/*
 * Copyright (C) 2012 Avionic Design GmbH
 * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
 *
 * 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.
 */

#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/iommu.h>
#include <linux/reset.h>

#include <soc/tegra/pmc.h>

#include "dc.h"
#include "drm.h"
#include "gem.h"

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_plane_helper.h>

struct tegra_dc_soc_info {
        bool supports_border_color;
        bool supports_interlacing;
        bool supports_cursor;
        bool supports_block_linear;
        unsigned int pitch_align;
        bool has_powergate;
};

struct tegra_plane {
        struct drm_plane base;
        unsigned int index;
};

static inline struct tegra_plane *to_tegra_plane(struct drm_plane *plane)
{
        return container_of(plane, struct tegra_plane, base);
}

struct tegra_dc_state {
        struct drm_crtc_state base;

        struct clk *clk;
        unsigned long pclk;
        unsigned int div;

        u32 planes;
};

static inline struct tegra_dc_state *to_dc_state(struct drm_crtc_state *state)
{
        if (state)
                return container_of(state, struct tegra_dc_state, base);

        return NULL;
}

struct tegra_plane_state {
        struct drm_plane_state base;

        struct tegra_bo_tiling tiling;
        u32 format;
        u32 swap;
};

static inline struct tegra_plane_state *
to_tegra_plane_state(struct drm_plane_state *state)
{
        if (state)
                return container_of(state, struct tegra_plane_state, base);

        return NULL;
}

static void tegra_dc_stats_reset(struct tegra_dc_stats *stats)
{
        stats->frames = 0;
        stats->vblank = 0;
        stats->underflow = 0;
        stats->overflow = 0;
}

/*
 * Reads the active copy of a register. This takes the dc->lock spinlock to
 * prevent races with the VBLANK processing which also needs access to the
 * active copy of some registers.
 */
static u32 tegra_dc_readl_active(struct tegra_dc *dc, unsigned long offset)
{
        unsigned long flags;
        u32 value;

        spin_lock_irqsave(&dc->lock, flags);

        tegra_dc_writel(dc, READ_MUX, DC_CMD_STATE_ACCESS);
        value = tegra_dc_readl(dc, offset);
        tegra_dc_writel(dc, 0, DC_CMD_STATE_ACCESS);

        spin_unlock_irqrestore(&dc->lock, flags);
        return value;
}

/*
 * Double-buffered registers have two copies: ASSEMBLY and ACTIVE. When the
 * *_ACT_REQ bits are set the ASSEMBLY copy is latched into the ACTIVE copy.
 * Latching happens mmediately if the display controller is in STOP mode or
 * on the next frame boundary otherwise.
 *
 * Triple-buffered registers have three copies: ASSEMBLY, ARM and ACTIVE. The
 * ASSEMBLY copy is latched into the ARM copy immediately after *_UPDATE bits
 * are written. When the *_ACT_REQ bits are written, the ARM copy is latched
 * into the ACTIVE copy, either immediately if the display controller is in
 * STOP mode, or at the next frame boundary otherwise.
 */
void tegra_dc_commit(struct tegra_dc *dc)
{
        tegra_dc_writel(dc, GENERAL_ACT_REQ << 8, DC_CMD_STATE_CONTROL);
        tegra_dc_writel(dc, GENERAL_ACT_REQ, DC_CMD_STATE_CONTROL);
}

static int tegra_dc_format(u32 fourcc, u32 *format, u32 *swap)
{
        /* assume no swapping of fetched data */
        if (swap)
                *swap = BYTE_SWAP_NOSWAP;

        switch (fourcc) {
        case DRM_FORMAT_XBGR8888:
                *format = WIN_COLOR_DEPTH_R8G8B8A8;
                break;

        case DRM_FORMAT_XRGB8888:
                *format = WIN_COLOR_DEPTH_B8G8R8A8;
                break;

        case DRM_FORMAT_RGB565:
                *format = WIN_COLOR_DEPTH_B5G6R5;
                break;

        case DRM_FORMAT_UYVY:
                *format = WIN_COLOR_DEPTH_YCbCr422;
                break;

        case DRM_FORMAT_YUYV:
                if (swap)
                        *swap = BYTE_SWAP_SWAP2;

                *format = WIN_COLOR_DEPTH_YCbCr422;
                break;

        case DRM_FORMAT_YUV420:
                *format = WIN_COLOR_DEPTH_YCbCr420P;
                break;

        case DRM_FORMAT_YUV422:
                *format = WIN_COLOR_DEPTH_YCbCr422P;
                break;

        default:
                return -EINVAL;
        }

        return 0;
}

static bool tegra_dc_format_is_yuv(unsigned int format, bool *planar)
{
        switch (format) {
        case WIN_COLOR_DEPTH_YCbCr422:
        case WIN_COLOR_DEPTH_YUV422:
                if (planar)
                        *planar = false;

                return true;

        case WIN_COLOR_DEPTH_YCbCr420P:
        case WIN_COLOR_DEPTH_YUV420P:
        case WIN_COLOR_DEPTH_YCbCr422P:
        case WIN_COLOR_DEPTH_YUV422P:
        case WIN_COLOR_DEPTH_YCbCr422R:
        case WIN_COLOR_DEPTH_YUV422R:
        case WIN_COLOR_DEPTH_YCbCr422RA:
        case WIN_COLOR_DEPTH_YUV422RA:
                if (planar)
                        *planar = true;

                return true;
        }

        if (planar)
                *planar = false;

        return false;
}

static inline u32 compute_dda_inc(unsigned int in, unsigned int out, bool v,
                                  unsigned int bpp)
{
        fixed20_12 outf = dfixed_init(out);
        fixed20_12 inf = dfixed_init(in);
        u32 dda_inc;
        int max;

        if (v)
                max = 15;
        else {
                switch (bpp) {
                case 2:
                        max = 8;
                        break;

                default:
                        WARN_ON_ONCE(1);
                        /* fallthrough */
                case 4:
                        max = 4;
                        break;
                }
        }

        outf.full = max_t(u32, outf.full - dfixed_const(1), dfixed_const(1));
        inf.full -= dfixed_const(1);

        dda_inc = dfixed_div(inf, outf);
        dda_inc = min_t(u32, dda_inc, dfixed_const(max));

        return dda_inc;
}

static inline u32 compute_initial_dda(unsigned int in)
{
        fixed20_12 inf = dfixed_init(in);
        return dfixed_frac(inf);
}

static void tegra_dc_setup_window(struct tegra_dc *dc, unsigned int index,
                                  const struct tegra_dc_window *window)
{
        unsigned h_offset, v_offset, h_size, v_size, h_dda, v_dda, bpp;
        unsigned long value, flags;
        bool yuv, planar;

        /*
         * For YUV planar modes, the number of bytes per pixel takes into
         * account only the luma component and therefore is 1.
         */
        yuv = tegra_dc_format_is_yuv(window->format, &planar);
        if (!yuv)
                bpp = window->bits_per_pixel / 8;
        else
                bpp = planar ? 1 : 2;

        spin_lock_irqsave(&dc->lock, flags);

        value = WINDOW_A_SELECT << index;
        tegra_dc_writel(dc, value, DC_CMD_DISPLAY_WINDOW_HEADER);

        tegra_dc_writel(dc, window->format, DC_WIN_COLOR_DEPTH);
        tegra_dc_writel(dc, window->swap, DC_WIN_BYTE_SWAP);

        value = V_POSITION(window->dst.y) | H_POSITION(window->dst.x);
        tegra_dc_writel(dc, value, DC_WIN_POSITION);

        value = V_SIZE(window->dst.h) | H_SIZE(window->dst.w);
        tegra_dc_writel(dc, value, DC_WIN_SIZE);

        h_offset = window->src.x * bpp;
        v_offset = window->src.y;
        h_size = window->src.w * bpp;
        v_size = window->src.h;

        value = V_PRESCALED_SIZE(v_size) | H_PRESCALED_SIZE(h_size);
        tegra_dc_writel(dc, value, DC_WIN_PRESCALED_SIZE);

        /*
         * For DDA computations the number of bytes per pixel for YUV planar
         * modes needs to take into account all Y, U and V components.
         */
        if (yuv && planar)
                bpp = 2;

        h_dda = compute_dda_inc(window->src.w, window->dst.w, false, bpp);
        v_dda = compute_dda_inc(window->src.h, window->dst.h, true, bpp);

        value = V_DDA_INC(v_dda) | H_DDA_INC(h_dda);
        tegra_dc_writel(dc, value, DC_WIN_DDA_INC);

        h_dda = compute_initial_dda(window->src.x);
        v_dda = compute_initial_dda(window->src.y);

        tegra_dc_writel(dc, h_dda, DC_WIN_H_INITIAL_DDA);
        tegra_dc_writel(dc, v_dda, DC_WIN_V_INITIAL_DDA);

        tegra_dc_writel(dc, 0, DC_WIN_UV_BUF_STRIDE);
        tegra_dc_writel(dc, 0, DC_WIN_BUF_STRIDE);

        tegra_dc_writel(dc, window->base[0], DC_WINBUF_START_ADDR);

        if (yuv && planar) {
                tegra_dc_writel(dc, window->base[1], DC_WINBUF_START_ADDR_U);
                tegra_dc_writel(dc, window->base[2], DC_WINBUF_START_ADDR_V);
                value = window->stride[1] << 16 | window->stride[0];
                tegra_dc_writel(dc, value, DC_WIN_LINE_STRIDE);
        } else {
                tegra_dc_writel(dc, window->stride[0], DC_WIN_LINE_STRIDE);
        }

        if (window->bottom_up)
                v_offset += window->src.h - 1;

        tegra_dc_writel(dc, h_offset, DC_WINBUF_ADDR_H_OFFSET);
        tegra_dc_writel(dc, v_offset, DC_WINBUF_ADDR_V_OFFSET);

        if (dc->soc->supports_block_linear) {
                unsigned long height = window->tiling.value;

                switch (window->tiling.mode) {
                case TEGRA_BO_TILING_MODE_PITCH:
                        value = DC_WINBUF_SURFACE_KIND_PITCH;
                        break;

                case TEGRA_BO_TILING_MODE_TILED:
                        value = DC_WINBUF_SURFACE_KIND_TILED;
                        break;

                case TEGRA_BO_TILING_MODE_BLOCK:
                        value = DC_WINBUF_SURFACE_KIND_BLOCK_HEIGHT(height) |
                                DC_WINBUF_SURFACE_KIND_BLOCK;
                        break;
                }

                tegra_dc_writel(dc, value, DC_WINBUF_SURFACE_KIND);
        } else {
                switch (window->tiling.mode) {
                case TEGRA_BO_TILING_MODE_PITCH:
                        value = DC_WIN_BUFFER_ADDR_MODE_LINEAR_UV |
                                DC_WIN_BUFFER_ADDR_MODE_LINEAR;
                        break;

                case TEGRA_BO_TILING_MODE_TILED:
                        value = DC_WIN_BUFFER_ADDR_MODE_TILE_UV |
                                DC_WIN_BUFFER_ADDR_MODE_TILE;
                        break;

                case TEGRA_BO_TILING_MODE_BLOCK:
                        /*
                         * No need to handle this here because ->atomic_check
                         * will already have filtered it out.
                         */
                        break;
                }

                tegra_dc_writel(dc, value, DC_WIN_BUFFER_ADDR_MODE);
        }

        value = WIN_ENABLE;

        if (yuv) {
                /* setup default colorspace conversion coefficients */
                tegra_dc_writel(dc, 0x00f0, DC_WIN_CSC_YOF);
                tegra_dc_writel(dc, 0x012a, DC_WIN_CSC_KYRGB);
                tegra_dc_writel(dc, 0x0000, DC_WIN_CSC_KUR);
                tegra_dc_writel(dc, 0x0198, DC_WIN_CSC_KVR);
                tegra_dc_writel(dc, 0x039b, DC_WIN_CSC_KUG);
                tegra_dc_writel(dc, 0x032f, DC_WIN_CSC_KVG);
                tegra_dc_writel(dc, 0x0204, DC_WIN_CSC_KUB);
                tegra_dc_writel(dc, 0x0000, DC_WIN_CSC_KVB);

                value |= CSC_ENABLE;
        } else if (window->bits_per_pixel < 24) {
                value |= COLOR_EXPAND;
        }

        if (window->bottom_up)
                value |= V_DIRECTION;

        tegra_dc_writel(dc, value, DC_WIN_WIN_OPTIONS);

        /*
         * Disable blending and assume Window A is the bottom-most window,
         * Window C is the top-most window and Window B is in the middle.
         */
        tegra_dc_writel(dc, 0xffff00, DC_WIN_BLEND_NOKEY);
        tegra_dc_writel(dc, 0xffff00, DC_WIN_BLEND_1WIN);

        switch (index) {
        case 0:
                tegra_dc_writel(dc, 0x000000, DC_WIN_BLEND_2WIN_X);
                tegra_dc_writel(dc, 0x000000, DC_WIN_BLEND_2WIN_Y);
                tegra_dc_writel(dc, 0x000000, DC_WIN_BLEND_3WIN_XY);
                break;

        case 1:
                tegra_dc_writel(dc, 0xffff00, DC_WIN_BLEND_2WIN_X);
                tegra_dc_writel(dc, 0x000000, DC_WIN_BLEND_2WIN_Y);
                tegra_dc_writel(dc, 0x000000, DC_WIN_BLEND_3WIN_XY);
                break;

        case 2:
                tegra_dc_writel(dc, 0xffff00, DC_WIN_BLEND_2WIN_X);
                tegra_dc_writel(dc, 0xffff00, DC_WIN_BLEND_2WIN_Y);
                tegra_dc_writel(dc, 0xffff00, DC_WIN_BLEND_3WIN_XY);
                break;
        }

        spin_unlock_irqrestore(&dc->lock, flags);
}

static void tegra_plane_destroy(struct drm_plane *plane)
{
        struct tegra_plane *p = to_tegra_plane(plane);

        drm_plane_cleanup(plane);
        kfree(p);
}

static const u32 tegra_primary_plane_formats[] = {
        DRM_FORMAT_XBGR8888,
        DRM_FORMAT_XRGB8888,
        DRM_FORMAT_RGB565,
};

static void tegra_primary_plane_destroy(struct drm_plane *plane)
{
        tegra_plane_destroy(plane);
}

static void tegra_plane_reset(struct drm_plane *plane)
{
        struct tegra_plane_state *state;

        if (plane->state)
                __drm_atomic_helper_plane_destroy_state(plane, plane->state);

        kfree(plane->state);
        plane->state = NULL;

        state = kzalloc(sizeof(*state), GFP_KERNEL);
        if (state) {
                plane->state = &state->base;
                plane->state->plane = plane;
        }
}

static struct drm_plane_state *tegra_plane_atomic_duplicate_state(struct drm_plane *plane)
{
        struct tegra_plane_state *state = to_tegra_plane_state(plane->state);
        struct tegra_plane_state *copy;

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

        __drm_atomic_helper_plane_duplicate_state(plane, &copy->base);
        copy->tiling = state->tiling;
        copy->format = state->format;
        copy->swap = state->swap;

        return &copy->base;
}

static void tegra_plane_atomic_destroy_state(struct drm_plane *plane,
                                             struct drm_plane_state *state)
{
        __drm_atomic_helper_plane_destroy_state(plane, state);
        kfree(state);
}

static const struct drm_plane_funcs tegra_primary_plane_funcs = {
        .update_plane = drm_atomic_helper_update_plane,
        .disable_plane = drm_atomic_helper_disable_plane,
        .destroy = tegra_primary_plane_destroy,
        .reset = tegra_plane_reset,
        .atomic_duplicate_state = tegra_plane_atomic_duplicate_state,
        .atomic_destroy_state = tegra_plane_atomic_destroy_state,
};

static int tegra_plane_prepare_fb(struct drm_plane *plane,
                                  const struct drm_plane_state *new_state)
{
        return 0;
}

static void tegra_plane_cleanup_fb(struct drm_plane *plane,
                                   const struct drm_plane_state *old_fb)
{
}

static int tegra_plane_state_add(struct tegra_plane *plane,
                                 struct drm_plane_state *state)
{
        struct drm_crtc_state *crtc_state;
        struct tegra_dc_state *tegra;

        /* Propagate errors from allocation or locking failures. */
        crtc_state = drm_atomic_get_crtc_state(state->state, state->crtc);
        if (IS_ERR(crtc_state))
                return PTR_ERR(crtc_state);

        tegra = to_dc_state(crtc_state);

        tegra->planes |= WIN_A_ACT_REQ << plane->index;

        return 0;
}

static int tegra_plane_atomic_check(struct drm_plane *plane,
                                    struct drm_plane_state *state)
{
        struct tegra_plane_state *plane_state = to_tegra_plane_state(state);
        struct tegra_bo_tiling *tiling = &plane_state->tiling;
        struct tegra_plane *tegra = to_tegra_plane(plane);
        struct tegra_dc *dc = to_tegra_dc(state->crtc);
        int err;

        /* no need for further checks if the plane is being disabled */
        if (!state->crtc)
                return 0;

        err = tegra_dc_format(state->fb->pixel_format, &plane_state->format,
                              &plane_state->swap);
        if (err < 0)
                return err;

        err = tegra_fb_get_tiling(state->fb, tiling);
        if (err < 0)
                return err;

        if (tiling->mode == TEGRA_BO_TILING_MODE_BLOCK &&
            !dc->soc->supports_block_linear) {
                DRM_ERROR("hardware doesn't support block linear mode\n");
                return -EINVAL;
        }

        /*
         * Tegra doesn't support different strides for U and V planes so we
         * error out if the user tries to display a framebuffer with such a
         * configuration.
         */
        if (drm_format_num_planes(state->fb->pixel_format) > 2) {
                if (state->fb->pitches[2] != state->fb->pitches[1]) {
                        DRM_ERROR("unsupported UV-plane configuration\n");
                        return -EINVAL;
                }
        }

        err = tegra_plane_state_add(tegra, state);
        if (err < 0)
                return err;

        return 0;
}

static void tegra_plane_atomic_update(struct drm_plane *plane,
                                      struct drm_plane_state *old_state)
{
        struct tegra_plane_state *state = to_tegra_plane_state(plane->state);
        struct tegra_dc *dc = to_tegra_dc(plane->state->crtc);
        struct drm_framebuffer *fb = plane->state->fb;
        struct tegra_plane *p = to_tegra_plane(plane);
        struct tegra_dc_window window;
        unsigned int i;

        /* rien ne va plus */
        if (!plane->state->crtc || !plane->state->fb)
                return;

        memset(&window, 0, sizeof(window));
        window.src.x = plane->state->src_x >> 16;
        window.src.y = plane->state->src_y >> 16;
        window.src.w = plane->state->src_w >> 16;
        window.src.h = plane->state->src_h >> 16;
        window.dst.x = plane->state->crtc_x;
        window.dst.y = plane->state->crtc_y;
        window.dst.w = plane->state->crtc_w;
        window.dst.h = plane->state->crtc_h;
        window.bits_per_pixel = fb->bits_per_pixel;
        window.bottom_up = tegra_fb_is_bottom_up(fb);

        /* copy from state */
        window.tiling = state->tiling;
        window.format = state->format;
        window.swap = state->swap;

        for (i = 0; i < drm_format_num_planes(fb->pixel_format); i++) {
                struct tegra_bo *bo = tegra_fb_get_plane(fb, i);

                window.base[i] = bo->paddr + fb->offsets[i];
                window.stride[i] = fb->pitches[i];
        }

        tegra_dc_setup_window(dc, p->index, &window);
}

static void tegra_plane_atomic_disable(struct drm_plane *plane,
                                       struct drm_plane_state *old_state)
{
        struct tegra_plane *p = to_tegra_plane(plane);
        struct tegra_dc *dc;
        unsigned long flags;
        u32 value;

        /* rien ne va plus */
        if (!old_state || !old_state->crtc)
                return;

        dc = to_tegra_dc(old_state->crtc);

        spin_lock_irqsave(&dc->lock, flags);

        value = WINDOW_A_SELECT << p->index;
        tegra_dc_writel(dc, value, DC_CMD_DISPLAY_WINDOW_HEADER);

        value = tegra_dc_readl(dc, DC_WIN_WIN_OPTIONS);
        value &= ~WIN_ENABLE;
        tegra_dc_writel(dc, value, DC_WIN_WIN_OPTIONS);

        spin_unlock_irqrestore(&dc->lock, flags);
}

static const struct drm_plane_helper_funcs tegra_primary_plane_helper_funcs = {
        .prepare_fb = tegra_plane_prepare_fb,
        .cleanup_fb = tegra_plane_cleanup_fb,
        .atomic_check = tegra_plane_atomic_check,
        .atomic_update = tegra_plane_atomic_update,
        .atomic_disable = tegra_plane_atomic_disable,
};

static struct drm_plane *tegra_dc_primary_plane_create(struct drm_device *drm,
                                                       struct tegra_dc *dc)
{
        /*
         * Ideally this would use drm_crtc_mask(), but that would require the
         * CRTC to already be in the mode_config's list of CRTCs. However, it
         * will only be added to that list in the drm_crtc_init_with_planes()
         * (in tegra_dc_init()), which in turn requires registration of these
         * planes. So we have ourselves a nice little chicken and egg problem
         * here.
         *
         * We work around this by manually creating the mask from the number
         * of CRTCs that have been registered, and should therefore always be
         * the same as drm_crtc_index() after registration.
         */
        unsigned long possible_crtcs = 1 << drm->mode_config.num_crtc;
        struct tegra_plane *plane;
        unsigned int num_formats;
        const u32 *formats;
        int err;

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

        num_formats = ARRAY_SIZE(tegra_primary_plane_formats);
        formats = tegra_primary_plane_formats;

        err = drm_universal_plane_init(drm, &plane->base, possible_crtcs,
                                       &tegra_primary_plane_funcs, formats,
                                       num_formats, DRM_PLANE_TYPE_PRIMARY);
        if (err < 0) {
                kfree(plane);
                return ERR_PTR(err);
        }

        drm_plane_helper_add(&plane->base, &tegra_primary_plane_helper_funcs);

        return &plane->base;
}

static const u32 tegra_cursor_plane_formats[] = {
        DRM_FORMAT_RGBA8888,
};

static int tegra_cursor_atomic_check(struct drm_plane *plane,
                                     struct drm_plane_state *state)
{
        struct tegra_plane *tegra = to_tegra_plane(plane);
        int err;

        /* no need for further checks if the plane is being disabled */
        if (!state->crtc)
                return 0;

        /* scaling not supported for cursor */
        if ((state->src_w >> 16 != state->crtc_w) ||
            (state->src_h >> 16 != state->crtc_h))
                return -EINVAL;

        /* only square cursors supported */
        if (state->src_w != state->src_h)
                return -EINVAL;

        if (state->crtc_w != 32 && state->crtc_w != 64 &&
            state->crtc_w != 128 && state->crtc_w != 256)
                return -EINVAL;

        err = tegra_plane_state_add(tegra, state);
        if (err < 0)
                return err;

        return 0;
}

static void tegra_cursor_atomic_update(struct drm_plane *plane,
                                       struct drm_plane_state *old_state)
{
        struct tegra_bo *bo = tegra_fb_get_plane(plane->state->fb, 0);
        struct tegra_dc *dc = to_tegra_dc(plane->state->crtc);
        struct drm_plane_state *state = plane->state;
        u32 value = CURSOR_CLIP_DISPLAY;

        /* rien ne va plus */
        if (!plane->state->crtc || !plane->state->fb)
                return;

        switch (state->crtc_w) {
        case 32:
                value |= CURSOR_SIZE_32x32;
                break;

        case 64:
                value |= CURSOR_SIZE_64x64;
                break;

        case 128:
                value |= CURSOR_SIZE_128x128;
                break;

        case 256:
                value |= CURSOR_SIZE_256x256;
                break;

        default:
                WARN(1, "cursor size %ux%u not supported\n", state->crtc_w,
                     state->crtc_h);
                return;
        }

        value |= (bo->paddr >> 10) & 0x3fffff;
        tegra_dc_writel(dc, value, DC_DISP_CURSOR_START_ADDR);

#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
        value = (bo->paddr >> 32) & 0x3;
        tegra_dc_writel(dc, value, DC_DISP_CURSOR_START_ADDR_HI);
#endif

        /* enable cursor and set blend mode */
        value = tegra_dc_readl(dc, DC_DISP_DISP_WIN_OPTIONS);
        value |= CURSOR_ENABLE;
        tegra_dc_writel(dc, value, DC_DISP_DISP_WIN_OPTIONS);

        value = tegra_dc_readl(dc, DC_DISP_BLEND_CURSOR_CONTROL);
        value &= ~CURSOR_DST_BLEND_MASK;
        value &= ~CURSOR_SRC_BLEND_MASK;
        value |= CURSOR_MODE_NORMAL;
        value |= CURSOR_DST_BLEND_NEG_K1_TIMES_SRC;
        value |= CURSOR_SRC_BLEND_K1_TIMES_SRC;
        value |= CURSOR_ALPHA;
        tegra_dc_writel(dc, value, DC_DISP_BLEND_CURSOR_CONTROL);

        /* position the cursor */
        value = (state->crtc_y & 0x3fff) << 16 | (state->crtc_x & 0x3fff);
        tegra_dc_writel(dc, value, DC_DISP_CURSOR_POSITION);
}

static void tegra_cursor_atomic_disable(struct drm_plane *plane,
                                        struct drm_plane_state *old_state)
{
        struct tegra_dc *dc;
        u32 value;

        /* rien ne va plus */
        if (!old_state || !old_state->crtc)
                return;

        dc = to_tegra_dc(old_state->crtc);

        value = tegra_dc_readl(dc, DC_DISP_DISP_WIN_OPTIONS);
        value &= ~CURSOR_ENABLE;
        tegra_dc_writel(dc, value, DC_DISP_DISP_WIN_OPTIONS);
}

static const struct drm_plane_funcs tegra_cursor_plane_funcs = {
        .update_plane = drm_atomic_helper_update_plane,
        .disable_plane = drm_atomic_helper_disable_plane,
        .destroy = tegra_plane_destroy,
        .reset = tegra_plane_reset,
        .atomic_duplicate_state = tegra_plane_atomic_duplicate_state,
        .atomic_destroy_state = tegra_plane_atomic_destroy_state,
};

static const struct drm_plane_helper_funcs tegra_cursor_plane_helper_funcs = {
        .prepare_fb = tegra_plane_prepare_fb,
        .cleanup_fb = tegra_plane_cleanup_fb,
        .atomic_check = tegra_cursor_atomic_check,
        .atomic_update = tegra_cursor_atomic_update,
        .atomic_disable = tegra_cursor_atomic_disable,
};

static struct drm_plane *tegra_dc_cursor_plane_create(struct drm_device *drm,
                                                      struct tegra_dc *dc)
{
        struct tegra_plane *plane;
        unsigned int num_formats;
        const u32 *formats;
        int err;

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

        /*
         * This index is kind of fake. The cursor isn't a regular plane, but
         * its update and activation request bits in DC_CMD_STATE_CONTROL do
         * use the same programming. Setting this fake index here allows the
         * code in tegra_add_plane_state() to do the right thing without the
         * need to special-casing the cursor plane.
         */
        plane->index = 6;

        num_formats = ARRAY_SIZE(tegra_cursor_plane_formats);
        formats = tegra_cursor_plane_formats;

        err = drm_universal_plane_init(drm, &plane->base, 1 << dc->pipe,
                                       &tegra_cursor_plane_funcs, formats,
                                       num_formats, DRM_PLANE_TYPE_CURSOR);
        if (err < 0) {
                kfree(plane);
                return ERR_PTR(err);
        }

        drm_plane_helper_add(&plane->base, &tegra_cursor_plane_helper_funcs);

        return &plane->base;
}

static void tegra_overlay_plane_destroy(struct drm_plane *plane)
{
        tegra_plane_destroy(plane);
}

static const struct drm_plane_funcs tegra_overlay_plane_funcs = {
        .update_plane = drm_atomic_helper_update_plane,
        .disable_plane = drm_atomic_helper_disable_plane,
        .destroy = tegra_overlay_plane_destroy,
        .reset = tegra_plane_reset,
        .atomic_duplicate_state = tegra_plane_atomic_duplicate_state,
        .atomic_destroy_state = tegra_plane_atomic_destroy_state,
};

static const uint32_t tegra_overlay_plane_formats[] = {
        DRM_FORMAT_XBGR8888,
        DRM_FORMAT_XRGB8888,
        DRM_FORMAT_RGB565,
        DRM_FORMAT_UYVY,
        DRM_FORMAT_YUYV,
        DRM_FORMAT_YUV420,
        DRM_FORMAT_YUV422,
};

static const struct drm_plane_helper_funcs tegra_overlay_plane_helper_funcs = {
        .prepare_fb = tegra_plane_prepare_fb,
        .cleanup_fb = tegra_plane_cleanup_fb,
        .atomic_check = tegra_plane_atomic_check,
        .atomic_update = tegra_plane_atomic_update,
        .atomic_disable = tegra_plane_atomic_disable,
};

static struct drm_plane *tegra_dc_overlay_plane_create(struct drm_device *drm,
                                                       struct tegra_dc *dc,
                                                       unsigned int index)
{
        struct tegra_plane *plane;
        unsigned int num_formats;
        const u32 *formats;
        int err;

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

        plane->index = index;

        num_formats = ARRAY_SIZE(tegra_overlay_plane_formats);
        formats = tegra_overlay_plane_formats;

        err = drm_universal_plane_init(drm, &plane->base, 1 << dc->pipe,
                                       &tegra_overlay_plane_funcs, formats,
                                       num_formats, DRM_PLANE_TYPE_OVERLAY);
        if (err < 0) {
                kfree(plane);
                return ERR_PTR(err);
        }

        drm_plane_helper_add(&plane->base, &tegra_overlay_plane_helper_funcs);

        return &plane->base;
}

static int tegra_dc_add_planes(struct drm_device *drm, struct tegra_dc *dc)
{
        struct drm_plane *plane;
        unsigned int i;

        for (i = 0; i < 2; i++) {
                plane = tegra_dc_overlay_plane_create(drm, dc, 1 + i);
                if (IS_ERR(plane))
                        return PTR_ERR(plane);
        }

        return 0;
}

u32 tegra_dc_get_vblank_counter(struct tegra_dc *dc)
{
        if (dc->syncpt)
                return host1x_syncpt_read(dc->syncpt);

        /* fallback to software emulated VBLANK counter */
        return drm_crtc_vblank_count(&dc->base);
}

void tegra_dc_enable_vblank(struct tegra_dc *dc)
{
        unsigned long value, flags;

        spin_lock_irqsave(&dc->lock, flags);

        value = tegra_dc_readl(dc, DC_CMD_INT_MASK);
        value |= VBLANK_INT;
        tegra_dc_writel(dc, value, DC_CMD_INT_MASK);

        spin_unlock_irqrestore(&dc->lock, flags);
}

void tegra_dc_disable_vblank(struct tegra_dc *dc)
{
        unsigned long value, flags;

        spin_lock_irqsave(&dc->lock, flags);

        value = tegra_dc_readl(dc, DC_CMD_INT_MASK);
        value &= ~VBLANK_INT;
        tegra_dc_writel(dc, value, DC_CMD_INT_MASK);

        spin_unlock_irqrestore(&dc->lock, flags);
}

static void tegra_dc_finish_page_flip(struct tegra_dc *dc)
{
        struct drm_device *drm = dc->base.dev;
        struct drm_crtc *crtc = &dc->base;
        unsigned long flags, base;
        struct tegra_bo *bo;

        spin_lock_irqsave(&drm->event_lock, flags);

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

        bo = tegra_fb_get_plane(crtc->primary->fb, 0);

        spin_lock(&dc->lock);

        /* check if new start address has been latched */
        tegra_dc_writel(dc, WINDOW_A_SELECT, DC_CMD_DISPLAY_WINDOW_HEADER);
        tegra_dc_writel(dc, READ_MUX, DC_CMD_STATE_ACCESS);
        base = tegra_dc_readl(dc, DC_WINBUF_START_ADDR);
        tegra_dc_writel(dc, 0, DC_CMD_STATE_ACCESS);

        spin_unlock(&dc->lock);

        if (base == bo->paddr + crtc->primary->fb->offsets[0]) {
                drm_crtc_send_vblank_event(crtc, dc->event);
                drm_crtc_vblank_put(crtc);
                dc->event = NULL;
        }

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

void tegra_dc_cancel_page_flip(struct drm_crtc *crtc, struct drm_file *file)
{
        struct tegra_dc *dc = to_tegra_dc(crtc);
        struct drm_device *drm = crtc->dev;
        unsigned long flags;

        spin_lock_irqsave(&drm->event_lock, flags);

        if (dc->event && dc->event->base.file_priv == file) {
                dc->event->base.destroy(&dc->event->base);
                drm_crtc_vblank_put(crtc);
                dc->event = NULL;
        }

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

static void tegra_dc_destroy(struct drm_crtc *crtc)
{
        drm_crtc_cleanup(crtc);
}

static void tegra_crtc_reset(struct drm_crtc *crtc)
{
        struct tegra_dc_state *state;

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

        kfree(crtc->state);
        crtc->state = NULL;

        state = kzalloc(sizeof(*state), GFP_KERNEL);
        if (state) {
                crtc->state = &state->base;
                crtc->state->crtc = crtc;
        }

        drm_crtc_vblank_reset(crtc);
}

static struct drm_crtc_state *
tegra_crtc_atomic_duplicate_state(struct drm_crtc *crtc)
{
        struct tegra_dc_state *state = to_dc_state(crtc->state);
        struct tegra_dc_state *copy;

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

        __drm_atomic_helper_crtc_duplicate_state(crtc, &copy->base);
        copy->clk = state->clk;
        copy->pclk = state->pclk;
        copy->div = state->div;
        copy->planes = state->planes;

        return &copy->base;
}

static void tegra_crtc_atomic_destroy_state(struct drm_crtc *crtc,
                                            struct drm_crtc_state *state)
{
        __drm_atomic_helper_crtc_destroy_state(crtc, state);
        kfree(state);
}

static const struct drm_crtc_funcs tegra_crtc_funcs = {
        .page_flip = drm_atomic_helper_page_flip,
        .set_config = drm_atomic_helper_set_config,
        .destroy = tegra_dc_destroy,
        .reset = tegra_crtc_reset,
        .atomic_duplicate_state = tegra_crtc_atomic_duplicate_state,
        .atomic_destroy_state = tegra_crtc_atomic_destroy_state,
};

static int tegra_dc_set_timings(struct tegra_dc *dc,
                                struct drm_display_mode *mode)
{
        unsigned int h_ref_to_sync = 1;
        unsigned int v_ref_to_sync = 1;
        unsigned long value;

        tegra_dc_writel(dc, 0x0, DC_DISP_DISP_TIMING_OPTIONS);

        value = (v_ref_to_sync << 16) | h_ref_to_sync;
        tegra_dc_writel(dc, value, DC_DISP_REF_TO_SYNC);

        value = ((mode->vsync_end - mode->vsync_start) << 16) |
                ((mode->hsync_end - mode->hsync_start) <<  0);
        tegra_dc_writel(dc, value, DC_DISP_SYNC_WIDTH);

        value = ((mode->vtotal - mode->vsync_end) << 16) |
                ((mode->htotal - mode->hsync_end) <<  0);
        tegra_dc_writel(dc, value, DC_DISP_BACK_PORCH);

        value = ((mode->vsync_start - mode->vdisplay) << 16) |
                ((mode->hsync_start - mode->hdisplay) <<  0);
        tegra_dc_writel(dc, value, DC_DISP_FRONT_PORCH);

        value = (mode->vdisplay << 16) | mode->hdisplay;
        tegra_dc_writel(dc, value, DC_DISP_ACTIVE);

        return 0;
}

/**
 * tegra_dc_state_setup_clock - check clock settings and store them in atomic
 *     state
 * @dc: display controller
 * @crtc_state: CRTC atomic state
 * @clk: parent clock for display controller
 * @pclk: pixel clock
 * @div: shift clock divider
 *
 * Returns:
 * 0 on success or a negative error-code on failure.
 */
int tegra_dc_state_setup_clock(struct tegra_dc *dc,
                               struct drm_crtc_state *crtc_state,
                               struct clk *clk, unsigned long pclk,
                               unsigned int div)
{
        struct tegra_dc_state *state = to_dc_state(crtc_state);

        if (!clk_has_parent(dc->clk, clk))
                return -EINVAL;

        state->clk = clk;
        state->pclk = pclk;
        state->div = div;

        return 0;
}

static void tegra_dc_commit_state(struct tegra_dc *dc,
                                  struct tegra_dc_state *state)
{
        u32 value;
        int err;

        err = clk_set_parent(dc->clk, state->clk);
        if (err < 0)
                dev_err(dc->dev, "failed to set parent clock: %d\n", err);

        /*
         * Outputs may not want to change the parent clock rate. This is only
         * relevant to Tegra20 where only a single display PLL is available.
         * Since that PLL would typically be used for HDMI, an internal LVDS
         * panel would need to be driven by some other clock such as PLL_P
         * which is shared with other peripherals. Changing the clock rate
         * should therefore be avoided.
         */
        if (state->pclk > 0) {
                err = clk_set_rate(state->clk, state->pclk);
                if (err < 0)
                        dev_err(dc->dev,
                                "failed to set clock rate to %lu Hz\n",
                                state->pclk);
        }

        DRM_DEBUG_KMS("rate: %lu, div: %u\n", clk_get_rate(dc->clk),
                      state->div);
        DRM_DEBUG_KMS("pclk: %lu\n", state->pclk);

        value = SHIFT_CLK_DIVIDER(state->div) | PIXEL_CLK_DIVIDER_PCD1;
        tegra_dc_writel(dc, value, DC_DISP_DISP_CLOCK_CONTROL);
}

static void tegra_dc_stop(struct tegra_dc *dc)
{
        u32 value;

        /* stop the display controller */
        value = tegra_dc_readl(dc, DC_CMD_DISPLAY_COMMAND);
        value &= ~DISP_CTRL_MODE_MASK;
        tegra_dc_writel(dc, value, DC_CMD_DISPLAY_COMMAND);

        tegra_dc_commit(dc);
}

static bool tegra_dc_idle(struct tegra_dc *dc)
{
        u32 value;

        value = tegra_dc_readl_active(dc, DC_CMD_DISPLAY_COMMAND);

        return (value & DISP_CTRL_MODE_MASK) == 0;
}

static int tegra_dc_wait_idle(struct tegra_dc *dc, unsigned long timeout)
{
        timeout = jiffies + msecs_to_jiffies(timeout);

        while (time_before(jiffies, timeout)) {
                if (tegra_dc_idle(dc))
                        return 0;

                usleep_range(1000, 2000);
        }

        dev_dbg(dc->dev, "timeout waiting for DC to become idle\n");
        return -ETIMEDOUT;
}

static void tegra_crtc_disable(struct drm_crtc *crtc)
{
        struct tegra_dc *dc = to_tegra_dc(crtc);
        u32 value;

        if (!tegra_dc_idle(dc)) {
                tegra_dc_stop(dc);

                /*
                 * Ignore the return value, there isn't anything useful to do
                 * in case this fails.
                 */
                tegra_dc_wait_idle(dc, 100);
        }

        /*
         * This should really be part of the RGB encoder driver, but clearing
         * these bits has the side-effect of stopping the display controller.
         * When that happens no VBLANK interrupts will be raised. At the same
         * time the encoder is disabled before the display controller, so the
         * above code is always going to timeout waiting for the controller
         * to go idle.
         *
         * Given the close coupling between the RGB encoder and the display
         * controller doing it here is still kind of okay. None of the other
         * encoder drivers require these bits to be cleared.
         *
         * XXX: Perhaps given that the display controller is switched off at
         * this point anyway maybe clearing these bits isn't even useful for
         * the RGB encoder?
         */
        if (dc->rgb) {
                value = tegra_dc_readl(dc, DC_CMD_DISPLAY_POWER_CONTROL);
                value &= ~(PW0_ENABLE | PW1_ENABLE | PW2_ENABLE | PW3_ENABLE |
                           PW4_ENABLE | PM0_ENABLE | PM1_ENABLE);
                tegra_dc_writel(dc, value, DC_CMD_DISPLAY_POWER_CONTROL);
        }

        tegra_dc_stats_reset(&dc->stats);
        drm_crtc_vblank_off(crtc);
}

static void tegra_crtc_enable(struct drm_crtc *crtc)
{
        struct drm_display_mode *mode = &crtc->state->adjusted_mode;
        struct tegra_dc_state *state = to_dc_state(crtc->state);
        struct tegra_dc *dc = to_tegra_dc(crtc);
        u32 value;

        tegra_dc_commit_state(dc, state);

        /* program display mode */
        tegra_dc_set_timings(dc, mode);

        /* interlacing isn't supported yet, so disable it */
        if (dc->soc->supports_interlacing) {
                value = tegra_dc_readl(dc, DC_DISP_INTERLACE_CONTROL);
                value &= ~INTERLACE_ENABLE;
                tegra_dc_writel(dc, value, DC_DISP_INTERLACE_CONTROL);
        }

        value = tegra_dc_readl(dc, DC_CMD_DISPLAY_COMMAND);
        value &= ~DISP_CTRL_MODE_MASK;
        value |= DISP_CTRL_MODE_C_DISPLAY;
        tegra_dc_writel(dc, value, DC_CMD_DISPLAY_COMMAND);

        value = tegra_dc_readl(dc, DC_CMD_DISPLAY_POWER_CONTROL);
        value |= PW0_ENABLE | PW1_ENABLE | PW2_ENABLE | PW3_ENABLE |
                 PW4_ENABLE | PM0_ENABLE | PM1_ENABLE;
        tegra_dc_writel(dc, value, DC_CMD_DISPLAY_POWER_CONTROL);

        tegra_dc_commit(dc);

        drm_crtc_vblank_on(crtc);
}

static int tegra_crtc_atomic_check(struct drm_crtc *crtc,
                                   struct drm_crtc_state *state)
{
        return 0;
}

static void tegra_crtc_atomic_begin(struct drm_crtc *crtc,
                                    struct drm_crtc_state *old_crtc_state)
{
        struct tegra_dc *dc = to_tegra_dc(crtc);

        if (crtc->state->event) {
                crtc->state->event->pipe = drm_crtc_index(crtc);

                WARN_ON(drm_crtc_vblank_get(crtc) != 0);

                dc->event = crtc->state->event;
                crtc->state->event = NULL;
        }
}

static void tegra_crtc_atomic_flush(struct drm_crtc *crtc,
                                    struct drm_crtc_state *old_crtc_state)
{
        struct tegra_dc_state *state = to_dc_state(crtc->state);
        struct tegra_dc *dc = to_tegra_dc(crtc);

        tegra_dc_writel(dc, state->planes << 8, DC_CMD_STATE_CONTROL);
        tegra_dc_writel(dc, state->planes, DC_CMD_STATE_CONTROL);
}

static const struct drm_crtc_helper_funcs tegra_crtc_helper_funcs = {
        .disable = tegra_crtc_disable,
        .enable = tegra_crtc_enable,
        .atomic_check = tegra_crtc_atomic_check,
        .atomic_begin = tegra_crtc_atomic_begin,
        .atomic_flush = tegra_crtc_atomic_flush,
};

static irqreturn_t tegra_dc_irq(int irq, void *data)
{
        struct tegra_dc *dc = data;
        unsigned long status;

        status = tegra_dc_readl(dc, DC_CMD_INT_STATUS);
        tegra_dc_writel(dc, status, DC_CMD_INT_STATUS);

        if (status & FRAME_END_INT) {
                /*
                dev_dbg(dc->dev, "%s(): frame end\n", __func__);
                */
                dc->stats.frames++;
        }

        if (status & VBLANK_INT) {
                /*
                dev_dbg(dc->dev, "%s(): vertical blank\n", __func__);
                */
                drm_crtc_handle_vblank(&dc->base);
                tegra_dc_finish_page_flip(dc);
                dc->stats.vblank++;
        }

        if (status & (WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT)) {
                /*
                dev_dbg(dc->dev, "%s(): underflow\n", __func__);
                */
                dc->stats.underflow++;
        }

        if (status & (WIN_A_OF_INT | WIN_B_OF_INT | WIN_C_OF_INT)) {
                /*
                dev_dbg(dc->dev, "%s(): overflow\n", __func__);
                */
                dc->stats.overflow++;
        }

        return IRQ_HANDLED;
}

static int tegra_dc_show_regs(struct seq_file *s, void *data)
{
        struct drm_info_node *node = s->private;
        struct tegra_dc *dc = node->info_ent->data;
        int err = 0;

        drm_modeset_lock_crtc(&dc->base, NULL);

        if (!dc->base.state->active) {
                err = -EBUSY;
                goto unlock;
        }

#define DUMP_REG(name)                                          \
        seq_printf(s, "%-40s %#05x %08x\n", #name, name,        \
                   tegra_dc_readl(dc, name))

        DUMP_REG(DC_CMD_GENERAL_INCR_SYNCPT);
        DUMP_REG(DC_CMD_GENERAL_INCR_SYNCPT_CNTRL);
        DUMP_REG(DC_CMD_GENERAL_INCR_SYNCPT_ERROR);
        DUMP_REG(DC_CMD_WIN_A_INCR_SYNCPT);
        DUMP_REG(DC_CMD_WIN_A_INCR_SYNCPT_CNTRL);
        DUMP_REG(DC_CMD_WIN_A_INCR_SYNCPT_ERROR);
        DUMP_REG(DC_CMD_WIN_B_INCR_SYNCPT);
        DUMP_REG(DC_CMD_WIN_B_INCR_SYNCPT_CNTRL);
        DUMP_REG(DC_CMD_WIN_B_INCR_SYNCPT_ERROR);
        DUMP_REG(DC_CMD_WIN_C_INCR_SYNCPT);
        DUMP_REG(DC_CMD_WIN_C_INCR_SYNCPT_CNTRL);
        DUMP_REG(DC_CMD_WIN_C_INCR_SYNCPT_ERROR);
        DUMP_REG(DC_CMD_CONT_SYNCPT_VSYNC);
        DUMP_REG(DC_CMD_DISPLAY_COMMAND_OPTION0);
        DUMP_REG(DC_CMD_DISPLAY_COMMAND);
        DUMP_REG(DC_CMD_SIGNAL_RAISE);
        DUMP_REG(DC_CMD_DISPLAY_POWER_CONTROL);
        DUMP_REG(DC_CMD_INT_STATUS);
        DUMP_REG(DC_CMD_INT_MASK);
        DUMP_REG(DC_CMD_INT_ENABLE);
        DUMP_REG(DC_CMD_INT_TYPE);
        DUMP_REG(DC_CMD_INT_POLARITY);
        DUMP_REG(DC_CMD_SIGNAL_RAISE1);
        DUMP_REG(DC_CMD_SIGNAL_RAISE2);
        DUMP_REG(DC_CMD_SIGNAL_RAISE3);
        DUMP_REG(DC_CMD_STATE_ACCESS);
        DUMP_REG(DC_CMD_STATE_CONTROL);
        DUMP_REG(DC_CMD_DISPLAY_WINDOW_HEADER);
        DUMP_REG(DC_CMD_REG_ACT_CONTROL);
        DUMP_REG(DC_COM_CRC_CONTROL);
        DUMP_REG(DC_COM_CRC_CHECKSUM);
        DUMP_REG(DC_COM_PIN_OUTPUT_ENABLE(0));
        DUMP_REG(DC_COM_PIN_OUTPUT_ENABLE(1));
        DUMP_REG(DC_COM_PIN_OUTPUT_ENABLE(2));
        DUMP_REG(DC_COM_PIN_OUTPUT_ENABLE(3));
        DUMP_REG(DC_COM_PIN_OUTPUT_POLARITY(0));
        DUMP_REG(DC_COM_PIN_OUTPUT_POLARITY(1));
        DUMP_REG(DC_COM_PIN_OUTPUT_POLARITY(2));
        DUMP_REG(DC_COM_PIN_OUTPUT_POLARITY(3));
        DUMP_REG(DC_COM_PIN_OUTPUT_DATA(0));
        DUMP_REG(DC_COM_PIN_OUTPUT_DATA(1));
        DUMP_REG(DC_COM_PIN_OUTPUT_DATA(2));
        DUMP_REG(DC_COM_PIN_OUTPUT_DATA(3));
        DUMP_REG(DC_COM_PIN_INPUT_ENABLE(0));
        DUMP_REG(DC_COM_PIN_INPUT_ENABLE(1));
        DUMP_REG(DC_COM_PIN_INPUT_ENABLE(2));
        DUMP_REG(DC_COM_PIN_INPUT_ENABLE(3));
        DUMP_REG(DC_COM_PIN_INPUT_DATA(0));
        DUMP_REG(DC_COM_PIN_INPUT_DATA(1));
        DUMP_REG(DC_COM_PIN_OUTPUT_SELECT(0));
        DUMP_REG(DC_COM_PIN_OUTPUT_SELECT(1));
        DUMP_REG(DC_COM_PIN_OUTPUT_SELECT(2));
        DUMP_REG(DC_COM_PIN_OUTPUT_SELECT(3));
        DUMP_REG(DC_COM_PIN_OUTPUT_SELECT(4));
        DUMP_REG(DC_COM_PIN_OUTPUT_SELECT(5));
        DUMP_REG(DC_COM_PIN_OUTPUT_SELECT(6));
        DUMP_REG(DC_COM_PIN_MISC_CONTROL);
        DUMP_REG(DC_COM_PIN_PM0_CONTROL);
        DUMP_REG(DC_COM_PIN_PM0_DUTY_CYCLE);
        DUMP_REG(DC_COM_PIN_PM1_CONTROL);
        DUMP_REG(DC_COM_PIN_PM1_DUTY_CYCLE);
        DUMP_REG(DC_COM_SPI_CONTROL);
        DUMP_REG(DC_COM_SPI_START_BYTE);
        DUMP_REG(DC_COM_HSPI_WRITE_DATA_AB);
        DUMP_REG(DC_COM_HSPI_WRITE_DATA_CD);
        DUMP_REG(DC_COM_HSPI_CS_DC);
        DUMP_REG(DC_COM_SCRATCH_REGISTER_A);
        DUMP_REG(DC_COM_SCRATCH_REGISTER_B);
        DUMP_REG(DC_COM_GPIO_CTRL);
        DUMP_REG(DC_COM_GPIO_DEBOUNCE_COUNTER);
        DUMP_REG(DC_COM_CRC_CHECKSUM_LATCHED);
        DUMP_REG(DC_DISP_DISP_SIGNAL_OPTIONS0);
        DUMP_REG(DC_DISP_DISP_SIGNAL_OPTIONS1);
        DUMP_REG(DC_DISP_DISP_WIN_OPTIONS);
        DUMP_REG(DC_DISP_DISP_MEM_HIGH_PRIORITY);
        DUMP_REG(DC_DISP_DISP_MEM_HIGH_PRIORITY_TIMER);
        DUMP_REG(DC_DISP_DISP_TIMING_OPTIONS);
        DUMP_REG(DC_DISP_REF_TO_SYNC);
        DUMP_REG(DC_DISP_SYNC_WIDTH);
        DUMP_REG(DC_DISP_BACK_PORCH);
        DUMP_REG(DC_DISP_ACTIVE);
        DUMP_REG(DC_DISP_FRONT_PORCH);
        DUMP_REG(DC_DISP_H_PULSE0_CONTROL);
        DUMP_REG(DC_DISP_H_PULSE0_POSITION_A);
        DUMP_REG(DC_DISP_H_PULSE0_POSITION_B);
        DUMP_REG(DC_DISP_H_PULSE0_POSITION_C);
        DUMP_REG(DC_DISP_H_PULSE0_POSITION_D);
        DUMP_REG(DC_DISP_H_PULSE1_CONTROL);
        DUMP_REG(DC_DISP_H_PULSE1_POSITION_A);
        DUMP_REG(DC_DISP_H_PULSE1_POSITION_B);
        DUMP_REG(DC_DISP_H_PULSE1_POSITION_C);
        DUMP_REG(DC_DISP_H_PULSE1_POSITION_D);
        DUMP_REG(DC_DISP_H_PULSE2_CONTROL);
        DUMP_REG(DC_DISP_H_PULSE2_POSITION_A);
        DUMP_REG(DC_DISP_H_PULSE2_POSITION_B);
        DUMP_REG(DC_DISP_H_PULSE2_POSITION_C);
        DUMP_REG(DC_DISP_H_PULSE2_POSITION_D);
        DUMP_REG(DC_DISP_V_PULSE0_CONTROL);
        DUMP_REG(DC_DISP_V_PULSE0_POSITION_A);
        DUMP_REG(DC_DISP_V_PULSE0_POSITION_B);
        DUMP_REG(DC_DISP_V_PULSE0_POSITION_C);
        DUMP_REG(DC_DISP_V_PULSE1_CONTROL);
        DUMP_REG(DC_DISP_V_PULSE1_POSITION_A);
        DUMP_REG(DC_DISP_V_PULSE1_POSITION_B);
        DUMP_REG(DC_DISP_V_PULSE1_POSITION_C);
        DUMP_REG(DC_DISP_V_PULSE2_CONTROL);
        DUMP_REG(DC_DISP_V_PULSE2_POSITION_A);
        DUMP_REG(DC_DISP_V_PULSE3_CONTROL);
        DUMP_REG(DC_DISP_V_PULSE3_POSITION_A);
        DUMP_REG(DC_DISP_M0_CONTROL);
        DUMP_REG(DC_DISP_M1_CONTROL);
        DUMP_REG(DC_DISP_DI_CONTROL);
        DUMP_REG(DC_DISP_PP_CONTROL);
        DUMP_REG(DC_DISP_PP_SELECT_A);
        DUMP_REG(DC_DISP_PP_SELECT_B);
        DUMP_REG(DC_DISP_PP_SELECT_C);
        DUMP_REG(DC_DISP_PP_SELECT_D);
        DUMP_REG(DC_DISP_DISP_CLOCK_CONTROL);
        DUMP_REG(DC_DISP_DISP_INTERFACE_CONTROL);
        DUMP_REG(DC_DISP_DISP_COLOR_CONTROL);
        DUMP_REG(DC_DISP_SHIFT_CLOCK_OPTIONS);
        DUMP_REG(DC_DISP_DATA_ENABLE_OPTIONS);
        DUMP_REG(DC_DISP_SERIAL_INTERFACE_OPTIONS);
        DUMP_REG(DC_DISP_LCD_SPI_OPTIONS);
        DUMP_REG(DC_DISP_BORDER_COLOR);
        DUMP_REG(DC_DISP_COLOR_KEY0_LOWER);
        DUMP_REG(DC_DISP_COLOR_KEY0_UPPER);
        DUMP_REG(DC_DISP_COLOR_KEY1_LOWER);
        DUMP_REG(DC_DISP_COLOR_KEY1_UPPER);
        DUMP_REG(DC_DISP_CURSOR_FOREGROUND);
        DUMP_REG(DC_DISP_CURSOR_BACKGROUND);
        DUMP_REG(DC_DISP_CURSOR_START_ADDR);
        DUMP_REG(DC_DISP_CURSOR_START_ADDR_NS);
        DUMP_REG(DC_DISP_CURSOR_POSITION);
        DUMP_REG(DC_DISP_CURSOR_POSITION_NS);
        DUMP_REG(DC_DISP_INIT_SEQ_CONTROL);
        DUMP_REG(DC_DISP_SPI_INIT_SEQ_DATA_A);
        DUMP_REG(DC_DISP_SPI_INIT_SEQ_DATA_B);
        DUMP_REG(DC_DISP_SPI_INIT_SEQ_DATA_C);
        DUMP_REG(DC_DISP_SPI_INIT_SEQ_DATA_D);
        DUMP_REG(DC_DISP_DC_MCCIF_FIFOCTRL);
        DUMP_REG(DC_DISP_MCCIF_DISPLAY0A_HYST);
        DUMP_REG(DC_DISP_MCCIF_DISPLAY0B_HYST);
        DUMP_REG(DC_DISP_MCCIF_DISPLAY1A_HYST);
        DUMP_REG(DC_DISP_MCCIF_DISPLAY1B_HYST);
        DUMP_REG(DC_DISP_DAC_CRT_CTRL);
        DUMP_REG(DC_DISP_DISP_MISC_CONTROL);
        DUMP_REG(DC_DISP_SD_CONTROL);
        DUMP_REG(DC_DISP_SD_CSC_COEFF);
        DUMP_REG(DC_DISP_SD_LUT(0));
        DUMP_REG(DC_DISP_SD_LUT(1));
        DUMP_REG(DC_DISP_SD_LUT(2));
        DUMP_REG(DC_DISP_SD_LUT(3));
        DUMP_REG(DC_DISP_SD_LUT(4));
        DUMP_REG(DC_DISP_SD_LUT(5));
        DUMP_REG(DC_DISP_SD_LUT(6));
        DUMP_REG(DC_DISP_SD_LUT(7));
        DUMP_REG(DC_DISP_SD_LUT(8));
        DUMP_REG(DC_DISP_SD_FLICKER_CONTROL);
        DUMP_REG(DC_DISP_DC_PIXEL_COUNT);
        DUMP_REG(DC_DISP_SD_HISTOGRAM(0));
        DUMP_REG(DC_DISP_SD_HISTOGRAM(1));
        DUMP_REG(DC_DISP_SD_HISTOGRAM(2));
        DUMP_REG(DC_DISP_SD_HISTOGRAM(3));
        DUMP_REG(DC_DISP_SD_HISTOGRAM(4));
        DUMP_REG(DC_DISP_SD_HISTOGRAM(5));
        DUMP_REG(DC_DISP_SD_HISTOGRAM(6));
        DUMP_REG(DC_DISP_SD_HISTOGRAM(7));
        DUMP_REG(DC_DISP_SD_BL_TF(0));
        DUMP_REG(DC_DISP_SD_BL_TF(1));
        DUMP_REG(DC_DISP_SD_BL_TF(2));
        DUMP_REG(DC_DISP_SD_BL_TF(3));
        DUMP_REG(DC_DISP_SD_BL_CONTROL);
        DUMP_REG(DC_DISP_SD_HW_K_VALUES);
        DUMP_REG(DC_DISP_SD_MAN_K_VALUES);
        DUMP_REG(DC_DISP_CURSOR_START_ADDR_HI);
        DUMP_REG(DC_DISP_BLEND_CURSOR_CONTROL);
        DUMP_REG(DC_WIN_WIN_OPTIONS);
        DUMP_REG(DC_WIN_BYTE_SWAP);
        DUMP_REG(DC_WIN_BUFFER_CONTROL);
        DUMP_REG(DC_WIN_COLOR_DEPTH);
        DUMP_REG(DC_WIN_POSITION);
        DUMP_REG(DC_WIN_SIZE);
        DUMP_REG(DC_WIN_PRESCALED_SIZE);
        DUMP_REG(DC_WIN_H_INITIAL_DDA);
        DUMP_REG(DC_WIN_V_INITIAL_DDA);
        DUMP_REG(DC_WIN_DDA_INC);
        DUMP_REG(DC_WIN_LINE_STRIDE);
        DUMP_REG(DC_WIN_BUF_STRIDE);
        DUMP_REG(DC_WIN_UV_BUF_STRIDE);
        DUMP_REG(DC_WIN_BUFFER_ADDR_MODE);
        DUMP_REG(DC_WIN_DV_CONTROL);
        DUMP_REG(DC_WIN_BLEND_NOKEY);
        DUMP_REG(DC_WIN_BLEND_1WIN);
        DUMP_REG(DC_WIN_BLEND_2WIN_X);
        DUMP_REG(DC_WIN_BLEND_2WIN_Y);
        DUMP_REG(DC_WIN_BLEND_3WIN_XY);
        DUMP_REG(DC_WIN_HP_FETCH_CONTROL);
        DUMP_REG(DC_WINBUF_START_ADDR);
        DUMP_REG(DC_WINBUF_START_ADDR_NS);
        DUMP_REG(DC_WINBUF_START_ADDR_U);
        DUMP_REG(DC_WINBUF_START_ADDR_U_NS);
        DUMP_REG(DC_WINBUF_START_ADDR_V);
        DUMP_REG(DC_WINBUF_START_ADDR_V_NS);
        DUMP_REG(DC_WINBUF_ADDR_H_OFFSET);
        DUMP_REG(DC_WINBUF_ADDR_H_OFFSET_NS);
        DUMP_REG(DC_WINBUF_ADDR_V_OFFSET);
        DUMP_REG(DC_WINBUF_ADDR_V_OFFSET_NS);
        DUMP_REG(DC_WINBUF_UFLOW_STATUS);
        DUMP_REG(DC_WINBUF_AD_UFLOW_STATUS);
        DUMP_REG(DC_WINBUF_BD_UFLOW_STATUS);
        DUMP_REG(DC_WINBUF_CD_UFLOW_STATUS);

#undef DUMP_REG

unlock:
        drm_modeset_unlock_crtc(&dc->base);
        return err;
}

static int tegra_dc_show_crc(struct seq_file *s, void *data)
{
        struct drm_info_node *node = s->private;
        struct tegra_dc *dc = node->info_ent->data;
        int err = 0;
        u32 value;

        drm_modeset_lock_crtc(&dc->base, NULL);

        if (!dc->base.state->active) {
                err = -EBUSY;
                goto unlock;
        }

        value = DC_COM_CRC_CONTROL_ACTIVE_DATA | DC_COM_CRC_CONTROL_ENABLE;
        tegra_dc_writel(dc, value, DC_COM_CRC_CONTROL);
        tegra_dc_commit(dc);

        drm_crtc_wait_one_vblank(&dc->base);
        drm_crtc_wait_one_vblank(&dc->base);

        value = tegra_dc_readl(dc, DC_COM_CRC_CHECKSUM);
        seq_printf(s, "%08x\n", value);

        tegra_dc_writel(dc, 0, DC_COM_CRC_CONTROL);

unlock:
        drm_modeset_unlock_crtc(&dc->base);
        return err;
}

static int tegra_dc_show_stats(struct seq_file *s, void *data)
{
        struct drm_info_node *node = s->private;
        struct tegra_dc *dc = node->info_ent->data;

        seq_printf(s, "frames: %lu\n", dc->stats.frames);
        seq_printf(s, "vblank: %lu\n", dc->stats.vblank);
        seq_printf(s, "underflow: %lu\n", dc->stats.underflow);
        seq_printf(s, "overflow: %lu\n", dc->stats.overflow);

        return 0;
}

static struct drm_info_list debugfs_files[] = {
        { "regs", tegra_dc_show_regs, 0, NULL },
        { "crc", tegra_dc_show_crc, 0, NULL },
        { "stats", tegra_dc_show_stats, 0, NULL },
};

static int tegra_dc_debugfs_init(struct tegra_dc *dc, struct drm_minor *minor)
{
        unsigned int i;
        char *name;
        int err;

        name = kasprintf(GFP_KERNEL, "dc.%d", dc->pipe);
        dc->debugfs = debugfs_create_dir(name, minor->debugfs_root);
        kfree(name);

        if (!dc->debugfs)
                return -ENOMEM;

        dc->debugfs_files = kmemdup(debugfs_files, sizeof(debugfs_files),
                                    GFP_KERNEL);
        if (!dc->debugfs_files) {
                err = -ENOMEM;
                goto remove;
        }

        for (i = 0; i < ARRAY_SIZE(debugfs_files); i++)
                dc->debugfs_files[i].data = dc;

        err = drm_debugfs_create_files(dc->debugfs_files,
                                       ARRAY_SIZE(debugfs_files),
                                       dc->debugfs, minor);
        if (err < 0)
                goto free;

        dc->minor = minor;

        return 0;

free:
        kfree(dc->debugfs_files);
        dc->debugfs_files = NULL;
remove:
        debugfs_remove(dc->debugfs);
        dc->debugfs = NULL;

        return err;
}

static int tegra_dc_debugfs_exit(struct tegra_dc *dc)
{
        drm_debugfs_remove_files(dc->debugfs_files, ARRAY_SIZE(debugfs_files),
                                 dc->minor);
        dc->minor = NULL;

        kfree(dc->debugfs_files);
        dc->debugfs_files = NULL;

        debugfs_remove(dc->debugfs);
        dc->debugfs = NULL;

        return 0;
}

static int tegra_dc_init(struct host1x_client *client)
{
        struct drm_device *drm = dev_get_drvdata(client->parent);
        unsigned long flags = HOST1X_SYNCPT_CLIENT_MANAGED;
        struct tegra_dc *dc = host1x_client_to_dc(client);
        struct tegra_drm *tegra = drm->dev_private;
        struct drm_plane *primary = NULL;
        struct drm_plane *cursor = NULL;
        u32 value;
        int err;

        dc->syncpt = host1x_syncpt_request(dc->dev, flags);
        if (!dc->syncpt)
                dev_warn(dc->dev, "failed to allocate syncpoint\n");

        if (tegra->domain) {
                err = iommu_attach_device(tegra->domain, dc->dev);
                if (err < 0) {
                        dev_err(dc->dev, "failed to attach to domain: %d\n",
                                err);
                        return err;
                }

                dc->domain = tegra->domain;
        }

        primary = tegra_dc_primary_plane_create(drm, dc);
        if (IS_ERR(primary)) {
                err = PTR_ERR(primary);
                goto cleanup;
        }

        if (dc->soc->supports_cursor) {
                cursor = tegra_dc_cursor_plane_create(drm, dc);
                if (IS_ERR(cursor)) {
                        err = PTR_ERR(cursor);
                        goto cleanup;
                }
        }

        err = drm_crtc_init_with_planes(drm, &dc->base, primary, cursor,
                                        &tegra_crtc_funcs);
        if (err < 0)
                goto cleanup;

        drm_mode_crtc_set_gamma_size(&dc->base, 256);
        drm_crtc_helper_add(&dc->base, &tegra_crtc_helper_funcs);

        /*
         * Keep track of the minimum pitch alignment across all display
         * controllers.
         */
        if (dc->soc->pitch_align > tegra->pitch_align)
                tegra->pitch_align = dc->soc->pitch_align;

        err = tegra_dc_rgb_init(drm, dc);
        if (err < 0 && err != -ENODEV) {
                dev_err(dc->dev, "failed to initialize RGB output: %d\n", err);
                goto cleanup;
        }

        err = tegra_dc_add_planes(drm, dc);
        if (err < 0)
                goto cleanup;

        if (IS_ENABLED(CONFIG_DEBUG_FS)) {
                err = tegra_dc_debugfs_init(dc, drm->primary);
                if (err < 0)
                        dev_err(dc->dev, "debugfs setup failed: %d\n", err);
        }

        err = devm_request_irq(dc->dev, dc->irq, tegra_dc_irq, 0,
                               dev_name(dc->dev), dc);
        if (err < 0) {
                dev_err(dc->dev, "failed to request IRQ#%u: %d\n", dc->irq,
                        err);
                goto cleanup;
        }

        /* initialize display controller */
        if (dc->syncpt) {
                u32 syncpt = host1x_syncpt_id(dc->syncpt);

                value = SYNCPT_CNTRL_NO_STALL;
                tegra_dc_writel(dc, value, DC_CMD_GENERAL_INCR_SYNCPT_CNTRL);

                value = SYNCPT_VSYNC_ENABLE | syncpt;
                tegra_dc_writel(dc, value, DC_CMD_CONT_SYNCPT_VSYNC);
        }

        value = WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT |
                WIN_A_OF_INT | WIN_B_OF_INT | WIN_C_OF_INT;
        tegra_dc_writel(dc, value, DC_CMD_INT_TYPE);

        value = WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT |
                WIN_A_OF_INT | WIN_B_OF_INT | WIN_C_OF_INT;
        tegra_dc_writel(dc, value, DC_CMD_INT_POLARITY);

        /* initialize timer */
        value = CURSOR_THRESHOLD(0) | WINDOW_A_THRESHOLD(0x20) |
                WINDOW_B_THRESHOLD(0x20) | WINDOW_C_THRESHOLD(0x20);
        tegra_dc_writel(dc, value, DC_DISP_DISP_MEM_HIGH_PRIORITY);

        value = CURSOR_THRESHOLD(0) | WINDOW_A_THRESHOLD(1) |
                WINDOW_B_THRESHOLD(1) | WINDOW_C_THRESHOLD(1);
        tegra_dc_writel(dc, value, DC_DISP_DISP_MEM_HIGH_PRIORITY_TIMER);

        value = VBLANK_INT | WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT |
                WIN_A_OF_INT | WIN_B_OF_INT | WIN_C_OF_INT;
        tegra_dc_writel(dc, value, DC_CMD_INT_ENABLE);

        value = WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT |
                WIN_A_OF_INT | WIN_B_OF_INT | WIN_C_OF_INT;
        tegra_dc_writel(dc, value, DC_CMD_INT_MASK);

        if (dc->soc->supports_border_color)
                tegra_dc_writel(dc, 0, DC_DISP_BORDER_COLOR);

        tegra_dc_stats_reset(&dc->stats);

        return 0;

cleanup:
        if (cursor)
                drm_plane_cleanup(cursor);

        if (primary)
                drm_plane_cleanup(primary);

        if (tegra->domain) {
                iommu_detach_device(tegra->domain, dc->dev);
                dc->domain = NULL;
        }

        return err;
}

static int tegra_dc_exit(struct host1x_client *client)
{
        struct tegra_dc *dc = host1x_client_to_dc(client);
        int err;

        devm_free_irq(dc->dev, dc->irq, dc);

        if (IS_ENABLED(CONFIG_DEBUG_FS)) {
                err = tegra_dc_debugfs_exit(dc);
                if (err < 0)
                        dev_err(dc->dev, "debugfs cleanup failed: %d\n", err);
        }

        err = tegra_dc_rgb_exit(dc);
        if (err) {
                dev_err(dc->dev, "failed to shutdown RGB output: %d\n", err);
                return err;
        }

        if (dc->domain) {
                iommu_detach_device(dc->domain, dc->dev);
                dc->domain = NULL;
        }

        host1x_syncpt_free(dc->syncpt);

        return 0;
}

static const struct host1x_client_ops dc_client_ops = {
        .init = tegra_dc_init,
        .exit = tegra_dc_exit,
};

static const struct tegra_dc_soc_info tegra20_dc_soc_info = {
        .supports_border_color = true,
        .supports_interlacing = false,
        .supports_cursor = false,
        .supports_block_linear = false,
        .pitch_align = 8,
        .has_powergate = false,
};

static const struct tegra_dc_soc_info tegra30_dc_soc_info = {
        .supports_border_color = true,
        .supports_interlacing = false,
        .supports_cursor = false,
        .supports_block_linear = false,
        .pitch_align = 8,
        .has_powergate = false,
};

static const struct tegra_dc_soc_info tegra114_dc_soc_info = {
        .supports_border_color = true,
        .supports_interlacing = false,
        .supports_cursor = false,
        .supports_block_linear = false,
        .pitch_align = 64,
        .has_powergate = true,
};

static const struct tegra_dc_soc_info tegra124_dc_soc_info = {
        .supports_border_color = false,
        .supports_interlacing = true,
        .supports_cursor = true,
        .supports_block_linear = true,
        .pitch_align = 64,
        .has_powergate = true,
};

static const struct tegra_dc_soc_info tegra210_dc_soc_info = {
        .supports_border_color = false,
        .supports_interlacing = true,
        .supports_cursor = true,
        .supports_block_linear = true,
        .pitch_align = 64,
        .has_powergate = true,
};

static const struct of_device_id tegra_dc_of_match[] = {
        {
                .compatible = "nvidia,tegra210-dc",
                .data = &tegra210_dc_soc_info,
        }, {
                .compatible = "nvidia,tegra124-dc",
                .data = &tegra124_dc_soc_info,
        }, {
                .compatible = "nvidia,tegra114-dc",
                .data = &tegra114_dc_soc_info,
        }, {
                .compatible = "nvidia,tegra30-dc",
                .data = &tegra30_dc_soc_info,
        }, {
                .compatible = "nvidia,tegra20-dc",
                .data = &tegra20_dc_soc_info,
        }, {
                /* sentinel */
        }
};
MODULE_DEVICE_TABLE(of, tegra_dc_of_match);

static int tegra_dc_parse_dt(struct tegra_dc *dc)
{
        struct device_node *np;
        u32 value = 0;
        int err;

        err = of_property_read_u32(dc->dev->of_node, "nvidia,head", &value);
        if (err < 0) {
                dev_err(dc->dev, "missing \"nvidia,head\" property\n");

                /*
                 * If the nvidia,head property isn't present, try to find the
                 * correct head number by looking up the position of this
                 * display controller's node within the device tree. Assuming
                 * that the nodes are ordered properly in the DTS file and
                 * that the translation into a flattened device tree blob
                 * preserves that ordering this will actually yield the right
                 * head number.
                 *
                 * If those assumptions don't hold, this will still work for
                 * cases where only a single display controller is used.
                 */
                for_each_matching_node(np, tegra_dc_of_match) {
                        if (np == dc->dev->of_node)
                                break;

                        value++;
                }
        }

        dc->pipe = value;

        return 0;
}

static int tegra_dc_probe(struct platform_device *pdev)
{
        const struct of_device_id *id;
        struct resource *regs;
        struct tegra_dc *dc;
        int err;

        dc = devm_kzalloc(&pdev->dev, sizeof(*dc), GFP_KERNEL);
        if (!dc)
                return -ENOMEM;

        id = of_match_node(tegra_dc_of_match, pdev->dev.of_node);
        if (!id)
                return -ENODEV;

        spin_lock_init(&dc->lock);
        INIT_LIST_HEAD(&dc->list);
        dc->dev = &pdev->dev;
        dc->soc = id->data;

        err = tegra_dc_parse_dt(dc);
        if (err < 0)
                return err;

        dc->clk = devm_clk_get(&pdev->dev, NULL);
        if (IS_ERR(dc->clk)) {
                dev_err(&pdev->dev, "failed to get clock\n");
                return PTR_ERR(dc->clk);
        }

        dc->rst = devm_reset_control_get(&pdev->dev, "dc");
        if (IS_ERR(dc->rst)) {
                dev_err(&pdev->dev, "failed to get reset\n");
                return PTR_ERR(dc->rst);

        }

        if (dc->soc->has_powergate) {
                if (dc->pipe == 0)
                        dc->powergate = TEGRA_POWERGATE_DIS;
                else
                        dc->powergate = TEGRA_POWERGATE_DISB;

                err = tegra_powergate_sequence_power_up(dc->powergate, dc->clk,
                                                        dc->rst);
                if (err < 0) {
                        dev_err(&pdev->dev, "failed to power partition: %d\n",
                                err);
                        return err;
                }
        } else {
                err = clk_prepare_enable(dc->clk);
                if (err < 0) {
                        dev_err(&pdev->dev, "failed to enable clock: %d\n",
                                err);
                        return err;
                }

                err = reset_control_deassert(dc->rst);
                if (err < 0) {
                        dev_err(&pdev->dev, "failed to deassert reset: %d\n",
                                err);
                        return err;
                }
        }

        regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        dc->regs = devm_ioremap_resource(&pdev->dev, regs);
        if (IS_ERR(dc->regs))
                return PTR_ERR(dc->regs);

        dc->irq = platform_get_irq(pdev, 0);
        if (dc->irq < 0) {
                dev_err(&pdev->dev, "failed to get IRQ\n");
                return -ENXIO;
        }

        INIT_LIST_HEAD(&dc->client.list);
        dc->client.ops = &dc_client_ops;
        dc->client.dev = &pdev->dev;

        err = tegra_dc_rgb_probe(dc);
        if (err < 0 && err != -ENODEV) {
                dev_err(&pdev->dev, "failed to probe RGB output: %d\n", err);
                return err;
        }

        err = host1x_client_register(&dc->client);
        if (err < 0) {
                dev_err(&pdev->dev, "failed to register host1x client: %d\n",
                        err);
                return err;
        }

        platform_set_drvdata(pdev, dc);

        return 0;
}

static int tegra_dc_remove(struct platform_device *pdev)
{
        struct tegra_dc *dc = platform_get_drvdata(pdev);
        int err;

        err = host1x_client_unregister(&dc->client);
        if (err < 0) {
                dev_err(&pdev->dev, "failed to unregister host1x client: %d\n",
                        err);
                return err;
        }

        err = tegra_dc_rgb_remove(dc);
        if (err < 0) {
                dev_err(&pdev->dev, "failed to remove RGB output: %d\n", err);
                return err;
        }

        reset_control_assert(dc->rst);

        if (dc->soc->has_powergate)
                tegra_powergate_power_off(dc->powergate);

        clk_disable_unprepare(dc->clk);

        return 0;
}

struct platform_driver tegra_dc_driver = {
        .driver = {
                .name = "tegra-dc",
                .of_match_table = tegra_dc_of_match,
        },
        .probe = tegra_dc_probe,
        .remove = tegra_dc_remove,
};