I am reading latest source codes(L3.0.35_4.1.0_130816_source) in linux/arch/arm/mach-mx6/board-mx6dl_sabresd.h...now..
/* USDHC3 */
MX6DL_PAD_SD3_CLK__USDHC3_CLK_50MHZ,
MX6DL_PAD_SD3_CMD__USDHC3_CMD_50MHZ,
MX6DL_PAD_SD3_DAT0__USDHC3_DAT0_50MHZ,
MX6DL_PAD_SD3_DAT1__USDHC3_DAT1_50MHZ,
MX6DL_PAD_SD3_DAT2__USDHC3_DAT2_50MHZ,
MX6DL_PAD_SD3_DAT3__USDHC3_DAT3_50MHZ,
MX6DL_PAD_SD3_DAT4__USDHC3_DAT4_50MHZ,
MX6DL_PAD_SD3_DAT5__USDHC3_DAT5_50MHZ,
MX6DL_PAD_SD3_DAT6__USDHC3_DAT6_50MHZ,
MX6DL_PAD_SD3_DAT7__USDHC3_DAT7_50MHZ,
/* SD3_CD */
MX6DL_PAD_NANDF_D0__GPIO_2_0,
/* SD3_WP */
MX6DL_PAD_NANDF_D1__GPIO_2_1,
/* USDHC4 */
MX6DL_PAD_SD4_CLK__USDHC4_CLK_50MHZ,
MX6DL_PAD_SD4_CMD__USDHC4_CMD_50MHZ,
MX6DL_PAD_SD4_DAT0__USDHC4_DAT0_50MHZ,
MX6DL_PAD_SD4_DAT1__USDHC4_DAT1_50MHZ,
MX6DL_PAD_SD4_DAT2__USDHC4_DAT2_50MHZ,
MX6DL_PAD_SD4_DAT3__USDHC4_DAT3_50MHZ,
MX6DL_PAD_SD4_DAT4__USDHC4_DAT4_50MHZ,
MX6DL_PAD_SD4_DAT5__USDHC4_DAT5_50MHZ,
MX6DL_PAD_SD4_DAT6__USDHC4_DAT6_50MHZ,
MX6DL_PAD_SD4_DAT7__USDHC4_DAT7_50MHZ,
So the difference betweent USDHC4 and USDHC3 is that there are SD3_WP and SD3_CD in USDHC3 while USDHC4 do not have.
So Does USDHC3 used for SD card while USDHC4 used for eMMC?
