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path: root/drivers/power/supply/max17040_battery.c
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Diffstat (limited to 'drivers/power/supply/max17040_battery.c')
-rw-r--r--drivers/power/supply/max17040_battery.c122
1 files changed, 118 insertions, 4 deletions
diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c
index 62499018e68b..8a1f0ee493aa 100644
--- a/drivers/power/supply/max17040_battery.c
+++ b/drivers/power/supply/max17040_battery.c
@@ -13,6 +13,7 @@
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/delay.h>
+#include <linux/interrupt.h>
#include <linux/power_supply.h>
#include <linux/max17040_battery.h>
#include <linux/slab.h>
@@ -28,6 +29,9 @@
#define MAX17040_DELAY 1000
#define MAX17040_BATTERY_FULL 95
+#define MAX17040_ATHD_MASK 0xFFC0
+#define MAX17040_ATHD_DEFAULT_POWER_UP 4
+
struct max17040_chip {
struct i2c_client *client;
struct delayed_work work;
@@ -42,6 +46,8 @@ struct max17040_chip {
int soc;
/* State Of Charge */
int status;
+ /* Low alert threshold from 32% to 1% of the State of Charge */
+ u32 low_soc_alert;
};
static int max17040_get_property(struct power_supply *psy,
@@ -98,6 +104,21 @@ static void max17040_reset(struct i2c_client *client)
max17040_write_reg(client, MAX17040_CMD, 0x0054);
}
+static int max17040_set_low_soc_alert(struct i2c_client *client, u32 level)
+{
+ int ret;
+ u16 data;
+
+ level = 32 - level;
+ data = max17040_read_reg(client, MAX17040_RCOMP);
+ /* clear the alrt bit and set LSb 5 bits */
+ data &= MAX17040_ATHD_MASK;
+ data |= level;
+ ret = max17040_write_reg(client, MAX17040_RCOMP, data);
+
+ return ret;
+}
+
static void max17040_get_vcell(struct i2c_client *client)
{
struct max17040_chip *chip = i2c_get_clientdata(client);
@@ -160,21 +181,81 @@ static void max17040_get_status(struct i2c_client *client)
chip->status = POWER_SUPPLY_STATUS_FULL;
}
+static int max17040_get_of_data(struct max17040_chip *chip)
+{
+ struct device *dev = &chip->client->dev;
+
+ chip->low_soc_alert = MAX17040_ATHD_DEFAULT_POWER_UP;
+ device_property_read_u32(dev,
+ "maxim,alert-low-soc-level",
+ &chip->low_soc_alert);
+
+ if (chip->low_soc_alert <= 0 || chip->low_soc_alert >= 33)
+ return -EINVAL;
+
+ return 0;
+}
+
+static void max17040_check_changes(struct i2c_client *client)
+{
+ max17040_get_vcell(client);
+ max17040_get_soc(client);
+ max17040_get_online(client);
+ max17040_get_status(client);
+}
+
static void max17040_work(struct work_struct *work)
{
struct max17040_chip *chip;
+ int last_soc, last_status;
chip = container_of(work, struct max17040_chip, work.work);
- max17040_get_vcell(chip->client);
- max17040_get_soc(chip->client);
- max17040_get_online(chip->client);
- max17040_get_status(chip->client);
+ /* store SOC and status to check changes */
+ last_soc = chip->soc;
+ last_status = chip->status;
+ max17040_check_changes(chip->client);
+
+ /* check changes and send uevent */
+ if (last_soc != chip->soc || last_status != chip->status)
+ power_supply_changed(chip->battery);
queue_delayed_work(system_power_efficient_wq, &chip->work,
MAX17040_DELAY);
}
+static irqreturn_t max17040_thread_handler(int id, void *dev)
+{
+ struct max17040_chip *chip = dev;
+ struct i2c_client *client = chip->client;
+
+ dev_warn(&client->dev, "IRQ: Alert battery low level");
+ /* read registers */
+ max17040_check_changes(chip->client);
+
+ /* send uevent */
+ power_supply_changed(chip->battery);
+
+ /* reset alert bit */
+ max17040_set_low_soc_alert(client, chip->low_soc_alert);
+
+ return IRQ_HANDLED;
+}
+
+static int max17040_enable_alert_irq(struct max17040_chip *chip)
+{
+ struct i2c_client *client = chip->client;
+ unsigned int flags;
+ int ret;
+
+ flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
+ ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
+ max17040_thread_handler, flags,
+ chip->battery->desc->name, chip);
+
+ return ret;
+}
+
static enum power_supply_property max17040_battery_props[] = {
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_ONLINE,
@@ -196,6 +277,7 @@ static int max17040_probe(struct i2c_client *client,
struct i2c_adapter *adapter = client->adapter;
struct power_supply_config psy_cfg = {};
struct max17040_chip *chip;
+ int ret;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
return -EIO;
@@ -206,6 +288,12 @@ static int max17040_probe(struct i2c_client *client,
chip->client = client;
chip->pdata = client->dev.platform_data;
+ ret = max17040_get_of_data(chip);
+ if (ret) {
+ dev_err(&client->dev,
+ "failed: low SOC alert OF data out of bounds\n");
+ return ret;
+ }
i2c_set_clientdata(client, chip);
psy_cfg.drv_data = chip;
@@ -220,6 +308,24 @@ static int max17040_probe(struct i2c_client *client,
max17040_reset(client);
max17040_get_version(client);
+ /* check interrupt */
+ if (client->irq && of_device_is_compatible(client->dev.of_node,
+ "maxim,max77836-battery")) {
+ ret = max17040_set_low_soc_alert(client, chip->low_soc_alert);
+ if (ret) {
+ dev_err(&client->dev,
+ "Failed to set low SOC alert: err %d\n", ret);
+ return ret;
+ }
+
+ ret = max17040_enable_alert_irq(chip);
+ if (ret) {
+ client->irq = 0;
+ dev_warn(&client->dev,
+ "Failed to get IRQ err %d\n", ret);
+ }
+ }
+
INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
queue_delayed_work(system_power_efficient_wq, &chip->work,
MAX17040_DELAY);
@@ -244,6 +350,10 @@ static int max17040_suspend(struct device *dev)
struct max17040_chip *chip = i2c_get_clientdata(client);
cancel_delayed_work(&chip->work);
+
+ if (client->irq && device_may_wakeup(dev))
+ enable_irq_wake(client->irq);
+
return 0;
}
@@ -254,6 +364,10 @@ static int max17040_resume(struct device *dev)
queue_delayed_work(system_power_efficient_wq, &chip->work,
MAX17040_DELAY);
+
+ if (client->irq && device_may_wakeup(dev))
+ disable_irq_wake(client->irq);
+
return 0;
}