xref: /openbmc/linux/drivers/mmc/host/atmel-mci.c (revision d586ebbb)
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 
30 #include <mach/atmel-mci.h>
31 #include <linux/atmel-mci.h>
32 
33 #include <asm/io.h>
34 #include <asm/unaligned.h>
35 
36 #include <mach/cpu.h>
37 #include <mach/board.h>
38 
39 #include "atmel-mci-regs.h"
40 
41 #define ATMCI_DATA_ERROR_FLAGS	(MCI_DCRCE | MCI_DTOE | MCI_OVRE | MCI_UNRE)
42 #define ATMCI_DMA_THRESHOLD	16
43 
44 enum {
45 	EVENT_CMD_COMPLETE = 0,
46 	EVENT_XFER_COMPLETE,
47 	EVENT_DATA_COMPLETE,
48 	EVENT_DATA_ERROR,
49 };
50 
51 enum atmel_mci_state {
52 	STATE_IDLE = 0,
53 	STATE_SENDING_CMD,
54 	STATE_SENDING_DATA,
55 	STATE_DATA_BUSY,
56 	STATE_SENDING_STOP,
57 	STATE_DATA_ERROR,
58 };
59 
60 struct atmel_mci_dma {
61 #ifdef CONFIG_MMC_ATMELMCI_DMA
62 	struct dma_chan			*chan;
63 	struct dma_async_tx_descriptor	*data_desc;
64 #endif
65 };
66 
67 /**
68  * struct atmel_mci - MMC controller state shared between all slots
69  * @lock: Spinlock protecting the queue and associated data.
70  * @regs: Pointer to MMIO registers.
71  * @sg: Scatterlist entry currently being processed by PIO code, if any.
72  * @pio_offset: Offset into the current scatterlist entry.
73  * @cur_slot: The slot which is currently using the controller.
74  * @mrq: The request currently being processed on @cur_slot,
75  *	or NULL if the controller is idle.
76  * @cmd: The command currently being sent to the card, or NULL.
77  * @data: The data currently being transferred, or NULL if no data
78  *	transfer is in progress.
79  * @dma: DMA client state.
80  * @data_chan: DMA channel being used for the current data transfer.
81  * @cmd_status: Snapshot of SR taken upon completion of the current
82  *	command. Only valid when EVENT_CMD_COMPLETE is pending.
83  * @data_status: Snapshot of SR taken upon completion of the current
84  *	data transfer. Only valid when EVENT_DATA_COMPLETE or
85  *	EVENT_DATA_ERROR is pending.
86  * @stop_cmdr: Value to be loaded into CMDR when the stop command is
87  *	to be sent.
88  * @tasklet: Tasklet running the request state machine.
89  * @pending_events: Bitmask of events flagged by the interrupt handler
90  *	to be processed by the tasklet.
91  * @completed_events: Bitmask of events which the state machine has
92  *	processed.
93  * @state: Tasklet state.
94  * @queue: List of slots waiting for access to the controller.
95  * @need_clock_update: Update the clock rate before the next request.
96  * @need_reset: Reset controller before next request.
97  * @mode_reg: Value of the MR register.
98  * @cfg_reg: Value of the CFG register.
99  * @bus_hz: The rate of @mck in Hz. This forms the basis for MMC bus
100  *	rate and timeout calculations.
101  * @mapbase: Physical address of the MMIO registers.
102  * @mck: The peripheral bus clock hooked up to the MMC controller.
103  * @pdev: Platform device associated with the MMC controller.
104  * @slot: Slots sharing this MMC controller.
105  *
106  * Locking
107  * =======
108  *
109  * @lock is a softirq-safe spinlock protecting @queue as well as
110  * @cur_slot, @mrq and @state. These must always be updated
111  * at the same time while holding @lock.
112  *
113  * @lock also protects mode_reg and need_clock_update since these are
114  * used to synchronize mode register updates with the queue
115  * processing.
116  *
117  * The @mrq field of struct atmel_mci_slot is also protected by @lock,
118  * and must always be written at the same time as the slot is added to
119  * @queue.
120  *
121  * @pending_events and @completed_events are accessed using atomic bit
122  * operations, so they don't need any locking.
123  *
124  * None of the fields touched by the interrupt handler need any
125  * locking. However, ordering is important: Before EVENT_DATA_ERROR or
126  * EVENT_DATA_COMPLETE is set in @pending_events, all data-related
127  * interrupts must be disabled and @data_status updated with a
128  * snapshot of SR. Similarly, before EVENT_CMD_COMPLETE is set, the
129  * CMDRDY interupt must be disabled and @cmd_status updated with a
130  * snapshot of SR, and before EVENT_XFER_COMPLETE can be set, the
131  * bytes_xfered field of @data must be written. This is ensured by
132  * using barriers.
133  */
134 struct atmel_mci {
135 	spinlock_t		lock;
136 	void __iomem		*regs;
137 
138 	struct scatterlist	*sg;
139 	unsigned int		pio_offset;
140 
141 	struct atmel_mci_slot	*cur_slot;
142 	struct mmc_request	*mrq;
143 	struct mmc_command	*cmd;
144 	struct mmc_data		*data;
145 
146 	struct atmel_mci_dma	dma;
147 	struct dma_chan		*data_chan;
148 
149 	u32			cmd_status;
150 	u32			data_status;
151 	u32			stop_cmdr;
152 
153 	struct tasklet_struct	tasklet;
154 	unsigned long		pending_events;
155 	unsigned long		completed_events;
156 	enum atmel_mci_state	state;
157 	struct list_head	queue;
158 
159 	bool			need_clock_update;
160 	bool			need_reset;
161 	u32			mode_reg;
162 	u32			cfg_reg;
163 	unsigned long		bus_hz;
164 	unsigned long		mapbase;
165 	struct clk		*mck;
166 	struct platform_device	*pdev;
167 
168 	struct atmel_mci_slot	*slot[ATMEL_MCI_MAX_NR_SLOTS];
169 };
170 
171 /**
172  * struct atmel_mci_slot - MMC slot state
173  * @mmc: The mmc_host representing this slot.
174  * @host: The MMC controller this slot is using.
175  * @sdc_reg: Value of SDCR to be written before using this slot.
176  * @mrq: mmc_request currently being processed or waiting to be
177  *	processed, or NULL when the slot is idle.
178  * @queue_node: List node for placing this node in the @queue list of
179  *	&struct atmel_mci.
180  * @clock: Clock rate configured by set_ios(). Protected by host->lock.
181  * @flags: Random state bits associated with the slot.
182  * @detect_pin: GPIO pin used for card detection, or negative if not
183  *	available.
184  * @wp_pin: GPIO pin used for card write protect sending, or negative
185  *	if not available.
186  * @detect_is_active_high: The state of the detect pin when it is active.
187  * @detect_timer: Timer used for debouncing @detect_pin interrupts.
188  */
189 struct atmel_mci_slot {
190 	struct mmc_host		*mmc;
191 	struct atmel_mci	*host;
192 
193 	u32			sdc_reg;
194 
195 	struct mmc_request	*mrq;
196 	struct list_head	queue_node;
197 
198 	unsigned int		clock;
199 	unsigned long		flags;
200 #define ATMCI_CARD_PRESENT	0
201 #define ATMCI_CARD_NEED_INIT	1
202 #define ATMCI_SHUTDOWN		2
203 
204 	int			detect_pin;
205 	int			wp_pin;
206 	bool			detect_is_active_high;
207 
208 	struct timer_list	detect_timer;
209 };
210 
211 #define atmci_test_and_clear_pending(host, event)		\
212 	test_and_clear_bit(event, &host->pending_events)
213 #define atmci_set_completed(host, event)			\
214 	set_bit(event, &host->completed_events)
215 #define atmci_set_pending(host, event)				\
216 	set_bit(event, &host->pending_events)
217 
218 /*
219  * Enable or disable features/registers based on
220  * whether the processor supports them
221  */
222 static bool mci_has_rwproof(void)
223 {
224 	if (cpu_is_at91sam9261() || cpu_is_at91rm9200())
225 		return false;
226 	else
227 		return true;
228 }
229 
230 /*
231  * The new MCI2 module isn't 100% compatible with the old MCI module,
232  * and it has a few nice features which we want to use...
233  */
234 static inline bool atmci_is_mci2(void)
235 {
236 	if (cpu_is_at91sam9g45())
237 		return true;
238 
239 	return false;
240 }
241 
242 
243 /*
244  * The debugfs stuff below is mostly optimized away when
245  * CONFIG_DEBUG_FS is not set.
246  */
247 static int atmci_req_show(struct seq_file *s, void *v)
248 {
249 	struct atmel_mci_slot	*slot = s->private;
250 	struct mmc_request	*mrq;
251 	struct mmc_command	*cmd;
252 	struct mmc_command	*stop;
253 	struct mmc_data		*data;
254 
255 	/* Make sure we get a consistent snapshot */
256 	spin_lock_bh(&slot->host->lock);
257 	mrq = slot->mrq;
258 
259 	if (mrq) {
260 		cmd = mrq->cmd;
261 		data = mrq->data;
262 		stop = mrq->stop;
263 
264 		if (cmd)
265 			seq_printf(s,
266 				"CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
267 				cmd->opcode, cmd->arg, cmd->flags,
268 				cmd->resp[0], cmd->resp[1], cmd->resp[2],
269 				cmd->resp[3], cmd->error);
270 		if (data)
271 			seq_printf(s, "DATA %u / %u * %u flg %x err %d\n",
272 				data->bytes_xfered, data->blocks,
273 				data->blksz, data->flags, data->error);
274 		if (stop)
275 			seq_printf(s,
276 				"CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
277 				stop->opcode, stop->arg, stop->flags,
278 				stop->resp[0], stop->resp[1], stop->resp[2],
279 				stop->resp[3], stop->error);
280 	}
281 
282 	spin_unlock_bh(&slot->host->lock);
283 
284 	return 0;
285 }
286 
287 static int atmci_req_open(struct inode *inode, struct file *file)
288 {
289 	return single_open(file, atmci_req_show, inode->i_private);
290 }
291 
292 static const struct file_operations atmci_req_fops = {
293 	.owner		= THIS_MODULE,
294 	.open		= atmci_req_open,
295 	.read		= seq_read,
296 	.llseek		= seq_lseek,
297 	.release	= single_release,
298 };
299 
300 static void atmci_show_status_reg(struct seq_file *s,
301 		const char *regname, u32 value)
302 {
303 	static const char	*sr_bit[] = {
304 		[0]	= "CMDRDY",
305 		[1]	= "RXRDY",
306 		[2]	= "TXRDY",
307 		[3]	= "BLKE",
308 		[4]	= "DTIP",
309 		[5]	= "NOTBUSY",
310 		[6]	= "ENDRX",
311 		[7]	= "ENDTX",
312 		[8]	= "SDIOIRQA",
313 		[9]	= "SDIOIRQB",
314 		[12]	= "SDIOWAIT",
315 		[14]	= "RXBUFF",
316 		[15]	= "TXBUFE",
317 		[16]	= "RINDE",
318 		[17]	= "RDIRE",
319 		[18]	= "RCRCE",
320 		[19]	= "RENDE",
321 		[20]	= "RTOE",
322 		[21]	= "DCRCE",
323 		[22]	= "DTOE",
324 		[23]	= "CSTOE",
325 		[24]	= "BLKOVRE",
326 		[25]	= "DMADONE",
327 		[26]	= "FIFOEMPTY",
328 		[27]	= "XFRDONE",
329 		[30]	= "OVRE",
330 		[31]	= "UNRE",
331 	};
332 	unsigned int		i;
333 
334 	seq_printf(s, "%s:\t0x%08x", regname, value);
335 	for (i = 0; i < ARRAY_SIZE(sr_bit); i++) {
336 		if (value & (1 << i)) {
337 			if (sr_bit[i])
338 				seq_printf(s, " %s", sr_bit[i]);
339 			else
340 				seq_puts(s, " UNKNOWN");
341 		}
342 	}
343 	seq_putc(s, '\n');
344 }
345 
346 static int atmci_regs_show(struct seq_file *s, void *v)
347 {
348 	struct atmel_mci	*host = s->private;
349 	u32			*buf;
350 
351 	buf = kmalloc(MCI_REGS_SIZE, GFP_KERNEL);
352 	if (!buf)
353 		return -ENOMEM;
354 
355 	/*
356 	 * Grab a more or less consistent snapshot. Note that we're
357 	 * not disabling interrupts, so IMR and SR may not be
358 	 * consistent.
359 	 */
360 	spin_lock_bh(&host->lock);
361 	clk_enable(host->mck);
362 	memcpy_fromio(buf, host->regs, MCI_REGS_SIZE);
363 	clk_disable(host->mck);
364 	spin_unlock_bh(&host->lock);
365 
366 	seq_printf(s, "MR:\t0x%08x%s%s CLKDIV=%u\n",
367 			buf[MCI_MR / 4],
368 			buf[MCI_MR / 4] & MCI_MR_RDPROOF ? " RDPROOF" : "",
369 			buf[MCI_MR / 4] & MCI_MR_WRPROOF ? " WRPROOF" : "",
370 			buf[MCI_MR / 4] & 0xff);
371 	seq_printf(s, "DTOR:\t0x%08x\n", buf[MCI_DTOR / 4]);
372 	seq_printf(s, "SDCR:\t0x%08x\n", buf[MCI_SDCR / 4]);
373 	seq_printf(s, "ARGR:\t0x%08x\n", buf[MCI_ARGR / 4]);
374 	seq_printf(s, "BLKR:\t0x%08x BCNT=%u BLKLEN=%u\n",
375 			buf[MCI_BLKR / 4],
376 			buf[MCI_BLKR / 4] & 0xffff,
377 			(buf[MCI_BLKR / 4] >> 16) & 0xffff);
378 	if (atmci_is_mci2())
379 		seq_printf(s, "CSTOR:\t0x%08x\n", buf[MCI_CSTOR / 4]);
380 
381 	/* Don't read RSPR and RDR; it will consume the data there */
382 
383 	atmci_show_status_reg(s, "SR", buf[MCI_SR / 4]);
384 	atmci_show_status_reg(s, "IMR", buf[MCI_IMR / 4]);
385 
386 	if (atmci_is_mci2()) {
387 		u32 val;
388 
389 		val = buf[MCI_DMA / 4];
390 		seq_printf(s, "DMA:\t0x%08x OFFSET=%u CHKSIZE=%u%s\n",
391 				val, val & 3,
392 				((val >> 4) & 3) ?
393 					1 << (((val >> 4) & 3) + 1) : 1,
394 				val & MCI_DMAEN ? " DMAEN" : "");
395 
396 		val = buf[MCI_CFG / 4];
397 		seq_printf(s, "CFG:\t0x%08x%s%s%s%s\n",
398 				val,
399 				val & MCI_CFG_FIFOMODE_1DATA ? " FIFOMODE_ONE_DATA" : "",
400 				val & MCI_CFG_FERRCTRL_COR ? " FERRCTRL_CLEAR_ON_READ" : "",
401 				val & MCI_CFG_HSMODE ? " HSMODE" : "",
402 				val & MCI_CFG_LSYNC ? " LSYNC" : "");
403 	}
404 
405 	kfree(buf);
406 
407 	return 0;
408 }
409 
410 static int atmci_regs_open(struct inode *inode, struct file *file)
411 {
412 	return single_open(file, atmci_regs_show, inode->i_private);
413 }
414 
415 static const struct file_operations atmci_regs_fops = {
416 	.owner		= THIS_MODULE,
417 	.open		= atmci_regs_open,
418 	.read		= seq_read,
419 	.llseek		= seq_lseek,
420 	.release	= single_release,
421 };
422 
423 static void atmci_init_debugfs(struct atmel_mci_slot *slot)
424 {
425 	struct mmc_host		*mmc = slot->mmc;
426 	struct atmel_mci	*host = slot->host;
427 	struct dentry		*root;
428 	struct dentry		*node;
429 
430 	root = mmc->debugfs_root;
431 	if (!root)
432 		return;
433 
434 	node = debugfs_create_file("regs", S_IRUSR, root, host,
435 			&atmci_regs_fops);
436 	if (IS_ERR(node))
437 		return;
438 	if (!node)
439 		goto err;
440 
441 	node = debugfs_create_file("req", S_IRUSR, root, slot, &atmci_req_fops);
442 	if (!node)
443 		goto err;
444 
445 	node = debugfs_create_u32("state", S_IRUSR, root, (u32 *)&host->state);
446 	if (!node)
447 		goto err;
448 
449 	node = debugfs_create_x32("pending_events", S_IRUSR, root,
450 				     (u32 *)&host->pending_events);
451 	if (!node)
452 		goto err;
453 
454 	node = debugfs_create_x32("completed_events", S_IRUSR, root,
455 				     (u32 *)&host->completed_events);
456 	if (!node)
457 		goto err;
458 
459 	return;
460 
461 err:
462 	dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n");
463 }
464 
465 static inline unsigned int ns_to_clocks(struct atmel_mci *host,
466 					unsigned int ns)
467 {
468 	return (ns * (host->bus_hz / 1000000) + 999) / 1000;
469 }
470 
471 static void atmci_set_timeout(struct atmel_mci *host,
472 		struct atmel_mci_slot *slot, struct mmc_data *data)
473 {
474 	static unsigned	dtomul_to_shift[] = {
475 		0, 4, 7, 8, 10, 12, 16, 20
476 	};
477 	unsigned	timeout;
478 	unsigned	dtocyc;
479 	unsigned	dtomul;
480 
481 	timeout = ns_to_clocks(host, data->timeout_ns) + data->timeout_clks;
482 
483 	for (dtomul = 0; dtomul < 8; dtomul++) {
484 		unsigned shift = dtomul_to_shift[dtomul];
485 		dtocyc = (timeout + (1 << shift) - 1) >> shift;
486 		if (dtocyc < 15)
487 			break;
488 	}
489 
490 	if (dtomul >= 8) {
491 		dtomul = 7;
492 		dtocyc = 15;
493 	}
494 
495 	dev_vdbg(&slot->mmc->class_dev, "setting timeout to %u cycles\n",
496 			dtocyc << dtomul_to_shift[dtomul]);
497 	mci_writel(host, DTOR, (MCI_DTOMUL(dtomul) | MCI_DTOCYC(dtocyc)));
498 }
499 
500 /*
501  * Return mask with command flags to be enabled for this command.
502  */
503 static u32 atmci_prepare_command(struct mmc_host *mmc,
504 				 struct mmc_command *cmd)
505 {
506 	struct mmc_data	*data;
507 	u32		cmdr;
508 
509 	cmd->error = -EINPROGRESS;
510 
511 	cmdr = MCI_CMDR_CMDNB(cmd->opcode);
512 
513 	if (cmd->flags & MMC_RSP_PRESENT) {
514 		if (cmd->flags & MMC_RSP_136)
515 			cmdr |= MCI_CMDR_RSPTYP_136BIT;
516 		else
517 			cmdr |= MCI_CMDR_RSPTYP_48BIT;
518 	}
519 
520 	/*
521 	 * This should really be MAXLAT_5 for CMD2 and ACMD41, but
522 	 * it's too difficult to determine whether this is an ACMD or
523 	 * not. Better make it 64.
524 	 */
525 	cmdr |= MCI_CMDR_MAXLAT_64CYC;
526 
527 	if (mmc->ios.bus_mode == MMC_BUSMODE_OPENDRAIN)
528 		cmdr |= MCI_CMDR_OPDCMD;
529 
530 	data = cmd->data;
531 	if (data) {
532 		cmdr |= MCI_CMDR_START_XFER;
533 		if (data->flags & MMC_DATA_STREAM)
534 			cmdr |= MCI_CMDR_STREAM;
535 		else if (data->blocks > 1)
536 			cmdr |= MCI_CMDR_MULTI_BLOCK;
537 		else
538 			cmdr |= MCI_CMDR_BLOCK;
539 
540 		if (data->flags & MMC_DATA_READ)
541 			cmdr |= MCI_CMDR_TRDIR_READ;
542 	}
543 
544 	return cmdr;
545 }
546 
547 static void atmci_start_command(struct atmel_mci *host,
548 		struct mmc_command *cmd, u32 cmd_flags)
549 {
550 	WARN_ON(host->cmd);
551 	host->cmd = cmd;
552 
553 	dev_vdbg(&host->pdev->dev,
554 			"start command: ARGR=0x%08x CMDR=0x%08x\n",
555 			cmd->arg, cmd_flags);
556 
557 	mci_writel(host, ARGR, cmd->arg);
558 	mci_writel(host, CMDR, cmd_flags);
559 }
560 
561 static void send_stop_cmd(struct atmel_mci *host, struct mmc_data *data)
562 {
563 	atmci_start_command(host, data->stop, host->stop_cmdr);
564 	mci_writel(host, IER, MCI_CMDRDY);
565 }
566 
567 #ifdef CONFIG_MMC_ATMELMCI_DMA
568 static void atmci_dma_cleanup(struct atmel_mci *host)
569 {
570 	struct mmc_data			*data = host->data;
571 
572 	if (data)
573 		dma_unmap_sg(&host->pdev->dev, data->sg, data->sg_len,
574 			     ((data->flags & MMC_DATA_WRITE)
575 			      ? DMA_TO_DEVICE : DMA_FROM_DEVICE));
576 }
577 
578 static void atmci_stop_dma(struct atmel_mci *host)
579 {
580 	struct dma_chan *chan = host->data_chan;
581 
582 	if (chan) {
583 		chan->device->device_terminate_all(chan);
584 		atmci_dma_cleanup(host);
585 	} else {
586 		/* Data transfer was stopped by the interrupt handler */
587 		atmci_set_pending(host, EVENT_XFER_COMPLETE);
588 		mci_writel(host, IER, MCI_NOTBUSY);
589 	}
590 }
591 
592 /* This function is called by the DMA driver from tasklet context. */
593 static void atmci_dma_complete(void *arg)
594 {
595 	struct atmel_mci	*host = arg;
596 	struct mmc_data		*data = host->data;
597 
598 	dev_vdbg(&host->pdev->dev, "DMA complete\n");
599 
600 	if (atmci_is_mci2())
601 		/* Disable DMA hardware handshaking on MCI */
602 		mci_writel(host, DMA, mci_readl(host, DMA) & ~MCI_DMAEN);
603 
604 	atmci_dma_cleanup(host);
605 
606 	/*
607 	 * If the card was removed, data will be NULL. No point trying
608 	 * to send the stop command or waiting for NBUSY in this case.
609 	 */
610 	if (data) {
611 		atmci_set_pending(host, EVENT_XFER_COMPLETE);
612 		tasklet_schedule(&host->tasklet);
613 
614 		/*
615 		 * Regardless of what the documentation says, we have
616 		 * to wait for NOTBUSY even after block read
617 		 * operations.
618 		 *
619 		 * When the DMA transfer is complete, the controller
620 		 * may still be reading the CRC from the card, i.e.
621 		 * the data transfer is still in progress and we
622 		 * haven't seen all the potential error bits yet.
623 		 *
624 		 * The interrupt handler will schedule a different
625 		 * tasklet to finish things up when the data transfer
626 		 * is completely done.
627 		 *
628 		 * We may not complete the mmc request here anyway
629 		 * because the mmc layer may call back and cause us to
630 		 * violate the "don't submit new operations from the
631 		 * completion callback" rule of the dma engine
632 		 * framework.
633 		 */
634 		mci_writel(host, IER, MCI_NOTBUSY);
635 	}
636 }
637 
638 static int
639 atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)
640 {
641 	struct dma_chan			*chan;
642 	struct dma_async_tx_descriptor	*desc;
643 	struct scatterlist		*sg;
644 	unsigned int			i;
645 	enum dma_data_direction		direction;
646 	unsigned int			sglen;
647 
648 	/*
649 	 * We don't do DMA on "complex" transfers, i.e. with
650 	 * non-word-aligned buffers or lengths. Also, we don't bother
651 	 * with all the DMA setup overhead for short transfers.
652 	 */
653 	if (data->blocks * data->blksz < ATMCI_DMA_THRESHOLD)
654 		return -EINVAL;
655 	if (data->blksz & 3)
656 		return -EINVAL;
657 
658 	for_each_sg(data->sg, sg, data->sg_len, i) {
659 		if (sg->offset & 3 || sg->length & 3)
660 			return -EINVAL;
661 	}
662 
663 	/* If we don't have a channel, we can't do DMA */
664 	chan = host->dma.chan;
665 	if (chan)
666 		host->data_chan = chan;
667 
668 	if (!chan)
669 		return -ENODEV;
670 
671 	if (atmci_is_mci2())
672 		mci_writel(host, DMA, MCI_DMA_CHKSIZE(3) | MCI_DMAEN);
673 
674 	if (data->flags & MMC_DATA_READ)
675 		direction = DMA_FROM_DEVICE;
676 	else
677 		direction = DMA_TO_DEVICE;
678 
679 	sglen = dma_map_sg(&host->pdev->dev, data->sg, data->sg_len, direction);
680 	if (sglen != data->sg_len)
681 		goto unmap_exit;
682 	desc = chan->device->device_prep_slave_sg(chan,
683 			data->sg, data->sg_len, direction,
684 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
685 	if (!desc)
686 		goto unmap_exit;
687 
688 	host->dma.data_desc = desc;
689 	desc->callback = atmci_dma_complete;
690 	desc->callback_param = host;
691 
692 	return 0;
693 unmap_exit:
694 	dma_unmap_sg(&host->pdev->dev, data->sg, sglen, direction);
695 	return -ENOMEM;
696 }
697 
698 static void atmci_submit_data(struct atmel_mci *host)
699 {
700 	struct dma_chan			*chan = host->data_chan;
701 	struct dma_async_tx_descriptor	*desc = host->dma.data_desc;
702 
703 	if (chan) {
704 		desc->tx_submit(desc);
705 		chan->device->device_issue_pending(chan);
706 	}
707 }
708 
709 #else /* CONFIG_MMC_ATMELMCI_DMA */
710 
711 static int atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)
712 {
713 	return -ENOSYS;
714 }
715 
716 static void atmci_submit_data(struct atmel_mci *host) {}
717 
718 static void atmci_stop_dma(struct atmel_mci *host)
719 {
720 	/* Data transfer was stopped by the interrupt handler */
721 	atmci_set_pending(host, EVENT_XFER_COMPLETE);
722 	mci_writel(host, IER, MCI_NOTBUSY);
723 }
724 
725 #endif /* CONFIG_MMC_ATMELMCI_DMA */
726 
727 /*
728  * Returns a mask of interrupt flags to be enabled after the whole
729  * request has been prepared.
730  */
731 static u32 atmci_prepare_data(struct atmel_mci *host, struct mmc_data *data)
732 {
733 	u32 iflags;
734 
735 	data->error = -EINPROGRESS;
736 
737 	WARN_ON(host->data);
738 	host->sg = NULL;
739 	host->data = data;
740 
741 	iflags = ATMCI_DATA_ERROR_FLAGS;
742 	if (atmci_prepare_data_dma(host, data)) {
743 		host->data_chan = NULL;
744 
745 		/*
746 		 * Errata: MMC data write operation with less than 12
747 		 * bytes is impossible.
748 		 *
749 		 * Errata: MCI Transmit Data Register (TDR) FIFO
750 		 * corruption when length is not multiple of 4.
751 		 */
752 		if (data->blocks * data->blksz < 12
753 				|| (data->blocks * data->blksz) & 3)
754 			host->need_reset = true;
755 
756 		host->sg = data->sg;
757 		host->pio_offset = 0;
758 		if (data->flags & MMC_DATA_READ)
759 			iflags |= MCI_RXRDY;
760 		else
761 			iflags |= MCI_TXRDY;
762 	}
763 
764 	return iflags;
765 }
766 
767 static void atmci_start_request(struct atmel_mci *host,
768 		struct atmel_mci_slot *slot)
769 {
770 	struct mmc_request	*mrq;
771 	struct mmc_command	*cmd;
772 	struct mmc_data		*data;
773 	u32			iflags;
774 	u32			cmdflags;
775 
776 	mrq = slot->mrq;
777 	host->cur_slot = slot;
778 	host->mrq = mrq;
779 
780 	host->pending_events = 0;
781 	host->completed_events = 0;
782 	host->data_status = 0;
783 
784 	if (host->need_reset) {
785 		mci_writel(host, CR, MCI_CR_SWRST);
786 		mci_writel(host, CR, MCI_CR_MCIEN);
787 		mci_writel(host, MR, host->mode_reg);
788 		if (atmci_is_mci2())
789 			mci_writel(host, CFG, host->cfg_reg);
790 		host->need_reset = false;
791 	}
792 	mci_writel(host, SDCR, slot->sdc_reg);
793 
794 	iflags = mci_readl(host, IMR);
795 	if (iflags)
796 		dev_warn(&slot->mmc->class_dev, "WARNING: IMR=0x%08x\n",
797 				iflags);
798 
799 	if (unlikely(test_and_clear_bit(ATMCI_CARD_NEED_INIT, &slot->flags))) {
800 		/* Send init sequence (74 clock cycles) */
801 		mci_writel(host, CMDR, MCI_CMDR_SPCMD_INIT);
802 		while (!(mci_readl(host, SR) & MCI_CMDRDY))
803 			cpu_relax();
804 	}
805 	iflags = 0;
806 	data = mrq->data;
807 	if (data) {
808 		atmci_set_timeout(host, slot, data);
809 
810 		/* Must set block count/size before sending command */
811 		mci_writel(host, BLKR, MCI_BCNT(data->blocks)
812 				| MCI_BLKLEN(data->blksz));
813 		dev_vdbg(&slot->mmc->class_dev, "BLKR=0x%08x\n",
814 			MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz));
815 
816 		iflags |= atmci_prepare_data(host, data);
817 	}
818 
819 	iflags |= MCI_CMDRDY;
820 	cmd = mrq->cmd;
821 	cmdflags = atmci_prepare_command(slot->mmc, cmd);
822 	atmci_start_command(host, cmd, cmdflags);
823 
824 	if (data)
825 		atmci_submit_data(host);
826 
827 	if (mrq->stop) {
828 		host->stop_cmdr = atmci_prepare_command(slot->mmc, mrq->stop);
829 		host->stop_cmdr |= MCI_CMDR_STOP_XFER;
830 		if (!(data->flags & MMC_DATA_WRITE))
831 			host->stop_cmdr |= MCI_CMDR_TRDIR_READ;
832 		if (data->flags & MMC_DATA_STREAM)
833 			host->stop_cmdr |= MCI_CMDR_STREAM;
834 		else
835 			host->stop_cmdr |= MCI_CMDR_MULTI_BLOCK;
836 	}
837 
838 	/*
839 	 * We could have enabled interrupts earlier, but I suspect
840 	 * that would open up a nice can of interesting race
841 	 * conditions (e.g. command and data complete, but stop not
842 	 * prepared yet.)
843 	 */
844 	mci_writel(host, IER, iflags);
845 }
846 
847 static void atmci_queue_request(struct atmel_mci *host,
848 		struct atmel_mci_slot *slot, struct mmc_request *mrq)
849 {
850 	dev_vdbg(&slot->mmc->class_dev, "queue request: state=%d\n",
851 			host->state);
852 
853 	spin_lock_bh(&host->lock);
854 	slot->mrq = mrq;
855 	if (host->state == STATE_IDLE) {
856 		host->state = STATE_SENDING_CMD;
857 		atmci_start_request(host, slot);
858 	} else {
859 		list_add_tail(&slot->queue_node, &host->queue);
860 	}
861 	spin_unlock_bh(&host->lock);
862 }
863 
864 static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
865 {
866 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
867 	struct atmel_mci	*host = slot->host;
868 	struct mmc_data		*data;
869 
870 	WARN_ON(slot->mrq);
871 
872 	/*
873 	 * We may "know" the card is gone even though there's still an
874 	 * electrical connection. If so, we really need to communicate
875 	 * this to the MMC core since there won't be any more
876 	 * interrupts as the card is completely removed. Otherwise,
877 	 * the MMC core might believe the card is still there even
878 	 * though the card was just removed very slowly.
879 	 */
880 	if (!test_bit(ATMCI_CARD_PRESENT, &slot->flags)) {
881 		mrq->cmd->error = -ENOMEDIUM;
882 		mmc_request_done(mmc, mrq);
883 		return;
884 	}
885 
886 	/* We don't support multiple blocks of weird lengths. */
887 	data = mrq->data;
888 	if (data && data->blocks > 1 && data->blksz & 3) {
889 		mrq->cmd->error = -EINVAL;
890 		mmc_request_done(mmc, mrq);
891 	}
892 
893 	atmci_queue_request(host, slot, mrq);
894 }
895 
896 static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
897 {
898 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
899 	struct atmel_mci	*host = slot->host;
900 	unsigned int		i;
901 
902 	slot->sdc_reg &= ~MCI_SDCBUS_MASK;
903 	switch (ios->bus_width) {
904 	case MMC_BUS_WIDTH_1:
905 		slot->sdc_reg |= MCI_SDCBUS_1BIT;
906 		break;
907 	case MMC_BUS_WIDTH_4:
908 		slot->sdc_reg |= MCI_SDCBUS_4BIT;
909 		break;
910 	}
911 
912 	if (ios->clock) {
913 		unsigned int clock_min = ~0U;
914 		u32 clkdiv;
915 
916 		spin_lock_bh(&host->lock);
917 		if (!host->mode_reg) {
918 			clk_enable(host->mck);
919 			mci_writel(host, CR, MCI_CR_SWRST);
920 			mci_writel(host, CR, MCI_CR_MCIEN);
921 			if (atmci_is_mci2())
922 				mci_writel(host, CFG, host->cfg_reg);
923 		}
924 
925 		/*
926 		 * Use mirror of ios->clock to prevent race with mmc
927 		 * core ios update when finding the minimum.
928 		 */
929 		slot->clock = ios->clock;
930 		for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
931 			if (host->slot[i] && host->slot[i]->clock
932 					&& host->slot[i]->clock < clock_min)
933 				clock_min = host->slot[i]->clock;
934 		}
935 
936 		/* Calculate clock divider */
937 		clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * clock_min) - 1;
938 		if (clkdiv > 255) {
939 			dev_warn(&mmc->class_dev,
940 				"clock %u too slow; using %lu\n",
941 				clock_min, host->bus_hz / (2 * 256));
942 			clkdiv = 255;
943 		}
944 
945 		host->mode_reg = MCI_MR_CLKDIV(clkdiv);
946 
947 		/*
948 		 * WRPROOF and RDPROOF prevent overruns/underruns by
949 		 * stopping the clock when the FIFO is full/empty.
950 		 * This state is not expected to last for long.
951 		 */
952 		if (mci_has_rwproof())
953 			host->mode_reg |= (MCI_MR_WRPROOF | MCI_MR_RDPROOF);
954 
955 		if (list_empty(&host->queue))
956 			mci_writel(host, MR, host->mode_reg);
957 		else
958 			host->need_clock_update = true;
959 
960 		spin_unlock_bh(&host->lock);
961 	} else {
962 		bool any_slot_active = false;
963 
964 		spin_lock_bh(&host->lock);
965 		slot->clock = 0;
966 		for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
967 			if (host->slot[i] && host->slot[i]->clock) {
968 				any_slot_active = true;
969 				break;
970 			}
971 		}
972 		if (!any_slot_active) {
973 			mci_writel(host, CR, MCI_CR_MCIDIS);
974 			if (host->mode_reg) {
975 				mci_readl(host, MR);
976 				clk_disable(host->mck);
977 			}
978 			host->mode_reg = 0;
979 		}
980 		spin_unlock_bh(&host->lock);
981 	}
982 
983 	switch (ios->power_mode) {
984 	case MMC_POWER_UP:
985 		set_bit(ATMCI_CARD_NEED_INIT, &slot->flags);
986 		break;
987 	default:
988 		/*
989 		 * TODO: None of the currently available AVR32-based
990 		 * boards allow MMC power to be turned off. Implement
991 		 * power control when this can be tested properly.
992 		 *
993 		 * We also need to hook this into the clock management
994 		 * somehow so that newly inserted cards aren't
995 		 * subjected to a fast clock before we have a chance
996 		 * to figure out what the maximum rate is. Currently,
997 		 * there's no way to avoid this, and there never will
998 		 * be for boards that don't support power control.
999 		 */
1000 		break;
1001 	}
1002 }
1003 
1004 static int atmci_get_ro(struct mmc_host *mmc)
1005 {
1006 	int			read_only = -ENOSYS;
1007 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1008 
1009 	if (gpio_is_valid(slot->wp_pin)) {
1010 		read_only = gpio_get_value(slot->wp_pin);
1011 		dev_dbg(&mmc->class_dev, "card is %s\n",
1012 				read_only ? "read-only" : "read-write");
1013 	}
1014 
1015 	return read_only;
1016 }
1017 
1018 static int atmci_get_cd(struct mmc_host *mmc)
1019 {
1020 	int			present = -ENOSYS;
1021 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1022 
1023 	if (gpio_is_valid(slot->detect_pin)) {
1024 		present = !(gpio_get_value(slot->detect_pin) ^
1025 			    slot->detect_is_active_high);
1026 		dev_dbg(&mmc->class_dev, "card is %spresent\n",
1027 				present ? "" : "not ");
1028 	}
1029 
1030 	return present;
1031 }
1032 
1033 static const struct mmc_host_ops atmci_ops = {
1034 	.request	= atmci_request,
1035 	.set_ios	= atmci_set_ios,
1036 	.get_ro		= atmci_get_ro,
1037 	.get_cd		= atmci_get_cd,
1038 };
1039 
1040 /* Called with host->lock held */
1041 static void atmci_request_end(struct atmel_mci *host, struct mmc_request *mrq)
1042 	__releases(&host->lock)
1043 	__acquires(&host->lock)
1044 {
1045 	struct atmel_mci_slot	*slot = NULL;
1046 	struct mmc_host		*prev_mmc = host->cur_slot->mmc;
1047 
1048 	WARN_ON(host->cmd || host->data);
1049 
1050 	/*
1051 	 * Update the MMC clock rate if necessary. This may be
1052 	 * necessary if set_ios() is called when a different slot is
1053 	 * busy transfering data.
1054 	 */
1055 	if (host->need_clock_update)
1056 		mci_writel(host, MR, host->mode_reg);
1057 
1058 	host->cur_slot->mrq = NULL;
1059 	host->mrq = NULL;
1060 	if (!list_empty(&host->queue)) {
1061 		slot = list_entry(host->queue.next,
1062 				struct atmel_mci_slot, queue_node);
1063 		list_del(&slot->queue_node);
1064 		dev_vdbg(&host->pdev->dev, "list not empty: %s is next\n",
1065 				mmc_hostname(slot->mmc));
1066 		host->state = STATE_SENDING_CMD;
1067 		atmci_start_request(host, slot);
1068 	} else {
1069 		dev_vdbg(&host->pdev->dev, "list empty\n");
1070 		host->state = STATE_IDLE;
1071 	}
1072 
1073 	spin_unlock(&host->lock);
1074 	mmc_request_done(prev_mmc, mrq);
1075 	spin_lock(&host->lock);
1076 }
1077 
1078 static void atmci_command_complete(struct atmel_mci *host,
1079 			struct mmc_command *cmd)
1080 {
1081 	u32		status = host->cmd_status;
1082 
1083 	/* Read the response from the card (up to 16 bytes) */
1084 	cmd->resp[0] = mci_readl(host, RSPR);
1085 	cmd->resp[1] = mci_readl(host, RSPR);
1086 	cmd->resp[2] = mci_readl(host, RSPR);
1087 	cmd->resp[3] = mci_readl(host, RSPR);
1088 
1089 	if (status & MCI_RTOE)
1090 		cmd->error = -ETIMEDOUT;
1091 	else if ((cmd->flags & MMC_RSP_CRC) && (status & MCI_RCRCE))
1092 		cmd->error = -EILSEQ;
1093 	else if (status & (MCI_RINDE | MCI_RDIRE | MCI_RENDE))
1094 		cmd->error = -EIO;
1095 	else
1096 		cmd->error = 0;
1097 
1098 	if (cmd->error) {
1099 		dev_dbg(&host->pdev->dev,
1100 			"command error: status=0x%08x\n", status);
1101 
1102 		if (cmd->data) {
1103 			atmci_stop_dma(host);
1104 			host->data = NULL;
1105 			mci_writel(host, IDR, MCI_NOTBUSY
1106 					| MCI_TXRDY | MCI_RXRDY
1107 					| ATMCI_DATA_ERROR_FLAGS);
1108 		}
1109 	}
1110 }
1111 
1112 static void atmci_detect_change(unsigned long data)
1113 {
1114 	struct atmel_mci_slot	*slot = (struct atmel_mci_slot *)data;
1115 	bool			present;
1116 	bool			present_old;
1117 
1118 	/*
1119 	 * atmci_cleanup_slot() sets the ATMCI_SHUTDOWN flag before
1120 	 * freeing the interrupt. We must not re-enable the interrupt
1121 	 * if it has been freed, and if we're shutting down, it
1122 	 * doesn't really matter whether the card is present or not.
1123 	 */
1124 	smp_rmb();
1125 	if (test_bit(ATMCI_SHUTDOWN, &slot->flags))
1126 		return;
1127 
1128 	enable_irq(gpio_to_irq(slot->detect_pin));
1129 	present = !(gpio_get_value(slot->detect_pin) ^
1130 		    slot->detect_is_active_high);
1131 	present_old = test_bit(ATMCI_CARD_PRESENT, &slot->flags);
1132 
1133 	dev_vdbg(&slot->mmc->class_dev, "detect change: %d (was %d)\n",
1134 			present, present_old);
1135 
1136 	if (present != present_old) {
1137 		struct atmel_mci	*host = slot->host;
1138 		struct mmc_request	*mrq;
1139 
1140 		dev_dbg(&slot->mmc->class_dev, "card %s\n",
1141 			present ? "inserted" : "removed");
1142 
1143 		spin_lock(&host->lock);
1144 
1145 		if (!present)
1146 			clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
1147 		else
1148 			set_bit(ATMCI_CARD_PRESENT, &slot->flags);
1149 
1150 		/* Clean up queue if present */
1151 		mrq = slot->mrq;
1152 		if (mrq) {
1153 			if (mrq == host->mrq) {
1154 				/*
1155 				 * Reset controller to terminate any ongoing
1156 				 * commands or data transfers.
1157 				 */
1158 				mci_writel(host, CR, MCI_CR_SWRST);
1159 				mci_writel(host, CR, MCI_CR_MCIEN);
1160 				mci_writel(host, MR, host->mode_reg);
1161 				if (atmci_is_mci2())
1162 					mci_writel(host, CFG, host->cfg_reg);
1163 
1164 				host->data = NULL;
1165 				host->cmd = NULL;
1166 
1167 				switch (host->state) {
1168 				case STATE_IDLE:
1169 					break;
1170 				case STATE_SENDING_CMD:
1171 					mrq->cmd->error = -ENOMEDIUM;
1172 					if (!mrq->data)
1173 						break;
1174 					/* fall through */
1175 				case STATE_SENDING_DATA:
1176 					mrq->data->error = -ENOMEDIUM;
1177 					atmci_stop_dma(host);
1178 					break;
1179 				case STATE_DATA_BUSY:
1180 				case STATE_DATA_ERROR:
1181 					if (mrq->data->error == -EINPROGRESS)
1182 						mrq->data->error = -ENOMEDIUM;
1183 					if (!mrq->stop)
1184 						break;
1185 					/* fall through */
1186 				case STATE_SENDING_STOP:
1187 					mrq->stop->error = -ENOMEDIUM;
1188 					break;
1189 				}
1190 
1191 				atmci_request_end(host, mrq);
1192 			} else {
1193 				list_del(&slot->queue_node);
1194 				mrq->cmd->error = -ENOMEDIUM;
1195 				if (mrq->data)
1196 					mrq->data->error = -ENOMEDIUM;
1197 				if (mrq->stop)
1198 					mrq->stop->error = -ENOMEDIUM;
1199 
1200 				spin_unlock(&host->lock);
1201 				mmc_request_done(slot->mmc, mrq);
1202 				spin_lock(&host->lock);
1203 			}
1204 		}
1205 		spin_unlock(&host->lock);
1206 
1207 		mmc_detect_change(slot->mmc, 0);
1208 	}
1209 }
1210 
1211 static void atmci_tasklet_func(unsigned long priv)
1212 {
1213 	struct atmel_mci	*host = (struct atmel_mci *)priv;
1214 	struct mmc_request	*mrq = host->mrq;
1215 	struct mmc_data		*data = host->data;
1216 	struct mmc_command	*cmd = host->cmd;
1217 	enum atmel_mci_state	state = host->state;
1218 	enum atmel_mci_state	prev_state;
1219 	u32			status;
1220 
1221 	spin_lock(&host->lock);
1222 
1223 	state = host->state;
1224 
1225 	dev_vdbg(&host->pdev->dev,
1226 		"tasklet: state %u pending/completed/mask %lx/%lx/%x\n",
1227 		state, host->pending_events, host->completed_events,
1228 		mci_readl(host, IMR));
1229 
1230 	do {
1231 		prev_state = state;
1232 
1233 		switch (state) {
1234 		case STATE_IDLE:
1235 			break;
1236 
1237 		case STATE_SENDING_CMD:
1238 			if (!atmci_test_and_clear_pending(host,
1239 						EVENT_CMD_COMPLETE))
1240 				break;
1241 
1242 			host->cmd = NULL;
1243 			atmci_set_completed(host, EVENT_CMD_COMPLETE);
1244 			atmci_command_complete(host, mrq->cmd);
1245 			if (!mrq->data || cmd->error) {
1246 				atmci_request_end(host, host->mrq);
1247 				goto unlock;
1248 			}
1249 
1250 			prev_state = state = STATE_SENDING_DATA;
1251 			/* fall through */
1252 
1253 		case STATE_SENDING_DATA:
1254 			if (atmci_test_and_clear_pending(host,
1255 						EVENT_DATA_ERROR)) {
1256 				atmci_stop_dma(host);
1257 				if (data->stop)
1258 					send_stop_cmd(host, data);
1259 				state = STATE_DATA_ERROR;
1260 				break;
1261 			}
1262 
1263 			if (!atmci_test_and_clear_pending(host,
1264 						EVENT_XFER_COMPLETE))
1265 				break;
1266 
1267 			atmci_set_completed(host, EVENT_XFER_COMPLETE);
1268 			prev_state = state = STATE_DATA_BUSY;
1269 			/* fall through */
1270 
1271 		case STATE_DATA_BUSY:
1272 			if (!atmci_test_and_clear_pending(host,
1273 						EVENT_DATA_COMPLETE))
1274 				break;
1275 
1276 			host->data = NULL;
1277 			atmci_set_completed(host, EVENT_DATA_COMPLETE);
1278 			status = host->data_status;
1279 			if (unlikely(status & ATMCI_DATA_ERROR_FLAGS)) {
1280 				if (status & MCI_DTOE) {
1281 					dev_dbg(&host->pdev->dev,
1282 							"data timeout error\n");
1283 					data->error = -ETIMEDOUT;
1284 				} else if (status & MCI_DCRCE) {
1285 					dev_dbg(&host->pdev->dev,
1286 							"data CRC error\n");
1287 					data->error = -EILSEQ;
1288 				} else {
1289 					dev_dbg(&host->pdev->dev,
1290 						"data FIFO error (status=%08x)\n",
1291 						status);
1292 					data->error = -EIO;
1293 				}
1294 			} else {
1295 				data->bytes_xfered = data->blocks * data->blksz;
1296 				data->error = 0;
1297 				mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS);
1298 			}
1299 
1300 			if (!data->stop) {
1301 				atmci_request_end(host, host->mrq);
1302 				goto unlock;
1303 			}
1304 
1305 			prev_state = state = STATE_SENDING_STOP;
1306 			if (!data->error)
1307 				send_stop_cmd(host, data);
1308 			/* fall through */
1309 
1310 		case STATE_SENDING_STOP:
1311 			if (!atmci_test_and_clear_pending(host,
1312 						EVENT_CMD_COMPLETE))
1313 				break;
1314 
1315 			host->cmd = NULL;
1316 			atmci_command_complete(host, mrq->stop);
1317 			atmci_request_end(host, host->mrq);
1318 			goto unlock;
1319 
1320 		case STATE_DATA_ERROR:
1321 			if (!atmci_test_and_clear_pending(host,
1322 						EVENT_XFER_COMPLETE))
1323 				break;
1324 
1325 			state = STATE_DATA_BUSY;
1326 			break;
1327 		}
1328 	} while (state != prev_state);
1329 
1330 	host->state = state;
1331 
1332 unlock:
1333 	spin_unlock(&host->lock);
1334 }
1335 
1336 static void atmci_read_data_pio(struct atmel_mci *host)
1337 {
1338 	struct scatterlist	*sg = host->sg;
1339 	void			*buf = sg_virt(sg);
1340 	unsigned int		offset = host->pio_offset;
1341 	struct mmc_data		*data = host->data;
1342 	u32			value;
1343 	u32			status;
1344 	unsigned int		nbytes = 0;
1345 
1346 	do {
1347 		value = mci_readl(host, RDR);
1348 		if (likely(offset + 4 <= sg->length)) {
1349 			put_unaligned(value, (u32 *)(buf + offset));
1350 
1351 			offset += 4;
1352 			nbytes += 4;
1353 
1354 			if (offset == sg->length) {
1355 				flush_dcache_page(sg_page(sg));
1356 				host->sg = sg = sg_next(sg);
1357 				if (!sg)
1358 					goto done;
1359 
1360 				offset = 0;
1361 				buf = sg_virt(sg);
1362 			}
1363 		} else {
1364 			unsigned int remaining = sg->length - offset;
1365 			memcpy(buf + offset, &value, remaining);
1366 			nbytes += remaining;
1367 
1368 			flush_dcache_page(sg_page(sg));
1369 			host->sg = sg = sg_next(sg);
1370 			if (!sg)
1371 				goto done;
1372 
1373 			offset = 4 - remaining;
1374 			buf = sg_virt(sg);
1375 			memcpy(buf, (u8 *)&value + remaining, offset);
1376 			nbytes += offset;
1377 		}
1378 
1379 		status = mci_readl(host, SR);
1380 		if (status & ATMCI_DATA_ERROR_FLAGS) {
1381 			mci_writel(host, IDR, (MCI_NOTBUSY | MCI_RXRDY
1382 						| ATMCI_DATA_ERROR_FLAGS));
1383 			host->data_status = status;
1384 			data->bytes_xfered += nbytes;
1385 			smp_wmb();
1386 			atmci_set_pending(host, EVENT_DATA_ERROR);
1387 			tasklet_schedule(&host->tasklet);
1388 			return;
1389 		}
1390 	} while (status & MCI_RXRDY);
1391 
1392 	host->pio_offset = offset;
1393 	data->bytes_xfered += nbytes;
1394 
1395 	return;
1396 
1397 done:
1398 	mci_writel(host, IDR, MCI_RXRDY);
1399 	mci_writel(host, IER, MCI_NOTBUSY);
1400 	data->bytes_xfered += nbytes;
1401 	smp_wmb();
1402 	atmci_set_pending(host, EVENT_XFER_COMPLETE);
1403 }
1404 
1405 static void atmci_write_data_pio(struct atmel_mci *host)
1406 {
1407 	struct scatterlist	*sg = host->sg;
1408 	void			*buf = sg_virt(sg);
1409 	unsigned int		offset = host->pio_offset;
1410 	struct mmc_data		*data = host->data;
1411 	u32			value;
1412 	u32			status;
1413 	unsigned int		nbytes = 0;
1414 
1415 	do {
1416 		if (likely(offset + 4 <= sg->length)) {
1417 			value = get_unaligned((u32 *)(buf + offset));
1418 			mci_writel(host, TDR, value);
1419 
1420 			offset += 4;
1421 			nbytes += 4;
1422 			if (offset == sg->length) {
1423 				host->sg = sg = sg_next(sg);
1424 				if (!sg)
1425 					goto done;
1426 
1427 				offset = 0;
1428 				buf = sg_virt(sg);
1429 			}
1430 		} else {
1431 			unsigned int remaining = sg->length - offset;
1432 
1433 			value = 0;
1434 			memcpy(&value, buf + offset, remaining);
1435 			nbytes += remaining;
1436 
1437 			host->sg = sg = sg_next(sg);
1438 			if (!sg) {
1439 				mci_writel(host, TDR, value);
1440 				goto done;
1441 			}
1442 
1443 			offset = 4 - remaining;
1444 			buf = sg_virt(sg);
1445 			memcpy((u8 *)&value + remaining, buf, offset);
1446 			mci_writel(host, TDR, value);
1447 			nbytes += offset;
1448 		}
1449 
1450 		status = mci_readl(host, SR);
1451 		if (status & ATMCI_DATA_ERROR_FLAGS) {
1452 			mci_writel(host, IDR, (MCI_NOTBUSY | MCI_TXRDY
1453 						| ATMCI_DATA_ERROR_FLAGS));
1454 			host->data_status = status;
1455 			data->bytes_xfered += nbytes;
1456 			smp_wmb();
1457 			atmci_set_pending(host, EVENT_DATA_ERROR);
1458 			tasklet_schedule(&host->tasklet);
1459 			return;
1460 		}
1461 	} while (status & MCI_TXRDY);
1462 
1463 	host->pio_offset = offset;
1464 	data->bytes_xfered += nbytes;
1465 
1466 	return;
1467 
1468 done:
1469 	mci_writel(host, IDR, MCI_TXRDY);
1470 	mci_writel(host, IER, MCI_NOTBUSY);
1471 	data->bytes_xfered += nbytes;
1472 	smp_wmb();
1473 	atmci_set_pending(host, EVENT_XFER_COMPLETE);
1474 }
1475 
1476 static void atmci_cmd_interrupt(struct atmel_mci *host, u32 status)
1477 {
1478 	mci_writel(host, IDR, MCI_CMDRDY);
1479 
1480 	host->cmd_status = status;
1481 	smp_wmb();
1482 	atmci_set_pending(host, EVENT_CMD_COMPLETE);
1483 	tasklet_schedule(&host->tasklet);
1484 }
1485 
1486 static irqreturn_t atmci_interrupt(int irq, void *dev_id)
1487 {
1488 	struct atmel_mci	*host = dev_id;
1489 	u32			status, mask, pending;
1490 	unsigned int		pass_count = 0;
1491 
1492 	do {
1493 		status = mci_readl(host, SR);
1494 		mask = mci_readl(host, IMR);
1495 		pending = status & mask;
1496 		if (!pending)
1497 			break;
1498 
1499 		if (pending & ATMCI_DATA_ERROR_FLAGS) {
1500 			mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS
1501 					| MCI_RXRDY | MCI_TXRDY);
1502 			pending &= mci_readl(host, IMR);
1503 
1504 			host->data_status = status;
1505 			smp_wmb();
1506 			atmci_set_pending(host, EVENT_DATA_ERROR);
1507 			tasklet_schedule(&host->tasklet);
1508 		}
1509 		if (pending & MCI_NOTBUSY) {
1510 			mci_writel(host, IDR,
1511 					ATMCI_DATA_ERROR_FLAGS | MCI_NOTBUSY);
1512 			if (!host->data_status)
1513 				host->data_status = status;
1514 			smp_wmb();
1515 			atmci_set_pending(host, EVENT_DATA_COMPLETE);
1516 			tasklet_schedule(&host->tasklet);
1517 		}
1518 		if (pending & MCI_RXRDY)
1519 			atmci_read_data_pio(host);
1520 		if (pending & MCI_TXRDY)
1521 			atmci_write_data_pio(host);
1522 
1523 		if (pending & MCI_CMDRDY)
1524 			atmci_cmd_interrupt(host, status);
1525 	} while (pass_count++ < 5);
1526 
1527 	return pass_count ? IRQ_HANDLED : IRQ_NONE;
1528 }
1529 
1530 static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id)
1531 {
1532 	struct atmel_mci_slot	*slot = dev_id;
1533 
1534 	/*
1535 	 * Disable interrupts until the pin has stabilized and check
1536 	 * the state then. Use mod_timer() since we may be in the
1537 	 * middle of the timer routine when this interrupt triggers.
1538 	 */
1539 	disable_irq_nosync(irq);
1540 	mod_timer(&slot->detect_timer, jiffies + msecs_to_jiffies(20));
1541 
1542 	return IRQ_HANDLED;
1543 }
1544 
1545 static int __init atmci_init_slot(struct atmel_mci *host,
1546 		struct mci_slot_pdata *slot_data, unsigned int id,
1547 		u32 sdc_reg)
1548 {
1549 	struct mmc_host			*mmc;
1550 	struct atmel_mci_slot		*slot;
1551 
1552 	mmc = mmc_alloc_host(sizeof(struct atmel_mci_slot), &host->pdev->dev);
1553 	if (!mmc)
1554 		return -ENOMEM;
1555 
1556 	slot = mmc_priv(mmc);
1557 	slot->mmc = mmc;
1558 	slot->host = host;
1559 	slot->detect_pin = slot_data->detect_pin;
1560 	slot->wp_pin = slot_data->wp_pin;
1561 	slot->detect_is_active_high = slot_data->detect_is_active_high;
1562 	slot->sdc_reg = sdc_reg;
1563 
1564 	mmc->ops = &atmci_ops;
1565 	mmc->f_min = DIV_ROUND_UP(host->bus_hz, 512);
1566 	mmc->f_max = host->bus_hz / 2;
1567 	mmc->ocr_avail	= MMC_VDD_32_33 | MMC_VDD_33_34;
1568 	if (slot_data->bus_width >= 4)
1569 		mmc->caps |= MMC_CAP_4_BIT_DATA;
1570 
1571 	mmc->max_hw_segs = 64;
1572 	mmc->max_phys_segs = 64;
1573 	mmc->max_req_size = 32768 * 512;
1574 	mmc->max_blk_size = 32768;
1575 	mmc->max_blk_count = 512;
1576 
1577 	/* Assume card is present initially */
1578 	set_bit(ATMCI_CARD_PRESENT, &slot->flags);
1579 	if (gpio_is_valid(slot->detect_pin)) {
1580 		if (gpio_request(slot->detect_pin, "mmc_detect")) {
1581 			dev_dbg(&mmc->class_dev, "no detect pin available\n");
1582 			slot->detect_pin = -EBUSY;
1583 		} else if (gpio_get_value(slot->detect_pin) ^
1584 				slot->detect_is_active_high) {
1585 			clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
1586 		}
1587 	}
1588 
1589 	if (!gpio_is_valid(slot->detect_pin))
1590 		mmc->caps |= MMC_CAP_NEEDS_POLL;
1591 
1592 	if (gpio_is_valid(slot->wp_pin)) {
1593 		if (gpio_request(slot->wp_pin, "mmc_wp")) {
1594 			dev_dbg(&mmc->class_dev, "no WP pin available\n");
1595 			slot->wp_pin = -EBUSY;
1596 		}
1597 	}
1598 
1599 	host->slot[id] = slot;
1600 	mmc_add_host(mmc);
1601 
1602 	if (gpio_is_valid(slot->detect_pin)) {
1603 		int ret;
1604 
1605 		setup_timer(&slot->detect_timer, atmci_detect_change,
1606 				(unsigned long)slot);
1607 
1608 		ret = request_irq(gpio_to_irq(slot->detect_pin),
1609 				atmci_detect_interrupt,
1610 				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
1611 				"mmc-detect", slot);
1612 		if (ret) {
1613 			dev_dbg(&mmc->class_dev,
1614 				"could not request IRQ %d for detect pin\n",
1615 				gpio_to_irq(slot->detect_pin));
1616 			gpio_free(slot->detect_pin);
1617 			slot->detect_pin = -EBUSY;
1618 		}
1619 	}
1620 
1621 	atmci_init_debugfs(slot);
1622 
1623 	return 0;
1624 }
1625 
1626 static void __exit atmci_cleanup_slot(struct atmel_mci_slot *slot,
1627 		unsigned int id)
1628 {
1629 	/* Debugfs stuff is cleaned up by mmc core */
1630 
1631 	set_bit(ATMCI_SHUTDOWN, &slot->flags);
1632 	smp_wmb();
1633 
1634 	mmc_remove_host(slot->mmc);
1635 
1636 	if (gpio_is_valid(slot->detect_pin)) {
1637 		int pin = slot->detect_pin;
1638 
1639 		free_irq(gpio_to_irq(pin), slot);
1640 		del_timer_sync(&slot->detect_timer);
1641 		gpio_free(pin);
1642 	}
1643 	if (gpio_is_valid(slot->wp_pin))
1644 		gpio_free(slot->wp_pin);
1645 
1646 	slot->host->slot[id] = NULL;
1647 	mmc_free_host(slot->mmc);
1648 }
1649 
1650 #ifdef CONFIG_MMC_ATMELMCI_DMA
1651 static bool filter(struct dma_chan *chan, void *slave)
1652 {
1653 	struct mci_dma_data	*sl = slave;
1654 
1655 	if (sl && find_slave_dev(sl) == chan->device->dev) {
1656 		chan->private = slave_data_ptr(sl);
1657 		return true;
1658 	} else {
1659 		return false;
1660 	}
1661 }
1662 
1663 static void atmci_configure_dma(struct atmel_mci *host)
1664 {
1665 	struct mci_platform_data	*pdata;
1666 
1667 	if (host == NULL)
1668 		return;
1669 
1670 	pdata = host->pdev->dev.platform_data;
1671 
1672 	if (pdata && find_slave_dev(pdata->dma_slave)) {
1673 		dma_cap_mask_t mask;
1674 
1675 		setup_dma_addr(pdata->dma_slave,
1676 			       host->mapbase + MCI_TDR,
1677 			       host->mapbase + MCI_RDR);
1678 
1679 		/* Try to grab a DMA channel */
1680 		dma_cap_zero(mask);
1681 		dma_cap_set(DMA_SLAVE, mask);
1682 		host->dma.chan =
1683 			dma_request_channel(mask, filter, pdata->dma_slave);
1684 	}
1685 	if (!host->dma.chan)
1686 		dev_notice(&host->pdev->dev, "DMA not available, using PIO\n");
1687 	else
1688 		dev_info(&host->pdev->dev,
1689 					"Using %s for DMA transfers\n",
1690 					dma_chan_name(host->dma.chan));
1691 }
1692 #else
1693 static void atmci_configure_dma(struct atmel_mci *host) {}
1694 #endif
1695 
1696 static int __init atmci_probe(struct platform_device *pdev)
1697 {
1698 	struct mci_platform_data	*pdata;
1699 	struct atmel_mci		*host;
1700 	struct resource			*regs;
1701 	unsigned int			nr_slots;
1702 	int				irq;
1703 	int				ret;
1704 
1705 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1706 	if (!regs)
1707 		return -ENXIO;
1708 	pdata = pdev->dev.platform_data;
1709 	if (!pdata)
1710 		return -ENXIO;
1711 	irq = platform_get_irq(pdev, 0);
1712 	if (irq < 0)
1713 		return irq;
1714 
1715 	host = kzalloc(sizeof(struct atmel_mci), GFP_KERNEL);
1716 	if (!host)
1717 		return -ENOMEM;
1718 
1719 	host->pdev = pdev;
1720 	spin_lock_init(&host->lock);
1721 	INIT_LIST_HEAD(&host->queue);
1722 
1723 	host->mck = clk_get(&pdev->dev, "mci_clk");
1724 	if (IS_ERR(host->mck)) {
1725 		ret = PTR_ERR(host->mck);
1726 		goto err_clk_get;
1727 	}
1728 
1729 	ret = -ENOMEM;
1730 	host->regs = ioremap(regs->start, regs->end - regs->start + 1);
1731 	if (!host->regs)
1732 		goto err_ioremap;
1733 
1734 	clk_enable(host->mck);
1735 	mci_writel(host, CR, MCI_CR_SWRST);
1736 	host->bus_hz = clk_get_rate(host->mck);
1737 	clk_disable(host->mck);
1738 
1739 	host->mapbase = regs->start;
1740 
1741 	tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)host);
1742 
1743 	ret = request_irq(irq, atmci_interrupt, 0, dev_name(&pdev->dev), host);
1744 	if (ret)
1745 		goto err_request_irq;
1746 
1747 	atmci_configure_dma(host);
1748 
1749 	platform_set_drvdata(pdev, host);
1750 
1751 	/* We need at least one slot to succeed */
1752 	nr_slots = 0;
1753 	ret = -ENODEV;
1754 	if (pdata->slot[0].bus_width) {
1755 		ret = atmci_init_slot(host, &pdata->slot[0],
1756 				0, MCI_SDCSEL_SLOT_A);
1757 		if (!ret)
1758 			nr_slots++;
1759 	}
1760 	if (pdata->slot[1].bus_width) {
1761 		ret = atmci_init_slot(host, &pdata->slot[1],
1762 				1, MCI_SDCSEL_SLOT_B);
1763 		if (!ret)
1764 			nr_slots++;
1765 	}
1766 
1767 	if (!nr_slots) {
1768 		dev_err(&pdev->dev, "init failed: no slot defined\n");
1769 		goto err_init_slot;
1770 	}
1771 
1772 	dev_info(&pdev->dev,
1773 			"Atmel MCI controller at 0x%08lx irq %d, %u slots\n",
1774 			host->mapbase, irq, nr_slots);
1775 
1776 	return 0;
1777 
1778 err_init_slot:
1779 #ifdef CONFIG_MMC_ATMELMCI_DMA
1780 	if (host->dma.chan)
1781 		dma_release_channel(host->dma.chan);
1782 #endif
1783 	free_irq(irq, host);
1784 err_request_irq:
1785 	iounmap(host->regs);
1786 err_ioremap:
1787 	clk_put(host->mck);
1788 err_clk_get:
1789 	kfree(host);
1790 	return ret;
1791 }
1792 
1793 static int __exit atmci_remove(struct platform_device *pdev)
1794 {
1795 	struct atmel_mci	*host = platform_get_drvdata(pdev);
1796 	unsigned int		i;
1797 
1798 	platform_set_drvdata(pdev, NULL);
1799 
1800 	for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
1801 		if (host->slot[i])
1802 			atmci_cleanup_slot(host->slot[i], i);
1803 	}
1804 
1805 	clk_enable(host->mck);
1806 	mci_writel(host, IDR, ~0UL);
1807 	mci_writel(host, CR, MCI_CR_MCIDIS);
1808 	mci_readl(host, SR);
1809 	clk_disable(host->mck);
1810 
1811 #ifdef CONFIG_MMC_ATMELMCI_DMA
1812 	if (host->dma.chan)
1813 		dma_release_channel(host->dma.chan);
1814 #endif
1815 
1816 	free_irq(platform_get_irq(pdev, 0), host);
1817 	iounmap(host->regs);
1818 
1819 	clk_put(host->mck);
1820 	kfree(host);
1821 
1822 	return 0;
1823 }
1824 
1825 static struct platform_driver atmci_driver = {
1826 	.remove		= __exit_p(atmci_remove),
1827 	.driver		= {
1828 		.name		= "atmel_mci",
1829 	},
1830 };
1831 
1832 static int __init atmci_init(void)
1833 {
1834 	return platform_driver_probe(&atmci_driver, atmci_probe);
1835 }
1836 
1837 static void __exit atmci_exit(void)
1838 {
1839 	platform_driver_unregister(&atmci_driver);
1840 }
1841 
1842 late_initcall(atmci_init); /* try to load after dma driver when built-in */
1843 module_exit(atmci_exit);
1844 
1845 MODULE_DESCRIPTION("Atmel Multimedia Card Interface driver");
1846 MODULE_AUTHOR("Haavard Skinnemoen <haavard.skinnemoen@atmel.com>");
1847 MODULE_LICENSE("GPL v2");
1848