ARM: tegra: Fix I2C bus frequencies on Apalis/Colibri

Use a faster speed of 400 kbit/s for regular I2C busses.

Use a slower speed of 10 kbit/s for DDC/EDID to improve reliability.

Use a slower speed of 100 kbit/s for power I2C to be within specs of
the LM95245 temperature sensor.

While at it further annotate I2C pin usage.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --git a/arch/arm/boot/dts/tegra124-apalis-eval.dts b/arch/arm/boot/dts/tegra124-apalis-eval.dts
index ecffcd1..66b6c45 100644 (file)
--- a/arch/arm/boot/dts/tegra124-apalis-eval.dts
+++ b/arch/arm/boot/dts/tegra124-apalis-eval.dts
@@ -105,7 +105,7 @@
         */
        i2c@7000c000 {
                status = "okay";
-               clock-frequency = <100000>;
+               clock-frequency = <400000>;
 
                pcie-switch@58 {
                        compatible = "plx,pex8605";
@@ -124,7 +124,6 @@
         */
        hdmi_ddc: i2c@7000c400 {
                status = "okay";
-               clock-frequency = <100000>;
        };
 
        /*
@@ -133,7 +132,7 @@
         */
        i2c@7000c500 {
                status = "okay";
-               clock-frequency = <100000>;
+               clock-frequency = <400000>;
        };
 
        /* I2C4 (DDC): unused */

diff --git a/arch/arm/boot/dts/tegra124-apalis.dtsi b/arch/arm/boot/dts/tegra124-apalis.dtsi
index 5d9b18e..7aef892 100644 (file)
--- a/arch/arm/boot/dts/tegra124-apalis.dtsi
+++ b/arch/arm/boot/dts/tegra124-apalis.dtsi
@@ -1579,7 +1579,7 @@
        };
 
        hdmi_ddc: i2c@7000c400 {
-               clock-frequency = <100000>;
+               clock-frequency = <10000>;
        };
 
        /* PWR_I2C: power I2C to audio codec, PMIC and temperature sensor */

diff --git a/arch/arm/boot/dts/tegra20-colibri-512.dtsi b/arch/arm/boot/dts/tegra20-colibri-512.dtsi
index 813ae34..5c202b3 100644 (file)
--- a/arch/arm/boot/dts/tegra20-colibri-512.dtsi
+++ b/arch/arm/boot/dts/tegra20-colibri-512.dtsi
@@ -213,21 +213,27 @@
                        GPIO_ACTIVE_HIGH>;
        };
 
+       /*
+        * GEN1_I2C: I2C_SDA/SCL on SODIMM pin 194/196 (e.g. RTC on carrier
+        * board)
+        */
        i2c@7000c000 {
                clock-frequency = <400000>;
        };
 
+       /* DDC_SCL/SDA on X3 pin 15/16 (e.g. display EDID) */
        i2c_ddc: i2c@7000c400 {
-               clock-frequency = <100000>;
+               clock-frequency = <10000>;
        };
 
-       i2c@7000c500 {
-               clock-frequency = <400000>;
-       };
+       /* GEN2_I2C: unused */
 
+       /* CAM/GEN3_I2C: used as EXT_IO1/2 GPIOs on SODIMM pin 133/127 */
+
+       /* PWR_I2C: power I2C to PMIC and temperature sensor (On-module) */
        i2c@7000d000 {
                status = "okay";
-               clock-frequency = <400000>;
+               clock-frequency = <100000>;
 
                pmic: tps6586x@34 {
                        compatible = "ti,tps6586x";

diff --git a/arch/arm/boot/dts/tegra30-apalis-eval.dts b/arch/arm/boot/dts/tegra30-apalis-eval.dts
index 07b945b..fdca527 100644 (file)
--- a/arch/arm/boot/dts/tegra30-apalis-eval.dts
+++ b/arch/arm/boot/dts/tegra30-apalis-eval.dts
@@ -79,7 +79,7 @@
         */
        i2c@7000c000 {
                status = "okay";
-               clock-frequency = <100000>;
+               clock-frequency = <400000>;
 
                pcie-switch@58 {
                        compatible = "plx,pex8605";

diff --git a/arch/arm/boot/dts/tegra30-apalis.dtsi b/arch/arm/boot/dts/tegra30-apalis.dtsi
index bfb7913..676a4c4 100644 (file)
--- a/arch/arm/boot/dts/tegra30-apalis.dtsi
+++ b/arch/arm/boot/dts/tegra30-apalis.dtsi
@@ -437,7 +437,7 @@
        };
 
        hdmiddc: i2c@7000c700 {
-               clock-frequency = <100000>;
+               clock-frequency = <10000>;
        };
 
        /*

diff --git a/arch/arm/boot/dts/tegra30-colibri-eval-v3.dts b/arch/arm/boot/dts/tegra30-colibri-eval-v3.dts
index b307feb..8c62833 100644 (file)
--- a/arch/arm/boot/dts/tegra30-colibri-eval-v3.dts
+++ b/arch/arm/boot/dts/tegra30-colibri-eval-v3.dts
@@ -56,7 +56,7 @@
         */
        i2c@7000c000 {
                status = "okay";
-               clock-frequency = <100000>;
+               clock-frequency = <400000>;
 
                /* M41T0M6 real time clock on carrier board */
                rtc@68 {

diff --git a/arch/arm/boot/dts/tegra30-colibri.dtsi b/arch/arm/boot/dts/tegra30-colibri.dtsi
index 139bfa0..1f77273 100644 (file)
--- a/arch/arm/boot/dts/tegra30-colibri.dtsi
+++ b/arch/arm/boot/dts/tegra30-colibri.dtsi
@@ -215,7 +215,7 @@
        };
 
        hdmiddc: i2c@7000c700 {
-               clock-frequency = <100000>;
+               clock-frequency = <10000>;
        };
 
        /*