fw_card_read_cycle_time(9)

✨ fw_card_read_cycle_time(9) ✨

okay so bestie, welcome to the Kernel API Manual 🎀 — this is fw_card_read_cycle_time, and it's literally the glow-up you need if you're trying to read from the Isochronous Cycle Timer Register of 1394 OHCI in the MMIO region for a controller card. no cap, that's the whole vibe. 💅

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💖 NAME 💖

fw_card_read_cycle_time — read from Isochronous Cycle Timer Register of 1394 OHCI in MMIO region for controller card.

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🌸 SYNOPSIS 🌸

int fw_card_read_cycle_time (struct fw_card *card , u32 *cycle_time );

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🦋 ARGUMENTS 🦋

• card — the instance of card for the 1394 OHCI controller. it's giving "which controller are we talking to" energy 🫶
• cycle_time — the mutual reference to the value of cycle time for the read operation. yes queen, it's a pointer, the value lands in there ✨

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👑 DESCRIPTION 👑

Okay so here's the tea 🍓: this function reads a value from the Isochronous Cycle Timer Register of 1394 OHCI in the MMIO region for the given controller card.

And bestie, listen — it accesses that region without any lock primitives or IRQ mask. like, no protection, no safety net, just raw access. that's the vibe it's serving, so don't come for it later 😭

When it returns successfully, the content of the value argument has a value aligned to host endianness, formatted by the CYCLE_TIME CSR Register of IEEE 1394 std. periodt. 💅

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🌈 CONTEXT 🌈

Any context. literally any. she's flexible like that 🧚

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🔥 RETURN 🔥

• 0 — read successfully. slay, we ate. 👑
• -ENODEV — the controller is unavailable due to being removed or unbound. 💀 rip, the card ghosted you.

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⭐ SEE ALSO ⭐

• Kernel file ./drivers/firewire/core-card.c — go read the source, iykyk 💜

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and that's the whole page, bestie!! 🎀 this little icon came from the ./drivers/firewire crew in October 2026, chillin' in the Kernel API Manual section 9 — mwah, go forth and read those cycle timers responsibly 💖✨🦋