tuning-step is the delay cell steps in tuning procedure. The default value
of tuning-step is 1. For imx6 series usdhc, tuning procedure can be passed
when the tuning-step value is 1. But imx7d usdhc need the tuning-step value
as 2, otherwise it can't pass the tuning procedure.
So this patch add the tuning-step setting in driver, so that user can set
the tuning-step value in dts.
Signed-off-by: Haibo Chen <haibo.chen@xxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci-esdhc-imx.c | 9 +++++++++
include/linux/platform_data/mmc-esdhc-imx.h | 1 +
2 files changed, 10 insertions(+)
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index b441eed..158f93b 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -75,6 +75,7 @@
#define ESDHC_STD_TUNING_EN (1 << 24)
/* NOTE: the minimum valid tuning start tap for mx6sl is 1 */
#define ESDHC_TUNING_START_TAP 0x1
+#define ESDHC_TUNING_STEP_SHIFT 16
/* pinctrl state */
#define ESDHC_PINCTRL_STATE_100MHZ "state_100mhz"
@@ -472,6 +473,7 @@ static void esdhc_writew_le(struct sdhci_host *host, u16 val, int reg)
} else if (imx_data->socdata->flags & ESDHC_FLAG_STD_TUNING) {
u32 v = readl(host->ioaddr + SDHCI_ACMD12_ERR);
u32 m = readl(host->ioaddr + ESDHC_MIX_CTRL);
+ u32 tuning_ctrl;
if (val & SDHCI_CTRL_TUNED_CLK) {
v |= ESDHC_MIX_CTRL_SMPCLK_SEL;
} else {
@@ -482,6 +484,11 @@ static void esdhc_writew_le(struct sdhci_host *host, u16 val, int reg)
if (val & SDHCI_CTRL_EXEC_TUNING) {
v |= ESDHC_MIX_CTRL_EXE_TUNE;
m |= ESDHC_MIX_CTRL_FBCLK_SEL;
+ tuning_ctrl = readl(host->ioaddr + ESDHC_TUNING_CTRL);
+ tuning_ctrl |= ESDHC_STD_TUNING_EN | ESDHC_TUNING_START_TAP;
+ if (imx_data->boarddata.tuning_step)
+ tuning_ctrl |= imx_data->boarddata.tuning_step << ESDHC_TUNING_STEP_SHIFT;
+ writel(tuning_ctrl, host->ioaddr + ESDHC_TUNING_CTRL);
} else {
v &= ~ESDHC_MIX_CTRL_EXE_TUNE;
}
@@ -949,6 +956,8 @@ sdhci_esdhc_imx_probe_dt(struct platform_device *pdev,
if (gpio_is_valid(boarddata->wp_gpio))
boarddata->wp_type = ESDHC_WP_GPIO;
+ of_property_read_u32(np, "fsl,tuning-step", &boarddata->tuning_step);
+
if (of_find_property(np, "no-1-8-v", NULL))
boarddata->support_vsel = false;
else
diff --git a/include/linux/platform_data/mmc-esdhc-imx.h b/include/linux/platform_data/mmc-esdhc-imx.h
index e1571ef..95ccab3 100644
--- a/include/linux/platform_data/mmc-esdhc-imx.h
+++ b/include/linux/platform_data/mmc-esdhc-imx.h
@@ -45,5 +45,6 @@ struct esdhc_platform_data {
int max_bus_width;
bool support_vsel;
unsigned int delay_line;
+ unsigned int tuning_step; /* The delay cell steps in tuning procedure */
};
#endif /* __ASM_ARCH_IMX_ESDHC_H */
--
1.9.1
--
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