1 files changed, 423 insertions, 0 deletions

diff --git a/drivers/power/supply/max8903_charger.c b/drivers/power/supply/max8903_charger.c
new file mode 100644
index 000000000..54d50b55f
--- /dev/null
+++ b/drivers/power/supply/max8903_charger.c
@@ -0,0 +1,423 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * max8903_charger.c - Maxim 8903 USB/Adapter Charger Driver
+ *
+ * Copyright (C) 2011 Samsung Electronics
+ * MyungJoo Ham <myungjoo.ham@samsung.com>
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+#include <linux/power_supply.h>
+#include <linux/platform_device.h>
+
+struct max8903_data {
+	struct device *dev;
+	struct power_supply *psy;
+	struct power_supply_desc psy_desc;
+	/*
+	 * GPIOs
+	 * chg, flt, dcm and usus are optional.
+	 * dok or uok must be present.
+	 * If dok is present, cen must be present.
+	 */
+	struct gpio_desc *cen; /* Charger Enable input */
+	struct gpio_desc *dok; /* DC (Adapter) Power OK output */
+	struct gpio_desc *uok; /* USB Power OK output */
+	struct gpio_desc *chg; /* Charger status output */
+	struct gpio_desc *flt; /* Fault output */
+	struct gpio_desc *dcm; /* Current-Limit Mode input (1: DC, 2: USB) */
+	struct gpio_desc *usus; /* USB Suspend Input (1: suspended) */
+	bool fault;
+	bool usb_in;
+	bool ta_in;
+};
+
+static enum power_supply_property max8903_charger_props[] = {
+	POWER_SUPPLY_PROP_STATUS, /* Charger status output */
+	POWER_SUPPLY_PROP_ONLINE, /* External power source */
+	POWER_SUPPLY_PROP_HEALTH, /* Fault or OK */
+};
+
+static int max8903_get_property(struct power_supply *psy,
+		enum power_supply_property psp,
+		union power_supply_propval *val)
+{
+	struct max8903_data *data = power_supply_get_drvdata(psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
+		if (data->chg) {
+			if (gpiod_get_value(data->chg))
+				/* CHG asserted */
+				val->intval = POWER_SUPPLY_STATUS_CHARGING;
+			else if (data->usb_in || data->ta_in)
+				val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+			else
+				val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+		}
+		break;
+	case POWER_SUPPLY_PROP_ONLINE:
+		val->intval = 0;
+		if (data->usb_in || data->ta_in)
+			val->intval = 1;
+		break;
+	case POWER_SUPPLY_PROP_HEALTH:
+		val->intval = POWER_SUPPLY_HEALTH_GOOD;
+		if (data->fault)
+			val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static irqreturn_t max8903_dcin(int irq, void *_data)
+{
+	struct max8903_data *data = _data;
+	bool ta_in;
+	enum power_supply_type old_type;
+
+	/*
+	 * This means the line is asserted.
+	 *
+	 * The signal is active low, but the inversion is handled in the GPIO
+	 * library as the line should be flagged GPIO_ACTIVE_LOW in the device
+	 * tree.
+	 */
+	ta_in = gpiod_get_value(data->dok);
+
+	if (ta_in == data->ta_in)
+		return IRQ_HANDLED;
+
+	data->ta_in = ta_in;
+
+	/* Set Current-Limit-Mode 1:DC 0:USB */
+	if (data->dcm)
+		gpiod_set_value(data->dcm, ta_in);
+
+	/* Charger Enable / Disable */
+	if (data->cen) {
+		int val;
+
+		if (ta_in)
+			/* Certainly enable if DOK is asserted */
+			val = 1;
+		else if (data->usb_in)
+			/* Enable if the USB charger is enabled */
+			val = 1;
+		else
+			/* Else default-disable */
+			val = 0;
+
+		gpiod_set_value(data->cen, val);
+	}
+
+	dev_dbg(data->dev, "TA(DC-IN) Charger %s.\n", ta_in ?
+			"Connected" : "Disconnected");
+
+	old_type = data->psy_desc.type;
+
+	if (data->ta_in)
+		data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
+	else if (data->usb_in)
+		data->psy_desc.type = POWER_SUPPLY_TYPE_USB;
+	else
+		data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
+
+	if (old_type != data->psy_desc.type)
+		power_supply_changed(data->psy);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t max8903_usbin(int irq, void *_data)
+{
+	struct max8903_data *data = _data;
+	bool usb_in;
+	enum power_supply_type old_type;
+
+	/*
+	 * This means the line is asserted.
+	 *
+	 * The signal is active low, but the inversion is handled in the GPIO
+	 * library as the line should be flagged GPIO_ACTIVE_LOW in the device
+	 * tree.
+	 */
+	usb_in = gpiod_get_value(data->uok);
+
+	if (usb_in == data->usb_in)
+		return IRQ_HANDLED;
+
+	data->usb_in = usb_in;
+
+	/* Do not touch Current-Limit-Mode */
+
+	/* Charger Enable / Disable */
+	if (data->cen) {
+		int val;
+
+		if (usb_in)
+			/* Certainly enable if UOK is asserted */
+			val = 1;
+		else if (data->ta_in)
+			/* Enable if the DC charger is enabled */
+			val = 1;
+		else
+			/* Else default-disable */
+			val = 0;
+
+		gpiod_set_value(data->cen, val);
+	}
+
+	dev_dbg(data->dev, "USB Charger %s.\n", usb_in ?
+			"Connected" : "Disconnected");
+
+	old_type = data->psy_desc.type;
+
+	if (data->ta_in)
+		data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
+	else if (data->usb_in)
+		data->psy_desc.type = POWER_SUPPLY_TYPE_USB;
+	else
+		data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
+
+	if (old_type != data->psy_desc.type)
+		power_supply_changed(data->psy);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t max8903_fault(int irq, void *_data)
+{
+	struct max8903_data *data = _data;
+	bool fault;
+
+	/*
+	 * This means the line is asserted.
+	 *
+	 * The signal is active low, but the inversion is handled in the GPIO
+	 * library as the line should be flagged GPIO_ACTIVE_LOW in the device
+	 * tree.
+	 */
+	fault = gpiod_get_value(data->flt);
+
+	if (fault == data->fault)
+		return IRQ_HANDLED;
+
+	data->fault = fault;
+
+	if (fault)
+		dev_err(data->dev, "Charger suffers a fault and stops.\n");
+	else
+		dev_err(data->dev, "Charger recovered from a fault.\n");
+
+	return IRQ_HANDLED;
+}
+
+static int max8903_setup_gpios(struct platform_device *pdev)
+{
+	struct max8903_data *data = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+	bool ta_in = false;
+	bool usb_in = false;
+	enum gpiod_flags flags;
+
+	data->dok = devm_gpiod_get_optional(dev, "dok", GPIOD_IN);
+	if (IS_ERR(data->dok))
+		return dev_err_probe(dev, PTR_ERR(data->dok),
+				     "failed to get DOK GPIO");
+	if (data->dok) {
+		gpiod_set_consumer_name(data->dok, data->psy_desc.name);
+		/*
+		 * The DC OK is pulled up to 1 and goes low when a charger
+		 * is plugged in (active low) but in the device tree the
+		 * line is marked as GPIO_ACTIVE_LOW so we get a 1 (asserted)
+		 * here if the DC charger is plugged in.
+		 */
+		ta_in = gpiod_get_value(data->dok);
+	}
+
+	data->uok = devm_gpiod_get_optional(dev, "uok", GPIOD_IN);
+	if (IS_ERR(data->uok))
+		return dev_err_probe(dev, PTR_ERR(data->uok),
+				     "failed to get UOK GPIO");
+	if (data->uok) {
+		gpiod_set_consumer_name(data->uok, data->psy_desc.name);
+		/*
+		 * The USB OK is pulled up to 1 and goes low when a USB charger
+		 * is plugged in (active low) but in the device tree the
+		 * line is marked as GPIO_ACTIVE_LOW so we get a 1 (asserted)
+		 * here if the USB charger is plugged in.
+		 */
+		usb_in = gpiod_get_value(data->uok);
+	}
+
+	/* Either DC OK or USB OK must be provided */
+	if (!data->dok && !data->uok) {
+		dev_err(dev, "no valid power source\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * If either charger is already connected at this point,
+	 * assert the CEN line and enable charging from the start.
+	 *
+	 * The line is active low but also marked with GPIO_ACTIVE_LOW
+	 * in the device tree, so when we assert the line with
+	 * GPIOD_OUT_HIGH the line will be driven low.
+	 */
+	flags = (ta_in || usb_in) ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
+	/*
+	 * If DC OK is provided, Charger Enable CEN is compulsory
+	 * so this is not optional here.
+	 */
+	data->cen = devm_gpiod_get(dev, "cen", flags);
+	if (IS_ERR(data->cen))
+		return dev_err_probe(dev, PTR_ERR(data->cen),
+				     "failed to get CEN GPIO");
+	gpiod_set_consumer_name(data->cen, data->psy_desc.name);
+
+	/*
+	 * If the DC charger is connected, then select it.
+	 *
+	 * The DCM line should be marked GPIO_ACTIVE_HIGH in the
+	 * device tree. Driving it high will enable the DC charger
+	 * input over the USB charger input.
+	 */
+	flags = ta_in ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
+	data->dcm = devm_gpiod_get_optional(dev, "dcm", flags);
+	if (IS_ERR(data->dcm))
+		return dev_err_probe(dev, PTR_ERR(data->dcm),
+				     "failed to get DCM GPIO");
+	gpiod_set_consumer_name(data->dcm, data->psy_desc.name);
+
+	data->chg = devm_gpiod_get_optional(dev, "chg", GPIOD_IN);
+	if (IS_ERR(data->chg))
+		return dev_err_probe(dev, PTR_ERR(data->chg),
+				     "failed to get CHG GPIO");
+	gpiod_set_consumer_name(data->chg, data->psy_desc.name);
+
+	data->flt = devm_gpiod_get_optional(dev, "flt", GPIOD_IN);
+	if (IS_ERR(data->flt))
+		return dev_err_probe(dev, PTR_ERR(data->flt),
+				     "failed to get FLT GPIO");
+	gpiod_set_consumer_name(data->flt, data->psy_desc.name);
+
+	data->usus = devm_gpiod_get_optional(dev, "usus", GPIOD_IN);
+	if (IS_ERR(data->usus))
+		return dev_err_probe(dev, PTR_ERR(data->usus),
+				     "failed to get USUS GPIO");
+	gpiod_set_consumer_name(data->usus, data->psy_desc.name);
+
+	data->fault = false;
+	data->ta_in = ta_in;
+	data->usb_in = usb_in;
+
+	return 0;
+}
+
+static int max8903_probe(struct platform_device *pdev)
+{
+	struct max8903_data *data;
+	struct device *dev = &pdev->dev;
+	struct power_supply_config psy_cfg = {};
+	int ret = 0;
+
+	data = devm_kzalloc(dev, sizeof(struct max8903_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->dev = dev;
+	platform_set_drvdata(pdev, data);
+
+	ret = max8903_setup_gpios(pdev);
+	if (ret)
+		return ret;
+
+	data->psy_desc.name = "max8903_charger";
+	data->psy_desc.type = (data->ta_in) ? POWER_SUPPLY_TYPE_MAINS :
+			((data->usb_in) ? POWER_SUPPLY_TYPE_USB :
+			 POWER_SUPPLY_TYPE_BATTERY);
+	data->psy_desc.get_property = max8903_get_property;
+	data->psy_desc.properties = max8903_charger_props;
+	data->psy_desc.num_properties = ARRAY_SIZE(max8903_charger_props);
+
+	psy_cfg.of_node = dev->of_node;
+	psy_cfg.drv_data = data;
+
+	data->psy = devm_power_supply_register(dev, &data->psy_desc, &psy_cfg);
+	if (IS_ERR(data->psy)) {
+		dev_err(dev, "failed: power supply register.\n");
+		return PTR_ERR(data->psy);
+	}
+
+	if (data->dok) {
+		ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->dok),
+					NULL, max8903_dcin,
+					IRQF_TRIGGER_FALLING |
+					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+					"MAX8903 DC IN", data);
+		if (ret) {
+			dev_err(dev, "Cannot request irq %d for DC (%d)\n",
+					gpiod_to_irq(data->dok), ret);
+			return ret;
+		}
+	}
+
+	if (data->uok) {
+		ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->uok),
+					NULL, max8903_usbin,
+					IRQF_TRIGGER_FALLING |
+					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+					"MAX8903 USB IN", data);
+		if (ret) {
+			dev_err(dev, "Cannot request irq %d for USB (%d)\n",
+					gpiod_to_irq(data->uok), ret);
+			return ret;
+		}
+	}
+
+	if (data->flt) {
+		ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->flt),
+					NULL, max8903_fault,
+					IRQF_TRIGGER_FALLING |
+					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+					"MAX8903 Fault", data);
+		if (ret) {
+			dev_err(dev, "Cannot request irq %d for Fault (%d)\n",
+					gpiod_to_irq(data->flt), ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static const struct of_device_id max8903_match_ids[] = {
+	{ .compatible = "maxim,max8903", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, max8903_match_ids);
+
+static struct platform_driver max8903_driver = {
+	.probe	= max8903_probe,
+	.driver = {
+		.name	= "max8903-charger",
+		.of_match_table = max8903_match_ids
+	},
+};
+
+module_platform_driver(max8903_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MAX8903 Charger Driver");
+MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
+MODULE_ALIAS("platform:max8903-charger");