diff --git a/08_gpio_led/test_module.c b/08_gpio_led/test_module.c deleted file mode 100644 index 543a71c..0000000 --- a/08_gpio_led/test_module.c +++ /dev/null @@ -1,71 +0,0 @@ -#include -#include -#include -#include -#include - -static char *device_label = ""; -module_param(device_label, charp, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP); -MODULE_PARM_DESC(device_label, "GPIO Device Label"); - -static char *gpio_pin_id = ""; -module_param(gpio_pin_id, charp, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP); -MODULE_PARM_DESC(gpio_pin_id, "GPIO Pin ID"); - -struct gpio_device *device; -struct gpio_desc *led_desc; - -// Copied from https://elixir.bootlin.com/linux/v6.6.79/source/drivers/gpio/gpiolib.c#L1085 -// gpio_device_find_by_label it's not available on Linux Kernel 6.6 but only with Linux Kernel 6.7+ -// static int gpiochip_match_name(struct gpio_chip *gc, void *data) -// { -// const char *name = data; - -// return !strcmp(gc->label, name); -// } - -static int __init gpio_led_init(void) { - int ret; - - // On Linux Kernel 6.7+ - device = gpio_device_find_by_label(device_label); - // Otherwise - // device = gpio_device_find(device_label, gpiochip_match_name); - if (!device) { - pr_err("Failed to get device"); - return -ENODEV; - } - - led_desc = gpiod_get(device->dev, gpio_pin_id, GPIOD_OUT_LOW); - if (IS_ERR(led_desc)) { - pr_err("Failed to get GPIO: %ld\n", PTR_ERR(led_desc)); - ret = PTR_ERR(led_desc); - goto fail; - } - - gpiod_set_value(led_desc, 1); - - pr_info("Bonjour! Le module est chargé.\n"); - return 0; - -fail: - gpio_device_put(device); - return -ENODEV; -} - -static void __exit gpio_led_exit(void) { - gpiod_set_value(led_desc, 0); - - gpiod_put(led_desc); - gpio_device_put(device); - - pr_info("Au revoir! Le module est déchargé.\n"); -} - -module_init(gpio_led_init); -module_exit(gpio_led_exit); - -MODULE_LICENSE("MIT License"); -MODULE_AUTHOR("Florian RICHER"); -MODULE_DESCRIPTION("Un module noyau pour utiliser un PIN GPIO d'une RPI en tant que LED"); -MODULE_VERSION("1.0"); diff --git a/08_gpio_led/Makefile b/08_gpio_pin_rpi3/Makefile similarity index 100% rename from 08_gpio_led/Makefile rename to 08_gpio_pin_rpi3/Makefile diff --git a/08_gpio_pin_rpi3/test_module.c b/08_gpio_pin_rpi3/test_module.c new file mode 100644 index 0000000..9bf2fe1 --- /dev/null +++ b/08_gpio_pin_rpi3/test_module.c @@ -0,0 +1,67 @@ +#include +#include +#include + +// gpiochip0: GPIOs 512-565, parent: platform/3f200000.gpio, pinctrl-bcm2835 +// From /sys/kernel/debug/gpio +#define RPI3_BCM2835_GPIO_OFFSET 512 +#define BCM_TO_LINUX_GPIO(bcm) (RPI3_BCM2835_GPIO_OFFSET + (bcm)) + +static int gpio_pin = -1; +module_param(gpio_pin, int, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); +MODULE_PARM_DESC(gpio_pin, "BCM GPIO pin number (e.g., 17)"); + +struct gpio_pin_rpi3 { + int linux_gpio; + int bcm_gpio; + struct gpio_desc *desc; +}; + +static struct gpio_pin_rpi3 pin; + +static int __init gpio_pin_rpi3_init(void) +{ + if (gpio_pin < 0) { + pr_err("gpio_pin_rpi3: You must specify 'gpio_pin' (e.g., gpio_pin=17)\n"); + return -EINVAL; + } + + pin.bcm_gpio = gpio_pin; + pin.linux_gpio = BCM_TO_LINUX_GPIO(pin.bcm_gpio); + + // Récupération du descripteur GPIO à partir du numéro Globale Linux + pin.desc = gpio_to_desc(pin.linux_gpio); + if (!pin.desc) { + pr_err("gpio_pin_rpi3: Le GPIO %d (BCM %d) non trouvé\n", pin.linux_gpio, pin.bcm_gpio); + return -ENODEV; + } + + // Réclame le PIN GPIO + if (gpiod_direction_output(pin.desc, 0)) { + pr_err("gpio_pin_rpi3: Impossible de configurer le GPIO %d\n", pin.linux_gpio); + gpiod_put(pin.desc); + return -EINVAL; + } + + // Allume la LED + gpiod_set_value(pin.desc, 1); + pr_info("gpio_pin_rpi3: GPIO %d (BCM %d) activé (LED ON)\n", pin.linux_gpio, pin.bcm_gpio); + + return 0; +} + +static void __exit gpio_pin_rpi3_exit(void) +{ + // Turn LED off and release GPIO + gpiod_set_value(pin.desc, 0); + gpiod_put(pin.desc); + pr_info("gpio_pin_rpi3: GPIO %d (BCM %d) libéré (LED OFF)\n", pin.linux_gpio, pin.bcm_gpio); +} + +module_init(gpio_pin_rpi3_init); +module_exit(gpio_pin_rpi3_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Florian RICHER "); +MODULE_DESCRIPTION("Un module noyau pour utiliser un PIN GPIO d'une RPI"); +MODULE_VERSION("1.0"); \ No newline at end of file