mx31: Introduce mx31_set_gpr function

Introduce mx31_set_gpr function for setting the GPR (General Purpose Register) on MX31.

This function can be useful for setting a group of pins into tied to some specific peripherals.

Reuse this function from the linux kernel.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/arch/arm/include/asm/arch-mx31/clock.h b/arch/arm/include/asm/arch-mx31/clock.h
index 2e3bce2..3e22d9a 100644
--- a/arch/arm/include/asm/arch-mx31/clock.h
+++ b/arch/arm/include/asm/arch-mx31/clock.h
@@ -37,6 +37,7 @@
 extern u32 imx_get_uartclk(void);
 extern void mx31_gpio_mux(unsigned long mode);
 extern void mx31_set_pad(enum iomux_pins pin, u32 config);
+extern void mx31_set_gpr(enum iomux_gp_func gp, char en);
 
 void mx31_uart1_hw_init(void);
 void mx31_spi2_hw_init(void);
diff --git a/arch/arm/include/asm/arch-mx31/imx-regs.h b/arch/arm/include/asm/arch-mx31/imx-regs.h
index 552c821..6ce008d 100644
--- a/arch/arm/include/asm/arch-mx31/imx-regs.h
+++ b/arch/arm/include/asm/arch-mx31/imx-regs.h
@@ -468,6 +468,44 @@
 	MX31_PIN_CAPTURE	= IOMUX_PIN(7,    327),
 };
 
+/*
+ * various IOMUX general purpose functions
+ */
+enum iomux_gp_func {
+	MUX_PGP_FIRI			= 1 << 0,
+	MUX_DDR_MODE			= 1 << 1,
+	MUX_PGP_CSPI_BB			= 1 << 2,
+	MUX_PGP_ATA_1			= 1 << 3,
+	MUX_PGP_ATA_2			= 1 << 4,
+	MUX_PGP_ATA_3			= 1 << 5,
+	MUX_PGP_ATA_4			= 1 << 6,
+	MUX_PGP_ATA_5			= 1 << 7,
+	MUX_PGP_ATA_6			= 1 << 8,
+	MUX_PGP_ATA_7			= 1 << 9,
+	MUX_PGP_ATA_8			= 1 << 10,
+	MUX_PGP_UH2			= 1 << 11,
+	MUX_SDCTL_CSD0_SEL		= 1 << 12,
+	MUX_SDCTL_CSD1_SEL		= 1 << 13,
+	MUX_CSPI1_UART3			= 1 << 14,
+	MUX_EXTDMAREQ2_MBX_SEL		= 1 << 15,
+	MUX_TAMPER_DETECT_EN		= 1 << 16,
+	MUX_PGP_USB_4WIRE		= 1 << 17,
+	MUX_PGP_USB_COMMON		= 1 << 18,
+	MUX_SDHC_MEMSTICK1		= 1 << 19,
+	MUX_SDHC_MEMSTICK2		= 1 << 20,
+	MUX_PGP_SPLL_BYP		= 1 << 21,
+	MUX_PGP_UPLL_BYP		= 1 << 22,
+	MUX_PGP_MSHC1_CLK_SEL		= 1 << 23,
+	MUX_PGP_MSHC2_CLK_SEL		= 1 << 24,
+	MUX_CSPI3_UART5_SEL		= 1 << 25,
+	MUX_PGP_ATA_9			= 1 << 26,
+	MUX_PGP_USB_SUSPEND		= 1 << 27,
+	MUX_PGP_USB_OTG_LOOPBACK	= 1 << 28,
+	MUX_PGP_USB_HS1_LOOPBACK	= 1 << 29,
+	MUX_PGP_USB_HS2_LOOPBACK	= 1 << 30,
+	MUX_CLKO_DDR_MODE		= 1 << 31,
+};
+
 /* Bit definitions for RCSR register in CCM */
 #define CCM_RCSR_NF16B	(1 << 31)
 #define CCM_RCSR_NFMS	(1 << 30)