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leds: triggers: gpio: Rewrite to use trigger-sources

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By providing a GPIO line as "trigger-sources" in the FWNODE
(such as from the device tree) and combining with the
GPIO trigger, we can support a GPIO LED trigger in a natural
way from the hardware description instead of using the
custom sysfs and deprecated global GPIO numberspace.

Example:

gpio: gpio@0 {
    compatible "my-gpio";
    gpio-controller;
    #gpio-cells = <2>;
    interrupt-controller;
    #interrupt-cells = <2>;
    #trigger-source-cells = <2>;
};

leds {
    compatible = "gpio-leds";
    led-my-gpio {
        label = "device:blue:myled";
        gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
        default-state = "off";
        linux,default-trigger = "gpio";
        trigger-sources = <&gpio 1 GPIO_ACTIVE_HIGH>;
    };
};

Make this the norm, unmark the driver as broken.

Delete the sysfs handling of GPIOs.

Since GPIO descriptors inherently can describe inversion,
the inversion handling can just be deleted.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230926-gpio-led-trigger-dt-v2-3-e06e458b788e@linaro.org
Signed-off-by: Lee Jones <lee@kernel.org>
This commit is contained in:
Linus Walleij
2023-09-26 23:48:13 +02:00
committed by Lee Jones
parent f9be4d5bb6
commit 4a11dbf04f
2 changed files with 41 additions and 101 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/leds/trigger/Kconfig
+1 -4
View File
@@ -83,13 +83,10 @@ config LEDS_TRIGGER_ACTIVITY
config LEDS_TRIGGER_GPIO
tristate "LED GPIO Trigger"
depends on GPIOLIB || COMPILE_TEST
depends on BROKEN
help
This allows LEDs to be controlled by gpio events. It's good
when using gpios as switches and triggering the needed LEDs
from there. One use case is n810's keypad LEDs that could
be triggered by this trigger when user slides up to show
keypad.
from there. Triggers are defined as device properties.
If unsure, say N.
drivers/leds/trigger/ledtrig-gpio.c
+40 -97
View File
@@ -3,12 +3,13 @@
* ledtrig-gio.c - LED Trigger Based on GPIO events
*
* Copyright 2009 Felipe Balbi <me@felipebalbi.com>
* Copyright 2023 Linus Walleij <linus.walleij@linaro.org>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/leds.h>
#include <linux/slab.h>
@@ -16,10 +17,8 @@
struct gpio_trig_data {
struct led_classdev *led;
unsigned desired_brightness; /* desired brightness when led is on */
unsigned inverted; /* true when gpio is inverted */
unsigned gpio; /* gpio that triggers the leds */
struct gpio_desc *gpiod; /* gpio that triggers the led */
};
static irqreturn_t gpio_trig_irq(int irq, void *_led)
@@ -28,10 +27,7 @@ static irqreturn_t gpio_trig_irq(int irq, void *_led)
struct gpio_trig_data *gpio_data = led_get_trigger_data(led);
int tmp;
tmp = gpio_get_value_cansleep(gpio_data->gpio);
if (gpio_data->inverted)
tmp = !tmp;
tmp = gpiod_get_value_cansleep(gpio_data->gpiod);
if (tmp) {
if (gpio_data->desired_brightness)
led_set_brightness_nosleep(gpio_data->led,
@@ -73,93 +69,8 @@ static ssize_t gpio_trig_brightness_store(struct device *dev,
static DEVICE_ATTR(desired_brightness, 0644, gpio_trig_brightness_show,
gpio_trig_brightness_store);
static ssize_t gpio_trig_inverted_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
return sprintf(buf, "%u\n", gpio_data->inverted);
}
static ssize_t gpio_trig_inverted_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t n)
{
struct led_classdev *led = led_trigger_get_led(dev);
struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
unsigned long inverted;
int ret;
ret = kstrtoul(buf, 10, &inverted);
if (ret < 0)
return ret;
if (inverted > 1)
return -EINVAL;
gpio_data->inverted = inverted;
/* After inverting, we need to update the LED. */
if (gpio_is_valid(gpio_data->gpio))
gpio_trig_irq(0, led);
return n;
}
static DEVICE_ATTR(inverted, 0644, gpio_trig_inverted_show,
gpio_trig_inverted_store);
static ssize_t gpio_trig_gpio_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
return sprintf(buf, "%u\n", gpio_data->gpio);
}
static ssize_t gpio_trig_gpio_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t n)
{
struct led_classdev *led = led_trigger_get_led(dev);
struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
unsigned gpio;
int ret;
ret = sscanf(buf, "%u", &gpio);
if (ret < 1) {
dev_err(dev, "couldn't read gpio number\n");
return -EINVAL;
}
if (gpio_data->gpio == gpio)
return n;
if (!gpio_is_valid(gpio)) {
if (gpio_is_valid(gpio_data->gpio))
free_irq(gpio_to_irq(gpio_data->gpio), led);
gpio_data->gpio = gpio;
return n;
}
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);
} else {
if (gpio_is_valid(gpio_data->gpio))
free_irq(gpio_to_irq(gpio_data->gpio), led);
gpio_data->gpio = gpio;
/* After changing the GPIO, we need to update the LED. */
gpio_trig_irq(0, led);
}
return ret ? ret : n;
}
static DEVICE_ATTR(gpio, 0644, gpio_trig_gpio_show, gpio_trig_gpio_store);
static struct attribute *gpio_trig_attrs[] = {
&dev_attr_desired_brightness.attr,
&dev_attr_inverted.attr,
&dev_attr_gpio.attr,
NULL
};
ATTRIBUTE_GROUPS(gpio_trig);
@@ -167,16 +78,48 @@ ATTRIBUTE_GROUPS(gpio_trig);
static int gpio_trig_activate(struct led_classdev *led)
{
struct gpio_trig_data *gpio_data;
struct device *dev = led->dev;
int ret;
gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL);
if (!gpio_data)
return -ENOMEM;
gpio_data->led = led;
gpio_data->gpio = -ENOENT;
/*
* The generic property "trigger-sources" is followed,
* and we hope that this is a GPIO.
*/
gpio_data->gpiod = fwnode_gpiod_get_index(dev->fwnode,
"trigger-sources",
0, GPIOD_IN,
"led-trigger");
if (IS_ERR(gpio_data->gpiod)) {
ret = PTR_ERR(gpio_data->gpiod);
kfree(gpio_data);
return ret;
}
if (!gpio_data->gpiod) {
dev_err(dev, "no valid GPIO for the trigger\n");
kfree(gpio_data);
return -EINVAL;
}
gpio_data->led = led;
led_set_trigger_data(led, gpio_data);
ret = request_threaded_irq(gpiod_to_irq(gpio_data->gpiod), 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);
gpiod_put(gpio_data->gpiod);
kfree(gpio_data);
return ret;
}
/* Finally update the LED to initial status */
gpio_trig_irq(0, led);
return 0;
}
@@ -184,8 +127,8 @@ static void gpio_trig_deactivate(struct led_classdev *led)
{
struct gpio_trig_data *gpio_data = led_get_trigger_data(led);
if (gpio_is_valid(gpio_data->gpio))
free_irq(gpio_to_irq(gpio_data->gpio), led);
free_irq(gpiod_to_irq(gpio_data->gpiod), led);
gpiod_put(gpio_data->gpiod);
kfree(gpio_data);
}