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1 /*
2  * MOXA ART MMC host driver.
3  *
4  * Copyright (C) 2014 Jonas Jensen
5  *
6  * Jonas Jensen <jonas.jensen@gmail.com>
7  *
8  * Based on code from
9  * Moxa Technologies Co., Ltd. <www.moxa.com>
10  *
11  * This file is licensed under the terms of the GNU General Public
12  * License version 2.  This program is licensed "as is" without any
13  * warranty of any kind, whether express or implied.
14  */
15 
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/platform_device.h>
19 #include <linux/delay.h>
20 #include <linux/interrupt.h>
21 #include <linux/blkdev.h>
22 #include <linux/dma-mapping.h>
23 #include <linux/dmaengine.h>
24 #include <linux/mmc/host.h>
25 #include <linux/mmc/sd.h>
26 #include <linux/sched.h>
27 #include <linux/io.h>
28 #include <linux/of_address.h>
29 #include <linux/of_irq.h>
30 #include <linux/clk.h>
31 #include <linux/bitops.h>
32 #include <linux/of_dma.h>
33 #include <linux/spinlock.h>
34 
35 #define REG_COMMAND		0
36 #define REG_ARGUMENT		4
37 #define REG_RESPONSE0		8
38 #define REG_RESPONSE1		12
39 #define REG_RESPONSE2		16
40 #define REG_RESPONSE3		20
41 #define REG_RESPONSE_COMMAND	24
42 #define REG_DATA_CONTROL	28
43 #define REG_DATA_TIMER		32
44 #define REG_DATA_LENGTH		36
45 #define REG_STATUS		40
46 #define REG_CLEAR		44
47 #define REG_INTERRUPT_MASK	48
48 #define REG_POWER_CONTROL	52
49 #define REG_CLOCK_CONTROL	56
50 #define REG_BUS_WIDTH		60
51 #define REG_DATA_WINDOW		64
52 #define REG_FEATURE		68
53 #define REG_REVISION		72
54 
55 /* REG_COMMAND */
56 #define CMD_SDC_RESET		BIT(10)
57 #define CMD_EN			BIT(9)
58 #define CMD_APP_CMD		BIT(8)
59 #define CMD_LONG_RSP		BIT(7)
60 #define CMD_NEED_RSP		BIT(6)
61 #define CMD_IDX_MASK		0x3f
62 
63 /* REG_RESPONSE_COMMAND */
64 #define RSP_CMD_APP		BIT(6)
65 #define RSP_CMD_IDX_MASK	0x3f
66 
67 /* REG_DATA_CONTROL */
68 #define DCR_DATA_FIFO_RESET     BIT(8)
69 #define DCR_DATA_THRES          BIT(7)
70 #define DCR_DATA_EN		BIT(6)
71 #define DCR_DMA_EN		BIT(5)
72 #define DCR_DATA_WRITE		BIT(4)
73 #define DCR_BLK_SIZE		0x0f
74 
75 /* REG_DATA_LENGTH */
76 #define DATA_LEN_MASK		0xffffff
77 
78 /* REG_STATUS */
79 #define WRITE_PROT		BIT(12)
80 #define CARD_DETECT		BIT(11)
81 /* 1-10 below can be sent to either registers, interrupt or clear. */
82 #define CARD_CHANGE		BIT(10)
83 #define FIFO_ORUN		BIT(9)
84 #define FIFO_URUN		BIT(8)
85 #define DATA_END		BIT(7)
86 #define CMD_SENT		BIT(6)
87 #define DATA_CRC_OK		BIT(5)
88 #define RSP_CRC_OK		BIT(4)
89 #define DATA_TIMEOUT		BIT(3)
90 #define RSP_TIMEOUT		BIT(2)
91 #define DATA_CRC_FAIL		BIT(1)
92 #define RSP_CRC_FAIL		BIT(0)
93 
94 #define MASK_RSP		(RSP_TIMEOUT | RSP_CRC_FAIL | \
95 				 RSP_CRC_OK  | CARD_DETECT  | CMD_SENT)
96 
97 #define MASK_DATA		(DATA_CRC_OK   | DATA_END | \
98 				 DATA_CRC_FAIL | DATA_TIMEOUT)
99 
100 #define MASK_INTR_PIO		(FIFO_URUN | FIFO_ORUN | CARD_CHANGE)
101 
102 /* REG_POWER_CONTROL */
103 #define SD_POWER_ON		BIT(4)
104 #define SD_POWER_MASK		0x0f
105 
106 /* REG_CLOCK_CONTROL */
107 #define CLK_HISPD		BIT(9)
108 #define CLK_OFF			BIT(8)
109 #define CLK_SD			BIT(7)
110 #define CLK_DIV_MASK		0x7f
111 
112 /* REG_BUS_WIDTH */
113 #define BUS_WIDTH_8		BIT(2)
114 #define BUS_WIDTH_4		BIT(1)
115 #define BUS_WIDTH_1		BIT(0)
116 
117 #define MMC_VDD_360		23
118 #define MIN_POWER		(MMC_VDD_360 - SD_POWER_MASK)
119 #define MAX_RETRIES		500000
120 
121 struct moxart_host {
122 	spinlock_t			lock;
123 
124 	void __iomem			*base;
125 
126 	phys_addr_t			reg_phys;
127 
128 	struct dma_chan			*dma_chan_tx;
129 	struct dma_chan                 *dma_chan_rx;
130 	struct dma_async_tx_descriptor	*tx_desc;
131 	struct mmc_host			*mmc;
132 	struct mmc_request		*mrq;
133 	struct scatterlist		*cur_sg;
134 	struct completion		dma_complete;
135 	struct completion		pio_complete;
136 
137 	u32				num_sg;
138 	u32				data_remain;
139 	u32				data_len;
140 	u32				fifo_width;
141 	u32				timeout;
142 	u32				rate;
143 
144 	long				sysclk;
145 
146 	bool				have_dma;
147 	bool				is_removed;
148 };
149 
moxart_init_sg(struct moxart_host * host,struct mmc_data * data)150 static inline void moxart_init_sg(struct moxart_host *host,
151 				  struct mmc_data *data)
152 {
153 	host->cur_sg = data->sg;
154 	host->num_sg = data->sg_len;
155 	host->data_remain = host->cur_sg->length;
156 
157 	if (host->data_remain > host->data_len)
158 		host->data_remain = host->data_len;
159 }
160 
moxart_next_sg(struct moxart_host * host)161 static inline int moxart_next_sg(struct moxart_host *host)
162 {
163 	int remain;
164 	struct mmc_data *data = host->mrq->cmd->data;
165 
166 	host->cur_sg++;
167 	host->num_sg--;
168 
169 	if (host->num_sg > 0) {
170 		host->data_remain = host->cur_sg->length;
171 		remain = host->data_len - data->bytes_xfered;
172 		if (remain > 0 && remain < host->data_remain)
173 			host->data_remain = remain;
174 	}
175 
176 	return host->num_sg;
177 }
178 
moxart_wait_for_status(struct moxart_host * host,u32 mask,u32 * status)179 static int moxart_wait_for_status(struct moxart_host *host,
180 				  u32 mask, u32 *status)
181 {
182 	int ret = -ETIMEDOUT;
183 	u32 i;
184 
185 	for (i = 0; i < MAX_RETRIES; i++) {
186 		*status = readl(host->base + REG_STATUS);
187 		if (!(*status & mask)) {
188 			udelay(5);
189 			continue;
190 		}
191 		writel(*status & mask, host->base + REG_CLEAR);
192 		ret = 0;
193 		break;
194 	}
195 
196 	if (ret)
197 		dev_err(mmc_dev(host->mmc), "timed out waiting for status\n");
198 
199 	return ret;
200 }
201 
202 
moxart_send_command(struct moxart_host * host,struct mmc_command * cmd)203 static void moxart_send_command(struct moxart_host *host,
204 	struct mmc_command *cmd)
205 {
206 	u32 status, cmdctrl;
207 
208 	writel(RSP_TIMEOUT  | RSP_CRC_OK |
209 	       RSP_CRC_FAIL | CMD_SENT, host->base + REG_CLEAR);
210 	writel(cmd->arg, host->base + REG_ARGUMENT);
211 
212 	cmdctrl = cmd->opcode & CMD_IDX_MASK;
213 	if (cmdctrl == SD_APP_SET_BUS_WIDTH    || cmdctrl == SD_APP_OP_COND   ||
214 	    cmdctrl == SD_APP_SEND_SCR         || cmdctrl == SD_APP_SD_STATUS ||
215 	    cmdctrl == SD_APP_SEND_NUM_WR_BLKS)
216 		cmdctrl |= CMD_APP_CMD;
217 
218 	if (cmd->flags & MMC_RSP_PRESENT)
219 		cmdctrl |= CMD_NEED_RSP;
220 
221 	if (cmd->flags & MMC_RSP_136)
222 		cmdctrl |= CMD_LONG_RSP;
223 
224 	writel(cmdctrl | CMD_EN, host->base + REG_COMMAND);
225 
226 	if (moxart_wait_for_status(host, MASK_RSP, &status) == -ETIMEDOUT)
227 		cmd->error = -ETIMEDOUT;
228 
229 	if (status & RSP_TIMEOUT) {
230 		cmd->error = -ETIMEDOUT;
231 		return;
232 	}
233 	if (status & RSP_CRC_FAIL) {
234 		cmd->error = -EIO;
235 		return;
236 	}
237 	if (status & RSP_CRC_OK) {
238 		if (cmd->flags & MMC_RSP_136) {
239 			cmd->resp[3] = readl(host->base + REG_RESPONSE0);
240 			cmd->resp[2] = readl(host->base + REG_RESPONSE1);
241 			cmd->resp[1] = readl(host->base + REG_RESPONSE2);
242 			cmd->resp[0] = readl(host->base + REG_RESPONSE3);
243 		} else {
244 			cmd->resp[0] = readl(host->base + REG_RESPONSE0);
245 		}
246 	}
247 }
248 
moxart_dma_complete(void * param)249 static void moxart_dma_complete(void *param)
250 {
251 	struct moxart_host *host = param;
252 
253 	complete(&host->dma_complete);
254 }
255 
moxart_transfer_dma(struct mmc_data * data,struct moxart_host * host)256 static void moxart_transfer_dma(struct mmc_data *data, struct moxart_host *host)
257 {
258 	u32 len, dir_data, dir_slave;
259 	unsigned long dma_time;
260 	struct dma_async_tx_descriptor *desc = NULL;
261 	struct dma_chan *dma_chan;
262 
263 	if (host->data_len == data->bytes_xfered)
264 		return;
265 
266 	if (data->flags & MMC_DATA_WRITE) {
267 		dma_chan = host->dma_chan_tx;
268 		dir_data = DMA_TO_DEVICE;
269 		dir_slave = DMA_MEM_TO_DEV;
270 	} else {
271 		dma_chan = host->dma_chan_rx;
272 		dir_data = DMA_FROM_DEVICE;
273 		dir_slave = DMA_DEV_TO_MEM;
274 	}
275 
276 	len = dma_map_sg(dma_chan->device->dev, data->sg,
277 			 data->sg_len, dir_data);
278 
279 	if (len > 0) {
280 		desc = dmaengine_prep_slave_sg(dma_chan, data->sg,
281 					       len, dir_slave,
282 					       DMA_PREP_INTERRUPT |
283 					       DMA_CTRL_ACK);
284 	} else {
285 		dev_err(mmc_dev(host->mmc), "dma_map_sg returned zero length\n");
286 	}
287 
288 	if (desc) {
289 		host->tx_desc = desc;
290 		desc->callback = moxart_dma_complete;
291 		desc->callback_param = host;
292 		dmaengine_submit(desc);
293 		dma_async_issue_pending(dma_chan);
294 	}
295 
296 	data->bytes_xfered += host->data_remain;
297 
298 	dma_time = wait_for_completion_interruptible_timeout(
299 		   &host->dma_complete, host->timeout);
300 
301 	dma_unmap_sg(dma_chan->device->dev,
302 		     data->sg, data->sg_len,
303 		     dir_data);
304 }
305 
306 
moxart_transfer_pio(struct moxart_host * host)307 static void moxart_transfer_pio(struct moxart_host *host)
308 {
309 	struct mmc_data *data = host->mrq->cmd->data;
310 	u32 *sgp, len = 0, remain, status;
311 
312 	if (host->data_len == data->bytes_xfered)
313 		return;
314 
315 	sgp = sg_virt(host->cur_sg);
316 	remain = host->data_remain;
317 
318 	if (data->flags & MMC_DATA_WRITE) {
319 		while (remain > 0) {
320 			if (moxart_wait_for_status(host, FIFO_URUN, &status)
321 			     == -ETIMEDOUT) {
322 				data->error = -ETIMEDOUT;
323 				complete(&host->pio_complete);
324 				return;
325 			}
326 			for (len = 0; len < remain && len < host->fifo_width;) {
327 				iowrite32(*sgp, host->base + REG_DATA_WINDOW);
328 				sgp++;
329 				len += 4;
330 			}
331 			remain -= len;
332 		}
333 
334 	} else {
335 		while (remain > 0) {
336 			if (moxart_wait_for_status(host, FIFO_ORUN, &status)
337 			    == -ETIMEDOUT) {
338 				data->error = -ETIMEDOUT;
339 				complete(&host->pio_complete);
340 				return;
341 			}
342 			for (len = 0; len < remain && len < host->fifo_width;) {
343 				/* SCR data must be read in big endian. */
344 				if (data->mrq->cmd->opcode == SD_APP_SEND_SCR)
345 					*sgp = ioread32be(host->base +
346 							  REG_DATA_WINDOW);
347 				else
348 					*sgp = ioread32(host->base +
349 							REG_DATA_WINDOW);
350 				sgp++;
351 				len += 4;
352 			}
353 			remain -= len;
354 		}
355 	}
356 
357 	data->bytes_xfered += host->data_remain - remain;
358 	host->data_remain = remain;
359 
360 	if (host->data_len != data->bytes_xfered)
361 		moxart_next_sg(host);
362 	else
363 		complete(&host->pio_complete);
364 }
365 
moxart_prepare_data(struct moxart_host * host)366 static void moxart_prepare_data(struct moxart_host *host)
367 {
368 	struct mmc_data *data = host->mrq->cmd->data;
369 	u32 datactrl;
370 	int blksz_bits;
371 
372 	if (!data)
373 		return;
374 
375 	host->data_len = data->blocks * data->blksz;
376 	blksz_bits = ffs(data->blksz) - 1;
377 	BUG_ON(1 << blksz_bits != data->blksz);
378 
379 	moxart_init_sg(host, data);
380 
381 	datactrl = DCR_DATA_EN | (blksz_bits & DCR_BLK_SIZE);
382 
383 	if (data->flags & MMC_DATA_WRITE)
384 		datactrl |= DCR_DATA_WRITE;
385 
386 	if ((host->data_len > host->fifo_width) && host->have_dma)
387 		datactrl |= DCR_DMA_EN;
388 
389 	writel(DCR_DATA_FIFO_RESET, host->base + REG_DATA_CONTROL);
390 	writel(MASK_DATA | FIFO_URUN | FIFO_ORUN, host->base + REG_CLEAR);
391 	writel(host->rate, host->base + REG_DATA_TIMER);
392 	writel(host->data_len, host->base + REG_DATA_LENGTH);
393 	writel(datactrl, host->base + REG_DATA_CONTROL);
394 }
395 
moxart_request(struct mmc_host * mmc,struct mmc_request * mrq)396 static void moxart_request(struct mmc_host *mmc, struct mmc_request *mrq)
397 {
398 	struct moxart_host *host = mmc_priv(mmc);
399 	unsigned long pio_time, flags;
400 	u32 status;
401 
402 	spin_lock_irqsave(&host->lock, flags);
403 
404 	init_completion(&host->dma_complete);
405 	init_completion(&host->pio_complete);
406 
407 	host->mrq = mrq;
408 
409 	if (readl(host->base + REG_STATUS) & CARD_DETECT) {
410 		mrq->cmd->error = -ETIMEDOUT;
411 		goto request_done;
412 	}
413 
414 	moxart_prepare_data(host);
415 	moxart_send_command(host, host->mrq->cmd);
416 
417 	if (mrq->cmd->data) {
418 		if ((host->data_len > host->fifo_width) && host->have_dma) {
419 
420 			writel(CARD_CHANGE, host->base + REG_INTERRUPT_MASK);
421 
422 			spin_unlock_irqrestore(&host->lock, flags);
423 
424 			moxart_transfer_dma(mrq->cmd->data, host);
425 
426 			spin_lock_irqsave(&host->lock, flags);
427 		} else {
428 
429 			writel(MASK_INTR_PIO, host->base + REG_INTERRUPT_MASK);
430 
431 			spin_unlock_irqrestore(&host->lock, flags);
432 
433 			/* PIO transfers start from interrupt. */
434 			pio_time = wait_for_completion_interruptible_timeout(
435 				   &host->pio_complete, host->timeout);
436 
437 			spin_lock_irqsave(&host->lock, flags);
438 		}
439 
440 		if (host->is_removed) {
441 			dev_err(mmc_dev(host->mmc), "card removed\n");
442 			mrq->cmd->error = -ETIMEDOUT;
443 			goto request_done;
444 		}
445 
446 		if (moxart_wait_for_status(host, MASK_DATA, &status)
447 		    == -ETIMEDOUT) {
448 			mrq->cmd->data->error = -ETIMEDOUT;
449 			goto request_done;
450 		}
451 
452 		if (status & DATA_CRC_FAIL)
453 			mrq->cmd->data->error = -ETIMEDOUT;
454 
455 		if (mrq->cmd->data->stop)
456 			moxart_send_command(host, mrq->cmd->data->stop);
457 	}
458 
459 request_done:
460 	spin_unlock_irqrestore(&host->lock, flags);
461 	mmc_request_done(host->mmc, mrq);
462 }
463 
moxart_irq(int irq,void * devid)464 static irqreturn_t moxart_irq(int irq, void *devid)
465 {
466 	struct moxart_host *host = (struct moxart_host *)devid;
467 	u32 status;
468 	unsigned long flags;
469 
470 	spin_lock_irqsave(&host->lock, flags);
471 
472 	status = readl(host->base + REG_STATUS);
473 	if (status & CARD_CHANGE) {
474 		host->is_removed = status & CARD_DETECT;
475 		if (host->is_removed && host->have_dma) {
476 			dmaengine_terminate_all(host->dma_chan_tx);
477 			dmaengine_terminate_all(host->dma_chan_rx);
478 		}
479 		host->mrq = NULL;
480 		writel(MASK_INTR_PIO, host->base + REG_CLEAR);
481 		writel(CARD_CHANGE, host->base + REG_INTERRUPT_MASK);
482 		mmc_detect_change(host->mmc, 0);
483 	}
484 	if (status & (FIFO_ORUN | FIFO_URUN) && host->mrq)
485 		moxart_transfer_pio(host);
486 
487 	spin_unlock_irqrestore(&host->lock, flags);
488 
489 	return IRQ_HANDLED;
490 }
491 
moxart_set_ios(struct mmc_host * mmc,struct mmc_ios * ios)492 static void moxart_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
493 {
494 	struct moxart_host *host = mmc_priv(mmc);
495 	unsigned long flags;
496 	u8 power, div;
497 	u32 ctrl;
498 
499 	spin_lock_irqsave(&host->lock, flags);
500 
501 	if (ios->clock) {
502 		for (div = 0; div < CLK_DIV_MASK; ++div) {
503 			if (ios->clock >= host->sysclk / (2 * (div + 1)))
504 				break;
505 		}
506 		ctrl = CLK_SD | div;
507 		host->rate = host->sysclk / (2 * (div + 1));
508 		if (host->rate > host->sysclk)
509 			ctrl |= CLK_HISPD;
510 		writel(ctrl, host->base + REG_CLOCK_CONTROL);
511 	}
512 
513 	if (ios->power_mode == MMC_POWER_OFF) {
514 		writel(readl(host->base + REG_POWER_CONTROL) & ~SD_POWER_ON,
515 		       host->base + REG_POWER_CONTROL);
516 	} else {
517 		if (ios->vdd < MIN_POWER)
518 			power = 0;
519 		else
520 			power = ios->vdd - MIN_POWER;
521 
522 		writel(SD_POWER_ON | (u32) power,
523 		       host->base + REG_POWER_CONTROL);
524 	}
525 
526 	switch (ios->bus_width) {
527 	case MMC_BUS_WIDTH_4:
528 		writel(BUS_WIDTH_4, host->base + REG_BUS_WIDTH);
529 		break;
530 	case MMC_BUS_WIDTH_8:
531 		writel(BUS_WIDTH_8, host->base + REG_BUS_WIDTH);
532 		break;
533 	default:
534 		writel(BUS_WIDTH_1, host->base + REG_BUS_WIDTH);
535 		break;
536 	}
537 
538 	spin_unlock_irqrestore(&host->lock, flags);
539 }
540 
541 
moxart_get_ro(struct mmc_host * mmc)542 static int moxart_get_ro(struct mmc_host *mmc)
543 {
544 	struct moxart_host *host = mmc_priv(mmc);
545 
546 	return !!(readl(host->base + REG_STATUS) & WRITE_PROT);
547 }
548 
549 static struct mmc_host_ops moxart_ops = {
550 	.request = moxart_request,
551 	.set_ios = moxart_set_ios,
552 	.get_ro = moxart_get_ro,
553 };
554 
moxart_probe(struct platform_device * pdev)555 static int moxart_probe(struct platform_device *pdev)
556 {
557 	struct device *dev = &pdev->dev;
558 	struct device_node *node = dev->of_node;
559 	struct resource res_mmc;
560 	struct mmc_host *mmc;
561 	struct moxart_host *host = NULL;
562 	struct dma_slave_config cfg;
563 	struct clk *clk;
564 	void __iomem *reg_mmc;
565 	dma_cap_mask_t mask;
566 	int irq, ret;
567 	u32 i;
568 
569 	mmc = mmc_alloc_host(sizeof(struct moxart_host), dev);
570 	if (!mmc) {
571 		dev_err(dev, "mmc_alloc_host failed\n");
572 		ret = -ENOMEM;
573 		goto out;
574 	}
575 
576 	ret = of_address_to_resource(node, 0, &res_mmc);
577 	if (ret) {
578 		dev_err(dev, "of_address_to_resource failed\n");
579 		goto out;
580 	}
581 
582 	irq = irq_of_parse_and_map(node, 0);
583 	if (irq <= 0) {
584 		dev_err(dev, "irq_of_parse_and_map failed\n");
585 		ret = -EINVAL;
586 		goto out;
587 	}
588 
589 	clk = of_clk_get(node, 0);
590 	if (IS_ERR(clk)) {
591 		dev_err(dev, "of_clk_get failed\n");
592 		ret = PTR_ERR(clk);
593 		goto out;
594 	}
595 
596 	reg_mmc = devm_ioremap_resource(dev, &res_mmc);
597 	if (IS_ERR(reg_mmc)) {
598 		ret = PTR_ERR(reg_mmc);
599 		goto out;
600 	}
601 
602 	mmc_of_parse(mmc);
603 
604 	dma_cap_zero(mask);
605 	dma_cap_set(DMA_SLAVE, mask);
606 
607 	host = mmc_priv(mmc);
608 	host->mmc = mmc;
609 	host->base = reg_mmc;
610 	host->reg_phys = res_mmc.start;
611 	host->timeout = msecs_to_jiffies(1000);
612 	host->sysclk = clk_get_rate(clk);
613 	host->fifo_width = readl(host->base + REG_FEATURE) << 2;
614 	host->dma_chan_tx = of_dma_request_slave_channel(node, "tx");
615 	host->dma_chan_rx = of_dma_request_slave_channel(node, "rx");
616 
617 	spin_lock_init(&host->lock);
618 
619 	mmc->ops = &moxart_ops;
620 	mmc->f_max = DIV_ROUND_CLOSEST(host->sysclk, 2);
621 	mmc->f_min = DIV_ROUND_CLOSEST(host->sysclk, CLK_DIV_MASK * 2);
622 	mmc->ocr_avail = 0xffff00;	/* Support 2.0v - 3.6v power. */
623 
624 	if (IS_ERR(host->dma_chan_tx) || IS_ERR(host->dma_chan_rx)) {
625 		dev_dbg(dev, "PIO mode transfer enabled\n");
626 		host->have_dma = false;
627 	} else {
628 		dev_dbg(dev, "DMA channels found (%p,%p)\n",
629 			 host->dma_chan_tx, host->dma_chan_rx);
630 		host->have_dma = true;
631 
632 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
633 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
634 
635 		cfg.direction = DMA_MEM_TO_DEV;
636 		cfg.src_addr = 0;
637 		cfg.dst_addr = host->reg_phys + REG_DATA_WINDOW;
638 		dmaengine_slave_config(host->dma_chan_tx, &cfg);
639 
640 		cfg.direction = DMA_DEV_TO_MEM;
641 		cfg.src_addr = host->reg_phys + REG_DATA_WINDOW;
642 		cfg.dst_addr = 0;
643 		dmaengine_slave_config(host->dma_chan_rx, &cfg);
644 	}
645 
646 	switch ((readl(host->base + REG_BUS_WIDTH) >> 3) & 3) {
647 	case 1:
648 		mmc->caps |= MMC_CAP_4_BIT_DATA;
649 		break;
650 	case 2:
651 		mmc->caps |= MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA;
652 		break;
653 	default:
654 		break;
655 	}
656 
657 	writel(0, host->base + REG_INTERRUPT_MASK);
658 
659 	writel(CMD_SDC_RESET, host->base + REG_COMMAND);
660 	for (i = 0; i < MAX_RETRIES; i++) {
661 		if (!(readl(host->base + REG_COMMAND) & CMD_SDC_RESET))
662 			break;
663 		udelay(5);
664 	}
665 
666 	ret = devm_request_irq(dev, irq, moxart_irq, 0, "moxart-mmc", host);
667 	if (ret)
668 		goto out;
669 
670 	dev_set_drvdata(dev, mmc);
671 	mmc_add_host(mmc);
672 
673 	dev_dbg(dev, "IRQ=%d, FIFO is %d bytes\n", irq, host->fifo_width);
674 
675 	return 0;
676 
677 out:
678 	if (mmc)
679 		mmc_free_host(mmc);
680 	return ret;
681 }
682 
moxart_remove(struct platform_device * pdev)683 static int moxart_remove(struct platform_device *pdev)
684 {
685 	struct mmc_host *mmc = dev_get_drvdata(&pdev->dev);
686 	struct moxart_host *host = mmc_priv(mmc);
687 
688 	dev_set_drvdata(&pdev->dev, NULL);
689 
690 	if (mmc) {
691 		if (!IS_ERR(host->dma_chan_tx))
692 			dma_release_channel(host->dma_chan_tx);
693 		if (!IS_ERR(host->dma_chan_rx))
694 			dma_release_channel(host->dma_chan_rx);
695 		mmc_remove_host(mmc);
696 		mmc_free_host(mmc);
697 
698 		writel(0, host->base + REG_INTERRUPT_MASK);
699 		writel(0, host->base + REG_POWER_CONTROL);
700 		writel(readl(host->base + REG_CLOCK_CONTROL) | CLK_OFF,
701 		       host->base + REG_CLOCK_CONTROL);
702 	}
703 
704 	kfree(host);
705 
706 	return 0;
707 }
708 
709 static const struct of_device_id moxart_mmc_match[] = {
710 	{ .compatible = "moxa,moxart-mmc" },
711 	{ .compatible = "faraday,ftsdc010" },
712 	{ }
713 };
714 
715 static struct platform_driver moxart_mmc_driver = {
716 	.probe      = moxart_probe,
717 	.remove     = moxart_remove,
718 	.driver     = {
719 		.name		= "mmc-moxart",
720 		.of_match_table	= moxart_mmc_match,
721 	},
722 };
723 module_platform_driver(moxart_mmc_driver);
724 
725 MODULE_ALIAS("platform:mmc-moxart");
726 MODULE_DESCRIPTION("MOXA ART MMC driver");
727 MODULE_LICENSE("GPL v2");
728 MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
729