STRUCT AD5686_STATE(9)

💅 struct ad5686_state(9) 💅

okay so bestie, welcome to the Kernel API Manual, section 9 — this is the whole entire lore drop on struct ad5686_state, which is literally just driver instance specific data. that's it. that's the vibe. it's the little bundle of everything one AD5686 driver instance needs to know about itself 🫶

✨ SYNOPSIS ✨

struct ad5686_state {
    struct device                   *dev;
    const struct ad5686_chip_info   *chip_info;
    const struct ad5686_bus_ops     *ops;
    struct gpio_desc                *ldac_gpio;
    struct gpio_desc                *gain_gpio;
    unsigned int                    pwr_down_mask;
    unsigned int                    pwr_down_mode;
    int scale_avail[4];
    unsigned short                  vref_mv;
    bool double_scale;
    bool use_internal_vref;
    struct mutex                    lock;
    void *bus_data;
    union {
      __be32 d32;
      __be16 d16;
      u8 d8[4];
    } data[AD5686_MAX_CHANNELS];
};

look at her. she's iconic. she's a struct. copy her exactly, no cap 🎀

🌸 Members 🌸

• dev — the device instance. the main character, fr.
• chip_info — chip model specific constants, available modes etc. iykyk, every chip's got its own little personality 🦋
• ops — bus specific operations. the how-do-i-actually-talk-to-this-thing manual.
• ldac_gpio — the LDAC pin GPIO descriptor. yes it's a real pin, no i will not be elaborating 💅
• gain_gpio — the GAIN pin GPIO descriptor. her sister pin. slay.
• pwr_down_mask — power down mask. it's giving bitmask energy.
• pwr_down_mode — current power down mode. key word current — this one changes, bestie 👀
• scale_avail — pre-calculated available scale values. already done, already ate, no math needed at runtime ✨
• vref_mv — actual reference voltage used. actual, as in the real one, as in not the theoretical one 😭
• double_scale — flag to indicate the gain multiplier is applied. a humble bool doing honest work.
• use_internal_vref — set to true if the internal reference voltage is used. set it to true, not "true", not 1, we're being proper here 🎀
• lock — lock to protect access to state fields, which includes the data buffer during regmap ops. do NOT skip the lock, i'm literally begging you 🫶 concurrency is a vibe killer if you ignore her.
• bus_data — bus specific data. mystery box. whatever the bus wants, honestly.
• data — transfer buffers. it's a union of __be32 d32, __be16 d16, and u8 d8[4], and there are [AD5686_MAX_CHANNELS] of them, so everyone gets their own lil buffer 🧚

🔥 SEE ALSO 🔥

• Kernel file ./drivers/iio/dac/ad5686.h
• struct ad5686_bus_ops(9)
• struct ad5686_chip_info(9)

go read those too, they're the supporting cast and honestly they deserved more screen time 💜

heads up bestie: use_internal_vref is a bool set to true when the internal reference voltage is the one in play, and lock is not decorative — it guards access to the state fields, including the data buffer during regmap ops. that part's not a suggestion, that's load-bearing 💀

and that's the page!! brought to you by ./drivers/iio/dac, dated October 2026 — signed, sealed, slayed. mwah 💖🌈⭐