Merge branch 'i2c-mux-dt-3' of https://github.com/peda-r/i2c-mux into i2c/for-4.9

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-26 00:49:37 +02:00 · 2016-08-26 00:49:37 +02:00 · 6d54f1446d
parent 0317e6c0f1 8a191a7ad4
commit 6d54f1446d
11 changed files with 214 additions and 35 deletions
--- a/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt
+++ b/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>;

--- a/Documentation/devicetree/bindings/i2c/i2c-arb.txt
+++ b/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;
+			};
+		};
+	};
--- a/Documentation/devicetree/bindings/i2c/i2c-gate.txt
+++ b/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>;
+			};
+		};
+	};
--- a/Documentation/devicetree/bindings/i2c/i2c-mux.txt
+++ b/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

--- a/Documentation/devicetree/bindings/i2c/nxp,pca9541.txt
+++ b/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>;
+			};
+		};
+	};
--- a/2
+++ b/2
@ -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
--- a/drivers/i2c/i2c-mux.c
+++ b/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);
 	}

 	/*
--- a/drivers/i2c/muxes/i2c-arb-gpio-challenge.c
+++ b/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;
--- a/drivers/i2c/muxes/i2c-mux-pca9541.c
+++ b/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,
--- a/drivers/i2c/muxes/i2c-mux-pca954x.c
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@ -42,6 +42,7 @@
 #include <linux/i2c/pca954x.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/pm.h>
 #include <linux/slab.h>

@ -58,14 +59,6 @@ enum pca_type {
 	pca_9548,
 };

-struct pca954x {
-	enum pca_type type;
-
-	u8 last_chan;		/* last register value */
-	u8 deselect;
-	struct i2c_client *client;
-};
-
 struct chip_desc {
 	u8 nchans;
 	u8 enable;	/* used for muxes only */
@ -75,6 +68,14 @@ struct chip_desc {
 	} muxtype;
 };

+struct pca954x {
+	const struct chip_desc *chip;
+
+	u8 last_chan;		/* last register value */
+	u8 deselect;
+	struct i2c_client *client;
+};
+
 /* Provide specs for the PCA954x types we know about */
 static const struct chip_desc chips[] = {
 	[pca_9540] = {
@ -119,6 +120,20 @@ static const struct i2c_device_id pca954x_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, pca954x_id);

+#ifdef CONFIG_OF
+static const struct of_device_id pca954x_of_match[] = {
+	{ .compatible = "nxp,pca9540", .data = &chips[pca_9540] },
+	{ .compatible = "nxp,pca9542", .data = &chips[pca_9542] },
+	{ .compatible = "nxp,pca9543", .data = &chips[pca_9543] },
+	{ .compatible = "nxp,pca9544", .data = &chips[pca_9544] },
+	{ .compatible = "nxp,pca9545", .data = &chips[pca_9545] },
+	{ .compatible = "nxp,pca9546", .data = &chips[pca_9546] },
+	{ .compatible = "nxp,pca9547", .data = &chips[pca_9547] },
+	{ .compatible = "nxp,pca9548", .data = &chips[pca_9548] },
+	{}
+};
+#endif
+
 /* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer()
   for this as they will try to lock adapter a second time */
 static int pca954x_reg_write(struct i2c_adapter *adap,
@ -151,7 +166,7 @@ static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
 {
 	struct pca954x *data = i2c_mux_priv(muxc);
 	struct i2c_client *client = data->client;
-	const struct chip_desc *chip = &chips[data->type];
+	const struct chip_desc *chip = data->chip;
 	u8 regval;
 	int ret = 0;

@ -197,6 +212,7 @@ static int pca954x_probe(struct i2c_client *client,
 	int num, force, class;
 	struct i2c_mux_core *muxc;
 	struct pca954x *data;
+	const struct of_device_id *match;
 	int ret;

 	if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
@ -226,14 +242,19 @@ static int pca954x_probe(struct i2c_client *client,
 		return -ENODEV;
 	}

-	data->type = id->driver_data;
+	match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
+	if (match)
+		data->chip = of_device_get_match_data(&client->dev);
+	else
+		data->chip = &chips[id->driver_data];
+
 	data->last_chan = 0;		   /* force the first selection */

 	idle_disconnect_dt = of_node &&
 		of_property_read_bool(of_node, "i2c-mux-idle-disconnect");

 	/* Now create an adapter for each channel */
-	for (num = 0; num < chips[data->type].nchans; num++) {
+	for (num = 0; num < data->chip->nchans; num++) {
 		bool idle_disconnect_pd = false;

 		force = 0;			  /* dynamic adap number */
@ -263,7 +284,7 @@ static int pca954x_probe(struct i2c_client *client,

 	dev_info(&client->dev,
 		 "registered %d multiplexed busses for I2C %s %s\n",
-		 num, chips[data->type].muxtype == pca954x_ismux
+		 num, data->chip->muxtype == pca954x_ismux
 				? "mux" : "switch", client->name);

 	return 0;
@ -299,6 +320,7 @@ static struct i2c_driver pca954x_driver = {
 	.driver		= {
 		.name	= "pca954x",
 		.pm	= &pca954x_pm,
+		.of_match_table = of_match_ptr(pca954x_of_match),
 	},
 	.probe		= pca954x_probe,
 	.remove		= pca954x_remove,
--- a/include/linux/i2c-mux.h
+++ b/include/linux/i2c-mux.h
@ -32,7 +32,9 @@
 struct i2c_mux_core {
 	struct i2c_adapter *parent;
 	struct device *dev;
-	bool mux_locked;
+	unsigned int mux_locked:1;
+	unsigned int arbitrator:1;
+	unsigned int gate:1;

 	void *priv;

@ -51,7 +53,9 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
 				   int (*deselect)(struct i2c_mux_core *, u32));

 /* flags for i2c_mux_alloc */
-#define I2C_MUX_LOCKED BIT(0)
+#define I2C_MUX_LOCKED     BIT(0)
+#define I2C_MUX_ARBITRATOR BIT(1)
+#define I2C_MUX_GATE       BIT(2)

 static inline void *i2c_mux_priv(struct i2c_mux_core *muxc)
 {