Tegra30: Add funcmux for UART over SD slot

Tegra 3 has UART-E exposable via SD card slot which may be
handy for debugging. This change only adds funcmux part, to
use UART-E on the device you additionally would need:
- set stdout-path to serial@70006400 (uarte)
- configure sdmmc1_dat3_py4 and sdmmc1_dat2_py5 pinmux for
  uarte
- disable or remove sdhci@7800000 node
- enable CONFIG_TEGRA_ENABLE_UARTE in defconfig
- set CFG_SYS_NS16550_COM to NV_PA_APB_UARTE_BASE in device
  header

Signed-off-by: Jonas Schwöbel <jonasschwoebel@yahoo.de>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>

arch/arm/include/asm/arch-tegra30/funcmux.h

@@ -16,5 +16,6 @@ enum {
 
 	/* UART configs */
 	FUNCMUX_UART1_ULPI = 0,
+	FUNCMUX_UART5_SDMMC1 = 1,
 };
 #endif	/* _TEGRA30_FUNCMUX_H_ */

arch/arm/mach-tegra/board.c

@@ -181,7 +181,7 @@ static int uart_configs[] = {
 	-1,
 	-1,
 	-1,
-	-1,
+	FUNCMUX_UART5_SDMMC1,  /* UARTE */
 #elif defined(CONFIG_TEGRA114)
 	-1,
 	-1,

drivers/pinctrl/tegra/funcmux-tegra30.c

@@ -33,6 +33,22 @@ int funcmux_select(enum periph_id id, int config)
 			break;
 		}
 		break;
+	case PERIPH_ID_UART5:
+		switch (config) {
+		case FUNCMUX_UART5_SDMMC1:
+			pinmux_set_func(PMUX_PINGRP_SDMMC1_DAT3_PY4,
+					PMUX_FUNC_UARTE);
+			pinmux_set_func(PMUX_PINGRP_SDMMC1_DAT2_PY5,
+					PMUX_FUNC_UARTE);
+
+			pinmux_set_io(PMUX_PINGRP_SDMMC1_DAT3_PY4, PMUX_PIN_OUTPUT);
+			pinmux_set_io(PMUX_PINGRP_SDMMC1_DAT2_PY5, PMUX_PIN_INPUT);
+
+			pinmux_tristate_disable(PMUX_PINGRP_SDMMC1_DAT3_PY4);
+			pinmux_tristate_disable(PMUX_PINGRP_SDMMC1_DAT2_PY5);
+			break;
+		}
+		break;
 
 	/* Add other periph IDs here as needed */