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| author | Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> | 2008-07-23 21:31:48 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-24 10:47:41 -0700 |
| commit | 3e074058d72486676f6fdf6fe803200c62dcb403 (patch) | |
| tree | de9d8c426198e9a10a04593abe8011c1e1822564 /include | |
| parent | 2d04a4a72d7e1519b4838f24bdd4b5d0f3f426dc (diff) | |
| download | kernel_samsung_smdk4412-3e074058d72486676f6fdf6fe803200c62dcb403.zip kernel_samsung_smdk4412-3e074058d72486676f6fdf6fe803200c62dcb403.tar.gz kernel_samsung_smdk4412-3e074058d72486676f6fdf6fe803200c62dcb403.tar.bz2 | |
fbdev: LCD backlight driver using Atmel PWM driver
This patch adds a platform driver using the ATMEL PWM driver to control a
backlight which requires a PWM signal and optional GPIO signal for discrete
on/off signal. It has been tested on Favr-32 board from EarthLCD.
The driver is configurable by supplying a struct with the platform data. See
the include/linux/atmel-pwm-bl.h for details.
The board code for Favr-32 will be submitted to the AVR32 kernel list.
Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/atmel-pwm-bl.h | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/include/linux/atmel-pwm-bl.h b/include/linux/atmel-pwm-bl.h new file mode 100644 index 0000000..0153a47 --- /dev/null +++ b/include/linux/atmel-pwm-bl.h @@ -0,0 +1,43 @@ +/* + * Copyright (C) 2007 Atmel Corporation + * + * Driver for the AT32AP700X PS/2 controller (PSIF). + * + * 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. + */ + +#ifndef __INCLUDE_ATMEL_PWM_BL_H +#define __INCLUDE_ATMEL_PWM_BL_H + +/** + * struct atmel_pwm_bl_platform_data + * @pwm_channel: which PWM channel in the PWM module to use. + * @pwm_frequency: PWM frequency to generate, the driver will try to be as + * close as the prescaler allows. + * @pwm_compare_max: value to use in the PWM channel compare register. + * @pwm_duty_max: maximum duty cycle value, must be less than or equal to + * pwm_compare_max. + * @pwm_duty_min: minimum duty cycle value, must be less than pwm_duty_max. + * @pwm_active_low: set to one if the low part of the PWM signal increases the + * brightness of the backlight. + * @gpio_on: GPIO line to control the backlight on/off, set to -1 if not used. + * @on_active_low: set to one if the on/off signal is on when GPIO is low. + * + * This struct must be added to the platform device in the board code. It is + * used by the atmel-pwm-bl driver to setup the GPIO to control on/off and the + * PWM device. + */ +struct atmel_pwm_bl_platform_data { + unsigned int pwm_channel; + unsigned int pwm_frequency; + unsigned int pwm_compare_max; + unsigned int pwm_duty_max; + unsigned int pwm_duty_min; + unsigned int pwm_active_low; + int gpio_on; + unsigned int on_active_low; +}; + +#endif /* __INCLUDE_ATMEL_PWM_BL_H */ |