STRUCT XIIC_I2C(9)

💜 struct xiic_i2c(9) 💜

okay so bestie, welcome to the Kernel API Manual ✨ — this one's all about struct xiic_i2c, which is literally the internal representation of the XIIC I2C bus. think of it as the backstage pass 🎀 to how the driver keeps track of itself. no cap, it's a whole vibe.

🌸 SYNOPSIS 🌸

so here's the whole struct, and yes you're gonna want to read every line because it's all load-bearing, iykyk:

struct xiic_i2c {
    struct device *dev;
    void __iomem *base;
    struct completion completion;
    struct i2c_adapter adap;
    struct i2c_msg *tx_msg;
    struct mutex lock;
    unsigned int tx_pos;
    unsigned int nmsgs;
    struct i2c_msg *rx_msg;
    int rx_pos;
    enum xiic_endian endianness;
    struct clk *clk;
    int irq;
    enum xilinx_i2c_state state;
    bool singlemaster;
    bool dynamic;
    bool prev_msg_tx;
    u32 quirks;
    bool smbus_block_read;
    unsigned int smbus_actual_len;
    unsigned long input_clk;
    unsigned int i2c_clk;
    bool atomic;
    spinlock_t atomic_lock;
    enum xilinx_i2c_state atomic_xfer_state;
 };

🦋 MEMBERS 🦋

okay this is the fun part — every single field, explained with the love and care it deserves 💖

• dev — pointer to the device structure 🫶
• base — the memory base of the HW registers, that's where the hardware lives fr
• completion — completion for callers, so the callers can chill until it's done
• adap — the kernel adapter representation, main character energy ngl
• tx_msg — messages from above that need to be sent 💌
• lock — mutual exclusion, keepin' things polite
• tx_pos — current pos in the TX message, like a little cursor
• nmsgs — number of messages in tx_msg
• rx_msg — the current RX message
• rx_pos — position within the current RX message
• endianness — big/little-endian byte order 🌀
• clk — pointer to the AXI4-lite input clock ⏰
• irq — interrupt number
• state — see STATE_ 👀
• singlemaster — indicates the bus is single master 👑
• dynamic — mode of the controller
• prev_msg_tx — previous message is Tx
• quirks — to hold platform specific bug info 🙈 (yes, a whole field for bug lore)
• smbus_block_read — flag to handle block read
• smbus_actual_len — valid byte count (length + payload + optional PEC) of a padded SMBus block read. msg->len is trimmed to this on completion. Zero when no trimming is needed. ✂️
• input_clk — input clock to the I2C controller
• i2c_clk — the I2C SCL frequency 🌈
• atomic — mode of transfer
• atomic_lock — lock for atomic transfer mode 🔒
• atomic_xfer_state — see STATE_ 👀 (yes, again — it's giving twin energy)

⭐ SEE ALSO ⭐

go check out the kernel file ./drivers/i2c/busses/i2c-xiic.c, plus struct timing_regs(9) and xiic_setclk(9) — all iconic, all worth your time 🧚

bestie reminder: nothing here is invented, this is all straight from the source, I would never do you like that 💅

and that's a wrap! 🌸 this page came from ./drivers/i2c/busses, dated October 2026, and it's struct xiic_i2c(9) in the Kernel API Manual — slay, go read the actual kernel now, periodt 🎀🔥