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https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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3e074058d7
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>
44 lines
1.5 KiB
C
44 lines
1.5 KiB
C
/*
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* Copyright (C) 2007 Atmel Corporation
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*
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* Driver for the AT32AP700X PS/2 controller (PSIF).
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published
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* by the Free Software Foundation.
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*/
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#ifndef __INCLUDE_ATMEL_PWM_BL_H
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#define __INCLUDE_ATMEL_PWM_BL_H
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/**
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* struct atmel_pwm_bl_platform_data
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* @pwm_channel: which PWM channel in the PWM module to use.
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* @pwm_frequency: PWM frequency to generate, the driver will try to be as
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* close as the prescaler allows.
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* @pwm_compare_max: value to use in the PWM channel compare register.
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* @pwm_duty_max: maximum duty cycle value, must be less than or equal to
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* pwm_compare_max.
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* @pwm_duty_min: minimum duty cycle value, must be less than pwm_duty_max.
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* @pwm_active_low: set to one if the low part of the PWM signal increases the
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* brightness of the backlight.
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* @gpio_on: GPIO line to control the backlight on/off, set to -1 if not used.
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* @on_active_low: set to one if the on/off signal is on when GPIO is low.
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*
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* This struct must be added to the platform device in the board code. It is
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* used by the atmel-pwm-bl driver to setup the GPIO to control on/off and the
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* PWM device.
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*/
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struct atmel_pwm_bl_platform_data {
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unsigned int pwm_channel;
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unsigned int pwm_frequency;
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unsigned int pwm_compare_max;
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unsigned int pwm_duty_max;
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unsigned int pwm_duty_min;
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unsigned int pwm_active_low;
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int gpio_on;
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unsigned int on_active_low;
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};
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#endif /* __INCLUDE_ATMEL_PWM_BL_H */
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