STRUCT GPIO_V2_LINE_REQUEST(9)

💅 NAME 💅

struct gpio_v2_line_request — okay bestie, this is literally the struct that holds all the info about you asking the kernel for some GPIO lines. It's giving "application form for pins" energy ✨

(also hi, this is the struct gpio_v2_line_request(9) page from the Kernel API Manual, welcome 🫶)

✨ SYNOPSIS ✨

struct gpio_v2_line_request {
    __u32 offsets[GPIO_V2_LINES_MAX];
    char consumer[GPIO_MAX_NAME_SIZE];
    struct gpio_v2_line_config config;
    __u32 num_lines;
    __u32 event_buffer_size;
    __u32 padding[5];
    __s32 fd;
 };

🎀 Members 🎀

okay so let's go field by field, no skipping, we're doing this properly 💖

• offsets — an array of the lines you want, each one specified by its offset index for the GPIO chip it belongs to. It's the GPIO_V2_LINES_MAX-sized guest list 🎟️
• consumer — the consumer label you want for the lines you picked, like "my-bitbanged-relay". This is your ~aesthetic~ name tag so everyone knows who's using the pins, iconic 💅
• config — the configuration you're requesting for the lines
• num_lines — how many lines you're actually requesting in this request, i.e. the number of valid fields in those GPIO_V2_LINES_MAX-sized arrays. Set it to 1 if you only want a single line, lowkey minimal of you 🌸
• event_buffer_size — a suggested minimum number of line events the kernel should buffer for you. Heads up: this only matters if edge detection is enabled in the configuration. And note — it's only a suggestion, bestie 😭 the kernel may allocate a larger buffer, or cap the size of the buffer. If this field is zero then the buffer size defaults to a minimum of num_lines * 16. Not me doing math at 2am 🧮
• padding — reserved for future use and it must be zero filled. fr fr, zero it out 🙈
• fd — after a successful GPIO_V2_GET_LINE_IOCTL operation, this contains a valid anonymous file descriptor representing the request. That's the payoff, the main character moment 👑

🦋 SEE ALSO 🦋

Kernel file ./include/uapi/linux/gpio.h, plus the whole friend group: struct gpiochip_info(9), enum gpio_v2_line_flag(9), struct gpio_v2_line_values(9), enum gpio_v2_line_attr_id(9), struct gpio_v2_line_attribute(9), struct gpio_v2_line_config_attribute(9), struct gpio_v2_line_config(9), struct gpio_v2_line_info(9), enum gpio_v2_line_changed_type(9), struct gpio_v2_line_info_changed(9), enum gpio_v2_line_event_id(9), struct gpio_v2_line_event(9), struct gpioline_info(9), struct gpioline_info_changed(9), struct gpiohandle_request(9), struct gpiohandle_config(9), struct gpiohandle_data(9), struct gpioevent_request(9), struct gpioevent_data(9). periodt 💜

ngl the whole squad is listed above, go say hi, they're all in ./include/uapi/linux 💀

okay that's the page!! this one came from ./include/uapi/linux, dated October 2026 — slay, go request some lines bestie, you got this 🌈⭐🎀