Most of this is newly added kerneldoc for the hotplug and output polling code. But I've also thrown in a bit lesser polish, most of it is tuning down the shouting RETURN: headers.
Overview documentation for the output probing and mode setting support code will be added in later patches.
Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_crtc_helper.c | 125 +++++++++++++++++++++++++++++++++----- 1 file changed, 111 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index 0f60150adfc3..a85517854073 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -114,8 +114,8 @@ static void drm_mode_validate_flag(struct drm_connector *connector, * @connector vfunc for drivers that use the crtc helpers for output mode * filtering and detection. * - * RETURNS: - * Number of modes found on @connector. + * Returns: + * The number of modes found on @connector. */ int drm_helper_probe_single_connector_modes(struct drm_connector *connector, uint32_t maxX, uint32_t maxY) @@ -217,10 +217,12 @@ EXPORT_SYMBOL(drm_helper_probe_single_connector_modes); * drm_helper_encoder_in_use - check if a given encoder is in use * @encoder: encoder to check * - * Walk @encoders's DRM device's mode_config and see if it's in use. + * Checks whether @encoder is with the current mode setting output configuration + * in use by any connector. This doesn't mean that it is actually enabled since + * the DPMS state is tracked separately. * - * RETURNS: - * True if @encoder is part of the mode_config, false otherwise. + * Returns: + * True if @encoder is used, false otherwise. */ bool drm_helper_encoder_in_use(struct drm_encoder *encoder) { @@ -239,10 +241,12 @@ EXPORT_SYMBOL(drm_helper_encoder_in_use); * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config * @crtc: CRTC to check * - * Walk @crtc's DRM device's mode_config and see if it's in use. + * Checks whether @crtc is with the current mode setting output configuration + * in use by any connector. This doesn't mean that it is actually enabled since + * the DPMS state is tracked separately. * - * RETURNS: - * True if @crtc is part of the mode_config, false otherwise. + * Returns: + * True if @crtc is used, false otherwise. */ bool drm_helper_crtc_in_use(struct drm_crtc *crtc) { @@ -278,8 +282,11 @@ drm_encoder_disable(struct drm_encoder *encoder) * drm_helper_disable_unused_functions - disable unused objects * @dev: DRM device * - * If an connector or CRTC isn't part of @dev's mode_config, it can be disabled - * by calling its dpms function, which should power it off. + * This function walks through the entire mode setting configuration of @dev. It + * will remove any crtc links of unused encoders and encoder links of + * disconnected connectors. Then it will disable all unused encoders and crtcs + * either by calling their disable callback if available or by calling their + * dpms callback with DRM_MODE_DPMS_OFF. */ void drm_helper_disable_unused_functions(struct drm_device *dev) { @@ -358,8 +365,8 @@ drm_crtc_prepare_encoders(struct drm_device *dev) * drm_crtc_helper_set_config() helper function to drive the mode setting * sequence. * - * RETURNS: - * True if the mode was set successfully, or false otherwise. + * Returns: + * True if the mode was set successfully, false otherwise. */ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc, struct drm_display_mode *mode, @@ -559,8 +566,8 @@ drm_crtc_helper_disable(struct drm_crtc *crtc) * kernel mode setting with the crtc helper functions and the assorted * ->prepare(), ->modeset() and ->commit() helper callbacks. * - * RETURNS: - * Returns 0 on success, -ERRNO on failure. + * Returns: + * Returns 0 on success, negative errno numbers on failure. */ int drm_crtc_helper_set_config(struct drm_mode_set *set) { @@ -916,6 +923,14 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode) } EXPORT_SYMBOL(drm_helper_connector_dpms);
+/** + * drm_helper_mode_fill_fb_struct - fill out framebuffer metadata + * @fb: drm_framebuffer object to fill out + * @mode_cmd: metadata from the userspace fb creation request + * + * This helper can be used in a drivers fb_create callback to pre-fill the fb's + * metadata fields. + */ void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb, struct drm_mode_fb_cmd2 *mode_cmd) { @@ -998,6 +1013,22 @@ void drm_helper_resume_force_mode(struct drm_device *dev) } EXPORT_SYMBOL(drm_helper_resume_force_mode);
+/** + * drm_kms_helper_hotplug_event - fire off KMS hotplug events + * @dev: drm_device whose connector state changed + * + * This function fires off the uevent for userspace and also calls the + * output_poll_changed function, which is most commonly used to inform the fbdev + * emulation code and allow it to update the fbcon output configuration. + * + * Drivers should call this from their hotplug handling code when a change is + * detected. Note that this function does not do any output detection of its + * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the + * driver already. + * + * This function must be called from process context with no mode + * setting locks held. + */ void drm_kms_helper_hotplug_event(struct drm_device *dev) { /* send a uevent + call fbdev */ @@ -1066,6 +1097,16 @@ static void output_poll_execute(struct work_struct *work) schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD); }
+/** + * drm_kms_helper_poll_disable - disable output polling + * @dev: drm_device + * + * This function disables the output polling work. + * + * Drivers can call this helper from their device suspend implementation. It is + * not an error to call this even when output polling isn't enabled or arlready + * disabled. + */ void drm_kms_helper_poll_disable(struct drm_device *dev) { if (!dev->mode_config.poll_enabled) @@ -1074,6 +1115,16 @@ void drm_kms_helper_poll_disable(struct drm_device *dev) } EXPORT_SYMBOL(drm_kms_helper_poll_disable);
+/** + * drm_kms_helper_poll_enable - re-enable output polling. + * @dev: drm_device + * + * This function re-enables the output polling work. + * + * Drivers can call this helper from their device resume implementation. It is + * an error to call this when the output polling support has not yet been set + * up. + */ void drm_kms_helper_poll_enable(struct drm_device *dev) { bool poll = false; @@ -1093,6 +1144,25 @@ void drm_kms_helper_poll_enable(struct drm_device *dev) } EXPORT_SYMBOL(drm_kms_helper_poll_enable);
+/** + * drm_kms_helper_poll_init - initialize and enable output polling + * @dev: drm_device + * + * This function intializes and then also enables output polling support for + * @dev. Drivers which do not have reliable hotplug support in hardware can use + * this helper infrastructure to regularly poll such connectors for changes in + * their connection state. + * + * Drivers can control which connectors are polled by setting the + * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On + * connectors where probing live outputs can result in visual distortion drivers + * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this. + * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are + * completely ignored by the polling logic. + * + * Note that a connector can be both polled and probed from the hotplug handler, + * in case the hotplug interrupt is known to be unreliable. + */ void drm_kms_helper_poll_init(struct drm_device *dev) { INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute); @@ -1102,12 +1172,39 @@ void drm_kms_helper_poll_init(struct drm_device *dev) } EXPORT_SYMBOL(drm_kms_helper_poll_init);
+/** + * drm_kms_helper_poll_fini - disable output polling and clean it up + * @dev: drm_device + */ void drm_kms_helper_poll_fini(struct drm_device *dev) { drm_kms_helper_poll_disable(dev); } EXPORT_SYMBOL(drm_kms_helper_poll_fini);
+/** + * drm_helper_hpd_irq_event - hotplug processing + * @dev: drm_device + * + * Drivers can use this helper function to run a detect cycle on all connectors + * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All + * other connectors are ignored, which is useful to avoid reprobing fixed + * panels. + * + * This helper function is useful for drivers which can't or don't track hotplug + * interrupts for each connector. + * + * Drivers which support hotplug interrupts for each connector individually and + * which have a more fine-grained detect logic should bypass this code and + * directly call drm_kms_helper_hotplug_event() in case the connector state + * changed. + * + * This function must be called from process context with no mode + * setting locks held. + * + * Note that a connector can be both polled and probed from the hotplug handler, + * in case the hotplug interrupt is known to be unreliable. + */ bool drm_helper_hpd_irq_event(struct drm_device *dev) { struct drm_connector *connector;