xref: /openbmc/linux/drivers/mmc/host/atmel-mci.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  * Atmel MultiMedia Card Interface driver
3  *
4  * Copyright (C) 2004-2008 Atmel Corporation
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 #include <linux/blkdev.h>
11 #include <linux/clk.h>
12 #include <linux/debugfs.h>
13 #include <linux/device.h>
14 #include <linux/dmaengine.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/err.h>
17 #include <linux/gpio.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/ioport.h>
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 #include <linux/scatterlist.h>
24 #include <linux/seq_file.h>
25 #include <linux/slab.h>
26 #include <linux/stat.h>
27 
28 #include <linux/mmc/host.h>
29 #include <linux/mmc/sdio.h>
30 
31 #include <mach/atmel-mci.h>
32 #include <linux/atmel-mci.h>
33 
34 #include <asm/io.h>
35 #include <asm/unaligned.h>
36 
37 #include <mach/cpu.h>
38 #include <mach/board.h>
39 
40 #include "atmel-mci-regs.h"
41 
42 #define ATMCI_DATA_ERROR_FLAGS	(MCI_DCRCE | MCI_DTOE | MCI_OVRE | MCI_UNRE)
43 #define ATMCI_DMA_THRESHOLD	16
44 
45 enum {
46 	EVENT_CMD_COMPLETE = 0,
47 	EVENT_XFER_COMPLETE,
48 	EVENT_DATA_COMPLETE,
49 	EVENT_DATA_ERROR,
50 };
51 
52 enum atmel_mci_state {
53 	STATE_IDLE = 0,
54 	STATE_SENDING_CMD,
55 	STATE_SENDING_DATA,
56 	STATE_DATA_BUSY,
57 	STATE_SENDING_STOP,
58 	STATE_DATA_ERROR,
59 };
60 
61 struct atmel_mci_dma {
62 #ifdef CONFIG_MMC_ATMELMCI_DMA
63 	struct dma_chan			*chan;
64 	struct dma_async_tx_descriptor	*data_desc;
65 #endif
66 };
67 
68 /**
69  * struct atmel_mci - MMC controller state shared between all slots
70  * @lock: Spinlock protecting the queue and associated data.
71  * @regs: Pointer to MMIO registers.
72  * @sg: Scatterlist entry currently being processed by PIO code, if any.
73  * @pio_offset: Offset into the current scatterlist entry.
74  * @cur_slot: The slot which is currently using the controller.
75  * @mrq: The request currently being processed on @cur_slot,
76  *	or NULL if the controller is idle.
77  * @cmd: The command currently being sent to the card, or NULL.
78  * @data: The data currently being transferred, or NULL if no data
79  *	transfer is in progress.
80  * @dma: DMA client state.
81  * @data_chan: DMA channel being used for the current data transfer.
82  * @cmd_status: Snapshot of SR taken upon completion of the current
83  *	command. Only valid when EVENT_CMD_COMPLETE is pending.
84  * @data_status: Snapshot of SR taken upon completion of the current
85  *	data transfer. Only valid when EVENT_DATA_COMPLETE or
86  *	EVENT_DATA_ERROR is pending.
87  * @stop_cmdr: Value to be loaded into CMDR when the stop command is
88  *	to be sent.
89  * @tasklet: Tasklet running the request state machine.
90  * @pending_events: Bitmask of events flagged by the interrupt handler
91  *	to be processed by the tasklet.
92  * @completed_events: Bitmask of events which the state machine has
93  *	processed.
94  * @state: Tasklet state.
95  * @queue: List of slots waiting for access to the controller.
96  * @need_clock_update: Update the clock rate before the next request.
97  * @need_reset: Reset controller before next request.
98  * @mode_reg: Value of the MR register.
99  * @cfg_reg: Value of the CFG register.
100  * @bus_hz: The rate of @mck in Hz. This forms the basis for MMC bus
101  *	rate and timeout calculations.
102  * @mapbase: Physical address of the MMIO registers.
103  * @mck: The peripheral bus clock hooked up to the MMC controller.
104  * @pdev: Platform device associated with the MMC controller.
105  * @slot: Slots sharing this MMC controller.
106  *
107  * Locking
108  * =======
109  *
110  * @lock is a softirq-safe spinlock protecting @queue as well as
111  * @cur_slot, @mrq and @state. These must always be updated
112  * at the same time while holding @lock.
113  *
114  * @lock also protects mode_reg and need_clock_update since these are
115  * used to synchronize mode register updates with the queue
116  * processing.
117  *
118  * The @mrq field of struct atmel_mci_slot is also protected by @lock,
119  * and must always be written at the same time as the slot is added to
120  * @queue.
121  *
122  * @pending_events and @completed_events are accessed using atomic bit
123  * operations, so they don't need any locking.
124  *
125  * None of the fields touched by the interrupt handler need any
126  * locking. However, ordering is important: Before EVENT_DATA_ERROR or
127  * EVENT_DATA_COMPLETE is set in @pending_events, all data-related
128  * interrupts must be disabled and @data_status updated with a
129  * snapshot of SR. Similarly, before EVENT_CMD_COMPLETE is set, the
130  * CMDRDY interupt must be disabled and @cmd_status updated with a
131  * snapshot of SR, and before EVENT_XFER_COMPLETE can be set, the
132  * bytes_xfered field of @data must be written. This is ensured by
133  * using barriers.
134  */
135 struct atmel_mci {
136 	spinlock_t		lock;
137 	void __iomem		*regs;
138 
139 	struct scatterlist	*sg;
140 	unsigned int		pio_offset;
141 
142 	struct atmel_mci_slot	*cur_slot;
143 	struct mmc_request	*mrq;
144 	struct mmc_command	*cmd;
145 	struct mmc_data		*data;
146 
147 	struct atmel_mci_dma	dma;
148 	struct dma_chan		*data_chan;
149 
150 	u32			cmd_status;
151 	u32			data_status;
152 	u32			stop_cmdr;
153 
154 	struct tasklet_struct	tasklet;
155 	unsigned long		pending_events;
156 	unsigned long		completed_events;
157 	enum atmel_mci_state	state;
158 	struct list_head	queue;
159 
160 	bool			need_clock_update;
161 	bool			need_reset;
162 	u32			mode_reg;
163 	u32			cfg_reg;
164 	unsigned long		bus_hz;
165 	unsigned long		mapbase;
166 	struct clk		*mck;
167 	struct platform_device	*pdev;
168 
169 	struct atmel_mci_slot	*slot[ATMEL_MCI_MAX_NR_SLOTS];
170 };
171 
172 /**
173  * struct atmel_mci_slot - MMC slot state
174  * @mmc: The mmc_host representing this slot.
175  * @host: The MMC controller this slot is using.
176  * @sdc_reg: Value of SDCR to be written before using this slot.
177  * @sdio_irq: SDIO irq mask for this slot.
178  * @mrq: mmc_request currently being processed or waiting to be
179  *	processed, or NULL when the slot is idle.
180  * @queue_node: List node for placing this node in the @queue list of
181  *	&struct atmel_mci.
182  * @clock: Clock rate configured by set_ios(). Protected by host->lock.
183  * @flags: Random state bits associated with the slot.
184  * @detect_pin: GPIO pin used for card detection, or negative if not
185  *	available.
186  * @wp_pin: GPIO pin used for card write protect sending, or negative
187  *	if not available.
188  * @detect_is_active_high: The state of the detect pin when it is active.
189  * @detect_timer: Timer used for debouncing @detect_pin interrupts.
190  */
191 struct atmel_mci_slot {
192 	struct mmc_host		*mmc;
193 	struct atmel_mci	*host;
194 
195 	u32			sdc_reg;
196 	u32			sdio_irq;
197 
198 	struct mmc_request	*mrq;
199 	struct list_head	queue_node;
200 
201 	unsigned int		clock;
202 	unsigned long		flags;
203 #define ATMCI_CARD_PRESENT	0
204 #define ATMCI_CARD_NEED_INIT	1
205 #define ATMCI_SHUTDOWN		2
206 
207 	int			detect_pin;
208 	int			wp_pin;
209 	bool			detect_is_active_high;
210 
211 	struct timer_list	detect_timer;
212 };
213 
214 #define atmci_test_and_clear_pending(host, event)		\
215 	test_and_clear_bit(event, &host->pending_events)
216 #define atmci_set_completed(host, event)			\
217 	set_bit(event, &host->completed_events)
218 #define atmci_set_pending(host, event)				\
219 	set_bit(event, &host->pending_events)
220 
221 /*
222  * Enable or disable features/registers based on
223  * whether the processor supports them
224  */
225 static bool mci_has_rwproof(void)
226 {
227 	if (cpu_is_at91sam9261() || cpu_is_at91rm9200())
228 		return false;
229 	else
230 		return true;
231 }
232 
233 /*
234  * The new MCI2 module isn't 100% compatible with the old MCI module,
235  * and it has a few nice features which we want to use...
236  */
237 static inline bool atmci_is_mci2(void)
238 {
239 	if (cpu_is_at91sam9g45())
240 		return true;
241 
242 	return false;
243 }
244 
245 
246 /*
247  * The debugfs stuff below is mostly optimized away when
248  * CONFIG_DEBUG_FS is not set.
249  */
250 static int atmci_req_show(struct seq_file *s, void *v)
251 {
252 	struct atmel_mci_slot	*slot = s->private;
253 	struct mmc_request	*mrq;
254 	struct mmc_command	*cmd;
255 	struct mmc_command	*stop;
256 	struct mmc_data		*data;
257 
258 	/* Make sure we get a consistent snapshot */
259 	spin_lock_bh(&slot->host->lock);
260 	mrq = slot->mrq;
261 
262 	if (mrq) {
263 		cmd = mrq->cmd;
264 		data = mrq->data;
265 		stop = mrq->stop;
266 
267 		if (cmd)
268 			seq_printf(s,
269 				"CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
270 				cmd->opcode, cmd->arg, cmd->flags,
271 				cmd->resp[0], cmd->resp[1], cmd->resp[2],
272 				cmd->resp[3], cmd->error);
273 		if (data)
274 			seq_printf(s, "DATA %u / %u * %u flg %x err %d\n",
275 				data->bytes_xfered, data->blocks,
276 				data->blksz, data->flags, data->error);
277 		if (stop)
278 			seq_printf(s,
279 				"CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
280 				stop->opcode, stop->arg, stop->flags,
281 				stop->resp[0], stop->resp[1], stop->resp[2],
282 				stop->resp[3], stop->error);
283 	}
284 
285 	spin_unlock_bh(&slot->host->lock);
286 
287 	return 0;
288 }
289 
290 static int atmci_req_open(struct inode *inode, struct file *file)
291 {
292 	return single_open(file, atmci_req_show, inode->i_private);
293 }
294 
295 static const struct file_operations atmci_req_fops = {
296 	.owner		= THIS_MODULE,
297 	.open		= atmci_req_open,
298 	.read		= seq_read,
299 	.llseek		= seq_lseek,
300 	.release	= single_release,
301 };
302 
303 static void atmci_show_status_reg(struct seq_file *s,
304 		const char *regname, u32 value)
305 {
306 	static const char	*sr_bit[] = {
307 		[0]	= "CMDRDY",
308 		[1]	= "RXRDY",
309 		[2]	= "TXRDY",
310 		[3]	= "BLKE",
311 		[4]	= "DTIP",
312 		[5]	= "NOTBUSY",
313 		[6]	= "ENDRX",
314 		[7]	= "ENDTX",
315 		[8]	= "SDIOIRQA",
316 		[9]	= "SDIOIRQB",
317 		[12]	= "SDIOWAIT",
318 		[14]	= "RXBUFF",
319 		[15]	= "TXBUFE",
320 		[16]	= "RINDE",
321 		[17]	= "RDIRE",
322 		[18]	= "RCRCE",
323 		[19]	= "RENDE",
324 		[20]	= "RTOE",
325 		[21]	= "DCRCE",
326 		[22]	= "DTOE",
327 		[23]	= "CSTOE",
328 		[24]	= "BLKOVRE",
329 		[25]	= "DMADONE",
330 		[26]	= "FIFOEMPTY",
331 		[27]	= "XFRDONE",
332 		[30]	= "OVRE",
333 		[31]	= "UNRE",
334 	};
335 	unsigned int		i;
336 
337 	seq_printf(s, "%s:\t0x%08x", regname, value);
338 	for (i = 0; i < ARRAY_SIZE(sr_bit); i++) {
339 		if (value & (1 << i)) {
340 			if (sr_bit[i])
341 				seq_printf(s, " %s", sr_bit[i]);
342 			else
343 				seq_puts(s, " UNKNOWN");
344 		}
345 	}
346 	seq_putc(s, '\n');
347 }
348 
349 static int atmci_regs_show(struct seq_file *s, void *v)
350 {
351 	struct atmel_mci	*host = s->private;
352 	u32			*buf;
353 
354 	buf = kmalloc(MCI_REGS_SIZE, GFP_KERNEL);
355 	if (!buf)
356 		return -ENOMEM;
357 
358 	/*
359 	 * Grab a more or less consistent snapshot. Note that we're
360 	 * not disabling interrupts, so IMR and SR may not be
361 	 * consistent.
362 	 */
363 	spin_lock_bh(&host->lock);
364 	clk_enable(host->mck);
365 	memcpy_fromio(buf, host->regs, MCI_REGS_SIZE);
366 	clk_disable(host->mck);
367 	spin_unlock_bh(&host->lock);
368 
369 	seq_printf(s, "MR:\t0x%08x%s%s CLKDIV=%u\n",
370 			buf[MCI_MR / 4],
371 			buf[MCI_MR / 4] & MCI_MR_RDPROOF ? " RDPROOF" : "",
372 			buf[MCI_MR / 4] & MCI_MR_WRPROOF ? " WRPROOF" : "",
373 			buf[MCI_MR / 4] & 0xff);
374 	seq_printf(s, "DTOR:\t0x%08x\n", buf[MCI_DTOR / 4]);
375 	seq_printf(s, "SDCR:\t0x%08x\n", buf[MCI_SDCR / 4]);
376 	seq_printf(s, "ARGR:\t0x%08x\n", buf[MCI_ARGR / 4]);
377 	seq_printf(s, "BLKR:\t0x%08x BCNT=%u BLKLEN=%u\n",
378 			buf[MCI_BLKR / 4],
379 			buf[MCI_BLKR / 4] & 0xffff,
380 			(buf[MCI_BLKR / 4] >> 16) & 0xffff);
381 	if (atmci_is_mci2())
382 		seq_printf(s, "CSTOR:\t0x%08x\n", buf[MCI_CSTOR / 4]);
383 
384 	/* Don't read RSPR and RDR; it will consume the data there */
385 
386 	atmci_show_status_reg(s, "SR", buf[MCI_SR / 4]);
387 	atmci_show_status_reg(s, "IMR", buf[MCI_IMR / 4]);
388 
389 	if (atmci_is_mci2()) {
390 		u32 val;
391 
392 		val = buf[MCI_DMA / 4];
393 		seq_printf(s, "DMA:\t0x%08x OFFSET=%u CHKSIZE=%u%s\n",
394 				val, val & 3,
395 				((val >> 4) & 3) ?
396 					1 << (((val >> 4) & 3) + 1) : 1,
397 				val & MCI_DMAEN ? " DMAEN" : "");
398 
399 		val = buf[MCI_CFG / 4];
400 		seq_printf(s, "CFG:\t0x%08x%s%s%s%s\n",
401 				val,
402 				val & MCI_CFG_FIFOMODE_1DATA ? " FIFOMODE_ONE_DATA" : "",
403 				val & MCI_CFG_FERRCTRL_COR ? " FERRCTRL_CLEAR_ON_READ" : "",
404 				val & MCI_CFG_HSMODE ? " HSMODE" : "",
405 				val & MCI_CFG_LSYNC ? " LSYNC" : "");
406 	}
407 
408 	kfree(buf);
409 
410 	return 0;
411 }
412 
413 static int atmci_regs_open(struct inode *inode, struct file *file)
414 {
415 	return single_open(file, atmci_regs_show, inode->i_private);
416 }
417 
418 static const struct file_operations atmci_regs_fops = {
419 	.owner		= THIS_MODULE,
420 	.open		= atmci_regs_open,
421 	.read		= seq_read,
422 	.llseek		= seq_lseek,
423 	.release	= single_release,
424 };
425 
426 static void atmci_init_debugfs(struct atmel_mci_slot *slot)
427 {
428 	struct mmc_host		*mmc = slot->mmc;
429 	struct atmel_mci	*host = slot->host;
430 	struct dentry		*root;
431 	struct dentry		*node;
432 
433 	root = mmc->debugfs_root;
434 	if (!root)
435 		return;
436 
437 	node = debugfs_create_file("regs", S_IRUSR, root, host,
438 			&atmci_regs_fops);
439 	if (IS_ERR(node))
440 		return;
441 	if (!node)
442 		goto err;
443 
444 	node = debugfs_create_file("req", S_IRUSR, root, slot, &atmci_req_fops);
445 	if (!node)
446 		goto err;
447 
448 	node = debugfs_create_u32("state", S_IRUSR, root, (u32 *)&host->state);
449 	if (!node)
450 		goto err;
451 
452 	node = debugfs_create_x32("pending_events", S_IRUSR, root,
453 				     (u32 *)&host->pending_events);
454 	if (!node)
455 		goto err;
456 
457 	node = debugfs_create_x32("completed_events", S_IRUSR, root,
458 				     (u32 *)&host->completed_events);
459 	if (!node)
460 		goto err;
461 
462 	return;
463 
464 err:
465 	dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n");
466 }
467 
468 static inline unsigned int ns_to_clocks(struct atmel_mci *host,
469 					unsigned int ns)
470 {
471 	return (ns * (host->bus_hz / 1000000) + 999) / 1000;
472 }
473 
474 static void atmci_set_timeout(struct atmel_mci *host,
475 		struct atmel_mci_slot *slot, struct mmc_data *data)
476 {
477 	static unsigned	dtomul_to_shift[] = {
478 		0, 4, 7, 8, 10, 12, 16, 20
479 	};
480 	unsigned	timeout;
481 	unsigned	dtocyc;
482 	unsigned	dtomul;
483 
484 	timeout = ns_to_clocks(host, data->timeout_ns) + data->timeout_clks;
485 
486 	for (dtomul = 0; dtomul < 8; dtomul++) {
487 		unsigned shift = dtomul_to_shift[dtomul];
488 		dtocyc = (timeout + (1 << shift) - 1) >> shift;
489 		if (dtocyc < 15)
490 			break;
491 	}
492 
493 	if (dtomul >= 8) {
494 		dtomul = 7;
495 		dtocyc = 15;
496 	}
497 
498 	dev_vdbg(&slot->mmc->class_dev, "setting timeout to %u cycles\n",
499 			dtocyc << dtomul_to_shift[dtomul]);
500 	mci_writel(host, DTOR, (MCI_DTOMUL(dtomul) | MCI_DTOCYC(dtocyc)));
501 }
502 
503 /*
504  * Return mask with command flags to be enabled for this command.
505  */
506 static u32 atmci_prepare_command(struct mmc_host *mmc,
507 				 struct mmc_command *cmd)
508 {
509 	struct mmc_data	*data;
510 	u32		cmdr;
511 
512 	cmd->error = -EINPROGRESS;
513 
514 	cmdr = MCI_CMDR_CMDNB(cmd->opcode);
515 
516 	if (cmd->flags & MMC_RSP_PRESENT) {
517 		if (cmd->flags & MMC_RSP_136)
518 			cmdr |= MCI_CMDR_RSPTYP_136BIT;
519 		else
520 			cmdr |= MCI_CMDR_RSPTYP_48BIT;
521 	}
522 
523 	/*
524 	 * This should really be MAXLAT_5 for CMD2 and ACMD41, but
525 	 * it's too difficult to determine whether this is an ACMD or
526 	 * not. Better make it 64.
527 	 */
528 	cmdr |= MCI_CMDR_MAXLAT_64CYC;
529 
530 	if (mmc->ios.bus_mode == MMC_BUSMODE_OPENDRAIN)
531 		cmdr |= MCI_CMDR_OPDCMD;
532 
533 	data = cmd->data;
534 	if (data) {
535 		cmdr |= MCI_CMDR_START_XFER;
536 
537 		if (cmd->opcode == SD_IO_RW_EXTENDED) {
538 			cmdr |= MCI_CMDR_SDIO_BLOCK;
539 		} else {
540 			if (data->flags & MMC_DATA_STREAM)
541 				cmdr |= MCI_CMDR_STREAM;
542 			else if (data->blocks > 1)
543 				cmdr |= MCI_CMDR_MULTI_BLOCK;
544 			else
545 				cmdr |= MCI_CMDR_BLOCK;
546 		}
547 
548 		if (data->flags & MMC_DATA_READ)
549 			cmdr |= MCI_CMDR_TRDIR_READ;
550 	}
551 
552 	return cmdr;
553 }
554 
555 static void atmci_start_command(struct atmel_mci *host,
556 		struct mmc_command *cmd, u32 cmd_flags)
557 {
558 	WARN_ON(host->cmd);
559 	host->cmd = cmd;
560 
561 	dev_vdbg(&host->pdev->dev,
562 			"start command: ARGR=0x%08x CMDR=0x%08x\n",
563 			cmd->arg, cmd_flags);
564 
565 	mci_writel(host, ARGR, cmd->arg);
566 	mci_writel(host, CMDR, cmd_flags);
567 }
568 
569 static void send_stop_cmd(struct atmel_mci *host, struct mmc_data *data)
570 {
571 	atmci_start_command(host, data->stop, host->stop_cmdr);
572 	mci_writel(host, IER, MCI_CMDRDY);
573 }
574 
575 #ifdef CONFIG_MMC_ATMELMCI_DMA
576 static void atmci_dma_cleanup(struct atmel_mci *host)
577 {
578 	struct mmc_data			*data = host->data;
579 
580 	if (data)
581 		dma_unmap_sg(&host->pdev->dev, data->sg, data->sg_len,
582 			     ((data->flags & MMC_DATA_WRITE)
583 			      ? DMA_TO_DEVICE : DMA_FROM_DEVICE));
584 }
585 
586 static void atmci_stop_dma(struct atmel_mci *host)
587 {
588 	struct dma_chan *chan = host->data_chan;
589 
590 	if (chan) {
591 	  chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
592 		atmci_dma_cleanup(host);
593 	} else {
594 		/* Data transfer was stopped by the interrupt handler */
595 		atmci_set_pending(host, EVENT_XFER_COMPLETE);
596 		mci_writel(host, IER, MCI_NOTBUSY);
597 	}
598 }
599 
600 /* This function is called by the DMA driver from tasklet context. */
601 static void atmci_dma_complete(void *arg)
602 {
603 	struct atmel_mci	*host = arg;
604 	struct mmc_data		*data = host->data;
605 
606 	dev_vdbg(&host->pdev->dev, "DMA complete\n");
607 
608 	if (atmci_is_mci2())
609 		/* Disable DMA hardware handshaking on MCI */
610 		mci_writel(host, DMA, mci_readl(host, DMA) & ~MCI_DMAEN);
611 
612 	atmci_dma_cleanup(host);
613 
614 	/*
615 	 * If the card was removed, data will be NULL. No point trying
616 	 * to send the stop command or waiting for NBUSY in this case.
617 	 */
618 	if (data) {
619 		atmci_set_pending(host, EVENT_XFER_COMPLETE);
620 		tasklet_schedule(&host->tasklet);
621 
622 		/*
623 		 * Regardless of what the documentation says, we have
624 		 * to wait for NOTBUSY even after block read
625 		 * operations.
626 		 *
627 		 * When the DMA transfer is complete, the controller
628 		 * may still be reading the CRC from the card, i.e.
629 		 * the data transfer is still in progress and we
630 		 * haven't seen all the potential error bits yet.
631 		 *
632 		 * The interrupt handler will schedule a different
633 		 * tasklet to finish things up when the data transfer
634 		 * is completely done.
635 		 *
636 		 * We may not complete the mmc request here anyway
637 		 * because the mmc layer may call back and cause us to
638 		 * violate the "don't submit new operations from the
639 		 * completion callback" rule of the dma engine
640 		 * framework.
641 		 */
642 		mci_writel(host, IER, MCI_NOTBUSY);
643 	}
644 }
645 
646 static int
647 atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)
648 {
649 	struct dma_chan			*chan;
650 	struct dma_async_tx_descriptor	*desc;
651 	struct scatterlist		*sg;
652 	unsigned int			i;
653 	enum dma_data_direction		direction;
654 	unsigned int			sglen;
655 
656 	/*
657 	 * We don't do DMA on "complex" transfers, i.e. with
658 	 * non-word-aligned buffers or lengths. Also, we don't bother
659 	 * with all the DMA setup overhead for short transfers.
660 	 */
661 	if (data->blocks * data->blksz < ATMCI_DMA_THRESHOLD)
662 		return -EINVAL;
663 	if (data->blksz & 3)
664 		return -EINVAL;
665 
666 	for_each_sg(data->sg, sg, data->sg_len, i) {
667 		if (sg->offset & 3 || sg->length & 3)
668 			return -EINVAL;
669 	}
670 
671 	/* If we don't have a channel, we can't do DMA */
672 	chan = host->dma.chan;
673 	if (chan)
674 		host->data_chan = chan;
675 
676 	if (!chan)
677 		return -ENODEV;
678 
679 	if (atmci_is_mci2())
680 		mci_writel(host, DMA, MCI_DMA_CHKSIZE(3) | MCI_DMAEN);
681 
682 	if (data->flags & MMC_DATA_READ)
683 		direction = DMA_FROM_DEVICE;
684 	else
685 		direction = DMA_TO_DEVICE;
686 
687 	sglen = dma_map_sg(&host->pdev->dev, data->sg, data->sg_len, direction);
688 	if (sglen != data->sg_len)
689 		goto unmap_exit;
690 	desc = chan->device->device_prep_slave_sg(chan,
691 			data->sg, data->sg_len, direction,
692 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
693 	if (!desc)
694 		goto unmap_exit;
695 
696 	host->dma.data_desc = desc;
697 	desc->callback = atmci_dma_complete;
698 	desc->callback_param = host;
699 
700 	return 0;
701 unmap_exit:
702 	dma_unmap_sg(&host->pdev->dev, data->sg, sglen, direction);
703 	return -ENOMEM;
704 }
705 
706 static void atmci_submit_data(struct atmel_mci *host)
707 {
708 	struct dma_chan			*chan = host->data_chan;
709 	struct dma_async_tx_descriptor	*desc = host->dma.data_desc;
710 
711 	if (chan) {
712 		desc->tx_submit(desc);
713 		chan->device->device_issue_pending(chan);
714 	}
715 }
716 
717 #else /* CONFIG_MMC_ATMELMCI_DMA */
718 
719 static int atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)
720 {
721 	return -ENOSYS;
722 }
723 
724 static void atmci_submit_data(struct atmel_mci *host) {}
725 
726 static void atmci_stop_dma(struct atmel_mci *host)
727 {
728 	/* Data transfer was stopped by the interrupt handler */
729 	atmci_set_pending(host, EVENT_XFER_COMPLETE);
730 	mci_writel(host, IER, MCI_NOTBUSY);
731 }
732 
733 #endif /* CONFIG_MMC_ATMELMCI_DMA */
734 
735 /*
736  * Returns a mask of interrupt flags to be enabled after the whole
737  * request has been prepared.
738  */
739 static u32 atmci_prepare_data(struct atmel_mci *host, struct mmc_data *data)
740 {
741 	u32 iflags;
742 
743 	data->error = -EINPROGRESS;
744 
745 	WARN_ON(host->data);
746 	host->sg = NULL;
747 	host->data = data;
748 
749 	iflags = ATMCI_DATA_ERROR_FLAGS;
750 	if (atmci_prepare_data_dma(host, data)) {
751 		host->data_chan = NULL;
752 
753 		/*
754 		 * Errata: MMC data write operation with less than 12
755 		 * bytes is impossible.
756 		 *
757 		 * Errata: MCI Transmit Data Register (TDR) FIFO
758 		 * corruption when length is not multiple of 4.
759 		 */
760 		if (data->blocks * data->blksz < 12
761 				|| (data->blocks * data->blksz) & 3)
762 			host->need_reset = true;
763 
764 		host->sg = data->sg;
765 		host->pio_offset = 0;
766 		if (data->flags & MMC_DATA_READ)
767 			iflags |= MCI_RXRDY;
768 		else
769 			iflags |= MCI_TXRDY;
770 	}
771 
772 	return iflags;
773 }
774 
775 static void atmci_start_request(struct atmel_mci *host,
776 		struct atmel_mci_slot *slot)
777 {
778 	struct mmc_request	*mrq;
779 	struct mmc_command	*cmd;
780 	struct mmc_data		*data;
781 	u32			iflags;
782 	u32			cmdflags;
783 
784 	mrq = slot->mrq;
785 	host->cur_slot = slot;
786 	host->mrq = mrq;
787 
788 	host->pending_events = 0;
789 	host->completed_events = 0;
790 	host->data_status = 0;
791 
792 	if (host->need_reset) {
793 		mci_writel(host, CR, MCI_CR_SWRST);
794 		mci_writel(host, CR, MCI_CR_MCIEN);
795 		mci_writel(host, MR, host->mode_reg);
796 		if (atmci_is_mci2())
797 			mci_writel(host, CFG, host->cfg_reg);
798 		host->need_reset = false;
799 	}
800 	mci_writel(host, SDCR, slot->sdc_reg);
801 
802 	iflags = mci_readl(host, IMR);
803 	if (iflags & ~(MCI_SDIOIRQA | MCI_SDIOIRQB))
804 		dev_warn(&slot->mmc->class_dev, "WARNING: IMR=0x%08x\n",
805 				iflags);
806 
807 	if (unlikely(test_and_clear_bit(ATMCI_CARD_NEED_INIT, &slot->flags))) {
808 		/* Send init sequence (74 clock cycles) */
809 		mci_writel(host, CMDR, MCI_CMDR_SPCMD_INIT);
810 		while (!(mci_readl(host, SR) & MCI_CMDRDY))
811 			cpu_relax();
812 	}
813 	iflags = 0;
814 	data = mrq->data;
815 	if (data) {
816 		atmci_set_timeout(host, slot, data);
817 
818 		/* Must set block count/size before sending command */
819 		mci_writel(host, BLKR, MCI_BCNT(data->blocks)
820 				| MCI_BLKLEN(data->blksz));
821 		dev_vdbg(&slot->mmc->class_dev, "BLKR=0x%08x\n",
822 			MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz));
823 
824 		iflags |= atmci_prepare_data(host, data);
825 	}
826 
827 	iflags |= MCI_CMDRDY;
828 	cmd = mrq->cmd;
829 	cmdflags = atmci_prepare_command(slot->mmc, cmd);
830 	atmci_start_command(host, cmd, cmdflags);
831 
832 	if (data)
833 		atmci_submit_data(host);
834 
835 	if (mrq->stop) {
836 		host->stop_cmdr = atmci_prepare_command(slot->mmc, mrq->stop);
837 		host->stop_cmdr |= MCI_CMDR_STOP_XFER;
838 		if (!(data->flags & MMC_DATA_WRITE))
839 			host->stop_cmdr |= MCI_CMDR_TRDIR_READ;
840 		if (data->flags & MMC_DATA_STREAM)
841 			host->stop_cmdr |= MCI_CMDR_STREAM;
842 		else
843 			host->stop_cmdr |= MCI_CMDR_MULTI_BLOCK;
844 	}
845 
846 	/*
847 	 * We could have enabled interrupts earlier, but I suspect
848 	 * that would open up a nice can of interesting race
849 	 * conditions (e.g. command and data complete, but stop not
850 	 * prepared yet.)
851 	 */
852 	mci_writel(host, IER, iflags);
853 }
854 
855 static void atmci_queue_request(struct atmel_mci *host,
856 		struct atmel_mci_slot *slot, struct mmc_request *mrq)
857 {
858 	dev_vdbg(&slot->mmc->class_dev, "queue request: state=%d\n",
859 			host->state);
860 
861 	spin_lock_bh(&host->lock);
862 	slot->mrq = mrq;
863 	if (host->state == STATE_IDLE) {
864 		host->state = STATE_SENDING_CMD;
865 		atmci_start_request(host, slot);
866 	} else {
867 		list_add_tail(&slot->queue_node, &host->queue);
868 	}
869 	spin_unlock_bh(&host->lock);
870 }
871 
872 static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
873 {
874 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
875 	struct atmel_mci	*host = slot->host;
876 	struct mmc_data		*data;
877 
878 	WARN_ON(slot->mrq);
879 
880 	/*
881 	 * We may "know" the card is gone even though there's still an
882 	 * electrical connection. If so, we really need to communicate
883 	 * this to the MMC core since there won't be any more
884 	 * interrupts as the card is completely removed. Otherwise,
885 	 * the MMC core might believe the card is still there even
886 	 * though the card was just removed very slowly.
887 	 */
888 	if (!test_bit(ATMCI_CARD_PRESENT, &slot->flags)) {
889 		mrq->cmd->error = -ENOMEDIUM;
890 		mmc_request_done(mmc, mrq);
891 		return;
892 	}
893 
894 	/* We don't support multiple blocks of weird lengths. */
895 	data = mrq->data;
896 	if (data && data->blocks > 1 && data->blksz & 3) {
897 		mrq->cmd->error = -EINVAL;
898 		mmc_request_done(mmc, mrq);
899 	}
900 
901 	atmci_queue_request(host, slot, mrq);
902 }
903 
904 static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
905 {
906 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
907 	struct atmel_mci	*host = slot->host;
908 	unsigned int		i;
909 
910 	slot->sdc_reg &= ~MCI_SDCBUS_MASK;
911 	switch (ios->bus_width) {
912 	case MMC_BUS_WIDTH_1:
913 		slot->sdc_reg |= MCI_SDCBUS_1BIT;
914 		break;
915 	case MMC_BUS_WIDTH_4:
916 		slot->sdc_reg |= MCI_SDCBUS_4BIT;
917 		break;
918 	}
919 
920 	if (ios->clock) {
921 		unsigned int clock_min = ~0U;
922 		u32 clkdiv;
923 
924 		spin_lock_bh(&host->lock);
925 		if (!host->mode_reg) {
926 			clk_enable(host->mck);
927 			mci_writel(host, CR, MCI_CR_SWRST);
928 			mci_writel(host, CR, MCI_CR_MCIEN);
929 			if (atmci_is_mci2())
930 				mci_writel(host, CFG, host->cfg_reg);
931 		}
932 
933 		/*
934 		 * Use mirror of ios->clock to prevent race with mmc
935 		 * core ios update when finding the minimum.
936 		 */
937 		slot->clock = ios->clock;
938 		for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
939 			if (host->slot[i] && host->slot[i]->clock
940 					&& host->slot[i]->clock < clock_min)
941 				clock_min = host->slot[i]->clock;
942 		}
943 
944 		/* Calculate clock divider */
945 		clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * clock_min) - 1;
946 		if (clkdiv > 255) {
947 			dev_warn(&mmc->class_dev,
948 				"clock %u too slow; using %lu\n",
949 				clock_min, host->bus_hz / (2 * 256));
950 			clkdiv = 255;
951 		}
952 
953 		host->mode_reg = MCI_MR_CLKDIV(clkdiv);
954 
955 		/*
956 		 * WRPROOF and RDPROOF prevent overruns/underruns by
957 		 * stopping the clock when the FIFO is full/empty.
958 		 * This state is not expected to last for long.
959 		 */
960 		if (mci_has_rwproof())
961 			host->mode_reg |= (MCI_MR_WRPROOF | MCI_MR_RDPROOF);
962 
963 		if (atmci_is_mci2()) {
964 			/* setup High Speed mode in relation with card capacity */
965 			if (ios->timing == MMC_TIMING_SD_HS)
966 				host->cfg_reg |= MCI_CFG_HSMODE;
967 			else
968 				host->cfg_reg &= ~MCI_CFG_HSMODE;
969 		}
970 
971 		if (list_empty(&host->queue)) {
972 			mci_writel(host, MR, host->mode_reg);
973 			if (atmci_is_mci2())
974 				mci_writel(host, CFG, host->cfg_reg);
975 		} else {
976 			host->need_clock_update = true;
977 		}
978 
979 		spin_unlock_bh(&host->lock);
980 	} else {
981 		bool any_slot_active = false;
982 
983 		spin_lock_bh(&host->lock);
984 		slot->clock = 0;
985 		for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
986 			if (host->slot[i] && host->slot[i]->clock) {
987 				any_slot_active = true;
988 				break;
989 			}
990 		}
991 		if (!any_slot_active) {
992 			mci_writel(host, CR, MCI_CR_MCIDIS);
993 			if (host->mode_reg) {
994 				mci_readl(host, MR);
995 				clk_disable(host->mck);
996 			}
997 			host->mode_reg = 0;
998 		}
999 		spin_unlock_bh(&host->lock);
1000 	}
1001 
1002 	switch (ios->power_mode) {
1003 	case MMC_POWER_UP:
1004 		set_bit(ATMCI_CARD_NEED_INIT, &slot->flags);
1005 		break;
1006 	default:
1007 		/*
1008 		 * TODO: None of the currently available AVR32-based
1009 		 * boards allow MMC power to be turned off. Implement
1010 		 * power control when this can be tested properly.
1011 		 *
1012 		 * We also need to hook this into the clock management
1013 		 * somehow so that newly inserted cards aren't
1014 		 * subjected to a fast clock before we have a chance
1015 		 * to figure out what the maximum rate is. Currently,
1016 		 * there's no way to avoid this, and there never will
1017 		 * be for boards that don't support power control.
1018 		 */
1019 		break;
1020 	}
1021 }
1022 
1023 static int atmci_get_ro(struct mmc_host *mmc)
1024 {
1025 	int			read_only = -ENOSYS;
1026 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1027 
1028 	if (gpio_is_valid(slot->wp_pin)) {
1029 		read_only = gpio_get_value(slot->wp_pin);
1030 		dev_dbg(&mmc->class_dev, "card is %s\n",
1031 				read_only ? "read-only" : "read-write");
1032 	}
1033 
1034 	return read_only;
1035 }
1036 
1037 static int atmci_get_cd(struct mmc_host *mmc)
1038 {
1039 	int			present = -ENOSYS;
1040 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1041 
1042 	if (gpio_is_valid(slot->detect_pin)) {
1043 		present = !(gpio_get_value(slot->detect_pin) ^
1044 			    slot->detect_is_active_high);
1045 		dev_dbg(&mmc->class_dev, "card is %spresent\n",
1046 				present ? "" : "not ");
1047 	}
1048 
1049 	return present;
1050 }
1051 
1052 static void atmci_enable_sdio_irq(struct mmc_host *mmc, int enable)
1053 {
1054 	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1055 	struct atmel_mci	*host = slot->host;
1056 
1057 	if (enable)
1058 		mci_writel(host, IER, slot->sdio_irq);
1059 	else
1060 		mci_writel(host, IDR, slot->sdio_irq);
1061 }
1062 
1063 static const struct mmc_host_ops atmci_ops = {
1064 	.request	= atmci_request,
1065 	.set_ios	= atmci_set_ios,
1066 	.get_ro		= atmci_get_ro,
1067 	.get_cd		= atmci_get_cd,
1068 	.enable_sdio_irq = atmci_enable_sdio_irq,
1069 };
1070 
1071 /* Called with host->lock held */
1072 static void atmci_request_end(struct atmel_mci *host, struct mmc_request *mrq)
1073 	__releases(&host->lock)
1074 	__acquires(&host->lock)
1075 {
1076 	struct atmel_mci_slot	*slot = NULL;
1077 	struct mmc_host		*prev_mmc = host->cur_slot->mmc;
1078 
1079 	WARN_ON(host->cmd || host->data);
1080 
1081 	/*
1082 	 * Update the MMC clock rate if necessary. This may be
1083 	 * necessary if set_ios() is called when a different slot is
1084 	 * busy transfering data.
1085 	 */
1086 	if (host->need_clock_update) {
1087 		mci_writel(host, MR, host->mode_reg);
1088 		if (atmci_is_mci2())
1089 			mci_writel(host, CFG, host->cfg_reg);
1090 	}
1091 
1092 	host->cur_slot->mrq = NULL;
1093 	host->mrq = NULL;
1094 	if (!list_empty(&host->queue)) {
1095 		slot = list_entry(host->queue.next,
1096 				struct atmel_mci_slot, queue_node);
1097 		list_del(&slot->queue_node);
1098 		dev_vdbg(&host->pdev->dev, "list not empty: %s is next\n",
1099 				mmc_hostname(slot->mmc));
1100 		host->state = STATE_SENDING_CMD;
1101 		atmci_start_request(host, slot);
1102 	} else {
1103 		dev_vdbg(&host->pdev->dev, "list empty\n");
1104 		host->state = STATE_IDLE;
1105 	}
1106 
1107 	spin_unlock(&host->lock);
1108 	mmc_request_done(prev_mmc, mrq);
1109 	spin_lock(&host->lock);
1110 }
1111 
1112 static void atmci_command_complete(struct atmel_mci *host,
1113 			struct mmc_command *cmd)
1114 {
1115 	u32		status = host->cmd_status;
1116 
1117 	/* Read the response from the card (up to 16 bytes) */
1118 	cmd->resp[0] = mci_readl(host, RSPR);
1119 	cmd->resp[1] = mci_readl(host, RSPR);
1120 	cmd->resp[2] = mci_readl(host, RSPR);
1121 	cmd->resp[3] = mci_readl(host, RSPR);
1122 
1123 	if (status & MCI_RTOE)
1124 		cmd->error = -ETIMEDOUT;
1125 	else if ((cmd->flags & MMC_RSP_CRC) && (status & MCI_RCRCE))
1126 		cmd->error = -EILSEQ;
1127 	else if (status & (MCI_RINDE | MCI_RDIRE | MCI_RENDE))
1128 		cmd->error = -EIO;
1129 	else
1130 		cmd->error = 0;
1131 
1132 	if (cmd->error) {
1133 		dev_dbg(&host->pdev->dev,
1134 			"command error: status=0x%08x\n", status);
1135 
1136 		if (cmd->data) {
1137 			atmci_stop_dma(host);
1138 			host->data = NULL;
1139 			mci_writel(host, IDR, MCI_NOTBUSY
1140 					| MCI_TXRDY | MCI_RXRDY
1141 					| ATMCI_DATA_ERROR_FLAGS);
1142 		}
1143 	}
1144 }
1145 
1146 static void atmci_detect_change(unsigned long data)
1147 {
1148 	struct atmel_mci_slot	*slot = (struct atmel_mci_slot *)data;
1149 	bool			present;
1150 	bool			present_old;
1151 
1152 	/*
1153 	 * atmci_cleanup_slot() sets the ATMCI_SHUTDOWN flag before
1154 	 * freeing the interrupt. We must not re-enable the interrupt
1155 	 * if it has been freed, and if we're shutting down, it
1156 	 * doesn't really matter whether the card is present or not.
1157 	 */
1158 	smp_rmb();
1159 	if (test_bit(ATMCI_SHUTDOWN, &slot->flags))
1160 		return;
1161 
1162 	enable_irq(gpio_to_irq(slot->detect_pin));
1163 	present = !(gpio_get_value(slot->detect_pin) ^
1164 		    slot->detect_is_active_high);
1165 	present_old = test_bit(ATMCI_CARD_PRESENT, &slot->flags);
1166 
1167 	dev_vdbg(&slot->mmc->class_dev, "detect change: %d (was %d)\n",
1168 			present, present_old);
1169 
1170 	if (present != present_old) {
1171 		struct atmel_mci	*host = slot->host;
1172 		struct mmc_request	*mrq;
1173 
1174 		dev_dbg(&slot->mmc->class_dev, "card %s\n",
1175 			present ? "inserted" : "removed");
1176 
1177 		spin_lock(&host->lock);
1178 
1179 		if (!present)
1180 			clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
1181 		else
1182 			set_bit(ATMCI_CARD_PRESENT, &slot->flags);
1183 
1184 		/* Clean up queue if present */
1185 		mrq = slot->mrq;
1186 		if (mrq) {
1187 			if (mrq == host->mrq) {
1188 				/*
1189 				 * Reset controller to terminate any ongoing
1190 				 * commands or data transfers.
1191 				 */
1192 				mci_writel(host, CR, MCI_CR_SWRST);
1193 				mci_writel(host, CR, MCI_CR_MCIEN);
1194 				mci_writel(host, MR, host->mode_reg);
1195 				if (atmci_is_mci2())
1196 					mci_writel(host, CFG, host->cfg_reg);
1197 
1198 				host->data = NULL;
1199 				host->cmd = NULL;
1200 
1201 				switch (host->state) {
1202 				case STATE_IDLE:
1203 					break;
1204 				case STATE_SENDING_CMD:
1205 					mrq->cmd->error = -ENOMEDIUM;
1206 					if (!mrq->data)
1207 						break;
1208 					/* fall through */
1209 				case STATE_SENDING_DATA:
1210 					mrq->data->error = -ENOMEDIUM;
1211 					atmci_stop_dma(host);
1212 					break;
1213 				case STATE_DATA_BUSY:
1214 				case STATE_DATA_ERROR:
1215 					if (mrq->data->error == -EINPROGRESS)
1216 						mrq->data->error = -ENOMEDIUM;
1217 					if (!mrq->stop)
1218 						break;
1219 					/* fall through */
1220 				case STATE_SENDING_STOP:
1221 					mrq->stop->error = -ENOMEDIUM;
1222 					break;
1223 				}
1224 
1225 				atmci_request_end(host, mrq);
1226 			} else {
1227 				list_del(&slot->queue_node);
1228 				mrq->cmd->error = -ENOMEDIUM;
1229 				if (mrq->data)
1230 					mrq->data->error = -ENOMEDIUM;
1231 				if (mrq->stop)
1232 					mrq->stop->error = -ENOMEDIUM;
1233 
1234 				spin_unlock(&host->lock);
1235 				mmc_request_done(slot->mmc, mrq);
1236 				spin_lock(&host->lock);
1237 			}
1238 		}
1239 		spin_unlock(&host->lock);
1240 
1241 		mmc_detect_change(slot->mmc, 0);
1242 	}
1243 }
1244 
1245 static void atmci_tasklet_func(unsigned long priv)
1246 {
1247 	struct atmel_mci	*host = (struct atmel_mci *)priv;
1248 	struct mmc_request	*mrq = host->mrq;
1249 	struct mmc_data		*data = host->data;
1250 	struct mmc_command	*cmd = host->cmd;
1251 	enum atmel_mci_state	state = host->state;
1252 	enum atmel_mci_state	prev_state;
1253 	u32			status;
1254 
1255 	spin_lock(&host->lock);
1256 
1257 	state = host->state;
1258 
1259 	dev_vdbg(&host->pdev->dev,
1260 		"tasklet: state %u pending/completed/mask %lx/%lx/%x\n",
1261 		state, host->pending_events, host->completed_events,
1262 		mci_readl(host, IMR));
1263 
1264 	do {
1265 		prev_state = state;
1266 
1267 		switch (state) {
1268 		case STATE_IDLE:
1269 			break;
1270 
1271 		case STATE_SENDING_CMD:
1272 			if (!atmci_test_and_clear_pending(host,
1273 						EVENT_CMD_COMPLETE))
1274 				break;
1275 
1276 			host->cmd = NULL;
1277 			atmci_set_completed(host, EVENT_CMD_COMPLETE);
1278 			atmci_command_complete(host, mrq->cmd);
1279 			if (!mrq->data || cmd->error) {
1280 				atmci_request_end(host, host->mrq);
1281 				goto unlock;
1282 			}
1283 
1284 			prev_state = state = STATE_SENDING_DATA;
1285 			/* fall through */
1286 
1287 		case STATE_SENDING_DATA:
1288 			if (atmci_test_and_clear_pending(host,
1289 						EVENT_DATA_ERROR)) {
1290 				atmci_stop_dma(host);
1291 				if (data->stop)
1292 					send_stop_cmd(host, data);
1293 				state = STATE_DATA_ERROR;
1294 				break;
1295 			}
1296 
1297 			if (!atmci_test_and_clear_pending(host,
1298 						EVENT_XFER_COMPLETE))
1299 				break;
1300 
1301 			atmci_set_completed(host, EVENT_XFER_COMPLETE);
1302 			prev_state = state = STATE_DATA_BUSY;
1303 			/* fall through */
1304 
1305 		case STATE_DATA_BUSY:
1306 			if (!atmci_test_and_clear_pending(host,
1307 						EVENT_DATA_COMPLETE))
1308 				break;
1309 
1310 			host->data = NULL;
1311 			atmci_set_completed(host, EVENT_DATA_COMPLETE);
1312 			status = host->data_status;
1313 			if (unlikely(status & ATMCI_DATA_ERROR_FLAGS)) {
1314 				if (status & MCI_DTOE) {
1315 					dev_dbg(&host->pdev->dev,
1316 							"data timeout error\n");
1317 					data->error = -ETIMEDOUT;
1318 				} else if (status & MCI_DCRCE) {
1319 					dev_dbg(&host->pdev->dev,
1320 							"data CRC error\n");
1321 					data->error = -EILSEQ;
1322 				} else {
1323 					dev_dbg(&host->pdev->dev,
1324 						"data FIFO error (status=%08x)\n",
1325 						status);
1326 					data->error = -EIO;
1327 				}
1328 			} else {
1329 				data->bytes_xfered = data->blocks * data->blksz;
1330 				data->error = 0;
1331 				mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS);
1332 			}
1333 
1334 			if (!data->stop) {
1335 				atmci_request_end(host, host->mrq);
1336 				goto unlock;
1337 			}
1338 
1339 			prev_state = state = STATE_SENDING_STOP;
1340 			if (!data->error)
1341 				send_stop_cmd(host, data);
1342 			/* fall through */
1343 
1344 		case STATE_SENDING_STOP:
1345 			if (!atmci_test_and_clear_pending(host,
1346 						EVENT_CMD_COMPLETE))
1347 				break;
1348 
1349 			host->cmd = NULL;
1350 			atmci_command_complete(host, mrq->stop);
1351 			atmci_request_end(host, host->mrq);
1352 			goto unlock;
1353 
1354 		case STATE_DATA_ERROR:
1355 			if (!atmci_test_and_clear_pending(host,
1356 						EVENT_XFER_COMPLETE))
1357 				break;
1358 
1359 			state = STATE_DATA_BUSY;
1360 			break;
1361 		}
1362 	} while (state != prev_state);
1363 
1364 	host->state = state;
1365 
1366 unlock:
1367 	spin_unlock(&host->lock);
1368 }
1369 
1370 static void atmci_read_data_pio(struct atmel_mci *host)
1371 {
1372 	struct scatterlist	*sg = host->sg;
1373 	void			*buf = sg_virt(sg);
1374 	unsigned int		offset = host->pio_offset;
1375 	struct mmc_data		*data = host->data;
1376 	u32			value;
1377 	u32			status;
1378 	unsigned int		nbytes = 0;
1379 
1380 	do {
1381 		value = mci_readl(host, RDR);
1382 		if (likely(offset + 4 <= sg->length)) {
1383 			put_unaligned(value, (u32 *)(buf + offset));
1384 
1385 			offset += 4;
1386 			nbytes += 4;
1387 
1388 			if (offset == sg->length) {
1389 				flush_dcache_page(sg_page(sg));
1390 				host->sg = sg = sg_next(sg);
1391 				if (!sg)
1392 					goto done;
1393 
1394 				offset = 0;
1395 				buf = sg_virt(sg);
1396 			}
1397 		} else {
1398 			unsigned int remaining = sg->length - offset;
1399 			memcpy(buf + offset, &value, remaining);
1400 			nbytes += remaining;
1401 
1402 			flush_dcache_page(sg_page(sg));
1403 			host->sg = sg = sg_next(sg);
1404 			if (!sg)
1405 				goto done;
1406 
1407 			offset = 4 - remaining;
1408 			buf = sg_virt(sg);
1409 			memcpy(buf, (u8 *)&value + remaining, offset);
1410 			nbytes += offset;
1411 		}
1412 
1413 		status = mci_readl(host, SR);
1414 		if (status & ATMCI_DATA_ERROR_FLAGS) {
1415 			mci_writel(host, IDR, (MCI_NOTBUSY | MCI_RXRDY
1416 						| ATMCI_DATA_ERROR_FLAGS));
1417 			host->data_status = status;
1418 			data->bytes_xfered += nbytes;
1419 			smp_wmb();
1420 			atmci_set_pending(host, EVENT_DATA_ERROR);
1421 			tasklet_schedule(&host->tasklet);
1422 			return;
1423 		}
1424 	} while (status & MCI_RXRDY);
1425 
1426 	host->pio_offset = offset;
1427 	data->bytes_xfered += nbytes;
1428 
1429 	return;
1430 
1431 done:
1432 	mci_writel(host, IDR, MCI_RXRDY);
1433 	mci_writel(host, IER, MCI_NOTBUSY);
1434 	data->bytes_xfered += nbytes;
1435 	smp_wmb();
1436 	atmci_set_pending(host, EVENT_XFER_COMPLETE);
1437 }
1438 
1439 static void atmci_write_data_pio(struct atmel_mci *host)
1440 {
1441 	struct scatterlist	*sg = host->sg;
1442 	void			*buf = sg_virt(sg);
1443 	unsigned int		offset = host->pio_offset;
1444 	struct mmc_data		*data = host->data;
1445 	u32			value;
1446 	u32			status;
1447 	unsigned int		nbytes = 0;
1448 
1449 	do {
1450 		if (likely(offset + 4 <= sg->length)) {
1451 			value = get_unaligned((u32 *)(buf + offset));
1452 			mci_writel(host, TDR, value);
1453 
1454 			offset += 4;
1455 			nbytes += 4;
1456 			if (offset == sg->length) {
1457 				host->sg = sg = sg_next(sg);
1458 				if (!sg)
1459 					goto done;
1460 
1461 				offset = 0;
1462 				buf = sg_virt(sg);
1463 			}
1464 		} else {
1465 			unsigned int remaining = sg->length - offset;
1466 
1467 			value = 0;
1468 			memcpy(&value, buf + offset, remaining);
1469 			nbytes += remaining;
1470 
1471 			host->sg = sg = sg_next(sg);
1472 			if (!sg) {
1473 				mci_writel(host, TDR, value);
1474 				goto done;
1475 			}
1476 
1477 			offset = 4 - remaining;
1478 			buf = sg_virt(sg);
1479 			memcpy((u8 *)&value + remaining, buf, offset);
1480 			mci_writel(host, TDR, value);
1481 			nbytes += offset;
1482 		}
1483 
1484 		status = mci_readl(host, SR);
1485 		if (status & ATMCI_DATA_ERROR_FLAGS) {
1486 			mci_writel(host, IDR, (MCI_NOTBUSY | MCI_TXRDY
1487 						| ATMCI_DATA_ERROR_FLAGS));
1488 			host->data_status = status;
1489 			data->bytes_xfered += nbytes;
1490 			smp_wmb();
1491 			atmci_set_pending(host, EVENT_DATA_ERROR);
1492 			tasklet_schedule(&host->tasklet);
1493 			return;
1494 		}
1495 	} while (status & MCI_TXRDY);
1496 
1497 	host->pio_offset = offset;
1498 	data->bytes_xfered += nbytes;
1499 
1500 	return;
1501 
1502 done:
1503 	mci_writel(host, IDR, MCI_TXRDY);
1504 	mci_writel(host, IER, MCI_NOTBUSY);
1505 	data->bytes_xfered += nbytes;
1506 	smp_wmb();
1507 	atmci_set_pending(host, EVENT_XFER_COMPLETE);
1508 }
1509 
1510 static void atmci_cmd_interrupt(struct atmel_mci *host, u32 status)
1511 {
1512 	mci_writel(host, IDR, MCI_CMDRDY);
1513 
1514 	host->cmd_status = status;
1515 	smp_wmb();
1516 	atmci_set_pending(host, EVENT_CMD_COMPLETE);
1517 	tasklet_schedule(&host->tasklet);
1518 }
1519 
1520 static void atmci_sdio_interrupt(struct atmel_mci *host, u32 status)
1521 {
1522 	int	i;
1523 
1524 	for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
1525 		struct atmel_mci_slot *slot = host->slot[i];
1526 		if (slot && (status & slot->sdio_irq)) {
1527 			mmc_signal_sdio_irq(slot->mmc);
1528 		}
1529 	}
1530 }
1531 
1532 
1533 static irqreturn_t atmci_interrupt(int irq, void *dev_id)
1534 {
1535 	struct atmel_mci	*host = dev_id;
1536 	u32			status, mask, pending;
1537 	unsigned int		pass_count = 0;
1538 
1539 	do {
1540 		status = mci_readl(host, SR);
1541 		mask = mci_readl(host, IMR);
1542 		pending = status & mask;
1543 		if (!pending)
1544 			break;
1545 
1546 		if (pending & ATMCI_DATA_ERROR_FLAGS) {
1547 			mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS
1548 					| MCI_RXRDY | MCI_TXRDY);
1549 			pending &= mci_readl(host, IMR);
1550 
1551 			host->data_status = status;
1552 			smp_wmb();
1553 			atmci_set_pending(host, EVENT_DATA_ERROR);
1554 			tasklet_schedule(&host->tasklet);
1555 		}
1556 		if (pending & MCI_NOTBUSY) {
1557 			mci_writel(host, IDR,
1558 					ATMCI_DATA_ERROR_FLAGS | MCI_NOTBUSY);
1559 			if (!host->data_status)
1560 				host->data_status = status;
1561 			smp_wmb();
1562 			atmci_set_pending(host, EVENT_DATA_COMPLETE);
1563 			tasklet_schedule(&host->tasklet);
1564 		}
1565 		if (pending & MCI_RXRDY)
1566 			atmci_read_data_pio(host);
1567 		if (pending & MCI_TXRDY)
1568 			atmci_write_data_pio(host);
1569 
1570 		if (pending & MCI_CMDRDY)
1571 			atmci_cmd_interrupt(host, status);
1572 
1573 		if (pending & (MCI_SDIOIRQA | MCI_SDIOIRQB))
1574 			atmci_sdio_interrupt(host, status);
1575 
1576 	} while (pass_count++ < 5);
1577 
1578 	return pass_count ? IRQ_HANDLED : IRQ_NONE;
1579 }
1580 
1581 static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id)
1582 {
1583 	struct atmel_mci_slot	*slot = dev_id;
1584 
1585 	/*
1586 	 * Disable interrupts until the pin has stabilized and check
1587 	 * the state then. Use mod_timer() since we may be in the
1588 	 * middle of the timer routine when this interrupt triggers.
1589 	 */
1590 	disable_irq_nosync(irq);
1591 	mod_timer(&slot->detect_timer, jiffies + msecs_to_jiffies(20));
1592 
1593 	return IRQ_HANDLED;
1594 }
1595 
1596 static int __init atmci_init_slot(struct atmel_mci *host,
1597 		struct mci_slot_pdata *slot_data, unsigned int id,
1598 		u32 sdc_reg, u32 sdio_irq)
1599 {
1600 	struct mmc_host			*mmc;
1601 	struct atmel_mci_slot		*slot;
1602 
1603 	mmc = mmc_alloc_host(sizeof(struct atmel_mci_slot), &host->pdev->dev);
1604 	if (!mmc)
1605 		return -ENOMEM;
1606 
1607 	slot = mmc_priv(mmc);
1608 	slot->mmc = mmc;
1609 	slot->host = host;
1610 	slot->detect_pin = slot_data->detect_pin;
1611 	slot->wp_pin = slot_data->wp_pin;
1612 	slot->detect_is_active_high = slot_data->detect_is_active_high;
1613 	slot->sdc_reg = sdc_reg;
1614 	slot->sdio_irq = sdio_irq;
1615 
1616 	mmc->ops = &atmci_ops;
1617 	mmc->f_min = DIV_ROUND_UP(host->bus_hz, 512);
1618 	mmc->f_max = host->bus_hz / 2;
1619 	mmc->ocr_avail	= MMC_VDD_32_33 | MMC_VDD_33_34;
1620 	if (sdio_irq)
1621 		mmc->caps |= MMC_CAP_SDIO_IRQ;
1622 	if (atmci_is_mci2())
1623 		mmc->caps |= MMC_CAP_SD_HIGHSPEED;
1624 	if (slot_data->bus_width >= 4)
1625 		mmc->caps |= MMC_CAP_4_BIT_DATA;
1626 
1627 	mmc->max_segs = 64;
1628 	mmc->max_req_size = 32768 * 512;
1629 	mmc->max_blk_size = 32768;
1630 	mmc->max_blk_count = 512;
1631 
1632 	/* Assume card is present initially */
1633 	set_bit(ATMCI_CARD_PRESENT, &slot->flags);
1634 	if (gpio_is_valid(slot->detect_pin)) {
1635 		if (gpio_request(slot->detect_pin, "mmc_detect")) {
1636 			dev_dbg(&mmc->class_dev, "no detect pin available\n");
1637 			slot->detect_pin = -EBUSY;
1638 		} else if (gpio_get_value(slot->detect_pin) ^
1639 				slot->detect_is_active_high) {
1640 			clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
1641 		}
1642 	}
1643 
1644 	if (!gpio_is_valid(slot->detect_pin))
1645 		mmc->caps |= MMC_CAP_NEEDS_POLL;
1646 
1647 	if (gpio_is_valid(slot->wp_pin)) {
1648 		if (gpio_request(slot->wp_pin, "mmc_wp")) {
1649 			dev_dbg(&mmc->class_dev, "no WP pin available\n");
1650 			slot->wp_pin = -EBUSY;
1651 		}
1652 	}
1653 
1654 	host->slot[id] = slot;
1655 	mmc_add_host(mmc);
1656 
1657 	if (gpio_is_valid(slot->detect_pin)) {
1658 		int ret;
1659 
1660 		setup_timer(&slot->detect_timer, atmci_detect_change,
1661 				(unsigned long)slot);
1662 
1663 		ret = request_irq(gpio_to_irq(slot->detect_pin),
1664 				atmci_detect_interrupt,
1665 				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
1666 				"mmc-detect", slot);
1667 		if (ret) {
1668 			dev_dbg(&mmc->class_dev,
1669 				"could not request IRQ %d for detect pin\n",
1670 				gpio_to_irq(slot->detect_pin));
1671 			gpio_free(slot->detect_pin);
1672 			slot->detect_pin = -EBUSY;
1673 		}
1674 	}
1675 
1676 	atmci_init_debugfs(slot);
1677 
1678 	return 0;
1679 }
1680 
1681 static void __exit atmci_cleanup_slot(struct atmel_mci_slot *slot,
1682 		unsigned int id)
1683 {
1684 	/* Debugfs stuff is cleaned up by mmc core */
1685 
1686 	set_bit(ATMCI_SHUTDOWN, &slot->flags);
1687 	smp_wmb();
1688 
1689 	mmc_remove_host(slot->mmc);
1690 
1691 	if (gpio_is_valid(slot->detect_pin)) {
1692 		int pin = slot->detect_pin;
1693 
1694 		free_irq(gpio_to_irq(pin), slot);
1695 		del_timer_sync(&slot->detect_timer);
1696 		gpio_free(pin);
1697 	}
1698 	if (gpio_is_valid(slot->wp_pin))
1699 		gpio_free(slot->wp_pin);
1700 
1701 	slot->host->slot[id] = NULL;
1702 	mmc_free_host(slot->mmc);
1703 }
1704 
1705 #ifdef CONFIG_MMC_ATMELMCI_DMA
1706 static bool filter(struct dma_chan *chan, void *slave)
1707 {
1708 	struct mci_dma_data	*sl = slave;
1709 
1710 	if (sl && find_slave_dev(sl) == chan->device->dev) {
1711 		chan->private = slave_data_ptr(sl);
1712 		return true;
1713 	} else {
1714 		return false;
1715 	}
1716 }
1717 
1718 static void atmci_configure_dma(struct atmel_mci *host)
1719 {
1720 	struct mci_platform_data	*pdata;
1721 
1722 	if (host == NULL)
1723 		return;
1724 
1725 	pdata = host->pdev->dev.platform_data;
1726 
1727 	if (pdata && find_slave_dev(pdata->dma_slave)) {
1728 		dma_cap_mask_t mask;
1729 
1730 		setup_dma_addr(pdata->dma_slave,
1731 			       host->mapbase + MCI_TDR,
1732 			       host->mapbase + MCI_RDR);
1733 
1734 		/* Try to grab a DMA channel */
1735 		dma_cap_zero(mask);
1736 		dma_cap_set(DMA_SLAVE, mask);
1737 		host->dma.chan =
1738 			dma_request_channel(mask, filter, pdata->dma_slave);
1739 	}
1740 	if (!host->dma.chan)
1741 		dev_notice(&host->pdev->dev, "DMA not available, using PIO\n");
1742 	else
1743 		dev_info(&host->pdev->dev,
1744 					"Using %s for DMA transfers\n",
1745 					dma_chan_name(host->dma.chan));
1746 }
1747 #else
1748 static void atmci_configure_dma(struct atmel_mci *host) {}
1749 #endif
1750 
1751 static int __init atmci_probe(struct platform_device *pdev)
1752 {
1753 	struct mci_platform_data	*pdata;
1754 	struct atmel_mci		*host;
1755 	struct resource			*regs;
1756 	unsigned int			nr_slots;
1757 	int				irq;
1758 	int				ret;
1759 
1760 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1761 	if (!regs)
1762 		return -ENXIO;
1763 	pdata = pdev->dev.platform_data;
1764 	if (!pdata)
1765 		return -ENXIO;
1766 	irq = platform_get_irq(pdev, 0);
1767 	if (irq < 0)
1768 		return irq;
1769 
1770 	host = kzalloc(sizeof(struct atmel_mci), GFP_KERNEL);
1771 	if (!host)
1772 		return -ENOMEM;
1773 
1774 	host->pdev = pdev;
1775 	spin_lock_init(&host->lock);
1776 	INIT_LIST_HEAD(&host->queue);
1777 
1778 	host->mck = clk_get(&pdev->dev, "mci_clk");
1779 	if (IS_ERR(host->mck)) {
1780 		ret = PTR_ERR(host->mck);
1781 		goto err_clk_get;
1782 	}
1783 
1784 	ret = -ENOMEM;
1785 	host->regs = ioremap(regs->start, resource_size(regs));
1786 	if (!host->regs)
1787 		goto err_ioremap;
1788 
1789 	clk_enable(host->mck);
1790 	mci_writel(host, CR, MCI_CR_SWRST);
1791 	host->bus_hz = clk_get_rate(host->mck);
1792 	clk_disable(host->mck);
1793 
1794 	host->mapbase = regs->start;
1795 
1796 	tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)host);
1797 
1798 	ret = request_irq(irq, atmci_interrupt, 0, dev_name(&pdev->dev), host);
1799 	if (ret)
1800 		goto err_request_irq;
1801 
1802 	atmci_configure_dma(host);
1803 
1804 	platform_set_drvdata(pdev, host);
1805 
1806 	/* We need at least one slot to succeed */
1807 	nr_slots = 0;
1808 	ret = -ENODEV;
1809 	if (pdata->slot[0].bus_width) {
1810 		ret = atmci_init_slot(host, &pdata->slot[0],
1811 				0, MCI_SDCSEL_SLOT_A, MCI_SDIOIRQA);
1812 		if (!ret)
1813 			nr_slots++;
1814 	}
1815 	if (pdata->slot[1].bus_width) {
1816 		ret = atmci_init_slot(host, &pdata->slot[1],
1817 				1, MCI_SDCSEL_SLOT_B, MCI_SDIOIRQB);
1818 		if (!ret)
1819 			nr_slots++;
1820 	}
1821 
1822 	if (!nr_slots) {
1823 		dev_err(&pdev->dev, "init failed: no slot defined\n");
1824 		goto err_init_slot;
1825 	}
1826 
1827 	dev_info(&pdev->dev,
1828 			"Atmel MCI controller at 0x%08lx irq %d, %u slots\n",
1829 			host->mapbase, irq, nr_slots);
1830 
1831 	return 0;
1832 
1833 err_init_slot:
1834 #ifdef CONFIG_MMC_ATMELMCI_DMA
1835 	if (host->dma.chan)
1836 		dma_release_channel(host->dma.chan);
1837 #endif
1838 	free_irq(irq, host);
1839 err_request_irq:
1840 	iounmap(host->regs);
1841 err_ioremap:
1842 	clk_put(host->mck);
1843 err_clk_get:
1844 	kfree(host);
1845 	return ret;
1846 }
1847 
1848 static int __exit atmci_remove(struct platform_device *pdev)
1849 {
1850 	struct atmel_mci	*host = platform_get_drvdata(pdev);
1851 	unsigned int		i;
1852 
1853 	platform_set_drvdata(pdev, NULL);
1854 
1855 	for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
1856 		if (host->slot[i])
1857 			atmci_cleanup_slot(host->slot[i], i);
1858 	}
1859 
1860 	clk_enable(host->mck);
1861 	mci_writel(host, IDR, ~0UL);
1862 	mci_writel(host, CR, MCI_CR_MCIDIS);
1863 	mci_readl(host, SR);
1864 	clk_disable(host->mck);
1865 
1866 #ifdef CONFIG_MMC_ATMELMCI_DMA
1867 	if (host->dma.chan)
1868 		dma_release_channel(host->dma.chan);
1869 #endif
1870 
1871 	free_irq(platform_get_irq(pdev, 0), host);
1872 	iounmap(host->regs);
1873 
1874 	clk_put(host->mck);
1875 	kfree(host);
1876 
1877 	return 0;
1878 }
1879 
1880 static struct platform_driver atmci_driver = {
1881 	.remove		= __exit_p(atmci_remove),
1882 	.driver		= {
1883 		.name		= "atmel_mci",
1884 	},
1885 };
1886 
1887 static int __init atmci_init(void)
1888 {
1889 	return platform_driver_probe(&atmci_driver, atmci_probe);
1890 }
1891 
1892 static void __exit atmci_exit(void)
1893 {
1894 	platform_driver_unregister(&atmci_driver);
1895 }
1896 
1897 late_initcall(atmci_init); /* try to load after dma driver when built-in */
1898 module_exit(atmci_exit);
1899 
1900 MODULE_DESCRIPTION("Atmel Multimedia Card Interface driver");
1901 MODULE_AUTHOR("Haavard Skinnemoen <haavard.skinnemoen@atmel.com>");
1902 MODULE_LICENSE("GPL v2");
1903