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

[Olliver Schinagl]

From: Olliver Schinagl <oli...@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 <oli...@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

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