On 26/03/2019 13:51, Heiko Stübner wrote:
Hi,
Am Dienstag, 26. März 2019, 14:39:42 CET schrieb Katsuhiro Suzuki:
Hello Tony, Robin,
I continue to investigate UART TX rising time problem. Recently, I found
one of cause of this problem.
In my environment, this problem occurred on linux-next only. U-Boot does
not face it. So I compared settings between U-Boot and linux-next. After
I found GRF_IO_VSEL (address 0xff77e640) register is differ.
Would you tell me what value is stored into this register?
My RockPro64, initially 0x00000000 is set but 0x00000003 is set during
linux boot. UART TX rising time becomes fine if set both bit 1 and bit 3
or clear both bits.
GRF_IO_VSEL is the voltage-domain selection for different domains,
see the &io_domains{} node in your rockpro64 dts.
The soc needs to know with what voltage some of its inputs are
supplied.
Bits are:
0 - bt656
1 - audio
2 - sdmmc
3 - gpio1833
These bits must correspond of the voltages of their regulators,
0 for 3.3V and 1 for 1.8V.
But the vcc1v8_dvp regulator connected to the bt656 input has
not changed since the initial submission of the devicetree.
Hmm, based on a look through the rockpro64 schematic, does this help?
Robin.
----->8-----
diff --git a/arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dts
b/arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dts
index 1f2394e0587d..d473ce290f0c 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dts
@@ -504,7 +504,7 @@
status = "okay";
bt656-supply = <&vcc1v8_dvp>;
- audio-supply = <&vcca1v8_codec>;
+ audio-supply = <&vcc_3v0>;
sdmmc-supply = <&vcc_sdio>;
gpio1830-supply = <&vcc_3v0>;
};
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