/*
 * 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 <drm/drm_gem_vram_helper.h>
#include <drm/drm_managed.h>

#include "ast_drv.h"

static void ast_cursor_fini(struct ast_private *ast)
{
        size_t i;
        struct drm_gem_vram_object *gbo;

        for (i = 0; i < ARRAY_SIZE(ast->cursor.gbo); ++i) {
                gbo = ast->cursor.gbo[i];
                drm_gem_vram_vunmap(gbo, &ast->cursor.map[i]);
                drm_gem_vram_unpin(gbo);
                drm_gem_vram_put(gbo);
        }
}

static void ast_cursor_release(struct drm_device *dev, void *ptr)
{
        struct ast_private *ast = to_ast_private(dev);

        ast_cursor_fini(ast);
}

/*
 * Allocate cursor BOs and pins them at the end of VRAM.
 */
int ast_cursor_init(struct ast_private *ast)
{
        struct drm_device *dev = &ast->base;
        size_t size, i;
        struct drm_gem_vram_object *gbo;
        struct dma_buf_map map;
        int ret;

        size = roundup(AST_HWC_SIZE + AST_HWC_SIGNATURE_SIZE, PAGE_SIZE);

        for (i = 0; i < ARRAY_SIZE(ast->cursor.gbo); ++i) {
                gbo = drm_gem_vram_create(dev, size, 0);
                if (IS_ERR(gbo)) {
                        ret = PTR_ERR(gbo);
                        goto err_drm_gem_vram_put;
                }
                ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM |
                                            DRM_GEM_VRAM_PL_FLAG_TOPDOWN);
                if (ret) {
                        drm_gem_vram_put(gbo);
                        goto err_drm_gem_vram_put;
                }
                ret = drm_gem_vram_vmap(gbo, &map);
                if (ret) {
                        drm_gem_vram_unpin(gbo);
                        drm_gem_vram_put(gbo);
                        goto err_drm_gem_vram_put;
                }

                ast->cursor.gbo[i] = gbo;
                ast->cursor.map[i] = map;
        }

        return drmm_add_action_or_reset(dev, ast_cursor_release, NULL);

err_drm_gem_vram_put:
        while (i) {
                --i;
                gbo = ast->cursor.gbo[i];
                drm_gem_vram_vunmap(gbo, &ast->cursor.map[i]);
                drm_gem_vram_unpin(gbo);
                drm_gem_vram_put(gbo);
        }
        return ret;
}

static void update_cursor_image(u8 __iomem *dst, const u8 *src, int width, int height)
{
        union {
                u32 ul;
                u8 b[4];
        } srcdata32[2], data32;
        union {
                u16 us;
                u8 b[2];
        } data16;
        u32 csum = 0;
        s32 alpha_dst_delta, last_alpha_dst_delta;
        u8 __iomem *dstxor;
        const u8 *srcxor;
        int i, j;
        u32 per_pixel_copy, two_pixel_copy;

        alpha_dst_delta = AST_MAX_HWC_WIDTH << 1;
        last_alpha_dst_delta = alpha_dst_delta - (width << 1);

        srcxor = src;
        dstxor = (u8 *)dst + last_alpha_dst_delta + (AST_MAX_HWC_HEIGHT - height) * alpha_dst_delta;
        per_pixel_copy = width & 1;
        two_pixel_copy = width >> 1;

        for (j = 0; j < height; j++) {
                for (i = 0; i < two_pixel_copy; i++) {
                        srcdata32[0].ul = *((u32 *)srcxor) & 0xf0f0f0f0;
                        srcdata32[1].ul = *((u32 *)(srcxor + 4)) & 0xf0f0f0f0;
                        data32.b[0] = srcdata32[0].b[1] | (srcdata32[0].b[0] >> 4);
                        data32.b[1] = srcdata32[0].b[3] | (srcdata32[0].b[2] >> 4);
                        data32.b[2] = srcdata32[1].b[1] | (srcdata32[1].b[0] >> 4);
                        data32.b[3] = srcdata32[1].b[3] | (srcdata32[1].b[2] >> 4);

                        writel(data32.ul, dstxor);
                        csum += data32.ul;

                        dstxor += 4;
                        srcxor += 8;

                }

                for (i = 0; i < per_pixel_copy; i++) {
                        srcdata32[0].ul = *((u32 *)srcxor) & 0xf0f0f0f0;
                        data16.b[0] = srcdata32[0].b[1] | (srcdata32[0].b[0] >> 4);
                        data16.b[1] = srcdata32[0].b[3] | (srcdata32[0].b[2] >> 4);
                        writew(data16.us, dstxor);
                        csum += (u32)data16.us;

                        dstxor += 2;
                        srcxor += 4;
                }
                dstxor += last_alpha_dst_delta;
        }

        /* write checksum + signature */
        dst += AST_HWC_SIZE;
        writel(csum, dst);
        writel(width, dst + AST_HWC_SIGNATURE_SizeX);
        writel(height, dst + AST_HWC_SIGNATURE_SizeY);
        writel(0, dst + AST_HWC_SIGNATURE_HOTSPOTX);
        writel(0, dst + AST_HWC_SIGNATURE_HOTSPOTY);
}

int ast_cursor_blit(struct ast_private *ast, struct drm_framebuffer *fb)
{
        struct drm_device *dev = &ast->base;
        struct drm_gem_vram_object *gbo;
        struct dma_buf_map map;
        int ret;
        void *src;
        void __iomem *dst;

        if (drm_WARN_ON_ONCE(dev, fb->width > AST_MAX_HWC_WIDTH) ||
            drm_WARN_ON_ONCE(dev, fb->height > AST_MAX_HWC_HEIGHT))
                return -EINVAL;

        gbo = drm_gem_vram_of_gem(fb->obj[0]);

        ret = drm_gem_vram_pin(gbo, 0);
        if (ret)
                return ret;
        ret = drm_gem_vram_vmap(gbo, &map);
        if (ret)
                goto err_drm_gem_vram_unpin;
        src = map.vaddr; /* TODO: Use mapping abstraction properly */

        dst = ast->cursor.map[ast->cursor.next_index].vaddr_iomem;

        /* do data transfer to cursor BO */
        update_cursor_image(dst, src, fb->width, fb->height);

        drm_gem_vram_vunmap(gbo, &map);
        drm_gem_vram_unpin(gbo);

        return 0;

err_drm_gem_vram_unpin:
        drm_gem_vram_unpin(gbo);
        return ret;
}

static void ast_cursor_set_base(struct ast_private *ast, u64 address)
{
        u8 addr0 = (address >> 3) & 0xff;
        u8 addr1 = (address >> 11) & 0xff;
        u8 addr2 = (address >> 19) & 0xff;

        ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xc8, addr0);
        ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xc9, addr1);
        ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xca, addr2);
}

void ast_cursor_page_flip(struct ast_private *ast)
{
        struct drm_device *dev = &ast->base;
        struct drm_gem_vram_object *gbo;
        s64 off;

        gbo = ast->cursor.gbo[ast->cursor.next_index];

        off = drm_gem_vram_offset(gbo);
        if (drm_WARN_ON_ONCE(dev, off < 0))
                return; /* Bug: we didn't pin the cursor HW BO to VRAM. */

        ast_cursor_set_base(ast, off);

        ++ast->cursor.next_index;
        ast->cursor.next_index %= ARRAY_SIZE(ast->cursor.gbo);
}

static void ast_cursor_set_location(struct ast_private *ast, u16 x, u16 y,
                                    u8 x_offset, u8 y_offset)
{
        u8 x0 = (x & 0x00ff);
        u8 x1 = (x & 0x0f00) >> 8;
        u8 y0 = (y & 0x00ff);
        u8 y1 = (y & 0x0700) >> 8;

        ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xc2, x_offset);
        ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xc3, y_offset);
        ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xc4, x0);
        ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xc5, x1);
        ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xc6, y0);
        ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xc7, y1);
}

void ast_cursor_show(struct ast_private *ast, int x, int y,
                     unsigned int offset_x, unsigned int offset_y)
{
        u8 x_offset, y_offset;
        u8 __iomem *dst;
        u8 __iomem *sig;
        u8 jreg;

        dst = ast->cursor.map[ast->cursor.next_index].vaddr;

        sig = dst + AST_HWC_SIZE;
        writel(x, sig + AST_HWC_SIGNATURE_X);
        writel(y, sig + AST_HWC_SIGNATURE_Y);

        if (x < 0) {
                x_offset = (-x) + offset_x;
                x = 0;
        } else {
                x_offset = offset_x;
        }
        if (y < 0) {
                y_offset = (-y) + offset_y;
                y = 0;
        } else {
                y_offset = offset_y;
        }

        ast_cursor_set_location(ast, x, y, x_offset, y_offset);

        /* dummy write to fire HWC */
        jreg = 0x02 |
               0x01; /* enable ARGB4444 cursor */
        ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xcb, 0xfc, jreg);
}

void ast_cursor_hide(struct ast_private *ast)
{
        ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xcb, 0xfc, 0x00);
}