STRUCT AX_SPI(9)

💖 NAME 💖

struct ax_spi — bestie, this is the definition that defines a spi driver instance ✨ like it's literally the blueprint for one whole SPI driver living its main character life 🫶

✨ SYNOPSIS ✨

struct ax_spi {
    void __iomem *regs;
    struct clk *ref_clk;
    struct clk *pclk;
    unsigned int clk_rate;
    u32 speed_hz;
    const u8 *tx_buf;
    u8 *rx_buf;
    int tx_bytes;
    int rx_bytes;
    unsigned int tx_fifo_depth;
    u32 current_rx_fifo_word;
    int bytes_left_in_current_rx_word;
    u32 current_rx_fifo_word_for_irq;
    int bytes_left_in_current_rx_word_for_irq;
    int rx_discard;
    int rx_copy_remaining;
 };

Ok so quick vibe check — this is the struct ax_spi from the Kernel API Manual, section 9. Every single field is iconic in its own way, so let's go through them one by one, no skips, no cap 💅

🎀 Members 🎀

• regs — the virtual address of the SPI controller registers. Like, where the hardware actually lives in memory, spiritually 🏠
• ref_clk — pointer to the peripheral clock. Its lil clock bestie ⏰
• pclk — pointer to the APB clock. Yeah, second clock, she's also invited 🎀
• clk_rate — reference clock rate in Hz. Numbers, we love her 🔢
• speed_hz — the current SPI bus clock speed in Hz. Current being the keyword, she can change 👑
• tx_buf — pointer to the TX buffer. Sending out the good stuff 📤
• rx_buf — pointer to the RX buffer. Receiving it right back 📥
• tx_bytes — number of bytes left to transfer. The countdown is real 😭
• rx_bytes — number of bytes requested. Not left — requested, important distinction bestie 🫶
• tx_fifo_depth — depth of the TX FIFO. How deep the queue goes, lowkey fascinating 🌊
• current_rx_fifo_word — buffers the 32-bit word read from RXFIFO. One whole word, kept safe 🧚
• bytes_left_in_current_rx_word — bytes to be extracted from the current 32-bit word. Extraction era 🔍
• current_rx_fifo_word_for_irq — buffers the 32-bit word read from RXFIFO for IRQ. Same energy, IRQ edition ⚡
• bytes_left_in_current_rx_word_for_irq — IRQ bytes to be extracted from the current 32-bit word. Yes the name is long, she earned it 💀
• rx_discard — number of bytes to discard. Bye, not needed 🙈
• rx_copy_remaining — number of bytes to copy. The keeper bytes 🍓

🌈 SEE ALSO 🌈

• Kernel file ./drivers/spi/spi-axiado.h — go read her, she's right there 📖

And that's the whole page, fr fr 💜 huge slay to ./drivers/spi for shipping this one — October 2026, struct ax_spi(9), signing off 🎀✨