// SPDX-License-Identifier: MIT
/*
 * Copyright 2018 Noralf Trønnes
 * Copyright (c) 2006-2009 Red Hat Inc.
 * Copyright (c) 2006-2008 Intel Corporation
 *   Jesse Barnes <jesse.barnes@intel.com>
 * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
 */

#include "drm/drm_modeset_lock.h"
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>

#include <drm/drm_atomic.h>
#include <drm/drm_client.h>
#include <drm/drm_connector.h>
#include <drm/drm_crtc.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_encoder.h>
#include <drm/drm_print.h>

#include "drm_crtc_internal.h"
#include "drm_internal.h"

#define DRM_CLIENT_MAX_CLONED_CONNECTORS        8

struct drm_client_offset {
        int x, y;
};

int drm_client_modeset_create(struct drm_client_dev *client)
{
        struct drm_device *dev = client->dev;
        unsigned int num_crtc = dev->mode_config.num_crtc;
        unsigned int max_connector_count = 1;
        struct drm_mode_set *modeset;
        struct drm_crtc *crtc;
        unsigned int i = 0;

        /* Add terminating zero entry to enable index less iteration */
        client->modesets = kcalloc(num_crtc + 1, sizeof(*client->modesets), GFP_KERNEL);
        if (!client->modesets)
                return -ENOMEM;

        mutex_init(&client->modeset_mutex);

        drm_for_each_crtc(crtc, dev)
                client->modesets[i++].crtc = crtc;

        /* Cloning is only supported in the single crtc case. */
        if (num_crtc == 1)
                max_connector_count = DRM_CLIENT_MAX_CLONED_CONNECTORS;

        for (modeset = client->modesets; modeset->crtc; modeset++) {
                modeset->connectors = kcalloc(max_connector_count,
                                              sizeof(*modeset->connectors), GFP_KERNEL);
                if (!modeset->connectors)
                        goto err_free;
        }

        return 0;

err_free:
        drm_client_modeset_free(client);

        return -ENOMEM;
}

static void drm_client_modeset_release(struct drm_client_dev *client)
{
        struct drm_mode_set *modeset;
        unsigned int i;

        drm_client_for_each_modeset(modeset, client) {
                drm_mode_destroy(client->dev, modeset->mode);
                modeset->mode = NULL;
                modeset->fb = NULL;

                for (i = 0; i < modeset->num_connectors; i++) {
                        drm_connector_put(modeset->connectors[i]);
                        modeset->connectors[i] = NULL;
                }
                modeset->num_connectors = 0;
        }
}

void drm_client_modeset_free(struct drm_client_dev *client)
{
        struct drm_mode_set *modeset;

        mutex_lock(&client->modeset_mutex);

        drm_client_modeset_release(client);

        drm_client_for_each_modeset(modeset, client)
                kfree(modeset->connectors);

        mutex_unlock(&client->modeset_mutex);

        mutex_destroy(&client->modeset_mutex);
        kfree(client->modesets);
}

static struct drm_mode_set *
drm_client_find_modeset(struct drm_client_dev *client, struct drm_crtc *crtc)
{
        struct drm_mode_set *modeset;

        drm_client_for_each_modeset(modeset, client)
                if (modeset->crtc == crtc)
                        return modeset;

        return NULL;
}

static struct drm_display_mode *
drm_connector_get_tiled_mode(struct drm_connector *connector)
{
        struct drm_display_mode *mode;

        list_for_each_entry(mode, &connector->modes, head) {
                if (mode->hdisplay == connector->tile_h_size &&
                    mode->vdisplay == connector->tile_v_size)
                        return mode;
        }
        return NULL;
}

static struct drm_display_mode *
drm_connector_fallback_non_tiled_mode(struct drm_connector *connector)
{
        struct drm_display_mode *mode;

        list_for_each_entry(mode, &connector->modes, head) {
                if (mode->hdisplay == connector->tile_h_size &&
                    mode->vdisplay == connector->tile_v_size)
                        continue;
                return mode;
        }
        return NULL;
}

static struct drm_display_mode *
drm_connector_has_preferred_mode(struct drm_connector *connector, int width, int height)
{
        struct drm_display_mode *mode;

        list_for_each_entry(mode, &connector->modes, head) {
                if (mode->hdisplay > width ||
                    mode->vdisplay > height)
                        continue;
                if (mode->type & DRM_MODE_TYPE_PREFERRED)
                        return mode;
        }
        return NULL;
}

static struct drm_display_mode *
drm_connector_pick_cmdline_mode(struct drm_connector *connector)
{
        struct drm_cmdline_mode *cmdline_mode;
        struct drm_display_mode *mode;
        bool prefer_non_interlace;

        cmdline_mode = &connector->cmdline_mode;
        if (cmdline_mode->specified == false)
                return NULL;

        /* attempt to find a matching mode in the list of modes
         *  we have gotten so far, if not add a CVT mode that conforms
         */
        if (cmdline_mode->rb || cmdline_mode->margins)
                goto create_mode;

        prefer_non_interlace = !cmdline_mode->interlace;
again:
        list_for_each_entry(mode, &connector->modes, head) {
                /* Check (optional) mode name first */
                if (!strcmp(mode->name, cmdline_mode->name))
                        return mode;

                /* check width/height */
                if (mode->hdisplay != cmdline_mode->xres ||
                    mode->vdisplay != cmdline_mode->yres)
                        continue;

                if (cmdline_mode->refresh_specified) {
                        if (drm_mode_vrefresh(mode) != cmdline_mode->refresh)
                                continue;
                }

                if (cmdline_mode->interlace) {
                        if (!(mode->flags & DRM_MODE_FLAG_INTERLACE))
                                continue;
                } else if (prefer_non_interlace) {
                        if (mode->flags & DRM_MODE_FLAG_INTERLACE)
                                continue;
                }
                return mode;
        }

        if (prefer_non_interlace) {
                prefer_non_interlace = false;
                goto again;
        }

create_mode:
        mode = drm_mode_create_from_cmdline_mode(connector->dev, cmdline_mode);
        if (mode)
                list_add(&mode->head, &connector->modes);

        return mode;
}

static bool drm_connector_enabled(struct drm_connector *connector, bool strict)
{
        bool enable;

        if (connector->display_info.non_desktop)
                return false;

        if (strict)
                enable = connector->status == connector_status_connected;
        else
                enable = connector->status != connector_status_disconnected;

        return enable;
}

static void drm_client_connectors_enabled(struct drm_connector **connectors,
                                          unsigned int connector_count,
                                          bool *enabled)
{
        bool any_enabled = false;
        struct drm_connector *connector;
        int i = 0;

        for (i = 0; i < connector_count; i++) {
                connector = connectors[i];
                enabled[i] = drm_connector_enabled(connector, true);
                DRM_DEBUG_KMS("connector %d enabled? %s\n", connector->base.id,
                              connector->display_info.non_desktop ? "non desktop" : enabled[i] ? "yes" : "no");

                any_enabled |= enabled[i];
        }

        if (any_enabled)
                return;

        for (i = 0; i < connector_count; i++)
                enabled[i] = drm_connector_enabled(connectors[i], false);
}

static bool drm_client_target_cloned(struct drm_device *dev,
                                     struct drm_connector **connectors,
                                     unsigned int connector_count,
                                     struct drm_display_mode **modes,
                                     struct drm_client_offset *offsets,
                                     bool *enabled, int width, int height)
{
        int count, i, j;
        bool can_clone = false;
        struct drm_display_mode *dmt_mode, *mode;

        /* only contemplate cloning in the single crtc case */
        if (dev->mode_config.num_crtc > 1)
                return false;

        count = 0;
        for (i = 0; i < connector_count; i++) {
                if (enabled[i])
                        count++;
        }

        /* only contemplate cloning if more than one connector is enabled */
        if (count <= 1)
                return false;

        /* check the command line or if nothing common pick 1024x768 */
        can_clone = true;
        for (i = 0; i < connector_count; i++) {
                if (!enabled[i])
                        continue;
                modes[i] = drm_connector_pick_cmdline_mode(connectors[i]);
                if (!modes[i]) {
                        can_clone = false;
                        break;
                }
                for (j = 0; j < i; j++) {
                        if (!enabled[j])
                                continue;
                        if (!drm_mode_match(modes[j], modes[i],
                                            DRM_MODE_MATCH_TIMINGS |
                                            DRM_MODE_MATCH_CLOCK |
                                            DRM_MODE_MATCH_FLAGS |
                                            DRM_MODE_MATCH_3D_FLAGS))
                                can_clone = false;
                }
        }

        if (can_clone) {
                DRM_DEBUG_KMS("can clone using command line\n");
                return true;
        }

        /* try and find a 1024x768 mode on each connector */
        can_clone = true;
        dmt_mode = drm_mode_find_dmt(dev, 1024, 768, 60, false);

        for (i = 0; i < connector_count; i++) {
                if (!enabled[i])
                        continue;

                list_for_each_entry(mode, &connectors[i]->modes, head) {
                        if (drm_mode_match(mode, dmt_mode,
                                           DRM_MODE_MATCH_TIMINGS |
                                           DRM_MODE_MATCH_CLOCK |
                                           DRM_MODE_MATCH_FLAGS |
                                           DRM_MODE_MATCH_3D_FLAGS))
                                modes[i] = mode;
                }
                if (!modes[i])
                        can_clone = false;
        }

        if (can_clone) {
                DRM_DEBUG_KMS("can clone using 1024x768\n");
                return true;
        }
        DRM_INFO("kms: can't enable cloning when we probably wanted to.\n");
        return false;
}

static int drm_client_get_tile_offsets(struct drm_connector **connectors,
                                       unsigned int connector_count,
                                       struct drm_display_mode **modes,
                                       struct drm_client_offset *offsets,
                                       int idx,
                                       int h_idx, int v_idx)
{
        struct drm_connector *connector;
        int i;
        int hoffset = 0, voffset = 0;

        for (i = 0; i < connector_count; i++) {
                connector = connectors[i];
                if (!connector->has_tile)
                        continue;

                if (!modes[i] && (h_idx || v_idx)) {
                        DRM_DEBUG_KMS("no modes for connector tiled %d %d\n", i,
                                      connector->base.id);
                        continue;
                }
                if (connector->tile_h_loc < h_idx)
                        hoffset += modes[i]->hdisplay;

                if (connector->tile_v_loc < v_idx)
                        voffset += modes[i]->vdisplay;
        }
        offsets[idx].x = hoffset;
        offsets[idx].y = voffset;
        DRM_DEBUG_KMS("returned %d %d for %d %d\n", hoffset, voffset, h_idx, v_idx);
        return 0;
}

static bool drm_client_target_preferred(struct drm_connector **connectors,
                                        unsigned int connector_count,
                                        struct drm_display_mode **modes,
                                        struct drm_client_offset *offsets,
                                        bool *enabled, int width, int height)
{
        const u64 mask = BIT_ULL(connector_count) - 1;
        struct drm_connector *connector;
        u64 conn_configured = 0;
        int tile_pass = 0;
        int num_tiled_conns = 0;
        int i;

        for (i = 0; i < connector_count; i++) {
                if (connectors[i]->has_tile &&
                    connectors[i]->status == connector_status_connected)
                        num_tiled_conns++;
        }

retry:
        for (i = 0; i < connector_count; i++) {
                connector = connectors[i];

                if (conn_configured & BIT_ULL(i))
                        continue;

                if (enabled[i] == false) {
                        conn_configured |= BIT_ULL(i);
                        continue;
                }

                /* first pass over all the untiled connectors */
                if (tile_pass == 0 && connector->has_tile)
                        continue;

                if (tile_pass == 1) {
                        if (connector->tile_h_loc != 0 ||
                            connector->tile_v_loc != 0)
                                continue;

                } else {
                        if (connector->tile_h_loc != tile_pass - 1 &&
                            connector->tile_v_loc != tile_pass - 1)
                        /* if this tile_pass doesn't cover any of the tiles - keep going */
                                continue;

                        /*
                         * find the tile offsets for this pass - need to find
                         * all tiles left and above
                         */
                        drm_client_get_tile_offsets(connectors, connector_count, modes, offsets, i,
                                                    connector->tile_h_loc, connector->tile_v_loc);
                }
                DRM_DEBUG_KMS("looking for cmdline mode on connector %d\n",
                              connector->base.id);

                /* got for command line mode first */
                modes[i] = drm_connector_pick_cmdline_mode(connector);
                if (!modes[i]) {
                        DRM_DEBUG_KMS("looking for preferred mode on connector %d %d\n",
                                      connector->base.id, connector->tile_group ? connector->tile_group->id : 0);
                        modes[i] = drm_connector_has_preferred_mode(connector, width, height);
                }
                /* No preferred modes, pick one off the list */
                if (!modes[i] && !list_empty(&connector->modes)) {
                        list_for_each_entry(modes[i], &connector->modes, head)
                                break;
                }
                /*
                 * In case of tiled mode if all tiles not present fallback to
                 * first available non tiled mode.
                 * After all tiles are present, try to find the tiled mode
                 * for all and if tiled mode not present due to fbcon size
                 * limitations, use first non tiled mode only for
                 * tile 0,0 and set to no mode for all other tiles.
                 */
                if (connector->has_tile) {
                        if (num_tiled_conns <
                            connector->num_h_tile * connector->num_v_tile ||
                            (connector->tile_h_loc == 0 &&
                             connector->tile_v_loc == 0 &&
                             !drm_connector_get_tiled_mode(connector))) {
                                DRM_DEBUG_KMS("Falling back to non tiled mode on Connector %d\n",
                                              connector->base.id);
                                modes[i] = drm_connector_fallback_non_tiled_mode(connector);
                        } else {
                                modes[i] = drm_connector_get_tiled_mode(connector);
                        }
                }

                DRM_DEBUG_KMS("found mode %s\n", modes[i] ? modes[i]->name :
                          "none");
                conn_configured |= BIT_ULL(i);
        }

        if ((conn_configured & mask) != mask) {
                tile_pass++;
                goto retry;
        }
        return true;
}

static bool connector_has_possible_crtc(struct drm_connector *connector,
                                        struct drm_crtc *crtc)
{
        struct drm_encoder *encoder;

        drm_connector_for_each_possible_encoder(connector, encoder) {
                if (encoder->possible_crtcs & drm_crtc_mask(crtc))
                        return true;
        }

        return false;
}

static int drm_client_pick_crtcs(struct drm_client_dev *client,
                                 struct drm_connector **connectors,
                                 unsigned int connector_count,
                                 struct drm_crtc **best_crtcs,
                                 struct drm_display_mode **modes,
                                 int n, int width, int height)
{
        struct drm_device *dev = client->dev;
        struct drm_connector *connector;
        int my_score, best_score, score;
        struct drm_crtc **crtcs, *crtc;
        struct drm_mode_set *modeset;
        int o;

        if (n == connector_count)
                return 0;

        connector = connectors[n];

        best_crtcs[n] = NULL;
        best_score = drm_client_pick_crtcs(client, connectors, connector_count,
                                           best_crtcs, modes, n + 1, width, height);
        if (modes[n] == NULL)
                return best_score;

        crtcs = kcalloc(connector_count, sizeof(*crtcs), GFP_KERNEL);
        if (!crtcs)
                return best_score;

        my_score = 1;
        if (connector->status == connector_status_connected)
                my_score++;
        if (connector->cmdline_mode.specified)
                my_score++;
        if (drm_connector_has_preferred_mode(connector, width, height))
                my_score++;

        /*
         * select a crtc for this connector and then attempt to configure
         * remaining connectors
         */
        drm_client_for_each_modeset(modeset, client) {
                crtc = modeset->crtc;

                if (!connector_has_possible_crtc(connector, crtc))
                        continue;

                for (o = 0; o < n; o++)
                        if (best_crtcs[o] == crtc)
                                break;

                if (o < n) {
                        /* ignore cloning unless only a single crtc */
                        if (dev->mode_config.num_crtc > 1)
                                continue;

                        if (!drm_mode_equal(modes[o], modes[n]))
                                continue;
                }

                crtcs[n] = crtc;
                memcpy(crtcs, best_crtcs, n * sizeof(*crtcs));
                score = my_score + drm_client_pick_crtcs(client, connectors, connector_count,
                                                         crtcs, modes, n + 1, width, height);
                if (score > best_score) {
                        best_score = score;
                        memcpy(best_crtcs, crtcs, connector_count * sizeof(*crtcs));
                }
        }

        kfree(crtcs);
        return best_score;
}

/* Try to read the BIOS display configuration and use it for the initial config */
static bool drm_client_firmware_config(struct drm_client_dev *client,
                                       struct drm_connector **connectors,
                                       unsigned int connector_count,
                                       struct drm_crtc **crtcs,
                                       struct drm_display_mode **modes,
                                       struct drm_client_offset *offsets,
                                       bool *enabled, int width, int height)
{
        const int count = min_t(unsigned int, connector_count, BITS_PER_LONG);
        unsigned long conn_configured, conn_seq, mask;
        struct drm_device *dev = client->dev;
        int i, j;
        bool *save_enabled;
        bool fallback = true, ret = true;
        int num_connectors_enabled = 0;
        int num_connectors_detected = 0;
        int num_tiled_conns = 0;
        struct drm_modeset_acquire_ctx ctx;

        if (!drm_drv_uses_atomic_modeset(dev))
                return false;

        if (WARN_ON(count <= 0))
                return false;

        save_enabled = kcalloc(count, sizeof(bool), GFP_KERNEL);
        if (!save_enabled)
                return false;

        drm_modeset_acquire_init(&ctx, 0);

        while (drm_modeset_lock_all_ctx(dev, &ctx) != 0)
                drm_modeset_backoff(&ctx);

        memcpy(save_enabled, enabled, count);
        mask = GENMASK(count - 1, 0);
        conn_configured = 0;
        for (i = 0; i < count; i++) {
                if (connectors[i]->has_tile &&
                    connectors[i]->status == connector_status_connected)
                        num_tiled_conns++;
        }
retry:
        conn_seq = conn_configured;
        for (i = 0; i < count; i++) {
                struct drm_connector *connector;
                struct drm_encoder *encoder;
                struct drm_crtc *new_crtc;

                connector = connectors[i];

                if (conn_configured & BIT(i))
                        continue;

                if (conn_seq == 0 && !connector->has_tile)
                        continue;

                if (connector->status == connector_status_connected)
                        num_connectors_detected++;

                if (!enabled[i]) {
                        DRM_DEBUG_KMS("connector %s not enabled, skipping\n",
                                      connector->name);
                        conn_configured |= BIT(i);
                        continue;
                }

                if (connector->force == DRM_FORCE_OFF) {
                        DRM_DEBUG_KMS("connector %s is disabled by user, skipping\n",
                                      connector->name);
                        enabled[i] = false;
                        continue;
                }

                encoder = connector->state->best_encoder;
                if (!encoder || WARN_ON(!connector->state->crtc)) {
                        if (connector->force > DRM_FORCE_OFF)
                                goto bail;

                        DRM_DEBUG_KMS("connector %s has no encoder or crtc, skipping\n",
                                      connector->name);
                        enabled[i] = false;
                        conn_configured |= BIT(i);
                        continue;
                }

                num_connectors_enabled++;

                new_crtc = connector->state->crtc;

                /*
                 * Make sure we're not trying to drive multiple connectors
                 * with a single CRTC, since our cloning support may not
                 * match the BIOS.
                 */
                for (j = 0; j < count; j++) {
                        if (crtcs[j] == new_crtc) {
                                DRM_DEBUG_KMS("fallback: cloned configuration\n");
                                goto bail;
                        }
                }

                DRM_DEBUG_KMS("looking for cmdline mode on connector %s\n",
                              connector->name);

                /* go for command line mode first */
                modes[i] = drm_connector_pick_cmdline_mode(connector);

                /* try for preferred next */
                if (!modes[i]) {
                        DRM_DEBUG_KMS("looking for preferred mode on connector %s %d\n",
                                      connector->name, connector->has_tile);
                        modes[i] = drm_connector_has_preferred_mode(connector, width, height);
                }

                /* No preferred mode marked by the EDID? Are there any modes? */
                if (!modes[i] && !list_empty(&connector->modes)) {
                        DRM_DEBUG_KMS("using first mode listed on connector %s\n",
                                      connector->name);
                        modes[i] = list_first_entry(&connector->modes,
                                                    struct drm_display_mode,
                                                    head);
                }

                /* last resort: use current mode */
                if (!modes[i]) {
                        /*
                         * IMPORTANT: We want to use the adjusted mode (i.e.
                         * after the panel fitter upscaling) as the initial
                         * config, not the input mode, which is what crtc->mode
                         * usually contains. But since our current
                         * code puts a mode derived from the post-pfit timings
                         * into crtc->mode this works out correctly.
                         *
                         * This is crtc->mode and not crtc->state->mode for the
                         * fastboot check to work correctly.
                         */
                        DRM_DEBUG_KMS("looking for current mode on connector %s\n",
                                      connector->name);
                        modes[i] = &connector->state->crtc->mode;
                }
                /*
                 * In case of tiled modes, if all tiles are not present
                 * then fallback to a non tiled mode.
                 */
                if (connector->has_tile &&
                    num_tiled_conns < connector->num_h_tile * connector->num_v_tile) {
                        DRM_DEBUG_KMS("Falling back to non tiled mode on Connector %d\n",
                                      connector->base.id);
                        modes[i] = drm_connector_fallback_non_tiled_mode(connector);
                }
                crtcs[i] = new_crtc;

                DRM_DEBUG_KMS("connector %s on [CRTC:%d:%s]: %dx%d%s\n",
                              connector->name,
                              connector->state->crtc->base.id,
                              connector->state->crtc->name,
                              modes[i]->hdisplay, modes[i]->vdisplay,
                              modes[i]->flags & DRM_MODE_FLAG_INTERLACE ? "i" : "");

                fallback = false;
                conn_configured |= BIT(i);
        }

        if ((conn_configured & mask) != mask && conn_configured != conn_seq)
                goto retry;

        /*
         * If the BIOS didn't enable everything it could, fall back to have the
         * same user experiencing of lighting up as much as possible like the
         * fbdev helper library.
         */
        if (num_connectors_enabled != num_connectors_detected &&
            num_connectors_enabled < dev->mode_config.num_crtc) {
                DRM_DEBUG_KMS("fallback: Not all outputs enabled\n");
                DRM_DEBUG_KMS("Enabled: %i, detected: %i\n", num_connectors_enabled,
                              num_connectors_detected);
                fallback = true;
        }

        if (fallback) {
bail:
                DRM_DEBUG_KMS("Not using firmware configuration\n");
                memcpy(enabled, save_enabled, count);
                ret = false;
        }

        drm_modeset_drop_locks(&ctx);
        drm_modeset_acquire_fini(&ctx);

        kfree(save_enabled);
        return ret;
}

/**
 * drm_client_modeset_probe() - Probe for displays
 * @client: DRM client
 * @width: Maximum display mode width (optional)
 * @height: Maximum display mode height (optional)
 *
 * This function sets up display pipelines for enabled connectors and stores the
 * config in the client's modeset array.
 *
 * Returns:
 * Zero on success or negative error code on failure.
 */
int drm_client_modeset_probe(struct drm_client_dev *client, unsigned int width, unsigned int height)
{
        struct drm_connector *connector, **connectors = NULL;
        struct drm_connector_list_iter conn_iter;
        struct drm_device *dev = client->dev;
        unsigned int total_modes_count = 0;
        struct drm_client_offset *offsets;
        unsigned int connector_count = 0;
        struct drm_display_mode **modes;
        struct drm_crtc **crtcs;
        int i, ret = 0;
        bool *enabled;

        DRM_DEBUG_KMS("\n");

        if (!width)
                width = dev->mode_config.max_width;
        if (!height)
                height = dev->mode_config.max_height;

        drm_connector_list_iter_begin(dev, &conn_iter);
        drm_client_for_each_connector_iter(connector, &conn_iter) {
                struct drm_connector **tmp;

                tmp = krealloc(connectors, (connector_count + 1) * sizeof(*connectors), GFP_KERNEL);
                if (!tmp) {
                        ret = -ENOMEM;
                        goto free_connectors;
                }

                connectors = tmp;
                drm_connector_get(connector);
                connectors[connector_count++] = connector;
        }
        drm_connector_list_iter_end(&conn_iter);

        if (!connector_count)
                return 0;

        crtcs = kcalloc(connector_count, sizeof(*crtcs), GFP_KERNEL);
        modes = kcalloc(connector_count, sizeof(*modes), GFP_KERNEL);
        offsets = kcalloc(connector_count, sizeof(*offsets), GFP_KERNEL);
        enabled = kcalloc(connector_count, sizeof(bool), GFP_KERNEL);
        if (!crtcs || !modes || !enabled || !offsets) {
                DRM_ERROR("Memory allocation failed\n");
                ret = -ENOMEM;
                goto out;
        }

        mutex_lock(&client->modeset_mutex);

        mutex_lock(&dev->mode_config.mutex);
        for (i = 0; i < connector_count; i++)
                total_modes_count += connectors[i]->funcs->fill_modes(connectors[i], width, height);
        if (!total_modes_count)
                DRM_DEBUG_KMS("No connectors reported connected with modes\n");
        drm_client_connectors_enabled(connectors, connector_count, enabled);

        if (!drm_client_firmware_config(client, connectors, connector_count, crtcs,
                                        modes, offsets, enabled, width, height)) {
                memset(modes, 0, connector_count * sizeof(*modes));
                memset(crtcs, 0, connector_count * sizeof(*crtcs));
                memset(offsets, 0, connector_count * sizeof(*offsets));

                if (!drm_client_target_cloned(dev, connectors, connector_count, modes,
                                              offsets, enabled, width, height) &&
                    !drm_client_target_preferred(connectors, connector_count, modes,
                                                 offsets, enabled, width, height))
                        DRM_ERROR("Unable to find initial modes\n");

                DRM_DEBUG_KMS("picking CRTCs for %dx%d config\n",
                              width, height);

                drm_client_pick_crtcs(client, connectors, connector_count,
                                      crtcs, modes, 0, width, height);
        }
        mutex_unlock(&dev->mode_config.mutex);

        drm_client_modeset_release(client);

        for (i = 0; i < connector_count; i++) {
                struct drm_display_mode *mode = modes[i];
                struct drm_crtc *crtc = crtcs[i];
                struct drm_client_offset *offset = &offsets[i];

                if (mode && crtc) {
                        struct drm_mode_set *modeset = drm_client_find_modeset(client, crtc);
                        struct drm_connector *connector = connectors[i];

                        DRM_DEBUG_KMS("desired mode %s set on crtc %d (%d,%d)\n",
                                      mode->name, crtc->base.id, offset->x, offset->y);

                        if (WARN_ON_ONCE(modeset->num_connectors == DRM_CLIENT_MAX_CLONED_CONNECTORS ||
                                         (dev->mode_config.num_crtc > 1 && modeset->num_connectors == 1))) {
                                ret = -EINVAL;
                                break;
                        }

                        modeset->mode = drm_mode_duplicate(dev, mode);
                        drm_connector_get(connector);
                        modeset->connectors[modeset->num_connectors++] = connector;
                        modeset->x = offset->x;
                        modeset->y = offset->y;
                }
        }

        mutex_unlock(&client->modeset_mutex);
out:
        kfree(crtcs);
        kfree(modes);
        kfree(offsets);
        kfree(enabled);
free_connectors:
        for (i = 0; i < connector_count; i++)
                drm_connector_put(connectors[i]);
        kfree(connectors);

        return ret;
}
EXPORT_SYMBOL(drm_client_modeset_probe);

/**
 * drm_client_rotation() - Check the initial rotation value
 * @modeset: DRM modeset
 * @rotation: Returned rotation value
 *
 * This function checks if the primary plane in @modeset can hw rotate
 * to match the rotation needed on its connector.
 *
 * Note: Currently only 0 and 180 degrees are supported.
 *
 * Return:
 * True if the plane can do the rotation, false otherwise.
 */
bool drm_client_rotation(struct drm_mode_set *modeset, unsigned int *rotation)
{
        struct drm_connector *connector = modeset->connectors[0];
        struct drm_plane *plane = modeset->crtc->primary;
        struct drm_cmdline_mode *cmdline;
        u64 valid_mask = 0;
        unsigned int i;

        if (!modeset->num_connectors)
                return false;

        switch (connector->display_info.panel_orientation) {
        case DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP:
                *rotation = DRM_MODE_ROTATE_180;
                break;
        case DRM_MODE_PANEL_ORIENTATION_LEFT_UP:
                *rotation = DRM_MODE_ROTATE_90;
                break;
        case DRM_MODE_PANEL_ORIENTATION_RIGHT_UP:
                *rotation = DRM_MODE_ROTATE_270;
                break;
        default:
                *rotation = DRM_MODE_ROTATE_0;
        }

        /**
         * The panel already defined the default rotation
         * through its orientation. Whatever has been provided
         * on the command line needs to be added to that.
         *
         * Unfortunately, the rotations are at different bit
         * indices, so the math to add them up are not as
         * trivial as they could.
         *
         * Reflections on the other hand are pretty trivial to deal with, a
         * simple XOR between the two handle the addition nicely.
         */
        cmdline = &connector->cmdline_mode;
        if (cmdline->specified && cmdline->rotation_reflection) {
                unsigned int cmdline_rest, panel_rest;
                unsigned int cmdline_rot, panel_rot;
                unsigned int sum_rot, sum_rest;

                panel_rot = ilog2(*rotation & DRM_MODE_ROTATE_MASK);
                cmdline_rot = ilog2(cmdline->rotation_reflection & DRM_MODE_ROTATE_MASK);
                sum_rot = (panel_rot + cmdline_rot) % 4;

                panel_rest = *rotation & ~DRM_MODE_ROTATE_MASK;
                cmdline_rest = cmdline->rotation_reflection & ~DRM_MODE_ROTATE_MASK;
                sum_rest = panel_rest ^ cmdline_rest;

                *rotation = (1 << sum_rot) | sum_rest;
        }

        /*
         * TODO: support 90 / 270 degree hardware rotation,
         * depending on the hardware this may require the framebuffer
         * to be in a specific tiling format.
         */
        if (((*rotation & DRM_MODE_ROTATE_MASK) != DRM_MODE_ROTATE_0 &&
             (*rotation & DRM_MODE_ROTATE_MASK) != DRM_MODE_ROTATE_180) ||
            !plane->rotation_property)
                return false;

        for (i = 0; i < plane->rotation_property->num_values; i++)
                valid_mask |= (1ULL << plane->rotation_property->values[i]);

        if (!(*rotation & valid_mask))
                return false;

        return true;
}
EXPORT_SYMBOL(drm_client_rotation);

static int drm_client_modeset_commit_atomic(struct drm_client_dev *client, bool active, bool check)
{
        struct drm_device *dev = client->dev;
        struct drm_plane *plane;
        struct drm_atomic_state *state;
        struct drm_modeset_acquire_ctx ctx;
        struct drm_mode_set *mode_set;
        int ret;

        drm_modeset_acquire_init(&ctx, 0);

        state = drm_atomic_state_alloc(dev);
        if (!state) {
                ret = -ENOMEM;
                goto out_ctx;
        }

        state->acquire_ctx = &ctx;
retry:
        drm_for_each_plane(plane, dev) {
                struct drm_plane_state *plane_state;

                plane_state = drm_atomic_get_plane_state(state, plane);
                if (IS_ERR(plane_state)) {
                        ret = PTR_ERR(plane_state);
                        goto out_state;
                }

                plane_state->rotation = DRM_MODE_ROTATE_0;

                /* disable non-primary: */
                if (plane->type == DRM_PLANE_TYPE_PRIMARY)
                        continue;

                ret = __drm_atomic_helper_disable_plane(plane, plane_state);
                if (ret != 0)
                        goto out_state;
        }

        drm_client_for_each_modeset(mode_set, client) {
                struct drm_plane *primary = mode_set->crtc->primary;
                unsigned int rotation;

                if (drm_client_rotation(mode_set, &rotation)) {
                        struct drm_plane_state *plane_state;

                        /* Cannot fail as we've already gotten the plane state above */
                        plane_state = drm_atomic_get_new_plane_state(state, primary);
                        plane_state->rotation = rotation;
                }

                ret = __drm_atomic_helper_set_config(mode_set, state);
                if (ret != 0)
                        goto out_state;

                /*
                 * __drm_atomic_helper_set_config() sets active when a
                 * mode is set, unconditionally clear it if we force DPMS off
                 */
                if (!active) {
                        struct drm_crtc *crtc = mode_set->crtc;
                        struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);

                        crtc_state->active = false;
                }
        }

        if (check)
                ret = drm_atomic_check_only(state);
        else
                ret = drm_atomic_commit(state);

out_state:
        if (ret == -EDEADLK)
                goto backoff;

        drm_atomic_state_put(state);
out_ctx:
        drm_modeset_drop_locks(&ctx);
        drm_modeset_acquire_fini(&ctx);

        return ret;

backoff:
        drm_atomic_state_clear(state);
        drm_modeset_backoff(&ctx);

        goto retry;
}

static int drm_client_modeset_commit_legacy(struct drm_client_dev *client)
{
        struct drm_device *dev = client->dev;
        struct drm_mode_set *mode_set;
        struct drm_plane *plane;
        int ret = 0;

        drm_modeset_lock_all(dev);
        drm_for_each_plane(plane, dev) {
                if (plane->type != DRM_PLANE_TYPE_PRIMARY)
                        drm_plane_force_disable(plane);

                if (plane->rotation_property)
                        drm_mode_plane_set_obj_prop(plane,
                                                    plane->rotation_property,
                                                    DRM_MODE_ROTATE_0);
        }

        drm_client_for_each_modeset(mode_set, client) {
                struct drm_crtc *crtc = mode_set->crtc;

                if (crtc->funcs->cursor_set2) {
                        ret = crtc->funcs->cursor_set2(crtc, NULL, 0, 0, 0, 0, 0);
                        if (ret)
                                goto out;
                } else if (crtc->funcs->cursor_set) {
                        ret = crtc->funcs->cursor_set(crtc, NULL, 0, 0, 0);
                        if (ret)
                                goto out;
                }

                ret = drm_mode_set_config_internal(mode_set);
                if (ret)
                        goto out;
        }
out:
        drm_modeset_unlock_all(dev);

        return ret;
}

/**
 * drm_client_modeset_check() - Check modeset configuration
 * @client: DRM client
 *
 * Check modeset configuration.
 *
 * Returns:
 * Zero on success or negative error code on failure.
 */
int drm_client_modeset_check(struct drm_client_dev *client)
{
        int ret;

        if (!drm_drv_uses_atomic_modeset(client->dev))
                return 0;

        mutex_lock(&client->modeset_mutex);
        ret = drm_client_modeset_commit_atomic(client, true, true);
        mutex_unlock(&client->modeset_mutex);

        return ret;
}
EXPORT_SYMBOL(drm_client_modeset_check);

/**
 * drm_client_modeset_commit_locked() - Force commit CRTC configuration
 * @client: DRM client
 *
 * Commit modeset configuration to crtcs without checking if there is a DRM
 * master. The assumption is that the caller already holds an internal DRM
 * master reference acquired with drm_master_internal_acquire().
 *
 * Returns:
 * Zero on success or negative error code on failure.
 */
int drm_client_modeset_commit_locked(struct drm_client_dev *client)
{
        struct drm_device *dev = client->dev;
        int ret;

        mutex_lock(&client->modeset_mutex);
        if (drm_drv_uses_atomic_modeset(dev))
                ret = drm_client_modeset_commit_atomic(client, true, false);
        else
                ret = drm_client_modeset_commit_legacy(client);
        mutex_unlock(&client->modeset_mutex);

        return ret;
}
EXPORT_SYMBOL(drm_client_modeset_commit_locked);

/**
 * drm_client_modeset_commit() - Commit CRTC configuration
 * @client: DRM client
 *
 * Commit modeset configuration to crtcs.
 *
 * Returns:
 * Zero on success or negative error code on failure.
 */
int drm_client_modeset_commit(struct drm_client_dev *client)
{
        struct drm_device *dev = client->dev;
        int ret;

        if (!drm_master_internal_acquire(dev))
                return -EBUSY;

        ret = drm_client_modeset_commit_locked(client);

        drm_master_internal_release(dev);

        return ret;
}
EXPORT_SYMBOL(drm_client_modeset_commit);

static void drm_client_modeset_dpms_legacy(struct drm_client_dev *client, int dpms_mode)
{
        struct drm_device *dev = client->dev;
        struct drm_connector *connector;
        struct drm_mode_set *modeset;
        struct drm_modeset_acquire_ctx ctx;
        int j;
        int ret;

        DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, 0, ret);
        drm_client_for_each_modeset(modeset, client) {
                if (!modeset->crtc->enabled)
                        continue;

                for (j = 0; j < modeset->num_connectors; j++) {
                        connector = modeset->connectors[j];
                        connector->funcs->dpms(connector, dpms_mode);
                        drm_object_property_set_value(&connector->base,
                                dev->mode_config.dpms_property, dpms_mode);
                }
        }
        DRM_MODESET_LOCK_ALL_END(dev, ctx, ret);
}

/**
 * drm_client_modeset_dpms() - Set DPMS mode
 * @client: DRM client
 * @mode: DPMS mode
 *
 * Note: For atomic drivers @mode is reduced to on/off.
 *
 * Returns:
 * Zero on success or negative error code on failure.
 */
int drm_client_modeset_dpms(struct drm_client_dev *client, int mode)
{
        struct drm_device *dev = client->dev;
        int ret = 0;

        if (!drm_master_internal_acquire(dev))
                return -EBUSY;

        mutex_lock(&client->modeset_mutex);
        if (drm_drv_uses_atomic_modeset(dev))
                ret = drm_client_modeset_commit_atomic(client, mode == DRM_MODE_DPMS_ON, false);
        else
                drm_client_modeset_dpms_legacy(client, mode);
        mutex_unlock(&client->modeset_mutex);

        drm_master_internal_release(dev);

        return ret;
}
EXPORT_SYMBOL(drm_client_modeset_dpms);