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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/leds/trigger/ledtrig-gpio.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/leds/trigger/ledtrig-gpio.c')
-rw-r--r-- | drivers/leds/trigger/ledtrig-gpio.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/drivers/leds/trigger/ledtrig-gpio.c b/drivers/leds/trigger/ledtrig-gpio.c new file mode 100644 index 000000000..0120faa3d --- /dev/null +++ b/drivers/leds/trigger/ledtrig-gpio.c @@ -0,0 +1,202 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ledtrig-gio.c - LED Trigger Based on GPIO events + * + * Copyright 2009 Felipe Balbi <me@felipebalbi.com> + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/gpio.h> +#include <linux/interrupt.h> +#include <linux/leds.h> +#include <linux/slab.h> +#include "../leds.h" + +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 */ +}; + +static irqreturn_t gpio_trig_irq(int irq, void *_led) +{ + struct led_classdev *led = _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; + + if (tmp) { + if (gpio_data->desired_brightness) + led_set_brightness_nosleep(gpio_data->led, + gpio_data->desired_brightness); + else + led_set_brightness_nosleep(gpio_data->led, LED_FULL); + } else { + led_set_brightness_nosleep(gpio_data->led, LED_OFF); + } + + return IRQ_HANDLED; +} + +static ssize_t gpio_trig_brightness_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->desired_brightness); +} + +static ssize_t gpio_trig_brightness_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t n) +{ + struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev); + unsigned desired_brightness; + int ret; + + ret = sscanf(buf, "%u", &desired_brightness); + if (ret < 1 || desired_brightness > 255) { + dev_err(dev, "invalid value\n"); + return -EINVAL; + } + + gpio_data->desired_brightness = desired_brightness; + + return n; +} +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); + +static int gpio_trig_activate(struct led_classdev *led) +{ + struct gpio_trig_data *gpio_data; + + gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL); + if (!gpio_data) + return -ENOMEM; + + gpio_data->led = led; + gpio_data->gpio = -ENOENT; + + led_set_trigger_data(led, gpio_data); + + return 0; +} + +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); + kfree(gpio_data); +} + +static struct led_trigger gpio_led_trigger = { + .name = "gpio", + .activate = gpio_trig_activate, + .deactivate = gpio_trig_deactivate, + .groups = gpio_trig_groups, +}; +module_led_trigger(gpio_led_trigger); + +MODULE_AUTHOR("Felipe Balbi <me@felipebalbi.com>"); +MODULE_DESCRIPTION("GPIO LED trigger"); +MODULE_LICENSE("GPL v2"); |