ENGR00315499-11 ARM:imx6 Change static environment SD/MMC storage to dynamic

imx6 boards (sabresd, sabreauto, arm2 and slevk) have multiple SD/MMC ports to boot.
But current uboot hard code the SD/MMC port for environment variables storage. So
if customer changes a port without modifying the configuration "CONFIG_SYS_MMC_ENV_DEV",
error will issue at saving and loading environment.

Implement a mechanism to detect SD/MMC port from SRC SMBR register, and override the
default "mmc_get_env_devno". The "board_late_mmc_env_init" is used to set "mmcdev"
when booting from SD/MMC port. Finally after booting from SD/MMC, the environment storage
device and "mmcdev" are both set to current SD/MMC port. Customers don't need to re-build
the image if booting from different SD/MMC port.

This patch also adds SD1 and SD3 support to imx6slevk BSP, and adds support for sabreauto
SD1 slot on base board.

Signed-off-by: Ye.Li <B37916@freescale.com>
Signed-off-by: Nitin Garg <nitin.garg@freescale.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/board/freescale/mx6sabresd/mx6sabresd.c b/board/freescale/mx6sabresd/mx6sabresd.c
index bdb6b13..0b283a8 100644
--- a/board/freescale/mx6sabresd/mx6sabresd.c
+++ b/board/freescale/mx6sabresd/mx6sabresd.c
@@ -292,6 +292,23 @@ struct fsl_esdhc_cfg usdhc_cfg[3] = {
 	{USDHC4_BASE_ADDR},
 };
 
+int mmc_get_env_devno(void)
+{
+	u32 soc_sbmr = readl(SRC_BASE_ADDR + 0x4);
+	u32 dev_no;
+
+	/* BOOT_CFG2[3] and BOOT_CFG2[4] */
+	dev_no = (soc_sbmr & 0x00001800) >> 11;
+
+	/* need ubstract 1 to map to the mmc device id
+	 * see the comments in board_mmc_init function
+	 */
+
+	dev_no--;
+
+	return dev_no;
+}
+
 #define USDHC2_CD_GPIO	IMX_GPIO_NR(2, 2)
 #define USDHC3_CD_GPIO	IMX_GPIO_NR(2, 0)
 
@@ -358,6 +375,17 @@ int board_mmc_init(bd_t *bis)
 
 	return status;
 }
+
+void board_late_mmc_env_init(void)
+{
+	char cmd[32];
+	u32 dev_no = mmc_get_env_devno();
+
+	setenv_ulong("mmcdev", dev_no);
+
+	sprintf(cmd, "mmc dev %d", dev_no);
+	run_command(cmd, 0);
+}
 #endif
 
 int mx6_rgmii_rework(struct phy_device *phydev)
@@ -641,6 +669,10 @@ int board_late_init(void)
 	add_board_boot_modes(board_boot_modes);
 #endif
 
+#ifdef CONFIG_ENV_IS_IN_MMC
+	board_late_mmc_env_init();
+#endif
+
 	return 0;
 }