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ARM: dts: Add i2c-arbitrator bus for exynos5250-snow 

We need to use the i2c-arbitrator to talk to any of the devices on i2c
bus 4 on exynos5250-snow so that we don't confuse the embedded
controller (EC).  Add the i2c-arbitrator to the device tree.  As we
add future devices (keyboard, sbs, tps65090) we'll add them on top of
this.

The arbitrated bus is numbered 104 simply as a convenience to make it
easier for people poking around to guess that it might have something
to do with the physical bus 4.

The addition is split between the cros5250-common and the snow device
tree file since not all cros5250-class devices use arbitration.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
This commit is contained in:
Doug Anderson 2013-04-16 16:29:01 +00:00 committed by Olof Johansson
parent 6cae0fafe3
commit 97a4a1ba0e
2 changed files with 27 additions and 1 deletions
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3
arch/arm/boot/dts/cros5250-common.dtsi
View File

@ -193,7 +193,8 @@ i2c@12C90000 {
};
i2c@12CA0000 {
status = "disabled";
samsung,i2c-sda-delay = <100>;
samsung,i2c-max-bus-freq = <66000>;
};
i2c@12CB0000 {

25
arch/arm/boot/dts/exynos5250-snow.dts
View File

@ -16,6 +16,10 @@ / {
model = "Google Snow";
compatible = "google,snow", "samsung,exynos5250";
aliases {
i2c104 = &i2c_104;
};
pinctrl@11400000 {
sd3_clk: sd3-clk {
samsung,pin-drv = <0>;
@ -44,6 +48,27 @@ lid-switch {
};
};
i2c-arbitrator {
compatible = "i2c-arb-gpio-challenge";
#address-cells = <1>;
#size-cells = <0>;
i2c-parent = <&{/i2c@12CA0000}>;
our-claim-gpio = <&gpf0 3 1>;
their-claim-gpios = <&gpe0 4 1>;
slew-delay-us = <10>;
wait-retry-us = <3000>;
wait-free-us = <50000>;
/* Use ID 104 as a hint that we're on physical bus 4 */
i2c_104: i2c@0 {
reg = <0>;
#address-cells = <1>;
#size-cells = <0>;
};
};
/*
* On Snow we've got SIP WiFi and so can keep drive strengths low to
* reduce EMI.