Improve the documentation for backlight_ops and adapt it to kernel-doc style.
v2: - Add intro for each field (Daniel)
Signed-off-by: Sam Ravnborg sam@ravnborg.org Reviewed-by: Daniel Thompson daniel.thompson@linaro.org Cc: Lee Jones lee.jones@linaro.org Cc: Daniel Thompson daniel.thompson@linaro.org Cc: Jingoo Han jingoohan1@gmail.com --- include/linux/backlight.h | 59 +++++++++++++++++++++++++++++++++++---- 1 file changed, 53 insertions(+), 6 deletions(-)
diff --git a/include/linux/backlight.h b/include/linux/backlight.h index a0a083b35c47..b6c1ab6c922a 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -55,19 +55,66 @@ enum backlight_scale { struct backlight_device; struct fb_info;
+/** + * struct backlight_ops - backlight operations + * + * The backlight operations are specifed when the backlight device is registered. + */ struct backlight_ops { + /** + * @options: Configure how operations are called from the core. + * + * The options parameter is used to adjust the behaviour of the core. + * Set BL_CORE_SUSPENDRESUME to get the update_status() operation called + * upon suspend and resume. + */ unsigned int options;
#define BL_CORE_SUSPENDRESUME (1 << 0)
- /* Notify the backlight driver some property has changed */ + /** + * @update_status: Operation called when properties have changed. + * + * Notify the backlight driver some property has changed. + * The update_status operation is protected by the update_lock. + * + * The backlight driver is expected to use backlight_is_blank() + * to check if the display is blanked and set brightness accordingly. + * update_status() is called when any of the properties has changed. + * + * RETURNS: + * + * 0 on sucees, negative error code if any failure occured. + */ int (*update_status)(struct backlight_device *); - /* Return the current backlight brightness (accounting for power, - fb_blank etc.) */ + + /** + * @get_brightness: Return the current backlight brightness. + * + * The driver may implement this as a readback from the HW. + * This operation is optional and if not present then the current + * brightness property value is used. + * + * RETURNS: + * + * A brightness value which is 0 or a positive numer. + * On failure a negative error code is returned. + */ int (*get_brightness)(struct backlight_device *); - /* Check if given framebuffer device is the one bound to this backlight; - return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */ - int (*check_fb)(struct backlight_device *, struct fb_info *); + + /** + * @check_fb: Check the framebuffer device. + * + * Check if given framebuffer device is the one bound to this backlight. + * This operation is optional and if not implemented it is assumed that the + * fbdev is always the one bound to the backlight. + * + * RETURNS: + * + * If info is NULL or the info matches the fbdev bound to the backlight return true. + * If info does not match the fbdev bound to the backlight return false. + */ + int (*check_fb)(struct backlight_device *bd, struct fb_info *info); };
/* This structure defines all the properties of a backlight */