[PATCH v3 1/2] dt-bindings: net: Add bindings for mdio mux consumers

[PATCH v3 1/2] dt-bindings: net: Add bindings for mdio mux consumers

[Pankaj Bansal]

When we use the bindings defined in Documentation/devicetree/bindings/mux
to define mdio mux in producer and consumer terms, it results in two
devices. one is mux producer and other is mux consumer.

Add the bindings needed for Mdio mux consumer devices.

Signed-off-by: Pankaj Bansal <pankaj.bansal@nxp.com>
---

Notes:
    V3:
    - No Change
    V2:
    - moved the bindings from mdio-mux.txt to new file mdio-mux-multiplexer.txt
    - changed compatible to mdio-mux-multiplexer

 .../bindings/net/mdio-mux-multiplexer.txt    | 83 ++++++++++++++++++
 1 file changed, 83 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/mdio-mux-multiplexer.txt b/Documentation/devicetree/bindings/net/mdio-mux-multiplexer.txt
new file mode 100644
index 000000000000..9d5384849929
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/mdio-mux-multiplexer.txt
@@ -0,0 +1,83 @@
+Properties for an MDIO bus multiplexer consumer device
+
+This is a special case of MDIO mux  when MDIO mux is defined as a consumer
+of a mux producer device. The mux producer can be of any type like mmio mux
+producer, gpio mux producer or generic register based mux producer.
+
+Required properties in addition to the MDIO Bus multiplexer properties:
+
+- compatible : should be "mmio-mux-multiplexer"
+- mux-controls : mux controller node to use for operating the mux
+- mdio-parent-bus : phandle to the parent MDIO bus.
+
+each child node of mdio bus multiplexer consumer device represent a mdio
+bus.
+
+for more information please refer
+Documentation/devicetree/bindings/mux/mux-controller.txt
+and Documentation/devicetree/bindings/net/mdio-mux.txt
+
+Example:
+In below example the Mux producer and consumer are separate nodes.
+
+&i2c0 {
+	fpga@66 { // fpga connected to i2c
+		compatible = "fsl,lx2160aqds-fpga", "fsl,fpga-qixis-i2c",
+			     "simple-mfd";
+		reg = <0x66>;
+
+		mux: mux-controller { // Mux Producer
+			compatible = "reg-mux";
+			#mux-control-cells = <1>;
+			mux-reg-masks = <0x54 0xf8>, /* 0: reg 0x54, bits 7:3 */
+					<0x54 0x07>; /* 1: reg 0x54, bits 2:0 */
+		};
+	};
+};
+
+mdio-mux-1 { // Mux consumer
+	compatible = "mdio-mux-multiplexer";
+	mux-controls = <&mux 0>;
+	mdio-parent-bus = <&emdio1>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	mdio@0 {
+		reg = <0x0>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+	};
+
+	mdio@8 {
+		reg = <0x8>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+	};
+
+	..
+	..
+};
+
+mdio-mux-2 { // Mux consumer
+	compatible = "mdio-mux-multiplexer";
+	mux-controls = <&mux 1>;
+	mdio-parent-bus = <&emdio2>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	mdio@0 {
+		reg = <0x0>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+	};
+
+	mdio@1 {
+		reg = <0x1>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+	};
+
+	..
+	..
+};
+
-- 
2.17.1

[PATCH v3 2/2] drivers: net: phy: mdio-mux: Add support for Generic Mux controls

[Pankaj Bansal]

Add support for Generic Mux controls, when Mdio mux node is a consumer
of mux produced by some other device.

Signed-off-by: Pankaj Bansal <pankaj.bansal@nxp.com>
---

Notes:
    V3:
    - Avoid recast from platform_get_drvdata
    - Check mux_control_deselect output in switch_fn
    - rearrange swithc_fn code to reduce code indentation by one tab
    - Add do_deselect boolean in driver data to indicate that mux_control_deselect
      has to be called, becuase mux_control_select has been called once.
    V2:
    - Moved the changes from mdio-mux module to new module mdio-mux-multiplexer
    - defined new CONFIG
    - using new compatible "mdio-mux-multiplexer"

 drivers/net/phy/Kconfig                |  12 +++
 drivers/net/phy/Makefile               |   1 +
 drivers/net/phy/mdio-mux-multiplexer.c | 122 +++++++++++++++++++++++
 3 files changed, 135 insertions(+)

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 3d187cd50eb0..7f66af446ec7 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -87,6 +87,18 @@ config MDIO_BUS_MUX_MMIOREG
 
 	  Currently, only 8/16/32 bits registers are supported.
 
+config MDIO_BUS_MUX_MULTIPLEXER
+	tristate "MDIO bus multiplexer using kernel multiplexer subsystem"
+	depends on OF
+	select MULTIPLEXER
+	select MDIO_BUS_MUX
+	help
+	  This module provides a driver for MDIO bus multiplexer
+	  that is controlled via the kernel multiplexer subsystem. The
+	  bus multiplexer connects one of several child MDIO busses to
+	  a parent bus.  Child bus selection is under the control of
+	  the kernel multiplexer subsystem.
+
 config MDIO_CAVIUM
 	tristate
 
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 5805c0b7d60e..766106237a90 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_MDIO_BUS_MUX)	+= mdio-mux.o
 obj-$(CONFIG_MDIO_BUS_MUX_BCM_IPROC)	+= mdio-mux-bcm-iproc.o
 obj-$(CONFIG_MDIO_BUS_MUX_GPIO)	+= mdio-mux-gpio.o
 obj-$(CONFIG_MDIO_BUS_MUX_MMIOREG) += mdio-mux-mmioreg.o
+obj-$(CONFIG_MDIO_BUS_MUX_MULTIPLEXER) += mdio-mux-multiplexer.o
 obj-$(CONFIG_MDIO_CAVIUM)	+= mdio-cavium.o
 obj-$(CONFIG_MDIO_GPIO)		+= mdio-gpio.o
 obj-$(CONFIG_MDIO_HISI_FEMAC)	+= mdio-hisi-femac.o
diff --git a/drivers/net/phy/mdio-mux-multiplexer.c b/drivers/net/phy/mdio-mux-multiplexer.c
new file mode 100644
index 000000000000..d6564381aa3e
--- /dev/null
+++ b/drivers/net/phy/mdio-mux-multiplexer.c
@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* MDIO bus multiplexer using kernel multiplexer subsystem
+ *
+ * Copyright 2019 NXP
+ */
+
+#include <linux/platform_device.h>
+#include <linux/mdio-mux.h>
+#include <linux/module.h>
+#include <linux/mux/consumer.h>
+
+struct mdio_mux_multiplexer_state {
+	struct mux_control *muxc;
+	bool do_deselect;
+	void *mux_handle;
+};
+
+/**
+ * mdio_mux_multiplexer_switch_fn - This function is called by the mdio-mux
+ *                                  layer when it thinks the mdio bus
+ *                                  multiplexer needs to switch.
+ * @current_child:  current value of the mux register.
+ * @desired_child: value of the 'reg' property of the target child MDIO node.
+ * @data: Private data used by this switch_fn passed to mdio_mux_init function
+ *        via mdio_mux_init(.., .., .., .., data, ..).
+ *
+ * The first time this function is called, current_child == -1.
+ * If current_child == desired_child, then the mux is already set to the
+ * correct bus.
+ */
+static int mdio_mux_multiplexer_switch_fn(int current_child, int desired_child,
+					  void *data)
+{
+	struct platform_device *pdev;
+	struct mdio_mux_multiplexer_state *s;
+	int ret = 0;
+
+	pdev = (struct platform_device *)data;
+	s = platform_get_drvdata(pdev);
+
+	if (!(current_child ^ desired_child))
+		return 0;
+
+	if (s->do_deselect)
+		ret = mux_control_deselect(s->muxc);
+	if (ret) {
+		dev_err(&pdev->dev, "mux_control_deselect failed in %s: %d\n",
+			__func__, ret);
+		return ret;
+	}
+
+	ret =  mux_control_select(s->muxc, desired_child);
+	if (!ret) {
+		dev_dbg(&pdev->dev, "%s %d -> %d\n", __func__, current_child,
+			desired_child);
+		s->do_deselect = true;
+	} else {
+		s->do_deselect = false;
+	}
+
+	return ret;
+}
+
+static int mdio_mux_multiplexer_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mdio_mux_multiplexer_state *s;
+	int ret = 0;
+
+	s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
+	if (!s)
+		return -ENOMEM;
+
+	s->muxc = devm_mux_control_get(dev, NULL);
+	if (IS_ERR(s->muxc)) {
+		ret = PTR_ERR(s->muxc);
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "Failed to get mux: %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, s);
+
+	ret = mdio_mux_init(&pdev->dev, pdev->dev.of_node,
+			    mdio_mux_multiplexer_switch_fn, &s->mux_handle,
+			    pdev, NULL);
+
+	return ret;
+}
+
+static int mdio_mux_multiplexer_remove(struct platform_device *pdev)
+{
+	struct mdio_mux_multiplexer_state *s = platform_get_drvdata(pdev);
+
+	mdio_mux_uninit(s->mux_handle);
+
+	if (s->do_deselect)
+		mux_control_deselect(s->muxc);
+
+	return 0;
+}
+
+static const struct of_device_id mdio_mux_multiplexer_match[] = {
+	{ .compatible = "mdio-mux-multiplexer", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mdio_mux_multiplexer_match);
+
+static struct platform_driver mdio_mux_multiplexer_driver = {
+	.driver = {
+		.name		= "mdio-mux-multiplexer",
+		.of_match_table	= mdio_mux_multiplexer_match,
+	},
+	.probe		= mdio_mux_multiplexer_probe,
+	.remove		= mdio_mux_multiplexer_remove,
+};
+
+module_platform_driver(mdio_mux_multiplexer_driver);
+
+MODULE_DESCRIPTION("MDIO bus multiplexer using kernel multiplexer subsystem");
+MODULE_AUTHOR("Pankaj Bansal <pankaj.bansal@nxp.com>");
+MODULE_LICENSE("GPL");
-- 
2.17.1

Re: [PATCH v3 1/2] dt-bindings: net: Add bindings for mdio mux consumers

[David Miller]

From: Pankaj Bansal <pankaj.bansal@nxp.com>
Date: Mon, 25 Feb 2019 06:16:53 +0000

> When we use the bindings defined in Documentation/devicetree/bindings/mux
> to define mdio mux in producer and consumer terms, it results in two
> devices. one is mux producer and other is mux consumer.
> 
> Add the bindings needed for Mdio mux consumer devices.
> 
> Signed-off-by: Pankaj Bansal <pankaj.bansal@nxp.com>

Applied.

Re: [PATCH v3 2/2] drivers: net: phy: mdio-mux: Add support for Generic Mux controls

[David Miller]

From: Pankaj Bansal <pankaj.bansal@nxp.com>
Date: Mon, 25 Feb 2019 06:16:55 +0000

> Add support for Generic Mux controls, when Mdio mux node is a consumer
> of mux produced by some other device.
> 
> Signed-off-by: Pankaj Bansal <pankaj.bansal@nxp.com>

Applied.