power: supply: smb347-charger: Implement device-tree support

This patch adds device-tree support to the SMB347 charger driver. All
legacy platform data now can be parsed from DT. Because of that and since
SMB347 is an I2C client driver, the IRQ number can be passed automatically
through client's IRQ variable if it's defined in DT. There is no need to
map GPIO to IRQ manually in the case of DT.

This patch is based on the original work made by:
Jonghwa Lee <jonghwa3.lee@samsung.com>
Link: https://patchwork.kernel.org/patch/4284731/Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: David Heidelberg <david@ixit.cz>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/supply/smb347-charger.c

@@ -1180,6 +1180,119 @@ static bool smb347_readable_reg(struct device *dev, unsigned int reg)
 	return smb347_volatile_reg(dev, reg);
 }
 
+static void smb347_dt_parse_pdata(struct device_node *np,
+				  struct smb347_charger_platform_data *pdata)
+{
+	pdata->soft_temp_limit_compensation =
+					SMB347_SOFT_TEMP_COMPENSATE_DEFAULT;
+	/*
+	 * These properties come from the battery info, still we need to
+	 * pre-initialize the values. See smb347_get_battery_info() below.
+	 */
+	pdata->soft_cold_temp_limit = SMB347_TEMP_USE_DEFAULT;
+	pdata->hard_cold_temp_limit = SMB347_TEMP_USE_DEFAULT;
+	pdata->soft_hot_temp_limit  = SMB347_TEMP_USE_DEFAULT;
+	pdata->hard_hot_temp_limit  = SMB347_TEMP_USE_DEFAULT;
+
+	/* Charging constraints */
+	of_property_read_u32(np, "summit,fast-voltage-threshold-microvolt",
+			     &pdata->pre_to_fast_voltage);
+	of_property_read_u32(np, "summit,mains-current-limit-microamp",
+			     &pdata->mains_current_limit);
+	of_property_read_u32(np, "summit,usb-current-limit-microamp",
+			     &pdata->usb_hc_current_limit);
+
+	/* For thermometer monitoring */
+	of_property_read_u32(np, "summit,chip-temperature-threshold-celsius",
+			     &pdata->chip_temp_threshold);
+	of_property_read_u32(np, "summit,soft-compensation-method",
+			     &pdata->soft_temp_limit_compensation);
+	of_property_read_u32(np, "summit,charge-current-compensation-microamp",
+			     &pdata->charge_current_compensation);
+
+	/* Supported charging mode */
+	pdata->use_mains =
+		of_property_read_bool(np, "summit,enable-mains-charging");
+	pdata->use_usb =
+		of_property_read_bool(np, "summit,enable-usb-charging");
+	pdata->use_usb_otg =
+		of_property_read_bool(np, "summit,enable-otg-charging");
+
+	/* Select charging control */
+	of_property_read_u32(np, "summit,enable-charge-control",
+			     &pdata->enable_control);
+
+	/* Interrupt support is optional */
+	if (!of_find_property(np, "interrupts", NULL))
+		pdata->irq_gpio = -1;
+}
+
+static int smb347_get_battery_info(struct smb347_charger *smb)
+{
+	struct smb347_charger_platform_data *pdata = (void *)smb->pdata;
+	struct power_supply_battery_info info = {};
+	struct power_supply *supply;
+	int err;
+
+	if (smb->mains)
+		supply = smb->mains;
+	else
+		supply = smb->usb;
+
+	err = power_supply_get_battery_info(supply, &info);
+	if (err == -ENXIO || err == -ENODEV)
+		return 0;
+	if (err)
+		return err;
+
+	if (info.constant_charge_current_max_ua != -EINVAL)
+		pdata->max_charge_current = info.constant_charge_current_max_ua;
+
+	if (info.constant_charge_voltage_max_uv != -EINVAL)
+		pdata->max_charge_voltage = info.constant_charge_voltage_max_uv;
+
+	if (info.precharge_current_ua != -EINVAL)
+		pdata->pre_charge_current = info.precharge_current_ua;
+
+	if (info.charge_term_current_ua != -EINVAL)
+		pdata->termination_current = info.charge_term_current_ua;
+
+	if (info.temp_alert_min != INT_MIN)
+		pdata->soft_cold_temp_limit = info.temp_alert_min;
+
+	if (info.temp_alert_max != INT_MAX)
+		pdata->soft_hot_temp_limit = info.temp_alert_max;
+
+	if (info.temp_min != INT_MIN)
+		pdata->hard_cold_temp_limit = info.temp_min;
+
+	if (info.temp_max != INT_MAX)
+		pdata->hard_hot_temp_limit = info.temp_max;
+
+	/* Suspend when battery temperature is outside hard limits */
+	if (pdata->hard_cold_temp_limit != SMB347_TEMP_USE_DEFAULT ||
+	    pdata->hard_hot_temp_limit != SMB347_TEMP_USE_DEFAULT)
+		pdata->suspend_on_hard_temp_limit = true;
+
+	return 0;
+}
+
+static struct smb347_charger_platform_data
+			*smb347_get_platdata(struct device *dev)
+{
+	struct smb347_charger_platform_data *pdata;
+
+	if (dev->of_node) {
+		pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+		if (pdata)
+			smb347_dt_parse_pdata(dev->of_node, pdata);
+	} else {
+		pdata = dev_get_platdata(dev);
+	}
+
+	return pdata;
+}
+
 static const struct regmap_config smb347_regmap = {
 	.reg_bits	= 8,
 	.val_bits	= 8,
@@ -1216,40 +1329,35 @@ static int smb347_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	static char *battery[] = { "smb347-battery" };
-	const struct smb347_charger_platform_data *pdata;
 	struct power_supply_config mains_usb_cfg = {}, battery_cfg = {};
 	struct device *dev = &client->dev;
 	struct smb347_charger *smb;
 	int ret;
 
-	pdata = dev->platform_data;
-	if (!pdata)
-		return -EINVAL;
-
-	if (!pdata->use_mains && !pdata->use_usb)
-		return -EINVAL;
-
 	smb = devm_kzalloc(dev, sizeof(*smb), GFP_KERNEL);
 	if (!smb)
 		return -ENOMEM;
 
+	smb->pdata = smb347_get_platdata(dev);
+	if (!smb->pdata)
+		return -ENODEV;
+
+	if (!smb->pdata->use_mains && !smb->pdata->use_usb)
+		return -EINVAL;
+
 	i2c_set_clientdata(client, smb);
 
 	mutex_init(&smb->lock);
 	smb->dev = &client->dev;
-	smb->pdata = pdata;
 
 	smb->regmap = devm_regmap_init_i2c(client, &smb347_regmap);
 	if (IS_ERR(smb->regmap))
 		return PTR_ERR(smb->regmap);
 
-	ret = smb347_hw_init(smb);
-	if (ret < 0)
-		return ret;
-
 	mains_usb_cfg.supplied_to = battery;
 	mains_usb_cfg.num_supplicants = ARRAY_SIZE(battery);
 	mains_usb_cfg.drv_data = smb;
+	mains_usb_cfg.of_node = dev->of_node;
 	if (smb->pdata->use_mains) {
 		smb->mains = devm_power_supply_register(dev, &smb347_mains_desc,
 							&mains_usb_cfg);
@@ -1270,11 +1378,19 @@ static int smb347_probe(struct i2c_client *client,
 	if (IS_ERR(smb->battery))
 		return PTR_ERR(smb->battery);
 
+	ret = smb347_get_battery_info(smb);
+	if (ret)
+		return ret;
+
+	ret = smb347_hw_init(smb);
+	if (ret < 0)
+		return ret;
+
 	/*
 	 * Interrupt pin is optional. If it is connected, we setup the
 	 * interrupt support here.
 	 */
-	if (pdata->irq_gpio >= 0) {
+	if (smb->pdata->irq_gpio >= 0) {
 		ret = smb347_irq_init(smb, client);
 		if (ret < 0) {
 			dev_warn(dev, "failed to initialize IRQ: %d\n", ret);
@@ -1302,9 +1418,16 @@ static const struct i2c_device_id smb347_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, smb347_id);
 
+static const struct of_device_id smb3xx_of_match[] = {
+	{ .compatible = "summit,smb347" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, smb3xx_of_match);
+
 static struct i2c_driver smb347_driver = {
 	.driver = {
 		.name = "smb347",
+		.of_match_table = smb3xx_of_match,
 	},
 	.probe        = smb347_probe,
 	.remove       = smb347_remove,