Add virtual leds with more complex structure and allocation

06_virtual_led_basic/test_module.c

@@ -3,8 +3,13 @@
 #include <linux/leds.h>
 #include <linux/module.h>
 
-static void virtual_led_set_brightness(struct led_classdev *led_cdev, enum led_brightness brightness) {
-	pr_info("Luminosité défini sur la LED %s à %d", led_cdev->name, brightness);
+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 struct led_classdev virtual_led = {
@@ -12,27 +17,28 @@ static struct led_classdev virtual_led = {
 	.color = LED_COLOR_ID_WHITE,
 	.brightness = 0,
 	.max_brightness = 255,
-	.brightness_set = virtual_led_set_brightness
+	.brightness_set = virtual_led_brightness_set,
+	.brightness_set = virtual_led_brightness_get
 };
 
 static int __init virtual_led_init(void) {
 	int ret;
-	pr_info("Chargement du module pour la LED virtuelle");
+	pr_info("Chargement du module pour la LED virtuelle\n");
 
 	ret = led_classdev_register(NULL, &virtual_led);
 	if (ret < 0) {
-		pr_err("Impossible d'ajouter la LED virtuelle");
+		pr_err("Impossible d'ajouter la LED virtuelle\n");
 		return ret;
 	}
 
-	pr_info("La LED virtuelle est ajouté");
+	pr_info("La LED virtuelle est ajouté\n");
 	return 0;
 }
 
 static void __exit virtual_led_exit(void) {
-	pr_info("Déchargement du module pour la LED virtuelle");
+	pr_info("Déchargement du module pour la LED virtuelle\n");
 	led_classdev_unregister(&virtual_led);
-	pr_info("La LED virtuelle est bien retiré");
+	pr_info("La LED virtuelle est bien retiré\n");
 }
 
 module_init(virtual_led_init);

07_virtual_leds_more_complex/Makefile

@@ -0,0 +1,7 @@
+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

07_virtual_leds_more_complex/test_module.c

@@ -0,0 +1,87 @@
+#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");