path: root/drivers/video/acornfb.c

/*
 *  linux/drivers/video/acornfb.c
 *
 *  Copyright (C) 1998-2001 Russell King
 *
 * 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.
 *
 * Frame buffer code for Acorn platforms
 *
 * NOTE: Most of the modes with X!=640 will disappear shortly.
 * NOTE: Startup setting of HS & VS polarity not supported.
 *       (do we need to support it if we're coming up in 640x480?)
 *
 * FIXME: (things broken by the "new improved" FBCON API)
 *  - Blanking 8bpp displays with VIDC
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/fb.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/gfp.h>

#include <mach/hardware.h>
#include <asm/irq.h>
#include <asm/mach-types.h>
#include <asm/pgtable.h>

#include "acornfb.h"

/*
 * Default resolution.
 * NOTE that it has to be supported in the table towards
 * the end of this file.
 */
#define DEFAULT_XRES	640
#define DEFAULT_YRES	480
#define DEFAULT_BPP	4

/*
 * define this to debug the video mode selection
 */
#undef DEBUG_MODE_SELECTION

/*
 * Translation from RISC OS monitor types to actual
 * HSYNC and VSYNC frequency ranges.  These are
 * probably not right, but they're the best info I
 * have.  Allow 1% either way on the nominal for TVs.
 */
#define NR_MONTYPES	6
static struct fb_monspecs monspecs[NR_MONTYPES] = {
	{	/* TV		*/
		.hfmin	= 15469,
		.hfmax	= 15781,
		.vfmin	= 49,
		.vfmax	= 51,
	}, {	/* Multi Freq	*/
		.hfmin	= 0,
		.hfmax	= 99999,
		.vfmin	= 0,
		.vfmax	= 199,
	}, {	/* Hi-res mono	*/
		.hfmin	= 58608,
		.hfmax	= 58608,
		.vfmin	= 64,
		.vfmax	= 64,
	}, {	/* VGA		*/
		.hfmin	= 30000,
		.hfmax	= 70000,
		.vfmin	= 60,
		.vfmax	= 60,
	}, {	/* SVGA		*/
		.hfmin	= 30000,
		.hfmax	= 70000,
		.vfmin	= 56,
		.vfmax	= 75,
	}, {
		.hfmin	= 30000,
		.hfmax	= 70000,
		.vfmin	= 60,
		.vfmax	= 60,
	}
};

static struct fb_info fb_info;
static struct acornfb_par current_par;
static struct vidc_timing current_vidc;

extern unsigned int vram_size;	/* set by setup.c */

#ifdef HAS_VIDC20
#include <mach/acornfb.h>

#define MAX_SIZE	2*1024*1024

/* VIDC20 has a different set of rules from the VIDC:
 *  hcr  : must be multiple of 4
 *  hswr : must be even
 *  hdsr : must be even
 *  hder : must be even
 *  vcr  : >= 2, (interlace, must be odd)
 *  vswr : >= 1
 *  vdsr : >= 1
 *  vder : >= vdsr
 */
static void acornfb_set_timing(struct fb_info *info)
{
	struct fb_var_screeninfo *var = &info->var;
	struct vidc_timing vidc;
	u_int vcr, fsize;
	u_int ext_ctl, dat_ctl;
	u_int words_per_line;

	memset(&vidc, 0, sizeof(vidc));

	vidc.h_sync_width	= var->hsync_len - 8;
	vidc.h_border_start	= vidc.h_sync_width + var->left_margin + 8 - 12;
	vidc.h_display_start	= vidc.h_border_start + 12 - 18;
	vidc.h_display_end	= vidc.h_display_start + var->xres;
	vidc.h_border_end	= vidc.h_display_end + 18 - 12;
	vidc.h_cycle		= vidc.h_border_end + var->right_margin + 12 - 8;
	vidc.h_interlace	= vidc.h_cycle / 2;
	vidc.v_sync_width	= var->vsync_len - 1;
	vidc.v_border_start	= vidc.v_sync_width + var->upper_margin;
	vidc.v_display_start