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Release 4.7 drivers/gpu/drm/drm_probe_helper.c

Directory: drivers/gpu/drm
/*
 * 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/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_edid.h>

/**
 * DOC: output probing helper overview
 *
 * This library provides some helper code for output probing. It provides an
 * implementation of the core connector->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; }

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static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector) { struct drm_display_mode *mode; if (!connector->cmdline_mode.specified) return 0; mode = drm_mode_create_from_cmdline_mode(connector->dev, &connector->cmdline_mode); if (mode == NULL) return 0; drm_mode_probed_add(connector, mode); return 1; }

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#define DRM_OUTPUT_POLL_PERIOD (10*HZ) /** * drm_kms_helper_poll_enable_locked - re-enable output polling. * @dev: drm_device * * This function re-enables the output polling work without * locking the mode_config mutex. * * This is like drm_kms_helper_poll_enable() however it is to be * called from a context where the mode_config mutex is locked * already. */
void drm_kms_helper_poll_enable_locked(struct drm_device *dev) { bool poll = false; struct drm_connector *connector; WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll) return; drm_for_each_connector(connector, dev) { if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT)) poll = true; } if (poll) schedule_delayed_work(&dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD); }

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EXPORT_SYMBOL(drm_kms_helper_poll_enable_locked); /** * 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 ->fill_modes() * @connector 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. * * - debugfs 'override_edid' (used for testing only) * - firmware EDID (drm_load_edid_firmware()) * - connector helper ->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_mode_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 againt basic connector * capabilites (interlace_allowed,doublescan_allowed,stereo_allowed) * - the optional connector ->mode_valid() helper can perform driver and/or * hardware specific checks * * 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; const struct drm_connector_helper_funcs *connector_funcs = connector->helper_private; int count = 0; int mode_flags = 0; bool verbose_prune = true; enum drm_connector_status old_status; WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id, connector->name); /* 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 { connector->status = connector->funcs->detect(connector, true); } /* * 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_DEBUG_KMS("[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) schedule_delayed_work(&dev->mode_config.output_poll_work, 0); } /* Re-enable polling in case the global poll config changed. */ if (drm_kms_helper_poll != dev->mode_config.poll_running) drm_kms_helper_poll_enable_locked(dev); dev->mode_config.poll_running = drm_kms_helper_poll; if (connector->status == connector_status_disconnected) { DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n", connector->base.id, connector->name); drm_mode_connector_update_edid_property(connector, NULL); verbose_prune = false; goto prune; } if (connector->override_edid) { struct edid *edid = (struct edid *) connector->edid_blob_ptr->data; count = drm_add_edid_modes(connector, edid); drm_edid_to_eld(connector, edid); } else { count = drm_load_edid_firmware(connector); if (count == 0) count = (*connector_funcs->get_modes)(connector); } if (count == 0 && connector->status == connector_status_connected) count = drm_add_modes_noedid(connector, 1024, 768); count += drm_helper_probe_add_cmdline_mode(connector); if (count == 0) goto prune; drm_mode_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) mode->status = drm_mode_validate_basic(mode); if (mode->status == MODE_OK) mode->status = drm_mode_validate_size(mode, maxX, maxY); if (mode->status == MODE_OK) mode->status = drm_mode_validate_flag(mode, mode_flags); if (mode->status == MODE_OK && connector_funcs->mode_valid) mode->status = connector_funcs->mode_valid(connector, mode); } prune: drm_mode_prune_invalid(dev, &connector->modes, verbose_prune); if (list_empty(&connector->modes)) return 0; list_for_each_entry(mode, &connector->modes, head) mode->vrefresh = drm_mode_vrefresh(mode); drm_mode_sort(&connector->modes); DRM_DEBUG_KMS("[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_mode_debug_printmodeline(mode); } return count; }

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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. */
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); }

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EXPORT_SYMBOL(drm_kms_helper_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; enum drm_connector_status old_status; bool repoll = false, changed; /* 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) goto out; mutex_lock(&dev->mode_config.mutex); drm_for_each_connector(connector, dev) { /* 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; connector->status = connector->funcs->detect(connector, false); if (old_status != connector->status) { 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_DEBUG_KMS("[CONNECTOR:%d:%s] " "status updated from %s to %s\n", connector->base.id, connector->name, old, new); changed = true; } } 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); }

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/** * 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) return; cancel_delayed_work_sync(&dev->mode_config.output_poll_work); }

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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) { mutex_lock(&dev->mode_config.mutex); drm_kms_helper_poll_enable_locked(dev); mutex_unlock(&dev->mode_config.mutex); }

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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); dev->mode_config.poll_enabled = true; drm_kms_helper_poll_enable(dev); }

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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); }

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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; enum drm_connector_status old_status; bool changed = false; if (!dev->mode_config.poll_enabled) return false; mutex_lock(&dev->mode_config.mutex); drm_for_each_connector(connector, dev) { /* Only handle HPD capable connectors. */ if (!(connector->polled & DRM_CONNECTOR_POLL_HPD)) continue; old_status = connector->status; connector->status = connector->funcs->detect(connector, false); DRM_DEBUG_KMS("[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)); if (old_status != connector->status) changed = true; } mutex_unlock(&dev->mode_config.mutex); if (changed) drm_kms_helper_hotplug_event(dev); return changed; }

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EXPORT_SYMBOL(drm_helper_hpd_irq_event);

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Directory: drivers/gpu/drm
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