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linux-next/include/linux/ks0108.h
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

50 lines
1.6 KiB
C

/*
* Filename: ks0108.h
* Version: 0.1.0
* Description: ks0108 LCD Controller driver header
* License: GPLv2
*
* 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
*
*/
#ifndef _KS0108_H_
#define _KS0108_H_
/* Write a byte to the data port */
extern void ks0108_writedata(unsigned char byte);
/* Write a byte to the control port */
extern void ks0108_writecontrol(unsigned char byte);
/* Set the controller's current display state (0..1) */
extern void ks0108_displaystate(unsigned char state);
/* Set the controller's current startline (0..63) */
extern void ks0108_startline(unsigned char startline);
/* Set the controller's current address (0..63) */
extern void ks0108_address(unsigned char address);
/* Set the controller's current page (0..7) */
extern void ks0108_page(unsigned char page);
/* Is the module inited? */
extern unsigned char ks0108_isinited(void);
#endif /* _KS0108_H_ */