// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2018 Linus Walleij <linus.walleij@linaro.org>
 * Parts of this file were based on the MCDE driver by Marcus Lorentzon
 * (C) ST-Ericsson SA 2013
 */
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dma-buf.h>
#include <linux/regulator/consumer.h>
#include <linux/media-bus-format.h>

#include <drm/drm_device.h>
#include <drm/drm_fb_dma_helper.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_print.h>
#include <drm/drm_simple_kms_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_vblank.h>
#include <video/mipi_display.h>

#include "mcde_drm.h"
#include "mcde_display_regs.h"

enum mcde_fifo {
        MCDE_FIFO_A,
        MCDE_FIFO_B,
        /* TODO: implement FIFO C0 and FIFO C1 */
};

enum mcde_channel {
        MCDE_CHANNEL_0 = 0,
        MCDE_CHANNEL_1,
        MCDE_CHANNEL_2,
        MCDE_CHANNEL_3,
};

enum mcde_extsrc {
        MCDE_EXTSRC_0 = 0,
        MCDE_EXTSRC_1,
        MCDE_EXTSRC_2,
        MCDE_EXTSRC_3,
        MCDE_EXTSRC_4,
        MCDE_EXTSRC_5,
        MCDE_EXTSRC_6,
        MCDE_EXTSRC_7,
        MCDE_EXTSRC_8,
        MCDE_EXTSRC_9,
};

enum mcde_overlay {
        MCDE_OVERLAY_0 = 0,
        MCDE_OVERLAY_1,
        MCDE_OVERLAY_2,
        MCDE_OVERLAY_3,
        MCDE_OVERLAY_4,
        MCDE_OVERLAY_5,
};

enum mcde_formatter {
        MCDE_DSI_FORMATTER_0 = 0,
        MCDE_DSI_FORMATTER_1,
        MCDE_DSI_FORMATTER_2,
        MCDE_DSI_FORMATTER_3,
        MCDE_DSI_FORMATTER_4,
        MCDE_DSI_FORMATTER_5,
        MCDE_DPI_FORMATTER_0,
        MCDE_DPI_FORMATTER_1,
};

void mcde_display_irq(struct mcde *mcde)
{
        u32 mispp, misovl, mischnl;
        bool vblank = false;

        /* Handle display IRQs */
        mispp = readl(mcde->regs + MCDE_MISPP);
        misovl = readl(mcde->regs + MCDE_MISOVL);
        mischnl = readl(mcde->regs + MCDE_MISCHNL);

        /*
         * Handle IRQs from the DSI link. All IRQs from the DSI links
         * are just latched onto the MCDE IRQ line, so we need to traverse
         * any active DSI masters and check if an IRQ is originating from
         * them.
         *
         * TODO: Currently only one DSI link is supported.
         */
        if (!mcde->dpi_output && mcde_dsi_irq(mcde->mdsi)) {
                u32 val;

                /*
                 * In oneshot mode we do not send continuous updates
                 * to the display, instead we only push out updates when
                 * the update function is called, then we disable the
                 * flow on the channel once we get the TE IRQ.
                 */
                if (mcde->flow_mode == MCDE_COMMAND_ONESHOT_FLOW) {
                        spin_lock(&mcde->flow_lock);
                        if (--mcde->flow_active == 0) {
                                dev_dbg(mcde->dev, "TE0 IRQ\n");
                                /* Disable FIFO A flow */
                                val = readl(mcde->regs + MCDE_CRA0);
                                val &= ~MCDE_CRX0_FLOEN;
                                writel(val, mcde->regs + MCDE_CRA0);
                        }
                        spin_unlock(&mcde->flow_lock);
                }
        }

        /* Vblank from one of the channels */
        if (mispp & MCDE_PP_VCMPA) {
                dev_dbg(mcde->dev, "chnl A vblank IRQ\n");
                vblank = true;
        }
        if (mispp & MCDE_PP_VCMPB) {
                dev_dbg(mcde->dev, "chnl B vblank IRQ\n");
                vblank = true;
        }
        if (mispp & MCDE_PP_VCMPC0)
                dev_dbg(mcde->dev, "chnl C0 vblank IRQ\n");
        if (mispp & MCDE_PP_VCMPC1)
                dev_dbg(mcde->dev, "chnl C1 vblank IRQ\n");
        if (mispp & MCDE_PP_VSCC0)
                dev_dbg(mcde->dev, "chnl C0 TE IRQ\n");
        if (mispp & MCDE_PP_VSCC1)
                dev_dbg(mcde->dev, "chnl C1 TE IRQ\n");
        writel(mispp, mcde->regs + MCDE_RISPP);

        if (vblank)
                drm_crtc_handle_vblank(&mcde->pipe.crtc);

        if (misovl)
                dev_info(mcde->dev, "some stray overlay IRQ %08x\n", misovl);
        writel(misovl, mcde->regs + MCDE_RISOVL);

        if (mischnl)
                dev_info(mcde->dev, "some stray channel error IRQ %08x\n",
                         mischnl);
        writel(mischnl, mcde->regs + MCDE_RISCHNL);
}

void mcde_display_disable_irqs(struct mcde *mcde)
{
        /* Disable all IRQs */
        writel(0, mcde->regs + MCDE_IMSCPP);
        writel(0, mcde->regs + MCDE_IMSCOVL);
        writel(0, mcde->regs + MCDE_IMSCCHNL);

        /* Clear any pending IRQs */
        writel(0xFFFFFFFF, mcde->regs + MCDE_RISPP);
        writel(0xFFFFFFFF, mcde->regs + MCDE_RISOVL);
        writel(0xFFFFFFFF, mcde->regs + MCDE_RISCHNL);
}

static int mcde_display_check(struct drm_simple_display_pipe *pipe,
                              struct drm_plane_state *pstate,
                              struct drm_crtc_state *cstate)
{
        const struct drm_display_mode *mode = &cstate->mode;
        struct drm_framebuffer *old_fb = pipe->plane.state->fb;
        struct drm_framebuffer *fb = pstate->fb;

        if (fb) {
                u32 offset = drm_fb_dma_get_gem_addr(fb, pstate, 0);

                /* FB base address must be dword aligned. */
                if (offset & 3) {
                        DRM_DEBUG_KMS("FB not 32-bit aligned\n");
                        return -EINVAL;
                }

                /*
                 * There's no pitch register, the mode's hdisplay
                 * controls this.
                 */
                if (fb->pitches[0] != mode->hdisplay * fb->format->cpp[0]) {
                        DRM_DEBUG_KMS("can't handle pitches\n");
                        return -EINVAL;
                }

                /*
                 * We can't change the FB format in a flicker-free
                 * manner (and only update it during CRTC enable).
                 */
                if (old_fb && old_fb->format != fb->format)
                        cstate->mode_changed = true;
        }

        return 0;
}

static int mcde_configure_extsrc(struct mcde *mcde, enum mcde_extsrc src,
                                 u32 format)
{
        u32 val;
        u32 conf;
        u32 cr;

        switch (src) {
        case MCDE_EXTSRC_0:
                conf = MCDE_EXTSRC0CONF;
                cr = MCDE_EXTSRC0CR;
                break;
        case MCDE_EXTSRC_1:
                conf = MCDE_EXTSRC1CONF;
                cr = MCDE_EXTSRC1CR;
                break;
        case MCDE_EXTSRC_2:
                conf = MCDE_EXTSRC2CONF;
                cr = MCDE_EXTSRC2CR;
                break;
        case MCDE_EXTSRC_3:
                conf = MCDE_EXTSRC3CONF;
                cr = MCDE_EXTSRC3CR;
                break;
        case MCDE_EXTSRC_4:
                conf = MCDE_EXTSRC4CONF;
                cr = MCDE_EXTSRC4CR;
                break;
        case MCDE_EXTSRC_5:
                conf = MCDE_EXTSRC5CONF;
                cr = MCDE_EXTSRC5CR;
                break;
        case MCDE_EXTSRC_6:
                conf = MCDE_EXTSRC6CONF;
                cr = MCDE_EXTSRC6CR;
                break;
        case MCDE_EXTSRC_7:
                conf = MCDE_EXTSRC7CONF;
                cr = MCDE_EXTSRC7CR;
                break;
        case MCDE_EXTSRC_8:
                conf = MCDE_EXTSRC8CONF;
                cr = MCDE_EXTSRC8CR;
                break;
        case MCDE_EXTSRC_9:
                conf = MCDE_EXTSRC9CONF;
                cr = MCDE_EXTSRC9CR;
                break;
        }

        /*
         * Configure external source 0 one buffer (buffer 0)
         * primary overlay ID 0.
         * From mcde_hw.c ovly_update_registers() in the vendor tree
         */
        val = 0 << MCDE_EXTSRCXCONF_BUF_ID_SHIFT;
        val |= 1 << MCDE_EXTSRCXCONF_BUF_NB_SHIFT;
        val |= 0 << MCDE_EXTSRCXCONF_PRI_OVLID_SHIFT;

        switch (format) {
        case DRM_FORMAT_ARGB8888:
                val |= MCDE_EXTSRCXCONF_BPP_ARGB8888 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                break;
        case DRM_FORMAT_ABGR8888:
                val |= MCDE_EXTSRCXCONF_BPP_ARGB8888 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                val |= MCDE_EXTSRCXCONF_BGR;
                break;
        case DRM_FORMAT_XRGB8888:
                val |= MCDE_EXTSRCXCONF_BPP_XRGB8888 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                break;
        case DRM_FORMAT_XBGR8888:
                val |= MCDE_EXTSRCXCONF_BPP_XRGB8888 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                val |= MCDE_EXTSRCXCONF_BGR;
                break;
        case DRM_FORMAT_RGB888:
                val |= MCDE_EXTSRCXCONF_BPP_RGB888 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                break;
        case DRM_FORMAT_BGR888:
                val |= MCDE_EXTSRCXCONF_BPP_RGB888 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                val |= MCDE_EXTSRCXCONF_BGR;
                break;
        case DRM_FORMAT_ARGB4444:
                val |= MCDE_EXTSRCXCONF_BPP_ARGB4444 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                break;
        case DRM_FORMAT_ABGR4444:
                val |= MCDE_EXTSRCXCONF_BPP_ARGB4444 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                val |= MCDE_EXTSRCXCONF_BGR;
                break;
        case DRM_FORMAT_XRGB4444:
                val |= MCDE_EXTSRCXCONF_BPP_RGB444 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                break;
        case DRM_FORMAT_XBGR4444:
                val |= MCDE_EXTSRCXCONF_BPP_RGB444 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                val |= MCDE_EXTSRCXCONF_BGR;
                break;
        case DRM_FORMAT_XRGB1555:
                val |= MCDE_EXTSRCXCONF_BPP_IRGB1555 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                break;
        case DRM_FORMAT_XBGR1555:
                val |= MCDE_EXTSRCXCONF_BPP_IRGB1555 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                val |= MCDE_EXTSRCXCONF_BGR;
                break;
        case DRM_FORMAT_RGB565:
                val |= MCDE_EXTSRCXCONF_BPP_RGB565 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                break;
        case DRM_FORMAT_BGR565:
                val |= MCDE_EXTSRCXCONF_BPP_RGB565 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                val |= MCDE_EXTSRCXCONF_BGR;
                break;
        case DRM_FORMAT_YUV422:
                val |= MCDE_EXTSRCXCONF_BPP_YCBCR422 <<
                        MCDE_EXTSRCXCONF_BPP_SHIFT;
                break;
        default:
                dev_err(mcde->dev, "Unknown pixel format 0x%08x\n",
                        format);
                return -EINVAL;
        }
        writel(val, mcde->regs + conf);

        /* Software select, primary */
        val = MCDE_EXTSRCXCR_SEL_MOD_SOFTWARE_SEL;
        val |= MCDE_EXTSRCXCR_MULTIOVL_CTRL_PRIMARY;
        writel(val, mcde->regs + cr);

        return 0;
}

static void mcde_configure_overlay(struct mcde *mcde, enum mcde_overlay ovl,
                                   enum mcde_extsrc src,
                                   enum mcde_channel ch,
                                   const struct drm_display_mode *mode,
                                   u32 format, int cpp)
{
        u32 val;
        u32 conf1;
        u32 conf2;
        u32 crop;
        u32 ljinc;
        u32 cr;
        u32 comp;
        u32 pixel_fetcher_watermark;

        switch (ovl) {
        case MCDE_OVERLAY_0:
                conf1 = MCDE_OVL0CONF;
                conf2 = MCDE_OVL0CONF2;
                crop = MCDE_OVL0CROP;
                ljinc = MCDE_OVL0LJINC;
                cr = MCDE_OVL0CR;
                comp = MCDE_OVL0COMP;
                break;
        case MCDE_OVERLAY_1:
                conf1 = MCDE_OVL1CONF;
                conf2 = MCDE_OVL1CONF2;
                crop = MCDE_OVL1CROP;
                ljinc = MCDE_OVL1LJINC;
                cr = MCDE_OVL1CR;
                comp = MCDE_OVL1COMP;
                break;
        case MCDE_OVERLAY_2:
                conf1 = MCDE_OVL2CONF;
                conf2 = MCDE_OVL2CONF2;
                crop = MCDE_OVL2CROP;
                ljinc = MCDE_OVL2LJINC;
                cr = MCDE_OVL2CR;
                comp = MCDE_OVL2COMP;
                break;
        case MCDE_OVERLAY_3:
                conf1 = MCDE_OVL3CONF;
                conf2 = MCDE_OVL3CONF2;
                crop = MCDE_OVL3CROP;
                ljinc = MCDE_OVL3LJINC;
                cr = MCDE_OVL3CR;
                comp = MCDE_OVL3COMP;
                break;
        case MCDE_OVERLAY_4:
                conf1 = MCDE_OVL4CONF;
                conf2 = MCDE_OVL4CONF2;
                crop = MCDE_OVL4CROP;
                ljinc = MCDE_OVL4LJINC;
                cr = MCDE_OVL4CR;
                comp = MCDE_OVL4COMP;
                break;
        case MCDE_OVERLAY_5:
                conf1 = MCDE_OVL5CONF;
                conf2 = MCDE_OVL5CONF2;
                crop = MCDE_OVL5CROP;
                ljinc = MCDE_OVL5LJINC;
                cr = MCDE_OVL5CR;
                comp = MCDE_OVL5COMP;
                break;
        }

        val = mode->hdisplay << MCDE_OVLXCONF_PPL_SHIFT;
        val |= mode->vdisplay << MCDE_OVLXCONF_LPF_SHIFT;
        /* Use external source 0 that we just configured */
        val |= src << MCDE_OVLXCONF_EXTSRC_ID_SHIFT;
        writel(val, mcde->regs + conf1);

        val = MCDE_OVLXCONF2_BP_PER_PIXEL_ALPHA;
        val |= 0xff << MCDE_OVLXCONF2_ALPHAVALUE_SHIFT;
        /* OPQ: overlay is opaque */
        switch (format) {
        case DRM_FORMAT_ARGB8888:
        case DRM_FORMAT_ABGR8888:
        case DRM_FORMAT_ARGB4444:
        case DRM_FORMAT_ABGR4444:
        case DRM_FORMAT_XRGB1555:
        case DRM_FORMAT_XBGR1555:
                /* No OPQ */
                break;
        case DRM_FORMAT_XRGB8888:
        case DRM_FORMAT_XBGR8888:
        case DRM_FORMAT_RGB888:
        case DRM_FORMAT_BGR888:
        case DRM_FORMAT_RGB565:
        case DRM_FORMAT_BGR565:
        case DRM_FORMAT_YUV422:
                val |= MCDE_OVLXCONF2_OPQ;
                break;
        default:
                dev_err(mcde->dev, "Unknown pixel format 0x%08x\n",
                        format);
                break;
        }

        /*
         * Pixel fetch watermark level is max 0x1FFF pixels.
         * Two basic rules should be followed:
         * 1. The value should be at least 256 bits.
         * 2. The sum of all active overlays pixelfetch watermark level
         *    multiplied with bits per pixel, should be lower than the
         *    size of input_fifo_size in bits.
         * 3. The value should be a multiple of a line (256 bits).
         */
        switch (cpp) {
        case 2:
                pixel_fetcher_watermark = 128;
                break;
        case 3:
                pixel_fetcher_watermark = 96;
                break;
        case 4:
                pixel_fetcher_watermark = 48;
                break;
        default:
                pixel_fetcher_watermark = 48;
                break;
        }
        dev_dbg(mcde->dev, "pixel fetcher watermark level %d pixels\n",
                pixel_fetcher_watermark);
        val |= pixel_fetcher_watermark << MCDE_OVLXCONF2_PIXELFETCHERWATERMARKLEVEL_SHIFT;
        writel(val, mcde->regs + conf2);

        /* Number of bytes to fetch per line */
        writel(mcde->stride, mcde->regs + ljinc);
        /* No cropping */
        writel(0, mcde->regs + crop);

        /* Set up overlay control register */
        val = MCDE_OVLXCR_OVLEN;
        val |= MCDE_OVLXCR_COLCCTRL_DISABLED;
        val |= MCDE_OVLXCR_BURSTSIZE_8W <<
                MCDE_OVLXCR_BURSTSIZE_SHIFT;
        val |= MCDE_OVLXCR_MAXOUTSTANDING_8_REQ <<
                MCDE_OVLXCR_MAXOUTSTANDING_SHIFT;
        /* Not using rotation but set it up anyways */
        val |= MCDE_OVLXCR_ROTBURSTSIZE_8W <<
                MCDE_OVLXCR_ROTBURSTSIZE_SHIFT;
        writel(val, mcde->regs + cr);

        /*
         * Set up the overlay compositor to route the overlay out to
         * the desired channel
         */
        val = ch << MCDE_OVLXCOMP_CH_ID_SHIFT;
        writel(val, mcde->regs + comp);
}

static void mcde_configure_channel(struct mcde *mcde, enum mcde_channel ch,
                                   enum mcde_fifo fifo,
                                   const struct drm_display_mode *mode)
{
        u32 val;
        u32 conf;
        u32 sync;
        u32 stat;
        u32 bgcol;
        u32 mux;

        switch (ch) {
        case MCDE_CHANNEL_0:
                conf = MCDE_CHNL0CONF;
                sync = MCDE_CHNL0SYNCHMOD;
                stat = MCDE_CHNL0STAT;
                bgcol = MCDE_CHNL0BCKGNDCOL;
                mux = MCDE_CHNL0MUXING;
                break;
        case MCDE_CHANNEL_1:
                conf = MCDE_CHNL1CONF;
                sync = MCDE_CHNL1SYNCHMOD;
                stat = MCDE_CHNL1STAT;
                bgcol = MCDE_CHNL1BCKGNDCOL;
                mux = MCDE_CHNL1MUXING;
                break;
        case MCDE_CHANNEL_2:
                conf = MCDE_CHNL2CONF;
                sync = MCDE_CHNL2SYNCHMOD;
                stat = MCDE_CHNL2STAT;
                bgcol = MCDE_CHNL2BCKGNDCOL;
                mux = MCDE_CHNL2MUXING;
                break;
        case MCDE_CHANNEL_3:
                conf = MCDE_CHNL3CONF;
                sync = MCDE_CHNL3SYNCHMOD;
                stat = MCDE_CHNL3STAT;
                bgcol = MCDE_CHNL3BCKGNDCOL;
                mux = MCDE_CHNL3MUXING;
                return;
        }

        /* Set up channel 0 sync (based on chnl_update_registers()) */
        switch (mcde->flow_mode) {
        case MCDE_COMMAND_ONESHOT_FLOW:
                /* Oneshot is achieved with software sync */
                val = MCDE_CHNLXSYNCHMOD_SRC_SYNCH_SOFTWARE
                        << MCDE_CHNLXSYNCHMOD_SRC_SYNCH_SHIFT;
                break;
        case MCDE_COMMAND_TE_FLOW:
                val = MCDE_CHNLXSYNCHMOD_SRC_SYNCH_HARDWARE
                        << MCDE_CHNLXSYNCHMOD_SRC_SYNCH_SHIFT;
                val |= MCDE_CHNLXSYNCHMOD_OUT_SYNCH_SRC_TE0
                        << MCDE_CHNLXSYNCHMOD_OUT_SYNCH_SRC_SHIFT;
                break;
        case MCDE_COMMAND_BTA_TE_FLOW:
                val = MCDE_CHNLXSYNCHMOD_SRC_SYNCH_HARDWARE
                        << MCDE_CHNLXSYNCHMOD_SRC_SYNCH_SHIFT;
                /*
                 * TODO:
                 * The vendor driver uses the formatter as sync source
                 * for BTA TE mode. Test to use TE if you have a panel
                 * that uses this mode.
                 */
                val |= MCDE_CHNLXSYNCHMOD_OUT_SYNCH_SRC_FORMATTER
                        << MCDE_CHNLXSYNCHMOD_OUT_SYNCH_SRC_SHIFT;
                break;
        case MCDE_VIDEO_TE_FLOW:
                val = MCDE_CHNLXSYNCHMOD_SRC_SYNCH_HARDWARE
                        << MCDE_CHNLXSYNCHMOD_SRC_SYNCH_SHIFT;
                val |= MCDE_CHNLXSYNCHMOD_OUT_SYNCH_SRC_TE0
                        << MCDE_CHNLXSYNCHMOD_OUT_SYNCH_SRC_SHIFT;
                break;
        case MCDE_VIDEO_FORMATTER_FLOW:
        case MCDE_DPI_FORMATTER_FLOW:
                val = MCDE_CHNLXSYNCHMOD_SRC_SYNCH_HARDWARE
                        << MCDE_CHNLXSYNCHMOD_SRC_SYNCH_SHIFT;
                val |= MCDE_CHNLXSYNCHMOD_OUT_SYNCH_SRC_FORMATTER
                        << MCDE_CHNLXSYNCHMOD_OUT_SYNCH_SRC_SHIFT;
                break;
        default:
                dev_err(mcde->dev, "unknown flow mode %d\n",
                        mcde->flow_mode);
                return;
        }

        writel(val, mcde->regs + sync);

        /* Set up pixels per line and lines per frame */
        val = (mode->hdisplay - 1) << MCDE_CHNLXCONF_PPL_SHIFT;
        val |= (mode->vdisplay - 1) << MCDE_CHNLXCONF_LPF_SHIFT;
        writel(val, mcde->regs + conf);

        /*
         * Normalize color conversion:
         * black background, OLED conversion disable on channel
         */
        val = MCDE_CHNLXSTAT_CHNLBLBCKGND_EN |
                MCDE_CHNLXSTAT_CHNLRD;
        writel(val, mcde->regs + stat);
        writel(0, mcde->regs + bgcol);

        /* Set up muxing: connect the channel to the desired FIFO */
        switch (fifo) {
        case MCDE_FIFO_A:
                writel(MCDE_CHNLXMUXING_FIFO_ID_FIFO_A,
                       mcde->regs + mux);
                break;
        case MCDE_FIFO_B:
                writel(MCDE_CHNLXMUXING_FIFO_ID_FIFO_B,
                       mcde->regs + mux);
                break;
        }

        /*
         * If using DPI configure the sync event.
         * TODO: this is for LCD only, it does not cover TV out.
         */
        if (mcde->dpi_output) {
                u32 stripwidth;

                stripwidth = 0xF000 / (mode->vdisplay * 4);
                dev_info(mcde->dev, "stripwidth: %d\n", stripwidth);

                val = MCDE_SYNCHCONF_HWREQVEVENT_ACTIVE_VIDEO |
                        (mode->hdisplay - 1 - stripwidth) << MCDE_SYNCHCONF_HWREQVCNT_SHIFT |
                        MCDE_SYNCHCONF_SWINTVEVENT_ACTIVE_VIDEO |
                        (mode->hdisplay - 1 - stripwidth) << MCDE_SYNCHCONF_SWINTVCNT_SHIFT;

                switch (fifo) {
                case MCDE_FIFO_A:
                        writel(val, mcde->regs + MCDE_SYNCHCONFA);
                        break;
                case MCDE_FIFO_B:
                        writel(val, mcde->regs + MCDE_SYNCHCONFB);
                        break;
                }
        }
}

static void mcde_configure_fifo(struct mcde *mcde, enum mcde_fifo fifo,
                                enum mcde_formatter fmt,
                                int fifo_wtrmrk)
{
        u32 val;
        u32 ctrl;
        u32 cr0, cr1;

        switch (fifo) {
        case MCDE_FIFO_A:
                ctrl = MCDE_CTRLA;
                cr0 = MCDE_CRA0;
                cr1 = MCDE_CRA1;
                break;
        case MCDE_FIFO_B:
                ctrl = MCDE_CTRLB;
                cr0 = MCDE_CRB0;
                cr1 = MCDE_CRB1;
                break;
        }

        val = fifo_wtrmrk << MCDE_CTRLX_FIFOWTRMRK_SHIFT;

        /*
         * Select the formatter to use for this FIFO
         *
         * The register definitions imply that different IDs should be used
         * by the DSI formatters depending on if they are in VID or CMD
         * mode, and the manual says they are dedicated but identical.
         * The vendor code uses them as it seems fit.
         */
        switch (fmt) {
        case MCDE_DSI_FORMATTER_0:
                val |= MCDE_CTRLX_FORMTYPE_DSI << MCDE_CTRLX_FORMTYPE_SHIFT;
                val |= MCDE_CTRLX_FORMID_DSI0VID << MCDE_CTRLX_FORMID_SHIFT;
                break;
        case MCDE_DSI_FORMATTER_1:
                val |= MCDE_CTRLX_FORMTYPE_DSI << MCDE_CTRLX_FORMTYPE_SHIFT;
                val |= MCDE_CTRLX_FORMID_DSI0CMD << MCDE_CTRLX_FORMID_SHIFT;
                break;
        case MCDE_DSI_FORMATTER_2:
                val |= MCDE_CTRLX_FORMTYPE_DSI << MCDE_CTRLX_FORMTYPE_SHIFT;
                val |= MCDE_CTRLX_FORMID_DSI1VID << MCDE_CTRLX_FORMID_SHIFT;
                break;
        case MCDE_DSI_FORMATTER_3:
                val |= MCDE_CTRLX_FORMTYPE_DSI << MCDE_CTRLX_FORMTYPE_SHIFT;
                val |= MCDE_CTRLX_FORMID_DSI1CMD << MCDE_CTRLX_FORMID_SHIFT;
                break;
        case MCDE_DSI_FORMATTER_4:
                val |= MCDE_CTRLX_FORMTYPE_DSI << MCDE_CTRLX_FORMTYPE_SHIFT;
                val |= MCDE_CTRLX_FORMID_DSI2VID << MCDE_CTRLX_FORMID_SHIFT;
                break;
        case MCDE_DSI_FORMATTER_5:
                val |= MCDE_CTRLX_FORMTYPE_DSI << MCDE_CTRLX_FORMTYPE_SHIFT;
                val |= MCDE_CTRLX_FORMID_DSI2CMD << MCDE_CTRLX_FORMID_SHIFT;
                break;
        case MCDE_DPI_FORMATTER_0:
                val |= MCDE_CTRLX_FORMTYPE_DPITV << MCDE_CTRLX_FORMTYPE_SHIFT;
                val |= MCDE_CTRLX_FORMID_DPIA << MCDE_CTRLX_FORMID_SHIFT;
                break;
        case MCDE_DPI_FORMATTER_1:
                val |= MCDE_CTRLX_FORMTYPE_DPITV << MCDE_CTRLX_FORMTYPE_SHIFT;
                val |= MCDE_CTRLX_FORMID_DPIB << MCDE_CTRLX_FORMID_SHIFT;
                break;
        }
        writel(val, mcde->regs + ctrl);

        /* Blend source with Alpha 0xff on FIFO */
        val = MCDE_CRX0_BLENDEN |
                0xff << MCDE_CRX0_ALPHABLEND_SHIFT;
        writel(val, mcde->regs + cr0);

        spin_lock(&mcde->fifo_crx1_lock);
        val = readl(mcde->regs + cr1);
        /*
         * Set-up from mcde_fmtr_dsi.c, fmtr_dsi_enable_video()
         * FIXME: a different clock needs to be selected for TV out.
         */
        if (mcde->dpi_output) {
                struct drm_connector *connector = drm_panel_bridge_connector(mcde->bridge);
                u32 bus_format;

                /* Assume RGB888 24 bit if we have no further info */
                if (!connector->display_info.num_bus_formats) {
                        dev_info(mcde->dev, "panel does not specify bus format, assume RGB888\n");
                        bus_format = MEDIA_BUS_FMT_RGB888_1X24;
                } else {
                        bus_format = connector->display_info.bus_formats[0];
                }

                /*
                 * Set up the CDWIN and OUTBPP for the LCD
                 *
                 * FIXME: fill this in if you know the correspondance between the MIPI
                 * DPI specification and the media bus formats.
                 */
                val &= ~MCDE_CRX1_CDWIN_MASK;
                val &= ~MCDE_CRX1_OUTBPP_MASK;
                switch (bus_format) {
                case MEDIA_BUS_FMT_RGB888_1X24:
                        val |= MCDE_CRX1_CDWIN_24BPP << MCDE_CRX1_CDWIN_SHIFT;
                        val |= MCDE_CRX1_OUTBPP_24BPP << MCDE_CRX1_OUTBPP_SHIFT;
                        break;
                default:
                        dev_err(mcde->dev, "unknown bus format, assume RGB888\n");
                        val |= MCDE_CRX1_CDWIN_24BPP << MCDE_CRX1_CDWIN_SHIFT;
                        val |= MCDE_CRX1_OUTBPP_24BPP << MCDE_CRX1_OUTBPP_SHIFT;
                        break;
                }
        } else {
                /* Use the MCDE clock for DSI */
                val &= ~MCDE_CRX1_CLKSEL_MASK;
                val |= MCDE_CRX1_CLKSEL_MCDECLK << MCDE_CRX1_CLKSEL_SHIFT;
        }
        writel(val, mcde->regs + cr1);
        spin_unlock(&mcde->fifo_crx1_lock);
};

static void mcde_configure_dsi_formatter(struct mcde *mcde,
                                         enum mcde_formatter fmt,
                                         u32 formatter_frame,
                                         int pkt_size)
{
        u32 val;
        u32 conf0;
        u32 frame;
        u32 pkt;
        u32 sync;
        u32 cmdw;
        u32 delay0, delay1;

        switch (fmt) {
        case MCDE_DSI_FORMATTER_0:
                conf0 = MCDE_DSIVID0CONF0;
                frame = MCDE_DSIVID0FRAME;
                pkt = MCDE_DSIVID0PKT;
                sync = MCDE_DSIVID0SYNC;
                cmdw = MCDE_DSIVID0CMDW;
                delay0 = MCDE_DSIVID0DELAY0;
                delay1 = MCDE_DSIVID0DELAY1;
                break;
        case MCDE_DSI_FORMATTER_1:
                conf0 = MCDE_DSIVID1CONF0;
                frame = MCDE_DSIVID1FRAME;
                pkt = MCDE_DSIVID1PKT;
                sync = MCDE_DSIVID1SYNC;
                cmdw = MCDE_DSIVID1CMDW;
                delay0 = MCDE_DSIVID1DELAY0;
                delay1 = MCDE_DSIVID1DELAY1;
                break;
        case MCDE_DSI_FORMATTER_2:
                conf0 = MCDE_DSIVID2CONF0;
                frame = MCDE_DSIVID2FRAME;
                pkt = MCDE_DSIVID2PKT;
                sync = MCDE_DSIVID2SYNC;
                cmdw = MCDE_DSIVID2CMDW;
                delay0 = MCDE_DSIVID2DELAY0;
                delay1 = MCDE_DSIVID2DELAY1;
                break;
        default:
                dev_err(mcde->dev, "tried to configure a non-DSI formatter as DSI\n");
                return;
        }

        /*
         * Enable formatter
         * 8 bit commands and DCS commands (notgen = not generic)
         */
        val = MCDE_DSICONF0_CMD8 | MCDE_DSICONF0_DCSVID_NOTGEN;
        if (mcde->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO)
                val |= MCDE_DSICONF0_VID_MODE_VID;
        switch (mcde->mdsi->format) {
        case MIPI_DSI_FMT_RGB888:
                val |= MCDE_DSICONF0_PACKING_RGB888 <<
                        MCDE_DSICONF0_PACKING_SHIFT;
                break;
        case MIPI_DSI_FMT_RGB666:
                val |= MCDE_DSICONF0_PACKING_RGB666 <<
                        MCDE_DSICONF0_PACKING_SHIFT;
                break;
        case MIPI_DSI_FMT_RGB666_PACKED:
                dev_err(mcde->dev,
                        "we cannot handle the packed RGB666 format\n");
                val |= MCDE_DSICONF0_PACKING_RGB666 <<
                        MCDE_DSICONF0_PACKING_SHIFT;
                break;
        case MIPI_DSI_FMT_RGB565:
                val |= MCDE_DSICONF0_PACKING_RGB565 <<
                        MCDE_DSICONF0_PACKING_SHIFT;
                break;
        default:
                dev_err(mcde->dev, "unknown DSI format\n");
                return;
        }
        writel(val, mcde->regs + conf0);

        writel(formatter_frame, mcde->regs + frame);
        writel(pkt_size, mcde->regs + pkt);
        writel(0, mcde->regs + sync);
        /* Define the MIPI command: we want to write into display memory */
        val = MIPI_DCS_WRITE_MEMORY_CONTINUE <<
                MCDE_DSIVIDXCMDW_CMDW_CONTINUE_SHIFT;
        val |= MIPI_DCS_WRITE_MEMORY_START <<
                MCDE_DSIVIDXCMDW_CMDW_START_SHIFT;
        writel(val, mcde->regs + cmdw);

        /*
         * FIXME: the vendor driver has some hack around this value in
         * CMD mode with autotrig.
         */
        writel(0, mcde->regs + delay0);
        writel(0, mcde->regs + delay1);
}

static void mcde_enable_fifo(struct mcde *mcde, enum mcde_fifo fifo)
{
        u32 val;
        u32 cr;

        switch (fifo) {
        case MCDE_FIFO_A:
                cr = MCDE_CRA0;
                break;
        case MCDE_FIFO_B:
                cr = MCDE_CRB0;
                break;
        default:
                dev_err(mcde->dev, "cannot enable FIFO %c\n",
                        'A' + fifo);
                return;
        }

        spin_lock(&mcde->flow_lock);
        val = readl(mcde->regs + cr);
        val |= MCDE_CRX0_FLOEN;
        writel(val, mcde->regs + cr);
        mcde->flow_active++;
        spin_unlock(&mcde->flow_lock);
}

static void mcde_disable_fifo(struct mcde *mcde, enum mcde_fifo fifo,
                              bool wait_for_drain)
{
        int timeout = 100;
        u32 val;
        u32 cr;

        switch (fifo) {
        case MCDE_FIFO_A:
                cr = MCDE_CRA0;
                break;
        case MCDE_FIFO_B:
                cr = MCDE_CRB0;
                break;
        default:
                dev_err(mcde->dev, "cannot disable FIFO %c\n",
                        'A' + fifo);
                return;
        }

        spin_lock(&mcde->flow_lock);
        val = readl(mcde->regs + cr);
        val &= ~MCDE_CRX0_FLOEN;
        writel(val, mcde->regs + cr);
        mcde->flow_active = 0;
        spin_unlock(&mcde->flow_lock);

        if (!wait_for_drain)
                return;

        /* Check that we really drained and stopped the flow */
        while (readl(mcde->regs + cr) & MCDE_CRX0_FLOEN) {
                usleep_range(1000, 1500);
                if (!--timeout) {
                        dev_err(mcde->dev,
                                "FIFO timeout while clearing FIFO %c\n",
                                'A' + fifo);
                        return;
                }
        }
}

/*
 * This drains a pipe i.e. a FIFO connected to a certain channel
 */
static void mcde_drain_pipe(struct mcde *mcde, enum mcde_fifo fifo,
                            enum mcde_channel ch)
{
        u32 val;
        u32 ctrl;
        u32 synsw;

        switch (fifo) {
        case MCDE_FIFO_A:
                ctrl = MCDE_CTRLA;
                break;
        case MCDE_FIFO_B:
                ctrl = MCDE_CTRLB;
                break;
        }

        switch (ch) {
        case MCDE_CHANNEL_0:
                synsw = MCDE_CHNL0SYNCHSW;
                break;
        case MCDE_CHANNEL_1:
                synsw = MCDE_CHNL1SYNCHSW;
                break;
        case MCDE_CHANNEL_2:
                synsw = MCDE_CHNL2SYNCHSW;
                break;
        case MCDE_CHANNEL_3:
                synsw = MCDE_CHNL3SYNCHSW;
                return;
        }

        val = readl(mcde->regs + ctrl);
        if (!(val & MCDE_CTRLX_FIFOEMPTY)) {
                dev_err(mcde->dev, "Channel A FIFO not empty (handover)\n");
                /* Attempt to clear the FIFO */
                mcde_enable_fifo(mcde, fifo);
                /* Trigger a software sync out on respective channel (0-3) */
                writel(MCDE_CHNLXSYNCHSW_SW_TRIG, mcde->regs + synsw);
                /* Disable FIFO A flow again */
                mcde_disable_fifo(mcde, fifo, true);
        }
}

static int mcde_dsi_get_pkt_div(int ppl, int fifo_size)
{
        /*
         * DSI command mode line packets should be split into an even number of
         * packets smaller than or equal to the fifo size.
         */
        int div;
        const int max_div = DIV_ROUND_UP(MCDE_MAX_WIDTH, fifo_size);

        for (div = 1; div < max_div; div++)
                if (ppl % div == 0 && ppl / div <= fifo_size)
                        return div;
        return 1;
}

static void mcde_setup_dpi(struct mcde *mcde, const struct drm_display_mode *mode,
                           int *fifo_wtrmrk_lvl)
{
        struct drm_connector *connector = drm_panel_bridge_connector(mcde->bridge);
        u32 hsw, hfp, hbp;
        u32 vsw, vfp, vbp;
        u32 val;

        /* FIXME: we only support LCD, implement TV out */
        hsw = mode->hsync_end - mode->hsync_start;
        hfp = mode->hsync_start - mode->hdisplay;
        hbp = mode->htotal - mode->hsync_end;
        vsw = mode->vsync_end - mode->vsync_start;
        vfp = mode->vsync_start - mode->vdisplay;
        vbp = mode->vtotal - mode->vsync_end;

        dev_info(mcde->dev, "output on DPI LCD from channel A\n");
        /* Display actual values */
        dev_info(mcde->dev, "HSW: %d, HFP: %d, HBP: %d, VSW: %d, VFP: %d, VBP: %d\n",
                 hsw, hfp, hbp, vsw, vfp, vbp);

        /*
         * The pixel fetcher is 128 64-bit words deep = 1024 bytes.
         * One overlay of 32bpp (4 cpp) assumed, fetch 160 pixels.
         * 160 * 4 = 640 bytes.
         */
        *fifo_wtrmrk_lvl = 640;

        /* Set up the main control, watermark level at 7 */
        val = 7 << MCDE_CONF0_IFIFOCTRLWTRMRKLVL_SHIFT;

        /*
         * This sets up the internal silicon muxing of the DPI
         * lines. This is how the silicon connects out to the
         * external pins, then the pins need to be further
         * configured into "alternate functions" using pin control
         * to actually get the signals out.
         *
         * FIXME: this is hardcoded to the only setting found in
         * the wild. If we need to use different settings for
         * different DPI displays, make this parameterizable from
         * the device tree.
         */
        /* 24 bits DPI: connect Ch A LSB to D[0:7] */
        val |= 0 << MCDE_CONF0_OUTMUX0_SHIFT;
        /* 24 bits DPI: connect Ch A MID to D[8:15] */
        val |= 1 << MCDE_CONF0_OUTMUX1_SHIFT;
        /* Don't care about this muxing */
        val |= 0 << MCDE_CONF0_OUTMUX2_SHIFT;
        /* Don't care about this muxing */
        val |= 0 << MCDE_CONF0_OUTMUX3_SHIFT;
        /* 24 bits DPI: connect Ch A MSB to D[32:39] */
        val |= 2 << MCDE_CONF0_OUTMUX4_SHIFT;
        /* Syncmux bits zero: DPI channel A */
        writel(val, mcde->regs + MCDE_CONF0);

        /* This hammers us into LCD mode */
        writel(0, mcde->regs + MCDE_TVCRA);

        /* Front porch and sync width */
        val = (vsw << MCDE_TVBL1_BEL1_SHIFT);
        val |= (vfp << MCDE_TVBL1_BSL1_SHIFT);
        writel(val, mcde->regs + MCDE_TVBL1A);
        /* The vendor driver sets the same value into TVBL2A */
        writel(val, mcde->regs + MCDE_TVBL2A);

        /* Vertical back porch */
        val = (vbp << MCDE_TVDVO_DVO1_SHIFT);
        /* The vendor drivers sets the same value into TVDVOA */
        val |= (vbp << MCDE_TVDVO_DVO2_SHIFT);
        writel(val, mcde->regs + MCDE_TVDVOA);

        /* Horizontal back porch, as 0 = 1 cycle we need to subtract 1 */
        writel((hbp - 1), mcde->regs + MCDE_TVTIM1A);

        /* Horizongal sync width and horizonal front porch, 0 = 1 cycle */
        val = ((hsw - 1) << MCDE_TVLBALW_LBW_SHIFT);
        val |= ((hfp - 1) << MCDE_TVLBALW_ALW_SHIFT);
        writel(val, mcde->regs + MCDE_TVLBALWA);

        /* Blank some TV registers we don't use */
        writel(0, mcde->regs + MCDE_TVISLA);
        writel(0, mcde->regs + MCDE_TVBLUA);

        /* Set up sync inversion etc */
        val = 0;
        if (mode->flags & DRM_MODE_FLAG_NHSYNC)
                val |= MCDE_LCDTIM1B_IHS;
        if (mode->flags & DRM_MODE_FLAG_NVSYNC)
                val |= MCDE_LCDTIM1B_IVS;
        if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW)
                val |= MCDE_LCDTIM1B_IOE;
        if (connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
                val |= MCDE_LCDTIM1B_IPC;
        writel(val, mcde->regs + MCDE_LCDTIM1A);
}

static void mcde_setup_dsi(struct mcde *mcde, const struct drm_display_mode *mode,
                           int cpp, int *fifo_wtrmrk_lvl, int *dsi_formatter_frame,
                           int *dsi_pkt_size)
{
        u32 formatter_ppl = mode->hdisplay; /* pixels per line */
        u32 formatter_lpf = mode->vdisplay; /* lines per frame */
        int formatter_frame;
        int formatter_cpp;
        int fifo_wtrmrk;
        u32 pkt_div;
        int pkt_size;
        u32 val;

        dev_info(mcde->dev, "output in %s mode, format %dbpp\n",
                 (mcde->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO) ?
                 "VIDEO" : "CMD",
                 mipi_dsi_pixel_format_to_bpp(mcde->mdsi->format));
        formatter_cpp =
                mipi_dsi_pixel_format_to_bpp(mcde->mdsi->format) / 8;
        dev_info(mcde->dev, "Overlay CPP: %d bytes, DSI formatter CPP %d bytes\n",
                 cpp, formatter_cpp);

        /* Set up the main control, watermark level at 7 */
        val = 7 << MCDE_CONF0_IFIFOCTRLWTRMRKLVL_SHIFT;

        /*
         * This is the internal silicon muxing of the DPI
         * (parallell display) lines. Since we are not using
         * this at all (we are using DSI) these are just
         * dummy values from the vendor tree.
         */
        val |= 3 << MCDE_CONF0_OUTMUX0_SHIFT;
        val |= 3 << MCDE_CONF0_OUTMUX1_SHIFT;
        val |= 0 << MCDE_CONF0_OUTMUX2_SHIFT;
        val |= 4 << MCDE_CONF0_OUTMUX3_SHIFT;
        val |= 5 << MCDE_CONF0_OUTMUX4_SHIFT;
        writel(val, mcde->regs + MCDE_CONF0);

        /* Calculations from mcde_fmtr_dsi.c, fmtr_dsi_enable_video() */

        /*
         * Set up FIFO A watermark level:
         * 128 for LCD 32bpp video mode
         * 48  for LCD 32bpp command mode
         * 128 for LCD 16bpp video mode
         * 64  for LCD 16bpp command mode
         * 128 for HDMI 32bpp
         * 192 for HDMI 16bpp
         */
        fifo_wtrmrk = mode->hdisplay;
        if (mcde->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
                fifo_wtrmrk = min(fifo_wtrmrk, 128);
                pkt_div = 1;
        } else {
                fifo_wtrmrk = min(fifo_wtrmrk, 48);
                /* The FIFO is 640 entries deep on this v3 hardware */
                pkt_div = mcde_dsi_get_pkt_div(mode->hdisplay, 640);
        }
        dev_dbg(mcde->dev, "FIFO watermark after flooring: %d bytes\n",
                fifo_wtrmrk);
        dev_dbg(mcde->dev, "Packet divisor: %d bytes\n", pkt_div);

        /* NOTE: pkt_div is 1 for video mode */
        pkt_size = (formatter_ppl * formatter_cpp) / pkt_div;
        /* Commands CMD8 need one extra byte */
        if (!(mcde->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO))
                pkt_size++;

        dev_dbg(mcde->dev, "DSI packet size: %d * %d bytes per line\n",
                pkt_size, pkt_div);
        dev_dbg(mcde->dev, "Overlay frame size: %u bytes\n",
                mode->hdisplay * mode->vdisplay * cpp);
        /* NOTE: pkt_div is 1 for video mode */
        formatter_frame = pkt_size * pkt_div * formatter_lpf;
        dev_dbg(mcde->dev, "Formatter frame size: %u bytes\n", formatter_frame);

        *fifo_wtrmrk_lvl = fifo_wtrmrk;
        *dsi_pkt_size = pkt_size;
        *dsi_formatter_frame = formatter_frame;
}

static void mcde_display_enable(struct drm_simple_display_pipe *pipe,
                                struct drm_crtc_state *cstate,
                                struct drm_plane_state *plane_state)
{
        struct drm_crtc *crtc = &pipe->crtc;
        struct drm_plane *plane = &pipe->plane;
        struct drm_device *drm = crtc->dev;
        struct mcde *mcde = to_mcde(drm);
        const struct drm_display_mode *mode = &cstate->mode;
        struct drm_framebuffer *fb = plane->state->fb;
        u32 format = fb->format->format;
        int dsi_pkt_size;
        int fifo_wtrmrk;
        int cpp = fb->format->cpp[0];
        u32 dsi_formatter_frame;
        u32 val;
        int ret;

        /* This powers up the entire MCDE block and the DSI hardware */
        ret = regulator_enable(mcde->epod);
        if (ret) {
                dev_err(drm->dev, "can't re-enable EPOD regulator\n");
                return;
        }

        dev_info(drm->dev, "enable MCDE, %d x %d format %p4cc\n",
                 mode->hdisplay, mode->vdisplay, &format);


        /* Clear any pending interrupts */
        mcde_display_disable_irqs(mcde);
        writel(0, mcde->regs + MCDE_IMSCERR);
        writel(0xFFFFFFFF, mcde->regs + MCDE_RISERR);

        if (mcde->dpi_output)
                mcde_setup_dpi(mcde, mode, &fifo_wtrmrk);
        else
                mcde_setup_dsi(mcde, mode, cpp, &fifo_wtrmrk,
                               &dsi_formatter_frame, &dsi_pkt_size);

        mcde->stride = mode->hdisplay * cpp;
        dev_dbg(drm->dev, "Overlay line stride: %u bytes\n",
                 mcde->stride);

        /* Drain the FIFO A + channel 0 pipe so we have a clean slate */
        mcde_drain_pipe(mcde, MCDE_FIFO_A, MCDE_CHANNEL_0);

        /*
         * We set up our display pipeline:
         * EXTSRC 0 -> OVERLAY 0 -> CHANNEL 0 -> FIFO A -> DSI FORMATTER 0
         *
         * First configure the external source (memory) on external source 0
         * using the desired bitstream/bitmap format
         */
        mcde_configure_extsrc(mcde, MCDE_EXTSRC_0, format);

        /*
         * Configure overlay 0 according to format and mode and take input
         * from external source 0 and route the output of this overlay to
         * channel 0
         */
        mcde_configure_overlay(mcde, MCDE_OVERLAY_0, MCDE_EXTSRC_0,
                               MCDE_CHANNEL_0, mode, format, cpp);

        /*
         * Configure pixel-per-line and line-per-frame for channel 0 and then
         * route channel 0 to FIFO A
         */
        mcde_configure_channel(mcde, MCDE_CHANNEL_0, MCDE_FIFO_A, mode);

        if (mcde->dpi_output) {
                unsigned long lcd_freq;

                /* Configure FIFO A to use DPI formatter 0 */
                mcde_configure_fifo(mcde, MCDE_FIFO_A, MCDE_DPI_FORMATTER_0,
                                    fifo_wtrmrk);

                /* Set up and enable the LCD clock */
                lcd_freq = clk_round_rate(mcde->fifoa_clk, mode->clock * 1000);
                ret = clk_set_rate(mcde->fifoa_clk, lcd_freq);
                if (ret)
                        dev_err(mcde->dev, "failed to set LCD clock rate %lu Hz\n",
                                lcd_freq);
                ret = clk_prepare_enable(mcde->fifoa_clk);
                if (ret) {
                        dev_err(mcde->dev, "failed to enable FIFO A DPI clock\n");
                        return;
                }
                dev_info(mcde->dev, "LCD FIFO A clk rate %lu Hz\n",
                         clk_get_rate(mcde->fifoa_clk));
        } else {
                /* Configure FIFO A to use DSI formatter 0 */
                mcde_configure_fifo(mcde, MCDE_FIFO_A, MCDE_DSI_FORMATTER_0,
                                    fifo_wtrmrk);

                /*
                 * This brings up the DSI bridge which is tightly connected
                 * to the MCDE DSI formatter.
                 */
                mcde_dsi_enable(mcde->bridge);

                /* Configure the DSI formatter 0 for the DSI panel output */
                mcde_configure_dsi_formatter(mcde, MCDE_DSI_FORMATTER_0,
                                             dsi_formatter_frame, dsi_pkt_size);
        }

        switch (mcde->flow_mode) {
        case MCDE_COMMAND_TE_FLOW:
        case MCDE_COMMAND_BTA_TE_FLOW:
        case MCDE_VIDEO_TE_FLOW:
                /* We are using TE in some combination */
                if (mode->flags & DRM_MODE_FLAG_NVSYNC)
                        val = MCDE_VSCRC_VSPOL;
                else
                        val = 0;
                writel(val, mcde->regs + MCDE_VSCRC0);
                /* Enable VSYNC capture on TE0 */
                val = readl(mcde->regs + MCDE_CRC);
                val |= MCDE_CRC_SYCEN0;
                writel(val, mcde->regs + MCDE_CRC);
                break;
        default:
                /* No TE capture */
                break;
        }

        drm_crtc_vblank_on(crtc);

        /*
         * If we're using oneshot mode we don't start the flow
         * until each time the display is given an update, and
         * then we disable it immediately after. For all other
         * modes (command or video) we start the FIFO flow
         * right here. This is necessary for the hardware to
         * behave right.
         */
        if (mcde->flow_mode != MCDE_COMMAND_ONESHOT_FLOW) {
                mcde_enable_fifo(mcde, MCDE_FIFO_A);
                dev_dbg(mcde->dev, "started MCDE video FIFO flow\n");
        }

        /* Enable MCDE with automatic clock gating */
        val = readl(mcde->regs + MCDE_CR);
        val |= MCDE_CR_MCDEEN | MCDE_CR_AUTOCLKG_EN;
        writel(val, mcde->regs + MCDE_CR);

        dev_info(drm->dev, "MCDE display is enabled\n");
}

static void mcde_display_disable(struct drm_simple_display_pipe *pipe)
{
        struct drm_crtc *crtc = &pipe->crtc;
        struct drm_device *drm = crtc->dev;
        struct mcde *mcde = to_mcde(drm);
        struct drm_pending_vblank_event *event;
        int ret;

        drm_crtc_vblank_off(crtc);

        /* Disable FIFO A flow */
        mcde_disable_fifo(mcde, MCDE_FIFO_A, true);

        if (mcde->dpi_output) {
                clk_disable_unprepare(mcde->fifoa_clk);
        } else {
                /* This disables the DSI bridge */
                mcde_dsi_disable(mcde->bridge);
        }

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

                spin_lock_irq(&crtc->dev->event_lock);
                drm_crtc_send_vblank_event(crtc, event);
                spin_unlock_irq(&crtc->dev->event_lock);
        }

        ret = regulator_disable(mcde->epod);
        if (ret)
                dev_err(drm->dev, "can't disable EPOD regulator\n");
        /* Make sure we are powered down (before we may power up again) */
        usleep_range(50000, 70000);

        dev_info(drm->dev, "MCDE display is disabled\n");
}

static void mcde_start_flow(struct mcde *mcde)
{
        /* Request a TE ACK only in TE+BTA mode */
        if (mcde->flow_mode == MCDE_COMMAND_BTA_TE_FLOW)
                mcde_dsi_te_request(mcde->mdsi);

        /* Enable FIFO A flow */
        mcde_enable_fifo(mcde, MCDE_FIFO_A);

        /*
         * If oneshot mode is enabled, the flow will be disabled
         * when the TE0 IRQ arrives in the interrupt handler. Otherwise
         * updates are continuously streamed to the display after this
         * point.
         */

        if (mcde->flow_mode == MCDE_COMMAND_ONESHOT_FLOW) {
                /* Trigger a software sync out on channel 0 */
                writel(MCDE_CHNLXSYNCHSW_SW_TRIG,
                       mcde->regs + MCDE_CHNL0SYNCHSW);

                /*
                 * Disable FIFO A flow again: since we are using TE sync we
                 * need to wait for the FIFO to drain before we continue
                 * so repeated calls to this function will not cause a mess
                 * in the hardware by pushing updates will updates are going
                 * on already.
                 */
                mcde_disable_fifo(mcde, MCDE_FIFO_A, true);
        }

        dev_dbg(mcde->dev, "started MCDE FIFO flow\n");
}

static void mcde_set_extsrc(struct mcde *mcde, u32 buffer_address)
{
        /* Write bitmap base address to register */
        writel(buffer_address, mcde->regs + MCDE_EXTSRCXA0);
        /*
         * Base address for next line this is probably only used
         * in interlace modes.
         */
        writel(buffer_address + mcde->stride, mcde->regs + MCDE_EXTSRCXA1);
}

static void mcde_display_update(struct drm_simple_display_pipe *pipe,
                                struct drm_plane_state *old_pstate)
{
        struct drm_crtc *crtc = &pipe->crtc;
        struct drm_device *drm = crtc->dev;
        struct mcde *mcde = to_mcde(drm);
        struct drm_pending_vblank_event *event = crtc->state->event;
        struct drm_plane *plane = &pipe->plane;
        struct drm_plane_state *pstate = plane->state;
        struct drm_framebuffer *fb = pstate->fb;

        /*
         * Handle any pending event first, we need to arm the vblank
         * interrupt before sending any update to the display so we don't
         * miss the interrupt.
         */
        if (event) {
                crtc->state->event = NULL;

                spin_lock_irq(&crtc->dev->event_lock);
                /*
                 * Hardware must be on before we can arm any vblank event,
                 * this is not a scanout controller where there is always
                 * some periodic update going on, it is completely frozen
                 * until we get an update. If MCDE output isn't yet enabled,
                 * we just send a vblank dummy event back.
                 */
                if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0) {
                        dev_dbg(mcde->dev, "arm vblank event\n");
                        drm_crtc_arm_vblank_event(crtc, event);
                } else {
                        dev_dbg(mcde->dev, "insert fake vblank event\n");
                        drm_crtc_send_vblank_event(crtc, event);
                }

                spin_unlock_irq(&crtc->dev->event_lock);
        }

        /*
         * We do not start sending framebuffer updates before the
         * display is enabled. Update events will however be dispatched
         * from the DRM core before the display is enabled.
         */
        if (fb) {
                mcde_set_extsrc(mcde, drm_fb_dma_get_gem_addr(fb, pstate, 0));
                dev_info_once(mcde->dev, "first update of display contents\n");
                /*
                 * Usually the flow is already active, unless we are in
                 * oneshot mode, then we need to kick the flow right here.
                 */
                if (mcde->flow_active == 0)
                        mcde_start_flow(mcde);
        } else {
                /*
                 * If an update is receieved before the MCDE is enabled
                 * (before mcde_display_enable() is called) we can't really
                 * do much with that buffer.
                 */
                dev_info(mcde->dev, "ignored a display update\n");
        }
}

static int mcde_display_enable_vblank(struct drm_simple_display_pipe *pipe)
{
        struct drm_crtc *crtc = &pipe->crtc;
        struct drm_device *drm = crtc->dev;
        struct mcde *mcde = to_mcde(drm);
        u32 val;

        /* Enable all VBLANK IRQs */
        val = MCDE_PP_VCMPA |
                MCDE_PP_VCMPB |
                MCDE_PP_VSCC0 |
                MCDE_PP_VSCC1 |
                MCDE_PP_VCMPC0 |
                MCDE_PP_VCMPC1;
        writel(val, mcde->regs + MCDE_IMSCPP);

        return 0;
}

static void mcde_display_disable_vblank(struct drm_simple_display_pipe *pipe)
{
        struct drm_crtc *crtc = &pipe->crtc;
        struct drm_device *drm = crtc->dev;
        struct mcde *mcde = to_mcde(drm);

        /* Disable all VBLANK IRQs */
        writel(0, mcde->regs + MCDE_IMSCPP);
        /* Clear any pending IRQs */
        writel(0xFFFFFFFF, mcde->regs + MCDE_RISPP);
}

static struct drm_simple_display_pipe_funcs mcde_display_funcs = {
        .check = mcde_display_check,
        .enable = mcde_display_enable,
        .disable = mcde_display_disable,
        .update = mcde_display_update,
        .enable_vblank = mcde_display_enable_vblank,
        .disable_vblank = mcde_display_disable_vblank,
};

int mcde_display_init(struct drm_device *drm)
{
        struct mcde *mcde = to_mcde(drm);
        int ret;
        static const u32 formats[] = {
                DRM_FORMAT_ARGB8888,
                DRM_FORMAT_ABGR8888,
                DRM_FORMAT_XRGB8888,
                DRM_FORMAT_XBGR8888,
                DRM_FORMAT_RGB888,
                DRM_FORMAT_BGR888,
                DRM_FORMAT_ARGB4444,
                DRM_FORMAT_ABGR4444,
                DRM_FORMAT_XRGB4444,
                DRM_FORMAT_XBGR4444,
                /* These are actually IRGB1555 so intensity bit is lost */
                DRM_FORMAT_XRGB1555,
                DRM_FORMAT_XBGR1555,
                DRM_FORMAT_RGB565,
                DRM_FORMAT_BGR565,
                DRM_FORMAT_YUV422,
        };

        ret = mcde_init_clock_divider(mcde);
        if (ret)
                return ret;

        ret = drm_simple_display_pipe_init(drm, &mcde->pipe,
                                           &mcde_display_funcs,
                                           formats, ARRAY_SIZE(formats),
                                           NULL,
                                           mcde->connector);
        if (ret)
                return ret;

        return 0;
}
EXPORT_SYMBOL_GPL(mcde_display_init);