Add 16-bit single register pin controller support

Enables the pinctrl-single driver to support 16-bit registers. Only
32-bit registers were supported previously. Reduced width registers are
required for some platforms, such as OMAP.

Signed-off-by: James Balean <james@balean.com.au>
Cc: Felix Brack <fb@ltec.ch>
Cc: Simon Glass <sjg@chromium.org>
Reviewed-by: Felix Brack <fb@ltec.ch>
Tested-by: Felix Brack <fb@ltec.ch>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
index d2dcec0..f19f779 100644
--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -47,27 +47,27 @@
 	int n, reg;
 	u32 val;
 
-	for (n = 0; n < count; n++) {
+	for (n = 0; n < count; n++, pins++) {
 		reg = fdt32_to_cpu(pins->reg);
 		if ((reg < 0) || (reg > pdata->offset)) {
 			dev_dbg(dev, "  invalid register offset 0x%08x\n", reg);
-			pins++;
 			continue;
 		}
 		reg += pdata->base;
+		val = fdt32_to_cpu(pins->val) & pdata->mask;
 		switch (pdata->width) {
+		case 16:
+			writew((readw(reg) & ~pdata->mask) | val, reg);
+			break;
 		case 32:
-			val = readl(reg) & ~pdata->mask;
-			val |= fdt32_to_cpu(pins->val) & pdata->mask;
-			writel(val, reg);
-			dev_dbg(dev, "  reg/val 0x%08x/0x%08x\n",
-				reg, val);
+			writel((readl(reg) & ~pdata->mask) | val, reg);
 			break;
 		default:
 			dev_warn(dev, "unsupported register width %i\n",
 				 pdata->width);
+			continue;
 		}
-		pins++;
+		dev_dbg(dev, "  reg/val 0x%08x/0x%08x\n",reg, val);
 	}
 	return 0;
 }