lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

atmel_lcdfb: backlight control

Browse Source 
On the sam9 EK boards, the LCD backlight is hooked up to a PWM output from
the LCD controller.  It's controlled by "contrast" registers though.

This patch lets boards declare that they have that kind of backlight
control.  The driver can then export this control, letting screenblank and
other operations actually take effect ...  reducing the typically
substantial power drain from the backlight.

Note that it's not fully cooked
  - doesn't force backlight off during system suspend
  - the "power" and "blank" events may not be done right
This should be easily added in the future.

[nicolas.ferre@atmel.com: remove unneeded inline and rename functions]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Brownell
2008-02-06 01:39:26 -08:00
committed by Linus Torvalds
parent b1230ee50a
commit a9a84c37d1
5 changed files with 135 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
include/video/atmel_lcdc.h
View File

@@ -22,7 +22,7 @@
#ifndef __ATMEL_LCDC_H__
#define __ATMEL_LCDC_H__
/* LCD Controller info data structure */
/* LCD Controller info data structure, stored in device platform_data */
struct atmel_lcdfb_info {
spinlock_t lock;
struct fb_info *info;
@@ -33,7 +33,14 @@ struct atmel_lcdfb_info {
struct platform_device *pdev;
struct clk *bus_clk;
struct clk *lcdc_clk;
unsigned int default_bpp;
#ifdef CONFIG_BACKLIGHT_ATMEL_LCDC
struct backlight_device *backlight;
u8 bl_power;
#endif
bool lcdcon_is_backlight;
u8 default_bpp;
unsigned int default_lcdcon2;
unsigned int default_dmacon;
void (*atmel_lcdfb_power_control)(int on);