[RFC PATCH v2 2/3] HID: input: Refactor battery code to use struct hid_battery

Lucas Zampieri posted 3 patches 3 weeks, 5 days ago
There is a newer version of this series
[RFC PATCH v2 2/3] HID: input: Refactor battery code to use struct hid_battery
Posted by Lucas Zampieri 3 weeks, 5 days ago
Refactor the battery handling code to use the newly introduced
struct hid_battery internally, replacing direct access to individual
power_supply and state fields.

The legacy dev->battery and dev->battery_* fields are maintained and
synchronized for backward compatibility. This refactoring prepares
the code for supporting multiple batteries per device in a subsequent
patch.

Signed-off-by: Lucas Zampieri <lzampier@redhat.com>
---
 drivers/hid/hid-input.c | 125 ++++++++++++++++++++++++++--------------
 1 file changed, 83 insertions(+), 42 deletions(-)

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index e56e7de53279..0e71efea9da3 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -454,7 +454,8 @@ static int hidinput_get_battery_property(struct power_supply *psy,
 					 enum power_supply_property prop,
 					 union power_supply_propval *val)
 {
-	struct hid_device *dev = power_supply_get_drvdata(psy);
+	struct hid_battery *bat = power_supply_get_drvdata(psy);
+	struct hid_device *dev = bat->dev;
 	int value;
 	int ret = 0;

@@ -465,13 +466,13 @@ static int hidinput_get_battery_property(struct power_supply *psy,
 		break;

 	case POWER_SUPPLY_PROP_CAPACITY:
-		if (dev->battery_status != HID_BATTERY_REPORTED &&
-		    !dev->battery_avoid_query) {
+		if (bat->status != HID_BATTERY_REPORTED &&
+		    !bat->avoid_query) {
 			value = hidinput_query_battery_capacity(dev);
 			if (value < 0)
 				return value;
 		} else  {
-			value = dev->battery_capacity;
+			value = bat->capacity;
 		}

 		val->intval = value;
@@ -482,20 +483,20 @@ static int hidinput_get_battery_property(struct power_supply *psy,
 		break;

 	case POWER_SUPPLY_PROP_STATUS:
-		if (dev->battery_status != HID_BATTERY_REPORTED &&
-		    !dev->battery_avoid_query) {
+		if (bat->status != HID_BATTERY_REPORTED &&
+		    !bat->avoid_query) {
 			value = hidinput_query_battery_capacity(dev);
 			if (value < 0)
 				return value;

-			dev->battery_capacity = value;
-			dev->battery_status = HID_BATTERY_QUERIED;
+			bat->capacity = value;
+			bat->status = HID_BATTERY_QUERIED;
 		}

-		if (dev->battery_status == HID_BATTERY_UNKNOWN)
+		if (bat->status == HID_BATTERY_UNKNOWN)
 			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
 		else
-			val->intval = dev->battery_charge_status;
+			val->intval = bat->charge_status;
 		break;

 	case POWER_SUPPLY_PROP_SCOPE:
@@ -513,8 +514,9 @@ static int hidinput_get_battery_property(struct power_supply *psy,
 static int hidinput_setup_battery(struct hid_device *dev, unsigned report_type,
 				  struct hid_field *field, bool is_percentage)
 {
+	struct hid_battery *bat;
 	struct power_supply_desc *psy_desc;
-	struct power_supply_config psy_cfg = { .drv_data = dev, };
+	struct power_supply_config psy_cfg;
 	unsigned quirks;
 	s32 min, max;
 	int error;
@@ -530,16 +532,22 @@ static int hidinput_setup_battery(struct hid_device *dev, unsigned report_type,
 	if (quirks & HID_BATTERY_QUIRK_IGNORE)
 		return 0;

-	psy_desc = kzalloc(sizeof(*psy_desc), GFP_KERNEL);
-	if (!psy_desc)
+	bat = kzalloc(sizeof(*bat), GFP_KERNEL);
+	if (!bat)
 		return -ENOMEM;

+	psy_desc = kzalloc(sizeof(*psy_desc), GFP_KERNEL);
+	if (!psy_desc) {
+		error = -ENOMEM;
+		goto err_free_bat;
+	}
+
 	psy_desc->name = kasprintf(GFP_KERNEL, "hid-%s-battery",
 				   strlen(dev->uniq) ?
 					dev->uniq : dev_name(&dev->dev));
 	if (!psy_desc->name) {
 		error = -ENOMEM;
-		goto err_free_mem;
+		goto err_free_desc;
 	}

 	psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
@@ -559,63 +567,85 @@ static int hidinput_setup_battery(struct hid_device *dev, unsigned report_type,
 	if (quirks & HID_BATTERY_QUIRK_FEATURE)
 		report_type = HID_FEATURE_REPORT;

-	dev->battery_min = min;
-	dev->battery_max = max;
-	dev->battery_report_type = report_type;
-	dev->battery_report_id = field->report->id;
-	dev->battery_charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
+	/* Initialize battery structure */
+	bat->dev = dev;
+	bat->min = min;
+	bat->max = max;
+	bat->report_type = report_type;
+	bat->report_id = field->report->id;
+	bat->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
+	bat->status = HID_BATTERY_UNKNOWN;

 	/*
 	 * Stylus is normally not connected to the device and thus we
 	 * can't query the device and get meaningful battery strength.
 	 * We have to wait for the device to report it on its own.
 	 */
-	dev->battery_avoid_query = report_type == HID_INPUT_REPORT &&
-				   field->physical == HID_DG_STYLUS;
+	bat->avoid_query = report_type == HID_INPUT_REPORT &&
+			   field->physical == HID_DG_STYLUS;

 	if (quirks & HID_BATTERY_QUIRK_AVOID_QUERY)
-		dev->battery_avoid_query = true;
+		bat->avoid_query = true;

-	dev->battery = power_supply_register(&dev->dev, psy_desc, &psy_cfg);
-	if (IS_ERR(dev->battery)) {
-		error = PTR_ERR(dev->battery);
+	psy_cfg.drv_data = bat;
+	bat->ps = power_supply_register(&dev->dev, psy_desc, &psy_cfg);
+	if (IS_ERR(bat->ps)) {
+		error = PTR_ERR(bat->ps);
 		hid_warn(dev, "can't register power supply: %d\n", error);
 		goto err_free_name;
 	}

-	power_supply_powers(dev->battery, &dev->dev);
+	power_supply_powers(bat->ps, &dev->dev);
+
+	/* Maintain legacy single battery fields for backward compatibility */
+	dev->battery = bat->ps;
+	dev->battery_min = bat->min;
+	dev->battery_max = bat->max;
+	dev->battery_report_type = bat->report_type;
+	dev->battery_report_id = bat->report_id;
+	dev->battery_charge_status = bat->charge_status;
+	dev->battery_status = bat->status;
+	dev->battery_avoid_query = bat->avoid_query;
+
 	return 0;

 err_free_name:
 	kfree(psy_desc->name);
-err_free_mem:
+err_free_desc:
 	kfree(psy_desc);
-	dev->battery = NULL;
+err_free_bat:
+	kfree(bat);
 	return error;
 }

 static void hidinput_cleanup_battery(struct hid_device *dev)
 {
+	struct hid_battery *bat;
 	const struct power_supply_desc *psy_desc;

 	if (!dev->battery)
 		return;

+	bat = power_supply_get_drvdata(dev->battery);
 	psy_desc = dev->battery->desc;
 	power_supply_unregister(dev->battery);
 	kfree(psy_desc->name);
 	kfree(psy_desc);
+	kfree(bat);
 	dev->battery = NULL;
 }

-static bool hidinput_update_battery_charge_status(struct hid_device *dev,
+static bool hidinput_update_battery_charge_status(struct hid_battery *bat,
 						  unsigned int usage, int value)
 {
 	switch (usage) {
 	case HID_BAT_CHARGING:
-		dev->battery_charge_status = value ?
-					     POWER_SUPPLY_STATUS_CHARGING :
-					     POWER_SUPPLY_STATUS_DISCHARGING;
+		bat->charge_status = value ?
+				     POWER_SUPPLY_STATUS_CHARGING :
+				     POWER_SUPPLY_STATUS_DISCHARGING;
+		/* Update legacy field for backward compatibility */
+		if (bat->dev->battery == bat->ps)
+			bat->dev->battery_charge_status = bat->charge_status;
 		return true;
 	}

@@ -625,32 +655,43 @@ static bool hidinput_update_battery_charge_status(struct hid_device *dev,
 static void hidinput_update_battery(struct hid_device *dev, unsigned int usage,
 				    int value)
 {
+	struct hid_battery *bat;
 	int capacity;

 	if (!dev->battery)
 		return;

-	if (hidinput_update_battery_charge_status(dev, usage, value)) {
-		power_supply_changed(dev->battery);
+	bat = power_supply_get_drvdata(dev->battery);
+
+	if (hidinput_update_battery_charge_status(bat, usage, value)) {
+		power_supply_changed(bat->ps);
 		return;
 	}

 	if ((usage & HID_USAGE_PAGE) == HID_UP_DIGITIZER && value == 0)
 		return;

-	if (value < dev->battery_min || value > dev->battery_max)
+	if (value < bat->min || value > bat->max)
 		return;

 	capacity = hidinput_scale_battery_capacity(dev, value);

-	if (dev->battery_status != HID_BATTERY_REPORTED ||
-	    capacity != dev->battery_capacity ||
-	    ktime_after(ktime_get_coarse(), dev->battery_ratelimit_time)) {
-		dev->battery_capacity = capacity;
-		dev->battery_status = HID_BATTERY_REPORTED;
-		dev->battery_ratelimit_time =
+	if (bat->status != HID_BATTERY_REPORTED ||
+	    capacity != bat->capacity ||
+	    ktime_after(ktime_get_coarse(), bat->ratelimit_time)) {
+		bat->capacity = capacity;
+		bat->status = HID_BATTERY_REPORTED;
+		bat->ratelimit_time =
 			ktime_add_ms(ktime_get_coarse(), 30 * 1000);
-		power_supply_changed(dev->battery);
+
+		/* Update legacy fields for backward compatibility */
+		if (dev->battery == bat->ps) {
+			dev->battery_capacity = bat->capacity;
+			dev->battery_status = bat->status;
+			dev->battery_ratelimit_time = bat->ratelimit_time;
+		}
+
+		power_supply_changed(bat->ps);
 	}
 }
 #else  /* !CONFIG_HID_BATTERY_STRENGTH */
--
2.51.1
Re: [RFC PATCH v2 2/3] HID: input: Refactor battery code to use struct hid_battery
Posted by Benjamin Tissoires 3 weeks, 4 days ago
On Nov 13 2025, Lucas Zampieri wrote:
> Refactor the battery handling code to use the newly introduced
> struct hid_battery internally, replacing direct access to individual
> power_supply and state fields.
> 
> The legacy dev->battery and dev->battery_* fields are maintained and
> synchronized for backward compatibility. This refactoring prepares
> the code for supporting multiple batteries per device in a subsequent
> patch.
> 
> Signed-off-by: Lucas Zampieri <lzampier@redhat.com>
> ---
>  drivers/hid/hid-input.c | 125 ++++++++++++++++++++++++++--------------
>  1 file changed, 83 insertions(+), 42 deletions(-)
> 
> diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
> index e56e7de53279..0e71efea9da3 100644
> --- a/drivers/hid/hid-input.c
> +++ b/drivers/hid/hid-input.c
> @@ -454,7 +454,8 @@ static int hidinput_get_battery_property(struct power_supply *psy,
>  					 enum power_supply_property prop,
>  					 union power_supply_propval *val)
>  {
> -	struct hid_device *dev = power_supply_get_drvdata(psy);
> +	struct hid_battery *bat = power_supply_get_drvdata(psy);
> +	struct hid_device *dev = bat->dev;
>  	int value;
>  	int ret = 0;
> 
> @@ -465,13 +466,13 @@ static int hidinput_get_battery_property(struct power_supply *psy,
>  		break;
> 
>  	case POWER_SUPPLY_PROP_CAPACITY:
> -		if (dev->battery_status != HID_BATTERY_REPORTED &&
> -		    !dev->battery_avoid_query) {
> +		if (bat->status != HID_BATTERY_REPORTED &&
> +		    !bat->avoid_query) {
>  			value = hidinput_query_battery_capacity(dev);
>  			if (value < 0)
>  				return value;
>  		} else  {
> -			value = dev->battery_capacity;
> +			value = bat->capacity;
>  		}
> 
>  		val->intval = value;
> @@ -482,20 +483,20 @@ static int hidinput_get_battery_property(struct power_supply *psy,
>  		break;
> 
>  	case POWER_SUPPLY_PROP_STATUS:
> -		if (dev->battery_status != HID_BATTERY_REPORTED &&
> -		    !dev->battery_avoid_query) {
> +		if (bat->status != HID_BATTERY_REPORTED &&
> +		    !bat->avoid_query) {
>  			value = hidinput_query_battery_capacity(dev);
>  			if (value < 0)
>  				return value;
> 
> -			dev->battery_capacity = value;
> -			dev->battery_status = HID_BATTERY_QUERIED;
> +			bat->capacity = value;
> +			bat->status = HID_BATTERY_QUERIED;
>  		}
> 
> -		if (dev->battery_status == HID_BATTERY_UNKNOWN)
> +		if (bat->status == HID_BATTERY_UNKNOWN)
>  			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
>  		else
> -			val->intval = dev->battery_charge_status;
> +			val->intval = bat->charge_status;
>  		break;
> 
>  	case POWER_SUPPLY_PROP_SCOPE:
> @@ -513,8 +514,9 @@ static int hidinput_get_battery_property(struct power_supply *psy,
>  static int hidinput_setup_battery(struct hid_device *dev, unsigned report_type,
>  				  struct hid_field *field, bool is_percentage)
>  {
> +	struct hid_battery *bat;
>  	struct power_supply_desc *psy_desc;
> -	struct power_supply_config psy_cfg = { .drv_data = dev, };
> +	struct power_supply_config psy_cfg;
>  	unsigned quirks;
>  	s32 min, max;
>  	int error;
> @@ -530,16 +532,22 @@ static int hidinput_setup_battery(struct hid_device *dev, unsigned report_type,
>  	if (quirks & HID_BATTERY_QUIRK_IGNORE)
>  		return 0;
> 
> -	psy_desc = kzalloc(sizeof(*psy_desc), GFP_KERNEL);
> -	if (!psy_desc)
> +	bat = kzalloc(sizeof(*bat), GFP_KERNEL);
> +	if (!bat)
>  		return -ENOMEM;
> 
> +	psy_desc = kzalloc(sizeof(*psy_desc), GFP_KERNEL);
> +	if (!psy_desc) {
> +		error = -ENOMEM;
> +		goto err_free_bat;
> +	}
> +
>  	psy_desc->name = kasprintf(GFP_KERNEL, "hid-%s-battery",
>  				   strlen(dev->uniq) ?
>  					dev->uniq : dev_name(&dev->dev));
>  	if (!psy_desc->name) {
>  		error = -ENOMEM;
> -		goto err_free_mem;
> +		goto err_free_desc;

I wonder if a devm conversion of the whole battery support handling
would not be beneficial here.

>  	}
> 
>  	psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
> @@ -559,63 +567,85 @@ static int hidinput_setup_battery(struct hid_device *dev, unsigned report_type,
>  	if (quirks & HID_BATTERY_QUIRK_FEATURE)
>  		report_type = HID_FEATURE_REPORT;
> 
> -	dev->battery_min = min;
> -	dev->battery_max = max;
> -	dev->battery_report_type = report_type;
> -	dev->battery_report_id = field->report->id;
> -	dev->battery_charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
> +	/* Initialize battery structure */
> +	bat->dev = dev;
> +	bat->min = min;
> +	bat->max = max;
> +	bat->report_type = report_type;
> +	bat->report_id = field->report->id;
> +	bat->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
> +	bat->status = HID_BATTERY_UNKNOWN;
> 
>  	/*
>  	 * Stylus is normally not connected to the device and thus we
>  	 * can't query the device and get meaningful battery strength.
>  	 * We have to wait for the device to report it on its own.
>  	 */
> -	dev->battery_avoid_query = report_type == HID_INPUT_REPORT &&
> -				   field->physical == HID_DG_STYLUS;
> +	bat->avoid_query = report_type == HID_INPUT_REPORT &&
> +			   field->physical == HID_DG_STYLUS;
> 
>  	if (quirks & HID_BATTERY_QUIRK_AVOID_QUERY)
> -		dev->battery_avoid_query = true;
> +		bat->avoid_query = true;
> 
> -	dev->battery = power_supply_register(&dev->dev, psy_desc, &psy_cfg);
> -	if (IS_ERR(dev->battery)) {
> -		error = PTR_ERR(dev->battery);
> +	psy_cfg.drv_data = bat;
> +	bat->ps = power_supply_register(&dev->dev, psy_desc, &psy_cfg);
> +	if (IS_ERR(bat->ps)) {
> +		error = PTR_ERR(bat->ps);
>  		hid_warn(dev, "can't register power supply: %d\n", error);
>  		goto err_free_name;
>  	}
> 
> -	power_supply_powers(dev->battery, &dev->dev);
> +	power_supply_powers(bat->ps, &dev->dev);
> +
> +	/* Maintain legacy single battery fields for backward compatibility */
> +	dev->battery = bat->ps;
> +	dev->battery_min = bat->min;
> +	dev->battery_max = bat->max;
> +	dev->battery_report_type = bat->report_type;
> +	dev->battery_report_id = bat->report_id;
> +	dev->battery_charge_status = bat->charge_status;
> +	dev->battery_status = bat->status;
> +	dev->battery_avoid_query = bat->avoid_query;

Already mentioned in the cover letter, but what's the point of keeping
those legacy fields when the exact same data is stored in bat?

> +
>  	return 0;
> 
>  err_free_name:
>  	kfree(psy_desc->name);
> -err_free_mem:
> +err_free_desc:
>  	kfree(psy_desc);
> -	dev->battery = NULL;
> +err_free_bat:
> +	kfree(bat);
>  	return error;
>  }
> 
>  static void hidinput_cleanup_battery(struct hid_device *dev)
>  {
> +	struct hid_battery *bat;
>  	const struct power_supply_desc *psy_desc;
> 
>  	if (!dev->battery)
>  		return;
> 
> +	bat = power_supply_get_drvdata(dev->battery);
>  	psy_desc = dev->battery->desc;
>  	power_supply_unregister(dev->battery);
>  	kfree(psy_desc->name);
>  	kfree(psy_desc);
> +	kfree(bat);
>  	dev->battery = NULL;
>  }
> 
> -static bool hidinput_update_battery_charge_status(struct hid_device *dev,
> +static bool hidinput_update_battery_charge_status(struct hid_battery *bat,
>  						  unsigned int usage, int value)
>  {
>  	switch (usage) {
>  	case HID_BAT_CHARGING:
> -		dev->battery_charge_status = value ?
> -					     POWER_SUPPLY_STATUS_CHARGING :
> -					     POWER_SUPPLY_STATUS_DISCHARGING;
> +		bat->charge_status = value ?
> +				     POWER_SUPPLY_STATUS_CHARGING :
> +				     POWER_SUPPLY_STATUS_DISCHARGING;
> +		/* Update legacy field for backward compatibility */
> +		if (bat->dev->battery == bat->ps)
> +			bat->dev->battery_charge_status = bat->charge_status;
>  		return true;
>  	}
> 
> @@ -625,32 +655,43 @@ static bool hidinput_update_battery_charge_status(struct hid_device *dev,
>  static void hidinput_update_battery(struct hid_device *dev, unsigned int usage,
>  				    int value)
>  {
> +	struct hid_battery *bat;
>  	int capacity;
> 
>  	if (!dev->battery)
>  		return;
> 
> -	if (hidinput_update_battery_charge_status(dev, usage, value)) {
> -		power_supply_changed(dev->battery);
> +	bat = power_supply_get_drvdata(dev->battery);
> +
> +	if (hidinput_update_battery_charge_status(bat, usage, value)) {
> +		power_supply_changed(bat->ps);
>  		return;
>  	}
> 
>  	if ((usage & HID_USAGE_PAGE) == HID_UP_DIGITIZER && value == 0)
>  		return;
> 
> -	if (value < dev->battery_min || value > dev->battery_max)
> +	if (value < bat->min || value > bat->max)
>  		return;
> 
>  	capacity = hidinput_scale_battery_capacity(dev, value);
> 
> -	if (dev->battery_status != HID_BATTERY_REPORTED ||
> -	    capacity != dev->battery_capacity ||
> -	    ktime_after(ktime_get_coarse(), dev->battery_ratelimit_time)) {
> -		dev->battery_capacity = capacity;
> -		dev->battery_status = HID_BATTERY_REPORTED;
> -		dev->battery_ratelimit_time =
> +	if (bat->status != HID_BATTERY_REPORTED ||
> +	    capacity != bat->capacity ||
> +	    ktime_after(ktime_get_coarse(), bat->ratelimit_time)) {
> +		bat->capacity = capacity;
> +		bat->status = HID_BATTERY_REPORTED;
> +		bat->ratelimit_time =
>  			ktime_add_ms(ktime_get_coarse(), 30 * 1000);
> -		power_supply_changed(dev->battery);
> +
> +		/* Update legacy fields for backward compatibility */
> +		if (dev->battery == bat->ps) {
> +			dev->battery_capacity = bat->capacity;
> +			dev->battery_status = bat->status;
> +			dev->battery_ratelimit_time = bat->ratelimit_time;
> +		}
> +
> +		power_supply_changed(bat->ps);
>  	}
>  }
>  #else  /* !CONFIG_HID_BATTERY_STRENGTH */
> --
> 2.51.1
> 

Cheers,
Benjamin
Re: [RFC PATCH v2 2/3] HID: input: Refactor battery code to use struct hid_battery
Posted by Lucas Zampieri 3 weeks, 1 day ago
On Thu, Nov 13, 2025 at 10:54 AM Benjamin Tissoires <bentiss@kernel.org> wrote:
>
> On Nov 13 2025, Lucas Zampieri wrote:
> > Refactor the battery handling code to use the newly introduced
> > struct hid_battery internally, replacing direct access to individual
> > power_supply and state fields.
> >
> > The legacy dev->battery and dev->battery_* fields are maintained and
> > synchronized for backward compatibility. This refactoring prepares
> > the code for supporting multiple batteries per device in a subsequent
> > patch.
> >
> > Signed-off-by: Lucas Zampieri <lzampier@redhat.com>
> > ---
> >  drivers/hid/hid-input.c | 125 ++++++++++++++++++++++++++--------------
> >  1 file changed, 83 insertions(+), 42 deletions(-)
> >
> > diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
> > index e56e7de53279..0e71efea9da3 100644
> > --- a/drivers/hid/hid-input.c
> > +++ b/drivers/hid/hid-input.c
> > @@ -454,7 +454,8 @@ static int hidinput_get_battery_property(struct power_supply *psy,
> >                                        enum power_supply_property prop,
> >                                        union power_supply_propval *val)
> >  {
> > -     struct hid_device *dev = power_supply_get_drvdata(psy);
> > +     struct hid_battery *bat = power_supply_get_drvdata(psy);
> > +     struct hid_device *dev = bat->dev;
> >       int value;
> >       int ret = 0;
> >
> > @@ -465,13 +466,13 @@ static int hidinput_get_battery_property(struct power_supply *psy,
> >               break;
> >
> >       case POWER_SUPPLY_PROP_CAPACITY:
> > -             if (dev->battery_status != HID_BATTERY_REPORTED &&
> > -                 !dev->battery_avoid_query) {
> > +             if (bat->status != HID_BATTERY_REPORTED &&
> > +                 !bat->avoid_query) {
> >                       value = hidinput_query_battery_capacity(dev);
> >                       if (value < 0)
> >                               return value;
> >               } else  {
> > -                     value = dev->battery_capacity;
> > +                     value = bat->capacity;
> >               }
> >
> >               val->intval = value;
> > @@ -482,20 +483,20 @@ static int hidinput_get_battery_property(struct power_supply *psy,
> >               break;
> >
> >       case POWER_SUPPLY_PROP_STATUS:
> > -             if (dev->battery_status != HID_BATTERY_REPORTED &&
> > -                 !dev->battery_avoid_query) {
> > +             if (bat->status != HID_BATTERY_REPORTED &&
> > +                 !bat->avoid_query) {
> >                       value = hidinput_query_battery_capacity(dev);
> >                       if (value < 0)
> >                               return value;
> >
> > -                     dev->battery_capacity = value;
> > -                     dev->battery_status = HID_BATTERY_QUERIED;
> > +                     bat->capacity = value;
> > +                     bat->status = HID_BATTERY_QUERIED;
> >               }
> >
> > -             if (dev->battery_status == HID_BATTERY_UNKNOWN)
> > +             if (bat->status == HID_BATTERY_UNKNOWN)
> >                       val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
> >               else
> > -                     val->intval = dev->battery_charge_status;
> > +                     val->intval = bat->charge_status;
> >               break;
> >
> >       case POWER_SUPPLY_PROP_SCOPE:
> > @@ -513,8 +514,9 @@ static int hidinput_get_battery_property(struct power_supply *psy,
> >  static int hidinput_setup_battery(struct hid_device *dev, unsigned report_type,
> >                                 struct hid_field *field, bool is_percentage)
> >  {
> > +     struct hid_battery *bat;
> >       struct power_supply_desc *psy_desc;
> > -     struct power_supply_config psy_cfg = { .drv_data = dev, };
> > +     struct power_supply_config psy_cfg;
> >       unsigned quirks;
> >       s32 min, max;
> >       int error;
> > @@ -530,16 +532,22 @@ static int hidinput_setup_battery(struct hid_device *dev, unsigned report_type,
> >       if (quirks & HID_BATTERY_QUIRK_IGNORE)
> >               return 0;
> >
> > -     psy_desc = kzalloc(sizeof(*psy_desc), GFP_KERNEL);
> > -     if (!psy_desc)
> > +     bat = kzalloc(sizeof(*bat), GFP_KERNEL);
> > +     if (!bat)
> >               return -ENOMEM;
> >
> > +     psy_desc = kzalloc(sizeof(*psy_desc), GFP_KERNEL);
> > +     if (!psy_desc) {
> > +             error = -ENOMEM;
> > +             goto err_free_bat;
> > +     }
> > +
> >       psy_desc->name = kasprintf(GFP_KERNEL, "hid-%s-battery",
> >                                  strlen(dev->uniq) ?
> >                                       dev->uniq : dev_name(&dev->dev));
> >       if (!psy_desc->name) {
> >               error = -ENOMEM;
> > -             goto err_free_mem;
> > +             goto err_free_desc;
>
> I wonder if a devm conversion of the whole battery support handling
> would not be beneficial here.
>
I'll give it a try and see how it looks.

> >       }
> >
> >       psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
> > @@ -559,63 +567,85 @@ static int hidinput_setup_battery(struct hid_device *dev, unsigned report_type,
> >       if (quirks & HID_BATTERY_QUIRK_FEATURE)
> >               report_type = HID_FEATURE_REPORT;
> >
> > -     dev->battery_min = min;
> > -     dev->battery_max = max;
> > -     dev->battery_report_type = report_type;
> > -     dev->battery_report_id = field->report->id;
> > -     dev->battery_charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
> > +     /* Initialize battery structure */
> > +     bat->dev = dev;
> > +     bat->min = min;
> > +     bat->max = max;
> > +     bat->report_type = report_type;
> > +     bat->report_id = field->report->id;
> > +     bat->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
> > +     bat->status = HID_BATTERY_UNKNOWN;
> >
> >       /*
> >        * Stylus is normally not connected to the device and thus we
> >        * can't query the device and get meaningful battery strength.
> >        * We have to wait for the device to report it on its own.
> >        */
> > -     dev->battery_avoid_query = report_type == HID_INPUT_REPORT &&
> > -                                field->physical == HID_DG_STYLUS;
> > +     bat->avoid_query = report_type == HID_INPUT_REPORT &&
> > +                        field->physical == HID_DG_STYLUS;
> >
> >       if (quirks & HID_BATTERY_QUIRK_AVOID_QUERY)
> > -             dev->battery_avoid_query = true;
> > +             bat->avoid_query = true;
> >
> > -     dev->battery = power_supply_register(&dev->dev, psy_desc, &psy_cfg);
> > -     if (IS_ERR(dev->battery)) {
> > -             error = PTR_ERR(dev->battery);
> > +     psy_cfg.drv_data = bat;
> > +     bat->ps = power_supply_register(&dev->dev, psy_desc, &psy_cfg);
> > +     if (IS_ERR(bat->ps)) {
> > +             error = PTR_ERR(bat->ps);
> >               hid_warn(dev, "can't register power supply: %d\n", error);
> >               goto err_free_name;
> >       }
> >
> > -     power_supply_powers(dev->battery, &dev->dev);
> > +     power_supply_powers(bat->ps, &dev->dev);
> > +
> > +     /* Maintain legacy single battery fields for backward compatibility */
> > +     dev->battery = bat->ps;
> > +     dev->battery_min = bat->min;
> > +     dev->battery_max = bat->max;
> > +     dev->battery_report_type = bat->report_type;
> > +     dev->battery_report_id = bat->report_id;
> > +     dev->battery_charge_status = bat->charge_status;
> > +     dev->battery_status = bat->status;
> > +     dev->battery_avoid_query = bat->avoid_query;
>
> Already mentioned in the cover letter, but what's the point of keeping
> those legacy fields when the exact same data is stored in bat?
>
Yep, now that I know that is better to have cohereand-API instead of
maintaining backwards compatiliby to a single battery structure that
was only internal, I'll update those as well.

> > +
> >       return 0;
> >
> >  err_free_name:
> >       kfree(psy_desc->name);
> > -err_free_mem:
> > +err_free_desc:
> >       kfree(psy_desc);
> > -     dev->battery = NULL;
> > +err_free_bat:
> > +     kfree(bat);
> >       return error;
> >  }
> >
> >  static void hidinput_cleanup_battery(struct hid_device *dev)
> >  {
> > +     struct hid_battery *bat;
> >       const struct power_supply_desc *psy_desc;
> >
> >       if (!dev->battery)
> >               return;
> >
> > +     bat = power_supply_get_drvdata(dev->battery);
> >       psy_desc = dev->battery->desc;
> >       power_supply_unregister(dev->battery);
> >       kfree(psy_desc->name);
> >       kfree(psy_desc);
> > +     kfree(bat);
> >       dev->battery = NULL;
> >  }
> >
> > -static bool hidinput_update_battery_charge_status(struct hid_device *dev,
> > +static bool hidinput_update_battery_charge_status(struct hid_battery *bat,
> >                                                 unsigned int usage, int value)
> >  {
> >       switch (usage) {
> >       case HID_BAT_CHARGING:
> > -             dev->battery_charge_status = value ?
> > -                                          POWER_SUPPLY_STATUS_CHARGING :
> > -                                          POWER_SUPPLY_STATUS_DISCHARGING;
> > +             bat->charge_status = value ?
> > +                                  POWER_SUPPLY_STATUS_CHARGING :
> > +                                  POWER_SUPPLY_STATUS_DISCHARGING;
> > +             /* Update legacy field for backward compatibility */
> > +             if (bat->dev->battery == bat->ps)
> > +                     bat->dev->battery_charge_status = bat->charge_status;
> >               return true;
> >       }
> >
> > @@ -625,32 +655,43 @@ static bool hidinput_update_battery_charge_status(struct hid_device *dev,
> >  static void hidinput_update_battery(struct hid_device *dev, unsigned int usage,
> >                                   int value)
> >  {
> > +     struct hid_battery *bat;
> >       int capacity;
> >
> >       if (!dev->battery)
> >               return;
> >
> > -     if (hidinput_update_battery_charge_status(dev, usage, value)) {
> > -             power_supply_changed(dev->battery);
> > +     bat = power_supply_get_drvdata(dev->battery);
> > +
> > +     if (hidinput_update_battery_charge_status(bat, usage, value)) {
> > +             power_supply_changed(bat->ps);
> >               return;
> >       }
> >
> >       if ((usage & HID_USAGE_PAGE) == HID_UP_DIGITIZER && value == 0)
> >               return;
> >
> > -     if (value < dev->battery_min || value > dev->battery_max)
> > +     if (value < bat->min || value > bat->max)
> >               return;
> >
> >       capacity = hidinput_scale_battery_capacity(dev, value);
> >
> > -     if (dev->battery_status != HID_BATTERY_REPORTED ||
> > -         capacity != dev->battery_capacity ||
> > -         ktime_after(ktime_get_coarse(), dev->battery_ratelimit_time)) {
> > -             dev->battery_capacity = capacity;
> > -             dev->battery_status = HID_BATTERY_REPORTED;
> > -             dev->battery_ratelimit_time =
> > +     if (bat->status != HID_BATTERY_REPORTED ||
> > +         capacity != bat->capacity ||
> > +         ktime_after(ktime_get_coarse(), bat->ratelimit_time)) {
> > +             bat->capacity = capacity;
> > +             bat->status = HID_BATTERY_REPORTED;
> > +             bat->ratelimit_time =
> >                       ktime_add_ms(ktime_get_coarse(), 30 * 1000);
> > -             power_supply_changed(dev->battery);
> > +
> > +             /* Update legacy fields for backward compatibility */
> > +             if (dev->battery == bat->ps) {
> > +                     dev->battery_capacity = bat->capacity;
> > +                     dev->battery_status = bat->status;
> > +                     dev->battery_ratelimit_time = bat->ratelimit_time;
> > +             }
> > +
> > +             power_supply_changed(bat->ps);
> >       }
> >  }
> >  #else  /* !CONFIG_HID_BATTERY_STRENGTH */
> > --
> > 2.51.1
> >
>
> Cheers,
> Benjamin
>

Best,
Lucas Zampieri