[PATCH 1/2] i2c: mux: add device tree support

[PATCH 1/2] i2c: mux: add device tree support

[Stephen Warren]

From: Stephen Warren <swarren@nvidia.com>

* Define core portions of the DT binding for I2C bus muxes.
* Enhance i2c_add_mux_adapter():
** Add parameters required for DT support. Update all callers.
** Set the appropriate adap->dev.of_node for the child bus.
** Call of_i2c_register_devices() for the child bus.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
Note: This series depends on the 3 patches I just sent that affect
of_find_i2c_device_by_node and implement of_find_i2c_adapter_by_node.
It might be useful to put this patch (and the others I sent) in
a separate tree so it can be merged into any SoC trees that wish to use
this new feature.

 Documentation/devicetree/bindings/i2c/i2cmux.txt |   45 ++++++++++++++++++++++
 drivers/i2c/i2c-mux.c                            |   23 +++++++++++-
 drivers/i2c/muxes/gpio-i2cmux.c                  |    5 +-
 drivers/i2c/muxes/pca9541.c                      |    4 +-
 drivers/i2c/muxes/pca954x.c                      |    4 +-
 include/linux/i2c-mux.h                          |    4 +-
 6 files changed, 77 insertions(+), 8 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2cmux.txt

diff --git a/Documentation/devicetree/bindings/i2c/i2cmux.txt b/Documentation/devicetree/bindings/i2c/i2cmux.txt
new file mode 100644
index 0000000..1e4e2bc
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2cmux.txt
@@ -0,0 +1,45 @@
+Common I2C mux bindings
+
+An I2C mux is a device that connects a master I2C bus to one of a number of
+child I2C busses, under programmatic control.
+
+Each I2C mux may define the set of child busses it supports in a different
+way. Some devices may have a hard-coded set of child ports, whereas others may
+support a varying set of child busses (especially when the bus mux is
+implemented using GPIOs or pin muxing). Any bindings required to represent
+this are the domain of the individual mux device.
+
+For each child bus, there shall be a node within the I2C mux's own node for
+that bus. This node will contain all the I2C devices on that bus, just like
+any other I2C bus. Each child bus shall be identified by some name. The set
+of child bus names is defined by the individual I2C mux's bindings. Bus names
+are used to construct the name of the bus's child node using the format
+i2c-bus-%s. Each child bus node needs the usual #address-cells and #size-cells
+properties.
+
+Example:
+
+	i2cmux {
+		// properties here omitted from the example.
+
+		i2c-bus-0 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			eeprom {
+				compatible = "eeprom";
+				reg = <0x50>;
+			};
+		};
+
+		i2c-bus-1 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			eeprom {
+				compatible = "eeprom";
+				reg = <0x50>;
+			};
+		};
+	};
+
diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
index d7a4833..8adeeec 100644
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -24,6 +24,7 @@
 #include <linux/slab.h>
 #include <linux/i2c.h>
 #include <linux/i2c-mux.h>
+#include <linux/of_i2c.h>
 
 /* multiplexer per channel data */
 struct i2c_mux_priv {
@@ -86,8 +87,10 @@ static u32 i2c_mux_functionality(struct i2c_adapter *adap)
 	return parent->algo->functionality(parent);
 }
 
-struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
+struct i2c_adapter *i2c_add_mux_adapter(struct device *dev,
+				struct i2c_adapter *parent,
 				void *mux_dev, u32 force_nr, u32 chan_id,
+				const char *chan_name,
 				int (*select) (struct i2c_adapter *,
 					       void *, u32),
 				int (*deselect) (struct i2c_adapter *,
@@ -124,6 +127,22 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
 	priv->adap.algo_data = priv;
 	priv->adap.dev.parent = &parent->dev;
 
+	if (dev->of_node) {
+		const char *name;
+
+		if (chan_name)
+			name = kasprintf(GFP_KERNEL, "i2c-bus-%s",
+					     chan_name);
+		else
+			name = kasprintf(GFP_KERNEL, "i2c-bus-%d",
+					     chan_id);
+
+		priv->adap.dev.of_node = of_find_node_by_name(dev->of_node,
+							      name);
+
+		kfree(name);
+	}
+
 	if (force_nr) {
 		priv->adap.nr = force_nr;
 		ret = i2c_add_numbered_adapter(&priv->adap);
@@ -141,6 +160,8 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
 	dev_info(&parent->dev, "Added multiplexed i2c bus %d\n",
 		 i2c_adapter_id(&priv->adap));
 
+	of_i2c_register_devices(&priv->adap);
+
 	return &priv->adap;
 }
 EXPORT_SYMBOL_GPL(i2c_add_mux_adapter);
diff --git a/drivers/i2c/muxes/gpio-i2cmux.c b/drivers/i2c/muxes/gpio-i2cmux.c
index e5fa695..7284c70 100644
--- a/drivers/i2c/muxes/gpio-i2cmux.c
+++ b/drivers/i2c/muxes/gpio-i2cmux.c
@@ -105,8 +105,9 @@ static int __devinit gpiomux_probe(struct platform_device *pdev)
 	for (i = 0; i < pdata->n_values; i++) {
 		u32 nr = pdata->base_nr ? (pdata->base_nr + i) : 0;
 
-		mux->adap[i] = i2c_add_mux_adapter(parent, mux, nr, i,
-						   gpiomux_select, deselect);
+		mux->adap[i] = i2c_add_mux_adapter(&pdev->dev, parent, mux, nr,
+						   i, NULL, gpiomux_select,
+						   deselect);
 		if (!mux->adap[i]) {
 			ret = -ENODEV;
 			dev_err(&pdev->dev, "Failed to add adapter %d\n", i);
diff --git a/drivers/i2c/muxes/pca9541.c b/drivers/i2c/muxes/pca9541.c
index e0df9b6..e1777fb 100644
--- a/drivers/i2c/muxes/pca9541.c
+++ b/drivers/i2c/muxes/pca9541.c
@@ -353,8 +353,8 @@ static int pca9541_probe(struct i2c_client *client,
 	force = 0;
 	if (pdata)
 		force = pdata->modes[0].adap_id;
-	data->mux_adap = i2c_add_mux_adapter(adap, client, force, 0,
-					     pca9541_select_chan,
+	data->mux_adap = i2c_add_mux_adapter(&client->dev, adap, client, force,
+					     0, NULL, pca9541_select_chan,
 					     pca9541_release_chan);
 
 	if (data->mux_adap == NULL) {
diff --git a/drivers/i2c/muxes/pca954x.c b/drivers/i2c/muxes/pca954x.c
index 0e37ef2..736a803 100644
--- a/drivers/i2c/muxes/pca954x.c
+++ b/drivers/i2c/muxes/pca954x.c
@@ -226,8 +226,8 @@ static int pca954x_probe(struct i2c_client *client,
 		}
 
 		data->virt_adaps[num] =
-			i2c_add_mux_adapter(adap, client,
-				force, num, pca954x_select_chan,
+			i2c_add_mux_adapter(&client->dev, adap, client,
+				force, num, NULL, pca954x_select_chan,
 				(pdata && pdata->modes[num].deselect_on_exit)
 					? pca954x_deselect_mux : NULL);
 
diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h
index 747f0cd..43fb11a 100644
--- a/include/linux/i2c-mux.h
+++ b/include/linux/i2c-mux.h
@@ -33,8 +33,10 @@
  * and deselect callback functions to perform hardware-specific
  * mux control.
  */
-struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
+struct i2c_adapter *i2c_add_mux_adapter(struct device *dev,
+				struct i2c_adapter *parent,
 				void *mux_dev, u32 force_nr, u32 chan_id,
+				const char *chan_name,
 				int (*select) (struct i2c_adapter *,
 					       void *mux_dev, u32 chan_id),
 				int (*deselect) (struct i2c_adapter *,
-- 
1.7.0.4

[PATCH 1/2] i2c: mux: add device tree support

[Stephen Warren]

From: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

* Define core portions of the DT binding for I2C bus muxes.
* Enhance i2c_add_mux_adapter():
** Add parameters required for DT support. Update all callers.
** Set the appropriate adap->dev.of_node for the child bus.
** Call of_i2c_register_devices() for the child bus.

Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
Note: This series depends on the 3 patches I just sent that affect
of_find_i2c_device_by_node and implement of_find_i2c_adapter_by_node.
It might be useful to put this patch (and the others I sent) in
a separate tree so it can be merged into any SoC trees that wish to use
this new feature.

 Documentation/devicetree/bindings/i2c/i2cmux.txt |   45 ++++++++++++++++++++++
 drivers/i2c/i2c-mux.c                            |   23 +++++++++++-
 drivers/i2c/muxes/gpio-i2cmux.c                  |    5 +-
 drivers/i2c/muxes/pca9541.c                      |    4 +-
 drivers/i2c/muxes/pca954x.c                      |    4 +-
 include/linux/i2c-mux.h                          |    4 +-
 6 files changed, 77 insertions(+), 8 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2cmux.txt

diff --git a/Documentation/devicetree/bindings/i2c/i2cmux.txt b/Documentation/devicetree/bindings/i2c/i2cmux.txt
new file mode 100644
index 0000000..1e4e2bc
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2cmux.txt
@@ -0,0 +1,45 @@
+Common I2C mux bindings
+
+An I2C mux is a device that connects a master I2C bus to one of a number of
+child I2C busses, under programmatic control.
+
+Each I2C mux may define the set of child busses it supports in a different
+way. Some devices may have a hard-coded set of child ports, whereas others may
+support a varying set of child busses (especially when the bus mux is
+implemented using GPIOs or pin muxing). Any bindings required to represent
+this are the domain of the individual mux device.
+
+For each child bus, there shall be a node within the I2C mux's own node for
+that bus. This node will contain all the I2C devices on that bus, just like
+any other I2C bus. Each child bus shall be identified by some name. The set
+of child bus names is defined by the individual I2C mux's bindings. Bus names
+are used to construct the name of the bus's child node using the format
+i2c-bus-%s. Each child bus node needs the usual #address-cells and #size-cells
+properties.
+
+Example:
+
+	i2cmux {
+		// properties here omitted from the example.
+
+		i2c-bus-0 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			eeprom {
+				compatible = "eeprom";
+				reg = <0x50>;
+			};
+		};
+
+		i2c-bus-1 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			eeprom {
+				compatible = "eeprom";
+				reg = <0x50>;
+			};
+		};
+	};
+
diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
index d7a4833..8adeeec 100644
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -24,6 +24,7 @@
 #include <linux/slab.h>
 #include <linux/i2c.h>
 #include <linux/i2c-mux.h>
+#include <linux/of_i2c.h>
 
 /* multiplexer per channel data */
 struct i2c_mux_priv {
@@ -86,8 +87,10 @@ static u32 i2c_mux_functionality(struct i2c_adapter *adap)
 	return parent->algo->functionality(parent);
 }
 
-struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
+struct i2c_adapter *i2c_add_mux_adapter(struct device *dev,
+				struct i2c_adapter *parent,
 				void *mux_dev, u32 force_nr, u32 chan_id,
+				const char *chan_name,
 				int (*select) (struct i2c_adapter *,
 					       void *, u32),
 				int (*deselect) (struct i2c_adapter *,
@@ -124,6 +127,22 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
 	priv->adap.algo_data = priv;
 	priv->adap.dev.parent = &parent->dev;
 
+	if (dev->of_node) {
+		const char *name;
+
+		if (chan_name)
+			name = kasprintf(GFP_KERNEL, "i2c-bus-%s",
+					     chan_name);
+		else
+			name = kasprintf(GFP_KERNEL, "i2c-bus-%d",
+					     chan_id);
+
+		priv->adap.dev.of_node = of_find_node_by_name(dev->of_node,
+							      name);
+
+		kfree(name);
+	}
+
 	if (force_nr) {
 		priv->adap.nr = force_nr;
 		ret = i2c_add_numbered_adapter(&priv->adap);
@@ -141,6 +160,8 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
 	dev_info(&parent->dev, "Added multiplexed i2c bus %d\n",
 		 i2c_adapter_id(&priv->adap));
 
+	of_i2c_register_devices(&priv->adap);
+
 	return &priv->adap;
 }
 EXPORT_SYMBOL_GPL(i2c_add_mux_adapter);
diff --git a/drivers/i2c/muxes/gpio-i2cmux.c b/drivers/i2c/muxes/gpio-i2cmux.c
index e5fa695..7284c70 100644
--- a/drivers/i2c/muxes/gpio-i2cmux.c
+++ b/drivers/i2c/muxes/gpio-i2cmux.c
@@ -105,8 +105,9 @@ static int __devinit gpiomux_probe(struct platform_device *pdev)
 	for (i = 0; i < pdata->n_values; i++) {
 		u32 nr = pdata->base_nr ? (pdata->base_nr + i) : 0;
 
-		mux->adap[i] = i2c_add_mux_adapter(parent, mux, nr, i,
-						   gpiomux_select, deselect);
+		mux->adap[i] = i2c_add_mux_adapter(&pdev->dev, parent, mux, nr,
+						   i, NULL, gpiomux_select,
+						   deselect);
 		if (!mux->adap[i]) {
 			ret = -ENODEV;
 			dev_err(&pdev->dev, "Failed to add adapter %d\n", i);
diff --git a/drivers/i2c/muxes/pca9541.c b/drivers/i2c/muxes/pca9541.c
index e0df9b6..e1777fb 100644
--- a/drivers/i2c/muxes/pca9541.c
+++ b/drivers/i2c/muxes/pca9541.c
@@ -353,8 +353,8 @@ static int pca9541_probe(struct i2c_client *client,
 	force = 0;
 	if (pdata)
 		force = pdata->modes[0].adap_id;
-	data->mux_adap = i2c_add_mux_adapter(adap, client, force, 0,
-					     pca9541_select_chan,
+	data->mux_adap = i2c_add_mux_adapter(&client->dev, adap, client, force,
+					     0, NULL, pca9541_select_chan,
 					     pca9541_release_chan);
 
 	if (data->mux_adap == NULL) {
diff --git a/drivers/i2c/muxes/pca954x.c b/drivers/i2c/muxes/pca954x.c
index 0e37ef2..736a803 100644
--- a/drivers/i2c/muxes/pca954x.c
+++ b/drivers/i2c/muxes/pca954x.c
@@ -226,8 +226,8 @@ static int pca954x_probe(struct i2c_client *client,
 		}
 
 		data->virt_adaps[num] =
-			i2c_add_mux_adapter(adap, client,
-				force, num, pca954x_select_chan,
+			i2c_add_mux_adapter(&client->dev, adap, client,
+				force, num, NULL, pca954x_select_chan,
 				(pdata && pdata->modes[num].deselect_on_exit)
 					? pca954x_deselect_mux : NULL);
 
diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h
index 747f0cd..43fb11a 100644
--- a/include/linux/i2c-mux.h
+++ b/include/linux/i2c-mux.h
@@ -33,8 +33,10 @@
  * and deselect callback functions to perform hardware-specific
  * mux control.
  */
-struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
+struct i2c_adapter *i2c_add_mux_adapter(struct device *dev,
+				struct i2c_adapter *parent,
 				void *mux_dev, u32 force_nr, u32 chan_id,
+				const char *chan_name,
 				int (*select) (struct i2c_adapter *,
 					       void *mux_dev, u32 chan_id),
 				int (*deselect) (struct i2c_adapter *,
-- 
1.7.0.4

[PATCH 2/2] i2c: Add generic I2C multiplexer using pinctrl API

[Stephen Warren]

From: Stephen Warren <swarren@nvidia.com>

This is useful for SoCs whose I2C module's signals can be routed to
different sets of pins at run-time, using the pinctrl API.

                                 +-----+  +-----+
                                 | dev |  | dev |
    +------------------------+   +-----+  +-----+
    | SoC                    |      |        |
    |                   /----|------+--------+
    |   +---+   +------+     | child bus A, on first set of pins
    |   |I2C|---|Pinmux|     |
    |   +---+   +------+     | child bus B, on second set of pins
    |                   \----|------+--------+--------+
    |                        |      |        |        |
    +------------------------+  +-----+  +-----+  +-----+
                                | dev |  | dev |  | dev |
                                +-----+  +-----+  +-----+

Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
Note: This patch depends on the latest pinctrl tree. In order to merge
this series into the I2C tree, you'll need to merge the pinctrl tree
into it first. However, the pinctrl tree doesn't yet have a stable tag/branch
that you can merge, so this patch can't actually be committed yet.

 .../devicetree/bindings/i2c/pinctrl-i2cmux.txt     |   66 ++++++
 drivers/i2c/muxes/Kconfig                          |   12 +
 drivers/i2c/muxes/Makefile                         |    1 +
 drivers/i2c/muxes/pinctrl-i2cmux.c                 |  246 ++++++++++++++++++++
 include/linux/pinctrl-i2cmux.h                     |   41 ++++
 5 files changed, 366 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/i2c/pinctrl-i2cmux.txt
 create mode 100644 drivers/i2c/muxes/pinctrl-i2cmux.c
 create mode 100644 include/linux/pinctrl-i2cmux.h

diff --git a/Documentation/devicetree/bindings/i2c/pinctrl-i2cmux.txt b/Documentation/devicetree/bindings/i2c/pinctrl-i2cmux.txt
new file mode 100644
index 0000000..9e37034
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/pinctrl-i2cmux.txt
@@ -0,0 +1,66 @@
+Pinctrl-based I2C Bus Mux
+
+This binding describes an I2C bus multiplexer that uses the pin multiplexing
+to route the I2C signals, and represents the pin multiplexing configuration
+using the pinctrl device tree bindings.
+
+Required properties:
+- compatible: pinctrl-i2cmux
+- i2c-parent: The phandle of the I2C bus this multiplexer's master-side port
+  is connected to.
+
+Also required are:
+
+* Standard pinctrl properties that specify the pin mux state for each child
+  bus. See ../pinctrl/pinctrl-bindings.txt.
+
+  For each named state defined in the pinctrl-names property, an I2C child bus
+  will be created, with that name. The only exception is that if the pinctrl
+  state named "idle" is defined, no bus will be created for that pinctrl
+  state.
+
+* I2C child bus nodes. See i2cmux.txt.
+
+Whenever an access is made to a device on a child bus, the relevant pinctrl
+state will be programmed into hardware.
+
+If an idle state is defined, whenever an access is not being made to a device
+on a child bus, the idle pinctrl state will be programmed into hardware.
+
+If an idle state is not defined, the most recently used pinctrl state will be
+left programmed into hardware whenever no access is being made of a device on
+a child bus.
+
+Example:
+
+	i2cmux {
+		compatible = "pinctrl-i2cmux";
+
+		i2c-parent = <&i2c1>;
+
+		pinctrl-names = "ddc", "pta", "idle";
+		pinctrl-0 = <&state_i2cmux_ddc>;
+		pinctrl-1 = <&state_i2cmux_pta>;
+		pinctrl-2 = <&state_i2cmux_idle>;
+
+		i2c-bus-ddc {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			eeprom {
+				compatible = "eeprom";
+				reg = <0x50>;
+			};
+		};
+
+		i2c-bus-pta {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			eeprom {
+				compatible = "eeprom";
+				reg = <0x50>;
+			};
+		};
+	};
+
diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig
index 90b7a01..8602384 100644
--- a/drivers/i2c/muxes/Kconfig
+++ b/drivers/i2c/muxes/Kconfig
@@ -37,4 +37,16 @@ config I2C_MUX_PCA954x
 	  This driver can also be built as a module.  If so, the module
 	  will be called pca954x.
 
+config I2C_MUX_PINCTRL
+	tristate "pinctrl-based I2C multiplexer"
+	depends on PINCTRL
+	help
+	  If you say yes to this option, support will be included for an I2C
+	  multiplexer that uses the pinctrl subsystem, i.e. pin multiplexing.
+	  This is useful for SoCs whose I2C module's signals can be routed to
+	  different sets of pins at run-time.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called pinctrl-i2cmux.
+
 endmenu
diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile
index 4640436..7ba65fc 100644
--- a/drivers/i2c/muxes/Makefile
+++ b/drivers/i2c/muxes/Makefile
@@ -4,5 +4,6 @@
 obj-$(CONFIG_I2C_MUX_GPIO)	+= gpio-i2cmux.o
 obj-$(CONFIG_I2C_MUX_PCA9541)	+= pca9541.o
 obj-$(CONFIG_I2C_MUX_PCA954x)	+= pca954x.o
+obj-$(CONFIG_I2C_MUX_PINCTRL)	+= pinctrl-i2cmux.o
 
 ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG
diff --git a/drivers/i2c/muxes/pinctrl-i2cmux.c b/drivers/i2c/muxes/pinctrl-i2cmux.c
new file mode 100644
index 0000000..bf4928b
--- /dev/null
+++ b/drivers/i2c/muxes/pinctrl-i2cmux.c
@@ -0,0 +1,246 @@
+/*
+ * I2C multiplexer using pinctrl API
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/of_i2c.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/pinctrl-i2cmux.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+struct pinctrl_mux {
+	struct pinctrl_i2cmux_platform_data *pdata;
+	struct pinctrl *pinctrl;
+	struct pinctrl_state **states;
+	struct pinctrl_state *state_idle;
+	struct i2c_adapter *parent;
+	struct i2c_adapter **busses;
+};
+
+static int pinctrl_mux_select(struct i2c_adapter *adap, void *data, u32 chan)
+{
+	struct pinctrl_mux *mux = data;
+
+	return pinctrl_select_state(mux->pinctrl, mux->states[chan]);
+}
+
+static int pinctrl_mux_deselect(struct i2c_adapter *adap, void *data, u32 chan)
+{
+	struct pinctrl_mux *mux = data;
+
+	return pinctrl_select_state(mux->pinctrl, mux->state_idle);
+}
+
+#ifdef CONFIG_OF
+static int pinctrl_mux_parse_dt(struct pinctrl_mux *mux,
+				struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int num_names, i, ret;
+	struct device_node *adapter_np;
+	struct i2c_adapter *adapter;
+
+	if (!np)
+		return 0;
+
+	mux->pdata = devm_kzalloc(&pdev->dev, sizeof(*mux->pdata), GFP_KERNEL);
+	if (!mux->pdata)
+		return -ENOMEM;
+
+	num_names = of_property_count_strings(np, "pinctrl-names");
+	if (num_names < 0)
+		return num_names;
+
+	mux->pdata->pinctrl_states = devm_kzalloc(&pdev->dev,
+		sizeof(*mux->pdata->pinctrl_states) * num_names,
+		GFP_KERNEL);
+	if (!mux->pdata->pinctrl_states)
+		return -ENOMEM;
+
+	for (i = 0; i < num_names; i++) {
+		ret = of_property_read_string_index(np, "pinctrl-names", i,
+			&mux->pdata->pinctrl_states[mux->pdata->bus_count]);
+		if (ret < 0)
+			return ret;
+		if (!strcmp(mux->pdata->pinctrl_states[mux->pdata->bus_count],
+			    "idle")) {
+			mux->pdata->pinctrl_state_idle = "idle";
+		} else {
+			mux->pdata->bus_count++;
+		}
+	}
+
+	adapter_np = of_parse_phandle(np, "i2c-parent", 0);
+	if (!adapter_np)
+		return -ENODEV;
+	adapter = of_find_i2c_adapter_by_node(adapter_np);
+	if (!adapter)
+		return -ENODEV;
+	mux->pdata->parent_bus_num = i2c_adapter_id(adapter);
+	put_device(&adapter->dev);
+
+	return 0;
+}
+#else
+static inline int pinctrl_mux_parse_dt(struct pinctrl_mux *mux,
+				       struct platform_device *pdev)
+{
+	return 0;
+}
+#endif
+
+static int __devinit pinctrl_mux_probe(struct platform_device *pdev)
+{
+	struct pinctrl_mux *mux;
+	int (*deselect)(struct i2c_adapter *, void *, u32);
+	int i, ret;
+
+	mux = devm_kzalloc(&pdev->dev, sizeof(*mux), GFP_KERNEL);
+	if (!mux) {
+		ret = -ENOMEM;
+		goto err;
+	}
+	platform_set_drvdata(pdev, mux);
+
+	mux->pdata = pdev->dev.platform_data;
+	if (!mux->pdata) {
+		ret = pinctrl_mux_parse_dt(mux, pdev);
+		if (ret < 0)
+			goto err;
+	}
+	if (!mux->pdata) {
+		dev_err(&pdev->dev, "Missing platform data\n");
+		ret = -ENODEV;
+		goto err;
+	}
+
+	mux->states = devm_kzalloc(&pdev->dev,
+				   sizeof(*mux->states) * mux->pdata->bus_count,
+				   GFP_KERNEL);
+	if (!mux->states) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	mux->busses = devm_kzalloc(&pdev->dev,
+				   sizeof(mux->busses) * mux->pdata->bus_count,
+				   GFP_KERNEL);
+	if (!mux->states) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	mux->pinctrl = devm_pinctrl_get(&pdev->dev);
+	if (IS_ERR(mux->pinctrl)) {
+		ret = PTR_ERR(mux->pinctrl);
+		goto err;
+	}
+	for (i = 0; i < mux->pdata->bus_count; i++) {
+		mux->states[i] = pinctrl_lookup_state(mux->pinctrl,
+						mux->pdata->pinctrl_states[i]);
+		if (IS_ERR(mux->states[i])) {
+			ret = PTR_ERR(mux->states[i]);
+			goto err;
+		}
+	}
+	if (mux->pdata->pinctrl_state_idle) {
+		mux->state_idle = pinctrl_lookup_state(mux->pinctrl,
+						mux->pdata->pinctrl_state_idle);
+		if (IS_ERR(mux->state_idle)) {
+			ret = PTR_ERR(mux->state_idle);
+			goto err;
+		}
+
+		deselect = pinctrl_mux_deselect;
+	} else {
+		deselect = NULL;
+	}
+
+	mux->parent = i2c_get_adapter(mux->pdata->parent_bus_num);
+	if (!mux->parent) {
+		dev_err(&pdev->dev, "Parent adapter (%d) not found\n",
+			mux->pdata->parent_bus_num);
+		ret = -ENODEV;
+		goto err;
+	}
+
+	for (i = 0; i < mux->pdata->bus_count; i++) {
+		u32 bus = mux->pdata->base_bus_num ?
+				(mux->pdata->base_bus_num + i) : 0;
+
+		mux->busses[i] = i2c_add_mux_adapter(&pdev->dev, mux->parent,
+						mux, bus, i,
+						mux->pdata->pinctrl_states[i],
+						pinctrl_mux_select,
+						deselect);
+		if (!mux->busses[i]) {
+			ret = -ENODEV;
+			dev_err(&pdev->dev, "Failed to add adapter %d\n", i);
+			goto err_del_adapter;
+		}
+	}
+
+	return 0;
+
+err_del_adapter:
+	for (; i > 0; i--)
+		i2c_del_mux_adapter(mux->busses[i - 1]);
+	i2c_put_adapter(mux->parent);
+err:
+	return ret;
+}
+
+static int __devexit pinctrl_mux_remove(struct platform_device *pdev)
+{
+	struct pinctrl_mux *mux = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = 0; i < mux->pdata->bus_count; i++)
+		i2c_del_mux_adapter(mux->busses[i]);
+
+	i2c_put_adapter(mux->parent);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id pinctrl_mux_of_match[] __devinitconst = {
+	{ .compatible = "pinctrl-i2cmux", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, pinctrl_mux_of_match);
+#endif
+
+static struct platform_driver pinctrl_mux_driver = {
+	.driver	= {
+		.name	= "pinctrl-i2cmux",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(pinctrl_mux_of_match),
+	},
+	.probe	= pinctrl_mux_probe,
+	.remove	= __devexit_p(pinctrl_mux_remove),
+};
+module_platform_driver(pinctrl_mux_driver);
+
+MODULE_DESCRIPTION("pinctrl-based I2C multiplexer driver");
+MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:pinctrl-i2cmux");
diff --git a/include/linux/pinctrl-i2cmux.h b/include/linux/pinctrl-i2cmux.h
new file mode 100644
index 0000000..046e420
--- /dev/null
+++ b/include/linux/pinctrl-i2cmux.h
@@ -0,0 +1,41 @@
+/*
+ * pinctrl-i2cmux platform data
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _LINUX_PINCTRL_I2CMUX_H
+#define _LINUX_PINCTRL_I2CMUX_H
+
+/**
+ * struct pinctrl_i2cmux_platform_data - Platform data for pinctrl-i2cmux
+ * @parent_bus_num: Parent I2C bus number
+ * @base_bus_num: Base I2C bus number for the child busses. 0 for dynamic.
+ * @bus_count: Number of child busses. Also the number of elements in
+ *	@pinctrl_states
+ * @pinctrl_states: The names of the pinctrl state to select for each child bus
+ * @pinctrl_state_idle: The pinctrl state to select when no child bus is being
+ *	accessed. If NULL, the most recently used pinctrl state will be left
+ *	selected.
+ */
+struct pinctrl_i2cmux_platform_data {
+	int parent_bus_num;
+	int base_bus_num;
+	int bus_count;
+	const char **pinctrl_states;
+	const char *pinctrl_state_idle;
+};
+
+#endif
-- 
1.7.0.4

[PATCH 2/2] i2c: Add generic I2C multiplexer using pinctrl API

[Stephen Warren]

From: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

This is useful for SoCs whose I2C module's signals can be routed to
different sets of pins at run-time, using the pinctrl API.

                                 +-----+  +-----+
                                 | dev |  | dev |
    +------------------------+   +-----+  +-----+
    | SoC                    |      |        |
    |                   /----|------+--------+
    |   +---+   +------+     | child bus A, on first set of pins
    |   |I2C|---|Pinmux|     |
    |   +---+   +------+     | child bus B, on second set of pins
    |                   \----|------+--------+--------+
    |                        |      |        |        |
    +------------------------+  +-----+  +-----+  +-----+
                                | dev |  | dev |  | dev |
                                +-----+  +-----+  +-----+

Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
Note: This patch depends on the latest pinctrl tree. In order to merge
this series into the I2C tree, you'll need to merge the pinctrl tree
into it first. However, the pinctrl tree doesn't yet have a stable tag/branch
that you can merge, so this patch can't actually be committed yet.

 .../devicetree/bindings/i2c/pinctrl-i2cmux.txt     |   66 ++++++
 drivers/i2c/muxes/Kconfig                          |   12 +
 drivers/i2c/muxes/Makefile                         |    1 +
 drivers/i2c/muxes/pinctrl-i2cmux.c                 |  246 ++++++++++++++++++++
 include/linux/pinctrl-i2cmux.h                     |   41 ++++
 5 files changed, 366 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/i2c/pinctrl-i2cmux.txt
 create mode 100644 drivers/i2c/muxes/pinctrl-i2cmux.c
 create mode 100644 include/linux/pinctrl-i2cmux.h

diff --git a/Documentation/devicetree/bindings/i2c/pinctrl-i2cmux.txt b/Documentation/devicetree/bindings/i2c/pinctrl-i2cmux.txt
new file mode 100644
index 0000000..9e37034
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/pinctrl-i2cmux.txt
@@ -0,0 +1,66 @@
+Pinctrl-based I2C Bus Mux
+
+This binding describes an I2C bus multiplexer that uses the pin multiplexing
+to route the I2C signals, and represents the pin multiplexing configuration
+using the pinctrl device tree bindings.
+
+Required properties:
+- compatible: pinctrl-i2cmux
+- i2c-parent: The phandle of the I2C bus this multiplexer's master-side port
+  is connected to.
+
+Also required are:
+
+* Standard pinctrl properties that specify the pin mux state for each child
+  bus. See ../pinctrl/pinctrl-bindings.txt.
+
+  For each named state defined in the pinctrl-names property, an I2C child bus
+  will be created, with that name. The only exception is that if the pinctrl
+  state named "idle" is defined, no bus will be created for that pinctrl
+  state.
+
+* I2C child bus nodes. See i2cmux.txt.
+
+Whenever an access is made to a device on a child bus, the relevant pinctrl
+state will be programmed into hardware.
+
+If an idle state is defined, whenever an access is not being made to a device
+on a child bus, the idle pinctrl state will be programmed into hardware.
+
+If an idle state is not defined, the most recently used pinctrl state will be
+left programmed into hardware whenever no access is being made of a device on
+a child bus.
+
+Example:
+
+	i2cmux {
+		compatible = "pinctrl-i2cmux";
+
+		i2c-parent = <&i2c1>;
+
+		pinctrl-names = "ddc", "pta", "idle";
+		pinctrl-0 = <&state_i2cmux_ddc>;
+		pinctrl-1 = <&state_i2cmux_pta>;
+		pinctrl-2 = <&state_i2cmux_idle>;
+
+		i2c-bus-ddc {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			eeprom {
+				compatible = "eeprom";
+				reg = <0x50>;
+			};
+		};
+
+		i2c-bus-pta {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			eeprom {
+				compatible = "eeprom";
+				reg = <0x50>;
+			};
+		};
+	};
+
diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig
index 90b7a01..8602384 100644
--- a/drivers/i2c/muxes/Kconfig
+++ b/drivers/i2c/muxes/Kconfig
@@ -37,4 +37,16 @@ config I2C_MUX_PCA954x
 	  This driver can also be built as a module.  If so, the module
 	  will be called pca954x.
 
+config I2C_MUX_PINCTRL
+	tristate "pinctrl-based I2C multiplexer"
+	depends on PINCTRL
+	help
+	  If you say yes to this option, support will be included for an I2C
+	  multiplexer that uses the pinctrl subsystem, i.e. pin multiplexing.
+	  This is useful for SoCs whose I2C module's signals can be routed to
+	  different sets of pins at run-time.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called pinctrl-i2cmux.
+
 endmenu
diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile
index 4640436..7ba65fc 100644
--- a/drivers/i2c/muxes/Makefile
+++ b/drivers/i2c/muxes/Makefile
@@ -4,5 +4,6 @@
 obj-$(CONFIG_I2C_MUX_GPIO)	+= gpio-i2cmux.o
 obj-$(CONFIG_I2C_MUX_PCA9541)	+= pca9541.o
 obj-$(CONFIG_I2C_MUX_PCA954x)	+= pca954x.o
+obj-$(CONFIG_I2C_MUX_PINCTRL)	+= pinctrl-i2cmux.o
 
 ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG
diff --git a/drivers/i2c/muxes/pinctrl-i2cmux.c b/drivers/i2c/muxes/pinctrl-i2cmux.c
new file mode 100644
index 0000000..bf4928b
--- /dev/null
+++ b/drivers/i2c/muxes/pinctrl-i2cmux.c
@@ -0,0 +1,246 @@
+/*
+ * I2C multiplexer using pinctrl API
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/of_i2c.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/pinctrl-i2cmux.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+struct pinctrl_mux {
+	struct pinctrl_i2cmux_platform_data *pdata;
+	struct pinctrl *pinctrl;
+	struct pinctrl_state **states;
+	struct pinctrl_state *state_idle;
+	struct i2c_adapter *parent;
+	struct i2c_adapter **busses;
+};
+
+static int pinctrl_mux_select(struct i2c_adapter *adap, void *data, u32 chan)
+{
+	struct pinctrl_mux *mux = data;
+
+	return pinctrl_select_state(mux->pinctrl, mux->states[chan]);
+}
+
+static int pinctrl_mux_deselect(struct i2c_adapter *adap, void *data, u32 chan)
+{
+	struct pinctrl_mux *mux = data;
+
+	return pinctrl_select_state(mux->pinctrl, mux->state_idle);
+}
+
+#ifdef CONFIG_OF
+static int pinctrl_mux_parse_dt(struct pinctrl_mux *mux,
+				struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int num_names, i, ret;
+	struct device_node *adapter_np;
+	struct i2c_adapter *adapter;
+
+	if (!np)
+		return 0;
+
+	mux->pdata = devm_kzalloc(&pdev->dev, sizeof(*mux->pdata), GFP_KERNEL);
+	if (!mux->pdata)
+		return -ENOMEM;
+
+	num_names = of_property_count_strings(np, "pinctrl-names");
+	if (num_names < 0)
+		return num_names;
+
+	mux->pdata->pinctrl_states = devm_kzalloc(&pdev->dev,
+		sizeof(*mux->pdata->pinctrl_states) * num_names,
+		GFP_KERNEL);
+	if (!mux->pdata->pinctrl_states)
+		return -ENOMEM;
+
+	for (i = 0; i < num_names; i++) {
+		ret = of_property_read_string_index(np, "pinctrl-names", i,
+			&mux->pdata->pinctrl_states[mux->pdata->bus_count]);
+		if (ret < 0)
+			return ret;
+		if (!strcmp(mux->pdata->pinctrl_states[mux->pdata->bus_count],
+			    "idle")) {
+			mux->pdata->pinctrl_state_idle = "idle";
+		} else {
+			mux->pdata->bus_count++;
+		}
+	}
+
+	adapter_np = of_parse_phandle(np, "i2c-parent", 0);
+	if (!adapter_np)
+		return -ENODEV;
+	adapter = of_find_i2c_adapter_by_node(adapter_np);
+	if (!adapter)
+		return -ENODEV;
+	mux->pdata->parent_bus_num = i2c_adapter_id(adapter);
+	put_device(&adapter->dev);
+
+	return 0;
+}
+#else
+static inline int pinctrl_mux_parse_dt(struct pinctrl_mux *mux,
+				       struct platform_device *pdev)
+{
+	return 0;
+}
+#endif
+
+static int __devinit pinctrl_mux_probe(struct platform_device *pdev)
+{
+	struct pinctrl_mux *mux;
+	int (*deselect)(struct i2c_adapter *, void *, u32);
+	int i, ret;
+
+	mux = devm_kzalloc(&pdev->dev, sizeof(*mux), GFP_KERNEL);
+	if (!mux) {
+		ret = -ENOMEM;
+		goto err;
+	}
+	platform_set_drvdata(pdev, mux);
+
+	mux->pdata = pdev->dev.platform_data;
+	if (!mux->pdata) {
+		ret = pinctrl_mux_parse_dt(mux, pdev);
+		if (ret < 0)
+			goto err;
+	}
+	if (!mux->pdata) {
+		dev_err(&pdev->dev, "Missing platform data\n");
+		ret = -ENODEV;
+		goto err;
+	}
+
+	mux->states = devm_kzalloc(&pdev->dev,
+				   sizeof(*mux->states) * mux->pdata->bus_count,
+				   GFP_KERNEL);
+	if (!mux->states) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	mux->busses = devm_kzalloc(&pdev->dev,
+				   sizeof(mux->busses) * mux->pdata->bus_count,
+				   GFP_KERNEL);
+	if (!mux->states) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	mux->pinctrl = devm_pinctrl_get(&pdev->dev);
+	if (IS_ERR(mux->pinctrl)) {
+		ret = PTR_ERR(mux->pinctrl);
+		goto err;
+	}
+	for (i = 0; i < mux->pdata->bus_count; i++) {
+		mux->states[i] = pinctrl_lookup_state(mux->pinctrl,
+						mux->pdata->pinctrl_states[i]);
+		if (IS_ERR(mux->states[i])) {
+			ret = PTR_ERR(mux->states[i]);
+			goto err;
+		}
+	}
+	if (mux->pdata->pinctrl_state_idle) {
+		mux->state_idle = pinctrl_lookup_state(mux->pinctrl,
+						mux->pdata->pinctrl_state_idle);
+		if (IS_ERR(mux->state_idle)) {
+			ret = PTR_ERR(mux->state_idle);
+			goto err;
+		}
+
+		deselect = pinctrl_mux_deselect;
+	} else {
+		deselect = NULL;
+	}
+
+	mux->parent = i2c_get_adapter(mux->pdata->parent_bus_num);
+	if (!mux->parent) {
+		dev_err(&pdev->dev, "Parent adapter (%d) not found\n",
+			mux->pdata->parent_bus_num);
+		ret = -ENODEV;
+		goto err;
+	}
+
+	for (i = 0; i < mux->pdata->bus_count; i++) {
+		u32 bus = mux->pdata->base_bus_num ?
+				(mux->pdata->base_bus_num + i) : 0;
+
+		mux->busses[i] = i2c_add_mux_adapter(&pdev->dev, mux->parent,
+						mux, bus, i,
+						mux->pdata->pinctrl_states[i],
+						pinctrl_mux_select,
+						deselect);
+		if (!mux->busses[i]) {
+			ret = -ENODEV;
+			dev_err(&pdev->dev, "Failed to add adapter %d\n", i);
+			goto err_del_adapter;
+		}
+	}
+
+	return 0;
+
+err_del_adapter:
+	for (; i > 0; i--)
+		i2c_del_mux_adapter(mux->busses[i - 1]);
+	i2c_put_adapter(mux->parent);
+err:
+	return ret;
+}
+
+static int __devexit pinctrl_mux_remove(struct platform_device *pdev)
+{
+	struct pinctrl_mux *mux = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = 0; i < mux->pdata->bus_count; i++)
+		i2c_del_mux_adapter(mux->busses[i]);
+
+	i2c_put_adapter(mux->parent);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id pinctrl_mux_of_match[] __devinitconst = {
+	{ .compatible = "pinctrl-i2cmux", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, pinctrl_mux_of_match);
+#endif
+
+static struct platform_driver pinctrl_mux_driver = {
+	.driver	= {
+		.name	= "pinctrl-i2cmux",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(pinctrl_mux_of_match),
+	},
+	.probe	= pinctrl_mux_probe,
+	.remove	= __devexit_p(pinctrl_mux_remove),
+};
+module_platform_driver(pinctrl_mux_driver);
+
+MODULE_DESCRIPTION("pinctrl-based I2C multiplexer driver");
+MODULE_AUTHOR("Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:pinctrl-i2cmux");
diff --git a/include/linux/pinctrl-i2cmux.h b/include/linux/pinctrl-i2cmux.h
new file mode 100644
index 0000000..046e420
--- /dev/null
+++ b/include/linux/pinctrl-i2cmux.h
@@ -0,0 +1,41 @@
+/*
+ * pinctrl-i2cmux platform data
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _LINUX_PINCTRL_I2CMUX_H
+#define _LINUX_PINCTRL_I2CMUX_H
+
+/**
+ * struct pinctrl_i2cmux_platform_data - Platform data for pinctrl-i2cmux
+ * @parent_bus_num: Parent I2C bus number
+ * @base_bus_num: Base I2C bus number for the child busses. 0 for dynamic.
+ * @bus_count: Number of child busses. Also the number of elements in
+ *	@pinctrl_states
+ * @pinctrl_states: The names of the pinctrl state to select for each child bus
+ * @pinctrl_state_idle: The pinctrl state to select when no child bus is being
+ *	accessed. If NULL, the most recently used pinctrl state will be left
+ *	selected.
+ */
+struct pinctrl_i2cmux_platform_data {
+	int parent_bus_num;
+	int base_bus_num;
+	int bus_count;
+	const char **pinctrl_states;
+	const char *pinctrl_state_idle;
+};
+
+#endif
-- 
1.7.0.4

Re: [PATCH 2/2] i2c: Add generic I2C multiplexer using pinctrl API

[Linus Walleij]

On Tue, Apr 17, 2012 at 8:49 PM, Stephen Warren <swarren@wwwdotorg.org> wrote:

> This is useful for SoCs whose I2C module's signals can be routed to
> different sets of pins at run-time, using the pinctrl API.
>
>                                 +-----+  +-----+
>                                 | dev |  | dev |
>    +------------------------+   +-----+  +-----+
>    | SoC                    |      |        |
>    |                   /----|------+--------+
>    |   +---+   +------+     | child bus A, on first set of pins
>    |   |I2C|---|Pinmux|     |
>    |   +---+   +------+     | child bus B, on second set of pins
>    |                   \----|------+--------+--------+
>    |                        |      |        |        |
>    +------------------------+  +-----+  +-----+  +-----+
>                                | dev |  | dev |  | dev |
>                                +-----+  +-----+  +-----+
>
> Signed-off-by: Stephen Warren <swarren@nvidia.com>

I remember you told me about this thing, it's really fascinating!
Acked-by: Linus Walleij <linus.walleij@linaro.org>

> Note: This patch depends on the latest pinctrl tree. In order to merge
> this series into the I2C tree, you'll need to merge the pinctrl tree
> into it first. However, the pinctrl tree doesn't yet have a stable tag/branch
> that you can merge, so this patch can't actually be committed yet.

I'll create a tag once I have the devm* stuff in place (it's so
good we just have to have it).

BTW another way is to have this ACK:ed by Jean/Dooks/Wolfram
and I just put it in the pinctrl tree, unless there is something
radical happening in the mux part of the I2C tree this merge
window?

Yours,
Linus Walleij

Re: [PATCH 2/2] i2c: Add generic I2C multiplexer using pinctrl API

[Linus Walleij]

On Tue, Apr 17, 2012 at 8:49 PM, Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org> wrote:

> This is useful for SoCs whose I2C module's signals can be routed to
> different sets of pins at run-time, using the pinctrl API.
>
>                                 +-----+  +-----+
>                                 | dev |  | dev |
>    +------------------------+   +-----+  +-----+
>    | SoC                    |      |        |
>    |                   /----|------+--------+
>    |   +---+   +------+     | child bus A, on first set of pins
>    |   |I2C|---|Pinmux|     |
>    |   +---+   +------+     | child bus B, on second set of pins
>    |                   \----|------+--------+--------+
>    |                        |      |        |        |
>    +------------------------+  +-----+  +-----+  +-----+
>                                | dev |  | dev |  | dev |
>                                +-----+  +-----+  +-----+
>
> Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

I remember you told me about this thing, it's really fascinating!
Acked-by: Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>

> Note: This patch depends on the latest pinctrl tree. In order to merge
> this series into the I2C tree, you'll need to merge the pinctrl tree
> into it first. However, the pinctrl tree doesn't yet have a stable tag/branch
> that you can merge, so this patch can't actually be committed yet.

I'll create a tag once I have the devm* stuff in place (it's so
good we just have to have it).

BTW another way is to have this ACK:ed by Jean/Dooks/Wolfram
and I just put it in the pinctrl tree, unless there is something
radical happening in the mux part of the I2C tree this merge
window?

Yours,
Linus Walleij

Re: [PATCH 1/2] i2c: mux: add device tree support

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 7987 bytes --]

On Tue, Apr 17, 2012 at 12:49:04PM -0600, Stephen Warren wrote:
> From: Stephen Warren <swarren@nvidia.com>
> 
> * Define core portions of the DT binding for I2C bus muxes.
> * Enhance i2c_add_mux_adapter():
> ** Add parameters required for DT support. Update all callers.
> ** Set the appropriate adap->dev.of_node for the child bus.
> ** Call of_i2c_register_devices() for the child bus.
> 
> Signed-off-by: Stephen Warren <swarren@nvidia.com>

David Daney (CCed) posted another variant [1]. Just looking at the
patches (and not really using them), I tend to like the approach using
<reg> better. But I am open for discussion, so I'd appreciate your
feedback.

Regards,

   Wolfram

[1] http://lkml.org/lkml/2012/4/12/423

> ---
> Note: This series depends on the 3 patches I just sent that affect
> of_find_i2c_device_by_node and implement of_find_i2c_adapter_by_node.
> It might be useful to put this patch (and the others I sent) in
> a separate tree so it can be merged into any SoC trees that wish to use
> this new feature.
> 
>  Documentation/devicetree/bindings/i2c/i2cmux.txt |   45 ++++++++++++++++++++++
>  drivers/i2c/i2c-mux.c                            |   23 +++++++++++-
>  drivers/i2c/muxes/gpio-i2cmux.c                  |    5 +-
>  drivers/i2c/muxes/pca9541.c                      |    4 +-
>  drivers/i2c/muxes/pca954x.c                      |    4 +-
>  include/linux/i2c-mux.h                          |    4 +-
>  6 files changed, 77 insertions(+), 8 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/i2c/i2cmux.txt
> 
> diff --git a/Documentation/devicetree/bindings/i2c/i2cmux.txt b/Documentation/devicetree/bindings/i2c/i2cmux.txt
> new file mode 100644
> index 0000000..1e4e2bc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/i2cmux.txt
> @@ -0,0 +1,45 @@
> +Common I2C mux bindings
> +
> +An I2C mux is a device that connects a master I2C bus to one of a number of
> +child I2C busses, under programmatic control.
> +
> +Each I2C mux may define the set of child busses it supports in a different
> +way. Some devices may have a hard-coded set of child ports, whereas others may
> +support a varying set of child busses (especially when the bus mux is
> +implemented using GPIOs or pin muxing). Any bindings required to represent
> +this are the domain of the individual mux device.
> +
> +For each child bus, there shall be a node within the I2C mux's own node for
> +that bus. This node will contain all the I2C devices on that bus, just like
> +any other I2C bus. Each child bus shall be identified by some name. The set
> +of child bus names is defined by the individual I2C mux's bindings. Bus names
> +are used to construct the name of the bus's child node using the format
> +i2c-bus-%s. Each child bus node needs the usual #address-cells and #size-cells
> +properties.
> +
> +Example:
> +
> +	i2cmux {
> +		// properties here omitted from the example.
> +
> +		i2c-bus-0 {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			eeprom {
> +				compatible = "eeprom";
> +				reg = <0x50>;
> +			};
> +		};
> +
> +		i2c-bus-1 {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			eeprom {
> +				compatible = "eeprom";
> +				reg = <0x50>;
> +			};
> +		};
> +	};
> +
> diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
> index d7a4833..8adeeec 100644
> --- a/drivers/i2c/i2c-mux.c
> +++ b/drivers/i2c/i2c-mux.c
> @@ -24,6 +24,7 @@
>  #include <linux/slab.h>
>  #include <linux/i2c.h>
>  #include <linux/i2c-mux.h>
> +#include <linux/of_i2c.h>
>  
>  /* multiplexer per channel data */
>  struct i2c_mux_priv {
> @@ -86,8 +87,10 @@ static u32 i2c_mux_functionality(struct i2c_adapter *adap)
>  	return parent->algo->functionality(parent);
>  }
>  
> -struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
> +struct i2c_adapter *i2c_add_mux_adapter(struct device *dev,
> +				struct i2c_adapter *parent,
>  				void *mux_dev, u32 force_nr, u32 chan_id,
> +				const char *chan_name,
>  				int (*select) (struct i2c_adapter *,
>  					       void *, u32),
>  				int (*deselect) (struct i2c_adapter *,
> @@ -124,6 +127,22 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
>  	priv->adap.algo_data = priv;
>  	priv->adap.dev.parent = &parent->dev;
>  
> +	if (dev->of_node) {
> +		const char *name;
> +
> +		if (chan_name)
> +			name = kasprintf(GFP_KERNEL, "i2c-bus-%s",
> +					     chan_name);
> +		else
> +			name = kasprintf(GFP_KERNEL, "i2c-bus-%d",
> +					     chan_id);
> +
> +		priv->adap.dev.of_node = of_find_node_by_name(dev->of_node,
> +							      name);
> +
> +		kfree(name);
> +	}
> +
>  	if (force_nr) {
>  		priv->adap.nr = force_nr;
>  		ret = i2c_add_numbered_adapter(&priv->adap);
> @@ -141,6 +160,8 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
>  	dev_info(&parent->dev, "Added multiplexed i2c bus %d\n",
>  		 i2c_adapter_id(&priv->adap));
>  
> +	of_i2c_register_devices(&priv->adap);
> +
>  	return &priv->adap;
>  }
>  EXPORT_SYMBOL_GPL(i2c_add_mux_adapter);
> diff --git a/drivers/i2c/muxes/gpio-i2cmux.c b/drivers/i2c/muxes/gpio-i2cmux.c
> index e5fa695..7284c70 100644
> --- a/drivers/i2c/muxes/gpio-i2cmux.c
> +++ b/drivers/i2c/muxes/gpio-i2cmux.c
> @@ -105,8 +105,9 @@ static int __devinit gpiomux_probe(struct platform_device *pdev)
>  	for (i = 0; i < pdata->n_values; i++) {
>  		u32 nr = pdata->base_nr ? (pdata->base_nr + i) : 0;
>  
> -		mux->adap[i] = i2c_add_mux_adapter(parent, mux, nr, i,
> -						   gpiomux_select, deselect);
> +		mux->adap[i] = i2c_add_mux_adapter(&pdev->dev, parent, mux, nr,
> +						   i, NULL, gpiomux_select,
> +						   deselect);
>  		if (!mux->adap[i]) {
>  			ret = -ENODEV;
>  			dev_err(&pdev->dev, "Failed to add adapter %d\n", i);
> diff --git a/drivers/i2c/muxes/pca9541.c b/drivers/i2c/muxes/pca9541.c
> index e0df9b6..e1777fb 100644
> --- a/drivers/i2c/muxes/pca9541.c
> +++ b/drivers/i2c/muxes/pca9541.c
> @@ -353,8 +353,8 @@ static int pca9541_probe(struct i2c_client *client,
>  	force = 0;
>  	if (pdata)
>  		force = pdata->modes[0].adap_id;
> -	data->mux_adap = i2c_add_mux_adapter(adap, client, force, 0,
> -					     pca9541_select_chan,
> +	data->mux_adap = i2c_add_mux_adapter(&client->dev, adap, client, force,
> +					     0, NULL, pca9541_select_chan,
>  					     pca9541_release_chan);
>  
>  	if (data->mux_adap == NULL) {
> diff --git a/drivers/i2c/muxes/pca954x.c b/drivers/i2c/muxes/pca954x.c
> index 0e37ef2..736a803 100644
> --- a/drivers/i2c/muxes/pca954x.c
> +++ b/drivers/i2c/muxes/pca954x.c
> @@ -226,8 +226,8 @@ static int pca954x_probe(struct i2c_client *client,
>  		}
>  
>  		data->virt_adaps[num] =
> -			i2c_add_mux_adapter(adap, client,
> -				force, num, pca954x_select_chan,
> +			i2c_add_mux_adapter(&client->dev, adap, client,
> +				force, num, NULL, pca954x_select_chan,
>  				(pdata && pdata->modes[num].deselect_on_exit)
>  					? pca954x_deselect_mux : NULL);
>  
> diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h
> index 747f0cd..43fb11a 100644
> --- a/include/linux/i2c-mux.h
> +++ b/include/linux/i2c-mux.h
> @@ -33,8 +33,10 @@
>   * and deselect callback functions to perform hardware-specific
>   * mux control.
>   */
> -struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
> +struct i2c_adapter *i2c_add_mux_adapter(struct device *dev,
> +				struct i2c_adapter *parent,
>  				void *mux_dev, u32 force_nr, u32 chan_id,
> +				const char *chan_name,
>  				int (*select) (struct i2c_adapter *,
>  					       void *mux_dev, u32 chan_id),
>  				int (*deselect) (struct i2c_adapter *,
> -- 
> 1.7.0.4
> 

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

[-- Attachment #2: Digital signature --]
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Re: [PATCH 1/2] i2c: mux: add device tree support

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 8045 bytes --]

On Tue, Apr 17, 2012 at 12:49:04PM -0600, Stephen Warren wrote:
> From: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> 
> * Define core portions of the DT binding for I2C bus muxes.
> * Enhance i2c_add_mux_adapter():
> ** Add parameters required for DT support. Update all callers.
> ** Set the appropriate adap->dev.of_node for the child bus.
> ** Call of_i2c_register_devices() for the child bus.
> 
> Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

David Daney (CCed) posted another variant [1]. Just looking at the
patches (and not really using them), I tend to like the approach using
<reg> better. But I am open for discussion, so I'd appreciate your
feedback.

Regards,

   Wolfram

[1] http://lkml.org/lkml/2012/4/12/423

> ---
> Note: This series depends on the 3 patches I just sent that affect
> of_find_i2c_device_by_node and implement of_find_i2c_adapter_by_node.
> It might be useful to put this patch (and the others I sent) in
> a separate tree so it can be merged into any SoC trees that wish to use
> this new feature.
> 
>  Documentation/devicetree/bindings/i2c/i2cmux.txt |   45 ++++++++++++++++++++++
>  drivers/i2c/i2c-mux.c                            |   23 +++++++++++-
>  drivers/i2c/muxes/gpio-i2cmux.c                  |    5 +-
>  drivers/i2c/muxes/pca9541.c                      |    4 +-
>  drivers/i2c/muxes/pca954x.c                      |    4 +-
>  include/linux/i2c-mux.h                          |    4 +-
>  6 files changed, 77 insertions(+), 8 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/i2c/i2cmux.txt
> 
> diff --git a/Documentation/devicetree/bindings/i2c/i2cmux.txt b/Documentation/devicetree/bindings/i2c/i2cmux.txt
> new file mode 100644
> index 0000000..1e4e2bc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/i2cmux.txt
> @@ -0,0 +1,45 @@
> +Common I2C mux bindings
> +
> +An I2C mux is a device that connects a master I2C bus to one of a number of
> +child I2C busses, under programmatic control.
> +
> +Each I2C mux may define the set of child busses it supports in a different
> +way. Some devices may have a hard-coded set of child ports, whereas others may
> +support a varying set of child busses (especially when the bus mux is
> +implemented using GPIOs or pin muxing). Any bindings required to represent
> +this are the domain of the individual mux device.
> +
> +For each child bus, there shall be a node within the I2C mux's own node for
> +that bus. This node will contain all the I2C devices on that bus, just like
> +any other I2C bus. Each child bus shall be identified by some name. The set
> +of child bus names is defined by the individual I2C mux's bindings. Bus names
> +are used to construct the name of the bus's child node using the format
> +i2c-bus-%s. Each child bus node needs the usual #address-cells and #size-cells
> +properties.
> +
> +Example:
> +
> +	i2cmux {
> +		// properties here omitted from the example.
> +
> +		i2c-bus-0 {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			eeprom {
> +				compatible = "eeprom";
> +				reg = <0x50>;
> +			};
> +		};
> +
> +		i2c-bus-1 {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			eeprom {
> +				compatible = "eeprom";
> +				reg = <0x50>;
> +			};
> +		};
> +	};
> +
> diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
> index d7a4833..8adeeec 100644
> --- a/drivers/i2c/i2c-mux.c
> +++ b/drivers/i2c/i2c-mux.c
> @@ -24,6 +24,7 @@
>  #include <linux/slab.h>
>  #include <linux/i2c.h>
>  #include <linux/i2c-mux.h>
> +#include <linux/of_i2c.h>
>  
>  /* multiplexer per channel data */
>  struct i2c_mux_priv {
> @@ -86,8 +87,10 @@ static u32 i2c_mux_functionality(struct i2c_adapter *adap)
>  	return parent->algo->functionality(parent);
>  }
>  
> -struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
> +struct i2c_adapter *i2c_add_mux_adapter(struct device *dev,
> +				struct i2c_adapter *parent,
>  				void *mux_dev, u32 force_nr, u32 chan_id,
> +				const char *chan_name,
>  				int (*select) (struct i2c_adapter *,
>  					       void *, u32),
>  				int (*deselect) (struct i2c_adapter *,
> @@ -124,6 +127,22 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
>  	priv->adap.algo_data = priv;
>  	priv->adap.dev.parent = &parent->dev;
>  
> +	if (dev->of_node) {
> +		const char *name;
> +
> +		if (chan_name)
> +			name = kasprintf(GFP_KERNEL, "i2c-bus-%s",
> +					     chan_name);
> +		else
> +			name = kasprintf(GFP_KERNEL, "i2c-bus-%d",
> +					     chan_id);
> +
> +		priv->adap.dev.of_node = of_find_node_by_name(dev->of_node,
> +							      name);
> +
> +		kfree(name);
> +	}
> +
>  	if (force_nr) {
>  		priv->adap.nr = force_nr;
>  		ret = i2c_add_numbered_adapter(&priv->adap);
> @@ -141,6 +160,8 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
>  	dev_info(&parent->dev, "Added multiplexed i2c bus %d\n",
>  		 i2c_adapter_id(&priv->adap));
>  
> +	of_i2c_register_devices(&priv->adap);
> +
>  	return &priv->adap;
>  }
>  EXPORT_SYMBOL_GPL(i2c_add_mux_adapter);
> diff --git a/drivers/i2c/muxes/gpio-i2cmux.c b/drivers/i2c/muxes/gpio-i2cmux.c
> index e5fa695..7284c70 100644
> --- a/drivers/i2c/muxes/gpio-i2cmux.c
> +++ b/drivers/i2c/muxes/gpio-i2cmux.c
> @@ -105,8 +105,9 @@ static int __devinit gpiomux_probe(struct platform_device *pdev)
>  	for (i = 0; i < pdata->n_values; i++) {
>  		u32 nr = pdata->base_nr ? (pdata->base_nr + i) : 0;
>  
> -		mux->adap[i] = i2c_add_mux_adapter(parent, mux, nr, i,
> -						   gpiomux_select, deselect);
> +		mux->adap[i] = i2c_add_mux_adapter(&pdev->dev, parent, mux, nr,
> +						   i, NULL, gpiomux_select,
> +						   deselect);
>  		if (!mux->adap[i]) {
>  			ret = -ENODEV;
>  			dev_err(&pdev->dev, "Failed to add adapter %d\n", i);
> diff --git a/drivers/i2c/muxes/pca9541.c b/drivers/i2c/muxes/pca9541.c
> index e0df9b6..e1777fb 100644
> --- a/drivers/i2c/muxes/pca9541.c
> +++ b/drivers/i2c/muxes/pca9541.c
> @@ -353,8 +353,8 @@ static int pca9541_probe(struct i2c_client *client,
>  	force = 0;
>  	if (pdata)
>  		force = pdata->modes[0].adap_id;
> -	data->mux_adap = i2c_add_mux_adapter(adap, client, force, 0,
> -					     pca9541_select_chan,
> +	data->mux_adap = i2c_add_mux_adapter(&client->dev, adap, client, force,
> +					     0, NULL, pca9541_select_chan,
>  					     pca9541_release_chan);
>  
>  	if (data->mux_adap == NULL) {
> diff --git a/drivers/i2c/muxes/pca954x.c b/drivers/i2c/muxes/pca954x.c
> index 0e37ef2..736a803 100644
> --- a/drivers/i2c/muxes/pca954x.c
> +++ b/drivers/i2c/muxes/pca954x.c
> @@ -226,8 +226,8 @@ static int pca954x_probe(struct i2c_client *client,
>  		}
>  
>  		data->virt_adaps[num] =
> -			i2c_add_mux_adapter(adap, client,
> -				force, num, pca954x_select_chan,
> +			i2c_add_mux_adapter(&client->dev, adap, client,
> +				force, num, NULL, pca954x_select_chan,
>  				(pdata && pdata->modes[num].deselect_on_exit)
>  					? pca954x_deselect_mux : NULL);
>  
> diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h
> index 747f0cd..43fb11a 100644
> --- a/include/linux/i2c-mux.h
> +++ b/include/linux/i2c-mux.h
> @@ -33,8 +33,10 @@
>   * and deselect callback functions to perform hardware-specific
>   * mux control.
>   */
> -struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
> +struct i2c_adapter *i2c_add_mux_adapter(struct device *dev,
> +				struct i2c_adapter *parent,
>  				void *mux_dev, u32 force_nr, u32 chan_id,
> +				const char *chan_name,
>  				int (*select) (struct i2c_adapter *,
>  					       void *mux_dev, u32 chan_id),
>  				int (*deselect) (struct i2c_adapter *,
> -- 
> 1.7.0.4
> 

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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Re: [PATCH 1/2] i2c: mux: add device tree support

[Stephen Warren]

On 04/23/2012 05:15 AM, Wolfram Sang wrote:
> On Tue, Apr 17, 2012 at 12:49:04PM -0600, Stephen Warren wrote:
>> From: Stephen Warren <swarren@nvidia.com>
>>
>> * Define core portions of the DT binding for I2C bus muxes.
>> * Enhance i2c_add_mux_adapter():
>> ** Add parameters required for DT support. Update all callers.
>> ** Set the appropriate adap->dev.of_node for the child bus.
>> ** Call of_i2c_register_devices() for the child bus.
>>
>> Signed-off-by: Stephen Warren <swarren@nvidia.com>
> 
> David Daney (CCed) posted another variant [1]. Just looking at the
> patches (and not really using them), I tend to like the approach using
> <reg> better. But I am open for discussion, so I'd appreciate your
> feedback.
> 
> Regards,
> 
>    Wolfram
> 
> [1] http://lkml.org/lkml/2012/4/12/423

Ah, that does look like a reasonable binding.

I had meant to call out to reviewers the potentially unusual use of
explicitly named sub-nodes, rather than using the usual reg-based matching.

The main reason I chose named sub-nodes for the busses was so the
sub-nodes would match the pinctrl named states. However, I think we can
make the pinctrl numbering match rather than the pinctrl naming instead.
The only issue is the "idle" state; if we allow it to exist anywhere in
the pinctrl-names list, it'll make the pinctrl numbering mismatch the
sub-node numbering. I think we can solve this by forcing the idle state
to be listed last in pinctrl-names (if it's listed at all). I'll update
my patches based on that David's patch.

Re: [PATCH 1/2] i2c: mux: add device tree support

[Stephen Warren]

On 04/23/2012 05:15 AM, Wolfram Sang wrote:
> On Tue, Apr 17, 2012 at 12:49:04PM -0600, Stephen Warren wrote:
>> From: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>>
>> * Define core portions of the DT binding for I2C bus muxes.
>> * Enhance i2c_add_mux_adapter():
>> ** Add parameters required for DT support. Update all callers.
>> ** Set the appropriate adap->dev.of_node for the child bus.
>> ** Call of_i2c_register_devices() for the child bus.
>>
>> Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> 
> David Daney (CCed) posted another variant [1]. Just looking at the
> patches (and not really using them), I tend to like the approach using
> <reg> better. But I am open for discussion, so I'd appreciate your
> feedback.
> 
> Regards,
> 
>    Wolfram
> 
> [1] http://lkml.org/lkml/2012/4/12/423

Ah, that does look like a reasonable binding.

I had meant to call out to reviewers the potentially unusual use of
explicitly named sub-nodes, rather than using the usual reg-based matching.

The main reason I chose named sub-nodes for the busses was so the
sub-nodes would match the pinctrl named states. However, I think we can
make the pinctrl numbering match rather than the pinctrl naming instead.
The only issue is the "idle" state; if we allow it to exist anywhere in
the pinctrl-names list, it'll make the pinctrl numbering mismatch the
sub-node numbering. I think we can solve this by forcing the idle state
to be listed last in pinctrl-names (if it's listed at all). I'll update
my patches based on that David's patch.

Re: [PATCH 1/2] i2c: mux: add device tree support

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 1311 bytes --]

On Mon, Apr 23, 2012 at 10:13:19AM -0600, Stephen Warren wrote:
> On 04/23/2012 05:15 AM, Wolfram Sang wrote:
> > On Tue, Apr 17, 2012 at 12:49:04PM -0600, Stephen Warren wrote:
> >> From: Stephen Warren <swarren@nvidia.com>
> >>
> >> * Define core portions of the DT binding for I2C bus muxes.
> >> * Enhance i2c_add_mux_adapter():
> >> ** Add parameters required for DT support. Update all callers.
> >> ** Set the appropriate adap->dev.of_node for the child bus.
> >> ** Call of_i2c_register_devices() for the child bus.
> >>
> >> Signed-off-by: Stephen Warren <swarren@nvidia.com>
> > 
> > David Daney (CCed) posted another variant [1]. Just looking at the
> > patches (and not really using them), I tend to like the approach using
> > <reg> better. But I am open for discussion, so I'd appreciate your
> > feedback.
> > 
> > Regards,
> > 
> >    Wolfram
> > 
> > [1] http://lkml.org/lkml/2012/4/12/423
> 
> Ah, that does look like a reasonable binding.

May I interpret this as an ack? :)

> to be listed last in pinctrl-names (if it's listed at all). I'll update
> my patches based on that David's patch.

Thanks.

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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Re: [PATCH 1/2] i2c: mux: add device tree support

[Wolfram Sang]

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On Mon, Apr 23, 2012 at 10:13:19AM -0600, Stephen Warren wrote:
> On 04/23/2012 05:15 AM, Wolfram Sang wrote:
> > On Tue, Apr 17, 2012 at 12:49:04PM -0600, Stephen Warren wrote:
> >> From: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> >>
> >> * Define core portions of the DT binding for I2C bus muxes.
> >> * Enhance i2c_add_mux_adapter():
> >> ** Add parameters required for DT support. Update all callers.
> >> ** Set the appropriate adap->dev.of_node for the child bus.
> >> ** Call of_i2c_register_devices() for the child bus.
> >>
> >> Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> > 
> > David Daney (CCed) posted another variant [1]. Just looking at the
> > patches (and not really using them), I tend to like the approach using
> > <reg> better. But I am open for discussion, so I'd appreciate your
> > feedback.
> > 
> > Regards,
> > 
> >    Wolfram
> > 
> > [1] http://lkml.org/lkml/2012/4/12/423
> 
> Ah, that does look like a reasonable binding.

May I interpret this as an ack? :)

> to be listed last in pinctrl-names (if it's listed at all). I'll update
> my patches based on that David's patch.

Thanks.

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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Re: [PATCH 1/2] i2c: mux: add device tree support

[David Daney]

On 04/23/2012 09:13 AM, Stephen Warren wrote:
> On 04/23/2012 05:15 AM, Wolfram Sang wrote:
>> On Tue, Apr 17, 2012 at 12:49:04PM -0600, Stephen Warren wrote:
>>> From: Stephen Warren<swarren@nvidia.com>
>>>
>>> * Define core portions of the DT binding for I2C bus muxes.
>>> * Enhance i2c_add_mux_adapter():
>>> ** Add parameters required for DT support. Update all callers.
>>> ** Set the appropriate adap->dev.of_node for the child bus.
>>> ** Call of_i2c_register_devices() for the child bus.
>>>
>>> Signed-off-by: Stephen Warren<swarren@nvidia.com>
>>
>> David Daney (CCed) posted another variant [1]. Just looking at the
>> patches (and not really using them), I tend to like the approach using
>> <reg>  better. But I am open for discussion, so I'd appreciate your
>> feedback.
>>
>> Regards,
>>
>>     Wolfram
>>
>> [1] http://lkml.org/lkml/2012/4/12/423
>
> Ah, that does look like a reasonable binding.
>

It was arrived at by iterating through several versions with Grant and Rob.

You make at least the third person (after me and Lars-Peter Clausen) 
wanting to use the device tree to configure the I2C muxes.  So at a 
minimum, it shows a need for this.

David Daney.

> I had meant to call out to reviewers the potentially unusual use of
> explicitly named sub-nodes, rather than using the usual reg-based matching.
>
> The main reason I chose named sub-nodes for the busses was so the
> sub-nodes would match the pinctrl named states. However, I think we can
> make the pinctrl numbering match rather than the pinctrl naming instead.
> The only issue is the "idle" state; if we allow it to exist anywhere in
> the pinctrl-names list, it'll make the pinctrl numbering mismatch the
> sub-node numbering. I think we can solve this by forcing the idle state
> to be listed last in pinctrl-names (if it's listed at all). I'll update
> my patches based on that David's patch.

Re: [PATCH 1/2] i2c: mux: add device tree support

[David Daney]

On 04/23/2012 09:13 AM, Stephen Warren wrote:
> On 04/23/2012 05:15 AM, Wolfram Sang wrote:
>> On Tue, Apr 17, 2012 at 12:49:04PM -0600, Stephen Warren wrote:
>>> From: Stephen Warren<swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>>>
>>> * Define core portions of the DT binding for I2C bus muxes.
>>> * Enhance i2c_add_mux_adapter():
>>> ** Add parameters required for DT support. Update all callers.
>>> ** Set the appropriate adap->dev.of_node for the child bus.
>>> ** Call of_i2c_register_devices() for the child bus.
>>>
>>> Signed-off-by: Stephen Warren<swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>>
>> David Daney (CCed) posted another variant [1]. Just looking at the
>> patches (and not really using them), I tend to like the approach using
>> <reg>  better. But I am open for discussion, so I'd appreciate your
>> feedback.
>>
>> Regards,
>>
>>     Wolfram
>>
>> [1] http://lkml.org/lkml/2012/4/12/423
>
> Ah, that does look like a reasonable binding.
>

It was arrived at by iterating through several versions with Grant and Rob.

You make at least the third person (after me and Lars-Peter Clausen) 
wanting to use the device tree to configure the I2C muxes.  So at a 
minimum, it shows a need for this.

David Daney.

> I had meant to call out to reviewers the potentially unusual use of
> explicitly named sub-nodes, rather than using the usual reg-based matching.
>
> The main reason I chose named sub-nodes for the busses was so the
> sub-nodes would match the pinctrl named states. However, I think we can
> make the pinctrl numbering match rather than the pinctrl naming instead.
> The only issue is the "idle" state; if we allow it to exist anywhere in
> the pinctrl-names list, it'll make the pinctrl numbering mismatch the
> sub-node numbering. I think we can solve this by forcing the idle state
> to be listed last in pinctrl-names (if it's listed at all). I'll update
> my patches based on that David's patch.