STRUCT AD9834_STATE(9)

💅 struct ad9834_state(9) — like, the whole entire vibe 💅

okay so this is a page from the Kernel API Manual, and it's literally all about struct ad9834_state, which is — say it with me — driver instance specific data ✨ no cap, that's the whole NAME. bestie, this struct is the main character of the ad9834 driver and we're gonna go through every single member together, one by one, no skipping 🫶

✨ SYNOPSIS ✨

here's the whole struct, character for character, because we do NOT paraphrase code in this house 💅

struct ad9834_state {
    struct spi_device               *spi;
    struct clk                      *mclk;
    unsigned short                  control;
    unsigned short                  devid;
    struct spi_transfer             xfer;
    struct spi_message              msg;
    struct spi_transfer             freq_xfer[2];
    struct spi_message              freq_msg;
    struct mutex                    lock;
    __be16 data;
    __be16 freq_data[2];
 };

look at her. gorgeous. eleven fields and every one of them pulling its weight 🔥

🎀 Members 🎀

• spi — a spi_device, aka the SPI device itself. the whole reason we're here tbh 💖
• mclk — the external master clock. she keeps time, she keeps everybody honest ⏰✨
• control — the cached control word. cached, bestie, as in we're holding onto it 🙈
• devid — the device id. it's giving "hi, who am i" 🪪
• xfer — the default spi transfer. the standard-issue one, the everyday icon 👑
• msg — the default spi message. see above but a message 💌
• freq_xfer — the tuning word spi transfer. this is the one doing the frequency stuff 🎶
• freq_msg — the tuning word spi message. same energy, message-flavoured 📨
• lock — a struct mutex that protects sensor state. do NOT skip the lock, i'm serious 😭🔒
• data — the spi transmit buffer. it's a __be16 and it carries your bytes 🧚
• freq_data — the tuning word spi transmit buffer, and yes it's __be16 freq_data[2], two of them, an icon ✌️

🌸 SEE ALSO 🌸

• Kernel file ./drivers/staging/iio/frequency/ad9834.c — go read the actual source, iykwim, it's right there 💜

okay that's the whole page!! mwah 💋 this was brought to you by ./drivers/staging/iio/frequency and dated October 2026 — go forth and tune some frequencies bestie, ily, bye 🦋🎀💖