[ARM] 5248/1: wm97xx generic battery driver

This patch adds generic battery driver for wm97xx chips.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 272 insertions, 0 deletions

diff --git a/drivers/power/wm97xx_battery.c b/drivers/power/wm97xx_battery.c
new file mode 100644
index 00000000000..8bde92126d3
--- /dev/null
+++ b/drivers/power/wm97xx_battery.c
@@ -0,0 +1,272 @@
+/*
+ * linux/drivers/power/wm97xx_battery.c
+ *
+ * Battery measurement code for WM97xx
+ *
+ * based on tosa_battery.c
+ *
+ * Copyright (C) 2008 Marek Vasut <marek.vasut@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/wm97xx.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include <linux/wm97xx_batt.h>
+
+static DEFINE_MUTEX(bat_lock);
+static struct work_struct bat_work;
+struct mutex work_lock;
+static int bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
+static struct wm97xx_batt_info *pdata;
+static enum power_supply_property *prop;
+
+static unsigned long wm97xx_read_bat(struct power_supply *bat_ps)
+{
+	return wm97xx_read_aux_adc(bat_ps->dev->parent->driver_data,
+					pdata->batt_aux) * pdata->batt_mult /
+					pdata->batt_div;
+}
+
+static unsigned long wm97xx_read_temp(struct power_supply *bat_ps)
+{
+	return wm97xx_read_aux_adc(bat_ps->dev->parent->driver_data,
+					pdata->temp_aux) * pdata->temp_mult /
+					pdata->temp_div;
+}
+
+static int wm97xx_bat_get_property(struct power_supply *bat_ps,
+			    enum power_supply_property psp,
+			    union power_supply_propval *val)
+{
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		val->intval = bat_status;
+		break;
+	case POWER_SUPPLY_PROP_TECHNOLOGY:
+		val->intval = pdata->batt_tech;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		if (pdata->batt_aux >= 0)
+			val->intval = wm97xx_read_bat(bat_ps);
+		else
+			return -EINVAL;
+		break;
+	case POWER_SUPPLY_PROP_TEMP:
+		if (pdata->temp_aux >= 0)
+			val->intval = wm97xx_read_temp(bat_ps);
+		else
+			return -EINVAL;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX:
+		if (pdata->max_voltage >= 0)
+			val->intval = pdata->max_voltage;
+		else
+			return -EINVAL;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MIN:
+		if (pdata->min_voltage >= 0)
+			val->intval = pdata->min_voltage;
+		else
+			return -EINVAL;
+		break;
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = 1;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
+{
+	schedule_work(&bat_work);
+}
+
+static void wm97xx_bat_update(struct power_supply *bat_ps)
+{
+	int old_status = bat_status;
+
+	mutex_lock(&work_lock);
+
+	bat_status = (pdata->charge_gpio >= 0) ?
+			(gpio_get_value(pdata->charge_gpio) ?
+			POWER_SUPPLY_STATUS_DISCHARGING :
+			POWER_SUPPLY_STATUS_CHARGING) :
+			POWER_SUPPLY_STATUS_UNKNOWN;
+
+	if (old_status != bat_status) {
+		pr_debug("%s: %i -> %i\n", bat_ps->name, old_status,
+					bat_status);
+		power_supply_changed(bat_ps);
+	}
+
+	mutex_unlock(&work_lock);
+}
+
+static struct power_supply bat_ps = {
+	.type			= POWER_SUPPLY_TYPE_BATTERY,
+	.get_property		= wm97xx_bat_get_property,
+	.external_power_changed = wm97xx_bat_external_power_changed,
+	.use_for_apm		= 1,
+};
+
+static void wm97xx_bat_work(struct work_struct *work)
+{
+	wm97xx_bat_update(&bat_ps);
+}
+
+#ifdef CONFIG_PM
+static int wm97xx_bat_suspend(struct platform_device *dev, pm_message_t state)
+{
+	flush_scheduled_work();
+	return 0;
+}
+
+static int wm97xx_bat_resume(struct platform_device *dev)
+{
+	schedule_work(&bat_work);
+	return 0;
+}
+#else
+#define wm97xx_bat_suspend NULL
+#define wm97xx_bat_resume NULL
+#endif
+
+static int __devinit wm97xx_bat_probe(struct platform_device *dev)
+{
+	int ret = 0;
+	int props = 1;	/* POWER_SUPPLY_PROP_PRESENT */
+	int i = 0;
+
+	if (dev->id != -1)
+		return -EINVAL;
+
+	mutex_init(&work_lock);
+
+	if (!pdata) {
+		dev_err(&dev->dev, "Please use wm97xx_bat_set_pdata\n");
+		return -EINVAL;
+	}
+
+	if (pdata->charge_gpio >= 0 && gpio_is_valid(pdata->charge_gpio)) {
+		ret = gpio_request(pdata->charge_gpio, "BATT CHRG");
+		if (ret)
+			goto err;
+		ret = gpio_direction_input(pdata->charge_gpio);
+		if (ret)
+			goto err2;
+		props++;	/* POWER_SUPPLY_PROP_STATUS */
+	}
+
+	if (pdata->batt_tech >= 0)
+		props++;	/* POWER_SUPPLY_PROP_TECHNOLOGY */
+	if (pdata->temp_aux >= 0)
+		props++;	/* POWER_SUPPLY_PROP_TEMP */
+	if (pdata->batt_aux >= 0)
+		props++;	/* POWER_SUPPLY_PROP_VOLTAGE_NOW */
+	if (pdata->max_voltage >= 0)
+		props++;	/* POWER_SUPPLY_PROP_VOLTAGE_MAX */
+	if (pdata->min_voltage >= 0)
+		props++;	/* POWER_SUPPLY_PROP_VOLTAGE_MIN */
+
+	prop = kzalloc(props * sizeof(*prop), GFP_KERNEL);
+	if (!prop)
+		goto err2;
+
+	prop[i++] = POWER_SUPPLY_PROP_PRESENT;
+	if (pdata->charge_gpio >= 0)
+		prop[i++] = POWER_SUPPLY_PROP_STATUS;
+	if (pdata->batt_tech >= 0)
+		prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
+	if (pdata->temp_aux >= 0)
+		prop[i++] = POWER_SUPPLY_PROP_TEMP;
+	if (pdata->batt_aux >= 0)
+		prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
+	if (pdata->max_voltage >= 0)
+		prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
+	if (pdata->min_voltage >= 0)
+		prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
+
+	INIT_WORK(&bat_work, wm97xx_bat_work);
+
+	if (!pdata->batt_name) {
+		dev_info(&dev->dev, "Please consider setting proper battery "
+				"name in platform definition file, falling "
+				"back to name \"wm97xx-batt\"\n");
+		bat_ps.name = "wm97xx-batt";
+	} else
+		bat_ps.name = pdata->batt_name;
+
+	bat_ps.properties = prop;
+	bat_ps.num_properties = props;
+
+	ret = power_supply_register(&dev->dev, &bat_ps);
+	if (!ret)
+		schedule_work(&bat_work);
+	else
+		goto err3;
+
+	return 0;
+err3:
+	kfree(prop);
+err2:
+	gpio_free(pdata->charge_gpio);
+err:
+	return ret;
+}
+
+static int __devexit wm97xx_bat_remove(struct platform_device *dev)
+{
+	if (pdata && pdata->charge_gpio && pdata->charge_gpio >= 0)
+		gpio_free(pdata->charge_gpio);
+	flush_scheduled_work();
+	power_supply_unregister(&bat_ps);
+	kfree(prop);
+	return 0;
+}
+
+static struct platform_driver wm97xx_bat_driver = {
+	.driver	= {
+		.name	= "wm97xx-battery",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= wm97xx_bat_probe,
+	.remove		= __devexit_p(wm97xx_bat_remove),
+	.suspend	= wm97xx_bat_suspend,
+	.resume		= wm97xx_bat_resume,
+};
+
+static int __init wm97xx_bat_init(void)
+{
+	return platform_driver_register(&wm97xx_bat_driver);
+}
+
+static void __exit wm97xx_bat_exit(void)
+{
+	platform_driver_unregister(&wm97xx_bat_driver);
+}
+
+void __init wm97xx_bat_set_pdata(struct wm97xx_batt_info *data)
+{
+	pdata = data;
+}
+EXPORT_SYMBOL_GPL(wm97xx_bat_set_pdata);
+
+module_init(wm97xx_bat_init);
+module_exit(wm97xx_bat_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
+MODULE_DESCRIPTION("WM97xx battery driver");