[PATCH v3 2/3] ARM: dts: Add i2c-arbitrator bus for exynos5250-snow

From: Doug Anderson <dianders@chromium.org>
To: Wolfram Sang <wsa@the-dreams.de>
Cc: Simon Glass <sjg@chromium.org>,
	Naveen Krishna Chatradhi <ch.naveen@samsung.com>,
	Grant Likely <grant.likely@secretlab.ca>,
	Yuvaraj Kumar <yuvaraj.cd@gmail.com>,
	Ben Dooks <ben.dooks@codethink.co.uk>,
	u.kleine-koenig@pengutronix.de,
	Mark Brown <broonie@opensource.wolfsonmicro.com>,
	Girish Shivananjappa <girish.shivananjappa@linaro.org>,
	bhushan.r@samsung.com, sreekumar.c@samsung.com,
	Prashanth G <prashanth.g@samsung.com>,
	Olof Johansson <olof@lixom.net>,
	Daniel Kurtz <djkurtz@chromium.org>,
	Grant Grundler <grundler@chromium.org>,
	Doug Anderson <dianders@chromium.org>,
	Russell King <linux@arm.linux.org.uk>,
	Kukjin Kim <kgene.kim@samsung.com>,
	Rahul Sharma <rahul.sharma@samsung.com>,
	Thomas Abraham <thomas.abraham@linaro.org>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v3 2/3] ARM: dts: Add i2c-arbitrator bus for exynos5250-snow
Date: Fri, 15 Feb 2013 11:46:12 -0800	[thread overview]
Message-ID: <1360957573-864-2-git-send-email-dianders@chromium.org> (raw)
In-Reply-To: <1360957573-864-1-git-send-email-dianders@chromium.org>

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 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 |  5 ++++-
 arch/arm/boot/dts/exynos5250-snow.dts  | 25 +++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/cros5250-common.dtsi b/arch/arm/boot/dts/cros5250-common.dtsi
index 46c0980..f451375 100644
--- a/arch/arm/boot/dts/cros5250-common.dtsi
+++ b/arch/arm/boot/dts/cros5250-common.dtsi
@@ -58,7 +58,10 @@
 	};
 
 	i2c@12CA0000 {
-		status = "disabled";
+		samsung,i2c-sda-delay = <100>;
+		samsung,i2c-max-bus-freq = <66000>;
+		gpios = <&gpa2 0 3 3 0>,
+			<&gpa2 1 3 3 0>;
 	};
 
 	i2c@12CB0000 {
diff --git a/arch/arm/boot/dts/exynos5250-snow.dts b/arch/arm/boot/dts/exynos5250-snow.dts
index 17dd951..d2d4b48 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;
+	};
+
 	gpio-keys {
 		compatible = "gpio-keys";
 
@@ -29,6 +33,27 @@
 		};
 	};
 
+	i2c-arbitrator {
+		compatible = "i2c-arbitrator-cros-ec";
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		i2c-parent = <&{/i2c@12CA0000}>;
+
+		ap-claim-gpio = <&gpf0 3 1 0x10000 0>;
+		ec-claim-gpio = <&gpe0 4 0 0x10003 0>;
+		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

