lkml.org 
[lkml]   [2013]   [Apr]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v5 2/3] ARM: dts: Add i2c-arbitrator bus for exynos5250-snow
    Date
    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>
    ---
    Changes in v5:
    - Adjust bindings as per Wolfram Sang.

    Changes in v4:
    - Changed mux gpio syntax to work atop Thomas's "ARM: dts: add pin
    state information in client nodes for Exynos5 platforms"; avoid
    adding gpios property to i2c@12CA0000 for the same reason.

    Changes in v3: None
    Changes in v2:
    - Use new device tree property names / compatible string.
    - Include that the GPIOs for arbitration are active low.

    arch/arm/boot/dts/cros5250-common.dtsi | 3 ++-
    arch/arm/boot/dts/exynos5250-snow.dts | 25 +++++++++++++++++++++++++
    2 files changed, 27 insertions(+), 1 deletion(-)

    diff --git a/arch/arm/boot/dts/cros5250-common.dtsi b/arch/arm/boot/dts/cros5250-common.dtsi
    index 8a5b3a6..0a61bbb 100644
    --- a/arch/arm/boot/dts/cros5250-common.dtsi
    +++ b/arch/arm/boot/dts/cros5250-common.dtsi
    @@ -193,7 +193,8 @@
    };

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

    i2c@12CB0000 {
    diff --git a/arch/arm/boot/dts/exynos5250-snow.dts b/arch/arm/boot/dts/exynos5250-snow.dts
    index 581ffae..fa85f58 100644
    --- a/arch/arm/boot/dts/exynos5250-snow.dts
    +++ b/arch/arm/boot/dts/exynos5250-snow.dts
    @@ -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 @@
    };
    };

    + 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.
    --
    1.8.1.3


    \
     
     \ /
      Last update: 2013-04-09 23:01    [W:3.469 / U:0.892 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site