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linux/drivers/video/68328fb.c
Laurent Pinchart 2e1e5979bb 68328fb: use display information in info not in var for panning 
We must not use any information in the passed var besides xoffset,
yoffset and vmode as otherwise applications might abuse it.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2011-08-19 10:28:58 +02:00

505 lines
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/*
* linux/drivers/video/68328fb.c -- Low level implementation of the
* mc68x328 LCD frame buffer device
*
* Copyright (C) 2003 Georges Menie
*
* This driver assumes an already configured controller (e.g. from config.c)
* Keep the code clean of board specific initialization.
*
* This code has not been tested with colors, colormap management functions
* are minimal (no colormap data written to the 68328 registers...)
*
* initial version of this driver:
* Copyright (C) 1998,1999 Kenneth Albanowski <kjahds@kjahds.com>,
* The Silver Hammer Group, Ltd.
*
* this version is based on :
*
* linux/drivers/video/vfb.c -- Virtual frame buffer device
*
* Copyright (C) 2002 James Simmons
*
* Copyright (C) 1997 Geert Uytterhoeven
*
* 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.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>
#include <linux/fb.h>
#include <linux/init.h>
#if defined(CONFIG_M68VZ328)
#include <asm/MC68VZ328.h>
#elif defined(CONFIG_M68EZ328)
#include <asm/MC68EZ328.h>
#elif defined(CONFIG_M68328)
#include <asm/MC68328.h>
#else
#error wrong architecture for the MC68x328 frame buffer device
#endif
#if defined(CONFIG_FB_68328_INVERT)
#define MC68X328FB_MONO_VISUAL FB_VISUAL_MONO01
#else
#define MC68X328FB_MONO_VISUAL FB_VISUAL_MONO10
#endif
static u_long videomemory;
static u_long videomemorysize;
static struct fb_info fb_info;
static u32 mc68x328fb_pseudo_palette[16];
static struct fb_var_screeninfo mc68x328fb_default __initdata = {
.red = { 0, 8, 0 },
.green = { 0, 8, 0 },
.blue = { 0, 8, 0 },
.activate = FB_ACTIVATE_TEST,
.height = -1,
.width = -1,
.pixclock = 20000,
.left_margin = 64,
.right_margin = 64,
.upper_margin = 32,
.lower_margin = 32,
.hsync_len = 64,
.vsync_len = 2,
.vmode = FB_VMODE_NONINTERLACED,
};
static struct fb_fix_screeninfo mc68x328fb_fix __initdata = {
.id = "68328fb",
.type = FB_TYPE_PACKED_PIXELS,
.xpanstep = 1,
.ypanstep = 1,
.ywrapstep = 1,
.accel = FB_ACCEL_NONE,
};
/*
* Interface used by the world
*/
int mc68x328fb_init(void);
int mc68x328fb_setup(char *);
static int mc68x328fb_check_var(struct fb_var_screeninfo *var,
struct fb_info *info);
static int mc68x328fb_set_par(struct fb_info *info);
static int mc68x328fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
u_int transp, struct fb_info *info);
static int mc68x328fb_pan_display(struct fb_var_screeninfo *var,
struct fb_info *info);
static int mc68x328fb_mmap(struct fb_info *info, struct vm_area_struct *vma);
static struct fb_ops mc68x328fb_ops = {
.fb_check_var = mc68x328fb_check_var,
.fb_set_par = mc68x328fb_set_par,
.fb_setcolreg = mc68x328fb_setcolreg,
.fb_pan_display = mc68x328fb_pan_display,
.fb_fillrect = cfb_fillrect,
.fb_copyarea = cfb_copyarea,
.fb_imageblit = cfb_imageblit,
.fb_mmap = mc68x328fb_mmap,
};
/*
* Internal routines
*/
static u_long get_line_length(int xres_virtual, int bpp)
{
u_long length;
length = xres_virtual * bpp;
length = (length + 31) & ~31;
length >>= 3;
return (length);
}
/*
* Setting the video mode has been split into two parts.
* First part, xxxfb_check_var, must not write anything
* to hardware, it should only verify and adjust var.
* This means it doesn't alter par but it does use hardware
* data from it to check this var.
*/
static int mc68x328fb_check_var(struct fb_var_screeninfo *var,
struct fb_info *info)
{
u_long line_length;
/*
* FB_VMODE_CONUPDATE and FB_VMODE_SMOOTH_XPAN are equal!
* as FB_VMODE_SMOOTH_XPAN is only used internally
*/
if (var->vmode & FB_VMODE_CONUPDATE) {
var->vmode |= FB_VMODE_YWRAP;
var->xoffset = info->var.xoffset;
var->yoffset = info->var.yoffset;
}
/*
* Some very basic checks
*/
if (!var->xres)
var->xres = 1;
if (!var->yres)
var->yres = 1;
if (var->xres > var->xres_virtual)
var->xres_virtual = var->xres;
if (var->yres > var->yres_virtual)
var->yres_virtual = var->yres;
if (var->bits_per_pixel <= 1)
var->bits_per_pixel = 1;
else if (var->bits_per_pixel <= 8)
var->bits_per_pixel = 8;
else if (var->bits_per_pixel <= 16)
var->bits_per_pixel = 16;
else if (var->bits_per_pixel <= 24)
var->bits_per_pixel = 24;
else if (var->bits_per_pixel <= 32)
var->bits_per_pixel = 32;
else
return -EINVAL;
if (var->xres_virtual < var->xoffset + var->xres)
var->xres_virtual = var->xoffset + var->xres;
if (var->yres_virtual < var->yoffset + var->yres)
var->yres_virtual = var->yoffset + var->yres;
/*
* Memory limit
*/
line_length =
get_line_length(var->xres_virtual, var->bits_per_pixel);
if (line_length * var->yres_virtual > videomemorysize)
return -ENOMEM;
/*
* Now that we checked it we alter var. The reason being is that the video
* mode passed in might not work but slight changes to it might make it
* work. This way we let the user know what is acceptable.
*/
switch (var->bits_per_pixel) {
case 1:
var->red.offset = 0;
var->red.length = 1;
var->green.offset = 0;
var->green.length = 1;
var->blue.offset = 0;
var->blue.length = 1;
var->transp.offset = 0;
var->transp.length = 0;
break;
case 8:
var->red.offset = 0;
var->red.length = 8;
var->green.offset = 0;
var->green.length = 8;
var->blue.offset = 0;
var->blue.length = 8;
var->transp.offset = 0;
var->transp.length = 0;
break;
case 16: /* RGBA 5551 */
if (var->transp.length) {
var->red.offset = 0;
var->red.length = 5;
var->green.offset = 5;
var->green.length = 5;
var->blue.offset = 10;
var->blue.length = 5;
var->transp.offset = 15;
var->transp.length = 1;
} else { /* RGB 565 */
var->red.offset = 0;
var->red.length = 5;
var->green.offset = 5;
var->green.length = 6;
var->blue.offset = 11;
var->blue.length = 5;
var->transp.offset = 0;
var->transp.length = 0;
}
break;
case 24: /* RGB 888 */
var->red.offset = 0;
var->red.length = 8;
var->green.offset = 8;
var->green.length = 8;
var->blue.offset = 16;
var->blue.length = 8;
var->transp.offset = 0;
var->transp.length = 0;
break;
case 32: /* RGBA 8888 */
var->red.offset = 0;
var->red.length = 8;
var->green.offset = 8;
var->green.length = 8;
var->blue.offset = 16;
var->blue.length = 8;
var->transp.offset = 24;
var->transp.length = 8;
break;
}
var->red.msb_right = 0;
var->green.msb_right = 0;
var->blue.msb_right = 0;
var->transp.msb_right = 0;
return 0;
}
/* This routine actually sets the video mode. It's in here where we
* the hardware state info->par and fix which can be affected by the
* change in par. For this driver it doesn't do much.
*/
static int mc68x328fb_set_par(struct fb_info *info)
{
info->fix.line_length = get_line_length(info->var.xres_virtual,
info->var.bits_per_pixel);
return 0;
}
/*
* Set a single color register. The values supplied are already
* rounded down to the hardware's capabilities (according to the
* entries in the var structure). Return != 0 for invalid regno.
*/
static int mc68x328fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
u_int transp, struct fb_info *info)
{
if (regno >= 256) /* no. of hw registers */
return 1;
/*
* Program hardware... do anything you want with transp
*/
/* grayscale works only partially under directcolor */
if (info->var.grayscale) {
/* grayscale = 0.30*R + 0.59*G + 0.11*B */
red = green = blue =
(red * 77 + green * 151 + blue * 28) >> 8;
}
/* Directcolor:
* var->{color}.offset contains start of bitfield
* var->{color}.length contains length of bitfield
* {hardwarespecific} contains width of RAMDAC
* cmap[X] is programmed to (X << red.offset) | (X << green.offset) | (X << blue.offset)
* RAMDAC[X] is programmed to (red, green, blue)
*
* Pseudocolor:
* uses offset = 0 && length = RAMDAC register width.
* var->{color}.offset is 0
* var->{color}.length contains width of DAC
* cmap is not used
* RAMDAC[X] is programmed to (red, green, blue)
* Truecolor:
* does not use DAC. Usually 3 are present.
* var->{color}.offset contains start of bitfield
* var->{color}.length contains length of bitfield
* cmap is programmed to (red << red.offset) | (green << green.offset) |
* (blue << blue.offset) | (transp << transp.offset)
* RAMDAC does not exist
*/
#define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16)
switch (info->fix.visual) {
case FB_VISUAL_TRUECOLOR:
case FB_VISUAL_PSEUDOCOLOR:
red = CNVT_TOHW(red, info->var.red.length);
green = CNVT_TOHW(green, info->var.green.length);
blue = CNVT_TOHW(blue, info->var.blue.length);
transp = CNVT_TOHW(transp, info->var.transp.length);
break;
case FB_VISUAL_DIRECTCOLOR:
red = CNVT_TOHW(red, 8); /* expect 8 bit DAC */
green = CNVT_TOHW(green, 8);
blue = CNVT_TOHW(blue, 8);
/* hey, there is bug in transp handling... */
transp = CNVT_TOHW(transp, 8);
break;
}
#undef CNVT_TOHW
/* Truecolor has hardware independent palette */
if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
u32 v;
if (regno >= 16)
return 1;
v = (red << info->var.red.offset) |
(green << info->var.green.offset) |
(blue << info->var.blue.offset) |
(transp << info->var.transp.offset);
switch (info->var.bits_per_pixel) {
case 8:
break;
case 16:
((u32 *) (info->pseudo_palette))[regno] = v;
break;
case 24:
case 32:
((u32 *) (info->pseudo_palette))[regno] = v;
break;
}
return 0;
}
return 0;
}
/*
* Pan or Wrap the Display
*
* This call looks only at xoffset, yoffset and the FB_VMODE_YWRAP flag
*/
static int mc68x328fb_pan_display(struct fb_var_screeninfo *var,
struct fb_info *info)
{
if (var->vmode & FB_VMODE_YWRAP) {
if (var->yoffset < 0
|| var->yoffset >= info->var.yres_virtual
|| var->xoffset)
return -EINVAL;
} else {
if (var->xoffset + info->var.xres > info->var.xres_virtual ||
var->yoffset + info->var.yres > info->var.yres_virtual)
return -EINVAL;
}
info->var.xoffset = var->xoffset;
info->var.yoffset = var->yoffset;
if (var->vmode & FB_VMODE_YWRAP)
info->var.vmode |= FB_VMODE_YWRAP;
else
info->var.vmode &= ~FB_VMODE_YWRAP;
return 0;
}
/*
* Most drivers don't need their own mmap function
*/
static int mc68x328fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
#ifndef MMU
/* this is uClinux (no MMU) specific code */
vma->vm_flags |= VM_RESERVED;
vma->vm_start = videomemory;
return 0;
#else
return -EINVAL;
#endif
}
int __init mc68x328fb_setup(char *options)
{
#if 0
char *this_opt;
#endif
if (!options || !*options)
return 1;
#if 0
while ((this_opt = strsep(&options, ",")) != NULL) {
if (!*this_opt)
continue;
if (!strncmp(this_opt, "disable", 7))
mc68x328fb_enable = 0;
}
#endif
return 1;
}
/*
* Initialisation
*/
int __init mc68x328fb_init(void)
{
#ifndef MODULE
char *option = NULL;
if (fb_get_options("68328fb", &option))
return -ENODEV;
mc68x328fb_setup(option);
#endif
/*
* initialize the default mode from the LCD controller registers
*/
mc68x328fb_default.xres = LXMAX;
mc68x328fb_default.yres = LYMAX+1;
mc68x328fb_default.xres_virtual = mc68x328fb_default.xres;
mc68x328fb_default.yres_virtual = mc68x328fb_default.yres;
mc68x328fb_default.bits_per_pixel = 1 + (LPICF & 0x01);
videomemory = LSSA;
videomemorysize = (mc68x328fb_default.xres_virtual+7) / 8 *
mc68x328fb_default.yres_virtual * mc68x328fb_default.bits_per_pixel;
fb_info.screen_base = (void *)videomemory;
fb_info.fbops = &mc68x328fb_ops;
fb_info.var = mc68x328fb_default;
fb_info.fix = mc68x328fb_fix;
fb_info.fix.smem_start = videomemory;
fb_info.fix.smem_len = videomemorysize;
fb_info.fix.line_length =
get_line_length(mc68x328fb_default.xres_virtual, mc68x328fb_default.bits_per_pixel);
fb_info.fix.visual = (mc68x328fb_default.bits_per_pixel) == 1 ?
MC68X328FB_MONO_VISUAL : FB_VISUAL_PSEUDOCOLOR;
if (fb_info.var.bits_per_pixel == 1) {
fb_info.var.red.length = fb_info.var.green.length = fb_info.var.blue.length = 1;
fb_info.var.red.offset = fb_info.var.green.offset = fb_info.var.blue.offset = 0;
}
fb_info.pseudo_palette = &mc68x328fb_pseudo_palette;
fb_info.flags = FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN;
if (fb_alloc_cmap(&fb_info.cmap, 256, 0))
return -ENOMEM;
if (register_framebuffer(&fb_info) < 0) {
fb_dealloc_cmap(&fb_info.cmap);
return -EINVAL;
}
printk(KERN_INFO
"fb%d: %s frame buffer device\n", fb_info.node, fb_info.fix.id);
printk(KERN_INFO
"fb%d: %dx%dx%d at 0x%08lx\n", fb_info.node,
mc68x328fb_default.xres_virtual, mc68x328fb_default.yres_virtual,
1 << mc68x328fb_default.bits_per_pixel, videomemory);
return 0;
}
module_init(mc68x328fb_init);
#ifdef MODULE
static void __exit mc68x328fb_cleanup(void)
{
unregister_framebuffer(&fb_info);
fb_dealloc_cmap(&fb_info.cmap);
}
module_exit(mc68x328fb_cleanup);
MODULE_LICENSE("GPL");
#endif /* MODULE */
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