cdns_wdt_start(9)

✨ cdns_wdt_start(9) ✨

okay bestie, so this is a page from the Kernel API Manual — the cdns_wdt girlies, watchdog division 💅 and today's main character is cdns_wdt_start. she enables AND starts the watchdog, which is honestly giving "i do it all" energy 🔥

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🎀 NAME 🎀

cdns_wdt_start — enable and start the watchdog. that's it, that's the vibe. 👑

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🦋 SYNOPSIS 🦋

int cdns_wdt_start (struct watchdog_device *wdd );

yes she returns an int, yes she takes exactly one thing, no we're not doing more than that ✨ (and yes, the spacing in *wdd ) is literally how it's written, don't come for me 🙈)

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🌸 ARGUMENTS 🌸

• wdd — the watchdog device 💖 like, the actual watchdog device struct, that's the whole argument, she's low maintenance.

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💜 DESCRIPTION 💜

okay so here's where it gets iconic. the counter value is calculated according to this formula, and you KNOW i'm putting it in a code block so nobody messes it up:

calculated count = (timeout * clock) / prescaler + 1

the calculated count then gets divided by 0x1000 to obtain the field value that we write to the counter control register. math ate, no cap. 🧮✨

then it clears the contents of the prescaler and the counter reset value. bye bestie 👋

next: it sets the prescaler to 4096, and sets the calculated count and the access key, all to write to the CCR Register. 🎀

and finally it sets the WDT (WDEN bit) plus EITHER the Reset signal (RSTEN bit) OR the Interrupt signal (IRQEN) — with a specified cycles — plus the access key, to write to the ZMR Register. both options are there, it's giving "choose your fighter" 🥊🌈

ngl the bit names matter here — WDEN, RSTEN, IRQEN, CCR Register, ZMR Register — so keep them exactly as they are when you're reading along, iykyk 💅

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⭐ RETURN ⭐

always 0. literally always. she does not miss, she does not fail, she returns 0 periodt. 🫶

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🍓 SEE ALSO 🍓

• Kernel file ./drivers/watchdog/cadence_wdt.c
• struct cdns_wdt(9)
• cdns_wdt_stop(9)
• cdns_wdt_reload(9)
• cdns_wdt_settimeout(9)
• cdns_wdt_irq_handler(9)
• cdns_wdt_probe(9)
• cdns_wdt_suspend(9)
• cdns_wdt_resume(9)

the whole friend group, honestly — go read them all, they're all linked, obsessed 😭💖

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and that's the page!! 💫 source/version: ./drivers/watchdog, dated October 2026 — so she's a fresh lil manual page, mwah 😘🦋 go forth and start some watchdogs bestie 💅👑