regmap_read...meout_atomic(9)

hiii bestie 💖 okay so this is the Kernel API Manual glow-up for regmap_read_poll_timeout_atomic. It’s giving kernel polling, but make it cute. Buckle up. 🎀

💖 NAME 💖

regmap_read_poll_timeout_atomic — poll until a condition is met or a timeout occurs. periodt. ✨

✨ SYNOPSIS ✨

the signature, verbatim:

regmap_read_poll_timeout_atomic (map , addr , val , cond , delay_us ,
       timeout_us );

🎀 ARGUMENTS 🎀

the cast, in order:

• map — the regmap to read from. 🫶
• addr — address to poll. 👀
• val — unsigned integer variable to read the value into. 🍓
• cond — break condition (usually involving val). 💅
• delay_us — time to udelay between reads in us (0 tight-loops). Please read the udelay function description for details and limitations, fr fr. 😭
• timeout_us — timeout in us, 0 means never timeout. ⏰

🌸 DESCRIPTION 🌸

This macro is modelled after the readx_poll_timeout_atomic macros in linux/iopoll.h. literally that’s the blueprint, bestie. 🦋

💀 NOTE 💀

real talk: in general regmap cannot be used in atomic context. If you want to use this macro then first setup your regmap for atomic use (flat or no cache and MMIO regmap). iykyk 💅

💜 RETURN 💜

here’s the tea:

• 0 — success, slay. ✅
• -ETIMEDOUT — a timeout happened. ⏰
• the regmap_read error return value — in case of a error read. 😬

In the two former cases (timeout and error read), the last read value at addr is stored in val. that’s the important bit. 🫶

🌈 SEE ALSO 🌈

the whole squad, all of it — no skips:

• Kernel file ./include/linux/regmap.h
• struct reg_default(9), struct reg_sequence(9), regmap_read_poll_timeout(9), regmap_field_read_poll_timeout(9), struct regmap_range(9), struct regmap_access_table(9), struct regmap_config(9), struct regmap_range_cfg(9), struct regmap_sdw_mbq_cfg(9), struct regmap_bus(9)
• regmap_init(9), regmap_init_i2c(9), regmap_init_mdio(9), regmap_init_sccb(9), regmap_init_slimbus(9), regmap_init_spi(9), regmap_init_spmi_base(9), regmap_init_spmi_ext(9), regmap_init_w1(9), regmap_init_mmio_clk(9), regmap_init_mmio(9), regmap_init_ac97(9), regmap_init_sdw(9), regmap_init_sdw_mbq(9), regmap_init_sdw_mbq_cfg(9), regmap_init_i3c(9), regmap_init_spi_avmm(9), regmap_init_fsi(9)
• devm_regmap_init(9), devm_regmap_init_i2c(9), devm_regmap_init_mdio(9), devm_regmap_init_sccb(9), devm_regmap_init_spi(9), devm_regmap_init_spmi_base(9), devm_regmap_init_spmi_ext(9), devm_regmap_init_w1(9), devm_regmap_init_mmio_clk(9), devm_regmap_init_mmio(9), devm_regmap_init_ac97(9), devm_regmap_init_sdw(9), devm_regmap_init_sdw_mbq(9), devm_regmap_init_sdw_mbq_cfg(9), devm_regmap_init_slimbus(9), devm_regmap_init_i3c(9), devm_regmap_init_spi_avmm(9), devm_regmap_init_fsi(9)
• struct reg_field(9), struct regmap_irq_type(9), struct regmap_irq(9), struct regmap_irq_chip(9)

xoxo, your kernel bestie 💋 — source/version: ./include/linux; date: October 2026. 🎀✨