imx6: iomux: Add generic function to set RGMII IO voltage on IMX6 SoCs

This commit provides generic function to set the RGMII/HSIC IO voltage
level on iMX6 devices.

Signed-off-by: Lukasz Majewski <lukma@denx.de>

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

@@ -178,4 +178,17 @@
 				|IOMUXC_GPR13_SATA_PHY_3_MASK \
 				|IOMUXC_GPR13_SATA_PHY_2_MASK \
 				|IOMUXC_GPR13_SATA_PHY_1_MASK)
+
+/*
+ * Setup RGMII voltage levels on iMX6 SoC - the
+ *
+ * IOMUXC_SW_PAD_CTL_GRP_DDR_TYPE_RGMII - register
+ *
+ * 1P2V_IO - USB_HSIC, MIPI_HSI
+ * 1P5V_IO - ENET pins
+ */
+#define IOMUXC_SW_PAD_CTL_GRP_DDR_TYPE_RGMII	0x020e0790
+#define DDR_SEL_1P2V_IO (0x2 << 18)
+#define DDR_SEL_1P5V_IO (0x3 << 18)
+
 #endif	/* __ASM_ARCH_IOMUX_H__ */

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

@@ -6,6 +6,7 @@
  */
 
 #include <asm/mach-imx/sys_proto.h>
+#include <asm/arch/iomux.h>
 
 #define USBPHY_PWD		0x00000000
 
@@ -16,3 +17,13 @@
 
 int imx6_pcie_toggle_power(void);
 int imx6_pcie_toggle_reset(void);
+
+/**
+ * iomuxc_set_rgmii_io_voltage - set voltage level of RGMII/USB pins
+ *
+ * @param io_vol - the voltage IO level of pins
+ */
+static inline void iomuxc_set_rgmii_io_voltage(int io_vol)
+{
+	__raw_writel(io_vol, IOMUXC_SW_PAD_CTL_GRP_DDR_TYPE_RGMII);
+}