mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 02:09:42 +00:00
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>
This commit is contained in:
commit
6d54f1446d
11 changed files with 214 additions and 35 deletions
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@ -44,8 +44,7 @@ Required properties:
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- our-claim-gpio: The GPIO that we use to claim the bus.
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- their-claim-gpios: The GPIOs that the other sides use to claim the bus.
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Note that some implementations may only support a single other master.
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- Standard I2C mux properties. See i2c-mux.txt in this directory.
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- Single I2C child bus node at reg 0. See i2c-mux.txt in this directory.
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- I2C arbitration bus node. See i2c-arb.txt in this directory.
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Optional properties:
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- slew-delay-us: microseconds to wait for a GPIO to go high. Default is 10 us.
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@ -63,8 +62,6 @@ Example:
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i2c-arbitrator {
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compatible = "i2c-arb-gpio-challenge";
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#address-cells = <1>;
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#size-cells = <0>;
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i2c-parent = <&{/i2c@12CA0000}>;
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@ -74,8 +71,7 @@ Example:
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wait-retry-us = <3000>;
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wait-free-us = <50000>;
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i2c@0 {
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reg = <0>;
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i2c-arb {
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#address-cells = <1>;
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#size-cells = <0>;
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35
Documentation/devicetree/bindings/i2c/i2c-arb.txt
Normal file
35
Documentation/devicetree/bindings/i2c/i2c-arb.txt
Normal file
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@ -0,0 +1,35 @@
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Common i2c arbitration bus properties.
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- i2c-arb child node
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Required properties for the i2c-arb child node:
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- #address-cells = <1>;
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- #size-cells = <0>;
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Optional properties for i2c-arb child node:
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- Child nodes conforming to i2c bus binding
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Example :
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/*
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An NXP pca9541 I2C bus master selector at address 0x74
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with a NXP pca8574 GPIO expander attached.
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*/
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arb@74 {
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compatible = "nxp,pca9541";
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reg = <0x74>;
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i2c-arb {
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#address-cells = <1>;
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#size-cells = <0>;
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gpio@38 {
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compatible = "nxp,pca8574";
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reg = <0x38>;
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#gpio-cells = <2>;
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gpio-controller;
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};
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};
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};
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41
Documentation/devicetree/bindings/i2c/i2c-gate.txt
Normal file
41
Documentation/devicetree/bindings/i2c/i2c-gate.txt
Normal file
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@ -0,0 +1,41 @@
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An i2c gate is useful to e.g. reduce the digital noise for RF tuners connected
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to the i2c bus. Gates are similar to arbitrators in that you need to perform
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some kind of operation to access the i2c bus past the arbitrator/gate, but
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there are no competing masters to consider for gates and therefore there is
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no arbitration happening for gates.
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Common i2c gate properties.
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- i2c-gate child node
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Required properties for the i2c-gate child node:
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- #address-cells = <1>;
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- #size-cells = <0>;
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Optional properties for i2c-gate child node:
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- Child nodes conforming to i2c bus binding
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Example :
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/*
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An Invensense mpu9150 at address 0x68 featuring an on-chip Asahi
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Kasei ak8975 compass behind a gate.
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*/
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mpu9150@68 {
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compatible = "invensense,mpu9150";
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reg = <0x68>;
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interrupt-parent = <&gpio1>;
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interrupts = <18 1>;
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i2c-gate {
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#address-cells = <1>;
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#size-cells = <0>;
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ax8975@c {
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compatible = "ak,ak8975";
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reg = <0x0c>;
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};
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};
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};
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@ -2,19 +2,32 @@ Common i2c bus multiplexer/switch properties.
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An i2c bus multiplexer/switch will have several child busses that are
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numbered uniquely in a device dependent manner. The nodes for an i2c bus
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multiplexer/switch will have one child node for each child
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bus.
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multiplexer/switch will have one child node for each child bus.
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Required properties:
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Optional properties:
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- #address-cells = <1>;
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This property is required is the i2c-mux child node does not exist.
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- #size-cells = <0>;
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This property is required is the i2c-mux child node does not exist.
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- i2c-mux
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For i2c multiplexers/switches that have child nodes that are a mixture
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of both i2c child busses and other child nodes, the 'i2c-mux' subnode
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can be used for populating the i2c child busses. If an 'i2c-mux'
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subnode is present, only subnodes of this will be considered as i2c
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child busses.
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Required properties for the i2c-mux child node:
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- #address-cells = <1>;
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- #size-cells = <0>;
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Required properties for child nodes:
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Required properties for i2c child bus nodes:
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- #address-cells = <1>;
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- #size-cells = <0>;
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- reg : The sub-bus number.
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Optional properties for child nodes:
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Optional properties for i2c child bus nodes:
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- Other properties specific to the multiplexer/switch hardware.
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- Child nodes conforming to i2c bus binding
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29
Documentation/devicetree/bindings/i2c/nxp,pca9541.txt
Normal file
29
Documentation/devicetree/bindings/i2c/nxp,pca9541.txt
Normal file
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@ -0,0 +1,29 @@
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* NXP PCA9541 I2C bus master selector
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Required Properties:
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- compatible: Must be "nxp,pca9541"
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- reg: The I2C address of the device.
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The following required properties are defined externally:
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- I2C arbitration bus node. See i2c-arb.txt in this directory.
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Example:
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i2c-arbitrator@74 {
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compatible = "nxp,pca9541";
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reg = <0x74>;
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i2c-arb {
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#address-cells = <1>;
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#size-cells = <0>;
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eeprom@54 {
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compatible = "at,24c08";
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reg = <0x54>;
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};
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};
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};
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@ -5675,6 +5675,8 @@ S: Maintained
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F: Documentation/i2c/i2c-topology
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F: Documentation/i2c/muxes/
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F: Documentation/devicetree/bindings/i2c/i2c-mux*
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F: Documentation/devicetree/bindings/i2c/i2c-arb*
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F: Documentation/devicetree/bindings/i2c/i2c-gate*
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F: drivers/i2c/i2c-mux.c
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F: drivers/i2c/muxes/
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F: include/linux/i2c-mux.h
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@ -255,6 +255,10 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
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muxc->dev = dev;
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if (flags & I2C_MUX_LOCKED)
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muxc->mux_locked = true;
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if (flags & I2C_MUX_ARBITRATOR)
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muxc->arbitrator = true;
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if (flags & I2C_MUX_GATE)
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muxc->gate = true;
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muxc->select = select;
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muxc->deselect = deselect;
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muxc->max_adapters = max_adapters;
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@ -335,18 +339,42 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
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* nothing if !CONFIG_OF.
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*/
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if (muxc->dev->of_node) {
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struct device_node *child;
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struct device_node *dev_node = muxc->dev->of_node;
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struct device_node *mux_node, *child = NULL;
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u32 reg;
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for_each_child_of_node(muxc->dev->of_node, child) {
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ret = of_property_read_u32(child, "reg", ®);
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if (ret)
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continue;
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if (chan_id == reg) {
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priv->adap.dev.of_node = child;
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break;
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if (muxc->arbitrator)
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mux_node = of_get_child_by_name(dev_node, "i2c-arb");
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else if (muxc->gate)
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mux_node = of_get_child_by_name(dev_node, "i2c-gate");
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else
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mux_node = of_get_child_by_name(dev_node, "i2c-mux");
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if (mux_node) {
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/* A "reg" property indicates an old-style DT entry */
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if (!of_property_read_u32(mux_node, "reg", ®)) {
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of_node_put(mux_node);
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mux_node = NULL;
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}
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}
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if (!mux_node)
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mux_node = of_node_get(dev_node);
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else if (muxc->arbitrator || muxc->gate)
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child = of_node_get(mux_node);
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if (!child) {
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for_each_child_of_node(mux_node, child) {
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ret = of_property_read_u32(child, "reg", ®);
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if (ret)
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continue;
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if (chan_id == reg)
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break;
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}
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}
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priv->adap.dev.of_node = child;
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of_node_put(mux_node);
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}
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/*
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@ -130,7 +130,7 @@ static int i2c_arbitrator_probe(struct platform_device *pdev)
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return -EINVAL;
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}
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muxc = i2c_mux_alloc(NULL, dev, 1, sizeof(*arb), 0,
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muxc = i2c_mux_alloc(NULL, dev, 1, sizeof(*arb), I2C_MUX_ARBITRATOR,
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i2c_arbitrator_select, i2c_arbitrator_deselect);
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if (!muxc)
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return -ENOMEM;
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@ -85,6 +85,13 @@ static const struct i2c_device_id pca9541_id[] = {
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MODULE_DEVICE_TABLE(i2c, pca9541_id);
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#ifdef CONFIG_OF
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static const struct of_device_id pca9541_of_match[] = {
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{ .compatible = "nxp,pca9541" },
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{}
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};
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#endif
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/*
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* Write to chip register. Don't use i2c_transfer()/i2c_smbus_xfer()
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* as they will try to lock the adapter a second time.
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force = 0;
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if (pdata)
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force = pdata->modes[0].adap_id;
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muxc = i2c_mux_alloc(adap, &client->dev, 1, sizeof(*data), 0,
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muxc = i2c_mux_alloc(adap, &client->dev, 1, sizeof(*data),
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I2C_MUX_ARBITRATOR,
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pca9541_select_chan, pca9541_release_chan);
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if (!muxc)
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return -ENOMEM;
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@ -382,6 +390,7 @@ static int pca9541_remove(struct i2c_client *client)
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static struct i2c_driver pca9541_driver = {
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.driver = {
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.name = "pca9541",
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.of_match_table = of_match_ptr(pca9541_of_match),
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},
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.probe = pca9541_probe,
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.remove = pca9541_remove,
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@ -42,6 +42,7 @@
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#include <linux/i2c/pca954x.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/pm.h>
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#include <linux/slab.h>
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@ -58,14 +59,6 @@ enum pca_type {
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pca_9548,
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};
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struct pca954x {
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enum pca_type type;
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u8 last_chan; /* last register value */
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u8 deselect;
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struct i2c_client *client;
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};
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struct chip_desc {
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u8 nchans;
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u8 enable; /* used for muxes only */
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@ -75,6 +68,14 @@ struct chip_desc {
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} muxtype;
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};
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struct pca954x {
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const struct chip_desc *chip;
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u8 last_chan; /* last register value */
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u8 deselect;
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struct i2c_client *client;
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};
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/* Provide specs for the PCA954x types we know about */
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static const struct chip_desc chips[] = {
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[pca_9540] = {
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@ -119,6 +120,20 @@ static const struct i2c_device_id pca954x_id[] = {
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};
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MODULE_DEVICE_TABLE(i2c, pca954x_id);
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#ifdef CONFIG_OF
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static const struct of_device_id pca954x_of_match[] = {
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{ .compatible = "nxp,pca9540", .data = &chips[pca_9540] },
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{ .compatible = "nxp,pca9542", .data = &chips[pca_9542] },
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{ .compatible = "nxp,pca9543", .data = &chips[pca_9543] },
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{ .compatible = "nxp,pca9544", .data = &chips[pca_9544] },
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{ .compatible = "nxp,pca9545", .data = &chips[pca_9545] },
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{ .compatible = "nxp,pca9546", .data = &chips[pca_9546] },
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{ .compatible = "nxp,pca9547", .data = &chips[pca_9547] },
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{ .compatible = "nxp,pca9548", .data = &chips[pca_9548] },
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{}
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};
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#endif
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/* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer()
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for this as they will try to lock adapter a second time */
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static int pca954x_reg_write(struct i2c_adapter *adap,
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{
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struct pca954x *data = i2c_mux_priv(muxc);
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struct i2c_client *client = data->client;
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const struct chip_desc *chip = &chips[data->type];
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const struct chip_desc *chip = data->chip;
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u8 regval;
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int ret = 0;
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@ -197,6 +212,7 @@ static int pca954x_probe(struct i2c_client *client,
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int num, force, class;
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struct i2c_mux_core *muxc;
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struct pca954x *data;
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const struct of_device_id *match;
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int ret;
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if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
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@ -226,14 +242,19 @@ static int pca954x_probe(struct i2c_client *client,
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return -ENODEV;
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}
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data->type = id->driver_data;
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match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
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if (match)
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data->chip = of_device_get_match_data(&client->dev);
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else
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data->chip = &chips[id->driver_data];
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data->last_chan = 0; /* force the first selection */
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idle_disconnect_dt = of_node &&
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of_property_read_bool(of_node, "i2c-mux-idle-disconnect");
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/* Now create an adapter for each channel */
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for (num = 0; num < chips[data->type].nchans; num++) {
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for (num = 0; num < data->chip->nchans; num++) {
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bool idle_disconnect_pd = false;
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force = 0; /* dynamic adap number */
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@ -263,7 +284,7 @@ static int pca954x_probe(struct i2c_client *client,
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dev_info(&client->dev,
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"registered %d multiplexed busses for I2C %s %s\n",
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num, chips[data->type].muxtype == pca954x_ismux
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num, data->chip->muxtype == pca954x_ismux
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? "mux" : "switch", client->name);
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return 0;
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@ -299,6 +320,7 @@ static struct i2c_driver pca954x_driver = {
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.driver = {
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.name = "pca954x",
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.pm = &pca954x_pm,
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.of_match_table = of_match_ptr(pca954x_of_match),
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},
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.probe = pca954x_probe,
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.remove = pca954x_remove,
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@ -32,7 +32,9 @@
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struct i2c_mux_core {
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struct i2c_adapter *parent;
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struct device *dev;
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bool mux_locked;
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unsigned int mux_locked:1;
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unsigned int arbitrator:1;
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unsigned int gate:1;
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void *priv;
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@ -51,7 +53,9 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
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int (*deselect)(struct i2c_mux_core *, u32));
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/* flags for i2c_mux_alloc */
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#define I2C_MUX_LOCKED BIT(0)
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#define I2C_MUX_LOCKED BIT(0)
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#define I2C_MUX_ARBITRATOR BIT(1)
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#define I2C_MUX_GATE BIT(2)
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static inline void *i2c_mux_priv(struct i2c_mux_core *muxc)
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{
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