wifi: rtw89: add thermal protect by digital voltage reduction

The temperature is rising when WiFi does high throughput, and reduce
voltage is a way to ease temperature.

The existing method to do thermal protect is to reduce TX duty, which
can affect throughput obviously. Before doing reduce TX duty (with -20
thermal value offset), driver does voltage reduction first, which doesn't
affect throughput but lower power consumption.

The voltage gram of register is 0.01 voltage, and the suggested maximum
reduction is 6 grams, which driver defines 6 as maximum voltage level.
When thermal value is over threshold, driver will try to adjust level and
corresponding register value. It should be adjust grams one by one with
additional 50 ms delay to ensure hardware work properly.

A note that the voltage must reset to normal value before entering power
save mode, otherwise WiFi card might get lost. Since it takes 50 ms delay
for each gram to adjust voltage, we stop to enter power save if protect
level is not zero.

By the way, adjust thermal threshold to 0xB4 as desired.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20260707091056.42771-10-pkshih@realtek.com

0 files changed, 0 insertions, 0 deletions