[U-Boot] [RFC Patch V3] drivers: mmc: omap_hsmmc: Fix IO Buffer on OMAP36xx

[Adam Ford]

On the OMAP36xx/37xx the CONTROL_WKUP_CTRL register has
a field (bit 6) named GPIO_IO_PWRDNZ.  If 0, the IO buffers which
are related to GPIO_126, 127 and 129 are disabled. Some boards may
need this for MMC. After the PBIAS is configured, this bit should
be set high to enable these GPIO pins.

V3:  The OMAP36xx datasheet states to clear this bit before changing
     PBIAS, so this update clears the bit before changing it.  This
     patch also makes the option dependant on MMC_OMAP_HS.
V2:  Make this feature a config option and add it to the MMC section
     of the Kconfig.  This allows the precompiler to only include it
     in a small handfull of OMAP36XX and 37XX boards using MMC1.

V1:  Original submission

Signed-off-by: Adam Ford <aford173 at gmail.com>

diff --git a/configs/omap3_logic_defconfig b/configs/omap3_logic_defconfig
index a71ce5f..e4bd87a 100644
--- a/configs/omap3_logic_defconfig
+++ b/configs/omap3_logic_defconfig
@@ -30,6 +30,7 @@ CONFIG_CMD_FAT=y
 CONFIG_CMD_FS_GENERIC=y
 CONFIG_CMD_UBI=y
 CONFIG_MMC_OMAP_HS=y
+CONFIG_MMC_OMAP36XX_PINS=y
 CONFIG_SYS_NS16550=y
 CONFIG_USB=y
 CONFIG_USB_MUSB_GADGET=y
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 9ed8da3..7ef2f51 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -148,6 +148,18 @@ config MMC_OMAP_HS
 
 	  If unsure, say N.
 
+config MMC_OMAP36XX_PINS
+	bool "Enable MMC1 on OMAP36xx/37xx"
+	depends on OMAP34XX && MMC_OMAP_HS
+	help
+	  This enables extended-drain in the MMC/SD/SDIO1I/O and
+	  GPIO-associated I/O cells (gpio_126, gpio_127, and gpio_129)
+	  specific to the OMAP36xx/37xx using MMC1
+
+	  If you have a controller with this interface, say Y here.
+
+	  If unsure, say N.
+
 config SH_SDHI
 	bool "SuperH/Renesas ARM SoCs on-chip SDHI host controller support"
 	depends on RMOBILE
diff --git a/drivers/mmc/omap_hsmmc.c b/drivers/mmc/omap_hsmmc.c
index b326846..b3f01ca 100644
--- a/drivers/mmc/omap_hsmmc.c
+++ b/drivers/mmc/omap_hsmmc.c
@@ -38,6 +38,7 @@
 #include <asm/arch/sys_proto.h>
 #endif
 #include <dm.h>
+#include <asm/arch-omap3/mux.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -102,19 +103,41 @@ static unsigned char mmc_board_init(struct mmc *mmc)
 	t2_t *t2_base = (t2_t *)T2_BASE;
 	struct prcm *prcm_base = (struct prcm *)PRCM_BASE;
 	u32 pbias_lite;
+	u32 cpu_family;
+	u32 wkup_ctrl;
 
 	pbias_lite = readl(&t2_base->pbias_lite);
 	pbias_lite &= ~(PBIASLITEPWRDNZ1 | PBIASLITEPWRDNZ0);
+
 #ifdef CONFIG_TARGET_OMAP3_CAIRO
 	/* for cairo board, we need to set up 1.8 Volt bias level on MMC1 */
 	pbias_lite &= ~PBIASLITEVMODE0;
 #endif
+
+#ifdef CONFIG_MMC_OMAP36XX_PINS
+	cpu_family = get_cpu_family();
+	if (cpu_family == CPU_OMAP36XX) {
+		wkup_ctrl = readl(OMAP34XX_CTRL_WKUP_CTRL);
+
+		/* Disable the extended drain IO on OMAP36xx before changing PBIAS */
+		wkup_ctrl &= ~OMAP34XX_CTRL_WKUP_CTRL_GPIO_IO_PWRDNZ;
+		writel(wkup_ctrl, OMAP34XX_CTRL_WKUP_CTRL);
+	}
+#endif
 	writel(pbias_lite, &t2_base->pbias_lite);
 
 	writel(pbias_lite | PBIASLITEPWRDNZ1 |
 		PBIASSPEEDCTRL0 | PBIASLITEPWRDNZ0,
 		&t2_base->pbias_lite);
 
+#ifdef CONFIG_MMC_OMAP36XX_PINS
+	if (cpu_family == CPU_OMAP36XX)
+		/* Enable the extended drain IO on OMAP36xx after changing PBIAS */
+		writel(wkup_ctrl |
+				OMAP34XX_CTRL_WKUP_CTRL_GPIO_IO_PWRDNZ,
+				OMAP34XX_CTRL_WKUP_CTRL);
+#endif
+
 	writel(readl(&t2_base->devconf0) | MMCSDIO1ADPCLKISEL,
 		&t2_base->devconf0);
 
-- 
2.7.4