ar9002_hw_set_channel(9)

💅 ar9002_hw_set_channel — kernel API manual energy

okay so this page is ar9002_hw_set_channel(9) from the Kernel API Manual, and it's genuinely one of those little functions that's lowkey the main character of the whole chip 🔥

✨ NAME ✨

ar9002_hw_set_channel — set channel on single-chip device 🎯

🌸 SYNOPSIS 🌸

int ar9002_hw_set_channel (struct ath_hw *ah , struct ath9k_channel
*chan );

🎀 ARGUMENTS 🎀

• ah — atheros hardware structure (this is the whole hardware vibe holder, bestie)
• chan — ngl the original page literally gives this one zero description 😭 so we're just gonna hold space for it 🫶

🦋 DESCRIPTION 🦋

okay so this is the function to change channel on single-chip devices — and by "single-chip devices" we mean all devices after ar9280. periodt. 👑

What it does: it takes the channel value in MHz and sets the hardware channel value. Simple, iconic, no notes. ✨

⚠️ heads up though — it assumes writes have been enabled to analog bus already. like, that's on you, it's not doing the vibe check for you 💀

Actual Expression, (yes, the original page really says it like that, and honestly? slay 🌈)

For 2GHz channel:

Channel Frequency = (3/4) * freq_ref * (chansel[8:0] + chanfrac[16:0]/2^17)   (freq_ref = 40MHz)

For 5GHz channel:

Channel Frequency = (3/2) * freq_ref * (chansel[8:0] + chanfrac[16:0]/2^10)   (freq_ref = 40MHz/(24>>amodeRefSel))

the way those fractions are just sitting there being all math-y 🧚 iykyk 💜

🔥 SEE ALSO 🔥

• Kernel file ./drivers/net/wireless/ath/ath9k/ar9002_phy.c
• Programming Atheros 802.11n analog front end radios(9)
• ar9002_hw_spur_mitigate(9)

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and that's the whole page, bestie 🎀 cute lil sign-off time: this one lives under ./drivers/net/wireless/ath/ath9k, it's dated October 2026, and the page itself is ar9002_hw_set_channel(9) 💖 go set some channels, ily 🫶✨