SCMDSPI(4)

💅 SCMDSPI(4) — like, the SPI frontend for the Sparkfun Serial Controlled Motor Driver, bestie

okay so this is a section 4 kernel interfaces manual page, SCMDSPI(4), and honestly? she's a whole vibe. let's get into it ✨

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🌸 NAME 🌸

scmdspi — the SPI frontend to the Sparkfun Serial Controlled Motor Driver 🎀

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✨ SYNOPSIS ✨

scmd* at spi? slave 0
scmd* at spi? slave 1

literally that's it. two lines. she's lowkey effortless 💅

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🦋 DESCRIPTION 🦋

okay so the scmdspi driver is the thing that provides the SPI frontend attachment for the Sparkfun SCMD device. that's the whole description, no cap — she shows up, she attaches over SPI, she slays 🫶

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🌈 SYSCTL VARIABLES 🌈

so the following sysctl(3) variables are inherited from scmd(4) — not invented here, just passed down like a cute hand-me-down:

• hw.scmd0.debug — if the driver is compiled with SCMD_DEBUG, this node will appear, and you can use it to set the debugging level. no SCMD_DEBUG, no node, that's the deal 🙈

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🎀 FILES 🎀

• /dev/scmdu — the character device that lets you get at the register space of a main u, SCMD device. yep, u is part of the literal name, don't come for me 👑

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🧚 SEE ALSO 🧚

iic(4), spi(4), scmdi2c(4), scmdspi(4), scmdctl(1), sysctl(8)

go read those, iykyk 💖

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⭐ HISTORY ⭐

the scmdspi driver first appeared in NetBSD 10.0. a legend was born, periodt 🌟

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👑 AUTHORS 👑

the scmdspi driver was written by Brad Spencer</> <brad@anduin.eldar.org>. thank you brad, we appreciate you fr fr 🫡

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💀 BUGS 💀

okay so this is the part where we're real with each other. when used in SPI mode, the SCMD device uses an odd method of doing reads that can become stuck. like, actually stuck. 😭

bestie pls note: check out the command spi_read_one in the scmdctl(1) utility to try and unstick the device when this happens. that's your rescue plan, keep it in your back pocket 🩹

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and that's the page!! this one came from the Debian build, dated December 1, 2021 — so like, vintage but still iconic. mwah 💋💖