[PATCH v7 08/15] ARM: mxs: Add iomux support

MXS-based SoCs implements iomux functions in block PINCTRL.

Signed-off-by: Shawn Guo <redacted>
---
[...]

diff --git a/arch/arm/mach-mxs/iomux.c b/arch/arm/mach-mxs/iomux.c
new file mode 100644
index 0000000..8c8cbf2
--- /dev/null
+++ b/arch/arm/mach-mxs/iomux.c

@@ -0,0 +1,101 @@
+[...]
+/*
+ * configures a single pad in the iomuxer
+ */
+int mxs_iomux_setup_pad(iomux_cfg_t pad)
+{
+	u32 reg, ofs, bp, bm;
+	void __iomem *iomux_base = MXS_IO_ADDRESS(MXS_PINCTRL_BASE_ADDR);
+
+	/* muxsel */
+	ofs = 0x100;
+	ofs += PAD_BANK(pad) * 0x20 + PAD_PIN(pad) / 16 * 0x10;
+	bp = PAD_PIN(pad) % 16 * 2;
+	bm = 0x3 << bp;
+	reg = __raw_readl(iomux_base + ofs);
+	reg &= ~bm;
+	reg |= PAD_MUXSEL(pad) << bp;
+	__raw_writel(reg, iomux_base + ofs);
+
+	/* drive */
+	ofs = cpu_is_mx23() ? 0x200 : 0x300;
+	ofs += PAD_BANK(pad) * 0x40 + PAD_PIN(pad) / 8 * 0x10;
+	/* mA */
+	if (PAD_MA_VALID(pad)) {
+		bp = PAD_PIN(pad) % 8 * 4;
+		bm = 0x3 << bp;
+		reg = __raw_readl(iomux_base + ofs);
+		reg &= ~bm;
+		reg |= PAD_MA(pad)  << bp;