| /* |
| * Copyright (c) 2006-2008 Intel Corporation |
| * Copyright (c) 2007 Dave Airlie <airlied@linux.ie> |
| * |
| * DRM core CRTC related functions |
| * |
| * Permission to use, copy, modify, distribute, and sell this software and its |
| * documentation for any purpose is hereby granted without fee, provided that |
| * the above copyright notice appear in all copies and that both that copyright |
| * notice and this permission notice appear in supporting documentation, and |
| * that the name of the copyright holders not be used in advertising or |
| * publicity pertaining to distribution of the software without specific, |
| * written prior permission. The copyright holders make no representations |
| * about the suitability of this software for any purpose. It is provided "as |
| * is" without express or implied warranty. |
| * |
| * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, |
| * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO |
| * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR |
| * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, |
| * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER |
| * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE |
| * OF THIS SOFTWARE. |
| * |
| * Authors: |
| * Keith Packard |
| * Eric Anholt <eric@anholt.net> |
| * Dave Airlie <airlied@linux.ie> |
| * Jesse Barnes <jesse.barnes@intel.com> |
| */ |
| |
| #include <linux/export.h> |
| #include <linux/moduleparam.h> |
| |
| #include <drm/drm_bridge.h> |
| #include <drm/drm_client.h> |
| #include <drm/drm_crtc.h> |
| #include <drm/drm_edid.h> |
| #include <drm/drm_fourcc.h> |
| #include <drm/drm_managed.h> |
| #include <drm/drm_modeset_helper_vtables.h> |
| #include <drm/drm_print.h> |
| #include <drm/drm_probe_helper.h> |
| #include <drm/drm_sysfs.h> |
| |
| #include "drm_crtc_helper_internal.h" |
| |
| /** |
| * DOC: output probing helper overview |
| * |
| * This library provides some helper code for output probing. It provides an |
| * implementation of the core &drm_connector_funcs.fill_modes interface with |
| * drm_helper_probe_single_connector_modes(). |
| * |
| * It also provides support for polling connectors with a work item and for |
| * generic hotplug interrupt handling where the driver doesn't or cannot keep |
| * track of a per-connector hpd interrupt. |
| * |
| * This helper library can be used independently of the modeset helper library. |
| * Drivers can also overwrite different parts e.g. use their own hotplug |
| * handling code to avoid probing unrelated outputs. |
| * |
| * The probe helpers share the function table structures with other display |
| * helper libraries. See &struct drm_connector_helper_funcs for the details. |
| */ |
| |
| static bool drm_kms_helper_poll = true; |
| module_param_named(poll, drm_kms_helper_poll, bool, 0600); |
| |
| static enum drm_mode_status |
| drm_mode_validate_flag(const struct drm_display_mode *mode, |
| int flags) |
| { |
| if ((mode->flags & DRM_MODE_FLAG_INTERLACE) && |
| !(flags & DRM_MODE_FLAG_INTERLACE)) |
| return MODE_NO_INTERLACE; |
| |
| if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) && |
| !(flags & DRM_MODE_FLAG_DBLSCAN)) |
| return MODE_NO_DBLESCAN; |
| |
| if ((mode->flags & DRM_MODE_FLAG_3D_MASK) && |
| !(flags & DRM_MODE_FLAG_3D_MASK)) |
| return MODE_NO_STEREO; |
| |
| return MODE_OK; |
| } |
| |
| static int |
| drm_mode_validate_pipeline(struct drm_display_mode *mode, |
| struct drm_connector *connector, |
| struct drm_modeset_acquire_ctx *ctx, |
| enum drm_mode_status *status) |
| { |
| struct drm_device *dev = connector->dev; |
| struct drm_encoder *encoder; |
| int ret; |
| |
| /* Step 1: Validate against connector */ |
| ret = drm_connector_mode_valid(connector, mode, ctx, status); |
| if (ret || *status != MODE_OK) |
| return ret; |
| |
| /* Step 2: Validate against encoders and crtcs */ |
| drm_connector_for_each_possible_encoder(connector, encoder) { |
| struct drm_bridge *bridge; |
| struct drm_crtc *crtc; |
| |
| *status = drm_encoder_mode_valid(encoder, mode); |
| if (*status != MODE_OK) { |
| /* No point in continuing for crtc check as this encoder |
| * will not accept the mode anyway. If all encoders |
| * reject the mode then, at exit, ret will not be |
| * MODE_OK. */ |
| continue; |
| } |
| |
| bridge = drm_bridge_chain_get_first_bridge(encoder); |
| *status = drm_bridge_chain_mode_valid(bridge, |
| &connector->display_info, |
| mode); |
| if (*status != MODE_OK) { |
| /* There is also no point in continuing for crtc check |
| * here. */ |
| continue; |
| } |
| |
| drm_for_each_crtc(crtc, dev) { |
| if (!drm_encoder_crtc_ok(encoder, crtc)) |
| continue; |
| |
| *status = drm_crtc_mode_valid(crtc, mode); |
| if (*status == MODE_OK) { |
| /* If we get to this point there is at least |
| * one combination of encoder+crtc that works |
| * for this mode. Lets return now. */ |
| return 0; |
| } |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector) |
| { |
| struct drm_cmdline_mode *cmdline_mode; |
| struct drm_display_mode *mode; |
| |
| cmdline_mode = &connector->cmdline_mode; |
| if (!cmdline_mode->specified) |
| return 0; |
| |
| /* Only add a GTF mode if we find no matching probed modes */ |
| list_for_each_entry(mode, &connector->probed_modes, head) { |
| if (mode->hdisplay != cmdline_mode->xres || |
| mode->vdisplay != cmdline_mode->yres) |
| continue; |
| |
| if (cmdline_mode->refresh_specified) { |
| /* The probed mode's vrefresh is set until later */ |
| if (drm_mode_vrefresh(mode) != cmdline_mode->refresh) |
| continue; |
| } |
| |
| /* Mark the matching mode as being preferred by the user */ |
| mode->type |= DRM_MODE_TYPE_USERDEF; |
| return 0; |
| } |
| |
| mode = drm_mode_create_from_cmdline_mode(connector->dev, |
| cmdline_mode); |
| if (mode == NULL) |
| return 0; |
| |
| drm_mode_probed_add(connector, mode); |
| return 1; |
| } |
| |
| enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc, |
| const struct drm_display_mode *mode) |
| { |
| const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private; |
| |
| if (!crtc_funcs || !crtc_funcs->mode_valid) |
| return MODE_OK; |
| |
| return crtc_funcs->mode_valid(crtc, mode); |
| } |
| |
| enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder, |
| const struct drm_display_mode *mode) |
| { |
| const struct drm_encoder_helper_funcs *encoder_funcs = |
| encoder->helper_private; |
| |
| if (!encoder_funcs || !encoder_funcs->mode_valid) |
| return MODE_OK; |
| |
| return encoder_funcs->mode_valid(encoder, mode); |
| } |
| |
| int |
| drm_connector_mode_valid(struct drm_connector *connector, |
| struct drm_display_mode *mode, |
| struct drm_modeset_acquire_ctx *ctx, |
| enum drm_mode_status *status) |
| { |
| const struct drm_connector_helper_funcs *connector_funcs = |
| connector->helper_private; |
| int ret = 0; |
| |
| if (!connector_funcs) |
| *status = MODE_OK; |
| else if (connector_funcs->mode_valid_ctx) |
| ret = connector_funcs->mode_valid_ctx(connector, mode, ctx, |
| status); |
| else if (connector_funcs->mode_valid) |
| *status = connector_funcs->mode_valid(connector, mode); |
| else |
| *status = MODE_OK; |
| |
| return ret; |
| } |
| |
| static void drm_kms_helper_disable_hpd(struct drm_device *dev) |
| { |
| struct drm_connector *connector; |
| struct drm_connector_list_iter conn_iter; |
| |
| drm_connector_list_iter_begin(dev, &conn_iter); |
| drm_for_each_connector_iter(connector, &conn_iter) { |
| const struct drm_connector_helper_funcs *funcs = |
| connector->helper_private; |
| |
| if (funcs && funcs->disable_hpd) |
| funcs->disable_hpd(connector); |
| } |
| drm_connector_list_iter_end(&conn_iter); |
| } |
| |
| static bool drm_kms_helper_enable_hpd(struct drm_device *dev) |
| { |
| bool poll = false; |
| struct drm_connector *connector; |
| struct drm_connector_list_iter conn_iter; |
| |
| drm_connector_list_iter_begin(dev, &conn_iter); |
| drm_for_each_connector_iter(connector, &conn_iter) { |
| const struct drm_connector_helper_funcs *funcs = |
| connector->helper_private; |
| |
| if (funcs && funcs->enable_hpd) |
| funcs->enable_hpd(connector); |
| |
| if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | |
| DRM_CONNECTOR_POLL_DISCONNECT)) |
| poll = true; |
| } |
| drm_connector_list_iter_end(&conn_iter); |
| |
| return poll; |
| } |
| |
| #define DRM_OUTPUT_POLL_PERIOD (10*HZ) |
| static void reschedule_output_poll_work(struct drm_device *dev) |
| { |
| unsigned long delay = DRM_OUTPUT_POLL_PERIOD; |
| |
| if (dev->mode_config.delayed_event) |
| /* |
| * FIXME: |
| * |
| * Use short (1s) delay to handle the initial delayed event. |
| * This delay should not be needed, but Optimus/nouveau will |
| * fail in a mysterious way if the delayed event is handled as |
| * soon as possible like it is done in |
| * drm_helper_probe_single_connector_modes() in case the poll |
| * was enabled before. |
| */ |
| delay = HZ; |
| |
| schedule_delayed_work(&dev->mode_config.output_poll_work, delay); |
| } |
| |
| /** |
| * drm_kms_helper_poll_enable - re-enable output polling. |
| * @dev: drm_device |
| * |
| * This function re-enables the output polling work, after it has been |
| * temporarily disabled using drm_kms_helper_poll_disable(), for example over |
| * suspend/resume. |
| * |
| * Drivers can call this helper from their device resume implementation. It is |
| * not an error to call this even when output polling isn't enabled. |
| * |
| * If device polling was never initialized before, this call will trigger a |
| * warning and return. |
| * |
| * Note that calls to enable and disable polling must be strictly ordered, which |
| * is automatically the case when they're only call from suspend/resume |
| * callbacks. |
| */ |
| void drm_kms_helper_poll_enable(struct drm_device *dev) |
| { |
| if (drm_WARN_ON_ONCE(dev, !dev->mode_config.poll_enabled) || |
| !drm_kms_helper_poll || dev->mode_config.poll_running) |
| return; |
| |
| if (drm_kms_helper_enable_hpd(dev) || |
| dev->mode_config.delayed_event) |
| reschedule_output_poll_work(dev); |
| |
| dev->mode_config.poll_running = true; |
| } |
| EXPORT_SYMBOL(drm_kms_helper_poll_enable); |
| |
| /** |
| * drm_kms_helper_poll_reschedule - reschedule the output polling work |
| * @dev: drm_device |
| * |
| * This function reschedules the output polling work, after polling for a |
| * connector has been enabled. |
| * |
| * Drivers must call this helper after enabling polling for a connector by |
| * setting %DRM_CONNECTOR_POLL_CONNECT / %DRM_CONNECTOR_POLL_DISCONNECT flags |
| * in drm_connector::polled. Note that after disabling polling by clearing these |
| * flags for a connector will stop the output polling work automatically if |
| * the polling is disabled for all other connectors as well. |
| * |
| * The function can be called only after polling has been enabled by calling |
| * drm_kms_helper_poll_init() / drm_kms_helper_poll_enable(). |
| */ |
| void drm_kms_helper_poll_reschedule(struct drm_device *dev) |
| { |
| if (dev->mode_config.poll_running) |
| reschedule_output_poll_work(dev); |
| } |
| EXPORT_SYMBOL(drm_kms_helper_poll_reschedule); |
| |
| static enum drm_connector_status |
| drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force) |
| { |
| const struct drm_connector_helper_funcs *funcs = connector->helper_private; |
| struct drm_modeset_acquire_ctx ctx; |
| int ret; |
| |
| drm_modeset_acquire_init(&ctx, 0); |
| |
| retry: |
| ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx); |
| if (!ret) { |
| if (funcs->detect_ctx) |
| ret = funcs->detect_ctx(connector, &ctx, force); |
| else if (connector->funcs->detect) |
| ret = connector->funcs->detect(connector, force); |
| else |
| ret = connector_status_connected; |
| } |
| |
| if (ret == -EDEADLK) { |
| drm_modeset_backoff(&ctx); |
| goto retry; |
| } |
| |
| if (WARN_ON(ret < 0)) |
| ret = connector_status_unknown; |
| |
| if (ret != connector->status) |
| connector->epoch_counter += 1; |
| |
| drm_modeset_drop_locks(&ctx); |
| drm_modeset_acquire_fini(&ctx); |
| |
| return ret; |
| } |
| |
| /** |
| * drm_helper_probe_detect - probe connector status |
| * @connector: connector to probe |
| * @ctx: acquire_ctx, or NULL to let this function handle locking. |
| * @force: Whether destructive probe operations should be performed. |
| * |
| * This function calls the detect callbacks of the connector. |
| * This function returns &drm_connector_status, or |
| * if @ctx is set, it might also return -EDEADLK. |
| */ |
| int |
| drm_helper_probe_detect(struct drm_connector *connector, |
| struct drm_modeset_acquire_ctx *ctx, |
| bool force) |
| { |
| const struct drm_connector_helper_funcs *funcs = connector->helper_private; |
| struct drm_device *dev = connector->dev; |
| int ret; |
| |
| if (!ctx) |
| return drm_helper_probe_detect_ctx(connector, force); |
| |
| ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx); |
| if (ret) |
| return ret; |
| |
| if (funcs->detect_ctx) |
| ret = funcs->detect_ctx(connector, ctx, force); |
| else if (connector->funcs->detect) |
| ret = connector->funcs->detect(connector, force); |
| else |
| ret = connector_status_connected; |
| |
| if (ret != connector->status) |
| connector->epoch_counter += 1; |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(drm_helper_probe_detect); |
| |
| static int drm_helper_probe_get_modes(struct drm_connector *connector) |
| { |
| const struct drm_connector_helper_funcs *connector_funcs = |
| connector->helper_private; |
| int count; |
| |
| count = connector_funcs->get_modes(connector); |
| |
| /* The .get_modes() callback should not return negative values. */ |
| if (count < 0) { |
| drm_err(connector->dev, ".get_modes() returned %pe\n", |
| ERR_PTR(count)); |
| count = 0; |
| } |
| |
| /* |
| * Fallback for when DDC probe failed in drm_get_edid() and thus skipped |
| * override/firmware EDID. |
| */ |
| if (count == 0 && connector->status == connector_status_connected) |
| count = drm_edid_override_connector_update(connector); |
| |
| return count; |
| } |
| |
| static int __drm_helper_update_and_validate(struct drm_connector *connector, |
| uint32_t maxX, uint32_t maxY, |
| struct drm_modeset_acquire_ctx *ctx) |
| { |
| struct drm_device *dev = connector->dev; |
| struct drm_display_mode *mode; |
| int mode_flags = 0; |
| int ret; |
| |
| drm_connector_list_update(connector); |
| |
| if (connector->interlace_allowed) |
| mode_flags |= DRM_MODE_FLAG_INTERLACE; |
| if (connector->doublescan_allowed) |
| mode_flags |= DRM_MODE_FLAG_DBLSCAN; |
| if (connector->stereo_allowed) |
| mode_flags |= DRM_MODE_FLAG_3D_MASK; |
| |
| list_for_each_entry(mode, &connector->modes, head) { |
| if (mode->status != MODE_OK) |
| continue; |
| |
| mode->status = drm_mode_validate_driver(dev, mode); |
| if (mode->status != MODE_OK) |
| continue; |
| |
| mode->status = drm_mode_validate_size(mode, maxX, maxY); |
| if (mode->status != MODE_OK) |
| continue; |
| |
| mode->status = drm_mode_validate_flag(mode, mode_flags); |
| if (mode->status != MODE_OK) |
| continue; |
| |
| mode->status = drm_mode_validate_ycbcr420(mode, connector); |
| if (mode->status != MODE_OK) |
| continue; |
| |
| ret = drm_mode_validate_pipeline(mode, connector, ctx, |
| &mode->status); |
| if (ret) { |
| drm_dbg_kms(dev, |
| "drm_mode_validate_pipeline failed: %d\n", |
| ret); |
| |
| if (drm_WARN_ON_ONCE(dev, ret != -EDEADLK)) |
| mode->status = MODE_ERROR; |
| else |
| return -EDEADLK; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * drm_helper_probe_single_connector_modes - get complete set of display modes |
| * @connector: connector to probe |
| * @maxX: max width for modes |
| * @maxY: max height for modes |
| * |
| * Based on the helper callbacks implemented by @connector in struct |
| * &drm_connector_helper_funcs try to detect all valid modes. Modes will first |
| * be added to the connector's probed_modes list, then culled (based on validity |
| * and the @maxX, @maxY parameters) and put into the normal modes list. |
| * |
| * Intended to be used as a generic implementation of the |
| * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers |
| * for output mode filtering and detection. |
| * |
| * The basic procedure is as follows |
| * |
| * 1. All modes currently on the connector's modes list are marked as stale |
| * |
| * 2. New modes are added to the connector's probed_modes list with |
| * drm_mode_probed_add(). New modes start their life with status as OK. |
| * Modes are added from a single source using the following priority order. |
| * |
| * - &drm_connector_helper_funcs.get_modes vfunc |
| * - if the connector status is connector_status_connected, standard |
| * VESA DMT modes up to 1024x768 are automatically added |
| * (drm_add_modes_noedid()) |
| * |
| * Finally modes specified via the kernel command line (video=...) are |
| * added in addition to what the earlier probes produced |
| * (drm_helper_probe_add_cmdline_mode()). These modes are generated |
| * using the VESA GTF/CVT formulas. |
| * |
| * 3. Modes are moved from the probed_modes list to the modes list. Potential |
| * duplicates are merged together (see drm_connector_list_update()). |
| * After this step the probed_modes list will be empty again. |
| * |
| * 4. Any non-stale mode on the modes list then undergoes validation |
| * |
| * - drm_mode_validate_basic() performs basic sanity checks |
| * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY |
| * (if specified) |
| * - drm_mode_validate_flag() checks the modes against basic connector |
| * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed) |
| * - the optional &drm_connector_helper_funcs.mode_valid or |
| * &drm_connector_helper_funcs.mode_valid_ctx helpers can perform driver |
| * and/or sink specific checks |
| * - the optional &drm_crtc_helper_funcs.mode_valid, |
| * &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid |
| * helpers can perform driver and/or source specific checks which are also |
| * enforced by the modeset/atomic helpers |
| * |
| * 5. Any mode whose status is not OK is pruned from the connector's modes list, |
| * accompanied by a debug message indicating the reason for the mode's |
| * rejection (see drm_mode_prune_invalid()). |
| * |
| * 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) |
| { |
| struct drm_device *dev = connector->dev; |
| struct drm_display_mode *mode; |
| int count = 0, ret; |
| enum drm_connector_status old_status; |
| struct drm_modeset_acquire_ctx ctx; |
| |
| WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); |
| |
| drm_modeset_acquire_init(&ctx, 0); |
| |
| drm_dbg_kms(dev, "[CONNECTOR:%d:%s]\n", connector->base.id, |
| connector->name); |
| |
| retry: |
| ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx); |
| if (ret == -EDEADLK) { |
| drm_modeset_backoff(&ctx); |
| goto retry; |
| } else |
| WARN_ON(ret < 0); |
| |
| /* set all old modes to the stale state */ |
| list_for_each_entry(mode, &connector->modes, head) |
| mode->status = MODE_STALE; |
| |
| old_status = connector->status; |
| |
| if (connector->force) { |
| if (connector->force == DRM_FORCE_ON || |
| connector->force == DRM_FORCE_ON_DIGITAL) |
| connector->status = connector_status_connected; |
| else |
| connector->status = connector_status_disconnected; |
| if (connector->funcs->force) |
| connector->funcs->force(connector); |
| } else { |
| ret = drm_helper_probe_detect(connector, &ctx, true); |
| |
| if (ret == -EDEADLK) { |
| drm_modeset_backoff(&ctx); |
| goto retry; |
| } else if (WARN(ret < 0, "Invalid return value %i for connector detection\n", ret)) |
| ret = connector_status_unknown; |
| |
| connector->status = ret; |
| } |
| |
| /* |
| * Normally either the driver's hpd code or the poll loop should |
| * pick up any changes and fire the hotplug event. But if |
| * userspace sneaks in a probe, we might miss a change. Hence |
| * check here, and if anything changed start the hotplug code. |
| */ |
| if (old_status != connector->status) { |
| drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n", |
| connector->base.id, connector->name, |
| drm_get_connector_status_name(old_status), |
| drm_get_connector_status_name(connector->status)); |
| |
| /* |
| * The hotplug event code might call into the fb |
| * helpers, and so expects that we do not hold any |
| * locks. Fire up the poll struct instead, it will |
| * disable itself again. |
| */ |
| dev->mode_config.delayed_event = true; |
| if (dev->mode_config.poll_enabled) |
| mod_delayed_work(system_wq, |
| &dev->mode_config.output_poll_work, |
| 0); |
| } |
| |
| /* |
| * Re-enable polling in case the global poll config changed but polling |
| * is still initialized. |
| */ |
| if (dev->mode_config.poll_enabled) |
| drm_kms_helper_poll_enable(dev); |
| |
| if (connector->status == connector_status_disconnected) { |
| drm_dbg_kms(dev, "[CONNECTOR:%d:%s] disconnected\n", |
| connector->base.id, connector->name); |
| drm_connector_update_edid_property(connector, NULL); |
| drm_mode_prune_invalid(dev, &connector->modes, false); |
| goto exit; |
| } |
| |
| count = drm_helper_probe_get_modes(connector); |
| |
| if (count == 0 && (connector->status == connector_status_connected || |
| connector->status == connector_status_unknown)) { |
| count = drm_add_modes_noedid(connector, 1024, 768); |
| |
| /* |
| * Section 4.2.2.6 (EDID Corruption Detection) of the DP 1.4a |
| * Link CTS specifies that 640x480 (the official "failsafe" |
| * mode) needs to be the default if there's no EDID. |
| */ |
| if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) |
| drm_set_preferred_mode(connector, 640, 480); |
| } |
| count += drm_helper_probe_add_cmdline_mode(connector); |
| if (count != 0) { |
| ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx); |
| if (ret == -EDEADLK) { |
| drm_modeset_backoff(&ctx); |
| goto retry; |
| } |
| } |
| |
| drm_mode_prune_invalid(dev, &connector->modes, true); |
| |
| /* |
| * Displayport spec section 5.2.1.2 ("Video Timing Format") says that |
| * all detachable sinks shall support 640x480 @60Hz as a fail safe |
| * mode. If all modes were pruned, perhaps because they need more |
| * lanes or a higher pixel clock than available, at least try to add |
| * in 640x480. |
| */ |
| if (list_empty(&connector->modes) && |
| connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) { |
| count = drm_add_modes_noedid(connector, 640, 480); |
| ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx); |
| if (ret == -EDEADLK) { |
| drm_modeset_backoff(&ctx); |
| goto retry; |
| } |
| drm_mode_prune_invalid(dev, &connector->modes, true); |
| } |
| |
| exit: |
| drm_modeset_drop_locks(&ctx); |
| drm_modeset_acquire_fini(&ctx); |
| |
| if (list_empty(&connector->modes)) |
| return 0; |
| |
| drm_mode_sort(&connector->modes); |
| |
| drm_dbg_kms(dev, "[CONNECTOR:%d:%s] probed modes:\n", |
| connector->base.id, connector->name); |
| |
| list_for_each_entry(mode, &connector->modes, head) { |
| drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V); |
| drm_dbg_kms(dev, "Probed mode: " DRM_MODE_FMT "\n", |
| DRM_MODE_ARG(mode)); |
| } |
| |
| return count; |
| } |
| EXPORT_SYMBOL(drm_helper_probe_single_connector_modes); |
| |
| /** |
| * 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. |
| * |
| * If only a single connector has changed, consider calling |
| * drm_kms_helper_connector_hotplug_event() instead. |
| */ |
| void drm_kms_helper_hotplug_event(struct drm_device *dev) |
| { |
| /* send a uevent + call fbdev */ |
| drm_sysfs_hotplug_event(dev); |
| if (dev->mode_config.funcs->output_poll_changed) |
| dev->mode_config.funcs->output_poll_changed(dev); |
| |
| drm_client_dev_hotplug(dev); |
| } |
| EXPORT_SYMBOL(drm_kms_helper_hotplug_event); |
| |
| /** |
| * drm_kms_helper_connector_hotplug_event - fire off a KMS connector hotplug event |
| * @connector: drm_connector which has changed |
| * |
| * This is the same as drm_kms_helper_hotplug_event(), except it fires a more |
| * fine-grained uevent for a single connector. |
| */ |
| void drm_kms_helper_connector_hotplug_event(struct drm_connector *connector) |
| { |
| struct drm_device *dev = connector->dev; |
| |
| /* send a uevent + call fbdev */ |
| drm_sysfs_connector_hotplug_event(connector); |
| if (dev->mode_config.funcs->output_poll_changed) |
| dev->mode_config.funcs->output_poll_changed(dev); |
| |
| drm_client_dev_hotplug(dev); |
| } |
| EXPORT_SYMBOL(drm_kms_helper_connector_hotplug_event); |
| |
| static void output_poll_execute(struct work_struct *work) |
| { |
| struct delayed_work *delayed_work = to_delayed_work(work); |
| struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work); |
| struct drm_connector *connector; |
| struct drm_connector_list_iter conn_iter; |
| enum drm_connector_status old_status; |
| bool repoll = false, changed; |
| u64 old_epoch_counter; |
| |
| if (!dev->mode_config.poll_enabled) |
| return; |
| |
| /* Pick up any changes detected by the probe functions. */ |
| changed = dev->mode_config.delayed_event; |
| dev->mode_config.delayed_event = false; |
| |
| if (!drm_kms_helper_poll) { |
| if (dev->mode_config.poll_running) { |
| drm_kms_helper_disable_hpd(dev); |
| dev->mode_config.poll_running = false; |
| } |
| goto out; |
| } |
| |
| if (!mutex_trylock(&dev->mode_config.mutex)) { |
| repoll = true; |
| goto out; |
| } |
| |
| drm_connector_list_iter_begin(dev, &conn_iter); |
| drm_for_each_connector_iter(connector, &conn_iter) { |
| /* Ignore forced connectors. */ |
| if (connector->force) |
| continue; |
| |
| /* Ignore HPD capable connectors and connectors where we don't |
| * want any hotplug detection at all for polling. */ |
| if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD) |
| continue; |
| |
| old_status = connector->status; |
| /* if we are connected and don't want to poll for disconnect |
| skip it */ |
| if (old_status == connector_status_connected && |
| !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT)) |
| continue; |
| |
| repoll = true; |
| |
| old_epoch_counter = connector->epoch_counter; |
| connector->status = drm_helper_probe_detect(connector, NULL, false); |
| if (old_epoch_counter != connector->epoch_counter) { |
| const char *old, *new; |
| |
| /* |
| * The poll work sets force=false when calling detect so |
| * that drivers can avoid to do disruptive tests (e.g. |
| * when load detect cycles could cause flickering on |
| * other, running displays). This bears the risk that we |
| * flip-flop between unknown here in the poll work and |
| * the real state when userspace forces a full detect |
| * call after receiving a hotplug event due to this |
| * change. |
| * |
| * Hence clamp an unknown detect status to the old |
| * value. |
| */ |
| if (connector->status == connector_status_unknown) { |
| connector->status = old_status; |
| continue; |
| } |
| |
| old = drm_get_connector_status_name(old_status); |
| new = drm_get_connector_status_name(connector->status); |
| |
| drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n", |
| connector->base.id, connector->name, |
| old, new); |
| drm_dbg_kms(dev, "[CONNECTOR:%d:%s] epoch counter %llu -> %llu\n", |
| connector->base.id, connector->name, |
| old_epoch_counter, connector->epoch_counter); |
| |
| changed = true; |
| } |
| } |
| drm_connector_list_iter_end(&conn_iter); |
| |
| mutex_unlock(&dev->mode_config.mutex); |
| |
| out: |
| if (changed) |
| drm_kms_helper_hotplug_event(dev); |
| |
| if (repoll) |
| schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD); |
| } |
| |
| /** |
| * drm_kms_helper_is_poll_worker - is %current task an output poll worker? |
| * |
| * Determine if %current task is an output poll worker. This can be used |
| * to select distinct code paths for output polling versus other contexts. |
| * |
| * One use case is to avoid a deadlock between the output poll worker and |
| * the autosuspend worker wherein the latter waits for polling to finish |
| * upon calling drm_kms_helper_poll_disable(), while the former waits for |
| * runtime suspend to finish upon calling pm_runtime_get_sync() in a |
| * connector ->detect hook. |
| */ |
| bool drm_kms_helper_is_poll_worker(void) |
| { |
| struct work_struct *work = current_work(); |
| |
| return work && work->func == output_poll_execute; |
| } |
| EXPORT_SYMBOL(drm_kms_helper_is_poll_worker); |
| |
| /** |
| * 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 already |
| * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable(). |
| * |
| * If however, the polling was never initialized, this call will trigger a |
| * warning and return |
| * |
| * Note that calls to enable and disable polling must be strictly ordered, which |
| * is automatically the case when they're only call from suspend/resume |
| * callbacks. |
| */ |
| void drm_kms_helper_poll_disable(struct drm_device *dev) |
| { |
| if (drm_WARN_ON(dev, !dev->mode_config.poll_enabled)) |
| return; |
| |
| if (dev->mode_config.poll_running) |
| drm_kms_helper_disable_hpd(dev); |
| |
| cancel_delayed_work_sync(&dev->mode_config.output_poll_work); |
| |
| dev->mode_config.poll_running = false; |
| } |
| EXPORT_SYMBOL(drm_kms_helper_poll_disable); |
| |
| /** |
| * drm_kms_helper_poll_init - initialize and enable output polling |
| * @dev: drm_device |
| * |
| * This function initializes 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); |
| dev->mode_config.poll_enabled = true; |
| |
| drm_kms_helper_poll_enable(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) |
| { |
| if (!dev->mode_config.poll_enabled) |
| return; |
| |
| drm_kms_helper_poll_disable(dev); |
| |
| dev->mode_config.poll_enabled = false; |
| } |
| EXPORT_SYMBOL(drm_kms_helper_poll_fini); |
| |
| static void drm_kms_helper_poll_init_release(struct drm_device *dev, void *res) |
| { |
| drm_kms_helper_poll_fini(dev); |
| } |
| |
| /** |
| * drmm_kms_helper_poll_init - initialize and enable output polling |
| * @dev: drm_device |
| * |
| * This function initializes and then also enables output polling support for |
| * @dev similar to drm_kms_helper_poll_init(). Polling will automatically be |
| * cleaned up when the DRM device goes away. |
| * |
| * See drm_kms_helper_poll_init() for more information. |
| * |
| * Returns: |
| * 0 on success, or a negative errno code otherwise. |
| */ |
| int drmm_kms_helper_poll_init(struct drm_device *dev) |
| { |
| drm_kms_helper_poll_init(dev); |
| |
| return drmm_add_action_or_reset(dev, drm_kms_helper_poll_init_release, dev); |
| } |
| EXPORT_SYMBOL(drmm_kms_helper_poll_init); |
| |
| static bool check_connector_changed(struct drm_connector *connector) |
| { |
| struct drm_device *dev = connector->dev; |
| enum drm_connector_status old_status; |
| u64 old_epoch_counter; |
| |
| /* Only handle HPD capable connectors. */ |
| drm_WARN_ON(dev, !(connector->polled & DRM_CONNECTOR_POLL_HPD)); |
| |
| drm_WARN_ON(dev, !mutex_is_locked(&dev->mode_config.mutex)); |
| |
| old_status = connector->status; |
| old_epoch_counter = connector->epoch_counter; |
| connector->status = drm_helper_probe_detect(connector, NULL, false); |
| |
| if (old_epoch_counter == connector->epoch_counter) { |
| drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Same epoch counter %llu\n", |
| connector->base.id, |
| connector->name, |
| connector->epoch_counter); |
| |
| return false; |
| } |
| |
| drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n", |
| connector->base.id, |
| connector->name, |
| drm_get_connector_status_name(old_status), |
| drm_get_connector_status_name(connector->status)); |
| |
| drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Changed epoch counter %llu => %llu\n", |
| connector->base.id, |
| connector->name, |
| old_epoch_counter, |
| connector->epoch_counter); |
| |
| return true; |
| } |
| |
| /** |
| * drm_connector_helper_hpd_irq_event - hotplug processing |
| * @connector: drm_connector |
| * |
| * Drivers can use this helper function to run a detect cycle on a connector |
| * which has the DRM_CONNECTOR_POLL_HPD flag set in its &polled member. |
| * |
| * This helper function is useful for drivers which can track hotplug |
| * interrupts for a single connector. Drivers that want to send a |
| * hotplug event for all connectors or can't track hotplug interrupts |
| * per connector need to use drm_helper_hpd_irq_event(). |
| * |
| * 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. |
| * |
| * Returns: |
| * A boolean indicating whether the connector status changed or not |
| */ |
| bool drm_connector_helper_hpd_irq_event(struct drm_connector *connector) |
| { |
| struct drm_device *dev = connector->dev; |
| bool changed; |
| |
| mutex_lock(&dev->mode_config.mutex); |
| changed = check_connector_changed(connector); |
| mutex_unlock(&dev->mode_config.mutex); |
| |
| if (changed) { |
| drm_kms_helper_connector_hotplug_event(connector); |
| drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Sent hotplug event\n", |
| connector->base.id, |
| connector->name); |
| } |
| |
| return changed; |
| } |
| EXPORT_SYMBOL(drm_connector_helper_hpd_irq_event); |
| |
| /** |
| * 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 can use |
| * drm_connector_helper_hpd_irq_event(). Alternatively, they 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. |
| * |
| * Returns: |
| * A boolean indicating whether the connector status changed or not |
| */ |
| bool drm_helper_hpd_irq_event(struct drm_device *dev) |
| { |
| struct drm_connector *connector, *first_changed_connector = NULL; |
| struct drm_connector_list_iter conn_iter; |
| int changed = 0; |
| |
| if (!dev->mode_config.poll_enabled) |
| return false; |
| |
| mutex_lock(&dev->mode_config.mutex); |
| drm_connector_list_iter_begin(dev, &conn_iter); |
| drm_for_each_connector_iter(connector, &conn_iter) { |
| /* Only handle HPD capable connectors. */ |
| if (!(connector->polled & DRM_CONNECTOR_POLL_HPD)) |
| continue; |
| |
| if (check_connector_changed(connector)) { |
| if (!first_changed_connector) { |
| drm_connector_get(connector); |
| first_changed_connector = connector; |
| } |
| |
| changed++; |
| } |
| } |
| drm_connector_list_iter_end(&conn_iter); |
| mutex_unlock(&dev->mode_config.mutex); |
| |
| if (changed == 1) |
| drm_kms_helper_connector_hotplug_event(first_changed_connector); |
| else if (changed > 0) |
| drm_kms_helper_hotplug_event(dev); |
| |
| if (first_changed_connector) |
| drm_connector_put(first_changed_connector); |
| |
| return changed; |
| } |
| EXPORT_SYMBOL(drm_helper_hpd_irq_event); |
| |
| /** |
| * drm_crtc_helper_mode_valid_fixed - Validates a display mode |
| * @crtc: the crtc |
| * @mode: the mode to validate |
| * @fixed_mode: the display hardware's mode |
| * |
| * Returns: |
| * MODE_OK on success, or another mode-status code otherwise. |
| */ |
| enum drm_mode_status drm_crtc_helper_mode_valid_fixed(struct drm_crtc *crtc, |
| const struct drm_display_mode *mode, |
| const struct drm_display_mode *fixed_mode) |
| { |
| if (mode->hdisplay != fixed_mode->hdisplay && mode->vdisplay != fixed_mode->vdisplay) |
| return MODE_ONE_SIZE; |
| else if (mode->hdisplay != fixed_mode->hdisplay) |
| return MODE_ONE_WIDTH; |
| else if (mode->vdisplay != fixed_mode->vdisplay) |
| return MODE_ONE_HEIGHT; |
| |
| return MODE_OK; |
| } |
| EXPORT_SYMBOL(drm_crtc_helper_mode_valid_fixed); |
| |
| /** |
| * drm_connector_helper_get_modes_fixed - Duplicates a display mode for a connector |
| * @connector: the connector |
| * @fixed_mode: the display hardware's mode |
| * |
| * This function duplicates a display modes for a connector. Drivers for hardware |
| * that only supports a single fixed mode can use this function in their connector's |
| * get_modes helper. |
| * |
| * Returns: |
| * The number of created modes. |
| */ |
| int drm_connector_helper_get_modes_fixed(struct drm_connector *connector, |
| const struct drm_display_mode *fixed_mode) |
| { |
| struct drm_device *dev = connector->dev; |
| struct drm_display_mode *mode; |
| |
| mode = drm_mode_duplicate(dev, fixed_mode); |
| if (!mode) { |
| drm_err(dev, "Failed to duplicate mode " DRM_MODE_FMT "\n", |
| DRM_MODE_ARG(fixed_mode)); |
| return 0; |
| } |
| |
| if (mode->name[0] == '\0') |
| drm_mode_set_name(mode); |
| |
| mode->type |= DRM_MODE_TYPE_PREFERRED; |
| drm_mode_probed_add(connector, mode); |
| |
| if (mode->width_mm) |
| connector->display_info.width_mm = mode->width_mm; |
| if (mode->height_mm) |
| connector->display_info.height_mm = mode->height_mm; |
| |
| return 1; |
| } |
| EXPORT_SYMBOL(drm_connector_helper_get_modes_fixed); |
| |
| /** |
| * drm_connector_helper_get_modes - Read EDID and update connector. |
| * @connector: The connector |
| * |
| * Read the EDID using drm_edid_read() (which requires that connector->ddc is |
| * set), and update the connector using the EDID. |
| * |
| * This can be used as the "default" connector helper .get_modes() hook if the |
| * driver does not need any special processing. This is sets the example what |
| * custom .get_modes() hooks should do regarding EDID read and connector update. |
| * |
| * Returns: Number of modes. |
| */ |
| int drm_connector_helper_get_modes(struct drm_connector *connector) |
| { |
| const struct drm_edid *drm_edid; |
| int count; |
| |
| drm_edid = drm_edid_read(connector); |
| |
| /* |
| * Unconditionally update the connector. If the EDID was read |
| * successfully, fill in the connector information derived from the |
| * EDID. Otherwise, if the EDID is NULL, clear the connector |
| * information. |
| */ |
| drm_edid_connector_update(connector, drm_edid); |
| |
| count = drm_edid_connector_add_modes(connector); |
| |
| drm_edid_free(drm_edid); |
| |
| return count; |
| } |
| EXPORT_SYMBOL(drm_connector_helper_get_modes); |
| |
| /** |
| * drm_connector_helper_tv_get_modes - Fills the modes availables to a TV connector |
| * @connector: The connector |
| * |
| * Fills the available modes for a TV connector based on the supported |
| * TV modes, and the default mode expressed by the kernel command line. |
| * |
| * This can be used as the default TV connector helper .get_modes() hook |
| * if the driver does not need any special processing. |
| * |
| * Returns: |
| * The number of modes added to the connector. |
| */ |
| int drm_connector_helper_tv_get_modes(struct drm_connector *connector) |
| { |
| struct drm_device *dev = connector->dev; |
| struct drm_property *tv_mode_property = |
| dev->mode_config.tv_mode_property; |
| struct drm_cmdline_mode *cmdline = &connector->cmdline_mode; |
| unsigned int ntsc_modes = BIT(DRM_MODE_TV_MODE_NTSC) | |
| BIT(DRM_MODE_TV_MODE_NTSC_443) | |
| BIT(DRM_MODE_TV_MODE_NTSC_J) | |
| BIT(DRM_MODE_TV_MODE_PAL_M); |
| unsigned int pal_modes = BIT(DRM_MODE_TV_MODE_PAL) | |
| BIT(DRM_MODE_TV_MODE_PAL_N) | |
| BIT(DRM_MODE_TV_MODE_SECAM); |
| unsigned int tv_modes[2] = { UINT_MAX, UINT_MAX }; |
| unsigned int i, supported_tv_modes = 0; |
| |
| if (!tv_mode_property) |
| return 0; |
| |
| for (i = 0; i < tv_mode_property->num_values; i++) |
| supported_tv_modes |= BIT(tv_mode_property->values[i]); |
| |
| if (((supported_tv_modes & ntsc_modes) && |
| (supported_tv_modes & pal_modes)) || |
| (supported_tv_modes & BIT(DRM_MODE_TV_MODE_MONOCHROME))) { |
| uint64_t default_mode; |
| |
| if (drm_object_property_get_default_value(&connector->base, |
| tv_mode_property, |
| &default_mode)) |
| return 0; |
| |
| if (cmdline->tv_mode_specified) |
| default_mode = cmdline->tv_mode; |
| |
| if (BIT(default_mode) & ntsc_modes) { |
| tv_modes[0] = DRM_MODE_TV_MODE_NTSC; |
| tv_modes[1] = DRM_MODE_TV_MODE_PAL; |
| } else { |
| tv_modes[0] = DRM_MODE_TV_MODE_PAL; |
| tv_modes[1] = DRM_MODE_TV_MODE_NTSC; |
| } |
| } else if (supported_tv_modes & ntsc_modes) { |
| tv_modes[0] = DRM_MODE_TV_MODE_NTSC; |
| } else if (supported_tv_modes & pal_modes) { |
| tv_modes[0] = DRM_MODE_TV_MODE_PAL; |
| } else { |
| return 0; |
| } |
| |
| for (i = 0; i < ARRAY_SIZE(tv_modes); i++) { |
| struct drm_display_mode *mode; |
| |
| if (tv_modes[i] == DRM_MODE_TV_MODE_NTSC) |
| mode = drm_mode_analog_ntsc_480i(dev); |
| else if (tv_modes[i] == DRM_MODE_TV_MODE_PAL) |
| mode = drm_mode_analog_pal_576i(dev); |
| else |
| break; |
| if (!mode) |
| return i; |
| if (!i) |
| mode->type |= DRM_MODE_TYPE_PREFERRED; |
| drm_mode_probed_add(connector, mode); |
| } |
| |
| return i; |
| } |
| EXPORT_SYMBOL(drm_connector_helper_tv_get_modes); |
| |
| /** |
| * drm_connector_helper_detect_from_ddc - Read EDID and detect connector status. |
| * @connector: The connector |
| * @ctx: Acquire context |
| * @force: Perform screen-destructive operations, if necessary |
| * |
| * Detects the connector status by reading the EDID using drm_probe_ddc(), |
| * which requires connector->ddc to be set. Returns connector_status_connected |
| * on success or connector_status_disconnected on failure. |
| * |
| * Returns: |
| * The connector status as defined by enum drm_connector_status. |
| */ |
| int drm_connector_helper_detect_from_ddc(struct drm_connector *connector, |
| struct drm_modeset_acquire_ctx *ctx, |
| bool force) |
| { |
| struct i2c_adapter *ddc = connector->ddc; |
| |
| if (!ddc) |
| return connector_status_unknown; |
| |
| if (drm_probe_ddc(ddc)) |
| return connector_status_connected; |
| |
| return connector_status_disconnected; |
| } |
| EXPORT_SYMBOL(drm_connector_helper_detect_from_ddc); |