[PATCH] POWER: Add gpio chager driver

From: Lars-Peter Clausen
Date: Thu Oct 21 2010 - 08:33:22 EST


This patch adds a simple driver for chargers indicating their online status
through a GPIO pin.

Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
---
drivers/power/Kconfig | 10 ++
drivers/power/Makefile | 1 +
drivers/power/gpio-charger.c | 184 ++++++++++++++++++++++++++++++++++++
include/linux/power/gpio-charger.h | 39 ++++++++
4 files changed, 234 insertions(+), 0 deletions(-)
create mode 100644 drivers/power/gpio-charger.c
create mode 100644 include/linux/power/gpio-charger.h

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 0734356..90b1940 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -166,4 +166,14 @@ config BATTERY_INTEL_MID
Say Y here to enable the battery driver on Intel MID
platforms.

+config CHARGER_GPIO
+ tristate "GPIO charger"
+ depends on GPIOLIB
+ help
+ Say Y to include support for chargers which report their online status
+ through a GPIO pin.
+
+ This driver can be build as a module. If so, the module will be
+ called gpio-chager.
+
endif # POWER_SUPPLY
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index 10143aa..2ca71ac 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -37,3 +37,4 @@ obj-$(CONFIG_BATTERY_S3C_ADC) += s3c_adc_battery.o
obj-$(CONFIG_CHARGER_PCF50633) += pcf50633-charger.o
obj-$(CONFIG_BATTERY_JZ4740) += jz4740-battery.o
obj-$(CONFIG_BATTERY_INTEL_MID) += intel_mid_battery.o
+obj-$(CONFIG_CHARGER_GPIO) += gpio-charger.o
diff --git a/drivers/power/gpio-charger.c b/drivers/power/gpio-charger.c
new file mode 100644
index 0000000..0a2ddfc
--- /dev/null
+++ b/drivers/power/gpio-charger.c
@@ -0,0 +1,184 @@
+/*
+ * Copyright (C) 2010, Lars-Peter Clausen <lars@xxxxxxxxxx>
+ * Driver for chargers which report their online status through a GPIO pin
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/slab.h>
+
+#include <linux/power/gpio-charger.h>
+
+struct gpio_charger {
+ const struct gpio_charger_platform_data *pdata;
+ int irq;
+
+ struct power_supply charger;
+};
+
+static irqreturn_t gpio_charger_irq(int irq, void *devid)
+{
+ struct power_supply *charger = devid;
+ power_supply_changed(charger);
+
+ return IRQ_HANDLED;
+}
+
+static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
+{
+ return container_of(psy, struct gpio_charger, charger);
+}
+
+static int gpio_charger_get_property(struct power_supply *psy,
+ enum power_supply_property psp, union power_supply_propval *val)
+{
+ struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
+ const struct gpio_charger_platform_data *pdata = gpio_charger->pdata;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_ONLINE:
+ val->intval = gpio_get_value(pdata->gpio);
+ val->intval ^= pdata->gpio_active_low;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static enum power_supply_property gpio_charger_properties[] = {
+ POWER_SUPPLY_PROP_ONLINE,
+};
+
+static int __devinit gpio_charger_probe(struct platform_device *pdev)
+{
+ const struct gpio_charger_platform_data *pdata = pdev->dev.platform_data;
+ struct gpio_charger *gpio_charger;
+ struct power_supply *charger;
+ int ret;
+
+ if (!pdata) {
+ dev_err(&pdev->dev, "No platform data");
+ return -EINVAL;
+ }
+
+ if (!gpio_is_valid(pdata->gpio)) {
+ dev_err(&pdev->dev, "Invalid gpio pin\n");
+ return -EINVAL;
+ }
+
+ gpio_charger = kzalloc(sizeof(*gpio_charger), GFP_KERNEL);
+
+ charger = &gpio_charger->charger;
+
+ charger->name = pdata->name;
+ charger->type = pdata->type;
+ charger->properties = gpio_charger_properties;
+ charger->num_properties = ARRAY_SIZE(gpio_charger_properties);
+ charger->get_property = gpio_charger_get_property;
+ charger->supplied_to = pdata->supplied_to;
+ charger->num_supplicants = pdata->num_supplicants;
+
+ ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret);
+ goto err_free;
+ }
+ ret = gpio_direction_input(pdata->gpio);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret);
+ goto err_gpio_free;
+ }
+
+ gpio_charger->irq = gpio_to_irq(pdata->gpio);
+ if (gpio_charger->irq >= 0) {
+ ret = request_irq(gpio_charger->irq, gpio_charger_irq,
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+ dev_name(&pdev->dev), charger);
+ if (ret) {
+ dev_warn(&pdev->dev, "Failed to request gpio irq: %d\n", ret);
+ gpio_charger->irq = -1;
+ }
+ }
+
+ gpio_charger->pdata = pdata;
+
+ ret = power_supply_register(&pdev->dev, charger);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to register power supply: %d\n", ret);
+ goto err_irq_free;
+ }
+
+ platform_set_drvdata(pdev, gpio_charger);
+
+ return 0;
+
+err_irq_free:
+ if (gpio_charger->irq >= 0)
+ free_irq(gpio_charger->irq, charger);
+err_gpio_free:
+ gpio_free(pdata->gpio);
+err_free:
+ kfree(gpio_charger);
+ return ret;
+}
+
+static int __devexit gpio_charger_remove(struct platform_device *pdev)
+{
+ struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
+ const struct gpio_charger_platform_data *pdata = gpio_charger->pdata;
+
+ power_supply_unregister(&gpio_charger->charger);
+
+ if (gpio_charger->irq >= 0)
+ free_irq(gpio_charger->irq, &gpio_charger->charger);
+ gpio_free(pdata->gpio);
+
+ platform_set_drvdata(pdev, NULL);
+ kfree(gpio_charger);
+
+ return 0;
+}
+
+static struct platform_driver gpio_charger_driver = {
+ .probe = gpio_charger_probe,
+ .remove = __devexit_p(gpio_charger_remove),
+ .driver = {
+ .name = "gpio-charger",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init gpio_charger_init(void)
+{
+ return platform_driver_register(&gpio_charger_driver);
+}
+module_init(gpio_charger_init);
+
+static void __exit gpio_charger_exit(void)
+{
+ platform_driver_unregister(&gpio_charger_driver);
+}
+module_exit(gpio_charger_exit);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:gpio-charger");
diff --git a/include/linux/power/gpio-charger.h b/include/linux/power/gpio-charger.h
new file mode 100644
index 0000000..404d5e6
--- /dev/null
+++ b/include/linux/power/gpio-charger.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2010, Lars-Peter Clausen <lars@xxxxxxxxxx>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#ifndef __LINUX_POWER_GPIO_CHARGER_H__
+#define __LINUX_POWER_GPIO_CHARGER_H__
+
+/*
+ * struct gpio_charger_platform_data - platform_data for gpio_charger devices
+ * @name: Name for the chargers power_supply device
+ * @type: Type of the charger
+ * @gpio: GPIO which is used to indicate the chargers status
+ * @gpio_active_low: Should be set to 1 if the GPIO is active low otherwise 0
+ * @supplied_to: Array of battery names to which this chargers supplies power
+ * @num_supplicants: Number of entries in the supplied_to array
+ */
+
+struct gpio_charger_platform_data {
+ const char *name;
+ enum power_supply_type type;
+
+ int gpio;
+ int gpio_active_low;
+
+ char **supplied_to;
+ size_t num_supplicants;
+};
+
+#endif
--
1.5.6.5

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