STRUCT HSI_PORT(9)

💅 struct hsi_port(9) — HSI port device 🎀

okay bestie, welcome to the hsi_port struct. this is a kernel API manual page, and honestly? it's giving "little struct that could." lowkey iconic. let's get into it ✨

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✨ NAME ✨

struct hsi_port — the HSI port device itself. that's the whole vibe. 🦋

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🌸 SYNOPSIS 🌸

struct hsi_port {
    struct device                   device;
    struct hsi_config               tx_cfg;
    struct hsi_config               rx_cfg;
    unsigned int                    num;
    unsigned int                    shared:1;
    int claimed;
    struct mutex                    lock;
    int (*async)(struct hsi_msg *msg);
    int (*setup)(struct hsi_client *cl);
    int (*flush)(struct hsi_client *cl);
    int (*start_tx)(struct hsi_client *cl);
    int (*stop_tx)(struct hsi_client *cl);
    int (*release)(struct hsi_client *cl);
    struct blocking_notifier_head   n_head;
 };

like, look at her. all those function pointers. main character energy fr fr 💅

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🧚 Members 🧚

okay so this is the part where we meet the whole cast. every single one of them. no skips, no cap. 💖

• device — the driver model representation of the device. like, the official paperwork that says "yes, this is a device." 🎀
• tx_cfg — the current TX path configuration. the transmit side's whole setup. ✨
• rx_cfg — the current RX path configuration. the receive side's whole setup. 💜
• num — the port number. which port is this? this one. 🔥
• shared — set when the port can be shared by different clients. sharing is caring, bestie 🫶
• claimed — reference count of clients which claimed the port. keeping track of who called dibs. 👑
• lock — serialize port claim. no fighting over the port, we have a mutex for that. 💅
• async — asynchronous transfer callback. yes, it's asynchronous. she doesn't wait around. 😭
• setup — callback to set the HSI client configuration. getting the client all set up. 🌸
• flush — callback to clean the HW state and destroy all pending transfers. dramatic? maybe. necessary? absolutely. 💀
• start_tx — callback to inform that a client wants to TX data. they're ready to send, bestie. ⭐
• stop_tx — callback to inform that a client no longer wishes to TX data. okay, they're done. 🙈
• release — callback to inform that a client no longer uses the port. freeing it up for the next person. 🍓
• n_head — notifier chain for signaling port events to the clients. the group chat for port events, basically. 🌈

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🌟 SEE ALSO 🌟

kernel file ./include/linux/hsi/hsi.h — and all her friends:

• struct hsi_channel(9)
• struct hsi_config(9)
• struct hsi_board_info(9)
• struct hsi_client(9)
• struct hsi_client_driver(9)
• struct hsi_msg(9)
• struct hsi_controller(9)
• hsi_id(9)
• hsi_port_id(9)
• hsi_setup(9)
• hsi_flush(9)
• hsi_async_read(9)
• hsi_async_write(9)
• hsi_start_tx(9)
• hsi_stop_tx(9)

iykyk 💜

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okay that's the whole page, bestie. ./include/linux/hsi, October 2026, struct hsi_port(9). slay. periodt. 🌈💅✨