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Add virtual leds with more complex structure and allocation

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This commit is contained in:
Florian RICHER 2025-02-23 15:40:29 +01:00
parent d0960cb6e6
commit 04de922e60
Signed by: florian.richer
GPG key ID: C73D37CBED7BFC77
2 changed files with 94 additions and 0 deletions
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7
07_virtual_leds_more_complex/Makefile Normal file
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obj-m += test_module.o
all:
make -C $(LINUX_MODULES_FOLDER)/build M=$(PWD) modules
clean:
make -C $(LINUX_MODULES_FOLDER)/build M=$(PWD) clean

87
07_virtual_leds_more_complex/test_module.c Normal file
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#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/module.h>
#define NUM_LEDS 5
struct flo_device {
struct led_classdev *leds[NUM_LEDS];
};
static struct flo_device flo_dev;
static void virtual_led_brightness_set(struct led_classdev *led_cdev, enum led_brightness brightness) {
pr_info("Luminosité défini sur la LED %s à %d\n", led_cdev->name, brightness);
}
static enum led_brightness virtual_led_brightness_get(struct led_classdev *led_cdev) {
pr_info("Luminosité lu sur la LED %s, valeur actuelle: %d\n", led_cdev->name, led_cdev->brightness);
return led_cdev->brightness;
}
static int __init virtual_led_init(void) {
int ret, i;
pr_info("Chargement du module pour les LEDs virtuelles\n");
for (i = 0; i < NUM_LEDS; i++) {
struct led_classdev *led = kzalloc(sizeof(struct led_classdev), GFP_KERNEL);
if (!led) {
pr_err("Échec de l'allocation de mémoire pour la LED %d\n", i);
ret = -ENOMEM;
goto fail;
}
led->name = kasprintf(GFP_KERNEL, "flo-led:white:flo-%d", i + 1);
led->color = LED_COLOR_ID_WHITE;
led->brightness = 0;
led->max_brightness = 255;
led->brightness_set = virtual_led_brightness_set;
led->brightness_get = virtual_led_brightness_get;
ret = led_classdev_register(NULL, led);
if (ret < 0) {
pr_err("Impossible d'ajouter la LED virtuelle %d\n", i);
kfree(led->name);
kfree(led);
goto fail;
}
flo_dev.leds[i] = led;
}
pr_info("Les LEDs virtuelles sont ajoutées\n");
return 0;
fail:
for (i--; i >= 0; i--) {
led_classdev_unregister(flo_dev.leds[i]);
kfree(flo_dev.leds[i]->name);
kfree(flo_dev.leds[i]);
}
pr_err("Les LEDs virtuelles n'ont pas pu être ajoutées\n");
return ret;
}
static void __exit virtual_led_exit(void) {
int i;
pr_info("Déchargement du module pour les LEDs virtuelles\n");
for (i = 0; i < NUM_LEDS; i++) {
if (flo_dev.leds[i]) {
led_classdev_unregister(flo_dev.leds[i]);
kfree(flo_dev.leds[i]->name);
kfree(flo_dev.leds[i]);
}
}
pr_info("Les LEDs virtuelles sont bien retirées\n");
}
module_init(virtual_led_init);
module_exit(virtual_led_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Florian RICHER");
MODULE_DESCRIPTION("Un module noyau qui ajoute des LEDs virtuelles");
MODULE_VERSION("1.0");