xref: /openbmc/linux/drivers/mmc/host/jz4740_mmc.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
4  *  Copyright (C) 2013, Imagination Technologies
5  *
6  *  JZ4740 SD/MMC controller driver
7  */
8 
9 #include <linux/bitops.h>
10 #include <linux/clk.h>
11 #include <linux/delay.h>
12 #include <linux/dmaengine.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/err.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/irq.h>
18 #include <linux/mmc/host.h>
19 #include <linux/mmc/slot-gpio.h>
20 #include <linux/module.h>
21 #include <linux/of_device.h>
22 #include <linux/pinctrl/consumer.h>
23 #include <linux/platform_device.h>
24 #include <linux/scatterlist.h>
25 
26 #include <asm/cacheflush.h>
27 
28 #define JZ_REG_MMC_STRPCL	0x00
29 #define JZ_REG_MMC_STATUS	0x04
30 #define JZ_REG_MMC_CLKRT	0x08
31 #define JZ_REG_MMC_CMDAT	0x0C
32 #define JZ_REG_MMC_RESTO	0x10
33 #define JZ_REG_MMC_RDTO		0x14
34 #define JZ_REG_MMC_BLKLEN	0x18
35 #define JZ_REG_MMC_NOB		0x1C
36 #define JZ_REG_MMC_SNOB		0x20
37 #define JZ_REG_MMC_IMASK	0x24
38 #define JZ_REG_MMC_IREG		0x28
39 #define JZ_REG_MMC_CMD		0x2C
40 #define JZ_REG_MMC_ARG		0x30
41 #define JZ_REG_MMC_RESP_FIFO	0x34
42 #define JZ_REG_MMC_RXFIFO	0x38
43 #define JZ_REG_MMC_TXFIFO	0x3C
44 #define JZ_REG_MMC_LPM		0x40
45 #define JZ_REG_MMC_DMAC		0x44
46 
47 #define JZ_MMC_STRPCL_EXIT_MULTIPLE BIT(7)
48 #define JZ_MMC_STRPCL_EXIT_TRANSFER BIT(6)
49 #define JZ_MMC_STRPCL_START_READWAIT BIT(5)
50 #define JZ_MMC_STRPCL_STOP_READWAIT BIT(4)
51 #define JZ_MMC_STRPCL_RESET BIT(3)
52 #define JZ_MMC_STRPCL_START_OP BIT(2)
53 #define JZ_MMC_STRPCL_CLOCK_CONTROL (BIT(1) | BIT(0))
54 #define JZ_MMC_STRPCL_CLOCK_STOP BIT(0)
55 #define JZ_MMC_STRPCL_CLOCK_START BIT(1)
56 
57 
58 #define JZ_MMC_STATUS_IS_RESETTING BIT(15)
59 #define JZ_MMC_STATUS_SDIO_INT_ACTIVE BIT(14)
60 #define JZ_MMC_STATUS_PRG_DONE BIT(13)
61 #define JZ_MMC_STATUS_DATA_TRAN_DONE BIT(12)
62 #define JZ_MMC_STATUS_END_CMD_RES BIT(11)
63 #define JZ_MMC_STATUS_DATA_FIFO_AFULL BIT(10)
64 #define JZ_MMC_STATUS_IS_READWAIT BIT(9)
65 #define JZ_MMC_STATUS_CLK_EN BIT(8)
66 #define JZ_MMC_STATUS_DATA_FIFO_FULL BIT(7)
67 #define JZ_MMC_STATUS_DATA_FIFO_EMPTY BIT(6)
68 #define JZ_MMC_STATUS_CRC_RES_ERR BIT(5)
69 #define JZ_MMC_STATUS_CRC_READ_ERROR BIT(4)
70 #define JZ_MMC_STATUS_TIMEOUT_WRITE BIT(3)
71 #define JZ_MMC_STATUS_CRC_WRITE_ERROR BIT(2)
72 #define JZ_MMC_STATUS_TIMEOUT_RES BIT(1)
73 #define JZ_MMC_STATUS_TIMEOUT_READ BIT(0)
74 
75 #define JZ_MMC_STATUS_READ_ERROR_MASK (BIT(4) | BIT(0))
76 #define JZ_MMC_STATUS_WRITE_ERROR_MASK (BIT(3) | BIT(2))
77 
78 
79 #define JZ_MMC_CMDAT_IO_ABORT BIT(11)
80 #define JZ_MMC_CMDAT_BUS_WIDTH_4BIT BIT(10)
81 #define JZ_MMC_CMDAT_BUS_WIDTH_8BIT (BIT(10) | BIT(9))
82 #define	JZ_MMC_CMDAT_BUS_WIDTH_MASK (BIT(10) | BIT(9))
83 #define JZ_MMC_CMDAT_DMA_EN BIT(8)
84 #define JZ_MMC_CMDAT_INIT BIT(7)
85 #define JZ_MMC_CMDAT_BUSY BIT(6)
86 #define JZ_MMC_CMDAT_STREAM BIT(5)
87 #define JZ_MMC_CMDAT_WRITE BIT(4)
88 #define JZ_MMC_CMDAT_DATA_EN BIT(3)
89 #define JZ_MMC_CMDAT_RESPONSE_FORMAT (BIT(2) | BIT(1) | BIT(0))
90 #define JZ_MMC_CMDAT_RSP_R1 1
91 #define JZ_MMC_CMDAT_RSP_R2 2
92 #define JZ_MMC_CMDAT_RSP_R3 3
93 
94 #define JZ_MMC_IRQ_SDIO BIT(7)
95 #define JZ_MMC_IRQ_TXFIFO_WR_REQ BIT(6)
96 #define JZ_MMC_IRQ_RXFIFO_RD_REQ BIT(5)
97 #define JZ_MMC_IRQ_END_CMD_RES BIT(2)
98 #define JZ_MMC_IRQ_PRG_DONE BIT(1)
99 #define JZ_MMC_IRQ_DATA_TRAN_DONE BIT(0)
100 
101 #define JZ_MMC_DMAC_DMA_SEL BIT(1)
102 #define JZ_MMC_DMAC_DMA_EN BIT(0)
103 
104 #define	JZ_MMC_LPM_DRV_RISING BIT(31)
105 #define	JZ_MMC_LPM_DRV_RISING_QTR_PHASE_DLY BIT(31)
106 #define	JZ_MMC_LPM_DRV_RISING_1NS_DLY BIT(30)
107 #define	JZ_MMC_LPM_SMP_RISING_QTR_OR_HALF_PHASE_DLY BIT(29)
108 #define	JZ_MMC_LPM_LOW_POWER_MODE_EN BIT(0)
109 
110 #define JZ_MMC_CLK_RATE 24000000
111 #define JZ_MMC_REQ_TIMEOUT_MS 5000
112 
113 enum jz4740_mmc_version {
114 	JZ_MMC_JZ4740,
115 	JZ_MMC_JZ4725B,
116 	JZ_MMC_JZ4760,
117 	JZ_MMC_JZ4780,
118 	JZ_MMC_X1000,
119 };
120 
121 enum jz4740_mmc_state {
122 	JZ4740_MMC_STATE_READ_RESPONSE,
123 	JZ4740_MMC_STATE_TRANSFER_DATA,
124 	JZ4740_MMC_STATE_SEND_STOP,
125 	JZ4740_MMC_STATE_DONE,
126 };
127 
128 /*
129  * The MMC core allows to prepare a mmc_request while another mmc_request
130  * is in-flight. This is used via the pre_req/post_req hooks.
131  * This driver uses the pre_req/post_req hooks to map/unmap the mmc_request.
132  * Following what other drivers do (sdhci, dw_mmc) we use the following cookie
133  * flags to keep track of the mmc_request mapping state.
134  *
135  * COOKIE_UNMAPPED: the request is not mapped.
136  * COOKIE_PREMAPPED: the request was mapped in pre_req,
137  * and should be unmapped in post_req.
138  * COOKIE_MAPPED: the request was mapped in the irq handler,
139  * and should be unmapped before mmc_request_done is called..
140  */
141 enum jz4780_cookie {
142 	COOKIE_UNMAPPED = 0,
143 	COOKIE_PREMAPPED,
144 	COOKIE_MAPPED,
145 };
146 
147 struct jz4740_mmc_host {
148 	struct mmc_host *mmc;
149 	struct platform_device *pdev;
150 	struct clk *clk;
151 
152 	enum jz4740_mmc_version version;
153 
154 	int irq;
155 
156 	void __iomem *base;
157 	struct resource *mem_res;
158 	struct mmc_request *req;
159 	struct mmc_command *cmd;
160 
161 	unsigned long waiting;
162 
163 	uint32_t cmdat;
164 
165 	uint32_t irq_mask;
166 
167 	spinlock_t lock;
168 
169 	struct timer_list timeout_timer;
170 	struct sg_mapping_iter miter;
171 	enum jz4740_mmc_state state;
172 
173 	/* DMA support */
174 	struct dma_chan *dma_rx;
175 	struct dma_chan *dma_tx;
176 	bool use_dma;
177 
178 /* The DMA trigger level is 8 words, that is to say, the DMA read
179  * trigger is when data words in MSC_RXFIFO is >= 8 and the DMA write
180  * trigger is when data words in MSC_TXFIFO is < 8.
181  */
182 #define JZ4740_MMC_FIFO_HALF_SIZE 8
183 };
184 
185 static void jz4740_mmc_write_irq_mask(struct jz4740_mmc_host *host,
186 				      uint32_t val)
187 {
188 	if (host->version >= JZ_MMC_JZ4725B)
189 		return writel(val, host->base + JZ_REG_MMC_IMASK);
190 	else
191 		return writew(val, host->base + JZ_REG_MMC_IMASK);
192 }
193 
194 static void jz4740_mmc_write_irq_reg(struct jz4740_mmc_host *host,
195 				     uint32_t val)
196 {
197 	if (host->version >= JZ_MMC_JZ4780)
198 		writel(val, host->base + JZ_REG_MMC_IREG);
199 	else
200 		writew(val, host->base + JZ_REG_MMC_IREG);
201 }
202 
203 static uint32_t jz4740_mmc_read_irq_reg(struct jz4740_mmc_host *host)
204 {
205 	if (host->version >= JZ_MMC_JZ4780)
206 		return readl(host->base + JZ_REG_MMC_IREG);
207 	else
208 		return readw(host->base + JZ_REG_MMC_IREG);
209 }
210 
211 /*----------------------------------------------------------------------------*/
212 /* DMA infrastructure */
213 
214 static void jz4740_mmc_release_dma_channels(struct jz4740_mmc_host *host)
215 {
216 	if (!host->use_dma)
217 		return;
218 
219 	dma_release_channel(host->dma_tx);
220 	dma_release_channel(host->dma_rx);
221 }
222 
223 static int jz4740_mmc_acquire_dma_channels(struct jz4740_mmc_host *host)
224 {
225 	host->dma_tx = dma_request_chan(mmc_dev(host->mmc), "tx");
226 	if (IS_ERR(host->dma_tx)) {
227 		dev_err(mmc_dev(host->mmc), "Failed to get dma_tx channel\n");
228 		return PTR_ERR(host->dma_tx);
229 	}
230 
231 	host->dma_rx = dma_request_chan(mmc_dev(host->mmc), "rx");
232 	if (IS_ERR(host->dma_rx)) {
233 		dev_err(mmc_dev(host->mmc), "Failed to get dma_rx channel\n");
234 		dma_release_channel(host->dma_tx);
235 		return PTR_ERR(host->dma_rx);
236 	}
237 
238 	return 0;
239 }
240 
241 static inline struct dma_chan *jz4740_mmc_get_dma_chan(struct jz4740_mmc_host *host,
242 						       struct mmc_data *data)
243 {
244 	return (data->flags & MMC_DATA_READ) ? host->dma_rx : host->dma_tx;
245 }
246 
247 static void jz4740_mmc_dma_unmap(struct jz4740_mmc_host *host,
248 				 struct mmc_data *data)
249 {
250 	struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
251 	enum dma_data_direction dir = mmc_get_dma_dir(data);
252 
253 	dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
254 	data->host_cookie = COOKIE_UNMAPPED;
255 }
256 
257 /* Prepares DMA data for current or next transfer.
258  * A request can be in-flight when this is called.
259  */
260 static int jz4740_mmc_prepare_dma_data(struct jz4740_mmc_host *host,
261 				       struct mmc_data *data,
262 				       int cookie)
263 {
264 	struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
265 	enum dma_data_direction dir = mmc_get_dma_dir(data);
266 	int sg_count;
267 
268 	if (data->host_cookie == COOKIE_PREMAPPED)
269 		return data->sg_count;
270 
271 	sg_count = dma_map_sg(chan->device->dev,
272 			data->sg,
273 			data->sg_len,
274 			dir);
275 
276 	if (sg_count <= 0) {
277 		dev_err(mmc_dev(host->mmc),
278 			"Failed to map scatterlist for DMA operation\n");
279 		return -EINVAL;
280 	}
281 
282 	data->sg_count = sg_count;
283 	data->host_cookie = cookie;
284 
285 	return data->sg_count;
286 }
287 
288 static int jz4740_mmc_start_dma_transfer(struct jz4740_mmc_host *host,
289 					 struct mmc_data *data)
290 {
291 	struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
292 	struct dma_async_tx_descriptor *desc;
293 	struct dma_slave_config conf = {
294 		.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
295 		.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
296 		.src_maxburst = JZ4740_MMC_FIFO_HALF_SIZE,
297 		.dst_maxburst = JZ4740_MMC_FIFO_HALF_SIZE,
298 	};
299 	int sg_count;
300 
301 	if (data->flags & MMC_DATA_WRITE) {
302 		conf.direction = DMA_MEM_TO_DEV;
303 		conf.dst_addr = host->mem_res->start + JZ_REG_MMC_TXFIFO;
304 	} else {
305 		conf.direction = DMA_DEV_TO_MEM;
306 		conf.src_addr = host->mem_res->start + JZ_REG_MMC_RXFIFO;
307 	}
308 
309 	sg_count = jz4740_mmc_prepare_dma_data(host, data, COOKIE_MAPPED);
310 	if (sg_count < 0)
311 		return sg_count;
312 
313 	dmaengine_slave_config(chan, &conf);
314 	desc = dmaengine_prep_slave_sg(chan, data->sg, sg_count,
315 			conf.direction,
316 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
317 	if (!desc) {
318 		dev_err(mmc_dev(host->mmc),
319 			"Failed to allocate DMA %s descriptor",
320 			 conf.direction == DMA_MEM_TO_DEV ? "TX" : "RX");
321 		goto dma_unmap;
322 	}
323 
324 	dmaengine_submit(desc);
325 	dma_async_issue_pending(chan);
326 
327 	return 0;
328 
329 dma_unmap:
330 	if (data->host_cookie == COOKIE_MAPPED)
331 		jz4740_mmc_dma_unmap(host, data);
332 	return -ENOMEM;
333 }
334 
335 static void jz4740_mmc_pre_request(struct mmc_host *mmc,
336 				   struct mmc_request *mrq)
337 {
338 	struct jz4740_mmc_host *host = mmc_priv(mmc);
339 	struct mmc_data *data = mrq->data;
340 
341 	if (!host->use_dma)
342 		return;
343 
344 	data->host_cookie = COOKIE_UNMAPPED;
345 	if (jz4740_mmc_prepare_dma_data(host, data, COOKIE_PREMAPPED) < 0)
346 		data->host_cookie = COOKIE_UNMAPPED;
347 }
348 
349 static void jz4740_mmc_post_request(struct mmc_host *mmc,
350 				    struct mmc_request *mrq,
351 				    int err)
352 {
353 	struct jz4740_mmc_host *host = mmc_priv(mmc);
354 	struct mmc_data *data = mrq->data;
355 
356 	if (data && data->host_cookie != COOKIE_UNMAPPED)
357 		jz4740_mmc_dma_unmap(host, data);
358 
359 	if (err) {
360 		struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
361 
362 		dmaengine_terminate_all(chan);
363 	}
364 }
365 
366 /*----------------------------------------------------------------------------*/
367 
368 static void jz4740_mmc_set_irq_enabled(struct jz4740_mmc_host *host,
369 	unsigned int irq, bool enabled)
370 {
371 	unsigned long flags;
372 
373 	spin_lock_irqsave(&host->lock, flags);
374 	if (enabled)
375 		host->irq_mask &= ~irq;
376 	else
377 		host->irq_mask |= irq;
378 
379 	jz4740_mmc_write_irq_mask(host, host->irq_mask);
380 	spin_unlock_irqrestore(&host->lock, flags);
381 }
382 
383 static void jz4740_mmc_clock_enable(struct jz4740_mmc_host *host,
384 	bool start_transfer)
385 {
386 	uint16_t val = JZ_MMC_STRPCL_CLOCK_START;
387 
388 	if (start_transfer)
389 		val |= JZ_MMC_STRPCL_START_OP;
390 
391 	writew(val, host->base + JZ_REG_MMC_STRPCL);
392 }
393 
394 static void jz4740_mmc_clock_disable(struct jz4740_mmc_host *host)
395 {
396 	uint32_t status;
397 	unsigned int timeout = 1000;
398 
399 	writew(JZ_MMC_STRPCL_CLOCK_STOP, host->base + JZ_REG_MMC_STRPCL);
400 	do {
401 		status = readl(host->base + JZ_REG_MMC_STATUS);
402 	} while (status & JZ_MMC_STATUS_CLK_EN && --timeout);
403 }
404 
405 static void jz4740_mmc_reset(struct jz4740_mmc_host *host)
406 {
407 	uint32_t status;
408 	unsigned int timeout = 1000;
409 
410 	writew(JZ_MMC_STRPCL_RESET, host->base + JZ_REG_MMC_STRPCL);
411 	udelay(10);
412 	do {
413 		status = readl(host->base + JZ_REG_MMC_STATUS);
414 	} while (status & JZ_MMC_STATUS_IS_RESETTING && --timeout);
415 }
416 
417 static void jz4740_mmc_request_done(struct jz4740_mmc_host *host)
418 {
419 	struct mmc_request *req;
420 	struct mmc_data *data;
421 
422 	req = host->req;
423 	data = req->data;
424 	host->req = NULL;
425 
426 	if (data && data->host_cookie == COOKIE_MAPPED)
427 		jz4740_mmc_dma_unmap(host, data);
428 	mmc_request_done(host->mmc, req);
429 }
430 
431 static unsigned int jz4740_mmc_poll_irq(struct jz4740_mmc_host *host,
432 	unsigned int irq)
433 {
434 	unsigned int timeout = 0x800;
435 	uint32_t status;
436 
437 	do {
438 		status = jz4740_mmc_read_irq_reg(host);
439 	} while (!(status & irq) && --timeout);
440 
441 	if (timeout == 0) {
442 		set_bit(0, &host->waiting);
443 		mod_timer(&host->timeout_timer,
444 			  jiffies + msecs_to_jiffies(JZ_MMC_REQ_TIMEOUT_MS));
445 		jz4740_mmc_set_irq_enabled(host, irq, true);
446 		return true;
447 	}
448 
449 	return false;
450 }
451 
452 static void jz4740_mmc_transfer_check_state(struct jz4740_mmc_host *host,
453 	struct mmc_data *data)
454 {
455 	int status;
456 
457 	status = readl(host->base + JZ_REG_MMC_STATUS);
458 	if (status & JZ_MMC_STATUS_WRITE_ERROR_MASK) {
459 		if (status & (JZ_MMC_STATUS_TIMEOUT_WRITE)) {
460 			host->req->cmd->error = -ETIMEDOUT;
461 			data->error = -ETIMEDOUT;
462 		} else {
463 			host->req->cmd->error = -EIO;
464 			data->error = -EIO;
465 		}
466 	} else if (status & JZ_MMC_STATUS_READ_ERROR_MASK) {
467 		if (status & (JZ_MMC_STATUS_TIMEOUT_READ)) {
468 			host->req->cmd->error = -ETIMEDOUT;
469 			data->error = -ETIMEDOUT;
470 		} else {
471 			host->req->cmd->error = -EIO;
472 			data->error = -EIO;
473 		}
474 	}
475 }
476 
477 static bool jz4740_mmc_write_data(struct jz4740_mmc_host *host,
478 	struct mmc_data *data)
479 {
480 	struct sg_mapping_iter *miter = &host->miter;
481 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_TXFIFO;
482 	uint32_t *buf;
483 	bool timeout;
484 	size_t i, j;
485 
486 	while (sg_miter_next(miter)) {
487 		buf = miter->addr;
488 		i = miter->length / 4;
489 		j = i / 8;
490 		i = i & 0x7;
491 		while (j) {
492 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
493 			if (unlikely(timeout))
494 				goto poll_timeout;
495 
496 			writel(buf[0], fifo_addr);
497 			writel(buf[1], fifo_addr);
498 			writel(buf[2], fifo_addr);
499 			writel(buf[3], fifo_addr);
500 			writel(buf[4], fifo_addr);
501 			writel(buf[5], fifo_addr);
502 			writel(buf[6], fifo_addr);
503 			writel(buf[7], fifo_addr);
504 			buf += 8;
505 			--j;
506 		}
507 		if (unlikely(i)) {
508 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
509 			if (unlikely(timeout))
510 				goto poll_timeout;
511 
512 			while (i) {
513 				writel(*buf, fifo_addr);
514 				++buf;
515 				--i;
516 			}
517 		}
518 		data->bytes_xfered += miter->length;
519 	}
520 	sg_miter_stop(miter);
521 
522 	return false;
523 
524 poll_timeout:
525 	miter->consumed = (void *)buf - miter->addr;
526 	data->bytes_xfered += miter->consumed;
527 	sg_miter_stop(miter);
528 
529 	return true;
530 }
531 
532 static bool jz4740_mmc_read_data(struct jz4740_mmc_host *host,
533 				struct mmc_data *data)
534 {
535 	struct sg_mapping_iter *miter = &host->miter;
536 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_RXFIFO;
537 	uint32_t *buf;
538 	uint32_t d;
539 	uint32_t status;
540 	size_t i, j;
541 	unsigned int timeout;
542 
543 	while (sg_miter_next(miter)) {
544 		buf = miter->addr;
545 		i = miter->length;
546 		j = i / 32;
547 		i = i & 0x1f;
548 		while (j) {
549 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
550 			if (unlikely(timeout))
551 				goto poll_timeout;
552 
553 			buf[0] = readl(fifo_addr);
554 			buf[1] = readl(fifo_addr);
555 			buf[2] = readl(fifo_addr);
556 			buf[3] = readl(fifo_addr);
557 			buf[4] = readl(fifo_addr);
558 			buf[5] = readl(fifo_addr);
559 			buf[6] = readl(fifo_addr);
560 			buf[7] = readl(fifo_addr);
561 
562 			buf += 8;
563 			--j;
564 		}
565 
566 		if (unlikely(i)) {
567 			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
568 			if (unlikely(timeout))
569 				goto poll_timeout;
570 
571 			while (i >= 4) {
572 				*buf++ = readl(fifo_addr);
573 				i -= 4;
574 			}
575 			if (unlikely(i > 0)) {
576 				d = readl(fifo_addr);
577 				memcpy(buf, &d, i);
578 			}
579 		}
580 		data->bytes_xfered += miter->length;
581 	}
582 	sg_miter_stop(miter);
583 
584 	/* For whatever reason there is sometime one word more in the fifo then
585 	 * requested */
586 	timeout = 1000;
587 	status = readl(host->base + JZ_REG_MMC_STATUS);
588 	while (!(status & JZ_MMC_STATUS_DATA_FIFO_EMPTY) && --timeout) {
589 		d = readl(fifo_addr);
590 		status = readl(host->base + JZ_REG_MMC_STATUS);
591 	}
592 
593 	return false;
594 
595 poll_timeout:
596 	miter->consumed = (void *)buf - miter->addr;
597 	data->bytes_xfered += miter->consumed;
598 	sg_miter_stop(miter);
599 
600 	return true;
601 }
602 
603 static void jz4740_mmc_timeout(struct timer_list *t)
604 {
605 	struct jz4740_mmc_host *host = from_timer(host, t, timeout_timer);
606 
607 	if (!test_and_clear_bit(0, &host->waiting))
608 		return;
609 
610 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, false);
611 
612 	host->req->cmd->error = -ETIMEDOUT;
613 	jz4740_mmc_request_done(host);
614 }
615 
616 static void jz4740_mmc_read_response(struct jz4740_mmc_host *host,
617 	struct mmc_command *cmd)
618 {
619 	int i;
620 	uint16_t tmp;
621 	void __iomem *fifo_addr = host->base + JZ_REG_MMC_RESP_FIFO;
622 
623 	if (cmd->flags & MMC_RSP_136) {
624 		tmp = readw(fifo_addr);
625 		for (i = 0; i < 4; ++i) {
626 			cmd->resp[i] = tmp << 24;
627 			tmp = readw(fifo_addr);
628 			cmd->resp[i] |= tmp << 8;
629 			tmp = readw(fifo_addr);
630 			cmd->resp[i] |= tmp >> 8;
631 		}
632 	} else {
633 		cmd->resp[0] = readw(fifo_addr) << 24;
634 		cmd->resp[0] |= readw(fifo_addr) << 8;
635 		cmd->resp[0] |= readw(fifo_addr) & 0xff;
636 	}
637 }
638 
639 static void jz4740_mmc_send_command(struct jz4740_mmc_host *host,
640 	struct mmc_command *cmd)
641 {
642 	uint32_t cmdat = host->cmdat;
643 
644 	host->cmdat &= ~JZ_MMC_CMDAT_INIT;
645 	jz4740_mmc_clock_disable(host);
646 
647 	host->cmd = cmd;
648 
649 	if (cmd->flags & MMC_RSP_BUSY)
650 		cmdat |= JZ_MMC_CMDAT_BUSY;
651 
652 	switch (mmc_resp_type(cmd)) {
653 	case MMC_RSP_R1B:
654 	case MMC_RSP_R1:
655 		cmdat |= JZ_MMC_CMDAT_RSP_R1;
656 		break;
657 	case MMC_RSP_R2:
658 		cmdat |= JZ_MMC_CMDAT_RSP_R2;
659 		break;
660 	case MMC_RSP_R3:
661 		cmdat |= JZ_MMC_CMDAT_RSP_R3;
662 		break;
663 	default:
664 		break;
665 	}
666 
667 	if (cmd->data) {
668 		cmdat |= JZ_MMC_CMDAT_DATA_EN;
669 		if (cmd->data->flags & MMC_DATA_WRITE)
670 			cmdat |= JZ_MMC_CMDAT_WRITE;
671 		if (host->use_dma) {
672 			/*
673 			 * The JZ4780's MMC controller has integrated DMA ability
674 			 * in addition to being able to use the external DMA
675 			 * controller. It moves DMA control bits to a separate
676 			 * register. The DMA_SEL bit chooses the external
677 			 * controller over the integrated one. Earlier SoCs
678 			 * can only use the external controller, and have a
679 			 * single DMA enable bit in CMDAT.
680 			 */
681 			if (host->version >= JZ_MMC_JZ4780) {
682 				writel(JZ_MMC_DMAC_DMA_EN | JZ_MMC_DMAC_DMA_SEL,
683 				       host->base + JZ_REG_MMC_DMAC);
684 			} else {
685 				cmdat |= JZ_MMC_CMDAT_DMA_EN;
686 			}
687 		} else if (host->version >= JZ_MMC_JZ4780) {
688 			writel(0, host->base + JZ_REG_MMC_DMAC);
689 		}
690 
691 		writew(cmd->data->blksz, host->base + JZ_REG_MMC_BLKLEN);
692 		writew(cmd->data->blocks, host->base + JZ_REG_MMC_NOB);
693 	}
694 
695 	writeb(cmd->opcode, host->base + JZ_REG_MMC_CMD);
696 	writel(cmd->arg, host->base + JZ_REG_MMC_ARG);
697 	writel(cmdat, host->base + JZ_REG_MMC_CMDAT);
698 
699 	jz4740_mmc_clock_enable(host, 1);
700 }
701 
702 static void jz_mmc_prepare_data_transfer(struct jz4740_mmc_host *host)
703 {
704 	struct mmc_command *cmd = host->req->cmd;
705 	struct mmc_data *data = cmd->data;
706 	int direction;
707 
708 	if (data->flags & MMC_DATA_READ)
709 		direction = SG_MITER_TO_SG;
710 	else
711 		direction = SG_MITER_FROM_SG;
712 
713 	sg_miter_start(&host->miter, data->sg, data->sg_len, direction);
714 }
715 
716 
717 static irqreturn_t jz_mmc_irq_worker(int irq, void *devid)
718 {
719 	struct jz4740_mmc_host *host = (struct jz4740_mmc_host *)devid;
720 	struct mmc_command *cmd = host->req->cmd;
721 	struct mmc_request *req = host->req;
722 	struct mmc_data *data = cmd->data;
723 	bool timeout = false;
724 
725 	if (cmd->error)
726 		host->state = JZ4740_MMC_STATE_DONE;
727 
728 	switch (host->state) {
729 	case JZ4740_MMC_STATE_READ_RESPONSE:
730 		if (cmd->flags & MMC_RSP_PRESENT)
731 			jz4740_mmc_read_response(host, cmd);
732 
733 		if (!data)
734 			break;
735 
736 		jz_mmc_prepare_data_transfer(host);
737 		fallthrough;
738 
739 	case JZ4740_MMC_STATE_TRANSFER_DATA:
740 		if (host->use_dma) {
741 			/* Use DMA if enabled.
742 			 * Data transfer direction is defined later by
743 			 * relying on data flags in
744 			 * jz4740_mmc_prepare_dma_data() and
745 			 * jz4740_mmc_start_dma_transfer().
746 			 */
747 			timeout = jz4740_mmc_start_dma_transfer(host, data);
748 			data->bytes_xfered = data->blocks * data->blksz;
749 		} else if (data->flags & MMC_DATA_READ)
750 			/* Use PIO if DMA is not enabled.
751 			 * Data transfer direction was defined before
752 			 * by relying on data flags in
753 			 * jz_mmc_prepare_data_transfer().
754 			 */
755 			timeout = jz4740_mmc_read_data(host, data);
756 		else
757 			timeout = jz4740_mmc_write_data(host, data);
758 
759 		if (unlikely(timeout)) {
760 			host->state = JZ4740_MMC_STATE_TRANSFER_DATA;
761 			break;
762 		}
763 
764 		jz4740_mmc_transfer_check_state(host, data);
765 
766 		timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_DATA_TRAN_DONE);
767 		if (unlikely(timeout)) {
768 			host->state = JZ4740_MMC_STATE_SEND_STOP;
769 			break;
770 		}
771 		jz4740_mmc_write_irq_reg(host, JZ_MMC_IRQ_DATA_TRAN_DONE);
772 		fallthrough;
773 
774 	case JZ4740_MMC_STATE_SEND_STOP:
775 		if (!req->stop)
776 			break;
777 
778 		jz4740_mmc_send_command(host, req->stop);
779 
780 		if (mmc_resp_type(req->stop) & MMC_RSP_BUSY) {
781 			timeout = jz4740_mmc_poll_irq(host,
782 						      JZ_MMC_IRQ_PRG_DONE);
783 			if (timeout) {
784 				host->state = JZ4740_MMC_STATE_DONE;
785 				break;
786 			}
787 		}
788 		fallthrough;
789 
790 	case JZ4740_MMC_STATE_DONE:
791 		break;
792 	}
793 
794 	if (!timeout)
795 		jz4740_mmc_request_done(host);
796 
797 	return IRQ_HANDLED;
798 }
799 
800 static irqreturn_t jz_mmc_irq(int irq, void *devid)
801 {
802 	struct jz4740_mmc_host *host = devid;
803 	struct mmc_command *cmd = host->cmd;
804 	uint32_t irq_reg, status, tmp;
805 
806 	status = readl(host->base + JZ_REG_MMC_STATUS);
807 	irq_reg = jz4740_mmc_read_irq_reg(host);
808 
809 	tmp = irq_reg;
810 	irq_reg &= ~host->irq_mask;
811 
812 	tmp &= ~(JZ_MMC_IRQ_TXFIFO_WR_REQ | JZ_MMC_IRQ_RXFIFO_RD_REQ |
813 		JZ_MMC_IRQ_PRG_DONE | JZ_MMC_IRQ_DATA_TRAN_DONE);
814 
815 	if (tmp != irq_reg)
816 		jz4740_mmc_write_irq_reg(host, tmp & ~irq_reg);
817 
818 	if (irq_reg & JZ_MMC_IRQ_SDIO) {
819 		jz4740_mmc_write_irq_reg(host, JZ_MMC_IRQ_SDIO);
820 		mmc_signal_sdio_irq(host->mmc);
821 		irq_reg &= ~JZ_MMC_IRQ_SDIO;
822 	}
823 
824 	if (host->req && cmd && irq_reg) {
825 		if (test_and_clear_bit(0, &host->waiting)) {
826 			del_timer(&host->timeout_timer);
827 
828 			if (status & JZ_MMC_STATUS_TIMEOUT_RES) {
829 				cmd->error = -ETIMEDOUT;
830 			} else if (status & JZ_MMC_STATUS_CRC_RES_ERR) {
831 				cmd->error = -EIO;
832 			} else if (status & (JZ_MMC_STATUS_CRC_READ_ERROR |
833 				    JZ_MMC_STATUS_CRC_WRITE_ERROR)) {
834 				if (cmd->data)
835 					cmd->data->error = -EIO;
836 				cmd->error = -EIO;
837 			}
838 
839 			jz4740_mmc_set_irq_enabled(host, irq_reg, false);
840 			jz4740_mmc_write_irq_reg(host, irq_reg);
841 
842 			return IRQ_WAKE_THREAD;
843 		}
844 	}
845 
846 	return IRQ_HANDLED;
847 }
848 
849 static int jz4740_mmc_set_clock_rate(struct jz4740_mmc_host *host, int rate)
850 {
851 	int div = 0;
852 	int real_rate;
853 
854 	jz4740_mmc_clock_disable(host);
855 	clk_set_rate(host->clk, host->mmc->f_max);
856 
857 	real_rate = clk_get_rate(host->clk);
858 
859 	while (real_rate > rate && div < 7) {
860 		++div;
861 		real_rate >>= 1;
862 	}
863 
864 	writew(div, host->base + JZ_REG_MMC_CLKRT);
865 
866 	if (real_rate > 25000000) {
867 		if (host->version >= JZ_MMC_JZ4780) {
868 			writel(JZ_MMC_LPM_DRV_RISING_QTR_PHASE_DLY |
869 				   JZ_MMC_LPM_SMP_RISING_QTR_OR_HALF_PHASE_DLY |
870 				   JZ_MMC_LPM_LOW_POWER_MODE_EN,
871 				   host->base + JZ_REG_MMC_LPM);
872 		} else if (host->version >= JZ_MMC_JZ4760) {
873 			writel(JZ_MMC_LPM_DRV_RISING |
874 				   JZ_MMC_LPM_LOW_POWER_MODE_EN,
875 				   host->base + JZ_REG_MMC_LPM);
876 		} else if (host->version >= JZ_MMC_JZ4725B)
877 			writel(JZ_MMC_LPM_LOW_POWER_MODE_EN,
878 				   host->base + JZ_REG_MMC_LPM);
879 	}
880 
881 	return real_rate;
882 }
883 
884 static void jz4740_mmc_request(struct mmc_host *mmc, struct mmc_request *req)
885 {
886 	struct jz4740_mmc_host *host = mmc_priv(mmc);
887 
888 	host->req = req;
889 
890 	jz4740_mmc_write_irq_reg(host, ~0);
891 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, true);
892 
893 	host->state = JZ4740_MMC_STATE_READ_RESPONSE;
894 	set_bit(0, &host->waiting);
895 	mod_timer(&host->timeout_timer,
896 		  jiffies + msecs_to_jiffies(JZ_MMC_REQ_TIMEOUT_MS));
897 	jz4740_mmc_send_command(host, req->cmd);
898 }
899 
900 static void jz4740_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
901 {
902 	struct jz4740_mmc_host *host = mmc_priv(mmc);
903 	if (ios->clock)
904 		jz4740_mmc_set_clock_rate(host, ios->clock);
905 
906 	switch (ios->power_mode) {
907 	case MMC_POWER_UP:
908 		jz4740_mmc_reset(host);
909 		if (!IS_ERR(mmc->supply.vmmc))
910 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
911 		host->cmdat |= JZ_MMC_CMDAT_INIT;
912 		clk_prepare_enable(host->clk);
913 		break;
914 	case MMC_POWER_ON:
915 		break;
916 	default:
917 		if (!IS_ERR(mmc->supply.vmmc))
918 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
919 		clk_disable_unprepare(host->clk);
920 		break;
921 	}
922 
923 	switch (ios->bus_width) {
924 	case MMC_BUS_WIDTH_1:
925 		host->cmdat &= ~JZ_MMC_CMDAT_BUS_WIDTH_MASK;
926 		break;
927 	case MMC_BUS_WIDTH_4:
928 		host->cmdat &= ~JZ_MMC_CMDAT_BUS_WIDTH_MASK;
929 		host->cmdat |= JZ_MMC_CMDAT_BUS_WIDTH_4BIT;
930 		break;
931 	case MMC_BUS_WIDTH_8:
932 		host->cmdat &= ~JZ_MMC_CMDAT_BUS_WIDTH_MASK;
933 		host->cmdat |= JZ_MMC_CMDAT_BUS_WIDTH_8BIT;
934 		break;
935 	default:
936 		break;
937 	}
938 }
939 
940 static void jz4740_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
941 {
942 	struct jz4740_mmc_host *host = mmc_priv(mmc);
943 	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_SDIO, enable);
944 }
945 
946 static const struct mmc_host_ops jz4740_mmc_ops = {
947 	.request	= jz4740_mmc_request,
948 	.pre_req	= jz4740_mmc_pre_request,
949 	.post_req	= jz4740_mmc_post_request,
950 	.set_ios	= jz4740_mmc_set_ios,
951 	.get_ro		= mmc_gpio_get_ro,
952 	.get_cd		= mmc_gpio_get_cd,
953 	.enable_sdio_irq = jz4740_mmc_enable_sdio_irq,
954 };
955 
956 static const struct of_device_id jz4740_mmc_of_match[] = {
957 	{ .compatible = "ingenic,jz4740-mmc", .data = (void *) JZ_MMC_JZ4740 },
958 	{ .compatible = "ingenic,jz4725b-mmc", .data = (void *)JZ_MMC_JZ4725B },
959 	{ .compatible = "ingenic,jz4760-mmc", .data = (void *) JZ_MMC_JZ4760 },
960 	{ .compatible = "ingenic,jz4775-mmc", .data = (void *) JZ_MMC_JZ4780 },
961 	{ .compatible = "ingenic,jz4780-mmc", .data = (void *) JZ_MMC_JZ4780 },
962 	{ .compatible = "ingenic,x1000-mmc", .data = (void *) JZ_MMC_X1000 },
963 	{},
964 };
965 MODULE_DEVICE_TABLE(of, jz4740_mmc_of_match);
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 	const struct of_device_id *match;
973 
974 	mmc = mmc_alloc_host(sizeof(struct jz4740_mmc_host), &pdev->dev);
975 	if (!mmc) {
976 		dev_err(&pdev->dev, "Failed to alloc mmc host structure\n");
977 		return -ENOMEM;
978 	}
979 
980 	host = mmc_priv(mmc);
981 
982 	match = of_match_device(jz4740_mmc_of_match, &pdev->dev);
983 	if (match) {
984 		host->version = (enum jz4740_mmc_version)match->data;
985 	} else {
986 		/* JZ4740 should be the only one using legacy probe */
987 		host->version = JZ_MMC_JZ4740;
988 	}
989 
990 	ret = mmc_of_parse(mmc);
991 	if (ret) {
992 		dev_err_probe(&pdev->dev, ret, "could not parse device properties\n");
993 		goto err_free_host;
994 	}
995 
996 	mmc_regulator_get_supply(mmc);
997 
998 	host->irq = platform_get_irq(pdev, 0);
999 	if (host->irq < 0) {
1000 		ret = host->irq;
1001 		goto err_free_host;
1002 	}
1003 
1004 	host->clk = devm_clk_get(&pdev->dev, "mmc");
1005 	if (IS_ERR(host->clk)) {
1006 		ret = PTR_ERR(host->clk);
1007 		dev_err(&pdev->dev, "Failed to get mmc clock\n");
1008 		goto err_free_host;
1009 	}
1010 
1011 	host->mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1012 	host->base = devm_ioremap_resource(&pdev->dev, host->mem_res);
1013 	if (IS_ERR(host->base)) {
1014 		ret = PTR_ERR(host->base);
1015 		goto err_free_host;
1016 	}
1017 
1018 	mmc->ops = &jz4740_mmc_ops;
1019 	if (!mmc->f_max)
1020 		mmc->f_max = JZ_MMC_CLK_RATE;
1021 	mmc->f_min = mmc->f_max / 128;
1022 	mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
1023 
1024 	/*
1025 	 * We use a fixed timeout of 5s, hence inform the core about it. A
1026 	 * future improvement should instead respect the cmd->busy_timeout.
1027 	 */
1028 	mmc->max_busy_timeout = JZ_MMC_REQ_TIMEOUT_MS;
1029 
1030 	mmc->max_blk_size = (1 << 10) - 1;
1031 	mmc->max_blk_count = (1 << 15) - 1;
1032 	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
1033 
1034 	mmc->max_segs = 128;
1035 	mmc->max_seg_size = mmc->max_req_size;
1036 
1037 	host->mmc = mmc;
1038 	host->pdev = pdev;
1039 	spin_lock_init(&host->lock);
1040 	host->irq_mask = ~0;
1041 
1042 	jz4740_mmc_reset(host);
1043 
1044 	ret = request_threaded_irq(host->irq, jz_mmc_irq, jz_mmc_irq_worker, 0,
1045 			dev_name(&pdev->dev), host);
1046 	if (ret) {
1047 		dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
1048 		goto err_free_host;
1049 	}
1050 
1051 	jz4740_mmc_clock_disable(host);
1052 	timer_setup(&host->timeout_timer, jz4740_mmc_timeout, 0);
1053 
1054 	ret = jz4740_mmc_acquire_dma_channels(host);
1055 	if (ret == -EPROBE_DEFER)
1056 		goto err_free_irq;
1057 	host->use_dma = !ret;
1058 
1059 	platform_set_drvdata(pdev, host);
1060 	ret = mmc_add_host(mmc);
1061 
1062 	if (ret) {
1063 		dev_err(&pdev->dev, "Failed to add mmc host: %d\n", ret);
1064 		goto err_release_dma;
1065 	}
1066 	dev_info(&pdev->dev, "Ingenic SD/MMC card driver registered\n");
1067 
1068 	dev_info(&pdev->dev, "Using %s, %d-bit mode\n",
1069 		 host->use_dma ? "DMA" : "PIO",
1070 		 (mmc->caps & MMC_CAP_8_BIT_DATA) ? 8 :
1071 		 ((mmc->caps & MMC_CAP_4_BIT_DATA) ? 4 : 1));
1072 
1073 	return 0;
1074 
1075 err_release_dma:
1076 	if (host->use_dma)
1077 		jz4740_mmc_release_dma_channels(host);
1078 err_free_irq:
1079 	free_irq(host->irq, host);
1080 err_free_host:
1081 	mmc_free_host(mmc);
1082 
1083 	return ret;
1084 }
1085 
1086 static int jz4740_mmc_remove(struct platform_device *pdev)
1087 {
1088 	struct jz4740_mmc_host *host = platform_get_drvdata(pdev);
1089 
1090 	del_timer_sync(&host->timeout_timer);
1091 	jz4740_mmc_set_irq_enabled(host, 0xff, false);
1092 	jz4740_mmc_reset(host);
1093 
1094 	mmc_remove_host(host->mmc);
1095 
1096 	free_irq(host->irq, host);
1097 
1098 	if (host->use_dma)
1099 		jz4740_mmc_release_dma_channels(host);
1100 
1101 	mmc_free_host(host->mmc);
1102 
1103 	return 0;
1104 }
1105 
1106 static int __maybe_unused jz4740_mmc_suspend(struct device *dev)
1107 {
1108 	return pinctrl_pm_select_sleep_state(dev);
1109 }
1110 
1111 static int __maybe_unused jz4740_mmc_resume(struct device *dev)
1112 {
1113 	return pinctrl_select_default_state(dev);
1114 }
1115 
1116 static SIMPLE_DEV_PM_OPS(jz4740_mmc_pm_ops, jz4740_mmc_suspend,
1117 	jz4740_mmc_resume);
1118 
1119 static struct platform_driver jz4740_mmc_driver = {
1120 	.probe = jz4740_mmc_probe,
1121 	.remove = jz4740_mmc_remove,
1122 	.driver = {
1123 		.name = "jz4740-mmc",
1124 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1125 		.of_match_table = of_match_ptr(jz4740_mmc_of_match),
1126 		.pm = pm_ptr(&jz4740_mmc_pm_ops),
1127 	},
1128 };
1129 
1130 module_platform_driver(jz4740_mmc_driver);
1131 
1132 MODULE_DESCRIPTION("JZ4740 SD/MMC controller driver");
1133 MODULE_LICENSE("GPL");
1134 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
1135