path: root/drivers/gpu/drm/mgag200/mgag200_mode.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2010 Matt Turner.
 * Copyright 2012 Red Hat
 *
 * Authors: Matthew Garrett
 *	    Matt Turner
 *	    Dave Airlie
 */

#include <linux/delay.h>
#include <linux/iosys-map.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_atomic_state_helper.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_damage_helper.h>
#include <drm/drm_format_helper.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>

#include "mgag200_drv.h"

#define MGAG200_LUT_SIZE 256

/*
 * This file contains setup code for the CRTC.
 */

static void mgag200_crtc_set_gamma_linear(struct mga_device *mdev,
					  const struct drm_format_info *format)
{
	int i;

	WREG8(DAC_INDEX + MGA1064_INDEX, 0);

	switch (format->format) {
	case DRM_FORMAT_RGB565:
		/* Use better interpolation, to take 32 values from 0 to 255 */
		for (i = 0; i < MGAG200_LUT_SIZE / 8; i++) {
			WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 8 + i / 4);
			WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 4 + i / 16);
			WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 8 + i / 4);
		}
		/* Green has one more bit, so add padding with 0 for red and blue. */
		for (i = MGAG200_LUT_SIZE / 8; i < MGAG200_LUT_SIZE / 4; i++) {
			WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
			WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 4 + i / 16);
			WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
		}
		break;
	case DRM_FORMAT_RGB888:
	case DRM_FORMAT_XRGB8888:
		for (i = 0; i < MGAG200_LUT_SIZE; i++) {
			WREG8(DAC_INDEX + MGA1064_COL_PAL, i);
			WREG8(DAC_INDEX + MGA1064_COL_PAL, i);
			WREG8(DAC_INDEX + MGA1064_COL_PAL, i);
		}
		break;
	default:
		drm_warn_once(&mdev->base, "Unsupported format %p4cc for gamma correction\n",
			      &format->format);
		break;
	}
}

static void mgag200_crtc_set_gamma(struct mga_device *mdev,
				   const struct drm_format_info *format,
				   struct drm_color_lut *lut)
{
	int i;

	WREG8(DAC_INDEX + MGA1064_INDEX, 0);

	switch (format->format) {
	case DRM_FORMAT_RGB565:
		/* Use better interpolation, to take 32 values from lut[0] to lut[255] */
		for (i = 0; i < MGAG200_LUT_SIZE / 8; i++) {
			WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 8 + i / 4].red >> 8);
			WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 4 + i / 16].green >> 8);
			WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 8 + i / 4].blue >> 8);
		}
		/* Green has one more bit, so add padding with 0 for red and blue. */
		for (i = MGAG200_LUT_SIZE / 8; i < MGAG200_LUT_SIZE / 4; i++) {
			WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
			WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 4 + i / 16].green >> 8);
			WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
		}
		break;
	case DRM_FORMAT_RGB888:
	case DRM_FORMAT_XRGB8888:
		for (i = 0; i < MGAG200_LUT_SIZE; i++) {
			WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i].red >> 8);
			WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i].green >> 8);
			WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i].blue >> 8);
		}
		break;
	default:
		drm_warn_once(&mdev->base, "Unsupported format %p4cc for gamma correction\n",
			      &format->format);
		break;
	}
}

static inline void mga_wait_vsync(struct mga_device *mdev)
{
	unsigned long timeout = jiffies + HZ/10;
	unsigned int status = 0;

	do {
		status = RREG32(MGAREG_Status);
	} while ((status & 0x08) && time_before(jiffies, timeout));
	timeout = jiffies + HZ/10;
	status = 0;
	do {
		status = RREG32(MGAREG_Status);
	} while (!