mmc: fsl_esdhc: add pulse width detection workaround

HS400 mode on the LS1028A SoC isn't reliable. The linux driver has a
workaroung for the pulse width detection. Apply this workaround in
u-boot, too.

This will make HS400 mode work reliably on the LS1028A SoC.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>

arch/arm/cpu/armv8/fsl-layerscape/Kconfig

@@ -48,6 +48,7 @@ config ARCH_LS1028A
 	select SYS_FSL_ERRATUM_A009942 if !TFABOOT
 	select SYS_FSL_ERRATUM_A050382
 	select SYS_FSL_ERRATUM_A011334
+	select SYS_FSL_ESDHC_UNRELIABLE_PULSE_DETECTION_WORKAROUND
 	select RESV_RAM if GIC_V3_ITS
 	imply PANIC_HANG
 

drivers/mmc/Kconfig

@@ -816,3 +816,6 @@ config SYS_FSL_ERRATUM_ESDHC_A001
 
 config SYS_FSL_ERRATUM_A011334
 	bool
+
+config SYS_FSL_ESDHC_UNRELIABLE_PULSE_DETECTION_WORKAROUND
+	bool

drivers/mmc/fsl_esdhc.c

@@ -71,7 +71,8 @@ struct fsl_esdhc {
 	uint	sdtimingctl;	/* SD timing control register */
 	char    reserved8[20];	/* reserved */
 	uint	dllcfg0;	/* DLL config 0 register */
-	char	reserved9[12];	/* reserved */
+	uint	dllcfg1;	/* DLL config 1 register */
+	char	reserved9[8];	/* reserved */
 	uint	dllstat0;	/* DLL status 0 register */
 	char    reserved10[664];/* reserved */
 	uint    esdhcctl;	/* eSDHC control register */
@@ -767,6 +768,9 @@ static int esdhc_init_common(struct fsl_esdhc_priv *priv, struct mmc *mmc)
 	/* Set timout to the maximum value */
 	esdhc_clrsetbits32(&regs->sysctl, SYSCTL_TIMEOUT_MASK, 14 << 16);
 
+	if (IS_ENABLED(CONFIG_SYS_FSL_ESDHC_UNRELIABLE_PULSE_DETECTION_WORKAROUND))
+		esdhc_clrbits32(&regs->dllcfg1, DLL_PD_PULSE_STRETCH_SEL);
+
 	return 0;
 }
 

include/fsl_esdhc.h

@@ -190,6 +190,9 @@
 #define DLL_RESET		0x40000000
 #define DLL_FREQ_SEL		0x08000000
 
+/* DLL config 1 register */
+#define DLL_PD_PULSE_STRETCH_SEL 0x80000000
+
 /* DLL status 0 register */
 #define DLL_STS_SLV_LOCK	0x08000000