On RK3399, a register bit must be set to enable Enhanced Strobe.
Let the Rockchip SDHCI driver set it when Enhanced Strobe configuration
is requested. However, having it set makes the lower-speed modes stop
working and makes reinitialization fail, so let it be unset as needed in
set_control_reg().
This is mostly ported from Linux's Arasan SDHCI driver which happens
to be the underlying IP. (drivers/mmc/host/sdhci-of-arasan.c in Linux
tree).
Signed-off-by: Alper Nebi Yasak <alpernebiya...@gmail.com>
---
Didn't add Reviewed-by tag due to changes.
Changes in v2:
- Unset ES bit in rk3399 set_control_reg() to fix a reinit issue
- Don't use unnecessary & for function pointer in ops struct
- Rename rk3399_set_enhanced_strobe -> rk3399_sdhci_set_enhanced_strobe
- Let set_enhanced_strobe() unset the ES bit if mode is not HS400_ES
drivers/mmc/rockchip_sdhci.c | 41 ++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)
diff --git a/drivers/mmc/rockchip_sdhci.c b/drivers/mmc/rockchip_sdhci.c
index f0d7ba4774d6..f920c5141142 100644
--- a/drivers/mmc/rockchip_sdhci.c
+++ b/drivers/mmc/rockchip_sdhci.c
@@ -42,6 +42,9 @@
((((x) >> PHYCTRL_DLLRDY_SHIFT) & PHYCTRL_DLLRDY_MASK) ==\
PHYCTRL_DLLRDY_DONE)
+#define ARASAN_VENDOR_REGISTER 0x78
+#define ARASAN_VENDOR_ENHANCED_STROBE BIT(0)
+
/* Rockchip specific Registers */
#define DWCMSHC_EMMC_DLL_CTRL 0x800
#define DWCMSHC_EMMC_DLL_CTRL_RESET BIT(1)
@@ -94,6 +97,7 @@ struct sdhci_data {
int (*get_phy)(struct udevice *dev);
void (*set_control_reg)(struct sdhci_host *host);
int (*set_ios_post)(struct sdhci_host *host);
+ int (*set_enhanced_strobe)(struct sdhci_host *host);
};
static int rk3399_emmc_phy_init(struct udevice *dev)
@@ -183,6 +187,21 @@ static int rk3399_emmc_get_phy(struct udevice *dev)
return 0;
}
+static int rk3399_sdhci_set_enhanced_strobe(struct sdhci_host *host)
+{
+ struct mmc *mmc = host->mmc;
+ u32 vendor;
+
+ vendor = sdhci_readl(host, ARASAN_VENDOR_REGISTER);
+ if (mmc->selected_mode == MMC_HS_400_ES)
+ vendor |= ARASAN_VENDOR_ENHANCED_STROBE;
+ else
+ vendor &= ~ARASAN_VENDOR_ENHANCED_STROBE;
+ sdhci_writel(host, vendor, ARASAN_VENDOR_REGISTER);
+
+ return 0;
+}
+
static void rk3399_sdhci_set_control_reg(struct sdhci_host *host)
{
struct rockchip_sdhc *priv = container_of(host, struct rockchip_sdhc,
host);
@@ -194,6 +213,15 @@ static void rk3399_sdhci_set_control_reg(struct sdhci_host
*host)
rk3399_emmc_phy_power_off(priv->phy);
sdhci_set_control_reg(host);
+
+ /*
+ * Reinitializing the device tries to set it to lower-speed modes
+ * first, which fails if the Enhanced Strobe bit is set, making
+ * the device impossible to use. Set the correct value here to
+ * let reinitialization attempts succeed.
+ */
+ if (CONFIG_IS_ENABLED(MMC_HS400_ES_SUPPORT))
+ rk3399_sdhci_set_enhanced_strobe(host);
};
static int rk3399_sdhci_set_ios_post(struct sdhci_host *host)
@@ -386,10 +414,22 @@ static int rockchip_sdhci_execute_tuning(struct mmc *mmc,
u8 opcode)
return ret;
}
+static int rockchip_sdhci_set_enhanced_strobe(struct sdhci_host *host)
+{
+ struct rockchip_sdhc *priv = container_of(host, struct rockchip_sdhc,
host);
+ struct sdhci_data *data = (struct sdhci_data
*)dev_get_driver_data(priv->dev);
+
+ if (data->set_enhanced_strobe)
+ return data->set_enhanced_strobe(host);
+
+ return -ENOTSUPP;
+}
+
static struct sdhci_ops rockchip_sdhci_ops = {
.set_ios_post = rockchip_sdhci_set_ios_post,
.platform_execute_tuning = &rockchip_sdhci_execute_tuning,
.set_control_reg = rockchip_sdhci_set_control_reg,
+ .set_enhanced_strobe = rockchip_sdhci_set_enhanced_strobe,
};
static int rockchip_sdhci_probe(struct udevice *dev)
@@ -472,6 +512,7 @@ static const struct sdhci_data rk3399_data = {
.emmc_phy_init = rk3399_emmc_phy_init,
.set_control_reg = rk3399_sdhci_set_control_reg,
.set_ios_post = rk3399_sdhci_set_ios_post,
+ .set_enhanced_strobe = rk3399_sdhci_set_enhanced_strobe,
};
static const struct sdhci_data rk3568_data = {
--
2.34.1
