platform/x86: dell-ddv: Expose the battery health to userspace

The health of a given battery is exposed over the Dell DDV WMI
interface using the "BatteryManufactureAceess" WMI method. The
resulting data contains, among other data, the health status of
the battery.

Expose this value to userspace using the power supply extension
interface.

Tested on a Dell Inspiron 3505.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20250429003606.303870-4-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/Documentation/wmi/devices/dell-wmi-ddv.rst b/Documentation/wmi/devices/dell-wmi-ddv.rst
index 41c553d..109d4c5 100644 (file)
--- a/Documentation/wmi/devices/dell-wmi-ddv.rst
+++ b/Documentation/wmi/devices/dell-wmi-ddv.rst
@@ -150,7 +150,40 @@ Returns the voltage flow of the battery in mV as an u16.
 WMI method BatteryManufactureAccess()
 -------------------------------------
 
-Returns a manufacture-defined value as an u16.
+Returns the health status of the battery as a u16.
+The health status encoded in the following manner:
+
+ - the third nibble contains the general failure mode
+ - the fourth nibble contains the specific failure code
+
+Valid failure modes are:
+
+ - permanent failure (``0x9``)
+ - overheat failure (``0xa``)
+ - overcurrent failure (``0xb``)
+
+All other failure modes are to be considered normal.
+
+The following failure codes are valid for a permanent failure:
+
+ - fuse blown (``0x0``)
+ - cell imbalance (``0x1``)
+ - overvoltage (``0x2``)
+ - fet failure (``0x3``)
+
+The last two bits of the failure code are to be ignored when the battery
+signals a permanent failure.
+
+The following failure codes a valid for a overheat failure:
+
+ - overheat at start of charging (``0x5``)
+ - overheat during charging (``0x7``)
+ - overheat during discharging (``0x8``)
+
+The following failure codes are valid for a overcurrent failure:
+
+ - overcurrent during charging (``0x6``)
+ - overcurrent during discharging (``0xb``)
 
 WMI method BatteryRelativeStateOfCharge()
 -----------------------------------------

diff --git a/drivers/platform/x86/dell/dell-wmi-ddv.c b/drivers/platform/x86/dell/dell-wmi-ddv.c
index 0d63934..67f3d71 100644 (file)
--- a/drivers/platform/x86/dell/dell-wmi-ddv.c
+++ b/drivers/platform/x86/dell/dell-wmi-ddv.c
@@ -47,6 +47,26 @@
 #define SBS_MANUFACTURE_MONTH_MASK     GENMASK(8, 5)
 #define SBS_MANUFACTURE_DAY_MASK       GENMASK(4, 0)
 
+#define MA_FAILURE_MODE_MASK                   GENMASK(11, 8)
+#define MA_FAILURE_MODE_PERMANENT              0x9
+#define MA_FAILURE_MODE_OVERHEAT               0xA
+#define MA_FAILURE_MODE_OVERCURRENT            0xB
+
+#define MA_PERMANENT_FAILURE_CODE_MASK         GENMASK(13, 12)
+#define MA_PERMANENT_FAILURE_FUSE_BLOWN                0x0
+#define MA_PERMANENT_FAILURE_CELL_IMBALANCE    0x1
+#define MA_PERMANENT_FAILURE_OVERVOLTAGE       0x2
+#define MA_PERMANENT_FAILURE_FET_FAILURE       0x3
+
+#define MA_OVERHEAT_FAILURE_CODE_MASK          GENMASK(15, 12)
+#define MA_OVERHEAT_FAILURE_START              0x5
+#define MA_OVERHEAT_FAILURE_CHARGING           0x7
+#define MA_OVERHEAT_FAILURE_DISCHARGING                0x8
+
+#define MA_OVERCURRENT_FAILURE_CODE_MASK       GENMASK(15, 12)
+#define MA_OVERCURRENT_FAILURE_CHARGING                0x6
+#define MA_OVERCURRENT_FAILURE_DISCHARGING     0xB
+
 #define DELL_EPPID_LENGTH      20
 #define DELL_EPPID_EXT_LENGTH  23
 
@@ -749,6 +769,72 @@ static ssize_t eppid_show(struct device *dev, struct device_attribute *attr, cha
        return ret;
 }
 
+static int dell_wmi_ddv_get_health(struct dell_wmi_ddv_data *data, u32 index,
+                                  union power_supply_propval *val)
+{
+       u32 value, code;
+       int ret;
+
+       ret = dell_wmi_ddv_query_integer(data->wdev, DELL_DDV_BATTERY_MANUFACTURER_ACCESS, index,
+                                        &value);
+       if (ret < 0)
+               return ret;
+
+       switch (FIELD_GET(MA_FAILURE_MODE_MASK, value)) {
+       case MA_FAILURE_MODE_PERMANENT:
+               code = FIELD_GET(MA_PERMANENT_FAILURE_CODE_MASK, value);
+               switch (code) {
+               case MA_PERMANENT_FAILURE_FUSE_BLOWN:
+                       val->intval = POWER_SUPPLY_HEALTH_BLOWN_FUSE;
+                       return 0;
+               case MA_PERMANENT_FAILURE_CELL_IMBALANCE:
+                       val->intval = POWER_SUPPLY_HEALTH_CELL_IMBALANCE;
+                       return 0;
+               case MA_PERMANENT_FAILURE_OVERVOLTAGE:
+                       val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+                       return 0;
+               case MA_PERMANENT_FAILURE_FET_FAILURE:
+                       val->intval = POWER_SUPPLY_HEALTH_DEAD;
+                       return 0;
+               default:
+                       dev_notice_once(&data->wdev->dev, "Unknown permanent failure code %u\n",
+                                       code);
+                       val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+                       return 0;
+               }
+       case MA_FAILURE_MODE_OVERHEAT:
+               code = FIELD_GET(MA_OVERHEAT_FAILURE_CODE_MASK, value);
+               switch (code) {
+               case MA_OVERHEAT_FAILURE_START:
+               case MA_OVERHEAT_FAILURE_CHARGING:
+               case MA_OVERHEAT_FAILURE_DISCHARGING:
+                       val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
+                       return 0;
+               default:
+                       dev_notice_once(&data->wdev->dev, "Unknown overheat failure code %u\n",
+                                       code);
+                       val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+                       return 0;
+               }
+       case MA_FAILURE_MODE_OVERCURRENT:
+               code = FIELD_GET(MA_OVERCURRENT_FAILURE_CODE_MASK, value);
+               switch (code) {
+               case MA_OVERCURRENT_FAILURE_CHARGING:
+               case MA_OVERCURRENT_FAILURE_DISCHARGING:
+                       val->intval = POWER_SUPPLY_HEALTH_OVERCURRENT;
+                       return 0;
+               default:
+                       dev_notice_once(&data->wdev->dev, "Unknown overcurrent failure code %u\n",
+                                       code);
+                       val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+                       return 0;
+               }
+       default:
+               val->intval = POWER_SUPPLY_HEALTH_GOOD;
+               return 0;
+       }
+}
+
 static int dell_wmi_ddv_get_manufacture_date(struct dell_wmi_ddv_data *data, u32 index,
                                             enum power_supply_property psp,
                                             union power_supply_propval *val)
@@ -806,6 +892,8 @@ static int dell_wmi_ddv_get_property(struct power_supply *psy, const struct powe
                return ret;
 
        switch (psp) {
+       case POWER_SUPPLY_PROP_HEALTH:
+               return dell_wmi_ddv_get_health(data, index, val);
        case POWER_SUPPLY_PROP_TEMP:
                ret = dell_wmi_ddv_query_integer(data->wdev, DELL_DDV_BATTERY_TEMPERATURE, index,
                                                 &value);
@@ -827,6 +915,7 @@ static int dell_wmi_ddv_get_property(struct power_supply *psy, const struct powe
 }
 
 static const enum power_supply_property dell_wmi_ddv_properties[] = {
+       POWER_SUPPLY_PROP_HEALTH,
        POWER_SUPPLY_PROP_TEMP,
        POWER_SUPPLY_PROP_MANUFACTURE_YEAR,
        POWER_SUPPLY_PROP_MANUFACTURE_MONTH,