Hi Stefan, > +#define MT76XX_I2C_INPUT_CLOCK 40000000 This is peripheral clock and should be reachable by devm_clk_get() and later clk_get_rate() should give value similar to MT76XX_I2C_INPUT_CLOCK. I don't have currently recent enough kernel to test it or prove it, but I see this in openwrt I2C driver for this platform https://github.com/openwrt/openwrt/blob/master/target/linux/ramips/patches-4.14/0045-i2c-add-mt7621-driver.patch Kind regards, Jan
