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 = 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 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 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) {
if (pwmbl->gpio_on != -1) {
gpio_set_value(pwmbl->gpio_on,
0 ^ pwmbl->pdata->on_active_low);
}
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);
if (pwmbl->gpio_on != -1) {
gpio_set_value(pwmbl->gpio_on,
1 ^ pwmbl->pdata->on_active_low);
}
}
return 0;
}
