Re: [RFC PATCH 05/21] alienware-wmi: Refactor rgb-zones sysfs group creation

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Wed, 4 Dec 2024, Kurt Borja wrote:

> Define zone_attrs statically with the use of helper macros and
> initialize the zone_attribute_group with driver's .dev_groups.
> 
> This makes match_zone() no longer needed, so drop it.
> 
> Signed-off-by: Kurt Borja <kuurtb@gmail.com>
> ---
>  drivers/platform/x86/dell/alienware-wmi.c | 137 ++++++++++------------
>  1 file changed, 60 insertions(+), 77 deletions(-)
> 
> diff --git a/drivers/platform/x86/dell/alienware-wmi.c b/drivers/platform/x86/dell/alienware-wmi.c
> index 78bbb4ef4526..fa7bbbb07b86 100644
> --- a/drivers/platform/x86/dell/alienware-wmi.c
> +++ b/drivers/platform/x86/dell/alienware-wmi.c
> @@ -378,7 +378,6 @@ struct color_platform {
>  
>  struct platform_zone {
>  	u8 location;
> -	struct device_attribute *attr;
>  	struct color_platform colors;
>  };
>  
> @@ -411,16 +410,10 @@ struct wmax_u32_args {
>  };
>  
>  static struct platform_device *platform_device;
> -static struct device_attribute *zone_dev_attrs;
> -static struct attribute **zone_attrs;
>  static struct platform_zone *zone_data;
>  static struct platform_profile_handler pp_handler;
>  static enum wmax_thermal_mode supported_thermal_profiles[PLATFORM_PROFILE_LAST];
>  
> -static struct attribute_group zone_attribute_group = {
> -	.name = "rgb_zones",
> -};
> -
>  static u8 interface;
>  static u8 lighting_control_state;
>  static u8 global_brightness;
> @@ -452,20 +445,6 @@ static int parse_rgb(const char *buf, struct color_platform *colors)
>  	return 0;
>  }
>  
> -static struct platform_zone *match_zone(struct device_attribute *attr)
> -{
> -	u8 zone;
> -
> -	for (zone = 0; zone < quirks->num_zones; zone++) {
> -		if ((struct device_attribute *)zone_data[zone].attr == attr) {
> -			pr_debug("alienware-wmi: matched zone location: %d\n",
> -				 zone_data[zone].location);
> -			return &zone_data[zone];
> -		}
> -	}
> -	return NULL;
> -}
> -
>  /*
>   * Individual RGB zone control
>   */
> @@ -510,12 +489,10 @@ static int alienware_update_led(struct platform_zone *zone)
>  }
>  
>  static ssize_t zone_show(struct device *dev, struct device_attribute *attr,
> -			 char *buf)
> +			 char *buf, u8 location)
>  {
>  	struct platform_zone *target_zone;
> -	target_zone = match_zone(attr);
> -	if (target_zone == NULL)
> -		return sprintf(buf, "red: -1, green: -1, blue: -1\n");
> +	target_zone = &zone_data[location];
>  	return sprintf(buf, "red: %d, green: %d, blue: %d\n",
>  		       target_zone->colors.red,
>  		       target_zone->colors.green, target_zone->colors.blue);
> @@ -523,15 +500,11 @@ static ssize_t zone_show(struct device *dev, struct device_attribute *attr,
>  }
>  
>  static ssize_t zone_set(struct device *dev, struct device_attribute *attr,
> -			const char *buf, size_t count)
> +			const char *buf, size_t count, u8 location)
>  {
>  	struct platform_zone *target_zone;
>  	int ret;
> -	target_zone = match_zone(attr);
> -	if (target_zone == NULL) {
> -		pr_err("alienware-wmi: invalid target zone\n");
> -		return 1;
> -	}
> +	target_zone = &zone_data[location];
>  	ret = parse_rgb(buf, &target_zone->colors);
>  	if (ret)
>  		return ret;
> @@ -539,6 +512,32 @@ static ssize_t zone_set(struct device *dev, struct device_attribute *attr,
>  	return ret ? ret : count;
>  }
>  
> +#define ALIENWARE_ZONE_SHOW_FUNC(_num)					\
> +	static ssize_t zone0##_num##_show(struct device *dev,		\
> +					struct device_attribute *attr,	\
> +					char *buf)			\
> +	{								\
> +		return zone_show(dev, attr, buf, _num);			\
> +	}
> +
> +#define ALIENWARE_ZONE_STORE_FUNC(_num)					\
> +	static ssize_t zone0##_num##_store(struct device *dev,		\
> +					struct device_attribute *attr,	\
> +					const char *buf, size_t count)	\
> +	{								\
> +		return zone_set(dev, attr, buf, count, _num);		\
> +	}
> +
> +#define ALIENWARE_ZONE_ATTR(_num)					\
> +	ALIENWARE_ZONE_SHOW_FUNC(_num)					\
> +	ALIENWARE_ZONE_STORE_FUNC(_num)					\
> +	static DEVICE_ATTR_RW(zone0##_num)
> +
> +ALIENWARE_ZONE_ATTR(0);
> +ALIENWARE_ZONE_ATTR(1);
> +ALIENWARE_ZONE_ATTR(2);
> +ALIENWARE_ZONE_ATTR(3);
> +
>  /*
>   * Lighting control state device attribute (Global)
>   */
> @@ -577,6 +576,33 @@ static ssize_t lighting_control_state_store(struct device *dev,
>  
>  static DEVICE_ATTR_RW(lighting_control_state);
>  
> +static umode_t zone_attr_visible(struct kobject *kobj,
> +				 struct attribute *attr, int n)
> +{
> +	return n < quirks->num_zones + 1 ? 0644 : 0;
> +}
> +
> +static bool zone_group_visible(struct kobject *kobj)
> +{
> +	return quirks->num_zones > 0;
> +}
> +DEFINE_SYSFS_GROUP_VISIBLE(zone);
> +
> +static struct attribute *zone_attrs[] = {
> +	&dev_attr_lighting_control_state.attr,
> +	&dev_attr_zone00.attr,
> +	&dev_attr_zone01.attr,
> +	&dev_attr_zone02.attr,
> +	&dev_attr_zone03.attr,
> +	NULL
> +};
> +
> +static struct attribute_group zone_attribute_group = {
> +	.name = "rgb_zones",
> +	.is_visible = SYSFS_GROUP_VISIBLE(zone),
> +	.attrs = zone_attrs,
> +};
> +
>  /*
>   * LED Brightness (Global)
>   */
> @@ -624,7 +650,6 @@ static struct led_classdev global_led = {
>  static int alienware_zone_init(struct platform_device *dev)
>  {
>  	u8 zone;
> -	char *name;
>  
>  	if (interface == WMAX) {
>  		lighting_control_state = WMAX_RUNNING;
> @@ -634,65 +659,22 @@ static int alienware_zone_init(struct platform_device *dev)
>  	global_led.max_brightness = 0x0F;
>  	global_brightness = global_led.max_brightness;
>  
> -	/*
> -	 *      - zone_dev_attrs num_zones + 1 is for individual zones and then
> -	 *        null terminated
> -	 *      - zone_attrs num_zones + 2 is for all attrs in zone_dev_attrs +
> -	 *        the lighting control + null terminated
> -	 *      - zone_data num_zones is for the distinct zones
> -	 */
> -	zone_dev_attrs =
> -	    kcalloc(quirks->num_zones + 1, sizeof(struct device_attribute),
> -		    GFP_KERNEL);
> -	if (!zone_dev_attrs)
> -		return -ENOMEM;
> -
> -	zone_attrs =
> -	    kcalloc(quirks->num_zones + 2, sizeof(struct attribute *),
> -		    GFP_KERNEL);
> -	if (!zone_attrs)
> -		return -ENOMEM;
> -
>  	zone_data =
>  	    kcalloc(quirks->num_zones, sizeof(struct platform_zone),
>  		    GFP_KERNEL);
>  	if (!zone_data)
>  		return -ENOMEM;
>  
> -	for (zone = 0; zone < quirks->num_zones; zone++) {
> -		name = kasprintf(GFP_KERNEL, "zone%02hhX", zone);
> -		if (name == NULL)
> -			return 1;
> -		sysfs_attr_init(&zone_dev_attrs[zone].attr);
> -		zone_dev_attrs[zone].attr.name = name;
> -		zone_dev_attrs[zone].attr.mode = 0644;
> -		zone_dev_attrs[zone].show = zone_show;
> -		zone_dev_attrs[zone].store = zone_set;
> +	for (zone = 0; zone < 4; zone++)

You allocate quirks->num_zones entries to zone_data above but use a 
literal here?

-- 
 i.


>  		zone_data[zone].location = zone;
> -		zone_attrs[zone] = &zone_dev_attrs[zone].attr;
> -		zone_data[zone].attr = &zone_dev_attrs[zone];
> -	}
> -	zone_attrs[quirks->num_zones] = &dev_attr_lighting_control_state.attr;
> -	zone_attribute_group.attrs = zone_attrs;
> -
> -	led_classdev_register(&dev->dev, &global_led);
>  
> -	return sysfs_create_group(&dev->dev.kobj, &zone_attribute_group);
> +	return led_classdev_register(&dev->dev, &global_led);
>  }
>  
>  static void alienware_zone_exit(struct platform_device *dev)
>  {
> -	u8 zone;
> -
> -	sysfs_remove_group(&dev->dev.kobj, &zone_attribute_group);
>  	led_classdev_unregister(&global_led);
> -	if (zone_dev_attrs) {
> -		for (zone = 0; zone < quirks->num_zones; zone++)
> -			kfree(zone_dev_attrs[zone].attr.name);
> -	}
> -	kfree(zone_dev_attrs);
>  	kfree(zone_data);
> -	kfree(zone_attrs);
>  }
>  
>  static acpi_status alienware_wmax_command(void *in_args, size_t in_size,
> @@ -1140,6 +1122,7 @@ static void remove_thermal_profile(void)
>   * Platform Driver
>   */
>  static const struct attribute_group *alienfx_groups[] = {
> +	&zone_attribute_group,
>  	&hdmi_attribute_group,
>  	&amplifier_attribute_group,
>  	&deepsleep_attribute_group,
>