mmc: stm32_sdmmc2: update pwron management
Correctly manage the SDMMC reset and card cycle power
to fully handle the power cycle added in the MMC uclass
and avoid issue with level-shifter with some uSDCARD.
3 states managed in driver:
1/ reset: SDMMC disable, signal HiZ
2/ power-cycle: SDMMC disable, signals drive to 0
3/ power-on: SDMMC enabled
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/drivers/mmc/stm32_sdmmc2.c b/drivers/mmc/stm32_sdmmc2.c
index e8292c4..a36612d 100644
--- a/drivers/mmc/stm32_sdmmc2.c
+++ b/drivers/mmc/stm32_sdmmc2.c
@@ -56,7 +56,10 @@
#define SDMMC_IDMABASE0 0x58 /* SDMMC DMA buffer 0 base address */
/* SDMMC_POWER register */
-#define SDMMC_POWER_PWRCTRL GENMASK(1, 0)
+#define SDMMC_POWER_PWRCTRL_MASK GENMASK(1, 0)
+#define SDMMC_POWER_PWRCTRL_OFF 0
+#define SDMMC_POWER_PWRCTRL_CYCLE 2
+#define SDMMC_POWER_PWRCTRL_ON 3
#define SDMMC_POWER_VSWITCH BIT(2)
#define SDMMC_POWER_VSWITCHEN BIT(3)
#define SDMMC_POWER_DIRPOL BIT(4)
@@ -440,23 +443,74 @@
return ret;
}
-static void stm32_sdmmc2_pwron(struct stm32_sdmmc2_priv *priv)
+/*
+ * Reset the SDMMC with the RCC.SDMMCxRST register bit.
+ * This will reset the SDMMC to the reset state and the CPSM and DPSM
+ * to the Idle state. SDMMC is disabled, Signals Hiz.
+ */
+static void stm32_sdmmc2_reset(struct stm32_sdmmc2_priv *priv)
{
/* Reset */
reset_assert(&priv->reset_ctl);
udelay(2);
reset_deassert(&priv->reset_ctl);
- udelay(1000);
+ /* init the needed SDMMC register after reset */
+ writel(priv->pwr_reg_msk, priv->base + SDMMC_POWER);
+}
- /* Set Power State to ON */
- writel(SDMMC_POWER_PWRCTRL | priv->pwr_reg_msk, priv->base + SDMMC_POWER);
+/*
+ * Set the SDMMC in power-cycle state.
+ * This will make that the SDMMC_D[7:0],
+ * SDMMC_CMD and SDMMC_CK are driven low, to prevent the card from being
+ * supplied through the signal lines.
+ */
+static void stm32_sdmmc2_pwrcycle(struct stm32_sdmmc2_priv *priv)
+{
+ if ((readl(priv->base + SDMMC_POWER) & SDMMC_POWER_PWRCTRL_MASK) ==
+ SDMMC_POWER_PWRCTRL_CYCLE)
+ return;
+
+ stm32_sdmmc2_reset(priv);
+ writel(SDMMC_POWER_PWRCTRL_CYCLE | priv->pwr_reg_msk,
+ priv->base + SDMMC_POWER);
+}
+
+/*
+ * set the SDMMC state Power-on: the card is clocked
+ * manage the SDMMC state control:
+ * Reset => Power-Cycle => Power-Off => Power
+ * PWRCTRL=10 PWCTRL=00 PWCTRL=11
+ */
+static void stm32_sdmmc2_pwron(struct stm32_sdmmc2_priv *priv)
+{
+ u32 pwrctrl =
+ readl(priv->base + SDMMC_POWER) & SDMMC_POWER_PWRCTRL_MASK;
+
+ if (pwrctrl == SDMMC_POWER_PWRCTRL_ON)
+ return;
+
+ /* warning: same PWRCTRL value after reset and for power-off state
+ * it is the reset state here = the only managed by the driver
+ */
+ if (pwrctrl == SDMMC_POWER_PWRCTRL_OFF) {
+ writel(SDMMC_POWER_PWRCTRL_CYCLE | priv->pwr_reg_msk,
+ priv->base + SDMMC_POWER);
+ }
/*
- * 1ms: required power up waiting time before starting the
- * SD initialization sequence
+ * the remaining case is SDMMC_POWER_PWRCTRL_CYCLE
+ * switch to Power-Off state: SDMCC disable, signals drive 1
*/
- udelay(1000);
+ writel(SDMMC_POWER_PWRCTRL_OFF | priv->pwr_reg_msk,
+ priv->base + SDMMC_POWER);
+
+ /* After the 1ms delay set the SDMMC to power-on */
+ mdelay(1);
+ writel(SDMMC_POWER_PWRCTRL_ON | priv->pwr_reg_msk,
+ priv->base + SDMMC_POWER);
+
+ /* during the first 74 SDMMC_CK cycles the SDMMC is still disabled. */
}
#define IS_RISING_EDGE(reg) (reg & SDMMC_CLKCR_NEGEDGE ? 0 : 1)
@@ -464,8 +518,6 @@
{
struct mmc *mmc = mmc_get_mmc_dev(dev);
struct stm32_sdmmc2_priv *priv = dev_get_priv(dev);
- struct stm32_sdmmc2_plat *plat = dev_get_platdata(dev);
- struct mmc_config *cfg = &plat->cfg;
u32 desired = mmc->clock;
u32 sys_clock = clk_get_rate(&priv->clk);
u32 clk = 0;
@@ -473,7 +525,9 @@
debug("%s: bus_with = %d, clock = %d\n", __func__,
mmc->bus_width, mmc->clock);
- if ((mmc->bus_width == 1) && (desired == cfg->f_min))
+ if (mmc->clk_disable)
+ stm32_sdmmc2_pwrcycle(priv);
+ else
stm32_sdmmc2_pwron(priv);
/*
@@ -577,6 +631,8 @@
upriv->mmc = &plat->mmc;
+ /* SDMMC init */
+ stm32_sdmmc2_reset(priv);
return 0;
clk_disable: