/*
 * Copyright (C) 2012 Texas Instruments
 * Author: Rob Clark <robdclark@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "drm_flip_work.h"
#include <drm/drm_plane_helper.h>

#include "tilcdc_drv.h"
#include "tilcdc_regs.h"

#define TILCDC_VBLANK_SAFETY_THRESHOLD_US 1000

struct tilcdc_crtc {
        struct drm_crtc base;

        const struct tilcdc_panel_info *info;
        struct drm_pending_vblank_event *event;
        int dpms;
        wait_queue_head_t frame_done_wq;
        bool frame_done;
        spinlock_t irq_lock;

        ktime_t last_vblank;

        struct drm_framebuffer *curr_fb;
        struct drm_framebuffer *next_fb;

        /* for deferred fb unref's: */
        struct drm_flip_work unref_work;

        /* Only set if an external encoder is connected */
        bool simulate_vesa_sync;

        int sync_lost_count;
        bool frame_intact;
};
#define to_tilcdc_crtc(x) container_of(x, struct tilcdc_crtc, base)

static void unref_worker(struct drm_flip_work *work, void *val)
{
        struct tilcdc_crtc *tilcdc_crtc =
                container_of(work, struct tilcdc_crtc, unref_work);
        struct drm_device *dev = tilcdc_crtc->base.dev;

        mutex_lock(&dev->mode_config.mutex);
        drm_framebuffer_unreference(val);
        mutex_unlock(&dev->mode_config.mutex);
}

static void set_scanout(struct drm_crtc *crtc, struct drm_framebuffer *fb)
{
        struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
        struct drm_device *dev = crtc->dev;
        struct drm_gem_cma_object *gem;
        unsigned int depth, bpp;
        dma_addr_t start, end;

        drm_fb_get_bpp_depth(fb->pixel_format, &depth, &bpp);
        gem = drm_fb_cma_get_gem_obj(fb, 0);

        start = gem->paddr + fb->offsets[0] +
                crtc->y * fb->pitches[0] +
                crtc->x * bpp / 8;

        end = start + (crtc->mode.vdisplay * fb->pitches[0]);

        tilcdc_write(dev, LCDC_DMA_FB_BASE_ADDR_0_REG, start);
        tilcdc_write(dev, LCDC_DMA_FB_CEILING_ADDR_0_REG, end);

        if (tilcdc_crtc->curr_fb)
                drm_flip_work_queue(&tilcdc_crtc->unref_work,
                        tilcdc_crtc->curr_fb);

        tilcdc_crtc->curr_fb = fb;
}

static void reset(struct drm_crtc *crtc)
{
        struct drm_device *dev = crtc->dev;
        struct tilcdc_drm_private *priv = dev->dev_private;

        if (priv->rev != 2)
                return;

        tilcdc_set(dev, LCDC_CLK_RESET_REG, LCDC_CLK_MAIN_RESET);
        usleep_range(250, 1000);
        tilcdc_clear(dev, LCDC_CLK_RESET_REG, LCDC_CLK_MAIN_RESET);
}

static void start(struct drm_crtc *crtc)
{
        struct drm_device *dev = crtc->dev;

        reset(crtc);

        tilcdc_clear(dev, LCDC_DMA_CTRL_REG, LCDC_DUAL_FRAME_BUFFER_ENABLE);
        tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_PALETTE_LOAD_MODE(DATA_ONLY));
        tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
}

static void stop(struct drm_crtc *crtc)
{
        struct drm_device *dev = crtc->dev;

        tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
}

static void tilcdc_crtc_destroy(struct drm_crtc *crtc)
{
        struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);

        tilcdc_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);

        of_node_put(crtc->port);
        drm_crtc_cleanup(crtc);
        drm_flip_work_cleanup(&tilcdc_crtc->unref_work);
}

static int tilcdc_verify_fb(struct drm_crtc *crtc, struct drm_framebuffer *fb)
{
        struct drm_device *dev = crtc->dev;
        unsigned int depth, bpp;

        drm_fb_get_bpp_depth(fb->pixel_format, &depth, &bpp);

        if (fb->pitches[0] != crtc->mode.hdisplay * bpp / 8) {
                dev_err(dev->dev,
                        "Invalid pitch: fb and crtc widths must be the same");
                return -EINVAL;
        }

        return 0;
}

static int tilcdc_crtc_page_flip(struct drm_crtc *crtc,
                struct drm_framebuffer *fb,
                struct drm_pending_vblank_event *event,
                uint32_t page_flip_flags)
{
        struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
        struct drm_device *dev = crtc->dev;
        int r;
        unsigned long flags;
        s64 tdiff;
        ktime_t next_vblank;

        r = tilcdc_verify_fb(crtc, fb);
        if (r)
                return r;

        if (tilcdc_crtc->event) {
                dev_err(dev->dev, "already pending page flip!\n");
                return -EBUSY;
        }

        drm_framebuffer_reference(fb);

        crtc->primary->fb = fb;

        pm_runtime_get_sync(dev->dev);

        spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);

        next_vblank = ktime_add_us(tilcdc_crtc->last_vblank,
                1000000 / crtc->hwmode.vrefresh);

        tdiff = ktime_to_us(ktime_sub(next_vblank, ktime_get()));

        if (tdiff >= TILCDC_VBLANK_SAFETY_THRESHOLD_US)
                set_scanout(crtc, fb);
        else
                tilcdc_crtc->next_fb = fb;

        tilcdc_crtc->event = event;

        spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);

        pm_runtime_put_sync(dev->dev);

        return 0;
}

void tilcdc_crtc_dpms(struct drm_crtc *crtc, int mode)
{
        struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
        struct drm_device *dev = crtc->dev;
        struct tilcdc_drm_private *priv = dev->dev_private;

        /* we really only care about on or off: */
        if (mode != DRM_MODE_DPMS_ON)
                mode = DRM_MODE_DPMS_OFF;

        if (tilcdc_crtc->dpms == mode)
                return;

        tilcdc_crtc->dpms = mode;

        if (mode == DRM_MODE_DPMS_ON) {
                pm_runtime_get_sync(dev->dev);
                start(crtc);
        } else {
                tilcdc_crtc->frame_done = false;
                stop(crtc);

                /*
                 * if necessary wait for framedone irq which will still come
                 * before putting things to sleep..
                 */
                if (priv->rev == 2) {
                        int ret = wait_event_timeout(
                                        tilcdc_crtc->frame_done_wq,
                                        tilcdc_crtc->frame_done,
                                        msecs_to_jiffies(50));
                        if (ret == 0)
                                dev_err(dev->dev, "timeout waiting for framedone\n");
                }

                pm_runtime_put_sync(dev->dev);

                if (tilcdc_crtc->next_fb) {
                        drm_flip_work_queue(&tilcdc_crtc->unref_work,
                                            tilcdc_crtc->next_fb);
                        tilcdc_crtc->next_fb = NULL;
                }

                if (tilcdc_crtc->curr_fb) {
                        drm_flip_work_queue(&tilcdc_crtc->unref_work,
                                            tilcdc_crtc->curr_fb);
                        tilcdc_crtc->curr_fb = NULL;
                }

                drm_flip_work_commit(&tilcdc_crtc->unref_work, priv->wq);
        }
}

static bool tilcdc_crtc_mode_fixup(struct drm_crtc *crtc,
                const struct drm_display_mode *mode,
                struct drm_display_mode *adjusted_mode)
{
        struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);

        if (!tilcdc_crtc->simulate_vesa_sync)
                return true;

        /*
         * tilcdc does not generate VESA-compliant sync but aligns
         * VS on the second edge of HS instead of first edge.
         * We use adjusted_mode, to fixup sync by aligning both rising
         * edges and add HSKEW offset to fix the sync.
         */
        adjusted_mode->hskew = mode->hsync_end - mode->hsync_start;
        adjusted_mode->flags |= DRM_MODE_FLAG_HSKEW;

        if (mode->flags & DRM_MODE_FLAG_NHSYNC) {
                adjusted_mode->flags |= DRM_MODE_FLAG_PHSYNC;
                adjusted_mode->flags &= ~DRM_MODE_FLAG_NHSYNC;
        } else {
                adjusted_mode->flags |= DRM_MODE_FLAG_NHSYNC;
                adjusted_mode->flags &= ~DRM_MODE_FLAG_PHSYNC;
        }

        return true;
}

static void tilcdc_crtc_prepare(struct drm_crtc *crtc)
{
        tilcdc_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
}

static void tilcdc_crtc_commit(struct drm_crtc *crtc)
{
        tilcdc_crtc_dpms(crtc, DRM_MODE_DPMS_ON);
}

static int tilcdc_crtc_mode_set(struct drm_crtc *crtc,
                struct drm_display_mode *mode,
                struct drm_display_mode *adjusted_mode,
                int x, int y,
                struct drm_framebuffer *old_fb)
{
        struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
        struct drm_device *dev = crtc->dev;
        struct tilcdc_drm_private *priv = dev->dev_private;
        const struct tilcdc_panel_info *info = tilcdc_crtc->info;
        uint32_t reg, hbp, hfp, hsw, vbp, vfp, vsw;
        int ret;

        ret = tilcdc_crtc_mode_valid(crtc, mode);
        if (WARN_ON(ret))
                return ret;

        if (WARN_ON(!info))
                return -EINVAL;

        ret = tilcdc_verify_fb(crtc, crtc->primary->fb);
        if (ret)
                return ret;

        pm_runtime_get_sync(dev->dev);

        /* Configure the Burst Size and fifo threshold of DMA: */
        reg = tilcdc_read(dev, LCDC_DMA_CTRL_REG) & ~0x00000770;
        switch (info->dma_burst_sz) {
        case 1:
                reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_1);
                break;
        case 2:
                reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_2);
                break;
        case 4:
                reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_4);
                break;
        case 8:
                reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_8);
                break;
        case 16:
                reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_16);
                break;
        default:
                return -EINVAL;
        }
        reg |= (info->fifo_th << 8);
        tilcdc_write(dev, LCDC_DMA_CTRL_REG, reg);

        /* Configure timings: */
        hbp = mode->htotal - mode->hsync_end;
        hfp = mode->hsync_start - mode->hdisplay;
        hsw = mode->hsync_end - mode->hsync_start;
        vbp = mode->vtotal - mode->vsync_end;
        vfp = mode->vsync_start - mode->vdisplay;
        vsw = mode->vsync_end - mode->vsync_start;

        DBG("%dx%d, hbp=%u, hfp=%u, hsw=%u, vbp=%u, vfp=%u, vsw=%u",
                        mode->hdisplay, mode->vdisplay, hbp, hfp, hsw, vbp, vfp, vsw);

        /* Configure the AC Bias Period and Number of Transitions per Interrupt: */
        reg = tilcdc_read(dev, LCDC_RASTER_TIMING_2_REG) & ~0x000fff00;
        reg |= LCDC_AC_BIAS_FREQUENCY(info->ac_bias) |
                LCDC_AC_BIAS_TRANSITIONS_PER_INT(info->ac_bias_intrpt);

        /*
         * subtract one from hfp, hbp, hsw because the hardware uses
         * a value of 0 as 1
         */
        if (priv->rev == 2) {
                /* clear bits we're going to set */
                reg &= ~0x78000033;
                reg |= ((hfp-1) & 0x300) >> 8;
                reg |= ((hbp-1) & 0x300) >> 4;
                reg |= ((hsw-1) & 0x3c0) << 21;
        }
        tilcdc_write(dev, LCDC_RASTER_TIMING_2_REG, reg);

        reg = (((mode->hdisplay >> 4) - 1) << 4) |
                (((hbp-1) & 0xff) << 24) |
                (((hfp-1) & 0xff) << 16) |
                (((hsw-1) & 0x3f) << 10);
        if (priv->rev == 2)
                reg |= (((mode->hdisplay >> 4) - 1) & 0x40) >> 3;
        tilcdc_write(dev, LCDC_RASTER_TIMING_0_REG, reg);

        reg = ((mode->vdisplay - 1) & 0x3ff) |
                ((vbp & 0xff) << 24) |
                ((vfp & 0xff) << 16) |
                (((vsw-1) & 0x3f) << 10);
        tilcdc_write(dev, LCDC_RASTER_TIMING_1_REG, reg);

        /*
         * be sure to set Bit 10 for the V2 LCDC controller,
         * otherwise limited to 1024 pixels width, stopping
         * 1920x1080 being suppoted.
         */
        if (priv->rev == 2) {
                if ((mode->vdisplay - 1) & 0x400) {
                        tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG,
                                LCDC_LPP_B10);
                } else {
                        tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG,
                                LCDC_LPP_B10);
                }
        }

        /* Configure display type: */
        reg = tilcdc_read(dev, LCDC_RASTER_CTRL_REG) &
                ~(LCDC_TFT_MODE | LCDC_MONO_8BIT_MODE | LCDC_MONOCHROME_MODE |
                        LCDC_V2_TFT_24BPP_MODE | LCDC_V2_TFT_24BPP_UNPACK | 0x000ff000);
        reg |= LCDC_TFT_MODE; /* no monochrome/passive support */
        if (info->tft_alt_mode)
                reg |= LCDC_TFT_ALT_ENABLE;
        if (priv->rev == 2) {
                unsigned int depth, bpp;

                drm_fb_get_bpp_depth(crtc->primary->fb->pixel_format, &depth, &bpp);
                switch (bpp) {
                case 16:
                        break;
                case 32:
                        reg |= LCDC_V2_TFT_24BPP_UNPACK;
                        /* fallthrough */
                case 24:
                        reg |= LCDC_V2_TFT_24BPP_MODE;
                        break;
                default:
                        dev_err(dev->dev, "invalid pixel format\n");
                        return -EINVAL;
                }
        }
        reg |= info->fdd < 12;
        tilcdc_write(dev, LCDC_RASTER_CTRL_REG, reg);

        if (info->invert_pxl_clk)
                tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_PIXEL_CLOCK);
        else
                tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_PIXEL_CLOCK);

        if (info->sync_ctrl)
                tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_CTRL);
        else
                tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_CTRL);

        if (info->sync_edge)
                tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_EDGE);
        else
                tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_EDGE);

        /*
         * use value from adjusted_mode here as this might have been
         * changed as part of the fixup for slave encoders to solve the
         * issue where tilcdc timings are not VESA compliant
         */
        if (adjusted_mode->flags & DRM_MODE_FLAG_NHSYNC)
                tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_HSYNC);
        else
                tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_HSYNC);

        if (mode->flags & DRM_MODE_FLAG_NVSYNC)
                tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_VSYNC);
        else
                tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_VSYNC);

        if (info->raster_order)
                tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ORDER);
        else
                tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ORDER);

        drm_framebuffer_reference(crtc->primary->fb);

        set_scanout(crtc, crtc->primary->fb);

        tilcdc_crtc_update_clk(crtc);

        pm_runtime_put_sync(dev->dev);

        return 0;
}

static int tilcdc_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
                struct drm_framebuffer *old_fb)
{
        struct drm_device *dev = crtc->dev;
        int r;

        r = tilcdc_verify_fb(crtc, crtc->primary->fb);
        if (r)
                return r;

        drm_framebuffer_reference(crtc->primary->fb);

        pm_runtime_get_sync(dev->dev);

        set_scanout(crtc, crtc->primary->fb);

        pm_runtime_put_sync(dev->dev);

        return 0;
}

static const struct drm_crtc_funcs tilcdc_crtc_funcs = {
                .destroy        = tilcdc_crtc_destroy,
                .set_config     = drm_crtc_helper_set_config,
                .page_flip      = tilcdc_crtc_page_flip,
};

static const struct drm_crtc_helper_funcs tilcdc_crtc_helper_funcs = {
                .dpms           = tilcdc_crtc_dpms,
                .mode_fixup     = tilcdc_crtc_mode_fixup,
                .prepare        = tilcdc_crtc_prepare,
                .commit         = tilcdc_crtc_commit,
                .mode_set       = tilcdc_crtc_mode_set,
                .mode_set_base  = tilcdc_crtc_mode_set_base,
};

int tilcdc_crtc_max_width(struct drm_crtc *crtc)
{
        struct drm_device *dev = crtc->dev;
        struct tilcdc_drm_private *priv = dev->dev_private;
        int max_width = 0;

        if (priv->rev == 1)
                max_width = 1024;
        else if (priv->rev == 2)
                max_width = 2048;

        return max_width;
}

int tilcdc_crtc_mode_valid(struct drm_crtc *crtc, struct drm_display_mode *mode)
{
        struct tilcdc_drm_private *priv = crtc->dev->dev_private;
        unsigned int bandwidth;
        uint32_t hbp, hfp, hsw, vbp, vfp, vsw;

        /*
         * check to see if the width is within the range that
         * the LCD Controller physically supports
         */
        if (mode->hdisplay > tilcdc_crtc_max_width(crtc))
                return MODE_VIRTUAL_X;

        /* width must be multiple of 16 */
        if (mode->hdisplay & 0xf)
                return MODE_VIRTUAL_X;

        if (mode->vdisplay > 2048)
                return MODE_VIRTUAL_Y;

        DBG("Processing mode %dx%d@%d with pixel clock %d",
                mode->hdisplay, mode->vdisplay,
                drm_mode_vrefresh(mode), mode->clock);

        hbp = mode->htotal - mode->hsync_end;
        hfp = mode->hsync_start - mode->hdisplay;
        hsw = mode->hsync_end - mode->hsync_start;
        vbp = mode->vtotal - mode->vsync_end;
        vfp = mode->vsync_start - mode->vdisplay;
        vsw = mode->vsync_end - mode->vsync_start;

        if ((hbp-1) & ~0x3ff) {
                DBG("Pruning mode: Horizontal Back Porch out of range");
                return MODE_HBLANK_WIDE;
        }

        if ((hfp-1) & ~0x3ff) {
                DBG("Pruning mode: Horizontal Front Porch out of range");
                return MODE_HBLANK_WIDE;
        }

        if ((hsw-1) & ~0x3ff) {
                DBG("Pruning mode: Horizontal Sync Width out of range");
                return MODE_HSYNC_WIDE;
        }

        if (vbp & ~0xff) {
                DBG("Pruning mode: Vertical Back Porch out of range");
                return MODE_VBLANK_WIDE;
        }

        if (vfp & ~0xff) {
                DBG("Pruning mode: Vertical Front Porch out of range");
                return MODE_VBLANK_WIDE;
        }

        if ((vsw-1) & ~0x3f) {
                DBG("Pruning mode: Vertical Sync Width out of range");
                return MODE_VSYNC_WIDE;
        }

        /*
         * some devices have a maximum allowed pixel clock
         * configured from the DT
         */
        if (mode->clock > priv->max_pixelclock) {
                DBG("Pruning mode: pixel clock too high");
                return MODE_CLOCK_HIGH;
        }

        /*
         * some devices further limit the max horizontal resolution
         * configured from the DT
         */
        if (mode->hdisplay > priv->max_width)
                return MODE_BAD_WIDTH;

        /* filter out modes that would require too much memory bandwidth: */
        bandwidth = mode->hdisplay * mode->vdisplay *
                drm_mode_vrefresh(mode);
        if (bandwidth > priv->max_bandwidth) {
                DBG("Pruning mode: exceeds defined bandwidth limit");
                return MODE_BAD;
        }

        return MODE_OK;
}

void tilcdc_crtc_set_panel_info(struct drm_crtc *crtc,
                const struct tilcdc_panel_info *info)
{
        struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
        tilcdc_crtc->info = info;
}

void tilcdc_crtc_set_simulate_vesa_sync(struct drm_crtc *crtc,
                                        bool simulate_vesa_sync)
{
        struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);

        tilcdc_crtc->simulate_vesa_sync = simulate_vesa_sync;
}

void tilcdc_crtc_update_clk(struct drm_crtc *crtc)
{
        struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
        struct drm_device *dev = crtc->dev;
        struct tilcdc_drm_private *priv = dev->dev_private;
        int dpms = tilcdc_crtc->dpms;
        unsigned long lcd_clk;
        const unsigned clkdiv = 2; /* using a fixed divider of 2 */
        int ret;

        pm_runtime_get_sync(dev->dev);

        if (dpms == DRM_MODE_DPMS_ON)
                tilcdc_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);

        /* mode.clock is in KHz, set_rate wants parameter in Hz */
        ret = clk_set_rate(priv->clk, crtc->mode.clock * 1000 * clkdiv);
        if (ret < 0) {
                dev_err(dev->dev, "failed to set display clock rate to: %d\n",
                                crtc->mode.clock);
                goto out;
        }

        lcd_clk = clk_get_rate(priv->clk);

        DBG("lcd_clk=%lu, mode clock=%d, div=%u",
                lcd_clk, crtc->mode.clock, clkdiv);

        /* Configure the LCD clock divisor. */
        tilcdc_write(dev, LCDC_CTRL_REG, LCDC_CLK_DIVISOR(clkdiv) |
                        LCDC_RASTER_MODE);

        if (priv->rev == 2)
                tilcdc_set(dev, LCDC_CLK_ENABLE_REG,
                                LCDC_V2_DMA_CLK_EN | LCDC_V2_LIDD_CLK_EN |
                                LCDC_V2_CORE_CLK_EN);

        if (dpms == DRM_MODE_DPMS_ON)
                tilcdc_crtc_dpms(crtc, DRM_MODE_DPMS_ON);

out:
        pm_runtime_put_sync(dev->dev);
}

#define SYNC_LOST_COUNT_LIMIT 50

irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc)
{
        struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
        struct drm_device *dev = crtc->dev;
        struct tilcdc_drm_private *priv = dev->dev_private;
        uint32_t stat;

        stat = tilcdc_read_irqstatus(dev);
        tilcdc_clear_irqstatus(dev, stat);

        if (stat & LCDC_END_OF_FRAME0) {
                unsigned long flags;
                bool skip_event = false;
                ktime_t now;

                now = ktime_get();

                drm_flip_work_commit(&tilcdc_crtc->unref_work, priv->wq);

                spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);

                tilcdc_crtc->last_vblank = now;

                if (tilcdc_crtc->next_fb) {
                        set_scanout(crtc, tilcdc_crtc->next_fb);
                        tilcdc_crtc->next_fb = NULL;
                        skip_event = true;
                }

                spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);

                drm_handle_vblank(dev, 0);

                if (!skip_event) {
                        struct drm_pending_vblank_event *event;

                        spin_lock_irqsave(&dev->event_lock, flags);

                        event = tilcdc_crtc->event;
                        tilcdc_crtc->event = NULL;
                        if (event)
                                drm_crtc_send_vblank_event(crtc, event);

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

                if (tilcdc_crtc->frame_intact)
                        tilcdc_crtc->sync_lost_count = 0;
                else
                        tilcdc_crtc->frame_intact = true;
        }

        if (priv->rev == 2) {
                if (stat & LCDC_FRAME_DONE) {
                        tilcdc_crtc->frame_done = true;
                        wake_up(&tilcdc_crtc->frame_done_wq);
                }
                tilcdc_write(dev, LCDC_END_OF_INT_IND_REG, 0);
        }

        if (stat & LCDC_SYNC_LOST) {
                dev_err_ratelimited(dev->dev, "%s(0x%08x): Sync lost",
                                    __func__, stat);
                tilcdc_crtc->frame_intact = false;
                if (tilcdc_crtc->sync_lost_count++ > SYNC_LOST_COUNT_LIMIT) {
                        dev_err(dev->dev,
                                "%s(0x%08x): Sync lost flood detected, disabling the interrupt",
                                __func__, stat);
                        tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
                                     LCDC_SYNC_LOST);
                }
        }

        if (stat & LCDC_FIFO_UNDERFLOW)
                dev_err_ratelimited(dev->dev, "%s(0x%08x): FIFO underfow",
                                    __func__, stat);

        return IRQ_HANDLED;
}

struct drm_crtc *tilcdc_crtc_create(struct drm_device *dev)
{
        struct tilcdc_drm_private *priv = dev->dev_private;
        struct tilcdc_crtc *tilcdc_crtc;
        struct drm_crtc *crtc;
        int ret;

        tilcdc_crtc = devm_kzalloc(dev->dev, sizeof(*tilcdc_crtc), GFP_KERNEL);
        if (!tilcdc_crtc) {
                dev_err(dev->dev, "allocation failed\n");
                return NULL;
        }

        crtc = &tilcdc_crtc->base;

        tilcdc_crtc->dpms = DRM_MODE_DPMS_OFF;
        init_waitqueue_head(&tilcdc_crtc->frame_done_wq);

        drm_flip_work_init(&tilcdc_crtc->unref_work,
                        "unref", unref_worker);

        spin_lock_init(&tilcdc_crtc->irq_lock);

        ret = drm_crtc_init(dev, crtc, &tilcdc_crtc_funcs);
        if (ret < 0)
                goto fail;

        drm_crtc_helper_add(crtc, &tilcdc_crtc_helper_funcs);

        if (priv->is_componentized) {
                struct device_node *ports =
                        of_get_child_by_name(dev->dev->of_node, "ports");

                if (ports) {
                        crtc->port = of_get_child_by_name(ports, "port");
                        of_node_put(ports);
                } else {
                        crtc->port =
                                of_get_child_by_name(dev->dev->of_node, "port");
                }
                if (!crtc->port) { /* This should never happen */
                        dev_err(dev->dev, "Port node not found in %s\n",
                                dev->dev->of_node->full_name);
                        goto fail;
                }
        }

        return crtc;

fail:
        tilcdc_crtc_destroy(crtc);
        return NULL;
}