xref: /openbmc/linux/drivers/mmc/host/atmel-mci.c (revision 7dd65feb)
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/stat.h>
26 
27 #include <linux/mmc/host.h>
28 
29 #include <mach/atmel-mci.h>
30 #include <linux/atmel-mci.h>
31 
32 #include <asm/io.h>
33 #include <asm/unaligned.h>
34 
35 #include <mach/cpu.h>
36 #include <mach/board.h>
37 
38 #include "atmel-mci-regs.h"
39 
40 #define ATMCI_DATA_ERROR_FLAGS	(MCI_DCRCE | MCI_DTOE | MCI_OVRE | MCI_UNRE)
41 #define ATMCI_DMA_THRESHOLD	16
42 
43 enum {
44 	EVENT_CMD_COMPLETE = 0,
45 	EVENT_XFER_COMPLETE,
46 	EVENT_DATA_COMPLETE,
47 	EVENT_DATA_ERROR,
48 };
49 
50 enum atmel_mci_state {
51 	STATE_IDLE = 0,
52 	STATE_SENDING_CMD,
53 	STATE_SENDING_DATA,
54 	STATE_DATA_BUSY,
55 	STATE_SENDING_STOP,
56 	STATE_DATA_ERROR,
57 };
58 
59 struct atmel_mci_dma {
60 #ifdef CONFIG_MMC_ATMELMCI_DMA
61 	struct dma_chan			*chan;
62 	struct dma_async_tx_descriptor	*data_desc;
63 #endif
64 };
65 
66 /**
67  * struct atmel_mci - MMC controller state shared between all slots
68  * @lock: Spinlock protecting the queue and associated data.
69  * @regs: Pointer to MMIO registers.
70  * @sg: Scatterlist entry currently being processed by PIO code, if any.
71  * @pio_offset: Offset into the current scatterlist entry.
72  * @cur_slot: The slot which is currently using the controller.
73  * @mrq: The request currently being processed on @cur_slot,
74  *	or NULL if the controller is idle.
75  * @cmd: The command currently being sent to the card, or NULL.
76  * @data: The data currently being transferred, or NULL if no data
77  *	transfer is in progress.
78  * @dma: DMA client state.
79  * @data_chan: DMA channel being used for the current data transfer.
80  * @cmd_status: Snapshot of SR taken upon completion of the current
81  *	command. Only valid when EVENT_CMD_COMPLETE is pending.
82  * @data_status: Snapshot of SR taken upon completion of the current
83  *	data transfer. Only valid when EVENT_DATA_COMPLETE or
84  *	EVENT_DATA_ERROR is pending.
85  * @stop_cmdr: Value to be loaded into CMDR when the stop command is
86  *	to be sent.
87  * @tasklet: Tasklet running the request state machine.
88  * @pending_events: Bitmask of events flagged by the interrupt handler
89  *	to be processed by the tasklet.
90  * @completed_events: Bitmask of events which the state machine has
91  *	processed.
92  * @state: Tasklet state.
93  * @queue: List of slots waiting for access to the controller.
94  * @need_clock_update: Update the clock rate before the next request.
95  * @need_reset: Reset controller before next request.
96  * @mode_reg: Value of the MR register.
97  * @cfg_reg: Value of the CFG register.
98  * @bus_hz: The rate of @mck in Hz. This forms the basis for MMC bus
99  *	rate and timeout calculations.
100  * @mapbase: Physical address of the MMIO registers.
101  * @mck: The peripheral bus clock hooked up to the MMC controller.
102  * @pdev: Platform device associated with the MMC controller.
103  * @slot: Slots sharing this MMC controller.
104  *
105  * Locking
106  * =======
107  *
108  * @lock is a softirq-safe spinlock protecting @queue as well as
109  * @cur_slot, @mrq and @state. These must always be updated
110  * at the same time while holding @lock.
111  *
112  * @lock also protects mode_reg and need_clock_update since these are
113  * used to synchronize mode register updates with the queue
114  * processing.
115  *
116  * The @mrq field of struct atmel_mci_slot is also protected by @lock,
117  * and must always be written at the same time as the slot is added to
118  * @queue.
119  *
120  * @pending_events and @completed_events are accessed using atomic bit
121  * operations, so they don't need any locking.
122  *
123  * None of the fields touched by the interrupt handler need any
124  * locking. However, ordering is important: Before EVENT_DATA_ERROR or
125  * EVENT_DATA_COMPLETE is set in @pending_events, all data-related
126  * interrupts must be disabled and @data_status updated with a
127  * snapshot of SR. Similarly, before EVENT_CMD_COMPLETE is set, the
128  * CMDRDY interupt must be disabled and @cmd_status updated with a
129  * snapshot of SR, and before EVENT_XFER_COMPLETE can be set, the
130  * bytes_xfered field of @data must be written. This is ensured by
131  * using barriers.
132  */
133 struct atmel_mci {
134 	spinlock_t		lock;
135 	void __iomem		*regs;
136 
137 	struct scatterlist	*sg;
138 	unsigned int		pio_offset;
139 
140 	struct atmel_mci_slot	*cur_slot;
141 	struct mmc_request	*mrq;
142 	struct mmc_command	*cmd;
143 	struct mmc_data		*data;
144 
145 	struct atmel_mci_dma	dma;
146 	struct dma_chan		*data_chan;
147 
148 	u32			cmd_status;
149 	u32			data_status;
150 	u32			stop_cmdr;
151 
152 	struct tasklet_struct	tasklet;
153 	unsigned long		pending_events;
154 	unsigned long		completed_events;
155 	enum atmel_mci_state	state;
156 	struct list_head	queue;
157 
158 	bool			need_clock_update;
159 	bool			need_reset;
160 	u32			mode_reg;
161 	u32			cfg_reg;
162 	unsigned long		bus_hz;
163 	unsigned long		mapbase;
164 	struct clk		*mck;
165 	struct platform_device	*pdev;
166 
167 	struct atmel_mci_slot	*slot[ATMEL_MCI_MAX_NR_SLOTS];
168 };
169 
170 /**
171  * struct atmel_mci_slot - MMC slot state
172  * @mmc: The mmc_host representing this slot.
173  * @host: The MMC controller this slot is using.
174  * @sdc_reg: Value of SDCR to be written before using this slot.
175  * @mrq: mmc_request currently being processed or waiting to be
176  *	processed, or NULL when the slot is idle.
177  * @queue_node: List node for placing this node in the @queue list of
178  *	&struct atmel_mci.
179  * @clock: Clock rate configured by set_ios(). Protected by host->lock.
180  * @flags: Random state bits associated with the slot.
181  * @detect_pin: GPIO pin used for card detection, or negative if not
182  *	available.
183  * @wp_pin: GPIO pin used for card write protect sending, or negative
184  *	if not available.
185  * @detect_is_active_high: The state of the detect pin when it is active.
186  * @detect_timer: Timer used for debouncing @detect_pin interrupts.
187  */
188 struct atmel_mci_slot {
189 	struct mmc_host		*mmc;
190 	struct atmel_mci	*host;
191 
192 	u32			sdc_reg;
193 
194 	struct mmc_request	*mrq;
195 	struct list_head	queue_node;
196 
197 	unsigned int		clock;
198 	unsigned long		flags;
199 #define ATMCI_CARD_PRESENT	0
200 #define ATMCI_CARD_NEED_INIT	1
201 #define ATMCI_SHUTDOWN		2
202 
203 	int			detect_pin;
204 	int			wp_pin;
205 	bool			detect_is_active_high;
206 
207 	struct timer_list	detect_timer;
208 };
209 
210 #define atmci_test_and_clear_pending(host, event)		\
211 	test_and_clear_bit(event, &host->pending_events)
212 #define atmci_set_completed(host, event)			\
213 	set_bit(event, &host->completed_events)
214 #define atmci_set_pending(host, event)				\
215 	set_bit(event, &host->pending_events)
216 
217 /*
218  * Enable or disable features/registers based on
219  * whether the processor supports them
220  */
221 static bool mci_has_rwproof(void)
222 {
223 	if (cpu_is_at91sam9261() || cpu_is_at91rm9200())
224 		return false;
225 	else
226 		return true;
227 }
228 
229 /*
230  * The new MCI2 module isn't 100% compatible with the old MCI module,
231  * and it has a few nice features which we want to use...
232  */
233 static inline bool atmci_is_mci2(void)
234 {
235 	if (cpu_is_at91sam9g45())
236 		return true;
237 
238 	return false;
239 }
240 
241 
242 /*
243  * The debugfs stuff below is mostly optimized away when
244  * CONFIG_DEBUG_FS is not set.
245  */
246 static int atmci_req_show(struct seq_file *s, void *v)
247 {
248 	struct atmel_mci_slot	*slot = s->private;
249 	struct mmc_request	*mrq;
250 	struct mmc_command	*cmd;
251 	struct mmc_command	*stop;
252 	struct mmc_data		*data;
253 
254 	/* Make sure we get a consistent snapshot */
255 	spin_lock_bh(&slot->host->lock);
256 	mrq = slot->mrq;
257 
258 	if (mrq) {
259 		cmd = mrq->cmd;
260 		data = mrq->data;
261 		stop = mrq->stop;
262 
263 		if (cmd)
264 			seq_printf(s,
265 				"CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
266 				cmd->opcode, cmd->arg, cmd->flags,
267 				cmd->resp[0], cmd->resp[1], cmd->resp[2],
268 				cmd->resp[2], cmd->error);
269 		if (data)
270 			seq_printf(s, "DATA %u / %u * %u flg %x err %d\n",
271 				data->bytes_xfered, data->blocks,
272 				data->blksz, data->flags, data->error);
273 		if (stop)
274 			seq_printf(s,
275 				"CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
276 				stop->opcode, stop->arg, stop->flags,
277 				stop->resp[0], stop->resp[1], stop->resp[2],
278 				stop->resp[2], stop->error);
279 	}
280 
281 	spin_unlock_bh(&slot->host->lock);
282 
283 	return 0;
284 }
285 
286 static int atmci_req_open(struct inode *inode, struct file *file)
287 {
288 	return single_open(file, atmci_req_show, inode->i_private);
289 }
290 
291 static const struct file_operations atmci_req_fops = {
292 	.owner		= THIS_MODULE,
293 	.open		= atmci_req_open,
294 	.read		= seq_read,
295 	.llseek		= seq_lseek,
296 	.release	= single_release,
297 };
298 
299 static void atmci_show_status_reg(struct seq_file *s,
300 		const char *regname, u32 value)
301 {
302 	static const char	*sr_bit[] = {
303 		[0]	= "CMDRDY",
304 		[1]	= "RXRDY",
305 		[2]	= "TXRDY",
306 		[3]	= "BLKE",
307 		[4]	= "DTIP",
308 		[5]	= "NOTBUSY",
309 		[6]	= "ENDRX",
310 		[7]	= "ENDTX",
311 		[8]	= "SDIOIRQA",
312 		[9]	= "SDIOIRQB",
313 		[12]	= "SDIOWAIT",
314 		[14]	= "RXBUFF",
315 		[15]	= "TXBUFE",
316 		[16]	= "RINDE",
317 		[17]	= "RDIRE",
318 		[18]	= "RCRCE",
319 		[19]	= "RENDE",
320 		[20]	= "RTOE",
321 		[21]	= "DCRCE",
322 		[22]	= "DTOE",
323 		[23]	= "CSTOE",
324 		[24]	= "BLKOVRE",
325 		[25]	= "DMADONE",
326 		[26]	= "FIFOEMPTY",
327 		[27]	= "XFRDONE",
328 		[30]	= "OVRE",
329 		[31]	= "UNRE",
330 	};
331 	unsigned int		i;
332 
333 	seq_printf(s, "%s:\t0x%08x", regname, value);
334 	for (i = 0; i < ARRAY_SIZE(sr_bit); i++) {
335 		if (value & (1 << i)) {
336 			if (sr_bit[i])
337 				seq_printf(s, " %s", sr_bit[i]);
338 			else
339 				seq_puts(s, " UNKNOWN");
340 		}
341 	}
342 	seq_putc(s, '\n');
343 }
344 
345 static int atmci_regs_show(struct seq_file *s, void *v)
346 {
347 	struct atmel_mci	*host = s->private;
348 	u32			*buf;
349 
350 	buf = kmalloc(MCI_REGS_SIZE, GFP_KERNEL);
351 	if (!buf)
352 		return -ENOMEM;
353 
354 	/*
355 	 * Grab a more or less consistent snapshot. Note that we're
356 	 * not disabling interrupts, so IMR and SR may not be
357 	 * consistent.
358 	 */
359 	spin_lock_bh(&host->lock);
360 	clk_enable(host->mck);
361 	memcpy_fromio(buf, host->regs, MCI_REGS_SIZE);
362 	clk_disable(host->mck);
363 	spin_unlock_bh(&host->lock);
364 
365 	seq_printf(s, "MR:\t0x%08x%s%s CLKDIV=%u\n",
366 			buf[MCI_MR / 4],
367 			buf[MCI_MR / 4] & MCI_MR_RDPROOF ? " RDPROOF" : "",
368 			buf[MCI_MR / 4] & MCI_MR_WRPROOF ? " WRPROOF" : "",
369 			buf[MCI_MR / 4] & 0xff);
370 	seq_printf(s, "DTOR:\t0x%08x\n", buf[MCI_DTOR / 4]);
371 	seq_printf(s, "SDCR:\t0x%08x\n", buf[MCI_SDCR / 4]);
372 	seq_printf(s, "ARGR:\t0x%08x\n", buf[MCI_ARGR / 4]);
373 	seq_printf(s, "BLKR:\t0x%08x BCNT=%u BLKLEN=%u\n",
374 			buf[MCI_BLKR / 4],
375 			buf[MCI_BLKR / 4] & 0xffff,
376 			(buf[MCI_BLKR / 4] >> 16) & 0xffff);
377 	if (atmci_is_mci2())
378 		seq_printf(s, "CSTOR:\t0x%08x\n", buf[MCI_CSTOR / 4]);
379 
380 	/* Don't read RSPR and RDR; it will consume the data there */
381 
382 	atmci_show_status_reg(s, "SR", buf[MCI_SR / 4]);
383 	atmci_show_status_reg(s, "IMR", buf[MCI_IMR / 4]);
384 
385 	if (atmci_is_mci2()) {
386 		u32 val;
387 
388 		val = buf[MCI_DMA / 4];
389 		seq_printf(s, "DMA:\t0x%08x OFFSET=%u CHKSIZE=%u%s\n",
390 				val, val & 3,
391 				((val >> 4) & 3) ?
392 					1 << (((val >> 4) & 3) + 1) : 1,
393 				val & MCI_DMAEN ? " DMAEN" : "");
394 
395 		val = buf[MCI_CFG / 4];
396 		seq_printf(s, "CFG:\t0x%08x%s%s%s%s\n",
397 				val,
398 				val & MCI_CFG_FIFOMODE_1DATA ? " FIFOMODE_ONE_DATA" : "",
399 				val & MCI_CFG_FERRCTRL_COR ? " FERRCTRL_CLEAR_ON_READ" : "",
400 				val & MCI_CFG_HSMODE ? " HSMODE" : "",
401 				val & MCI_CFG_LSYNC ? " LSYNC" : "");
402 	}
403 
404 	kfree(buf);
405 
406 	return 0;
407 }
408 
409 static int atmci_regs_open(struct inode *inode, struct file *file)
410 {
411 	return single_open(file, atmci_regs_show, inode->i_private);
412 }
413 
414 static const struct file_operations atmci_regs_fops = {
415 	.owner		= THIS_MODULE,
416 	.open		= atmci_regs_open,
417 	.read		= seq_read,
418 	.llseek		= seq_lseek,
419 	.release	= single_release,
420 };
421 
422 static void atmci_init_debugfs(struct atmel_mci_slot *slot)
423 {
424 	struct mmc_host		*mmc = slot->mmc;
425 	struct atmel_mci	*host = slot->host;
426 	struct dentry		*root;
427 	struct dentry		*node;
428 
429 	root = mmc->debugfs_root;
430 	if (!root)
431 		return;
432 
433 	node = debugfs_create_file("regs", S_IRUSR, root, host,
434 			&atmci_regs_fops);
435 	if (IS_ERR(node))
436 		return;
437 	if (!node)
438 		goto err;
439 
440 	node = debugfs_create_file("req", S_IRUSR, root, slot, &atmci_req_fops);
441 	if (!node)
442 		goto err;
443 
444 	node = debugfs_create_u32("state", S_IRUSR, root, (u32 *)&host->state);
445 	if (!node)
446 		goto err;
447 
448 	node = debugfs_create_x32("pending_events", S_IRUSR, root,
449 				     (u32 *)&host->pending_events);
450 	if (!node)
451 		goto err;
452 
453 	node = debugfs_create_x32("completed_events", S_IRUSR, root,
454 				     (u32 *)&host->completed_events);
455 	if (!node)
456 		goto err;
457 
458 	return;
459 
460 err:
461 	dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n");
462 }
463 
464 static inline unsigned int ns_to_clocks(struct atmel_mci *host,
465 					unsigned int ns)
466 {
467 	return (ns * (host->bus_hz / 1000000) + 999) / 1000;
468 }
469 
470 static void atmci_set_timeout(struct atmel_mci *host,
471 		struct atmel_mci_slot *slot, struct mmc_data *data)
472 {
473 	static unsigned	dtomul_to_shift[] = {
474 		0, 4, 7, 8, 10, 12, 16, 20
475 	};
476 	unsigned	timeout;
477 	unsigned	dtocyc;
478 	unsigned	dtomul;
479 
480 	timeout = ns_to_clocks(host, data->timeout_ns) + data->timeout_clks;
481 
482 	for (dtomul = 0; dtomul < 8; dtomul++) {
483 		unsigned shift = dtomul_to_shift[dtomul];
484 		dtocyc = (timeout + (1 << shift) - 1) >> shift;
485 		if (dtocyc < 15)
486 			break;
487 	}
488 
489 	if (dtomul >= 8) {
490 		dtomul = 7;
491 		dtocyc = 15;
492 	}
493 
494 	dev_vdbg(&slot->mmc->class_dev, "setting timeout to %u cycles\n",
495 			dtocyc << dtomul_to_shift[dtomul]);
496 	mci_writel(host, DTOR, (MCI_DTOMUL(dtomul) | MCI_DTOCYC(dtocyc)));
497 }
498 
499 /*
500  * Return mask with command flags to be enabled for this command.
501  */
502 static u32 atmci_prepare_command(struct mmc_host *mmc,
503 				 struct mmc_command *cmd)
504 {
505 	struct mmc_data	*data;
506 	u32		cmdr;
507 
508 	cmd->error = -EINPROGRESS;
509 
510 	cmdr = MCI_CMDR_CMDNB(cmd->opcode);
511 
512 	if (cmd->flags & MMC_RSP_PRESENT) {
513 		if (cmd->flags & MMC_RSP_136)
514 			cmdr |= MCI_CMDR_RSPTYP_136BIT;
515 		else
516 			cmdr |= MCI_CMDR_RSPTYP_48BIT;
517 	}
518 
519 	/*
520 	 * This should really be MAXLAT_5 for CMD2 and ACMD41, but
521 	 * it's too difficult to determine whether this is an ACMD or
522 	 * not. Better make it 64.
523 	 */
524 	cmdr |= MCI_CMDR_MAXLAT_64CYC;
525 
526 	if (mmc->ios.bus_mode == MMC_BUSMODE_OPENDRAIN)
527 		cmdr |= MCI_CMDR_OPDCMD;
528 
529 	data = cmd->data;
530 	if (data) {
531 		cmdr |= MCI_CMDR_START_XFER;
532 		if (data->flags & MMC_DATA_STREAM)
533 			cmdr |= MCI_CMDR_STREAM;
534 		else if (data->blocks > 1)
535 			cmdr |= MCI_CMDR_MULTI_BLOCK;
536 		else
537 			cmdr |= MCI_CMDR_BLOCK;
538 
539 		if (data->flags & MMC_DATA_READ)
540 			cmdr |= MCI_CMDR_TRDIR_READ;
541 	}
542 
543 	return cmdr;
544 }
545 
546 static void atmci_start_command(struct atmel_mci *host,
547 		struct mmc_command *cmd, u32 cmd_flags)
548 {
549 	WARN_ON(host->cmd);
550 	host->cmd = cmd;
551 
552 	dev_vdbg(&host->pdev->dev,
553 			"start command: ARGR=0x%08x CMDR=0x%08x\n",
554 			cmd->arg, cmd_flags);
555 
556 	mci_writel(host, ARGR, cmd->arg);
557 	mci_writel(host, CMDR, cmd_flags);
558 }
559 
560 static void send_stop_cmd(struct atmel_mci *host, struct mmc_data *data)
561 {
562 	atmci_start_command(host, data->stop, host->stop_cmdr);
563 	mci_writel(host, IER, MCI_CMDRDY);
564 }
565 
566 #ifdef CONFIG_MMC_ATMELMCI_DMA
567 static void atmci_dma_cleanup(struct atmel_mci *host)
568 {
569 	struct mmc_data			*data = host->data;
570 
571 	dma_unmap_sg(&host->pdev->dev, data->sg, data->sg_len,
572 		     ((data->flags & MMC_DATA_WRITE)
573 		      ? DMA_TO_DEVICE : DMA_FROM_DEVICE));
574 }
575 
576 static void atmci_stop_dma(struct atmel_mci *host)
577 {
578 	struct dma_chan *chan = host->data_chan;
579 
580 	if (chan) {
581 		chan->device->device_terminate_all(chan);
582 		atmci_dma_cleanup(host);
583 	} else {
584 		/* Data transfer was stopped by the interrupt handler */
585 		atmci_set_pending(host, EVENT_XFER_COMPLETE);
586 		mci_writel(host, IER, MCI_NOTBUSY);
587 	}
588 }
589 
590 /* This function is called by the DMA driver from tasklet context. */
591 static void atmci_dma_complete(void *arg)
592 {
593 	struct atmel_mci	*host = arg;
594 	struct mmc_data		*data = host->data;
595 
596 	dev_vdbg(&host->pdev->dev, "DMA complete\n");
597 
598 	if (atmci_is_mci2())
599 		/* Disable DMA hardware handshaking on MCI */
600 		mci_writel(host, DMA, mci_readl(host, DMA) & ~MCI_DMAEN);
601 
602 	atmci_dma_cleanup(host);
603 
604 	/*
605 	 * If the card was removed, data will be NULL. No point trying
606 	 * to send the stop command or waiting for NBUSY in this case.
607 	 */
608 	if (data) {
609 		atmci_set_pending(host, EVENT_XFER_COMPLETE);
610 		tasklet_schedule(&host->tasklet);
611 
612 		/*
613 		 * Regardless of what the documentation says, we have
614 		 * to wait for NOTBUSY even after block read
615 		 * operations.
616 		 *
617 		 * When the DMA transfer is complete, the controller
618 		 * may still be reading the CRC from the card, i.e.
619 		 * the data transfer is still in progress and we
620 		 * haven't seen all the potential error bits yet.
621 		 *
622 		 * The interrupt handler will schedule a different
623 		 * tasklet to finish things up when the data transfer
624 		 * is completely done.
625 		 *
626 		 * We may not complete the mmc request here anyway
627 		 * because the mmc layer may call back and cause us to
628 		 * violate the "don't submit new operations from the
629 		 * completion callback" rule of the dma engine
630 		 * framework.
631 		 */
632 		mci_writel(host, IER, MCI_NOTBUSY);
633 	}
634 }
635 
636 static int
637 atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)
638 {
639 	struct dma_chan			*chan;
640 	struct dma_async_tx_descriptor	*desc;
641 	struct scatterlist		*sg;
642 	unsigned int			i;
643 	enum dma_data_direction		direction;
644 	unsigned int			sglen;
645 
646 	/*
647 	 * We don't do DMA on "complex" transfers, i.e. with
648 	 * non-word-aligned buffers or lengths. Also, we don't bother
649 	 * with all the DMA setup overhead for short transfers.
650 	 */
651 	if (data->blocks * data->blksz < ATMCI_DMA_THRESHOLD)
652 		return -EINVAL;
653 	if (data->blksz & 3)
654 		return -EINVAL;
655 
656 	for_each_sg(data->sg, sg, data->sg_len, i) {
657 		if (sg->offset & 3 || sg->length & 3)
658 			return -EINVAL;
659 	}
660 
661 	/* If we don't have a channel, we can't do DMA */
662 	chan = host->dma.chan;
663 	if (chan)
664 		host->data_chan = chan;
665 
666 	if (!chan)
667 		return -ENODEV;
668 
669 	if (atmci_is_mci2())
670 		mci_writel(host, DMA, MCI_DMA_CHKSIZE(3) | MCI_DMAEN);
671 
672 	if (data->flags & MMC_DATA_READ)
673 		direction = DMA_FROM_DEVICE;
674 	else
675 		direction = DMA_TO_DEVICE;
676 
677 	sglen = dma_map_sg(&host->pdev->dev, data->sg, data->sg_len, direction);
678 	if (sglen != data->sg_len)
679 		goto unmap_exit;
680 	desc = chan->device->device_prep_slave_sg(chan,
681 			data->sg, data->sg_len, direction,
682 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
683 	if (!desc)
684 		goto unmap_exit;
685 
686 	host->dma.data_desc = desc;
687 	desc->callback = atmci_dma_complete;
688 	desc->callback_param = host;
689 
690 	return 0;
691 unmap_exit:
692 	dma_unmap_sg(&host->pdev->dev, data->sg, sglen, direction);
693 	return -ENOMEM;
694 }
695 
696 static void atmci_submit_data(struct atmel_mci *host)
697 {
698 	struct dma_chan			*chan = host->data_chan;
699 	struct dma_async_tx_descriptor	*desc = host->dma.data_desc;
700 
701 	if (chan) {
702 		desc->tx_submit(desc);
703 		chan->device->device_issue_pending(chan);
704 	}
705 }
706 
707 #else /* CONFIG_MMC_ATMELMCI_DMA */
708 
709 static int atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)
710 {
711 	return -ENOSYS;
712 }
713 
714 static void atmci_submit_data(struct atmel_mci *host) {}
715 
716 static void atmci_stop_dma(struct atmel_mci *host)
717 {
718 	/* Data transfer was stopped by the interrupt handler */
719 	atmci_set_pending(host, EVENT_XFER_COMPLETE);
720 	mci_writel(host, IER, MCI_NOTBUSY);
721 }
722 
723 #endif /* CONFIG_MMC_ATMELMCI_DMA */
724 
725 /*
726  * Returns a mask of interrupt flags to be enabled after the whole
727  * request has been prepared.
728  */
729 static u32 atmci_prepare_data(struct atmel_mci *host, struct mmc_data *data)
730 {
731 	u32 iflags;
732 
733 	data->error = -EINPROGRESS;
734 
735 	WARN_ON(host->data);
736 	host->sg = NULL;
737 	host->data = data;
738 
739 	iflags = ATMCI_DATA_ERROR_FLAGS;
740 	if (atmci_prepare_data_dma(host, data)) {
741 		host->data_chan = NULL;
742 
743 		/*
744 		 * Errata: MMC data write operation with less than 12
745 		 * bytes is impossible.
746 		 *
747 		 * Errata: MCI Transmit Data Register (TDR) FIFO
748 		 * corruption when length is not multiple of 4.
749 		 */
750 		if (data->blocks * data->blksz < 12
751 				|| (data->blocks * data->blksz) & 3)
752 			host->need_reset = true;
753 
754 		host->sg = data->sg;
755 		host->pio_offset = 0;
756 		if (data->flags & MMC_DATA_READ)
757 			iflags |= MCI_RXRDY;
758 		else
759 			iflags |= MCI_TXRDY;
760 	}
761 
762 	return iflags;
763 }
764 
765 static void atmci_start_request(struct atmel_mci *host,
766 		struct atmel_mci_slot *slot)
767 {
768 	struct mmc_request	*mrq;
769 	struct mmc_command	*cmd;
770 	struct mmc_data		*data;
771 	u32			iflags;
772 	u32			cmdflags;
773 
774 	mrq = slot->mrq;
775 	host->cur_slot = slot;
776 	host->mrq = mrq;
777 
778 	host->pending_events = 0;
779 	host->completed_events = 0;
780 	host->data_status = 0;
781 
782 	if (host->need_reset) {
783 		mci_writel(host, CR, MCI_CR_SWRST);
784 		mci_writel(host, CR, MCI_CR_MCIEN);
785 		mci_writel(host, MR, host->mode_reg);
786 		if (atmci_is_mci2())
787 			mci_writel(host, CFG, host->cfg_reg);
788 		host->need_reset = false;
789 	}
790 	mci_writel(host, SDCR, slot->sdc_reg);
791 
792 	iflags = mci_readl(host, IMR);
793 	if (iflags)
794 		dev_warn(&slot->mmc->class_dev, "WARNING: IMR=0x%08x\n",
795 				iflags);
796 
797 	if (unlikely(test_and_clear_bit(ATMCI_CARD_NEED_INIT, &slot->flags))) {
798 		/* Send init sequence (74 clock cycles) */
799 		mci_writel(host, CMDR, MCI_CMDR_SPCMD_INIT);
800 		while (!(mci_readl(host, SR) & MCI_CMDRDY))
801 			cpu_relax();
802 	}
803 	iflags = 0;
804 	data = mrq->data;
805 	if (data) {
806 		atmci_set_timeout(host, slot, data);
807 
808 		/* Must set block count/size before sending command */
809 		mci_writel(host, BLKR, MCI_BCNT(data->blocks)
810 				| MCI_BLKLEN(data->blksz));
811 		dev_vdbg(&slot->mmc->class_dev, "BLKR=0x%08x\n",
812 			MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz));
813 
814 		iflags |= atmci_prepare_data(host, data);
815 	}
816 
817 	iflags |= MCI_CMDRDY;
818 	cmd = mrq->cmd;
819 	cmdflags = atmci_prepare_command(slot->mmc, cmd);
820 	atmci_start_command(host, cmd, cmdflags);
821 
822 	if (data)
823 		atmci_submit_data(host);
824 
825 	if (mrq->stop) {
826 		host->stop_cmdr = atmci_prepare_command(slot->mmc, mrq->stop);
827 		host->stop_cmdr |= MCI_CMDR_STOP_XFER;
828 		if (!(data->flags & MMC_DATA_WRITE))
829 			host->stop_cmdr |= MCI_CMDR_TRDIR_READ;
830 		if (data->flags & MMC_DATA_STREAM)
831 			host->stop_cmdr |= MCI_CMDR_STREAM;
832 		else
833 			host->stop_cmdr |= MCI_CMDR_MULTI_BLOCK;
834 	}
835 
836 	/*
837 	 * We could have enabled interrupts earlier, but I suspect
838 	 * that would open up a nice can of interesting race
839 	 * conditions (e.g. command and data complete, but stop not
840 	 * prepared yet.)
841 	 */
842 	mci_writel(host, IER, iflags);
843 }
844 
845 static void atmci_queue_request(struct atmel_mci *host,
846 		struct atmel_mci_slot *slot, struct mmc_request *mrq)
847 {
848 	dev_vdbg(&slot->mmc->class_dev, "queue request: state=%d\n",
849 			host->state);
850 
851 	spin_lock_bh(&host->lock);
852 	slot->mrq = mrq;
853 	if (host->state == STATE_IDLE) {
854 		host->state = STATE_SENDING_CMD;
855 		atmci_start_request(host, slot);
856 	} else {
857 		list_add_tail(&slot->queue_node, &host->queue);
858 	}
859 	spin_unlock_bh(&host->lock);
860 }
861 
862 static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
863 {
864 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
865 	struct atmel_mci	*host = slot->host;
866 	struct mmc_data		*data;
867 
868 	WARN_ON(slot->mrq);
869 
870 	/*
871 	 * We may "know" the card is gone even though there's still an
872 	 * electrical connection. If so, we really need to communicate
873 	 * this to the MMC core since there won't be any more
874 	 * interrupts as the card is completely removed. Otherwise,
875 	 * the MMC core might believe the card is still there even
876 	 * though the card was just removed very slowly.
877 	 */
878 	if (!test_bit(ATMCI_CARD_PRESENT, &slot->flags)) {
879 		mrq->cmd->error = -ENOMEDIUM;
880 		mmc_request_done(mmc, mrq);
881 		return;
882 	}
883 
884 	/* We don't support multiple blocks of weird lengths. */
885 	data = mrq->data;
886 	if (data && data->blocks > 1 && data->blksz & 3) {
887 		mrq->cmd->error = -EINVAL;
888 		mmc_request_done(mmc, mrq);
889 	}
890 
891 	atmci_queue_request(host, slot, mrq);
892 }
893 
894 static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
895 {
896 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
897 	struct atmel_mci	*host = slot->host;
898 	unsigned int		i;
899 
900 	slot->sdc_reg &= ~MCI_SDCBUS_MASK;
901 	switch (ios->bus_width) {
902 	case MMC_BUS_WIDTH_1:
903 		slot->sdc_reg |= MCI_SDCBUS_1BIT;
904 		break;
905 	case MMC_BUS_WIDTH_4:
906 		slot->sdc_reg |= MCI_SDCBUS_4BIT;
907 		break;
908 	}
909 
910 	if (ios->clock) {
911 		unsigned int clock_min = ~0U;
912 		u32 clkdiv;
913 
914 		spin_lock_bh(&host->lock);
915 		if (!host->mode_reg) {
916 			clk_enable(host->mck);
917 			mci_writel(host, CR, MCI_CR_SWRST);
918 			mci_writel(host, CR, MCI_CR_MCIEN);
919 			if (atmci_is_mci2())
920 				mci_writel(host, CFG, host->cfg_reg);
921 		}
922 
923 		/*
924 		 * Use mirror of ios->clock to prevent race with mmc
925 		 * core ios update when finding the minimum.
926 		 */
927 		slot->clock = ios->clock;
928 		for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
929 			if (host->slot[i] && host->slot[i]->clock
930 					&& host->slot[i]->clock < clock_min)
931 				clock_min = host->slot[i]->clock;
932 		}
933 
934 		/* Calculate clock divider */
935 		clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * clock_min) - 1;
936 		if (clkdiv > 255) {
937 			dev_warn(&mmc->class_dev,
938 				"clock %u too slow; using %lu\n",
939 				clock_min, host->bus_hz / (2 * 256));
940 			clkdiv = 255;
941 		}
942 
943 		host->mode_reg = MCI_MR_CLKDIV(clkdiv);
944 
945 		/*
946 		 * WRPROOF and RDPROOF prevent overruns/underruns by
947 		 * stopping the clock when the FIFO is full/empty.
948 		 * This state is not expected to last for long.
949 		 */
950 		if (mci_has_rwproof())
951 			host->mode_reg |= (MCI_MR_WRPROOF | MCI_MR_RDPROOF);
952 
953 		if (list_empty(&host->queue))
954 			mci_writel(host, MR, host->mode_reg);
955 		else
956 			host->need_clock_update = true;
957 
958 		spin_unlock_bh(&host->lock);
959 	} else {
960 		bool any_slot_active = false;
961 
962 		spin_lock_bh(&host->lock);
963 		slot->clock = 0;
964 		for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
965 			if (host->slot[i] && host->slot[i]->clock) {
966 				any_slot_active = true;
967 				break;
968 			}
969 		}
970 		if (!any_slot_active) {
971 			mci_writel(host, CR, MCI_CR_MCIDIS);
972 			if (host->mode_reg) {
973 				mci_readl(host, MR);
974 				clk_disable(host->mck);
975 			}
976 			host->mode_reg = 0;
977 		}
978 		spin_unlock_bh(&host->lock);
979 	}
980 
981 	switch (ios->power_mode) {
982 	case MMC_POWER_UP:
983 		set_bit(ATMCI_CARD_NEED_INIT, &slot->flags);
984 		break;
985 	default:
986 		/*
987 		 * TODO: None of the currently available AVR32-based
988 		 * boards allow MMC power to be turned off. Implement
989 		 * power control when this can be tested properly.
990 		 *
991 		 * We also need to hook this into the clock management
992 		 * somehow so that newly inserted cards aren't
993 		 * subjected to a fast clock before we have a chance
994 		 * to figure out what the maximum rate is. Currently,
995 		 * there's no way to avoid this, and there never will
996 		 * be for boards that don't support power control.
997 		 */
998 		break;
999 	}
1000 }
1001 
1002 static int atmci_get_ro(struct mmc_host *mmc)
1003 {
1004 	int			read_only = -ENOSYS;
1005 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1006 
1007 	if (gpio_is_valid(slot->wp_pin)) {
1008 		read_only = gpio_get_value(slot->wp_pin);
1009 		dev_dbg(&mmc->class_dev, "card is %s\n",
1010 				read_only ? "read-only" : "read-write");
1011 	}
1012 
1013 	return read_only;
1014 }
1015 
1016 static int atmci_get_cd(struct mmc_host *mmc)
1017 {
1018 	int			present = -ENOSYS;
1019 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1020 
1021 	if (gpio_is_valid(slot->detect_pin)) {
1022 		present = !(gpio_get_value(slot->detect_pin) ^
1023 			    slot->detect_is_active_high);
1024 		dev_dbg(&mmc->class_dev, "card is %spresent\n",
1025 				present ? "" : "not ");
1026 	}
1027 
1028 	return present;
1029 }
1030 
1031 static const struct mmc_host_ops atmci_ops = {
1032 	.request	= atmci_request,
1033 	.set_ios	= atmci_set_ios,
1034 	.get_ro		= atmci_get_ro,
1035 	.get_cd		= atmci_get_cd,
1036 };
1037 
1038 /* Called with host->lock held */
1039 static void atmci_request_end(struct atmel_mci *host, struct mmc_request *mrq)
1040 	__releases(&host->lock)
1041 	__acquires(&host->lock)
1042 {
1043 	struct atmel_mci_slot	*slot = NULL;
1044 	struct mmc_host		*prev_mmc = host->cur_slot->mmc;
1045 
1046 	WARN_ON(host->cmd || host->data);
1047 
1048 	/*
1049 	 * Update the MMC clock rate if necessary. This may be
1050 	 * necessary if set_ios() is called when a different slot is
1051 	 * busy transfering data.
1052 	 */
1053 	if (host->need_clock_update)
1054 		mci_writel(host, MR, host->mode_reg);
1055 
1056 	host->cur_slot->mrq = NULL;
1057 	host->mrq = NULL;
1058 	if (!list_empty(&host->queue)) {
1059 		slot = list_entry(host->queue.next,
1060 				struct atmel_mci_slot, queue_node);
1061 		list_del(&slot->queue_node);
1062 		dev_vdbg(&host->pdev->dev, "list not empty: %s is next\n",
1063 				mmc_hostname(slot->mmc));
1064 		host->state = STATE_SENDING_CMD;
1065 		atmci_start_request(host, slot);
1066 	} else {
1067 		dev_vdbg(&host->pdev->dev, "list empty\n");
1068 		host->state = STATE_IDLE;
1069 	}
1070 
1071 	spin_unlock(&host->lock);
1072 	mmc_request_done(prev_mmc, mrq);
1073 	spin_lock(&host->lock);
1074 }
1075 
1076 static void atmci_command_complete(struct atmel_mci *host,
1077 			struct mmc_command *cmd)
1078 {
1079 	u32		status = host->cmd_status;
1080 
1081 	/* Read the response from the card (up to 16 bytes) */
1082 	cmd->resp[0] = mci_readl(host, RSPR);
1083 	cmd->resp[1] = mci_readl(host, RSPR);
1084 	cmd->resp[2] = mci_readl(host, RSPR);
1085 	cmd->resp[3] = mci_readl(host, RSPR);
1086 
1087 	if (status & MCI_RTOE)
1088 		cmd->error = -ETIMEDOUT;
1089 	else if ((cmd->flags & MMC_RSP_CRC) && (status & MCI_RCRCE))
1090 		cmd->error = -EILSEQ;
1091 	else if (status & (MCI_RINDE | MCI_RDIRE | MCI_RENDE))
1092 		cmd->error = -EIO;
1093 	else
1094 		cmd->error = 0;
1095 
1096 	if (cmd->error) {
1097 		dev_dbg(&host->pdev->dev,
1098 			"command error: status=0x%08x\n", status);
1099 
1100 		if (cmd->data) {
1101 			host->data = NULL;
1102 			atmci_stop_dma(host);
1103 			mci_writel(host, IDR, MCI_NOTBUSY
1104 					| MCI_TXRDY | MCI_RXRDY
1105 					| ATMCI_DATA_ERROR_FLAGS);
1106 		}
1107 	}
1108 }
1109 
1110 static void atmci_detect_change(unsigned long data)
1111 {
1112 	struct atmel_mci_slot	*slot = (struct atmel_mci_slot *)data;
1113 	bool			present;
1114 	bool			present_old;
1115 
1116 	/*
1117 	 * atmci_cleanup_slot() sets the ATMCI_SHUTDOWN flag before
1118 	 * freeing the interrupt. We must not re-enable the interrupt
1119 	 * if it has been freed, and if we're shutting down, it
1120 	 * doesn't really matter whether the card is present or not.
1121 	 */
1122 	smp_rmb();
1123 	if (test_bit(ATMCI_SHUTDOWN, &slot->flags))
1124 		return;
1125 
1126 	enable_irq(gpio_to_irq(slot->detect_pin));
1127 	present = !(gpio_get_value(slot->detect_pin) ^
1128 		    slot->detect_is_active_high);
1129 	present_old = test_bit(ATMCI_CARD_PRESENT, &slot->flags);
1130 
1131 	dev_vdbg(&slot->mmc->class_dev, "detect change: %d (was %d)\n",
1132 			present, present_old);
1133 
1134 	if (present != present_old) {
1135 		struct atmel_mci	*host = slot->host;
1136 		struct mmc_request	*mrq;
1137 
1138 		dev_dbg(&slot->mmc->class_dev, "card %s\n",
1139 			present ? "inserted" : "removed");
1140 
1141 		spin_lock(&host->lock);
1142 
1143 		if (!present)
1144 			clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
1145 		else
1146 			set_bit(ATMCI_CARD_PRESENT, &slot->flags);
1147 
1148 		/* Clean up queue if present */
1149 		mrq = slot->mrq;
1150 		if (mrq) {
1151 			if (mrq == host->mrq) {
1152 				/*
1153 				 * Reset controller to terminate any ongoing
1154 				 * commands or data transfers.
1155 				 */
1156 				mci_writel(host, CR, MCI_CR_SWRST);
1157 				mci_writel(host, CR, MCI_CR_MCIEN);
1158 				mci_writel(host, MR, host->mode_reg);
1159 				if (atmci_is_mci2())
1160 					mci_writel(host, CFG, host->cfg_reg);
1161 
1162 				host->data = NULL;
1163 				host->cmd = NULL;
1164 
1165 				switch (host->state) {
1166 				case STATE_IDLE:
1167 					break;
1168 				case STATE_SENDING_CMD:
1169 					mrq->cmd->error = -ENOMEDIUM;
1170 					if (!mrq->data)
1171 						break;
1172 					/* fall through */
1173 				case STATE_SENDING_DATA:
1174 					mrq->data->error = -ENOMEDIUM;
1175 					atmci_stop_dma(host);
1176 					break;
1177 				case STATE_DATA_BUSY:
1178 				case STATE_DATA_ERROR:
1179 					if (mrq->data->error == -EINPROGRESS)
1180 						mrq->data->error = -ENOMEDIUM;
1181 					if (!mrq->stop)
1182 						break;
1183 					/* fall through */
1184 				case STATE_SENDING_STOP:
1185 					mrq->stop->error = -ENOMEDIUM;
1186 					break;
1187 				}
1188 
1189 				atmci_request_end(host, mrq);
1190 			} else {
1191 				list_del(&slot->queue_node);
1192 				mrq->cmd->error = -ENOMEDIUM;
1193 				if (mrq->data)
1194 					mrq->data->error = -ENOMEDIUM;
1195 				if (mrq->stop)
1196 					mrq->stop->error = -ENOMEDIUM;
1197 
1198 				spin_unlock(&host->lock);
1199 				mmc_request_done(slot->mmc, mrq);
1200 				spin_lock(&host->lock);
1201 			}
1202 		}
1203 		spin_unlock(&host->lock);
1204 
1205 		mmc_detect_change(slot->mmc, 0);
1206 	}
1207 }
1208 
1209 static void atmci_tasklet_func(unsigned long priv)
1210 {
1211 	struct atmel_mci	*host = (struct atmel_mci *)priv;
1212 	struct mmc_request	*mrq = host->mrq;
1213 	struct mmc_data		*data = host->data;
1214 	struct mmc_command	*cmd = host->cmd;
1215 	enum atmel_mci_state	state = host->state;
1216 	enum atmel_mci_state	prev_state;
1217 	u32			status;
1218 
1219 	spin_lock(&host->lock);
1220 
1221 	state = host->state;
1222 
1223 	dev_vdbg(&host->pdev->dev,
1224 		"tasklet: state %u pending/completed/mask %lx/%lx/%x\n",
1225 		state, host->pending_events, host->completed_events,
1226 		mci_readl(host, IMR));
1227 
1228 	do {
1229 		prev_state = state;
1230 
1231 		switch (state) {
1232 		case STATE_IDLE:
1233 			break;
1234 
1235 		case STATE_SENDING_CMD:
1236 			if (!atmci_test_and_clear_pending(host,
1237 						EVENT_CMD_COMPLETE))
1238 				break;
1239 
1240 			host->cmd = NULL;
1241 			atmci_set_completed(host, EVENT_CMD_COMPLETE);
1242 			atmci_command_complete(host, mrq->cmd);
1243 			if (!mrq->data || cmd->error) {
1244 				atmci_request_end(host, host->mrq);
1245 				goto unlock;
1246 			}
1247 
1248 			prev_state = state = STATE_SENDING_DATA;
1249 			/* fall through */
1250 
1251 		case STATE_SENDING_DATA:
1252 			if (atmci_test_and_clear_pending(host,
1253 						EVENT_DATA_ERROR)) {
1254 				atmci_stop_dma(host);
1255 				if (data->stop)
1256 					send_stop_cmd(host, data);
1257 				state = STATE_DATA_ERROR;
1258 				break;
1259 			}
1260 
1261 			if (!atmci_test_and_clear_pending(host,
1262 						EVENT_XFER_COMPLETE))
1263 				break;
1264 
1265 			atmci_set_completed(host, EVENT_XFER_COMPLETE);
1266 			prev_state = state = STATE_DATA_BUSY;
1267 			/* fall through */
1268 
1269 		case STATE_DATA_BUSY:
1270 			if (!atmci_test_and_clear_pending(host,
1271 						EVENT_DATA_COMPLETE))
1272 				break;
1273 
1274 			host->data = NULL;
1275 			atmci_set_completed(host, EVENT_DATA_COMPLETE);
1276 			status = host->data_status;
1277 			if (unlikely(status & ATMCI_DATA_ERROR_FLAGS)) {
1278 				if (status & MCI_DTOE) {
1279 					dev_dbg(&host->pdev->dev,
1280 							"data timeout error\n");
1281 					data->error = -ETIMEDOUT;
1282 				} else if (status & MCI_DCRCE) {
1283 					dev_dbg(&host->pdev->dev,
1284 							"data CRC error\n");
1285 					data->error = -EILSEQ;
1286 				} else {
1287 					dev_dbg(&host->pdev->dev,
1288 						"data FIFO error (status=%08x)\n",
1289 						status);
1290 					data->error = -EIO;
1291 				}
1292 			} else {
1293 				data->bytes_xfered = data->blocks * data->blksz;
1294 				data->error = 0;
1295 			}
1296 
1297 			if (!data->stop) {
1298 				atmci_request_end(host, host->mrq);
1299 				goto unlock;
1300 			}
1301 
1302 			prev_state = state = STATE_SENDING_STOP;
1303 			if (!data->error)
1304 				send_stop_cmd(host, data);
1305 			/* fall through */
1306 
1307 		case STATE_SENDING_STOP:
1308 			if (!atmci_test_and_clear_pending(host,
1309 						EVENT_CMD_COMPLETE))
1310 				break;
1311 
1312 			host->cmd = NULL;
1313 			atmci_command_complete(host, mrq->stop);
1314 			atmci_request_end(host, host->mrq);
1315 			goto unlock;
1316 
1317 		case STATE_DATA_ERROR:
1318 			if (!atmci_test_and_clear_pending(host,
1319 						EVENT_XFER_COMPLETE))
1320 				break;
1321 
1322 			state = STATE_DATA_BUSY;
1323 			break;
1324 		}
1325 	} while (state != prev_state);
1326 
1327 	host->state = state;
1328 
1329 unlock:
1330 	spin_unlock(&host->lock);
1331 }
1332 
1333 static void atmci_read_data_pio(struct atmel_mci *host)
1334 {
1335 	struct scatterlist	*sg = host->sg;
1336 	void			*buf = sg_virt(sg);
1337 	unsigned int		offset = host->pio_offset;
1338 	struct mmc_data		*data = host->data;
1339 	u32			value;
1340 	u32			status;
1341 	unsigned int		nbytes = 0;
1342 
1343 	do {
1344 		value = mci_readl(host, RDR);
1345 		if (likely(offset + 4 <= sg->length)) {
1346 			put_unaligned(value, (u32 *)(buf + offset));
1347 
1348 			offset += 4;
1349 			nbytes += 4;
1350 
1351 			if (offset == sg->length) {
1352 				flush_dcache_page(sg_page(sg));
1353 				host->sg = sg = sg_next(sg);
1354 				if (!sg)
1355 					goto done;
1356 
1357 				offset = 0;
1358 				buf = sg_virt(sg);
1359 			}
1360 		} else {
1361 			unsigned int remaining = sg->length - offset;
1362 			memcpy(buf + offset, &value, remaining);
1363 			nbytes += remaining;
1364 
1365 			flush_dcache_page(sg_page(sg));
1366 			host->sg = sg = sg_next(sg);
1367 			if (!sg)
1368 				goto done;
1369 
1370 			offset = 4 - remaining;
1371 			buf = sg_virt(sg);
1372 			memcpy(buf, (u8 *)&value + remaining, offset);
1373 			nbytes += offset;
1374 		}
1375 
1376 		status = mci_readl(host, SR);
1377 		if (status & ATMCI_DATA_ERROR_FLAGS) {
1378 			mci_writel(host, IDR, (MCI_NOTBUSY | MCI_RXRDY
1379 						| ATMCI_DATA_ERROR_FLAGS));
1380 			host->data_status = status;
1381 			data->bytes_xfered += nbytes;
1382 			smp_wmb();
1383 			atmci_set_pending(host, EVENT_DATA_ERROR);
1384 			tasklet_schedule(&host->tasklet);
1385 			return;
1386 		}
1387 	} while (status & MCI_RXRDY);
1388 
1389 	host->pio_offset = offset;
1390 	data->bytes_xfered += nbytes;
1391 
1392 	return;
1393 
1394 done:
1395 	mci_writel(host, IDR, MCI_RXRDY);
1396 	mci_writel(host, IER, MCI_NOTBUSY);
1397 	data->bytes_xfered += nbytes;
1398 	smp_wmb();
1399 	atmci_set_pending(host, EVENT_XFER_COMPLETE);
1400 }
1401 
1402 static void atmci_write_data_pio(struct atmel_mci *host)
1403 {
1404 	struct scatterlist	*sg = host->sg;
1405 	void			*buf = sg_virt(sg);
1406 	unsigned int		offset = host->pio_offset;
1407 	struct mmc_data		*data = host->data;
1408 	u32			value;
1409 	u32			status;
1410 	unsigned int		nbytes = 0;
1411 
1412 	do {
1413 		if (likely(offset + 4 <= sg->length)) {
1414 			value = get_unaligned((u32 *)(buf + offset));
1415 			mci_writel(host, TDR, value);
1416 
1417 			offset += 4;
1418 			nbytes += 4;
1419 			if (offset == sg->length) {
1420 				host->sg = sg = sg_next(sg);
1421 				if (!sg)
1422 					goto done;
1423 
1424 				offset = 0;
1425 				buf = sg_virt(sg);
1426 			}
1427 		} else {
1428 			unsigned int remaining = sg->length - offset;
1429 
1430 			value = 0;
1431 			memcpy(&value, buf + offset, remaining);
1432 			nbytes += remaining;
1433 
1434 			host->sg = sg = sg_next(sg);
1435 			if (!sg) {
1436 				mci_writel(host, TDR, value);
1437 				goto done;
1438 			}
1439 
1440 			offset = 4 - remaining;
1441 			buf = sg_virt(sg);
1442 			memcpy((u8 *)&value + remaining, buf, offset);
1443 			mci_writel(host, TDR, value);
1444 			nbytes += offset;
1445 		}
1446 
1447 		status = mci_readl(host, SR);
1448 		if (status & ATMCI_DATA_ERROR_FLAGS) {
1449 			mci_writel(host, IDR, (MCI_NOTBUSY | MCI_TXRDY
1450 						| ATMCI_DATA_ERROR_FLAGS));
1451 			host->data_status = status;
1452 			data->bytes_xfered += nbytes;
1453 			smp_wmb();
1454 			atmci_set_pending(host, EVENT_DATA_ERROR);
1455 			tasklet_schedule(&host->tasklet);
1456 			return;
1457 		}
1458 	} while (status & MCI_TXRDY);
1459 
1460 	host->pio_offset = offset;
1461 	data->bytes_xfered += nbytes;
1462 
1463 	return;
1464 
1465 done:
1466 	mci_writel(host, IDR, MCI_TXRDY);
1467 	mci_writel(host, IER, MCI_NOTBUSY);
1468 	data->bytes_xfered += nbytes;
1469 	smp_wmb();
1470 	atmci_set_pending(host, EVENT_XFER_COMPLETE);
1471 }
1472 
1473 static void atmci_cmd_interrupt(struct atmel_mci *host, u32 status)
1474 {
1475 	mci_writel(host, IDR, MCI_CMDRDY);
1476 
1477 	host->cmd_status = status;
1478 	smp_wmb();
1479 	atmci_set_pending(host, EVENT_CMD_COMPLETE);
1480 	tasklet_schedule(&host->tasklet);
1481 }
1482 
1483 static irqreturn_t atmci_interrupt(int irq, void *dev_id)
1484 {
1485 	struct atmel_mci	*host = dev_id;
1486 	u32			status, mask, pending;
1487 	unsigned int		pass_count = 0;
1488 
1489 	do {
1490 		status = mci_readl(host, SR);
1491 		mask = mci_readl(host, IMR);
1492 		pending = status & mask;
1493 		if (!pending)
1494 			break;
1495 
1496 		if (pending & ATMCI_DATA_ERROR_FLAGS) {
1497 			mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS
1498 					| MCI_RXRDY | MCI_TXRDY);
1499 			pending &= mci_readl(host, IMR);
1500 
1501 			host->data_status = status;
1502 			smp_wmb();
1503 			atmci_set_pending(host, EVENT_DATA_ERROR);
1504 			tasklet_schedule(&host->tasklet);
1505 		}
1506 		if (pending & MCI_NOTBUSY) {
1507 			mci_writel(host, IDR,
1508 					ATMCI_DATA_ERROR_FLAGS | MCI_NOTBUSY);
1509 			if (!host->data_status)
1510 				host->data_status = status;
1511 			smp_wmb();
1512 			atmci_set_pending(host, EVENT_DATA_COMPLETE);
1513 			tasklet_schedule(&host->tasklet);
1514 		}
1515 		if (pending & MCI_RXRDY)
1516 			atmci_read_data_pio(host);
1517 		if (pending & MCI_TXRDY)
1518 			atmci_write_data_pio(host);
1519 
1520 		if (pending & MCI_CMDRDY)
1521 			atmci_cmd_interrupt(host, status);
1522 	} while (pass_count++ < 5);
1523 
1524 	return pass_count ? IRQ_HANDLED : IRQ_NONE;
1525 }
1526 
1527 static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id)
1528 {
1529 	struct atmel_mci_slot	*slot = dev_id;
1530 
1531 	/*
1532 	 * Disable interrupts until the pin has stabilized and check
1533 	 * the state then. Use mod_timer() since we may be in the
1534 	 * middle of the timer routine when this interrupt triggers.
1535 	 */
1536 	disable_irq_nosync(irq);
1537 	mod_timer(&slot->detect_timer, jiffies + msecs_to_jiffies(20));
1538 
1539 	return IRQ_HANDLED;
1540 }
1541 
1542 static int __init atmci_init_slot(struct atmel_mci *host,
1543 		struct mci_slot_pdata *slot_data, unsigned int id,
1544 		u32 sdc_reg)
1545 {
1546 	struct mmc_host			*mmc;
1547 	struct atmel_mci_slot		*slot;
1548 
1549 	mmc = mmc_alloc_host(sizeof(struct atmel_mci_slot), &host->pdev->dev);
1550 	if (!mmc)
1551 		return -ENOMEM;
1552 
1553 	slot = mmc_priv(mmc);
1554 	slot->mmc = mmc;
1555 	slot->host = host;
1556 	slot->detect_pin = slot_data->detect_pin;
1557 	slot->wp_pin = slot_data->wp_pin;
1558 	slot->detect_is_active_high = slot_data->detect_is_active_high;
1559 	slot->sdc_reg = sdc_reg;
1560 
1561 	mmc->ops = &atmci_ops;
1562 	mmc->f_min = DIV_ROUND_UP(host->bus_hz, 512);
1563 	mmc->f_max = host->bus_hz / 2;
1564 	mmc->ocr_avail	= MMC_VDD_32_33 | MMC_VDD_33_34;
1565 	if (slot_data->bus_width >= 4)
1566 		mmc->caps |= MMC_CAP_4_BIT_DATA;
1567 
1568 	mmc->max_hw_segs = 64;
1569 	mmc->max_phys_segs = 64;
1570 	mmc->max_req_size = 32768 * 512;
1571 	mmc->max_blk_size = 32768;
1572 	mmc->max_blk_count = 512;
1573 
1574 	/* Assume card is present initially */
1575 	set_bit(ATMCI_CARD_PRESENT, &slot->flags);
1576 	if (gpio_is_valid(slot->detect_pin)) {
1577 		if (gpio_request(slot->detect_pin, "mmc_detect")) {
1578 			dev_dbg(&mmc->class_dev, "no detect pin available\n");
1579 			slot->detect_pin = -EBUSY;
1580 		} else if (gpio_get_value(slot->detect_pin) ^
1581 				slot->detect_is_active_high) {
1582 			clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
1583 		}
1584 	}
1585 
1586 	if (!gpio_is_valid(slot->detect_pin))
1587 		mmc->caps |= MMC_CAP_NEEDS_POLL;
1588 
1589 	if (gpio_is_valid(slot->wp_pin)) {
1590 		if (gpio_request(slot->wp_pin, "mmc_wp")) {
1591 			dev_dbg(&mmc->class_dev, "no WP pin available\n");
1592 			slot->wp_pin = -EBUSY;
1593 		}
1594 	}
1595 
1596 	host->slot[id] = slot;
1597 	mmc_add_host(mmc);
1598 
1599 	if (gpio_is_valid(slot->detect_pin)) {
1600 		int ret;
1601 
1602 		setup_timer(&slot->detect_timer, atmci_detect_change,
1603 				(unsigned long)slot);
1604 
1605 		ret = request_irq(gpio_to_irq(slot->detect_pin),
1606 				atmci_detect_interrupt,
1607 				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
1608 				"mmc-detect", slot);
1609 		if (ret) {
1610 			dev_dbg(&mmc->class_dev,
1611 				"could not request IRQ %d for detect pin\n",
1612 				gpio_to_irq(slot->detect_pin));
1613 			gpio_free(slot->detect_pin);
1614 			slot->detect_pin = -EBUSY;
1615 		}
1616 	}
1617 
1618 	atmci_init_debugfs(slot);
1619 
1620 	return 0;
1621 }
1622 
1623 static void __exit atmci_cleanup_slot(struct atmel_mci_slot *slot,
1624 		unsigned int id)
1625 {
1626 	/* Debugfs stuff is cleaned up by mmc core */
1627 
1628 	set_bit(ATMCI_SHUTDOWN, &slot->flags);
1629 	smp_wmb();
1630 
1631 	mmc_remove_host(slot->mmc);
1632 
1633 	if (gpio_is_valid(slot->detect_pin)) {
1634 		int pin = slot->detect_pin;
1635 
1636 		free_irq(gpio_to_irq(pin), slot);
1637 		del_timer_sync(&slot->detect_timer);
1638 		gpio_free(pin);
1639 	}
1640 	if (gpio_is_valid(slot->wp_pin))
1641 		gpio_free(slot->wp_pin);
1642 
1643 	slot->host->slot[id] = NULL;
1644 	mmc_free_host(slot->mmc);
1645 }
1646 
1647 #ifdef CONFIG_MMC_ATMELMCI_DMA
1648 static bool filter(struct dma_chan *chan, void *slave)
1649 {
1650 	struct mci_dma_data	*sl = slave;
1651 
1652 	if (sl && find_slave_dev(sl) == chan->device->dev) {
1653 		chan->private = slave_data_ptr(sl);
1654 		return true;
1655 	} else {
1656 		return false;
1657 	}
1658 }
1659 
1660 static void atmci_configure_dma(struct atmel_mci *host)
1661 {
1662 	struct mci_platform_data	*pdata;
1663 
1664 	if (host == NULL)
1665 		return;
1666 
1667 	pdata = host->pdev->dev.platform_data;
1668 
1669 	if (pdata && find_slave_dev(pdata->dma_slave)) {
1670 		dma_cap_mask_t mask;
1671 
1672 		setup_dma_addr(pdata->dma_slave,
1673 			       host->mapbase + MCI_TDR,
1674 			       host->mapbase + MCI_RDR);
1675 
1676 		/* Try to grab a DMA channel */
1677 		dma_cap_zero(mask);
1678 		dma_cap_set(DMA_SLAVE, mask);
1679 		host->dma.chan =
1680 			dma_request_channel(mask, filter, pdata->dma_slave);
1681 	}
1682 	if (!host->dma.chan)
1683 		dev_notice(&host->pdev->dev, "DMA not available, using PIO\n");
1684 	else
1685 		dev_info(&host->pdev->dev,
1686 					"Using %s for DMA transfers\n",
1687 					dma_chan_name(host->dma.chan));
1688 }
1689 #else
1690 static void atmci_configure_dma(struct atmel_mci *host) {}
1691 #endif
1692 
1693 static int __init atmci_probe(struct platform_device *pdev)
1694 {
1695 	struct mci_platform_data	*pdata;
1696 	struct atmel_mci		*host;
1697 	struct resource			*regs;
1698 	unsigned int			nr_slots;
1699 	int				irq;
1700 	int				ret;
1701 
1702 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1703 	if (!regs)
1704 		return -ENXIO;
1705 	pdata = pdev->dev.platform_data;
1706 	if (!pdata)
1707 		return -ENXIO;
1708 	irq = platform_get_irq(pdev, 0);
1709 	if (irq < 0)
1710 		return irq;
1711 
1712 	host = kzalloc(sizeof(struct atmel_mci), GFP_KERNEL);
1713 	if (!host)
1714 		return -ENOMEM;
1715 
1716 	host->pdev = pdev;
1717 	spin_lock_init(&host->lock);
1718 	INIT_LIST_HEAD(&host->queue);
1719 
1720 	host->mck = clk_get(&pdev->dev, "mci_clk");
1721 	if (IS_ERR(host->mck)) {
1722 		ret = PTR_ERR(host->mck);
1723 		goto err_clk_get;
1724 	}
1725 
1726 	ret = -ENOMEM;
1727 	host->regs = ioremap(regs->start, regs->end - regs->start + 1);
1728 	if (!host->regs)
1729 		goto err_ioremap;
1730 
1731 	clk_enable(host->mck);
1732 	mci_writel(host, CR, MCI_CR_SWRST);
1733 	host->bus_hz = clk_get_rate(host->mck);
1734 	clk_disable(host->mck);
1735 
1736 	host->mapbase = regs->start;
1737 
1738 	tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)host);
1739 
1740 	ret = request_irq(irq, atmci_interrupt, 0, dev_name(&pdev->dev), host);
1741 	if (ret)
1742 		goto err_request_irq;
1743 
1744 	atmci_configure_dma(host);
1745 
1746 	platform_set_drvdata(pdev, host);
1747 
1748 	/* We need at least one slot to succeed */
1749 	nr_slots = 0;
1750 	ret = -ENODEV;
1751 	if (pdata->slot[0].bus_width) {
1752 		ret = atmci_init_slot(host, &pdata->slot[0],
1753 				MCI_SDCSEL_SLOT_A, 0);
1754 		if (!ret)
1755 			nr_slots++;
1756 	}
1757 	if (pdata->slot[1].bus_width) {
1758 		ret = atmci_init_slot(host, &pdata->slot[1],
1759 				MCI_SDCSEL_SLOT_B, 1);
1760 		if (!ret)
1761 			nr_slots++;
1762 	}
1763 
1764 	if (!nr_slots) {
1765 		dev_err(&pdev->dev, "init failed: no slot defined\n");
1766 		goto err_init_slot;
1767 	}
1768 
1769 	dev_info(&pdev->dev,
1770 			"Atmel MCI controller at 0x%08lx irq %d, %u slots\n",
1771 			host->mapbase, irq, nr_slots);
1772 
1773 	return 0;
1774 
1775 err_init_slot:
1776 #ifdef CONFIG_MMC_ATMELMCI_DMA
1777 	if (host->dma.chan)
1778 		dma_release_channel(host->dma.chan);
1779 #endif
1780 	free_irq(irq, host);
1781 err_request_irq:
1782 	iounmap(host->regs);
1783 err_ioremap:
1784 	clk_put(host->mck);
1785 err_clk_get:
1786 	kfree(host);
1787 	return ret;
1788 }
1789 
1790 static int __exit atmci_remove(struct platform_device *pdev)
1791 {
1792 	struct atmel_mci	*host = platform_get_drvdata(pdev);
1793 	unsigned int		i;
1794 
1795 	platform_set_drvdata(pdev, NULL);
1796 
1797 	for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
1798 		if (host->slot[i])
1799 			atmci_cleanup_slot(host->slot[i], i);
1800 	}
1801 
1802 	clk_enable(host->mck);
1803 	mci_writel(host, IDR, ~0UL);
1804 	mci_writel(host, CR, MCI_CR_MCIDIS);
1805 	mci_readl(host, SR);
1806 	clk_disable(host->mck);
1807 
1808 #ifdef CONFIG_MMC_ATMELMCI_DMA
1809 	if (host->dma.chan)
1810 		dma_release_channel(host->dma.chan);
1811 #endif
1812 
1813 	free_irq(platform_get_irq(pdev, 0), host);
1814 	iounmap(host->regs);
1815 
1816 	clk_put(host->mck);
1817 	kfree(host);
1818 
1819 	return 0;
1820 }
1821 
1822 static struct platform_driver atmci_driver = {
1823 	.remove		= __exit_p(atmci_remove),
1824 	.driver		= {
1825 		.name		= "atmel_mci",
1826 	},
1827 };
1828 
1829 static int __init atmci_init(void)
1830 {
1831 	return platform_driver_probe(&atmci_driver, atmci_probe);
1832 }
1833 
1834 static void __exit atmci_exit(void)
1835 {
1836 	platform_driver_unregister(&atmci_driver);
1837 }
1838 
1839 late_initcall(atmci_init); /* try to load after dma driver when built-in */
1840 module_exit(atmci_exit);
1841 
1842 MODULE_DESCRIPTION("Atmel Multimedia Card Interface driver");
1843 MODULE_AUTHOR("Haavard Skinnemoen <haavard.skinnemoen@atmel.com>");
1844 MODULE_LICENSE("GPL v2");
1845