diff mbox series

[v8,2/2] mmc: Add mmc driver for Sunplus SP7021

Message ID 511e17e91ffa16d2a26d1e77f832a0771e2c4017.1658719324.git.tonyhuang.sunplus@gmail.com
State Superseded
Headers show
Series Add mmc driver for Sunplus SP7021 SOC | expand

Commit Message

Tony Huang July 25, 2022, 5:01 a.m. UTC
This is a patch for mmc driver for Sunplus SP7021 SOC.
Supports eMMC 4.41 DDR 104MB/s speed mode.

Signed-off-by: Tony Huang <tonyhuang.sunplus@gmail.com>
---
Changes in v5:
 - Addressed comments from Krzysztof.
 - Remove the relevant sdcard code.
 - Submit the emmc code only.

Changes in v6:
 - Addressed comments from Arnd.
 - Use SYSTEM_SLEEP_PM_OPS instead of SET_SYSTEM_SLEEP_PM_OPS.
 - Use RUNTIME_PM_OPS instead of SET_RUNTIME_PM_OPS.
 - Remove #ifdef check.
 - Fixed mutex lock and unlock imbalance issue.

Changes in v7:
 - Addressed comments from kernel test robot.
 - Remove unused vairable.
 - Add previous prototype.
 - Addressed make error and warning in kernel 5.18-rc1.

Changes in v8:
 - Addressed comments from Uffe.

 MAINTAINERS                    |    1 +
 drivers/mmc/host/Kconfig       |    9 +
 drivers/mmc/host/Makefile      |    1 +
 drivers/mmc/host/sunplus-mmc.c | 1012 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 1023 insertions(+)
 create mode 100644 drivers/mmc/host/sunplus-mmc.c

Comments

Ulf Hansson Aug. 17, 2022, 4:08 p.m. UTC | #1
[...]

> +struct spmmc_host {
> +       void __iomem *base;
> +       struct clk *clk;
> +       struct reset_control *rstc;
> +       spinlock_t lock; /* Prevent races with irq handler */
> +       struct mutex mrq_lock; /* protect spmmc_set_ios() context and spmmc_request() */
> +       struct mmc_host *mmc;
> +       struct mmc_request *mrq; /* current mrq */
> +       int irq;
> +       int power_state; /* current power state: off/up/on */
> +       int ddr_enabled;
> +       int signal_voltage;
> +       int dmapio_mode;
> +       /*
> +        * for purpose of reducing context switch, only when transfer data that
> +        * length is greater than `dma_int_threshold' should use interrupt
> +        */
> +       int dma_int_threshold;

I don't quite see how this is being used in the code. Is the threshold
dynamically changed or could it be defined as constant value instead?

> +       struct sg_mapping_iter sg_miter; /* for pio mode to access sglist */
> +       struct spmmc_tuning_info tuning_info;
> +};
> +
> +/*
> + * wait for transaction done, return -1 if error.
> + */
> +static inline int spmmc_wait_finish(struct spmmc_host *host)
> +{
> +       /* Wait for transaction finish */
> +       unsigned long timeout = jiffies + msecs_to_jiffies(5000);
> +
> +       while (!time_after(jiffies, timeout)) {
> +               if (readl(host->base + SPMMC_SD_STATE_REG) & SPMMC_SDSTATE_FINISH)
> +                       return 0;
> +               if (readl(host->base + SPMMC_SD_STATE_REG) & SPMMC_SDSTATE_ERROR)
> +                       return -EIO;
> +       }

Please convert the above and similar loops for timeouts for the entire
file, into using readl_poll_timeout().

Moreover, please define the timeout values as constants.

Note that, there are other places in this file where the similar loop
exists, please change them accordingly too.

[...]

> +
> +static void spmmc_send_stop_cmd(struct spmmc_host *host)
> +{
> +       struct mmc_command stop = {};
> +       u32 value;
> +
> +       stop.opcode = MMC_STOP_TRANSMISSION;
> +       stop.arg = 0;
> +       stop.flags = MMC_RSP_R1B;
> +       spmmc_prepare_cmd(host, &stop);
> +       value = readl(host->base + SPMMC_SD_INT_REG);
> +       value &= ~SPMMC_SDINT_SDCMPEN;
> +       value |= FIELD_PREP(SPMMC_SDINT_SDCMPEN, 0);
> +       writel(value, host->base + SPMMC_SD_INT_REG);
> +       spmmc_trigger_transaction(host);
> +       spmmc_wait_finish(host);
> +}
> +
> +static int spmmc_check_error(struct spmmc_host *host, struct mmc_request *mrq)
> +{
> +       int ret = 0;
> +       struct mmc_command *cmd = mrq->cmd;
> +       struct mmc_data *data = mrq->data;
> +
> +       u32 value = readl(host->base + SPMMC_SD_STATE_REG);
> +       u32 crc_token = FIELD_GET(SPMMC_CRCTOKEN_CHECK_RESULT, value);
> +
> +       if (value & SPMMC_SDSTATE_ERROR) {
> +               u32 timing_cfg0 = 0;
> +
> +               value = readl(host->base + SPMMC_SD_STATUS_REG);
> +
> +               if (host->tuning_info.enable_tuning) {
> +                       timing_cfg0 = readl(host->base + SPMMC_SD_TIMING_CONFIG0_REG);
> +                       host->tuning_info.rd_crc_dly = FIELD_GET(SPMMC_SD_READ_CRC_DELAY,
> +                                                                timing_cfg0);
> +                       host->tuning_info.rd_dat_dly = FIELD_GET(SPMMC_SD_READ_DATA_DELAY,
> +                                                                timing_cfg0);
> +                       host->tuning_info.rd_rsp_dly = FIELD_GET(SPMMC_SD_READ_RESPONSE_DELAY,
> +                                                                timing_cfg0);
> +                       host->tuning_info.wr_cmd_dly = FIELD_GET(SPMMC_SD_WRITE_COMMAND_DELAY,
> +                                                                timing_cfg0);
> +                       host->tuning_info.wr_dat_dly = FIELD_GET(SPMMC_SD_WRITE_DATA_DELAY,
> +                                                                timing_cfg0);
> +               }
> +
> +               if (value & SPMMC_SDSTATUS_RSP_TIMEOUT) {
> +                       ret = -ETIMEDOUT;
> +                       host->tuning_info.wr_cmd_dly++;
> +               } else if (value & SPMMC_SDSTATUS_RSP_CRC7_ERROR) {
> +                       ret = -EILSEQ;
> +                       host->tuning_info.rd_rsp_dly++;
> +               } else if (data) {
> +                       if ((value & SPMMC_SDSTATUS_STB_TIMEOUT)) {
> +                               ret = -ETIMEDOUT;
> +                               host->tuning_info.rd_dat_dly++;
> +                       } else if (value & SPMMC_SDSTATUS_RDATA_CRC16_ERROR) {
> +                               ret = -EILSEQ;
> +                               host->tuning_info.rd_dat_dly++;
> +                       } else if (value & SPMMC_SDSTATUS_CARD_CRC_CHECK_TIMEOUT) {
> +                               ret = -ETIMEDOUT;
> +                               host->tuning_info.rd_crc_dly++;
> +                       } else if (value & SPMMC_SDSTATUS_CRC_TOKEN_CHECK_ERROR) {
> +                               ret = -EILSEQ;
> +                               if (crc_token == 0x5)
> +                                       host->tuning_info.wr_dat_dly++;
> +                               else
> +                                       host->tuning_info.rd_crc_dly++;
> +                       }
> +               }
> +               cmd->error = ret;
> +               if (data) {
> +                       data->error = ret;
> +                       data->bytes_xfered = 0;
> +               }
> +               if (!host->tuning_info.need_tuning && host->tuning_info.enable_tuning)
> +                       cmd->retries = SPMMC_MAX_RETRIES;
> +               spmmc_sw_reset(host);
> +
> +               if (host->tuning_info.enable_tuning) {
> +                       timing_cfg0 |= FIELD_PREP(SPMMC_SD_READ_CRC_DELAY,
> +                                                      host->tuning_info.rd_crc_dly);
> +                       timing_cfg0 |= FIELD_PREP(SPMMC_SD_READ_DATA_DELAY,
> +                                                      host->tuning_info.rd_dat_dly);
> +                       timing_cfg0 |= FIELD_PREP(SPMMC_SD_READ_RESPONSE_DELAY,
> +                                                      host->tuning_info.rd_rsp_dly);
> +                       timing_cfg0 |= FIELD_PREP(SPMMC_SD_WRITE_COMMAND_DELAY,
> +                                                      host->tuning_info.wr_cmd_dly);
> +                       timing_cfg0 |= FIELD_PREP(SPMMC_SD_WRITE_DATA_DELAY,
> +                                                      host->tuning_info.wr_dat_dly);
> +                       writel(timing_cfg0, host->base + SPMMC_SD_TIMING_CONFIG0_REG);
> +               }
> +       } else if (data) {
> +               data->error = 0;
> +               data->bytes_xfered = data->blocks * data->blksz;
> +       }
> +       host->tuning_info.need_tuning = ret;
> +    /* controller will not send cmd 12 automatically if error occurred */

Is this comment really correct? It looks like the below code, ends up
sending a stop command no matter whether the request failed, no?

> +       if (cmd->opcode == MMC_READ_MULTIPLE_BLOCK ||
> +           cmd->opcode == MMC_WRITE_MULTIPLE_BLOCK) {

Unless this is needed due to a specific HW-controller behaviour, I
would rather rely on that we check for "mrq->data->stop", as that
indicates (from the SD/eMMC specification point of view) whether we
need to send the stop command.

Moreover, in this way, we can avoid creating our own "mmc_command" in
spmmc_send_stop_cmd(), but can instead just use "mrq->data->stop".

> +               spmmc_send_stop_cmd(host);
> +               spmmc_sw_reset(host);
> +       }
> +
> +       return ret;
> +}

[...]

> +static void spmmc_set_power_mode(struct spmmc_host *host, struct mmc_ios *ios)
> +{
> +       if (host->power_state == ios->power_mode)
> +               return;
> +
> +       switch (ios->power_mode) {
> +               /* power off->up->on */
> +       case MMC_POWER_ON:
> +               spmmc_controller_init(host);
> +               break;
> +       case MMC_POWER_UP:
> +               break;
> +       case MMC_POWER_OFF:
> +               pm_runtime_put(host->mmc->parent);

This looks wrong to me. Unless you can explain more exactly what goes on here.

If there is an external regulator to power the card (the eMMC/SD/SDIO
card), that card should be power-controlled by calling
mmc_regulator_set_ocr() somewhere around in this function.

> +               break;
> +       }
> +       host->power_state = ios->power_mode;
> +}

[...]

> +
> +static int spmmc_drv_probe(struct platform_device *pdev)
> +{
> +       struct mmc_host *mmc;
> +       struct resource *res;
> +       struct spmmc_host *host;
> +       int ret = 0;
> +
> +       mmc = mmc_alloc_host(sizeof(*host), &pdev->dev);
> +       if (!mmc) {
> +               ret = -ENOMEM;
> +               goto probe_free_host;
> +       }
> +
> +       host = mmc_priv(mmc);
> +       host->mmc = mmc;
> +       host->power_state = MMC_POWER_UNDEFINED;
> +       host->dma_int_threshold = 1024;
> +       host->dmapio_mode = SPMMC_DMA_MODE;
> +
> +       host->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
> +       if (IS_ERR(host->base))
> +               return PTR_ERR(host->base);
> +
> +       host->clk = devm_clk_get(&pdev->dev, NULL);
> +       if (IS_ERR(host->clk))
> +               return dev_err_probe(&pdev->dev, PTR_ERR(host->clk), "clk get fail\n");
> +
> +       host->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
> +       if (IS_ERR(host->rstc))
> +               return dev_err_probe(&pdev->dev, PTR_ERR(host->rstc), "rst get fail\n");
> +
> +       host->irq = platform_get_irq(pdev, 0);
> +       if (host->irq <= 0)
> +               return host->irq;
> +
> +       ret = devm_request_threaded_irq(&pdev->dev, host->irq,
> +                                       spmmc_irq, spmmc_func_finish_req, IRQF_SHARED,
> +                       NULL, host);
> +       if (ret)
> +               return ret;
> +
> +       ret = clk_prepare_enable(host->clk);
> +       if (ret)
> +               return dev_err_probe(&pdev->dev, ret, "failed to enable clk\n");
> +
> +       ret = mmc_of_parse(mmc);
> +       if (ret)
> +               goto probe_free_host;
> +
> +       spin_lock_init(&host->lock);
> +       mutex_init(&host->mrq_lock);
> +       mmc->ops = &spmmc_ops;
> +       mmc->f_min = SPMMC_MIN_CLK;
> +       if (mmc->f_max > SPMMC_MAX_CLK)
> +               mmc->f_max = SPMMC_MAX_CLK;
> +
> +       ret = mmc_regulator_get_supply(mmc);
> +       if (ret)
> +               goto probe_free_host;
> +
> +       if (!mmc->ocr_avail)
> +               mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
> +       mmc->max_seg_size = SPMMC_MAX_BLK_COUNT * 512;
> +       mmc->max_segs = SPMMC_MAX_DMA_MEMORY_SECTORS;
> +       mmc->max_req_size = SPMMC_MAX_BLK_COUNT * 512;
> +       mmc->max_blk_size = 512;
> +       mmc->max_blk_count = SPMMC_MAX_BLK_COUNT;
> +
> +       dev_set_drvdata(&pdev->dev, host);
> +       spmmc_controller_init(host);
> +       spmmc_set_sdmmc_mode(host);
> +       host->tuning_info.enable_tuning = 1;
> +       pm_runtime_set_active(&pdev->dev);
> +       pm_runtime_enable(&pdev->dev);
> +       mmc_add_host(mmc);
> +
> +       return ret;
> +
> +probe_free_host:
> +       if (mmc)
> +               mmc_free_host(mmc);
> +
> +       return ret;
> +}
> +
> +static int spmmc_drv_remove(struct platform_device *dev)
> +{
> +       struct spmmc_host *host = platform_get_drvdata(dev);
> +
> +       mmc_remove_host(host->mmc);
> +       clk_disable(host->clk);

This doesn't work, because there are no guarantees that the host is
runtime resumed at this point. Hence, the clock may be disabled
already.

To fix this, you should replace the above call to clk_disable() with a
call to pm_runtime_get_sync() instead.

> +       clk_disable_unprepare(host->clk);
> +       pm_runtime_disable(&dev->dev);

As you need to call pm_runtime_get_sync() above, you then need to
restore the runtime PM usage count here. So, add a call to
pm_runtime_put_noidle() here, that should do it.

> +       platform_set_drvdata(dev, NULL);
> +       mmc_free_host(host->mmc);
> +
> +       return 0;
> +}
> +
> +static int spmmc_pm_suspend(struct device *dev)
> +{
> +       pm_runtime_force_suspend(dev);
> +
> +       return 0;
> +}
> +
> +static int spmmc_pm_resume(struct device *dev)
> +{
> +       pm_runtime_force_resume(dev);
> +
> +       return 0;
> +}

Both spmmc_pm_suspend() and spmmc_pm_resume() can be entirely dropped,
see more below.

> +
> +static int spmmc_pm_runtime_suspend(struct device *dev)
> +{
> +       struct spmmc_host *host;
> +
> +       host = dev_get_drvdata(dev);
> +       clk_disable(host->clk);

You should replace the above call to clk_disable() with a call to
clk_disable_unprepare().

> +
> +       return 0;
> +}
> +
> +static int spmmc_pm_runtime_resume(struct device *dev)
> +{
> +       struct spmmc_host *host;
> +
> +       host = dev_get_drvdata(dev);
> +
> +       return clk_enable(host->clk);

You should replace the above call to clk_enable() with a call to
clk_prepare_enable().

> +}
> +
> +static const struct dev_pm_ops spmmc_pm_ops = {
> +       SYSTEM_SLEEP_PM_OPS(spmmc_pm_suspend, spmmc_pm_resume)
> +       RUNTIME_PM_OPS(spmmc_pm_runtime_suspend, spmmc_pm_runtime_resume, NULL)
> +};

The above can be replaced with:

static DEFINE_RUNTIME_DEV_PM_OPS(spmmc_pm_ops,
spmmc_pm_runtime_suspend, spmmc_pm_runtime_resume, NULL);

The system suspend/resume callback will then be set to
pm_runtime_force_suspend|resume(), which seems to be what you need.

> +
> +static const struct of_device_id spmmc_of_table[] = {
> +       {
> +               .compatible = "sunplus,sp7021-mmc",
> +       },
> +       {/* sentinel */}
> +};
> +MODULE_DEVICE_TABLE(of, spmmc_of_table);
> +
> +static struct platform_driver spmmc_driver = {
> +       .probe = spmmc_drv_probe,
> +       .remove = spmmc_drv_remove,
> +       .driver = {
> +               .name = "spmmc",
> +               .pm = pm_ptr(&spmmc_pm_ops),
> +               .of_match_table = spmmc_of_table,
> +       },
> +};
> +module_platform_driver(spmmc_driver);
> +
> +MODULE_AUTHOR("Tony Huang <tonyhuang.sunplus@gmail.com>");
> +MODULE_AUTHOR("Li-hao Kuo <lhjeff911@gmail.com>");
> +MODULE_DESCRIPTION("Sunplus MMC controller driver");
> +MODULE_LICENSE("GPL");

Kind regards
Uffe
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index cdd809a..2439234 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18874,6 +18874,7 @@  M:	Tony Huang <tonyhuang.sunplus@gmail.com>
 M:	Li-hao Kuo <lhjeff911@gmail.com>
 S:	Maintained
 F:	Documentation/devicetree/bindings/mmc/sunplus,mmc.yaml
+F:	drivers/mmc/host/sunplus-mmc.c
 
 SUNPLUS OCOTP DRIVER
 M:	Vincent Shih <vincent.sunplus@gmail.com>
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index af6c3c3..d99ee3b 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -14,6 +14,15 @@  config MMC_DEBUG
 	  added host drivers please don't invent their private macro for
 	  debugging.
 
+config MMC_SUNPLUS
+	tristate "Sunplus SP7021 MMC Controller"
+	depends on ARCH_SUNPLUS || COMPILE_TEST
+	help
+	  If you say yes here, you will get support for eMMC host interface
+	  on Sunplus SoCs.
+
+	  If unsure, say N
+
 config MMC_ARMMMCI
 	tristate "ARM AMBA Multimedia Card Interface support"
 	depends on ARM_AMBA
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 4e4ceb3..ba0c6d0 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -97,6 +97,7 @@  obj-$(CONFIG_MMC_SDHCI_MICROCHIP_PIC32)	+= sdhci-pic32.o
 obj-$(CONFIG_MMC_SDHCI_BRCMSTB)		+= sdhci-brcmstb.o
 obj-$(CONFIG_MMC_SDHCI_OMAP)		+= sdhci-omap.o
 obj-$(CONFIG_MMC_SDHCI_SPRD)		+= sdhci-sprd.o
+obj-$(CONFIG_MMC_SUNPLUS)		+= sunplus-mmc.o
 obj-$(CONFIG_MMC_CQHCI)			+= cqhci.o
 cqhci-y					+= cqhci-core.o
 cqhci-$(CONFIG_MMC_CRYPTO)		+= cqhci-crypto.o
diff --git a/drivers/mmc/host/sunplus-mmc.c b/drivers/mmc/host/sunplus-mmc.c
new file mode 100644
index 0000000..45a7100
--- /dev/null
+++ b/drivers/mmc/host/sunplus-mmc.c
@@ -0,0 +1,1012 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) Sunplus Inc.
+ * Author: Tony Huang <tonyhuang.sunplus@gmail.com>
+ * Author: Li-hao Kuo <lhjeff911@gmail.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/mmc/core.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/mmc.h>
+#include <linux/mmc/sdio.h>
+#include <linux/mmc/slot-gpio.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+
+#define SPMMC_MIN_CLK			400000
+#define SPMMC_MAX_CLK			52000000
+#define SPMMC_MAX_BLK_COUNT		65536
+#define SPMMC_MAX_TUNABLE_DLY	7
+
+#define SPMMC_CARD_MEDIATYPE_SRCDST_REG 0x0000
+#define SPMMC_MEDIA_TYPE		GENMASK(2, 0)
+#define SPMMC_DMA_SOURCE		GENMASK(6, 4)
+#define SPMMC_DMA_DESTINATION		GENMASK(10, 8)
+#define SPMMC_MEDIA_NONE	0
+#define SPMMC_MEDIA_SD		6
+#define SPMMC_MEDIA_MS		7
+
+#define SPMMC_SDRAM_SECTOR_0_SIZE_REG	0x0008
+#define SPMMC_DMA_BASE_ADDR_REG		0x000C
+#define SPMMC_HW_DMA_CTRL_REG		0x0010
+#define SPMMC_HW_DMA_RST	BIT(9)
+#define SPMMC_DMAIDLE		BIT(10)
+
+#define SPMMC_MAX_DMA_MEMORY_SECTORS	8
+
+#define SPMMC_SDRAM_SECTOR_1_ADDR_REG 0x0018
+
+#define SPMMC_SD_INT_REG	0x0088
+#define SPMMC_SDINT_SDCMPEN	BIT(0)
+#define SPMMC_SDINT_SDCMP	BIT(1)
+#define SPMMC_SDINT_SDCMPCLR	BIT(2)
+#define SPMMC_SDINT_SDIOEN	BIT(3)
+#define SPMMC_SDINT_SDIO	BIT(4)
+#define SPMMC_SDINT_SDIOCLR	BIT(5)
+
+#define SPMMC_SD_PAGE_NUM_REG	0x008C
+
+#define SPMMC_SD_CONFIG0_REG	0x0090
+#define SPMMC_SD_PIO_MODE	BIT(0)
+#define SPMMC_SD_DDR_MODE	BIT(1)
+#define SPMMC_SD_LEN_MODE	BIT(2)
+#define SPMMC_SD_TRANS_MODE	GENMASK(5, 4)
+#define SPMMC_SD_AUTO_RESPONSE	BIT(6)
+#define SPMMC_SD_CMD_DUMMY	BIT(7)
+#define SPMMC_SD_RSP_CHK_EN	BIT(8)
+#define SPMMC_SDIO_MODE		BIT(9)
+#define SPMMC_SD_MMC_MODE	BIT(10)
+#define SPMMC_SD_DATA_WD	BIT(11)
+#define SPMMC_RX4_EN		BIT(14)
+#define SPMMC_SD_RSP_TYPE	BIT(15)
+#define SPMMC_MMC8_EN		BIT(18)
+#define SPMMC_CLOCK_DIVISION	GENMASK(31, 20)
+
+#define SPMMC_SDIO_CTRL_REG		0x0094
+#define SPMMC_INT_MULTI_TRIG		BIT(6)
+
+#define SPMMC_SD_RST_REG		0x0098
+#define SPMMC_SD_CTRL_REG		0x009C
+#define SPMMC_NEW_COMMAND_TRIGGER	BIT(0)
+#define SPMMC_DUMMY_CLOCK_TRIGGER	BIT(1)
+
+#define SPMMC_SD_STATUS_REG						0x00A0
+#define SPMMC_SDSTATUS_DUMMY_READY				BIT(0)
+#define SPMMC_SDSTATUS_RSP_BUF_FULL				BIT(1)
+#define SPMMC_SDSTATUS_TX_DATA_BUF_EMPTY		BIT(2)
+#define SPMMC_SDSTATUS_RX_DATA_BUF_FULL			BIT(3)
+#define SPMMC_SDSTATUS_CMD_PIN_STATUS			BIT(4)
+#define SPMMC_SDSTATUS_DAT0_PIN_STATUS			BIT(5)
+#define SPMMC_SDSTATUS_RSP_TIMEOUT				BIT(6)
+#define SPMMC_SDSTATUS_CARD_CRC_CHECK_TIMEOUT	BIT(7)
+#define SPMMC_SDSTATUS_STB_TIMEOUT				BIT(8)
+#define SPMMC_SDSTATUS_RSP_CRC7_ERROR			BIT(9)
+#define SPMMC_SDSTATUS_CRC_TOKEN_CHECK_ERROR	BIT(10)
+#define SPMMC_SDSTATUS_RDATA_CRC16_ERROR		BIT(11)
+#define SPMMC_SDSTATUS_SUSPEND_STATE_READY		BIT(12)
+#define SPMMC_SDSTATUS_BUSY_CYCLE				BIT(13)
+#define SPMMC_SDSTATUS_DAT1_PIN_STATUS			BIT(14)
+#define SPMMC_SDSTATUS_SD_SENSE_STATUS			BIT(15)
+#define SPMMC_SDSTATUS_BOOT_ACK_TIMEOUT			BIT(16)
+#define SPMMC_SDSTATUS_BOOT_DATA_TIMEOUT		BIT(17)
+#define SPMMC_SDSTATUS_BOOT_ACK_ERROR			BIT(18)
+
+#define SPMMC_SD_STATE_REG		0x00A4
+#define SPMMC_CRCTOKEN_CHECK_RESULT	GENMASK(6, 4)
+#define SPMMC_SDSTATE_ERROR		BIT(13)
+#define SPMMC_SDSTATE_FINISH	BIT(14)
+
+#define SPMMC_SD_HW_STATE_REG		0x00A8
+#define SPMMC_SD_BLOCKSIZE_REG		0x00AC
+
+#define SPMMC_SD_CONFIG1_REG		0x00B0
+#define SPMMC_TX_DUMMY_NUM		GENMASK(8, 0)
+#define SPMMC_SD_HIGH_SPEED_EN		BIT(31)
+
+#define SPMMC_SD_TIMING_CONFIG0_REG 0x00B4
+#define SPMMC_SD_CLOCK_DELAY	GENMASK(2, 0)
+#define SPMMC_SD_WRITE_DATA_DELAY	GENMASK(6, 4)
+#define SPMMC_SD_WRITE_COMMAND_DELAY	GENMASK(10, 8)
+#define SPMMC_SD_READ_RESPONSE_DELAY	GENMASK(14, 12)
+#define SPMMC_SD_READ_DATA_DELAY	GENMASK(18, 16)
+#define SPMMC_SD_READ_CRC_DELAY	GENMASK(22, 20)
+
+#define SPMMC_SD_PIODATATX_REG		0x00BC
+#define SPMMC_SD_PIODATARX_REG		0x00C0
+#define SPMMC_SD_CMDBUF0_3_REG		0x00C4
+#define SPMMC_SD_CMDBUF4_REG		0x00C8
+#define SPMMC_SD_RSPBUF0_3_REG		0x00CC
+#define SPMMC_SD_RSPBUF4_5_REG		0x00D0
+
+#define SPMMC_MAX_RETRIES (8 * 8)
+
+struct spmmc_tuning_info {
+	int enable_tuning;
+	int need_tuning;
+	int retried; /* how many times has been retried */
+	u32 rd_crc_dly:3;
+	u32 rd_dat_dly:3;
+	u32 rd_rsp_dly:3;
+	u32 wr_cmd_dly:3;
+	u32 wr_dat_dly:3;
+	u32 clk_dly:3;
+};
+
+#define SPMMC_DMA_MODE 0
+#define	SPMMC_PIO_MODE 1
+
+struct spmmc_host {
+	void __iomem *base;
+	struct clk *clk;
+	struct reset_control *rstc;
+	spinlock_t lock; /* Prevent races with irq handler */
+	struct mutex mrq_lock; /* protect spmmc_set_ios() context and spmmc_request() */
+	struct mmc_host *mmc;
+	struct mmc_request *mrq; /* current mrq */
+	int irq;
+	int power_state; /* current power state: off/up/on */
+	int ddr_enabled;
+	int signal_voltage;
+	int dmapio_mode;
+	/*
+	 * for purpose of reducing context switch, only when transfer data that
+	 * length is greater than `dma_int_threshold' should use interrupt
+	 */
+	int dma_int_threshold;
+	struct sg_mapping_iter sg_miter; /* for pio mode to access sglist */
+	struct spmmc_tuning_info tuning_info;
+};
+
+/*
+ * wait for transaction done, return -1 if error.
+ */
+static inline int spmmc_wait_finish(struct spmmc_host *host)
+{
+	/* Wait for transaction finish */
+	unsigned long timeout = jiffies + msecs_to_jiffies(5000);
+
+	while (!time_after(jiffies, timeout)) {
+		if (readl(host->base + SPMMC_SD_STATE_REG) & SPMMC_SDSTATE_FINISH)
+			return 0;
+		if (readl(host->base + SPMMC_SD_STATE_REG) & SPMMC_SDSTATE_ERROR)
+			return -EIO;
+	}
+
+	return -ETIMEDOUT;
+}
+
+static inline int spmmc_wait_sdstatus(struct spmmc_host *host, unsigned int status_bit)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(5000);
+
+	while (!time_after(jiffies, timeout)) {
+		if (readl(host->base + SPMMC_SD_STATUS_REG) & status_bit)
+			return 0;
+		if (readl(host->base + SPMMC_SD_STATE_REG) & SPMMC_SDSTATE_ERROR)
+			return -EIO;
+	}
+
+	return -ETIMEDOUT;
+}
+
+#define spmmc_wait_rspbuf_full(host) spmmc_wait_sdstatus(host, SPMMC_SDSTATUS_RSP_BUF_FULL)
+#define spmmc_wait_rxbuf_full(host) spmmc_wait_sdstatus(host, SPMMC_SDSTATUS_RX_DATA_BUF_FULL)
+#define spmmc_wait_txbuf_empty(host) spmmc_wait_sdstatus(host, SPMMC_SDSTATUS_TX_DATA_BUF_EMPTY)
+
+static void spmmc_get_rsp(struct spmmc_host *host, struct mmc_command *cmd)
+{
+	u32 value0_3, value4_5;
+
+	if (!(cmd->flags & MMC_RSP_PRESENT))
+		return;
+	if (cmd->flags & MMC_RSP_136) {
+		if (spmmc_wait_rspbuf_full(host))
+			return;
+		value0_3 = readl(host->base + SPMMC_SD_RSPBUF0_3_REG);
+		value4_5 = readl(host->base + SPMMC_SD_RSPBUF4_5_REG) & 0xffff;
+		cmd->resp[0] = (value0_3 << 8) | (value4_5 >> 8);
+		cmd->resp[1] = value4_5 << 24;
+		value0_3 = readl(host->base + SPMMC_SD_RSPBUF0_3_REG);
+		value4_5 = readl(host->base + SPMMC_SD_RSPBUF4_5_REG) & 0xffff;
+		cmd->resp[1] |= value0_3 >> 8;
+		cmd->resp[2] = value0_3 << 24;
+		cmd->resp[2] |= value4_5 << 8;
+		value0_3 = readl(host->base + SPMMC_SD_RSPBUF0_3_REG);
+		value4_5 = readl(host->base + SPMMC_SD_RSPBUF4_5_REG) & 0xffff;
+		cmd->resp[2] |= value0_3 >> 24;
+		cmd->resp[3] = value0_3 << 8;
+		cmd->resp[3] |= value4_5 >> 8;
+	} else {
+		if (spmmc_wait_rspbuf_full(host))
+			return;
+		value0_3 = readl(host->base + SPMMC_SD_RSPBUF0_3_REG);
+		value4_5 = readl(host->base + SPMMC_SD_RSPBUF4_5_REG) & 0xffff;
+		cmd->resp[0] = (value0_3 << 8) | (value4_5 >> 8);
+		cmd->resp[1] = value4_5 << 24;
+	}
+}
+
+static void spmmc_set_bus_clk(struct spmmc_host *host, int clk)
+{
+	unsigned int clkdiv;
+	int f_min = host->mmc->f_min;
+	int f_max = host->mmc->f_max;
+	u32 value = readl(host->base + SPMMC_SD_CONFIG0_REG);
+
+	if (clk < f_min)
+		clk = f_min;
+	if (clk > f_max)
+		clk = f_max;
+
+	clkdiv = (clk_get_rate(host->clk) + clk) / clk - 1;
+	if (clkdiv > 0xfff)
+		clkdiv = 0xfff;
+
+	value |= FIELD_PREP(SPMMC_CLOCK_DIVISION, clkdiv);
+	writel(value, host->base + SPMMC_SD_CONFIG0_REG);
+}
+
+static void spmmc_set_bus_timing(struct spmmc_host *host, unsigned int timing)
+{
+	u32 value = readl(host->base + SPMMC_SD_CONFIG1_REG);
+	int clkdiv = FIELD_GET(SPMMC_CLOCK_DIVISION, readl(host->base + SPMMC_SD_CONFIG0_REG));
+	int delay = clkdiv / 2 < 7 ? clkdiv / 2 : 7;
+	int hs_en = 1;
+
+	host->ddr_enabled = 0;
+	switch (timing) {
+	case MMC_TIMING_LEGACY:
+		hs_en = 0;
+		break;
+	case MMC_TIMING_MMC_HS:
+	case MMC_TIMING_SD_HS:
+	case MMC_TIMING_UHS_SDR50:
+	case MMC_TIMING_UHS_SDR104:
+	case MMC_TIMING_MMC_HS200:
+		hs_en = 1;
+		break;
+	case MMC_TIMING_UHS_DDR50:
+		host->ddr_enabled = 1;
+		break;
+	case MMC_TIMING_MMC_DDR52:
+		host->ddr_enabled = 1;
+		break;
+	default:
+		hs_en = 0;
+		break;
+	}
+
+	if (hs_en) {
+		value |= SPMMC_SD_HIGH_SPEED_EN;
+		writel(value, host->base + SPMMC_SD_CONFIG1_REG);
+		value = readl(host->base + SPMMC_SD_TIMING_CONFIG0_REG);
+		value |= FIELD_PREP(SPMMC_SD_WRITE_DATA_DELAY, delay);
+		value |= FIELD_PREP(SPMMC_SD_WRITE_COMMAND_DELAY, delay);
+		writel(value, host->base + SPMMC_SD_TIMING_CONFIG0_REG);
+	} else {
+		value &= ~SPMMC_SD_HIGH_SPEED_EN;
+		writel(value, host->base + SPMMC_SD_CONFIG1_REG);
+	}
+	if (host->ddr_enabled) {
+		value = readl(host->base + SPMMC_SD_CONFIG0_REG);
+		value |= SPMMC_SD_DDR_MODE;
+		writel(value, host->base + SPMMC_SD_CONFIG0_REG);
+	} else {
+		value = readl(host->base + SPMMC_SD_CONFIG0_REG);
+		value &= ~SPMMC_SD_DDR_MODE;
+		writel(value, host->base + SPMMC_SD_CONFIG0_REG);
+	}
+}
+
+static void spmmc_set_bus_width(struct spmmc_host *host, int width)
+{
+	u32 value = readl(host->base + SPMMC_SD_CONFIG0_REG);
+
+	switch (width) {
+	case MMC_BUS_WIDTH_8:
+		value &= ~SPMMC_SD_DATA_WD;
+		value |= SPMMC_MMC8_EN;
+		break;
+	case MMC_BUS_WIDTH_4:
+		value |= SPMMC_SD_DATA_WD;
+		value &= ~SPMMC_MMC8_EN;
+		break;
+	default:
+		value &= ~SPMMC_SD_DATA_WD;
+		value &= ~SPMMC_MMC8_EN;
+		break;
+	};
+	writel(value, host->base + SPMMC_SD_CONFIG0_REG);
+}
+
+/*
+ * select the working mode of controller: sd/sdio/emmc
+ */
+static void spmmc_set_sdmmc_mode(struct spmmc_host *host)
+{
+	u32 value = readl(host->base + SPMMC_SD_CONFIG0_REG);
+
+	value |= SPMMC_SD_MMC_MODE;
+	value &= ~SPMMC_SDIO_MODE;
+	writel(value, host->base + SPMMC_SD_CONFIG0_REG);
+}
+
+static void spmmc_sw_reset(struct spmmc_host *host)
+{
+	u32 value;
+
+	/*
+	 * Must reset dma operation first, or it will
+	 * be stuck on sd_state == 0x1c00 because of
+	 * a controller software reset bug
+	 */
+	value = readl(host->base + SPMMC_HW_DMA_CTRL_REG);
+	value |= SPMMC_DMAIDLE;
+	writel(value, host->base + SPMMC_HW_DMA_CTRL_REG);
+	value &= ~SPMMC_DMAIDLE;
+	writel(value, host->base + SPMMC_HW_DMA_CTRL_REG);
+	value = readl(host->base + SPMMC_HW_DMA_CTRL_REG);
+	value |= SPMMC_HW_DMA_RST;
+	writel(value, host->base + SPMMC_HW_DMA_CTRL_REG);
+	writel(0x7, host->base + SPMMC_SD_RST_REG);
+	while (readl(host->base + SPMMC_SD_HW_STATE_REG) & BIT(6))
+		;
+}
+
+static void spmmc_prepare_cmd(struct spmmc_host *host, struct mmc_command *cmd)
+{
+	u32 value;
+
+	/* add start bit, according to spec, command format */
+	value = ((cmd->opcode | 0x40) << 24) | (cmd->arg >> 8);
+	writel(value, host->base + SPMMC_SD_CMDBUF0_3_REG);
+	writeb(cmd->arg & 0xff, host->base + SPMMC_SD_CMDBUF4_REG);
+
+	/* disable interrupt if needed */
+	value = readl(host->base + SPMMC_SD_INT_REG);
+	value |= SPMMC_SDINT_SDCMPCLR;
+	value &= ~SPMMC_SDINT_SDCMPEN;
+	writel(value, host->base + SPMMC_SD_INT_REG);
+
+	value = readl(host->base + SPMMC_SD_CONFIG0_REG);
+	value &= ~SPMMC_SD_TRANS_MODE;
+	value |= SPMMC_SD_CMD_DUMMY;
+	if (cmd->flags & MMC_RSP_PRESENT) {
+		value |= SPMMC_SD_AUTO_RESPONSE;
+	} else {
+		value &= ~SPMMC_SD_AUTO_RESPONSE;
+		writel(value, host->base + SPMMC_SD_CONFIG0_REG);
+
+		return;
+	}
+	/*
+	 * Currently, host is not capable of checking R2's CRC7,
+	 * thus, enable crc7 check only for 48 bit response commands
+	 */
+	if (cmd->flags & MMC_RSP_CRC && !(cmd->flags & MMC_RSP_136))
+		value |= SPMMC_SD_RSP_CHK_EN;
+	else
+		value &= ~SPMMC_SD_RSP_CHK_EN;
+
+	if (cmd->flags & MMC_RSP_136)
+		value |= SPMMC_SD_RSP_TYPE;
+	else
+		value &= ~SPMMC_SD_RSP_TYPE;
+	writel(value, host->base + SPMMC_SD_CONFIG0_REG);
+}
+
+static void spmmc_prepare_data(struct spmmc_host *host, struct mmc_data *data)
+{
+	u32 value, srcdst;
+
+	writel(data->blocks - 1, host->base + SPMMC_SD_PAGE_NUM_REG);
+	writel(data->blksz - 1, host->base + SPMMC_SD_BLOCKSIZE_REG);
+	value = readl(host->base + SPMMC_SD_CONFIG0_REG);
+	if (data->flags & MMC_DATA_READ) {
+		value |= FIELD_PREP(SPMMC_SD_TRANS_MODE, 2);
+		value &= ~SPMMC_SD_AUTO_RESPONSE;
+		value &= ~SPMMC_SD_CMD_DUMMY;
+		srcdst = readl(host->base + SPMMC_CARD_MEDIATYPE_SRCDST_REG);
+		srcdst |= FIELD_PREP(SPMMC_DMA_SOURCE, 0x2);
+		srcdst |= FIELD_PREP(SPMMC_DMA_DESTINATION, 0x1);
+		writel(srcdst, host->base + SPMMC_CARD_MEDIATYPE_SRCDST_REG);
+	} else {
+		value |= FIELD_PREP(SPMMC_SD_TRANS_MODE, 1);
+		srcdst = readl(host->base + SPMMC_CARD_MEDIATYPE_SRCDST_REG);
+		srcdst |= FIELD_PREP(SPMMC_DMA_SOURCE, 0x1);
+		srcdst |= FIELD_PREP(SPMMC_DMA_DESTINATION, 0x2);
+		writel(srcdst, host->base + SPMMC_CARD_MEDIATYPE_SRCDST_REG);
+	}
+
+	value |= SPMMC_SD_LEN_MODE;
+	if (host->dmapio_mode == SPMMC_DMA_MODE) {
+		struct scatterlist *sg;
+		dma_addr_t dma_addr;
+		unsigned int dma_size;
+		u32 *reg_addr;
+		int i, count = 1;
+
+		count = dma_map_sg(host->mmc->parent, data->sg, data->sg_len,
+				   mmc_get_dma_dir(data));
+		if (!count || count > SPMMC_MAX_DMA_MEMORY_SECTORS) {
+			data->error = -EINVAL;
+
+			return;
+		}
+		for_each_sg(data->sg, sg, count, i) {
+			dma_addr = sg_dma_address(sg);
+			dma_size = sg_dma_len(sg) / data->blksz - 1;
+			if (i == 0) {
+				writel(dma_addr, host->base + SPMMC_DMA_BASE_ADDR_REG);
+				writel(dma_size, host->base + SPMMC_SDRAM_SECTOR_0_SIZE_REG);
+			} else {
+				reg_addr = host->base + SPMMC_SDRAM_SECTOR_1_ADDR_REG + (i - 1) * 2;
+				writel(dma_addr, reg_addr);
+				writel(dma_size, reg_addr + 1);
+			}
+		}
+		value &= ~SPMMC_SD_PIO_MODE;
+		writel(value, host->base + SPMMC_SD_CONFIG0_REG);
+		/* enable interrupt if needed */
+		value = readl(host->base + SPMMC_SD_INT_REG);
+		value |= SPMMC_SDINT_SDCMPEN;
+		writel(value, host->base + SPMMC_SD_INT_REG);
+	} else {
+		value |= SPMMC_SD_PIO_MODE;
+		value |= SPMMC_RX4_EN;
+		writel(value, host->base + SPMMC_SD_CONFIG0_REG);
+	}
+}
+
+static inline void spmmc_trigger_transaction(struct spmmc_host *host)
+{
+	u32 value = readl(host->base + SPMMC_SD_CTRL_REG);
+
+	value |= SPMMC_NEW_COMMAND_TRIGGER;
+	writel(value, host->base + SPMMC_SD_CTRL_REG);
+}
+
+static void spmmc_send_stop_cmd(struct spmmc_host *host)
+{
+	struct mmc_command stop = {};
+	u32 value;
+
+	stop.opcode = MMC_STOP_TRANSMISSION;
+	stop.arg = 0;
+	stop.flags = MMC_RSP_R1B;
+	spmmc_prepare_cmd(host, &stop);
+	value = readl(host->base + SPMMC_SD_INT_REG);
+	value &= ~SPMMC_SDINT_SDCMPEN;
+	value |= FIELD_PREP(SPMMC_SDINT_SDCMPEN, 0);
+	writel(value, host->base + SPMMC_SD_INT_REG);
+	spmmc_trigger_transaction(host);
+	spmmc_wait_finish(host);
+}
+
+static int spmmc_check_error(struct spmmc_host *host, struct mmc_request *mrq)
+{
+	int ret = 0;
+	struct mmc_command *cmd = mrq->cmd;
+	struct mmc_data *data = mrq->data;
+
+	u32 value = readl(host->base + SPMMC_SD_STATE_REG);
+	u32 crc_token = FIELD_GET(SPMMC_CRCTOKEN_CHECK_RESULT, value);
+
+	if (value & SPMMC_SDSTATE_ERROR) {
+		u32 timing_cfg0 = 0;
+
+		value = readl(host->base + SPMMC_SD_STATUS_REG);
+
+		if (host->tuning_info.enable_tuning) {
+			timing_cfg0 = readl(host->base + SPMMC_SD_TIMING_CONFIG0_REG);
+			host->tuning_info.rd_crc_dly = FIELD_GET(SPMMC_SD_READ_CRC_DELAY,
+								 timing_cfg0);
+			host->tuning_info.rd_dat_dly = FIELD_GET(SPMMC_SD_READ_DATA_DELAY,
+								 timing_cfg0);
+			host->tuning_info.rd_rsp_dly = FIELD_GET(SPMMC_SD_READ_RESPONSE_DELAY,
+								 timing_cfg0);
+			host->tuning_info.wr_cmd_dly = FIELD_GET(SPMMC_SD_WRITE_COMMAND_DELAY,
+								 timing_cfg0);
+			host->tuning_info.wr_dat_dly = FIELD_GET(SPMMC_SD_WRITE_DATA_DELAY,
+								 timing_cfg0);
+		}
+
+		if (value & SPMMC_SDSTATUS_RSP_TIMEOUT) {
+			ret = -ETIMEDOUT;
+			host->tuning_info.wr_cmd_dly++;
+		} else if (value & SPMMC_SDSTATUS_RSP_CRC7_ERROR) {
+			ret = -EILSEQ;
+			host->tuning_info.rd_rsp_dly++;
+		} else if (data) {
+			if ((value & SPMMC_SDSTATUS_STB_TIMEOUT)) {
+				ret = -ETIMEDOUT;
+				host->tuning_info.rd_dat_dly++;
+			} else if (value & SPMMC_SDSTATUS_RDATA_CRC16_ERROR) {
+				ret = -EILSEQ;
+				host->tuning_info.rd_dat_dly++;
+			} else if (value & SPMMC_SDSTATUS_CARD_CRC_CHECK_TIMEOUT) {
+				ret = -ETIMEDOUT;
+				host->tuning_info.rd_crc_dly++;
+			} else if (value & SPMMC_SDSTATUS_CRC_TOKEN_CHECK_ERROR) {
+				ret = -EILSEQ;
+				if (crc_token == 0x5)
+					host->tuning_info.wr_dat_dly++;
+				else
+					host->tuning_info.rd_crc_dly++;
+			}
+		}
+		cmd->error = ret;
+		if (data) {
+			data->error = ret;
+			data->bytes_xfered = 0;
+		}
+		if (!host->tuning_info.need_tuning && host->tuning_info.enable_tuning)
+			cmd->retries = SPMMC_MAX_RETRIES;
+		spmmc_sw_reset(host);
+
+		if (host->tuning_info.enable_tuning) {
+			timing_cfg0 |= FIELD_PREP(SPMMC_SD_READ_CRC_DELAY,
+						       host->tuning_info.rd_crc_dly);
+			timing_cfg0 |= FIELD_PREP(SPMMC_SD_READ_DATA_DELAY,
+						       host->tuning_info.rd_dat_dly);
+			timing_cfg0 |= FIELD_PREP(SPMMC_SD_READ_RESPONSE_DELAY,
+						       host->tuning_info.rd_rsp_dly);
+			timing_cfg0 |= FIELD_PREP(SPMMC_SD_WRITE_COMMAND_DELAY,
+						       host->tuning_info.wr_cmd_dly);
+			timing_cfg0 |= FIELD_PREP(SPMMC_SD_WRITE_DATA_DELAY,
+						       host->tuning_info.wr_dat_dly);
+			writel(timing_cfg0, host->base + SPMMC_SD_TIMING_CONFIG0_REG);
+		}
+	} else if (data) {
+		data->error = 0;
+		data->bytes_xfered = data->blocks * data->blksz;
+	}
+	host->tuning_info.need_tuning = ret;
+    /* controller will not send cmd 12 automatically if error occurred */
+	if (cmd->opcode == MMC_READ_MULTIPLE_BLOCK ||
+	    cmd->opcode == MMC_WRITE_MULTIPLE_BLOCK) {
+		spmmc_send_stop_cmd(host);
+		spmmc_sw_reset(host);
+	}
+
+	return ret;
+}
+
+/*
+ * the strategy is:
+ * 1. if several continuous delays are acceptable, we choose a middle one;
+ * 2. otherwise, we choose the first one.
+ */
+static inline int __find_best_delay(u8 candidate_dly)
+{
+	int f, w, value;
+
+	if (!candidate_dly)
+		return 0;
+	f = ffs(candidate_dly) - 1;
+	w = hweight8(candidate_dly);
+	value = ((1 << w) - 1) << f;
+	if (0xff == (value & ~candidate_dly))
+		return (f + w / 2);
+	else
+		return (f);
+}
+
+static void spmmc_xfer_data_pio(struct spmmc_host *host, struct mmc_data *data)
+{
+	u32 *buf;
+	int data_left = data->blocks * data->blksz;
+	int consumed, remain;
+
+	struct sg_mapping_iter *sg_miter = &host->sg_miter;
+	unsigned int flags = 0;
+
+	if (data->flags & MMC_DATA_WRITE)
+		flags |= SG_MITER_FROM_SG;
+	else
+		flags |= SG_MITER_TO_SG;
+	sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
+	while (data_left > 0) {
+		consumed = 0;
+		if (!sg_miter_next(sg_miter))
+			break;
+		buf = sg_miter->addr;
+		remain = sg_miter->length;
+		do {
+			if (data->flags & MMC_DATA_WRITE) {
+				if (spmmc_wait_txbuf_empty(host))
+					goto done;
+				writel(*buf, host->base + SPMMC_SD_PIODATATX_REG);
+			} else {
+				if (spmmc_wait_rxbuf_full(host))
+					goto done;
+				*buf = readl(host->base + SPMMC_SD_PIODATARX_REG);
+			}
+			buf++;
+			/* tx/rx 4 bytes one time in pio mode */
+			consumed += 4;
+			remain -= 4;
+		} while (remain);
+		sg_miter->consumed = consumed;
+		data_left -= consumed;
+	}
+done:
+	sg_miter_stop(sg_miter);
+}
+
+static void spmmc_controller_init(struct spmmc_host *host)
+{
+	u32 value;
+	int ret = reset_control_assert(host->rstc);
+
+	if (!ret) {
+		usleep_range(1000, 1250);
+		ret = reset_control_deassert(host->rstc);
+	}
+
+	value = readl(host->base + SPMMC_CARD_MEDIATYPE_SRCDST_REG);
+	value |= FIELD_PREP(SPMMC_MEDIA_TYPE, SPMMC_MEDIA_SD);
+	writel(value, host->base + SPMMC_CARD_MEDIATYPE_SRCDST_REG);
+}
+
+static void spmmc_set_power_mode(struct spmmc_host *host, struct mmc_ios *ios)
+{
+	if (host->power_state == ios->power_mode)
+		return;
+
+	switch (ios->power_mode) {
+		/* power off->up->on */
+	case MMC_POWER_ON:
+		spmmc_controller_init(host);
+		break;
+	case MMC_POWER_UP:
+		break;
+	case MMC_POWER_OFF:
+		pm_runtime_put(host->mmc->parent);
+		break;
+	}
+	host->power_state = ios->power_mode;
+}
+
+/*
+ * 1. unmap scatterlist if needed;
+ * 2. get response & check error conditions;
+ * 3. unlock host->mrq_lock
+ * 4. notify mmc layer the request is done
+ */
+static void spmmc_finish_request(struct spmmc_host *host, struct mmc_request *mrq)
+{
+	struct mmc_command *cmd;
+	struct mmc_data *data;
+
+	if (!mrq)
+		return;
+
+	cmd = mrq->cmd;
+	data = mrq->data;
+
+	if (data && SPMMC_DMA_MODE == host->dmapio_mode)
+		dma_unmap_sg(host->mmc->parent, data->sg, data->sg_len, mmc_get_dma_dir(data));
+
+	spmmc_get_rsp(host, cmd);
+	spmmc_check_error(host, mrq);
+	host->mrq = NULL;
+	mmc_request_done(host->mmc, mrq);
+}
+
+/* Interrupt Service Routine */
+static irqreturn_t spmmc_irq(int irq, void *dev_id)
+{
+	struct spmmc_host *host = dev_id;
+	u32 value = readl(host->base + SPMMC_SD_INT_REG);
+
+	spin_lock(&host->lock);
+	if ((value & SPMMC_SDINT_SDCMP) && (value & SPMMC_SDINT_SDCMPEN)) {
+		value &= ~SPMMC_SDINT_SDCMPEN;
+		value |= SPMMC_SDINT_SDCMPCLR;
+		writel(value, host->base + SPMMC_SD_INT_REG);
+		spmmc_finish_request(host, host->mrq);
+	}
+	spin_unlock(&host->lock);
+
+	return IRQ_HANDLED;
+}
+
+static void spmmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+	struct spmmc_host *host = mmc_priv(mmc);
+	struct mmc_data *data;
+	struct mmc_command *cmd;
+
+	mutex_lock(&host->mrq_lock);
+	host->mrq = mrq;
+	data = mrq->data;
+	cmd = mrq->cmd;
+
+	spmmc_prepare_cmd(host, cmd);
+	/* we need manually read response R2. */
+	if (cmd->flags & MMC_RSP_136) {
+		spmmc_trigger_transaction(host);
+		spmmc_get_rsp(host, cmd);
+		spmmc_wait_finish(host);
+		spmmc_check_error(host, mrq);
+		host->mrq = NULL;
+		mmc_request_done(host->mmc, mrq);
+	} else {
+		if (data)
+			spmmc_prepare_data(host, data);
+
+		if (host->dmapio_mode == SPMMC_PIO_MODE && data) {
+			u32 value;
+			/* pio data transfer do not use interrupt */
+			value = readl(host->base + SPMMC_SD_INT_REG);
+			value &= ~SPMMC_SDINT_SDCMPEN;
+			writel(value, host->base + SPMMC_SD_INT_REG);
+			spmmc_trigger_transaction(host);
+			spmmc_xfer_data_pio(host, data);
+			spmmc_wait_finish(host);
+			spmmc_finish_request(host, mrq);
+		} else {
+			spmmc_trigger_transaction(host);
+			spmmc_wait_finish(host);
+			spmmc_finish_request(host, mrq);
+		}
+	}
+	mutex_unlock(&host->mrq_lock);
+}
+
+static void spmmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct spmmc_host *host = (struct spmmc_host *)mmc_priv(mmc);
+
+	mutex_lock(&host->mrq_lock);
+	spmmc_set_power_mode(host, ios);
+	spmmc_set_bus_clk(host, ios->clock);
+	spmmc_set_bus_timing(host, ios->timing);
+	spmmc_set_bus_width(host, ios->bus_width);
+	/* ensure mode is correct, because we might have hw reset the controller */
+	spmmc_set_sdmmc_mode(host);
+	mutex_unlock(&host->mrq_lock);
+}
+
+/*
+ * Return values for the get_cd callback should be:
+ *   0 for a absent card
+ *   1 for a present card
+ *   -ENOSYS when not supported (equal to NULL callback)
+ *   or a negative errno value when something bad happened
+ */
+static int spmmc_get_cd(struct mmc_host *mmc)
+{
+	int ret = 0;
+
+	if (mmc_can_gpio_cd(mmc))
+		ret = mmc_gpio_get_cd(mmc);
+
+	if (ret < 0)
+		ret = 0;
+
+	return ret;
+}
+
+static int spmmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
+{
+	struct spmmc_host *host = mmc_priv(mmc);
+	u8 smpl_dly = 0, candidate_dly = 0;
+	u32 value;
+
+	host->tuning_info.enable_tuning = 0;
+	do {
+		value = readl(host->base + SPMMC_SD_TIMING_CONFIG0_REG);
+		value |= FIELD_PREP(SPMMC_SD_READ_RESPONSE_DELAY, smpl_dly);
+		value |= FIELD_PREP(SPMMC_SD_READ_DATA_DELAY, smpl_dly);
+		value |= FIELD_PREP(SPMMC_SD_READ_CRC_DELAY, smpl_dly);
+		writel(value, host->base + SPMMC_SD_TIMING_CONFIG0_REG);
+
+		if (!mmc_send_tuning(mmc, opcode, NULL)) {
+			candidate_dly |= (1 << smpl_dly);
+			break;
+		}
+	} while (smpl_dly++ <= SPMMC_MAX_TUNABLE_DLY);
+	host->tuning_info.enable_tuning = 1;
+
+	if (candidate_dly) {
+		smpl_dly = __find_best_delay(candidate_dly);
+		value = readl(host->base + SPMMC_SD_TIMING_CONFIG0_REG);
+		value |= FIELD_PREP(SPMMC_SD_READ_RESPONSE_DELAY, smpl_dly);
+		value |= FIELD_PREP(SPMMC_SD_READ_DATA_DELAY, smpl_dly);
+		value |= FIELD_PREP(SPMMC_SD_READ_CRC_DELAY, smpl_dly);
+		writel(value, host->base + SPMMC_SD_TIMING_CONFIG0_REG);
+		return 0;
+	}
+
+	return -EIO;
+}
+
+static const struct mmc_host_ops spmmc_ops = {
+	.request = spmmc_request,
+	.set_ios = spmmc_set_ios,
+	.get_cd = spmmc_get_cd,
+	.execute_tuning = spmmc_execute_tuning,
+};
+
+static irqreturn_t spmmc_func_finish_req(int irq, void *dev_id)
+{
+	struct spmmc_host *host = dev_id;
+
+	spin_lock(&host->lock);
+	spmmc_finish_request(host, host->mrq);
+	spin_unlock(&host->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int spmmc_drv_probe(struct platform_device *pdev)
+{
+	struct mmc_host *mmc;
+	struct resource *res;
+	struct spmmc_host *host;
+	int ret = 0;
+
+	mmc = mmc_alloc_host(sizeof(*host), &pdev->dev);
+	if (!mmc) {
+		ret = -ENOMEM;
+		goto probe_free_host;
+	}
+
+	host = mmc_priv(mmc);
+	host->mmc = mmc;
+	host->power_state = MMC_POWER_UNDEFINED;
+	host->dma_int_threshold = 1024;
+	host->dmapio_mode = SPMMC_DMA_MODE;
+
+	host->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(host->base))
+		return PTR_ERR(host->base);
+
+	host->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(host->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(host->clk), "clk get fail\n");
+
+	host->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(host->rstc))
+		return dev_err_probe(&pdev->dev, PTR_ERR(host->rstc), "rst get fail\n");
+
+	host->irq = platform_get_irq(pdev, 0);
+	if (host->irq <= 0)
+		return host->irq;
+
+	ret = devm_request_threaded_irq(&pdev->dev, host->irq,
+					spmmc_irq, spmmc_func_finish_req, IRQF_SHARED,
+			NULL, host);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(host->clk);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "failed to enable clk\n");
+
+	ret = mmc_of_parse(mmc);
+	if (ret)
+		goto probe_free_host;
+
+	spin_lock_init(&host->lock);
+	mutex_init(&host->mrq_lock);
+	mmc->ops = &spmmc_ops;
+	mmc->f_min = SPMMC_MIN_CLK;
+	if (mmc->f_max > SPMMC_MAX_CLK)
+		mmc->f_max = SPMMC_MAX_CLK;
+
+	ret = mmc_regulator_get_supply(mmc);
+	if (ret)
+		goto probe_free_host;
+
+	if (!mmc->ocr_avail)
+		mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
+	mmc->max_seg_size = SPMMC_MAX_BLK_COUNT * 512;
+	mmc->max_segs = SPMMC_MAX_DMA_MEMORY_SECTORS;
+	mmc->max_req_size = SPMMC_MAX_BLK_COUNT * 512;
+	mmc->max_blk_size = 512;
+	mmc->max_blk_count = SPMMC_MAX_BLK_COUNT;
+
+	dev_set_drvdata(&pdev->dev, host);
+	spmmc_controller_init(host);
+	spmmc_set_sdmmc_mode(host);
+	host->tuning_info.enable_tuning = 1;
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+	mmc_add_host(mmc);
+
+	return ret;
+
+probe_free_host:
+	if (mmc)
+		mmc_free_host(mmc);
+
+	return ret;
+}
+
+static int spmmc_drv_remove(struct platform_device *dev)
+{
+	struct spmmc_host *host = platform_get_drvdata(dev);
+
+	mmc_remove_host(host->mmc);
+	clk_disable(host->clk);
+	clk_disable_unprepare(host->clk);
+	pm_runtime_disable(&dev->dev);
+	platform_set_drvdata(dev, NULL);
+	mmc_free_host(host->mmc);
+
+	return 0;
+}
+
+static int spmmc_pm_suspend(struct device *dev)
+{
+	pm_runtime_force_suspend(dev);
+
+	return 0;
+}
+
+static int spmmc_pm_resume(struct device *dev)
+{
+	pm_runtime_force_resume(dev);
+
+	return 0;
+}
+
+static int spmmc_pm_runtime_suspend(struct device *dev)
+{
+	struct spmmc_host *host;
+
+	host = dev_get_drvdata(dev);
+	clk_disable(host->clk);
+
+	return 0;
+}
+
+static int spmmc_pm_runtime_resume(struct device *dev)
+{
+	struct spmmc_host *host;
+
+	host = dev_get_drvdata(dev);
+
+	return clk_enable(host->clk);
+}
+
+static const struct dev_pm_ops spmmc_pm_ops = {
+	SYSTEM_SLEEP_PM_OPS(spmmc_pm_suspend, spmmc_pm_resume)
+	RUNTIME_PM_OPS(spmmc_pm_runtime_suspend, spmmc_pm_runtime_resume, NULL)
+};
+
+static const struct of_device_id spmmc_of_table[] = {
+	{
+		.compatible = "sunplus,sp7021-mmc",
+	},
+	{/* sentinel */}
+};
+MODULE_DEVICE_TABLE(of, spmmc_of_table);
+
+static struct platform_driver spmmc_driver = {
+	.probe = spmmc_drv_probe,
+	.remove = spmmc_drv_remove,
+	.driver = {
+		.name = "spmmc",
+		.pm = pm_ptr(&spmmc_pm_ops),
+		.of_match_table = spmmc_of_table,
+	},
+};
+module_platform_driver(spmmc_driver);
+
+MODULE_AUTHOR("Tony Huang <tonyhuang.sunplus@gmail.com>");
+MODULE_AUTHOR("Li-hao Kuo <lhjeff911@gmail.com>");
+MODULE_DESCRIPTION("Sunplus MMC controller driver");
+MODULE_LICENSE("GPL");