regmap_raw_write_async(9)

💅 regmap_raw_write_async(9) — a.k.a. the Kernel API Manual page you're literally about to understand

okay bestie, settle in 🎀 this one lives in the Kernel API Manual and it's honestly kind of a baddie. It's one function, it does exactly one thing, and it does it fast.

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✨ NAME ✨

regmap_raw_write_async — write raw values to one or more registers asynchronously 🦋

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✨ SYNOPSIS ✨

int regmap_raw_write_async (struct regmap *map , unsigned int reg ,
                            const void *val , size_t val_len );

ngl that signature is giving "four args, no notes" 💅

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✨ ARGUMENTS ✨

• map — the register map you're writing to. Your target. The main character of this whole operation 👑
• reg — the initial register to write to. Like, where the party starts.
• val — the block of data to be written, laid out for direct transmission to the device. No formatting, no vibes check, no nothing — it goes out exactly as-is. 🚨 Important: this pointer must stay valid until regmap_async_complete is called. Like, do not let it wander off and get freed while the bus is still working, I am begging 😭
• val_len — the length of the data that val points to. Yes, you have to tell it. It's not gonna count for you, bestie.

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✨ DESCRIPTION ✨

So this function is built for situations like firmware download — you know, the classic "I have a huge block of data and it all needs to get to the device" moment. 🌈 And the whole point: no formatting will be done on the data provided. Zero. None. It is what it is. Periodt.

If the underlying bus is cool with it, the write gets scheduled asynchronously — which is a fancy way of saying it helps you maximise I/O speed on higher speed buses like SPI 🔥. Go off, throughput.

And whenever you want to be sure all those async writes have actually finished, you call regmap_async_complete. That's your "okay are we done yet" check 🫶

Returns: a value of zero on success 🎉, and a negative errno in the error cases 💀.

lowkey remember: "zero good, negative errno bad." That's the whole personality test.

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✨ SEE ALSO ✨

Kernel file ./drivers/base/regmap/regmap.c — and then, bestie, here comes the entire friend group 💖:

• devm_regmap_field_alloc(9)
• regmap_field_bulk_alloc(9)
• devm_regmap_field_bulk_alloc(9)
• regmap_field_bulk_free(9)
• devm_regmap_field_bulk_free(9)
• devm_regmap_field_free(9)
• regmap_field_alloc(9)
• regmap_field_free(9)
• regmap_reinit_cache(9)
• regmap_exit(9)
• dev_get_regmap(9)
• regmap_get_device(9)
• regmap_can_raw_write(9)
• regmap_get_raw_read_max(9)
• regmap_get_raw_write_max(9)
• regmap_write(9)
• regmap_write_async(9)
• regmap_raw_write(9)
• regmap_noinc_write(9)
• regmap_field_update_bits_base(9)
• regmap_field_test_bits(9)
• regmap_fields_update_bits_base(9)
• regmap_bulk_write(9)
• regmap_multi_reg_write(9)
• regmap_multi_reg_write_bypassed(9)
• regmap_read(9)
• regmap_read_bypassed(9)
• regmap_raw_read(9)
• regmap_noinc_read(9)
• regmap_field_read(9)
• regmap_fields_read(9)
• regmap_bulk_read(9)
• regmap_multi_reg_read(9)
• regmap_update_bits_base(9)
• regmap_test_bits(9)
• regmap_async_complete(9)
• regmap_register_patch(9)
• regmap_get_val_bytes(9)
• regmap_get_max_register(9)
• regmap_get_reg_stride(9)
• regmap_might_sleep(9)

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aaaand that's the page!! 🧚 go forth and write your raw bytes asynchronously, you absolute icon 💜

./drivers/base/regmap 🫶 October 2026 — that's the where and the when, bestie, and this manpage has officially left the group chat 😭✌️