xref: /openbmc/linux/drivers/mmc/host/au1xmmc.c (revision 9cfc5c90)
1 /*
2  * linux/drivers/mmc/host/au1xmmc.c - AU1XX0 MMC driver
3  *
4  *  Copyright (c) 2005, Advanced Micro Devices, Inc.
5  *
6  *  Developed with help from the 2.4.30 MMC AU1XXX controller including
7  *  the following copyright notices:
8  *     Copyright (c) 2003-2004 Embedded Edge, LLC.
9  *     Portions Copyright (C) 2002 Embedix, Inc
10  *     Copyright 2002 Hewlett-Packard Company
11 
12  *  2.6 version of this driver inspired by:
13  *     (drivers/mmc/wbsd.c) Copyright (C) 2004-2005 Pierre Ossman,
14  *     All Rights Reserved.
15  *     (drivers/mmc/pxa.c) Copyright (C) 2003 Russell King,
16  *     All Rights Reserved.
17  *
18 
19  * This program is free software; you can redistribute it and/or modify
20  * it under the terms of the GNU General Public License version 2 as
21  * published by the Free Software Foundation.
22  */
23 
24 /* Why don't we use the SD controllers' carddetect feature?
25  *
26  * From the AU1100 MMC application guide:
27  * If the Au1100-based design is intended to support both MultiMediaCards
28  * and 1- or 4-data bit SecureDigital cards, then the solution is to
29  * connect a weak (560KOhm) pull-up resistor to connector pin 1.
30  * In doing so, a MMC card never enters SPI-mode communications,
31  * but now the SecureDigital card-detect feature of CD/DAT3 is ineffective
32  * (the low to high transition will not occur).
33  */
34 
35 #include <linux/clk.h>
36 #include <linux/module.h>
37 #include <linux/init.h>
38 #include <linux/platform_device.h>
39 #include <linux/mm.h>
40 #include <linux/interrupt.h>
41 #include <linux/dma-mapping.h>
42 #include <linux/scatterlist.h>
43 #include <linux/leds.h>
44 #include <linux/mmc/host.h>
45 #include <linux/slab.h>
46 
47 #include <asm/io.h>
48 #include <asm/mach-au1x00/au1000.h>
49 #include <asm/mach-au1x00/au1xxx_dbdma.h>
50 #include <asm/mach-au1x00/au1100_mmc.h>
51 
52 #define DRIVER_NAME "au1xxx-mmc"
53 
54 /* Set this to enable special debugging macros */
55 /* #define DEBUG */
56 
57 #ifdef DEBUG
58 #define DBG(fmt, idx, args...)	\
59 	pr_debug("au1xmmc(%d): DEBUG: " fmt, idx, ##args)
60 #else
61 #define DBG(fmt, idx, args...) do {} while (0)
62 #endif
63 
64 /* Hardware definitions */
65 #define AU1XMMC_DESCRIPTOR_COUNT 1
66 
67 /* max DMA seg size: 64KB on Au1100, 4MB on Au1200 */
68 #define AU1100_MMC_DESCRIPTOR_SIZE 0x0000ffff
69 #define AU1200_MMC_DESCRIPTOR_SIZE 0x003fffff
70 
71 #define AU1XMMC_OCR (MMC_VDD_27_28 | MMC_VDD_28_29 | MMC_VDD_29_30 | \
72 		     MMC_VDD_30_31 | MMC_VDD_31_32 | MMC_VDD_32_33 | \
73 		     MMC_VDD_33_34 | MMC_VDD_34_35 | MMC_VDD_35_36)
74 
75 /* This gives us a hard value for the stop command that we can write directly
76  * to the command register.
77  */
78 #define STOP_CMD	\
79 	(SD_CMD_RT_1B | SD_CMD_CT_7 | (0xC << SD_CMD_CI_SHIFT) | SD_CMD_GO)
80 
81 /* This is the set of interrupts that we configure by default. */
82 #define AU1XMMC_INTERRUPTS 				\
83 	(SD_CONFIG_SC | SD_CONFIG_DT | SD_CONFIG_RAT |	\
84 	 SD_CONFIG_CR | SD_CONFIG_I)
85 
86 /* The poll event (looking for insert/remove events runs twice a second. */
87 #define AU1XMMC_DETECT_TIMEOUT (HZ/2)
88 
89 struct au1xmmc_host {
90 	struct mmc_host *mmc;
91 	struct mmc_request *mrq;
92 
93 	u32 flags;
94 	void __iomem *iobase;
95 	u32 clock;
96 	u32 bus_width;
97 	u32 power_mode;
98 
99 	int status;
100 
101 	struct {
102 		int len;
103 		int dir;
104 	} dma;
105 
106 	struct {
107 		int index;
108 		int offset;
109 		int len;
110 	} pio;
111 
112 	u32 tx_chan;
113 	u32 rx_chan;
114 
115 	int irq;
116 
117 	struct tasklet_struct finish_task;
118 	struct tasklet_struct data_task;
119 	struct au1xmmc_platform_data *platdata;
120 	struct platform_device *pdev;
121 	struct resource *ioarea;
122 	struct clk *clk;
123 };
124 
125 /* Status flags used by the host structure */
126 #define HOST_F_XMIT	0x0001
127 #define HOST_F_RECV	0x0002
128 #define HOST_F_DMA	0x0010
129 #define HOST_F_DBDMA	0x0020
130 #define HOST_F_ACTIVE	0x0100
131 #define HOST_F_STOP	0x1000
132 
133 #define HOST_S_IDLE	0x0001
134 #define HOST_S_CMD	0x0002
135 #define HOST_S_DATA	0x0003
136 #define HOST_S_STOP	0x0004
137 
138 /* Easy access macros */
139 #define HOST_STATUS(h)	((h)->iobase + SD_STATUS)
140 #define HOST_CONFIG(h)	((h)->iobase + SD_CONFIG)
141 #define HOST_ENABLE(h)	((h)->iobase + SD_ENABLE)
142 #define HOST_TXPORT(h)	((h)->iobase + SD_TXPORT)
143 #define HOST_RXPORT(h)	((h)->iobase + SD_RXPORT)
144 #define HOST_CMDARG(h)	((h)->iobase + SD_CMDARG)
145 #define HOST_BLKSIZE(h)	((h)->iobase + SD_BLKSIZE)
146 #define HOST_CMD(h)	((h)->iobase + SD_CMD)
147 #define HOST_CONFIG2(h)	((h)->iobase + SD_CONFIG2)
148 #define HOST_TIMEOUT(h)	((h)->iobase + SD_TIMEOUT)
149 #define HOST_DEBUG(h)	((h)->iobase + SD_DEBUG)
150 
151 #define DMA_CHANNEL(h)	\
152 	(((h)->flags & HOST_F_XMIT) ? (h)->tx_chan : (h)->rx_chan)
153 
154 static inline int has_dbdma(void)
155 {
156 	switch (alchemy_get_cputype()) {
157 	case ALCHEMY_CPU_AU1200:
158 	case ALCHEMY_CPU_AU1300:
159 		return 1;
160 	default:
161 		return 0;
162 	}
163 }
164 
165 static inline void IRQ_ON(struct au1xmmc_host *host, u32 mask)
166 {
167 	u32 val = __raw_readl(HOST_CONFIG(host));
168 	val |= mask;
169 	__raw_writel(val, HOST_CONFIG(host));
170 	wmb(); /* drain writebuffer */
171 }
172 
173 static inline void FLUSH_FIFO(struct au1xmmc_host *host)
174 {
175 	u32 val = __raw_readl(HOST_CONFIG2(host));
176 
177 	__raw_writel(val | SD_CONFIG2_FF, HOST_CONFIG2(host));
178 	wmb(); /* drain writebuffer */
179 	mdelay(1);
180 
181 	/* SEND_STOP will turn off clock control - this re-enables it */
182 	val &= ~SD_CONFIG2_DF;
183 
184 	__raw_writel(val, HOST_CONFIG2(host));
185 	wmb(); /* drain writebuffer */
186 }
187 
188 static inline void IRQ_OFF(struct au1xmmc_host *host, u32 mask)
189 {
190 	u32 val = __raw_readl(HOST_CONFIG(host));
191 	val &= ~mask;
192 	__raw_writel(val, HOST_CONFIG(host));
193 	wmb(); /* drain writebuffer */
194 }
195 
196 static inline void SEND_STOP(struct au1xmmc_host *host)
197 {
198 	u32 config2;
199 
200 	WARN_ON(host->status != HOST_S_DATA);
201 	host->status = HOST_S_STOP;
202 
203 	config2 = __raw_readl(HOST_CONFIG2(host));
204 	__raw_writel(config2 | SD_CONFIG2_DF, HOST_CONFIG2(host));
205 	wmb(); /* drain writebuffer */
206 
207 	/* Send the stop command */
208 	__raw_writel(STOP_CMD, HOST_CMD(host));
209 	wmb(); /* drain writebuffer */
210 }
211 
212 static void au1xmmc_set_power(struct au1xmmc_host *host, int state)
213 {
214 	if (host->platdata && host->platdata->set_power)
215 		host->platdata->set_power(host->mmc, state);
216 }
217 
218 static int au1xmmc_card_inserted(struct mmc_host *mmc)
219 {
220 	struct au1xmmc_host *host = mmc_priv(mmc);
221 
222 	if (host->platdata && host->platdata->card_inserted)
223 		return !!host->platdata->card_inserted(host->mmc);
224 
225 	return -ENOSYS;
226 }
227 
228 static int au1xmmc_card_readonly(struct mmc_host *mmc)
229 {
230 	struct au1xmmc_host *host = mmc_priv(mmc);
231 
232 	if (host->platdata && host->platdata->card_readonly)
233 		return !!host->platdata->card_readonly(mmc);
234 
235 	return -ENOSYS;
236 }
237 
238 static void au1xmmc_finish_request(struct au1xmmc_host *host)
239 {
240 	struct mmc_request *mrq = host->mrq;
241 
242 	host->mrq = NULL;
243 	host->flags &= HOST_F_ACTIVE | HOST_F_DMA;
244 
245 	host->dma.len = 0;
246 	host->dma.dir = 0;
247 
248 	host->pio.index  = 0;
249 	host->pio.offset = 0;
250 	host->pio.len = 0;
251 
252 	host->status = HOST_S_IDLE;
253 
254 	mmc_request_done(host->mmc, mrq);
255 }
256 
257 static void au1xmmc_tasklet_finish(unsigned long param)
258 {
259 	struct au1xmmc_host *host = (struct au1xmmc_host *) param;
260 	au1xmmc_finish_request(host);
261 }
262 
263 static int au1xmmc_send_command(struct au1xmmc_host *host, int wait,
264 				struct mmc_command *cmd, struct mmc_data *data)
265 {
266 	u32 mmccmd = (cmd->opcode << SD_CMD_CI_SHIFT);
267 
268 	switch (mmc_resp_type(cmd)) {
269 	case MMC_RSP_NONE:
270 		break;
271 	case MMC_RSP_R1:
272 		mmccmd |= SD_CMD_RT_1;
273 		break;
274 	case MMC_RSP_R1B:
275 		mmccmd |= SD_CMD_RT_1B;
276 		break;
277 	case MMC_RSP_R2:
278 		mmccmd |= SD_CMD_RT_2;
279 		break;
280 	case MMC_RSP_R3:
281 		mmccmd |= SD_CMD_RT_3;
282 		break;
283 	default:
284 		pr_info("au1xmmc: unhandled response type %02x\n",
285 			mmc_resp_type(cmd));
286 		return -EINVAL;
287 	}
288 
289 	if (data) {
290 		if (data->flags & MMC_DATA_READ) {
291 			if (data->blocks > 1)
292 				mmccmd |= SD_CMD_CT_4;
293 			else
294 				mmccmd |= SD_CMD_CT_2;
295 		} else if (data->flags & MMC_DATA_WRITE) {
296 			if (data->blocks > 1)
297 				mmccmd |= SD_CMD_CT_3;
298 			else
299 				mmccmd |= SD_CMD_CT_1;
300 		}
301 	}
302 
303 	__raw_writel(cmd->arg, HOST_CMDARG(host));
304 	wmb(); /* drain writebuffer */
305 
306 	if (wait)
307 		IRQ_OFF(host, SD_CONFIG_CR);
308 
309 	__raw_writel((mmccmd | SD_CMD_GO), HOST_CMD(host));
310 	wmb(); /* drain writebuffer */
311 
312 	/* Wait for the command to go on the line */
313 	while (__raw_readl(HOST_CMD(host)) & SD_CMD_GO)
314 		/* nop */;
315 
316 	/* Wait for the command to come back */
317 	if (wait) {
318 		u32 status = __raw_readl(HOST_STATUS(host));
319 
320 		while (!(status & SD_STATUS_CR))
321 			status = __raw_readl(HOST_STATUS(host));
322 
323 		/* Clear the CR status */
324 		__raw_writel(SD_STATUS_CR, HOST_STATUS(host));
325 
326 		IRQ_ON(host, SD_CONFIG_CR);
327 	}
328 
329 	return 0;
330 }
331 
332 static void au1xmmc_data_complete(struct au1xmmc_host *host, u32 status)
333 {
334 	struct mmc_request *mrq = host->mrq;
335 	struct mmc_data *data;
336 	u32 crc;
337 
338 	WARN_ON((host->status != HOST_S_DATA) && (host->status != HOST_S_STOP));
339 
340 	if (host->mrq == NULL)
341 		return;
342 
343 	data = mrq->cmd->data;
344 
345 	if (status == 0)
346 		status = __raw_readl(HOST_STATUS(host));
347 
348 	/* The transaction is really over when the SD_STATUS_DB bit is clear */
349 	while ((host->flags & HOST_F_XMIT) && (status & SD_STATUS_DB))
350 		status = __raw_readl(HOST_STATUS(host));
351 
352 	data->error = 0;
353 	dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len, host->dma.dir);
354 
355         /* Process any errors */
356 	crc = (status & (SD_STATUS_WC | SD_STATUS_RC));
357 	if (host->flags & HOST_F_XMIT)
358 		crc |= ((status & 0x07) == 0x02) ? 0 : 1;
359 
360 	if (crc)
361 		data->error = -EILSEQ;
362 
363 	/* Clear the CRC bits */
364 	__raw_writel(SD_STATUS_WC | SD_STATUS_RC, HOST_STATUS(host));
365 
366 	data->bytes_xfered = 0;
367 
368 	if (!data->error) {
369 		if (host->flags & (HOST_F_DMA | HOST_F_DBDMA)) {
370 			u32 chan = DMA_CHANNEL(host);
371 
372 			chan_tab_t *c = *((chan_tab_t **)chan);
373 			au1x_dma_chan_t *cp = c->chan_ptr;
374 			data->bytes_xfered = cp->ddma_bytecnt;
375 		} else
376 			data->bytes_xfered =
377 				(data->blocks * data->blksz) - host->pio.len;
378 	}
379 
380 	au1xmmc_finish_request(host);
381 }
382 
383 static void au1xmmc_tasklet_data(unsigned long param)
384 {
385 	struct au1xmmc_host *host = (struct au1xmmc_host *)param;
386 
387 	u32 status = __raw_readl(HOST_STATUS(host));
388 	au1xmmc_data_complete(host, status);
389 }
390 
391 #define AU1XMMC_MAX_TRANSFER 8
392 
393 static void au1xmmc_send_pio(struct au1xmmc_host *host)
394 {
395 	struct mmc_data *data;
396 	int sg_len, max, count;
397 	unsigned char *sg_ptr, val;
398 	u32 status;
399 	struct scatterlist *sg;
400 
401 	data = host->mrq->data;
402 
403 	if (!(host->flags & HOST_F_XMIT))
404 		return;
405 
406 	/* This is the pointer to the data buffer */
407 	sg = &data->sg[host->pio.index];
408 	sg_ptr = sg_virt(sg) + host->pio.offset;
409 
410 	/* This is the space left inside the buffer */
411 	sg_len = data->sg[host->pio.index].length - host->pio.offset;
412 
413 	/* Check if we need less than the size of the sg_buffer */
414 	max = (sg_len > host->pio.len) ? host->pio.len : sg_len;
415 	if (max > AU1XMMC_MAX_TRANSFER)
416 		max = AU1XMMC_MAX_TRANSFER;
417 
418 	for (count = 0; count < max; count++) {
419 		status = __raw_readl(HOST_STATUS(host));
420 
421 		if (!(status & SD_STATUS_TH))
422 			break;
423 
424 		val = *sg_ptr++;
425 
426 		__raw_writel((unsigned long)val, HOST_TXPORT(host));
427 		wmb(); /* drain writebuffer */
428 	}
429 
430 	host->pio.len -= count;
431 	host->pio.offset += count;
432 
433 	if (count == sg_len) {
434 		host->pio.index++;
435 		host->pio.offset = 0;
436 	}
437 
438 	if (host->pio.len == 0) {
439 		IRQ_OFF(host, SD_CONFIG_TH);
440 
441 		if (host->flags & HOST_F_STOP)
442 			SEND_STOP(host);
443 
444 		tasklet_schedule(&host->data_task);
445 	}
446 }
447 
448 static void au1xmmc_receive_pio(struct au1xmmc_host *host)
449 {
450 	struct mmc_data *data;
451 	int max, count, sg_len = 0;
452 	unsigned char *sg_ptr = NULL;
453 	u32 status, val;
454 	struct scatterlist *sg;
455 
456 	data = host->mrq->data;
457 
458 	if (!(host->flags & HOST_F_RECV))
459 		return;
460 
461 	max = host->pio.len;
462 
463 	if (host->pio.index < host->dma.len) {
464 		sg = &data->sg[host->pio.index];
465 		sg_ptr = sg_virt(sg) + host->pio.offset;
466 
467 		/* This is the space left inside the buffer */
468 		sg_len = sg_dma_len(&data->sg[host->pio.index]) - host->pio.offset;
469 
470 		/* Check if we need less than the size of the sg_buffer */
471 		if (sg_len < max)
472 			max = sg_len;
473 	}
474 
475 	if (max > AU1XMMC_MAX_TRANSFER)
476 		max = AU1XMMC_MAX_TRANSFER;
477 
478 	for (count = 0; count < max; count++) {
479 		status = __raw_readl(HOST_STATUS(host));
480 
481 		if (!(status & SD_STATUS_NE))
482 			break;
483 
484 		if (status & SD_STATUS_RC) {
485 			DBG("RX CRC Error [%d + %d].\n", host->pdev->id,
486 					host->pio.len, count);
487 			break;
488 		}
489 
490 		if (status & SD_STATUS_RO) {
491 			DBG("RX Overrun [%d + %d]\n", host->pdev->id,
492 					host->pio.len, count);
493 			break;
494 		}
495 		else if (status & SD_STATUS_RU) {
496 			DBG("RX Underrun [%d + %d]\n", host->pdev->id,
497 					host->pio.len,	count);
498 			break;
499 		}
500 
501 		val = __raw_readl(HOST_RXPORT(host));
502 
503 		if (sg_ptr)
504 			*sg_ptr++ = (unsigned char)(val & 0xFF);
505 	}
506 
507 	host->pio.len -= count;
508 	host->pio.offset += count;
509 
510 	if (sg_len && count == sg_len) {
511 		host->pio.index++;
512 		host->pio.offset = 0;
513 	}
514 
515 	if (host->pio.len == 0) {
516 		/* IRQ_OFF(host, SD_CONFIG_RA | SD_CONFIG_RF); */
517 		IRQ_OFF(host, SD_CONFIG_NE);
518 
519 		if (host->flags & HOST_F_STOP)
520 			SEND_STOP(host);
521 
522 		tasklet_schedule(&host->data_task);
523 	}
524 }
525 
526 /* This is called when a command has been completed - grab the response
527  * and check for errors.  Then start the data transfer if it is indicated.
528  */
529 static void au1xmmc_cmd_complete(struct au1xmmc_host *host, u32 status)
530 {
531 	struct mmc_request *mrq = host->mrq;
532 	struct mmc_command *cmd;
533 	u32 r[4];
534 	int i, trans;
535 
536 	if (!host->mrq)
537 		return;
538 
539 	cmd = mrq->cmd;
540 	cmd->error = 0;
541 
542 	if (cmd->flags & MMC_RSP_PRESENT) {
543 		if (cmd->flags & MMC_RSP_136) {
544 			r[0] = __raw_readl(host->iobase + SD_RESP3);
545 			r[1] = __raw_readl(host->iobase + SD_RESP2);
546 			r[2] = __raw_readl(host->iobase + SD_RESP1);
547 			r[3] = __raw_readl(host->iobase + SD_RESP0);
548 
549 			/* The CRC is omitted from the response, so really
550 			 * we only got 120 bytes, but the engine expects
551 			 * 128 bits, so we have to shift things up.
552 			 */
553 			for (i = 0; i < 4; i++) {
554 				cmd->resp[i] = (r[i] & 0x00FFFFFF) << 8;
555 				if (i != 3)
556 					cmd->resp[i] |= (r[i + 1] & 0xFF000000) >> 24;
557 			}
558 		} else {
559 			/* Techincally, we should be getting all 48 bits of
560 			 * the response (SD_RESP1 + SD_RESP2), but because
561 			 * our response omits the CRC, our data ends up
562 			 * being shifted 8 bits to the right.  In this case,
563 			 * that means that the OSR data starts at bit 31,
564 			 * so we can just read RESP0 and return that.
565 			 */
566 			cmd->resp[0] = __raw_readl(host->iobase + SD_RESP0);
567 		}
568 	}
569 
570         /* Figure out errors */
571 	if (status & (SD_STATUS_SC | SD_STATUS_WC | SD_STATUS_RC))
572 		cmd->error = -EILSEQ;
573 
574 	trans = host->flags & (HOST_F_XMIT | HOST_F_RECV);
575 
576 	if (!trans || cmd->error) {
577 		IRQ_OFF(host, SD_CONFIG_TH | SD_CONFIG_RA | SD_CONFIG_RF);
578 		tasklet_schedule(&host->finish_task);
579 		return;
580 	}
581 
582 	host->status = HOST_S_DATA;
583 
584 	if ((host->flags & (HOST_F_DMA | HOST_F_DBDMA))) {
585 		u32 channel = DMA_CHANNEL(host);
586 
587 		/* Start the DBDMA as soon as the buffer gets something in it */
588 
589 		if (host->flags & HOST_F_RECV) {
590 			u32 mask = SD_STATUS_DB | SD_STATUS_NE;
591 
592 			while((status & mask) != mask)
593 				status = __raw_readl(HOST_STATUS(host));
594 		}
595 
596 		au1xxx_dbdma_start(channel);
597 	}
598 }
599 
600 static void au1xmmc_set_clock(struct au1xmmc_host *host, int rate)
601 {
602 	unsigned int pbus = clk_get_rate(host->clk);
603 	unsigned int divisor = ((pbus / rate) / 2) - 1;
604 	u32 config;
605 
606 	config = __raw_readl(HOST_CONFIG(host));
607 
608 	config &= ~(SD_CONFIG_DIV);
609 	config |= (divisor & SD_CONFIG_DIV) | SD_CONFIG_DE;
610 
611 	__raw_writel(config, HOST_CONFIG(host));
612 	wmb(); /* drain writebuffer */
613 }
614 
615 static int au1xmmc_prepare_data(struct au1xmmc_host *host,
616 				struct mmc_data *data)
617 {
618 	int datalen = data->blocks * data->blksz;
619 
620 	if (data->flags & MMC_DATA_READ)
621 		host->flags |= HOST_F_RECV;
622 	else
623 		host->flags |= HOST_F_XMIT;
624 
625 	if (host->mrq->stop)
626 		host->flags |= HOST_F_STOP;
627 
628 	host->dma.dir = DMA_BIDIRECTIONAL;
629 
630 	host->dma.len = dma_map_sg(mmc_dev(host->mmc), data->sg,
631 				   data->sg_len, host->dma.dir);
632 
633 	if (host->dma.len == 0)
634 		return -ETIMEDOUT;
635 
636 	__raw_writel(data->blksz - 1, HOST_BLKSIZE(host));
637 
638 	if (host->flags & (HOST_F_DMA | HOST_F_DBDMA)) {
639 		int i;
640 		u32 channel = DMA_CHANNEL(host);
641 
642 		au1xxx_dbdma_stop(channel);
643 
644 		for (i = 0; i < host->dma.len; i++) {
645 			u32 ret = 0, flags = DDMA_FLAGS_NOIE;
646 			struct scatterlist *sg = &data->sg[i];
647 			int sg_len = sg->length;
648 
649 			int len = (datalen > sg_len) ? sg_len : datalen;
650 
651 			if (i == host->dma.len - 1)
652 				flags = DDMA_FLAGS_IE;
653 
654 			if (host->flags & HOST_F_XMIT) {
655 				ret = au1xxx_dbdma_put_source(channel,
656 					sg_phys(sg), len, flags);
657 			} else {
658 				ret = au1xxx_dbdma_put_dest(channel,
659 					sg_phys(sg), len, flags);
660 			}
661 
662 			if (!ret)
663 				goto dataerr;
664 
665 			datalen -= len;
666 		}
667 	} else {
668 		host->pio.index = 0;
669 		host->pio.offset = 0;
670 		host->pio.len = datalen;
671 
672 		if (host->flags & HOST_F_XMIT)
673 			IRQ_ON(host, SD_CONFIG_TH);
674 		else
675 			IRQ_ON(host, SD_CONFIG_NE);
676 			/* IRQ_ON(host, SD_CONFIG_RA | SD_CONFIG_RF); */
677 	}
678 
679 	return 0;
680 
681 dataerr:
682 	dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
683 			host->dma.dir);
684 	return -ETIMEDOUT;
685 }
686 
687 /* This actually starts a command or data transaction */
688 static void au1xmmc_request(struct mmc_host* mmc, struct mmc_request* mrq)
689 {
690 	struct au1xmmc_host *host = mmc_priv(mmc);
691 	int ret = 0;
692 
693 	WARN_ON(irqs_disabled());
694 	WARN_ON(host->status != HOST_S_IDLE);
695 
696 	host->mrq = mrq;
697 	host->status = HOST_S_CMD;
698 
699 	/* fail request immediately if no card is present */
700 	if (0 == au1xmmc_card_inserted(mmc)) {
701 		mrq->cmd->error = -ENOMEDIUM;
702 		au1xmmc_finish_request(host);
703 		return;
704 	}
705 
706 	if (mrq->data) {
707 		FLUSH_FIFO(host);
708 		ret = au1xmmc_prepare_data(host, mrq->data);
709 	}
710 
711 	if (!ret)
712 		ret = au1xmmc_send_command(host, 0, mrq->cmd, mrq->data);
713 
714 	if (ret) {
715 		mrq->cmd->error = ret;
716 		au1xmmc_finish_request(host);
717 	}
718 }
719 
720 static void au1xmmc_reset_controller(struct au1xmmc_host *host)
721 {
722 	/* Apply the clock */
723 	__raw_writel(SD_ENABLE_CE, HOST_ENABLE(host));
724 	wmb(); /* drain writebuffer */
725 	mdelay(1);
726 
727 	__raw_writel(SD_ENABLE_R | SD_ENABLE_CE, HOST_ENABLE(host));
728 	wmb(); /* drain writebuffer */
729 	mdelay(5);
730 
731 	__raw_writel(~0, HOST_STATUS(host));
732 	wmb(); /* drain writebuffer */
733 
734 	__raw_writel(0, HOST_BLKSIZE(host));
735 	__raw_writel(0x001fffff, HOST_TIMEOUT(host));
736 	wmb(); /* drain writebuffer */
737 
738 	__raw_writel(SD_CONFIG2_EN, HOST_CONFIG2(host));
739 	wmb(); /* drain writebuffer */
740 
741 	__raw_writel(SD_CONFIG2_EN | SD_CONFIG2_FF, HOST_CONFIG2(host));
742 	wmb(); /* drain writebuffer */
743 	mdelay(1);
744 
745 	__raw_writel(SD_CONFIG2_EN, HOST_CONFIG2(host));
746 	wmb(); /* drain writebuffer */
747 
748 	/* Configure interrupts */
749 	__raw_writel(AU1XMMC_INTERRUPTS, HOST_CONFIG(host));
750 	wmb(); /* drain writebuffer */
751 }
752 
753 
754 static void au1xmmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
755 {
756 	struct au1xmmc_host *host = mmc_priv(mmc);
757 	u32 config2;
758 
759 	if (ios->power_mode == MMC_POWER_OFF)
760 		au1xmmc_set_power(host, 0);
761 	else if (ios->power_mode == MMC_POWER_ON) {
762 		au1xmmc_set_power(host, 1);
763 	}
764 
765 	if (ios->clock && ios->clock != host->clock) {
766 		au1xmmc_set_clock(host, ios->clock);
767 		host->clock = ios->clock;
768 	}
769 
770 	config2 = __raw_readl(HOST_CONFIG2(host));
771 	switch (ios->bus_width) {
772 	case MMC_BUS_WIDTH_8:
773 		config2 |= SD_CONFIG2_BB;
774 		break;
775 	case MMC_BUS_WIDTH_4:
776 		config2 &= ~SD_CONFIG2_BB;
777 		config2 |= SD_CONFIG2_WB;
778 		break;
779 	case MMC_BUS_WIDTH_1:
780 		config2 &= ~(SD_CONFIG2_WB | SD_CONFIG2_BB);
781 		break;
782 	}
783 	__raw_writel(config2, HOST_CONFIG2(host));
784 	wmb(); /* drain writebuffer */
785 }
786 
787 #define STATUS_TIMEOUT (SD_STATUS_RAT | SD_STATUS_DT)
788 #define STATUS_DATA_IN  (SD_STATUS_NE)
789 #define STATUS_DATA_OUT (SD_STATUS_TH)
790 
791 static irqreturn_t au1xmmc_irq(int irq, void *dev_id)
792 {
793 	struct au1xmmc_host *host = dev_id;
794 	u32 status;
795 
796 	status = __raw_readl(HOST_STATUS(host));
797 
798 	if (!(status & SD_STATUS_I))
799 		return IRQ_NONE;	/* not ours */
800 
801 	if (status & SD_STATUS_SI)	/* SDIO */
802 		mmc_signal_sdio_irq(host->mmc);
803 
804 	if (host->mrq && (status & STATUS_TIMEOUT)) {
805 		if (status & SD_STATUS_RAT)
806 			host->mrq->cmd->error = -ETIMEDOUT;
807 		else if (status & SD_STATUS_DT)
808 			host->mrq->data->error = -ETIMEDOUT;
809 
810 		/* In PIO mode, interrupts might still be enabled */
811 		IRQ_OFF(host, SD_CONFIG_NE | SD_CONFIG_TH);
812 
813 		/* IRQ_OFF(host, SD_CONFIG_TH | SD_CONFIG_RA | SD_CONFIG_RF); */
814 		tasklet_schedule(&host->finish_task);
815 	}
816 #if 0
817 	else if (status & SD_STATUS_DD) {
818 		/* Sometimes we get a DD before a NE in PIO mode */
819 		if (!(host->flags & HOST_F_DMA) && (status & SD_STATUS_NE))
820 			au1xmmc_receive_pio(host);
821 		else {
822 			au1xmmc_data_complete(host, status);
823 			/* tasklet_schedule(&host->data_task); */
824 		}
825 	}
826 #endif
827 	else if (status & SD_STATUS_CR) {
828 		if (host->status == HOST_S_CMD)
829 			au1xmmc_cmd_complete(host, status);
830 
831 	} else if (!(host->flags & HOST_F_DMA)) {
832 		if ((host->flags & HOST_F_XMIT) && (status & STATUS_DATA_OUT))
833 			au1xmmc_send_pio(host);
834 		else if ((host->flags & HOST_F_RECV) && (status & STATUS_DATA_IN))
835 			au1xmmc_receive_pio(host);
836 
837 	} else if (status & 0x203F3C70) {
838 			DBG("Unhandled status %8.8x\n", host->pdev->id,
839 				status);
840 	}
841 
842 	__raw_writel(status, HOST_STATUS(host));
843 	wmb(); /* drain writebuffer */
844 
845 	return IRQ_HANDLED;
846 }
847 
848 /* 8bit memory DMA device */
849 static dbdev_tab_t au1xmmc_mem_dbdev = {
850 	.dev_id		= DSCR_CMD0_ALWAYS,
851 	.dev_flags	= DEV_FLAGS_ANYUSE,
852 	.dev_tsize	= 0,
853 	.dev_devwidth	= 8,
854 	.dev_physaddr	= 0x00000000,
855 	.dev_intlevel	= 0,
856 	.dev_intpolarity = 0,
857 };
858 static int memid;
859 
860 static void au1xmmc_dbdma_callback(int irq, void *dev_id)
861 {
862 	struct au1xmmc_host *host = (struct au1xmmc_host *)dev_id;
863 
864 	/* Avoid spurious interrupts */
865 	if (!host->mrq)
866 		return;
867 
868 	if (host->flags & HOST_F_STOP)
869 		SEND_STOP(host);
870 
871 	tasklet_schedule(&host->data_task);
872 }
873 
874 static int au1xmmc_dbdma_init(struct au1xmmc_host *host)
875 {
876 	struct resource *res;
877 	int txid, rxid;
878 
879 	res = platform_get_resource(host->pdev, IORESOURCE_DMA, 0);
880 	if (!res)
881 		return -ENODEV;
882 	txid = res->start;
883 
884 	res = platform_get_resource(host->pdev, IORESOURCE_DMA, 1);
885 	if (!res)
886 		return -ENODEV;
887 	rxid = res->start;
888 
889 	if (!memid)
890 		return -ENODEV;
891 
892 	host->tx_chan = au1xxx_dbdma_chan_alloc(memid, txid,
893 				au1xmmc_dbdma_callback, (void *)host);
894 	if (!host->tx_chan) {
895 		dev_err(&host->pdev->dev, "cannot allocate TX DMA\n");
896 		return -ENODEV;
897 	}
898 
899 	host->rx_chan = au1xxx_dbdma_chan_alloc(rxid, memid,
900 				au1xmmc_dbdma_callback, (void *)host);
901 	if (!host->rx_chan) {
902 		dev_err(&host->pdev->dev, "cannot allocate RX DMA\n");
903 		au1xxx_dbdma_chan_free(host->tx_chan);
904 		return -ENODEV;
905 	}
906 
907 	au1xxx_dbdma_set_devwidth(host->tx_chan, 8);
908 	au1xxx_dbdma_set_devwidth(host->rx_chan, 8);
909 
910 	au1xxx_dbdma_ring_alloc(host->tx_chan, AU1XMMC_DESCRIPTOR_COUNT);
911 	au1xxx_dbdma_ring_alloc(host->rx_chan, AU1XMMC_DESCRIPTOR_COUNT);
912 
913 	/* DBDMA is good to go */
914 	host->flags |= HOST_F_DMA | HOST_F_DBDMA;
915 
916 	return 0;
917 }
918 
919 static void au1xmmc_dbdma_shutdown(struct au1xmmc_host *host)
920 {
921 	if (host->flags & HOST_F_DMA) {
922 		host->flags &= ~HOST_F_DMA;
923 		au1xxx_dbdma_chan_free(host->tx_chan);
924 		au1xxx_dbdma_chan_free(host->rx_chan);
925 	}
926 }
927 
928 static void au1xmmc_enable_sdio_irq(struct mmc_host *mmc, int en)
929 {
930 	struct au1xmmc_host *host = mmc_priv(mmc);
931 
932 	if (en)
933 		IRQ_ON(host, SD_CONFIG_SI);
934 	else
935 		IRQ_OFF(host, SD_CONFIG_SI);
936 }
937 
938 static const struct mmc_host_ops au1xmmc_ops = {
939 	.request	= au1xmmc_request,
940 	.set_ios	= au1xmmc_set_ios,
941 	.get_ro		= au1xmmc_card_readonly,
942 	.get_cd		= au1xmmc_card_inserted,
943 	.enable_sdio_irq = au1xmmc_enable_sdio_irq,
944 };
945 
946 static int au1xmmc_probe(struct platform_device *pdev)
947 {
948 	struct mmc_host *mmc;
949 	struct au1xmmc_host *host;
950 	struct resource *r;
951 	int ret, iflag;
952 
953 	mmc = mmc_alloc_host(sizeof(struct au1xmmc_host), &pdev->dev);
954 	if (!mmc) {
955 		dev_err(&pdev->dev, "no memory for mmc_host\n");
956 		ret = -ENOMEM;
957 		goto out0;
958 	}
959 
960 	host = mmc_priv(mmc);
961 	host->mmc = mmc;
962 	host->platdata = pdev->dev.platform_data;
963 	host->pdev = pdev;
964 
965 	ret = -ENODEV;
966 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
967 	if (!r) {
968 		dev_err(&pdev->dev, "no mmio defined\n");
969 		goto out1;
970 	}
971 
972 	host->ioarea = request_mem_region(r->start, resource_size(r),
973 					   pdev->name);
974 	if (!host->ioarea) {
975 		dev_err(&pdev->dev, "mmio already in use\n");
976 		goto out1;
977 	}
978 
979 	host->iobase = ioremap(r->start, 0x3c);
980 	if (!host->iobase) {
981 		dev_err(&pdev->dev, "cannot remap mmio\n");
982 		goto out2;
983 	}
984 
985 	r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
986 	if (!r) {
987 		dev_err(&pdev->dev, "no IRQ defined\n");
988 		goto out3;
989 	}
990 	host->irq = r->start;
991 
992 	mmc->ops = &au1xmmc_ops;
993 
994 	mmc->f_min =   450000;
995 	mmc->f_max = 24000000;
996 
997 	mmc->max_blk_size = 2048;
998 	mmc->max_blk_count = 512;
999 
1000 	mmc->ocr_avail = AU1XMMC_OCR;
1001 	mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
1002 	mmc->max_segs = AU1XMMC_DESCRIPTOR_COUNT;
1003 
1004 	iflag = IRQF_SHARED;	/* Au1100/Au1200: one int for both ctrls */
1005 
1006 	switch (alchemy_get_cputype()) {
1007 	case ALCHEMY_CPU_AU1100:
1008 		mmc->max_seg_size = AU1100_MMC_DESCRIPTOR_SIZE;
1009 		break;
1010 	case ALCHEMY_CPU_AU1200:
1011 		mmc->max_seg_size = AU1200_MMC_DESCRIPTOR_SIZE;
1012 		break;
1013 	case ALCHEMY_CPU_AU1300:
1014 		iflag = 0;	/* nothing is shared */
1015 		mmc->max_seg_size = AU1200_MMC_DESCRIPTOR_SIZE;
1016 		mmc->f_max = 52000000;
1017 		if (host->ioarea->start == AU1100_SD0_PHYS_ADDR)
1018 			mmc->caps |= MMC_CAP_8_BIT_DATA;
1019 		break;
1020 	}
1021 
1022 	ret = request_irq(host->irq, au1xmmc_irq, iflag, DRIVER_NAME, host);
1023 	if (ret) {
1024 		dev_err(&pdev->dev, "cannot grab IRQ\n");
1025 		goto out3;
1026 	}
1027 
1028 	host->clk = clk_get(&pdev->dev, ALCHEMY_PERIPH_CLK);
1029 	if (IS_ERR(host->clk)) {
1030 		dev_err(&pdev->dev, "cannot find clock\n");
1031 		ret = PTR_ERR(host->clk);
1032 		goto out_irq;
1033 	}
1034 
1035 	ret = clk_prepare_enable(host->clk);
1036 	if (ret) {
1037 		dev_err(&pdev->dev, "cannot enable clock\n");
1038 		goto out_clk;
1039 	}
1040 
1041 	host->status = HOST_S_IDLE;
1042 
1043 	/* board-specific carddetect setup, if any */
1044 	if (host->platdata && host->platdata->cd_setup) {
1045 		ret = host->platdata->cd_setup(mmc, 1);
1046 		if (ret) {
1047 			dev_warn(&pdev->dev, "board CD setup failed\n");
1048 			mmc->caps |= MMC_CAP_NEEDS_POLL;
1049 		}
1050 	} else
1051 		mmc->caps |= MMC_CAP_NEEDS_POLL;
1052 
1053 	/* platform may not be able to use all advertised caps */
1054 	if (host->platdata)
1055 		mmc->caps &= ~(host->platdata->mask_host_caps);
1056 
1057 	tasklet_init(&host->data_task, au1xmmc_tasklet_data,
1058 			(unsigned long)host);
1059 
1060 	tasklet_init(&host->finish_task, au1xmmc_tasklet_finish,
1061 			(unsigned long)host);
1062 
1063 	if (has_dbdma()) {
1064 		ret = au1xmmc_dbdma_init(host);
1065 		if (ret)
1066 			pr_info(DRIVER_NAME ": DBDMA init failed; using PIO\n");
1067 	}
1068 
1069 #ifdef CONFIG_LEDS_CLASS
1070 	if (host->platdata && host->platdata->led) {
1071 		struct led_classdev *led = host->platdata->led;
1072 		led->name = mmc_hostname(mmc);
1073 		led->brightness = LED_OFF;
1074 		led->default_trigger = mmc_hostname(mmc);
1075 		ret = led_classdev_register(mmc_dev(mmc), led);
1076 		if (ret)
1077 			goto out5;
1078 	}
1079 #endif
1080 
1081 	au1xmmc_reset_controller(host);
1082 
1083 	ret = mmc_add_host(mmc);
1084 	if (ret) {
1085 		dev_err(&pdev->dev, "cannot add mmc host\n");
1086 		goto out6;
1087 	}
1088 
1089 	platform_set_drvdata(pdev, host);
1090 
1091 	pr_info(DRIVER_NAME ": MMC Controller %d set up at %p"
1092 		" (mode=%s)\n", pdev->id, host->iobase,
1093 		host->flags & HOST_F_DMA ? "dma" : "pio");
1094 
1095 	return 0;	/* all ok */
1096 
1097 out6:
1098 #ifdef CONFIG_LEDS_CLASS
1099 	if (host->platdata && host->platdata->led)
1100 		led_classdev_unregister(host->platdata->led);
1101 out5:
1102 #endif
1103 	__raw_writel(0, HOST_ENABLE(host));
1104 	__raw_writel(0, HOST_CONFIG(host));
1105 	__raw_writel(0, HOST_CONFIG2(host));
1106 	wmb(); /* drain writebuffer */
1107 
1108 	if (host->flags & HOST_F_DBDMA)
1109 		au1xmmc_dbdma_shutdown(host);
1110 
1111 	tasklet_kill(&host->data_task);
1112 	tasklet_kill(&host->finish_task);
1113 
1114 	if (host->platdata && host->platdata->cd_setup &&
1115 	    !(mmc->caps & MMC_CAP_NEEDS_POLL))
1116 		host->platdata->cd_setup(mmc, 0);
1117 out_clk:
1118 	clk_disable_unprepare(host->clk);
1119 	clk_put(host->clk);
1120 out_irq:
1121 	free_irq(host->irq, host);
1122 out3:
1123 	iounmap((void *)host->iobase);
1124 out2:
1125 	release_resource(host->ioarea);
1126 	kfree(host->ioarea);
1127 out1:
1128 	mmc_free_host(mmc);
1129 out0:
1130 	return ret;
1131 }
1132 
1133 static int au1xmmc_remove(struct platform_device *pdev)
1134 {
1135 	struct au1xmmc_host *host = platform_get_drvdata(pdev);
1136 
1137 	if (host) {
1138 		mmc_remove_host(host->mmc);
1139 
1140 #ifdef CONFIG_LEDS_CLASS
1141 		if (host->platdata && host->platdata->led)
1142 			led_classdev_unregister(host->platdata->led);
1143 #endif
1144 
1145 		if (host->platdata && host->platdata->cd_setup &&
1146 		    !(host->mmc->caps & MMC_CAP_NEEDS_POLL))
1147 			host->platdata->cd_setup(host->mmc, 0);
1148 
1149 		__raw_writel(0, HOST_ENABLE(host));
1150 		__raw_writel(0, HOST_CONFIG(host));
1151 		__raw_writel(0, HOST_CONFIG2(host));
1152 		wmb(); /* drain writebuffer */
1153 
1154 		tasklet_kill(&host->data_task);
1155 		tasklet_kill(&host->finish_task);
1156 
1157 		if (host->flags & HOST_F_DBDMA)
1158 			au1xmmc_dbdma_shutdown(host);
1159 
1160 		au1xmmc_set_power(host, 0);
1161 
1162 		clk_disable_unprepare(host->clk);
1163 		clk_put(host->clk);
1164 
1165 		free_irq(host->irq, host);
1166 		iounmap((void *)host->iobase);
1167 		release_resource(host->ioarea);
1168 		kfree(host->ioarea);
1169 
1170 		mmc_free_host(host->mmc);
1171 	}
1172 	return 0;
1173 }
1174 
1175 #ifdef CONFIG_PM
1176 static int au1xmmc_suspend(struct platform_device *pdev, pm_message_t state)
1177 {
1178 	struct au1xmmc_host *host = platform_get_drvdata(pdev);
1179 
1180 	__raw_writel(0, HOST_CONFIG2(host));
1181 	__raw_writel(0, HOST_CONFIG(host));
1182 	__raw_writel(0xffffffff, HOST_STATUS(host));
1183 	__raw_writel(0, HOST_ENABLE(host));
1184 	wmb(); /* drain writebuffer */
1185 
1186 	return 0;
1187 }
1188 
1189 static int au1xmmc_resume(struct platform_device *pdev)
1190 {
1191 	struct au1xmmc_host *host = platform_get_drvdata(pdev);
1192 
1193 	au1xmmc_reset_controller(host);
1194 
1195 	return 0;
1196 }
1197 #else
1198 #define au1xmmc_suspend NULL
1199 #define au1xmmc_resume NULL
1200 #endif
1201 
1202 static struct platform_driver au1xmmc_driver = {
1203 	.probe         = au1xmmc_probe,
1204 	.remove        = au1xmmc_remove,
1205 	.suspend       = au1xmmc_suspend,
1206 	.resume        = au1xmmc_resume,
1207 	.driver        = {
1208 		.name  = DRIVER_NAME,
1209 	},
1210 };
1211 
1212 static int __init au1xmmc_init(void)
1213 {
1214 	if (has_dbdma()) {
1215 		/* DSCR_CMD0_ALWAYS has a stride of 32 bits, we need a stride
1216 		* of 8 bits.  And since devices are shared, we need to create
1217 		* our own to avoid freaking out other devices.
1218 		*/
1219 		memid = au1xxx_ddma_add_device(&au1xmmc_mem_dbdev);
1220 		if (!memid)
1221 			pr_err("au1xmmc: cannot add memory dbdma\n");
1222 	}
1223 	return platform_driver_register(&au1xmmc_driver);
1224 }
1225 
1226 static void __exit au1xmmc_exit(void)
1227 {
1228 	if (has_dbdma() && memid)
1229 		au1xxx_ddma_del_device(memid);
1230 
1231 	platform_driver_unregister(&au1xmmc_driver);
1232 }
1233 
1234 module_init(au1xmmc_init);
1235 module_exit(au1xmmc_exit);
1236 
1237 MODULE_AUTHOR("Advanced Micro Devices, Inc");
1238 MODULE_DESCRIPTION("MMC/SD driver for the Alchemy Au1XXX");
1239 MODULE_LICENSE("GPL");
1240 MODULE_ALIAS("platform:au1xxx-mmc");
1241