Hi, I need to control a board (WiFi HaLow based on NRC7292 chipset) from an RK3399-based system (currently Rockpi N10) After tests it appeared that this board requires the SPI clock frequency to be 16 MHz. Other frequencies result in communication errors. Details of my tests are available here:
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Unfortunately, it seems that RK3399 is able to generate the SPI clock frequencies only equal to 37.5MHz/N So I can't produce 16MHz. I have tried to adjust the appropriate clock frequencies in the device tree:
diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi b/arch/arm64/boot/dts/rockchip/rk3399.dtsi index 89d2cc0..13a974e 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi @@ -1365,8 +1365,8 @@ cru: clock-controller@ff760000 { assigned-clock-rates = , , ,- , ,
- ,
- , ,
- , , , , , , ,
(please see
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) However, it seems that the above modification does not change the real clock frequency. Has anybody here experience in adjusting clock frequencies in RK3399?
Thank you very much in advance, Best regards, Wojtek