leds: trigger: gpio: Use threaded IRQ

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@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

1 files 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);