xref: /openbmc/linux/drivers/mmc/host/atmel-mci.c (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
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/err.h>
15 #include <linux/gpio.h>
16 #include <linux/init.h>
17 #include <linux/interrupt.h>
18 #include <linux/ioport.h>
19 #include <linux/module.h>
20 #include <linux/platform_device.h>
21 #include <linux/scatterlist.h>
22 #include <linux/seq_file.h>
23 #include <linux/stat.h>
24 
25 #include <linux/mmc/host.h>
26 
27 #include <asm/atmel-mci.h>
28 #include <asm/io.h>
29 #include <asm/unaligned.h>
30 
31 #include <asm/arch/board.h>
32 
33 #include "atmel-mci-regs.h"
34 
35 #define ATMCI_DATA_ERROR_FLAGS	(MCI_DCRCE | MCI_DTOE | MCI_OVRE | MCI_UNRE)
36 
37 enum {
38 	EVENT_CMD_COMPLETE = 0,
39 	EVENT_DATA_ERROR,
40 	EVENT_DATA_COMPLETE,
41 	EVENT_STOP_SENT,
42 	EVENT_STOP_COMPLETE,
43 	EVENT_XFER_COMPLETE,
44 };
45 
46 struct atmel_mci {
47 	struct mmc_host		*mmc;
48 	void __iomem		*regs;
49 
50 	struct scatterlist	*sg;
51 	unsigned int		pio_offset;
52 
53 	struct mmc_request	*mrq;
54 	struct mmc_command	*cmd;
55 	struct mmc_data		*data;
56 
57 	u32			cmd_status;
58 	u32			data_status;
59 	u32			stop_status;
60 	u32			stop_cmdr;
61 
62 	u32			mode_reg;
63 	u32			sdc_reg;
64 
65 	struct tasklet_struct	tasklet;
66 	unsigned long		pending_events;
67 	unsigned long		completed_events;
68 
69 	int			present;
70 	int			detect_pin;
71 	int			wp_pin;
72 
73 	/* For detect pin debouncing */
74 	struct timer_list	detect_timer;
75 
76 	unsigned long		bus_hz;
77 	unsigned long		mapbase;
78 	struct clk		*mck;
79 	struct platform_device	*pdev;
80 };
81 
82 #define atmci_is_completed(host, event)				\
83 	test_bit(event, &host->completed_events)
84 #define atmci_test_and_clear_pending(host, event)		\
85 	test_and_clear_bit(event, &host->pending_events)
86 #define atmci_test_and_set_completed(host, event)		\
87 	test_and_set_bit(event, &host->completed_events)
88 #define atmci_set_completed(host, event)			\
89 	set_bit(event, &host->completed_events)
90 #define atmci_set_pending(host, event)				\
91 	set_bit(event, &host->pending_events)
92 #define atmci_clear_pending(host, event)			\
93 	clear_bit(event, &host->pending_events)
94 
95 /*
96  * The debugfs stuff below is mostly optimized away when
97  * CONFIG_DEBUG_FS is not set.
98  */
99 static int atmci_req_show(struct seq_file *s, void *v)
100 {
101 	struct atmel_mci	*host = s->private;
102 	struct mmc_request	*mrq = host->mrq;
103 	struct mmc_command	*cmd;
104 	struct mmc_command	*stop;
105 	struct mmc_data		*data;
106 
107 	/* Make sure we get a consistent snapshot */
108 	spin_lock_irq(&host->mmc->lock);
109 
110 	if (mrq) {
111 		cmd = mrq->cmd;
112 		data = mrq->data;
113 		stop = mrq->stop;
114 
115 		if (cmd)
116 			seq_printf(s,
117 				"CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
118 				cmd->opcode, cmd->arg, cmd->flags,
119 				cmd->resp[0], cmd->resp[1], cmd->resp[2],
120 				cmd->resp[2], cmd->error);
121 		if (data)
122 			seq_printf(s, "DATA %u / %u * %u flg %x err %d\n",
123 				data->bytes_xfered, data->blocks,
124 				data->blksz, data->flags, data->error);
125 		if (stop)
126 			seq_printf(s,
127 				"CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
128 				stop->opcode, stop->arg, stop->flags,
129 				stop->resp[0], stop->resp[1], stop->resp[2],
130 				stop->resp[2], stop->error);
131 	}
132 
133 	spin_unlock_irq(&host->mmc->lock);
134 
135 	return 0;
136 }
137 
138 static int atmci_req_open(struct inode *inode, struct file *file)
139 {
140 	return single_open(file, atmci_req_show, inode->i_private);
141 }
142 
143 static const struct file_operations atmci_req_fops = {
144 	.owner		= THIS_MODULE,
145 	.open		= atmci_req_open,
146 	.read		= seq_read,
147 	.llseek		= seq_lseek,
148 	.release	= single_release,
149 };
150 
151 static void atmci_show_status_reg(struct seq_file *s,
152 		const char *regname, u32 value)
153 {
154 	static const char	*sr_bit[] = {
155 		[0]	= "CMDRDY",
156 		[1]	= "RXRDY",
157 		[2]	= "TXRDY",
158 		[3]	= "BLKE",
159 		[4]	= "DTIP",
160 		[5]	= "NOTBUSY",
161 		[8]	= "SDIOIRQA",
162 		[9]	= "SDIOIRQB",
163 		[16]	= "RINDE",
164 		[17]	= "RDIRE",
165 		[18]	= "RCRCE",
166 		[19]	= "RENDE",
167 		[20]	= "RTOE",
168 		[21]	= "DCRCE",
169 		[22]	= "DTOE",
170 		[30]	= "OVRE",
171 		[31]	= "UNRE",
172 	};
173 	unsigned int		i;
174 
175 	seq_printf(s, "%s:\t0x%08x", regname, value);
176 	for (i = 0; i < ARRAY_SIZE(sr_bit); i++) {
177 		if (value & (1 << i)) {
178 			if (sr_bit[i])
179 				seq_printf(s, " %s", sr_bit[i]);
180 			else
181 				seq_puts(s, " UNKNOWN");
182 		}
183 	}
184 	seq_putc(s, '\n');
185 }
186 
187 static int atmci_regs_show(struct seq_file *s, void *v)
188 {
189 	struct atmel_mci	*host = s->private;
190 	u32			*buf;
191 
192 	buf = kmalloc(MCI_REGS_SIZE, GFP_KERNEL);
193 	if (!buf)
194 		return -ENOMEM;
195 
196 	/* Grab a more or less consistent snapshot */
197 	spin_lock_irq(&host->mmc->lock);
198 	memcpy_fromio(buf, host->regs, MCI_REGS_SIZE);
199 	spin_unlock_irq(&host->mmc->lock);
200 
201 	seq_printf(s, "MR:\t0x%08x%s%s CLKDIV=%u\n",
202 			buf[MCI_MR / 4],
203 			buf[MCI_MR / 4] & MCI_MR_RDPROOF ? " RDPROOF" : "",
204 			buf[MCI_MR / 4] & MCI_MR_WRPROOF ? " WRPROOF" : "",
205 			buf[MCI_MR / 4] & 0xff);
206 	seq_printf(s, "DTOR:\t0x%08x\n", buf[MCI_DTOR / 4]);
207 	seq_printf(s, "SDCR:\t0x%08x\n", buf[MCI_SDCR / 4]);
208 	seq_printf(s, "ARGR:\t0x%08x\n", buf[MCI_ARGR / 4]);
209 	seq_printf(s, "BLKR:\t0x%08x BCNT=%u BLKLEN=%u\n",
210 			buf[MCI_BLKR / 4],
211 			buf[MCI_BLKR / 4] & 0xffff,
212 			(buf[MCI_BLKR / 4] >> 16) & 0xffff);
213 
214 	/* Don't read RSPR and RDR; it will consume the data there */
215 
216 	atmci_show_status_reg(s, "SR", buf[MCI_SR / 4]);
217 	atmci_show_status_reg(s, "IMR", buf[MCI_IMR / 4]);
218 
219 	return 0;
220 }
221 
222 static int atmci_regs_open(struct inode *inode, struct file *file)
223 {
224 	return single_open(file, atmci_regs_show, inode->i_private);
225 }
226 
227 static const struct file_operations atmci_regs_fops = {
228 	.owner		= THIS_MODULE,
229 	.open		= atmci_regs_open,
230 	.read		= seq_read,
231 	.llseek		= seq_lseek,
232 	.release	= single_release,
233 };
234 
235 static void atmci_init_debugfs(struct atmel_mci *host)
236 {
237 	struct mmc_host	*mmc;
238 	struct dentry	*root;
239 	struct dentry	*node;
240 	struct resource	*res;
241 
242 	mmc = host->mmc;
243 	root = mmc->debugfs_root;
244 	if (!root)
245 		return;
246 
247 	node = debugfs_create_file("regs", S_IRUSR, root, host,
248 			&atmci_regs_fops);
249 	if (IS_ERR(node))
250 		return;
251 	if (!node)
252 		goto err;
253 
254 	res = platform_get_resource(host->pdev, IORESOURCE_MEM, 0);
255 	node->d_inode->i_size = res->end - res->start + 1;
256 
257 	node = debugfs_create_file("req", S_IRUSR, root, host, &atmci_req_fops);
258 	if (!node)
259 		goto err;
260 
261 	node = debugfs_create_x32("pending_events", S_IRUSR, root,
262 				     (u32 *)&host->pending_events);
263 	if (!node)
264 		goto err;
265 
266 	node = debugfs_create_x32("completed_events", S_IRUSR, root,
267 				     (u32 *)&host->completed_events);
268 	if (!node)
269 		goto err;
270 
271 	return;
272 
273 err:
274 	dev_err(&host->pdev->dev,
275 		"failed to initialize debugfs for controller\n");
276 }
277 
278 static void atmci_enable(struct atmel_mci *host)
279 {
280 	clk_enable(host->mck);
281 	mci_writel(host, CR, MCI_CR_MCIEN);
282 	mci_writel(host, MR, host->mode_reg);
283 	mci_writel(host, SDCR, host->sdc_reg);
284 }
285 
286 static void atmci_disable(struct atmel_mci *host)
287 {
288 	mci_writel(host, CR, MCI_CR_SWRST);
289 
290 	/* Stall until write is complete, then disable the bus clock */
291 	mci_readl(host, SR);
292 	clk_disable(host->mck);
293 }
294 
295 static inline unsigned int ns_to_clocks(struct atmel_mci *host,
296 					unsigned int ns)
297 {
298 	return (ns * (host->bus_hz / 1000000) + 999) / 1000;
299 }
300 
301 static void atmci_set_timeout(struct atmel_mci *host,
302 			      struct mmc_data *data)
303 {
304 	static unsigned	dtomul_to_shift[] = {
305 		0, 4, 7, 8, 10, 12, 16, 20
306 	};
307 	unsigned	timeout;
308 	unsigned	dtocyc;
309 	unsigned	dtomul;
310 
311 	timeout = ns_to_clocks(host, data->timeout_ns) + data->timeout_clks;
312 
313 	for (dtomul = 0; dtomul < 8; dtomul++) {
314 		unsigned shift = dtomul_to_shift[dtomul];
315 		dtocyc = (timeout + (1 << shift) - 1) >> shift;
316 		if (dtocyc < 15)
317 			break;
318 	}
319 
320 	if (dtomul >= 8) {
321 		dtomul = 7;
322 		dtocyc = 15;
323 	}
324 
325 	dev_vdbg(&host->mmc->class_dev, "setting timeout to %u cycles\n",
326 			dtocyc << dtomul_to_shift[dtomul]);
327 	mci_writel(host, DTOR, (MCI_DTOMUL(dtomul) | MCI_DTOCYC(dtocyc)));
328 }
329 
330 /*
331  * Return mask with command flags to be enabled for this command.
332  */
333 static u32 atmci_prepare_command(struct mmc_host *mmc,
334 				 struct mmc_command *cmd)
335 {
336 	struct mmc_data	*data;
337 	u32		cmdr;
338 
339 	cmd->error = -EINPROGRESS;
340 
341 	cmdr = MCI_CMDR_CMDNB(cmd->opcode);
342 
343 	if (cmd->flags & MMC_RSP_PRESENT) {
344 		if (cmd->flags & MMC_RSP_136)
345 			cmdr |= MCI_CMDR_RSPTYP_136BIT;
346 		else
347 			cmdr |= MCI_CMDR_RSPTYP_48BIT;
348 	}
349 
350 	/*
351 	 * This should really be MAXLAT_5 for CMD2 and ACMD41, but
352 	 * it's too difficult to determine whether this is an ACMD or
353 	 * not. Better make it 64.
354 	 */
355 	cmdr |= MCI_CMDR_MAXLAT_64CYC;
356 
357 	if (mmc->ios.bus_mode == MMC_BUSMODE_OPENDRAIN)
358 		cmdr |= MCI_CMDR_OPDCMD;
359 
360 	data = cmd->data;
361 	if (data) {
362 		cmdr |= MCI_CMDR_START_XFER;
363 		if (data->flags & MMC_DATA_STREAM)
364 			cmdr |= MCI_CMDR_STREAM;
365 		else if (data->blocks > 1)
366 			cmdr |= MCI_CMDR_MULTI_BLOCK;
367 		else
368 			cmdr |= MCI_CMDR_BLOCK;
369 
370 		if (data->flags & MMC_DATA_READ)
371 			cmdr |= MCI_CMDR_TRDIR_READ;
372 	}
373 
374 	return cmdr;
375 }
376 
377 static void atmci_start_command(struct atmel_mci *host,
378 				struct mmc_command *cmd,
379 				u32 cmd_flags)
380 {
381 	/* Must read host->cmd after testing event flags */
382 	smp_rmb();
383 	WARN_ON(host->cmd);
384 	host->cmd = cmd;
385 
386 	dev_vdbg(&host->mmc->class_dev,
387 			"start command: ARGR=0x%08x CMDR=0x%08x\n",
388 			cmd->arg, cmd_flags);
389 
390 	mci_writel(host, ARGR, cmd->arg);
391 	mci_writel(host, CMDR, cmd_flags);
392 }
393 
394 static void send_stop_cmd(struct mmc_host *mmc, struct mmc_data *data)
395 {
396 	struct atmel_mci *host = mmc_priv(mmc);
397 
398 	atmci_start_command(host, data->stop, host->stop_cmdr);
399 	mci_writel(host, IER, MCI_CMDRDY);
400 }
401 
402 static void atmci_request_end(struct mmc_host *mmc, struct mmc_request *mrq)
403 {
404 	struct atmel_mci *host = mmc_priv(mmc);
405 
406 	WARN_ON(host->cmd || host->data);
407 	host->mrq = NULL;
408 
409 	atmci_disable(host);
410 
411 	mmc_request_done(mmc, mrq);
412 }
413 
414 /*
415  * Returns a mask of interrupt flags to be enabled after the whole
416  * request has been prepared.
417  */
418 static u32 atmci_submit_data(struct mmc_host *mmc, struct mmc_data *data)
419 {
420 	struct atmel_mci	*host = mmc_priv(mmc);
421 	u32			iflags;
422 
423 	data->error = -EINPROGRESS;
424 
425 	WARN_ON(host->data);
426 	host->sg = NULL;
427 	host->data = data;
428 
429 	mci_writel(host, BLKR, MCI_BCNT(data->blocks)
430 			| MCI_BLKLEN(data->blksz));
431 	dev_vdbg(&mmc->class_dev, "BLKR=0x%08x\n",
432 			MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz));
433 
434 	iflags = ATMCI_DATA_ERROR_FLAGS;
435 	host->sg = data->sg;
436 	host->pio_offset = 0;
437 	if (data->flags & MMC_DATA_READ)
438 		iflags |= MCI_RXRDY;
439 	else
440 		iflags |= MCI_TXRDY;
441 
442 	return iflags;
443 }
444 
445 static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
446 {
447 	struct atmel_mci	*host = mmc_priv(mmc);
448 	struct mmc_data		*data;
449 	struct mmc_command	*cmd;
450 	u32			iflags;
451 	u32			cmdflags = 0;
452 
453 	iflags = mci_readl(host, IMR);
454 	if (iflags)
455 		dev_warn(&mmc->class_dev, "WARNING: IMR=0x%08x\n",
456 				mci_readl(host, IMR));
457 
458 	WARN_ON(host->mrq != NULL);
459 
460 	/*
461 	 * We may "know" the card is gone even though there's still an
462 	 * electrical connection. If so, we really need to communicate
463 	 * this to the MMC core since there won't be any more
464 	 * interrupts as the card is completely removed. Otherwise,
465 	 * the MMC core might believe the card is still there even
466 	 * though the card was just removed very slowly.
467 	 */
468 	if (!host->present) {
469 		mrq->cmd->error = -ENOMEDIUM;
470 		mmc_request_done(mmc, mrq);
471 		return;
472 	}
473 
474 	host->mrq = mrq;
475 	host->pending_events = 0;
476 	host->completed_events = 0;
477 
478 	atmci_enable(host);
479 
480 	/* We don't support multiple blocks of weird lengths. */
481 	data = mrq->data;
482 	if (data) {
483 		if (data->blocks > 1 && data->blksz & 3)
484 			goto fail;
485 		atmci_set_timeout(host, data);
486 	}
487 
488 	iflags = MCI_CMDRDY;
489 	cmd = mrq->cmd;
490 	cmdflags = atmci_prepare_command(mmc, cmd);
491 	atmci_start_command(host, cmd, cmdflags);
492 
493 	if (data)
494 		iflags |= atmci_submit_data(mmc, data);
495 
496 	if (mrq->stop) {
497 		host->stop_cmdr = atmci_prepare_command(mmc, mrq->stop);
498 		host->stop_cmdr |= MCI_CMDR_STOP_XFER;
499 		if (!(data->flags & MMC_DATA_WRITE))
500 			host->stop_cmdr |= MCI_CMDR_TRDIR_READ;
501 		if (data->flags & MMC_DATA_STREAM)
502 			host->stop_cmdr |= MCI_CMDR_STREAM;
503 		else
504 			host->stop_cmdr |= MCI_CMDR_MULTI_BLOCK;
505 	}
506 
507 	/*
508 	 * We could have enabled interrupts earlier, but I suspect
509 	 * that would open up a nice can of interesting race
510 	 * conditions (e.g. command and data complete, but stop not
511 	 * prepared yet.)
512 	 */
513 	mci_writel(host, IER, iflags);
514 
515 	return;
516 
517 fail:
518 	atmci_disable(host);
519 	host->mrq = NULL;
520 	mrq->cmd->error = -EINVAL;
521 	mmc_request_done(mmc, mrq);
522 }
523 
524 static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
525 {
526 	struct atmel_mci	*host = mmc_priv(mmc);
527 
528 	if (ios->clock) {
529 		u32 clkdiv;
530 
531 		/* Set clock rate */
532 		clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * ios->clock) - 1;
533 		if (clkdiv > 255) {
534 			dev_warn(&mmc->class_dev,
535 				"clock %u too slow; using %lu\n",
536 				ios->clock, host->bus_hz / (2 * 256));
537 			clkdiv = 255;
538 		}
539 
540 		host->mode_reg = MCI_MR_CLKDIV(clkdiv) | MCI_MR_WRPROOF
541 					| MCI_MR_RDPROOF;
542 	}
543 
544 	switch (ios->bus_width) {
545 	case MMC_BUS_WIDTH_1:
546 		host->sdc_reg = 0;
547 		break;
548 	case MMC_BUS_WIDTH_4:
549 		host->sdc_reg = MCI_SDCBUS_4BIT;
550 		break;
551 	}
552 
553 	switch (ios->power_mode) {
554 	case MMC_POWER_ON:
555 		/* Send init sequence (74 clock cycles) */
556 		atmci_enable(host);
557 		mci_writel(host, CMDR, MCI_CMDR_SPCMD_INIT);
558 		while (!(mci_readl(host, SR) & MCI_CMDRDY))
559 			cpu_relax();
560 		atmci_disable(host);
561 		break;
562 	default:
563 		/*
564 		 * TODO: None of the currently available AVR32-based
565 		 * boards allow MMC power to be turned off. Implement
566 		 * power control when this can be tested properly.
567 		 */
568 		break;
569 	}
570 }
571 
572 static int atmci_get_ro(struct mmc_host *mmc)
573 {
574 	int			read_only = 0;
575 	struct atmel_mci	*host = mmc_priv(mmc);
576 
577 	if (gpio_is_valid(host->wp_pin)) {
578 		read_only = gpio_get_value(host->wp_pin);
579 		dev_dbg(&mmc->class_dev, "card is %s\n",
580 				read_only ? "read-only" : "read-write");
581 	} else {
582 		dev_dbg(&mmc->class_dev,
583 			"no pin for checking read-only switch."
584 			" Assuming write-enable.\n");
585 	}
586 
587 	return read_only;
588 }
589 
590 static struct mmc_host_ops atmci_ops = {
591 	.request	= atmci_request,
592 	.set_ios	= atmci_set_ios,
593 	.get_ro		= atmci_get_ro,
594 };
595 
596 static void atmci_command_complete(struct atmel_mci *host,
597 			struct mmc_command *cmd, u32 status)
598 {
599 	/* Read the response from the card (up to 16 bytes) */
600 	cmd->resp[0] = mci_readl(host, RSPR);
601 	cmd->resp[1] = mci_readl(host, RSPR);
602 	cmd->resp[2] = mci_readl(host, RSPR);
603 	cmd->resp[3] = mci_readl(host, RSPR);
604 
605 	if (status & MCI_RTOE)
606 		cmd->error = -ETIMEDOUT;
607 	else if ((cmd->flags & MMC_RSP_CRC) && (status & MCI_RCRCE))
608 		cmd->error = -EILSEQ;
609 	else if (status & (MCI_RINDE | MCI_RDIRE | MCI_RENDE))
610 		cmd->error = -EIO;
611 	else
612 		cmd->error = 0;
613 
614 	if (cmd->error) {
615 		dev_dbg(&host->mmc->class_dev,
616 			"command error: status=0x%08x\n", status);
617 
618 		if (cmd->data) {
619 			host->data = NULL;
620 			mci_writel(host, IDR, MCI_NOTBUSY
621 					| MCI_TXRDY | MCI_RXRDY
622 					| ATMCI_DATA_ERROR_FLAGS);
623 		}
624 	}
625 }
626 
627 static void atmci_detect_change(unsigned long data)
628 {
629 	struct atmel_mci *host = (struct atmel_mci *)data;
630 	struct mmc_request *mrq = host->mrq;
631 	int present;
632 
633 	/*
634 	 * atmci_remove() sets detect_pin to -1 before freeing the
635 	 * interrupt. We must not re-enable the interrupt if it has
636 	 * been freed.
637 	 */
638 	smp_rmb();
639 	if (!gpio_is_valid(host->detect_pin))
640 		return;
641 
642 	enable_irq(gpio_to_irq(host->detect_pin));
643 	present = !gpio_get_value(host->detect_pin);
644 
645 	dev_vdbg(&host->pdev->dev, "detect change: %d (was %d)\n",
646 			present, host->present);
647 
648 	if (present != host->present) {
649 		dev_dbg(&host->mmc->class_dev, "card %s\n",
650 			present ? "inserted" : "removed");
651 		host->present = present;
652 
653 		/* Reset controller if card is gone */
654 		if (!present) {
655 			mci_writel(host, CR, MCI_CR_SWRST);
656 			mci_writel(host, IDR, ~0UL);
657 			mci_writel(host, CR, MCI_CR_MCIEN);
658 		}
659 
660 		/* Clean up queue if present */
661 		if (mrq) {
662 			/*
663 			 * Reset controller to terminate any ongoing
664 			 * commands or data transfers.
665 			 */
666 			mci_writel(host, CR, MCI_CR_SWRST);
667 
668 			if (!atmci_is_completed(host, EVENT_CMD_COMPLETE))
669 				mrq->cmd->error = -ENOMEDIUM;
670 
671 			if (mrq->data && !atmci_is_completed(host,
672 						EVENT_DATA_COMPLETE)) {
673 				host->data = NULL;
674 				mrq->data->error = -ENOMEDIUM;
675 			}
676 			if (mrq->stop && !atmci_is_completed(host,
677 						EVENT_STOP_COMPLETE))
678 				mrq->stop->error = -ENOMEDIUM;
679 
680 			host->cmd = NULL;
681 			atmci_request_end(host->mmc, mrq);
682 		}
683 
684 		mmc_detect_change(host->mmc, 0);
685 	}
686 }
687 
688 static void atmci_tasklet_func(unsigned long priv)
689 {
690 	struct mmc_host		*mmc = (struct mmc_host *)priv;
691 	struct atmel_mci	*host = mmc_priv(mmc);
692 	struct mmc_request	*mrq = host->mrq;
693 	struct mmc_data		*data = host->data;
694 
695 	dev_vdbg(&mmc->class_dev,
696 		"tasklet: pending/completed/mask %lx/%lx/%x\n",
697 		host->pending_events, host->completed_events,
698 		mci_readl(host, IMR));
699 
700 	if (atmci_test_and_clear_pending(host, EVENT_CMD_COMPLETE)) {
701 		/*
702 		 * host->cmd must be set to NULL before the interrupt
703 		 * handler sees EVENT_CMD_COMPLETE
704 		 */
705 		host->cmd = NULL;
706 		smp_wmb();
707 		atmci_set_completed(host, EVENT_CMD_COMPLETE);
708 		atmci_command_complete(host, mrq->cmd, host->cmd_status);
709 
710 		if (!mrq->cmd->error && mrq->stop
711 				&& atmci_is_completed(host, EVENT_XFER_COMPLETE)
712 				&& !atmci_test_and_set_completed(host,
713 					EVENT_STOP_SENT))
714 			send_stop_cmd(host->mmc, mrq->data);
715 	}
716 	if (atmci_test_and_clear_pending(host, EVENT_STOP_COMPLETE)) {
717 		/*
718 		 * host->cmd must be set to NULL before the interrupt
719 		 * handler sees EVENT_STOP_COMPLETE
720 		 */
721 		host->cmd = NULL;
722 		smp_wmb();
723 		atmci_set_completed(host, EVENT_STOP_COMPLETE);
724 		atmci_command_complete(host, mrq->stop, host->stop_status);
725 	}
726 	if (atmci_test_and_clear_pending(host, EVENT_DATA_ERROR)) {
727 		u32 status = host->data_status;
728 
729 		dev_vdbg(&mmc->class_dev, "data error: status=%08x\n", status);
730 
731 		atmci_set_completed(host, EVENT_DATA_ERROR);
732 		atmci_set_completed(host, EVENT_DATA_COMPLETE);
733 
734 		if (status & MCI_DTOE) {
735 			dev_dbg(&mmc->class_dev,
736 					"data timeout error\n");
737 			data->error = -ETIMEDOUT;
738 		} else if (status & MCI_DCRCE) {
739 			dev_dbg(&mmc->class_dev, "data CRC error\n");
740 			data->error = -EILSEQ;
741 		} else {
742 			dev_dbg(&mmc->class_dev,
743 					"data FIFO error (status=%08x)\n",
744 					status);
745 			data->error = -EIO;
746 		}
747 
748 		if (host->present && data->stop
749 				&& atmci_is_completed(host, EVENT_CMD_COMPLETE)
750 				&& !atmci_test_and_set_completed(
751 					host, EVENT_STOP_SENT))
752 			send_stop_cmd(host->mmc, data);
753 
754 		host->data = NULL;
755 	}
756 	if (atmci_test_and_clear_pending(host, EVENT_DATA_COMPLETE)) {
757 		atmci_set_completed(host, EVENT_DATA_COMPLETE);
758 
759 		if (!atmci_is_completed(host, EVENT_DATA_ERROR)) {
760 			data->bytes_xfered = data->blocks * data->blksz;
761 			data->error = 0;
762 		}
763 
764 		host->data = NULL;
765 	}
766 
767 	if (host->mrq && !host->cmd && !host->data)
768 		atmci_request_end(mmc, host->mrq);
769 }
770 
771 static void atmci_read_data_pio(struct atmel_mci *host)
772 {
773 	struct scatterlist	*sg = host->sg;
774 	void			*buf = sg_virt(sg);
775 	unsigned int		offset = host->pio_offset;
776 	struct mmc_data		*data = host->data;
777 	u32			value;
778 	u32			status;
779 	unsigned int		nbytes = 0;
780 
781 	do {
782 		value = mci_readl(host, RDR);
783 		if (likely(offset + 4 <= sg->length)) {
784 			put_unaligned(value, (u32 *)(buf + offset));
785 
786 			offset += 4;
787 			nbytes += 4;
788 
789 			if (offset == sg->length) {
790 				host->sg = sg = sg_next(sg);
791 				if (!sg)
792 					goto done;
793 
794 				offset = 0;
795 				buf = sg_virt(sg);
796 			}
797 		} else {
798 			unsigned int remaining = sg->length - offset;
799 			memcpy(buf + offset, &value, remaining);
800 			nbytes += remaining;
801 
802 			flush_dcache_page(sg_page(sg));
803 			host->sg = sg = sg_next(sg);
804 			if (!sg)
805 				goto done;
806 
807 			offset = 4 - remaining;
808 			buf = sg_virt(sg);
809 			memcpy(buf, (u8 *)&value + remaining, offset);
810 			nbytes += offset;
811 		}
812 
813 		status = mci_readl(host, SR);
814 		if (status & ATMCI_DATA_ERROR_FLAGS) {
815 			mci_writel(host, IDR, (MCI_NOTBUSY | MCI_RXRDY
816 						| ATMCI_DATA_ERROR_FLAGS));
817 			host->data_status = status;
818 			atmci_set_pending(host, EVENT_DATA_ERROR);
819 			tasklet_schedule(&host->tasklet);
820 			break;
821 		}
822 	} while (status & MCI_RXRDY);
823 
824 	host->pio_offset = offset;
825 	data->bytes_xfered += nbytes;
826 
827 	return;
828 
829 done:
830 	mci_writel(host, IDR, MCI_RXRDY);
831 	mci_writel(host, IER, MCI_NOTBUSY);
832 	data->bytes_xfered += nbytes;
833 	atmci_set_completed(host, EVENT_XFER_COMPLETE);
834 	if (data->stop && atmci_is_completed(host, EVENT_CMD_COMPLETE)
835 			&& !atmci_test_and_set_completed(host, EVENT_STOP_SENT))
836 		send_stop_cmd(host->mmc, data);
837 }
838 
839 static void atmci_write_data_pio(struct atmel_mci *host)
840 {
841 	struct scatterlist	*sg = host->sg;
842 	void			*buf = sg_virt(sg);
843 	unsigned int		offset = host->pio_offset;
844 	struct mmc_data		*data = host->data;
845 	u32			value;
846 	u32			status;
847 	unsigned int		nbytes = 0;
848 
849 	do {
850 		if (likely(offset + 4 <= sg->length)) {
851 			value = get_unaligned((u32 *)(buf + offset));
852 			mci_writel(host, TDR, value);
853 
854 			offset += 4;
855 			nbytes += 4;
856 			if (offset == sg->length) {
857 				host->sg = sg = sg_next(sg);
858 				if (!sg)
859 					goto done;
860 
861 				offset = 0;
862 				buf = sg_virt(sg);
863 			}
864 		} else {
865 			unsigned int remaining = sg->length - offset;
866 
867 			value = 0;
868 			memcpy(&value, buf + offset, remaining);
869 			nbytes += remaining;
870 
871 			host->sg = sg = sg_next(sg);
872 			if (!sg) {
873 				mci_writel(host, TDR, value);
874 				goto done;
875 			}
876 
877 			offset = 4 - remaining;
878 			buf = sg_virt(sg);
879 			memcpy((u8 *)&value + remaining, buf, offset);
880 			mci_writel(host, TDR, value);
881 			nbytes += offset;
882 		}
883 
884 		status = mci_readl(host, SR);
885 		if (status & ATMCI_DATA_ERROR_FLAGS) {
886 			mci_writel(host, IDR, (MCI_NOTBUSY | MCI_TXRDY
887 						| ATMCI_DATA_ERROR_FLAGS));
888 			host->data_status = status;
889 			atmci_set_pending(host, EVENT_DATA_ERROR);
890 			tasklet_schedule(&host->tasklet);
891 			break;
892 		}
893 	} while (status & MCI_TXRDY);
894 
895 	host->pio_offset = offset;
896 	data->bytes_xfered += nbytes;
897 
898 	return;
899 
900 done:
901 	mci_writel(host, IDR, MCI_TXRDY);
902 	mci_writel(host, IER, MCI_NOTBUSY);
903 	data->bytes_xfered += nbytes;
904 	atmci_set_completed(host, EVENT_XFER_COMPLETE);
905 	if (data->stop && atmci_is_completed(host, EVENT_CMD_COMPLETE)
906 			&& !atmci_test_and_set_completed(host, EVENT_STOP_SENT))
907 		send_stop_cmd(host->mmc, data);
908 }
909 
910 static void atmci_cmd_interrupt(struct mmc_host *mmc, u32 status)
911 {
912 	struct atmel_mci	*host = mmc_priv(mmc);
913 
914 	mci_writel(host, IDR, MCI_CMDRDY);
915 
916 	if (atmci_is_completed(host, EVENT_STOP_SENT)) {
917 		host->stop_status = status;
918 		atmci_set_pending(host, EVENT_STOP_COMPLETE);
919 	} else {
920 		host->cmd_status = status;
921 		atmci_set_pending(host, EVENT_CMD_COMPLETE);
922 	}
923 
924 	tasklet_schedule(&host->tasklet);
925 }
926 
927 static irqreturn_t atmci_interrupt(int irq, void *dev_id)
928 {
929 	struct mmc_host		*mmc = dev_id;
930 	struct atmel_mci	*host = mmc_priv(mmc);
931 	u32			status, mask, pending;
932 	unsigned int		pass_count = 0;
933 
934 	spin_lock(&mmc->lock);
935 
936 	do {
937 		status = mci_readl(host, SR);
938 		mask = mci_readl(host, IMR);
939 		pending = status & mask;
940 		if (!pending)
941 			break;
942 
943 		if (pending & ATMCI_DATA_ERROR_FLAGS) {
944 			mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS
945 					| MCI_RXRDY | MCI_TXRDY);
946 			pending &= mci_readl(host, IMR);
947 			host->data_status = status;
948 			atmci_set_pending(host, EVENT_DATA_ERROR);
949 			tasklet_schedule(&host->tasklet);
950 		}
951 		if (pending & MCI_NOTBUSY) {
952 			mci_writel(host, IDR, (MCI_NOTBUSY
953 					       | ATMCI_DATA_ERROR_FLAGS));
954 			atmci_set_pending(host, EVENT_DATA_COMPLETE);
955 			tasklet_schedule(&host->tasklet);
956 		}
957 		if (pending & MCI_RXRDY)
958 			atmci_read_data_pio(host);
959 		if (pending & MCI_TXRDY)
960 			atmci_write_data_pio(host);
961 
962 		if (pending & MCI_CMDRDY)
963 			atmci_cmd_interrupt(mmc, status);
964 	} while (pass_count++ < 5);
965 
966 	spin_unlock(&mmc->lock);
967 
968 	return pass_count ? IRQ_HANDLED : IRQ_NONE;
969 }
970 
971 static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id)
972 {
973 	struct mmc_host		*mmc = dev_id;
974 	struct atmel_mci	*host = mmc_priv(mmc);
975 
976 	/*
977 	 * Disable interrupts until the pin has stabilized and check
978 	 * the state then. Use mod_timer() since we may be in the
979 	 * middle of the timer routine when this interrupt triggers.
980 	 */
981 	disable_irq_nosync(irq);
982 	mod_timer(&host->detect_timer, jiffies + msecs_to_jiffies(20));
983 
984 	return IRQ_HANDLED;
985 }
986 
987 static int __init atmci_probe(struct platform_device *pdev)
988 {
989 	struct mci_platform_data	*pdata;
990 	struct atmel_mci *host;
991 	struct mmc_host *mmc;
992 	struct resource *regs;
993 	int irq;
994 	int ret;
995 
996 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
997 	if (!regs)
998 		return -ENXIO;
999 	pdata = pdev->dev.platform_data;
1000 	if (!pdata)
1001 		return -ENXIO;
1002 	irq = platform_get_irq(pdev, 0);
1003 	if (irq < 0)
1004 		return irq;
1005 
1006 	mmc = mmc_alloc_host(sizeof(struct atmel_mci), &pdev->dev);
1007 	if (!mmc)
1008 		return -ENOMEM;
1009 
1010 	host = mmc_priv(mmc);
1011 	host->pdev = pdev;
1012 	host->mmc = mmc;
1013 	host->detect_pin = pdata->detect_pin;
1014 	host->wp_pin = pdata->wp_pin;
1015 
1016 	host->mck = clk_get(&pdev->dev, "mci_clk");
1017 	if (IS_ERR(host->mck)) {
1018 		ret = PTR_ERR(host->mck);
1019 		goto err_clk_get;
1020 	}
1021 
1022 	ret = -ENOMEM;
1023 	host->regs = ioremap(regs->start, regs->end - regs->start + 1);
1024 	if (!host->regs)
1025 		goto err_ioremap;
1026 
1027 	clk_enable(host->mck);
1028 	mci_writel(host, CR, MCI_CR_SWRST);
1029 	host->bus_hz = clk_get_rate(host->mck);
1030 	clk_disable(host->mck);
1031 
1032 	host->mapbase = regs->start;
1033 
1034 	mmc->ops = &atmci_ops;
1035 	mmc->f_min = (host->bus_hz + 511) / 512;
1036 	mmc->f_max = host->bus_hz / 2;
1037 	mmc->ocr_avail	= MMC_VDD_32_33 | MMC_VDD_33_34;
1038 	mmc->caps |= MMC_CAP_4_BIT_DATA;
1039 
1040 	mmc->max_hw_segs = 64;
1041 	mmc->max_phys_segs = 64;
1042 	mmc->max_req_size = 32768 * 512;
1043 	mmc->max_blk_size = 32768;
1044 	mmc->max_blk_count = 512;
1045 
1046 	tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)mmc);
1047 
1048 	ret = request_irq(irq, atmci_interrupt, 0, pdev->dev.bus_id, mmc);
1049 	if (ret)
1050 		goto err_request_irq;
1051 
1052 	/* Assume card is present if we don't have a detect pin */
1053 	host->present = 1;
1054 	if (gpio_is_valid(host->detect_pin)) {
1055 		if (gpio_request(host->detect_pin, "mmc_detect")) {
1056 			dev_dbg(&mmc->class_dev, "no detect pin available\n");
1057 			host->detect_pin = -1;
1058 		} else {
1059 			host->present = !gpio_get_value(host->detect_pin);
1060 		}
1061 	}
1062 	if (gpio_is_valid(host->wp_pin)) {
1063 		if (gpio_request(host->wp_pin, "mmc_wp")) {
1064 			dev_dbg(&mmc->class_dev, "no WP pin available\n");
1065 			host->wp_pin = -1;
1066 		}
1067 	}
1068 
1069 	platform_set_drvdata(pdev, host);
1070 
1071 	mmc_add_host(mmc);
1072 
1073 	if (gpio_is_valid(host->detect_pin)) {
1074 		setup_timer(&host->detect_timer, atmci_detect_change,
1075 				(unsigned long)host);
1076 
1077 		ret = request_irq(gpio_to_irq(host->detect_pin),
1078 				atmci_detect_interrupt,
1079 				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
1080 				"mmc-detect", mmc);
1081 		if (ret) {
1082 			dev_dbg(&mmc->class_dev,
1083 				"could not request IRQ %d for detect pin\n",
1084 				gpio_to_irq(host->detect_pin));
1085 			gpio_free(host->detect_pin);
1086 			host->detect_pin = -1;
1087 		}
1088 	}
1089 
1090 	dev_info(&mmc->class_dev,
1091 			"Atmel MCI controller at 0x%08lx irq %d\n",
1092 			host->mapbase, irq);
1093 
1094 	atmci_init_debugfs(host);
1095 
1096 	return 0;
1097 
1098 err_request_irq:
1099 	iounmap(host->regs);
1100 err_ioremap:
1101 	clk_put(host->mck);
1102 err_clk_get:
1103 	mmc_free_host(mmc);
1104 	return ret;
1105 }
1106 
1107 static int __exit atmci_remove(struct platform_device *pdev)
1108 {
1109 	struct atmel_mci *host = platform_get_drvdata(pdev);
1110 
1111 	platform_set_drvdata(pdev, NULL);
1112 
1113 	if (host) {
1114 		/* Debugfs stuff is cleaned up by mmc core */
1115 
1116 		if (gpio_is_valid(host->detect_pin)) {
1117 			int pin = host->detect_pin;
1118 
1119 			/* Make sure the timer doesn't enable the interrupt */
1120 			host->detect_pin = -1;
1121 			smp_wmb();
1122 
1123 			free_irq(gpio_to_irq(pin), host->mmc);
1124 			del_timer_sync(&host->detect_timer);
1125 			gpio_free(pin);
1126 		}
1127 
1128 		mmc_remove_host(host->mmc);
1129 
1130 		clk_enable(host->mck);
1131 		mci_writel(host, IDR, ~0UL);
1132 		mci_writel(host, CR, MCI_CR_MCIDIS);
1133 		mci_readl(host, SR);
1134 		clk_disable(host->mck);
1135 
1136 		if (gpio_is_valid(host->wp_pin))
1137 			gpio_free(host->wp_pin);
1138 
1139 		free_irq(platform_get_irq(pdev, 0), host->mmc);
1140 		iounmap(host->regs);
1141 
1142 		clk_put(host->mck);
1143 
1144 		mmc_free_host(host->mmc);
1145 	}
1146 	return 0;
1147 }
1148 
1149 static struct platform_driver atmci_driver = {
1150 	.remove		= __exit_p(atmci_remove),
1151 	.driver		= {
1152 		.name		= "atmel_mci",
1153 	},
1154 };
1155 
1156 static int __init atmci_init(void)
1157 {
1158 	return platform_driver_probe(&atmci_driver, atmci_probe);
1159 }
1160 
1161 static void __exit atmci_exit(void)
1162 {
1163 	platform_driver_unregister(&atmci_driver);
1164 }
1165 
1166 module_init(atmci_init);
1167 module_exit(atmci_exit);
1168 
1169 MODULE_DESCRIPTION("Atmel Multimedia Card Interface driver");
1170 MODULE_AUTHOR("Haavard Skinnemoen <haavard.skinnemoen@atmel.com>");
1171 MODULE_LICENSE("GPL v2");
1172