+++ /dev/null
-/*
- * Copyright (C) 2008 Atmel Corporation
- *
- * Backlight driver using Atmel PWM peripheral.
- *
- * 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.
- */
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/fb.h>
-#include <linux/gpio.h>
-#include <linux/backlight.h>
-#include <linux/atmel_pwm.h>
-#include <linux/atmel-pwm-bl.h>
-#include <linux/slab.h>
-
-struct atmel_pwm_bl {
- const struct atmel_pwm_bl_platform_data *pdata;
- struct backlight_device *bldev;
- struct platform_device *pdev;
- struct pwm_channel pwmc;
- int gpio_on;
-};
-
-static void atmel_pwm_bl_set_gpio_on(struct atmel_pwm_bl *pwmbl, int on)
-{
- if (!gpio_is_valid(pwmbl->gpio_on))
- return;
-
- gpio_set_value(pwmbl->gpio_on, on ^ pwmbl->pdata->on_active_low);
-}
-
-static int atmel_pwm_bl_set_intensity(struct backlight_device *bd)
-{
- struct atmel_pwm_bl *pwmbl = bl_get_data(bd);
- int intensity = bd->props.brightness;
- int pwm_duty;
-
- if (bd->props.power != FB_BLANK_UNBLANK)
- intensity = 0;
- if (bd->props.fb_blank != FB_BLANK_UNBLANK)
- intensity = 0;
-
- if (pwmbl->pdata->pwm_active_low)
- pwm_duty = pwmbl->pdata->pwm_duty_min + intensity;
- else
- pwm_duty = pwmbl->pdata->pwm_duty_max - intensity;
-
- if (pwm_duty > pwmbl->pdata->pwm_duty_max)
- pwm_duty = pwmbl->pdata->pwm_duty_max;
- if (pwm_duty < pwmbl->pdata->pwm_duty_min)
- pwm_duty = pwmbl->pdata->pwm_duty_min;
-
- if (!intensity) {
- atmel_pwm_bl_set_gpio_on(pwmbl, 0);
- pwm_channel_writel(&pwmbl->pwmc, PWM_CUPD, pwm_duty);
- pwm_channel_disable(&pwmbl->pwmc);
- } else {
- pwm_channel_enable(&pwmbl->pwmc);
- pwm_channel_writel(&pwmbl->pwmc, PWM_CUPD, pwm_duty);
- atmel_pwm_bl_set_gpio_on(pwmbl, 1);
- }
-
- return 0;
-}
-
-static int atmel_pwm_bl_get_intensity(struct backlight_device *bd)
-{
- struct atmel_pwm_bl *pwmbl = bl_get_data(bd);
- u32 cdty;
- u32 intensity;
-
- cdty = pwm_channel_readl(&pwmbl->pwmc, PWM_CDTY);
- if (pwmbl->pdata->pwm_active_low)
- intensity = cdty - pwmbl->pdata->pwm_duty_min;
- else
- intensity = pwmbl->pdata->pwm_duty_max - cdty;
-
- return intensity & 0xffff;
-}
-
-static int atmel_pwm_bl_init_pwm(struct atmel_pwm_bl *pwmbl)
-{
- unsigned long pwm_rate = pwmbl->pwmc.mck;
- unsigned long prescale = DIV_ROUND_UP(pwm_rate,
- (pwmbl->pdata->pwm_frequency *
- pwmbl->pdata->pwm_compare_max)) - 1;
-
- /*
- * Prescale must be power of two and maximum 0xf in size because of
- * hardware limit. PWM speed will be:
- * PWM module clock speed / (2 ^ prescale).
- */
- prescale = fls(prescale);
- if (prescale > 0xf)
- prescale = 0xf;
-
- pwm_channel_writel(&pwmbl->pwmc, PWM_CMR, prescale);
- pwm_channel_writel(&pwmbl->pwmc, PWM_CDTY,
- pwmbl->pdata->pwm_duty_min +
- pwmbl->bldev->props.brightness);
- pwm_channel_writel(&pwmbl->pwmc, PWM_CPRD,
- pwmbl->pdata->pwm_compare_max);
-
- dev_info(&pwmbl->pdev->dev, "Atmel PWM backlight driver (%lu Hz)\n",
- pwmbl->pwmc.mck / pwmbl->pdata->pwm_compare_max /
- (1 << prescale));
-
- return pwm_channel_enable(&pwmbl->pwmc);
-}
-
-static const struct backlight_ops atmel_pwm_bl_ops = {
- .get_brightness = atmel_pwm_bl_get_intensity,
- .update_status = atmel_pwm_bl_set_intensity,
-};
-
-static int atmel_pwm_bl_probe(struct platform_device *pdev)
-{
- struct backlight_properties props;
- const struct atmel_pwm_bl_platform_data *pdata;
- struct backlight_device *bldev;
- struct atmel_pwm_bl *pwmbl;
- unsigned long flags;
- int retval;
-
- pdata = dev_get_platdata(&pdev->dev);
- if (!pdata)
- return -ENODEV;
-
- if (pdata->pwm_compare_max < pdata->pwm_duty_max ||
- pdata->pwm_duty_min > pdata->pwm_duty_max ||
- pdata->pwm_frequency == 0)
- return -EINVAL;
-
- pwmbl = devm_kzalloc(&pdev->dev, sizeof(struct atmel_pwm_bl),
- GFP_KERNEL);
- if (!pwmbl)
- return -ENOMEM;
-
- pwmbl->pdev = pdev;
- pwmbl->pdata = pdata;
- pwmbl->gpio_on = pdata->gpio_on;
-
- retval = pwm_channel_alloc(pdata->pwm_channel, &pwmbl->pwmc);
- if (retval)
- return retval;
-
- if (gpio_is_valid(pwmbl->gpio_on)) {
- /* Turn display off by default. */
- if (pdata->on_active_low)
- flags = GPIOF_OUT_INIT_HIGH;
- else
- flags = GPIOF_OUT_INIT_LOW;
-
- retval = devm_gpio_request_one(&pdev->dev, pwmbl->gpio_on,
- flags, "gpio_atmel_pwm_bl");
- if (retval)
- goto err_free_pwm;
- }
-
- memset(&props, 0, sizeof(struct backlight_properties));
- props.type = BACKLIGHT_RAW;
- props.max_brightness = pdata->pwm_duty_max - pdata->pwm_duty_min;
- bldev = devm_backlight_device_register(&pdev->dev, "atmel-pwm-bl",
- &pdev->dev, pwmbl, &atmel_pwm_bl_ops,
- &props);
- if (IS_ERR(bldev)) {
- retval = PTR_ERR(bldev);
- goto err_free_pwm;
- }
-
- pwmbl->bldev = bldev;
-
- platform_set_drvdata(pdev, pwmbl);
-
- /* Power up the backlight by default at middle intesity. */
- bldev->props.power = FB_BLANK_UNBLANK;
- bldev->props.brightness = bldev->props.max_brightness / 2;
-
- retval = atmel_pwm_bl_init_pwm(pwmbl);
- if (retval)
- goto err_free_pwm;
-
- atmel_pwm_bl_set_intensity(bldev);
-
- return 0;
-
-err_free_pwm:
- pwm_channel_free(&pwmbl->pwmc);
-
- return retval;
-}
-
-static int atmel_pwm_bl_remove(struct platform_device *pdev)
-{
- struct atmel_pwm_bl *pwmbl = platform_get_drvdata(pdev);
-
- atmel_pwm_bl_set_gpio_on(pwmbl, 0);
- pwm_channel_disable(&pwmbl->pwmc);
- pwm_channel_free(&pwmbl->pwmc);
-
- return 0;
-}
-
-static struct platform_driver atmel_pwm_bl_driver = {
- .driver = {
- .name = "atmel-pwm-bl",
- },
- /* REVISIT add suspend() and resume() */
- .probe = atmel_pwm_bl_probe,
- .remove = atmel_pwm_bl_remove,
-};
-
-module_platform_driver(atmel_pwm_bl_driver);
-
-MODULE_AUTHOR("Hans-Christian egtvedt <hans-christian.egtvedt@atmel.com>");
-MODULE_DESCRIPTION("Atmel PWM backlight driver");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:atmel-pwm-bl");
+++ /dev/null
-/*
- * 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 */
projects / cascardo / linux.git / commitdiff