> +In SUPPORTED hw_control_configure() should return 0 or 1 if the LED driver supports the
> +requested blink mode (flags) or not.
-EOPNOTSUPP might be clearer.
> +In ZERO hw_control_configure() should return 0 with success operation or error.
> +
> +The unsigned long flag is specific to the trigger and change across them. It's in the LED
> +driver interest know how to elaborate this flag and to declare support for a
> +particular trigger. For this exact reason explicit support for the specific
> +trigger is mandatory or the driver returns -EOPNOTSUPP if asked to enter offload mode
> +with a not supported trigger.
> +If the driver returns -EOPNOTSUPP on hw_control_configure(), the trigger activation will
> +fail as the driver doesn't support that specific offload trigger or doesn't know
> +how to handle the provided flags.
> +
> Known Issues
> ============
>
> diff --git a/include/linux/leds.h b/include/linux/leds.h
> index 09ff1dc6f48d..b5aad67fecfb 100644
> --- a/include/linux/leds.h
> +++ b/include/linux/leds.h
> @@ -73,6 +73,16 @@ enum led_blink_modes {
> SOFTWARE_HARDWARE_CONTROLLED,
> };
>
> +#ifdef CONFIG_LEDS_HARDWARE_CONTROL
> +enum blink_mode_cmd {
> + BLINK_MODE_ENABLE, /* Enable the hardware blink mode */
> + BLINK_MODE_DISABLE, /* Disable the hardware blink mode */
> + BLINK_MODE_READ, /* Read the status of the hardware blink mode */
> + BLINK_MODE_SUPPORTED, /* Ask the driver if the hardware blink mode is supported */
> + BLINK_MODE_ZERO, /* Disable any hardware blink active */
> +};
> +#endif
Skip the #ifdef. The enum itself takes no space if never used, and it
makes the driver simpler if they always exist.
> +
> struct led_classdev {
> const char *name;
> unsigned int brightness;
> @@ -185,6 +195,17 @@ struct led_classdev {
> * the old status but that is not mandatory and also putting it off is accepted.
> */
> int (*hw_control_stop)(struct led_classdev *led_cdev);
> + /* This will be used to configure the various blink modes LED support in hardware
> + * mode.
> + * The LED driver require to support the active trigger and will elaborate the
> + * unsigned long flag and do the operation based on the provided cmd.
> + * Current operation are enable,disable,supported and status.
> + * A trigger will use this to enable or disable the asked blink mode, check the
> + * status of the blink mode or ask if the blink mode can run in hardware mode.
> + */
> + int (*hw_control_configure)(struct led_classdev *led_cdev,
> + unsigned long flag,
> + enum blink_mode_cmd cmd);
> #endif
> #endif
>
> @@ -454,6 +475,24 @@ static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
> return led_cdev->trigger_data;
> }
>
> +#ifdef CONFIG_LEDS_HARDWARE_CONTROL
> +static inline bool led_trigger_blink_mode_is_supported(struct led_classdev *led_cdev,
> + unsigned long flag)
> +{
> + int ret;
> +
> + /* Sanity check: make sure led support hw mode */
> + if (led_cdev->blink_mode == SOFTWARE_CONTROLLED)
> + return false;
> +
> + ret = led_cdev->hw_control_configure(led_cdev, flag, BLINK_MODE_SUPPORTED);
> + if (ret > 0)
> + return true;
> +
> + return false;
> +}
> +#endif
Please add a version which returns false when
CONFIG_LEDS_HARDWARE_CONTROL is disabled.
Does this actually need to be an inline function?
Andrew
