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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
leds: Teach leds-gpio to handle timer-unsafe GPIOs
Teach the new leds-gpio driver that some GPIOs can't be accessed from
timer callbacks ... which is how all today's standard triggers use them.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
authored by David Brownell and committed by Richard Purdie 00852279 22e03f3b
+26
-1
drivers/leds/leds-gpio.c
+26
-1
drivers/leds/leds-gpio.c
···
13
#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/leds.h>
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#include <asm/gpio.h>
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struct gpio_led_data {
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struct led_classdev cdev;
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unsigned gpio;
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u8 active_low;
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};
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static void gpio_led_set(struct led_classdev *led_cdev,
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enum led_brightness value)
···
49
if (led_dat->active_low)
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level = !level;
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52
-
gpio_set_value(led_dat->gpio, level);
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}
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static int __init gpio_led_probe(struct platform_device *pdev)
···
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led_dat->cdev.name = cur_led->name;
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led_dat->cdev.default_trigger = cur_led->default_trigger;
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led_dat->gpio = cur_led->gpio;
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led_dat->active_low = cur_led->active_low;
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led_dat->cdev.brightness_set = gpio_led_set;
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led_dat->cdev.brightness = cur_led->active_low ? LED_FULL : LED_OFF;
···
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gpio_free(led_dat->gpio);
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goto err;
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}
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}
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platform_set_drvdata(pdev, leds_data);
···
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gpio_free(leds_data[i].gpio);
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}
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}
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kfree(leds_data);
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return ret;
···
13
#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/leds.h>
16
+
#include <linux/workqueue.h>
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+
18
#include <asm/gpio.h>
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struct gpio_led_data {
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struct led_classdev cdev;
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unsigned gpio;
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+
struct work_struct work;
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+
u8 new_level;
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+
u8 can_sleep;
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u8 active_low;
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};
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+
static void gpio_led_work(struct work_struct *work)
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+
{
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+
struct gpio_led_data *led_dat =
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+
container_of(work, struct gpio_led_data, work);
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+
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+
gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
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+
}
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static void gpio_led_set(struct led_classdev *led_cdev,
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enum led_brightness value)
···
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if (led_dat->active_low)
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level = !level;
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40
+
/* setting GPIOs with I2C/etc requires a preemptible task context */
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+
if (led_dat->can_sleep) {
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+
if (preempt_count()) {
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+
led_dat->new_level = level;
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+
schedule_work(&led_dat->work);
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+
} else
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+
gpio_set_value_cansleep(led_dat->gpio, level);
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+
} else
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+
gpio_set_value(led_dat->gpio, level);
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}
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static int __init gpio_led_probe(struct platform_device *pdev)
···
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led_dat->cdev.name = cur_led->name;
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led_dat->cdev.default_trigger = cur_led->default_trigger;
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led_dat->gpio = cur_led->gpio;
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+
led_dat->can_sleep = gpio_cansleep(cur_led->gpio);
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led_dat->active_low = cur_led->active_low;
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led_dat->cdev.brightness_set = gpio_led_set;
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led_dat->cdev.brightness = cur_led->active_low ? LED_FULL : LED_OFF;
···
77
gpio_free(led_dat->gpio);
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goto err;
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}
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+
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+
INIT_WORK(&led_dat->work, gpio_led_work);
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}
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platform_set_drvdata(pdev, leds_data);
···
90
gpio_free(leds_data[i].gpio);
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}
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}
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+
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+
flush_scheduled_work();
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kfree(leds_data);
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return ret;