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Date:      Wed, 28 May 2014 06:11:12 +0000 (UTC)
From:      Ruslan Bukin <br@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r266785 - in head/sys: arm/samsung/exynos boot/fdt/dts/arm
Message-ID:  <201405280611.s4S6BCR9068863@svn.freebsd.org>
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Author: br
Date: Wed May 28 06:11:12 2014
New Revision: 266785
URL: http://svnweb.freebsd.org/changeset/base/266785

Log:
  Describe I2C arbitrator device in DTS and use it for Chromebook Snow only.
  
  Submitted by:	Maxim Ignatenko <gelraen.ua@gmail.com>

Modified:
  head/sys/arm/samsung/exynos/chrome_ec.c
  head/sys/boot/fdt/dts/arm/exynos5250-chromebook-snow.dts

Modified: head/sys/arm/samsung/exynos/chrome_ec.c
==============================================================================
--- head/sys/arm/samsung/exynos/chrome_ec.c	Wed May 28 06:02:04 2014	(r266784)
+++ head/sys/arm/samsung/exynos/chrome_ec.c	Wed May 28 06:11:12 2014	(r266785)
@@ -60,12 +60,11 @@ __FBSDID("$FreeBSD$");
 
 #include <arm/samsung/exynos/chrome_ec.h>
 
-/* TODO: export to DTS */
-#define OUR_GPIO	177
-#define EC_GPIO		168
-
 struct ec_softc {
 	device_t	dev;
+	int		have_arbitrator;
+	pcell_t		our_gpio;
+	pcell_t		ec_gpio;
 };
 
 struct ec_softc *ec_sc;
@@ -82,17 +81,24 @@ bus_claim(struct ec_softc *sc)
 	device_t gpio_dev;
 	int status;
 
+	if (sc->our_gpio == 0 || sc->ec_gpio == 0) {
+		device_printf(sc->dev, "i2c arbitrator is not configured\n");
+		return (1);
+	}
+
 	gpio_dev = devclass_get_device(devclass_find("gpio"), 0);
-        if (gpio_dev == NULL) {
+	if (gpio_dev == NULL) {
 		device_printf(sc->dev, "cant find gpio_dev\n");
 		return (1);
 	}
 
 	/* Say we want the bus */
-	GPIO_PIN_SET(gpio_dev, OUR_GPIO, GPIO_PIN_LOW);
+	GPIO_PIN_SET(gpio_dev, sc->our_gpio, GPIO_PIN_LOW);
+
+	/* TODO(imax): insert a delay to allow EC to react. */
 
 	/* Check EC decision */
-	GPIO_PIN_GET(gpio_dev, EC_GPIO, &status);
+	GPIO_PIN_GET(gpio_dev, sc->ec_gpio, &status);
 
 	if (status == 1) {
 		/* Okay. We have bus */
@@ -108,13 +114,18 @@ bus_release(struct ec_softc *sc)
 {
 	device_t gpio_dev;
 
+	if (sc->our_gpio == 0 || sc->ec_gpio == 0) {
+		device_printf(sc->dev, "i2c arbitrator is not configured\n");
+		return (1);
+	}
+
 	gpio_dev = devclass_get_device(devclass_find("gpio"), 0);
-        if (gpio_dev == NULL) {
+	if (gpio_dev == NULL) {
 		device_printf(sc->dev, "cant find gpio_dev\n");
 		return (1);
 	}
 
-	GPIO_PIN_SET(gpio_dev, OUR_GPIO, GPIO_PIN_HIGH);
+	GPIO_PIN_SET(gpio_dev, sc->our_gpio, GPIO_PIN_HIGH);
 
 	return (0);
 }
@@ -209,6 +220,28 @@ int ec_hello(void)
 	return (0);
 }
 
+static void
+configure_i2c_arbitrator(struct ec_softc *sc)
+{
+	phandle_t arbitrator;
+
+	/* TODO(imax): look for compatible entry instead of hard-coded path */
+	arbitrator = OF_finddevice("/i2c-arbitrator");
+	if (arbitrator > 0 &&
+	    OF_hasprop(arbitrator, "freebsd,our-gpio") &&
+	    OF_hasprop(arbitrator, "freebsd,ec-gpio")) {
+		sc->have_arbitrator = 1;
+		OF_getencprop(arbitrator, "freebsd,our-gpio",
+		    &sc->our_gpio, sizeof(sc->our_gpio));
+		OF_getencprop(arbitrator, "freebsd,ec-gpio",
+		    &sc->ec_gpio, sizeof(sc->ec_gpio));
+	} else {
+		sc->have_arbitrator = 0;
+		sc->our_gpio = 0;
+		sc->ec_gpio = 0;
+	}
+}
+
 static int
 ec_attach(device_t dev)
 {
@@ -219,6 +252,8 @@ ec_attach(device_t dev)
 
 	ec_sc = sc;
 
+	configure_i2c_arbitrator(sc);
+
 	/*
 	 * Claim the bus.
 	 *
@@ -227,7 +262,7 @@ ec_attach(device_t dev)
 	 *
 	 */
 
-	if (bus_claim(sc) != 0) {
+	if (sc->have_arbitrator && bus_claim(sc) != 0) {
 		return (ENXIO);
 	}
 
@@ -241,7 +276,9 @@ ec_detach(device_t dev)
 
 	sc = device_get_softc(dev);
 
-	bus_release(sc);
+	if (sc->have_arbitrator) {
+		bus_release(sc);
+	}
 
 	return (0);
 }

Modified: head/sys/boot/fdt/dts/arm/exynos5250-chromebook-snow.dts
==============================================================================
--- head/sys/boot/fdt/dts/arm/exynos5250-chromebook-snow.dts	Wed May 28 06:02:04 2014	(r266784)
+++ head/sys/boot/fdt/dts/arm/exynos5250-chromebook-snow.dts	Wed May 28 06:11:12 2014	(r266785)
@@ -65,6 +65,11 @@
 		};
 	};
 
+	i2c-arbitrator {
+		freebsd,our-gpio = <177>;
+		freebsd,ec-gpio = <168>;
+	};
+
 	chosen {
 		stdin = &serial2;
 		stdout = &serial2;

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