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/errno.h>
21#include <linux/interrupt.h>
22#include <linux/blkdev.h>
23#include <linux/dma-mapping.h>
24#include <linux/dmaengine.h>
25#include <linux/mmc/host.h>
26#include <linux/mmc/sd.h>
27#include <linux/sched.h>
28#include <linux/io.h>
29#include <linux/of_address.h>
30#include <linux/of_irq.h>
31#include <linux/clk.h>
32#include <linux/bitops.h>
33#include <linux/of_dma.h>
34#include <linux/spinlock.h>
35
36#define REG_COMMAND		0
37#define REG_ARGUMENT		4
38#define REG_RESPONSE0		8
39#define REG_RESPONSE1		12
40#define REG_RESPONSE2		16
41#define REG_RESPONSE3		20
42#define REG_RESPONSE_COMMAND	24
43#define REG_DATA_CONTROL	28
44#define REG_DATA_TIMER		32
45#define REG_DATA_LENGTH		36
46#define REG_STATUS		40
47#define REG_CLEAR		44
48#define REG_INTERRUPT_MASK	48
49#define REG_POWER_CONTROL	52
50#define REG_CLOCK_CONTROL	56
51#define REG_BUS_WIDTH		60
52#define REG_DATA_WINDOW		64
53#define REG_FEATURE		68
54#define REG_REVISION		72
55
56/* REG_COMMAND */
57#define CMD_SDC_RESET		BIT(10)
58#define CMD_EN			BIT(9)
59#define CMD_APP_CMD		BIT(8)
60#define CMD_LONG_RSP		BIT(7)
61#define CMD_NEED_RSP		BIT(6)
62#define CMD_IDX_MASK		0x3f
63
64/* REG_RESPONSE_COMMAND */
65#define RSP_CMD_APP		BIT(6)
66#define RSP_CMD_IDX_MASK	0x3f
67
68/* REG_DATA_CONTROL */
69#define DCR_DATA_FIFO_RESET     BIT(8)
70#define DCR_DATA_THRES          BIT(7)
71#define DCR_DATA_EN		BIT(6)
72#define DCR_DMA_EN		BIT(5)
73#define DCR_DATA_WRITE		BIT(4)
74#define DCR_BLK_SIZE		0x0f
75
76/* REG_DATA_LENGTH */
77#define DATA_LEN_MASK		0xffffff
78
79/* REG_STATUS */
80#define WRITE_PROT		BIT(12)
81#define CARD_DETECT		BIT(11)
82/* 1-10 below can be sent to either registers, interrupt or clear. */
83#define CARD_CHANGE		BIT(10)
84#define FIFO_ORUN		BIT(9)
85#define FIFO_URUN		BIT(8)
86#define DATA_END		BIT(7)
87#define CMD_SENT		BIT(6)
88#define DATA_CRC_OK		BIT(5)
89#define RSP_CRC_OK		BIT(4)
90#define DATA_TIMEOUT		BIT(3)
91#define RSP_TIMEOUT		BIT(2)
92#define DATA_CRC_FAIL		BIT(1)
93#define RSP_CRC_FAIL		BIT(0)
94
95#define MASK_RSP		(RSP_TIMEOUT | RSP_CRC_FAIL | \
96				 RSP_CRC_OK  | CARD_DETECT  | CMD_SENT)
97
98#define MASK_DATA		(DATA_CRC_OK   | DATA_END | \
99				 DATA_CRC_FAIL | DATA_TIMEOUT)
100
101#define MASK_INTR_PIO		(FIFO_URUN | FIFO_ORUN | CARD_CHANGE)
102
103/* REG_POWER_CONTROL */
104#define SD_POWER_ON		BIT(4)
105#define SD_POWER_MASK		0x0f
106
107/* REG_CLOCK_CONTROL */
108#define CLK_HISPD		BIT(9)
109#define CLK_OFF			BIT(8)
110#define CLK_SD			BIT(7)
111#define CLK_DIV_MASK		0x7f
112
113/* REG_BUS_WIDTH */
114#define BUS_WIDTH_4_SUPPORT	BIT(3)
115#define BUS_WIDTH_4		BIT(2)
116#define BUS_WIDTH_1		BIT(0)
117
118#define MMC_VDD_360		23
119#define MIN_POWER		(MMC_VDD_360 - SD_POWER_MASK)
120#define MAX_RETRIES		500000
121
122struct moxart_host {
123	spinlock_t			lock;
124
125	void __iomem			*base;
126
127	phys_addr_t			reg_phys;
128
129	struct dma_chan			*dma_chan_tx;
130	struct dma_chan                 *dma_chan_rx;
131	struct dma_async_tx_descriptor	*tx_desc;
132	struct mmc_host			*mmc;
133	struct mmc_request		*mrq;
134	struct scatterlist		*cur_sg;
135	struct completion		dma_complete;
136	struct completion		pio_complete;
137
138	u32				num_sg;
139	u32				data_remain;
140	u32				data_len;
141	u32				fifo_width;
142	u32				timeout;
143	u32				rate;
144
145	long				sysclk;
146
147	bool				have_dma;
148	bool				is_removed;
149};
150
151static inline void moxart_init_sg(struct moxart_host *host,
152				  struct mmc_data *data)
153{
154	host->cur_sg = data->sg;
155	host->num_sg = data->sg_len;
156	host->data_remain = host->cur_sg->length;
157
158	if (host->data_remain > host->data_len)
159		host->data_remain = host->data_len;
160}
161
162static inline int moxart_next_sg(struct moxart_host *host)
163{
164	int remain;
165	struct mmc_data *data = host->mrq->cmd->data;
166
167	host->cur_sg++;
168	host->num_sg--;
169
170	if (host->num_sg > 0) {
171		host->data_remain = host->cur_sg->length;
172		remain = host->data_len - data->bytes_xfered;
173		if (remain > 0 && remain < host->data_remain)
174			host->data_remain = remain;
175	}
176
177	return host->num_sg;
178}
179
180static int moxart_wait_for_status(struct moxart_host *host,
181				  u32 mask, u32 *status)
182{
183	int ret = -ETIMEDOUT;
184	u32 i;
185
186	for (i = 0; i < MAX_RETRIES; i++) {
187		*status = readl(host->base + REG_STATUS);
188		if (!(*status & mask)) {
189			udelay(5);
190			continue;
191		}
192		writel(*status & mask, host->base + REG_CLEAR);
193		ret = 0;
194		break;
195	}
196
197	if (ret)
198		dev_err(mmc_dev(host->mmc), "timed out waiting for status\n");
199
200	return ret;
201}
202
203
204static void moxart_send_command(struct moxart_host *host,
205	struct mmc_command *cmd)
206{
207	u32 status, cmdctrl;
208
209	writel(RSP_TIMEOUT  | RSP_CRC_OK |
210	       RSP_CRC_FAIL | CMD_SENT, host->base + REG_CLEAR);
211	writel(cmd->arg, host->base + REG_ARGUMENT);
212
213	cmdctrl = cmd->opcode & CMD_IDX_MASK;
214	if (cmdctrl == SD_APP_SET_BUS_WIDTH    || cmdctrl == SD_APP_OP_COND   ||
215	    cmdctrl == SD_APP_SEND_SCR         || cmdctrl == SD_APP_SD_STATUS ||
216	    cmdctrl == SD_APP_SEND_NUM_WR_BLKS)
217		cmdctrl |= CMD_APP_CMD;
218
219	if (cmd->flags & MMC_RSP_PRESENT)
220		cmdctrl |= CMD_NEED_RSP;
221
222	if (cmd->flags & MMC_RSP_136)
223		cmdctrl |= CMD_LONG_RSP;
224
225	writel(cmdctrl | CMD_EN, host->base + REG_COMMAND);
226
227	if (moxart_wait_for_status(host, MASK_RSP, &status) == -ETIMEDOUT)
228		cmd->error = -ETIMEDOUT;
229
230	if (status & RSP_TIMEOUT) {
231		cmd->error = -ETIMEDOUT;
232		return;
233	}
234	if (status & RSP_CRC_FAIL) {
235		cmd->error = -EIO;
236		return;
237	}
238	if (status & RSP_CRC_OK) {
239		if (cmd->flags & MMC_RSP_136) {
240			cmd->resp[3] = readl(host->base + REG_RESPONSE0);
241			cmd->resp[2] = readl(host->base + REG_RESPONSE1);
242			cmd->resp[1] = readl(host->base + REG_RESPONSE2);
243			cmd->resp[0] = readl(host->base + REG_RESPONSE3);
244		} else {
245			cmd->resp[0] = readl(host->base + REG_RESPONSE0);
246		}
247	}
248}
249
250static void moxart_dma_complete(void *param)
251{
252	struct moxart_host *host = param;
253
254	complete(&host->dma_complete);
255}
256
257static void moxart_transfer_dma(struct mmc_data *data, struct moxart_host *host)
258{
259	u32 len, dir_slave;
260	long dma_time;
261	struct dma_async_tx_descriptor *desc = NULL;
262	struct dma_chan *dma_chan;
263
264	if (host->data_len == data->bytes_xfered)
265		return;
266
267	if (data->flags & MMC_DATA_WRITE) {
268		dma_chan = host->dma_chan_tx;
269		dir_slave = DMA_MEM_TO_DEV;
270	} else {
271		dma_chan = host->dma_chan_rx;
272		dir_slave = DMA_DEV_TO_MEM;
273	}
274
275	len = dma_map_sg(dma_chan->device->dev, data->sg,
276			 data->sg_len, mmc_get_dma_dir(data));
277
278	if (len > 0) {
279		desc = dmaengine_prep_slave_sg(dma_chan, data->sg,
280					       len, dir_slave,
281					       DMA_PREP_INTERRUPT |
282					       DMA_CTRL_ACK);
283	} else {
284		dev_err(mmc_dev(host->mmc), "dma_map_sg returned zero length\n");
285	}
286
287	if (desc) {
288		host->tx_desc = desc;
289		desc->callback = moxart_dma_complete;
290		desc->callback_param = host;
291		dmaengine_submit(desc);
292		dma_async_issue_pending(dma_chan);
293	}
294
295	data->bytes_xfered += host->data_remain;
296
297	dma_time = wait_for_completion_interruptible_timeout(
298		   &host->dma_complete, host->timeout);
299
300	dma_unmap_sg(dma_chan->device->dev,
301		     data->sg, data->sg_len,
302		     mmc_get_dma_dir(data));
303}
304
305
306static void moxart_transfer_pio(struct moxart_host *host)
307{
308	struct mmc_data *data = host->mrq->cmd->data;
309	u32 *sgp, len = 0, remain, status;
310
311	if (host->data_len == data->bytes_xfered)
312		return;
313
314	sgp = sg_virt(host->cur_sg);
315	remain = host->data_remain;
316
317	if (data->flags & MMC_DATA_WRITE) {
318		while (remain > 0) {
319			if (moxart_wait_for_status(host, FIFO_URUN, &status)
320			     == -ETIMEDOUT) {
321				data->error = -ETIMEDOUT;
322				complete(&host->pio_complete);
323				return;
324			}
325			for (len = 0; len < remain && len < host->fifo_width;) {
326				iowrite32(*sgp, host->base + REG_DATA_WINDOW);
327				sgp++;
328				len += 4;
329			}
330			remain -= len;
331		}
332
333	} else {
334		while (remain > 0) {
335			if (moxart_wait_for_status(host, FIFO_ORUN, &status)
336			    == -ETIMEDOUT) {
337				data->error = -ETIMEDOUT;
338				complete(&host->pio_complete);
339				return;
340			}
341			for (len = 0; len < remain && len < host->fifo_width;) {
342				*sgp = ioread32(host->base + REG_DATA_WINDOW);
343				sgp++;
344				len += 4;
345			}
346			remain -= len;
347		}
348	}
349
350	data->bytes_xfered += host->data_remain - remain;
351	host->data_remain = remain;
352
353	if (host->data_len != data->bytes_xfered)
354		moxart_next_sg(host);
355	else
356		complete(&host->pio_complete);
357}
358
359static void moxart_prepare_data(struct moxart_host *host)
360{
361	struct mmc_data *data = host->mrq->cmd->data;
362	u32 datactrl;
363	int blksz_bits;
364
365	if (!data)
366		return;
367
368	host->data_len = data->blocks * data->blksz;
369	blksz_bits = ffs(data->blksz) - 1;
370	BUG_ON(1 << blksz_bits != data->blksz);
371
372	moxart_init_sg(host, data);
373
374	datactrl = DCR_DATA_EN | (blksz_bits & DCR_BLK_SIZE);
375
376	if (data->flags & MMC_DATA_WRITE)
377		datactrl |= DCR_DATA_WRITE;
378
379	if ((host->data_len > host->fifo_width) && host->have_dma)
380		datactrl |= DCR_DMA_EN;
381
382	writel(DCR_DATA_FIFO_RESET, host->base + REG_DATA_CONTROL);
383	writel(MASK_DATA | FIFO_URUN | FIFO_ORUN, host->base + REG_CLEAR);
384	writel(host->rate, host->base + REG_DATA_TIMER);
385	writel(host->data_len, host->base + REG_DATA_LENGTH);
386	writel(datactrl, host->base + REG_DATA_CONTROL);
387}
388
389static void moxart_request(struct mmc_host *mmc, struct mmc_request *mrq)
390{
391	struct moxart_host *host = mmc_priv(mmc);
392	long pio_time;
393	unsigned long flags;
394	u32 status;
395
396	spin_lock_irqsave(&host->lock, flags);
397
398	init_completion(&host->dma_complete);
399	init_completion(&host->pio_complete);
400
401	host->mrq = mrq;
402
403	if (readl(host->base + REG_STATUS) & CARD_DETECT) {
404		mrq->cmd->error = -ETIMEDOUT;
405		goto request_done;
406	}
407
408	moxart_prepare_data(host);
409	moxart_send_command(host, host->mrq->cmd);
410
411	if (mrq->cmd->data) {
412		if ((host->data_len > host->fifo_width) && host->have_dma) {
413
414			writel(CARD_CHANGE, host->base + REG_INTERRUPT_MASK);
415
416			spin_unlock_irqrestore(&host->lock, flags);
417
418			moxart_transfer_dma(mrq->cmd->data, host);
419
420			spin_lock_irqsave(&host->lock, flags);
421		} else {
422
423			writel(MASK_INTR_PIO, host->base + REG_INTERRUPT_MASK);
424
425			spin_unlock_irqrestore(&host->lock, flags);
426
427			/* PIO transfers start from interrupt. */
428			pio_time = wait_for_completion_interruptible_timeout(
429				   &host->pio_complete, host->timeout);
430
431			spin_lock_irqsave(&host->lock, flags);
432		}
433
434		if (host->is_removed) {
435			dev_err(mmc_dev(host->mmc), "card removed\n");
436			mrq->cmd->error = -ETIMEDOUT;
437			goto request_done;
438		}
439
440		if (moxart_wait_for_status(host, MASK_DATA, &status)
441		    == -ETIMEDOUT) {
442			mrq->cmd->data->error = -ETIMEDOUT;
443			goto request_done;
444		}
445
446		if (status & DATA_CRC_FAIL)
447			mrq->cmd->data->error = -ETIMEDOUT;
448
449		if (mrq->cmd->data->stop)
450			moxart_send_command(host, mrq->cmd->data->stop);
451	}
452
453request_done:
454	spin_unlock_irqrestore(&host->lock, flags);
455	mmc_request_done(host->mmc, mrq);
456}
457
458static irqreturn_t moxart_irq(int irq, void *devid)
459{
460	struct moxart_host *host = (struct moxart_host *)devid;
461	u32 status;
462	unsigned long flags;
463
464	spin_lock_irqsave(&host->lock, flags);
465
466	status = readl(host->base + REG_STATUS);
467	if (status & CARD_CHANGE) {
468		host->is_removed = status & CARD_DETECT;
469		if (host->is_removed && host->have_dma) {
470			dmaengine_terminate_all(host->dma_chan_tx);
471			dmaengine_terminate_all(host->dma_chan_rx);
472		}
473		host->mrq = NULL;
474		writel(MASK_INTR_PIO, host->base + REG_CLEAR);
475		writel(CARD_CHANGE, host->base + REG_INTERRUPT_MASK);
476		mmc_detect_change(host->mmc, 0);
477	}
478	if (status & (FIFO_ORUN | FIFO_URUN) && host->mrq)
479		moxart_transfer_pio(host);
480
481	spin_unlock_irqrestore(&host->lock, flags);
482
483	return IRQ_HANDLED;
484}
485
486static void moxart_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
487{
488	struct moxart_host *host = mmc_priv(mmc);
489	unsigned long flags;
490	u8 power, div;
491	u32 ctrl;
492
493	spin_lock_irqsave(&host->lock, flags);
494
495	if (ios->clock) {
496		for (div = 0; div < CLK_DIV_MASK; ++div) {
497			if (ios->clock >= host->sysclk / (2 * (div + 1)))
498				break;
499		}
500		ctrl = CLK_SD | div;
501		host->rate = host->sysclk / (2 * (div + 1));
502		if (host->rate > host->sysclk)
503			ctrl |= CLK_HISPD;
504		writel(ctrl, host->base + REG_CLOCK_CONTROL);
505	}
506
507	if (ios->power_mode == MMC_POWER_OFF) {
508		writel(readl(host->base + REG_POWER_CONTROL) & ~SD_POWER_ON,
509		       host->base + REG_POWER_CONTROL);
510	} else {
511		if (ios->vdd < MIN_POWER)
512			power = 0;
513		else
514			power = ios->vdd - MIN_POWER;
515
516		writel(SD_POWER_ON | (u32) power,
517		       host->base + REG_POWER_CONTROL);
518	}
519
520	switch (ios->bus_width) {
521	case MMC_BUS_WIDTH_4:
522		writel(BUS_WIDTH_4, host->base + REG_BUS_WIDTH);
523		break;
524	default:
525		writel(BUS_WIDTH_1, host->base + REG_BUS_WIDTH);
526		break;
527	}
528
529	spin_unlock_irqrestore(&host->lock, flags);
530}
531
532
533static int moxart_get_ro(struct mmc_host *mmc)
534{
535	struct moxart_host *host = mmc_priv(mmc);
536
537	return !!(readl(host->base + REG_STATUS) & WRITE_PROT);
538}
539
540static const struct mmc_host_ops moxart_ops = {
541	.request = moxart_request,
542	.set_ios = moxart_set_ios,
543	.get_ro = moxart_get_ro,
544};
545
546static int moxart_probe(struct platform_device *pdev)
547{
548	struct device *dev = &pdev->dev;
549	struct device_node *node = dev->of_node;
550	struct resource res_mmc;
551	struct mmc_host *mmc;
552	struct moxart_host *host = NULL;
553	struct dma_slave_config cfg;
554	struct clk *clk;
555	void __iomem *reg_mmc;
556	int irq, ret;
557	u32 i;
558
559	mmc = mmc_alloc_host(sizeof(struct moxart_host), dev);
560	if (!mmc) {
561		dev_err(dev, "mmc_alloc_host failed\n");
562		ret = -ENOMEM;
563		goto out_mmc;
564	}
565
566	ret = of_address_to_resource(node, 0, &res_mmc);
567	if (ret) {
568		dev_err(dev, "of_address_to_resource failed\n");
569		goto out_mmc;
570	}
571
572	irq = irq_of_parse_and_map(node, 0);
573	if (irq <= 0) {
574		dev_err(dev, "irq_of_parse_and_map failed\n");
575		ret = -EINVAL;
576		goto out_mmc;
577	}
578
579	clk = devm_clk_get(dev, NULL);
580	if (IS_ERR(clk)) {
581		ret = PTR_ERR(clk);
582		goto out_mmc;
583	}
584
585	reg_mmc = devm_ioremap_resource(dev, &res_mmc);
586	if (IS_ERR(reg_mmc)) {
587		ret = PTR_ERR(reg_mmc);
588		goto out_mmc;
589	}
590
591	ret = mmc_of_parse(mmc);
592	if (ret)
593		goto out_mmc;
594
595	host = mmc_priv(mmc);
596	host->mmc = mmc;
597	host->base = reg_mmc;
598	host->reg_phys = res_mmc.start;
599	host->timeout = msecs_to_jiffies(1000);
600	host->sysclk = clk_get_rate(clk);
601	host->fifo_width = readl(host->base + REG_FEATURE) << 2;
602	host->dma_chan_tx = dma_request_chan(dev, "tx");
603	host->dma_chan_rx = dma_request_chan(dev, "rx");
604
605	spin_lock_init(&host->lock);
606
607	mmc->ops = &moxart_ops;
608	mmc->f_max = DIV_ROUND_CLOSEST(host->sysclk, 2);
609	mmc->f_min = DIV_ROUND_CLOSEST(host->sysclk, CLK_DIV_MASK * 2);
610	mmc->ocr_avail = 0xffff00;	/* Support 2.0v - 3.6v power. */
611
612	if (IS_ERR(host->dma_chan_tx) || IS_ERR(host->dma_chan_rx)) {
613		if (PTR_ERR(host->dma_chan_tx) == -EPROBE_DEFER ||
614		    PTR_ERR(host->dma_chan_rx) == -EPROBE_DEFER) {
615			ret = -EPROBE_DEFER;
616			goto out;
617		}
618		if (!IS_ERR(host->dma_chan_tx)) {
619			dma_release_channel(host->dma_chan_tx);
620			host->dma_chan_tx = NULL;
621		}
622		if (!IS_ERR(host->dma_chan_rx)) {
623			dma_release_channel(host->dma_chan_rx);
624			host->dma_chan_rx = NULL;
625		}
626		dev_dbg(dev, "PIO mode transfer enabled\n");
627		host->have_dma = false;
628	} else {
629		dev_dbg(dev, "DMA channels found (%p,%p)\n",
630			 host->dma_chan_tx, host->dma_chan_rx);
631		host->have_dma = true;
632
633		memset(&cfg, 0, sizeof(cfg));
634		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
635		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
636
637		cfg.direction = DMA_MEM_TO_DEV;
638		cfg.src_addr = 0;
639		cfg.dst_addr = host->reg_phys + REG_DATA_WINDOW;
640		dmaengine_slave_config(host->dma_chan_tx, &cfg);
641
642		cfg.direction = DMA_DEV_TO_MEM;
643		cfg.src_addr = host->reg_phys + REG_DATA_WINDOW;
644		cfg.dst_addr = 0;
645		dmaengine_slave_config(host->dma_chan_rx, &cfg);
646	}
647
648	if (readl(host->base + REG_BUS_WIDTH) & BUS_WIDTH_4_SUPPORT)
649		mmc->caps |= MMC_CAP_4_BIT_DATA;
650
651	writel(0, host->base + REG_INTERRUPT_MASK);
652
653	writel(CMD_SDC_RESET, host->base + REG_COMMAND);
654	for (i = 0; i < MAX_RETRIES; i++) {
655		if (!(readl(host->base + REG_COMMAND) & CMD_SDC_RESET))
656			break;
657		udelay(5);
658	}
659
660	ret = devm_request_irq(dev, irq, moxart_irq, 0, "moxart-mmc", host);
661	if (ret)
662		goto out;
663
664	dev_set_drvdata(dev, mmc);
665	ret = mmc_add_host(mmc);
666	if (ret)
667		goto out;
668
669	dev_dbg(dev, "IRQ=%d, FIFO is %d bytes\n", irq, host->fifo_width);
670
671	return 0;
672
673out:
674	if (!IS_ERR_OR_NULL(host->dma_chan_tx))
675		dma_release_channel(host->dma_chan_tx);
676	if (!IS_ERR_OR_NULL(host->dma_chan_rx))
677		dma_release_channel(host->dma_chan_rx);
678out_mmc:
679	if (mmc)
680		mmc_free_host(mmc);
681	return ret;
682}
683
684static int moxart_remove(struct platform_device *pdev)
685{
686	struct mmc_host *mmc = dev_get_drvdata(&pdev->dev);
687	struct moxart_host *host = mmc_priv(mmc);
688
689	dev_set_drvdata(&pdev->dev, NULL);
690
691	if (!IS_ERR_OR_NULL(host->dma_chan_tx))
692		dma_release_channel(host->dma_chan_tx);
693	if (!IS_ERR_OR_NULL(host->dma_chan_rx))
694		dma_release_channel(host->dma_chan_rx);
695	mmc_remove_host(mmc);
696
697	writel(0, host->base + REG_INTERRUPT_MASK);
698	writel(0, host->base + REG_POWER_CONTROL);
699	writel(readl(host->base + REG_CLOCK_CONTROL) | CLK_OFF,
700	       host->base + REG_CLOCK_CONTROL);
701	mmc_free_host(mmc);
702
703	return 0;
704}
705
706static const struct of_device_id moxart_mmc_match[] = {
707	{ .compatible = "moxa,moxart-mmc" },
708	{ .compatible = "faraday,ftsdc010" },
709	{ }
710};
711MODULE_DEVICE_TABLE(of, moxart_mmc_match);
712
713static struct platform_driver moxart_mmc_driver = {
714	.probe      = moxart_probe,
715	.remove     = moxart_remove,
716	.driver     = {
717		.name		= "mmc-moxart",
718		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
719		.of_match_table	= moxart_mmc_match,
720	},
721};
722module_platform_driver(moxart_mmc_driver);
723
724MODULE_ALIAS("platform:mmc-moxart");
725MODULE_DESCRIPTION("MOXA ART MMC driver");
726MODULE_LICENSE("GPL v2");
727MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
728