pinctrl: pinctrl-single: Add 'pinctrl-single, bits' support

The TI Davinci (da850/l138/am1808) use pinctrl-single,bits for
pinmuxing peripherals.  This patch allosw the pinctrl-single
driver to parse the pinctrl-single,bits options and correctly
setup devices.

Signed-off-by: Adam Ford <aford173@gmail.com>

drivers/pinctrl/pinctrl-single.c

@@ -16,6 +16,7 @@ struct single_pdata {
 	int offset;		/* index of last configuration register */
 	u32 mask;		/* configuration-value mask bits */
 	int width;		/* configuration register bit width */
+	bool bits_per_mux;
 };
 
 struct single_fdt_pin_cfg {
@@ -23,6 +24,12 @@ struct single_fdt_pin_cfg {
 	fdt32_t val;		/* configuration register value */
 };
 
+struct single_fdt_bits_cfg {
+	fdt32_t reg;		/* configuration register offset */
+	fdt32_t val;		/* configuration register value */
+	fdt32_t mask;		/* configuration register mask */
+};
+
 /**
  * single_configure_pins() - Configure pins based on FDT data
  *
@@ -71,15 +78,53 @@ static int single_configure_pins(struct udevice *dev,
 	return 0;
 }
 
+static int single_configure_bits(struct udevice *dev,
+				 const struct single_fdt_bits_cfg *pins,
+				 int size)
+{
+	struct single_pdata *pdata = dev->platdata;
+	int count = size / sizeof(struct single_fdt_bits_cfg);
+	phys_addr_t n, reg;
+	u32 val, mask;
+
+	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%pa\n", &reg);
+			continue;
+		}
+		reg += pdata->base;
+
+		mask = fdt32_to_cpu(pins->mask);
+		val = fdt32_to_cpu(pins->val) & mask;
+
+		switch (pdata->width) {
+		case 16:
+			writew((readw(reg) & ~mask) | val, reg);
+			break;
+		case 32:
+			writel((readl(reg) & ~mask) | val, reg);
+			break;
+		default:
+			dev_warn(dev, "unsupported register width %i\n",
+				 pdata->width);
+			continue;
+		}
+		dev_dbg(dev, "  reg/val 0x%pa/0x%08x\n", &reg, val);
+	}
+	return 0;
+}
 static int single_set_state(struct udevice *dev,
 			    struct udevice *config)
 {
 	const void *fdt = gd->fdt_blob;
 	const struct single_fdt_pin_cfg *prop;
+	const struct single_fdt_bits_cfg *prop_bits;
 	int len;
 
 	prop = fdt_getprop(fdt, dev_of_offset(config), "pinctrl-single,pins",
 			   &len);
+
 	if (prop) {
 		dev_dbg(dev, "configuring pins for %s\n", config->name);
 		if (len % sizeof(struct single_fdt_pin_cfg)) {
@@ -87,9 +132,24 @@ static int single_set_state(struct udevice *dev,
 			return -FDT_ERR_BADSTRUCTURE;
 		}
 		single_configure_pins(dev, prop, len);
-		len = 0;
+		return 0;
 	}
 
+	/* pinctrl-single,pins not found so check for pinctrl-single,bits */
+	prop_bits = fdt_getprop(fdt, dev_of_offset(config),
+				"pinctrl-single,bits",
+				    &len);
+	if (prop_bits) {
+		dev_dbg(dev, "configuring pins for %s\n", config->name);
+		if (len % sizeof(struct single_fdt_bits_cfg)) {
+			dev_dbg(dev, "  invalid bits configuration in fdt\n");
+			return -FDT_ERR_BADSTRUCTURE;
+		}
+		single_configure_bits(dev, prop_bits, len);
+		return 0;
+	}
+
+	/* Neither 'pinctrl-single,pins' nor 'pinctrl-single,bits' were found */
 	return len;
 }
 
@@ -119,6 +179,9 @@ static int single_ofdata_to_platdata(struct udevice *dev)
 	pdata->mask = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
 				     "pinctrl-single,function-mask",
 				     0xffffffff);
+	pdata->bits_per_mux = fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
+					      "pinctrl-single,bit-per-mux");
+
 	return 0;
 }