xref: /openbmc/linux/drivers/mmc/host/atmel-mci.c (revision 384740dc)
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 <mach/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 	clk_enable(host->mck);
199 	memcpy_fromio(buf, host->regs, MCI_REGS_SIZE);
200 	clk_disable(host->mck);
201 	spin_unlock_irq(&host->mmc->lock);
202 
203 	seq_printf(s, "MR:\t0x%08x%s%s CLKDIV=%u\n",
204 			buf[MCI_MR / 4],
205 			buf[MCI_MR / 4] & MCI_MR_RDPROOF ? " RDPROOF" : "",
206 			buf[MCI_MR / 4] & MCI_MR_WRPROOF ? " WRPROOF" : "",
207 			buf[MCI_MR / 4] & 0xff);
208 	seq_printf(s, "DTOR:\t0x%08x\n", buf[MCI_DTOR / 4]);
209 	seq_printf(s, "SDCR:\t0x%08x\n", buf[MCI_SDCR / 4]);
210 	seq_printf(s, "ARGR:\t0x%08x\n", buf[MCI_ARGR / 4]);
211 	seq_printf(s, "BLKR:\t0x%08x BCNT=%u BLKLEN=%u\n",
212 			buf[MCI_BLKR / 4],
213 			buf[MCI_BLKR / 4] & 0xffff,
214 			(buf[MCI_BLKR / 4] >> 16) & 0xffff);
215 
216 	/* Don't read RSPR and RDR; it will consume the data there */
217 
218 	atmci_show_status_reg(s, "SR", buf[MCI_SR / 4]);
219 	atmci_show_status_reg(s, "IMR", buf[MCI_IMR / 4]);
220 
221 	kfree(buf);
222 
223 	return 0;
224 }
225 
226 static int atmci_regs_open(struct inode *inode, struct file *file)
227 {
228 	return single_open(file, atmci_regs_show, inode->i_private);
229 }
230 
231 static const struct file_operations atmci_regs_fops = {
232 	.owner		= THIS_MODULE,
233 	.open		= atmci_regs_open,
234 	.read		= seq_read,
235 	.llseek		= seq_lseek,
236 	.release	= single_release,
237 };
238 
239 static void atmci_init_debugfs(struct atmel_mci *host)
240 {
241 	struct mmc_host	*mmc;
242 	struct dentry	*root;
243 	struct dentry	*node;
244 
245 	mmc = host->mmc;
246 	root = mmc->debugfs_root;
247 	if (!root)
248 		return;
249 
250 	node = debugfs_create_file("regs", S_IRUSR, root, host,
251 			&atmci_regs_fops);
252 	if (IS_ERR(node))
253 		return;
254 	if (!node)
255 		goto err;
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 	dev_vdbg(&mmc->class_dev, "BLKR=0x%08x\n",
430 			MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz));
431 
432 	iflags = ATMCI_DATA_ERROR_FLAGS;
433 	host->sg = data->sg;
434 	host->pio_offset = 0;
435 	if (data->flags & MMC_DATA_READ)
436 		iflags |= MCI_RXRDY;
437 	else
438 		iflags |= MCI_TXRDY;
439 
440 	return iflags;
441 }
442 
443 static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
444 {
445 	struct atmel_mci	*host = mmc_priv(mmc);
446 	struct mmc_data		*data;
447 	struct mmc_command	*cmd;
448 	u32			iflags;
449 	u32			cmdflags = 0;
450 
451 	iflags = mci_readl(host, IMR);
452 	if (iflags)
453 		dev_warn(&mmc->class_dev, "WARNING: IMR=0x%08x\n",
454 				mci_readl(host, IMR));
455 
456 	WARN_ON(host->mrq != NULL);
457 
458 	/*
459 	 * We may "know" the card is gone even though there's still an
460 	 * electrical connection. If so, we really need to communicate
461 	 * this to the MMC core since there won't be any more
462 	 * interrupts as the card is completely removed. Otherwise,
463 	 * the MMC core might believe the card is still there even
464 	 * though the card was just removed very slowly.
465 	 */
466 	if (!host->present) {
467 		mrq->cmd->error = -ENOMEDIUM;
468 		mmc_request_done(mmc, mrq);
469 		return;
470 	}
471 
472 	host->mrq = mrq;
473 	host->pending_events = 0;
474 	host->completed_events = 0;
475 
476 	atmci_enable(host);
477 
478 	/* We don't support multiple blocks of weird lengths. */
479 	data = mrq->data;
480 	if (data) {
481 		if (data->blocks > 1 && data->blksz & 3)
482 			goto fail;
483 		atmci_set_timeout(host, data);
484 
485 		/* Must set block count/size before sending command */
486 		mci_writel(host, BLKR, MCI_BCNT(data->blocks)
487 				| MCI_BLKLEN(data->blksz));
488 	}
489 
490 	iflags = MCI_CMDRDY;
491 	cmd = mrq->cmd;
492 	cmdflags = atmci_prepare_command(mmc, cmd);
493 	atmci_start_command(host, cmd, cmdflags);
494 
495 	if (data)
496 		iflags |= atmci_submit_data(mmc, data);
497 
498 	if (mrq->stop) {
499 		host->stop_cmdr = atmci_prepare_command(mmc, mrq->stop);
500 		host->stop_cmdr |= MCI_CMDR_STOP_XFER;
501 		if (!(data->flags & MMC_DATA_WRITE))
502 			host->stop_cmdr |= MCI_CMDR_TRDIR_READ;
503 		if (data->flags & MMC_DATA_STREAM)
504 			host->stop_cmdr |= MCI_CMDR_STREAM;
505 		else
506 			host->stop_cmdr |= MCI_CMDR_MULTI_BLOCK;
507 	}
508 
509 	/*
510 	 * We could have enabled interrupts earlier, but I suspect
511 	 * that would open up a nice can of interesting race
512 	 * conditions (e.g. command and data complete, but stop not
513 	 * prepared yet.)
514 	 */
515 	mci_writel(host, IER, iflags);
516 
517 	return;
518 
519 fail:
520 	atmci_disable(host);
521 	host->mrq = NULL;
522 	mrq->cmd->error = -EINVAL;
523 	mmc_request_done(mmc, mrq);
524 }
525 
526 static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
527 {
528 	struct atmel_mci	*host = mmc_priv(mmc);
529 
530 	if (ios->clock) {
531 		u32 clkdiv;
532 
533 		/* Set clock rate */
534 		clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * ios->clock) - 1;
535 		if (clkdiv > 255) {
536 			dev_warn(&mmc->class_dev,
537 				"clock %u too slow; using %lu\n",
538 				ios->clock, host->bus_hz / (2 * 256));
539 			clkdiv = 255;
540 		}
541 
542 		host->mode_reg = MCI_MR_CLKDIV(clkdiv) | MCI_MR_WRPROOF
543 					| MCI_MR_RDPROOF;
544 	}
545 
546 	switch (ios->bus_width) {
547 	case MMC_BUS_WIDTH_1:
548 		host->sdc_reg = 0;
549 		break;
550 	case MMC_BUS_WIDTH_4:
551 		host->sdc_reg = MCI_SDCBUS_4BIT;
552 		break;
553 	}
554 
555 	switch (ios->power_mode) {
556 	case MMC_POWER_ON:
557 		/* Send init sequence (74 clock cycles) */
558 		atmci_enable(host);
559 		mci_writel(host, CMDR, MCI_CMDR_SPCMD_INIT);
560 		while (!(mci_readl(host, SR) & MCI_CMDRDY))
561 			cpu_relax();
562 		atmci_disable(host);
563 		break;
564 	default:
565 		/*
566 		 * TODO: None of the currently available AVR32-based
567 		 * boards allow MMC power to be turned off. Implement
568 		 * power control when this can be tested properly.
569 		 */
570 		break;
571 	}
572 }
573 
574 static int atmci_get_ro(struct mmc_host *mmc)
575 {
576 	int			read_only = 0;
577 	struct atmel_mci	*host = mmc_priv(mmc);
578 
579 	if (gpio_is_valid(host->wp_pin)) {
580 		read_only = gpio_get_value(host->wp_pin);
581 		dev_dbg(&mmc->class_dev, "card is %s\n",
582 				read_only ? "read-only" : "read-write");
583 	} else {
584 		dev_dbg(&mmc->class_dev,
585 			"no pin for checking read-only switch."
586 			" Assuming write-enable.\n");
587 	}
588 
589 	return read_only;
590 }
591 
592 static struct mmc_host_ops atmci_ops = {
593 	.request	= atmci_request,
594 	.set_ios	= atmci_set_ios,
595 	.get_ro		= atmci_get_ro,
596 };
597 
598 static void atmci_command_complete(struct atmel_mci *host,
599 			struct mmc_command *cmd, u32 status)
600 {
601 	/* Read the response from the card (up to 16 bytes) */
602 	cmd->resp[0] = mci_readl(host, RSPR);
603 	cmd->resp[1] = mci_readl(host, RSPR);
604 	cmd->resp[2] = mci_readl(host, RSPR);
605 	cmd->resp[3] = mci_readl(host, RSPR);
606 
607 	if (status & MCI_RTOE)
608 		cmd->error = -ETIMEDOUT;
609 	else if ((cmd->flags & MMC_RSP_CRC) && (status & MCI_RCRCE))
610 		cmd->error = -EILSEQ;
611 	else if (status & (MCI_RINDE | MCI_RDIRE | MCI_RENDE))
612 		cmd->error = -EIO;
613 	else
614 		cmd->error = 0;
615 
616 	if (cmd->error) {
617 		dev_dbg(&host->mmc->class_dev,
618 			"command error: status=0x%08x\n", status);
619 
620 		if (cmd->data) {
621 			host->data = NULL;
622 			mci_writel(host, IDR, MCI_NOTBUSY
623 					| MCI_TXRDY | MCI_RXRDY
624 					| ATMCI_DATA_ERROR_FLAGS);
625 		}
626 	}
627 }
628 
629 static void atmci_detect_change(unsigned long data)
630 {
631 	struct atmel_mci *host = (struct atmel_mci *)data;
632 	struct mmc_request *mrq = host->mrq;
633 	int present;
634 
635 	/*
636 	 * atmci_remove() sets detect_pin to -1 before freeing the
637 	 * interrupt. We must not re-enable the interrupt if it has
638 	 * been freed.
639 	 */
640 	smp_rmb();
641 	if (!gpio_is_valid(host->detect_pin))
642 		return;
643 
644 	enable_irq(gpio_to_irq(host->detect_pin));
645 	present = !gpio_get_value(host->detect_pin);
646 
647 	dev_vdbg(&host->pdev->dev, "detect change: %d (was %d)\n",
648 			present, host->present);
649 
650 	if (present != host->present) {
651 		dev_dbg(&host->mmc->class_dev, "card %s\n",
652 			present ? "inserted" : "removed");
653 		host->present = present;
654 
655 		/* Reset controller if card is gone */
656 		if (!present) {
657 			mci_writel(host, CR, MCI_CR_SWRST);
658 			mci_writel(host, IDR, ~0UL);
659 			mci_writel(host, CR, MCI_CR_MCIEN);
660 		}
661 
662 		/* Clean up queue if present */
663 		if (mrq) {
664 			/*
665 			 * Reset controller to terminate any ongoing
666 			 * commands or data transfers.
667 			 */
668 			mci_writel(host, CR, MCI_CR_SWRST);
669 
670 			if (!atmci_is_completed(host, EVENT_CMD_COMPLETE))
671 				mrq->cmd->error = -ENOMEDIUM;
672 
673 			if (mrq->data && !atmci_is_completed(host,
674 						EVENT_DATA_COMPLETE)) {
675 				host->data = NULL;
676 				mrq->data->error = -ENOMEDIUM;
677 			}
678 			if (mrq->stop && !atmci_is_completed(host,
679 						EVENT_STOP_COMPLETE))
680 				mrq->stop->error = -ENOMEDIUM;
681 
682 			host->cmd = NULL;
683 			atmci_request_end(host->mmc, mrq);
684 		}
685 
686 		mmc_detect_change(host->mmc, 0);
687 	}
688 }
689 
690 static void atmci_tasklet_func(unsigned long priv)
691 {
692 	struct mmc_host		*mmc = (struct mmc_host *)priv;
693 	struct atmel_mci	*host = mmc_priv(mmc);
694 	struct mmc_request	*mrq = host->mrq;
695 	struct mmc_data		*data = host->data;
696 
697 	dev_vdbg(&mmc->class_dev,
698 		"tasklet: pending/completed/mask %lx/%lx/%x\n",
699 		host->pending_events, host->completed_events,
700 		mci_readl(host, IMR));
701 
702 	if (atmci_test_and_clear_pending(host, EVENT_CMD_COMPLETE)) {
703 		/*
704 		 * host->cmd must be set to NULL before the interrupt
705 		 * handler sees EVENT_CMD_COMPLETE
706 		 */
707 		host->cmd = NULL;
708 		smp_wmb();
709 		atmci_set_completed(host, EVENT_CMD_COMPLETE);
710 		atmci_command_complete(host, mrq->cmd, host->cmd_status);
711 
712 		if (!mrq->cmd->error && mrq->stop
713 				&& atmci_is_completed(host, EVENT_XFER_COMPLETE)
714 				&& !atmci_test_and_set_completed(host,
715 					EVENT_STOP_SENT))
716 			send_stop_cmd(host->mmc, mrq->data);
717 	}
718 	if (atmci_test_and_clear_pending(host, EVENT_STOP_COMPLETE)) {
719 		/*
720 		 * host->cmd must be set to NULL before the interrupt
721 		 * handler sees EVENT_STOP_COMPLETE
722 		 */
723 		host->cmd = NULL;
724 		smp_wmb();
725 		atmci_set_completed(host, EVENT_STOP_COMPLETE);
726 		atmci_command_complete(host, mrq->stop, host->stop_status);
727 	}
728 	if (atmci_test_and_clear_pending(host, EVENT_DATA_ERROR)) {
729 		u32 status = host->data_status;
730 
731 		dev_vdbg(&mmc->class_dev, "data error: status=%08x\n", status);
732 
733 		atmci_set_completed(host, EVENT_DATA_ERROR);
734 		atmci_set_completed(host, EVENT_DATA_COMPLETE);
735 
736 		if (status & MCI_DTOE) {
737 			dev_dbg(&mmc->class_dev,
738 					"data timeout error\n");
739 			data->error = -ETIMEDOUT;
740 		} else if (status & MCI_DCRCE) {
741 			dev_dbg(&mmc->class_dev, "data CRC error\n");
742 			data->error = -EILSEQ;
743 		} else {
744 			dev_dbg(&mmc->class_dev,
745 					"data FIFO error (status=%08x)\n",
746 					status);
747 			data->error = -EIO;
748 		}
749 
750 		if (host->present && data->stop
751 				&& atmci_is_completed(host, EVENT_CMD_COMPLETE)
752 				&& !atmci_test_and_set_completed(
753 					host, EVENT_STOP_SENT))
754 			send_stop_cmd(host->mmc, data);
755 
756 		host->data = NULL;
757 	}
758 	if (atmci_test_and_clear_pending(host, EVENT_DATA_COMPLETE)) {
759 		atmci_set_completed(host, EVENT_DATA_COMPLETE);
760 
761 		if (!atmci_is_completed(host, EVENT_DATA_ERROR)) {
762 			data->bytes_xfered = data->blocks * data->blksz;
763 			data->error = 0;
764 		}
765 
766 		host->data = NULL;
767 	}
768 
769 	if (host->mrq && !host->cmd && !host->data)
770 		atmci_request_end(mmc, host->mrq);
771 }
772 
773 static void atmci_read_data_pio(struct atmel_mci *host)
774 {
775 	struct scatterlist	*sg = host->sg;
776 	void			*buf = sg_virt(sg);
777 	unsigned int		offset = host->pio_offset;
778 	struct mmc_data		*data = host->data;
779 	u32			value;
780 	u32			status;
781 	unsigned int		nbytes = 0;
782 
783 	do {
784 		value = mci_readl(host, RDR);
785 		if (likely(offset + 4 <= sg->length)) {
786 			put_unaligned(value, (u32 *)(buf + offset));
787 
788 			offset += 4;
789 			nbytes += 4;
790 
791 			if (offset == sg->length) {
792 				host->sg = sg = sg_next(sg);
793 				if (!sg)
794 					goto done;
795 
796 				offset = 0;
797 				buf = sg_virt(sg);
798 			}
799 		} else {
800 			unsigned int remaining = sg->length - offset;
801 			memcpy(buf + offset, &value, remaining);
802 			nbytes += remaining;
803 
804 			flush_dcache_page(sg_page(sg));
805 			host->sg = sg = sg_next(sg);
806 			if (!sg)
807 				goto done;
808 
809 			offset = 4 - remaining;
810 			buf = sg_virt(sg);
811 			memcpy(buf, (u8 *)&value + remaining, offset);
812 			nbytes += offset;
813 		}
814 
815 		status = mci_readl(host, SR);
816 		if (status & ATMCI_DATA_ERROR_FLAGS) {
817 			mci_writel(host, IDR, (MCI_NOTBUSY | MCI_RXRDY
818 						| ATMCI_DATA_ERROR_FLAGS));
819 			host->data_status = status;
820 			atmci_set_pending(host, EVENT_DATA_ERROR);
821 			tasklet_schedule(&host->tasklet);
822 			break;
823 		}
824 	} while (status & MCI_RXRDY);
825 
826 	host->pio_offset = offset;
827 	data->bytes_xfered += nbytes;
828 
829 	return;
830 
831 done:
832 	mci_writel(host, IDR, MCI_RXRDY);
833 	mci_writel(host, IER, MCI_NOTBUSY);
834 	data->bytes_xfered += nbytes;
835 	atmci_set_completed(host, EVENT_XFER_COMPLETE);
836 	if (data->stop && atmci_is_completed(host, EVENT_CMD_COMPLETE)
837 			&& !atmci_test_and_set_completed(host, EVENT_STOP_SENT))
838 		send_stop_cmd(host->mmc, data);
839 }
840 
841 static void atmci_write_data_pio(struct atmel_mci *host)
842 {
843 	struct scatterlist	*sg = host->sg;
844 	void			*buf = sg_virt(sg);
845 	unsigned int		offset = host->pio_offset;
846 	struct mmc_data		*data = host->data;
847 	u32			value;
848 	u32			status;
849 	unsigned int		nbytes = 0;
850 
851 	do {
852 		if (likely(offset + 4 <= sg->length)) {
853 			value = get_unaligned((u32 *)(buf + offset));
854 			mci_writel(host, TDR, value);
855 
856 			offset += 4;
857 			nbytes += 4;
858 			if (offset == sg->length) {
859 				host->sg = sg = sg_next(sg);
860 				if (!sg)
861 					goto done;
862 
863 				offset = 0;
864 				buf = sg_virt(sg);
865 			}
866 		} else {
867 			unsigned int remaining = sg->length - offset;
868 
869 			value = 0;
870 			memcpy(&value, buf + offset, remaining);
871 			nbytes += remaining;
872 
873 			host->sg = sg = sg_next(sg);
874 			if (!sg) {
875 				mci_writel(host, TDR, value);
876 				goto done;
877 			}
878 
879 			offset = 4 - remaining;
880 			buf = sg_virt(sg);
881 			memcpy((u8 *)&value + remaining, buf, offset);
882 			mci_writel(host, TDR, value);
883 			nbytes += offset;
884 		}
885 
886 		status = mci_readl(host, SR);
887 		if (status & ATMCI_DATA_ERROR_FLAGS) {
888 			mci_writel(host, IDR, (MCI_NOTBUSY | MCI_TXRDY
889 						| ATMCI_DATA_ERROR_FLAGS));
890 			host->data_status = status;
891 			atmci_set_pending(host, EVENT_DATA_ERROR);
892 			tasklet_schedule(&host->tasklet);
893 			break;
894 		}
895 	} while (status & MCI_TXRDY);
896 
897 	host->pio_offset = offset;
898 	data->bytes_xfered += nbytes;
899 
900 	return;
901 
902 done:
903 	mci_writel(host, IDR, MCI_TXRDY);
904 	mci_writel(host, IER, MCI_NOTBUSY);
905 	data->bytes_xfered += nbytes;
906 	atmci_set_completed(host, EVENT_XFER_COMPLETE);
907 	if (data->stop && atmci_is_completed(host, EVENT_CMD_COMPLETE)
908 			&& !atmci_test_and_set_completed(host, EVENT_STOP_SENT))
909 		send_stop_cmd(host->mmc, data);
910 }
911 
912 static void atmci_cmd_interrupt(struct mmc_host *mmc, u32 status)
913 {
914 	struct atmel_mci	*host = mmc_priv(mmc);
915 
916 	mci_writel(host, IDR, MCI_CMDRDY);
917 
918 	if (atmci_is_completed(host, EVENT_STOP_SENT)) {
919 		host->stop_status = status;
920 		atmci_set_pending(host, EVENT_STOP_COMPLETE);
921 	} else {
922 		host->cmd_status = status;
923 		atmci_set_pending(host, EVENT_CMD_COMPLETE);
924 	}
925 
926 	tasklet_schedule(&host->tasklet);
927 }
928 
929 static irqreturn_t atmci_interrupt(int irq, void *dev_id)
930 {
931 	struct mmc_host		*mmc = dev_id;
932 	struct atmel_mci	*host = mmc_priv(mmc);
933 	u32			status, mask, pending;
934 	unsigned int		pass_count = 0;
935 
936 	spin_lock(&mmc->lock);
937 
938 	do {
939 		status = mci_readl(host, SR);
940 		mask = mci_readl(host, IMR);
941 		pending = status & mask;
942 		if (!pending)
943 			break;
944 
945 		if (pending & ATMCI_DATA_ERROR_FLAGS) {
946 			mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS
947 					| MCI_RXRDY | MCI_TXRDY);
948 			pending &= mci_readl(host, IMR);
949 			host->data_status = status;
950 			atmci_set_pending(host, EVENT_DATA_ERROR);
951 			tasklet_schedule(&host->tasklet);
952 		}
953 		if (pending & MCI_NOTBUSY) {
954 			mci_writel(host, IDR, (MCI_NOTBUSY
955 					       | ATMCI_DATA_ERROR_FLAGS));
956 			atmci_set_pending(host, EVENT_DATA_COMPLETE);
957 			tasklet_schedule(&host->tasklet);
958 		}
959 		if (pending & MCI_RXRDY)
960 			atmci_read_data_pio(host);
961 		if (pending & MCI_TXRDY)
962 			atmci_write_data_pio(host);
963 
964 		if (pending & MCI_CMDRDY)
965 			atmci_cmd_interrupt(mmc, status);
966 	} while (pass_count++ < 5);
967 
968 	spin_unlock(&mmc->lock);
969 
970 	return pass_count ? IRQ_HANDLED : IRQ_NONE;
971 }
972 
973 static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id)
974 {
975 	struct mmc_host		*mmc = dev_id;
976 	struct atmel_mci	*host = mmc_priv(mmc);
977 
978 	/*
979 	 * Disable interrupts until the pin has stabilized and check
980 	 * the state then. Use mod_timer() since we may be in the
981 	 * middle of the timer routine when this interrupt triggers.
982 	 */
983 	disable_irq_nosync(irq);
984 	mod_timer(&host->detect_timer, jiffies + msecs_to_jiffies(20));
985 
986 	return IRQ_HANDLED;
987 }
988 
989 static int __init atmci_probe(struct platform_device *pdev)
990 {
991 	struct mci_platform_data	*pdata;
992 	struct atmel_mci *host;
993 	struct mmc_host *mmc;
994 	struct resource *regs;
995 	int irq;
996 	int ret;
997 
998 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
999 	if (!regs)
1000 		return -ENXIO;
1001 	pdata = pdev->dev.platform_data;
1002 	if (!pdata)
1003 		return -ENXIO;
1004 	irq = platform_get_irq(pdev, 0);
1005 	if (irq < 0)
1006 		return irq;
1007 
1008 	mmc = mmc_alloc_host(sizeof(struct atmel_mci), &pdev->dev);
1009 	if (!mmc)
1010 		return -ENOMEM;
1011 
1012 	host = mmc_priv(mmc);
1013 	host->pdev = pdev;
1014 	host->mmc = mmc;
1015 	host->detect_pin = pdata->detect_pin;
1016 	host->wp_pin = pdata->wp_pin;
1017 
1018 	host->mck = clk_get(&pdev->dev, "mci_clk");
1019 	if (IS_ERR(host->mck)) {
1020 		ret = PTR_ERR(host->mck);
1021 		goto err_clk_get;
1022 	}
1023 
1024 	ret = -ENOMEM;
1025 	host->regs = ioremap(regs->start, regs->end - regs->start + 1);
1026 	if (!host->regs)
1027 		goto err_ioremap;
1028 
1029 	clk_enable(host->mck);
1030 	mci_writel(host, CR, MCI_CR_SWRST);
1031 	host->bus_hz = clk_get_rate(host->mck);
1032 	clk_disable(host->mck);
1033 
1034 	host->mapbase = regs->start;
1035 
1036 	mmc->ops = &atmci_ops;
1037 	mmc->f_min = (host->bus_hz + 511) / 512;
1038 	mmc->f_max = host->bus_hz / 2;
1039 	mmc->ocr_avail	= MMC_VDD_32_33 | MMC_VDD_33_34;
1040 	mmc->caps |= MMC_CAP_4_BIT_DATA;
1041 
1042 	mmc->max_hw_segs = 64;
1043 	mmc->max_phys_segs = 64;
1044 	mmc->max_req_size = 32768 * 512;
1045 	mmc->max_blk_size = 32768;
1046 	mmc->max_blk_count = 512;
1047 
1048 	tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)mmc);
1049 
1050 	ret = request_irq(irq, atmci_interrupt, 0, pdev->dev.bus_id, mmc);
1051 	if (ret)
1052 		goto err_request_irq;
1053 
1054 	/* Assume card is present if we don't have a detect pin */
1055 	host->present = 1;
1056 	if (gpio_is_valid(host->detect_pin)) {
1057 		if (gpio_request(host->detect_pin, "mmc_detect")) {
1058 			dev_dbg(&mmc->class_dev, "no detect pin available\n");
1059 			host->detect_pin = -1;
1060 		} else {
1061 			host->present = !gpio_get_value(host->detect_pin);
1062 		}
1063 	}
1064 
1065 	if (!gpio_is_valid(host->detect_pin))
1066 		mmc->caps |= MMC_CAP_NEEDS_POLL;
1067 
1068 	if (gpio_is_valid(host->wp_pin)) {
1069 		if (gpio_request(host->wp_pin, "mmc_wp")) {
1070 			dev_dbg(&mmc->class_dev, "no WP pin available\n");
1071 			host->wp_pin = -1;
1072 		}
1073 	}
1074 
1075 	platform_set_drvdata(pdev, host);
1076 
1077 	mmc_add_host(mmc);
1078 
1079 	if (gpio_is_valid(host->detect_pin)) {
1080 		setup_timer(&host->detect_timer, atmci_detect_change,
1081 				(unsigned long)host);
1082 
1083 		ret = request_irq(gpio_to_irq(host->detect_pin),
1084 				atmci_detect_interrupt,
1085 				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
1086 				"mmc-detect", mmc);
1087 		if (ret) {
1088 			dev_dbg(&mmc->class_dev,
1089 				"could not request IRQ %d for detect pin\n",
1090 				gpio_to_irq(host->detect_pin));
1091 			gpio_free(host->detect_pin);
1092 			host->detect_pin = -1;
1093 		}
1094 	}
1095 
1096 	dev_info(&mmc->class_dev,
1097 			"Atmel MCI controller at 0x%08lx irq %d\n",
1098 			host->mapbase, irq);
1099 
1100 	atmci_init_debugfs(host);
1101 
1102 	return 0;
1103 
1104 err_request_irq:
1105 	iounmap(host->regs);
1106 err_ioremap:
1107 	clk_put(host->mck);
1108 err_clk_get:
1109 	mmc_free_host(mmc);
1110 	return ret;
1111 }
1112 
1113 static int __exit atmci_remove(struct platform_device *pdev)
1114 {
1115 	struct atmel_mci *host = platform_get_drvdata(pdev);
1116 
1117 	platform_set_drvdata(pdev, NULL);
1118 
1119 	if (host) {
1120 		/* Debugfs stuff is cleaned up by mmc core */
1121 
1122 		if (gpio_is_valid(host->detect_pin)) {
1123 			int pin = host->detect_pin;
1124 
1125 			/* Make sure the timer doesn't enable the interrupt */
1126 			host->detect_pin = -1;
1127 			smp_wmb();
1128 
1129 			free_irq(gpio_to_irq(pin), host->mmc);
1130 			del_timer_sync(&host->detect_timer);
1131 			gpio_free(pin);
1132 		}
1133 
1134 		mmc_remove_host(host->mmc);
1135 
1136 		clk_enable(host->mck);
1137 		mci_writel(host, IDR, ~0UL);
1138 		mci_writel(host, CR, MCI_CR_MCIDIS);
1139 		mci_readl(host, SR);
1140 		clk_disable(host->mck);
1141 
1142 		if (gpio_is_valid(host->wp_pin))
1143 			gpio_free(host->wp_pin);
1144 
1145 		free_irq(platform_get_irq(pdev, 0), host->mmc);
1146 		iounmap(host->regs);
1147 
1148 		clk_put(host->mck);
1149 
1150 		mmc_free_host(host->mmc);
1151 	}
1152 	return 0;
1153 }
1154 
1155 static struct platform_driver atmci_driver = {
1156 	.remove		= __exit_p(atmci_remove),
1157 	.driver		= {
1158 		.name		= "atmel_mci",
1159 	},
1160 };
1161 
1162 static int __init atmci_init(void)
1163 {
1164 	return platform_driver_probe(&atmci_driver, atmci_probe);
1165 }
1166 
1167 static void __exit atmci_exit(void)
1168 {
1169 	platform_driver_unregister(&atmci_driver);
1170 }
1171 
1172 module_init(atmci_init);
1173 module_exit(atmci_exit);
1174 
1175 MODULE_DESCRIPTION("Atmel Multimedia Card Interface driver");
1176 MODULE_AUTHOR("Haavard Skinnemoen <haavard.skinnemoen@atmel.com>");
1177 MODULE_LICENSE("GPL v2");
1178