xref: /openbmc/linux/drivers/mmc/host/jz4740_mmc.c (revision e3b9f1e8)
1 /*
2  *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
3  *  JZ4740 SD/MMC controller driver
4  *
5  *  This program is free software; you can redistribute  it and/or modify it
6  *  under  the terms of  the GNU General  Public License as published by the
7  *  Free Software Foundation;  either version 2 of the  License, or (at your
8  *  option) any later version.
9  *
10  *  You should have received a copy of the  GNU General Public License along
11  *  with this program; if not, write  to the Free Software Foundation, Inc.,
12  *  675 Mass Ave, Cambridge, MA 02139, USA.
13  *
14  */
15 
16 #include <linux/mmc/host.h>
17 #include <linux/mmc/slot-gpio.h>
18 #include <linux/err.h>
19 #include <linux/io.h>
20 #include <linux/irq.h>
21 #include <linux/interrupt.h>
22 #include <linux/module.h>
23 #include <linux/pinctrl/consumer.h>
24 #include <linux/platform_device.h>
25 #include <linux/delay.h>
26 #include <linux/scatterlist.h>
27 #include <linux/clk.h>
28 
29 #include <linux/bitops.h>
30 #include <linux/gpio.h>
31 #include <asm/cacheflush.h>
32 #include <linux/dma-mapping.h>
33 #include <linux/dmaengine.h>
34 
35 #include <asm/mach-jz4740/dma.h>
36 #include <asm/mach-jz4740/jz4740_mmc.h>
37 
38 #define JZ_REG_MMC_STRPCL	0x00
39 #define JZ_REG_MMC_STATUS	0x04
40 #define JZ_REG_MMC_CLKRT	0x08
41 #define JZ_REG_MMC_CMDAT	0x0C
42 #define JZ_REG_MMC_RESTO	0x10
43 #define JZ_REG_MMC_RDTO		0x14
44 #define JZ_REG_MMC_BLKLEN	0x18
45 #define JZ_REG_MMC_NOB		0x1C
46 #define JZ_REG_MMC_SNOB		0x20
47 #define JZ_REG_MMC_IMASK	0x24
48 #define JZ_REG_MMC_IREG		0x28
49 #define JZ_REG_MMC_CMD		0x2C
50 #define JZ_REG_MMC_ARG		0x30
51 #define JZ_REG_MMC_RESP_FIFO	0x34
52 #define JZ_REG_MMC_RXFIFO	0x38
53 #define JZ_REG_MMC_TXFIFO	0x3C
54 
55 #define JZ_MMC_STRPCL_EXIT_MULTIPLE BIT(7)
56 #define JZ_MMC_STRPCL_EXIT_TRANSFER BIT(6)
57 #define JZ_MMC_STRPCL_START_READWAIT BIT(5)
58 #define JZ_MMC_STRPCL_STOP_READWAIT BIT(4)
59 #define JZ_MMC_STRPCL_RESET BIT(3)
60 #define JZ_MMC_STRPCL_START_OP BIT(2)
61 #define JZ_MMC_STRPCL_CLOCK_CONTROL (BIT(1) | BIT(0))
62 #define JZ_MMC_STRPCL_CLOCK_STOP BIT(0)
63 #define JZ_MMC_STRPCL_CLOCK_START BIT(1)
64 
65 
66 #define JZ_MMC_STATUS_IS_RESETTING BIT(15)
67 #define JZ_MMC_STATUS_SDIO_INT_ACTIVE BIT(14)
68 #define JZ_MMC_STATUS_PRG_DONE BIT(13)
69 #define JZ_MMC_STATUS_DATA_TRAN_DONE BIT(12)
70 #define JZ_MMC_STATUS_END_CMD_RES BIT(11)
71 #define JZ_MMC_STATUS_DATA_FIFO_AFULL BIT(10)
72 #define JZ_MMC_STATUS_IS_READWAIT BIT(9)
73 #define JZ_MMC_STATUS_CLK_EN BIT(8)
74 #define JZ_MMC_STATUS_DATA_FIFO_FULL BIT(7)
75 #define JZ_MMC_STATUS_DATA_FIFO_EMPTY BIT(6)
76 #define JZ_MMC_STATUS_CRC_RES_ERR BIT(5)
77 #define JZ_MMC_STATUS_CRC_READ_ERROR BIT(4)
78 #define JZ_MMC_STATUS_TIMEOUT_WRITE BIT(3)
79 #define JZ_MMC_STATUS_CRC_WRITE_ERROR BIT(2)
80 #define JZ_MMC_STATUS_TIMEOUT_RES BIT(1)
81 #define JZ_MMC_STATUS_TIMEOUT_READ BIT(0)
82 
83 #define JZ_MMC_STATUS_READ_ERROR_MASK (BIT(4) | BIT(0))
84 #define JZ_MMC_STATUS_WRITE_ERROR_MASK (BIT(3) | BIT(2))
85 
86 
87 #define JZ_MMC_CMDAT_IO_ABORT BIT(11)
88 #define JZ_MMC_CMDAT_BUS_WIDTH_4BIT BIT(10)
89 #define JZ_MMC_CMDAT_DMA_EN BIT(8)
90 #define JZ_MMC_CMDAT_INIT BIT(7)
91 #define JZ_MMC_CMDAT_BUSY BIT(6)
92 #define JZ_MMC_CMDAT_STREAM BIT(5)
93 #define JZ_MMC_CMDAT_WRITE BIT(4)
94 #define JZ_MMC_CMDAT_DATA_EN BIT(3)
95 #define JZ_MMC_CMDAT_RESPONSE_FORMAT (BIT(2) | BIT(1) | BIT(0))
96 #define JZ_MMC_CMDAT_RSP_R1 1
97 #define JZ_MMC_CMDAT_RSP_R2 2
98 #define JZ_MMC_CMDAT_RSP_R3 3
99 
100 #define JZ_MMC_IRQ_SDIO BIT(7)
101 #define JZ_MMC_IRQ_TXFIFO_WR_REQ BIT(6)
102 #define JZ_MMC_IRQ_RXFIFO_RD_REQ BIT(5)
103 #define JZ_MMC_IRQ_END_CMD_RES BIT(2)
104 #define JZ_MMC_IRQ_PRG_DONE BIT(1)
105 #define JZ_MMC_IRQ_DATA_TRAN_DONE BIT(0)
106 
107 
108 #define JZ_MMC_CLK_RATE 24000000
109 
110 enum jz4740_mmc_state {
111 	JZ4740_MMC_STATE_READ_RESPONSE,
112 	JZ4740_MMC_STATE_TRANSFER_DATA,
113 	JZ4740_MMC_STATE_SEND_STOP,
114 	JZ4740_MMC_STATE_DONE,
115 };
116 
117 struct jz4740_mmc_host_next {
118 	int sg_len;
119 	s32 cookie;
120 };
121 
122 struct jz4740_mmc_host {
123 	struct mmc_host *mmc;
124 	struct platform_device *pdev;
125 	struct jz4740_mmc_platform_data *pdata;
126 	struct clk *clk;
127 
128 	int irq;
129 	int card_detect_irq;
130 
131 	void __iomem *base;
132 	struct resource *mem_res;
133 	struct mmc_request *req;
134 	struct mmc_command *cmd;
135 
136 	unsigned long waiting;
137 
138 	uint32_t cmdat;
139 
140 	uint16_t irq_mask;
141 
142 	spinlock_t lock;
143 
144 	struct timer_list timeout_timer;
145 	struct sg_mapping_iter miter;
146 	enum jz4740_mmc_state state;
147 
148 	/* DMA support */
149 	struct dma_chan *dma_rx;
150 	struct dma_chan *dma_tx;
151 	struct jz4740_mmc_host_next next_data;
152 	bool use_dma;
153 	int sg_len;
154 
155 /* The DMA trigger level is 8 words, that is to say, the DMA read
156  * trigger is when data words in MSC_RXFIFO is >= 8 and the DMA write
157  * trigger is when data words in MSC_TXFIFO is < 8.
158  */
159 #define JZ4740_MMC_FIFO_HALF_SIZE 8
160 };
161 
162 /*----------------------------------------------------------------------------*/
163 /* DMA infrastructure */
164 
165 static void jz4740_mmc_release_dma_channels(struct jz4740_mmc_host *host)
166 {
167 	if (!host->use_dma)
168 		return;
169 
170 	dma_release_channel(host->dma_tx);
171 	dma_release_channel(host->dma_rx);
172 }
173 
174 static int jz4740_mmc_acquire_dma_channels(struct jz4740_mmc_host *host)
175 {
176 	dma_cap_mask_t mask;
177 
178 	dma_cap_zero(mask);
179 	dma_cap_set(DMA_SLAVE, mask);
180 
181 	host->dma_tx = dma_request_channel(mask, NULL, host);
182 	if (!host->dma_tx) {
183 		dev_err(mmc_dev(host->mmc), "Failed to get dma_tx channel\n");
184 		return -ENODEV;
185 	}
186 
187 	host->dma_rx = dma_request_channel(mask, NULL, host);
188 	if (!host->dma_rx) {
189 		dev_err(mmc_dev(host->mmc), "Failed to get dma_rx channel\n");
190 		goto free_master_write;
191 	}
192 
193 	/* Initialize DMA pre request cookie */
194 	host->next_data.cookie = 1;
195 
196 	return 0;
197 
198 free_master_write:
199 	dma_release_channel(host->dma_tx);
200 	return -ENODEV;
201 }
202 
203 static inline struct dma_chan *jz4740_mmc_get_dma_chan(struct jz4740_mmc_host *host,
204 						       struct mmc_data *data)
205 {
206 	return (data->flags & MMC_DATA_READ) ? host->dma_rx : host->dma_tx;
207 }
208 
209 static void jz4740_mmc_dma_unmap(struct jz4740_mmc_host *host,
210 				 struct mmc_data *data)
211 {
212 	struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
213 	enum dma_data_direction dir = mmc_get_dma_dir(data);
214 
215 	dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
216 }
217 
218 /* Prepares DMA data for current/next transfer, returns non-zero on failure */
219 static int jz4740_mmc_prepare_dma_data(struct jz4740_mmc_host *host,
220 				       struct mmc_data *data,
221 				       struct jz4740_mmc_host_next *next,
222 				       struct dma_chan *chan)
223 {
224 	struct jz4740_mmc_host_next *next_data = &host->next_data;
225 	enum dma_data_direction dir = mmc_get_dma_dir(data);
226 	int sg_len;
227 
228 	if (!next && data->host_cookie &&
229 	    data->host_cookie != host->next_data.cookie) {
230 		dev_warn(mmc_dev(host->mmc),
231 			 "[%s] invalid cookie: data->host_cookie %d host->next_data.cookie %d\n",
232 			 __func__,
233 			 data->host_cookie,
234 			 host->next_data.cookie);
235 		data->host_cookie = 0;
236 	}
237 
238 	/* Check if next job is already prepared */
239 	if (next || data->host_cookie != host->next_data.cookie) {
240 		sg_len = dma_map_sg(chan->device->dev,
241 				    data->sg,
242 				    data->sg_len,
243 				    dir);
244 
245 	} else {
246 		sg_len = next_data->sg_len;
247 		next_data->sg_len = 0;
248 	}
249 
250 	if (sg_len <= 0) {
251 		dev_err(mmc_dev(host->mmc),
252 			"Failed to map scatterlist for DMA operation\n");
253 		return -EINVAL;
254 	}
255 
256 	if (next) {
257 		next->sg_len = sg_len;
258 		data->host_cookie = ++next->cookie < 0 ? 1 : next->cookie;
259 	} else
260 		host->sg_len = sg_len;
261 
262 	return 0;
263 }
264 
265 static int jz4740_mmc_start_dma_transfer(struct jz4740_mmc_host *host,
266 					 struct mmc_data *data)
267 {
268 	int ret;
269 	struct dma_chan *chan;
270 	struct dma_async_tx_descriptor *desc;
271 	struct dma_slave_config conf = {
272 		.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
273 		.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
274 		.src_maxburst = JZ4740_MMC_FIFO_HALF_SIZE,
275 		.dst_maxburst = JZ4740_MMC_FIFO_HALF_SIZE,
276 	};
277 
278 	if (data->flags & MMC_DATA_WRITE) {
279 		conf.direction = DMA_MEM_TO_DEV;
280 		conf.dst_addr = host->mem_res->start + JZ_REG_MMC_TXFIFO;
281 		conf.slave_id = JZ4740_DMA_TYPE_MMC_TRANSMIT;
282 		chan = host->dma_tx;
283 	} else {
284 		conf.direction = DMA_DEV_TO_MEM;
285 		conf.src_addr = host->mem_res->start + JZ_REG_MMC_RXFIFO;
286 		conf.slave_id = JZ4740_DMA_TYPE_MMC_RECEIVE;
287 		chan = host->dma_rx;
288 	}
289 
290 	ret = jz4740_mmc_prepare_dma_data(host, data, NULL, chan);
291 	if (ret)
292 		return ret;
293 
294 	dmaengine_slave_config(chan, &conf);
295 	desc = dmaengine_prep_slave_sg(chan,
296 				       data->sg,
297 				       host->sg_len,
298 				       conf.direction,
299 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
300 	if (!desc) {
301 		dev_err(mmc_dev(host->mmc),
302 			"Failed to allocate DMA %s descriptor",
303 			 conf.direction == DMA_MEM_TO_DEV ? "TX" : "RX");
304 		goto dma_unmap;
305 	}
306 
307 	dmaengine_submit(desc);
308 	dma_async_issue_pending(chan);
309 
310 	return 0;
311 
312 dma_unmap:
313 	jz4740_mmc_dma_unmap(host, data);
314 	return -ENOMEM;
315 }
316 
317 static void jz4740_mmc_pre_request(struct mmc_host *mmc,
318 				   struct mmc_request *mrq)
319 {
320 	struct jz4740_mmc_host *host = mmc_priv(mmc);
321 	struct mmc_data *data = mrq->data;
322 	struct jz4740_mmc_host_next *next_data = &host->next_data;
323 
324 	BUG_ON(data->host_cookie);
325 
326 	if (host->use_dma) {
327 		struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
328 
329 		if (jz4740_mmc_prepare_dma_data(host, data, next_data, chan))
330 			data->host_cookie = 0;
331 	}
332 }
333 
334 static void jz4740_mmc_post_request(struct mmc_host *mmc,
335 				    struct mmc_request *mrq,
336 				    int err)
337 {
338 	struct jz4740_mmc_host *host = mmc_priv(mmc);
339 	struct mmc_data *data = mrq->data;
340 
341 	if (host->use_dma && data->host_cookie) {
342 		jz4740_mmc_dma_unmap(host, data);
343 		data->host_cookie = 0;
344 	}
345 
346 	if (err) {
347 		struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
348 
349 		dmaengine_terminate_all(chan);
350 	}
351 }
352 
353 /*----------------------------------------------------------------------------*/
354 
355 static void jz4740_mmc_set_irq_enabled(struct jz4740_mmc_host *host,
356 	unsigned int irq, bool enabled)
357 {
358 	unsigned long flags;
359 
360 	spin_lock_irqsave(&host->lock, flags);
361 	if (enabled)
362 		host->irq_mask &= ~irq;
363 	else
364 		host->irq_mask |= irq;
365 	spin_unlock_irqrestore(&host->lock, flags);
366 
367 	writew(host->irq_mask, host->base + JZ_REG_MMC_IMASK);
368 }
369 
370 static void jz4740_mmc_clock_enable(struct jz4740_mmc_host *host,
371 	bool start_transfer)
372 {
373 	uint16_t val = JZ_MMC_STRPCL_CLOCK_START;
374 
375 	if (start_transfer)
376 		val |= JZ_MMC_STRPCL_START_OP;
377 
378 	writew(val, host->base + JZ_REG_MMC_STRPCL);
379 }
380 
381 static void jz4740_mmc_clock_disable(struct jz4740_mmc_host *host)
382 {
383 	uint32_t status;
384 	unsigned int timeout = 1000;
385 
386 	writew(JZ_MMC_STRPCL_CLOCK_STOP, host->base + JZ_REG_MMC_STRPCL);
387 	do {
388 		status = readl(host->base + JZ_REG_MMC_STATUS);
389 	} while (status & JZ_MMC_STATUS_CLK_EN && --timeout);
390 }
391 
392 static void jz4740_mmc_reset(struct jz4740_mmc_host *host)
393 {
394 	uint32_t status;
395 	unsigned int timeout = 1000;
396 
397 	writew(JZ_MMC_STRPCL_RESET, host->base + JZ_REG_MMC_STRPCL);
398 	udelay(10);
399 	do {
400 		status = readl(host->base + JZ_REG_MMC_STATUS);
401 	} while (status & JZ_MMC_STATUS_IS_RESETTING && --timeout);
402 }
403 
404 static void jz4740_mmc_request_done(struct jz4740_mmc_host *host)
405 {
406 	struct mmc_request *req;
407 
408 	req = host->req;
409 	host->req = NULL;
410 
411 	mmc_request_done(host->mmc, req);
412 }
413 
414 static unsigned int jz4740_mmc_poll_irq(struct jz4740_mmc_host *host,
415 	unsigned int irq)
416 {
417 	unsigned int timeout = 0x800;
418 	uint16_t status;
419 
420 	do {
421 		status = readw(host->base + JZ_REG_MMC_IREG);
422 	} while (!(status & irq) && --timeout);
423 
424 	if (timeout == 0) {
425 		set_bit(0, &host->waiting);
426 		mod_timer(&host->timeout_timer, jiffies + 5*HZ);
427 		jz4740_mmc_set_irq_enabled(host, irq, true);
428 		return true;
429 	}
430 
431 	return false;
432 }
433 
434 static void jz4740_mmc_transfer_check_state(struct jz4740_mmc_host *host,
435 	struct mmc_data *data)
436 {
437 	int status;
438 
439 	status = readl(host->base + JZ_REG_MMC_STATUS);
440 	if (status & JZ_MMC_STATUS_WRITE_ERROR_MASK) {
441 		if (status & (JZ_MMC_STATUS_TIMEOUT_WRITE)) {
442 			host->req->cmd->error = -ETIMEDOUT;
443 			data->error = -ETIMEDOUT;
444 		} else {
445 			host->req->cmd->error = -EIO;
446 			data->error = -EIO;
447 		}
448 	} else if (status & JZ_MMC_STATUS_READ_ERROR_MASK) {
449 		if (status & (JZ_MMC_STATUS_TIMEOUT_READ)) {
450 			host->req->cmd->error = -ETIMEDOUT;
451 			data->error = -ETIMEDOUT;
452 		} else {
453 			host->req->cmd->error = -EIO;
454 			data->error = -EIO;
455 		}
456 	}
457 }
458 
459 static bool jz4740_mmc_write_data(struct jz4740_mmc_host *host,
460 	struct mmc_data *data)
461 {
462 	struct sg_mapping_iter *miter = &host->miter;
463 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_TXFIFO;
464 	uint32_t *buf;
465 	bool timeout;
466 	size_t i, j;
467 
468 	while (sg_miter_next(miter)) {
469 		buf = miter->addr;
470 		i = miter->length / 4;
471 		j = i / 8;
472 		i = i & 0x7;
473 		while (j) {
474 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
475 			if (unlikely(timeout))
476 				goto poll_timeout;
477 
478 			writel(buf[0], fifo_addr);
479 			writel(buf[1], fifo_addr);
480 			writel(buf[2], fifo_addr);
481 			writel(buf[3], fifo_addr);
482 			writel(buf[4], fifo_addr);
483 			writel(buf[5], fifo_addr);
484 			writel(buf[6], fifo_addr);
485 			writel(buf[7], fifo_addr);
486 			buf += 8;
487 			--j;
488 		}
489 		if (unlikely(i)) {
490 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
491 			if (unlikely(timeout))
492 				goto poll_timeout;
493 
494 			while (i) {
495 				writel(*buf, fifo_addr);
496 				++buf;
497 				--i;
498 			}
499 		}
500 		data->bytes_xfered += miter->length;
501 	}
502 	sg_miter_stop(miter);
503 
504 	return false;
505 
506 poll_timeout:
507 	miter->consumed = (void *)buf - miter->addr;
508 	data->bytes_xfered += miter->consumed;
509 	sg_miter_stop(miter);
510 
511 	return true;
512 }
513 
514 static bool jz4740_mmc_read_data(struct jz4740_mmc_host *host,
515 				struct mmc_data *data)
516 {
517 	struct sg_mapping_iter *miter = &host->miter;
518 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_RXFIFO;
519 	uint32_t *buf;
520 	uint32_t d;
521 	uint16_t status;
522 	size_t i, j;
523 	unsigned int timeout;
524 
525 	while (sg_miter_next(miter)) {
526 		buf = miter->addr;
527 		i = miter->length;
528 		j = i / 32;
529 		i = i & 0x1f;
530 		while (j) {
531 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
532 			if (unlikely(timeout))
533 				goto poll_timeout;
534 
535 			buf[0] = readl(fifo_addr);
536 			buf[1] = readl(fifo_addr);
537 			buf[2] = readl(fifo_addr);
538 			buf[3] = readl(fifo_addr);
539 			buf[4] = readl(fifo_addr);
540 			buf[5] = readl(fifo_addr);
541 			buf[6] = readl(fifo_addr);
542 			buf[7] = readl(fifo_addr);
543 
544 			buf += 8;
545 			--j;
546 		}
547 
548 		if (unlikely(i)) {
549 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
550 			if (unlikely(timeout))
551 				goto poll_timeout;
552 
553 			while (i >= 4) {
554 				*buf++ = readl(fifo_addr);
555 				i -= 4;
556 			}
557 			if (unlikely(i > 0)) {
558 				d = readl(fifo_addr);
559 				memcpy(buf, &d, i);
560 			}
561 		}
562 		data->bytes_xfered += miter->length;
563 
564 		/* This can go away once MIPS implements
565 		 * flush_kernel_dcache_page */
566 		flush_dcache_page(miter->page);
567 	}
568 	sg_miter_stop(miter);
569 
570 	/* For whatever reason there is sometime one word more in the fifo then
571 	 * requested */
572 	timeout = 1000;
573 	status = readl(host->base + JZ_REG_MMC_STATUS);
574 	while (!(status & JZ_MMC_STATUS_DATA_FIFO_EMPTY) && --timeout) {
575 		d = readl(fifo_addr);
576 		status = readl(host->base + JZ_REG_MMC_STATUS);
577 	}
578 
579 	return false;
580 
581 poll_timeout:
582 	miter->consumed = (void *)buf - miter->addr;
583 	data->bytes_xfered += miter->consumed;
584 	sg_miter_stop(miter);
585 
586 	return true;
587 }
588 
589 static void jz4740_mmc_timeout(struct timer_list *t)
590 {
591 	struct jz4740_mmc_host *host = from_timer(host, t, timeout_timer);
592 
593 	if (!test_and_clear_bit(0, &host->waiting))
594 		return;
595 
596 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, false);
597 
598 	host->req->cmd->error = -ETIMEDOUT;
599 	jz4740_mmc_request_done(host);
600 }
601 
602 static void jz4740_mmc_read_response(struct jz4740_mmc_host *host,
603 	struct mmc_command *cmd)
604 {
605 	int i;
606 	uint16_t tmp;
607 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_RESP_FIFO;
608 
609 	if (cmd->flags & MMC_RSP_136) {
610 		tmp = readw(fifo_addr);
611 		for (i = 0; i < 4; ++i) {
612 			cmd->resp[i] = tmp << 24;
613 			tmp = readw(fifo_addr);
614 			cmd->resp[i] |= tmp << 8;
615 			tmp = readw(fifo_addr);
616 			cmd->resp[i] |= tmp >> 8;
617 		}
618 	} else {
619 		cmd->resp[0] = readw(fifo_addr) << 24;
620 		cmd->resp[0] |= readw(fifo_addr) << 8;
621 		cmd->resp[0] |= readw(fifo_addr) & 0xff;
622 	}
623 }
624 
625 static void jz4740_mmc_send_command(struct jz4740_mmc_host *host,
626 	struct mmc_command *cmd)
627 {
628 	uint32_t cmdat = host->cmdat;
629 
630 	host->cmdat &= ~JZ_MMC_CMDAT_INIT;
631 	jz4740_mmc_clock_disable(host);
632 
633 	host->cmd = cmd;
634 
635 	if (cmd->flags & MMC_RSP_BUSY)
636 		cmdat |= JZ_MMC_CMDAT_BUSY;
637 
638 	switch (mmc_resp_type(cmd)) {
639 	case MMC_RSP_R1B:
640 	case MMC_RSP_R1:
641 		cmdat |= JZ_MMC_CMDAT_RSP_R1;
642 		break;
643 	case MMC_RSP_R2:
644 		cmdat |= JZ_MMC_CMDAT_RSP_R2;
645 		break;
646 	case MMC_RSP_R3:
647 		cmdat |= JZ_MMC_CMDAT_RSP_R3;
648 		break;
649 	default:
650 		break;
651 	}
652 
653 	if (cmd->data) {
654 		cmdat |= JZ_MMC_CMDAT_DATA_EN;
655 		if (cmd->data->flags & MMC_DATA_WRITE)
656 			cmdat |= JZ_MMC_CMDAT_WRITE;
657 		if (host->use_dma)
658 			cmdat |= JZ_MMC_CMDAT_DMA_EN;
659 
660 		writew(cmd->data->blksz, host->base + JZ_REG_MMC_BLKLEN);
661 		writew(cmd->data->blocks, host->base + JZ_REG_MMC_NOB);
662 	}
663 
664 	writeb(cmd->opcode, host->base + JZ_REG_MMC_CMD);
665 	writel(cmd->arg, host->base + JZ_REG_MMC_ARG);
666 	writel(cmdat, host->base + JZ_REG_MMC_CMDAT);
667 
668 	jz4740_mmc_clock_enable(host, 1);
669 }
670 
671 static void jz_mmc_prepare_data_transfer(struct jz4740_mmc_host *host)
672 {
673 	struct mmc_command *cmd = host->req->cmd;
674 	struct mmc_data *data = cmd->data;
675 	int direction;
676 
677 	if (data->flags & MMC_DATA_READ)
678 		direction = SG_MITER_TO_SG;
679 	else
680 		direction = SG_MITER_FROM_SG;
681 
682 	sg_miter_start(&host->miter, data->sg, data->sg_len, direction);
683 }
684 
685 
686 static irqreturn_t jz_mmc_irq_worker(int irq, void *devid)
687 {
688 	struct jz4740_mmc_host *host = (struct jz4740_mmc_host *)devid;
689 	struct mmc_command *cmd = host->req->cmd;
690 	struct mmc_request *req = host->req;
691 	struct mmc_data *data = cmd->data;
692 	bool timeout = false;
693 
694 	if (cmd->error)
695 		host->state = JZ4740_MMC_STATE_DONE;
696 
697 	switch (host->state) {
698 	case JZ4740_MMC_STATE_READ_RESPONSE:
699 		if (cmd->flags & MMC_RSP_PRESENT)
700 			jz4740_mmc_read_response(host, cmd);
701 
702 		if (!data)
703 			break;
704 
705 		jz_mmc_prepare_data_transfer(host);
706 
707 	case JZ4740_MMC_STATE_TRANSFER_DATA:
708 		if (host->use_dma) {
709 			/* Use DMA if enabled.
710 			 * Data transfer direction is defined later by
711 			 * relying on data flags in
712 			 * jz4740_mmc_prepare_dma_data() and
713 			 * jz4740_mmc_start_dma_transfer().
714 			 */
715 			timeout = jz4740_mmc_start_dma_transfer(host, data);
716 			data->bytes_xfered = data->blocks * data->blksz;
717 		} else if (data->flags & MMC_DATA_READ)
718 			/* Use PIO if DMA is not enabled.
719 			 * Data transfer direction was defined before
720 			 * by relying on data flags in
721 			 * jz_mmc_prepare_data_transfer().
722 			 */
723 			timeout = jz4740_mmc_read_data(host, data);
724 		else
725 			timeout = jz4740_mmc_write_data(host, data);
726 
727 		if (unlikely(timeout)) {
728 			host->state = JZ4740_MMC_STATE_TRANSFER_DATA;
729 			break;
730 		}
731 
732 		jz4740_mmc_transfer_check_state(host, data);
733 
734 		timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_DATA_TRAN_DONE);
735 		if (unlikely(timeout)) {
736 			host->state = JZ4740_MMC_STATE_SEND_STOP;
737 			break;
738 		}
739 		writew(JZ_MMC_IRQ_DATA_TRAN_DONE, host->base + JZ_REG_MMC_IREG);
740 
741 	case JZ4740_MMC_STATE_SEND_STOP:
742 		if (!req->stop)
743 			break;
744 
745 		jz4740_mmc_send_command(host, req->stop);
746 
747 		if (mmc_resp_type(req->stop) & MMC_RSP_BUSY) {
748 			timeout = jz4740_mmc_poll_irq(host,
749 						      JZ_MMC_IRQ_PRG_DONE);
750 			if (timeout) {
751 				host->state = JZ4740_MMC_STATE_DONE;
752 				break;
753 			}
754 		}
755 	case JZ4740_MMC_STATE_DONE:
756 		break;
757 	}
758 
759 	if (!timeout)
760 		jz4740_mmc_request_done(host);
761 
762 	return IRQ_HANDLED;
763 }
764 
765 static irqreturn_t jz_mmc_irq(int irq, void *devid)
766 {
767 	struct jz4740_mmc_host *host = devid;
768 	struct mmc_command *cmd = host->cmd;
769 	uint16_t irq_reg, status, tmp;
770 
771 	irq_reg = readw(host->base + JZ_REG_MMC_IREG);
772 
773 	tmp = irq_reg;
774 	irq_reg &= ~host->irq_mask;
775 
776 	tmp &= ~(JZ_MMC_IRQ_TXFIFO_WR_REQ | JZ_MMC_IRQ_RXFIFO_RD_REQ |
777 		JZ_MMC_IRQ_PRG_DONE | JZ_MMC_IRQ_DATA_TRAN_DONE);
778 
779 	if (tmp != irq_reg)
780 		writew(tmp & ~irq_reg, host->base + JZ_REG_MMC_IREG);
781 
782 	if (irq_reg & JZ_MMC_IRQ_SDIO) {
783 		writew(JZ_MMC_IRQ_SDIO, host->base + JZ_REG_MMC_IREG);
784 		mmc_signal_sdio_irq(host->mmc);
785 		irq_reg &= ~JZ_MMC_IRQ_SDIO;
786 	}
787 
788 	if (host->req && cmd && irq_reg) {
789 		if (test_and_clear_bit(0, &host->waiting)) {
790 			del_timer(&host->timeout_timer);
791 
792 			status = readl(host->base + JZ_REG_MMC_STATUS);
793 
794 			if (status & JZ_MMC_STATUS_TIMEOUT_RES) {
795 					cmd->error = -ETIMEDOUT;
796 			} else if (status & JZ_MMC_STATUS_CRC_RES_ERR) {
797 					cmd->error = -EIO;
798 			} else if (status & (JZ_MMC_STATUS_CRC_READ_ERROR |
799 				    JZ_MMC_STATUS_CRC_WRITE_ERROR)) {
800 					if (cmd->data)
801 							cmd->data->error = -EIO;
802 					cmd->error = -EIO;
803 			}
804 
805 			jz4740_mmc_set_irq_enabled(host, irq_reg, false);
806 			writew(irq_reg, host->base + JZ_REG_MMC_IREG);
807 
808 			return IRQ_WAKE_THREAD;
809 		}
810 	}
811 
812 	return IRQ_HANDLED;
813 }
814 
815 static int jz4740_mmc_set_clock_rate(struct jz4740_mmc_host *host, int rate)
816 {
817 	int div = 0;
818 	int real_rate;
819 
820 	jz4740_mmc_clock_disable(host);
821 	clk_set_rate(host->clk, JZ_MMC_CLK_RATE);
822 
823 	real_rate = clk_get_rate(host->clk);
824 
825 	while (real_rate > rate && div < 7) {
826 		++div;
827 		real_rate >>= 1;
828 	}
829 
830 	writew(div, host->base + JZ_REG_MMC_CLKRT);
831 	return real_rate;
832 }
833 
834 static void jz4740_mmc_request(struct mmc_host *mmc, struct mmc_request *req)
835 {
836 	struct jz4740_mmc_host *host = mmc_priv(mmc);
837 
838 	host->req = req;
839 
840 	writew(0xffff, host->base + JZ_REG_MMC_IREG);
841 
842 	writew(JZ_MMC_IRQ_END_CMD_RES, host->base + JZ_REG_MMC_IREG);
843 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, true);
844 
845 	host->state = JZ4740_MMC_STATE_READ_RESPONSE;
846 	set_bit(0, &host->waiting);
847 	mod_timer(&host->timeout_timer, jiffies + 5*HZ);
848 	jz4740_mmc_send_command(host, req->cmd);
849 }
850 
851 static void jz4740_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
852 {
853 	struct jz4740_mmc_host *host = mmc_priv(mmc);
854 	if (ios->clock)
855 		jz4740_mmc_set_clock_rate(host, ios->clock);
856 
857 	switch (ios->power_mode) {
858 	case MMC_POWER_UP:
859 		jz4740_mmc_reset(host);
860 		if (gpio_is_valid(host->pdata->gpio_power))
861 			gpio_set_value(host->pdata->gpio_power,
862 					!host->pdata->power_active_low);
863 		host->cmdat |= JZ_MMC_CMDAT_INIT;
864 		clk_prepare_enable(host->clk);
865 		break;
866 	case MMC_POWER_ON:
867 		break;
868 	default:
869 		if (gpio_is_valid(host->pdata->gpio_power))
870 			gpio_set_value(host->pdata->gpio_power,
871 					host->pdata->power_active_low);
872 		clk_disable_unprepare(host->clk);
873 		break;
874 	}
875 
876 	switch (ios->bus_width) {
877 	case MMC_BUS_WIDTH_1:
878 		host->cmdat &= ~JZ_MMC_CMDAT_BUS_WIDTH_4BIT;
879 		break;
880 	case MMC_BUS_WIDTH_4:
881 		host->cmdat |= JZ_MMC_CMDAT_BUS_WIDTH_4BIT;
882 		break;
883 	default:
884 		break;
885 	}
886 }
887 
888 static void jz4740_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
889 {
890 	struct jz4740_mmc_host *host = mmc_priv(mmc);
891 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_SDIO, enable);
892 }
893 
894 static const struct mmc_host_ops jz4740_mmc_ops = {
895 	.request	= jz4740_mmc_request,
896 	.pre_req	= jz4740_mmc_pre_request,
897 	.post_req	= jz4740_mmc_post_request,
898 	.set_ios	= jz4740_mmc_set_ios,
899 	.get_ro		= mmc_gpio_get_ro,
900 	.get_cd		= mmc_gpio_get_cd,
901 	.enable_sdio_irq = jz4740_mmc_enable_sdio_irq,
902 };
903 
904 static int jz4740_mmc_request_gpio(struct device *dev, int gpio,
905 	const char *name, bool output, int value)
906 {
907 	int ret;
908 
909 	if (!gpio_is_valid(gpio))
910 		return 0;
911 
912 	ret = gpio_request(gpio, name);
913 	if (ret) {
914 		dev_err(dev, "Failed to request %s gpio: %d\n", name, ret);
915 		return ret;
916 	}
917 
918 	if (output)
919 		gpio_direction_output(gpio, value);
920 	else
921 		gpio_direction_input(gpio);
922 
923 	return 0;
924 }
925 
926 static int jz4740_mmc_request_gpios(struct mmc_host *mmc,
927 	struct platform_device *pdev)
928 {
929 	struct jz4740_mmc_platform_data *pdata = pdev->dev.platform_data;
930 	int ret = 0;
931 
932 	if (!pdata)
933 		return 0;
934 
935 	if (!pdata->card_detect_active_low)
936 		mmc->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
937 	if (!pdata->read_only_active_low)
938 		mmc->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
939 
940 	if (gpio_is_valid(pdata->gpio_card_detect)) {
941 		ret = mmc_gpio_request_cd(mmc, pdata->gpio_card_detect, 0);
942 		if (ret)
943 			return ret;
944 	}
945 
946 	if (gpio_is_valid(pdata->gpio_read_only)) {
947 		ret = mmc_gpio_request_ro(mmc, pdata->gpio_read_only);
948 		if (ret)
949 			return ret;
950 	}
951 
952 	return jz4740_mmc_request_gpio(&pdev->dev, pdata->gpio_power,
953 			"MMC read only", true, pdata->power_active_low);
954 }
955 
956 static void jz4740_mmc_free_gpios(struct platform_device *pdev)
957 {
958 	struct jz4740_mmc_platform_data *pdata = pdev->dev.platform_data;
959 
960 	if (!pdata)
961 		return;
962 
963 	if (gpio_is_valid(pdata->gpio_power))
964 		gpio_free(pdata->gpio_power);
965 }
966 
967 static int jz4740_mmc_probe(struct platform_device* pdev)
968 {
969 	int ret;
970 	struct mmc_host *mmc;
971 	struct jz4740_mmc_host *host;
972 	struct jz4740_mmc_platform_data *pdata;
973 
974 	pdata = pdev->dev.platform_data;
975 
976 	mmc = mmc_alloc_host(sizeof(struct jz4740_mmc_host), &pdev->dev);
977 	if (!mmc) {
978 		dev_err(&pdev->dev, "Failed to alloc mmc host structure\n");
979 		return -ENOMEM;
980 	}
981 
982 	host = mmc_priv(mmc);
983 	host->pdata = pdata;
984 
985 	host->irq = platform_get_irq(pdev, 0);
986 	if (host->irq < 0) {
987 		ret = host->irq;
988 		dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
989 		goto err_free_host;
990 	}
991 
992 	host->clk = devm_clk_get(&pdev->dev, "mmc");
993 	if (IS_ERR(host->clk)) {
994 		ret = PTR_ERR(host->clk);
995 		dev_err(&pdev->dev, "Failed to get mmc clock\n");
996 		goto err_free_host;
997 	}
998 
999 	host->mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1000 	host->base = devm_ioremap_resource(&pdev->dev, host->mem_res);
1001 	if (IS_ERR(host->base)) {
1002 		ret = PTR_ERR(host->base);
1003 		dev_err(&pdev->dev, "Failed to ioremap base memory\n");
1004 		goto err_free_host;
1005 	}
1006 
1007 	ret = jz4740_mmc_request_gpios(mmc, pdev);
1008 	if (ret)
1009 		goto err_release_dma;
1010 
1011 	mmc->ops = &jz4740_mmc_ops;
1012 	mmc->f_min = JZ_MMC_CLK_RATE / 128;
1013 	mmc->f_max = JZ_MMC_CLK_RATE;
1014 	mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
1015 	mmc->caps = (pdata && pdata->data_1bit) ? 0 : MMC_CAP_4_BIT_DATA;
1016 	mmc->caps |= MMC_CAP_SDIO_IRQ;
1017 
1018 	mmc->max_blk_size = (1 << 10) - 1;
1019 	mmc->max_blk_count = (1 << 15) - 1;
1020 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
1021 
1022 	mmc->max_segs = 128;
1023 	mmc->max_seg_size = mmc->max_req_size;
1024 
1025 	host->mmc = mmc;
1026 	host->pdev = pdev;
1027 	spin_lock_init(&host->lock);
1028 	host->irq_mask = 0xffff;
1029 
1030 	ret = request_threaded_irq(host->irq, jz_mmc_irq, jz_mmc_irq_worker, 0,
1031 			dev_name(&pdev->dev), host);
1032 	if (ret) {
1033 		dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
1034 		goto err_free_gpios;
1035 	}
1036 
1037 	jz4740_mmc_reset(host);
1038 	jz4740_mmc_clock_disable(host);
1039 	timer_setup(&host->timeout_timer, jz4740_mmc_timeout, 0);
1040 
1041 	host->use_dma = true;
1042 	if (host->use_dma && jz4740_mmc_acquire_dma_channels(host) != 0)
1043 		host->use_dma = false;
1044 
1045 	platform_set_drvdata(pdev, host);
1046 	ret = mmc_add_host(mmc);
1047 
1048 	if (ret) {
1049 		dev_err(&pdev->dev, "Failed to add mmc host: %d\n", ret);
1050 		goto err_free_irq;
1051 	}
1052 	dev_info(&pdev->dev, "JZ SD/MMC card driver registered\n");
1053 
1054 	dev_info(&pdev->dev, "Using %s, %d-bit mode\n",
1055 		 host->use_dma ? "DMA" : "PIO",
1056 		 (mmc->caps & MMC_CAP_4_BIT_DATA) ? 4 : 1);
1057 
1058 	return 0;
1059 
1060 err_free_irq:
1061 	free_irq(host->irq, host);
1062 err_free_gpios:
1063 	jz4740_mmc_free_gpios(pdev);
1064 err_release_dma:
1065 	if (host->use_dma)
1066 		jz4740_mmc_release_dma_channels(host);
1067 err_free_host:
1068 	mmc_free_host(mmc);
1069 
1070 	return ret;
1071 }
1072 
1073 static int jz4740_mmc_remove(struct platform_device *pdev)
1074 {
1075 	struct jz4740_mmc_host *host = platform_get_drvdata(pdev);
1076 
1077 	del_timer_sync(&host->timeout_timer);
1078 	jz4740_mmc_set_irq_enabled(host, 0xff, false);
1079 	jz4740_mmc_reset(host);
1080 
1081 	mmc_remove_host(host->mmc);
1082 
1083 	free_irq(host->irq, host);
1084 
1085 	jz4740_mmc_free_gpios(pdev);
1086 
1087 	if (host->use_dma)
1088 		jz4740_mmc_release_dma_channels(host);
1089 
1090 	mmc_free_host(host->mmc);
1091 
1092 	return 0;
1093 }
1094 
1095 #ifdef CONFIG_PM_SLEEP
1096 
1097 static int jz4740_mmc_suspend(struct device *dev)
1098 {
1099 	return pinctrl_pm_select_sleep_state(dev);
1100 }
1101 
1102 static int jz4740_mmc_resume(struct device *dev)
1103 {
1104 	return pinctrl_pm_select_default_state(dev);
1105 }
1106 
1107 static SIMPLE_DEV_PM_OPS(jz4740_mmc_pm_ops, jz4740_mmc_suspend,
1108 	jz4740_mmc_resume);
1109 #define JZ4740_MMC_PM_OPS (&jz4740_mmc_pm_ops)
1110 #else
1111 #define JZ4740_MMC_PM_OPS NULL
1112 #endif
1113 
1114 static struct platform_driver jz4740_mmc_driver = {
1115 	.probe = jz4740_mmc_probe,
1116 	.remove = jz4740_mmc_remove,
1117 	.driver = {
1118 		.name = "jz4740-mmc",
1119 		.pm = JZ4740_MMC_PM_OPS,
1120 	},
1121 };
1122 
1123 module_platform_driver(jz4740_mmc_driver);
1124 
1125 MODULE_DESCRIPTION("JZ4740 SD/MMC controller driver");
1126 MODULE_LICENSE("GPL");
1127 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
1128