mmc: sunxi: Add driver for SD/MMC hosts found on Allwinner sunxi SoCs

The Allwinner sunxi mmc host uses dma in bus-master mode using a built-in
designware idmac controller, which is identical to the one found in the mmc-dw
hosts. However the rest of the host is not identical to mmc-dw, it deals with
sending stop commands in hardware which makes it significantly different
from the mmc-dw devices.

Signed-off-by: David Lanzendörfer <david.lanzendoerfer@o2s.ch>
[hdegoede@redhat.com: various cleanups and fixes]
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Chris Ball <chris@printf.net>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

3 files changed, 1057 insertions, 0 deletions

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 8aaf8c1f3f63..d50ac1ca11ea 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -694,3 +694,10 @@ config MMC_REALTEK_PCI
 	help
 	  Say Y here to include driver code to support SD/MMC card interface
 	  of Realtek PCI-E card reader
+
+config MMC_SUNXI
+	tristate "Allwinner sunxi SD/MMC Host Controller support"
+	depends on ARCH_SUNXI
+	help
+	  This selects support for the SD/MMC Host Controller on
+	  Allwinner sunxi SoCs.
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 0c8aa5e1e304..3072bfb6d26a 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_MMC_JZ4740)	+= jz4740_mmc.o
 obj-$(CONFIG_MMC_VUB300)	+= vub300.o
 obj-$(CONFIG_MMC_USHC)		+= ushc.o
 obj-$(CONFIG_MMC_WMT)		+= wmt-sdmmc.o
+obj-$(CONFIG_MMC_SUNXI)		+= sunxi-mmc.o
 
 obj-$(CONFIG_MMC_REALTEK_PCI)	+= rtsx_pci_sdmmc.o
 
diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
new file mode 100644
index 000000000000..024f67c98cdc
--- /dev/null
+++ b/drivers/mmc/host/sunxi-mmc.c
@@ -0,0 +1,1049 @@
+/*
+ * Driver for sunxi SD/MMC host controllers
+ * (C) Copyright 2007-2011 Reuuimlla Technology Co., Ltd.
+ * (C) Copyright 2007-2011 Aaron Maoye <leafy.myeh@reuuimllatech.com>
+ * (C) Copyright 2013-2014 O2S GmbH <www.o2s.ch>
+ * (C) Copyright 2013-2014 David Lanzend�rfer <david.lanzendoerfer@o2s.ch>
+ * (C) Copyright 2013-2014 Hans de Goede <hdegoede@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+
+#include <linux/clk.h>
+#include <linux/clk-private.h>
+#include <linux/clk/sunxi.h>
+
+#include <linux/gpio.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/scatterlist.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <linux/reset.h>
+
+#include <linux/of_address.h>
+#include <linux/of_gpio.h>
+#include <linux/of_platform.h>
+
+#include <linux/mmc/host.h>
+#include <linux/mmc/sd.h>
+#include <linux/mmc/sdio.h>
+#include <linux/mmc/mmc.h>
+#include <linux/mmc/core.h>
+#include <linux/mmc/card.h>
+#include <linux/mmc/slot-gpio.h>
+
+/* register offset definitions */
+#define SDXC_REG_GCTRL	(0x00) /* SMC Global Control Register */
+#define SDXC_REG_CLKCR	(0x04) /* SMC Clock Control Register */
+#define SDXC_REG_TMOUT	(0x08) /* SMC Time Out Register */
+#define SDXC_REG_WIDTH	(0x0C) /* SMC Bus Width Register */
+#define SDXC_REG_BLKSZ	(0x10) /* SMC Block Size Register */
+#define SDXC_REG_BCNTR	(0x14) /* SMC Byte Count Register */
+#define SDXC_REG_CMDR	(0x18) /* SMC Command Register */
+#define SDXC_REG_CARG	(0x1C) /* SMC Argument Register */
+#define SDXC_REG_RESP0	(0x20) /* SMC Response Register 0 */
+#define SDXC_REG_RESP1	(0x24) /* SMC Response Register 1 */
+#define SDXC_REG_RESP2	(0x28) /* SMC Response Register 2 */
+#define SDXC_REG_RESP3	(0x2C) /* SMC Response Register 3 */
+#define SDXC_REG_IMASK	(0x30) /* SMC Interrupt Mask Register */
+#define SDXC_REG_MISTA	(0x34) /* SMC Masked Interrupt Status Register */
+#define SDXC_REG_RINTR	(0x38) /* SMC Raw Interrupt Status Register */
+#define SDXC_REG_STAS	(0x3C) /* SMC Status Register */
+#define SDXC_REG_FTRGL	(0x40) /* SMC FIFO Threshold Watermark Registe */
+#define SDXC_REG_FUNS	(0x44) /* SMC Function Select Register */
+#define SDXC_REG_CBCR	(0x48) /* SMC CIU Byte Count Register */
+#define SDXC_REG_BBCR	(0x4C) /* SMC BIU Byte Count Register */
+#define SDXC_REG_DBGC	(0x50) /* SMC Debug Enable Register */
+#define SDXC_REG_HWRST	(0x78) /* SMC Card Hardware Reset for Register */
+#define SDXC_REG_DMAC	(0x80) /* SMC IDMAC Control Register */
+#define SDXC_REG_DLBA	(0x84) /* SMC IDMAC Descriptor List Base Addre */
+#define SDXC_REG_IDST	(0x88) /* SMC IDMAC Status Register */
+#define SDXC_REG_IDIE	(0x8C) /* SMC IDMAC Interrupt Enable Register */
+#define SDXC_REG_CHDA	(0x90)
+#define SDXC_REG_CBDA	(0x94)
+
+#define mmc_readl(host, reg) \
+	readl((host)->reg_base + SDXC_##reg)
+#define mmc_writel(host, reg, value) \
+	writel((value), (host)->reg_base + SDXC_##reg)
+
+/* global control register bits */
+#define SDXC_SOFT_RESET			BIT(0)
+#define SDXC_FIFO_RESET			BIT(1)
+#define SDXC_DMA_RESET			BIT(2)
+#define SDXC_INTERRUPT_ENABLE_BIT	BIT(4)
+#define SDXC_DMA_ENABLE_BIT		BIT(5)
+#define SDXC_DEBOUNCE_ENABLE_BIT	BIT(8)
+#define SDXC_POSEDGE_LATCH_DATA		BIT(9)
+#define SDXC_DDR_MODE			BIT(10)
+#define SDXC_MEMORY_ACCESS_DONE		BIT(29)
+#define SDXC_ACCESS_DONE_DIRECT		BIT(30)
+#define SDXC_ACCESS_BY_AHB		BIT(31)
+#define SDXC_ACCESS_BY_DMA		(0 << 31)
+#define SDXC_HARDWARE_RESET \
+	(SDXC_SOFT_RESET | SDXC_FIFO_RESET | SDXC_DMA_RESET)
+
+/* clock control bits */
+#define SDXC_CARD_CLOCK_ON		BIT(16)
+#define SDXC_LOW_POWER_ON		BIT(17)
+
+/* bus width */
+#define SDXC_WIDTH1			0
+#define SDXC_WIDTH4			1
+#define SDXC_WIDTH8			2
+
+/* smc command bits */
+#define SDXC_RESP_EXPIRE		BIT(6)
+#define SDXC_LONG_RESPONSE		BIT(7)
+#define SDXC_CHECK_RESPONSE_CRC		BIT(8)
+#define SDXC_DATA_EXPIRE		BIT(9)
+#define SDXC_WRITE			BIT(10)
+#define SDXC_SEQUENCE_MODE		BIT(11)
+#define SDXC_SEND_AUTO_STOP		BIT(12)
+#define SDXC_WAIT_PRE_OVER		BIT(13)
+#define SDXC_STOP_ABORT_CMD		BIT(14)
+#define SDXC_SEND_INIT_SEQUENCE		BIT(15)
+#define SDXC_UPCLK_ONLY			BIT(21)
+#define SDXC_READ_CEATA_DEV		BIT(22)
+#define SDXC_CCS_EXPIRE			BIT(23)
+#define SDXC_ENABLE_BIT_BOOT		BIT(24)
+#define SDXC_ALT_BOOT_OPTIONS		BIT(25)
+#define SDXC_BOOT_ACK_EXPIRE		BIT(26)
+#define SDXC_BOOT_ABORT			BIT(27)
+#define SDXC_VOLTAGE_SWITCH	        BIT(28)
+#define SDXC_USE_HOLD_REGISTER	        BIT(29)
+#define SDXC_START			BIT(31)
+
+/* interrupt bits */
+#define SDXC_RESP_ERROR			BIT(1)
+#define SDXC_COMMAND_DONE		BIT(2)
+#define SDXC_DATA_OVER			BIT(3)
+#define SDXC_TX_DATA_REQUEST		BIT(4)
+#define SDXC_RX_DATA_REQUEST		BIT(5)
+#define SDXC_RESP_CRC_ERROR		BIT(6)
+#define SDXC_DATA_CRC_ERROR		BIT(7)
+#define SDXC_RESP_TIMEOUT		BIT(8)
+#define SDXC_DATA_TIMEOUT		BIT(9)
+#define SDXC_VOLTAGE_CHANGE_DONE	BIT(10)
+#define SDXC_FIFO_RUN_ERROR		BIT(11)
+#define SDXC_HARD_WARE_LOCKED		BIT(12)
+#define SDXC_START_BIT_ERROR		BIT(13)
+#define SDXC_AUTO_COMMAND_DONE		BIT(14)
+#define SDXC_END_BIT_ERROR		BIT(15)
+#define SDXC_SDIO_INTERRUPT		BIT(16)
+#define SDXC_CARD_INSERT		BIT(30)
+#define SDXC_CARD_REMOVE		BIT(31)
+#define SDXC_INTERRUPT_ERROR_BIT \
+	(SDXC_RESP_ERROR | SDXC_RESP_CRC_ERROR | SDXC_DATA_CRC_ERROR | \
+	 SDXC_RESP_TIMEOUT | SDXC_DATA_TIMEOUT | SDXC_FIFO_RUN_ERROR | \
+	 SDXC_HARD_WARE_LOCKED | SDXC_START_BIT_ERROR | SDXC_END_BIT_ERROR)
+#define SDXC_INTERRUPT_DONE_BIT \
+	(SDXC_AUTO_COMMAND_DONE | SDXC_DATA_OVER | \
+	 SDXC_COMMAND_DONE | SDXC_VOLTAGE_CHANGE_DONE)
+
+/* status */
+#define SDXC_RXWL_FLAG			BIT(0)
+#define SDXC_TXWL_FLAG			BIT(1)
+#define SDXC_FIFO_EMPTY			BIT(2)
+#define SDXC_FIFO_FULL			BIT(3)
+#define SDXC_CARD_PRESENT		BIT(8)
+#define SDXC_CARD_DATA_BUSY		BIT(9)
+#define SDXC_DATA_FSM_BUSY		BIT(10)
+#define SDXC_DMA_REQUEST		BIT(31)
+#define SDXC_FIFO_SIZE			16
+
+/* Function select */
+#define SDXC_CEATA_ON			(0xceaa << 16)
+#define SDXC_SEND_IRQ_RESPONSE		BIT(0)
+#define SDXC_SDIO_READ_WAIT		BIT(1)
+#define SDXC_ABORT_READ_DATA		BIT(2)
+#define SDXC_SEND_CCSD			BIT(8)
+#define SDXC_SEND_AUTO_STOPCCSD		BIT(9)
+#define SDXC_CEATA_DEV_IRQ_ENABLE	BIT(10)
+
+/* IDMA controller bus mod bit field */
+#define SDXC_IDMAC_SOFT_RESET		BIT(0)
+#define SDXC_IDMAC_FIX_BURST		BIT(1)
+#define SDXC_IDMAC_IDMA_ON		BIT(7)
+#define SDXC_IDMAC_REFETCH_DES		BIT(31)
+
+/* IDMA status bit field */
+#define SDXC_IDMAC_TRANSMIT_INTERRUPT		BIT(0)
+#define SDXC_IDMAC_RECEIVE_INTERRUPT		BIT(1)
+#define SDXC_IDMAC_FATAL_BUS_ERROR		BIT(2)
+#define SDXC_IDMAC_DESTINATION_INVALID		BIT(4)
+#define SDXC_IDMAC_CARD_ERROR_SUM		BIT(5)
+#define SDXC_IDMAC_NORMAL_INTERRUPT_SUM		BIT(8)
+#define SDXC_IDMAC_ABNORMAL_INTERRUPT_SUM	BIT(9)
+#define SDXC_IDMAC_HOST_ABORT_INTERRUPT		BIT(10)
+#define SDXC_IDMAC_IDLE				(0 << 13)
+#define SDXC_IDMAC_SUSPEND			(1 << 13)
+#define SDXC_IDMAC_DESC_READ			(2 << 13)
+#define SDXC_IDMAC_DESC_CHECK			(3 << 13)
+#define SDXC_IDMAC_READ_REQUEST_WAIT		(4 << 13)
+#define SDXC_IDMAC_WRITE_REQUEST_WAIT		(5 << 13)
+#define SDXC_IDMAC_READ				(6 << 13)
+#define SDXC_IDMAC_WRITE			(7 << 13)
+#define SDXC_IDMAC_DESC_CLOSE			(8 << 13)
+
+/*
+* If the idma-des-size-bits of property is ie 13, bufsize bits are:
+*  Bits  0-12: buf1 size
+*  Bits 13-25: buf2 size
+*  Bits 26-31: not used
+* Since we only ever set buf1 size, we can simply store it directly.
+*/
+#define SDXC_IDMAC_DES0_DIC	BIT(1)  /* disable interrupt on completion */
+#define SDXC_IDMAC_DES0_LD	BIT(2)  /* last descriptor */
+#define SDXC_IDMAC_DES0_FD	BIT(3)  /* first descriptor */
+#define SDXC_IDMAC_DES0_CH	BIT(4)  /* chain mode */
+#define SDXC_IDMAC_DES0_ER	BIT(5)  /* end of ring */
+#define SDXC_IDMAC_DES0_CES	BIT(30) /* card error summary */
+#define SDXC_IDMAC_DES0_OWN	BIT(31) /* 1-idma owns it, 0-host owns it */
+
+struct sunxi_idma_des {
+	u32	config;
+	u32	buf_size;
+	u32	buf_addr_ptr1;
+	u32	buf_addr_ptr2;
+};
+
+struct sunxi_mmc_host {
+	struct mmc_host	*mmc;
+	struct reset_control *reset;
+
+	/* IO mapping base */
+	void __iomem	*reg_base;
+
+	/* clock management */
+	struct clk	*clk_ahb;
+	struct clk	*clk_mmc;
+
+	/* irq */
+	spinlock_t	lock;
+	int		irq;
+	u32		int_sum;
+	u32		sdio_imask;
+
+	/* dma */
+	u32		idma_des_size_bits;
+	dma_addr_t	sg_dma;
+	void		*sg_cpu;
+	bool		wait_dma;
+
+	struct mmc_request *mrq;
+	struct mmc_request *manual_stop_mrq;
+	int		ferror;
+};
+
+static int sunxi_mmc_reset_host(struct sunxi_mmc_host *host)
+{
+	unsigned long expire = jiffies + msecs_to_jiffies(250);
+	u32 rval;
+
+	mmc_writel(host, REG_CMDR, SDXC_HARDWARE_RESET);
+	do {
+		rval = mmc_readl(host, REG_GCTRL);
+	} while (time_before(jiffies, expire) && (rval & SDXC_HARDWARE_RESET));
+
+	if (rval & SDXC_HARDWARE_RESET) {
+		dev_err(mmc_dev(host->mmc), "fatal err reset timeout\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int sunxi_mmc_init_host(struct mmc_host *mmc)
+{
+	u32 rval;
+	struct sunxi_mmc_host *host = mmc_priv(mmc);
+
+	if (sunxi_mmc_reset_host(host))
+		return -EIO;
+
+	mmc_writel(host, REG_FTRGL, 0x20070008);
+	mmc_writel(host, REG_TMOUT, 0xffffffff);
+	mmc_writel(host, REG_IMASK, host->sdio_imask);
+	mmc_writel(host, REG_RINTR, 0xffffffff);
+	mmc_writel(host, REG_DBGC, 0xdeb);
+	mmc_writel(host, REG_FUNS, SDXC_CEATA_ON);
+	mmc_writel(host, REG_DLBA, host->sg_dma);
+
+	rval = mmc_readl(host, REG_GCTRL);
+	rval |= SDXC_INTERRUPT_ENABLE_BIT;
+	rval &= ~SDXC_ACCESS_DONE_DIRECT;
+	mmc_writel(host, REG_GCTRL, rval);
+
+	return 0;
+}
+
+static void sunxi_mmc_init_idma_des(struct sunxi_mmc_host *host,
+				    struct mmc_data *data)
+{
+	struct sunxi_idma_des *pdes = (struct sunxi_idma_des *)host->sg_cpu;
+	struct sunxi_idma_des *pdes_pa = (struct sunxi_idma_des *)host->sg_dma;
+	int i, max_len = (1 << host->idma_des_size_bits);
+
+	for (i = 0; i < data->sg_len; i++) {
+		pdes[i].config = SDXC_IDMAC_DES0_CH | SDXC_IDMAC_DES0_OWN |
+				 SDXC_IDMAC_DES0_DIC;
+
+		if (data->sg[i].length == max_len)
+			pdes[i].buf_size = 0; /* 0 == max_len */
+		else
+			pdes[i].buf_size = data->sg[i].length;
+
+		pdes[i].buf_addr_ptr1 = sg_dma_address(&data->sg[i]);
+		pdes[i].buf_addr_ptr2 = (u32)&pdes_pa[i + 1];
+	}
+
+	pdes[0].config |= SDXC_IDMAC_DES0_FD;
+	pdes[i - 1].config = SDXC_IDMAC_DES0_OWN | SDXC_IDMAC_DES0_LD;
+
+	/*
+	 * Avoid the io-store starting the idmac hitting io-mem before the
+	 * descriptors hit the main-mem.
+	 */
+	wmb();
+}
+
+static enum dma_data_direction sunxi_mmc_get_dma_dir(struct mmc_data *data)
+{
+	if (data->flags & MMC_DATA_WRITE)
+		return DMA_TO_DEVICE;
+	else
+		return DMA_FROM_DEVICE;
+}
+
+static int sunxi_mmc_map_dma(struct sunxi_mmc_host *host,
+			     struct mmc_data *data)
+{
+	u32 i, dma_len;
+	struct scatterlist *sg;
+
+	dma_len = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
+			     sunxi_mmc_get_dma_dir(data));
+	if (dma_len == 0) {
+		dev_err(mmc_dev(host->mmc), "dma_map_sg failed\n");
+		return -ENOMEM;
+	}
+
+	for_each_sg(data->sg, sg, data->sg_len, i) {
+		if (sg->offset & 3 || sg->length & 3) {
+			dev_err(mmc_dev(host->mmc),
+				"unaligned scatterlist: os %x length %d\n",
+				sg->offset, sg->length);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static void sunxi_mmc_start_dma(struct sunxi_mmc_host *host,
+				struct mmc_data *data)
+{
+	u32 rval;
+
+	sunxi_mmc_init_idma_des(host, data);
+
+	rval = mmc_readl(host, REG_GCTRL);
+	rval |= SDXC_DMA_ENABLE_BIT;
+	mmc_writel(host, REG_GCTRL, rval);
+	rval |= SDXC_DMA_RESET;
+	mmc_writel(host, REG_GCTRL, rval);
+
+	mmc_writel(host, REG_DMAC, SDXC_IDMAC_SOFT_RESET);
+
+	if (!(data->flags & MMC_DATA_WRITE))
+		mmc_writel(host, REG_IDIE, SDXC_IDMAC_RECEIVE_INTERRUPT);
+
+	mmc_writel(host, REG_DMAC,
+		   SDXC_IDMAC_FIX_BURST | SDXC_IDMAC_IDMA_ON);
+}
+
+static void sunxi_mmc_send_manual_stop(struct sunxi_mmc_host *host,
+				       struct mmc_request *req)
+{
+	u32 arg, cmd_val, ri;
+	unsigned long expire = jiffies + msecs_to_jiffies(1000);
+
+	cmd_val = SDXC_START | SDXC_RESP_EXPIRE |
+		  SDXC_STOP_ABORT_CMD | SDXC_CHECK_RESPONSE_CRC;
+
+	if (req->cmd->opcode == SD_IO_RW_EXTENDED) {
+		cmd_val |= SD_IO_RW_DIRECT;
+		arg = (1 << 31) | (0 << 28) | (SDIO_CCCR_ABORT << 9) |
+		      ((req->cmd->arg >> 28) & 0x7);
+	} else {
+		cmd_val |= MMC_STOP_TRANSMISSION;
+		arg = 0;
+	}
+
+	mmc_writel(host, REG_CARG, arg);
+	mmc_writel(host, REG_CMDR, cmd_val);
+
+	do {
+		ri = mmc_readl(host, REG_RINTR);
+	} while (!(ri & (SDXC_COMMAND_DONE | SDXC_INTERRUPT_ERROR_BIT)) &&
+		 time_before(jiffies, expire));
+
+	if (!(ri & SDXC_COMMAND_DONE) || (ri & SDXC_INTERRUPT_ERROR_BIT)) {
+		dev_err(mmc_dev(host->mmc), "send stop command failed\n");
+		if (req->stop)
+			req->stop->resp[0] = -ETIMEDOUT;
+	} else {
+		if (req->stop)
+			req->stop->resp[0] = mmc_readl(host, REG_RESP0);
+	}
+
+	mmc_writel(host, REG_RINTR, 0xffff);
+}
+
+static void sunxi_mmc_dump_errinfo(struct sunxi_mmc_host *host)
+{
+	struct mmc_command *cmd = host->mrq->cmd;
+	struct mmc_data *data = host->mrq->data;
+
+	/* For some cmds timeout is normal with sd/mmc cards */
+	if ((host->int_sum & SDXC_INTERRUPT_ERROR_BIT) ==
+		SDXC_RESP_TIMEOUT && (cmd->opcode == SD_IO_SEND_OP_COND ||
+				      cmd->opcode == SD_IO_RW_DIRECT))
+		return;
+
+	dev_err(mmc_dev(host->mmc),
+		"smc %d err, cmd %d,%s%s%s%s%s%s%s%s%s%s !!\n",
+		host->mmc->index, cmd->opcode,
+		data ? (data->flags & MMC_DATA_WRITE ? " WR" : " RD") : "",
+		host->int_sum & SDXC_RESP_ERROR     ? " RE"     : "",
+		host->int_sum & SDXC_RESP_CRC_ERROR  ? " RCE"    : "",
+		host->int_sum & SDXC_DATA_CRC_ERROR  ? " DCE"    : "",
+		host->int_sum & SDXC_RESP_TIMEOUT ? " RTO"    : "",
+		host->int_sum & SDXC_DATA_TIMEOUT ? " DTO"    : "",
+		host->int_sum & SDXC_FIFO_RUN_ERROR  ? " FE"     : "",
+		host->int_sum & SDXC_HARD_WARE_LOCKED ? " HL"     : "",
+		host->int_sum & SDXC_START_BIT_ERROR ? " SBE"    : "",
+		host->int_sum & SDXC_END_BIT_ERROR   ? " EBE"    : ""
+		);
+}
+
+/* Called in interrupt context! */
+static irqreturn_t sunxi_mmc_finalize_request(struct sunxi_mmc_host *host)
+{
+	struct mmc_request *mrq = host->mrq;
+	struct mmc_data *data = mrq->data;
+	u32 rval;
+
+	mmc_writel(host, REG_IMASK, host->sdio_imask);
+	mmc_writel(host, REG_IDIE, 0);
+
+	if (host->int_sum & SDXC_INTERRUPT_ERROR_BIT) {
+		sunxi_mmc_dump_errinfo(host);
+		mrq->cmd->error = -ETIMEDOUT;
+
+		if (data) {
+			data->error = -ETIMEDOUT;
+			host->manual_stop_mrq = mrq;
+		}
+
+		if (mrq->stop)
+			mrq->stop->error = -ETIMEDOUT;
+	} else {
+		if (mrq->cmd->flags & MMC_RSP_136) {
+			mrq->cmd->resp[0] = mmc_readl(host, REG_RESP3);
+			mrq->cmd->resp[1] = mmc_readl(host, REG_RESP2);
+			mrq->cmd->resp[2] = mmc_readl(host, REG_RESP1);
+			mrq->cmd->resp[3] = mmc_readl(host, REG_RESP0);
+		} else {
+			mrq->cmd->resp[0] = mmc_readl(host, REG_RESP0);
+		}
+
+		if (data)
+			data->bytes_xfered = data->blocks * data->blksz;
+	}
+
+	if (data) {
+		mmc_writel(host, REG_IDST, 0x337);
+		mmc_writel(host, REG_DMAC, 0);
+		rval = mmc_readl(host, REG_GCTRL);
+		rval |= SDXC_DMA_RESET;
+		mmc_writel(host, REG_GCTRL, rval);
+		rval &= ~SDXC_DMA_ENABLE_BIT;
+		mmc_writel(host, REG_GCTRL, rval);
+		rval |= SDXC_FIFO_RESET;
+		mmc_writel(host, REG_GCTRL, rval);
+		dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
+				     sunxi_mmc_get_dma_dir(data));
+	}
+
+	mmc_writel(host, REG_RINTR, 0xffff);
+
+	host->mrq = NULL;
+	host->int_sum = 0;
+	host->wait_dma = false;
+
+	return host->manual_stop_mrq ? IRQ_WAKE_THREAD : IRQ_HANDLED;
+}
+
+static irqreturn_t sunxi_mmc_irq(int irq, void *dev_id)
+{
+	struct sunxi_mmc_host *host = dev_id;
+	struct mmc_request *mrq;
+	u32 msk_int, idma_int;
+	bool finalize = false;
+	bool sdio_int = false;
+	irqreturn_t ret = IRQ_HANDLED;
+
+	spin_lock(&host->lock);
+
+	idma_int  = mmc_readl(host, REG_IDST);
+	msk_int   = mmc_readl(host, REG_MISTA);
+
+	dev_dbg(mmc_dev(host->mmc), "irq: rq %p mi %08x idi %08x\n",
+		host->mrq, msk_int, idma_int);
+
+	mrq = host->mrq;
+	if (mrq) {
+		if (idma_int & SDXC_IDMAC_RECEIVE_INTERRUPT)
+			host->wait_dma = false;
+
+		host->int_sum |= msk_int;
+
+		/* Wait for COMMAND_DONE on RESPONSE_TIMEOUT before finalize */
+		if ((host->int_sum & SDXC_RESP_TIMEOUT) &&
+				!(host->int_sum & SDXC_COMMAND_DONE))
+			mmc_writel(host, REG_IMASK,
+				   host->sdio_imask | SDXC_COMMAND_DONE);
+		/* Don't wait for dma on error */
+		else if (host->int_sum & SDXC_INTERRUPT_ERROR_BIT)
+			finalize = true;
+		else if ((host->int_sum & SDXC_INTERRUPT_DONE_BIT) &&
+				!host->wait_dma)
+			finalize = true;
+	}
+
+	if (msk_int & SDXC_SDIO_INTERRUPT)
+		sdio_int = true;
+
+	mmc_writel(host, REG_RINTR, msk_int);
+	mmc_writel(host, REG_IDST, idma_int);
+
+	if (finalize)
+		ret = sunxi_mmc_finalize_request(host);
+
+	spin_unlock(&host->lock);
+
+	if (finalize && ret == IRQ_HANDLED)
+		mmc_request_done(host->mmc, mrq);
+
+	if (sdio_int)
+		mmc_signal_sdio_irq(host->mmc);
+
+	return ret;
+}
+
+static irqreturn_t sunxi_mmc_handle_manual_stop(int irq, void *dev_id)
+{
+	struct sunxi_mmc_host *host = dev_id;
+	struct mmc_request *mrq;
+	unsigned long iflags;
+
+	spin_lock_irqsave(&host->lock, iflags);
+	mrq = host->manual_stop_mrq;
+	spin_unlock_irqrestore(&host->lock, iflags);
+
+	if (!mrq) {
+		dev_err(mmc_dev(host->mmc), "no request for manual stop\n");
+		return IRQ_HANDLED;
+	}
+
+	dev_err(mmc_dev(host->mmc), "data error, sending stop command\n");
+	sunxi_mmc_send_manual_stop(host, mrq);
+
+	spin_lock_irqsave(&host->lock, iflags);
+	host->manual_stop_mrq = NULL;
+	spin_unlock_irqrestore(&host->lock, iflags);
+
+	mmc_request_done(host->mmc, mrq);
+
+	return IRQ_HANDLED;
+}
+
+static int sunxi_mmc_oclk_onoff(struct sunxi_mmc_host *host, u32 oclk_en)
+{
+	unsigned long expire = jiffies + msecs_to_jiffies(250);
+	u32 rval;
+
+	rval = mmc_readl(host, REG_CLKCR);
+	rval &= ~(SDXC_CARD_CLOCK_ON | SDXC_LOW_POWER_ON);
+
+	if (oclk_en)
+		rval |= SDXC_CARD_CLOCK_ON;
+
+	mmc_writel(host, REG_CLKCR, rval);
+
+	rval = SDXC_START | SDXC_UPCLK_ONLY | SDXC_WAIT_PRE_OVER;
+	mmc_writel(host, REG_CMDR, rval);
+
+	do {
+		rval = mmc_readl(host, REG_CMDR);
+	} while (time_before(jiffies, expire) && (rval & SDXC_START));
+
+	/* clear irq status bits set by the command */
+	mmc_writel(host, REG_RINTR,
+		   mmc_readl(host, REG_RINTR) & ~SDXC_SDIO_INTERRUPT);
+
+	if (rval & SDXC_START) {
+		dev_err(mmc_dev(host->mmc), "fatal err update clk timeout\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int sunxi_mmc_clk_set_rate(struct sunxi_mmc_host *host,
+				  struct mmc_ios *ios)
+{
+	u32 rate, oclk_dly, rval, sclk_dly, src_clk;
+	int ret;
+
+	rate = clk_round_rate(host->clk_mmc, ios->clock);
+	dev_dbg(mmc_dev(host->mmc), "setting clk to %d, rounded %d\n",
+		ios->clock, rate);
+
+	/* setting clock rate */
+	ret = clk_set_rate(host->clk_mmc, rate);
+	if (ret) {
+		dev_err(mmc_dev(host->mmc), "error setting clk to %d: %d\n",
+			rate, ret);
+		return ret;
+	}
+
+	ret = sunxi_mmc_oclk_onoff(host, 0);
+	if (ret)
+		return ret;
+
+	/* clear internal divider */
+	rval = mmc_readl(host, REG_CLKCR);
+	rval &= ~0xff;
+	mmc_writel(host, REG_CLKCR, rval);
+
+	/* determine delays */
+	if (rate <= 400000) {
+		oclk_dly = 0;
+		sclk_dly = 7;
+	} else if (rate <= 25000000) {
+		oclk_dly = 0;
+		sclk_dly = 5;
+	} else if (rate <= 50000000) {
+		if (ios->timing == MMC_TIMING_UHS_DDR50) {
+			oclk_dly = 2;
+			sclk_dly = 4;
+		} else {
+			oclk_dly = 3;
+			sclk_dly = 5;
+		}
+	} else {
+		/* rate > 50000000 */
+		oclk_dly = 2;
+		sclk_dly = 4;
+	}
+
+	src_clk = clk_get_rate(clk_get_parent(host->clk_mmc));
+	if (src_clk >= 300000000 && src_clk <= 400000000) {
+		if (oclk_dly)
+			oclk_dly--;
+		if (sclk_dly)
+			sclk_dly--;
+	}
+
+	clk_sunxi_mmc_phase_control(host->clk_mmc, sclk_dly, oclk_dly);
+
+	return sunxi_mmc_oclk_onoff(host, 1);
+}
+
+static void sunxi_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct sunxi_mmc_host *host = mmc_priv(mmc);
+	u32 rval;
+
+	/* Set the power state */
+	switch (ios->power_mode) {
+	case MMC_POWER_ON:
+		break;
+
+	case MMC_POWER_UP:
+		mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
+
+		host->ferror = sunxi_mmc_init_host(mmc);
+		if (host->ferror)
+			return;
+
+		dev_dbg(mmc_dev(mmc), "power on!\n");
+		break;
+
+	case MMC_POWER_OFF:
+		dev_dbg(mmc_dev(mmc), "power off!\n");
+		sunxi_mmc_reset_host(host);
+		mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
+		break;
+	}
+
+	/* set bus width */
+	switch (ios->bus_width) {
+	case MMC_BUS_WIDTH_1:
+		mmc_writel(host, REG_WIDTH, SDXC_WIDTH1);
+		break;
+	case MMC_BUS_WIDTH_4:
+		mmc_writel(host, REG_WIDTH, SDXC_WIDTH4);
+		break;
+	case MMC_BUS_WIDTH_8:
+		mmc_writel(host, REG_WIDTH, SDXC_WIDTH8);
+		break;
+	}
+
+	/* set ddr mode */
+	rval = mmc_readl(host, REG_GCTRL);
+	if (ios->timing == MMC_TIMING_UHS_DDR50)
+		rval |= SDXC_DDR_MODE;
+	else
+		rval &= ~SDXC_DDR_MODE;
+	mmc_writel(host, REG_GCTRL, rval);
+
+	/* set up clock */
+	if (ios->clock && ios->power_mode) {
+		host->ferror = sunxi_mmc_clk_set_rate(host, ios);
+		/* Android code had a usleep_range(50000, 55000); here */
+	}
+}
+
+static void sunxi_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+	struct sunxi_mmc_host *host = mmc_priv(mmc);
+	unsigned long flags;
+	u32 imask;
+
+	spin_lock_irqsave(&host->lock, flags);
+
+	imask = mmc_readl(host, REG_IMASK);
+	if (enable) {
+		host->sdio_imask = SDXC_SDIO_INTERRUPT;
+		imask |= SDXC_SDIO_INTERRUPT;
+	} else {
+		host->sdio_imask = 0;
+		imask &= ~SDXC_SDIO_INTERRUPT;
+	}
+	mmc_writel(host, REG_IMASK, imask);
+	spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void sunxi_mmc_hw_reset(struct mmc_host *mmc)
+{
+	struct sunxi_mmc_host *host = mmc_priv(mmc);
+	mmc_writel(host, REG_HWRST, 0);
+	udelay(10);
+	mmc_writel(host, REG_HWRST, 1);
+	udelay(300);
+}
+
+static void sunxi_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+	struct sunxi_mmc_host *host = mmc_priv(mmc);
+	struct mmc_command *cmd = mrq->cmd;
+	struct mmc_data *data = mrq->data;
+	unsigned long iflags;
+	u32 imask = SDXC_INTERRUPT_ERROR_BIT;
+	u32 cmd_val = SDXC_START | (cmd->opcode & 0x3f);
+	int ret;
+
+	/* Check for set_ios errors (should never happen) */
+	if (host->ferror) {
+		mrq->cmd->error = host->ferror;
+		mmc_request_done(mmc, mrq);
+		return;
+	}
+
+	if (data) {
+		ret = sunxi_mmc_map_dma(host, data);
+		if (ret < 0) {
+			dev_err(mmc_dev(mmc), "map DMA failed\n");
+			cmd->error = ret;
+			data->error = ret;
+			mmc_request_done(mmc, mrq);
+			return;
+		}
+	}
+
+	if (cmd->opcode == MMC_GO_IDLE_STATE) {
+		cmd_val |= SDXC_SEND_INIT_SEQUENCE;
+		imask |= SDXC_COMMAND_DONE;
+	}
+
+	if (cmd->flags & MMC_RSP_PRESENT) {
+		cmd_val |= SDXC_RESP_EXPIRE;
+		if (cmd->flags & MMC_RSP_136)
+			cmd_val |= SDXC_LONG_RESPONSE;
+		if (cmd->flags & MMC_RSP_CRC)
+			cmd_val |= SDXC_CHECK_RESPONSE_CRC;
+
+		if ((cmd->flags & MMC_CMD_MASK) == MMC_CMD_ADTC) {
+			cmd_val |= SDXC_DATA_EXPIRE | SDXC_WAIT_PRE_OVER;
+			if (cmd->data->flags & MMC_DATA_STREAM) {
+				imask |= SDXC_AUTO_COMMAND_DONE;
+				cmd_val |= SDXC_SEQUENCE_MODE |
+					   SDXC_SEND_AUTO_STOP;
+			}
+
+			if (cmd->data->stop) {
+				imask |= SDXC_AUTO_COMMAND_DONE;
+				cmd_val |= SDXC_SEND_AUTO_STOP;
+			} else {
+				imask |= SDXC_DATA_OVER;
+			}
+
+			if (cmd->data->flags & MMC_DATA_WRITE)
+				cmd_val |= SDXC_WRITE;
+			else
+				host->wait_dma = true;
+		} else {
+			imask |= SDXC_COMMAND_DONE;
+		}
+	} else {
+		imask |= SDXC_COMMAND_DONE;
+	}
+
+	dev_dbg(mmc_dev(mmc), "cmd %d(%08x) arg %x ie 0x%08x len %d\n",
+		cmd_val & 0x3f, cmd_val, cmd->arg, imask,
+		mrq->data ? mrq->data->blksz * mrq->data->blocks : 0);
+
+	spin_lock_irqsave(&host->lock, iflags);
+
+	if (host->mrq || host->manual_stop_mrq) {
+		spin_unlock_irqrestore(&host->lock, iflags);
+
+		if (data)
+			dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
+				     sunxi_mmc_get_dma_dir(data));
+
+		dev_err(mmc_dev(mmc), "request already pending\n");
+		mrq->cmd->error = -EBUSY;
+		mmc_request_done(mmc, mrq);
+		return;
+	}
+
+	if (data) {
+		mmc_writel(host, REG_BLKSZ, data->blksz);
+		mmc_writel(host, REG_BCNTR, data->blksz * data->blocks);
+		sunxi_mmc_start_dma(host, data);
+	}
+
+	host->mrq = mrq;
+	mmc_writel(host, REG_IMASK, host->sdio_imask | imask);
+	mmc_writel(host, REG_CARG, cmd->arg);
+	mmc_writel(host, REG_CMDR, cmd_val);
+
+	spin_unlock_irqrestore(&host->lock, iflags);
+}
+
+static const struct of_device_id sunxi_mmc_of_match[] = {
+	{ .compatible = "allwinner,sun4i-a10-mmc", },
+	{ .compatible = "allwinner,sun5i-a13-mmc", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sunxi_mmc_of_match);
+
+static struct mmc_host_ops sunxi_mmc_ops = {
+	.request	 = sunxi_mmc_request,
+	.set_ios	 = sunxi_mmc_set_ios,
+	.get_ro		 = mmc_gpio_get_ro,
+	.get_cd		 = mmc_gpio_get_cd,
+	.enable_sdio_irq = sunxi_mmc_enable_sdio_irq,
+	.hw_reset	 = sunxi_mmc_hw_reset,
+};
+
+static int sunxi_mmc_resource_request(struct sunxi_mmc_host *host,
+				      struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int ret;
+
+	if (of_device_is_compatible(np, "allwinner,sun4i-a10-mmc"))
+		host->idma_des_size_bits = 13;
+	else
+		host->idma_des_size_bits = 16;
+
+	ret = mmc_regulator_get_supply(host->mmc);
+	if (ret) {
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "Could not get vmmc supply\n");
+		return ret;
+	}
+
+	host->reg_base = devm_ioremap_resource(&pdev->dev,
+			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
+	if (IS_ERR(host->reg_base))
+		return PTR_ERR(host->reg_base);
+
+	host->clk_ahb = devm_clk_get(&pdev->dev, "ahb");
+	if (IS_ERR(host->clk_ahb)) {
+		dev_err(&pdev->dev, "Could not get ahb clock\n");
+		return PTR_ERR(host->clk_ahb);
+	}
+
+	host->clk_mmc = devm_clk_get(&pdev->dev, "mmc");
+	if (IS_ERR(host->clk_mmc)) {
+		dev_err(&pdev->dev, "Could not get mmc clock\n");
+		return PTR_ERR(host->clk_mmc);
+	}
+
+	host->reset = devm_reset_control_get(&pdev->dev, "ahb");
+
+	ret = clk_prepare_enable(host->clk_ahb);
+	if (ret) {
+		dev_err(&pdev->dev, "Enable ahb clk err %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(host->clk_mmc);
+	if (ret) {
+		dev_err(&pdev->dev, "Enable mmc clk err %d\n", ret);
+		goto error_disable_clk_ahb;
+	}
+
+	if (!IS_ERR(host->reset)) {
+		ret = reset_control_deassert(host->reset);
+		if (ret) {
+			dev_err(&pdev->dev, "reset err %d\n", ret);
+			goto error_disable_clk_mmc;
+		}
+	}
+
+	/*
+	 * Sometimes the controller asserts the irq on boot for some reason,
+	 * make sure the controller is in a sane state before enabling irqs.
+	 */
+	ret = sunxi_mmc_reset_host(host);
+	if (ret)
+		goto error_assert_reset;
+
+	host->irq = platform_get_irq(pdev, 0);
+	return devm_request_threaded_irq(&pdev->dev, host->irq, sunxi_mmc_irq,
+			sunxi_mmc_handle_manual_stop, 0, "sunxi-mmc", host);
+
+error_assert_reset:
+	if (!IS_ERR(host->reset))
+		reset_control_assert(host->reset);
+error_disable_clk_mmc:
+	clk_disable_unprepare(host->clk_mmc);
+error_disable_clk_ahb:
+	clk_disable_unprepare(host->clk_ahb);
+	return ret;
+}
+
+static int sunxi_mmc_probe(struct platform_device *pdev)
+{
+	struct sunxi_mmc_host *host;
+	struct mmc_host *mmc;
+	int ret;
+
+	mmc = mmc_alloc_host(sizeof(struct sunxi_mmc_host), &pdev->dev);
+	if (!mmc) {
+		dev_err(&pdev->dev, "mmc alloc host failed\n");
+		return -ENOMEM;
+	}
+
+	host = mmc_priv(mmc);
+	host->mmc = mmc;
+	spin_lock_init(&host->lock);
+
+	ret = sunxi_mmc_resource_request(host, pdev);
+	if (ret)
+		goto error_free_host;
+
+	host->sg_cpu = dma_alloc_coherent(&pdev->dev, PAGE_SIZE,
+					  &host->sg_dma, GFP_KERNEL);
+	if (!host->sg_cpu) {
+		dev_err(&pdev->dev, "Failed to allocate DMA descriptor mem\n");
+		ret = -ENOMEM;
+		goto error_free_host;
+	}
+
+	mmc->ops		= &sunxi_mmc_ops;
+	mmc->max_blk_count	= 8192;
+	mmc->max_blk_size	= 4096;
+	mmc->max_segs		= PAGE_SIZE / sizeof(struct sunxi_idma_des);
+	mmc->max_seg_size	= (1 << host->idma_des_size_bits);
+	mmc->max_req_size	= mmc->max_seg_size * mmc->max_segs;
+	/* 400kHz ~ 50MHz */
+	mmc->f_min		=   400000;
+	mmc->f_max		= 50000000;
+	mmc->caps	       |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED;
+
+	ret = mmc_of_parse(mmc);
+	if (ret)
+		goto error_free_dma;
+
+	ret = mmc_add_host(mmc);
+	if (ret)
+		goto error_free_dma;
+
+	dev_info(&pdev->dev, "base:0x%p irq:%u\n", host->reg_base, host->irq);
+	platform_set_drvdata(pdev, mmc);
+	return 0;
+
+error_free_dma:
+	dma_free_coherent(&pdev->dev, PAGE_SIZE, host->sg_cpu, host->sg_dma);
+error_free_host:
+	mmc_free_host(mmc);
+	return ret;
+}
+
+static int sunxi_mmc_remove(struct platform_device *pdev)
+{
+	struct mmc_host	*mmc = platform_get_drvdata(pdev);
+	struct sunxi_mmc_host *host = mmc_priv(mmc);
+
+	mmc_remove_host(mmc);
+	disable_irq(host->irq);
+	sunxi_mmc_reset_host(host);
+
+	if (!IS_ERR(host->reset))
+		reset_control_assert(host->reset);
+
+	clk_disable_unprepare(host->clk_mmc);
+	clk_disable_unprepare(host->clk_ahb);
+
+	dma_free_coherent(&pdev->dev, PAGE_SIZE, host->sg_cpu, host->sg_dma);
+	mmc_free_host(mmc);
+
+	return 0;
+}
+
+static struct platform_driver sunxi_mmc_driver = {
+	.driver = {
+		.name	= "sunxi-mmc",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(sunxi_mmc_of_match),
+	},
+	.probe		= sunxi_mmc_probe,
+	.remove		= sunxi_mmc_remove,
+};
+module_platform_driver(sunxi_mmc_driver);
+
+MODULE_DESCRIPTION("Allwinner's SD/MMC Card Controller Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("David Lanzend�rfer <david.lanzendoerfer@o2s.ch>");
+MODULE_ALIAS("platform:sunxi-mmc");