[PATCH 2/2] leds: trigger: gpio: Use threaded IRQ

From: Jan Kiszka
Date: Fri May 26 2017 - 09:18:30 EST


This both simplifies the code because we can drop the workqueue
indirection, and it enables using the trigger for GPIOs that work with
threaded IRQs themselves.

Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---
drivers/leds/trigger/ledtrig-gpio.c | 29 ++++++-----------------------
1 file changed, 6 insertions(+), 23 deletions(-)

diff --git a/drivers/leds/trigger/ledtrig-gpio.c b/drivers/leds/trigger/ledtrig-gpio.c
index 93d6b82e6437..8891e88d54dd 100644
--- a/drivers/leds/trigger/ledtrig-gpio.c
+++ b/drivers/leds/trigger/ledtrig-gpio.c
@@ -14,14 +14,12 @@
#include <linux/init.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
-#include <linux/workqueue.h>
#include <linux/leds.h>
#include <linux/slab.h>
#include "../leds.h"

struct gpio_trig_data {
struct led_classdev *led;
- struct work_struct work;

unsigned desired_brightness; /* desired brightness when led is on */
unsigned inverted; /* true when gpio is inverted */
@@ -32,22 +30,8 @@ static irqreturn_t gpio_trig_irq(int irq, void *_led)
{
struct led_classdev *led = _led;
struct gpio_trig_data *gpio_data = led->trigger_data;
-
- /* just schedule_work since gpio_get_value can sleep */
- schedule_work(&gpio_data->work);
-
- return IRQ_HANDLED;
-};
-
-static void gpio_trig_work(struct work_struct *work)
-{
- struct gpio_trig_data *gpio_data = container_of(work,
- struct gpio_trig_data, work);
int tmp;

- if (!gpio_data->gpio)
- return;
-
tmp = gpio_get_value_cansleep(gpio_data->gpio);
if (gpio_data->inverted)
tmp = !tmp;
@@ -61,6 +45,8 @@ static void gpio_trig_work(struct work_struct *work)
} else {
led_set_brightness_nosleep(gpio_data->led, LED_OFF);
}
+
+ return IRQ_HANDLED;
}

static ssize_t gpio_trig_brightness_show(struct device *dev,
@@ -120,7 +106,7 @@ static ssize_t gpio_trig_inverted_store(struct device *dev,
gpio_data->inverted = inverted;

/* After inverting, we need to update the LED. */
- schedule_work(&gpio_data->work);
+ gpio_trig_irq(0, led);

return n;
}
@@ -147,7 +133,6 @@ static ssize_t gpio_trig_gpio_store(struct device *dev,
ret = sscanf(buf, "%u", &gpio);
if (ret < 1) {
dev_err(dev, "couldn't read gpio number\n");
- flush_work(&gpio_data->work);
return -EINVAL;
}

@@ -161,8 +146,8 @@ static ssize_t gpio_trig_gpio_store(struct device *dev,
return n;
}

- ret = request_irq(gpio_to_irq(gpio), gpio_trig_irq,
- IRQF_SHARED | IRQF_TRIGGER_RISING
+ ret = request_threaded_irq(gpio_to_irq(gpio), NULL, gpio_trig_irq,
+ IRQF_ONESHOT | IRQF_SHARED | IRQF_TRIGGER_RISING
| IRQF_TRIGGER_FALLING, "ledtrig-gpio", led);
if (ret) {
dev_err(dev, "request_irq failed with error %d\n", ret);
@@ -171,7 +156,7 @@ static ssize_t gpio_trig_gpio_store(struct device *dev,
free_irq(gpio_to_irq(gpio_data->gpio), led);
gpio_data->gpio = gpio;
/* After changing the GPIO, we need to update the LED. */
- schedule_work(&gpio_data->work);
+ gpio_trig_irq(0, led);
}

return ret ? ret : n;
@@ -201,7 +186,6 @@ static void gpio_trig_activate(struct led_classdev *led)

gpio_data->led = led;
led->trigger_data = gpio_data;
- INIT_WORK(&gpio_data->work, gpio_trig_work);
led->activated = true;

return;
@@ -224,7 +208,6 @@ static void gpio_trig_deactivate(struct led_classdev *led)
device_remove_file(led->dev, &dev_attr_gpio);
device_remove_file(led->dev, &dev_attr_inverted);
device_remove_file(led->dev, &dev_attr_desired_brightness);
- flush_work(&gpio_data->work);
if (gpio_data->gpio != 0)
free_irq(gpio_to_irq(gpio_data->gpio), led);
kfree(gpio_data);
--
2.12.0