[PATCH v1] power: max17042_battery: add HEALTH and TEMP_* properties support

Ramakrishna Pallala
2015-05-04T15:31:46Z

This patch adds the support for following battery properties
to max17042 fuel gauge driver.

POWER_SUPPLY_PROP_TEMP_ALERT_MIN
POWER_SUPPLY_PROP_TEMP_ALERT_MAX
POWER_SUPPLY_PROP_TEMP_MIN
POWER_SUPPLY_PROP_TEMP_MAX
POWER_SUPPLY_PROP_HEALTH

Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
---
drivers/power/max17042_battery.c | 190 ++++++++++++++++++++++++++++++--
include/linux/power/max17042_battery.h | 4 +
2 files changed, 183 insertions(+), 11 deletions(-)

diff --git a/drivers/power/max17042_battery.c b/drivers/power/max17042_battery.c
index 6cc5e87..9af610c 100644
--- a/drivers/power/max17042_battery.c
+++ b/drivers/power/max17042_battery.c
@@ -63,6 +63,8 @@
#define dP_ACC_100 0x1900
#define dP_ACC_200 0x3200

+#define MAX17042_VMAX_TOLERANCE 50 /* 50 mV */
+
struct max17042_chip {
struct i2c_client *client;
struct regmap *regmap;
@@ -85,10 +87,94 @@ static enum power_supply_property max17042_battery_props[] = {
POWER_SUPPLY_PROP_CHARGE_FULL,
POWER_SUPPLY_PROP_CHARGE_COUNTER,
POWER_SUPPLY_PROP_TEMP,
+ POWER_SUPPLY_PROP_TEMP_ALERT_MIN,
+ POWER_SUPPLY_PROP_TEMP_ALERT_MAX,
+ POWER_SUPPLY_PROP_TEMP_MIN,
+ POWER_SUPPLY_PROP_TEMP_MAX,
+ POWER_SUPPLY_PROP_HEALTH,
POWER_SUPPLY_PROP_CURRENT_NOW,
POWER_SUPPLY_PROP_CURRENT_AVG,
};

+static int max17042_get_temperature(struct max17042_chip *chip, int *temp)
+{
+ int ret;
+ u32 data;
+ struct regmap *map = chip->regmap;
+
+ ret = regmap_read(map, MAX17042_TEMP, &data);
+ if (ret < 0)
+ return ret;
+
+ *temp = data;
+ /* The value is signed. */
+ if (*temp & 0x8000) {
+ *temp = (0x7fff & ~*temp) + 1;
+ *temp *= -1;
+ }
+
+ /* The value is converted into deci-centigrade scale */
+ /* Units of LSB = 1 / 256 degree Celsius */
+ *temp = *temp * 10 / 256;
+ return 0;
+}
+
+static int max17042_get_battery_health(struct max17042_chip *chip, int *health)
+{
+ int temp, vavg, vbatt, ret;
+ u32 val;
+
+ ret = regmap_read(chip->regmap, MAX17042_AvgVCELL, &val);
+ if (ret < 0)
+ goto health_error;
+
+ /* bits [0-3] unused */
+ vavg = val * 625 / 8;
+ /* Convert to millivolts */
+ vavg /= 1000;
+
+ ret = regmap_read(chip->regmap, MAX17042_VCELL, &val);
+ if (ret < 0)
+ goto health_error;
+
+ /* bits [0-3] unused */
+ vbatt = val * 625 / 8;
+ /* Convert to millivolts */
+ vbatt /= 1000;
+
+ if (vavg < chip->pdata->vmin) {
+ *health = POWER_SUPPLY_HEALTH_DEAD;
+ goto out;
+ }
+
+ if (vbatt > chip->pdata->vmax + MAX17042_VMAX_TOLERENCE) {
+ *health = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+ goto out;
+ }
+
+ ret = max17042_get_temperature(chip, &temp);
+ if (ret < 0)
+ goto health_error;
+
+ if (temp <= chip->pdata->temp_min) {
+ *health = POWER_SUPPLY_HEALTH_COLD;
+ goto out;
+ }
+
+ if (temp >= chip->pdata->temp_max) {
+ *health = POWER_SUPPLY_HEALTH_OVERHEAT;
+ goto out;
+ }
+
+ *health = POWER_SUPPLY_HEALTH_GOOD;
+
+out:
+ return 0;
+
+health_error:
+ return ret;
+}
+
static int max17042_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
@@ -181,19 +267,34 @@ static int max17042_get_property(struct power_supply *psy,
val->intval = data * 1000 / 2;
break;
case POWER_SUPPLY_PROP_TEMP:
- ret = regmap_read(map, MAX17042_TEMP, &data);
+ ret = max17042_get_temperature(chip, &val->intval);
+ if (ret < 0)
+ return ret;
+ break;
+ case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
+ ret = regmap_read(map, MAX17042_TALRT_Th, &data);
+ if (ret < 0)
+ return ret;
+ /* LSB is Alert Minimum. In deci-centigrade */
+ val->intval = (data & 0xff) * 10;
+ break;
+ case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
+ ret = regmap_read(map, MAX17042_TALRT_Th, &data);
+ if (ret < 0)
+ return ret;
+ /* MSB is Alert Maximum. In deci-centigrade */
+ val->intval = (data >> 8) * 10;
+ break;
+ case POWER_SUPPLY_PROP_TEMP_MIN:
+ val->intval = chip->pdata->temp_min;
+ break;
+ case POWER_SUPPLY_PROP_TEMP_MAX:
+ val->intval = chip->pdata->temp_max;
+ break;
+ case POWER_SUPPLY_PROP_HEALTH:
+ ret = max17042_get_battery_health(chip, &val->intval);
if (ret < 0)
return ret;
-
- val->intval = data;
- /* The value is signed. */
- if (val->intval & 0x8000) {
- val->intval = (0x7fff & ~val->intval) + 1;
- val->intval *= -1;
- }
- /* The value is converted into deci-centigrade scale */
- /* Units of LSB = 1 / 256 degree Celsius */
- val->intval = val->intval * 10 / 256;
break;
case POWER_SUPPLY_PROP_CURRENT_NOW:
if (chip->pdata->enable_current_sense) {
@@ -237,6 +338,69 @@ static int max17042_get_property(struct power_supply *psy,
return 0;
}

+static int max17042_set_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ const union power_supply_propval *val)
+{
+ struct max17042_chip *chip = power_supply_get_drvdata(psy);
+ struct regmap *map = chip->regmap;
+ int ret = 0;
+ u32 data;
+ int8_t temp;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
+ ret = regmap_read(map, MAX17042_TALRT_Th, &data);
+ if (ret < 0)
+ return ret;
+
+ /* Input in deci-centigrade, convert to centigrade */
+ temp = val->intval / 10;
+ /* force min < max */
+ if (temp >= (int8_t)(data >> 8))
+ temp = (int8_t)(data >> 8) - 1;
+ /* Write both MAX and MIN ALERT */
+ data = (data & 0xff00) + temp;
+ ret = regmap_write(map, MAX17042_TALRT_Th, data);
+ break;
+ case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
+ ret = regmap_read(map, MAX17042_TALRT_Th, &data);
+ if (ret < 0)
+ return ret;
+
+ /* Input in Deci-Centigrade, convert to centigrade */
+ temp = val->intval / 10;
+ /* force max > min */
+ if (temp <= (int8_t)(data & 0xff))
+ temp = (int8_t)(data & 0xff) + 1;
+ /* Write both MAX and MIN ALERT */
+ data = (data & 0xff) + (temp << 8);
+ ret = regmap_write(map, MAX17042_TALRT_Th, data);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+static int max17042_property_is_writeable(struct power_supply *psy,
+ enum power_supply_property psp)
+{
+ int ret;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
+ case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
+ ret = 1;
+ break;
+ default:
+ ret = 0;
+ }
+
+ return ret;
+}
+
static int max17042_write_verify_reg(struct regmap *map, u8 reg, u32 value)
{
int retries = 8;
@@ -665,6 +829,8 @@ static const struct power_supply_desc max17042_psy_desc = {
.name = "max170xx_battery",
.type = POWER_SUPPLY_TYPE_BATTERY,
.get_property = max17042_get_property,
+ .set_property = max17042_set_property,
+ .property_is_writeable = max17042_property_is_writeable,
.properties = max17042_battery_props,
.num_properties = ARRAY_SIZE(max17042_battery_props),
};
@@ -673,6 +839,8 @@ static const struct power_supply_desc max17042_no_current_sense_psy_desc = {
.name = "max170xx_battery",
.type = POWER_SUPPLY_TYPE_BATTERY,
.get_property = max17042_get_property,
+ .set_property = max17042_set_property,
+ .property_is_writeable = max17042_property_is_writeable,
.properties = max17042_battery_props,
.num_properties = ARRAY_SIZE(max17042_battery_props) - 2,
};
diff --git a/include/linux/power/max17042_battery.h b/include/linux/power/max17042_battery.h
index cf112b4..522757a 100644
--- a/include/linux/power/max17042_battery.h
+++ b/include/linux/power/max17042_battery.h
@@ -215,6 +215,10 @@ struct max17042_platform_data {
* the datasheet although it can be changed by board designers.
*/
unsigned int r_sns;
+ int vmin; /* in millivolts */
+ int vmax; /* in millivolts */
+ int temp_min; /* in tenths of degree Celsius */
+ int temp_max; /* in tenths of degree Celsius */
};

#endif /* __MAX17042_BATTERY_H_ */
--
1.7.9.5