Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1408 insertions, 0 deletions

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
new file mode 100644
index 000000000..7e571cc71
--- /dev/null
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -0,0 +1,1408 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Amlogic SD/eMMC driver for the GX/S905 family SoCs
+ *
+ * Copyright (c) 2016 BayLibre, SAS.
+ * Author: Kevin Hilman <khilman@baylibre.com>
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/iopoll.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/ioport.h>
+#include <linux/dma-mapping.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/mmc.h>
+#include <linux/mmc/sdio.h>
+#include <linux/mmc/slot-gpio.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+#include <linux/interrupt.h>
+#include <linux/bitfield.h>
+#include <linux/pinctrl/consumer.h>
+
+#define DRIVER_NAME "meson-gx-mmc"
+
+#define SD_EMMC_CLOCK 0x0
+#define   CLK_DIV_MASK GENMASK(5, 0)
+#define   CLK_SRC_MASK GENMASK(7, 6)
+#define   CLK_CORE_PHASE_MASK GENMASK(9, 8)
+#define   CLK_TX_PHASE_MASK GENMASK(11, 10)
+#define   CLK_RX_PHASE_MASK GENMASK(13, 12)
+#define   CLK_PHASE_0 0
+#define   CLK_PHASE_180 2
+#define   CLK_V2_TX_DELAY_MASK GENMASK(19, 16)
+#define   CLK_V2_RX_DELAY_MASK GENMASK(23, 20)
+#define   CLK_V2_ALWAYS_ON BIT(24)
+#define   CLK_V2_IRQ_SDIO_SLEEP BIT(25)
+
+#define   CLK_V3_TX_DELAY_MASK GENMASK(21, 16)
+#define   CLK_V3_RX_DELAY_MASK GENMASK(27, 22)
+#define   CLK_V3_ALWAYS_ON BIT(28)
+#define   CLK_V3_IRQ_SDIO_SLEEP BIT(29)
+
+#define   CLK_TX_DELAY_MASK(h)		(h->data->tx_delay_mask)
+#define   CLK_RX_DELAY_MASK(h)		(h->data->rx_delay_mask)
+#define   CLK_ALWAYS_ON(h)		(h->data->always_on)
+#define   CLK_IRQ_SDIO_SLEEP(h)		(h->data->irq_sdio_sleep)
+
+#define SD_EMMC_DELAY 0x4
+#define SD_EMMC_ADJUST 0x8
+#define   ADJUST_ADJ_DELAY_MASK GENMASK(21, 16)
+#define   ADJUST_DS_EN BIT(15)
+#define   ADJUST_ADJ_EN BIT(13)
+
+#define SD_EMMC_DELAY1 0x4
+#define SD_EMMC_DELAY2 0x8
+#define SD_EMMC_V3_ADJUST 0xc
+
+#define SD_EMMC_CALOUT 0x10
+#define SD_EMMC_START 0x40
+#define   START_DESC_INIT BIT(0)
+#define   START_DESC_BUSY BIT(1)
+#define   START_DESC_ADDR_MASK GENMASK(31, 2)
+
+#define SD_EMMC_CFG 0x44
+#define   CFG_BUS_WIDTH_MASK GENMASK(1, 0)
+#define   CFG_BUS_WIDTH_1 0x0
+#define   CFG_BUS_WIDTH_4 0x1
+#define   CFG_BUS_WIDTH_8 0x2
+#define   CFG_DDR BIT(2)
+#define   CFG_BLK_LEN_MASK GENMASK(7, 4)
+#define   CFG_RESP_TIMEOUT_MASK GENMASK(11, 8)
+#define   CFG_RC_CC_MASK GENMASK(15, 12)
+#define   CFG_STOP_CLOCK BIT(22)
+#define   CFG_CLK_ALWAYS_ON BIT(18)
+#define   CFG_CHK_DS BIT(20)
+#define   CFG_AUTO_CLK BIT(23)
+#define   CFG_ERR_ABORT BIT(27)
+
+#define SD_EMMC_STATUS 0x48
+#define   STATUS_BUSY BIT(31)
+#define   STATUS_DESC_BUSY BIT(30)
+#define   STATUS_DATI GENMASK(23, 16)
+
+#define SD_EMMC_IRQ_EN 0x4c
+#define   IRQ_RXD_ERR_MASK GENMASK(7, 0)
+#define   IRQ_TXD_ERR BIT(8)
+#define   IRQ_DESC_ERR BIT(9)
+#define   IRQ_RESP_ERR BIT(10)
+#define   IRQ_CRC_ERR \
+	(IRQ_RXD_ERR_MASK | IRQ_TXD_ERR | IRQ_DESC_ERR | IRQ_RESP_ERR)
+#define   IRQ_RESP_TIMEOUT BIT(11)
+#define   IRQ_DESC_TIMEOUT BIT(12)
+#define   IRQ_TIMEOUTS \
+	(IRQ_RESP_TIMEOUT | IRQ_DESC_TIMEOUT)
+#define   IRQ_END_OF_CHAIN BIT(13)
+#define   IRQ_RESP_STATUS BIT(14)
+#define   IRQ_SDIO BIT(15)
+#define   IRQ_EN_MASK \
+	(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN)
+
+#define SD_EMMC_CMD_CFG 0x50
+#define SD_EMMC_CMD_ARG 0x54
+#define SD_EMMC_CMD_DAT 0x58
+#define SD_EMMC_CMD_RSP 0x5c
+#define SD_EMMC_CMD_RSP1 0x60
+#define SD_EMMC_CMD_RSP2 0x64
+#define SD_EMMC_CMD_RSP3 0x68
+
+#define SD_EMMC_RXD 0x94
+#define SD_EMMC_TXD 0x94
+#define SD_EMMC_LAST_REG SD_EMMC_TXD
+
+#define SD_EMMC_SRAM_DATA_BUF_LEN 1536
+#define SD_EMMC_SRAM_DATA_BUF_OFF 0x200
+
+#define SD_EMMC_CFG_BLK_SIZE 512 /* internal buffer max: 512 bytes */
+#define SD_EMMC_CFG_RESP_TIMEOUT 256 /* in clock cycles */
+#define SD_EMMC_CMD_TIMEOUT 1024 /* in ms */
+#define SD_EMMC_CMD_TIMEOUT_DATA 4096 /* in ms */
+#define SD_EMMC_CFG_CMD_GAP 16 /* in clock cycles */
+#define SD_EMMC_DESC_BUF_LEN PAGE_SIZE
+
+#define SD_EMMC_PRE_REQ_DONE BIT(0)
+#define SD_EMMC_DESC_CHAIN_MODE BIT(1)
+
+#define MUX_CLK_NUM_PARENTS 2
+
+struct meson_mmc_data {
+	unsigned int tx_delay_mask;
+	unsigned int rx_delay_mask;
+	unsigned int always_on;
+	unsigned int adjust;
+	unsigned int irq_sdio_sleep;
+};
+
+struct sd_emmc_desc {
+	u32 cmd_cfg;
+	u32 cmd_arg;
+	u32 cmd_data;
+	u32 cmd_resp;
+};
+
+struct meson_host {
+	struct	device		*dev;
+	struct	meson_mmc_data *data;
+	struct	mmc_host	*mmc;
+	struct	mmc_command	*cmd;
+
+	void __iomem *regs;
+	struct clk *core_clk;
+	struct clk *mux_clk;
+	struct clk *mmc_clk;
+	unsigned long req_rate;
+	bool ddr;
+
+	bool dram_access_quirk;
+
+	struct pinctrl *pinctrl;
+	struct pinctrl_state *pins_clk_gate;
+
+	unsigned int bounce_buf_size;
+	void *bounce_buf;
+	void __iomem *bounce_iomem_buf;
+	dma_addr_t bounce_dma_addr;
+	struct sd_emmc_desc *descs;
+	dma_addr_t descs_dma_addr;
+
+	int irq;
+
+	bool vqmmc_enabled;
+	bool needs_pre_post_req;
+
+	spinlock_t lock;
+};
+
+#define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
+#define CMD_CFG_BLOCK_MODE BIT(9)
+#define CMD_CFG_R1B BIT(10)
+#define CMD_CFG_END_OF_CHAIN BIT(11)
+#define CMD_CFG_TIMEOUT_MASK GENMASK(15, 12)
+#define CMD_CFG_NO_RESP BIT(16)
+#define CMD_CFG_NO_CMD BIT(17)
+#define CMD_CFG_DATA_IO BIT(18)
+#define CMD_CFG_DATA_WR BIT(19)
+#define CMD_CFG_RESP_NOCRC BIT(20)
+#define CMD_CFG_RESP_128 BIT(21)
+#define CMD_CFG_RESP_NUM BIT(22)
+#define CMD_CFG_DATA_NUM BIT(23)
+#define CMD_CFG_CMD_INDEX_MASK GENMASK(29, 24)
+#define CMD_CFG_ERROR BIT(30)
+#define CMD_CFG_OWNER BIT(31)
+
+#define CMD_DATA_MASK GENMASK(31, 2)
+#define CMD_DATA_BIG_ENDIAN BIT(1)
+#define CMD_DATA_SRAM BIT(0)
+#define CMD_RESP_MASK GENMASK(31, 1)
+#define CMD_RESP_SRAM BIT(0)
+
+static unsigned int meson_mmc_get_timeout_msecs(struct mmc_data *data)
+{
+	unsigned int timeout = data->timeout_ns / NSEC_PER_MSEC;
+
+	if (!timeout)
+		return SD_EMMC_CMD_TIMEOUT_DATA;
+
+	timeout = roundup_pow_of_two(timeout);
+
+	return min(timeout, 32768U); /* max. 2^15 ms */
+}
+
+static struct mmc_command *meson_mmc_get_next_command(struct mmc_command *cmd)
+{
+	if (cmd->opcode == MMC_SET_BLOCK_COUNT && !cmd->error)
+		return cmd->mrq->cmd;
+	else if (mmc_op_multi(cmd->opcode) &&
+		 (!cmd->mrq->sbc || cmd->error || cmd->data->error))
+		return cmd->mrq->stop;
+	else
+		return NULL;
+}
+
+static void meson_mmc_get_transfer_mode(struct mmc_host *mmc,
+					struct mmc_request *mrq)
+{
+	struct meson_host *host = mmc_priv(mmc);
+	struct mmc_data *data = mrq->data;
+	struct scatterlist *sg;
+	int i;
+
+	/*
+	 * When Controller DMA cannot directly access DDR memory, disable
+	 * support for Chain Mode to directly use the internal SRAM using
+	 * the bounce buffer mode.
+	 */
+	if (host->dram_access_quirk)
+		return;
+
+	/* SD_IO_RW_EXTENDED (CMD53) can also use block mode under the hood */
+	if (data->blocks > 1 || mrq->cmd->opcode == SD_IO_RW_EXTENDED) {
+		/*
+		 * In block mode DMA descriptor format, "length" field indicates
+		 * number of blocks and there is no way to pass DMA size that
+		 * is not multiple of SDIO block size, making it impossible to
+		 * tie more than one memory buffer with single SDIO block.
+		 * Block mode sg buffer size should be aligned with SDIO block
+		 * size, otherwise chain mode could not be used.
+		 */
+		for_each_sg(data->sg, sg, data->sg_len, i) {
+			if (sg->length % data->blksz) {
+				dev_warn_once(mmc_dev(mmc),
+					      "unaligned sg len %u blksize %u, disabling descriptor DMA for transfer\n",
+					      sg->length, data->blksz);
+				return;
+			}
+		}
+	}
+
+	for_each_sg(data->sg, sg, data->sg_len, i) {
+		/* check for 8 byte alignment */
+		if (sg->offset % 8) {
+			dev_warn_once(mmc_dev(mmc),
+				      "unaligned sg offset %u, disabling descriptor DMA for transfer\n",
+				      sg->offset);
+			return;
+		}
+	}
+
+	data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
+}
+
+static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)
+{
+	return data->host_cookie & SD_EMMC_DESC_CHAIN_MODE;
+}
+
+static inline bool meson_mmc_bounce_buf_read(const struct mmc_data *data)
+{
+	return data && data->flags & MMC_DATA_READ &&
+	       !meson_mmc_desc_chain_mode(data);
+}
+
+static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+	struct mmc_data *data = mrq->data;
+
+	if (!data)
+		return;
+
+	meson_mmc_get_transfer_mode(mmc, mrq);
+	data->host_cookie |= SD_EMMC_PRE_REQ_DONE;
+
+	if (!meson_mmc_desc_chain_mode(data))
+		return;
+
+	data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
+                                   mmc_get_dma_dir(data));
+	if (!data->sg_count)
+		dev_err(mmc_dev(mmc), "dma_map_sg failed");
+}
+
+static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
+			       int err)
+{
+	struct mmc_data *data = mrq->data;
+
+	if (data && meson_mmc_desc_chain_mode(data) && data->sg_count)
+		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
+			     mmc_get_dma_dir(data));
+}
+
+/*
+ * Gating the clock on this controller is tricky.  It seems the mmc clock
+ * is also used by the controller.  It may crash during some operation if the
+ * clock is stopped.  The safest thing to do, whenever possible, is to keep
+ * clock running at stop it at the pad using the pinmux.
+ */
+static void meson_mmc_clk_gate(struct meson_host *host)
+{
+	u32 cfg;
+
+	if (host->pins_clk_gate) {
+		pinctrl_select_state(host->pinctrl, host->pins_clk_gate);
+	} else {
+		/*
+		 * If the pinmux is not provided - default to the classic and
+		 * unsafe method
+		 */
+		cfg = readl(host->regs + SD_EMMC_CFG);
+		cfg |= CFG_STOP_CLOCK;
+		writel(cfg, host->regs + SD_EMMC_CFG);
+	}
+}
+
+static void meson_mmc_clk_ungate(struct meson_host *host)
+{
+	u32 cfg;
+
+	if (host->pins_clk_gate)
+		pinctrl_select_default_state(host->dev);
+
+	/* Make sure the clock is not stopped in the controller */
+	cfg = readl(host->regs + SD_EMMC_CFG);
+	cfg &= ~CFG_STOP_CLOCK;
+	writel(cfg, host->regs + SD_EMMC_CFG);
+}
+
+static int meson_mmc_clk_set(struct meson_host *host, unsigned long rate,
+			     bool ddr)
+{
+	struct mmc_host *mmc = host->mmc;
+	int ret;
+	u32 cfg;
+
+	/* Same request - bail-out */
+	if (host->ddr == ddr && host->req_rate == rate)
+		return 0;
+
+	/* stop clock */
+	meson_mmc_clk_gate(host);
+	host->req_rate = 0;
+	mmc->actual_clock = 0;
+
+	/* return with clock being stopped */
+	if (!rate)
+		return 0;
+
+	/* Stop the clock during rate change to avoid glitches */
+	cfg = readl(host->regs + SD_EMMC_CFG);
+	cfg |= CFG_STOP_CLOCK;
+	writel(cfg, host->regs + SD_EMMC_CFG);
+
+	if (ddr) {
+		/* DDR modes require higher module clock */
+		rate <<= 1;
+		cfg |= CFG_DDR;
+	} else {
+		cfg &= ~CFG_DDR;
+	}
+	writel(cfg, host->regs + SD_EMMC_CFG);
+	host->ddr = ddr;
+
+	ret = clk_set_rate(host->mmc_clk, rate);
+	if (ret) {
+		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
+			rate, ret);
+		return ret;
+	}
+
+	host->req_rate = rate;
+	mmc->actual_clock = clk_get_rate(host->mmc_clk);
+
+	/* We should report the real output frequency of the controller */
+	if (ddr) {
+		host->req_rate >>= 1;
+		mmc->actual_clock >>= 1;
+	}
+
+	dev_dbg(host->dev, "clk rate: %u Hz\n", mmc->actual_clock);
+	if (rate != mmc->actual_clock)
+		dev_dbg(host->dev, "requested rate was %lu\n", rate);
+
+	/* (re)start clock */
+	meson_mmc_clk_ungate(host);
+
+	return 0;
+}
+
+/*
+ * The SD/eMMC IP block has an internal mux and divider used for
+ * generating the MMC clock.  Use the clock framework to create and
+ * manage these clocks.
+ */
+static int meson_mmc_clk_init(struct meson_host *host)
+{
+	struct clk_init_data init;
+	struct clk_mux *mux;
+	struct clk_divider *div;
+	char clk_name[32];
+	int i, ret = 0;
+	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
+	const char *clk_parent[1];
+	u32 clk_reg;
+
+	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
+	clk_reg = CLK_ALWAYS_ON(host);
+	clk_reg |= CLK_DIV_MASK;
+	clk_reg |= FIELD_PREP(CLK_CORE_PHASE_MASK, CLK_PHASE_180);
+	clk_reg |= FIELD_PREP(CLK_TX_PHASE_MASK, CLK_PHASE_0);
+	clk_reg |= FIELD_PREP(CLK_RX_PHASE_MASK, CLK_PHASE_0);
+	if (host->mmc->caps & MMC_CAP_SDIO_IRQ)
+		clk_reg |= CLK_IRQ_SDIO_SLEEP(host);
+	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
+
+	/* get the mux parents */
+	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
+		struct clk *clk;
+		char name[16];
+
+		snprintf(name, sizeof(name), "clkin%d", i);
+		clk = devm_clk_get(host->dev, name);
+		if (IS_ERR(clk))
+			return dev_err_probe(host->dev, PTR_ERR(clk),
+					     "Missing clock %s\n", name);
+
+		mux_parent_names[i] = __clk_get_name(clk);
+	}
+
+	/* create the mux */
+	mux = devm_kzalloc(host->dev, sizeof(*mux), GFP_KERNEL);
+	if (!mux)
+		return -ENOMEM;
+
+	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
+	init.name = clk_name;
+	init.ops = &clk_mux_ops;
+	init.flags = 0;
+	init.parent_names = mux_parent_names;
+	init.num_parents = MUX_CLK_NUM_PARENTS;
+
+	mux->reg = host->regs + SD_EMMC_CLOCK;
+	mux->shift = __ffs(CLK_SRC_MASK);
+	mux->mask = CLK_SRC_MASK >> mux->shift;
+	mux->hw.init = &init;
+
+	host->mux_clk = devm_clk_register(host->dev, &mux->hw);
+	if (WARN_ON(IS_ERR(host->mux_clk)))
+		return PTR_ERR(host->mux_clk);
+
+	/* create the divider */
+	div = devm_kzalloc(host->dev, sizeof(*div), GFP_KERNEL);
+	if (!div)
+		return -ENOMEM;
+
+	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
+	init.name = clk_name;
+	init.ops = &clk_divider_ops;
+	init.flags = CLK_SET_RATE_PARENT;
+	clk_parent[0] = __clk_get_name(host->mux_clk);
+	init.parent_names = clk_parent;
+	init.num_parents = 1;
+
+	div->reg = host->regs + SD_EMMC_CLOCK;
+	div->shift = __ffs(CLK_DIV_MASK);
+	div->width = __builtin_popcountl(CLK_DIV_MASK);
+	div->hw.init = &init;
+	div->flags = CLK_DIVIDER_ONE_BASED;
+
+	host->mmc_clk = devm_clk_register(host->dev, &div->hw);
+	if (WARN_ON(IS_ERR(host->mmc_clk)))
+		return PTR_ERR(host->mmc_clk);
+
+	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
+	host->mmc->f_min = clk_round_rate(host->mmc_clk, 400000);
+	ret = clk_set_rate(host->mmc_clk, host->mmc->f_min);
+	if (ret)
+		return ret;
+
+	return clk_prepare_enable(host->mmc_clk);
+}
+
+static void meson_mmc_disable_resampling(struct meson_host *host)
+{
+	unsigned int val = readl(host->regs + host->data->adjust);
+
+	val &= ~ADJUST_ADJ_EN;
+	writel(val, host->regs + host->data->adjust);
+}
+
+static void meson_mmc_reset_resampling(struct meson_host *host)
+{
+	unsigned int val;
+
+	meson_mmc_disable_resampling(host);
+
+	val = readl(host->regs + host->data->adjust);
+	val &= ~ADJUST_ADJ_DELAY_MASK;
+	writel(val, host->regs + host->data->adjust);
+}
+
+static int meson_mmc_resampling_tuning(struct mmc_host *mmc, u32 opcode)
+{
+	struct meson_host *host = mmc_priv(mmc);
+	unsigned int val, dly, max_dly, i;
+	int ret;
+
+	/* Resampling is done using the source clock */
+	max_dly = DIV_ROUND_UP(clk_get_rate(host->mux_clk),
+			       clk_get_rate(host->mmc_clk));
+
+	val = readl(host->regs + host->data->adjust);
+	val |= ADJUST_ADJ_EN;
+	writel(val, host->regs + host->data->adjust);
+
+	if (mmc_doing_retune(mmc))
+		dly = FIELD_GET(ADJUST_ADJ_DELAY_MASK, val) + 1;
+	else
+		dly = 0;
+
+	for (i = 0; i < max_dly; i++) {
+		val &= ~ADJUST_ADJ_DELAY_MASK;
+		val |= FIELD_PREP(ADJUST_ADJ_DELAY_MASK, (dly + i) % max_dly);
+		writel(val, host->regs + host->data->adjust);
+
+		ret = mmc_send_tuning(mmc, opcode, NULL);
+		if (!ret) {
+			dev_dbg(mmc_dev(mmc), "resampling delay: %u\n",
+				(dly + i) % max_dly);
+			return 0;
+		}
+	}
+
+	meson_mmc_reset_resampling(host);
+	return -EIO;
+}
+
+static int meson_mmc_prepare_ios_clock(struct meson_host *host,
+				       struct mmc_ios *ios)
+{
+	bool ddr;
+
+	switch (ios->timing) {
+	case MMC_TIMING_MMC_DDR52:
+	case MMC_TIMING_UHS_DDR50:
+		ddr = true;
+		break;
+
+	default:
+		ddr = false;
+		break;
+	}
+
+	return meson_mmc_clk_set(host, ios->clock, ddr);
+}
+
+static void meson_mmc_check_resampling(struct meson_host *host,
+				       struct mmc_ios *ios)
+{
+	switch (ios->timing) {
+	case MMC_TIMING_LEGACY:
+	case MMC_TIMING_MMC_HS:
+	case MMC_TIMING_SD_HS:
+	case MMC_TIMING_MMC_DDR52:
+		meson_mmc_disable_resampling(host);
+		break;
+	}
+}
+
+static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct meson_host *host = mmc_priv(mmc);
+	u32 bus_width, val;
+	int err;
+
+	/*
+	 * GPIO regulator, only controls switching between 1v8 and
+	 * 3v3, doesn't support MMC_POWER_OFF, MMC_POWER_ON.
+	 */
+	switch (ios->power_mode) {
+	case MMC_POWER_OFF:
+		if (!IS_ERR(mmc->supply.vmmc))
+			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
+
+		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
+			regulator_disable(mmc->supply.vqmmc);
+			host->vqmmc_enabled = false;
+		}
+
+		break;
+
+	case MMC_POWER_UP:
+		if (!IS_ERR(mmc->supply.vmmc))
+			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
+
+		break;
+
+	case MMC_POWER_ON:
+		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
+			int ret = regulator_enable(mmc->supply.vqmmc);
+
+			if (ret < 0)
+				dev_err(host->dev,
+					"failed to enable vqmmc regulator\n");
+			else
+				host->vqmmc_enabled = true;
+		}
+
+		break;
+	}
+
+	/* Bus width */
+	switch (ios->bus_width) {
+	case MMC_BUS_WIDTH_1:
+		bus_width = CFG_BUS_WIDTH_1;
+		break;
+	case MMC_BUS_WIDTH_4:
+		bus_width = CFG_BUS_WIDTH_4;
+		break;
+	case MMC_BUS_WIDTH_8:
+		bus_width = CFG_BUS_WIDTH_8;
+		break;
+	default:
+		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
+			ios->bus_width);
+		bus_width = CFG_BUS_WIDTH_4;
+	}
+
+	val = readl(host->regs + SD_EMMC_CFG);
+	val &= ~CFG_BUS_WIDTH_MASK;
+	val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width);
+	writel(val, host->regs + SD_EMMC_CFG);
+
+	meson_mmc_check_resampling(host, ios);
+	err = meson_mmc_prepare_ios_clock(host, ios);
+	if (err)
+		dev_err(host->dev, "Failed to set clock: %d\n,", err);
+
+	dev_dbg(host->dev, "SD_EMMC_CFG:  0x%08x\n", val);
+}
+
+static void meson_mmc_request_done(struct mmc_host *mmc,
+				   struct mmc_request *mrq)
+{
+	struct meson_host *host = mmc_priv(mmc);
+
+	host->cmd = NULL;
+	if (host->needs_pre_post_req)
+		meson_mmc_post_req(mmc, mrq, 0);
+	mmc_request_done(host->mmc, mrq);
+}
+
+static void meson_mmc_set_blksz(struct mmc_host *mmc, unsigned int blksz)
+{
+	struct meson_host *host = mmc_priv(mmc);
+	u32 cfg, blksz_old;
+
+	cfg = readl(host->regs + SD_EMMC_CFG);
+	blksz_old = FIELD_GET(CFG_BLK_LEN_MASK, cfg);
+
+	if (!is_power_of_2(blksz))
+		dev_err(host->dev, "blksz %u is not a power of 2\n", blksz);
+
+	blksz = ilog2(blksz);
+
+	/* check if block-size matches, if not update */
+	if (blksz == blksz_old)
+		return;
+
+	dev_dbg(host->dev, "%s: update blk_len %d -> %d\n", __func__,
+		blksz_old, blksz);
+
+	cfg &= ~CFG_BLK_LEN_MASK;
+	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, blksz);
+	writel(cfg, host->regs + SD_EMMC_CFG);
+}
+
+static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg)
+{
+	if (cmd->flags & MMC_RSP_PRESENT) {
+		if (cmd->flags & MMC_RSP_136)
+			*cmd_cfg |= CMD_CFG_RESP_128;
+		*cmd_cfg |= CMD_CFG_RESP_NUM;
+
+		if (!(cmd->flags & MMC_RSP_CRC))
+			*cmd_cfg |= CMD_CFG_RESP_NOCRC;
+
+		if (cmd->flags & MMC_RSP_BUSY)
+			*cmd_cfg |= CMD_CFG_R1B;
+	} else {
+		*cmd_cfg |= CMD_CFG_NO_RESP;
+	}
+}
+
+static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
+{
+	struct meson_host *host = mmc_priv(mmc);
+	struct sd_emmc_desc *desc = host->descs;
+	struct mmc_data *data = host->cmd->data;
+	struct scatterlist *sg;
+	u32 start;
+	int i;
+
+	if (data->flags & MMC_DATA_WRITE)
+		cmd_cfg |= CMD_CFG_DATA_WR;
+
+	if (data->blocks > 1) {
+		cmd_cfg |= CMD_CFG_BLOCK_MODE;
+		meson_mmc_set_blksz(mmc, data->blksz);
+	}
+
+	for_each_sg(data->sg, sg, data->sg_count, i) {
+		unsigned int len = sg_dma_len(sg);
+
+		if (data->blocks > 1)
+			len /= data->blksz;
+
+		desc[i].cmd_cfg = cmd_cfg;
+		desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len);
+		if (i > 0)
+			desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
+		desc[i].cmd_arg = host->cmd->arg;
+		desc[i].cmd_resp = 0;
+		desc[i].cmd_data = sg_dma_address(sg);
+	}
+	desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
+
+	dma_wmb(); /* ensure descriptor is written before kicked */
+	start = host->descs_dma_addr | START_DESC_BUSY;
+	writel(start, host->regs + SD_EMMC_START);
+}
+
+/* local sg copy for dram_access_quirk */
+static void meson_mmc_copy_buffer(struct meson_host *host, struct mmc_data *data,
+				  size_t buflen, bool to_buffer)
+{
+	unsigned int sg_flags = SG_MITER_ATOMIC;
+	struct scatterlist *sgl = data->sg;
+	unsigned int nents = data->sg_len;
+	struct sg_mapping_iter miter;
+	unsigned int offset = 0;
+
+	if (to_buffer)
+		sg_flags |= SG_MITER_FROM_SG;
+	else
+		sg_flags |= SG_MITER_TO_SG;
+
+	sg_miter_start(&miter, sgl, nents, sg_flags);
+
+	while ((offset < buflen) && sg_miter_next(&miter)) {
+		unsigned int buf_offset = 0;
+		unsigned int len, left;
+		u32 *buf = miter.addr;
+
+		len = min(miter.length, buflen - offset);
+		left = len;
+
+		if (to_buffer) {
+			do {
+				writel(*buf++, host->bounce_iomem_buf + offset + buf_offset);
+
+				buf_offset += 4;
+				left -= 4;
+			} while (left);
+		} else {
+			do {
+				*buf++ = readl(host->bounce_iomem_buf + offset + buf_offset);
+
+				buf_offset += 4;
+				left -= 4;
+			} while (left);
+		}
+
+		offset += len;
+	}
+
+	sg_miter_stop(&miter);
+}
+
+static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
+{
+	struct meson_host *host = mmc_priv(mmc);
+	struct mmc_data *data = cmd->data;
+	u32 cmd_cfg = 0, cmd_data = 0;
+	unsigned int xfer_bytes = 0;
+
+	/* Setup descriptors */
+	dma_rmb();
+
+	host->cmd = cmd;
+
+	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
+	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
+
+	meson_mmc_set_response_bits(cmd, &cmd_cfg);
+
+	/* data? */
+	if (data) {
+		data->bytes_xfered = 0;
+		cmd_cfg |= CMD_CFG_DATA_IO;
+		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
+				      ilog2(meson_mmc_get_timeout_msecs(data)));
+
+		if (meson_mmc_desc_chain_mode(data)) {
+			meson_mmc_desc_chain_transfer(mmc, cmd_cfg);
+			return;
+		}
+
+		if (data->blocks > 1) {
+			cmd_cfg |= CMD_CFG_BLOCK_MODE;
+			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK,
+					      data->blocks);
+			meson_mmc_set_blksz(mmc, data->blksz);
+		} else {
+			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, data->blksz);
+		}
+
+		xfer_bytes = data->blksz * data->blocks;
+		if (data->flags & MMC_DATA_WRITE) {
+			cmd_cfg |= CMD_CFG_DATA_WR;
+			WARN_ON(xfer_bytes > host->bounce_buf_size);
+			if (host->dram_access_quirk)
+				meson_mmc_copy_buffer(host, data, xfer_bytes, true);
+			else
+				sg_copy_to_buffer(data->sg, data->sg_len,
+						  host->bounce_buf, xfer_bytes);
+			dma_wmb();
+		}
+
+		cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
+	} else {
+		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
+				      ilog2(SD_EMMC_CMD_TIMEOUT));
+	}
+
+	/* Last descriptor */
+	cmd_cfg |= CMD_CFG_END_OF_CHAIN;
+	writel(cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
+	writel(cmd_data, host->regs + SD_EMMC_CMD_DAT);
+	writel(0, host->regs + SD_EMMC_CMD_RSP);
+	wmb(); /* ensure descriptor is written before kicked */
+	writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG);
+}
+
+static int meson_mmc_validate_dram_access(struct mmc_host *mmc, struct mmc_data *data)
+{
+	struct scatterlist *sg;
+	int i;
+
+	/* Reject request if any element offset or size is not 32bit aligned */
+	for_each_sg(data->sg, sg, data->sg_len, i) {
+		if (!IS_ALIGNED(sg->offset, sizeof(u32)) ||
+		    !IS_ALIGNED(sg->length, sizeof(u32))) {
+			dev_err(mmc_dev(mmc), "unaligned sg offset %u len %u\n",
+				data->sg->offset, data->sg->length);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+	struct meson_host *host = mmc_priv(mmc);
+	host->needs_pre_post_req = mrq->data &&
+			!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
+
+	/*
+	 * The memory at the end of the controller used as bounce buffer for
+	 * the dram_access_quirk only accepts 32bit read/write access,
+	 * check the aligment and length of the data before starting the request.
+	 */
+	if (host->dram_access_quirk && mrq->data) {
+		mrq->cmd->error = meson_mmc_validate_dram_access(mmc, mrq->data);
+		if (mrq->cmd->error) {
+			mmc_request_done(mmc, mrq);
+			return;
+		}
+	}
+
+	if (host->needs_pre_post_req) {
+		meson_mmc_get_transfer_mode(mmc, mrq);
+		if (!meson_mmc_desc_chain_mode(mrq->data))
+			host->needs_pre_post_req = false;
+	}
+
+	if (host->needs_pre_post_req)
+		meson_mmc_pre_req(mmc, mrq);
+
+	/* Stop execution */
+	writel(0, host->regs + SD_EMMC_START);
+
+	meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
+}
+
+static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
+{
+	struct meson_host *host = mmc_priv(mmc);
+
+	if (cmd->flags & MMC_RSP_136) {
+		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
+		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
+		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
+		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
+	} else if (cmd->flags & MMC_RSP_PRESENT) {
+		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
+	}
+}
+
+static void __meson_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+	struct meson_host *host = mmc_priv(mmc);
+	u32 reg_irqen = IRQ_EN_MASK;
+
+	if (enable)
+		reg_irqen |= IRQ_SDIO;
+	writel(reg_irqen, host->regs + SD_EMMC_IRQ_EN);
+}
+
+static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
+{
+	struct meson_host *host = dev_id;
+	struct mmc_command *cmd;
+	u32 status, raw_status, irq_mask = IRQ_EN_MASK;
+	irqreturn_t ret = IRQ_NONE;
+
+	if (host->mmc->caps & MMC_CAP_SDIO_IRQ)
+		irq_mask |= IRQ_SDIO;
+	raw_status = readl(host->regs + SD_EMMC_STATUS);
+	status = raw_status & irq_mask;
+
+	if (!status) {
+		dev_dbg(host->dev,
+			"Unexpected IRQ! irq_en 0x%08x - status 0x%08x\n",
+			 irq_mask, raw_status);
+		return IRQ_NONE;
+	}
+
+	if (WARN_ON(!host))
+		return IRQ_NONE;
+
+	/* ack all raised interrupts */
+	writel(status, host->regs + SD_EMMC_STATUS);
+
+	cmd = host->cmd;
+
+	if (status & IRQ_SDIO) {
+		spin_lock(&host->lock);
+		__meson_mmc_enable_sdio_irq(host->mmc, 0);
+		sdio_signal_irq(host->mmc);
+		spin_unlock(&host->lock);
+		status &= ~IRQ_SDIO;
+		if (!status)
+			return IRQ_HANDLED;
+	}
+
+	if (WARN_ON(!cmd))
+		return IRQ_NONE;
+
+	cmd->error = 0;
+	if (status & IRQ_CRC_ERR) {
+		dev_dbg(host->dev, "CRC Error - status 0x%08x\n", status);
+		cmd->error = -EILSEQ;
+		ret = IRQ_WAKE_THREAD;
+		goto out;
+	}
+
+	if (status & IRQ_TIMEOUTS) {
+		dev_dbg(host->dev, "Timeout - status 0x%08x\n", status);
+		cmd->error = -ETIMEDOUT;
+		ret = IRQ_WAKE_THREAD;
+		goto out;
+	}
+
+	meson_mmc_read_resp(host->mmc, cmd);
+
+	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
+		struct mmc_data *data = cmd->data;
+
+		if (data && !cmd->error)
+			data->bytes_xfered = data->blksz * data->blocks;
+
+		return IRQ_WAKE_THREAD;
+	}
+
+out:
+	if (cmd->error) {
+		/* Stop desc in case of errors */
+		u32 start = readl(host->regs + SD_EMMC_START);
+
+		start &= ~START_DESC_BUSY;
+		writel(start, host->regs + SD_EMMC_START);
+	}
+
+	return ret;
+}
+
+static int meson_mmc_wait_desc_stop(struct meson_host *host)
+{
+	u32 status;
+
+	/*
+	 * It may sometimes take a while for it to actually halt. Here, we
+	 * are giving it 5ms to comply
+	 *
+	 * If we don't confirm the descriptor is stopped, it might raise new
+	 * IRQs after we have called mmc_request_done() which is bad.
+	 */
+
+	return readl_poll_timeout(host->regs + SD_EMMC_STATUS, status,
+				  !(status & (STATUS_BUSY | STATUS_DESC_BUSY)),
+				  100, 5000);
+}
+
+static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
+{
+	struct meson_host *host = dev_id;
+	struct mmc_command *next_cmd, *cmd = host->cmd;
+	struct mmc_data *data;
+	unsigned int xfer_bytes;
+
+	if (WARN_ON(!cmd))
+		return IRQ_NONE;
+
+	if (cmd->error) {
+		meson_mmc_wait_desc_stop(host);
+		meson_mmc_request_done(host->mmc, cmd->mrq);
+
+		return IRQ_HANDLED;
+	}
+
+	data = cmd->data;
+	if (meson_mmc_bounce_buf_read(data)) {
+		xfer_bytes = data->blksz * data->blocks;
+		WARN_ON(xfer_bytes > host->bounce_buf_size);
+		if (host->dram_access_quirk)
+			meson_mmc_copy_buffer(host, data, xfer_bytes, false);
+		else
+			sg_copy_from_buffer(data->sg, data->sg_len,
+					    host->bounce_buf, xfer_bytes);
+	}
+
+	next_cmd = meson_mmc_get_next_command(cmd);
+	if (next_cmd)
+		meson_mmc_start_cmd(host->mmc, next_cmd);
+	else
+		meson_mmc_request_done(host->mmc, cmd->mrq);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * NOTE: we only need this until the GPIO/pinctrl driver can handle
+ * interrupts.  For now, the MMC core will use this for polling.
+ */
+static int meson_mmc_get_cd(struct mmc_host *mmc)
+{
+	int status = mmc_gpio_get_cd(mmc);
+
+	if (status == -ENOSYS)
+		return 1; /* assume present */
+
+	return status;
+}
+
+static void meson_mmc_cfg_init(struct meson_host *host)
+{
+	u32 cfg = 0;
+
+	cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
+			  ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
+	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));
+	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));
+
+	/* abort chain on R/W errors */
+	cfg |= CFG_ERR_ABORT;
+
+	writel(cfg, host->regs + SD_EMMC_CFG);
+}
+
+static int meson_mmc_card_busy(struct mmc_host *mmc)
+{
+	struct meson_host *host = mmc_priv(mmc);
+	u32 regval;
+
+	regval = readl(host->regs + SD_EMMC_STATUS);
+
+	/* We are only interrested in lines 0 to 3, so mask the other ones */
+	return !(FIELD_GET(STATUS_DATI, regval) & 0xf);
+}
+
+static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	int ret;
+
+	/* vqmmc regulator is available */
+	if (!IS_ERR(mmc->supply.vqmmc)) {
+		/*
+		 * The usual amlogic setup uses a GPIO to switch from one
+		 * regulator to the other. While the voltage ramp up is
+		 * pretty fast, care must be taken when switching from 3.3v
+		 * to 1.8v. Please make sure the regulator framework is aware
+		 * of your own regulator constraints
+		 */
+		ret = mmc_regulator_set_vqmmc(mmc, ios);
+		return ret < 0 ? ret : 0;
+	}
+
+	/* no vqmmc regulator, assume fixed regulator at 3/3.3V */
+	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
+		return 0;
+
+	return -EINVAL;
+}
+
+static void meson_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+	struct meson_host *host = mmc_priv(mmc);
+	unsigned long flags;
+
+	spin_lock_irqsave(&host->lock, flags);
+	__meson_mmc_enable_sdio_irq(mmc, enable);
+	spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void meson_mmc_ack_sdio_irq(struct mmc_host *mmc)
+{
+	meson_mmc_enable_sdio_irq(mmc, 1);
+}
+
+static const struct mmc_host_ops meson_mmc_ops = {
+	.request	= meson_mmc_request,
+	.set_ios	= meson_mmc_set_ios,
+	.get_cd         = meson_mmc_get_cd,
+	.pre_req	= meson_mmc_pre_req,
+	.post_req	= meson_mmc_post_req,
+	.execute_tuning = meson_mmc_resampling_tuning,
+	.card_busy	= meson_mmc_card_busy,
+	.start_signal_voltage_switch = meson_mmc_voltage_switch,
+	.enable_sdio_irq = meson_mmc_enable_sdio_irq,
+	.ack_sdio_irq	= meson_mmc_ack_sdio_irq,
+};
+
+static int meson_mmc_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct meson_host *host;
+	struct mmc_host *mmc;
+	int ret;
+
+	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
+	if (!mmc)
+		return -ENOMEM;
+	host = mmc_priv(mmc);
+	host->mmc = mmc;
+	host->dev = &pdev->dev;
+	dev_set_drvdata(&pdev->dev, host);
+
+	/* The G12A SDIO Controller needs an SRAM bounce buffer */
+	host->dram_access_quirk = device_property_read_bool(&pdev->dev,
+					"amlogic,dram-access-quirk");
+
+	/* Get regulators and the supported OCR mask */
+	host->vqmmc_enabled = false;
+	ret = mmc_regulator_get_supply(mmc);
+	if (ret)
+		goto free_host;
+
+	ret = mmc_of_parse(mmc);
+	if (ret) {
+		if (ret != -EPROBE_DEFER)
+			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
+		goto free_host;
+	}
+
+	mmc->caps |= MMC_CAP_CMD23;
+
+	if (mmc->caps & MMC_CAP_SDIO_IRQ)
+		mmc->caps2 |= MMC_CAP2_SDIO_IRQ_NOTHREAD;
+
+	host->data = (struct meson_mmc_data *)
+		of_device_get_match_data(&pdev->dev);
+	if (!host->data) {
+		ret = -EINVAL;
+		goto free_host;
+	}
+
+	ret = device_reset_optional(&pdev->dev);
+	if (ret) {
+		dev_err_probe(&pdev->dev, ret, "device reset failed\n");
+		goto free_host;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	host->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(host->regs)) {
+		ret = PTR_ERR(host->regs);
+		goto free_host;
+	}
+
+	host->irq = platform_get_irq(pdev, 0);
+	if (host->irq < 0) {
+		ret = host->irq;
+		goto free_host;
+	}
+
+	host->pinctrl = devm_pinctrl_get(&pdev->dev);
+	if (IS_ERR(host->pinctrl)) {
+		ret = PTR_ERR(host->pinctrl);
+		goto free_host;
+	}
+
+	host->pins_clk_gate = pinctrl_lookup_state(host->pinctrl,
+						   "clk-gate");
+	if (IS_ERR(host->pins_clk_gate)) {
+		dev_warn(&pdev->dev,
+			 "can't get clk-gate pinctrl, using clk_stop bit\n");
+		host->pins_clk_gate = NULL;
+	}
+
+	host->core_clk = devm_clk_get(&pdev->dev, "core");
+	if (IS_ERR(host->core_clk)) {
+		ret = PTR_ERR(host->core_clk);
+		goto free_host;
+	}
+
+	ret = clk_prepare_enable(host->core_clk);
+	if (ret)
+		goto free_host;
+
+	ret = meson_mmc_clk_init(host);
+	if (ret)
+		goto err_core_clk;
+
+	/* set config to sane default */
+	meson_mmc_cfg_init(host);
+
+	/* Stop execution */
+	writel(0, host->regs + SD_EMMC_START);
+
+	/* clear, ack and enable interrupts */
+	writel(0, host->regs + SD_EMMC_IRQ_EN);
+	writel(IRQ_EN_MASK, host->regs + SD_EMMC_STATUS);
+	writel(IRQ_EN_MASK, host->regs + SD_EMMC_IRQ_EN);
+
+	ret = request_threaded_irq(host->irq, meson_mmc_irq,
+				   meson_mmc_irq_thread, IRQF_ONESHOT,
+				   dev_name(&pdev->dev), host);
+	if (ret)
+		goto err_init_clk;
+
+	spin_lock_init(&host->lock);
+
+	if (host->dram_access_quirk) {
+		/* Limit segments to 1 due to low available sram memory */
+		mmc->max_segs = 1;
+		/* Limit to the available sram memory */
+		mmc->max_blk_count = SD_EMMC_SRAM_DATA_BUF_LEN /
+				     mmc->max_blk_size;
+	} else {
+		mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
+		mmc->max_segs = SD_EMMC_DESC_BUF_LEN /
+				sizeof(struct sd_emmc_desc);
+	}
+	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
+	mmc->max_seg_size = mmc->max_req_size;
+
+	/*
+	 * At the moment, we don't know how to reliably enable HS400.
+	 * From the different datasheets, it is not even clear if this mode
+	 * is officially supported by any of the SoCs
+	 */
+	mmc->caps2 &= ~MMC_CAP2_HS400;
+
+	if (host->dram_access_quirk) {
+		/*
+		 * The MMC Controller embeds 1,5KiB of internal SRAM
+		 * that can be used to be used as bounce buffer.
+		 * In the case of the G12A SDIO controller, use these
+		 * instead of the DDR memory
+		 */
+		host->bounce_buf_size = SD_EMMC_SRAM_DATA_BUF_LEN;
+		host->bounce_iomem_buf = host->regs + SD_EMMC_SRAM_DATA_BUF_OFF;
+		host->bounce_dma_addr = res->start + SD_EMMC_SRAM_DATA_BUF_OFF;
+	} else {
+		/* data bounce buffer */
+		host->bounce_buf_size = mmc->max_req_size;
+		host->bounce_buf =
+			dmam_alloc_coherent(host->dev, host->bounce_buf_size,
+					    &host->bounce_dma_addr, GFP_KERNEL);
+		if (host->bounce_buf == NULL) {
+			dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
+			ret = -ENOMEM;
+			goto err_free_irq;
+		}
+	}
+
+	host->descs = dmam_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
+					  &host->descs_dma_addr, GFP_KERNEL);
+	if (!host->descs) {
+		dev_err(host->dev, "Allocating descriptor DMA buffer failed\n");
+		ret = -ENOMEM;
+		goto err_free_irq;
+	}
+
+	mmc->ops = &meson_mmc_ops;
+	ret = mmc_add_host(mmc);
+	if (ret)
+		goto err_free_irq;
+
+	return 0;
+
+err_free_irq:
+	free_irq(host->irq, host);
+err_init_clk:
+	clk_disable_unprepare(host->mmc_clk);
+err_core_clk:
+	clk_disable_unprepare(host->core_clk);
+free_host:
+	mmc_free_host(mmc);
+	return ret;
+}
+
+static int meson_mmc_remove(struct platform_device *pdev)
+{
+	struct meson_host *host = dev_get_drvdata(&pdev->dev);
+
+	mmc_remove_host(host->mmc);
+
+	/* disable interrupts */
+	writel(0, host->regs + SD_EMMC_IRQ_EN);
+	free_irq(host->irq, host);
+
+	clk_disable_unprepare(host->mmc_clk);
+	clk_disable_unprepare(host->core_clk);
+
+	mmc_free_host(host->mmc);
+	return 0;
+}
+
+static const struct meson_mmc_data meson_gx_data = {
+	.tx_delay_mask	= CLK_V2_TX_DELAY_MASK,
+	.rx_delay_mask	= CLK_V2_RX_DELAY_MASK,
+	.always_on	= CLK_V2_ALWAYS_ON,
+	.adjust		= SD_EMMC_ADJUST,
+	.irq_sdio_sleep	= CLK_V2_IRQ_SDIO_SLEEP,
+};
+
+static const struct meson_mmc_data meson_axg_data = {
+	.tx_delay_mask	= CLK_V3_TX_DELAY_MASK,
+	.rx_delay_mask	= CLK_V3_RX_DELAY_MASK,
+	.always_on	= CLK_V3_ALWAYS_ON,
+	.adjust		= SD_EMMC_V3_ADJUST,
+	.irq_sdio_sleep	= CLK_V3_IRQ_SDIO_SLEEP,
+};
+
+static const struct of_device_id meson_mmc_of_match[] = {
+	{ .compatible = "amlogic,meson-gx-mmc",		.data = &meson_gx_data },
+	{ .compatible = "amlogic,meson-gxbb-mmc", 	.data = &meson_gx_data },
+	{ .compatible = "amlogic,meson-gxl-mmc",	.data = &meson_gx_data },
+	{ .compatible = "amlogic,meson-gxm-mmc",	.data = &meson_gx_data },
+	{ .compatible = "amlogic,meson-axg-mmc",	.data = &meson_axg_data },
+	{}
+};
+MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
+
+static struct platform_driver meson_mmc_driver = {
+	.probe		= meson_mmc_probe,
+	.remove		= meson_mmc_remove,
+	.driver		= {
+		.name = DRIVER_NAME,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.of_match_table = meson_mmc_of_match,
+	},
+};
+
+module_platform_driver(meson_mmc_driver);
+
+MODULE_DESCRIPTION("Amlogic S905*/GX*/AXG SD/eMMC driver");
+MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
+MODULE_LICENSE("GPL v2");