path: root/drivers/mmc/sunxi_mmc.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2007-2011
 * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
 * Aaron <leafy.myeh@allwinnertech.com>
 *
 * MMC driver for allwinner sunxi platform.
 *
 * This driver is used by the (ARM) SPL with the legacy MMC interface, and
 * by U-Boot proper using the full DM interface. The actual hardware access
 * code is common, and comes first in this file.
 * The legacy MMC interface implementation comes next, followed by the
 * proper DM_MMC implementation at the end.
 */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <log.h>
#include <malloc.h>
#include <mmc.h>
#include <clk.h>
#include <reset.h>
#include <asm/gpio.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/cpu.h>
#include <asm/arch/mmc.h>
#include <linux/delay.h>
#include <sunxi_gpio.h>

#ifndef CCM_MMC_CTRL_MODE_SEL_NEW
#define CCM_MMC_CTRL_MODE_SEL_NEW	0
#endif

struct sunxi_mmc_plat {
	struct mmc_config cfg;
	struct mmc mmc;
};

struct sunxi_mmc_priv {
	unsigned mmc_no;
	uint32_t *mclkreg;
	unsigned fatal_err;
	struct gpio_desc cd_gpio;	/* Change Detect GPIO */
	struct sunxi_mmc *reg;
	struct mmc_config cfg;
};

/*
 * All A64 and later MMC controllers feature auto-calibration. This would
 * normally be detected via the compatible string, but we need something
 * which works in the SPL as well.
 */
static bool sunxi_mmc_can_calibrate(void)
{
	return IS_ENABLED(CONFIG_MACH_SUN50I) ||
	       IS_ENABLED(CONFIG_MACH_SUN50I_H5) ||
	       IS_ENABLED(CONFIG_SUN50I_GEN_H6) ||
	       IS_ENABLED(CONFIG_SUNXI_GEN_NCAT2) ||
	       IS_ENABLED(CONFIG_MACH_SUN8I_R40);
}

static int mmc_set_mod_clk(struct sunxi_mmc_priv *priv, unsigned int hz)
{
	unsigned int pll, pll_hz, div, n, oclk_dly, sclk_dly;
	bool new_mode = IS_ENABLED(CONFIG_MMC_SUNXI_HAS_NEW_MODE);
	u32 val = 0;

	/* A83T support new mode only on eMMC */
	if (IS_ENABLED(CONFIG_MACH_SUN8I_A83T) && priv->mmc_no != 2)
		new_mode = false;

	if (hz <= 24000000) {
		pll = CCM_MMC_CTRL_OSCM24;
		pll_hz = 24000000;
	} else {
#ifdef CONFIG_MACH_SUN9I
		pll = CCM_MMC_CTRL_PLL_PERIPH0;
		pll_hz = clock_get_pll4_periph0();
#else
		/*
		 * SoCs since the A64 (H5, H6, H616) actually use the doubled
		 * rate of PLL6/PERIPH0 as an input clock, but compensate for
		 * that with a fixed post-divider of 2 in the mod clock.
		 * This cancels each other out, so for simplicity we just
		 * pretend it's always PLL6 without a post divider here.
		 */
		pll = CCM_MMC_CTRL_PLL6;
		pll_hz = clock_get_pll6();
#endif
	}

	div = pll_hz / hz;
	if (pll_hz % hz)
		div++;

	n = 0;
	while (div > 16) {
		n++;
		div = (div + 1) / 2;
	}

	if (n > 3) {
		printf("mmc %u error cannot set clock to %u\n", priv->mmc_no,
		       hz);
		return -1;
	}

	/* determine delays */
	if (hz <= 400000) {
		oclk_dly = 0;
		sclk_dly = 0;
	} else if (hz <= 25000000) {
		oclk_dly = 0;
		sclk_dly = 5;
	} else {
		if (IS_ENABLED(CONFIG_MACH_SUN9I)) {
			if (hz <= 52000000)
				oclk_dly = 5;
			else
				oclk_dly = 2;
		} else {
			if (hz <= 52000000)
				oclk_dly = 3;
			else
				oclk_dly = 1;
		}
		sclk_dly = 4;
	}

	if (new_mode) {
		val |= CCM_MMC_CTRL_MODE_SEL_NEW;
		setbits_le32(&priv->reg->ntsr, SUNXI_MMC_NTSR_MODE_SEL_NEW);
	}

	if (!sunxi_mmc_can_calibrate()) {
		/*
		 * Use hardcoded delay values if controller doesn't support
		 * calibration
		 */
		val = CCM_MMC_CTRL_OCLK_DLY(oclk_dly) |
			CCM_MMC_CTRL_SCLK_DLY(sclk_dly);
	}

	writel(CCM_MMC_CTRL_ENABLE| pll | CCM_MMC_CTRL_N(n) |
	       CCM_MMC_CTRL_M(div) | val, priv->mclkreg);

	debug("mmc %u set mod-clk req %u parent %u n %u m %u rate %u\n",
	      priv->mmc_no, hz, pll_hz, 1u << n, div, pll_hz / (1u << n) / div);

	return 0;
}

static int mmc_update_clk(struct sunxi_mmc_priv *priv)
{
	unsigned int cmd;
	unsigned timeout_msecs = 2000;
	unsigned long start = get_timer(0);

	cmd = SUNXI_MMC_CMD_START |
	      SUNXI_MMC_CMD_UPCLK_ONLY |
	      SUNXI_MMC_CMD_WAIT_PRE_OVER;

	writel(cmd, &priv->reg->cmd);
	while (readl(&priv->reg->cmd) & SUNXI_MMC_CMD_START) {
		if (get_timer(start) > timeout_msecs)
			return -1;
	}

	/* clock update sets various irq status bits, clear these */
	writel(readl(&priv->reg->rint), &priv->reg->rint);

	return 0;
}

static int mmc_config_clock(struct sunxi_mmc_priv *priv, struct mmc *mmc)
{
	unsigned rval = readl(&priv->reg->clkcr);

	/* Disable Clock */
	rval &= ~SUNXI_MMC_CLK_ENABLE;
	writel(rval, &priv->reg->clkcr);
	if (mmc_update_clk(priv))
		return -1;

	/* Set mod_clk to new rate */
	if (mmc_set_mod_clk(priv, mmc->clock))
		return -1;

	/* Clear internal divider */
	rval &= ~SUNXI_MMC_CLK_DIVIDER_MASK;
	writel(rval, &priv->reg->clkcr);

#if defined(CONFIG_SUNXI_GEN_SUN6I) || defined(CONFIG_SUN50I_GEN_H6) || defined(CONFIG_SUNXI_GEN_NCAT2)
	/* A64 supports calibration of delays on MMC controller and we
	 * have to set delay of zero before starting calibration.
	 * Allwinner BSP driver sets a delay only in the case of
	 * using HS400 which is not supported by mainline U-Boot or
	 * Linux at the moment
	 */
	if (sunxi_mmc_can_calibrate())
		writel(SUNXI_MMC_CAL_DL_SW_EN, &priv->reg->samp_dl);
#endif

	/* Re-enable Clock */
	rval |= SUNXI_MMC_CLK_ENABLE;
	writel(rval, &priv->reg->clkcr);
	if (mmc_update_clk(priv))
		return -1;

	return 0;
}

static int sunxi_mmc_set_ios_common(struct sunxi_mmc_priv *priv,
				    struct mmc *mmc)
{
	debug("set ios: bus_width: %x, clock: %d\n",
	      mmc->bus_width, mmc->clock);

	/* Change clock first */
	if (mmc->clock && mmc_config_clock(priv, mmc) != 0) {
		priv->fatal_err = 1;
		return -EINVAL;
	}

	/* Change bus width */
	if (mmc->bus_width == 8)
		writel(0x2, &priv->reg->width);
	else if (mmc->bus_width == 4)
		writel(0x1, &priv->reg->width);
	else
		writel(0x0, &priv->reg->width);

	return 0;
}

static int mmc_trans_data_by_cpu(struct sunxi_mmc_priv *priv, struct mmc *mmc,
				 struct mmc_data *data)
{
	const int reading = !!(data->flags & MMC_DATA_READ);
	const uint32_t status_bit = reading ? SUNXI_MMC_STATUS_FIFO_EMPTY :
					      SUNXI_MMC_STATUS_FIFO_FULL;
	unsigned i;
	unsigned *buff = (unsigned int *)(reading ? data->dest : data->src);
	unsigned word_cnt = (data->blocksize * data->blocks) >> 2;
	unsigned timeout_msecs = word_cnt >> 6;
	uint32_t status;
	unsigned long  start;

	if (timeout_msecs < 2000)
		timeout_msecs = 2000;

	/* Always read / write data through the CPU */
	setbits_le32(&priv->reg->gctrl, SUNXI_MMC_GCTRL_ACCESS_BY_AHB);

	start = get_timer(0);

	for (i = 0; i < word_cnt;) {
		unsigned int in_fifo;

		while ((status = readl(&priv->reg->status)) & status_bit) {
			if (get_timer(start) > timeout_msecs)
				return -1;
		}

		/*
		 * For writing we do not easily know the FIFO size, so have
		 * to check the FIFO status after every word written.
		 * TODO: For optimisation we could work out a minimum FIFO
		 * size across all SoCs, and use that together with the current
		 * fill level to write chunks of words.
		 */
		if (!reading) {
			writel(buff[i++], &priv->reg->fifo);
			continue;
		}

		/*
		 * The status register holds the current FIFO level, so we
		 * can be sure to collect as many words from the FIFO
		 * register without checking the status register after every
		 * read. That saves half of the costly MMIO reads, effectively
		 * doubling the read performance.
		 * Some SoCs (A20) report a level of 0 if the FIFO is
		 * completely full (value masked out?). Use a safe minimal
		 * FIFO size in this case.
		 */
		in_fifo = SUNXI_MMC_STATUS_FIFO_LEVEL(status);
		if (in_fifo == 0 && (status & SUNXI_MMC_STATUS_FIFO_FULL))
			in_fifo = 32;
		for (; in_fifo > 0; in_fifo--)
			buff[i++] = readl_relaxed(&priv->reg->fifo);
		dmb();
	}

	return 0;
}

static int mmc_rint_wait(struct sunxi_mmc_priv *priv, struct mmc *mmc,
			 uint timeout_msecs, uint done_bit, const char *what)
{
	unsigned int status;
	unsigned long start = get_timer(0);

	do {
		status = readl(&priv->reg->rint);
		if ((get_timer(start) > timeout_msecs) ||
		    (status & SUNXI_MMC_RINT_INTERRUPT_ERROR_BIT)) {
			debug("%s timeout %x\n", what,
			      status & SUNXI_MMC_RINT_INTERRUPT_ERROR_BIT);
			return -ETIMEDOUT;
		}
	} while (!(status & done_bit));

	return 0;
}

static int sunxi_mmc_send_cmd_common(struct sunxi_mmc_priv *priv,
				     struct mmc *mmc, struct mmc_cmd *cmd,
				     struct mmc_data *data)
{
	unsigned int cmdval = SUNXI_MMC_CMD_START;
	unsigned int timeout_msecs;
	int error = 0;
	unsigned int status = 0;
	unsigned int bytecnt = 0;

	if (priv->fatal_err)
		return -1;
	if (cmd->resp_type & MMC_RSP_BUSY)
		debug("mmc cmd %d check rsp busy\n", cmd->cmdidx);
	if (cmd->cmdidx == 12)
		return 0;

	if (!cmd->cmdidx)
		cmdval |= SUNXI_MMC_CMD_SEND_INIT_SEQ;
	if (cmd->resp_type & MMC_RSP_PRESENT)
		cmdval |= SUNXI_MMC_CMD_RESP_EXPIRE;
	if (cmd->resp_type & MMC_RSP_136)
		cmdval |= SUNXI_MMC_CMD_LONG_RESPONSE;
	if (cmd->resp_type & MMC_RSP_CRC)
		cmdval |= SUNXI_MMC_CMD_CHK_RESPONSE_CRC;

	if (data) {
		if ((u32)(long)data->dest & 0x3) {
			error = -1;
			goto out;
		}

		cmdval |= SUNXI_MMC_CMD_DATA_EXPIRE|SUNXI_MMC_CMD_WAIT_PRE_OVER;
		if (data->flags & MMC_DATA_WRITE)
			cmdval |= SUNXI_MMC_CMD_WRITE;
		if (data->blocks > 1)
			cmdval |= SUNXI_MMC_CMD_AUTO_STOP;
		writel(data->blocksize, &priv->reg->blksz);
		writel(data->blocks * data->blocksize, &priv->reg->bytecnt);
	}

	debug("mmc %d, cmd %d(0x%08x), arg 0x%08x\n", priv->mmc_no,
	      cmd->cmdidx, cmdval | cmd->cmdidx, cmd->cmdarg);
	writel(cmd->cmdarg, &priv->reg->arg);

	if (!data)
		writel(cmdval | cmd->cmdidx, &priv->reg->cmd);

	/*
	 * transfer data and check status
	 * STATREG[2] : FIFO empty
	 * STATREG[3] : FIFO full
	 */
	if (data) {
		int ret = 0;

		bytecnt = data->blocksize * data->blocks;
		debug("trans data %d bytes\n", bytecnt);
		writel(cmdval | cmd->cmdidx, &priv->reg->cmd);
		ret = mmc_trans_data_by_cpu(priv, mmc, data);
		if (ret) {
			error = readl(&priv->reg->rint) &
				SUNXI_MMC_RINT_INTERRUPT_ERROR_BIT;
			error = -ETIMEDOUT;
			goto out;
		}
	}

	error = mmc_rint_wait(priv, mmc, 1000, SUNXI_MMC_RINT_COMMAND_DONE,
			      "cmd");
	if (error)
		goto out;

	if (data) {
		timeout_msecs = 120;
		debug("cacl timeout %x msec\n", timeout_msecs);
		error = mmc_rint_wait(priv, mmc, timeout_msecs,
				      data->blocks > 1 ?
				      SUNXI_MMC_RINT_AUTO_COMMAND_DONE :
				      SUNXI_MMC_RINT_DATA_OVER,
				      "data");
		if (error)
			goto out;
	}

	if (cmd->resp_type & MMC_RSP_BUSY) {
		unsigned long start = get_timer(0);
		timeout_msecs = 2000;

		do {
			status = readl(&priv->reg->status);
			if (get_timer(start) > timeout_msecs) {
				debug("busy timeout\n");
				error = -ETIMEDOUT;
				goto out;
			}
		} while (status & SUNXI_MMC_STATUS_CARD_DATA_BUSY);
	}

	if (cmd->resp_type & MMC_RSP_136) {
		cmd->response[0] = readl(&priv->reg->resp3);
		cmd->response[1] = readl(&priv->reg->resp2);
		cmd->response[2] = readl(&priv->reg->resp1);
		cmd->response[3] = readl(&priv->reg->resp0);
		debug("mmc resp 0x%08x 0x%08x 0x%08x 0x%08x\n",
		      cmd->response[3], cmd->response[2],
		      cmd->response[1], cmd->response[0]);
	} else {
		cmd->response[0] = readl(&priv->reg->resp0);
		debug("mmc resp 0x%08x\n", cmd->response[0]);
	}
out:
	if (error < 0) {
		writel(SUNXI_MMC_GCTRL_RESET, &priv->reg->gctrl);
		mmc_update_clk(priv);
	}
	writel(0xffffffff, &priv->reg->rint);
	writel(readl(&priv->reg->gctrl) | SUNXI_MMC_GCTRL_FIFO_RESET,
	       &priv->reg->gctrl);

	return error;
}

/* non-DM code here is used by the (ARM) SPL only */

#if !CONFIG_IS_ENABLED(DM_MMC)
/* support 4 mmc hosts */
struct sunxi_mmc_priv mmc_host[4];

static int mmc_resource_init(int sdc_no)
{
	struct sunxi_mmc_priv *priv = &mmc_host[sdc_no];
	struct sunxi_ccm_reg *ccm = (struct sunxi_ccm_reg *)SUNXI_CCM_BASE;

	debug("init mmc %d resource\n", sdc_no);

	switch (sdc_no) {
	case 0:
		priv->reg = (struct sunxi_mmc *)SUNXI_MMC0_BASE;
		priv->mclkreg = &ccm->sd0_clk_cfg;
		break;
	case 1:
		priv->reg = (struct sunxi_mmc *)SUNXI_MMC1_BASE;
		priv->mclkreg = &ccm->sd1_clk_cfg;
		break;
#ifdef SUNXI_MMC2_BASE
	case 2:
		priv->reg = (struct sunxi_mmc *)SUNXI_MMC2_BASE;
		priv->mclkreg = &ccm->sd2_clk_cfg;
		break;
#endif
#ifdef SUNXI_MMC3_BASE
	case 3:
		priv->reg = (struct sunxi_mmc *)SUNXI_MMC3_BASE;
		priv->mclkreg = &ccm->sd3_clk_cfg;
		break;
#endif
	default:
		printf("Wrong mmc number %d\n", sdc_no);
		return -1;
	}
	priv->mmc_no = sdc_no;

	return 0;
}

static int sunxi_mmc_core_init(struct mmc *mmc)
{
	struct sunxi_mmc_priv *priv = mmc->priv;

	/* Reset controller */
	writel(SUNXI_MMC_GCTRL_RESET, &priv->reg->gctrl);
	udelay(1000);

	return 0;
}

static int sunxi_mmc_set_ios_legacy(struct mmc *mmc)
{
	struct sunxi_mmc_priv *priv = mmc->priv;

	return sunxi_mmc_set_ios_common(priv, mmc);
}

static int sunxi_mmc_send_cmd_legacy(struct mmc *mmc, struct mmc_cmd *cmd,
				     struct mmc_data *data)
{
	struct sunxi_mmc_priv *priv = mmc->priv;

	return sunxi_mmc_send_cmd_common(priv, mmc, cmd, data);
}

/* .getcd is not needed by the SPL */
static const struct mmc_ops sunxi_mmc_ops = {
	.send_cmd	= sunxi_mmc_send_cmd_legacy,
	.set_ios	= sunxi_mmc_set_ios_legacy,
	.init		= sunxi_mmc_core_init,
};

struct mmc *sunxi_mmc_init(int sdc_no)
{
	struct sunxi_ccm_reg *ccm = (struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
	struct sunxi_mmc_priv *priv = &mmc_host[sdc_no];
	struct mmc_config *cfg = &priv->cfg;
	int ret;

	memset(priv, '\0', sizeof(struct sunxi_mmc_priv));

	cfg->name = "SUNXI SD/MMC";
	cfg->ops  = &sunxi_mmc_ops;

	cfg->voltages = MMC_VDD_32_33 | MMC_VDD_33_34;
	cfg->host_caps = MMC_MODE_4BIT;

	if ((IS_ENABLED(CONFIG_MACH_SUN50I) || IS_ENABLED(CONFIG_MACH_SUN8I) ||
	    IS_ENABLED(CONFIG_SUN50I_GEN_H6)) && (sdc_no == 2))
		cfg->host_caps = MMC_MODE_8BIT;

	cfg->host_caps |= MMC_MODE_HS_52MHz | MMC_MODE_HS;
	cfg->b_max = CONFIG_SYS_MMC_MAX_BLK_COUNT;

	cfg->f_min = 400000;
	cfg->f_max = 52000000;

	if (mmc_resource_init(sdc_no) != 0)
		return NULL;

	/* config ahb clock */
	debug("init mmc %d clock and io\n", sdc_no);
#if !defined(CONFIG_SUN50I_GEN_H6) && !defined(CONFIG_SUNXI_GEN_NCAT2)
	setbits_le32(&ccm->ahb_gate0, 1 << AHB_GATE_OFFSET_MMC(sdc_no));

#ifdef CONFIG_SUNXI_GEN_SUN6I
	/* unassert reset */
	setbits_le32(&ccm->ahb_reset0_cfg, 1 << AHB_RESET_OFFSET_MMC(sdc_no));
#endif
#if defined(CONFIG_MACH_SUN9I)
	/* sun9i has a mmc-common module, also set the gate and reset there */
	writel(SUNXI_MMC_COMMON_CLK_GATE | SUNXI_MMC_COMMON_RESET,
	       SUNXI_MMC_COMMON_BASE + 4 * sdc_no);
#endif
#else /* CONFIG_SUN50I_GEN_H6 */
	setbits_le32(&ccm->sd_gate_reset, 1 << sdc_no);
	/* unassert reset */
	setbits_le32(&ccm->sd_gate_reset, 1 << (RESET_SHIFT + sdc_no));
#endif
	ret = mmc_set_mod_clk(priv, 24000000);
	if (ret)
		return NULL;

	return mmc_create(cfg, priv);
}

#else /* CONFIG_DM_MMC code below, as used by U-Boot proper */

static int sunxi_mmc_set_ios(struct udevice *dev)
{
	struct sunxi_mmc_plat *plat = dev_get_plat(dev);
	struct sunxi_mmc_priv *priv = dev_get_priv(dev);

	return sunxi_mmc_set_ios_common(priv, &plat->mmc);
}

static int sunxi_mmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
			      struct mmc_data *data)
{
	struct sunxi_mmc_plat *plat = dev_get_plat(dev);
	struct sunxi_mmc_priv *priv = dev_get_priv(dev);

	return sunxi_mmc_send_cmd_common(priv, &plat->mmc, cmd, data);
}

static int sunxi_mmc_getcd(struct udevice *dev)
{
	struct mmc *mmc = mmc_get_mmc_dev(dev);
	struct sunxi_mmc_priv *priv = dev_get_priv(dev);

	/* If polling, assume that the card is always present. */
	if ((mmc->cfg->host_caps & MMC_CAP_NONREMOVABLE) ||
	    (mmc->cfg->host_caps & MMC_CAP_NEEDS_POLL))
		return 1;

	if (dm_gpio_is_valid(&priv->cd_gpio)) {
		int cd_state = dm_gpio_get_value(&priv->cd_gpio);

		if (mmc->cfg->host_caps & MMC_CAP_CD_ACTIVE_HIGH)
			return !cd_state;
		else
			return cd_state;
	}
	return 1;
}

static const struct dm_mmc_ops sunxi_mmc_ops = {
	.send_cmd	= sunxi_mmc_send_cmd,
	.set_ios	= sunxi_mmc_set_ios,
	.get_cd		= sunxi_mmc_getcd,
};

static unsigned get_mclk_offset(void)
{
	if (IS_ENABLED(CONFIG_MACH_SUN9I_A80))
		return 0x410;

	if (IS_ENABLED(CONFIG_SUN50I_GEN_H6) || IS_ENABLED(CONFIG_SUNXI_GEN_NCAT2))
		return 0x830;

	return 0x88;
};

static int sunxi_mmc_probe(struct udevice *dev)
{
	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
	struct sunxi_mmc_plat *plat = dev_get_plat(dev);
	struct sunxi_mmc_priv *priv = dev_get_priv(dev);
	struct reset_ctl_bulk reset_bulk;
	struct clk gate_clk;
	struct mmc_config *cfg = &plat->cfg;
	struct ofnode_phandle_args args;
	u32 *ccu_reg;
	int ret;

	cfg->name = dev->name;

	cfg->voltages = MMC_VDD_32_33 | MMC_VDD_33_34;
	cfg->host_caps = MMC_MODE_HS_52MHz | MMC_MODE_HS;
	cfg->b_max = CONFIG_SYS_MMC_MAX_BLK_COUNT;

	cfg->f_min = 400000;
	cfg->f_max = 52000000;

	ret = mmc_of_parse(dev, cfg);
	if (ret)
		return ret;

	priv->reg = dev_read_addr_ptr(dev);

	/* We don't have a sunxi clock driver so find the clock address here */
	ret = dev_read_phandle_with_args(dev, "clocks", "#clock-cells", 0,
					  1, &args);
	if (ret)
		return ret;
	ccu_reg = (u32 *)(uintptr_t)ofnode_get_addr(args.node);

	priv->mmc_no = ((uintptr_t)priv->reg - SUNXI_MMC0_BASE) / 0x1000;
	priv->mclkreg = (void *)ccu_reg + get_mclk_offset() + priv->mmc_no * 4;

	ret = clk_get_by_name(dev, "ahb", &gate_clk);
	if (!ret)
		clk_enable(&gate_clk);

	ret = reset_get_bulk(dev, &reset_bulk);
	if (!ret)
		reset_deassert_bulk(&reset_bulk);

	ret = mmc_set_mod_clk(priv, 24000000);
	if (ret)
		return ret;

	/* This GPIO is optional */
	gpio_request_by_name(dev, "cd-gpios", 0, &priv->cd_gpio,
			     GPIOD_IS_IN | GPIOD_PULL_UP);

	upriv->mmc = &plat->mmc;

	/* Reset controller */
	writel(SUNXI_MMC_GCTRL_RESET, &priv->reg->gctrl);
	udelay(1000);

	return 0;
}

static int sunxi_mmc_bind(struct udevice *dev)
{
	struct sunxi_mmc_plat *plat = dev_get_plat(dev);

	return mmc_bind(dev, &plat->mmc, &plat->cfg);
}

static const struct udevice_id sunxi_mmc_ids[] = {
	{ .compatible = "allwinner,sun4i-a10-mmc" },
	{ .compatible = "allwinner,sun5i-a13-mmc" },
	{ .compatible = "allwinner,sun7i-a20-mmc" },
	{ .compatible = "allwinner,sun8i-a83t-emmc" },
	{ .compatible = "allwinner,sun9i-a80-mmc" },
	{ .compatible = "allwinner,sun50i-a64-mmc" },
	{ .compatible = "allwinner,sun50i-a64-emmc" },
	{ .compatible = "allwinner,sun50i-h6-mmc" },
	{ .compatible = "allwinner,sun50i-h6-emmc" },
	{ .compatible = "allwinner,sun50i-a100-mmc" },
	{ .compatible = "allwinner,sun50i-a100-emmc" },
	{ /* sentinel */ }
};

U_BOOT_DRIVER(sunxi_mmc_drv) = {
	.name		= "sunxi_mmc",
	.id		= UCLASS_MMC,
	.of_match	= sunxi_mmc_ids,
	.bind		= sunxi_mmc_bind,
	.probe		= sunxi_mmc_probe,
	.ops		= &sunxi_mmc_ops,
	.plat_auto	= sizeof(struct sunxi_mmc_plat),
	.priv_auto	= sizeof(struct sunxi_mmc_priv),
};
#endif