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

The manufacture date of a given battery is exposed over the Dell DDV
WMI interface using the "BatteryManufactureDate" WMI method. The
resulting data contains the manufacture date of the battery encoded
inside a 16-bit value as described in the Smart Battery Data
Specification.

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/20250429003606.303870-3-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 f10a623acca1a2b82db5ca34ae8e6f06ff46554d..41c553d5c77d02da8b93719674d0fd73f937022a 100644 (file)
--- a/Documentation/wmi/devices/dell-wmi-ddv.rst
+++ b/Documentation/wmi/devices/dell-wmi-ddv.rst
@@ -118,9 +118,6 @@ The date is encoded in the following manner:
 - bits 5 to 8 contain the manufacture month.
 - bits 9 to 15 contain the manufacture year biased by 1980.
 
-.. note::
-   The data format needs to be verified on more machines.
-
 WMI method BatterySerialNumber()
 --------------------------------
 

diff --git a/drivers/platform/x86/dell/dell-wmi-ddv.c b/drivers/platform/x86/dell/dell-wmi-ddv.c
index 711639001be42869635c102ebe7e0e962fe5d91e..0d63934416e917ab5fe8153b233eea42c10ae127 100644 (file)
--- a/drivers/platform/x86/dell/dell-wmi-ddv.c
+++ b/drivers/platform/x86/dell/dell-wmi-ddv.c
@@ -8,6 +8,7 @@
 #define pr_format(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/acpi.h>
+#include <linux/bitfield.h>
 #include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/device/driver.h>
@@ -42,6 +43,10 @@
 /* Battery indices 1, 2 and 3 */
 #define DELL_DDV_NUM_BATTERIES         3
 
+#define SBS_MANUFACTURE_YEAR_MASK      GENMASK(15, 9)
+#define SBS_MANUFACTURE_MONTH_MASK     GENMASK(8, 5)
+#define SBS_MANUFACTURE_DAY_MASK       GENMASK(4, 0)
+
 #define DELL_EPPID_LENGTH      20
 #define DELL_EPPID_EXT_LENGTH  23
 
@@ -744,6 +749,50 @@ static ssize_t eppid_show(struct device *dev, struct device_attribute *attr, cha
        return ret;
 }
 
+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)
+{
+       u16 year, month, day;
+       u32 value;
+       int ret;
+
+       ret = dell_wmi_ddv_query_integer(data->wdev, DELL_DDV_BATTERY_MANUFACTURE_DATE,
+                                        index, &value);
+       if (ret < 0)
+               return ret;
+       if (value > U16_MAX)
+               return -ENXIO;
+
+       /*
+        * Some devices report a invalid manufacture date value
+        * like 0.0.1980. Because of this we have to check the
+        * whole value before exposing parts of it to user space.
+        */
+       year = FIELD_GET(SBS_MANUFACTURE_YEAR_MASK, value) + 1980;
+       month = FIELD_GET(SBS_MANUFACTURE_MONTH_MASK, value);
+       if (month < 1 || month > 12)
+               return -ENODATA;
+
+       day = FIELD_GET(SBS_MANUFACTURE_DAY_MASK, value);
+       if (day < 1 || day > 31)
+               return -ENODATA;
+
+       switch (psp) {
+       case POWER_SUPPLY_PROP_MANUFACTURE_YEAR:
+               val->intval = year;
+               return 0;
+       case POWER_SUPPLY_PROP_MANUFACTURE_MONTH:
+               val->intval = month;
+               return 0;
+       case POWER_SUPPLY_PROP_MANUFACTURE_DAY:
+               val->intval = day;
+               return 0;
+       default:
+               return -EINVAL;
+       }
+}
+
 static int dell_wmi_ddv_get_property(struct power_supply *psy, const struct power_supply_ext *ext,
                                     void *drvdata, enum power_supply_property psp,
                                     union power_supply_propval *val)
@@ -768,6 +817,10 @@ static int dell_wmi_ddv_get_property(struct power_supply *psy, const struct powe
                 */
                val->intval = value - 2732;
                return 0;
+       case POWER_SUPPLY_PROP_MANUFACTURE_YEAR:
+       case POWER_SUPPLY_PROP_MANUFACTURE_MONTH:
+       case POWER_SUPPLY_PROP_MANUFACTURE_DAY:
+               return dell_wmi_ddv_get_manufacture_date(data, index, psp, val);
        default:
                return -EINVAL;
        }
@@ -775,6 +828,9 @@ 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_TEMP,
+       POWER_SUPPLY_PROP_MANUFACTURE_YEAR,
+       POWER_SUPPLY_PROP_MANUFACTURE_MONTH,
+       POWER_SUPPLY_PROP_MANUFACTURE_DAY,
 };
 
 static const struct power_supply_ext dell_wmi_ddv_extension = {