Merge branch 'i2c-mux-dt-3' of https://github.com/peda-r/i2c-mux into…

… i2c/for-4.9

Signed-off-by: Wolfram Sang <[email protected]>

Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt

@@ -44,8 +44,7 @@ Required properties:
 - our-claim-gpio: The GPIO that we use to claim the bus.
 - their-claim-gpios: The GPIOs that the other sides use to claim the bus.
   Note that some implementations may only support a single other master.
-- Standard I2C mux properties. See i2c-mux.txt in this directory.
-- Single I2C child bus node at reg 0. See i2c-mux.txt in this directory.
+- I2C arbitration bus node. See i2c-arb.txt in this directory.
 
 Optional properties:
 - slew-delay-us: microseconds to wait for a GPIO to go high. Default is 10 us.
@@ -63,8 +62,6 @@ Example:
 
 	i2c-arbitrator {
 		compatible = "i2c-arb-gpio-challenge";
-		#address-cells = <1>;
-		#size-cells = <0>;
 
 		i2c-parent = <&{/i2c@12CA0000}>;
 
@@ -74,8 +71,7 @@ Example:
 		wait-retry-us = <3000>;
 		wait-free-us = <50000>;
 
-		i2c@0 {
-			reg = <0>;
+		i2c-arb {
 			#address-cells = <1>;
 			#size-cells = <0>;
 

Documentation/devicetree/bindings/i2c/i2c-arb.txt

@@ -0,0 +1,35 @@
+Common i2c arbitration bus properties.
+
+- i2c-arb child node
+
+Required properties for the i2c-arb child node:
+- #address-cells = <1>;
+- #size-cells = <0>;
+
+Optional properties for i2c-arb child node:
+- Child nodes conforming to i2c bus binding
+
+
+Example :
+
+	/*
+	   An NXP pca9541 I2C bus master selector at address 0x74
+	   with a NXP pca8574 GPIO expander attached.
+	 */
+
+	arb@74 {
+		compatible = "nxp,pca9541";
+		reg = <0x74>;
+
+		i2c-arb {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			gpio@38 {
+				compatible = "nxp,pca8574";
+				reg = <0x38>;
+				#gpio-cells = <2>;
+				gpio-controller;
+			};
+		};
+	};

Documentation/devicetree/bindings/i2c/i2c-gate.txt

@@ -0,0 +1,41 @@
+An i2c gate is useful to e.g. reduce the digital noise for RF tuners connected
+to the i2c bus. Gates are similar to arbitrators in that you need to perform
+some kind of operation to access the i2c bus past the arbitrator/gate, but
+there are no competing masters to consider for gates and therefore there is
+no arbitration happening for gates.
+
+Common i2c gate properties.
+
+- i2c-gate child node
+
+Required properties for the i2c-gate child node:
+- #address-cells = <1>;
+- #size-cells = <0>;
+
+Optional properties for i2c-gate child node:
+- Child nodes conforming to i2c bus binding
+
+
+Example :
+
+	/*
+	   An Invensense mpu9150 at address 0x68 featuring an on-chip Asahi
+	   Kasei ak8975 compass behind a gate.
+	 */
+
+	mpu9150@68 {
+		compatible = "invensense,mpu9150";
+		reg = <0x68>;
+		interrupt-parent = <&gpio1>;
+		interrupts = <18 1>;
+
+		i2c-gate {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			ax8975@c {
+				compatible = "ak,ak8975";
+				reg = <0x0c>;
+			};
+		};
+	};

Documentation/devicetree/bindings/i2c/i2c-mux.txt

@@ -2,19 +2,32 @@ Common i2c bus multiplexer/switch properties.
 
 An i2c bus multiplexer/switch will have several child busses that are
 numbered uniquely in a device dependent manner.  The nodes for an i2c bus
-multiplexer/switch will have one child node for each child
-bus.
+multiplexer/switch will have one child node for each child bus.
 
-Required properties:
+Optional properties:
+- #address-cells = <1>;
+   This property is required is the i2c-mux child node does not exist.
+
+- #size-cells = <0>;
+   This property is required is the i2c-mux child node does not exist.
+
+- i2c-mux
+   For i2c multiplexers/switches that have child nodes that are a mixture
+   of both i2c child busses and other child nodes, the 'i2c-mux' subnode
+   can be used for populating the i2c child busses.  If an 'i2c-mux'
+   subnode is present, only subnodes of this will be considered as i2c
+   child busses.
+
+Required properties for the i2c-mux child node:
 - #address-cells = <1>;
 - #size-cells = <0>;
 
-Required properties for child nodes:
+Required properties for i2c child bus nodes:
 - #address-cells = <1>;
 - #size-cells = <0>;
 - reg : The sub-bus number.
 
-Optional properties for child nodes:
+Optional properties for i2c child bus nodes:
 - Other properties specific to the multiplexer/switch hardware.
 - Child nodes conforming to i2c bus binding
 

Documentation/devicetree/bindings/i2c/nxp,pca9541.txt

@@ -0,0 +1,29 @@
+* NXP PCA9541 I2C bus master selector
+
+Required Properties:
+
+  - compatible: Must be "nxp,pca9541"
+
+  - reg: The I2C address of the device.
+
+  The following required properties are defined externally:
+
+  - I2C arbitration bus node. See i2c-arb.txt in this directory.
+
+
+Example:
+
+	i2c-arbitrator@74 {
+		compatible = "nxp,pca9541";
+		reg = <0x74>;
+
+		i2c-arb {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			eeprom@54 {
+				compatible = "at,24c08";
+				reg = <0x54>;
+			};
+		};
+	};

MAINTAINERS

@@ -5675,6 +5675,8 @@ S:	Maintained
 F:	Documentation/i2c/i2c-topology
 F:	Documentation/i2c/muxes/
 F:	Documentation/devicetree/bindings/i2c/i2c-mux*
+F:	Documentation/devicetree/bindings/i2c/i2c-arb*
+F:	Documentation/devicetree/bindings/i2c/i2c-gate*
 F:	drivers/i2c/i2c-mux.c
 F:	drivers/i2c/muxes/
 F:	include/linux/i2c-mux.h

drivers/i2c/i2c-mux.c

@@ -255,6 +255,10 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
 	muxc->dev = dev;
 	if (flags & I2C_MUX_LOCKED)
 		muxc->mux_locked = true;
+	if (flags & I2C_MUX_ARBITRATOR)
+		muxc->arbitrator = true;
+	if (flags & I2C_MUX_GATE)
+		muxc->gate = true;
 	muxc->select = select;
 	muxc->deselect = deselect;
 	muxc->max_adapters = max_adapters;
@@ -335,18 +339,42 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
 	 * nothing if !CONFIG_OF.
 	 */
 	if (muxc->dev->of_node) {
-		struct device_node *child;
+		struct device_node *dev_node = muxc->dev->of_node;
+		struct device_node *mux_node, *child = NULL;
 		u32 reg;
 
-		for_each_child_of_node(muxc->dev->of_node, child) {
-			ret = of_property_read_u32(child, "reg", &reg);
-			if (ret)
-				continue;
-			if (chan_id == reg) {
-				priv->adap.dev.of_node = child;
-				break;
+		if (muxc->arbitrator)
+			mux_node = of_get_child_by_name(dev_node, "i2c-arb");
+		else if (muxc->gate)
+			mux_node = of_get_child_by_name(dev_node, "i2c-gate");
+		else
+			mux_node = of_get_child_by_name(dev_node, "i2c-mux");
+
+		if (mux_node) {
+			/* A "reg" property indicates an old-style DT entry */
+			if (!of_property_read_u32(mux_node, "reg", &reg)) {
+				of_node_put(mux_node);
+				mux_node = NULL;
+			}
+		}
+
+		if (!mux_node)
+			mux_node = of_node_get(dev_node);
+		else if (muxc->arbitrator || muxc->gate)
+			child = of_node_get(mux_node);
+
+		if (!child) {
+			for_each_child_of_node(mux_node, child) {
+				ret = of_property_read_u32(child, "reg", &reg);
+				if (ret)
+					continue;
+				if (chan_id == reg)
+					break;
 			}
 		}
+
+		priv->adap.dev.of_node = child;
+		of_node_put(mux_node);
 	}
 
 	/*

drivers/i2c/muxes/i2c-arb-gpio-challenge.c

@@ -130,7 +130,7 @@ static int i2c_arbitrator_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	muxc = i2c_mux_alloc(NULL, dev, 1, sizeof(*arb), 0,
+	muxc = i2c_mux_alloc(NULL, dev, 1, sizeof(*arb), I2C_MUX_ARBITRATOR,
 			     i2c_arbitrator_select, i2c_arbitrator_deselect);
 	if (!muxc)
 		return -ENOMEM;

drivers/i2c/muxes/i2c-mux-pca9541.c

@@ -85,6 +85,13 @@ static const struct i2c_device_id pca9541_id[] = {
 
 MODULE_DEVICE_TABLE(i2c, pca9541_id);
 
+#ifdef CONFIG_OF
+static const struct of_device_id pca9541_of_match[] = {
+	{ .compatible = "nxp,pca9541" },
+	{}
+};
+#endif
+
 /*
  * Write to chip register. Don't use i2c_transfer()/i2c_smbus_xfer()
  * as they will try to lock the adapter a second time.
@@ -349,7 +356,8 @@ static int pca9541_probe(struct i2c_client *client,
 	force = 0;
 	if (pdata)
 		force = pdata->modes[0].adap_id;
-	muxc = i2c_mux_alloc(adap, &client->dev, 1, sizeof(*data), 0,
+	muxc = i2c_mux_alloc(adap, &client->dev, 1, sizeof(*data),
+			     I2C_MUX_ARBITRATOR,
 			     pca9541_select_chan, pca9541_release_chan);
 	if (!muxc)
 		return -ENOMEM;
@@ -382,6 +390,7 @@ static int pca9541_remove(struct i2c_client *client)
 static struct i2c_driver pca9541_driver = {
 	.driver = {
 		   .name = "pca9541",
+		   .of_match_table = of_match_ptr(pca9541_of_match),
 		   },
 	.probe = pca9541_probe,
 	.remove = pca9541_remove,