drivers/mmc/host/pxamci.c - linux-imx - Git at Google

 /*
  *  linux/drivers/mmc/host/pxa.c - PXA MMCI driver
  *
  *  Copyright (C) 2003 Russell King, All Rights Reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  *  This hardware is really sick:
  *   - No way to clear interrupts.
  *   - Have to turn off the clock whenever we touch the device.
  *   - Doesn't tell you how many data blocks were transferred.
  *  Yuck!
  *
  *	1 and 3 byte data transfers not supported
  *	max block length up to 1023
  */
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/ioport.h>
 #include <linux/platform_device.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/dmaengine.h>
 #include <linux/dma-mapping.h>
 #include <linux/dma/pxa-dma.h>
 #include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/mmc/host.h>
 #include <linux/mmc/slot-gpio.h>
 #include <linux/io.h>
 #include <linux/regulator/consumer.h>
 #include <linux/gpio.h>
 #include <linux/gfp.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/of_device.h>

 #include <asm/sizes.h>

 #include <mach/hardware.h>
 #include <linux/platform_data/mmc-pxamci.h>

 #include "pxamci.h"

 #define DRIVER_NAME	"pxa2xx-mci"

 #define NR_SG	1
 #define CLKRT_OFF	(~0)

 #define mmc_has_26MHz()		(cpu_is_pxa300() || cpu_is_pxa310() \
 				|| cpu_is_pxa935())

 struct pxamci_host {
 	struct mmc_host		*mmc;
 	spinlock_t		lock;
 	struct resource		*res;
 	void __iomem		*base;
 	struct clk		*clk;
 	unsigned long		clkrate;
 	int			irq;
 	unsigned int		clkrt;
 	unsigned int		cmdat;
 	unsigned int		imask;
 	unsigned int		power_mode;
 	struct pxamci_platform_data *pdata;

 	struct mmc_request	*mrq;
 	struct mmc_command	*cmd;
 	struct mmc_data		*data;

 	struct dma_chan		*dma_chan_rx;
 	struct dma_chan		*dma_chan_tx;
 	dma_cookie_t		dma_cookie;
 	dma_addr_t		sg_dma;
 	unsigned int		dma_len;

 	unsigned int		dma_dir;
 	unsigned int		dma_drcmrrx;
 	unsigned int		dma_drcmrtx;

 	struct regulator	*vcc;
 };

 static inline void pxamci_init_ocr(struct pxamci_host *host)
 {
 #ifdef CONFIG_REGULATOR
 	host->vcc = devm_regulator_get_optional(mmc_dev(host->mmc), "vmmc");

 	if (IS_ERR(host->vcc))
 		host->vcc = NULL;
 	else {
 		host->mmc->ocr_avail = mmc_regulator_get_ocrmask(host->vcc);
 		if (host->pdata && host->pdata->ocr_mask)
 			dev_warn(mmc_dev(host->mmc),
 				"ocr_mask/setpower will not be used\n");
 	}
 #endif
 	if (host->vcc == NULL) {
 		/* fall-back to platform data */
 		host->mmc->ocr_avail = host->pdata ?
 			host->pdata->ocr_mask :
 			MMC_VDD_32_33 | MMC_VDD_33_34;
 	}
 }

 static inline int pxamci_set_power(struct pxamci_host *host,
 				    unsigned char power_mode,
 				    unsigned int vdd)
 {
 	int on;

 	if (host->vcc) {
 		int ret;

 		if (power_mode == MMC_POWER_UP) {
 			ret = mmc_regulator_set_ocr(host->mmc, host->vcc, vdd);
 			if (ret)
 				return ret;
 		} else if (power_mode == MMC_POWER_OFF) {
 			ret = mmc_regulator_set_ocr(host->mmc, host->vcc, 0);
 			if (ret)
 				return ret;
 		}
 	}
 	if (!host->vcc && host->pdata &&
 	    gpio_is_valid(host->pdata->gpio_power)) {
 		on = ((1 << vdd) & host->pdata->ocr_mask);
 		gpio_set_value(host->pdata->gpio_power,
 			       !!on ^ host->pdata->gpio_power_invert);
 	}
 	if (!host->vcc && host->pdata && host->pdata->setpower)
 		return host->pdata->setpower(mmc_dev(host->mmc), vdd);

 	return 0;
 }

 static void pxamci_stop_clock(struct pxamci_host *host)
 {
 	if (readl(host->base + MMC_STAT) & STAT_CLK_EN) {
 		unsigned long timeout = 10000;
 		unsigned int v;

 		writel(STOP_CLOCK, host->base + MMC_STRPCL);

 		do {
 			v = readl(host->base + MMC_STAT);
 			if (!(v & STAT_CLK_EN))
 				break;
 			udelay(1);
 		} while (timeout--);

 		if (v & STAT_CLK_EN)
 			dev_err(mmc_dev(host->mmc), "unable to stop clock\n");
 	}
 }

 static void pxamci_enable_irq(struct pxamci_host *host, unsigned int mask)
 {
 	unsigned long flags;

 	spin_lock_irqsave(&host->lock, flags);
 	host->imask &= ~mask;
 	writel(host->imask, host->base + MMC_I_MASK);
 	spin_unlock_irqrestore(&host->lock, flags);
 }

 static void pxamci_disable_irq(struct pxamci_host *host, unsigned int mask)
 {
 	unsigned long flags;

 	spin_lock_irqsave(&host->lock, flags);
 	host->imask |= mask;
 	writel(host->imask, host->base + MMC_I_MASK);
 	spin_unlock_irqrestore(&host->lock, flags);
 }

 static void pxamci_dma_irq(void *param);

 static void pxamci_setup_data(struct pxamci_host *host, struct mmc_data *data)
 {
 	struct dma_async_tx_descriptor *tx;
 	enum dma_data_direction direction;
 	struct dma_slave_config	config;
 	struct dma_chan *chan;
 	unsigned int nob = data->blocks;
 	unsigned long long clks;
 	unsigned int timeout;
 	int ret;

 	host->data = data;

 	writel(nob, host->base + MMC_NOB);
 	writel(data->blksz, host->base + MMC_BLKLEN);

 	clks = (unsigned long long)data->timeout_ns * host->clkrate;
 	do_div(clks, 1000000000UL);
 	timeout = (unsigned int)clks + (data->timeout_clks << host->clkrt);
 	writel((timeout + 255) / 256, host->base + MMC_RDTO);

 	memset(&config, 0, sizeof(config));
 	config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 	config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 	config.src_addr = host->res->start + MMC_RXFIFO;
 	config.dst_addr = host->res->start + MMC_TXFIFO;
 	config.src_maxburst = 32;
 	config.dst_maxburst = 32;

 	if (data->flags & MMC_DATA_READ) {
 		host->dma_dir = DMA_FROM_DEVICE;
 		direction = DMA_DEV_TO_MEM;
 		chan = host->dma_chan_rx;
 	} else {
 		host->dma_dir = DMA_TO_DEVICE;
 		direction = DMA_MEM_TO_DEV;
 		chan = host->dma_chan_tx;
 	}

 	config.direction = direction;

 	ret = dmaengine_slave_config(chan, &config);
 	if (ret < 0) {
 		dev_err(mmc_dev(host->mmc), "dma slave config failed\n");
 		return;
 	}

 	host->dma_len = dma_map_sg(chan->device->dev, data->sg, data->sg_len,
 				   host->dma_dir);

 	tx = dmaengine_prep_slave_sg(chan, data->sg, host->dma_len, direction,
 				     DMA_PREP_INTERRUPT);
 	if (!tx) {
 		dev_err(mmc_dev(host->mmc), "prep_slave_sg() failed\n");
 		return;
 	}

 	if (!(data->flags & MMC_DATA_READ)) {
 		tx->callback = pxamci_dma_irq;
 		tx->callback_param = host;
 	}

 	host->dma_cookie = dmaengine_submit(tx);

 	/*
 	 * workaround for erratum #91:
 	 * only start DMA now if we are doing a read,
 	 * otherwise we wait until CMD/RESP has finished
 	 * before starting DMA.
 	 */
 	if (!cpu_is_pxa27x() || data->flags & MMC_DATA_READ)
 		dma_async_issue_pending(chan);
 }

 static void pxamci_start_cmd(struct pxamci_host *host, struct mmc_command *cmd, unsigned int cmdat)
 {
 	WARN_ON(host->cmd != NULL);
 	host->cmd = cmd;

 	if (cmd->flags & MMC_RSP_BUSY)
 		cmdat |= CMDAT_BUSY;

 #define RSP_TYPE(x)	((x) & ~(MMC_RSP_BUSY|MMC_RSP_OPCODE))
 	switch (RSP_TYPE(mmc_resp_type(cmd))) {
 	case RSP_TYPE(MMC_RSP_R1): /* r1, r1b, r6, r7 */
 		cmdat |= CMDAT_RESP_SHORT;
 		break;
 	case RSP_TYPE(MMC_RSP_R3):
 		cmdat |= CMDAT_RESP_R3;
 		break;
 	case RSP_TYPE(MMC_RSP_R2):
 		cmdat |= CMDAT_RESP_R2;
 		break;
 	default:
 		break;
 	}

 	writel(cmd->opcode, host->base + MMC_CMD);
 	writel(cmd->arg >> 16, host->base + MMC_ARGH);
 	writel(cmd->arg & 0xffff, host->base + MMC_ARGL);
 	writel(cmdat, host->base + MMC_CMDAT);
 	writel(host->clkrt, host->base + MMC_CLKRT);

 	writel(START_CLOCK, host->base + MMC_STRPCL);

 	pxamci_enable_irq(host, END_CMD_RES);
 }

 static void pxamci_finish_request(struct pxamci_host *host, struct mmc_request *mrq)
 {
 	host->mrq = NULL;
 	host->cmd = NULL;
 	host->data = NULL;
 	mmc_request_done(host->mmc, mrq);
 }

 static int pxamci_cmd_done(struct pxamci_host *host, unsigned int stat)
 {
 	struct mmc_command *cmd = host->cmd;
 	int i;
 	u32 v;

 	if (!cmd)
 		return 0;

 	host->cmd = NULL;

 	/*
 	 * Did I mention this is Sick.  We always need to
 	 * discard the upper 8 bits of the first 16-bit word.
 	 */
 	v = readl(host->base + MMC_RES) & 0xffff;
 	for (i = 0; i < 4; i++) {
 		u32 w1 = readl(host->base + MMC_RES) & 0xffff;
 		u32 w2 = readl(host->base + MMC_RES) & 0xffff;
 		cmd->resp[i] = v << 24 | w1 << 8 | w2 >> 8;
 		v = w2;
 	}

 	if (stat & STAT_TIME_OUT_RESPONSE) {
 		cmd->error = -ETIMEDOUT;
 	} else if (stat & STAT_RES_CRC_ERR && cmd->flags & MMC_RSP_CRC) {
 		/*
 		 * workaround for erratum #42:
 		 * Intel PXA27x Family Processor Specification Update Rev 001
 		 * A bogus CRC error can appear if the msb of a 136 bit
 		 * response is a one.
 		 */
 		if (cpu_is_pxa27x() &&
 		    (cmd->flags & MMC_RSP_136 && cmd->resp[0] & 0x80000000))
 			pr_debug("ignoring CRC from command %d - *risky*\n", cmd->opcode);
 		else
 			cmd->error = -EILSEQ;
 	}

 	pxamci_disable_irq(host, END_CMD_RES);
 	if (host->data && !cmd->error) {
 		pxamci_enable_irq(host, DATA_TRAN_DONE);
 		/*
 		 * workaround for erratum #91, if doing write
 		 * enable DMA late
 		 */
 		if (cpu_is_pxa27x() && host->data->flags & MMC_DATA_WRITE)
 			dma_async_issue_pending(host->dma_chan_tx);
 	} else {
 		pxamci_finish_request(host, host->mrq);
 	}

 	return 1;
 }

 static int pxamci_data_done(struct pxamci_host *host, unsigned int stat)
 {
 	struct mmc_data *data = host->data;
 	struct dma_chan *chan;

 	if (!data)
 		return 0;

 	if (data->flags & MMC_DATA_READ)
 		chan = host->dma_chan_rx;
 	else
 		chan = host->dma_chan_tx;
 	dma_unmap_sg(chan->device->dev,
 		     data->sg, data->sg_len, host->dma_dir);

 	if (stat & STAT_READ_TIME_OUT)
 		data->error = -ETIMEDOUT;
 	else if (stat & (STAT_CRC_READ_ERROR|STAT_CRC_WRITE_ERROR))
 		data->error = -EILSEQ;

 	/*
 	 * There appears to be a hardware design bug here.  There seems to
 	 * be no way to find out how much data was transferred to the card.
 	 * This means that if there was an error on any block, we mark all
 	 * data blocks as being in error.
 	 */
 	if (!data->error)
 		data->bytes_xfered = data->blocks * data->blksz;
 	else
 		data->bytes_xfered = 0;

 	pxamci_disable_irq(host, DATA_TRAN_DONE);

 	host->data = NULL;
 	if (host->mrq->stop) {
 		pxamci_stop_clock(host);
 		pxamci_start_cmd(host, host->mrq->stop, host->cmdat);
 	} else {
 		pxamci_finish_request(host, host->mrq);
 	}

 	return 1;
 }

 static irqreturn_t pxamci_irq(int irq, void *devid)
 {
 	struct pxamci_host *host = devid;
 	unsigned int ireg;
 	int handled = 0;

 	ireg = readl(host->base + MMC_I_REG) & ~readl(host->base + MMC_I_MASK);

 	if (ireg) {
 		unsigned stat = readl(host->base + MMC_STAT);

 		pr_debug("PXAMCI: irq %08x stat %08x\n", ireg, stat);

 		if (ireg & END_CMD_RES)
 			handled |= pxamci_cmd_done(host, stat);
 		if (ireg & DATA_TRAN_DONE)
 			handled |= pxamci_data_done(host, stat);
 		if (ireg & SDIO_INT) {
 			mmc_signal_sdio_irq(host->mmc);
 			handled = 1;
 		}
 	}

 	return IRQ_RETVAL(handled);
 }

 static void pxamci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 {
 	struct pxamci_host *host = mmc_priv(mmc);
 	unsigned int cmdat;

 	WARN_ON(host->mrq != NULL);

 	host->mrq = mrq;

 	pxamci_stop_clock(host);

 	cmdat = host->cmdat;
 	host->cmdat &= ~CMDAT_INIT;

 	if (mrq->data) {
 		pxamci_setup_data(host, mrq->data);

 		cmdat &= ~CMDAT_BUSY;
 		cmdat |= CMDAT_DATAEN | CMDAT_DMAEN;
 		if (mrq->data->flags & MMC_DATA_WRITE)
 			cmdat |= CMDAT_WRITE;
 	}

 	pxamci_start_cmd(host, mrq->cmd, cmdat);
 }

 static int pxamci_get_ro(struct mmc_host *mmc)
 {
 	struct pxamci_host *host = mmc_priv(mmc);

 	if (host->pdata && gpio_is_valid(host->pdata->gpio_card_ro))
 		return mmc_gpio_get_ro(mmc);
 	if (host->pdata && host->pdata->get_ro)
 		return !!host->pdata->get_ro(mmc_dev(mmc));
 	/*
 	 * Board doesn't support read only detection; let the mmc core
 	 * decide what to do.
 	 */
 	return -ENOSYS;
 }

 static void pxamci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 {
 	struct pxamci_host *host = mmc_priv(mmc);

 	if (ios->clock) {
 		unsigned long rate = host->clkrate;
 		unsigned int clk = rate / ios->clock;

 		if (host->clkrt == CLKRT_OFF)
 			clk_prepare_enable(host->clk);

 		if (ios->clock == 26000000) {
 			/* to support 26MHz */
 			host->clkrt = 7;
 		} else {
 			/* to handle (19.5MHz, 26MHz) */
 			if (!clk)
 				clk = 1;

 			/*
 			 * clk might result in a lower divisor than we
 			 * desire.  check for that condition and adjust
 			 * as appropriate.
 			 */
 			if (rate / clk > ios->clock)
 				clk <<= 1;
 			host->clkrt = fls(clk) - 1;
 		}

 		/*
 		 * we write clkrt on the next command
 		 */
 	} else {
 		pxamci_stop_clock(host);
 		if (host->clkrt != CLKRT_OFF) {
 			host->clkrt = CLKRT_OFF;
 			clk_disable_unprepare(host->clk);
 		}
 	}

 	if (host->power_mode != ios->power_mode) {
 		int ret;

 		host->power_mode = ios->power_mode;

 		ret = pxamci_set_power(host, ios->power_mode, ios->vdd);
 		if (ret) {
 			dev_err(mmc_dev(mmc), "unable to set power\n");
 			/*
 			 * The .set_ios() function in the mmc_host_ops
 			 * struct return void, and failing to set the
 			 * power should be rare so we print an error and
 			 * return here.
 			 */
 			return;
 		}

 		if (ios->power_mode == MMC_POWER_ON)
 			host->cmdat |= CMDAT_INIT;
 	}

 	if (ios->bus_width == MMC_BUS_WIDTH_4)
 		host->cmdat |= CMDAT_SD_4DAT;
 	else
 		host->cmdat &= ~CMDAT_SD_4DAT;

 	dev_dbg(mmc_dev(mmc), "PXAMCI: clkrt = %x cmdat = %x\n",
 		host->clkrt, host->cmdat);
 }

 static void pxamci_enable_sdio_irq(struct mmc_host *host, int enable)
 {
 	struct pxamci_host *pxa_host = mmc_priv(host);

 	if (enable)
 		pxamci_enable_irq(pxa_host, SDIO_INT);
 	else
 		pxamci_disable_irq(pxa_host, SDIO_INT);
 }

 static const struct mmc_host_ops pxamci_ops = {
 	.request		= pxamci_request,
 	.get_cd			= mmc_gpio_get_cd,
 	.get_ro			= pxamci_get_ro,
 	.set_ios		= pxamci_set_ios,
 	.enable_sdio_irq	= pxamci_enable_sdio_irq,
 };

 static void pxamci_dma_irq(void *param)
 {
 	struct pxamci_host *host = param;
 	struct dma_tx_state state;
 	enum dma_status status;
 	struct dma_chan *chan;
 	unsigned long flags;

 	spin_lock_irqsave(&host->lock, flags);

 	if (!host->data)
 		goto out_unlock;

 	if (host->data->flags & MMC_DATA_READ)
 		chan = host->dma_chan_rx;
 	else
 		chan = host->dma_chan_tx;

 	status = dmaengine_tx_status(chan, host->dma_cookie, &state);

 	if (likely(status == DMA_COMPLETE)) {
 		writel(BUF_PART_FULL, host->base + MMC_PRTBUF);
 	} else {
 		pr_err("%s: DMA error on %s channel\n", mmc_hostname(host->mmc),
 			host->data->flags & MMC_DATA_READ ? "rx" : "tx");
 		host->data->error = -EIO;
 		pxamci_data_done(host, 0);
 	}

 out_unlock:
 	spin_unlock_irqrestore(&host->lock, flags);
 }

 static irqreturn_t pxamci_detect_irq(int irq, void *devid)
 {
 	struct pxamci_host *host = mmc_priv(devid);

 	mmc_detect_change(devid, msecs_to_jiffies(host->pdata->detect_delay_ms));
 	return IRQ_HANDLED;
 }

 #ifdef CONFIG_OF
 static const struct of_device_id pxa_mmc_dt_ids[] = {
         { .compatible = "marvell,pxa-mmc" },
         { }
 };

 MODULE_DEVICE_TABLE(of, pxa_mmc_dt_ids);

 static int pxamci_of_init(struct platform_device *pdev)
 {
         struct device_node *np = pdev->dev.of_node;
         struct pxamci_platform_data *pdata;
         u32 tmp;

         if (!np)
                 return 0;

         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
         if (!pdata)
                 return -ENOMEM;

 	pdata->gpio_card_detect =
 		of_get_named_gpio(np, "cd-gpios", 0);
 	pdata->gpio_card_ro =
 		of_get_named_gpio(np, "wp-gpios", 0);

 	/* pxa-mmc specific */
 	pdata->gpio_power =
 		of_get_named_gpio(np, "pxa-mmc,gpio-power", 0);

 	if (of_property_read_u32(np, "pxa-mmc,detect-delay-ms", &tmp) == 0)
 		pdata->detect_delay_ms = tmp;

         pdev->dev.platform_data = pdata;

         return 0;
 }
 #else
 static int pxamci_of_init(struct platform_device *pdev)
 {
         return 0;
 }
 #endif

 static int pxamci_probe(struct platform_device *pdev)
 {
 	struct mmc_host *mmc;
 	struct pxamci_host *host = NULL;
 	struct resource *r, *dmarx, *dmatx;
 	struct pxad_param param_rx, param_tx;
 	int ret, irq, gpio_cd = -1, gpio_ro = -1, gpio_power = -1;
 	dma_cap_mask_t mask;

 	ret = pxamci_of_init(pdev);
 	if (ret)
 		return ret;

 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
 		return irq;

 	mmc = mmc_alloc_host(sizeof(struct pxamci_host), &pdev->dev);
 	if (!mmc) {
 		ret = -ENOMEM;
 		goto out;
 	}

 	mmc->ops = &pxamci_ops;

 	/*
 	 * We can do SG-DMA, but we don't because we never know how much
 	 * data we successfully wrote to the card.
 	 */
 	mmc->max_segs = NR_SG;

 	/*
 	 * Our hardware DMA can handle a maximum of one page per SG entry.
 	 */
 	mmc->max_seg_size = PAGE_SIZE;

 	/*
 	 * Block length register is only 10 bits before PXA27x.
 	 */
 	mmc->max_blk_size = cpu_is_pxa25x() ? 1023 : 2048;

 	/*
 	 * Block count register is 16 bits.
 	 */
 	mmc->max_blk_count = 65535;

 	host = mmc_priv(mmc);
 	host->mmc = mmc;
 	host->pdata = pdev->dev.platform_data;
 	host->clkrt = CLKRT_OFF;

 	host->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(host->clk)) {
 		ret = PTR_ERR(host->clk);
 		host->clk = NULL;
 		goto out;
 	}

 	host->clkrate = clk_get_rate(host->clk);

 	/*
 	 * Calculate minimum clock rate, rounding up.
 	 */
 	mmc->f_min = (host->clkrate + 63) / 64;
 	mmc->f_max = (mmc_has_26MHz()) ? 26000000 : host->clkrate;

 	pxamci_init_ocr(host);

 	mmc->caps = 0;
 	host->cmdat = 0;
 	if (!cpu_is_pxa25x()) {
 		mmc->caps |= MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
 		host->cmdat |= CMDAT_SDIO_INT_EN;
 		if (mmc_has_26MHz())
 			mmc->caps |= MMC_CAP_MMC_HIGHSPEED |
 				     MMC_CAP_SD_HIGHSPEED;
 	}

 	spin_lock_init(&host->lock);
 	host->res = r;
 	host->irq = irq;
 	host->imask = MMC_I_MASK_ALL;

 	host->base = devm_ioremap_resource(&pdev->dev, r);
 	if (IS_ERR(host->base)) {
 		ret = PTR_ERR(host->base);
 		goto out;
 	}

 	/*
 	 * Ensure that the host controller is shut down, and setup
 	 * with our defaults.
 	 */
 	pxamci_stop_clock(host);
 	writel(0, host->base + MMC_SPI);
 	writel(64, host->base + MMC_RESTO);
 	writel(host->imask, host->base + MMC_I_MASK);

 	ret = devm_request_irq(&pdev->dev, host->irq, pxamci_irq, 0,
 			       DRIVER_NAME, host);
 	if (ret)
 		goto out;

 	platform_set_drvdata(pdev, mmc);

 	if (!pdev->dev.of_node) {
 		dmarx = platform_get_resource(pdev, IORESOURCE_DMA, 0);
 		dmatx = platform_get_resource(pdev, IORESOURCE_DMA, 1);
 		if (!dmarx || !dmatx) {
 			ret = -ENXIO;
 			goto out;
 		}
 		param_rx.prio = PXAD_PRIO_LOWEST;
 		param_rx.drcmr = dmarx->start;
 		param_tx.prio = PXAD_PRIO_LOWEST;
 		param_tx.drcmr = dmatx->start;
 	}

 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);

 	host->dma_chan_rx =
 		dma_request_slave_channel_compat(mask, pxad_filter_fn,
 						 &param_rx, &pdev->dev, "rx");
 	if (host->dma_chan_rx == NULL) {
 		dev_err(&pdev->dev, "unable to request rx dma channel\n");
 		ret = -ENODEV;
 		goto out;
 	}

 	host->dma_chan_tx =
 		dma_request_slave_channel_compat(mask, pxad_filter_fn,
 						 &param_tx,  &pdev->dev, "tx");
 	if (host->dma_chan_tx == NULL) {
 		dev_err(&pdev->dev, "unable to request tx dma channel\n");
 		ret = -ENODEV;
 		goto out;
 	}

 	if (host->pdata) {
 		gpio_cd = host->pdata->gpio_card_detect;
 		gpio_ro = host->pdata->gpio_card_ro;
 		gpio_power = host->pdata->gpio_power;
 	}
 	if (gpio_is_valid(gpio_power)) {
 		ret = devm_gpio_request(&pdev->dev, gpio_power,
 					"mmc card power");
 		if (ret) {
 			dev_err(&pdev->dev, "Failed requesting gpio_power %d\n",
 				gpio_power);
 			goto out;
 		}
 		gpio_direction_output(gpio_power,
 				      host->pdata->gpio_power_invert);
 	}
 	if (gpio_is_valid(gpio_ro)) {
 		ret = mmc_gpio_request_ro(mmc, gpio_ro);
 		if (ret) {
 			dev_err(&pdev->dev, "Failed requesting gpio_ro %d\n",
 				gpio_ro);
 			goto out;
 		} else {
 			mmc->caps2 |= host->pdata->gpio_card_ro_invert ?
 				0 : MMC_CAP2_RO_ACTIVE_HIGH;
 		}
 	}

 	if (gpio_is_valid(gpio_cd))
 		ret = mmc_gpio_request_cd(mmc, gpio_cd, 0);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed requesting gpio_cd %d\n", gpio_cd);
 		goto out;
 	}

 	if (host->pdata && host->pdata->init)
 		host->pdata->init(&pdev->dev, pxamci_detect_irq, mmc);

 	if (gpio_is_valid(gpio_power) && host->pdata->setpower)
 		dev_warn(&pdev->dev, "gpio_power and setpower() both defined\n");
 	if (gpio_is_valid(gpio_ro) && host->pdata->get_ro)
 		dev_warn(&pdev->dev, "gpio_ro and get_ro() both defined\n");

 	mmc_add_host(mmc);

 	return 0;

 out:
 	if (host) {
 		if (host->dma_chan_rx)
 			dma_release_channel(host->dma_chan_rx);
 		if (host->dma_chan_tx)
 			dma_release_channel(host->dma_chan_tx);
 	}
 	if (mmc)
 		mmc_free_host(mmc);
 	return ret;
 }

 static int pxamci_remove(struct platform_device *pdev)
 {
 	struct mmc_host *mmc = platform_get_drvdata(pdev);
 	int gpio_cd = -1, gpio_ro = -1, gpio_power = -1;

 	if (mmc) {
 		struct pxamci_host *host = mmc_priv(mmc);

 		mmc_remove_host(mmc);

 		if (host->pdata) {
 			gpio_cd = host->pdata->gpio_card_detect;
 			gpio_ro = host->pdata->gpio_card_ro;
 			gpio_power = host->pdata->gpio_power;
 		}
 		if (host->pdata && host->pdata->exit)
 			host->pdata->exit(&pdev->dev, mmc);

 		pxamci_stop_clock(host);
 		writel(TXFIFO_WR_REQ|RXFIFO_RD_REQ|CLK_IS_OFF|STOP_CMD|
 		       END_CMD_RES|PRG_DONE|DATA_TRAN_DONE,
 		       host->base + MMC_I_MASK);

 		dmaengine_terminate_all(host->dma_chan_rx);
 		dmaengine_terminate_all(host->dma_chan_tx);
 		dma_release_channel(host->dma_chan_rx);
 		dma_release_channel(host->dma_chan_tx);

 		mmc_free_host(mmc);
 	}
 	return 0;
 }

 static struct platform_driver pxamci_driver = {
 	.probe		= pxamci_probe,
 	.remove		= pxamci_remove,
 	.driver		= {
 		.name	= DRIVER_NAME,
 		.of_match_table = of_match_ptr(pxa_mmc_dt_ids),
 	},
 };

 module_platform_driver(pxamci_driver);

 MODULE_DESCRIPTION("PXA Multimedia Card Interface Driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:pxa2xx-mci");
	/*
	* linux/drivers/mmc/host/pxa.c - PXA MMCI driver
	*
	* Copyright (C) 2003 Russell King, All Rights Reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* This hardware is really sick:
	* - No way to clear interrupts.
	* - Have to turn off the clock whenever we touch the device.
	* - Doesn't tell you how many data blocks were transferred.
	* Yuck!
	*
	* 1 and 3 byte data transfers not supported
	* max block length up to 1023
	*/
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/ioport.h>
	#include <linux/platform_device.h>
	#include <linux/delay.h>
	#include <linux/interrupt.h>
	#include <linux/dmaengine.h>
	#include <linux/dma-mapping.h>
	#include <linux/dma/pxa-dma.h>
	#include <linux/clk.h>
	#include <linux/err.h>
	#include <linux/mmc/host.h>
	#include <linux/mmc/slot-gpio.h>
	#include <linux/io.h>
	#include <linux/regulator/consumer.h>
	#include <linux/gpio.h>
	#include <linux/gfp.h>
	#include <linux/of.h>
	#include <linux/of_gpio.h>
	#include <linux/of_device.h>

	#include <asm/sizes.h>

	#include <mach/hardware.h>
	#include <linux/platform_data/mmc-pxamci.h>

	#include "pxamci.h"

	#define DRIVER_NAME "pxa2xx-mci"

	#define NR_SG 1
	#define CLKRT_OFF (~0)

	#define mmc_has_26MHz() (cpu_is_pxa300() \|\| cpu_is_pxa310() \
	\|\| cpu_is_pxa935())

	struct pxamci_host {
	struct mmc_host *mmc;
	spinlock_t lock;
	struct resource *res;
	void __iomem *base;
	struct clk *clk;
	unsigned long clkrate;
	int irq;
	unsigned int clkrt;
	unsigned int cmdat;
	unsigned int imask;
	unsigned int power_mode;
	struct pxamci_platform_data *pdata;

	struct mmc_request *mrq;
	struct mmc_command *cmd;
	struct mmc_data *data;

	struct dma_chan *dma_chan_rx;
	struct dma_chan *dma_chan_tx;
	dma_cookie_t dma_cookie;
	dma_addr_t sg_dma;
	unsigned int dma_len;

	unsigned int dma_dir;
	unsigned int dma_drcmrrx;
	unsigned int dma_drcmrtx;

	struct regulator *vcc;
	};

	static inline void pxamci_init_ocr(struct pxamci_host *host)
	{
	#ifdef CONFIG_REGULATOR
	host->vcc = devm_regulator_get_optional(mmc_dev(host->mmc), "vmmc");

	if (IS_ERR(host->vcc))
	host->vcc = NULL;
	else {
	host->mmc->ocr_avail = mmc_regulator_get_ocrmask(host->vcc);
	if (host->pdata && host->pdata->ocr_mask)
	dev_warn(mmc_dev(host->mmc),
	"ocr_mask/setpower will not be used\n");
	}
	#endif
	if (host->vcc == NULL) {
	/* fall-back to platform data */
	host->mmc->ocr_avail = host->pdata ?
	host->pdata->ocr_mask :
	MMC_VDD_32_33 \| MMC_VDD_33_34;
	}
	}

	static inline int pxamci_set_power(struct pxamci_host *host,
	unsigned char power_mode,
	unsigned int vdd)
	{
	int on;

	if (host->vcc) {
	int ret;

	if (power_mode == MMC_POWER_UP) {
	ret = mmc_regulator_set_ocr(host->mmc, host->vcc, vdd);
	if (ret)
	return ret;
	} else if (power_mode == MMC_POWER_OFF) {
	ret = mmc_regulator_set_ocr(host->mmc, host->vcc, 0);
	if (ret)
	return ret;
	}
	}
	if (!host->vcc && host->pdata &&
	gpio_is_valid(host->pdata->gpio_power)) {
	on = ((1 << vdd) & host->pdata->ocr_mask);
	gpio_set_value(host->pdata->gpio_power,
	!!on ^ host->pdata->gpio_power_invert);
	}
	if (!host->vcc && host->pdata && host->pdata->setpower)
	return host->pdata->setpower(mmc_dev(host->mmc), vdd);

	return 0;
	}

	static void pxamci_stop_clock(struct pxamci_host *host)
	{
	if (readl(host->base + MMC_STAT) & STAT_CLK_EN) {
	unsigned long timeout = 10000;
	unsigned int v;

	writel(STOP_CLOCK, host->base + MMC_STRPCL);

	do {
	v = readl(host->base + MMC_STAT);
	if (!(v & STAT_CLK_EN))
	break;
	udelay(1);
	} while (timeout--);

	if (v & STAT_CLK_EN)
	dev_err(mmc_dev(host->mmc), "unable to stop clock\n");
	}
	}

	static void pxamci_enable_irq(struct pxamci_host *host, unsigned int mask)
	{
	unsigned long flags;

	spin_lock_irqsave(&host->lock, flags);
	host->imask &= ~mask;
	writel(host->imask, host->base + MMC_I_MASK);
	spin_unlock_irqrestore(&host->lock, flags);
	}

	static void pxamci_disable_irq(struct pxamci_host *host, unsigned int mask)
	{
	unsigned long flags;

	spin_lock_irqsave(&host->lock, flags);
	host->imask \|= mask;
	writel(host->imask, host->base + MMC_I_MASK);
	spin_unlock_irqrestore(&host->lock, flags);
	}

	static void pxamci_dma_irq(void *param);

	static void pxamci_setup_data(struct pxamci_host host, struct mmc_data data)
	{
	struct dma_async_tx_descriptor *tx;
	enum dma_data_direction direction;
	struct dma_slave_config config;
	struct dma_chan *chan;
	unsigned int nob = data->blocks;
	unsigned long long clks;
	unsigned int timeout;
	int ret;

	host->data = data;

	writel(nob, host->base + MMC_NOB);
	writel(data->blksz, host->base + MMC_BLKLEN);

	clks = (unsigned long long)data->timeout_ns * host->clkrate;
	do_div(clks, 1000000000UL);
	timeout = (unsigned int)clks + (data->timeout_clks << host->clkrt);
	writel((timeout + 255) / 256, host->base + MMC_RDTO);

	memset(&config, 0, sizeof(config));
	config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
	config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
	config.src_addr = host->res->start + MMC_RXFIFO;
	config.dst_addr = host->res->start + MMC_TXFIFO;
	config.src_maxburst = 32;
	config.dst_maxburst = 32;

	if (data->flags & MMC_DATA_READ) {
	host->dma_dir = DMA_FROM_DEVICE;
	direction = DMA_DEV_TO_MEM;
	chan = host->dma_chan_rx;
	} else {
	host->dma_dir = DMA_TO_DEVICE;
	direction = DMA_MEM_TO_DEV;
	chan = host->dma_chan_tx;
	}

	config.direction = direction;

	ret = dmaengine_slave_config(chan, &config);
	if (ret < 0) {
	dev_err(mmc_dev(host->mmc), "dma slave config failed\n");
	return;
	}

	host->dma_len = dma_map_sg(chan->device->dev, data->sg, data->sg_len,
	host->dma_dir);

	tx = dmaengine_prep_slave_sg(chan, data->sg, host->dma_len, direction,
	DMA_PREP_INTERRUPT);
	if (!tx) {
	dev_err(mmc_dev(host->mmc), "prep_slave_sg() failed\n");
	return;
	}

	if (!(data->flags & MMC_DATA_READ)) {
	tx->callback = pxamci_dma_irq;
	tx->callback_param = host;
	}

	host->dma_cookie = dmaengine_submit(tx);

	/*
	* workaround for erratum #91:
	* only start DMA now if we are doing a read,
	* otherwise we wait until CMD/RESP has finished
	* before starting DMA.
	*/
	if (!cpu_is_pxa27x() \|\| data->flags & MMC_DATA_READ)
	dma_async_issue_pending(chan);
	}

	static void pxamci_start_cmd(struct pxamci_host host, struct mmc_command cmd, unsigned int cmdat)
	{
	WARN_ON(host->cmd != NULL);
	host->cmd = cmd;

	if (cmd->flags & MMC_RSP_BUSY)
	cmdat \|= CMDAT_BUSY;

	#define RSP_TYPE(x) ((x) & ~(MMC_RSP_BUSY\|MMC_RSP_OPCODE))
	switch (RSP_TYPE(mmc_resp_type(cmd))) {
	case RSP_TYPE(MMC_RSP_R1): /* r1, r1b, r6, r7 */
	cmdat \|= CMDAT_RESP_SHORT;
	break;
	case RSP_TYPE(MMC_RSP_R3):
	cmdat \|= CMDAT_RESP_R3;
	break;
	case RSP_TYPE(MMC_RSP_R2):
	cmdat \|= CMDAT_RESP_R2;
	break;
	default:
	break;
	}

	writel(cmd->opcode, host->base + MMC_CMD);
	writel(cmd->arg >> 16, host->base + MMC_ARGH);
	writel(cmd->arg & 0xffff, host->base + MMC_ARGL);
	writel(cmdat, host->base + MMC_CMDAT);
	writel(host->clkrt, host->base + MMC_CLKRT);

	writel(START_CLOCK, host->base + MMC_STRPCL);

	pxamci_enable_irq(host, END_CMD_RES);
	}

	static void pxamci_finish_request(struct pxamci_host host, struct mmc_request mrq)
	{
	host->mrq = NULL;
	host->cmd = NULL;
	host->data = NULL;
	mmc_request_done(host->mmc, mrq);
	}

	static int pxamci_cmd_done(struct pxamci_host *host, unsigned int stat)
	{
	struct mmc_command *cmd = host->cmd;
	int i;
	u32 v;

	if (!cmd)
	return 0;

	host->cmd = NULL;

	/*
	* Did I mention this is Sick. We always need to
	* discard the upper 8 bits of the first 16-bit word.
	*/
	v = readl(host->base + MMC_RES) & 0xffff;
	for (i = 0; i < 4; i++) {
	u32 w1 = readl(host->base + MMC_RES) & 0xffff;
	u32 w2 = readl(host->base + MMC_RES) & 0xffff;
	cmd->resp[i] = v << 24 \| w1 << 8 \| w2 >> 8;
	v = w2;
	}

	if (stat & STAT_TIME_OUT_RESPONSE) {
	cmd->error = -ETIMEDOUT;
	} else if (stat & STAT_RES_CRC_ERR && cmd->flags & MMC_RSP_CRC) {
	/*
	* workaround for erratum #42:
	* Intel PXA27x Family Processor Specification Update Rev 001
	* A bogus CRC error can appear if the msb of a 136 bit
	* response is a one.
	*/
	if (cpu_is_pxa27x() &&
	(cmd->flags & MMC_RSP_136 && cmd->resp[0] & 0x80000000))
	pr_debug("ignoring CRC from command %d - risky\n", cmd->opcode);
	else
	cmd->error = -EILSEQ;
	}

	pxamci_disable_irq(host, END_CMD_RES);
	if (host->data && !cmd->error) {
	pxamci_enable_irq(host, DATA_TRAN_DONE);
	/*
	* workaround for erratum #91, if doing write
	* enable DMA late
	*/
	if (cpu_is_pxa27x() && host->data->flags & MMC_DATA_WRITE)
	dma_async_issue_pending(host->dma_chan_tx);
	} else {
	pxamci_finish_request(host, host->mrq);
	}

	return 1;
	}

	static int pxamci_data_done(struct pxamci_host *host, unsigned int stat)
	{
	struct mmc_data *data = host->data;
	struct dma_chan *chan;

	if (!data)
	return 0;

	if (data->flags & MMC_DATA_READ)
	chan = host->dma_chan_rx;
	else
	chan = host->dma_chan_tx;
	dma_unmap_sg(chan->device->dev,
	data->sg, data->sg_len, host->dma_dir);

	if (stat & STAT_READ_TIME_OUT)
	data->error = -ETIMEDOUT;
	else if (stat & (STAT_CRC_READ_ERROR\|STAT_CRC_WRITE_ERROR))
	data->error = -EILSEQ;

	/*
	* There appears to be a hardware design bug here. There seems to
	* be no way to find out how much data was transferred to the card.
	* This means that if there was an error on any block, we mark all
	* data blocks as being in error.
	*/
	if (!data->error)
	data->bytes_xfered = data->blocks * data->blksz;
	else
	data->bytes_xfered = 0;

	pxamci_disable_irq(host, DATA_TRAN_DONE);

	host->data = NULL;
	if (host->mrq->stop) {
	pxamci_stop_clock(host);
	pxamci_start_cmd(host, host->mrq->stop, host->cmdat);
	} else {
	pxamci_finish_request(host, host->mrq);
	}

	return 1;
	}

	static irqreturn_t pxamci_irq(int irq, void *devid)
	{
	struct pxamci_host *host = devid;
	unsigned int ireg;
	int handled = 0;

	ireg = readl(host->base + MMC_I_REG) & ~readl(host->base + MMC_I_MASK);

	if (ireg) {
	unsigned stat = readl(host->base + MMC_STAT);

	pr_debug("PXAMCI: irq %08x stat %08x\n", ireg, stat);

	if (ireg & END_CMD_RES)
	handled \|= pxamci_cmd_done(host, stat);
	if (ireg & DATA_TRAN_DONE)
	handled \|= pxamci_data_done(host, stat);
	if (ireg & SDIO_INT) {
	mmc_signal_sdio_irq(host->mmc);
	handled = 1;
	}
	}

	return IRQ_RETVAL(handled);
	}

	static void pxamci_request(struct mmc_host mmc, struct mmc_request mrq)
	{
	struct pxamci_host *host = mmc_priv(mmc);
	unsigned int cmdat;

	WARN_ON(host->mrq != NULL);

	host->mrq = mrq;

	pxamci_stop_clock(host);

	cmdat = host->cmdat;
	host->cmdat &= ~CMDAT_INIT;

	if (mrq->data) {
	pxamci_setup_data(host, mrq->data);

	cmdat &= ~CMDAT_BUSY;
	cmdat \|= CMDAT_DATAEN \| CMDAT_DMAEN;
	if (mrq->data->flags & MMC_DATA_WRITE)
	cmdat \|= CMDAT_WRITE;
	}

	pxamci_start_cmd(host, mrq->cmd, cmdat);
	}

	static int pxamci_get_ro(struct mmc_host *mmc)
	{
	struct pxamci_host *host = mmc_priv(mmc);

	if (host->pdata && gpio_is_valid(host->pdata->gpio_card_ro))
	return mmc_gpio_get_ro(mmc);
	if (host->pdata && host->pdata->get_ro)
	return !!host->pdata->get_ro(mmc_dev(mmc));
	/*
	* Board doesn't support read only detection; let the mmc core
	* decide what to do.
	*/
	return -ENOSYS;
	}

	static void pxamci_set_ios(struct mmc_host mmc, struct mmc_ios ios)
	{
	struct pxamci_host *host = mmc_priv(mmc);

	if (ios->clock) {
	unsigned long rate = host->clkrate;
	unsigned int clk = rate / ios->clock;

	if (host->clkrt == CLKRT_OFF)
	clk_prepare_enable(host->clk);

	if (ios->clock == 26000000) {
	/* to support 26MHz */
	host->clkrt = 7;
	} else {
	/* to handle (19.5MHz, 26MHz) */
	if (!clk)
	clk = 1;

	/*
	* clk might result in a lower divisor than we
	* desire. check for that condition and adjust
	* as appropriate.
	*/
	if (rate / clk > ios->clock)
	clk <<= 1;
	host->clkrt = fls(clk) - 1;
	}

	/*
	* we write clkrt on the next command
	*/
	} else {
	pxamci_stop_clock(host);
	if (host->clkrt != CLKRT_OFF) {
	host->clkrt = CLKRT_OFF;
	clk_disable_unprepare(host->clk);
	}
	}

	if (host->power_mode != ios->power_mode) {
	int ret;

	host->power_mode = ios->power_mode;

	ret = pxamci_set_power(host, ios->power_mode, ios->vdd);
	if (ret) {
	dev_err(mmc_dev(mmc), "unable to set power\n");
	/*
	* The .set_ios() function in the mmc_host_ops
	* struct return void, and failing to set the
	* power should be rare so we print an error and
	* return here.
	*/
	return;
	}

	if (ios->power_mode == MMC_POWER_ON)
	host->cmdat \|= CMDAT_INIT;
	}

	if (ios->bus_width == MMC_BUS_WIDTH_4)
	host->cmdat \|= CMDAT_SD_4DAT;
	else
	host->cmdat &= ~CMDAT_SD_4DAT;

	dev_dbg(mmc_dev(mmc), "PXAMCI: clkrt = %x cmdat = %x\n",
	host->clkrt, host->cmdat);
	}

	static void pxamci_enable_sdio_irq(struct mmc_host *host, int enable)
	{
	struct pxamci_host *pxa_host = mmc_priv(host);

	if (enable)
	pxamci_enable_irq(pxa_host, SDIO_INT);
	else
	pxamci_disable_irq(pxa_host, SDIO_INT);
	}

	static const struct mmc_host_ops pxamci_ops = {
	.request = pxamci_request,
	.get_cd = mmc_gpio_get_cd,
	.get_ro = pxamci_get_ro,
	.set_ios = pxamci_set_ios,
	.enable_sdio_irq = pxamci_enable_sdio_irq,
	};

	static void pxamci_dma_irq(void *param)
	{
	struct pxamci_host *host = param;
	struct dma_tx_state state;
	enum dma_status status;
	struct dma_chan *chan;
	unsigned long flags;

	spin_lock_irqsave(&host->lock, flags);

	if (!host->data)
	goto out_unlock;

	if (host->data->flags & MMC_DATA_READ)
	chan = host->dma_chan_rx;
	else
	chan = host->dma_chan_tx;

	status = dmaengine_tx_status(chan, host->dma_cookie, &state);

	if (likely(status == DMA_COMPLETE)) {
	writel(BUF_PART_FULL, host->base + MMC_PRTBUF);
	} else {
	pr_err("%s: DMA error on %s channel\n", mmc_hostname(host->mmc),
	host->data->flags & MMC_DATA_READ ? "rx" : "tx");
	host->data->error = -EIO;
	pxamci_data_done(host, 0);
	}

	out_unlock:
	spin_unlock_irqrestore(&host->lock, flags);
	}

	static irqreturn_t pxamci_detect_irq(int irq, void *devid)
	{
	struct pxamci_host *host = mmc_priv(devid);

	mmc_detect_change(devid, msecs_to_jiffies(host->pdata->detect_delay_ms));
	return IRQ_HANDLED;
	}

	#ifdef CONFIG_OF
	static const struct of_device_id pxa_mmc_dt_ids[] = {
	{ .compatible = "marvell,pxa-mmc" },
	{ }
	};

	MODULE_DEVICE_TABLE(of, pxa_mmc_dt_ids);

	static int pxamci_of_init(struct platform_device *pdev)
	{
	struct device_node *np = pdev->dev.of_node;
	struct pxamci_platform_data *pdata;
	u32 tmp;

	if (!np)
	return 0;

	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
	return -ENOMEM;

	pdata->gpio_card_detect =
	of_get_named_gpio(np, "cd-gpios", 0);
	pdata->gpio_card_ro =
	of_get_named_gpio(np, "wp-gpios", 0);

	/* pxa-mmc specific */
	pdata->gpio_power =
	of_get_named_gpio(np, "pxa-mmc,gpio-power", 0);

	if (of_property_read_u32(np, "pxa-mmc,detect-delay-ms", &tmp) == 0)
	pdata->detect_delay_ms = tmp;

	pdev->dev.platform_data = pdata;

	return 0;
	}
	#else
	static int pxamci_of_init(struct platform_device *pdev)
	{
	return 0;
	}
	#endif

	static int pxamci_probe(struct platform_device *pdev)
	{
	struct mmc_host *mmc;
	struct pxamci_host *host = NULL;
	struct resource r, dmarx, *dmatx;
	struct pxad_param param_rx, param_tx;
	int ret, irq, gpio_cd = -1, gpio_ro = -1, gpio_power = -1;
	dma_cap_mask_t mask;

	ret = pxamci_of_init(pdev);
	if (ret)
	return ret;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
	return irq;

	mmc = mmc_alloc_host(sizeof(struct pxamci_host), &pdev->dev);
	if (!mmc) {
	ret = -ENOMEM;
	goto out;
	}

	mmc->ops = &pxamci_ops;

	/*
	* We can do SG-DMA, but we don't because we never know how much
	* data we successfully wrote to the card.
	*/
	mmc->max_segs = NR_SG;

	/*
	* Our hardware DMA can handle a maximum of one page per SG entry.
	*/
	mmc->max_seg_size = PAGE_SIZE;

	/*
	* Block length register is only 10 bits before PXA27x.
	*/
	mmc->max_blk_size = cpu_is_pxa25x() ? 1023 : 2048;

	/*
	* Block count register is 16 bits.
	*/
	mmc->max_blk_count = 65535;

	host = mmc_priv(mmc);
	host->mmc = mmc;
	host->pdata = pdev->dev.platform_data;
	host->clkrt = CLKRT_OFF;

	host->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(host->clk)) {
	ret = PTR_ERR(host->clk);
	host->clk = NULL;
	goto out;
	}

	host->clkrate = clk_get_rate(host->clk);

	/*
	* Calculate minimum clock rate, rounding up.
	*/
	mmc->f_min = (host->clkrate + 63) / 64;
	mmc->f_max = (mmc_has_26MHz()) ? 26000000 : host->clkrate;

	pxamci_init_ocr(host);

	mmc->caps = 0;
	host->cmdat = 0;
	if (!cpu_is_pxa25x()) {
	mmc->caps \|= MMC_CAP_4_BIT_DATA \| MMC_CAP_SDIO_IRQ;
	host->cmdat \|= CMDAT_SDIO_INT_EN;
	if (mmc_has_26MHz())
	mmc->caps \|= MMC_CAP_MMC_HIGHSPEED \|
	MMC_CAP_SD_HIGHSPEED;
	}

	spin_lock_init(&host->lock);
	host->res = r;
	host->irq = irq;
	host->imask = MMC_I_MASK_ALL;

	host->base = devm_ioremap_resource(&pdev->dev, r);
	if (IS_ERR(host->base)) {
	ret = PTR_ERR(host->base);
	goto out;
	}

	/*
	* Ensure that the host controller is shut down, and setup
	* with our defaults.
	*/
	pxamci_stop_clock(host);
	writel(0, host->base + MMC_SPI);
	writel(64, host->base + MMC_RESTO);
	writel(host->imask, host->base + MMC_I_MASK);

	ret = devm_request_irq(&pdev->dev, host->irq, pxamci_irq, 0,
	DRIVER_NAME, host);
	if (ret)
	goto out;

	platform_set_drvdata(pdev, mmc);

	if (!pdev->dev.of_node) {
	dmarx = platform_get_resource(pdev, IORESOURCE_DMA, 0);
	dmatx = platform_get_resource(pdev, IORESOURCE_DMA, 1);
	if (!dmarx \|\| !dmatx) {
	ret = -ENXIO;
	goto out;
	}
	param_rx.prio = PXAD_PRIO_LOWEST;
	param_rx.drcmr = dmarx->start;
	param_tx.prio = PXAD_PRIO_LOWEST;
	param_tx.drcmr = dmatx->start;
	}

	dma_cap_zero(mask);
	dma_cap_set(DMA_SLAVE, mask);

	host->dma_chan_rx =
	dma_request_slave_channel_compat(mask, pxad_filter_fn,
	&param_rx, &pdev->dev, "rx");
	if (host->dma_chan_rx == NULL) {
	dev_err(&pdev->dev, "unable to request rx dma channel\n");
	ret = -ENODEV;
	goto out;
	}

	host->dma_chan_tx =
	dma_request_slave_channel_compat(mask, pxad_filter_fn,
	&param_tx, &pdev->dev, "tx");
	if (host->dma_chan_tx == NULL) {
	dev_err(&pdev->dev, "unable to request tx dma channel\n");
	ret = -ENODEV;
	goto out;
	}

	if (host->pdata) {
	gpio_cd = host->pdata->gpio_card_detect;
	gpio_ro = host->pdata->gpio_card_ro;
	gpio_power = host->pdata->gpio_power;
	}
	if (gpio_is_valid(gpio_power)) {
	ret = devm_gpio_request(&pdev->dev, gpio_power,
	"mmc card power");
	if (ret) {
	dev_err(&pdev->dev, "Failed requesting gpio_power %d\n",
	gpio_power);
	goto out;
	}
	gpio_direction_output(gpio_power,
	host->pdata->gpio_power_invert);
	}
	if (gpio_is_valid(gpio_ro)) {
	ret = mmc_gpio_request_ro(mmc, gpio_ro);
	if (ret) {
	dev_err(&pdev->dev, "Failed requesting gpio_ro %d\n",
	gpio_ro);
	goto out;
	} else {
	mmc->caps2 \|= host->pdata->gpio_card_ro_invert ?
	0 : MMC_CAP2_RO_ACTIVE_HIGH;
	}
	}

	if (gpio_is_valid(gpio_cd))
	ret = mmc_gpio_request_cd(mmc, gpio_cd, 0);
	if (ret) {
	dev_err(&pdev->dev, "Failed requesting gpio_cd %d\n", gpio_cd);
	goto out;
	}

	if (host->pdata && host->pdata->init)
	host->pdata->init(&pdev->dev, pxamci_detect_irq, mmc);

	if (gpio_is_valid(gpio_power) && host->pdata->setpower)
	dev_warn(&pdev->dev, "gpio_power and setpower() both defined\n");
	if (gpio_is_valid(gpio_ro) && host->pdata->get_ro)
	dev_warn(&pdev->dev, "gpio_ro and get_ro() both defined\n");

	mmc_add_host(mmc);

	return 0;

	out:
	if (host) {
	if (host->dma_chan_rx)
	dma_release_channel(host->dma_chan_rx);
	if (host->dma_chan_tx)
	dma_release_channel(host->dma_chan_tx);
	}
	if (mmc)
	mmc_free_host(mmc);
	return ret;
	}

	static int pxamci_remove(struct platform_device *pdev)
	{
	struct mmc_host *mmc = platform_get_drvdata(pdev);
	int gpio_cd = -1, gpio_ro = -1, gpio_power = -1;

	if (mmc) {
	struct pxamci_host *host = mmc_priv(mmc);

	mmc_remove_host(mmc);

	if (host->pdata) {
	gpio_cd = host->pdata->gpio_card_detect;
	gpio_ro = host->pdata->gpio_card_ro;
	gpio_power = host->pdata->gpio_power;
	}
	if (host->pdata && host->pdata->exit)
	host->pdata->exit(&pdev->dev, mmc);

	pxamci_stop_clock(host);
	writel(TXFIFO_WR_REQ\|RXFIFO_RD_REQ\|CLK_IS_OFF\|STOP_CMD\|
	END_CMD_RES\|PRG_DONE\|DATA_TRAN_DONE,
	host->base + MMC_I_MASK);

	dmaengine_terminate_all(host->dma_chan_rx);
	dmaengine_terminate_all(host->dma_chan_tx);
	dma_release_channel(host->dma_chan_rx);
	dma_release_channel(host->dma_chan_tx);

	mmc_free_host(mmc);
	}
	return 0;
	}

	static struct platform_driver pxamci_driver = {
	.probe = pxamci_probe,
	.remove = pxamci_remove,
	.driver = {
	.name = DRIVER_NAME,
	.of_match_table = of_match_ptr(pxa_mmc_dt_ids),
	},
	};

	module_platform_driver(pxamci_driver);

	MODULE_DESCRIPTION("PXA Multimedia Card Interface Driver");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:pxa2xx-mci");