[PATCH v2 3/4] power: supply: max17040: Config alert SOC low level threshold from FDT

Matheus Castello
2019-04-15T01:26:34Z

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 | 56 ++++++++++++++++++++++---
1 file changed, 50 insertions(+), 6 deletions(-)

diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c
index 8d2f8ed3f44c..f036f272d52f 100644
--- a/drivers/power/supply/max17040_battery.c
+++ b/drivers/power/supply/max17040_battery.c
@@ -29,6 +29,9 @@
#define MAX17040_DELAY 1000
#define MAX17040_BATTERY_FULL 95

+#define MAX17040_ATHD_MASK 0xFFE0
+#define MAX17040_ATHD_DEFAULT_POWER_UP 4
+
struct max17040_chip {
struct i2c_client *client;
struct delayed_work work;
@@ -43,6 +46,8 @@ struct max17040_chip {
int soc;
/* State Of Charge */
int status;
+ /* Alert threshold from 32% to 1% of the State of Charge */
+ u32 alert_threshold;
};

static int max17040_get_property(struct power_supply *psy,
@@ -119,6 +124,27 @@ static void max17040_get_soc(struct i2c_client *client)
chip->soc = (soc >> 8);
}

+static int max17040_set_soc_threshold(struct i2c_client *client, u32 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 */
+ level = 32 - level;
+ data = max17040_read_reg(client, MAX17040_RCOMP);
+ data &= MAX17040_ATHD_MASK;
+ 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;
@@ -161,6 +187,16 @@ 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_u32(np, "maxim,alert-soc-level",
+ &chip->alert_threshold))
+ chip->alert_threshold = MAX17040_ATHD_DEFAULT_POWER_UP;
+}
+
static void max17040_check_changes(struct i2c_client *client)
{
max17040_get_vcell(client);
@@ -226,6 +262,7 @@ 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;
@@ -237,16 +274,26 @@ static int max17040_probe(struct i2c_client *client,
return PTR_ERR(chip->battery);
}

+ max17040_reset(client);
+ max17040_get_version(client);
+
/* check interrupt */
if (client->irq) {
int ret;
- unsigned int flags;
+
+ ret = max17040_set_soc_threshold(client, chip->alert_threshold);
+ if (ret) {
+ dev_err(&client->dev,
+ "Failed to set SOC alert threshold: err %d\n",
+ ret);
+ return ret;
+ }

dev_info(&client->dev, "IRQ: enabled\n");
- flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;

ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
- max17040_thread_handler, flags,
+ max17040_thread_handler,
+ (client->flags | IRQF_ONESHOT),
chip->battery->desc->name,
chip);

@@ -258,9 +305,6 @@ static int max17040_probe(struct i2c_client *client,
}
}

- max17040_reset(client);
- max17040_get_version(client);
-
INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
queue_delayed_work(system_power_efficient_wq, &chip->work,
MAX17040_DELAY);
--
2.17.0