path: root/drivers/gpu/drm/ast/ast_mode.c

/*
 * 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,<