[PATCH AUTOSEL 4.19 044/205] arm64: dts: stratix10: i2c clock running out of spec

From: Sasha Levin
Date: Fri Nov 08 2019 - 06:39:02 EST


From: Alan Tull <atull@xxxxxxxxxx>

[ Upstream commit c8da1d15b8a4957f105ad77bb1404d72e304566f ]

DesignWare I2C controller was observed running at 105.93kHz rather
than the specified 100kHz. Adjust device tree settings to bring it
within spec (a slightly conservative 98 MHz).

Signed-off-by: Alan Tull <atull@xxxxxxxxxx>
Signed-off-by: Dinh Nguyen <dinguyen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/arm64/boot/dts/altera/socfpga_stratix10_socdk.dts | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/altera/socfpga_stratix10_socdk.dts b/arch/arm64/boot/dts/altera/socfpga_stratix10_socdk.dts
index 7c661753bfaf4..faa017d4cd56b 100644
--- a/arch/arm64/boot/dts/altera/socfpga_stratix10_socdk.dts
+++ b/arch/arm64/boot/dts/altera/socfpga_stratix10_socdk.dts
@@ -124,6 +124,8 @@
&i2c1 {
status = "okay";
clock-frequency = <100000>;
+ i2c-sda-falling-time-ns = <890>; /* hcnt */
+ i2c-sdl-falling-time-ns = <890>; /* lcnt */

adc@14 {
compatible = "lltc,ltc2497";
--
2.20.1