// 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/of.h>
#include <linux/pm_runtime.h>
#include <linux/spinlock.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_print.h>
#include <drm/drm_vblank.h>
#include <drm/drm_simple_kms_helper.h>
#include <drm/drm_bridge.h>

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

void komeda_crtc_get_color_config(struct drm_crtc_state *crtc_st,
                                  u32 *color_depths, u32 *color_formats)
{
        struct drm_connector *conn;
        struct drm_connector_state *conn_st;
        u32 conn_color_formats = ~0u;
        int i, min_bpc = 31, conn_bpc = 0;

        for_each_new_connector_in_state(crtc_st->state, conn, conn_st, i) {
                if (conn_st->crtc != crtc_st->crtc)
                        continue;

                conn_bpc = conn->display_info.bpc ? conn->display_info.bpc : 8;
                conn_color_formats &= conn->display_info.color_formats;

                if (conn_bpc < min_bpc)
                        min_bpc = conn_bpc;
        }

        /* connector doesn't config any color_format, use RGB444 as default */
        if (!conn_color_formats)
                conn_color_formats = DRM_COLOR_FORMAT_RGB444;

        *color_depths = GENMASK(min_bpc, 0);
        *color_formats = conn_color_formats;
}

static void komeda_crtc_update_clock_ratio(struct komeda_crtc_state *kcrtc_st)
{
        u64 pxlclk, aclk;

        if (!kcrtc_st->base.active) {
                kcrtc_st->clock_ratio = 0;
                return;
        }

        pxlclk = kcrtc_st->base.adjusted_mode.crtc_clock * 1000ULL;
        aclk = komeda_crtc_get_aclk(kcrtc_st);

        kcrtc_st->clock_ratio = div64_u64(aclk << 32, pxlclk);
}

/**
 * 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_atomic_state *state)
{
        struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
                                                                          crtc);
        struct komeda_crtc *kcrtc = to_kcrtc(crtc);
        struct komeda_crtc_state *kcrtc_st = to_kcrtc_st(crtc_state);
        int err;

        if (drm_atomic_crtc_needs_modeset(crtc_state))
                komeda_crtc_update_clock_ratio(kcrtc_st);

        if (crtc_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->slave, kcrtc_st);
        if (err)
                return err;

        err = komeda_release_unclaimed_resources(kcrtc->master, kcrtc_st);
        if (err)
                return err;

        return 0;
}

/* 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 drm_device *drm = kcrtc->base.dev;
        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);
        struct drm_display_mode *mode = &kcrtc_st->base.adjusted_mode;
        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_err(drm, "failed to change opmode: 0x%x -> 0x%x.\n,",
                        mdev->dpmode, new_mode);
                goto unlock;
        }

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

        err = clk_set_rate(master->pxlclk, mode->crtc_clock * 1000);
        if (err)
                drm_err(drm, "failed to set pxlclk for pipe%d\n", master->id);
        err = clk_prepare_enable(master->pxlclk);
        if (err)
                drm_err(drm, "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 drm_device *drm = kcrtc->base.dev;
        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_err(drm, "failed to change opmode: 0x%x -> 0x%x.\n,",
                        mdev->dpmode, new_mode);
                goto unlock;
        }

        mdev->dpmode = new_mode;

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

unlock:
        mutex_unlock(&mdev->lock);

        return err;
}

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

        if (events & KOMEDA_EVENT_VSYNC)
                drm_crtc_handle_vblank(crtc);

        if (events & KOMEDA_EVENT_EOW) {
                struct komeda_wb_connector *wb_conn = kcrtc->wb_conn;

                if (wb_conn)
                        drm_writeback_signal_completion(&wb_conn->base, 0);
                else
                        drm_warn(drm, "CRTC[%d]: EOW happen but no wb_connector.\n",
                                 drm_crtc_index(&kcrtc->base));
        }
        /* 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(drm, "CRTC[%d]: FLIP happened 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;
        struct komeda_pipeline *slave = kcrtc->slave;
        struct komeda_wb_connector *wb_conn = kcrtc->wb_conn;
        struct drm_connector_state *conn_st;

        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);

        if (slave && has_bit(slave->id, kcrtc_st->affected_pipes))
                komeda_pipeline_update(slave, old->state);

        conn_st = wb_conn ? wb_conn->base.base.state : NULL;
        if (conn_st && conn_st->writeback_job)
                drm_writeback_queue_job(&wb_conn->base, conn_st);

        /* 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_atomic_state *state)
{
        struct drm_crtc_state *old = drm_atomic_get_old_crtc_state(state,
                                                                   crtc);
        pm_runtime_get_sync(crtc->dev->dev);
        komeda_crtc_prepare(to_kcrtc(crtc));
        drm_crtc_vblank_on(crtc);
        WARN_ON(drm_crtc_vblank_get(crtc));
        komeda_crtc_do_flush(crtc, old);
}

void
komeda_crtc_flush_and_wait_for_flip_done(struct komeda_crtc *kcrtc,
                                         struct completion *input_flip_done)
{
        struct drm_device *drm = kcrtc->base.dev;
        struct komeda_dev *mdev = kcrtc->master->mdev;
        struct completion *flip_done;
        struct completion temp;

        /* if caller doesn't send a flip_done, use a private flip_done */
        if (input_flip_done) {
                flip_done = input_flip_done;
        } else {
                init_completion(&temp);
                kcrtc->disable_done = &temp;
                flip_done = &temp;
        }

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

        /* wait the flip take affect.*/
        if (wait_for_completion_timeout(flip_done, HZ) == 0) {
                drm_err(drm, "wait pipe%d flip done timeout\n", kcrtc->master->id);
                if (!input_flip_done) {
                        unsigned long flags;

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

static void
komeda_crtc_atomic_disable(struct drm_crtc *crtc,
                           struct drm_atomic_state *state)
{
        struct drm_crtc_state *old = drm_atomic_get_old_crtc_state(state,
                                                                   crtc);
        struct komeda_crtc *kcrtc = to_kcrtc(crtc);
        struct komeda_crtc_state *old_st = to_kcrtc_st(old);
        struct komeda_pipeline *master = kcrtc->master;
        struct komeda_pipeline *slave  = kcrtc->slave;
        struct completion *disable_done;
        bool needs_phase2 = false;

        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 (slave && has_bit(slave->id, old_st->active_pipes))
                komeda_pipeline_disable(slave, old->state);

        if (has_bit(master->id, old_st->active_pipes))
                needs_phase2 = 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()
         */
        disable_done = (needs_phase2 || crtc->state->active) ?
                       NULL : &crtc->state->commit->flip_done;

        /* wait phase 1 disable done */
        komeda_crtc_flush_and_wait_for_flip_done(kcrtc, disable_done);

        /* phase 2 */
        if (needs_phase2) {
                komeda_pipeline_disable(kcrtc->master, old->state);

                disable_done = crtc->state->active ?
                               NULL : &crtc->state->commit->flip_done;

                komeda_crtc_flush_and_wait_for_flip_done(kcrtc, disable_done);
        }

        drm_crtc_vblank_put(crtc);
        drm_crtc_vblank_off(crtc);
        komeda_crtc_unprepare(kcrtc);
        pm_runtime_put(crtc->dev->dev);
}

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

        komeda_crtc_do_flush(crtc, old);
}

/* Returns the minimum frequency of the aclk rate (main engine clock) in Hz */
static unsigned long
komeda_calc_min_aclk_rate(struct komeda_crtc *kcrtc,
                          unsigned long pxlclk)
{
        /* Once dual-link one display pipeline drives two display outputs,
         * the aclk needs run on the double rate of pxlclk
         */
        if (kcrtc->master->dual_link)
                return pxlclk * 2;
        else
                return pxlclk;
}

/* Get current aclk rate that specified by state */
unsigned long komeda_crtc_get_aclk(struct komeda_crtc_state *kcrtc_st)
{
        struct drm_crtc *crtc = kcrtc_st->base.crtc;
        struct komeda_dev *mdev = crtc->dev->dev_private;
        unsigned long pxlclk = kcrtc_st->base.adjusted_mode.crtc_clock * 1000;
        unsigned long min_aclk;

        min_aclk = komeda_calc_min_aclk_rate(to_kcrtc(crtc), pxlclk);

        return clk_round_rate(mdev->aclk, min_aclk);
}

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;
        unsigned long min_pxlclk, min_aclk;

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

        min_pxlclk = m->clock * 1000;
        if (master->dual_link)
                min_pxlclk /= 2;

        if (min_pxlclk != clk_round_rate(master->pxlclk, min_pxlclk)) {
                DRM_DEBUG_ATOMIC("pxlclk doesn't support %lu Hz\n", min_pxlclk);

                return MODE_NOCLOCK;
        }

        min_aclk = komeda_calc_min_aclk_rate(to_kcrtc(crtc), min_pxlclk);
        if (clk_round_rate(mdev->aclk, min_aclk) < min_aclk) {
                DRM_DEBUG_ATOMIC("engine clk can't satisfy the requirement of %s-clk: %lu.\n",
                                 m->name, min_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);
        unsigned long clk_rate;

        drm_mode_set_crtcinfo(adjusted_mode, 0);
        /* In dual link half the horizontal settings */
        if (kcrtc->master->dual_link) {
                adjusted_mode->crtc_clock /= 2;
                adjusted_mode->crtc_hdisplay /= 2;
                adjusted_mode->crtc_hsync_start /= 2;
                adjusted_mode->crtc_hsync_end /= 2;
                adjusted_mode->crtc_htotal /= 2;
        }

        clk_rate = adjusted_mode->crtc_clock * 1000;
        /* crtc_clock will be used as the komeda output pixel clock */
        adjusted_mode->crtc_clock = clk_round_rate(kcrtc->master->pxlclk,
                                                   clk_rate) / 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_obj(*state);
        if (state)
                __drm_atomic_helper_crtc_reset(crtc, &state->base);
}

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_obj(*new);
        if (!new)
                return NULL;

        __drm_atomic_helper_crtc_duplicate_state(crtc, &new->base);

        new->affected_pipes = old->active_pipes;
        new->clock_ratio = old->clock_ratio;
        new->max_slave_zorder = old->max_slave_zorder;

        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 = {
        .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 drm_device *drm = &kms->base;
        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  = komeda_pipeline_get_slave(master);

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

                drm_info(drm, "CRTC-%d: master(pipe-%d) slave(%s).\n",
                         kms->n_crtcs, master->id, str);

                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_attach_bridge(struct device *dev,
                                struct komeda_pipeline *pipe,
                                struct drm_encoder *encoder)
{
        struct drm_device *drm = encoder->dev;
        struct drm_bridge *bridge;
        int err;

        bridge = devm_drm_of_get_bridge(dev, pipe->of_node,
                                        KOMEDA_OF_PORT_OUTPUT, 0);
        if (IS_ERR(bridge))
                return dev_err_probe(dev, PTR_ERR(bridge), "remote bridge not found for pipe: %s\n",
                                     of_node_full_name(pipe->of_node));

        err = drm_bridge_attach(encoder, bridge, NULL, 0);
        if (err)
                drm_err(drm, "bridge_attach() failed for pipe: %s\n",
                        of_node_full_name(pipe->of_node));

        return err;
}

static int komeda_crtc_add(struct komeda_kms_dev *kms,
                           struct komeda_crtc *kcrtc)
{
        struct drm_crtc *crtc = &kcrtc->base;
        struct drm_device *base = &kms->base;
        struct komeda_pipeline *pipe = kcrtc->master;
        struct drm_encoder *encoder = &kcrtc->encoder;
        int err;

        err = drm_crtc_init_with_planes(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);

        crtc->port = pipe->of_output_port;

        /* Construct an encoder for each pipeline and attach it to the remote
         * bridge
         */
        kcrtc->encoder.possible_crtcs = drm_crtc_mask(crtc);
        err = drm_simple_encoder_init(base, encoder, DRM_MODE_ENCODER_TMDS);
        if (err)
                return err;

        if (pipe->of_output_links[0]) {
                err = komeda_attach_bridge(base->dev, pipe, encoder);
                if (err)
                        return err;
        }

        drm_crtc_enable_color_mgmt(crtc, 0, true, KOMEDA_COLOR_LUT_SIZE);

        komeda_pipeline_dump(pipe);

        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;
}