// SPDX-License-Identifier: GPL-2.0
/*
 * (C) COPYRIGHT 2018 ARM Limited. All rights reserved.
 * Author: James.Qian.Wang <james.qian.wang@arm.com>
 *
 */
#include <linux/clk.h>
#include <linux/pm_runtime.h>
#include <linux/spinlock.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_plane_helper.h>
#include <drm/drm_print.h>
#include <drm/drm_vblank.h>

#include "komeda_dev.h"
#include "komeda_kms.h"

/**
 * komeda_crtc_atomic_check - build display output data flow
 * @crtc: DRM crtc
 * @state: the crtc state object
 *
 * crtc_atomic_check is the final check stage, so beside build a display data
 * pipeline according to the crtc_state, but still needs to release or disable
 * the unclaimed pipeline resources.
 *
 * RETURNS:
 * Zero for success or -errno
 */
static int
komeda_crtc_atomic_check(struct drm_crtc *crtc,
                         struct drm_crtc_state *state)
{
        struct komeda_crtc *kcrtc = to_kcrtc(crtc);
        struct komeda_crtc_state *kcrtc_st = to_kcrtc_st(state);
        int err;

        if (state->active) {
                err = komeda_build_display_data_flow(kcrtc, kcrtc_st);
                if (err)
                        return err;
        }

        /* release unclaimed pipeline resources */
        err = komeda_release_unclaimed_resources(kcrtc->master, kcrtc_st);
        if (err)
                return err;

        return 0;
}

static u32 komeda_calc_mclk(struct komeda_crtc_state *kcrtc_st)
{
        unsigned long mclk = kcrtc_st->base.adjusted_mode.clock * 1000;

        return mclk;
}

/* For active a crtc, mainly need two parts of preparation
 * 1. adjust display operation mode.
 * 2. enable needed clk
 */
static int
komeda_crtc_prepare(struct komeda_crtc *kcrtc)
{
        struct komeda_dev *mdev = kcrtc->base.dev->dev_private;
        struct komeda_pipeline *master = kcrtc->master;
        struct komeda_crtc_state *kcrtc_st = to_kcrtc_st(kcrtc->base.state);
        unsigned long pxlclk_rate = kcrtc_st->base.adjusted_mode.clock * 1000;
        u32 new_mode;
        int err;

        mutex_lock(&mdev->lock);

        new_mode = mdev->dpmode | BIT(master->id);
        if (WARN_ON(new_mode == mdev->dpmode)) {
                err = 0;
                goto unlock;
        }

        err = mdev->funcs->change_opmode(mdev, new_mode);
        if (err) {
                DRM_ERROR("failed to change opmode: 0x%x -> 0x%x.\n,",
                          mdev->dpmode, new_mode);
                goto unlock;
        }

        mdev->dpmode = new_mode;
        /* Only need to enable mclk on single display mode, but no need to
         * enable mclk it on dual display mode, since the dual mode always
         * switch from single display mode, the mclk already enabled, no need
         * to enable it again.
         */
        if (new_mode != KOMEDA_MODE_DUAL_DISP) {
                err = clk_set_rate(mdev->mclk, komeda_calc_mclk(kcrtc_st));
                if (err)
                        DRM_ERROR("failed to set mclk.\n");
                err = clk_prepare_enable(mdev->mclk);
                if (err)
                        DRM_ERROR("failed to enable mclk.\n");
        }

        err = clk_prepare_enable(master->aclk);
        if (err)
                DRM_ERROR("failed to enable axi clk for pipe%d.\n", master->id);
        err = clk_set_rate(master->pxlclk, pxlclk_rate);
        if (err)
                DRM_ERROR("failed to set pxlclk for pipe%d\n", master->id);
        err = clk_prepare_enable(master->pxlclk);
        if (err)
                DRM_ERROR("failed to enable pxl clk for pipe%d.\n", master->id);

unlock:
        mutex_unlock(&mdev->lock);

        return err;
}

static int
komeda_crtc_unprepare(struct komeda_crtc *kcrtc)
{
        struct komeda_dev *mdev = kcrtc->base.dev->dev_private;
        struct komeda_pipeline *master = kcrtc->master;
        u32 new_mode;
        int err;

        mutex_lock(&mdev->lock);

        new_mode = mdev->dpmode & (~BIT(master->id));

        if (WARN_ON(new_mode == mdev->dpmode)) {
                err = 0;
                goto unlock;
        }

        err = mdev->funcs->change_opmode(mdev, new_mode);
        if (err) {
                DRM_ERROR("failed to change opmode: 0x%x -> 0x%x.\n,",
                          mdev->dpmode, new_mode);
                goto unlock;
        }

        mdev->dpmode = new_mode;

        clk_disable_unprepare(master->pxlclk);
        clk_disable_unprepare(master->aclk);
        if (new_mode == KOMEDA_MODE_INACTIVE)
                clk_disable_unprepare(mdev->mclk);

unlock:
        mutex_unlock(&mdev->lock);

        return err;
}

void komeda_crtc_handle_event(struct komeda_crtc   *kcrtc,
                              struct komeda_events *evts)
{
        struct drm_crtc *crtc = &kcrtc->base;
        u32 events = evts->pipes[kcrtc->master->id];

        if (events & KOMEDA_EVENT_VSYNC)
                drm_crtc_handle_vblank(crtc);

        /* will handle it together with the write back support */
        if (events & KOMEDA_EVENT_EOW)
                DRM_DEBUG("EOW.\n");

        if (events & KOMEDA_EVENT_FLIP) {
                unsigned long flags;
                struct drm_pending_vblank_event *event;

                spin_lock_irqsave(&crtc->dev->event_lock, flags);
                if (kcrtc->disable_done) {
                        complete_all(kcrtc->disable_done);
                        kcrtc->disable_done = NULL;
                } else if (crtc->state->event) {
                        event = crtc->state->event;
                        /*
                         * Consume event before notifying drm core that flip
                         * happened.
                         */
                        crtc->state->event = NULL;
                        drm_crtc_send_vblank_event(crtc, event);
                } else {
                        DRM_WARN("CRTC[%d]: FLIP happen but no pending commit.\n",
                                 drm_crtc_index(&kcrtc->base));
                }
                spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
        }
}

static void
komeda_crtc_do_flush(struct drm_crtc *crtc,
                     struct drm_crtc_state *old)
{
        struct komeda_crtc *kcrtc = to_kcrtc(crtc);
        struct komeda_crtc_state *kcrtc_st = to_kcrtc_st(crtc->state);
        struct komeda_dev *mdev = kcrtc->base.dev->dev_private;
        struct komeda_pipeline *master = kcrtc->master;

        DRM_DEBUG_ATOMIC("CRTC%d_FLUSH: active_pipes: 0x%x, affected: 0x%x.\n",
                         drm_crtc_index(crtc),
                         kcrtc_st->active_pipes, kcrtc_st->affected_pipes);

        /* step 1: update the pipeline/component state to HW */
        if (has_bit(master->id, kcrtc_st->affected_pipes))
                komeda_pipeline_update(master, old->state);

        /* step 2: notify the HW to kickoff the update */
        mdev->funcs->flush(mdev, master->id, kcrtc_st->active_pipes);
}

static void
komeda_crtc_atomic_enable(struct drm_crtc *crtc,
                          struct drm_crtc_state *old)
{
        komeda_crtc_prepare(to_kcrtc(crtc));
        drm_crtc_vblank_on(crtc);
        komeda_crtc_do_flush(crtc, old);
}

static void
komeda_crtc_atomic_disable(struct drm_crtc *crtc,
                           struct drm_crtc_state *old)
{
        struct komeda_crtc *kcrtc = to_kcrtc(crtc);
        struct komeda_crtc_state *old_st = to_kcrtc_st(old);
        struct komeda_dev *mdev = crtc->dev->dev_private;
        struct komeda_pipeline *master = kcrtc->master;
        struct completion *disable_done = &crtc->state->commit->flip_done;
        struct completion temp;
        int timeout;

        DRM_DEBUG_ATOMIC("CRTC%d_DISABLE: active_pipes: 0x%x, affected: 0x%x.\n",
                         drm_crtc_index(crtc),
                         old_st->active_pipes, old_st->affected_pipes);

        if (has_bit(master->id, old_st->active_pipes))
                komeda_pipeline_disable(master, old->state);

        /* crtc_disable has two scenarios according to the state->active switch.
         * 1. active -> inactive
         *    this commit is a disable commit. and the commit will be finished
         *    or done after the disable operation. on this case we can directly
         *    use the crtc->state->event to tracking the HW disable operation.
         * 2. active -> active
         *    the crtc->commit is not for disable, but a modeset operation when
         *    crtc is active, such commit actually has been completed by 3
         *    DRM operations:
         *    crtc_disable, update_planes(crtc_flush), crtc_enable
         *    so on this case the crtc->commit is for the whole process.
         *    we can not use it for tracing the disable, we need a temporary
         *    flip_done for tracing the disable. and crtc->state->event for
         *    the crtc_enable operation.
         *    That's also the reason why skip modeset commit in
         *    komeda_crtc_atomic_flush()
         */
        if (crtc->state->active) {
                struct komeda_pipeline_state *pipe_st;
                /* clear the old active_comps to zero */
                pipe_st = komeda_pipeline_get_old_state(master, old->state);
                pipe_st->active_comps = 0;

                init_completion(&temp);
                kcrtc->disable_done = &temp;
                disable_done = &temp;
        }

        mdev->funcs->flush(mdev, master->id, 0);

        /* wait the disable take affect.*/
        timeout = wait_for_completion_timeout(disable_done, HZ);
        if (timeout == 0) {
                DRM_ERROR("disable pipeline%d timeout.\n", kcrtc->master->id);
                if (crtc->state->active) {
                        unsigned long flags;

                        spin_lock_irqsave(&crtc->dev->event_lock, flags);
                        kcrtc->disable_done = NULL;
                        spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
                }
        }

        drm_crtc_vblank_off(crtc);
        komeda_crtc_unprepare(kcrtc);
}

static void
komeda_crtc_atomic_flush(struct drm_crtc *crtc,
                         struct drm_crtc_state *old)
{
        /* commit with modeset will be handled in enable/disable */
        if (drm_atomic_crtc_needs_modeset(crtc->state))
                return;

        komeda_crtc_do_flush(crtc, old);
}

static enum drm_mode_status
komeda_crtc_mode_valid(struct drm_crtc *crtc, const struct drm_display_mode *m)
{
        struct komeda_dev *mdev = crtc->dev->dev_private;
        struct komeda_crtc *kcrtc = to_kcrtc(crtc);
        struct komeda_pipeline *master = kcrtc->master;
        long mode_clk, pxlclk;

        if (m->flags & DRM_MODE_FLAG_INTERLACE)
                return MODE_NO_INTERLACE;

        /* main clock/AXI clk must be faster than pxlclk*/
        mode_clk = m->clock * 1000;
        pxlclk = clk_round_rate(master->pxlclk, mode_clk);
        if (pxlclk != mode_clk) {
                DRM_DEBUG_ATOMIC("pxlclk doesn't support %ld Hz\n", mode_clk);

                return MODE_NOCLOCK;
        }

        if (clk_round_rate(mdev->mclk, mode_clk) < pxlclk) {
                DRM_DEBUG_ATOMIC("mclk can't satisfy the requirement of %s-clk: %ld.\n",
                                 m->name, pxlclk);

                return MODE_CLOCK_HIGH;
        }

        if (clk_round_rate(master->aclk, mode_clk) < pxlclk) {
                DRM_DEBUG_ATOMIC("aclk can't satisfy the requirement of %s-clk: %ld.\n",
                                 m->name, pxlclk);

                return MODE_CLOCK_HIGH;
        }

        return MODE_OK;
}

static bool komeda_crtc_mode_fixup(struct drm_crtc *crtc,
                                   const struct drm_display_mode *m,
                                   struct drm_display_mode *adjusted_mode)
{
        struct komeda_crtc *kcrtc = to_kcrtc(crtc);
        struct komeda_pipeline *master = kcrtc->master;
        long mode_clk = m->clock * 1000;

        adjusted_mode->clock = clk_round_rate(master->pxlclk, mode_clk) / 1000;

        return true;
}

static const struct drm_crtc_helper_funcs komeda_crtc_helper_funcs = {
        .atomic_check   = komeda_crtc_atomic_check,
        .atomic_flush   = komeda_crtc_atomic_flush,
        .atomic_enable  = komeda_crtc_atomic_enable,
        .atomic_disable = komeda_crtc_atomic_disable,
        .mode_valid     = komeda_crtc_mode_valid,
        .mode_fixup     = komeda_crtc_mode_fixup,
};

static void komeda_crtc_reset(struct drm_crtc *crtc)
{
        struct komeda_crtc_state *state;

        if (crtc->state)
                __drm_atomic_helper_crtc_destroy_state(crtc->state);

        kfree(to_kcrtc_st(crtc->state));
        crtc->state = NULL;

        state = kzalloc(sizeof(*state), GFP_KERNEL);
        if (state) {
                crtc->state = &state->base;
                crtc->state->crtc = crtc;
        }
}

static struct drm_crtc_state *
komeda_crtc_atomic_duplicate_state(struct drm_crtc *crtc)
{
        struct komeda_crtc_state *old = to_kcrtc_st(crtc->state);
        struct komeda_crtc_state *new;

        new = kzalloc(sizeof(*new), GFP_KERNEL);
        if (!new)
                return NULL;

        __drm_atomic_helper_crtc_duplicate_state(crtc, &new->base);

        new->affected_pipes = old->active_pipes;

        return &new->base;
}

static void komeda_crtc_atomic_destroy_state(struct drm_crtc *crtc,
                                             struct drm_crtc_state *state)
{
        __drm_atomic_helper_crtc_destroy_state(state);
        kfree(to_kcrtc_st(state));
}

static int komeda_crtc_vblank_enable(struct drm_crtc *crtc)
{
        struct komeda_dev *mdev = crtc->dev->dev_private;
        struct komeda_crtc *kcrtc = to_kcrtc(crtc);

        mdev->funcs->on_off_vblank(mdev, kcrtc->master->id, true);
        return 0;
}

static void komeda_crtc_vblank_disable(struct drm_crtc *crtc)
{
        struct komeda_dev *mdev = crtc->dev->dev_private;
        struct komeda_crtc *kcrtc = to_kcrtc(crtc);

        mdev->funcs->on_off_vblank(mdev, kcrtc->master->id, false);
}

static const struct drm_crtc_funcs komeda_crtc_funcs = {
        .gamma_set              = drm_atomic_helper_legacy_gamma_set,
        .destroy                = drm_crtc_cleanup,
        .set_config             = drm_atomic_helper_set_config,
        .page_flip              = drm_atomic_helper_page_flip,
        .reset                  = komeda_crtc_reset,
        .atomic_duplicate_state = komeda_crtc_atomic_duplicate_state,
        .atomic_destroy_state   = komeda_crtc_atomic_destroy_state,
        .enable_vblank          = komeda_crtc_vblank_enable,
        .disable_vblank         = komeda_crtc_vblank_disable,
};

int komeda_kms_setup_crtcs(struct komeda_kms_dev *kms,
                           struct komeda_dev *mdev)
{
        struct komeda_crtc *crtc;
        struct komeda_pipeline *master;
        char str[16];
        int i;

        kms->n_crtcs = 0;

        for (i = 0; i < mdev->n_pipelines; i++) {
                crtc = &kms->crtcs[kms->n_crtcs];
                master = mdev->pipelines[i];

                crtc->master = master;
                crtc->slave  = NULL;

                if (crtc->slave)
                        sprintf(str, "pipe-%d", crtc->slave->id);
                else
                        sprintf(str, "None");

                DRM_INFO("crtc%d: master(pipe-%d) slave(%s) output: %s.\n",
                         kms->n_crtcs, master->id, str,
                         master->of_output_dev ?
                         master->of_output_dev->full_name : "None");

                kms->n_crtcs++;
        }

        return 0;
}

static struct drm_plane *
get_crtc_primary(struct komeda_kms_dev *kms, struct komeda_crtc *crtc)
{
        struct komeda_plane *kplane;
        struct drm_plane *plane;

        drm_for_each_plane(plane, &kms->base) {
                if (plane->type != DRM_PLANE_TYPE_PRIMARY)
                        continue;

                kplane = to_kplane(plane);
                /* only master can be primary */
                if (kplane->layer->base.pipeline == crtc->master)
                        return plane;
        }

        return NULL;
}

static int komeda_crtc_add(struct komeda_kms_dev *kms,
                           struct komeda_crtc *kcrtc)
{
        struct drm_crtc *crtc = &kcrtc->base;
        int err;

        err = drm_crtc_init_with_planes(&kms->base, crtc,
                                        get_crtc_primary(kms, kcrtc), NULL,
                                        &komeda_crtc_funcs, NULL);
        if (err)
                return err;

        drm_crtc_helper_add(crtc, &komeda_crtc_helper_funcs);
        drm_crtc_vblank_reset(crtc);

        crtc->port = kcrtc->master->of_output_port;

        return 0;
}

int komeda_kms_add_crtcs(struct komeda_kms_dev *kms, struct komeda_dev *mdev)
{
        int i, err;

        for (i = 0; i < kms->n_crtcs; i++) {
                err = komeda_crtc_add(kms, &kms->crtcs[i]);
                if (err)
                        return err;
        }

        return 0;
}