iomux-v3: Add support for mx6sl LVE bit

On mx6sl there is a LVE (Low Voltage Enable) bit in the IOMUXC_SW_PAD_CTL
register that can enable or disable low voltage on the pad.

LVE is bit 22 of IOMUXC_SW_PAD_CTL register, but in order to make the
calculation easier we can define it as a flag in bit 1, since this bit is unused.

Add support for it.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Otavio Salvador <otavio@ossystems.com.br>

arch/arm/imx-common/iomux-v3.c

@@ -30,6 +30,14 @@ void imx_iomux_v3_setup_pad(iomux_v3_cfg_t pad)
 		(pad & MUX_PAD_CTRL_OFS_MASK) >> MUX_PAD_CTRL_OFS_SHIFT;
 	u32 pad_ctrl = (pad & MUX_PAD_CTRL_MASK) >> MUX_PAD_CTRL_SHIFT;
 
+#if defined CONFIG_MX6SL
+	/* Check whether LVE bit needs to be set */
+	if (pad_ctrl & PAD_CTL_LVE) {
+		pad_ctrl &= ~PAD_CTL_LVE;
+		pad_ctrl |= PAD_CTL_LVE_BIT;
+	}
+#endif
+
 	if (mux_ctrl_ofs)
 		__raw_writel(mux_mode, base + mux_ctrl_ofs);
 

arch/arm/include/asm/imx-common/iomux-v3.h

@@ -111,6 +111,11 @@ typedef u64 iomux_v3_cfg_t;
 #define PAD_CTL_DSE_40ohm	(6 << 3)
 #define PAD_CTL_DSE_34ohm	(7 << 3)
 
+#if defined CONFIG_MX6SL
+#define PAD_CTL_LVE		(1 << 1)
+#define PAD_CTL_LVE_BIT		(1 << 22)
+#endif
+
 #elif defined(CONFIG_VF610)
 
 #define PAD_MUX_MODE_SHIFT	20