regulator: lp872x: support the device tree feature

This patch enables the DT structure of the LP8720 and LP8725 device.
The LP872x platform data is generated when the device tree is configured.
Even if the platform data is NULL, it is no issue at all because the driver is
configured with the default mode.

Signed-off-by: Milo(Woogyom) Kim <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

Documentation/devicetree/bindings/regulator/lp872x.txt

···
+Binding for TI/National Semiconductor LP872x Driver
+
+Required properties:
+  - compatible: "ti,lp8720" or "ti,lp8725"
+  - reg: I2C slave address. 0x7d = LP8720, 0x7a = LP8725
+
+Optional properties:
+  - ti,general-config: the value of LP872X_GENERAL_CFG register (u8)
+    (LP8720)
+    bit[2]: BUCK output voltage control by external DVS pin or register
+            1 = external pin, 0 = bit7 of register 08h
+    bit[1]: sleep control by external DVS pin or register
+            1 = external pin, 0 = bit6 of register 08h
+    bit[0]: time step unit(usec). 1 = 25, 0 = 50
+
+    (LP8725)
+    bit[7:6]: time step unit(usec). 00 = 32, 01 = 64, 10 = 128, 11 = 256
+    bit[4]:   BUCK2 enable control. 1 = enable, 0 = disable
+    bit[3]:   BUCK2 output voltage register address. 1 = 0Ah, 0 = 0Bh
+    bit[2]:   BUCK1 output voltage control by external DVS pin or register
+              1 = register 08h, 0 = DVS
+    bit[1]:   LDO sleep control. 1 = sleep mode, 0 = normal
+    bit[0]:   BUCK1 enable control, 1 = enable, 0 = disable
+
+    For more details, please see the datasheet.
+
+  - ti,update-config: define it when LP872X_GENERAL_CFG register should be set
+  - ti,dvs-gpio: GPIO specifier for external DVS pin control of LP872x devices.
+  - ti,dvs-vsel: DVS selector. 0 = SEL_V1, 1 = SEL_V2.
+  - ti,dvs-state: initial DVS pin state. 0 = DVS_LOW, 1 = DVS_HIGH.
+
+  Sub nodes for regulator_init_data
+    LP8720 has maximum 6 nodes. (child name: ldo1 ~ 5 and buck)
+    LP8725 has maximum 9 nodes. (child name: ldo1 ~ 5, lilo1,2 and buck1,2)
+    For more details, please see the following binding document.
+    (Documentation/devicetree/bindings/regulator/regulator.txt)
+
+Datasheet
+  - LP8720: http://www.ti.com/lit/ds/symlink/lp8720.pdf
+  - LP8725: http://www.ti.com/lit/ds/symlink/lp8725.pdf
+
+Example 1) LP8720
+
+lp8720@7d {
+	compatible = "ti,lp8720";
+	reg = <0x7d>;
+
+	/* external DVS pin used, timestep is 25usec */
+	ti,general-config = /bits/ 8 <0x03>;
+	ti,update-config;
+
+	/*
+	 * The dvs-gpio depends on the processor environment.
+	 * For example, following GPIO specifier means GPIO134 in OMAP4.
+	 */
+	ti,dvs-gpio = <&gpio5 6 0>;
+	ti,dvs-vsel = /bits/ 8 <1>;		/* SEL_V2 */
+	ti,dvs-state = /bits/ 8 <1>;		/* DVS_HIGH */
+
+	vaf: ldo1 {
+		regulator-min-microvolt = <1200000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
+	vmmc: ldo2 {
+		regulator-min-microvolt = <1200000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
+	vcam_io: ldo3 {
+		regulator-min-microvolt = <1200000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-boot-on;
+	};
+
+	vcam_core: ldo4 {
+		regulator-min-microvolt = <800000>;
+		regulator-max-microvolt = <2850000>;
+		regulator-boot-on;
+	};
+
+	vcam: ldo5 {
+		regulator-min-microvolt = <1200000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
+	vcc: buck {
+		regulator-name = "VBUCK";
+		regulator-min-microvolt = <800000>;
+		regulator-max-microvolt = <2300000>;
+	};
+};
+
+Example 2) LP8725
+
+lp8725@7a {
+	compatible = "ti,lp8725";
+	reg = <0x7a>;
+
+	/* Enable BUCK1,2, no DVS, normal LDO mode, timestep is 256usec */
+	ti,general-config = /bits/ 8 <0xdd>;
+	ti,update-config;
+
+	vcam_io: ldo1 {
+		regulator-min-microvolt = <1200000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
+	vcam_core: ldo2 {
+		regulator-min-microvolt = <1200000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
+	vcam: ldo3 {
+		regulator-min-microvolt = <1200000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
+	vcmmb_io: ldo4 {
+		regulator-min-microvolt = <1200000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-boot-on;
+	};
+
+	vcmmb_core: ldo5 {
+		regulator-min-microvolt = <1200000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-boot-on;
+	};
+
+	vaux1: lilo1 {
+		regulator-name = "VAUX1";
+		regulator-min-microvolt = <800000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
+	vaux2: lilo2 {
+		regulator-name = "VAUX2";
+		regulator-min-microvolt = <800000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
+	vcc1: buck1 {
+		regulator-name = "VBUCK1";
+		regulator-min-microvolt = <800000>;
+		regulator-max-microvolt = <3000000>;
+		regulator-min-microamp  = <460000>;
+		regulator-max-microamp  = <1370000>;
+		regulator-boot-on;
+	};
+
+	vcc2: buck2 {
+		regulator-name = "VBUCK2";
+		regulator-min-microvolt = <800000>;
+		regulator-max-microvolt = <3000000>;
+		regulator-min-microamp  = <460000>;
+		regulator-max-microamp  = <1370000>;
+		regulator-boot-on;
+	};
+};

drivers/regulator/lp872x.c

···
 #include <linux/regulator/lp872x.h>
 #include <linux/regulator/driver.h>
 #include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/regulator/of_regulator.h>
 
 /* Registers : LP8720/8725 shared */
 #define LP872X_GENERAL_CFG		0x00
···
 
 	gpio = dvs->gpio;
 	if (!gpio_is_valid(gpio)) {
-		dev_err(lp->dev, "invalid gpio: %d\n", gpio);
-		return -EINVAL;
+		dev_warn(lp->dev, "invalid gpio: %d\n", gpio);
+		goto set_default_dvs_mode;
 	}
 
 	pinstate = dvs->init_state;
···
 	.max_register = MAX_REGISTERS,
 };
 
+#ifdef CONFIG_OF
+
+#define LP872X_VALID_OPMODE	(REGULATOR_MODE_FAST | REGULATOR_MODE_NORMAL)
+
+static struct of_regulator_match lp8720_matches[] = {
+	{ .name = "ldo1", .driver_data = (void *)LP8720_ID_LDO1, },
+	{ .name = "ldo2", .driver_data = (void *)LP8720_ID_LDO2, },
+	{ .name = "ldo3", .driver_data = (void *)LP8720_ID_LDO3, },
+	{ .name = "ldo4", .driver_data = (void *)LP8720_ID_LDO4, },
+	{ .name = "ldo5", .driver_data = (void *)LP8720_ID_LDO5, },
+	{ .name = "buck", .driver_data = (void *)LP8720_ID_BUCK, },
+};
+
+static struct of_regulator_match lp8725_matches[] = {
+	{ .name = "ldo1", .driver_data = (void *)LP8725_ID_LDO1, },
+	{ .name = "ldo2", .driver_data = (void *)LP8725_ID_LDO2, },
+	{ .name = "ldo3", .driver_data = (void *)LP8725_ID_LDO3, },
+	{ .name = "ldo4", .driver_data = (void *)LP8725_ID_LDO4, },
+	{ .name = "ldo5", .driver_data = (void *)LP8725_ID_LDO5, },
+	{ .name = "lilo1", .driver_data = (void *)LP8725_ID_LILO1, },
+	{ .name = "lilo2", .driver_data = (void *)LP8725_ID_LILO2, },
+	{ .name = "buck1", .driver_data = (void *)LP8725_ID_BUCK1, },
+	{ .name = "buck2", .driver_data = (void *)LP8725_ID_BUCK2, },
+};
+
+static struct lp872x_platform_data
+*lp872x_populate_pdata_from_dt(struct device *dev, enum lp872x_id which)
+{
+	struct device_node *np = dev->of_node;
+	struct lp872x_platform_data *pdata;
+	struct of_regulator_match *match;
+	struct regulator_init_data *d;
+	int num_matches;
+	int count;
+	int i;
+	u8 dvs_state;
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		goto out;
+
+	of_property_read_u8(np, "ti,general-config", &pdata->general_config);
+	if (of_find_property(np, "ti,update-config", NULL))
+		pdata->update_config = true;
+
+	pdata->dvs = devm_kzalloc(dev, sizeof(struct lp872x_dvs), GFP_KERNEL);
+	if (!pdata->dvs)
+		goto out;
+
+	pdata->dvs->gpio = of_get_named_gpio(np, "ti,dvs-gpio", 0);
+	of_property_read_u8(np, "ti,dvs-vsel", (u8 *)&pdata->dvs->vsel);
+	of_property_read_u8(np, "ti,dvs-state", &dvs_state);
+	pdata->dvs->init_state = dvs_state ? DVS_HIGH : DVS_LOW;
+
+	if (of_get_child_count(np) == 0)
+		goto out;
+
+	switch (which) {
+	case LP8720:
+		match = lp8720_matches;
+		num_matches = ARRAY_SIZE(lp8720_matches);
+		break;
+	case LP8725:
+		match = lp8725_matches;
+		num_matches = ARRAY_SIZE(lp8725_matches);
+		break;
+	default:
+		goto out;
+	}
+
+	count = of_regulator_match(dev, np, match, num_matches);
+	if (count <= 0)
+		goto out;
+
+	for (i = 0; i < num_matches; i++) {
+		pdata->regulator_data[i].id = (int)match[i].driver_data;
+		pdata->regulator_data[i].init_data = match[i].init_data;
+
+		/* Operation mode configuration for buck/buck1/buck2 */
+		if (strncmp(match[i].name, "buck", 4))
+			continue;
+
+		d = pdata->regulator_data[i].init_data;
+		d->constraints.valid_modes_mask |= LP872X_VALID_OPMODE;
+		d->constraints.valid_ops_mask |= REGULATOR_CHANGE_MODE;
+	}
+out:
+	return pdata;
+}
+#else
+static struct lp872x_platform_data
+*lp872x_populate_pdata_from_dt(struct device *dev, enum lp872x_id which)
+{
+	return NULL;
+}
+#endif
+
 static int lp872x_probe(struct i2c_client *cl, const struct i2c_device_id *id)
 {
 	struct lp872x *lp;
···
 		[LP8720] = LP8720_NUM_REGULATORS,
 		[LP8725] = LP8725_NUM_REGULATORS,
 	};
+
+	if (cl->dev.of_node)
+		cl->dev.platform_data = lp872x_populate_pdata_from_dt(&cl->dev,
+					      (enum lp872x_id)id->driver_data);
 
 	lp = devm_kzalloc(&cl->dev, sizeof(struct lp872x), GFP_KERNEL);
 	if (!lp)
···
 	return 0;
 }
 
+static const struct of_device_id lp872x_dt_ids[] = {
+	{ .compatible = "ti,lp8720", },
+	{ .compatible = "ti,lp8725", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, lp872x_dt_ids);
+
 static const struct i2c_device_id lp872x_ids[] = {
 	{"lp8720", LP8720},
 	{"lp8725", LP8725},
···
 	.driver = {
 		.name = "lp872x",
 		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(lp872x_dt_ids),
 	},
 	.probe = lp872x_probe,
 	.remove = lp872x_remove,