sdio_writew(9)

💅 sdio_writew — the kernel API manual, bestie edition

okay so this is sdio_writew(9) from the Kernel API Manual, and honestly? it's giving "tiny function, big responsibility." let's get into it 🎀

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✨ NAME ✨

sdio_writew — write a 16 bit integer to a SDIO function 🦋

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✨ SYNOPSIS ✨

void sdio_writew (struct sdio_func *func , u16 b , unsigned int addr ,
       int *err_ret );

like, that's the whole signature. she's compact. she's iconic. 👑

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✨ ARGUMENTS ✨

• func — the SDIO function you're accessing 💫 like, which one are we talking to
• b — the integer you're writing. yes bestie, that's the actual payload
• addr — the address you're writing to 📍
• err_ret — optional status value from the transfer — she's optional but she's reporting, so keep an eye on her 👀

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✨ DESCRIPTION ✨

So basically: this writes a 16 bit integer into the address space of a given SDIO function. that's it, that's the whole vibe. 💅

and err_ret will contain the status of the actual transfer — like, the receipts of what actually went down, no cap. 🧾✨

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✨ SEE ALSO ✨

Kernel file ./drivers/mmc/core/sdio_io.c — and the whole friend group, fr fr:

• sdio_claim_host(9)
• sdio_release_host(9)
• sdio_enable_func(9)
• sdio_disable_func(9)
• sdio_set_block_size(9)
• sdio_align_size(9)
• sdio_readb(9)
• sdio_writeb(9)
• sdio_writeb_readb(9)
• sdio_memcpy_fromio(9)
• sdio_memcpy_toio(9)
• sdio_readsb(9)
• sdio_writesb(9)
• sdio_readw(9)
• sdio_readl(9)
• sdio_writel(9)
• sdio_f0_readb(9)
• sdio_f0_writeb(9)
• sdio_get_host_pm_caps(9)
• sdio_set_host_pm_flags(9)
• sdio_retune_crc_disable(9)
• sdio_retune_crc_enable(9)
• sdio_retune_hold_now(9)
• sdio_retune_release(9)

like, that's the entire group chat. go say hi. 🫶

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okay that's the page!! big kiss from ./drivers/mmc/core 💖 dated October 2026, and the page is literally just sdio_writew(9) again because that's how manpages do. slay. 🌸✨