power: max17042_battery: add HEALTH and TEMP_* properties support

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>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

2 files changed, 183 insertions, 11 deletions

diff --git a/drivers/power/max17042_battery.c b/drivers/power/max17042_battery.c
index 6cc5e87ec031..748d9762e89b 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_TOLERANCE) {
+                *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 cf112b4075c8..522757ac9cd4 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_ */