The I2C LCD display on the Cyclone5 and Arria5 devkits is only capable of
the standard 100 kHz clock. Set the "clock-frequency" of the I2C node
to be 100000.
Signed-off-by: Dinh Nguyen <dinguyen@xxxxxxxxxx>
---
arch/arm/boot/dts/socfpga_arria5_socdk.dts | 8 ++++++++
arch/arm/boot/dts/socfpga_cyclone5_socdk.dts | 8 ++++++++
2 files changed, 16 insertions(+)
diff --git a/arch/arm/boot/dts/socfpga_arria5_socdk.dts b/arch/arm/boot/dts/socfpga_arria5_socdk.dts
index fa70c39..8672edf 100644
--- a/arch/arm/boot/dts/socfpga_arria5_socdk.dts
+++ b/arch/arm/boot/dts/socfpga_arria5_socdk.dts
@@ -98,6 +98,14 @@
&i2c0 {
status = "okay";
+ clock-frequency = <100000>;
+
+ /*
+ * adjust the falling times to decrease the i2c frequency to 50Khz
+ * because the LCD module does not work at the standard 100Khz
+ */
+ i2c-sda-falling-time-ns = <5000>;
+ i2c-scl-falling-time-ns = <5000>;
eeprom@51 {
compatible = "atmel,24c32";
diff --git a/arch/arm/boot/dts/socfpga_cyclone5_socdk.dts b/arch/arm/boot/dts/socfpga_cyclone5_socdk.dts
index 6d3188b..24650ba 100644
--- a/arch/arm/boot/dts/socfpga_cyclone5_socdk.dts
+++ b/arch/arm/boot/dts/socfpga_cyclone5_socdk.dts
@@ -98,6 +98,14 @@
&i2c0 {
status = "okay";
+ clock-frequency = <100000>;
+
+ /*
+ * adjust the falling times to decrease the i2c frequency to 50Khz
+ * because the LCD module does not work at the standard 100Khz
+ */
+ i2c-sda-falling-time-ns = <5000>;
+ i2c-scl-falling-time-ns = <5000>;
eeprom@51 {
compatible = "atmel,24c32";
--
2.7.4
--
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