[PATCH 09/10] pwm: pwm_gpio: add pulse option

Olliver Schinagl
2015-10-26T21:34:33Z

From: Olliver Schinagl <oliver@schinagl.nl>

With the newly added pwm_pulse option added to the PWM framework, this
patch adds the pulse functionality to the gpio_pwm driver.

Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
---
drivers/pwm/pwm-gpio.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)

diff --git a/drivers/pwm/pwm-gpio.c b/drivers/pwm/pwm-gpio.c
index cf4b170..24c27b1 100644
--- a/drivers/pwm/pwm-gpio.c
+++ b/drivers/pwm/pwm-gpio.c
@@ -40,6 +40,8 @@ struct gpio_pwm_data {
bool pin_on;
int on_time;
int off_time;
+ unsigned int count;
+ bool pulse;
bool run;
};

@@ -80,6 +82,16 @@ enum hrtimer_restart gpio_pwm_timer(struct hrtimer *timer)
gpio_data->pin_on = false;
}

+ if (gpio_data->count > 0)
+ gpio_data->count--;
+ if (!gpio_data->count && gpio_data->pulse) {
+ struct pwm_device *pwm = container_of((void *)gpio_data,
+ struct pwm_device,
+ chip_data);
+ pwm_pulse_done(pwm);
+ return HRTIMER_NORESTART;
+ }
+
return HRTIMER_RESTART;
}

@@ -88,6 +100,10 @@ static int gpio_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
{
struct gpio_pwm_data *gpio_data = pwm_get_chip_data(pwm);

+ /* A full pulse is both the on and off time, and since counting each
+ * iteration of the timer is easy and clean, we need double the count.
+ */
+ gpio_data->count = count * 2;
gpio_data->on_time = duty_ns;
gpio_data->off_time = period_ns - duty_ns;

@@ -111,6 +127,9 @@ static int gpio_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
if (gpio_data->run)
return -EBUSY;

+ if (pwm->pulse_count)
+ gpio_data->pulse = true;
+ gpio_data->count = pwm->pulse_count;
gpio_data->run = true;
if (gpio_data->off_time) {
hrtimer_start(&gpio_data->timer, ktime_set(0, 0),
@@ -130,6 +149,7 @@ static void gpio_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
struct gpio_pwm_data *gpio_data = pwm_get_chip_data(pwm);

gpio_data->run = false;
+ gpio_data->pulse = false;
if (!gpio_data->off_time)
gpio_pwm_off(gpio_data);
}
@@ -196,6 +216,8 @@ static int gpio_pwm_probe(struct platform_device *pdev)
gpio_data->timer.function = &gpio_pwm_timer;
gpio_data->gpiod = gpiod;
gpio_data->pin_on = false;
+ gpio_data->count = 0;
+ gpio_data->pulse = false;
gpio_data->run = false;

if (hrtimer_is_hres_active(&gpio_data->timer))
--
2.6.1