card was removed, data will be NULL. No point trying
668 	 * to send the stop command or waiting for NBUSY in this case.
669 	 */
670 	if (host->data) {
671 		atmci_set_pending(host, EVENT_XFER_COMPLETE);
672 		tasklet_schedule(&host->tasklet);
673 		atmci_writel(host, ATMCI_IER, ATMCI_NOTBUSY);
674 	}
675 }
676 
677 static void atmci_dma_cleanup(struct atmel_mci *host)
678 {
679 	struct mmc_data                 *data = host->data;
680 
681 	if (data)
682 		dma_unmap_sg(host->dma.chan->device->dev,
683 				data->sg, data->sg_len,
684 				((data->flags & MMC_DATA_WRITE)
685 				 ? DMA_TO_DEVICE : DMA_FROM_DEVICE));
686 }
687 
688 /*
689  * This function is called by the DMA driver from tasklet context.
690  */
691 static void atmci_dma_complete(void *arg)
692 {
693 	struct atmel_mci	*host = arg;
694 	struct mmc_data		*data = host->data;
695 
696 	dev_vdbg(&host->pdev->dev, "DMA complete\n");
697 
698 	if (host->caps.has_dma)
699 		/* Disable DMA hardware handshaking on MCI */
700 		atmci_writel(host, ATMCI_DMA, atmci_readl(host, ATMCI_DMA) & ~ATMCI_DMAEN);
701 
702 	atmci_dma_cleanup(host);
703 
704 	/*
705 	 * If the card was removed, data will be NULL. No point trying
706 	 * to send the stop command or waiting for NBUSY in this case.
707 	 */
708 	if (data) {
709 		atmci_set_pending(host, EVENT_XFER_COMPLETE);
710 		tasklet_schedule(&host->tasklet);
711 
712 		/*
713 		 * Regardless of what the documentation says, we have
714 		 * to wait for NOTBUSY even after block read
715 		 * operations.
716 		 *
717 		 * When the DMA transfer is complete, the controller
718 		 * may still be reading the CRC from the card, i.e.
719 		 * the data transfer is still in progress and we
720 		 * haven't seen all the potential error bits yet.
721 		 *
722 		 * The interrupt handler will schedule a different
723 		 * tasklet to finish things up when the data transfer
724 		 * is completely done.
725 		 *
726 		 * We may not complete the mmc request here anyway
727 		 * because the mmc layer may call back and cause us to
728 		 * violate the "don't submit new operations from the
729 		 * completion callback" rule of the dma engine
730 		 * framework.
731 		 */
732 		atmci_writel(host, ATMCI_IER, ATMCI_NOTBUSY);
733 	}
734 }
735 
736 /*
737  * Returns a mask of interrupt flags to be enabled after the whole
738  * request has been prepared.
739  */
740 static u32 atmci_prepare_data(struct atmel_mci *host, struct mmc_data *data)
741 {
742 	u32 iflags;
743 
744 	data->error = -EINPROGRESS;
745 
746 	host->sg = data->sg;
747 	host->data = data;
748 	host->data_chan = NULL;
749 
750 	iflags = ATMCI_DATA_ERROR_FLAGS;
751 
752 	/*
753 	 * Errata: MMC data write operation with less than 12
754 	 * bytes is impossible.
755 	 *
756 	 * Errata: MCI Transmit Data Register (TDR) FIFO
757 	 * corruption when length is not multiple of 4.
758 	 */
759 	if (data->blocks * data->blksz < 12
760 			|| (data->blocks * data->blksz) & 3)
761 		host->need_reset = true;
762 
763 	host->pio_offset = 0;
764 	if (data->flags & MMC_DATA_READ)
765 		iflags |= ATMCI_RXRDY;
766 	else
767 		iflags |= ATMCI_TXRDY;
768 
769 	return iflags;
770 }
771 
772 /*
773  * Set interrupt flags and set block length into the MCI mode register even
774  * if this value is also accessible in the MCI block register. It seems to be
775  * necessary before the High Speed MCI version. It also map sg and configure
776  * PDC registers.
777  */
778 static u32
779 atmci_prepare_data_pdc(struct atmel_mci *host, struct mmc_data *data)
780 {
781 	u32 iflags, tmp;
782 	unsigned int sg_len;
783 	enum dma_data_direction dir;
784 
785 	data->error = -EINPROGRESS;
786 
787 	host->data = data;
788 	host->sg = data->sg;
789 	iflags = ATMCI_DATA_ERROR_FLAGS;
790 
791 	/* Enable pdc mode */
792 	atmci_writel(host, ATMCI_MR, host->mode_reg | ATMCI_MR_PDCMODE);
793 
794 	if (data->flags & MMC_DATA_READ) {
795 		dir = DMA_FROM_DEVICE;
796 		iflags |= ATMCI_ENDRX | ATMCI_RXBUFF;
797 	} else {
798 		dir = DMA_TO_DEVICE;
799 		iflags |= ATMCI_ENDTX | ATMCI_TXBUFE;
800 	}
801 
802 	/* Set BLKLEN */
803 	tmp = atmci_readl(host, ATMCI_MR);
804 	tmp &= 0x0000ffff;
805 	tmp |= ATMCI_BLKLEN(data->blksz);
806 	atmci_writel(host, ATMCI_MR, tmp);
807 
808 	/* Configure PDC */
809 	host->data_size = data->blocks * data->blksz;
810 	sg_len = dma_map_sg(&host->pdev->dev, data->sg, data->sg_len, dir);
811 	if (host->data_size)
812 		atmci_pdc_set_both_buf(host,
813 			((dir == DMA_FROM_DEVICE) ? XFER_RECEIVE : XFER_TRANSMIT));
814 
815 	return iflags;
816 }
817 
818 static u32
819 atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)
820 {
821 	struct dma_chan			*chan;
822 	struct dma_async_tx_descriptor	*desc;
823 	struct scatterlist		*sg;
824 	unsigned int			i;
825 	enum dma_data_direction		direction;
826 	enum dma_transfer_direction	slave_dirn;
827 	unsigned int			sglen;
828 	u32 iflags;
829 
830 	data->error = -EINPROGRESS;
831 
832 	WARN_ON(host->data);
833 	host->sg = NULL;
834 	host->data = data;
835 
836 	iflags = ATMCI_DATA_ERROR_FLAGS;
837 
838 	/*
839 	 * We don't do DMA on "complex" transfers, i.e. with
840 	 * non-word-aligned buffers or lengths. Also, we don't bother
841 	 * with all the DMA setup overhead for short transfers.
842 	 */
843 	if (data->blocks * data->blksz < ATMCI_DMA_THRESHOLD)
844 		return atmci_prepare_data(host, data);
845 	if (data->blksz & 3)
846 		return atmci_prepare_data(host, data);
847 
848 	for_each_sg(data->sg, sg, data->sg_len, i) {
849 		if (sg->offset & 3 || sg->length & 3)
850 			return atmci_prepare_data(host, data);
851 	}
852 
853 	/* If we don't have a channel, we can't do DMA */
854 	chan = host->dma.chan;
855 	if (chan)
856 		host->data_chan = chan;
857 
858 	if (!chan)
859 		return -ENODEV;
860 
861 	if (host->caps.has_dma)
862 		atmci_writel(host, ATMCI_DMA, ATMCI_DMA_CHKSIZE(3) | ATMCI_DMAEN);
863 
864 	if (data->flags & MMC_DATA_READ) {
865 		direction = DMA_FROM_DEVICE;
866 		slave_dirn = DMA_DEV_TO_MEM;
867 	} else {
868 		direction = DMA_TO_DEVICE;
869 		slave_dirn = DMA_MEM_TO_DEV;
870 	}
871 
872 	sglen = dma_map_sg(chan->device->dev, data->sg,
873 			data->sg_len, direction);
874 
875 	desc = chan->device->device_prep_slave_sg(chan,
876 			data->sg, sglen, slave_dirn,
877 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
878 	if (!desc)
879 		goto unmap_exit;
880 
881 	host->dma.data_desc = desc;
882 	desc->callback = atmci_dma_complete;
883 	desc->callback_param = host;
884 
885 	return iflags;
886 unmap_exit:
887 	dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, direction);
888 	return -ENOMEM;
889 }
890 
891 static void
892 atmci_submit_data(struct atmel_mci *host, struct mmc_data *data)
893 {
894 	return;
895 }
896 
897 /*
898  * Start PDC according to transfer direction.
899  */
900 static void
901 atmci_submit_data_pdc(struct atmel_mci *host, struct mmc_data *data)
902 {
903 	if (data->flags & MMC_DATA_READ)
904 		atmci_writel(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTEN);
905 	else
906 		atmci_writel(host, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN);
907 }
908 
909 static void
910 atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)
911 {
912 	struct dma_chan			*chan = host->data_chan;
913 	struct dma_async_tx_descriptor	*desc = host->dma.data_desc;
914 
915 	if (chan) {
916 		dmaengine_submit(desc);
917 		dma_async_issue_pending(chan);
918 	}
919 }
920 
921 static void atmci_stop_transfer(struct atmel_mci *host)
922 {
923 	atmci_set_pending(host, EVENT_XFER_COMPLETE);
924 	atmci_writel(host, ATMCI_IER, ATMCI_NOTBUSY);
925 }
926 
927 /*
928  * Stop data transfer because error(s) occured.
929  */
930 static void atmci_stop_transfer_pdc(struct atmel_mci *host)
931 {
932 	atmci_set_pending(host, EVENT_XFER_COMPLETE);
933 	atmci_writel(host, ATMCI_IER, ATMCI_NOTBUSY);
934 }
935 
936 static void atmci_stop_transfer_dma(struct atmel_mci *host)
937 {
938 	struct dma_chan *chan = host->data_chan;
939 
940 	if (chan) {
941 		dmaengine_terminate_all(chan);
942 		atmci_dma_cleanup(host);
943 	} else {
944 		/* Data transfer was stopped by the interrupt handler */
945 		atmci_set_pending(host, EVENT_XFER_COMPLETE);
946 		atmci_writel(host, ATMCI_IER, ATMCI_NOTBUSY);
947 	}
948 }
949 
950 /*
951  * Start a request: prepare data if needed, prepare the command and activate
952  * interrupts.
953  */
954 static void atmci_start_request(struct atmel_mci *host,
955 		struct atmel_mci_slot *slot)
956 {
957 	struct mmc_request	*mrq;
958 	struct mmc_command	*cmd;
959 	struct mmc_data		*data;
960 	u32			iflags;
961 	u32			cmdflags;
962 
963 	mrq = slot->mrq;
964 	host->cur_slot = slot;
965 	host->mrq = mrq;
966 
967 	host->pending_events = 0;
968 	host->completed_events = 0;
969 	host->data_status = 0;
970 
971 	if (host->need_reset) {
972 		iflags = atmci_readl(host, ATMCI_IMR);
973 		iflags &= (ATMCI_SDIOIRQA | ATMCI_SDIOIRQB);
974 		atmci_writel(host, ATMCI_CR, ATMCI_CR_SWRST);
975 		atmci_writel(host, ATMCI_CR, ATMCI_CR_MCIEN);
976 		atmci_writel(host, ATMCI_MR, host->mode_reg);
977 		if (host->caps.has_cfg_reg)
978 			atmci_writel(host, ATMCI_CFG, host->cfg_reg);
979 		atmci_writel(host, ATMCI_IER, iflags);
980 		host->need_reset = false;
981 	}
982 	atmci_writel(host, ATMCI_SDCR, slot->sdc_reg);
983 
984 	iflags = atmci_readl(host, ATMCI_IMR);
985 	if (iflags & ~(ATMCI_SDIOIRQA | ATMCI_SDIOIRQB))
986 		dev_warn(&slot->mmc->class_dev, "WARNING: IMR=0x%08x\n",
987 				iflags);
988 
989 	if (unlikely(test_and_clear_bit(ATMCI_CARD_NEED_INIT, &slot->flags))) {
990 		/* Send init sequence (74 clock cycles) */
991 		atmci_writel(host, ATMCI_CMDR, ATMCI_CMDR_SPCMD_INIT);
992 		while (!(atmci_readl(host, ATMCI_SR) & ATMCI_CMDRDY))
993 			cpu_relax();
994 	}
995 	iflags = 0;
996 	data = mrq->data;
997 	if (data) {
998 		atmci_set_timeout(host, slot, data);
999 
1000 		/* Must set block count/size before sending command */
1001 		atmci_writel(host, ATMCI_BLKR, ATMCI_BCNT(data->blocks)
1002 				| ATMCI_BLKLEN(data->blksz));
1003 		dev_vdbg(&slot->mmc->class_dev, "BLKR=0x%08x\n",
1004 			ATMCI_BCNT(data->blocks) | ATMCI_BLKLEN(data->blksz));
1005 
1006 		iflags |= host->prepare_data(host, data);
1007 	}
1008 
1009 	iflags |= ATMCI_CMDRDY;
1010 	cmd = mrq->cmd;
1011 	cmdflags = atmci_prepare_command(slot->mmc, cmd);
1012 	atmci_send_command(host, cmd, cmdflags);
1013 
1014 	if (data)
1015 		host->submit_data(host, data);
1016 
1017 	if (mrq->stop) {
1018 		host->stop_cmdr = atmci_prepare_command(slot->mmc, mrq->stop);
1019 		host->stop_cmdr |= ATMCI_CMDR_STOP_XFER;
1020 		if (!(data->flags & MMC_DATA_WRITE))
1021 			host->stop_cmdr |= ATMCI_CMDR_TRDIR_READ;
1022 		if (data->flags & MMC_DATA_STREAM)
1023 			host->stop_cmdr |= ATMCI_CMDR_STREAM;
1024 		else
1025 			host->stop_cmdr |= ATMCI_CMDR_MULTI_BLOCK;
1026 	}
1027 
1028 	/*
1029 	 * We could have enabled interrupts earlier, but I suspect
1030 	 * that would open up a nice can of interesting race
1031 	 * conditions (e.g. command and data complete, but stop not
1032 	 * prepared yet.)
1033 	 */
1034 	atmci_writel(host, ATMCI_IER, iflags);
1035 }
1036 
1037 static void atmci_queue_request(struct atmel_mci *host,
1038 		struct atmel_mci_slot *slot, struct mmc_request *mrq)
1039 {
1040 	dev_vdbg(&slot->mmc->class_dev, "queue request: state=%d\n",
1041 			host->state);
1042 
1043 	spin_lock_bh(&host->lock);
1044 	slot->mrq = mrq;
1045 	if (host->state == STATE_IDLE) {
1046 		host->state = STATE_SENDING_CMD;
1047 		atmci_start_request(host, slot);
1048 	} else {
1049 		list_add_tail(&slot->queue_node, &host->queue);
1050 	}
1051 	spin_unlock_bh(&host->lock);
1052 }
1053 
1054 static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
1055 {
1056 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1057 	struct atmel_mci	*host = slot->host;
1058 	struct mmc_data		*data;
1059 
1060 	WARN_ON(slot->mrq);
1061 
1062 	/*
1063 	 * We may "know" the card is gone even though there's still an
1064 	 * electrical connection. If so, we really need to communicate
1065 	 * this to the MMC core since there won't be any more
1066 	 * interrupts as the card is completely removed. Otherwise,
1067 	 * the MMC core might believe the card is still there even
1068 	 * though the card was just removed very slowly.
1069 	 */
1070 	if (!test_bit(ATMCI_CARD_PRESENT, &slot->flags)) {
1071 		mrq->cmd->error = -ENOMEDIUM;
1072 		mmc_request_done(mmc, mrq);
1073 		return;
1074 	}
1075 
1076 	/* We don't support multiple blocks of weird lengths. */
1077 	data = mrq->data;
1078 	if (data && data->blocks > 1 && data->blksz & 3) {
1079 		mrq->cmd->error = -EINVAL;
1080 		mmc_request_done(mmc, mrq);
1081 	}
1082 
1083 	atmci_queue_request(host, slot, mrq);
1084 }
1085 
1086 static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
1087 {
1088 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1089 	struct atmel_mci	*host = slot->host;
1090 	unsigned int		i;
1091 
1092 	slot->sdc_reg &= ~ATMCI_SDCBUS_MASK;
1093 	switch (ios->bus_width) {
1094 	case MMC_BUS_WIDTH_1:
1095 		slot->sdc_reg |= ATMCI_SDCBUS_1BIT;
1096 		break;
1097 	case MMC_BUS_WIDTH_4:
1098 		slot->sdc_reg |= ATMCI_SDCBUS_4BIT;
1099 		break;
1100 	}
1101 
1102 	if (ios->clock) {
1103 		unsigned int clock_min = ~0U;
1104 		u32 clkdiv;
1105 
1106 		spin_lock_bh(&host->lock);
1107 		if (!host->mode_reg) {
1108 			clk_enable(host->mck);
1109 			atmci_writel(host, ATMCI_CR, ATMCI_CR_SWRST);
1110 			atmci_writel(host, ATMCI_CR, ATMCI_CR_MCIEN);
1111 			if (host->caps.has_cfg_reg)
1112 				atmci_writel(host, ATMCI_CFG, host->cfg_reg);
1113 		}
1114 
1115 		/*
1116 		 * Use mirror of ios->clock to prevent race with mmc
1117 		 * core ios update when finding the minimum.
1118 		 */
1119 		slot->clock = ios->clock;
1120 		for (i = 0; i < ATMCI_MAX_NR_SLOTS; i++) {
1121 			if (host->slot[i] && host->slot[i]->clock
1122 					&& host->slot[i]->clock < clock_min)
1123 				clock_min = host->slot[i]->clock;
1124 		}
1125 
1126 		/* Calculate clock divider */
1127 		clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * clock_min) - 1;
1128 		if (clkdiv > 255) {
1129 			dev_warn(&mmc->class_dev,
1130 				"clock %u too slow; using %lu\n",
1131 				clock_min, host->bus_hz / (2 * 256));
1132 			clkdiv = 255;
1133 		}
1134 
1135 		host->mode_reg = ATMCI_MR_CLKDIV(clkdiv);
1136 
1137 		/*
1138 		 * WRPROOF and RDPROOF prevent overruns/underruns by
1139 		 * stopping the clock when the FIFO is full/empty.
1140 		 * This state is not expected to last for long.
1141 		 */
1142 		if (host->caps.has_rwproof)
1143 			host->mode_reg |= (ATMCI_MR_WRPROOF | ATMCI_MR_RDPROOF);
1144 
1145 		if (host->caps.has_cfg_reg) {
1146 			/* setup High Speed mode in relation with card capacity */
1147 			if (ios->timing == MMC_TIMING_SD_HS)
1148 				host->cfg_reg |= ATMCI_CFG_HSMODE;
1149 			else
1150 				host->cfg_reg &= ~ATMCI_CFG_HSMODE;
1151 		}
1152 
1153 		if (list_empty(&host->queue)) {
1154 			atmci_writel(host, ATMCI_MR, host->mode_reg);
1155 			if (host->caps.has_cfg_reg)
1156 				atmci_writel(host, ATMCI_CFG, host->cfg_reg);
1157 		} else {
1158 			host->need_clock_update = true;
1159 		}
1160 
1161 		spin_unlock_bh(&host->lock);
1162 	} else {
1163 		bool any_slot_active = false;
1164 
1165 		spin_lock_bh(&host->lock);
1166 		slot->clock = 0;
1167 		for (i = 0; i < ATMCI_MAX_NR_SLOTS; i++) {
1168 			if (host->slot[i] && host->slot[i]->clock) {
1169 				any_slot_active = true;
1170 				break;
1171 			}
1172 		}
1173 		if (!any_slot_active) {
1174 			atmci_writel(host, ATMCI_CR, ATMCI_CR_MCIDIS);
1175 			if (host->mode_reg) {
1176 				atmci_readl(host, ATMCI_MR);
1177 				clk_disable(host->mck);
1178 			}
1179 			host->mode_reg = 0;
1180 		}
1181 		spin_unlock_bh(&host->lock);
1182 	}
1183 
1184 	switch (ios->power_mode) {
1185 	case MMC_POWER_UP:
1186 		set_bit(ATMCI_CARD_NEED_INIT, &slot->flags);
1187 		break;
1188 	default:
1189 		/*
1190 		 * TODO: None of the currently available AVR32-based
1191 		 * boards allow MMC power to be turned off. Implement
1192 		 * power control when this can be tested properly.
1193 		 *
1194 		 * We also need to hook this into the clock management
1195 		 * somehow so that newly inserted cards aren't
1196 		 * subjected to a fast clock before we have a chance
1197 		 * to figure out what the maximum rate is. Currently,
1198 		 * there's no way to avoid this, and there never will
1199 		 * be for boards that don't support power control.
1200 		 */
1201 		break;
1202 	}
1203 }
1204 
1205 static int atmci_get_ro(struct mmc_host *mmc)
1206 {
1207 	int			read_only = -ENOSYS;
1208 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1209 
1210 	if (gpio_is_valid(slot->wp_pin)) {
1211 		read_only = gpio_get_value(slot->wp_pin);
1212 		dev_dbg(&mmc->class_dev, "card is %s\n",
1213 				read_only ? "read-only" : "read-write");
1214 	}
1215 
1216 	return read_only;
1217 }
1218 
1219 static int atmci_get_cd(struct mmc_host *mmc)
1220 {
1221 	int			present = -ENOSYS;
1222 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1223 
1224 	if (gpio_is_valid(slot->detect_pin)) {
1225 		present = !(gpio_get_value(slot->detect_pin) ^
1226 			    slot->detect_is_active_high);
1227 		dev_dbg(&mmc->class_dev, "card is %spresent\n",
1228 				present ? "" : "not ");
1229 	}
1230 
1231 	return present;
1232 }
1233 
1234 static void atmci_enable_sdio_irq(struct mmc_host *mmc, int enable)
1235 {
1236 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1237 	struct atmel_mci	*host = slot->host;
1238 
1239 	if (enable)
1240 		atmci_writel(host, ATMCI_IER, slot->sdio_irq);
1241 	else
1242 		atmci_writel(host, ATMCI_IDR, slot->sdio_irq);
1243 }
1244 
1245 static const struct mmc_host_ops atmci_ops = {
1246 	.request	= atmci_request,
1247 	.set_ios	= atmci_set_ios,
1248 	.get_ro		= atmci_get_ro,
1249 	.get_cd		= atmci_get_cd,
1250 	.enable_sdio_irq = atmci_enable_sdio_irq,
1251 };
1252 
1253 /* Called with host->lock held */
1254 static void atmci_request_end(struct atmel_mci *host, struct mmc_request *mrq)
1255 	__releases(&host->lock)
1256 	__acquires(&host->lock)
1257 {
1258 	struct atmel_mci_slot	*slot = NULL;
1259 	struct mmc_host		*prev_mmc = host->cur_slot->mmc;
1260 
1261 	WARN_ON(host->cmd || host->data);
1262 
1263 	/*
1264 	 * Update the MMC clock rate if necessary. This may be
1265 	 * necessary if set_ios() is called when a different slot is
1266 	 * busy transferring data.
1267 	 */
1268 	if (host->need_clock_update) {
1269 		atmci_writel(host, ATMCI_MR, host->mode_reg);
1270 		if (host->caps.has_cfg_reg)
1271 			atmci_writel(host, ATMCI_CFG, host->cfg_reg);
1272 	}
1273 
1274 	host->cur_slot->mrq = NULL;
1275 	host->mrq = NULL;
1276 	if (!list_empty(&host->queue)) {
1277 		slot = list_entry(host->queue.next,
1278 				struct atmel_mci_slot, queue_node);
1279 		list_del(&slot->queue_node);
1280 		dev_vdbg(&host->pdev->dev, "list not empty: %s is next\n",
1281 				mmc_hostname(slot->mmc));
1282 		host->state = STATE_SENDING_CMD;
1283 		atmci_start_request(host, slot);
1284 	} else {
1285 		dev_vdbg(&host->pdev->dev, "list empty\n");
1286 		host->state = STATE_IDLE;
1287 	}
1288 
1289 	spin_unlock(&host->lock);
1290 	mmc_request_done(prev_mmc, mrq);
1291 	spin_lock(&host->lock);
1292 }
1293 
1294 static void atmci_command_complete(struct atmel_mci *host,
1295 			struct mmc_command *cmd)
1296 {
1297 	u32		status = host->cmd_status;
1298 
1299 	/* Read the response from the card (up to 16 bytes) */
1300 	cmd->resp[0] = atmci_readl(host, ATMCI_RSPR);
1301 	cmd->resp[1] = atmci_readl(host, ATMCI_RSPR);
1302 	cmd->resp[2] = atmci_readl(host, ATMCI_RSPR);
1303 	cmd->resp[3] = atmci_readl(host, ATMCI_RSPR);
1304 
1305 	if (status & ATMCI_RTOE)
1306 		cmd->error = -ETIMEDOUT;
1307 	else if ((cmd->flags & MMC_RSP_CRC) && (status & ATMCI_RCRCE))
1308 		cmd->error = -EILSEQ;
1309 	else if (status & (ATMCI_RINDE | ATMCI_RDIRE | ATMCI_RENDE))
1310 		cmd->error = -EIO;
1311 	else
1312 		cmd->error = 0;
1313 
1314 	if (cmd->error) {
1315 		dev_dbg(&host->pdev->dev,
1316 			"command error: status=0x%08x\n", status);
1317 
1318 		if (cmd->data) {
1319 			host->stop_transfer(host);
1320 			host->data = NULL;
1321 			atmci_writel(host, ATMCI_IDR, ATMCI_NOTBUSY
1322 					| ATMCI_TXRDY | ATMCI_RXRDY
1323 					| ATMCI_DATA_ERROR_FLAGS);
1324 		}
1325 	}
1326 }
1327 
1328 static void atmci_detect_change(unsigned long data)
1329 {
1330 	struct atmel_mci_slot	*slot = (struct atmel_mci_slot *)data;
1331 	bool			present;
1332 	bool			present_old;
1333 
1334 	/*
1335 	 * atmci_cleanup_slot() sets the ATMCI_SHUTDOWN flag before
1336 	 * freeing the interrupt. We must not re-enable the interrupt
1337 	 * if it has been freed, and if we're shutting down, it
1338 	 * doesn't really matter whether the card is present or not.
1339 	 */
1340 	smp_rmb();
1341 	if (test_bit(ATMCI_SHUTDOWN, &slot->flags))
1342 		return;
1343 
1344 	enable_irq(gpio_to_irq(slot->detect_pin));
1345 	present = !(gpio_get_value(slot->detect_pin) ^
1346 		    slot->detect_is_active_high);
1347 	present_old = test_bit(ATMCI_CARD_PRESENT, &slot->flags);
1348 
1349 	dev_vdbg(&slot->mmc->class_dev, "detect change: %d (was %d)\n",
1350 			present, present_old);
1351 
1352 	if (present != present_old) {
1353 		struct atmel_mci	*host = slot->host;
1354 		struct mmc_request	*mrq;
1355 
1356 		dev_dbg(&slot->mmc->class_dev, "card %s\n",
1357 			present ? "inserted" : "removed");
1358 
1359 		spin_lock(&host->lock);
1360 
1361 		if (!present)
1362 			clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
1363 		else
1364 			set_bit(ATMCI_CARD_PRESENT, &slot->flags);
1365 
1366 		/* Clean up queue if present */
1367 		mrq = slot->mrq;
1368 		if (mrq) {
1369 			if (mrq == host->mrq) {
1370 				/*
1371 				 * Reset controller to terminate any ongoing
1372 				 * commands or data transfers.
1373 				 */
1374 				atmci_writel(host, ATMCI_CR, ATMCI_CR_SWRST);
1375 				atmci_writel(host, ATMCI_CR, ATMCI_CR_MCIEN);
1376 				atmci_writel(host, ATMCI_MR, host->mode_reg);
1377 				if (host->caps.has_cfg_reg)
1378 					atmci_writel(host, ATMCI_CFG, host->cfg_reg);
1379 
1380 				host->data = NULL;
1381 				host->cmd = NULL;
1382 
1383 				switch (host->state) {
1384 				case STATE_IDLE:
1385 					break;
1386 				case STATE_SENDING_CMD:
1387 					mrq->cmd->error = -ENOMEDIUM;
1388 					if (!mrq->data)
1389 						break;
1390 					/* fall through */
1391 				case STATE_SENDING_DATA:
1392 					mrq->data->error = -ENOMEDIUM;
1393 					host->stop_transfer(host);
1394 					break;
1395 				case STATE_DATA_BUSY:
1396 				case STATE_DATA_ERROR:
1397 					if (mrq->data->error == -EINPROGRESS)
1398 						mrq->data->error = -ENOMEDIUM;
1399 					if (!mrq->stop)
1400 						break;
1401 					/* fall through */
1402 				case STATE_SENDING_STOP:
1403 					mrq->stop->error = -ENOMEDIUM;
1404 					break;
1405 				}
1406 
1407 				atmci_request_end(host, mrq);
1408 			} else {
1409 				list_del(&slot->queue_node);
1410 				mrq->cmd->error = -ENOMEDIUM;
1411 				if (mrq->data)
1412 					mrq->data->error = -ENOMEDIUM;
1413 				if (mrq->stop)
1414 					mrq->stop->error = -ENOMEDIUM;
1415 
1416 				spin_unlock(&host->lock);
1417 				mmc_request_done(slot->mmc, mrq);
1418 				spin_lock(&host->lock);
1419 			}
1420 		}
1421 		spin_unlock(&host->lock);
1422 
1423 		mmc_detect_change(slot->mmc, 0);
1424 	}
1425 }
1426 
1427 static void atmci_tasklet_func(unsigned long priv)
1428 {
1429 	struct atmel_mci	*host = (struct atmel_mci *)priv;
1430 	struct mmc_request	*mrq = host->mrq;
1431 	struct mmc_data		*data = host->data;
1432 	struct mmc_command	*cmd = host->cmd;
1433 	enum atmel_mci_state	state = host->state;
1434 	enum atmel_mci_state	prev_state;
1435 	u32			status;
1436 
1437 	spin_lock(&host->lock);
1438 
1439 	state = host->state;
1440 
1441 	dev_vdbg(&host->pdev->dev,
1442 		"tasklet: state %u pending/completed/mask %lx/%lx/%x\n",
1443 		state, host->pending_events, host->completed_events,
1444 		atmci_readl(host, ATMCI_IMR));
1445 
1446 	do {
1447 		prev_state = state;
1448 
1449 		switch (state) {
1450 		case STATE_IDLE:
1451 			break;
1452 
1453 		case STATE_SENDING_CMD:
1454 			if (!atmci_test_and_clear_pending(host,
1455 						EVENT_CMD_COMPLETE))
1456 				break;
1457 
1458 			host->cmd = NULL;
1459 			atmci_set_completed(host, EVENT_CMD_COMPLETE);
1460 			atmci_command_complete(host, mrq->cmd);
1461 			if (!mrq->data || cmd->error) {
1462 				atmci_request_end(host, host->mrq);
1463 				goto unlock;
1464 			}
1465 
1466 			prev_state = state = STATE_SENDING_DATA;
1467 			/* fall through */
1468 
1469 		case STATE_SENDING_DATA:
1470 			if (atmci_test_and_clear_pending(host,
1471 						EVENT_DATA_ERROR)) {
1472 				host->stop_transfer(host);
1473 				if (data->stop)
1474 					atmci_send_stop_cmd(host, data);
1475 				state = STATE_DATA_ERROR;
1476 				break;
1477 			}
1478 
1479 			if (!atmci_test_and_clear_pending(host,
1480 						EVENT_XFER_COMPLETE))
1481 				break;
1482 
1483 			atmci_set_completed(host, EVENT_XFER_COMPLETE);
1484 			prev_state = state = STATE_DATA_BUSY;
1485 			/* fall through */
1486 
1487 		case STATE_DATA_BUSY:
1488 			if (!atmci_test_and_clear_pending(host,
1489 						EVENT_DATA_COMPLETE))
1490 				break;
1491 
1492 			host->data = NULL;
1493 			atmci_set_completed(host, EVENT_DATA_COMPLETE);
1494 			status = host->data_status;
1495 			if (unlikely(status & ATMCI_DATA_ERROR_FLAGS)) {
1496 				if (status & ATMCI_DTOE) {
1497 					dev_dbg(&host->pdev->dev,
1498 							"data timeout error\n");
1499 					data->error = -ETIMEDOUT;
1500 				} else if (status & ATMCI_DCRCE) {
1501 					dev_dbg(&host->pdev->dev,
1502 							"data CRC error\n");
1503 					data->error = -EILSEQ;
1504 				} else {
1505 					dev_dbg(&host->pdev->dev,
1506 						"data FIFO error (status=%08x)\n",
1507 						status);
1508 					data->error = -EIO;
1509 				}
1510 			} else {
1511 				data->bytes_xfered = data->blocks * data->blksz;
1512 				data->error = 0;
1513 				atmci_writel(host, ATMCI_IDR, ATMCI_DATA_ERROR_FLAGS);
1514 			}
1515 
1516 			if (!data->stop) {
1517 				atmci_request_end(host, host->mrq);
1518 				goto unlock;
1519 			}
1520 
1521 			prev_state = state = STATE_SENDING_STOP;
1522 			if (!data->error)
1523 				atmci_send_stop_cmd(host, data);
1524 			/* fall through */
1525 
1526 		case STATE_SENDING_STOP:
1527 			if (!atmci_test_and_clear_pending(host,
1528 						EVENT_CMD_COMPLETE))
1529 				break;
1530 
1531 			host->cmd = NULL;
1532 			atmci_command_complete(host, mrq->stop);
1533 			atmci_request_end(host, host->mrq);
1534 			goto unlock;
1535 
1536 		case STATE_DATA_ERROR:
1537 			if (!atmci_test_and_clear_pending(host,
1538 						EVENT_XFER_COMPLETE))
1539 				break;
1540 
1541 			state = STATE_DATA_BUSY;
1542 			break;
1543 		}
1544 	} while (state != prev_state);
1545 
1546 	host->state = state;
1547 
1548 unlock:
1549 	spin_unlock(&host->lock);
1550 }
1551 
1552 static void atmci_read_data_pio(struct atmel_mci *host)
1553 {
1554 	struct scatterlist	*sg = host->sg;
1555 	void			*buf = sg_virt(sg);
1556 	unsigned int		offset = host->pio_offset;
1557 	struct mmc_data		*data = host->data;
1558 	u32			value;
1559 	u32			status;
1560 	unsigned int		nbytes = 0;
1561 
1562 	do {
1563 		value = atmci_readl(host, ATMCI_RDR);
1564 		if (likely(offset + 4 <= sg->length)) {
1565 			put_unaligned(value, (u32 *)(buf + offset));
1566 
1567 			offset += 4;
1568 			nbytes += 4;
1569 
1570 			if (offset == sg->length) {
1571 				flush_dcache_page(sg_page(sg));
1572 				host->sg = sg = sg_next(sg);
1573 				if (!sg)
1574 					goto done;
1575 
1576 				offset = 0;
1577 				buf = sg_virt(sg);
1578 			}
1579 		} else {
1580 			unsigned int remaining = sg->length - offset;
1581 			memcpy(buf + offset, &value, remaining);
1582 			nbytes += remaining;
1583 
1584 			flush_dcache_page(sg_page(sg));
1585 			host->sg = sg = sg_next(sg);
1586 			if (!sg)
1587 				goto done;
1588 
1589 			offset = 4 - remaining;
1590 			buf = sg_virt(sg);
1591 			memcpy(buf, (u8 *)&value + remaining, offset);
1592 			nbytes += offset;
1593 		}
1594 
1595 		status = atmci_readl(host, ATMCI_SR);
1596 		if (status & ATMCI_DATA_ERROR_FLAGS) {
1597 			atmci_writel(host, ATMCI_IDR, (ATMCI_NOTBUSY | ATMCI_RXRDY
1598 						| ATMCI_DATA_ERROR_FLAGS));
1599 			host->data_status = status;
1600 			data->bytes_xfered += nbytes;
1601 			smp_wmb();
1602 			atmci_set_pending(host, EVENT_DATA_ERROR);
1603 			tasklet_schedule(&host->tasklet);
1604 			return;
1605 		}
1606 	} while (status & ATMCI_RXRDY);
1607 
1608 	host->pio_offset = offset;
1609 	data->bytes_xfered += nbytes;
1610 
1611 	return;
1612 
1613 done:
1614 	atmci_writel(host, ATMCI_IDR, ATMCI_RXRDY);
1615 	atmci_writel(host, ATMCI_IER, ATMCI_NOTBUSY);
1616 	data->bytes_xfered += nbytes;
1617 	smp_wmb();
1618 	atmci_set_pending(host, EVENT_XFER_COMPLETE);
1619 }
1620 
1621 static void atmci_write_data_pio(struct atmel_mci *host)
1622 {
1623 	struct scatterlist	*sg = host->sg;
1624 	void			*buf = sg_virt(sg);
1625 	unsigned int		offset = host->pio_offset;
1626 	struct mmc_data		*data = host->data;
1627 	u32			value;
1628 	u32			status;
1629 	unsigned int		nbytes = 0;
1630 
1631 	do {
1632 		if (likely(offset + 4 <= sg->length)) {
1633 			value = get_unaligned((u32 *)(buf + offset));
1634 			atmci_writel(host, ATMCI_TDR, value);
1635 
1636 			offset += 4;
1637 			nbytes += 4;
1638 			if (offset == sg->length) {
1639 				host->sg = sg = sg_next(sg);
1640 				if (!sg)
1641 					goto done;
1642 
1643 				offset = 0;
1644 				buf = sg_virt(sg);
1645 			}
1646 		} else {
1647 			unsigned int remaining = sg->length - offset;
1648 
1649 			value = 0;
1650 			memcpy(&value, buf + offset, remaining);
1651 			nbytes += remaining;
1652 
1653 			host->sg = sg = sg_next(sg);
1654 			if (!sg) {
1655 				atmci_writel(host, ATMCI_TDR, value);
1656 				goto done;
1657 			}
1658 
1659 			offset = 4 - remaining;
1660 			buf = sg_virt(sg);
1661 			memcpy((u8 *)&value + remaining, buf, offset);
1662 			atmci_writel(host, ATMCI_TDR, value);
1663 			nbytes += offset;
1664 		}
1665 
1666 		status = atmci_readl(host, ATMCI_SR);
1667 		if (status & ATMCI_DATA_ERROR_FLAGS) {
1668 			atmci_writel(host, ATMCI_IDR, (ATMCI_NOTBUSY | ATMCI_TXRDY
1669 						| ATMCI_DATA_ERROR_FLAGS));
1670 			host->data_status = status;
1671 			data->bytes_xfered += nbytes;
1672 			smp_wmb();
1673 			atmci_set_pending(host, EVENT_DATA_ERROR);
1674 			tasklet_schedule(&host->tasklet);
1675 			return;
1676 		}
1677 	} while (status & ATMCI_TXRDY);
1678 
1679 	host->pio_offset = offset;
1680 	data->bytes_xfered += nbytes;
1681 
1682 	return;
1683 
1684 done:
1685 	atmci_writel(host, ATMCI_IDR, ATMCI_TXRDY);
1686 	atmci_writel(host, ATMCI_IER, ATMCI_NOTBUSY);
1687 	data->bytes_xfered += nbytes;
1688 	smp_wmb();
1689 	atmci_set_pending(host, EVENT_XFER_COMPLETE);
1690 }
1691 
1692 static void atmci_cmd_interrupt(struct atmel_mci *host, u32 status)
1693 {
1694 	atmci_writel(host, ATMCI_IDR, ATMCI_CMDRDY);
1695 
1696 	host->cmd_status = status;
1697 	smp_wmb();
1698 	atmci_set_pending(host, EVENT_CMD_COMPLETE);
1699 	tasklet_schedule(&host->tasklet);
1700 }
1701 
1702 static void atmci_sdio_interrupt(struct atmel_mci *host, u32 status)
1703 {
1704 	int	i;
1705 
1706 	for (i = 0; i < ATMCI_MAX_NR_SLOTS; i++) {
1707 		struct atmel_mci_slot *slot = host->slot[i];
1708 		if (slot && (status & slot->sdio_irq)) {
1709 			mmc_signal_sdio_irq(slot->mmc);
1710 		}
1711 	}
1712 }
1713 
1714 
1715 static irqreturn_t atmci_interrupt(int irq, void *dev_id)
1716 {
1717 	struct atmel_mci	*host = dev_id;
1718 	u32			status, mask, pending;
1719 	unsigned int		pass_count = 0;
1720 
1721 	do {
1722 		status = atmci_readl(host, ATMCI_SR);
1723 		mask = atmci_readl(host, ATMCI_IMR);
1724 		pending = status & mask;
1725 		if (!pending)
1726 			break;
1727 
1728 		if (pending & ATMCI_DATA_ERROR_FLAGS) {
1729 			atmci_writel(host, ATMCI_IDR, ATMCI_DATA_ERROR_FLAGS
1730 					| ATMCI_RXRDY | ATMCI_TXRDY);
1731 			pending &= atmci_readl(host, ATMCI_IMR);
1732 
1733 			host->data_status = status;
1734 			smp_wmb();
1735 			atmci_set_pending(host, EVENT_DATA_ERROR);
1736 			tasklet_schedule(&host->tasklet);
1737 		}
1738 
1739 		if (pending & ATMCI_TXBUFE) {
1740 			atmci_writel(host, ATMCI_IDR, ATMCI_TXBUFE);
1741 			atmci_writel(host, ATMCI_IDR, ATMCI_ENDTX);
1742 			/*
1743 			 * We can receive this interruption before having configured
1744 			 * the second pdc buffer, so we need to reconfigure first and
1745 			 * second buffers again
1746 			 */
1747 			if (host->data_size) {
1748 				atmci_pdc_set_both_buf(host, XFER_TRANSMIT);
1749 				atmci_writel(host, ATMCI_IER, ATMCI_ENDTX);
1750 				atmci_writel(host, ATMCI_IER, ATMCI_TXBUFE);
1751 			} else {
1752 				atmci_pdc_complete(host);
1753 			}
1754 		} else if (pending & ATMCI_ENDTX) {
1755 			atmci_writel(host, ATMCI_IDR, ATMCI_ENDTX);
1756 
1757 			if (host->data_size) {
1758 				atmci_pdc_set_single_buf(host,
1759 						XFER_TRANSMIT, PDC_SECOND_BUF);
1760 				atmci_writel(host, ATMCI_IER, ATMCI_ENDTX);
1761 			}
1762 		}
1763 
1764 		if (pending & ATMCI_RXBUFF) {
1765 			atmci_writel(host, ATMCI_IDR, ATMCI_RXBUFF);
1766 			atmci_writel(host, ATMCI_IDR, ATMCI_ENDRX);
1767 			/*
1768 			 * We can receive this interruption before having configured
1769 			 * the second pdc buffer, so we need to reconfigure first and
1770 			 * second buffers again
1771 			 */
1772 			if (host->data_size) {
1773 				atmci_pdc_set_both_buf(host, XFER_RECEIVE);
1774 				atmci_writel(host, ATMCI_IER, ATMCI_ENDRX);
1775 				atmci_writel(host, ATMCI_IER, ATMCI_RXBUFF);
1776 			} else {
1777 				atmci_pdc_complete(host);
1778 			}
1779 		} else if (pending & ATMCI_ENDRX) {
1780 			atmci_writel(host, ATMCI_IDR, ATMCI_ENDRX);
1781 
1782 			if (host->data_size) {
1783 				atmci_pdc_set_single_buf(host,
1784 						XFER_RECEIVE, PDC_SECOND_BUF);
1785 				atmci_writel(host, ATMCI_IER, ATMCI_ENDRX);
1786 			}
1787 		}
1788 
1789 
1790 		if (pending & ATMCI_NOTBUSY) {
1791 			atmci_writel(host, ATMCI_IDR,
1792 					ATMCI_DATA_ERROR_FLAGS | ATMCI_NOTBUSY);
1793 			if (!host->data_status)
1794 				host->data_status = status;
1795 			smp_wmb();
1796 			atmci_set_pending(host, EVENT_DATA_COMPLETE);
1797 			tasklet_schedule(&host->tasklet);
1798 		}
1799 		if (pending & ATMCI_RXRDY)
1800 			atmci_read_data_pio(host);
1801 		if (pending & ATMCI_TXRDY)
1802 			atmci_write_data_pio(host);
1803 
1804 		if (pending & ATMCI_CMDRDY)
1805 			atmci_cmd_interrupt(host, status);
1806 
1807 		if (pending & (ATMCI_SDIOIRQA | ATMCI_SDIOIRQB))
1808 			atmci_sdio_interrupt(host, status);
1809 
1810 	} while (pass_count++ < 5);
1811 
1812 	return pass_count ? IRQ_HANDLED : IRQ_NONE;
1813 }
1814 
1815 static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id)
1816 {
1817 	struct atmel_mci_slot	*slot = dev_id;
1818 
1819 	/*
1820 	 * Disable interrupts until the pin has stabilized and check
1821 	 * the state then. Use mod_timer() since we may be in the
1822 	 * middle of the timer routine when this interrupt triggers.
1823 	 */
1824 	disable_irq_nosync(irq);
1825 	mod_timer(&slot->detect_timer, jiffies + msecs_to_jiffies(20));
1826 
1827 	return IRQ_HANDLED;
1828 }
1829 
1830 static int __init atmci_init_slot(struct atmel_mci *host,
1831 		struct mci_slot_pdata *slot_data, unsigned int id,
1832 		u32 sdc_reg, u32 sdio_irq)
1833 {
1834 	struct mmc_host			*mmc;
1835 	struct atmel_mci_slot		*slot;
1836 
1837 	mmc = mmc_alloc_host(sizeof(struct atmel_mci_slot), &host->pdev->dev);
1838 	if (!mmc)
1839 		return -ENOMEM;
1840 
1841 	slot = mmc_priv(mmc);
1842 	slot->mmc = mmc;
1843 	slot->host = host;
1844 	slot->detect_pin = slot_data->detect_pin;
1845 	slot->wp_pin = slot_data->wp_pin;
1846 	slot->detect_is_active_high = slot_data->detect_is_active_high;
1847 	slot->sdc_reg = sdc_reg;
1848 	slot->sdio_irq = sdio_irq;
1849 
1850 	mmc->ops = &atmci_ops;
1851 	mmc->f_min = DIV_ROUND_UP(host->bus_hz, 512);
1852 	mmc->f_max = host->bus_hz / 2;
1853 	mmc->ocr_avail	= MMC_VDD_32_33 | MMC_VDD_33_34;
1854 	if (sdio_irq)
1855 		mmc->caps |= MMC_CAP_SDIO_IRQ;
1856 	if (host->caps.has_highspeed)
1857 		mmc->caps |= MMC_CAP_SD_HIGHSPEED;
1858 	if (slot_data->bus_width >= 4)
1859 		mmc->caps |= MMC_CAP_4_BIT_DATA;
1860 
1861 	mmc->max_segs = 64;
1862 	mmc->max_req_size = 32768 * 512;
1863 	mmc->max_blk_size = 32768;
1864 	mmc->max_blk_count = 512;
1865 
1866 	/* Assume card is present initially */
1867 	set_bit(ATMCI_CARD_PRESENT, &slot->flags);
1868 	if (gpio_is_valid(slot->detect_pin)) {
1869 		if (gpio_request(slot->detect_pin, "mmc_detect")) {
1870 			dev_dbg(&mmc->class_dev, "no detect pin available\n");
1871 			slot->detect_pin = -EBUSY;
1872 		} else if (gpio_get_value(slot->detect_pin) ^
1873 				slot->detect_is_active_high) {
1874 			clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
1875 		}
1876 	}
1877 
1878 	if (!gpio_is_valid(slot->detect_pin))
1879 		mmc->caps |= MMC_CAP_NEEDS_POLL;
1880 
1881 	if (gpio_is_valid(slot->wp_pin)) {
1882 		if (gpio_request(slot->wp_pin, "mmc_wp")) {
1883 			dev_dbg(&mmc->class_dev, "no WP pin available\n");
1884 			slot->wp_pin = -EBUSY;
1885 		}
1886 	}
1887 
1888 	host->slot[id] = slot;
1889 	mmc_add_host(mmc);
1890 
1891 	if (gpio_is_valid(slot->detect_pin)) {
1892 		int ret;
1893 
1894 		setup_timer(&slot->detect_timer, atmci_detect_change,
1895 				(unsigned long)slot);
1896 
1897 		ret = request_irq(gpio_to_irq(slot->detect_pin),
1898 				atmci_detect_interrupt,
1899 				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
1900 				"mmc-detect", slot);
1901 		if (ret) {
1902 			dev_dbg(&mmc->class_dev,
1903 				"could not request IRQ %d for detect pin\n",
1904 				gpio_to_irq(slot->detect_pin));
1905 			gpio_free(slot->detect_pin);
1906 			slot->detect_pin = -EBUSY;
1907 		}
1908 	}
1909 
1910 	atmci_init_debugfs(slot);
1911 
1912 	return 0;
1913 }
1914 
1915 static void __exit atmci_cleanup_slot(struct atmel_mci_slot *slot,
1916 		unsigned int id)
1917 {
1918 	/* Debugfs stuff is cleaned up by mmc core */
1919 
1920 	set_bit(ATMCI_SHUTDOWN, &slot->flags);
1921 	smp_wmb();
1922 
1923 	mmc_remove_host(slot->mmc);
1924 
1925 	if (gpio_is_valid(slot->detect_pin)) {
1926 		int pin = slot->detect_pin;
1927 
1928 		free_irq(gpio_to_irq(pin), slot);
1929 		del_timer_sync(&slot->detect_timer);
1930 		gpio_free(pin);
1931 	}
1932 	if (gpio_is_valid(slot->wp_pin))
1933 		gpio_free(slot->wp_pin);
1934 
1935 	slot->host->slot[id] = NULL;
1936 	mmc_free_host(slot->mmc);
1937 }
1938 
1939 static bool atmci_filter(struct dma_chan *chan, void *slave)
1940 {
1941 	struct mci_dma_data	*sl = slave;
1942 
1943 	if (sl && find_slave_dev(sl) == chan->device->dev) {
1944 		chan->private = slave_data_ptr(sl);
1945 		return true;
1946 	} else {
1947 		return false;
1948 	}
1949 }
1950 
1951 static bool atmci_configure_dma(struct atmel_mci *host)
1952 {
1953 	struct mci_platform_data	*pdata;
1954 
1955 	if (host == NULL)
1956 		return false;
1957 
1958 	pdata = host->pdev->dev.platform_data;
1959 
1960 	if (pdata && find_slave_dev(pdata->dma_slave)) {
1961 		dma_cap_mask_t mask;
1962 
1963 		setup_dma_addr(pdata->dma_slave,
1964 			       host->mapbase + ATMCI_TDR,
1965 			       host->mapbase + ATMCI_RDR);
1966 
1967 		/* Try to grab a DMA channel */
1968 		dma_cap_zero(mask);
1969 		dma_cap_set(DMA_SLAVE, mask);
1970 		host->dma.chan =
1971 			dma_request_channel(mask, atmci_filter, pdata->dma_slave);
1972 	}
1973 	if (!host->dma.chan) {
1974 		dev_warn(&host->pdev->dev, "no DMA channel available\n");
1975 		return false;
1976 	} else {
1977 		dev_info(&host->pdev->dev,
1978 					"Using %s for DMA transfers\n",
1979 					dma_chan_name(host->dma.chan));
1980 		return true;
1981 	}
1982 }
1983 
1984 static inline unsigned int atmci_get_version(struct atmel_mci *host)
1985 {
1986 	return atmci_readl(host, ATMCI_VERSION) & 0x00000fff;
1987 }
1988 
1989 /*
1990  * HSMCI (High Speed MCI) module is not fully compatible with MCI module.
1991  * HSMCI provides DMA support and a new config register but no more supports
1992  * PDC.
1993  */
1994 static void __init atmci_get_cap(struct atmel_mci *host)
1995 {
1996 	unsigned int version;
1997 
1998 	version = atmci_get_version(host);
1999 	dev_info(&host->pdev->dev,
2000 			"version: 0x%x\n", version);
2001 
2002 	host->caps.has_dma = 0;
2003 	host->caps.has_pdc = 0;
2004 	host->caps.has_cfg_reg = 0;
2005 	host->caps.has_cstor_reg = 0;
2006 	host->caps.has_highspeed = 0;
2007 	host->caps.has_rwproof = 0;
2008 
2009 	/* keep only major version number */
2010 	switch (version & 0xf00) {
2011 	case 0x100:
2012 	case 0x200:
2013 		host->caps.has_pdc = 1;
2014 		host->caps.has_rwproof = 1;
2015 		break;
2016 	case 0x300:
2017 	case 0x400:
2018 	case 0x500:
2019 #ifdef CONFIG_AT_HDMAC
2020 		host->caps.has_dma = 1;
2021 #else
2022 		host->caps.has_dma = 0;
2023 		dev_info(&host->pdev->dev,
2024 			"has dma capability but dma engine is not selected, then use pio\n");
2025 #endif
2026 		host->caps.has_cfg_reg = 1;
2027 		host->caps.has_cstor_reg = 1;
2028 		host->caps.has_highspeed = 1;
2029 		host->caps.has_rwproof = 1;
2030 		break;
2031 	default:
2032 		dev_warn(&host->pdev->dev,
2033 				"Unmanaged mci version, set minimum capabilities\n");
2034 		break;
2035 	}
2036 }
2037 
2038 static int __init atmci_probe(struct platform_device *pdev)
2039 {
2040 	struct mci_platform_data	*pdata;
2041 	struct atmel_mci		*host;
2042 	struct resource			*regs;
2043 	unsigned int			nr_slots;
2044 	int				irq;
2045 	int				ret;
2046 
2047 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2048 	if (!regs)
2049 		return -ENXIO;
2050 	pdata = pdev->dev.platform_data;
2051 	if (!pdata)
2052 		return -ENXIO;
2053 	irq = platform_get_irq(pdev, 0);
2054 	if (irq < 0)
2055 		return irq;
2056 
2057 	host = kzalloc(sizeof(struct atmel_mci), GFP_KERNEL);
2058 	if (!host)
2059 		return -ENOMEM;
2060 
2061 	host->pdev = pdev;
2062 	spin_lock_init(&host->lock);
2063 	INIT_LIST_HEAD(&host->queue);
2064 
2065 	host->mck = clk_get(&pdev->dev, "mci_clk");
2066 	if (IS_ERR(host->mck)) {
2067 		ret = PTR_ERR(host->mck);
2068 		goto err_clk_get;
2069 	}
2070 
2071 	ret = -ENOMEM;
2072 	host->regs = ioremap(regs->start, resource_size(regs));
2073 	if (!host->regs)
2074 		goto err_ioremap;
2075 
2076 	clk_enable(host->mck);
2077 	atmci_writel(host, ATMCI_CR, ATMCI_CR_SWRST);
2078 	host->bus_hz = clk_get_rate(host->mck);
2079 	clk_disable(host->mck);
2080 
2081 	host->mapbase = regs->start;
2082 
2083 	tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)host);
2084 
2085 	ret = request_irq(irq, atmci_interrupt, 0, dev_name(&pdev->dev), host);
2086 	if (ret)
2087 		goto err_request_irq;
2088 
2089 	/* Get MCI capabilities and set operations according to it */
2090 	atmci_get_cap(host);
2091 	if (host->caps.has_dma && atmci_configure_dma(host)) {
2092 		host->prepare_data = &atmci_prepare_data_dma;
2093 		host->submit_data = &atmci_submit_data_dma;
2094 		host->stop_transfer = &atmci_stop_transfer_dma;
2095 	} else if (host->caps.has_pdc) {
2096 		dev_info(&pdev->dev, "using PDC\n");
2097 		host->prepare_data = &atmci_prepare_data_pdc;
2098 		host->submit_data = &atmci_submit_data_pdc;
2099 		host->stop_transfer = &atmci_stop_transfer_pdc;
2100 	} else {
2101 		dev_info(&pdev->dev, "using PIO\n");
2102 		host->prepare_data = &atmci_prepare_data;
2103 		host->submit_data = &atmci_submit_data;
2104 		host->stop_transfer = &atmci_stop_transfer;
2105 	}
2106 
2107 	platform_set_drvdata(pdev, host);
2108 
2109 	/* We need at least one slot to succeed */
2110 	nr_slots = 0;
2111 	ret = -ENODEV;
2112 	if (pdata->slot[0].bus_width) {
2113 		ret = atmci_init_slot(host, &pdata->slot[0],
2114 				0, ATMCI_SDCSEL_SLOT_A, ATMCI_SDIOIRQA);
2115 		if (!ret)
2116 			nr_slots++;
2117 	}
2118 	if (pdata->slot[1].bus_width) {
2119 		ret = atmci_init_slot(host, &pdata->slot[1],
2120 				1, ATMCI_SDCSEL_SLOT_B, ATMCI_SDIOIRQB);
2121 		if (!ret)
2122 			nr_slots++;
2123 	}
2124 
2125 	if (!nr_slots) {
2126 		dev_err(&pdev->dev, "init failed: no slot defined\n");
2127 		goto err_init_slot;
2128 	}
2129 
2130 	dev_info(&pdev->dev,
2131 			"Atmel MCI controller at 0x%08lx irq %d, %u slots\n",
2132 			host->mapbase, irq, nr_slots);
2133 
2134 	return 0;
2135 
2136 err_init_slot:
2137 	if (host->dma.chan)
2138 		dma_release_channel(host->dma.chan);
2139 	free_irq(irq, host);
2140 err_request_irq:
2141 	iounmap(host->regs);
2142 err_ioremap:
2143 	clk_put(host->mck);
2144 err_clk_get:
2145 	kfree(host);
2146 	return ret;
2147 }
2148 
2149 static int __exit atmci_remove(struct platform_device *pdev)
2150 {
2151 	struct atmel_mci	*host = platform_get_drvdata(pdev);
2152 	unsigned int		i;
2153 
2154 	platform_set_drvdata(pdev, NULL);
2155 
2156 	for (i = 0; i < ATMCI_MAX_NR_SLOTS; i++) {
2157 		if (host->slot[i])
2158 			atmci_cleanup_slot(host->slot[i], i);
2159 	}
2160 
2161 	clk_enable(host->mck);
2162 	atmci_writel(host, ATMCI_IDR, ~0UL);
2163 	atmci_writel(host, ATMCI_CR, ATMCI_CR_MCIDIS);
2164 	atmci_readl(host, ATMCI_SR);
2165 	clk_disable(host->mck);
2166 
2167 #ifdef CONFIG_MMC_ATMELMCI_DMA
2168 	if (host->dma.chan)
2169 		dma_release_channel(host->dma.chan);
2170 #endif
2171 
2172 	free_irq(platform_get_irq(pdev, 0), host);
2173 	iounmap(host->regs);
2174 
2175 	clk_put(host->mck);
2176 	kfree(host);
2177 
2178 	return 0;
2179 }
2180 
2181 #ifdef CONFIG_PM
2182 static int atmci_suspend(struct device *dev)
2183 {
2184 	struct atmel_mci *host = dev_get_drvdata(dev);
2185 	int i;
2186 
2187 	 for (i = 0; i < ATMCI_MAX_NR_SLOTS; i++) {
2188 		struct atmel_mci_slot *slot = host->slot[i];
2189 		int ret;
2190 
2191 		if (!slot)
2192 			continue;
2193 		ret = mmc_suspend_host(slot->mmc);
2194 		if (ret < 0) {
2195 			while (--i >= 0) {
2196 				slot = host->slot[i];
2197 				if (slot
2198 				&& test_bit(ATMCI_SUSPENDED, &slot->flags)) {
2199 					mmc_resume_host(host->slot[i]->mmc);
2200 					clear_bit(ATMCI_SUSPENDED, &slot->flags);
2201 				}
2202 			}
2203 			return ret;
2204 		} else {
2205 			set_bit(ATMCI_SUSPENDED, &slot->flags);
2206 		}
2207 	}
2208 
2209 	return 0;
2210 }
2211 
2212 static int atmci_resume(struct device *dev)
2213 {
2214 	struct atmel_mci *host = dev_get_drvdata(dev);
2215 	int i;
2216 	int ret = 0;
2217 
2218 	for (i = 0; i < ATMCI_MAX_NR_SLOTS; i++) {
2219 		struct atmel_mci_slot *slot = host->slot[i];
2220 		int err;
2221 
2222 		slot = host->slot[i];
2223 		if (!slot)
2224 			continue;
2225 		if (!test_bit(ATMCI_SUSPENDED, &slot->flags))
2226 			continue;
2227 		err = mmc_resume_host(slot->mmc);
2228 		if (err < 0)
2229 			ret = err;
2230 		else
2231 			clear_bit(ATMCI_SUSPENDED, &slot->flags);
2232 	}
2233 
2234 	return ret;
2235 }
2236 static SIMPLE_DEV_PM_OPS(atmci_pm, atmci_suspend, atmci_resume);
2237 #define ATMCI_PM_OPS	(&atmci_pm)
2238 #else
2239 #define ATMCI_PM_OPS	NULL
2240 #endif
2241 
2242 static struct platform_driver atmci_driver = {
2243 	.remove		= __exit_p(atmci_remove),
2244 	.driver		= {
2245 		.name		= "atmel_mci",
2246 		.pm		= ATMCI_PM_OPS,
2247 	},
2248 };
2249 
2250 static int __init atmci_init(void)
2251 {
2252 	return platform_driver_probe(&atmci_driver, atmci_probe);
2253 }
2254 
2255 static void __exit atmci_exit(void)
2256 {
2257 	platform_driver_unregister(&atmci_driver);
2258 }
2259 
2260 late_initcall(atmci_init); /* try to load after dma driver when built-in */
2261 module_exit(atmci_exit);
2262 
2263 MODULE_DESCRIPTION("Atmel Multimedia Card Interface driver");
2264 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
2265 MODULE_LICENSE("GPL v2");
2266