kernel-fxtec-pro1x/drivers/auxdisplay/cfag12864bfb.c
Miguel Ojeda 34173a4aad [PATCH] cfag12864b: fix crash when built-in and no parport present
The problem comes when ks0108/cfag12864b are built-in and no parallel port is
present.  ks0108_init() is called first, as it should be, but fails to load
(as there is no parallel port to use).

After that, cfag12864b_init() gets called, without knowing anything about
ks0108 failed, and calls ks0108_writecontrol(), which dereferences an
uninitialized pointer.

Init order is OK, I think.  The problem is how to stop cfag12864b_init() being
called if ks0108 failed to load.  modprobe does it for us, but, how when
built-in?

Signed-off-by: Miguel Ojeda Sandonis <maxextreme@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-20 17:10:14 -08:00

188 lines
4.5 KiB
C

/*
* Filename: cfag12864bfb.c
* Version: 0.1.0
* Description: cfag12864b LCD framebuffer driver
* License: GPLv2
* Depends: cfag12864b
*
* Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
* Date: 2006-10-31
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/fb.h>
#include <linux/mm.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/cfag12864b.h>
#define CFAG12864BFB_NAME "cfag12864bfb"
static struct fb_fix_screeninfo cfag12864bfb_fix __initdata = {
.id = "cfag12864b",
.type = FB_TYPE_PACKED_PIXELS,
.visual = FB_VISUAL_MONO10,
.xpanstep = 0,
.ypanstep = 0,
.ywrapstep = 0,
.line_length = CFAG12864B_WIDTH / 8,
.accel = FB_ACCEL_NONE,
};
static struct fb_var_screeninfo cfag12864bfb_var __initdata = {
.xres = CFAG12864B_WIDTH,
.yres = CFAG12864B_HEIGHT,
.xres_virtual = CFAG12864B_WIDTH,
.yres_virtual = CFAG12864B_HEIGHT,
.bits_per_pixel = 1,
.red = { 0, 1, 0 },
.green = { 0, 1, 0 },
.blue = { 0, 1, 0 },
.left_margin = 0,
.right_margin = 0,
.upper_margin = 0,
.lower_margin = 0,
.vmode = FB_VMODE_NONINTERLACED,
};
static int cfag12864bfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
return vm_insert_page(vma, vma->vm_start,
virt_to_page(cfag12864b_buffer));
}
static struct fb_ops cfag12864bfb_ops = {
.owner = THIS_MODULE,
.fb_fillrect = cfb_fillrect,
.fb_copyarea = cfb_copyarea,
.fb_imageblit = cfb_imageblit,
.fb_mmap = cfag12864bfb_mmap,
};
static int __init cfag12864bfb_probe(struct platform_device *device)
{
int ret = -EINVAL;
struct fb_info *info = framebuffer_alloc(0, &device->dev);
if (!info)
goto none;
info->screen_base = (char __iomem *) cfag12864b_buffer;
info->screen_size = CFAG12864B_SIZE;
info->fbops = &cfag12864bfb_ops;
info->fix = cfag12864bfb_fix;
info->var = cfag12864bfb_var;
info->pseudo_palette = NULL;
info->par = NULL;
info->flags = FBINFO_FLAG_DEFAULT;
if (register_framebuffer(info) < 0)
goto fballoced;
platform_set_drvdata(device, info);
printk(KERN_INFO "fb%d: %s frame buffer device\n", info->node,
info->fix.id);
return 0;
fballoced:
framebuffer_release(info);
none:
return ret;
}
static int cfag12864bfb_remove(struct platform_device *device)
{
struct fb_info *info = platform_get_drvdata(device);
if (info) {
unregister_framebuffer(info);
framebuffer_release(info);
}
return 0;
}
static struct platform_driver cfag12864bfb_driver = {
.probe = cfag12864bfb_probe,
.remove = cfag12864bfb_remove,
.driver = {
.name = CFAG12864BFB_NAME,
},
};
static struct platform_device *cfag12864bfb_device;
static int __init cfag12864bfb_init(void)
{
int ret = -EINVAL;
/* cfag12864b_init() must be called first */
if (!cfag12864b_isinited()) {
printk(KERN_ERR CFAG12864BFB_NAME ": ERROR: "
"cfag12864b is not initialized\n");
goto none;
}
if (cfag12864b_enable()) {
printk(KERN_ERR CFAG12864BFB_NAME ": ERROR: "
"can't enable cfag12864b refreshing (being used)\n");
return -ENODEV;
}
ret = platform_driver_register(&cfag12864bfb_driver);
if (!ret) {
cfag12864bfb_device =
platform_device_alloc(CFAG12864BFB_NAME, 0);
if (cfag12864bfb_device)
ret = platform_device_add(cfag12864bfb_device);
else
ret = -ENOMEM;
if (ret) {
platform_device_put(cfag12864bfb_device);
platform_driver_unregister(&cfag12864bfb_driver);
}
}
none:
return ret;
}
static void __exit cfag12864bfb_exit(void)
{
platform_device_unregister(cfag12864bfb_device);
platform_driver_unregister(&cfag12864bfb_driver);
cfag12864b_disable();
}
module_init(cfag12864bfb_init);
module_exit(cfag12864bfb_exit);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Miguel Ojeda Sandonis <maxextreme@gmail.com>");
MODULE_DESCRIPTION("cfag12864b LCD framebuffer driver");