[PATCH v2 1/3] tegra: add funcmux for exposing UART over uSD slot on Tegra 20

[Artur Kowalski]

UART-A can be exposed through uSD, this was tested on Transformer T20
but should work on all Ventana-based boards.

TX is exported on SDD pingroup corresponding to uSD CLK pin
RX is exported on SDB which is CMD pin in uSD slot

Signed-off-by: Artur Kowalski <arturkow2000 at gmail.com>
---

Changes in v2:
- fixed indentation of preprocessor directives

 arch/arm/include/asm/arch-tegra20/funcmux.h | 1 +
 arch/arm/mach-tegra/board.c                 | 2 ++
 arch/arm/mach-tegra/tegra20/Kconfig         | 3 +++
 drivers/pinctrl/tegra/funcmux-tegra20.c     | 9 ++++++++-
 4 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/arm/include/asm/arch-tegra20/funcmux.h b/arch/arm/include/asm/arch-tegra20/funcmux.h
index e9e96c1f933..bafcf857620 100644
--- a/arch/arm/include/asm/arch-tegra20/funcmux.h
+++ b/arch/arm/include/asm/arch-tegra20/funcmux.h
@@ -19,6 +19,7 @@ enum {
 	FUNCMUX_UART1_UAA_UAB,
 	FUNCMUX_UART1_GPU,
 	FUNCMUX_UART1_SDIO1,
+	FUNCMUX_UART1_SDB_SDD,
 	FUNCMUX_UART2_UAD = 0,
 	FUNCMUX_UART4_GMC = 0,
 
diff --git a/arch/arm/mach-tegra/board.c b/arch/arm/mach-tegra/board.c
index 7ca56a3b081..7597034fa48 100644
--- a/arch/arm/mach-tegra/board.c
+++ b/arch/arm/mach-tegra/board.c
@@ -169,6 +169,8 @@ static int uart_configs[] = {
 	FUNCMUX_UART1_GPU,
  #elif defined(CONFIG_TEGRA_UARTA_SDIO1)
 	FUNCMUX_UART1_SDIO1,
+ #elif defined(CONFIG_TEGRA_UARTA_SDB_SDD)
+	FUNCMUX_UART1_SDB_SDD,
  #else
 	FUNCMUX_UART1_IRRX_IRTX,
 #endif
diff --git a/arch/arm/mach-tegra/tegra20/Kconfig b/arch/arm/mach-tegra/tegra20/Kconfig
index e2735d93e28..3349f1e2786 100644
--- a/arch/arm/mach-tegra/tegra20/Kconfig
+++ b/arch/arm/mach-tegra/tegra20/Kconfig
@@ -17,6 +17,9 @@ config TEGRA_UARTA_GPU
 config TEGRA_UARTA_SDIO1
 	bool
 
+config TEGRA_UARTA_SDB_SDD
+	bool
+
 choice
 	prompt "Tegra20 board select"
 	optional
diff --git a/drivers/pinctrl/tegra/funcmux-tegra20.c b/drivers/pinctrl/tegra/funcmux-tegra20.c
index 951ae196161..f60d5aad3a4 100644
--- a/drivers/pinctrl/tegra/funcmux-tegra20.c
+++ b/drivers/pinctrl/tegra/funcmux-tegra20.c
@@ -62,8 +62,15 @@ int funcmux_select(enum periph_id id, int config)
 			pinmux_tristate_disable(PMUX_PINGRP_SDIO1);
 			bad_config = 0;
 			break;
+		case FUNCMUX_UART1_SDB_SDD:
+			pinmux_set_func(PMUX_PINGRP_SDB, PMUX_FUNC_UARTA);
+			pinmux_set_func(PMUX_PINGRP_SDD, PMUX_FUNC_UARTA);
+			pinmux_tristate_disable(PMUX_PINGRP_SDB);
+			pinmux_tristate_disable(PMUX_PINGRP_SDD);
+			bad_config = 0;
+			break;
 		}
-		if (!bad_config) {
+		if (!bad_config && config != FUNCMUX_UART1_SDB_SDD) {
 			/*
 			 * Tegra appears to boot with function UARTA pre-
 			 * selected on mux group SDB. If two mux groups are
-- 
2.48.1