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  1. /*
  2.  * Copyright (c) 2006-2008 Intel Corporation
  3.  * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
  4.  *
  5.  * DRM core CRTC related functions
  6.  *
  7.  * Permission to use, copy, modify, distribute, and sell this software and its
  8.  * documentation for any purpose is hereby granted without fee, provided that
  9.  * the above copyright notice appear in all copies and that both that copyright
  10.  * notice and this permission notice appear in supporting documentation, and
  11.  * that the name of the copyright holders not be used in advertising or
  12.  * publicity pertaining to distribution of the software without specific,
  13.  * written prior permission.  The copyright holders make no representations
  14.  * about the suitability of this software for any purpose.  It is provided "as
  15.  * is" without express or implied warranty.
  16.  *
  17.  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  18.  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  19.  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  20.  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  21.  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  22.  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  23.  * OF THIS SOFTWARE.
  24.  *
  25.  * Authors:
  26.  *      Keith Packard
  27.  *      Eric Anholt <eric@anholt.net>
  28.  *      Dave Airlie <airlied@linux.ie>
  29.  *      Jesse Barnes <jesse.barnes@intel.com>
  30.  */
  31.  
  32. #include <linux/kernel.h>
  33. #include <linux/export.h>
  34. #include <linux/moduleparam.h>
  35.  
  36. #include <drm/drmP.h>
  37. #include <drm/drm_atomic.h>
  38. #include <drm/drm_crtc.h>
  39. #include <drm/drm_fourcc.h>
  40. #include <drm/drm_crtc_helper.h>
  41. #include <drm/drm_fb_helper.h>
  42. #include <drm/drm_plane_helper.h>
  43. #include <drm/drm_atomic_helper.h>
  44. #include <drm/drm_edid.h>
  45.  
  46. /**
  47.  * DOC: overview
  48.  *
  49.  * The CRTC modeset helper library provides a default set_config implementation
  50.  * in drm_crtc_helper_set_config(). Plus a few other convenience functions using
  51.  * the same callbacks which drivers can use to e.g. restore the modeset
  52.  * configuration on resume with drm_helper_resume_force_mode().
  53.  *
  54.  * Note that this helper library doesn't track the current power state of CRTCs
  55.  * and encoders. It can call callbacks like ->dpms() even though the hardware is
  56.  * already in the desired state. This deficiency has been fixed in the atomic
  57.  * helpers.
  58.  *
  59.  * The driver callbacks are mostly compatible with the atomic modeset helpers,
  60.  * except for the handling of the primary plane: Atomic helpers require that the
  61.  * primary plane is implemented as a real standalone plane and not directly tied
  62.  * to the CRTC state. For easier transition this library provides functions to
  63.  * implement the old semantics required by the CRTC helpers using the new plane
  64.  * and atomic helper callbacks.
  65.  *
  66.  * Drivers are strongly urged to convert to the atomic helpers (by way of first
  67.  * converting to the plane helpers). New drivers must not use these functions
  68.  * but need to implement the atomic interface instead, potentially using the
  69.  * atomic helpers for that.
  70.  *
  71.  * These legacy modeset helpers use the same function table structures as
  72.  * all other modesetting helpers. See the documentation for struct
  73.  * &drm_crtc_helper_funcs, struct &drm_encoder_helper_funcs and struct
  74.  * &drm_connector_helper_funcs.
  75.  */
  76.  
  77. /**
  78.  * drm_helper_move_panel_connectors_to_head() - move panels to the front in the
  79.  *                                              connector list
  80.  * @dev: drm device to operate on
  81.  *
  82.  * Some userspace presumes that the first connected connector is the main
  83.  * display, where it's supposed to display e.g. the login screen. For
  84.  * laptops, this should be the main panel. Use this function to sort all
  85.  * (eDP/LVDS) panels to the front of the connector list, instead of
  86.  * painstakingly trying to initialize them in the right order.
  87.  */
  88. void drm_helper_move_panel_connectors_to_head(struct drm_device *dev)
  89. {
  90.         struct drm_connector *connector, *tmp;
  91.         struct list_head panel_list;
  92.  
  93.         INIT_LIST_HEAD(&panel_list);
  94.  
  95.         list_for_each_entry_safe(connector, tmp,
  96.                                  &dev->mode_config.connector_list, head) {
  97.                 if (connector->connector_type == DRM_MODE_CONNECTOR_LVDS ||
  98.                     connector->connector_type == DRM_MODE_CONNECTOR_eDP)
  99.                         list_move_tail(&connector->head, &panel_list);
  100.         }
  101.  
  102.         list_splice(&panel_list, &dev->mode_config.connector_list);
  103. }
  104. EXPORT_SYMBOL(drm_helper_move_panel_connectors_to_head);
  105.  
  106. /**
  107.  * drm_helper_encoder_in_use - check if a given encoder is in use
  108.  * @encoder: encoder to check
  109.  *
  110.  * Checks whether @encoder is with the current mode setting output configuration
  111.  * in use by any connector. This doesn't mean that it is actually enabled since
  112.  * the DPMS state is tracked separately.
  113.  *
  114.  * Returns:
  115.  * True if @encoder is used, false otherwise.
  116.  */
  117. bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
  118. {
  119.         struct drm_connector *connector;
  120.         struct drm_device *dev = encoder->dev;
  121.  
  122.         /*
  123.          * We can expect this mutex to be locked if we are not panicking.
  124.          * Locking is currently fubar in the panic handler.
  125.          */
  126.         if (!oops_in_progress) {
  127.                 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
  128.                 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
  129.         }
  130.  
  131.         drm_for_each_connector(connector, dev)
  132.                 if (connector->encoder == encoder)
  133.                         return true;
  134.         return false;
  135. }
  136. EXPORT_SYMBOL(drm_helper_encoder_in_use);
  137.  
  138. /**
  139.  * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
  140.  * @crtc: CRTC to check
  141.  *
  142.  * Checks whether @crtc is with the current mode setting output configuration
  143.  * in use by any connector. This doesn't mean that it is actually enabled since
  144.  * the DPMS state is tracked separately.
  145.  *
  146.  * Returns:
  147.  * True if @crtc is used, false otherwise.
  148.  */
  149. bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
  150. {
  151.         struct drm_encoder *encoder;
  152.         struct drm_device *dev = crtc->dev;
  153.  
  154.         /*
  155.          * We can expect this mutex to be locked if we are not panicking.
  156.          * Locking is currently fubar in the panic handler.
  157.          */
  158.         if (!oops_in_progress)
  159.                 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
  160.  
  161.         drm_for_each_encoder(encoder, dev)
  162.                 if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
  163.                         return true;
  164.         return false;
  165. }
  166. EXPORT_SYMBOL(drm_helper_crtc_in_use);
  167.  
  168. static void
  169. drm_encoder_disable(struct drm_encoder *encoder)
  170. {
  171.         const struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
  172.  
  173.         drm_bridge_disable(encoder->bridge);
  174.  
  175.         if (encoder_funcs->disable)
  176.                 (*encoder_funcs->disable)(encoder);
  177.         else
  178.                 (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
  179.  
  180.         drm_bridge_post_disable(encoder->bridge);
  181. }
  182.  
  183. static void __drm_helper_disable_unused_functions(struct drm_device *dev)
  184. {
  185.         struct drm_encoder *encoder;
  186.         struct drm_crtc *crtc;
  187.  
  188.         drm_warn_on_modeset_not_all_locked(dev);
  189.  
  190.         drm_for_each_encoder(encoder, dev) {
  191.                 if (!drm_helper_encoder_in_use(encoder)) {
  192.                         drm_encoder_disable(encoder);
  193.                         /* disconnect encoder from any connector */
  194.                         encoder->crtc = NULL;
  195.                 }
  196.         }
  197.  
  198.         drm_for_each_crtc(crtc, dev) {
  199.                 const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
  200.                 crtc->enabled = drm_helper_crtc_in_use(crtc);
  201.                 if (!crtc->enabled) {
  202.                         if (crtc_funcs->disable)
  203.                                 (*crtc_funcs->disable)(crtc);
  204.                         else
  205.                                 (*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
  206.                         crtc->primary->fb = NULL;
  207.                 }
  208.         }
  209. }
  210.  
  211. /**
  212.  * drm_helper_disable_unused_functions - disable unused objects
  213.  * @dev: DRM device
  214.  *
  215.  * This function walks through the entire mode setting configuration of @dev. It
  216.  * will remove any CRTC links of unused encoders and encoder links of
  217.  * disconnected connectors. Then it will disable all unused encoders and CRTCs
  218.  * either by calling their disable callback if available or by calling their
  219.  * dpms callback with DRM_MODE_DPMS_OFF.
  220.  *
  221.  * NOTE:
  222.  *
  223.  * This function is part of the legacy modeset helper library and will cause
  224.  * major confusion with atomic drivers. This is because atomic helpers guarantee
  225.  * to never call ->disable() hooks on a disabled function, or ->enable() hooks
  226.  * on an enabled functions. drm_helper_disable_unused_functions() on the other
  227.  * hand throws such guarantees into the wind and calls disable hooks
  228.  * unconditionally on unused functions.
  229.  */
  230. void drm_helper_disable_unused_functions(struct drm_device *dev)
  231. {
  232.         drm_modeset_lock_all(dev);
  233.         __drm_helper_disable_unused_functions(dev);
  234.         drm_modeset_unlock_all(dev);
  235. }
  236. EXPORT_SYMBOL(drm_helper_disable_unused_functions);
  237.  
  238. /*
  239.  * Check the CRTC we're going to map each output to vs. its current
  240.  * CRTC.  If they don't match, we have to disable the output and the CRTC
  241.  * since the driver will have to re-route things.
  242.  */
  243. static void
  244. drm_crtc_prepare_encoders(struct drm_device *dev)
  245. {
  246.         const struct drm_encoder_helper_funcs *encoder_funcs;
  247.         struct drm_encoder *encoder;
  248.  
  249.         drm_for_each_encoder(encoder, dev) {
  250.                 encoder_funcs = encoder->helper_private;
  251.                 /* Disable unused encoders */
  252.                 if (encoder->crtc == NULL)
  253.                         drm_encoder_disable(encoder);
  254.                 /* Disable encoders whose CRTC is about to change */
  255.                 if (encoder_funcs->get_crtc &&
  256.                     encoder->crtc != (*encoder_funcs->get_crtc)(encoder))
  257.                         drm_encoder_disable(encoder);
  258.         }
  259. }
  260.  
  261. /**
  262.  * drm_crtc_helper_set_mode - internal helper to set a mode
  263.  * @crtc: CRTC to program
  264.  * @mode: mode to use
  265.  * @x: horizontal offset into the surface
  266.  * @y: vertical offset into the surface
  267.  * @old_fb: old framebuffer, for cleanup
  268.  *
  269.  * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
  270.  * to fixup or reject the mode prior to trying to set it. This is an internal
  271.  * helper that drivers could e.g. use to update properties that require the
  272.  * entire output pipe to be disabled and re-enabled in a new configuration. For
  273.  * example for changing whether audio is enabled on a hdmi link or for changing
  274.  * panel fitter or dither attributes. It is also called by the
  275.  * drm_crtc_helper_set_config() helper function to drive the mode setting
  276.  * sequence.
  277.  *
  278.  * Returns:
  279.  * True if the mode was set successfully, false otherwise.
  280.  */
  281. bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
  282.                               struct drm_display_mode *mode,
  283.                               int x, int y,
  284.                               struct drm_framebuffer *old_fb)
  285. {
  286.         struct drm_device *dev = crtc->dev;
  287.         struct drm_display_mode *adjusted_mode, saved_mode, saved_hwmode;
  288.         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
  289.         const struct drm_encoder_helper_funcs *encoder_funcs;
  290.         int saved_x, saved_y;
  291.         bool saved_enabled;
  292.         struct drm_encoder *encoder;
  293.         bool ret = true;
  294.  
  295.         drm_warn_on_modeset_not_all_locked(dev);
  296.  
  297.         saved_enabled = crtc->enabled;
  298.         crtc->enabled = drm_helper_crtc_in_use(crtc);
  299.         if (!crtc->enabled)
  300.                 return true;
  301.  
  302.         adjusted_mode = drm_mode_duplicate(dev, mode);
  303.         if (!adjusted_mode) {
  304.                 crtc->enabled = saved_enabled;
  305.                 return false;
  306.         }
  307.  
  308.         saved_mode = crtc->mode;
  309.         saved_hwmode = crtc->hwmode;
  310.         saved_x = crtc->x;
  311.         saved_y = crtc->y;
  312.  
  313.         /* Update crtc values up front so the driver can rely on them for mode
  314.          * setting.
  315.          */
  316.         crtc->mode = *mode;
  317.         crtc->x = x;
  318.         crtc->y = y;
  319.  
  320.         /* Pass our mode to the connectors and the CRTC to give them a chance to
  321.          * adjust it according to limitations or connector properties, and also
  322.          * a chance to reject the mode entirely.
  323.          */
  324.         drm_for_each_encoder(encoder, dev) {
  325.  
  326.                 if (encoder->crtc != crtc)
  327.                         continue;
  328.  
  329.                 ret = drm_bridge_mode_fixup(encoder->bridge,
  330.                         mode, adjusted_mode);
  331.                 if (!ret) {
  332.                         DRM_DEBUG_KMS("Bridge fixup failed\n");
  333.                         goto done;
  334.                 }
  335.  
  336.                 encoder_funcs = encoder->helper_private;
  337.                 if (encoder_funcs->mode_fixup) {
  338.                         if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
  339.                                                               adjusted_mode))) {
  340.                                 DRM_DEBUG_KMS("Encoder fixup failed\n");
  341.                                 goto done;
  342.                         }
  343.                 }
  344.         }
  345.  
  346.         if (crtc_funcs->mode_fixup) {
  347.                 if (!(ret = crtc_funcs->mode_fixup(crtc, mode,
  348.                                                 adjusted_mode))) {
  349.                         DRM_DEBUG_KMS("CRTC fixup failed\n");
  350.                         goto done;
  351.                 }
  352.         }
  353.         DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name);
  354.  
  355.         crtc->hwmode = *adjusted_mode;
  356.  
  357.         /* Prepare the encoders and CRTCs before setting the mode. */
  358.         drm_for_each_encoder(encoder, dev) {
  359.  
  360.                 if (encoder->crtc != crtc)
  361.                         continue;
  362.  
  363.                 drm_bridge_disable(encoder->bridge);
  364.  
  365.                 encoder_funcs = encoder->helper_private;
  366.                 /* Disable the encoders as the first thing we do. */
  367.                 encoder_funcs->prepare(encoder);
  368.  
  369.                 drm_bridge_post_disable(encoder->bridge);
  370.         }
  371.  
  372.         drm_crtc_prepare_encoders(dev);
  373.  
  374.         crtc_funcs->prepare(crtc);
  375.  
  376.         /* Set up the DPLL and any encoders state that needs to adjust or depend
  377.          * on the DPLL.
  378.          */
  379.         ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
  380.         if (!ret)
  381.             goto done;
  382.  
  383.         drm_for_each_encoder(encoder, dev) {
  384.  
  385.                 if (encoder->crtc != crtc)
  386.                         continue;
  387.  
  388.                 DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%d:%s]\n",
  389.                         encoder->base.id, encoder->name,
  390.                         mode->base.id, mode->name);
  391.                 encoder_funcs = encoder->helper_private;
  392.                 encoder_funcs->mode_set(encoder, mode, adjusted_mode);
  393.  
  394.                 drm_bridge_mode_set(encoder->bridge, mode, adjusted_mode);
  395.         }
  396.  
  397.         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
  398.         crtc_funcs->commit(crtc);
  399.  
  400.         drm_for_each_encoder(encoder, dev) {
  401.  
  402.                 if (encoder->crtc != crtc)
  403.                         continue;
  404.  
  405.                 drm_bridge_pre_enable(encoder->bridge);
  406.  
  407.                 encoder_funcs = encoder->helper_private;
  408.                 encoder_funcs->commit(encoder);
  409.  
  410.                 drm_bridge_enable(encoder->bridge);
  411.         }
  412.  
  413.         /* Calculate and store various constants which
  414.          * are later needed by vblank and swap-completion
  415.          * timestamping. They are derived from true hwmode.
  416.          */
  417.         drm_calc_timestamping_constants(crtc, &crtc->hwmode);
  418.  
  419.         /* FIXME: add subpixel order */
  420. done:
  421.         drm_mode_destroy(dev, adjusted_mode);
  422.         if (!ret) {
  423.                 crtc->enabled = saved_enabled;
  424.                 crtc->mode = saved_mode;
  425.                 crtc->hwmode = saved_hwmode;
  426.                 crtc->x = saved_x;
  427.                 crtc->y = saved_y;
  428.         }
  429.  
  430.         return ret;
  431. }
  432. EXPORT_SYMBOL(drm_crtc_helper_set_mode);
  433.  
  434. static void
  435. drm_crtc_helper_disable(struct drm_crtc *crtc)
  436. {
  437.         struct drm_device *dev = crtc->dev;
  438.         struct drm_connector *connector;
  439.         struct drm_encoder *encoder;
  440.  
  441.         /* Decouple all encoders and their attached connectors from this crtc */
  442.         drm_for_each_encoder(encoder, dev) {
  443.                 if (encoder->crtc != crtc)
  444.                         continue;
  445.  
  446.                 drm_for_each_connector(connector, dev) {
  447.                         if (connector->encoder != encoder)
  448.                                 continue;
  449.  
  450.                         connector->encoder = NULL;
  451.  
  452.                         /*
  453.                          * drm_helper_disable_unused_functions() ought to be
  454.                          * doing this, but since we've decoupled the encoder
  455.                          * from the connector above, the required connection
  456.                          * between them is henceforth no longer available.
  457.                          */
  458.                         connector->dpms = DRM_MODE_DPMS_OFF;
  459.                 }
  460.         }
  461.  
  462.         __drm_helper_disable_unused_functions(dev);
  463. }
  464.  
  465. /**
  466.  * drm_crtc_helper_set_config - set a new config from userspace
  467.  * @set: mode set configuration
  468.  *
  469.  * The drm_crtc_helper_set_config() helper function implements the set_config
  470.  * callback of struct &drm_crtc_funcs for drivers using the legacy CRTC helpers.
  471.  *
  472.  * It first tries to locate the best encoder for each connector by calling the
  473.  * connector ->best_encoder() (struct &drm_connector_helper_funcs) helper
  474.  * operation.
  475.  *
  476.  * After locating the appropriate encoders, the helper function will call the
  477.  * mode_fixup encoder and CRTC helper operations to adjust the requested mode,
  478.  * or reject it completely in which case an error will be returned to the
  479.  * application. If the new configuration after mode adjustment is identical to
  480.  * the current configuration the helper function will return without performing
  481.  * any other operation.
  482.  *
  483.  * If the adjusted mode is identical to the current mode but changes to the
  484.  * frame buffer need to be applied, the drm_crtc_helper_set_config() function
  485.  * will call the CRTC ->mode_set_base() (struct &drm_crtc_helper_funcs) helper
  486.  * operation.
  487.  *
  488.  * If the adjusted mode differs from the current mode, or if the
  489.  * ->mode_set_base() helper operation is not provided, the helper function
  490.  * performs a full mode set sequence by calling the ->prepare(), ->mode_set()
  491.  * and ->commit() CRTC and encoder helper operations, in that order.
  492.  * Alternatively it can also use the dpms and disable helper operations. For
  493.  * details see struct &drm_crtc_helper_funcs and struct
  494.  * &drm_encoder_helper_funcs.
  495.  *
  496.  * This function is deprecated.  New drivers must implement atomic modeset
  497.  * support, for which this function is unsuitable. Instead drivers should use
  498.  * drm_atomic_helper_set_config().
  499.  *
  500.  * Returns:
  501.  * Returns 0 on success, negative errno numbers on failure.
  502.  */
  503. int drm_crtc_helper_set_config(struct drm_mode_set *set)
  504. {
  505.         struct drm_device *dev;
  506.         struct drm_crtc *new_crtc;
  507.         struct drm_encoder *save_encoders, *new_encoder, *encoder;
  508.         bool mode_changed = false; /* if true do a full mode set */
  509.         bool fb_changed = false; /* if true and !mode_changed just do a flip */
  510.         struct drm_connector *save_connectors, *connector;
  511.         int count = 0, ro, fail = 0;
  512.         const struct drm_crtc_helper_funcs *crtc_funcs;
  513.         struct drm_mode_set save_set;
  514.         int ret;
  515.         int i;
  516.  
  517.         DRM_DEBUG_KMS("\n");
  518.  
  519.         BUG_ON(!set);
  520.         BUG_ON(!set->crtc);
  521.         BUG_ON(!set->crtc->helper_private);
  522.  
  523.         /* Enforce sane interface api - has been abused by the fb helper. */
  524.         BUG_ON(!set->mode && set->fb);
  525.         BUG_ON(set->fb && set->num_connectors == 0);
  526.  
  527.         crtc_funcs = set->crtc->helper_private;
  528.  
  529.         if (!set->mode)
  530.                 set->fb = NULL;
  531.  
  532.         if (set->fb) {
  533.                 DRM_DEBUG_KMS("[CRTC:%d:%s] [FB:%d] #connectors=%d (x y) (%i %i)\n",
  534.                               set->crtc->base.id, set->crtc->name,
  535.                               set->fb->base.id,
  536.                               (int)set->num_connectors, set->x, set->y);
  537.         } else {
  538.                 DRM_DEBUG_KMS("[CRTC:%d:%s] [NOFB]\n",
  539.                               set->crtc->base.id, set->crtc->name);
  540.                 drm_crtc_helper_disable(set->crtc);
  541.                 return 0;
  542.         }
  543.  
  544.         dev = set->crtc->dev;
  545.  
  546.         drm_warn_on_modeset_not_all_locked(dev);
  547.  
  548.         /*
  549.          * Allocate space for the backup of all (non-pointer) encoder and
  550.          * connector data.
  551.          */
  552.         save_encoders = kzalloc(dev->mode_config.num_encoder *
  553.                                 sizeof(struct drm_encoder), GFP_KERNEL);
  554.         if (!save_encoders)
  555.                 return -ENOMEM;
  556.  
  557.         save_connectors = kzalloc(dev->mode_config.num_connector *
  558.                                 sizeof(struct drm_connector), GFP_KERNEL);
  559.         if (!save_connectors) {
  560.                 kfree(save_encoders);
  561.                 return -ENOMEM;
  562.         }
  563.  
  564.         /*
  565.          * Copy data. Note that driver private data is not affected.
  566.          * Should anything bad happen only the expected state is
  567.          * restored, not the drivers personal bookkeeping.
  568.          */
  569.         count = 0;
  570.         drm_for_each_encoder(encoder, dev) {
  571.                 save_encoders[count++] = *encoder;
  572.         }
  573.  
  574.         count = 0;
  575.         drm_for_each_connector(connector, dev) {
  576.                 save_connectors[count++] = *connector;
  577.         }
  578.  
  579.         save_set.crtc = set->crtc;
  580.         save_set.mode = &set->crtc->mode;
  581.         save_set.x = set->crtc->x;
  582.         save_set.y = set->crtc->y;
  583.         save_set.fb = set->crtc->primary->fb;
  584.  
  585.         /* We should be able to check here if the fb has the same properties
  586.          * and then just flip_or_move it */
  587.         if (set->crtc->primary->fb != set->fb) {
  588.                 /* If we have no fb then treat it as a full mode set */
  589.                 if (set->crtc->primary->fb == NULL) {
  590.                         DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
  591.                         mode_changed = true;
  592.                 } else if (set->fb->pixel_format !=
  593.                            set->crtc->primary->fb->pixel_format) {
  594.                         mode_changed = true;
  595.                 } else
  596.                         fb_changed = true;
  597.         }
  598.  
  599.         if (set->x != set->crtc->x || set->y != set->crtc->y)
  600.                 fb_changed = true;
  601.  
  602.         if (!drm_mode_equal(set->mode, &set->crtc->mode)) {
  603.                 DRM_DEBUG_KMS("modes are different, full mode set\n");
  604.                 drm_mode_debug_printmodeline(&set->crtc->mode);
  605.                 drm_mode_debug_printmodeline(set->mode);
  606.                 mode_changed = true;
  607.         }
  608.  
  609.         /* a) traverse passed in connector list and get encoders for them */
  610.         count = 0;
  611.         drm_for_each_connector(connector, dev) {
  612.                 const struct drm_connector_helper_funcs *connector_funcs =
  613.                         connector->helper_private;
  614.                 new_encoder = connector->encoder;
  615.                 for (ro = 0; ro < set->num_connectors; ro++) {
  616.                         if (set->connectors[ro] == connector) {
  617.                                 new_encoder = connector_funcs->best_encoder(connector);
  618.                                 /* if we can't get an encoder for a connector
  619.                                    we are setting now - then fail */
  620.                                 if (new_encoder == NULL)
  621.                                         /* don't break so fail path works correct */
  622.                                         fail = 1;
  623.  
  624.                                 if (connector->dpms != DRM_MODE_DPMS_ON) {
  625.                                         DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
  626.                                         mode_changed = true;
  627.                                 }
  628.  
  629.                                 break;
  630.                         }
  631.                 }
  632.  
  633.                 if (new_encoder != connector->encoder) {
  634.                         DRM_DEBUG_KMS("encoder changed, full mode switch\n");
  635.                         mode_changed = true;
  636.                         /* If the encoder is reused for another connector, then
  637.                          * the appropriate crtc will be set later.
  638.                          */
  639.                         if (connector->encoder)
  640.                                 connector->encoder->crtc = NULL;
  641.                         connector->encoder = new_encoder;
  642.                 }
  643.         }
  644.  
  645.         if (fail) {
  646.                 ret = -EINVAL;
  647.                 goto fail;
  648.         }
  649.  
  650.         count = 0;
  651.         drm_for_each_connector(connector, dev) {
  652.                 if (!connector->encoder)
  653.                         continue;
  654.  
  655.                 if (connector->encoder->crtc == set->crtc)
  656.                         new_crtc = NULL;
  657.                 else
  658.                         new_crtc = connector->encoder->crtc;
  659.  
  660.                 for (ro = 0; ro < set->num_connectors; ro++) {
  661.                         if (set->connectors[ro] == connector)
  662.                                 new_crtc = set->crtc;
  663.                 }
  664.  
  665.                 /* Make sure the new CRTC will work with the encoder */
  666.                 if (new_crtc &&
  667.                     !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
  668.                         ret = -EINVAL;
  669.                         goto fail;
  670.                 }
  671.                 if (new_crtc != connector->encoder->crtc) {
  672.                         DRM_DEBUG_KMS("crtc changed, full mode switch\n");
  673.                         mode_changed = true;
  674.                         connector->encoder->crtc = new_crtc;
  675.                 }
  676.                 if (new_crtc) {
  677.                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d:%s]\n",
  678.                                       connector->base.id, connector->name,
  679.                                       new_crtc->base.id, new_crtc->name);
  680.                 } else {
  681.                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
  682.                                       connector->base.id, connector->name);
  683.                 }
  684.         }
  685.  
  686.         /* mode_set_base is not a required function */
  687.         if (fb_changed && !crtc_funcs->mode_set_base)
  688.                 mode_changed = true;
  689.  
  690.         if (mode_changed) {
  691.                 if (drm_helper_crtc_in_use(set->crtc)) {
  692.                         DRM_DEBUG_KMS("attempting to set mode from"
  693.                                         " userspace\n");
  694.                         drm_mode_debug_printmodeline(set->mode);
  695.                         set->crtc->primary->fb = set->fb;
  696.                         if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
  697.                                                       set->x, set->y,
  698.                                                       save_set.fb)) {
  699.                                 DRM_ERROR("failed to set mode on [CRTC:%d:%s]\n",
  700.                                           set->crtc->base.id, set->crtc->name);
  701.                                 set->crtc->primary->fb = save_set.fb;
  702.                                 ret = -EINVAL;
  703.                                 goto fail;
  704.                         }
  705.                         DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
  706.                         for (i = 0; i < set->num_connectors; i++) {
  707.                                 DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
  708.                                               set->connectors[i]->name);
  709.                                 set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
  710.                         }
  711.                 }
  712.                 __drm_helper_disable_unused_functions(dev);
  713.         } else if (fb_changed) {
  714.                 set->crtc->x = set->x;
  715.                 set->crtc->y = set->y;
  716.                 set->crtc->primary->fb = set->fb;
  717.                 ret = crtc_funcs->mode_set_base(set->crtc,
  718.                                                 set->x, set->y, save_set.fb);
  719.                 if (ret != 0) {
  720.                         set->crtc->x = save_set.x;
  721.                         set->crtc->y = save_set.y;
  722.                         set->crtc->primary->fb = save_set.fb;
  723.                         goto fail;
  724.                 }
  725.         }
  726.  
  727.         kfree(save_connectors);
  728.         kfree(save_encoders);
  729.         return 0;
  730.  
  731. fail:
  732.         /* Restore all previous data. */
  733.         count = 0;
  734.         drm_for_each_encoder(encoder, dev) {
  735.                 *encoder = save_encoders[count++];
  736.         }
  737.  
  738.         count = 0;
  739.         drm_for_each_connector(connector, dev) {
  740.                 *connector = save_connectors[count++];
  741.         }
  742.  
  743.         /* Try to restore the config */
  744.         if (mode_changed &&
  745.             !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
  746.                                       save_set.y, save_set.fb))
  747.                 DRM_ERROR("failed to restore config after modeset failure\n");
  748.  
  749.         kfree(save_connectors);
  750.         kfree(save_encoders);
  751.         return ret;
  752. }
  753. EXPORT_SYMBOL(drm_crtc_helper_set_config);
  754.  
  755. static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
  756. {
  757.         int dpms = DRM_MODE_DPMS_OFF;
  758.         struct drm_connector *connector;
  759.         struct drm_device *dev = encoder->dev;
  760.  
  761.         drm_for_each_connector(connector, dev)
  762.                 if (connector->encoder == encoder)
  763.                         if (connector->dpms < dpms)
  764.                                 dpms = connector->dpms;
  765.         return dpms;
  766. }
  767.  
  768. /* Helper which handles bridge ordering around encoder dpms */
  769. static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
  770. {
  771.         struct drm_bridge *bridge = encoder->bridge;
  772.         const struct drm_encoder_helper_funcs *encoder_funcs;
  773.  
  774.         if (mode == DRM_MODE_DPMS_ON)
  775.                 drm_bridge_pre_enable(bridge);
  776.         else
  777.                 drm_bridge_disable(bridge);
  778.  
  779.         encoder_funcs = encoder->helper_private;
  780.         if (encoder_funcs->dpms)
  781.                 encoder_funcs->dpms(encoder, mode);
  782.  
  783.         if (mode == DRM_MODE_DPMS_ON)
  784.                 drm_bridge_enable(bridge);
  785.         else
  786.                 drm_bridge_post_disable(bridge);
  787. }
  788.  
  789. static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
  790. {
  791.         int dpms = DRM_MODE_DPMS_OFF;
  792.         struct drm_connector *connector;
  793.         struct drm_device *dev = crtc->dev;
  794.  
  795.         drm_for_each_connector(connector, dev)
  796.                 if (connector->encoder && connector->encoder->crtc == crtc)
  797.                         if (connector->dpms < dpms)
  798.                                 dpms = connector->dpms;
  799.         return dpms;
  800. }
  801.  
  802. /**
  803.  * drm_helper_connector_dpms() - connector dpms helper implementation
  804.  * @connector: affected connector
  805.  * @mode: DPMS mode
  806.  *
  807.  * The drm_helper_connector_dpms() helper function implements the ->dpms()
  808.  * callback of struct &drm_connector_funcs for drivers using the legacy CRTC helpers.
  809.  *
  810.  * This is the main helper function provided by the CRTC helper framework for
  811.  * implementing the DPMS connector attribute. It computes the new desired DPMS
  812.  * state for all encoders and CRTCs in the output mesh and calls the ->dpms()
  813.  * callbacks provided by the driver in struct &drm_crtc_helper_funcs and struct
  814.  * &drm_encoder_helper_funcs appropriately.
  815.  *
  816.  * This function is deprecated.  New drivers must implement atomic modeset
  817.  * support, for which this function is unsuitable. Instead drivers should use
  818.  * drm_atomic_helper_connector_dpms().
  819.  *
  820.  * Returns:
  821.  * Always returns 0.
  822.  */
  823. int drm_helper_connector_dpms(struct drm_connector *connector, int mode)
  824. {
  825.         struct drm_encoder *encoder = connector->encoder;
  826.         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
  827.         int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
  828.  
  829.         if (mode == connector->dpms)
  830.                 return 0;
  831.  
  832.         old_dpms = connector->dpms;
  833.         connector->dpms = mode;
  834.  
  835.         if (encoder)
  836.                 encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
  837.  
  838.         /* from off to on, do crtc then encoder */
  839.         if (mode < old_dpms) {
  840.                 if (crtc) {
  841.                         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
  842.                         if (crtc_funcs->dpms)
  843.                                 (*crtc_funcs->dpms) (crtc,
  844.                                                      drm_helper_choose_crtc_dpms(crtc));
  845.                 }
  846.                 if (encoder)
  847.                         drm_helper_encoder_dpms(encoder, encoder_dpms);
  848.         }
  849.  
  850.         /* from on to off, do encoder then crtc */
  851.         if (mode > old_dpms) {
  852.                 if (encoder)
  853.                         drm_helper_encoder_dpms(encoder, encoder_dpms);
  854.                 if (crtc) {
  855.                         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
  856.                         if (crtc_funcs->dpms)
  857.                                 (*crtc_funcs->dpms) (crtc,
  858.                                                      drm_helper_choose_crtc_dpms(crtc));
  859.                 }
  860.         }
  861.  
  862.         return 0;
  863. }
  864. EXPORT_SYMBOL(drm_helper_connector_dpms);
  865.  
  866. /**
  867.  * drm_helper_mode_fill_fb_struct - fill out framebuffer metadata
  868.  * @fb: drm_framebuffer object to fill out
  869.  * @mode_cmd: metadata from the userspace fb creation request
  870.  *
  871.  * This helper can be used in a drivers fb_create callback to pre-fill the fb's
  872.  * metadata fields.
  873.  */
  874. void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
  875.                                     const struct drm_mode_fb_cmd2 *mode_cmd)
  876. {
  877.         int i;
  878.  
  879.         fb->width = mode_cmd->width;
  880.         fb->height = mode_cmd->height;
  881.         for (i = 0; i < 4; i++) {
  882.                 fb->pitches[i] = mode_cmd->pitches[i];
  883.                 fb->offsets[i] = mode_cmd->offsets[i];
  884.                 fb->modifier[i] = mode_cmd->modifier[i];
  885.         }
  886.         drm_fb_get_bpp_depth(mode_cmd->pixel_format, &fb->depth,
  887.                                     &fb->bits_per_pixel);
  888.         fb->pixel_format = mode_cmd->pixel_format;
  889.         fb->flags = mode_cmd->flags;
  890. }
  891. EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct);
  892.  
  893. /**
  894.  * drm_helper_resume_force_mode - force-restore mode setting configuration
  895.  * @dev: drm_device which should be restored
  896.  *
  897.  * Drivers which use the mode setting helpers can use this function to
  898.  * force-restore the mode setting configuration e.g. on resume or when something
  899.  * else might have trampled over the hw state (like some overzealous old BIOSen
  900.  * tended to do).
  901.  *
  902.  * This helper doesn't provide a error return value since restoring the old
  903.  * config should never fail due to resource allocation issues since the driver
  904.  * has successfully set the restored configuration already. Hence this should
  905.  * boil down to the equivalent of a few dpms on calls, which also don't provide
  906.  * an error code.
  907.  *
  908.  * Drivers where simply restoring an old configuration again might fail (e.g.
  909.  * due to slight differences in allocating shared resources when the
  910.  * configuration is restored in a different order than when userspace set it up)
  911.  * need to use their own restore logic.
  912.  *
  913.  * This function is deprecated. New drivers should implement atomic mode-
  914.  * setting and use the atomic suspend/resume helpers.
  915.  *
  916.  * See also:
  917.  * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
  918.  */
  919. void drm_helper_resume_force_mode(struct drm_device *dev)
  920. {
  921.         struct drm_crtc *crtc;
  922.         struct drm_encoder *encoder;
  923.         const struct drm_crtc_helper_funcs *crtc_funcs;
  924.         int encoder_dpms;
  925.         bool ret;
  926.  
  927.         drm_modeset_lock_all(dev);
  928.         drm_for_each_crtc(crtc, dev) {
  929.  
  930.                 if (!crtc->enabled)
  931.                         continue;
  932.  
  933.                 ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
  934.                                                crtc->x, crtc->y, crtc->primary->fb);
  935.  
  936.                 /* Restoring the old config should never fail! */
  937.                 if (ret == false)
  938.                         DRM_ERROR("failed to set mode on crtc %p\n", crtc);
  939.  
  940.                 /* Turn off outputs that were already powered off */
  941.                 if (drm_helper_choose_crtc_dpms(crtc)) {
  942.                         drm_for_each_encoder(encoder, dev) {
  943.  
  944.                                 if(encoder->crtc != crtc)
  945.                                         continue;
  946.  
  947.                                 encoder_dpms = drm_helper_choose_encoder_dpms(
  948.                                                         encoder);
  949.  
  950.                                 drm_helper_encoder_dpms(encoder, encoder_dpms);
  951.                         }
  952.  
  953.                         crtc_funcs = crtc->helper_private;
  954.                         if (crtc_funcs->dpms)
  955.                                 (*crtc_funcs->dpms) (crtc,
  956.                                                      drm_helper_choose_crtc_dpms(crtc));
  957.                 }
  958.         }
  959.  
  960.         /* disable the unused connectors while restoring the modesetting */
  961.         __drm_helper_disable_unused_functions(dev);
  962.         drm_modeset_unlock_all(dev);
  963. }
  964. EXPORT_SYMBOL(drm_helper_resume_force_mode);
  965.  
  966. /**
  967.  * drm_helper_crtc_mode_set - mode_set implementation for atomic plane helpers
  968.  * @crtc: DRM CRTC
  969.  * @mode: DRM display mode which userspace requested
  970.  * @adjusted_mode: DRM display mode adjusted by ->mode_fixup callbacks
  971.  * @x: x offset of the CRTC scanout area on the underlying framebuffer
  972.  * @y: y offset of the CRTC scanout area on the underlying framebuffer
  973.  * @old_fb: previous framebuffer
  974.  *
  975.  * This function implements a callback useable as the ->mode_set callback
  976.  * required by the CRTC helpers. Besides the atomic plane helper functions for
  977.  * the primary plane the driver must also provide the ->mode_set_nofb callback
  978.  * to set up the CRTC.
  979.  *
  980.  * This is a transitional helper useful for converting drivers to the atomic
  981.  * interfaces.
  982.  */
  983. int drm_helper_crtc_mode_set(struct drm_crtc *crtc, struct drm_display_mode *mode,
  984.                              struct drm_display_mode *adjusted_mode, int x, int y,
  985.                              struct drm_framebuffer *old_fb)
  986. {
  987.         struct drm_crtc_state *crtc_state;
  988.         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
  989.         int ret;
  990.  
  991.         if (crtc->funcs->atomic_duplicate_state)
  992.                 crtc_state = crtc->funcs->atomic_duplicate_state(crtc);
  993.         else {
  994.                 if (!crtc->state)
  995.                         drm_atomic_helper_crtc_reset(crtc);
  996.  
  997.                 crtc_state = drm_atomic_helper_crtc_duplicate_state(crtc);
  998.         }
  999.  
  1000.         if (!crtc_state)
  1001.                 return -ENOMEM;
  1002.  
  1003.         crtc_state->planes_changed = true;
  1004.         crtc_state->mode_changed = true;
  1005.         ret = drm_atomic_set_mode_for_crtc(crtc_state, mode);
  1006.         if (ret)
  1007.                 goto out;
  1008.         drm_mode_copy(&crtc_state->adjusted_mode, adjusted_mode);
  1009.  
  1010.         if (crtc_funcs->atomic_check) {
  1011.                 ret = crtc_funcs->atomic_check(crtc, crtc_state);
  1012.                 if (ret)
  1013.                         goto out;
  1014.         }
  1015.  
  1016.         swap(crtc->state, crtc_state);
  1017.  
  1018.         crtc_funcs->mode_set_nofb(crtc);
  1019.  
  1020.         ret = drm_helper_crtc_mode_set_base(crtc, x, y, old_fb);
  1021.  
  1022. out:
  1023.         if (crtc_state) {
  1024.                 if (crtc->funcs->atomic_destroy_state)
  1025.                         crtc->funcs->atomic_destroy_state(crtc, crtc_state);
  1026.                 else
  1027.                         drm_atomic_helper_crtc_destroy_state(crtc, crtc_state);
  1028.         }
  1029.  
  1030.         return ret;
  1031. }
  1032. EXPORT_SYMBOL(drm_helper_crtc_mode_set);
  1033.  
  1034. /**
  1035.  * drm_helper_crtc_mode_set_base - mode_set_base implementation for atomic plane helpers
  1036.  * @crtc: DRM CRTC
  1037.  * @x: x offset of the CRTC scanout area on the underlying framebuffer
  1038.  * @y: y offset of the CRTC scanout area on the underlying framebuffer
  1039.  * @old_fb: previous framebuffer
  1040.  *
  1041.  * This function implements a callback useable as the ->mode_set_base used
  1042.  * required by the CRTC helpers. The driver must provide the atomic plane helper
  1043.  * functions for the primary plane.
  1044.  *
  1045.  * This is a transitional helper useful for converting drivers to the atomic
  1046.  * interfaces.
  1047.  */
  1048. int drm_helper_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
  1049.                                   struct drm_framebuffer *old_fb)
  1050. {
  1051.         struct drm_plane_state *plane_state;
  1052.         struct drm_plane *plane = crtc->primary;
  1053.  
  1054.         if (plane->funcs->atomic_duplicate_state)
  1055.                 plane_state = plane->funcs->atomic_duplicate_state(plane);
  1056.         else if (plane->state)
  1057.                 plane_state = drm_atomic_helper_plane_duplicate_state(plane);
  1058.         else
  1059.                 plane_state = kzalloc(sizeof(*plane_state), GFP_KERNEL);
  1060.         if (!plane_state)
  1061.                 return -ENOMEM;
  1062.         plane_state->plane = plane;
  1063.  
  1064.         plane_state->crtc = crtc;
  1065.         drm_atomic_set_fb_for_plane(plane_state, crtc->primary->fb);
  1066.         plane_state->crtc_x = 0;
  1067.         plane_state->crtc_y = 0;
  1068.         plane_state->crtc_h = crtc->mode.vdisplay;
  1069.         plane_state->crtc_w = crtc->mode.hdisplay;
  1070.         plane_state->src_x = x << 16;
  1071.         plane_state->src_y = y << 16;
  1072.         plane_state->src_h = crtc->mode.vdisplay << 16;
  1073.         plane_state->src_w = crtc->mode.hdisplay << 16;
  1074.  
  1075.         return drm_plane_helper_commit(plane, plane_state, old_fb);
  1076. }
  1077. EXPORT_SYMBOL(drm_helper_crtc_mode_set_base);
  1078.  
  1079. /**
  1080.  * drm_helper_crtc_enable_color_mgmt - enable color management properties
  1081.  * @crtc: DRM CRTC
  1082.  * @degamma_lut_size: the size of the degamma lut (before CSC)
  1083.  * @gamma_lut_size: the size of the gamma lut (after CSC)
  1084.  *
  1085.  * This function lets the driver enable the color correction properties on a
  1086.  * CRTC. This includes 3 degamma, csc and gamma properties that userspace can
  1087.  * set and 2 size properties to inform the userspace of the lut sizes.
  1088.  */
  1089. void drm_helper_crtc_enable_color_mgmt(struct drm_crtc *crtc,
  1090.                                        int degamma_lut_size,
  1091.                                        int gamma_lut_size)
  1092. {
  1093.         struct drm_device *dev = crtc->dev;
  1094.         struct drm_mode_config *config = &dev->mode_config;
  1095.  
  1096.         drm_object_attach_property(&crtc->base,
  1097.                                    config->degamma_lut_property, 0);
  1098.         drm_object_attach_property(&crtc->base,
  1099.                                    config->ctm_property, 0);
  1100.         drm_object_attach_property(&crtc->base,
  1101.                                    config->gamma_lut_property, 0);
  1102.  
  1103.         drm_object_attach_property(&crtc->base,
  1104.                                    config->degamma_lut_size_property,
  1105.                                    degamma_lut_size);
  1106.         drm_object_attach_property(&crtc->base,
  1107.                                    config->gamma_lut_size_property,
  1108.                                    gamma_lut_size);
  1109. }
  1110. EXPORT_SYMBOL(drm_helper_crtc_enable_color_mgmt);
  1111.