[PATCH 2/4] power: supply: max17040: Config alert SOC low level threshold from FDT

Matheus Castello
2018-07-23T04:08:14Z

For configuration of fuel gauge alert for a low level state of charge
interrupt we add a function to config level threshold and a device tree
binding property to set it in flatned device tree node.

Now we can use "maxim,alert-soc-level" property with the values from
1 up to 32 to configure alert interrupt threshold.

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
---
drivers/power/supply/max17040_battery.c | 36 +++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)

diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c
index 6e54e58814a9..3efa52d32b44 100644
--- a/drivers/power/supply/max17040_battery.c
+++ b/drivers/power/supply/max17040_battery.c
@@ -47,6 +47,8 @@ struct max17040_chip {
int soc;
/* State Of Charge */
int status;
+ /* Alert threshold */
+ int alert_threshold;
};

static int max17040_get_property(struct power_supply *psy,
@@ -123,6 +125,28 @@ static void max17040_get_soc(struct i2c_client *client)
chip->soc = (soc >> 8);
}

+static int max17040_set_soc_threshold(struct i2c_client *client, u8 level)
+{
+ int ret;
+ u16 data;
+
+ /* check if level is between 1% and 32% */
+ if (level > 0 && level < 33) {
+ /* alert threshold use LSb 5 bits from RCOMP */
+ /* two's-complements form: 00000 = 32% and 11111 = 1% */
+ level = 32 - level;
+ data = max17040_read_reg(client, MAX17040_RCOMP);
+ data &= 0xFFE0;
+ data |= level;
+ max17040_write_reg(client, MAX17040_RCOMP, data);
+ ret = 0;
+ } else {
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
static void max17040_get_version(struct i2c_client *client)
{
u16 version;
@@ -165,6 +189,16 @@ static void max17040_get_status(struct i2c_client *client)
chip->status = POWER_SUPPLY_STATUS_FULL;
}

+static void max17040_get_of_data(struct max17040_chip *chip)
+{
+ struct device *dev = &chip->client->dev;
+ struct device_node *np = dev->of_node;
+
+ if (of_property_read_s32(np, "maxim,alert-soc-level",
+ &chip->alert_threshold))
+ chip->alert_threshold = 4;
+}
+
static void max17040_work(struct work_struct *work)
{
struct max17040_chip *chip;
@@ -231,6 +265,7 @@ static int max17040_probe(struct i2c_client *client,

chip->client = client;
chip->pdata = client->dev.platform_data;
+ max17040_get_of_data(chip);

i2c_set_clientdata(client, chip);
psy_cfg.drv_data = chip;
@@ -262,6 +297,7 @@ static int max17040_probe(struct i2c_client *client,

max17040_reset(client);
max17040_get_version(client);
+ max17040_set_soc_threshold(client, chip->alert_threshold);

INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
queue_delayed_work(system_power_efficient_wq, &chip->work,
--
2.13.3