power: supply: add AC power supply driver for AXP20X and AXP22X PMICs

The X-Powers AXP20X and AXP22X PMICs expose the status of AC power
supply.

Moreover, the AXP20X can also expose the current current and voltage
values of the AC power supply.

This adds the driver which exposes the status of the AC power supply of
the AXP20X and AXP22X PMICs.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
[removed unused elements from struct axp20x_ac_power]
Signed-off-by: Sebastian Reichel <sre@kernel.org>

drivers/power/supply/Kconfig

@@ -220,6 +220,18 @@ config BATTERY_DA9150
 	  This driver can also be built as a module. If so, the module will be
 	  called da9150-fg.
 
+config CHARGER_AXP20X
+	tristate "X-Powers AXP20X and AXP22X AC power supply driver"
+	depends on MFD_AXP20X
+	depends on AXP20X_ADC
+	depends on IIO
+	help
+	  Say Y here to enable support for X-Powers AXP20X and AXP22X PMICs' AC
+	  power supply.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called axp20x_ac_power.
+
 config AXP288_CHARGER
 	tristate "X-Powers AXP288 Charger"
 	depends on MFD_AXP20X && EXTCON_AXP288

drivers/power/supply/Makefile

@@ -18,6 +18,7 @@ obj-$(CONFIG_TEST_POWER)	+= test_power.o
 
 obj-$(CONFIG_BATTERY_88PM860X)	+= 88pm860x_battery.o
 obj-$(CONFIG_BATTERY_ACT8945A)	+= act8945a_charger.o
+obj-$(CONFIG_CHARGER_AXP20X)	+= axp20x_ac_power.o
 obj-$(CONFIG_BATTERY_DS2760)	+= ds2760_battery.o
 obj-$(CONFIG_BATTERY_DS2780)	+= ds2780_battery.o
 obj-$(CONFIG_BATTERY_DS2781)	+= ds2781_battery.o

drivers/power/supply/axp20x_ac_power.c

@@ -0,0 +1,253 @@
+/*
+ * AXP20X and AXP22X PMICs' ACIN power supply driver
+ *
+ * Copyright (C) 2016 Free Electrons
+ *	Quentin Schulz <quentin.schulz@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under  the terms of the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mfd/axp20x.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/iio/consumer.h>
+
+#define AXP20X_PWR_STATUS_ACIN_PRESENT	BIT(7)
+#define AXP20X_PWR_STATUS_ACIN_AVAIL	BIT(6)
+
+#define DRVNAME "axp20x-ac-power-supply"
+
+struct axp20x_ac_power {
+	struct regmap *regmap;
+	struct power_supply *supply;
+	struct iio_channel *acin_v;
+	struct iio_channel *acin_i;
+};
+
+static irqreturn_t axp20x_ac_power_irq(int irq, void *devid)
+{
+	struct axp20x_ac_power *power = devid;
+
+	power_supply_changed(power->supply);
+
+	return IRQ_HANDLED;
+}
+
+static int axp20x_ac_power_get_property(struct power_supply *psy,
+					enum power_supply_property psp,
+					union power_supply_propval *val)
+{
+	struct axp20x_ac_power *power = power_supply_get_drvdata(psy);
+	int ret, reg;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_HEALTH:
+		ret = regmap_read(power->regmap, AXP20X_PWR_INPUT_STATUS, &reg);
+		if (ret)
+			return ret;
+
+		if (reg & AXP20X_PWR_STATUS_ACIN_PRESENT) {
+			val->intval = POWER_SUPPLY_HEALTH_GOOD;
+			return 0;
+		}
+
+		val->intval = POWER_SUPPLY_HEALTH_UNKNOWN;
+		return 0;
+
+	case POWER_SUPPLY_PROP_PRESENT:
+		ret = regmap_read(power->regmap, AXP20X_PWR_INPUT_STATUS, &reg);
+		if (ret)
+			return ret;
+
+		val->intval = !!(reg & AXP20X_PWR_STATUS_ACIN_PRESENT);
+		return 0;
+
+	case POWER_SUPPLY_PROP_ONLINE:
+		ret = regmap_read(power->regmap, AXP20X_PWR_INPUT_STATUS, &reg);
+		if (ret)
+			return ret;
+
+		val->intval = !!(reg & AXP20X_PWR_STATUS_ACIN_AVAIL);
+		return 0;
+
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		ret = iio_read_channel_processed(power->acin_v, &val->intval);
+		if (ret)
+			return ret;
+
+		/* IIO framework gives mV but Power Supply framework gives uV */
+		val->intval *= 1000;
+
+		return 0;
+
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+		ret = iio_read_channel_processed(power->acin_i, &val->intval);
+		if (ret)
+			return ret;
+
+		/* IIO framework gives mA but Power Supply framework gives uA */
+		val->intval *= 1000;
+
+		return 0;
+
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static enum power_supply_property axp20x_ac_power_properties[] = {
+	POWER_SUPPLY_PROP_HEALTH,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+};
+
+static enum power_supply_property axp22x_ac_power_properties[] = {
+	POWER_SUPPLY_PROP_HEALTH,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_ONLINE,
+};
+
+static const struct power_supply_desc axp20x_ac_power_desc = {
+	.name = "axp20x-ac",
+	.type = POWER_SUPPLY_TYPE_MAINS,
+	.properties = axp20x_ac_power_properties,
+	.num_properties = ARRAY_SIZE(axp20x_ac_power_properties),
+	.get_property = axp20x_ac_power_get_property,
+};
+
+static const struct power_supply_desc axp22x_ac_power_desc = {
+	.name = "axp22x-ac",
+	.type = POWER_SUPPLY_TYPE_MAINS,
+	.properties = axp22x_ac_power_properties,
+	.num_properties = ARRAY_SIZE(axp22x_ac_power_properties),
+	.get_property = axp20x_ac_power_get_property,
+};
+
+struct axp_data {
+	const struct power_supply_desc	*power_desc;
+	bool				acin_adc;
+};
+
+static const struct axp_data axp20x_data = {
+	.power_desc = &axp20x_ac_power_desc,
+	.acin_adc = true,
+};
+
+static const struct axp_data axp22x_data = {
+	.power_desc = &axp22x_ac_power_desc,
+	.acin_adc = false,
+};
+
+static int axp20x_ac_power_probe(struct platform_device *pdev)
+{
+	struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
+	struct power_supply_config psy_cfg = {};
+	struct axp20x_ac_power *power;
+	struct axp_data *axp_data;
+	static const char * const irq_names[] = { "ACIN_PLUGIN", "ACIN_REMOVAL",
+		NULL };
+	int i, irq, ret;
+
+	if (!of_device_is_available(pdev->dev.of_node))
+		return -ENODEV;
+
+	if (!axp20x) {
+		dev_err(&pdev->dev, "Parent drvdata not set\n");
+		return -EINVAL;
+	}
+
+	power = devm_kzalloc(&pdev->dev, sizeof(*power), GFP_KERNEL);
+	if (!power)
+		return -ENOMEM;
+
+	axp_data = (struct axp_data *)of_device_get_match_data(&pdev->dev);
+
+	if (axp_data->acin_adc) {
+		power->acin_v = devm_iio_channel_get(&pdev->dev, "acin_v");
+		if (IS_ERR(power->acin_v)) {
+			if (PTR_ERR(power->acin_v) == -ENODEV)
+				return -EPROBE_DEFER;
+			return PTR_ERR(power->acin_v);
+		}
+
+		power->acin_i = devm_iio_channel_get(&pdev->dev, "acin_i");
+		if (IS_ERR(power->acin_i)) {
+			if (PTR_ERR(power->acin_i) == -ENODEV)
+				return -EPROBE_DEFER;
+			return PTR_ERR(power->acin_i);
+		}
+	}
+
+	power->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+
+	platform_set_drvdata(pdev, power);
+
+	psy_cfg.of_node = pdev->dev.of_node;
+	psy_cfg.drv_data = power;
+
+	power->supply = devm_power_supply_register(&pdev->dev,
+						   axp_data->power_desc,
+						   &psy_cfg);
+	if (IS_ERR(power->supply))
+		return PTR_ERR(power->supply);
+
+	/* Request irqs after registering, as irqs may trigger immediately */
+	for (i = 0; irq_names[i]; i++) {
+		irq = platform_get_irq_byname(pdev, irq_names[i]);
+		if (irq < 0) {
+			dev_warn(&pdev->dev, "No IRQ for %s: %d\n",
+				 irq_names[i], irq);
+			continue;
+		}
+		irq = regmap_irq_get_virq(axp20x->regmap_irqc, irq);
+		ret = devm_request_any_context_irq(&pdev->dev, irq,
+						   axp20x_ac_power_irq, 0,
+						   DRVNAME, power);
+		if (ret < 0)
+			dev_warn(&pdev->dev, "Error requesting %s IRQ: %d\n",
+				 irq_names[i], ret);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id axp20x_ac_power_match[] = {
+	{
+		.compatible = "x-powers,axp202-ac-power-supply",
+		.data = (void *)&axp20x_data,
+	}, {
+		.compatible = "x-powers,axp221-ac-power-supply",
+		.data = (void *)&axp22x_data,
+	}, { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, axp20x_ac_power_match);
+
+static struct platform_driver axp20x_ac_power_driver = {
+	.probe = axp20x_ac_power_probe,
+	.driver = {
+		.name = DRVNAME,
+		.of_match_table = axp20x_ac_power_match,
+	},
+};
+
+module_platform_driver(axp20x_ac_power_driver);
+
+MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
+MODULE_DESCRIPTION("AXP20X and AXP22X PMICs' AC power supply driver");
+MODULE_LICENSE("GPL");