// SPDX-License-Identifier: GPL-2.0
/*
 * ZynqMP DisplayPort Subsystem - KMS API
 *
 * Copyright (C) 2017 - 2021 Xilinx, Inc.
 *
 * Authors:
 * - Hyun Woo Kwon <hyun.kwon@xilinx.com>
 * - Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 */

#include <drm/clients/drm_client_setup.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_blend.h>
#include <drm/drm_bridge.h>
#include <drm/drm_bridge_connector.h>
#include <drm/drm_connector.h>
#include <drm/drm_crtc.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_dumb_buffers.h>
#include <drm/drm_encoder.h>
#include <drm/drm_fbdev_dma.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_managed.h>
#include <drm/drm_mode_config.h>
#include <drm/drm_plane.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>
#include <drm/drm_vblank.h>

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/pm_runtime.h>
#include <linux/spinlock.h>

#include "zynqmp_disp.h"
#include "zynqmp_dp.h"
#include "zynqmp_dpsub.h"
#include "zynqmp_kms.h"

static inline struct zynqmp_dpsub *to_zynqmp_dpsub(struct drm_device *drm)
{
        return container_of(drm, struct zynqmp_dpsub_drm, dev)->dpsub;
}

/* -----------------------------------------------------------------------------
 * DRM Planes
 */

static int zynqmp_dpsub_plane_atomic_check(struct drm_plane *plane,
                                           struct drm_atomic_state *state)
{
        struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state,
                                                                                 plane);
        struct drm_crtc_state *crtc_state;

        if (!new_plane_state->crtc)
                return 0;

        crtc_state = drm_atomic_get_crtc_state(state, new_plane_state->crtc);
        if (IS_ERR(crtc_state))
                return PTR_ERR(crtc_state);

        return drm_atomic_helper_check_plane_state(new_plane_state,
                                                   crtc_state,
                                                   DRM_PLANE_NO_SCALING,
                                                   DRM_PLANE_NO_SCALING,
                                                   false, false);
}

static void zynqmp_dpsub_plane_atomic_disable(struct drm_plane *plane,
                                              struct drm_atomic_state *state)
{
        struct drm_plane_state *old_state = drm_atomic_get_old_plane_state(state,
                                                                           plane);
        struct zynqmp_dpsub *dpsub = to_zynqmp_dpsub(plane->dev);
        struct zynqmp_disp_layer *layer = dpsub->layers[plane->index];

        if (!old_state->fb)
                return;

        zynqmp_disp_layer_disable(layer);

        if (plane->index == ZYNQMP_DPSUB_LAYER_GFX)
                zynqmp_disp_blend_set_global_alpha(dpsub->disp, false,
                                                   plane->state->alpha >> 8);
}

static void zynqmp_dpsub_plane_atomic_update(struct drm_plane *plane,
                                             struct drm_atomic_state *state)
{
        struct drm_plane_state *old_state = drm_atomic_get_old_plane_state(state, plane);
        struct drm_plane_state *new_state = drm_atomic_get_new_plane_state(state, plane);
        struct zynqmp_dpsub *dpsub = to_zynqmp_dpsub(plane->dev);
        struct zynqmp_disp_layer *layer = dpsub->layers[plane->index];
        bool format_changed = false;

        if (!old_state->fb ||
            old_state->fb->format->format != new_state->fb->format->format)
                format_changed = true;

        /*
         * If the format has changed (including going from a previously
         * disabled state to any format), reconfigure the format. Disable the
         * plane first if needed.
         */
        if (format_changed) {
                if (old_state->fb)
                        zynqmp_disp_layer_disable(layer);

                zynqmp_disp_layer_set_format(layer, new_state->fb->format);
        }

        zynqmp_disp_layer_update(layer, new_state);

        if (plane->index == ZYNQMP_DPSUB_LAYER_GFX)
                zynqmp_disp_blend_set_global_alpha(dpsub->disp, true,
                                                   plane->state->alpha >> 8);

        /*
         * Unconditionally enable the layer, as it may have been disabled
         * previously either explicitly to reconfigure layer format, or
         * implicitly after DPSUB reset during display mode change. DRM
         * framework calls this callback for enabled planes only.
         */
        zynqmp_disp_layer_enable(layer);
}

static const struct drm_plane_helper_funcs zynqmp_dpsub_plane_helper_funcs = {
        .atomic_check           = zynqmp_dpsub_plane_atomic_check,
        .atomic_update          = zynqmp_dpsub_plane_atomic_update,
        .atomic_disable         = zynqmp_dpsub_plane_atomic_disable,
};

static const struct drm_plane_funcs zynqmp_dpsub_plane_funcs = {
        .update_plane           = drm_atomic_helper_update_plane,
        .disable_plane          = drm_atomic_helper_disable_plane,
        .destroy                = drm_plane_cleanup,
        .reset                  = drm_atomic_helper_plane_reset,
        .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
        .atomic_destroy_state   = drm_atomic_helper_plane_destroy_state,
};

static int zynqmp_dpsub_create_planes(struct zynqmp_dpsub *dpsub)
{
        unsigned int i;
        int ret;

        for (i = 0; i < ARRAY_SIZE(dpsub->drm->planes); i++) {
                struct zynqmp_disp_layer *layer = dpsub->layers[i];
                struct drm_plane *plane = &dpsub->drm->planes[i];
                enum drm_plane_type type;
                unsigned int num_formats;
                u32 *formats;

                formats = zynqmp_disp_layer_drm_formats(layer, &num_formats);
                if (!formats)
                        return -ENOMEM;

                /* Graphics layer is primary, and video layer is overlay. */
                type = i == ZYNQMP_DPSUB_LAYER_VID
                     ? DRM_PLANE_TYPE_OVERLAY : DRM_PLANE_TYPE_PRIMARY;
                ret = drm_universal_plane_init(&dpsub->drm->dev, plane, 0,
                                               &zynqmp_dpsub_plane_funcs,
                                               formats, num_formats,
                                               NULL, type, NULL);
                kfree(formats);
                if (ret)
                        return ret;

                drm_plane_helper_add(plane, &zynqmp_dpsub_plane_helper_funcs);

                drm_plane_create_zpos_immutable_property(plane, i);
                if (i == ZYNQMP_DPSUB_LAYER_GFX)
                        drm_plane_create_alpha_property(plane);
        }

        return 0;
}

/* -----------------------------------------------------------------------------
 * DRM CRTC
 */

static inline struct zynqmp_dpsub *crtc_to_dpsub(struct drm_crtc *crtc)
{
        return container_of(crtc, struct zynqmp_dpsub_drm, crtc)->dpsub;
}

static void zynqmp_dpsub_crtc_atomic_enable(struct drm_crtc *crtc,
                                            struct drm_atomic_state *state)
{
        struct zynqmp_dpsub *dpsub = crtc_to_dpsub(crtc);
        struct drm_display_mode *adjusted_mode = &crtc->state->adjusted_mode;
        int ret, vrefresh;

        pm_runtime_get_sync(dpsub->dev);

        zynqmp_disp_setup_clock(dpsub->disp, adjusted_mode->clock * 1000);

        ret = clk_prepare_enable(dpsub->vid_clk);
        if (ret) {
                dev_err(dpsub->dev, "failed to enable a pixel clock\n");
                pm_runtime_put_sync(dpsub->dev);
                return;
        }

        zynqmp_disp_enable(dpsub->disp);

        /* Delay of 3 vblank intervals for timing gen to be stable */
        vrefresh = (adjusted_mode->clock * 1000) /
                   (adjusted_mode->vtotal * adjusted_mode->htotal);
        msleep(3 * 1000 / vrefresh);
}

static void zynqmp_dpsub_crtc_atomic_disable(struct drm_crtc *crtc,
                                             struct drm_atomic_state *state)
{
        struct zynqmp_dpsub *dpsub = crtc_to_dpsub(crtc);
        struct drm_plane_state *old_plane_state;

        /*
         * Disable the plane if active. The old plane state can be NULL in the
         * .shutdown() path if the plane is already disabled, skip
         * zynqmp_disp_plane_atomic_disable() in that case.
         */
        old_plane_state = drm_atomic_get_old_plane_state(state, crtc->primary);
        if (old_plane_state)
                zynqmp_dpsub_plane_atomic_disable(crtc->primary, state);

        zynqmp_disp_disable(dpsub->disp);

        drm_crtc_vblank_off(crtc);

        spin_lock_irq(&crtc->dev->event_lock);
        if (crtc->state->event) {
                drm_crtc_send_vblank_event(crtc, crtc->state->event);
                crtc->state->event = NULL;
        }
        spin_unlock_irq(&crtc->dev->event_lock);

        clk_disable_unprepare(dpsub->vid_clk);
        pm_runtime_put_sync(dpsub->dev);
}

static int zynqmp_dpsub_crtc_atomic_check(struct drm_crtc *crtc,
                                          struct drm_atomic_state *state)
{
        return drm_atomic_add_affected_planes(state, crtc);
}

static void zynqmp_dpsub_crtc_atomic_begin(struct drm_crtc *crtc,
                                           struct drm_atomic_state *state)
{
        drm_crtc_vblank_on(crtc);
}

static void zynqmp_dpsub_crtc_atomic_flush(struct drm_crtc *crtc,
                                           struct drm_atomic_state *state)
{
        if (crtc->state->event) {
                struct drm_pending_vblank_event *event;

                /* Consume the flip_done event from atomic helper. */
                event = crtc->state->event;
                crtc->state->event = NULL;

                event->pipe = drm_crtc_index(crtc);

                WARN_ON(drm_crtc_vblank_get(crtc) != 0);

                spin_lock_irq(&crtc->dev->event_lock);
                drm_crtc_arm_vblank_event(crtc, event);
                spin_unlock_irq(&crtc->dev->event_lock);
        }
}

static const struct drm_crtc_helper_funcs zynqmp_dpsub_crtc_helper_funcs = {
        .atomic_enable  = zynqmp_dpsub_crtc_atomic_enable,
        .atomic_disable = zynqmp_dpsub_crtc_atomic_disable,
        .atomic_check   = zynqmp_dpsub_crtc_atomic_check,
        .atomic_begin   = zynqmp_dpsub_crtc_atomic_begin,
        .atomic_flush   = zynqmp_dpsub_crtc_atomic_flush,
};

static int zynqmp_dpsub_crtc_enable_vblank(struct drm_crtc *crtc)
{
        struct zynqmp_dpsub *dpsub = crtc_to_dpsub(crtc);

        zynqmp_dp_enable_vblank(dpsub->dp);

        return 0;
}

static void zynqmp_dpsub_crtc_disable_vblank(struct drm_crtc *crtc)
{
        struct zynqmp_dpsub *dpsub = crtc_to_dpsub(crtc);

        zynqmp_dp_disable_vblank(dpsub->dp);
}

static const struct drm_crtc_funcs zynqmp_dpsub_crtc_funcs = {
        .destroy                = drm_crtc_cleanup,
        .set_config             = drm_atomic_helper_set_config,
        .page_flip              = drm_atomic_helper_page_flip,
        .reset                  = drm_atomic_helper_crtc_reset,
        .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
        .atomic_destroy_state   = drm_atomic_helper_crtc_destroy_state,
        .enable_vblank          = zynqmp_dpsub_crtc_enable_vblank,
        .disable_vblank         = zynqmp_dpsub_crtc_disable_vblank,
};

static int zynqmp_dpsub_create_crtc(struct zynqmp_dpsub *dpsub)
{
        struct drm_plane *plane = &dpsub->drm->planes[ZYNQMP_DPSUB_LAYER_GFX];
        struct drm_crtc *crtc = &dpsub->drm->crtc;
        int ret;

        ret = drm_crtc_init_with_planes(&dpsub->drm->dev, crtc, plane,
                                        NULL, &zynqmp_dpsub_crtc_funcs, NULL);
        if (ret < 0)
                return ret;

        drm_crtc_helper_add(crtc, &zynqmp_dpsub_crtc_helper_funcs);

        /* Start with vertical blanking interrupt reporting disabled. */
        drm_crtc_vblank_off(crtc);

        return 0;
}

static void zynqmp_dpsub_map_crtc_to_plane(struct zynqmp_dpsub *dpsub)
{
        u32 possible_crtcs = drm_crtc_mask(&dpsub->drm->crtc);
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(dpsub->drm->planes); i++)
                dpsub->drm->planes[i].possible_crtcs = possible_crtcs;
}

/**
 * zynqmp_dpsub_drm_handle_vblank - Handle the vblank event
 * @dpsub: DisplayPort subsystem
 *
 * This function handles the vblank interrupt, and sends an event to
 * CRTC object. This will be called by the DP vblank interrupt handler.
 */
void zynqmp_dpsub_drm_handle_vblank(struct zynqmp_dpsub *dpsub)
{
        drm_crtc_handle_vblank(&dpsub->drm->crtc);
}

/* -----------------------------------------------------------------------------
 * Dumb Buffer & Framebuffer Allocation
 */

static int zynqmp_dpsub_dumb_create(struct drm_file *file_priv,
                                    struct drm_device *drm,
                                    struct drm_mode_create_dumb *args)
{
        struct zynqmp_dpsub *dpsub = to_zynqmp_dpsub(drm);
        int ret;

        /* Enforce the alignment constraints of the DMA engine. */
        ret = drm_mode_size_dumb(drm, args, dpsub->dma_align, 0);
        if (ret)
                return ret;

        return drm_gem_dma_dumb_create_internal(file_priv, drm, args);
}

static struct drm_framebuffer *
zynqmp_dpsub_fb_create(struct drm_device *drm, struct drm_file *file_priv,
                       const struct drm_format_info *info,
                       const struct drm_mode_fb_cmd2 *mode_cmd)
{
        struct zynqmp_dpsub *dpsub = to_zynqmp_dpsub(drm);
        struct drm_mode_fb_cmd2 cmd = *mode_cmd;
        unsigned int i;

        /* Enforce the alignment constraints of the DMA engine. */
        for (i = 0; i < ARRAY_SIZE(cmd.pitches); ++i)
                cmd.pitches[i] = ALIGN(cmd.pitches[i], dpsub->dma_align);

        return drm_gem_fb_create(drm, file_priv, info, &cmd);
}

static const struct drm_mode_config_funcs zynqmp_dpsub_mode_config_funcs = {
        .fb_create              = zynqmp_dpsub_fb_create,
        .atomic_check           = drm_atomic_helper_check,
        .atomic_commit          = drm_atomic_helper_commit,
};

/* -----------------------------------------------------------------------------
 * DRM/KMS Driver
 */

DEFINE_DRM_GEM_DMA_FOPS(zynqmp_dpsub_drm_fops);

static const struct drm_driver zynqmp_dpsub_drm_driver = {
        .driver_features                = DRIVER_MODESET | DRIVER_GEM |
                                          DRIVER_ATOMIC,

        DRM_GEM_DMA_DRIVER_OPS_WITH_DUMB_CREATE(zynqmp_dpsub_dumb_create),
        DRM_FBDEV_DMA_DRIVER_OPS,

        .fops                           = &zynqmp_dpsub_drm_fops,

        .name                           = "zynqmp-dpsub",
        .desc                           = "Xilinx DisplayPort Subsystem Driver",
        .major                          = 1,
        .minor                          = 0,
};

static int zynqmp_dpsub_kms_init(struct zynqmp_dpsub *dpsub)
{
        struct drm_encoder *encoder = &dpsub->drm->encoder;
        struct drm_connector *connector;
        int ret;

        /* Create the planes and the CRTC. */
        ret = zynqmp_dpsub_create_planes(dpsub);
        if (ret)
                return ret;

        ret = zynqmp_dpsub_create_crtc(dpsub);
        if (ret < 0)
                return ret;

        zynqmp_dpsub_map_crtc_to_plane(dpsub);

        /* Create the encoder and attach the bridge. */
        encoder->possible_crtcs |= drm_crtc_mask(&dpsub->drm->crtc);
        drm_simple_encoder_init(&dpsub->drm->dev, encoder, DRM_MODE_ENCODER_NONE);

        ret = drm_bridge_attach(encoder, dpsub->bridge, NULL,
                                DRM_BRIDGE_ATTACH_NO_CONNECTOR);
        if (ret) {
                dev_err(dpsub->dev, "failed to attach bridge to encoder\n");
                goto err_encoder;
        }

        /* Create the connector for the chain of bridges. */
        connector = drm_bridge_connector_init(&dpsub->drm->dev, encoder);
        if (IS_ERR(connector)) {
                dev_err(dpsub->dev, "failed to created connector\n");
                ret = PTR_ERR(connector);
                goto err_encoder;
        }

        ret = drm_connector_attach_encoder(connector, encoder);
        if (ret < 0) {
                dev_err(dpsub->dev, "failed to attach connector to encoder\n");
                goto err_encoder;
        }

        return 0;

err_encoder:
        drm_encoder_cleanup(encoder);
        return ret;
}

static void zynqmp_dpsub_drm_release(struct drm_device *drm, void *res)
{
        struct zynqmp_dpsub_drm *dpdrm = res;

        zynqmp_dpsub_release(dpdrm->dpsub);
}

int zynqmp_dpsub_drm_init(struct zynqmp_dpsub *dpsub)
{
        struct zynqmp_dpsub_drm *dpdrm;
        struct drm_device *drm;
        int ret;

        /*
         * Allocate the drm_device and immediately add a cleanup action to
         * release the zynqmp_dpsub instance. If any of those operations fail,
         * dpsub->drm will remain NULL, which tells the caller that it must
         * cleanup manually.
         */
        dpdrm = devm_drm_dev_alloc(dpsub->dev, &zynqmp_dpsub_drm_driver,
                                   struct zynqmp_dpsub_drm, dev);
        if (IS_ERR(dpdrm))
                return PTR_ERR(dpdrm);

        dpdrm->dpsub = dpsub;
        drm = &dpdrm->dev;

        ret = drmm_add_action(drm, zynqmp_dpsub_drm_release, dpdrm);
        if (ret < 0)
                return ret;

        dpsub->drm = dpdrm;

        /* Initialize mode config, vblank and the KMS poll helper. */
        ret = drmm_mode_config_init(drm);
        if (ret < 0)
                return ret;

        drm->mode_config.funcs = &zynqmp_dpsub_mode_config_funcs;
        drm->mode_config.min_width = 0;
        drm->mode_config.min_height = 0;
        drm->mode_config.max_width = ZYNQMP_DISP_MAX_WIDTH;
        drm->mode_config.max_height = ZYNQMP_DISP_MAX_HEIGHT;

        ret = drm_vblank_init(drm, 1);
        if (ret)
                return ret;

        ret = zynqmp_dpsub_kms_init(dpsub);
        if (ret < 0)
                goto err_poll_fini;

        drm_kms_helper_poll_init(drm);

        /* Reset all components and register the DRM device. */
        drm_mode_config_reset(drm);

        ret = drm_dev_register(drm, 0);
        if (ret < 0)
                goto err_poll_fini;

        /* Initialize fbdev generic emulation. */
        drm_client_setup_with_fourcc(drm, DRM_FORMAT_RGB888);

        return 0;

err_poll_fini:
        drm_kms_helper_poll_fini(drm);
        return ret;
}

void zynqmp_dpsub_drm_cleanup(struct zynqmp_dpsub *dpsub)
{
        struct drm_device *drm = &dpsub->drm->dev;

        drm_dev_unplug(drm);
        drm_atomic_helper_shutdown(drm);
        drm_encoder_cleanup(&dpsub->drm->encoder);
        drm_kms_helper_poll_fini(drm);
}