[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 000000000000..8bde92126d34
--- /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");