power: max17040: get thermal data from adc if available

Since fuel gauge does not support thermal monitoring,
some vendors may couple this fuel gauge with thermal/adc
sensor to monitor battery cell exact temperature.

Add this feature by adding optional iio thermal channel.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Iskren Chernev <me@iskren.info>
Link: https://lore.kernel.org/r/20230731073613.10394-4-clamor95@gmail.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 663a1c4238066eddacbab1a1f2ade63cc1e79807..d99db3a049f2c0af5cc73a7c1eeb5bd677258657 100644 (file)
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -374,7 +374,7 @@ config AXP288_FUEL_GAUGE
 
 config BATTERY_MAX17040
        tristate "Maxim MAX17040/17041/17043 family Fuel Gauge"
-       depends on I2C
+       depends on I2C && IIO
        select REGMAP_I2C
        help
          Driver supports Maxim fuel-gauge systems for lithium-ion (Li+)

diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c
index 92caf6c7a48c06abb3debfffe09ac51863bdca49..51310f6e4803b92468cde3aaf8a641a215846b69 100644 (file)
--- a/drivers/power/supply/max17040_battery.c
+++ b/drivers/power/supply/max17040_battery.c
@@ -18,6 +18,7 @@
 #include <linux/of.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
+#include <linux/iio/consumer.h>
 
 #define MAX17040_VCELL 0x02
 #define MAX17040_SOC   0x04
@@ -142,6 +143,7 @@ struct max17040_chip {
        struct delayed_work             work;
        struct power_supply             *battery;
        struct chip_data                data;
+       struct iio_channel              *channel_temp;
 
        /* battery capacity */
        int soc;
@@ -404,6 +406,13 @@ static int max17040_get_property(struct power_supply *psy,
        case POWER_SUPPLY_PROP_STATUS:
                power_supply_get_property_from_supplier(psy, psp, val);
                break;
+       case POWER_SUPPLY_PROP_TEMP:
+               if (!chip->channel_temp)
+                       return -ENODATA;
+
+               iio_read_channel_processed_scale(chip->channel_temp,
+                                                &val->intval, 10);
+               break;
        default:
                return -EINVAL;
        }
@@ -424,6 +433,7 @@ static enum power_supply_property max17040_battery_props[] = {
        POWER_SUPPLY_PROP_CAPACITY,
        POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN,
        POWER_SUPPLY_PROP_STATUS,
+       POWER_SUPPLY_PROP_TEMP,
 };
 
 static const struct power_supply_desc max17040_battery_desc = {
@@ -469,6 +479,17 @@ static int max17040_probe(struct i2c_client *client)
        i2c_set_clientdata(client, chip);
        psy_cfg.drv_data = chip;
 
+       /* Switch to devm_iio_channel_get_optional when available  */
+       chip->channel_temp = devm_iio_channel_get(&client->dev, "temp");
+       if (IS_ERR(chip->channel_temp)) {
+               ret = PTR_ERR(chip->channel_temp);
+               if (ret != -ENODEV)
+                       return dev_err_probe(&client->dev, PTR_ERR(chip->channel_temp),
+                                            "failed to get temp\n");
+               else
+                       chip->channel_temp = NULL;
+       }
+
        chip->battery = devm_power_supply_register(&client->dev,
                                &max17040_battery_desc, &psy_cfg);
        if (IS_ERR(chip->battery)) {