/*
 * i.MX IPUv3 Graphics driver
 *
 * Copyright (C) 2011 Sascha Hauer, Pengutronix
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */
#include <linux/component.h>
#include <linux/module.h>
#include <linux/export.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <drm/drmP.h>
#include <drm/drm_crtc_helper.h>
#include <linux/fb.h>
#include <linux/clk.h>
#include <linux/errno.h>
#include <linux/reservation.h>
#include <linux/dma-buf.h>
#include <drm/drm_gem_cma_helper.h>
#include <drm/drm_fb_cma_helper.h>

#include <video/imx-ipu-v3.h>
#include "imx-drm.h"
#include "ipuv3-plane.h"

#define DRIVER_DESC             "i.MX IPUv3 Graphics"

enum ipu_flip_status {
        IPU_FLIP_NONE,
        IPU_FLIP_PENDING,
        IPU_FLIP_SUBMITTED,
};

struct ipu_flip_work {
        struct work_struct              unref_work;
        struct drm_gem_object           *bo;
        struct drm_pending_vblank_event *page_flip_event;
        struct work_struct              fence_work;
        struct ipu_crtc                 *crtc;
        struct fence                    *excl;
        unsigned                        shared_count;
        struct fence                    **shared;
};

struct ipu_crtc {
        struct device           *dev;
        struct drm_crtc         base;
        struct imx_drm_crtc     *imx_crtc;

        /* plane[0] is the full plane, plane[1] is the partial plane */
        struct ipu_plane        *plane[2];

        struct ipu_dc           *dc;
        struct ipu_di           *di;
        int                     enabled;
        enum ipu_flip_status    flip_state;
        struct workqueue_struct *flip_queue;
        struct ipu_flip_work    *flip_work;
        int                     irq;
        u32                     bus_format;
        int                     di_hsync_pin;
        int                     di_vsync_pin;
};

#define to_ipu_crtc(x) container_of(x, struct ipu_crtc, base)

static void ipu_fb_enable(struct ipu_crtc *ipu_crtc)
{
        struct ipu_soc *ipu = dev_get_drvdata(ipu_crtc->dev->parent);

        if (ipu_crtc->enabled)
                return;

        ipu_dc_enable(ipu);
        ipu_plane_enable(ipu_crtc->plane[0]);
        /* Start DC channel and DI after IDMAC */
        ipu_dc_enable_channel(ipu_crtc->dc);
        ipu_di_enable(ipu_crtc->di);
        drm_crtc_vblank_on(&ipu_crtc->base);

        ipu_crtc->enabled = 1;
}

static void ipu_fb_disable(struct ipu_crtc *ipu_crtc)
{
        struct ipu_soc *ipu = dev_get_drvdata(ipu_crtc->dev->parent);

        if (!ipu_crtc->enabled)
                return;

        /* Stop DC channel and DI before IDMAC */
        ipu_dc_disable_channel(ipu_crtc->dc);
        ipu_di_disable(ipu_crtc->di);
        ipu_plane_disable(ipu_crtc->plane[0]);
        ipu_dc_disable(ipu);
        drm_crtc_vblank_off(&ipu_crtc->base);

        ipu_crtc->enabled = 0;
}

static void ipu_crtc_dpms(struct drm_crtc *crtc, int mode)
{
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);

        dev_dbg(ipu_crtc->dev, "%s mode: %d\n", __func__, mode);

        switch (mode) {
        case DRM_MODE_DPMS_ON:
                ipu_fb_enable(ipu_crtc);
                break;
        case DRM_MODE_DPMS_STANDBY:
        case DRM_MODE_DPMS_SUSPEND:
        case DRM_MODE_DPMS_OFF:
                ipu_fb_disable(ipu_crtc);
                break;
        }
}

static void ipu_flip_unref_work_func(struct work_struct *__work)
{
        struct ipu_flip_work *work =
                        container_of(__work, struct ipu_flip_work, unref_work);

        drm_gem_object_unreference_unlocked(work->bo);
        kfree(work);
}

static void ipu_flip_fence_work_func(struct work_struct *__work)
{
        struct ipu_flip_work *work =
                        container_of(__work, struct ipu_flip_work, fence_work);
        int i;

        /* wait for all fences attached to the FB obj to signal */
        if (work->excl) {
                fence_wait(work->excl, false);
                fence_put(work->excl);
        }
        for (i = 0; i < work->shared_count; i++) {
                fence_wait(work->shared[i], false);
                fence_put(work->shared[i]);
        }

        work->crtc->flip_state = IPU_FLIP_SUBMITTED;
}

static int ipu_page_flip(struct drm_crtc *crtc,
                struct drm_framebuffer *fb,
                struct drm_pending_vblank_event *event,
                uint32_t page_flip_flags)
{
        struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
        struct ipu_flip_work *flip_work;
        int ret;

        if (ipu_crtc->flip_state != IPU_FLIP_NONE)
                return -EBUSY;

        ret = imx_drm_crtc_vblank_get(ipu_crtc->imx_crtc);
        if (ret) {
                dev_dbg(ipu_crtc->dev, "failed to acquire vblank counter\n");
                list_del(&event->base.link);

                return ret;
        }

        flip_work = kzalloc(sizeof *flip_work, GFP_KERNEL);
        if (!flip_work) {
                ret = -ENOMEM;
                goto put_vblank;
        }
        INIT_WORK(&flip_work->unref_work, ipu_flip_unref_work_func);
        flip_work->page_flip_event = event;

        /* get BO backing the old framebuffer and take a reference */
        flip_work->bo = &drm_fb_cma_get_gem_obj(crtc->primary->fb, 0)->base;
        drm_gem_object_reference(flip_work->bo);

        ipu_crtc->flip_work = flip_work;
        /*
         * If the object has a DMABUF attached, we need to wait on its fences
         * if there are any.
         */
        if (cma_obj->base.dma_buf) {
                INIT_WORK(&flip_work->fence_work, ipu_flip_fence_work_func);
                flip_work->crtc = ipu_crtc;

                ret = reservation_object_get_fences_rcu(
                                cma_obj->base.dma_buf->resv, &flip_work->excl,
                                &flip_work->shared_count, &flip_work->shared);

                if (unlikely(ret)) {
                        DRM_ERROR("failed to get fences for buffer\n");
                        goto free_flip_work;
                }

                /* No need to queue the worker if the are no fences */
                if (!flip_work->excl && !flip_work->shared_count) {
                        ipu_crtc->flip_state = IPU_FLIP_SUBMITTED;
                } else {
                        ipu_crtc->flip_state = IPU_FLIP_PENDING;
                        queue_work(ipu_crtc->flip_queue,
                                   &flip_work->fence_work);
                }
        } else {
                ipu_crtc->flip_state = IPU_FLIP_SUBMITTED;
        }

        return 0;

free_flip_work:
        drm_gem_object_unreference_unlocked(flip_work->bo);
        kfree(flip_work);
        ipu_crtc->flip_work = NULL;
put_vblank:
        imx_drm_crtc_vblank_put(ipu_crtc->imx_crtc);

        return ret;
}

static const struct drm_crtc_funcs ipu_crtc_funcs = {
        .set_config = drm_crtc_helper_set_config,
        .destroy = drm_crtc_cleanup,
        .page_flip = ipu_page_flip,
};

static int ipu_crtc_mode_set(struct drm_crtc *crtc,
                               struct drm_display_mode *orig_mode,
                               struct drm_display_mode *mode,
                               int x, int y,
                               struct drm_framebuffer *old_fb)
{
        struct drm_device *dev = crtc->dev;
        struct drm_encoder *encoder;
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
        struct ipu_di_signal_cfg sig_cfg = {};
        unsigned long encoder_types = 0;
        int ret;

        dev_dbg(ipu_crtc->dev, "%s: mode->hdisplay: %d\n", __func__,
                        mode->hdisplay);
        dev_dbg(ipu_crtc->dev, "%s: mode->vdisplay: %d\n", __func__,
                        mode->vdisplay);

        list_for_each_entry(encoder, &dev->mode_config.encoder_list, head)
                if (encoder->crtc == crtc)
                        encoder_types |= BIT(encoder->encoder_type);

        dev_dbg(ipu_crtc->dev, "%s: attached to encoder types 0x%lx\n",
                __func__, encoder_types);

        /*
         * If we have DAC or LDB, then we need the IPU DI clock to be
         * the same as the LDB DI clock. For TVDAC, derive the IPU DI
         * clock from 27 MHz TVE_DI clock, but allow to divide it.
         */
        if (encoder_types & (BIT(DRM_MODE_ENCODER_DAC) |
                             BIT(DRM_MODE_ENCODER_LVDS)))
                sig_cfg.clkflags = IPU_DI_CLKMODE_SYNC | IPU_DI_CLKMODE_EXT;
        else if (encoder_types & BIT(DRM_MODE_ENCODER_TVDAC))
                sig_cfg.clkflags = IPU_DI_CLKMODE_EXT;
        else
                sig_cfg.clkflags = 0;

        sig_cfg.enable_pol = 1;
        sig_cfg.clk_pol = 0;
        sig_cfg.bus_format = ipu_crtc->bus_format;
        sig_cfg.v_to_h_sync = 0;
        sig_cfg.hsync_pin = ipu_crtc->di_hsync_pin;
        sig_cfg.vsync_pin = ipu_crtc->di_vsync_pin;

        drm_display_mode_to_videomode(mode, &sig_cfg.mode);

        ret = ipu_dc_init_sync(ipu_crtc->dc, ipu_crtc->di,
                               mode->flags & DRM_MODE_FLAG_INTERLACE,
                               ipu_crtc->bus_format, mode->hdisplay);
        if (ret) {
                dev_err(ipu_crtc->dev,
                                "initializing display controller failed with %d\n",
                                ret);
                return ret;
        }

        ret = ipu_di_init_sync_panel(ipu_crtc->di, &sig_cfg);
        if (ret) {
                dev_err(ipu_crtc->dev,
                                "initializing panel failed with %d\n", ret);
                return ret;
        }

        return ipu_plane_mode_set(ipu_crtc->plane[0], crtc, mode,
                                  crtc->primary->fb,
                                  0, 0, mode->hdisplay, mode->vdisplay,
                                  x, y, mode->hdisplay, mode->vdisplay,
                                  mode->flags & DRM_MODE_FLAG_INTERLACE);
}

static void ipu_crtc_handle_pageflip(struct ipu_crtc *ipu_crtc)
{
        unsigned long flags;
        struct drm_device *drm = ipu_crtc->base.dev;
        struct ipu_flip_work *work = ipu_crtc->flip_work;

        spin_lock_irqsave(&drm->event_lock, flags);
        if (work->page_flip_event)
                drm_crtc_send_vblank_event(&ipu_crtc->base,
                                           work->page_flip_event);
        imx_drm_crtc_vblank_put(ipu_crtc->imx_crtc);
        spin_unlock_irqrestore(&drm->event_lock, flags);
}

static irqreturn_t ipu_irq_handler(int irq, void *dev_id)
{
        struct ipu_crtc *ipu_crtc = dev_id;

        imx_drm_handle_vblank(ipu_crtc->imx_crtc);

        if (ipu_crtc->flip_state == IPU_FLIP_SUBMITTED) {
                struct ipu_plane *plane = ipu_crtc->plane[0];

                ipu_plane_set_base(plane, ipu_crtc->base.primary->fb,
                                   plane->x, plane->y);
                ipu_crtc_handle_pageflip(ipu_crtc);
                queue_work(ipu_crtc->flip_queue,
                           &ipu_crtc->flip_work->unref_work);
                ipu_crtc->flip_state = IPU_FLIP_NONE;
        }

        return IRQ_HANDLED;
}

static bool ipu_crtc_mode_fixup(struct drm_crtc *crtc,
                                  const struct drm_display_mode *mode,
                                  struct drm_display_mode *adjusted_mode)
{
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
        struct videomode vm;
        int ret;

        drm_display_mode_to_videomode(adjusted_mode, &vm);

        ret = ipu_di_adjust_videomode(ipu_crtc->di, &vm);
        if (ret)
                return false;

        drm_display_mode_from_videomode(&vm, adjusted_mode);

        return true;
}

static void ipu_crtc_prepare(struct drm_crtc *crtc)
{
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);

        ipu_fb_disable(ipu_crtc);
}

static void ipu_crtc_commit(struct drm_crtc *crtc)
{
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);

        ipu_fb_enable(ipu_crtc);
}

static const struct drm_crtc_helper_funcs ipu_helper_funcs = {
        .dpms = ipu_crtc_dpms,
        .mode_fixup = ipu_crtc_mode_fixup,
        .mode_set = ipu_crtc_mode_set,
        .prepare = ipu_crtc_prepare,
        .commit = ipu_crtc_commit,
};

static int ipu_enable_vblank(struct drm_crtc *crtc)
{
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);

        enable_irq(ipu_crtc->irq);

        return 0;
}

static void ipu_disable_vblank(struct drm_crtc *crtc)
{
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);

        disable_irq_nosync(ipu_crtc->irq);
}

static int ipu_set_interface_pix_fmt(struct drm_crtc *crtc,
                u32 bus_format, int hsync_pin, int vsync_pin)
{
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);

        ipu_crtc->bus_format = bus_format;
        ipu_crtc->di_hsync_pin = hsync_pin;
        ipu_crtc->di_vsync_pin = vsync_pin;

        return 0;
}

static const struct imx_drm_crtc_helper_funcs ipu_crtc_helper_funcs = {
        .enable_vblank = ipu_enable_vblank,
        .disable_vblank = ipu_disable_vblank,
        .set_interface_pix_fmt = ipu_set_interface_pix_fmt,
        .crtc_funcs = &ipu_crtc_funcs,
        .crtc_helper_funcs = &ipu_helper_funcs,
};

static void ipu_put_resources(struct ipu_crtc *ipu_crtc)
{
        if (!IS_ERR_OR_NULL(ipu_crtc->dc))
                ipu_dc_put(ipu_crtc->dc);
        if (!IS_ERR_OR_NULL(ipu_crtc->di))
                ipu_di_put(ipu_crtc->di);
}

static int ipu_get_resources(struct ipu_crtc *ipu_crtc,
                struct ipu_client_platformdata *pdata)
{
        struct ipu_soc *ipu = dev_get_drvdata(ipu_crtc->dev->parent);
        int ret;

        ipu_crtc->dc = ipu_dc_get(ipu, pdata->dc);
        if (IS_ERR(ipu_crtc->dc)) {
                ret = PTR_ERR(ipu_crtc->dc);
                goto err_out;
        }

        ipu_crtc->di = ipu_di_get(ipu, pdata->di);
        if (IS_ERR(ipu_crtc->di)) {
                ret = PTR_ERR(ipu_crtc->di);
                goto err_out;
        }

        return 0;
err_out:
        ipu_put_resources(ipu_crtc);

        return ret;
}

static int ipu_crtc_init(struct ipu_crtc *ipu_crtc,
        struct ipu_client_platformdata *pdata, struct drm_device *drm)
{
        struct ipu_soc *ipu = dev_get_drvdata(ipu_crtc->dev->parent);
        int dp = -EINVAL;
        int ret;

        ret = ipu_get_resources(ipu_crtc, pdata);
        if (ret) {
                dev_err(ipu_crtc->dev, "getting resources failed with %d.\n",
                                ret);
                return ret;
        }

        if (pdata->dp >= 0)
                dp = IPU_DP_FLOW_SYNC_BG;
        ipu_crtc->plane[0] = ipu_plane_init(drm, ipu, pdata->dma[0], dp, 0,
                                            DRM_PLANE_TYPE_PRIMARY);
        if (IS_ERR(ipu_crtc->plane[0])) {
                ret = PTR_ERR(ipu_crtc->plane[0]);
                goto err_put_resources;
        }

        ret = imx_drm_add_crtc(drm, &ipu_crtc->base, &ipu_crtc->imx_crtc,
                        &ipu_crtc->plane[0]->base, &ipu_crtc_helper_funcs,
                        ipu_crtc->dev->of_node);
        if (ret) {
                dev_err(ipu_crtc->dev, "adding crtc failed with %d.\n", ret);
                goto err_put_resources;
        }

        ret = ipu_plane_get_resources(ipu_crtc->plane[0]);
        if (ret) {
                dev_err(ipu_crtc->dev, "getting plane 0 resources failed with %d.\n",
                        ret);
                goto err_remove_crtc;
        }

        /* If this crtc is using the DP, add an overlay plane */
        if (pdata->dp >= 0 && pdata->dma[1] > 0) {
                ipu_crtc->plane[1] = ipu_plane_init(drm, ipu, pdata->dma[1],
                                                IPU_DP_FLOW_SYNC_FG,
                                                drm_crtc_mask(&ipu_crtc->base),
                                                DRM_PLANE_TYPE_OVERLAY);
                if (IS_ERR(ipu_crtc->plane[1]))
                        ipu_crtc->plane[1] = NULL;
        }

        ipu_crtc->irq = ipu_plane_irq(ipu_crtc->plane[0]);
        ret = devm_request_irq(ipu_crtc->dev, ipu_crtc->irq, ipu_irq_handler, 0,
                        "imx_drm", ipu_crtc);
        if (ret < 0) {
                dev_err(ipu_crtc->dev, "irq request failed with %d.\n", ret);
                goto err_put_plane_res;
        }
        /* Only enable IRQ when we actually need it to trigger work. */
        disable_irq(ipu_crtc->irq);

        ipu_crtc->flip_queue = create_singlethread_workqueue("ipu-crtc-flip");

        return 0;

err_put_plane_res:
        ipu_plane_put_resources(ipu_crtc->plane[0]);
err_remove_crtc:
        imx_drm_remove_crtc(ipu_crtc->imx_crtc);
err_put_resources:
        ipu_put_resources(ipu_crtc);

        return ret;
}

static int ipu_drm_bind(struct device *dev, struct device *master, void *data)
{
        struct ipu_client_platformdata *pdata = dev->platform_data;
        struct drm_device *drm = data;
        struct ipu_crtc *ipu_crtc;
        int ret;

        ipu_crtc = devm_kzalloc(dev, sizeof(*ipu_crtc), GFP_KERNEL);
        if (!ipu_crtc)
                return -ENOMEM;

        ipu_crtc->dev = dev;

        ret = ipu_crtc_init(ipu_crtc, pdata, drm);
        if (ret)
                return ret;

        dev_set_drvdata(dev, ipu_crtc);

        return 0;
}

static void ipu_drm_unbind(struct device *dev, struct device *master,
        void *data)
{
        struct ipu_crtc *ipu_crtc = dev_get_drvdata(dev);

        imx_drm_remove_crtc(ipu_crtc->imx_crtc);

        destroy_workqueue(ipu_crtc->flip_queue);
        ipu_plane_put_resources(ipu_crtc->plane[0]);
        ipu_put_resources(ipu_crtc);
}

static const struct component_ops ipu_crtc_ops = {
        .bind = ipu_drm_bind,
        .unbind = ipu_drm_unbind,
};

static int ipu_drm_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        int ret;

        if (!dev->platform_data)
                return -EINVAL;

        ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
        if (ret)
                return ret;

        return component_add(dev, &ipu_crtc_ops);
}

static int ipu_drm_remove(struct platform_device *pdev)
{
        component_del(&pdev->dev, &ipu_crtc_ops);
        return 0;
}

static struct platform_driver ipu_drm_driver = {
        .driver = {
                .name = "imx-ipuv3-crtc",
        },
        .probe = ipu_drm_probe,
        .remove = ipu_drm_remove,
};
module_platform_driver(ipu_drm_driver);

MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:imx-ipuv3-crtc");