[PATCH v3 10/16] bq27x00: Poll battery state

From: Lars-Peter Clausen
Date: Tue Feb 22 2011 - 01:44:19 EST


This patch adds support for polling the battery state and generating a
power_supply_changed() event if it has changed.

Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
Tested-by: Grazvydas Ignotas <notasas@xxxxxxxxx>
---
drivers/power/bq27x00_battery.c | 58 +++++++++++++++++++++++++++++++++++---
1 files changed, 53 insertions(+), 5 deletions(-)

diff --git a/drivers/power/bq27x00_battery.c b/drivers/power/bq27x00_battery.c
index dbe3fcb..25350fc 100644
--- a/drivers/power/bq27x00_battery.c
+++ b/drivers/power/bq27x00_battery.c
@@ -74,10 +74,13 @@ struct bq27x00_device_info {

struct bq27x00_reg_cache cache;
unsigned long last_update;
+ struct delayed_work work;

struct power_supply bat;

struct bq27x00_access_methods bus;
+
+ struct mutex lock;
};

static enum power_supply_property bq27x00_battery_props[] = {
@@ -93,6 +96,11 @@ static enum power_supply_property bq27x00_battery_props[] = {
POWER_SUPPLY_PROP_TECHNOLOGY,
};

+static unsigned int poll_interval = 360;
+module_param(poll_interval, uint, 0644);
+MODULE_PARM_DESC(poll_interval, "battery poll interval in seconds - " \
+ "0 disables polling");
+
/*
* Common code for BQ27x00 devices
*/
@@ -169,6 +177,21 @@ static void bq27x00_update(struct bq27x00_device_info *di)
di->last_update = jiffies;
}

+static void bq27x00_battery_poll(struct work_struct *work)
+{
+ struct bq27x00_device_info *di =
+ container_of(work, struct bq27x00_device_info, work.work);
+
+ bq27x00_update(di);
+
+ if (poll_interval > 0) {
+ /* The timer does not have to be accurate. */
+ set_timer_slack(&di->work.timer, poll_interval * HZ / 4);
+ schedule_delayed_work(&di->work, poll_interval * HZ);
+ }
+}
+
+
/*
* Return the battery temperature in tenths of degree Celsius
* Or < 0 if something fails.
@@ -283,8 +306,12 @@ static int bq27x00_battery_get_property(struct power_supply *psy,
int ret = 0;
struct bq27x00_device_info *di = to_bq27x00_device_info(psy);

- if (time_is_before_jiffies(di->last_update + 5 * HZ))
- bq27x00_update(di);
+ mutex_lock(&di->lock);
+ if (time_is_before_jiffies(di->last_update + 5 * HZ)) {
+ cancel_delayed_work_sync(&di->work);
+ bq27x00_battery_poll(&di->work.work);
+ }
+ mutex_unlock(&di->lock);

if (psp != POWER_SUPPLY_PROP_PRESENT && di->cache.flags < 0)
return -ENODEV;
@@ -327,6 +354,14 @@ static int bq27x00_battery_get_property(struct power_supply *psy,
return ret;
}

+static void bq27x00_external_power_changed(struct power_supply *psy)
+{
+ struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
+
+ cancel_delayed_work_sync(&di->work);
+ schedule_delayed_work(&di->work, 0);
+}
+
static int bq27x00_powersupply_init(struct bq27x00_device_info *di)
{
int ret;
@@ -335,7 +370,10 @@ static int bq27x00_powersupply_init(struct bq27x00_device_info *di)
di->bat.properties = bq27x00_battery_props;
di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
di->bat.get_property = bq27x00_battery_get_property;
- di->bat.external_power_changed = NULL;
+ di->bat.external_power_changed = bq27x00_external_power_changed;
+
+ INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll);
+ mutex_init(&di->lock);

ret = power_supply_register(di->dev, &di->bat);
if (ret) {
@@ -350,6 +388,15 @@ static int bq27x00_powersupply_init(struct bq27x00_device_info *di)
return 0;
}

+static void bq27x00_powersupply_unregister(struct bq27x00_device_info *di)
+{
+ cancel_delayed_work_sync(&di->work);
+
+ power_supply_unregister(&di->bat);
+
+ mutex_destroy(&di->lock);
+}
+

/* i2c specific code */
#ifdef CONFIG_BATTERY_BQ27X00_I2C
@@ -457,7 +504,7 @@ static int bq27x00_battery_remove(struct i2c_client *client)
{
struct bq27x00_device_info *di = i2c_get_clientdata(client);

- power_supply_unregister(&di->bat);
+ bq27x00_powersupply_unregister(di);

kfree(di->bat.name);

@@ -590,7 +637,8 @@ static int __devexit bq27000_battery_remove(struct platform_device *pdev)
{
struct bq27x00_device_info *di = platform_get_drvdata(pdev);

- power_supply_unregister(&di->bat);
+ bq27x00_powersupply_unregister(di);
+
platform_set_drvdata(pdev, NULL);
kfree(di);

--
1.7.2.3

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