/*
 * Copyright 2012 Red Hat Inc.
 * Parts based on xf86-video-ast
 * Copyright (c) 2005 ASPEED Technology Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 */
/*
 * Authors: Dave Airlie <airlied@redhat.com>
 */

#include <linux/delay.h>
#include <linux/pci.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_color_mgmt.h>
#include <drm/drm_crtc.h>
#include <drm/drm_damage_helper.h>
#include <drm/drm_format_helper.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_gem_shmem_helper.h>
#include <drm/drm_managed.h>
#include <drm/drm_panic.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>

#include "ast_drv.h"
#include "ast_tables.h"
#include "ast_vbios.h"

#define AST_LUT_SIZE 256

#define AST_PRIMARY_PLANE_MAX_OFFSET    (BIT(16) - 1)

static unsigned long ast_fb_vram_offset(void)
{
        return 0; // with shmem, the primary plane is always at offset 0
}

static unsigned long ast_fb_vram_size(struct ast_device *ast)
{
        struct drm_device *dev = &ast->base;
        unsigned long offset = ast_fb_vram_offset(); // starts at offset
        long cursor_offset = ast_cursor_vram_offset(ast); // ends at cursor offset

        if (cursor_offset < 0)
                cursor_offset = ast->vram_size; // no cursor; it's all ours
        if (drm_WARN_ON_ONCE(dev, offset > cursor_offset))
                return 0; // cannot legally happen; signal error
        return cursor_offset - offset;
}

static void ast_set_gamma_lut(struct drm_crtc *crtc, unsigned int index,
                              u16 red, u16 green, u16 blue)
{
        struct drm_device *dev = crtc->dev;
        struct ast_device *ast = to_ast_device(dev);
        u8 i8 = index & 0xff;
        u8 r8 = red >> 8;
        u8 g8 = green >> 8;
        u8 b8 = blue >> 8;

        if (drm_WARN_ON_ONCE(dev, index != i8))
                return; /* driver bug */

        ast_io_write8(ast, AST_IO_VGADWR, i8);
        ast_io_read8(ast, AST_IO_VGASRI);
        ast_io_write8(ast, AST_IO_VGAPDR, r8);
        ast_io_read8(ast, AST_IO_VGASRI);
        ast_io_write8(ast, AST_IO_VGAPDR, g8);
        ast_io_read8(ast, AST_IO_VGASRI);
        ast_io_write8(ast, AST_IO_VGAPDR, b8);
        ast_io_read8(ast, AST_IO_VGASRI);
}

static void ast_crtc_fill_gamma(struct ast_device *ast,
                                const struct drm_format_info *format)
{
        struct drm_crtc *crtc = &ast->crtc;

        switch (format->format) {
        case DRM_FORMAT_C8:
                /* gamma table is used as color palette */
                drm_crtc_fill_palette_8(crtc, ast_set_gamma_lut);
                break;
        case DRM_FORMAT_RGB565:
                /* also uses 8-bit gamma ramp on low-color modes */
                fallthrough;
        case DRM_FORMAT_XRGB8888:
                drm_crtc_fill_gamma_888(crtc, ast_set_gamma_lut);
                break;
        default:
                drm_warn_once(&ast->base, "Unsupported format %p4cc for gamma correction\n",
                              &format->format);
                break;
        }
}

static void ast_crtc_load_gamma(struct ast_device *ast,
                                const struct drm_format_info *format,
                                struct drm_color_lut *lut)
{
        struct drm_crtc *crtc = &ast->crtc;

        switch (format->format) {
        case DRM_FORMAT_C8:
                /* gamma table is used as color palette */
                drm_crtc_load_palette_8(crtc, lut, ast_set_gamma_lut);
                break;
        case DRM_FORMAT_RGB565:
                /* also uses 8-bit gamma ramp on low-color modes */
                fallthrough;
        case DRM_FORMAT_XRGB8888:
                drm_crtc_load_gamma_888(crtc, lut, ast_set_gamma_lut);
                break;
        default:
                drm_warn_once(&ast->base, "Unsupported format %p4cc for gamma correction\n",
                              &format->format);
                break;
        }
}

static void ast_set_vbios_color_reg(struct ast_device *ast,
                                    const struct drm_format_info *format,
                                    const struct ast_vbios_enhtable *vmode)
{
        u32 color_index;

        switch (format->cpp[0]) {
        case 1:
                color_index = VGAModeIndex - 1;
                break;
        case 2:
                color_index = HiCModeIndex;
                break;
        case 3:
        case 4:
                color_index = TrueCModeIndex;
                break;
        default:
                return;
        }

        ast_set_index_reg(ast, AST_IO_VGACRI, 0x8c, (u8)((color_index & 0x0f) << 4));

        ast_set_index_reg(ast, AST_IO_VGACRI, 0x91, 0x00);

        if (vmode->flags & NewModeInfo) {
                ast_set_index_reg(ast, AST_IO_VGACRI, 0x91, 0xa8);
                ast_set_index_reg(ast, AST_IO_VGACRI, 0x92, format->cpp[0] * 8);
        }
}

static void ast_set_vbios_mode_reg(struct ast_device *ast,
                                   const struct drm_display_mode *adjusted_mode,
                                   const struct ast_vbios_enhtable *vmode)
{
        u32 refresh_rate_index, mode_id;

        refresh_rate_index = vmode->refresh_rate_index;
        mode_id = vmode->mode_id;

        ast_set_index_reg(ast, AST_IO_VGACRI, 0x8d, refresh_rate_index & 0xff);
        ast_set_index_reg(ast, AST_IO_VGACRI, 0x8e, mode_id & 0xff);

        ast_set_index_reg(ast, AST_IO_VGACRI, 0x91, 0x00);

        if (vmode->flags & NewModeInfo) {
                ast_set_index_reg(ast, AST_IO_VGACRI, 0x91, 0xa8);
                ast_set_index_reg(ast, AST_IO_VGACRI, 0x93, adjusted_mode->clock / 1000);
                ast_set_index_reg(ast, AST_IO_VGACRI, 0x94, adjusted_mode->crtc_hdisplay);
                ast_set_index_reg(ast, AST_IO_VGACRI, 0x95, adjusted_mode->crtc_hdisplay >> 8);
                ast_set_index_reg(ast, AST_IO_VGACRI, 0x96, adjusted_mode->crtc_vdisplay);
                ast_set_index_reg(ast, AST_IO_VGACRI, 0x97, adjusted_mode->crtc_vdisplay >> 8);
        }
}

static void ast_set_std_reg(struct ast_device *ast,
                            struct drm_display_mode *mode,
                            const struct ast_vbios_stdtable *stdtable)
{
        u32 i;
        u8 jreg;

        jreg = stdtable->misc;
        ast_io_write8(ast, AST_IO_VGAMR_W, jreg);

        /* Set SEQ; except Screen Disable field */
        ast_set_index_reg(ast, AST_IO_VGASRI, 0x00, 0x03);
        ast_set_index_reg_mask(ast, AST_IO_VGASRI, 0x01, 0x20, stdtable->seq[0]);
        for (i = 1; i < 4; i++) {
                jreg = stdtable->seq[i];
                ast_set_index_reg(ast, AST_IO_VGASRI, (i + 1), jreg);
        }

        /* Set CRTC; except base address and offset */
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x11, 0x7f, 0x00);
        for (i = 0; i < 12; i++)
                ast_set_index_reg(ast, AST_IO_VGACRI, i, stdtable->crtc[i]);
        for (i = 14; i < 19; i++)
                ast_set_index_reg(ast, AST_IO_VGACRI, i, stdtable->crtc[i]);
        for (i = 20; i < 25; i++)
                ast_set_index_reg(ast, AST_IO_VGACRI, i, stdtable->crtc[i]);

        /* set AR */
        jreg = ast_io_read8(ast, AST_IO_VGAIR1_R);
        for (i = 0; i < 20; i++) {
                jreg = stdtable->ar[i];
                ast_io_write8(ast, AST_IO_VGAARI_W, (u8)i);
                ast_io_write8(ast, AST_IO_VGAARI_W, jreg);
        }
        ast_io_write8(ast, AST_IO_VGAARI_W, 0x14);
        ast_io_write8(ast, AST_IO_VGAARI_W, 0x00);

        jreg = ast_io_read8(ast, AST_IO_VGAIR1_R);
        ast_io_write8(ast, AST_IO_VGAARI_W, 0x20);

        /* Set GR */
        for (i = 0; i < 9; i++)
                ast_set_index_reg(ast, AST_IO_VGAGRI, i, stdtable->gr[i]);
}

static void ast_set_crtc_reg(struct ast_device *ast, struct drm_display_mode *mode,
                             const struct ast_vbios_enhtable *vmode)
{
        u8 jreg05 = 0, jreg07 = 0, jreg09 = 0, jregAC = 0, jregAD = 0, jregAE = 0;
        u16 temp;
        unsigned char crtc_hsync_precatch = 0;

        if (ast->quirks->crtc_hsync_precatch_needed && (vmode->flags & AST2500PreCatchCRT))
                crtc_hsync_precatch = 40;

        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x11, 0x7f, 0x00);

        temp = (mode->crtc_htotal >> 3) - 5;
        if (temp & 0x100)
                jregAC |= 0x01; /* HT D[8] */
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x00, 0x00, temp);

        temp = (mode->crtc_hdisplay >> 3) - 1;
        if (temp & 0x100)
                jregAC |= 0x04; /* HDE D[8] */
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x01, 0x00, temp);

        temp = (mode->crtc_hblank_start >> 3) - 1;
        if (temp & 0x100)
                jregAC |= 0x10; /* HBS D[8] */
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x02, 0x00, temp);

        temp = ((mode->crtc_hblank_end >> 3) - 1) & 0x7f;
        if (temp & 0x20)
                jreg05 |= 0x80;  /* HBE D[5] */
        if (temp & 0x40)
                jregAD |= 0x01;  /* HBE D[5] */
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x03, 0xE0, (temp & 0x1f));

        temp = ((mode->crtc_hsync_start - crtc_hsync_precatch) >> 3) - 1;
        if (temp & 0x100)
                jregAC |= 0x40; /* HRS D[5] */
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x04, 0x00, temp);

        temp = (((mode->crtc_hsync_end - crtc_hsync_precatch) >> 3) - 1) & 0x3f;
        if (temp & 0x20)
                jregAD |= 0x04; /* HRE D[5] */
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x05, 0x60, (u8)((temp & 0x1f) | jreg05));

        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xAC, 0x00, jregAC);
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xAD, 0x00, jregAD);

        if (ast->quirks->crtc_hsync_add4_needed && mode->crtc_vdisplay == 1080)
                ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xFC, 0xFD, 0x02);
        else
                ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xFC, 0xFD, 0x00);

        /* vert timings */
        temp = (mode->crtc_vtotal) - 2;
        if (temp & 0x100)
                jreg07 |= 0x01;
        if (temp & 0x200)
                jreg07 |= 0x20;
        if (temp & 0x400)
                jregAE |= 0x01;
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x06, 0x00, temp);

        temp = (mode->crtc_vsync_start) - 1;
        if (temp & 0x100)
                jreg07 |= 0x04;
        if (temp & 0x200)
                jreg07 |= 0x80;
        if (temp & 0x400)
                jregAE |= 0x08;
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x10, 0x00, temp);

        temp = (mode->crtc_vsync_end - 1) & 0x3f;
        if (temp & 0x10)
                jregAE |= 0x20;
        if (temp & 0x20)
                jregAE |= 0x40;
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x11, 0x70, temp & 0xf);

        temp = mode->crtc_vdisplay - 1;
        if (temp & 0x100)
                jreg07 |= 0x02;
        if (temp & 0x200)
                jreg07 |= 0x40;
        if (temp & 0x400)
                jregAE |= 0x02;
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x12, 0x00, temp);

        temp = mode->crtc_vblank_start - 1;
        if (temp & 0x100)
                jreg07 |= 0x08;
        if (temp & 0x200)
                jreg09 |= 0x20;
        if (temp & 0x400)
                jregAE |= 0x04;
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x15, 0x00, temp);

        temp = mode->crtc_vblank_end - 1;
        if (temp & 0x100)
                jregAE |= 0x10;
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x16, 0x00, temp);

        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x07, 0x00, jreg07);
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x09, 0xdf, jreg09);
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xAE, 0x00, (jregAE | 0x80));

        if (crtc_hsync_precatch)
                ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xb6, 0x3f, 0x80);
        else
                ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xb6, 0x3f, 0x00);

        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x11, 0x7f, 0x80);
}

static void ast_set_offset_reg(struct ast_device *ast,
                               struct drm_framebuffer *fb)
{
        u16 offset;

        offset = fb->pitches[0] >> 3;
        ast_set_index_reg(ast, AST_IO_VGACRI, 0x13, (offset & 0xff));
        ast_set_index_reg(ast, AST_IO_VGACRI, 0xb0, (offset >> 8) & 0x3f);
}

static void ast_set_dclk_reg(struct ast_device *ast,
                             struct drm_display_mode *mode,
                             const struct ast_vbios_enhtable *vmode)
{
        const struct ast_vbios_dclk_info *clk_info = &ast->dclk_table[vmode->dclk_index];

        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xc0, 0x00, clk_info->param1);
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xc1, 0x00, clk_info->param2);
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xbb, 0x0f,
                               (clk_info->param3 & 0xc0) |
                               ((clk_info->param3 & 0x3) << 4));
}

static void ast_set_color_reg(struct ast_device *ast,
                              const struct drm_format_info *format)
{
        u8 jregA0 = 0, jregA3 = 0, jregA8 = 0;

        switch (format->cpp[0] * 8) {
        case 8:
                jregA0 = 0x70;
                jregA3 = 0x01;
                jregA8 = 0x00;
                break;
        case 15:
        case 16:
                jregA0 = 0x70;
                jregA3 = 0x04;
                jregA8 = 0x02;
                break;
        case 32:
                jregA0 = 0x70;
                jregA3 = 0x08;
                jregA8 = 0x02;
                break;
        }

        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xa0, 0x8f, jregA0);
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xa3, 0xf0, jregA3);
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xa8, 0xfd, jregA8);
}

static void ast_set_crtthd_reg(struct ast_device *ast)
{
        u8 vgacra6 = ast->quirks->crtc_mem_req_threshold_low;
        u8 vgacra7 = ast->quirks->crtc_mem_req_threshold_high;

        ast_set_index_reg(ast, AST_IO_VGACRI, 0xa7, vgacra7);
        ast_set_index_reg(ast, AST_IO_VGACRI, 0xa6, vgacra6);
}

static void ast_set_sync_reg(struct ast_device *ast,
                             struct drm_display_mode *mode,
                             const struct ast_vbios_enhtable *vmode)
{
        u8 jreg;

        jreg  = ast_io_read8(ast, AST_IO_VGAMR_R);
        jreg &= ~0xC0;
        if (vmode->flags & NVSync)
                jreg |= 0x80;
        if (vmode->flags & NHSync)
                jreg |= 0x40;
        ast_io_write8(ast, AST_IO_VGAMR_W, jreg);
}

static void ast_set_start_address_crt1(struct ast_device *ast,
                                       unsigned int offset)
{
        u32 addr;

        addr = offset >> 2;
        ast_set_index_reg(ast, AST_IO_VGACRI, 0x0d, (u8)(addr & 0xff));
        ast_set_index_reg(ast, AST_IO_VGACRI, 0x0c, (u8)((addr >> 8) & 0xff));
        ast_set_index_reg(ast, AST_IO_VGACRI, 0xaf, (u8)((addr >> 16) & 0xff));

}

static void ast_wait_for_vretrace(struct ast_device *ast)
{
        unsigned long timeout = jiffies + HZ;
        u8 vgair1;

        do {
                vgair1 = ast_io_read8(ast, AST_IO_VGAIR1_R);
        } while (!(vgair1 & AST_IO_VGAIR1_VREFRESH) && time_before(jiffies, timeout));
}

/*
 * Planes
 */

int ast_plane_init(struct drm_device *dev, struct ast_plane *ast_plane,
                   u64 offset, unsigned long size,
                   uint32_t possible_crtcs,
                   const struct drm_plane_funcs *funcs,
                   const uint32_t *formats, unsigned int format_count,
                   const uint64_t *format_modifiers,
                   enum drm_plane_type type)
{
        struct drm_plane *plane = &ast_plane->base;

        ast_plane->offset = offset;
        ast_plane->size = size;

        return drm_universal_plane_init(dev, plane, possible_crtcs, funcs,
                                        formats, format_count, format_modifiers,
                                        type, NULL);
}

void __iomem *ast_plane_vaddr(struct ast_plane *ast_plane)
{
        struct ast_device *ast = to_ast_device(ast_plane->base.dev);

        return ast->vram + ast_plane->offset;
}

/*
 * Primary plane
 */

static const uint32_t ast_primary_plane_formats[] = {
        DRM_FORMAT_XRGB8888,
        DRM_FORMAT_RGB565,
        DRM_FORMAT_C8,
};

static int ast_primary_plane_helper_atomic_check(struct drm_plane *plane,
                                                 struct drm_atomic_state *state)
{
        struct drm_device *dev = plane->dev;
        struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane);
        struct drm_crtc_state *new_crtc_state = NULL;
        struct ast_crtc_state *new_ast_crtc_state;
        int ret;

        if (new_plane_state->crtc)
                new_crtc_state = drm_atomic_get_new_crtc_state(state, new_plane_state->crtc);

        ret = drm_atomic_helper_check_plane_state(new_plane_state, new_crtc_state,
                                                  DRM_PLANE_NO_SCALING,
                                                  DRM_PLANE_NO_SCALING,
                                                  false, true);
        if (ret) {
                return ret;
        } else if (!new_plane_state->visible) {
                if (drm_WARN_ON(dev, new_plane_state->crtc)) /* cannot legally happen */
                        return -EINVAL;
                else
                        return 0;
        }

        new_ast_crtc_state = to_ast_crtc_state(new_crtc_state);

        new_ast_crtc_state->format = new_plane_state->fb->format;

        return 0;
}

static void ast_handle_damage(struct ast_plane *ast_plane, struct iosys_map *src,
                              struct drm_framebuffer *fb,
                              const struct drm_rect *clip,
                              struct drm_format_conv_state *fmtcnv_state)
{
        struct iosys_map dst = IOSYS_MAP_INIT_VADDR_IOMEM(ast_plane_vaddr(ast_plane));

        iosys_map_incr(&dst, drm_fb_clip_offset(fb->pitches[0], fb->format, clip));

#if defined(__BIG_ENDIAN)
        drm_fb_swab(&dst, fb->pitches, src, fb, clip, !src[0].is_iomem, fmtcnv_state);
#else
        drm_fb_memcpy(&dst, fb->pitches, src, fb, clip);
#endif
}

static void ast_primary_plane_helper_atomic_update(struct drm_plane *plane,
                                                   struct drm_atomic_state *state)
{
        struct drm_device *dev = plane->dev;
        struct ast_device *ast = to_ast_device(dev);
        struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
        struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
        struct drm_framebuffer *fb = plane_state->fb;
        struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
        struct drm_framebuffer *old_fb = old_plane_state->fb;
        struct ast_plane *ast_plane = to_ast_plane(plane);
        struct drm_crtc *crtc = plane_state->crtc;
        struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
        struct drm_rect damage;
        struct drm_atomic_helper_damage_iter iter;

        if (!old_fb || (fb->format != old_fb->format) || crtc_state->mode_changed) {
                struct ast_crtc_state *ast_crtc_state = to_ast_crtc_state(crtc_state);

                ast_set_color_reg(ast, fb->format);
                ast_set_vbios_color_reg(ast, fb->format, ast_crtc_state->vmode);
        }

        /* if the buffer comes from another device */
        if (drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE) == 0) {
                drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
                drm_atomic_for_each_plane_damage(&iter, &damage) {
                        ast_handle_damage(ast_plane, shadow_plane_state->data, fb, &damage,
                                          &shadow_plane_state->fmtcnv_state);
                }

                drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
        }

        /*
         * Some BMCs stop scanning out the video signal after the driver
         * reprogrammed the offset. This stalls display output for several
         * seconds and makes the display unusable. Therefore only update
         * the offset if it changes.
         */
        if (!old_fb || old_fb->pitches[0] != fb->pitches[0])
                ast_set_offset_reg(ast, fb);
}

static void ast_primary_plane_helper_atomic_enable(struct drm_plane *plane,
                                                   struct drm_atomic_state *state)
{
        struct ast_device *ast = to_ast_device(plane->dev);
        struct ast_plane *ast_plane = to_ast_plane(plane);

        /*
         * Some BMCs stop scanning out the video signal after the driver
         * reprogrammed the scanout address. This stalls display
         * output for several seconds and makes the display unusable.
         * Therefore only reprogram the address after enabling the plane.
         */
        ast_set_start_address_crt1(ast, (u32)ast_plane->offset);
}

static void ast_primary_plane_helper_atomic_disable(struct drm_plane *plane,
                                                    struct drm_atomic_state *state)
{
        /*
         * Keep this empty function to avoid calling
         * atomic_update when disabling the plane.
         */
}

static int ast_primary_plane_helper_get_scanout_buffer(struct drm_plane *plane,
                                                       struct drm_scanout_buffer *sb)
{
        struct ast_plane *ast_plane = to_ast_plane(plane);

        if (plane->state && plane->state->fb) {
                sb->format = plane->state->fb->format;
                sb->width = plane->state->fb->width;
                sb->height = plane->state->fb->height;
                sb->pitch[0] = plane->state->fb->pitches[0];
                iosys_map_set_vaddr_iomem(&sb->map[0], ast_plane_vaddr(ast_plane));
                return 0;
        }
        return -ENODEV;
}

static const struct drm_plane_helper_funcs ast_primary_plane_helper_funcs = {
        DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
        .atomic_check = ast_primary_plane_helper_atomic_check,
        .atomic_update = ast_primary_plane_helper_atomic_update,
        .atomic_enable = ast_primary_plane_helper_atomic_enable,
        .atomic_disable = ast_primary_plane_helper_atomic_disable,
        .get_scanout_buffer = ast_primary_plane_helper_get_scanout_buffer,
};

static const struct drm_plane_funcs ast_primary_plane_funcs = {
        .update_plane = drm_atomic_helper_update_plane,
        .disable_plane = drm_atomic_helper_disable_plane,
        .destroy = drm_plane_cleanup,
        DRM_GEM_SHADOW_PLANE_FUNCS,
};

static int ast_primary_plane_init(struct ast_device *ast)
{
        struct drm_device *dev = &ast->base;
        struct ast_plane *ast_primary_plane = &ast->primary_plane;
        struct drm_plane *primary_plane = &ast_primary_plane->base;
        u64 offset = ast_fb_vram_offset();
        unsigned long size = ast_fb_vram_size(ast);
        int ret;

        ret = ast_plane_init(dev, ast_primary_plane, offset, size,
                             0x01, &ast_primary_plane_funcs,
                             ast_primary_plane_formats, ARRAY_SIZE(ast_primary_plane_formats),
                             NULL, DRM_PLANE_TYPE_PRIMARY);
        if (ret) {
                drm_err(dev, "ast_plane_init() failed: %d\n", ret);
                return ret;
        }
        drm_plane_helper_add(primary_plane, &ast_primary_plane_helper_funcs);
        drm_plane_enable_fb_damage_clips(primary_plane);

        return 0;
}

/*
 * CRTC
 */

static enum drm_mode_status
ast_crtc_helper_mode_valid(struct drm_crtc *crtc, const struct drm_display_mode *mode)
{
        struct ast_device *ast = to_ast_device(crtc->dev);
        const struct ast_vbios_enhtable *vmode;

        vmode = ast_vbios_find_mode(ast, mode);
        if (!vmode)
                return MODE_NOMODE;

        return MODE_OK;
}

static void ast_crtc_helper_mode_set_nofb(struct drm_crtc *crtc)
{
        struct drm_device *dev = crtc->dev;
        struct ast_device *ast = to_ast_device(dev);
        struct drm_crtc_state *crtc_state = crtc->state;
        struct ast_crtc_state *ast_crtc_state = to_ast_crtc_state(crtc_state);
        const struct ast_vbios_stdtable *std_table = ast_crtc_state->std_table;
        const struct ast_vbios_enhtable *vmode = ast_crtc_state->vmode;
        struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;

        /*
         * Ensure that no scanout takes place before reprogramming mode
         * and format registers.
         *
         * TODO: Get vblank interrupts working and remove this line.
         */
        ast_wait_for_vretrace(ast);

        ast_set_vbios_mode_reg(ast, adjusted_mode, vmode);
        ast_set_index_reg(ast, AST_IO_VGACRI, 0xa1, 0x06);
        ast_set_std_reg(ast, adjusted_mode, std_table);
        ast_set_crtc_reg(ast, adjusted_mode, vmode);
        ast_set_dclk_reg(ast, adjusted_mode, vmode);
        ast_set_crtthd_reg(ast);
        ast_set_sync_reg(ast, adjusted_mode, vmode);
}

static int ast_crtc_helper_atomic_check(struct drm_crtc *crtc,
                                        struct drm_atomic_state *state)
{
        struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
        struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
        struct drm_crtc_state *old_crtc_state = drm_atomic_get_old_crtc_state(state, crtc);
        struct ast_crtc_state *old_ast_crtc_state = to_ast_crtc_state(old_crtc_state);
        struct drm_device *dev = crtc->dev;
        struct ast_device *ast = to_ast_device(dev);
        struct ast_crtc_state *ast_state;
        const struct drm_format_info *format;
        const struct ast_vbios_enhtable *vmode;
        unsigned int hborder = 0;
        unsigned int vborder = 0;
        int ret;

        if (!crtc_state->enable)
                return 0;

        ret = drm_atomic_helper_check_crtc_primary_plane(crtc_state);
        if (ret)
                return ret;

        ast_state = to_ast_crtc_state(crtc_state);

        format = ast_state->format;
        if (drm_WARN_ON_ONCE(dev, !format))
                return -EINVAL; /* BUG: We didn't set format in primary check(). */

        /*
         * The gamma LUT has to be reloaded after changing the primary
         * plane's color format.
         */
        if (old_ast_crtc_state->format != format)
                crtc_state->color_mgmt_changed = true;

        if (crtc_state->color_mgmt_changed && crtc_state->gamma_lut) {
                if (crtc_state->gamma_lut->length !=
                    AST_LUT_SIZE * sizeof(struct drm_color_lut)) {
                        drm_err(dev, "Wrong size for gamma_lut %zu\n",
                                crtc_state->gamma_lut->length);
                        return -EINVAL;
                }
        }

        /*
         * Set register tables.
         *
         * TODO: These tables mix all kinds of fields and should
         *       probably be resolved into various helper functions.
         */
        switch (format->format) {
        case DRM_FORMAT_C8:
                ast_state->std_table = &vbios_stdtable[VGAModeIndex];
                break;
        case DRM_FORMAT_RGB565:
                ast_state->std_table = &vbios_stdtable[HiCModeIndex];
                break;
        case DRM_FORMAT_RGB888:
        case DRM_FORMAT_XRGB8888:
                ast_state->std_table = &vbios_stdtable[TrueCModeIndex];
                break;
        default:
                return -EINVAL;
        }

        /*
         * Find the VBIOS mode and adjust the DRM display mode accordingly
         * if a full modeset is required. Otherwise keep the existing values.
         */
        if (drm_atomic_crtc_needs_modeset(crtc_state)) {
                vmode = ast_vbios_find_mode(ast, &crtc_state->mode);
                if (!vmode)
                        return -EINVAL;
                ast_state->vmode = vmode;

                if (vmode->flags & HBorder)
                        hborder = 8;
                if (vmode->flags & VBorder)
                        vborder = 8;

                adjusted_mode->crtc_hdisplay = vmode->hde;
                adjusted_mode->crtc_hblank_start = vmode->hde + hborder;
                adjusted_mode->crtc_hblank_end = vmode->ht - hborder;
                adjusted_mode->crtc_hsync_start = vmode->hde + hborder + vmode->hfp;
                adjusted_mode->crtc_hsync_end = vmode->hde + hborder + vmode->hfp + vmode->hsync;
                adjusted_mode->crtc_htotal = vmode->ht;

                adjusted_mode->crtc_vdisplay = vmode->vde;
                adjusted_mode->crtc_vblank_start = vmode->vde + vborder;
                adjusted_mode->crtc_vblank_end = vmode->vt - vborder;
                adjusted_mode->crtc_vsync_start = vmode->vde + vborder + vmode->vfp;
                adjusted_mode->crtc_vsync_end = vmode->vde + vborder + vmode->vfp + vmode->vsync;
                adjusted_mode->crtc_vtotal = vmode->vt;
        }

        return 0;
}

static void
ast_crtc_helper_atomic_flush(struct drm_crtc *crtc,
                             struct drm_atomic_state *state)
{
        struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
                                                                          crtc);
        struct drm_device *dev = crtc->dev;
        struct ast_device *ast = to_ast_device(dev);
        struct ast_crtc_state *ast_crtc_state = to_ast_crtc_state(crtc_state);

        /*
         * The gamma LUT has to be reloaded after changing the primary
         * plane's color format.
         */
        if (crtc_state->enable && crtc_state->color_mgmt_changed) {
                if (crtc_state->gamma_lut)
                        ast_crtc_load_gamma(ast,
                                            ast_crtc_state->format,
                                            crtc_state->gamma_lut->data);
                else
                        ast_crtc_fill_gamma(ast, ast_crtc_state->format);
        }
}

static void ast_crtc_helper_atomic_enable(struct drm_crtc *crtc, struct drm_atomic_state *state)
{
        struct ast_device *ast = to_ast_device(crtc->dev);
        u8 vgacr17 = 0x00;
        u8 vgacrb6 = 0xff;

        vgacr17 |= AST_IO_VGACR17_SYNC_ENABLE;
        vgacrb6 &= ~(AST_IO_VGACRB6_VSYNC_OFF | AST_IO_VGACRB6_HSYNC_OFF);

        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x17, 0x7f, vgacr17);
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xb6, 0xfc, vgacrb6);
}

static void ast_crtc_helper_atomic_disable(struct drm_crtc *crtc, struct drm_atomic_state *state)
{
        struct drm_crtc_state *old_crtc_state = drm_atomic_get_old_crtc_state(state, crtc);
        struct ast_device *ast = to_ast_device(crtc->dev);
        u8 vgacr17 = 0xff;

        vgacr17 &= ~AST_IO_VGACR17_SYNC_ENABLE;
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x17, 0x7f, vgacr17);

        /*
         * HW cursors require the underlying primary plane and CRTC to
         * display a valid mode and image. This is not the case during
         * full modeset operations. So we temporarily disable any active
         * plane, including the HW cursor. Each plane's atomic_update()
         * helper will re-enable it if necessary.
         *
         * We only do this during *full* modesets. It does not affect
         * simple pageflips on the planes.
         */
        drm_atomic_helper_disable_planes_on_crtc(old_crtc_state, false);
}

static const struct drm_crtc_helper_funcs ast_crtc_helper_funcs = {
        .mode_valid = ast_crtc_helper_mode_valid,
        .mode_set_nofb = ast_crtc_helper_mode_set_nofb,
        .atomic_check = ast_crtc_helper_atomic_check,
        .atomic_flush = ast_crtc_helper_atomic_flush,
        .atomic_enable = ast_crtc_helper_atomic_enable,
        .atomic_disable = ast_crtc_helper_atomic_disable,
};

static void ast_crtc_reset(struct drm_crtc *crtc)
{
        struct ast_crtc_state *ast_state = kzalloc_obj(*ast_state);

        if (crtc->state)
                crtc->funcs->atomic_destroy_state(crtc, crtc->state);

        if (ast_state)
                __drm_atomic_helper_crtc_reset(crtc, &ast_state->base);
        else
                __drm_atomic_helper_crtc_reset(crtc, NULL);
}

static struct drm_crtc_state *
ast_crtc_atomic_duplicate_state(struct drm_crtc *crtc)
{
        struct ast_crtc_state *new_ast_state, *ast_state;
        struct drm_device *dev = crtc->dev;

        if (drm_WARN_ON(dev, !crtc->state))
                return NULL;

        new_ast_state = kmalloc_obj(*new_ast_state);
        if (!new_ast_state)
                return NULL;
        __drm_atomic_helper_crtc_duplicate_state(crtc, &new_ast_state->base);

        ast_state = to_ast_crtc_state(crtc->state);

        new_ast_state->format = ast_state->format;
        new_ast_state->std_table = ast_state->std_table;
        new_ast_state->vmode = ast_state->vmode;

        return &new_ast_state->base;
}

static void ast_crtc_atomic_destroy_state(struct drm_crtc *crtc,
                                          struct drm_crtc_state *state)
{
        struct ast_crtc_state *ast_state = to_ast_crtc_state(state);

        __drm_atomic_helper_crtc_destroy_state(&ast_state->base);
        kfree(ast_state);
}

static const struct drm_crtc_funcs ast_crtc_funcs = {
        .reset = ast_crtc_reset,
        .destroy = drm_crtc_cleanup,
        .set_config = drm_atomic_helper_set_config,
        .page_flip = drm_atomic_helper_page_flip,
        .atomic_duplicate_state = ast_crtc_atomic_duplicate_state,
        .atomic_destroy_state = ast_crtc_atomic_destroy_state,
};

static int ast_crtc_init(struct ast_device *ast)
{
        struct drm_device *dev = &ast->base;
        struct drm_crtc *crtc = &ast->crtc;
        int ret;

        ret = drm_crtc_init_with_planes(dev, crtc, &ast->primary_plane.base,
                                        &ast->cursor_plane.base.base, &ast_crtc_funcs,
                                        NULL);
        if (ret)
                return ret;

        drm_mode_crtc_set_gamma_size(crtc, AST_LUT_SIZE);
        drm_crtc_enable_color_mgmt(crtc, 0, false, AST_LUT_SIZE);

        drm_crtc_helper_add(crtc, &ast_crtc_helper_funcs);

        return 0;
}

/*
 * Mode config
 */

static void ast_mode_config_helper_atomic_commit_tail(struct drm_atomic_state *state)
{
        struct ast_device *ast = to_ast_device(state->dev);

        /*
         * Concurrent operations could possibly trigger a call to
         * drm_connector_helper_funcs.get_modes by reading the display
         * modes. Protect access to registers by acquiring the modeset
         * lock.
         */
        mutex_lock(&ast->modeset_lock);
        drm_atomic_helper_commit_tail(state);
        mutex_unlock(&ast->modeset_lock);
}

static const struct drm_mode_config_helper_funcs ast_mode_config_helper_funcs = {
        .atomic_commit_tail = ast_mode_config_helper_atomic_commit_tail,
};

static enum drm_mode_status ast_mode_config_mode_valid(struct drm_device *dev,
                                                       const struct drm_display_mode *mode)
{
        const struct drm_format_info *info = drm_format_info(DRM_FORMAT_XRGB8888);
        struct ast_device *ast = to_ast_device(dev);
        unsigned long max_fb_size = ast_fb_vram_size(ast);
        u64 pitch;

        if (drm_WARN_ON_ONCE(dev, !info))
                return MODE_ERROR; /* driver bug */

        pitch = drm_format_info_min_pitch(info, 0, mode->hdisplay);
        if (!pitch)
                return MODE_BAD_WIDTH;
        if (pitch > AST_PRIMARY_PLANE_MAX_OFFSET)
                return MODE_BAD_WIDTH; /* maximum programmable pitch */
        if (pitch > max_fb_size / mode->vdisplay)
                return MODE_MEM;

        return MODE_OK;
}

static const struct drm_mode_config_funcs ast_mode_config_funcs = {
        .fb_create = drm_gem_fb_create_with_dirty,
        .mode_valid = ast_mode_config_mode_valid,
        .atomic_check = drm_atomic_helper_check,
        .atomic_commit = drm_atomic_helper_commit,
};

int ast_mode_config_init(struct ast_device *ast)
{
        struct drm_device *dev = &ast->base;
        int ret;

        ret = drmm_mutex_init(dev, &ast->modeset_lock);
        if (ret)
                return ret;

        ret = drmm_mode_config_init(dev);
        if (ret)
                return ret;

        dev->mode_config.funcs = &ast_mode_config_funcs;
        dev->mode_config.min_width = 0;
        dev->mode_config.min_height = 0;
        dev->mode_config.preferred_depth = 24;

        if (ast->support_fullhd) {
                dev->mode_config.max_width = 1920;
                dev->mode_config.max_height = 2048;
        } else {
                dev->mode_config.max_width = 1600;
                dev->mode_config.max_height = 1200;
        }

        dev->mode_config.helper_private = &ast_mode_config_helper_funcs;

        ret = ast_primary_plane_init(ast);
        if (ret)
                return ret;

        ret = ast_cursor_plane_init(ast);
        if (ret)
                return ret;

        ret = ast_crtc_init(ast);
        if (ret)
                return ret;

        switch (ast->tx_chip) {
        case AST_TX_NONE:
                ret = ast_vga_output_init(ast);
                break;
        case AST_TX_SIL164:
                ret = ast_sil164_output_init(ast);
                break;
        case AST_TX_DP501:
                ret = ast_dp501_output_init(ast);
                break;
        case AST_TX_ASTDP:
                ret = ast_astdp_output_init(ast);
                break;
        }
        if (ret)
                return ret;

        drm_mode_config_reset(dev);
        drmm_kms_helper_poll_init(dev);

        return 0;
}