STRUCT I3C_CCC_CMD_PAYLOAD(9)

🦋 struct i3c_ccc_cmd_payload(9) 🦋

okay so this is a page from the Kernel API Manual bestie, and it's all about struct i3c_ccc_cmd_payload — literally the payload container for CCCs. tiny struct, big responsibilities 💅

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✨ NAME ✨

struct i3c_ccc_cmd_payload — the CCC payload, that's it, that's the vibe 🎀

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✨ SYNOPSIS ✨

struct i3c_ccc_cmd_payload {
    u16 len;
    u16 actual_len;
    u16 optional_bytes;
    void *data;
 };

look at her. four members. no notes. 👑

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✨ Members ✨

• len — the payload length you're requesting, like the length you asked for when you placed the order 🛍️
• actual_len — how many bytes actually came back on a GET CCC (the driver fills this one in for you, so don't go touching it yourself, mwah 🫶)
• optional_bytes — GET CCCs are allowed to come back with up to this many fewer bytes than len, so yes, under-delivery is legal here, no cap 😭
• data — the payload data itself. and listen: this buffer must be DMA-able. non-negotiable. the hardware needs to be able to reach it directly, so do not hand it some random stack buffer and hope for the best 💀

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✨ SEE ALSO ✨

all the siblings and cousins, fr fr 🧚

• Kernel file ./include/linux/i3c/ccc.h
• struct i3c_ccc_events(9)
• struct i3c_ccc_mwl(9)
• struct i3c_ccc_mrl(9)
• struct i3c_ccc_dev_desc(9)
• struct i3c_ccc_defslvs(9)
• enum i3c_ccc_test_mode(9)
• struct i3c_ccc_enttm(9)
• struct i3c_ccc_setda(9)
• struct i3c_ccc_getpid(9)
• struct i3c_ccc_getbcr(9)
• struct i3c_ccc_getdcr(9)
• struct i3c_ccc_getstatus(9)
• struct i3c_ccc_getaccmst(9)
• struct i3c_ccc_bridged_slave_desc(9)
• struct i3c_ccc_setbrgtgt(9)
• enum i3c_sdr_max_data_rate(9)
• enum i3c_tsco(9)
• struct i3c_ccc_getmxds(9)
• struct i3c_ccc_gethdrcap(9)
• enum i3c_ccc_setxtime_subcmd(9)
• struct i3c_ccc_setxtime(9)
• struct i3c_ccc_getxtime(9)
• struct i3c_ccc_cmd_dest(9)
• struct i3c_ccc_cmd(9)

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bestie reminder one more time because it matters: data must be <red>DMA-able</red>. that's the whole assignment. 🔥

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and that's the page!! sourced from ./include/linux/i3c, dated October 2026 — mwah, go read the rest of the i3c headers, ily, bye 💖🌸