Add access to the function2 gpio register. This probably has to be
converted into a pimux driver later on. This is needed for some setup
functions on the Arduino Yun.

--- a/arch/mips/ath79/common.h
+++ b/arch/mips/ath79/common.h
@@ -30,6 +30,7 @@ void ath79_ddr_wb_flush(unsigned int reg
 void ath79_gpio_function_enable(u32 mask);
 void ath79_gpio_function_disable(u32 mask);
 void ath79_gpio_function_setup(u32 set, u32 clear);
+void ath79_gpio_function2_setup(u32 set, u32 clear);
 void ath79_gpio_output_select(unsigned gpio, u8 val);
 int ath79_gpio_direction_select(unsigned gpio, bool oe);
 void ath79_gpio_init(void);
--- a/arch/mips/ath79/gpio.c
+++ b/arch/mips/ath79/gpio.c
@@ -43,6 +43,31 @@ static void __iomem *ath79_gpio_get_func
 	return ath79_gpio_base + reg;
 }
 
+static void __iomem *ath79_gpio_get_function2_reg(void)
+{
+	u32 reg = 0;
+
+	if (soc_is_ar71xx() ||
+	    soc_is_ar724x() ||
+	    soc_is_ar913x() ||
+	    soc_is_ar933x())
+		reg = AR71XX_GPIO_REG_FUNC_2;
+	else
+		BUG();
+
+	return ath79_gpio_base + reg;
+}
+
+
+void ath79_gpio_function2_setup(u32 set, u32 clear)
+{
+	void __iomem *reg = ath79_gpio_get_function2_reg();
+
+	__raw_writel((__raw_readl(reg) & ~clear) | set, reg);
+	/* flush write */
+	__raw_readl(reg);
+}
+
 void ath79_gpio_function_setup(u32 set, u32 clear)
 {
 	void __iomem *reg = ath79_gpio_get_function_reg();
--- a/arch/mips/include/asm/mach-ath79/ar71xx_regs.h
+++ b/arch/mips/include/asm/mach-ath79/ar71xx_regs.h
@@ -855,6 +855,7 @@
 #define AR71XX_GPIO_REG_INT_PENDING	0x20
 #define AR71XX_GPIO_REG_INT_ENABLE	0x24
 #define AR71XX_GPIO_REG_FUNC		0x28
+#define AR71XX_GPIO_REG_FUNC_2		0x30
 
 #define AR934X_GPIO_REG_OUT_FUNC0	0x2c
 #define AR934X_GPIO_REG_OUT_FUNC1	0x30
@@ -979,6 +980,8 @@
 #define AR724X_GPIO_FUNC_UART_EN		BIT(1)
 #define AR724X_GPIO_FUNC_JTAG_DISABLE		BIT(0)
 
+#define AR933X_GPIO_FUNC2_JUMPSTART_DISABLE 	BIT(9)
+
 #define AR913X_GPIO_FUNC_WMAC_LED_EN		BIT(22)
 #define AR913X_GPIO_FUNC_EXP_PORT_CS_EN		BIT(21)
 #define AR913X_GPIO_FUNC_I2S_REFCLKEN		BIT(20)