wandboard: Add card detection for SOM MicroSD card

This add support to identify if the card is connected or not; so it
does not try to communicate with the controller if no card is
available.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>

arch/arm/include/asm/arch-mx6/mx6dl_pins.h

@@ -66,6 +66,7 @@ enum {
 	MX6_PAD_EIM_D28__I2C1_SDA		= IOMUX_PAD(0x0544, 0x0174, 1 | IOMUX_CONFIG_SION, 0x086C, 1, 0),
 	MX6_PAD_EIM_D28__GPIO_3_28		= IOMUX_PAD(0x0544, 0x0174, 5, 0x0000, 0, 0),
 	MX6_PAD_EIM_D29__GPIO_3_29		= IOMUX_PAD(0x0548, 0x0178, 5, 0x0000, 0, 0),
+	MX6_PAD_EIM_DA9__GPIO_3_9		= IOMUX_PAD(0x0590, 0x01C0, 5, 0x0000, 0, 0),
 	MX6_PAD_ENET_MDC__ENET_MDC		= IOMUX_PAD(0x05B8, 0x01E8, 1, 0x0000, 0,  0),
 	MX6_PAD_ENET_MDIO__ENET_MDIO		= IOMUX_PAD(0x05BC, 0x01EC, 1, 0x0810, 0, 0),
 	MX6_PAD_ENET_REF_CLK__ENET_TX_CLK	= IOMUX_PAD(0x05C0, 0x01F0, 1, 0x0000, 0, 0),

board/wandboard/wandboard.c

@@ -38,6 +38,7 @@ DECLARE_GLOBAL_DATA_PTR;
 	PAD_CTL_PUS_100K_UP | PAD_CTL_SPEED_MED   |		\
 	PAD_CTL_DSE_40ohm   | PAD_CTL_HYS)
 
+#define USDHC3_CD_GPIO		IMX_GPIO_NR(3, 9)
 #define ETH_PHY_RESET		IMX_GPIO_NR(3, 29)
 
 int dram_init(void)
@@ -59,6 +60,8 @@ static iomux_v3_cfg_t const usdhc3_pads[] = {
 	MX6_PAD_SD3_DAT1__USDHC3_DAT1 | MUX_PAD_CTRL(USDHC_PAD_CTRL),
 	MX6_PAD_SD3_DAT2__USDHC3_DAT2 | MUX_PAD_CTRL(USDHC_PAD_CTRL),
 	MX6_PAD_SD3_DAT3__USDHC3_DAT3 | MUX_PAD_CTRL(USDHC_PAD_CTRL),
+	/* SOM MicroSD Card Detect */
+	MX6_PAD_EIM_DA9__GPIO_3_9     | MUX_PAD_CTRL(NO_PAD_CTRL),
 };
 
 static iomux_v3_cfg_t const enet_pads[] = {
@@ -100,12 +103,27 @@ static struct fsl_esdhc_cfg usdhc_cfg[1] = {
 	{USDHC3_BASE_ADDR},
 };
 
+int board_mmc_getcd(struct mmc *mmc)
+{
+	struct fsl_esdhc_cfg *cfg = (struct fsl_esdhc_cfg *)mmc->priv;
+	int ret = 0;
+
+	switch (cfg->esdhc_base) {
+	case USDHC3_BASE_ADDR:
+		ret = !gpio_get_value(USDHC3_CD_GPIO);
+		break;
+	}
+
+	return ret;
+}
+
 int board_mmc_init(bd_t *bis)
 {
 	imx_iomux_v3_setup_multiple_pads(usdhc3_pads, ARRAY_SIZE(usdhc3_pads));
 
 	usdhc_cfg[0].sdhc_clk = mxc_get_clock(MXC_ESDHC3_CLK);
 	usdhc_cfg[0].max_bus_width = 4;
+	gpio_direction_input(USDHC3_CD_GPIO);
 
 	return fsl_esdhc_initialize(bis, &usdhc_cfg[0]);
 }