armv8: ls1012a: define esdhc_status_fixup for RDB board

On LS1012ARDB board, three dual 1:4 mux/demux devices drive the SDHC2
signals to eMMC, SDIO wifi, SPI and Ardiuno shield. Only when we select
eMMC and SDIO wifi, the SDHC2 could be used. Otherwise, the command
inhibit bits of eSDHC2_PRSSTAT register will never release. This would
cause below continious error messages in linux since it uses polling
mode to detect card.
"mmc1: Controller never released inhibit bit(s)."
"mmc1: Controller never released inhibit bit(s)."
"mmc1: Controller never released inhibit bit(s)."
This patch is to define esdhc_status_fixup function for RDB to disable
SDHC2 status if no SDIO wifi or eMMC is selected.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>

board/freescale/ls1012ardb/ls1012ardb.c

@@ -113,6 +113,44 @@ int board_init(void)
 	return 0;
 }
 
+int esdhc_status_fixup(void *blob, const char *compat)
+{
+	char esdhc0_path[] = "/soc/esdhc@1560000";
+	char esdhc1_path[] = "/soc/esdhc@1580000";
+	u8 io = 0;
+	u8 mux_sdhc2;
+
+	do_fixup_by_path(blob, esdhc0_path, "status", "okay",
+			 sizeof("okay"), 1);
+
+	i2c_set_bus_num(0);
+
+	/*
+	 * The I2C IO-expander for mux select is used to control the muxing
+	 * of various onboard interfaces.
+	 *
+	 * IO1[3:2] indicates SDHC2 interface demultiplexer select lines.
+	 *	00 - SDIO wifi
+	 *	01 - GPIO (to Arduino)
+	 *	10 - eMMC Memory
+	 *	11 - SPI
+	 */
+	if (i2c_read(I2C_MUX_IO1_ADDR, 0, 1, &io, 1) < 0) {
+		printf("Error reading i2c boot information!\n");
+		return 0; /* Don't want to hang() on this error */
+	}
+
+	mux_sdhc2 = (io & 0x0c) >> 2;
+	/* Enable SDHC2 only when use SDIO wifi and eMMC */
+	if (mux_sdhc2 == 2 || mux_sdhc2 == 0)
+		do_fixup_by_path(blob, esdhc1_path, "status", "okay",
+				 sizeof("okay"), 1);
+	else
+		do_fixup_by_path(blob, esdhc1_path, "status", "disabled",
+				 sizeof("disabled"), 1);
+	return 0;
+}
+
 int ft_board_setup(void *blob, bd_t *bd)
 {
 	arch_fixup_fdt(blob);