sdw_nwrite(9)

💫 sdw_nwrite — the kernel API manual, but make it make sense 💫

okay so bestie, welcome to sdw_nwrite(9) from the Kernel API Manual — this is the one that writes "n" contiguous SDW Slave registers ✨

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🌸 NAME 🌸

sdw_nwrite — write "n" contiguous SDW Slave registers 💅

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🎀 SYNOPSIS 🎀

int sdw_nwrite (struct sdw_slave *slave , u32 addr , size_t count ,
const u8 *val );

like, that's the whole signature, no cap 🫶

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🦋 ARGUMENTS 🦋

• slave — the SDW Slave, obviously 💁‍♀️
• addr — the register address, as in where we're writing
• count — length, aka how many of the things
• val — the buffer holding the values you wanna write

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✨ DESCRIPTION ✨

so here's the tea ☕ — this version of the function will take a PM reference to the slave device. literally grabbing that reference before it does anything else, periodt.

💀 fair warning bestie: if the message crosses a page boundary, each page will be transferred under a separate invocation of the msg_lock. not one big lock, not two pages for the price of one — separate invocations. that's just how it is 🙈

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🌈 SEE ALSO 🌈

all the sibling functions, iykyk 🧚 — and the kernel file you'll find them hanging out in:

• kernel file ./drivers/soundwire/bus.c
• sdw_bus_master_add(9)
• sdw_bus_master_delete(9)
• sdw_transfer(9)
• sdw_show_ping_status(9)
• sdw_transfer_defer(9)
• sdw_nread_no_pm(9)
• sdw_nwrite_no_pm(9)
• sdw_write_no_pm(9)
• sdw_read_no_pm(9)
• sdw_nread(9)
• sdw_read(9)
• sdw_write(9)
• sdw_bus_prep_clk_stop(9)
• sdw_bus_clk_stop(9)
• sdw_bus_exit_clk_stop(9)
• sdw_handle_slave_status(9)

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okay that's the whole page, mwah 💋 — this iconic little number lives in ./drivers/soundwire, dated October 2026, and it's sdw_nwrite(9) forever and ever 🎀💖⭐