spi_nor_otp_write_secr(9)

💅 spi_nor_otp_write_secr(9) 💅

ok so bestie, this is a page straight out of the Kernel API Manual, and today's main character is spi_nor_otp_write_secr — the function that writes a security register. yes, that security register. let's get into it 🎀

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✨ NAME ✨

spi_nor_otp_write_secr — write security register. that's it, that's the whole vibe. short, sweet, iconic 👑

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🌸 SYNOPSIS 🌸

int spi_nor_otp_write_secr (struct spi_nor *nor , loff_t addr , size_t
len , const u8 *buf );

look at that signature. it's giving "i know exactly what i'm doing" energy, fr fr 💅

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🦋 ARGUMENTS 🦋

• nor — pointer to struct spi_nor, aka the whole reason we're here. bestie for real, this is your flash's little ID card.
• addr — the offset you're writing to. pick your spot, no cap 📍
• len — the number of bytes you're writing. keep track, okay? counting matters 🙈
• buf — pointer to the source buffer. this is where your data lives before it gets yeeted into the flash ✨

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💜 DESCRIPTION 💜

so the whole thing: this function writes a security register using the SPINOR_OP_PSECR commands. that's the operation name, copy it exactly, i don't make the rules 😌

if you're sitting here like "wait, what even is a 'security register'?" — totally fair, and the answer is literally documented elsewhere: check out the documentation of spi_nor_otp_read_secr. it's the sibling page, they ate 💖

this method is used on GigaDevice and Winbond flashes. two brands, one function, we love to see it 🌈

⚠️ okay, important, pay attention bestie: the write must not span multiple registers. like, do NOT cross those boundaries. it's not a vibe, it's a hard no 🚫💀

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⭐ RETURN ⭐

• number of bytes written successfully — slay, it worked 💖
• -errno otherwise — not slay, something went sideways 😭

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🧚 SEE ALSO 🧚

• Kernel file ./drivers/mtd/spi-nor/otp.c
• spi_nor_otp_read_secr(9)
• spi_nor_otp_erase_secr(9)
• spi_nor_otp_lock_sr2(9)
• spi_nor_otp_is_locked_sr2(9)

go read the whole friend group, they're all linked, iykyk 🫶

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aaaand that's the page! 🎀 this one comes from ./drivers/mtd/spi-nor and it's dated October 2026 — so mark your calendar, screenshot it, send it to the group chat, whatever you gotta do. bye bestie, go write those security registers responsibly 💅✨🍓