From: Haibo Chen <haibo.chen@xxxxxxx>
USDHC hardware auto tuning circuit support check 1/4/8 data lines
and cmd line. Out of reset uSDHC, it default select check 4 data
lines and do not check cmd line. This is incorrect if we use 8 data
lines. So need to config the auto tuning mode according to current
bus width.
Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx>
---
drivers/mmc/host/sdhci-esdhc-imx.c | 33 ++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index a49fac719fca..f18d169bc8ff 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -94,6 +94,11 @@
#define ESDHC_VEND_SPEC2 0xc8
#define ESDHC_VEND_SPEC2_EN_BUSY_IRQ (1 << 8)
+#define ESDHC_VEND_SPEC2_AUTO_TUNE_8BIT_EN (1 << 4)
+#define ESDHC_VEND_SPEC2_AUTO_TUNE_4BIT_EN (0 << 4)
+#define ESDHC_VEND_SPEC2_AUTO_TUNE_1BIT_EN (2 << 4)
+#define ESDHC_VEND_SPEC2_AUTO_TUNE_CMD_EN (1 << 6)
+#define ESDHC_VEND_SPEC2_AUTO_TUNE_MODE_MASK (7 << 4)
#define ESDHC_TUNING_CTRL 0xcc
#define ESDHC_STD_TUNING_EN (1 << 24)
@@ -114,6 +119,7 @@
#define ESDHC_CTRL_4BITBUS (0x1 << 1)
#define ESDHC_CTRL_8BITBUS (0x2 << 1)
#define ESDHC_CTRL_BUSWIDTH_MASK (0x3 << 1)
+#define USDHC_GET_BUSWIDTH(c) (c & ESDHC_CTRL_BUSWIDTH_MASK)
/*
* There is an INT DMA ERR mismatch between eSDHC and STD SDHC SPEC:
@@ -407,6 +413,30 @@ static inline void esdhc_wait_for_card_clock_gate_off(struct sdhci_host *host)
dev_warn(mmc_dev(host->mmc), "%s: card clock still not gate off in 100us!.\n", __func__);
}
+/* Enable the auto tuning circuit to check the CMD line and BUS line */
+static inline void usdhc_auto_tuning_mode_sel(struct sdhci_host *host)
+{
+ u32 buswidth, auto_tune_buswidth;
+
+ buswidth = USDHC_GET_BUSWIDTH(readl(host->ioaddr + SDHCI_HOST_CONTROL));
+
+ switch (buswidth) {
+ case ESDHC_CTRL_8BITBUS:
+ auto_tune_buswidth = ESDHC_VEND_SPEC2_AUTO_TUNE_8BIT_EN;
+ break;
+ case ESDHC_CTRL_4BITBUS:
+ auto_tune_buswidth = ESDHC_VEND_SPEC2_AUTO_TUNE_4BIT_EN;
+ break;
+ default: /* 1BITBUS */
+ auto_tune_buswidth = ESDHC_VEND_SPEC2_AUTO_TUNE_1BIT_EN;
+ break;
+ }
+
+ esdhc_clrset_le(host, ESDHC_VEND_SPEC2_AUTO_TUNE_MODE_MASK,
+ auto_tune_buswidth | ESDHC_VEND_SPEC2_AUTO_TUNE_CMD_EN,
+ ESDHC_VEND_SPEC2);
+}
+
static u32 esdhc_readl_le(struct sdhci_host *host, int reg)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -643,6 +673,7 @@ static void esdhc_writew_le(struct sdhci_host *host, u16 val, int reg)
v |= ESDHC_MIX_CTRL_EXE_TUNE;
m |= ESDHC_MIX_CTRL_FBCLK_SEL;
m |= ESDHC_MIX_CTRL_AUTO_TUNE_EN;
+ usdhc_auto_tuning_mode_sel(host);
} else {
v &= ~ESDHC_MIX_CTRL_EXE_TUNE;
}
@@ -1012,6 +1043,8 @@ static void esdhc_post_tuning(struct sdhci_host *host)
{
u32 reg;
+ usdhc_auto_tuning_mode_sel(host);
+
reg = readl(host->ioaddr + ESDHC_MIX_CTRL);
reg &= ~ESDHC_MIX_CTRL_EXE_TUNE;
reg |= ESDHC_MIX_CTRL_AUTO_TUNE_EN;
--
2.17.1
