STRUCT CDNS_SPI(9)

💖✨ struct cdns_spi(9) — Kernel API Manual ✨💖

okay bestie, this is the struct cdns_spi(9) page from the Kernel API Manual, section 9, and it is literally the whole tea on the SPI driver instance 💅 no cap.

🌸 NAME 🌸

struct cdns_spi — this definition defines the spi driver instance. It’s giving “the struct that holds the driver’s whole situation,” periodt. 🫶

🦋 SYNOPSIS 🦋

struct cdns_spi {
    void __iomem *regs;
    struct clk *ref_clk;
    struct clk *pclk;
    unsigned int clk_rate;
    u32 speed_hz;
    const void *txbuf;
    void *rxbuf;
    int tx_bytes;
    int rx_bytes;
    u8 n_bytes;
    u8 dev_busy;
    u32 is_decoded_cs;
    unsigned int tx_fifo_depth;
    struct reset_control *rstc;
};

🎀 Members 🎀

okay so here’s the member-by-member breakdown, bestie — every single one, no skipping, fr fr:

• regs — virtual address of the SPI controller registers.
• ref_clk — pointer to the peripheral clock.
• pclk — pointer to the APB clock.
• clk_rate — reference clock frequency, taken from ref_clk.
• speed_hz — current SPI bus clock speed in Hz.
• txbuf — pointer to the TX buffer.
• rxbuf — pointer to the RX buffer.
• tx_bytes — number of bytes left to transfer.
• rx_bytes — number of bytes requested.
• n_bytes — number of bytes per word.
• dev_busy — device busy flag.
• is_decoded_cs — flag for decoder property set or not.
• tx_fifo_depth — depth of the TX FIFO.
• rstc — optional reset control for SPI controller.

🌈 SEE ALSO 🌈

Kernel file ./drivers/spi/spi-cadence.c, plus all these iconic functions: cdns_spi_init_hw(9), cdns_spi_chipselect(9), cdns_spi_config_clock_mode(9), cdns_spi_config_clock_freq(9), cdns_spi_setup_transfer(9), cdns_spi_process_fifo(9), cdns_spi_irq(9), cdns_transfer_one(9), cdns_prepare_transfer_hardware(9), cdns_unprepare_transfer_hardware(9), cdns_spi_detect_fifo_depth(9), cdns_target_abort(9), cdns_spi_probe(9), cdns_spi_remove(9), cdns_spi_suspend(9), cdns_spi_resume(9), cdns_spi_runtime_resume(9), cdns_spi_runtime_suspend(9). Go read them if you want the full lore, iykyk 💜.

okay that’s the whole page, mwah 💋 — source/version is ./drivers/spi, date is October 2026, and it’s all for struct cdns_spi(9). slay ✨