ARM: dts: socfpga: set desired i2c clock on Cyclone5 and Arria5 devkits

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@kernel.org>

diff --git a/arch/arm/boot/dts/socfpga_arria5_socdk.dts b/arch/arm/boot/dts/socfpga_arria5_socdk.dts
index fa70c394dcfe557c16307c2b702aee66356f793b..8672edf9ba4ebccb6c4b131909bccd6d9d8070bb 100644 (file)
--- 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 6d3188bfefd838e8b6b5964c73297e60e9098fd8..24650bafcef473c5e19170e8b980a0b20bec0d47 100644 (file)
--- 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";