path: root/drivers/video/mbx/mbxfb.c

/*
 *  linux/drivers/video/mbx/mbxfb.c
 *
 *  Copyright (C) 2006-2007 8D Technologies inc
 *  Raphael Assenat <raph@8d.com>
 *  	- Added video overlay support
 *  	- Various improvements
 *
 *  Copyright (C) 2006 Compulab, Ltd.
 *  Mike Rapoport <mike@compulab.co.il>
 *  	- Creation of driver
 *
 *   Based on pxafb.c
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive for
 * more details.
 *
 *   Intel 2700G (Marathon) Graphics Accelerator Frame Buffer Driver
 *
 */

#include <linux/delay.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>

#include <asm/io.h>

#include <video/mbxfb.h>

#include "regs.h"
#include "reg_bits.h"

static unsigned long virt_base_2700;

#define write_reg(val, reg) do { writel((val), (reg)); } while(0)

/* Without this delay, the graphics appears somehow scaled and
 * there is a lot of jitter in scanlines. This delay is probably
 * needed only after setting some specific register(s) somewhere,
 * not all over the place... */
#define write_reg_dly(val, reg) do { writel((val), reg); udelay(1000); } while(0)

#define MIN_XRES	16
#define MIN_YRES	16
#define MAX_XRES	2048
#define MAX_YRES	2048

#define MAX_PALETTES	16

/* FIXME: take care of different chip revisions with different sizes
   of ODFB */
#define MEMORY_OFFSET	0x60000

struct mbxfb_info {
	struct device *dev;

	struct resource *fb_res;
	struct resource *fb_req;

	struct resource *reg_res;
	struct resource *reg_req;

	void __iomem *fb_virt_addr;
	unsigned long fb_phys_addr;

	void __iomem *reg_virt_addr;
	unsigned long reg_phys_addr;

	int (*platform_probe) (struct fb_info * fb);
	int (*platform_remove) (struct fb_info * fb);

	u32 pseudo_palette[MAX_PALETTES];
#ifdef CONFIG_FB_MBX_DEBUG
	void *debugfs_data;
#endif

};

static struct fb_var_screeninfo mbxfb_default __devinitdata = {
	.xres = 640,
	.yres = 480,
	.xres_virtual = 640,
	.yres_virtual = 480,
	.bits_per_pixel = 16,
	.red = {11, 5, 0},
	.green = {5, 6, 0},
	.blue = {0, 5, 0},
	.activate = FB_ACTIVATE_TEST,
	.height = -1,
	.width = -1,
	.pixclock = 40000,
	.left_margin = 48,
	.right_margin = 16,
	.upper_margin = 33,
	.lower_margin = 10,
	.hsync_len = 96,
	.vsync_len = 2,
	.vmode = FB_VMODE_NONINTERLACED,
	.sync = FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,
};

static struct fb_fix_screeninfo mbxfb_fix  __devinitdata = {
	.id = "MBX",
	.type = FB_TYPE_PACKED_PIXELS,
	.visual = FB_VISUAL_TRUECOLOR,
	.xpanstep = 0,
	.ypanstep = 0,
	.ywrapstep = 0,
	.accel = FB_ACCEL_NONE,
};

struct pixclock_div {
	u8 m;
	u8 n;
	u8 p;
};

static unsigned int mbxfb_get_pixclock(unsigned int pixclock_ps,
				       struct pixclock_div *div)
{
	u8 m, n, p;
	unsigned int err = 0;
	unsigned int min_err = ~0x0;
	unsigned int clk;
	unsigned int best_clk = 0;
	unsigned int ref_clk = 13000;	/* FIXME: take from platform data */
	unsigned int pixclock;

	/* convert pixclock to KHz */
	pixclock = PICOS2KHZ(pixclock_ps);

	/* PLL output freq = (ref_clk * M) / (N * 2^P)
	 *
	 * M: 1 to 63
	 * N: 1 to 7
	 * P: 0 to 7
	 */

	/* RAPH: When N==1, the resulting pixel clock appears to
	 * get divided by 2. Preventing N=1 by starting the following
	 * loop at 2 prevents this. Is this a bug with my chip
	 * revision or something I dont understand? */
	for (m = 1; m < 64; m++) {
		for (n = 2; n < 8; n++) {
			for (p = 0; p < 8; p++) {
				clk = (ref_clk * m) / (n * (1 << p));
				err = (clk > pixclock) ? (clk - pixclock) :