// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2018 Texas Instruments Incorporated - https://www.ti.com/
 * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
 */

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_crtc.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_fb_cma_helper.h>
#include <drm/drm_gem_cma_helper.h>
#include <drm/drm_plane_helper.h>
#include <drm/drm_vblank.h>

#include "tidss_crtc.h"
#include "tidss_dispc.h"
#include "tidss_drv.h"
#include "tidss_irq.h"
#include "tidss_plane.h"

/* Page flip and frame done IRQs */

static void tidss_crtc_finish_page_flip(struct tidss_crtc *tcrtc)
{
        struct drm_device *ddev = tcrtc->crtc.dev;
        struct tidss_device *tidss = to_tidss(ddev);
        struct drm_pending_vblank_event *event;
        unsigned long flags;
        bool busy;

        spin_lock_irqsave(&ddev->event_lock, flags);

        /*
         * New settings are taken into use at VFP, and GO bit is cleared at
         * the same time. This happens before the vertical blank interrupt.
         * So there is a small change that the driver sets GO bit after VFP, but
         * before vblank, and we have to check for that case here.
         */
        busy = dispc_vp_go_busy(tidss->dispc, tcrtc->hw_videoport);
        if (busy) {
                spin_unlock_irqrestore(&ddev->event_lock, flags);
                return;
        }

        event = tcrtc->event;
        tcrtc->event = NULL;

        if (!event) {
                spin_unlock_irqrestore(&ddev->event_lock, flags);
                return;
        }

        drm_crtc_send_vblank_event(&tcrtc->crtc, event);

        spin_unlock_irqrestore(&ddev->event_lock, flags);

        drm_crtc_vblank_put(&tcrtc->crtc);
}

void tidss_crtc_vblank_irq(struct drm_crtc *crtc)
{
        struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);

        drm_crtc_handle_vblank(crtc);

        tidss_crtc_finish_page_flip(tcrtc);
}

void tidss_crtc_framedone_irq(struct drm_crtc *crtc)
{
        struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);

        complete(&tcrtc->framedone_completion);
}

void tidss_crtc_error_irq(struct drm_crtc *crtc, u64 irqstatus)
{
        struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);

        dev_err_ratelimited(crtc->dev->dev, "CRTC%u SYNC LOST: (irq %llx)\n",
                            tcrtc->hw_videoport, irqstatus);
}

/* drm_crtc_helper_funcs */

static int tidss_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 drm_device *ddev = crtc->dev;
        struct tidss_device *tidss = to_tidss(ddev);
        struct dispc_device *dispc = tidss->dispc;
        struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
        u32 hw_videoport = tcrtc->hw_videoport;
        const struct drm_display_mode *mode;
        enum drm_mode_status ok;

        dev_dbg(ddev->dev, "%s\n", __func__);

        if (!crtc_state->enable)
                return 0;

        mode = &crtc_state->adjusted_mode;

        ok = dispc_vp_mode_valid(dispc, hw_videoport, mode);
        if (ok != MODE_OK) {
                dev_dbg(ddev->dev, "%s: bad mode: %ux%u pclk %u kHz\n",
                        __func__, mode->hdisplay, mode->vdisplay, mode->clock);
                return -EINVAL;
        }

        return dispc_vp_bus_check(dispc, hw_videoport, crtc_state);
}

/*
 * This needs all affected planes to be present in the atomic
 * state. The untouched planes are added to the state in
 * tidss_atomic_check().
 */
static void tidss_crtc_position_planes(struct tidss_device *tidss,
                                       struct drm_crtc *crtc,
                                       struct drm_crtc_state *old_state,
                                       bool newmodeset)
{
        struct drm_atomic_state *ostate = old_state->state;
        struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
        struct drm_crtc_state *cstate = crtc->state;
        int layer;

        if (!newmodeset && !cstate->zpos_changed &&
            !to_tidss_crtc_state(cstate)->plane_pos_changed)
                return;

        for (layer = 0; layer < tidss->feat->num_planes; layer++) {
                struct drm_plane_state *pstate;
                struct drm_plane *plane;
                bool layer_active = false;
                int i;

                for_each_new_plane_in_state(ostate, plane, pstate, i) {
                        if (pstate->crtc != crtc || !pstate->visible)
                                continue;

                        if (pstate->normalized_zpos == layer) {
                                layer_active = true;
                                break;
                        }
                }

                if (layer_active) {
                        struct tidss_plane *tplane = to_tidss_plane(plane);

                        dispc_ovr_set_plane(tidss->dispc, tplane->hw_plane_id,
                                            tcrtc->hw_videoport,
                                            pstate->crtc_x, pstate->crtc_y,
                                            layer);
                }
                dispc_ovr_enable_layer(tidss->dispc, tcrtc->hw_videoport, layer,
                                       layer_active);
        }
}

static void tidss_crtc_atomic_flush(struct drm_crtc *crtc,
                                    struct drm_atomic_state *state)
{
        struct drm_crtc_state *old_crtc_state = drm_atomic_get_old_crtc_state(state,
                                                                              crtc);
        struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
        struct drm_device *ddev = crtc->dev;
        struct tidss_device *tidss = to_tidss(ddev);
        unsigned long flags;

        dev_dbg(ddev->dev,
                "%s: %s enabled %d, needs modeset %d, event %p\n", __func__,
                crtc->name, drm_atomic_crtc_needs_modeset(crtc->state),
                crtc->state->enable, crtc->state->event);

        /* There is nothing to do if CRTC is not going to be enabled. */
        if (!crtc->state->enable)
                return;

        /*
         * Flush CRTC changes with go bit only if new modeset is not
         * coming, so CRTC is enabled trough out the commit.
         */
        if (drm_atomic_crtc_needs_modeset(crtc->state))
                return;

        /* If the GO bit is stuck we better quit here. */
        if (WARN_ON(dispc_vp_go_busy(tidss->dispc, tcrtc->hw_videoport)))
                return;

        /* We should have event if CRTC is enabled through out this commit. */
        if (WARN_ON(!crtc->state->event))
                return;

        /* Write vp properties to HW if needed. */
        dispc_vp_setup(tidss->dispc, tcrtc->hw_videoport, crtc->state, false);

        /* Update plane positions if needed. */
        tidss_crtc_position_planes(tidss, crtc, old_crtc_state, false);

        WARN_ON(drm_crtc_vblank_get(crtc) != 0);

        spin_lock_irqsave(&ddev->event_lock, flags);
        dispc_vp_go(tidss->dispc, tcrtc->hw_videoport);

        WARN_ON(tcrtc->event);

        tcrtc->event = crtc->state->event;
        crtc->state->event = NULL;

        spin_unlock_irqrestore(&ddev->event_lock, flags);
}

static void tidss_crtc_atomic_enable(struct drm_crtc *crtc,
                                     struct drm_atomic_state *state)
{
        struct drm_crtc_state *old_state = drm_atomic_get_old_crtc_state(state,
                                                                         crtc);
        struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
        struct drm_device *ddev = crtc->dev;
        struct tidss_device *tidss = to_tidss(ddev);
        const struct drm_display_mode *mode = &crtc->state->adjusted_mode;
        unsigned long flags;
        int r;

        dev_dbg(ddev->dev, "%s, event %p\n", __func__, crtc->state->event);

        tidss_runtime_get(tidss);

        r = dispc_vp_set_clk_rate(tidss->dispc, tcrtc->hw_videoport,
                                  mode->clock * 1000);
        if (r != 0)
                return;

        r = dispc_vp_enable_clk(tidss->dispc, tcrtc->hw_videoport);
        if (r != 0)
                return;

        dispc_vp_setup(tidss->dispc, tcrtc->hw_videoport, crtc->state, true);
        tidss_crtc_position_planes(tidss, crtc, old_state, true);

        /* Turn vertical blanking interrupt reporting on. */
        drm_crtc_vblank_on(crtc);

        dispc_vp_prepare(tidss->dispc, tcrtc->hw_videoport, crtc->state);

        dispc_vp_enable(tidss->dispc, tcrtc->hw_videoport, crtc->state);

        spin_lock_irqsave(&ddev->event_lock, flags);

        if (crtc->state->event) {
                drm_crtc_send_vblank_event(crtc, crtc->state->event);
                crtc->state->event = NULL;
        }

        spin_unlock_irqrestore(&ddev->event_lock, flags);
}

static void tidss_crtc_atomic_disable(struct drm_crtc *crtc,
                                      struct drm_atomic_state *state)
{
        struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
        struct drm_device *ddev = crtc->dev;
        struct tidss_device *tidss = to_tidss(ddev);
        unsigned long flags;

        dev_dbg(ddev->dev, "%s, event %p\n", __func__, crtc->state->event);

        reinit_completion(&tcrtc->framedone_completion);

        dispc_vp_disable(tidss->dispc, tcrtc->hw_videoport);

        if (!wait_for_completion_timeout(&tcrtc->framedone_completion,
                                         msecs_to_jiffies(500)))
                dev_err(tidss->dev, "Timeout waiting for framedone on crtc %d",
                        tcrtc->hw_videoport);

        dispc_vp_unprepare(tidss->dispc, tcrtc->hw_videoport);

        spin_lock_irqsave(&ddev->event_lock, flags);
        if (crtc->state->event) {
                drm_crtc_send_vblank_event(crtc, crtc->state->event);
                crtc->state->event = NULL;
        }
        spin_unlock_irqrestore(&ddev->event_lock, flags);

        drm_crtc_vblank_off(crtc);

        dispc_vp_disable_clk(tidss->dispc, tcrtc->hw_videoport);

        tidss_runtime_put(tidss);
}

static
enum drm_mode_status tidss_crtc_mode_valid(struct drm_crtc *crtc,
                                           const struct drm_display_mode *mode)
{
        struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
        struct drm_device *ddev = crtc->dev;
        struct tidss_device *tidss = to_tidss(ddev);

        return dispc_vp_mode_valid(tidss->dispc, tcrtc->hw_videoport, mode);
}

static const struct drm_crtc_helper_funcs tidss_crtc_helper_funcs = {
        .atomic_check = tidss_crtc_atomic_check,
        .atomic_flush = tidss_crtc_atomic_flush,
        .atomic_enable = tidss_crtc_atomic_enable,
        .atomic_disable = tidss_crtc_atomic_disable,

        .mode_valid = tidss_crtc_mode_valid,
};

/* drm_crtc_funcs */

static int tidss_crtc_enable_vblank(struct drm_crtc *crtc)
{
        struct drm_device *ddev = crtc->dev;
        struct tidss_device *tidss = to_tidss(ddev);

        dev_dbg(ddev->dev, "%s\n", __func__);

        tidss_runtime_get(tidss);

        tidss_irq_enable_vblank(crtc);

        return 0;
}

static void tidss_crtc_disable_vblank(struct drm_crtc *crtc)
{
        struct drm_device *ddev = crtc->dev;
        struct tidss_device *tidss = to_tidss(ddev);

        dev_dbg(ddev->dev, "%s\n", __func__);

        tidss_irq_disable_vblank(crtc);

        tidss_runtime_put(tidss);
}

static void tidss_crtc_reset(struct drm_crtc *crtc)
{
        struct tidss_crtc_state *tcrtc;

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

        kfree(crtc->state);

        tcrtc = kzalloc(sizeof(*tcrtc), GFP_KERNEL);
        if (!tcrtc) {
                crtc->state = NULL;
                return;
        }

        __drm_atomic_helper_crtc_reset(crtc, &tcrtc->base);
}

static struct drm_crtc_state *tidss_crtc_duplicate_state(struct drm_crtc *crtc)
{
        struct tidss_crtc_state *state, *current_state;

        if (WARN_ON(!crtc->state))
                return NULL;

        current_state = to_tidss_crtc_state(crtc->state);

        state = kmalloc(sizeof(*state), GFP_KERNEL);
        if (!state)
                return NULL;

        __drm_atomic_helper_crtc_duplicate_state(crtc, &state->base);

        state->plane_pos_changed = false;

        state->bus_format = current_state->bus_format;
        state->bus_flags = current_state->bus_flags;

        return &state->base;
}

static void tidss_crtc_destroy(struct drm_crtc *crtc)
{
        struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);

        drm_crtc_cleanup(crtc);
        kfree(tcrtc);
}

static const struct drm_crtc_funcs tidss_crtc_funcs = {
        .reset = tidss_crtc_reset,
        .destroy = tidss_crtc_destroy,
        .set_config = drm_atomic_helper_set_config,
        .page_flip = drm_atomic_helper_page_flip,
        .atomic_duplicate_state = tidss_crtc_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
        .enable_vblank = tidss_crtc_enable_vblank,
        .disable_vblank = tidss_crtc_disable_vblank,
};

struct tidss_crtc *tidss_crtc_create(struct tidss_device *tidss,
                                     u32 hw_videoport,
                                     struct drm_plane *primary)
{
        struct tidss_crtc *tcrtc;
        struct drm_crtc *crtc;
        unsigned int gamma_lut_size = 0;
        bool has_ctm = tidss->feat->vp_feat.color.has_ctm;
        int ret;

        tcrtc = kzalloc(sizeof(*tcrtc), GFP_KERNEL);
        if (!tcrtc)
                return ERR_PTR(-ENOMEM);

        tcrtc->hw_videoport = hw_videoport;
        init_completion(&tcrtc->framedone_completion);

        crtc =  &tcrtc->crtc;

        ret = drm_crtc_init_with_planes(&tidss->ddev, crtc, primary,
                                        NULL, &tidss_crtc_funcs, NULL);
        if (ret < 0) {
                kfree(tcrtc);
                return ERR_PTR(ret);
        }

        drm_crtc_helper_add(crtc, &tidss_crtc_helper_funcs);

        /*
         * The dispc gamma functions adapt to what ever size we ask
         * from it no matter what HW supports. X-server assumes 256
         * element gamma tables so lets use that.
         */
        if (tidss->feat->vp_feat.color.gamma_size)
                gamma_lut_size = 256;

        drm_crtc_enable_color_mgmt(crtc, 0, has_ctm, gamma_lut_size);
        if (gamma_lut_size)
                drm_mode_crtc_set_gamma_size(crtc, gamma_lut_size);

        return tcrtc;
}