[PATCH 1/2] dt-bindings: net: add marvell smi2usb bindings

[PATCH 1/2] dt-bindings: net: add marvell smi2usb bindings

[Tobias Waldekranz]

Describe how the smi2usb controller can optionally use device tree
bindings to reference attached devices such as switches.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
---
 .../bindings/net/marvell,smi2usb.yaml         | 65 +++++++++++++++++++
 MAINTAINERS                                   |  6 ++
 2 files changed, 71 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/marvell,smi2usb.yaml

diff --git a/Documentation/devicetree/bindings/net/marvell,smi2usb.yaml b/Documentation/devicetree/bindings/net/marvell,smi2usb.yaml
new file mode 100644
index 000000000000..498a19bf7326
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/marvell,smi2usb.yaml
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/marvell,smi2usb.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Marvell SMI2USB MDIO Controller
+
+maintainers:
+  - Tobias Waldekranz <tobias@waldekranz.com>
+
+description: |+
+  This controller is mounted on development boards for Marvell's Link Street
+  family of Ethernet switches. It allows you to configure the switch's registers
+  using the standard MDIO interface.
+
+  Since the device is connected over USB, there is no strict requirement of
+  having a device tree representation of the device. But in order to use it with
+  the mv88e6xxx driver, you need a device tree node in which to place the switch
+  definition.
+
+allOf:
+  - $ref: "mdio.yaml#"
+
+properties:
+  compatible:
+    const: usb1286,1fa4
+  reg:
+    maxItems: 1
+    description: The USB port number on the host controller
+
+required:
+  - compatible
+  - reg
+  - "#address-cells"
+  - "#size-cells"
+
+examples:
+  - |
+    /* USB host controller */
+    &usb1 {
+            smi2usb: mdio@1 {
+                    compatible = "usb1286,1fa4";
+                    reg = <1>;
+                    #address-cells = <1>;
+                    #size-cells = <0>;
+            };
+    };
+
+    /* MV88E6390X devboard */
+    &smi2usb {
+            switch@0 {
+                    compatible = "marvell,mv88e6190";
+                    status = "ok";
+                    reg = <0x0>;
+
+                    ports {
+                            /* Port definitions */
+                    };
+
+                    mdio {
+                            /* PHY definitions */
+                    };
+            };
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index 5dbee41045bc..83bb7ce3e23e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10096,6 +10096,12 @@ S:	Maintained
 F:	drivers/mtd/nand/raw/marvell_nand.c
 F:	Documentation/devicetree/bindings/mtd/marvell-nand.txt
 
+MARVELL SMI2USB MDIO CONTROLLER DRIVER
+M:	Tobias Waldekranz <tobias@waldekranz.com>
+L:	netdev@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/net/marvell,smi2usb.yaml
+
 MARVELL SOC MMC/SD/SDIO CONTROLLER DRIVER
 M:	Nicolas Pitre <nico@fluxnic.net>
 S:	Odd Fixes
-- 
2.17.1

[PATCH 2/2] net: phy: marvell smi2usb mdio controller

[Tobias Waldekranz]

An MDIO controller present on development boards for Marvell switches
from the Link Street (88E6xxx) family.

Using this module, you can use the following setup as a development
platform for switchdev and DSA related work.

   .-------.      .-----------------.
   |      USB----USB                |
   |  SoC  |      |  88E6390X-DB  ETH1-10
   |      ETH----ETH0               |
   '-------'      '-----------------'

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
---
 MAINTAINERS                    |   1 +
 drivers/net/phy/Kconfig        |   7 ++
 drivers/net/phy/Makefile       |   1 +
 drivers/net/phy/mdio-smi2usb.c | 137 +++++++++++++++++++++++++++++++++
 4 files changed, 146 insertions(+)
 create mode 100644 drivers/net/phy/mdio-smi2usb.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 83bb7ce3e23e..a7771e577832 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10100,6 +10100,7 @@ MARVELL SMI2USB MDIO CONTROLLER DRIVER
 M:	Tobias Waldekranz <tobias@waldekranz.com>
 L:	netdev@vger.kernel.org
 S:	Maintained
+F:	drivers/net/phy/mdio-smi2usb.c
 F:	Documentation/devicetree/bindings/net/marvell,smi2usb.yaml
 
 MARVELL SOC MMC/SD/SDIO CONTROLLER DRIVER
diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index cc7f1df855da..ddde79c6f354 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -189,6 +189,13 @@ config MDIO_OCTEON
 	  buses. It is required by the Octeon and ThunderX ethernet device
 	  drivers on some systems.
 
+config MDIO_SMI2USB
+	tristate "Marvell SMI2USB"
+	depends on OF_MDIO && USB
+	help
+	  A USB to MDIO converter present on development boards for
+	  Marvell's Link Street family of Ethernet switches.
+
 config MDIO_SUN4I
 	tristate "Allwinner sun4i MDIO interface support"
 	depends on ARCH_SUNXI || COMPILE_TEST
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 70774ab474e6..fcbe4bd26747 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_MDIO_IPQ8064)	+= mdio-ipq8064.o
 obj-$(CONFIG_MDIO_MOXART)	+= mdio-moxart.o
 obj-$(CONFIG_MDIO_MSCC_MIIM)	+= mdio-mscc-miim.o
 obj-$(CONFIG_MDIO_OCTEON)	+= mdio-octeon.o
+obj-$(CONFIG_MDIO_SMI2USB)	+= mdio-smi2usb.o
 obj-$(CONFIG_MDIO_SUN4I)	+= mdio-sun4i.o
 obj-$(CONFIG_MDIO_THUNDER)	+= mdio-thunder.o
 obj-$(CONFIG_MDIO_XGENE)	+= mdio-xgene.o
diff --git a/drivers/net/phy/mdio-smi2usb.c b/drivers/net/phy/mdio-smi2usb.c
new file mode 100644
index 000000000000..6f022dca618c
--- /dev/null
+++ b/drivers/net/phy/mdio-smi2usb.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_mdio.h>
+#include <linux/phy.h>
+#include <linux/usb.h>
+
+#define USB_MARVELL_VID	0x1286
+
+static const struct usb_device_id smi2usb_table[] = {
+	{ USB_DEVICE(USB_MARVELL_VID, 0x1fa4) },
+
+	{}
+};
+MODULE_DEVICE_TABLE(usb, smi2usb_table);
+
+enum {
+	SMI_CMD_PREAMBLE0,
+	SMI_CMD_PREAMBLE1,
+	SMI_CMD_ADDR,
+	SMI_CMD_VAL,
+};
+
+struct smi2usb {
+	struct usb_device *udev;
+	struct usb_interface *intf;
+
+	struct mii_bus *mdio;
+
+	__le16 buf[4];
+};
+
+static int smi2usb_mdio_read(struct mii_bus *mdio, int dev, int reg)
+{
+	struct smi2usb *smi = mdio->priv;
+	int err, alen;
+
+	if (dev & MII_ADDR_C45)
+		return -EOPNOTSUPP;
+
+	smi->buf[SMI_CMD_ADDR] = cpu_to_le16(0xa400 | (dev << 5) | reg);
+
+	err = usb_bulk_msg(smi->udev, usb_sndbulkpipe(smi->udev, 2),
+			   smi->buf, 6, &alen, 100);
+	if (err)
+		return err;
+
+	err = usb_bulk_msg(smi->udev, usb_rcvbulkpipe(smi->udev, 6),
+			   &smi->buf[SMI_CMD_VAL], 2, &alen, 100);
+	if (err)
+		return err;
+
+	return le16_to_cpu(smi->buf[SMI_CMD_VAL]);
+}
+
+static int smi2usb_mdio_write(struct mii_bus *mdio, int dev, int reg, u16 val)
+{
+	struct smi2usb *smi = mdio->priv;
+	int alen;
+
+	if (dev & MII_ADDR_C45)
+		return -EOPNOTSUPP;
+
+	smi->buf[SMI_CMD_ADDR] = cpu_to_le16(0x8000 | (dev << 5) | reg);
+	smi->buf[SMI_CMD_VAL]  = cpu_to_le16(val);
+
+	return usb_bulk_msg(smi->udev, usb_sndbulkpipe(smi->udev, 2),
+			    smi->buf, 8, &alen, 100);
+}
+
+static int smi2usb_probe(struct usb_interface *interface,
+			 const struct usb_device_id *id)
+{
+	struct smi2usb *smi;
+	struct mii_bus *mdio;
+	struct device *dev = &interface->dev;
+	int err = -ENOMEM;
+
+	mdio = devm_mdiobus_alloc_size(dev, sizeof(*smi));
+	if (!mdio)
+		goto err;
+
+	smi = mdio->priv;
+	smi->mdio = mdio;
+	smi->udev = usb_get_dev(interface_to_usbdev(interface));
+	smi->intf = usb_get_intf(interface);
+
+	/* Reversed from USB PCAPs, no idea what these mean. */
+	smi->buf[SMI_CMD_PREAMBLE0] = cpu_to_le16(0xe800);
+	smi->buf[SMI_CMD_PREAMBLE1] = cpu_to_le16(0x0001);
+
+	usb_set_intfdata(interface, smi);
+
+	snprintf(mdio->id, MII_BUS_ID_SIZE, "smi2usb-%s", dev_name(dev));
+	mdio->name = mdio->id;
+	mdio->parent = dev;
+	mdio->read = smi2usb_mdio_read;
+	mdio->write = smi2usb_mdio_write;
+
+	err = of_mdiobus_register(mdio, dev->of_node);
+	if (err)
+		goto err_put;
+
+	return 0;
+
+err_put:
+	usb_put_intf(interface);
+	usb_put_dev(interface_to_usbdev(interface));
+err:
+	return err;
+}
+
+static void smi2usb_disconnect(struct usb_interface *interface)
+{
+	struct smi2usb *smi;
+
+	smi = usb_get_intfdata(interface);
+	mdiobus_unregister(smi->mdio);
+	usb_set_intfdata(interface, NULL);
+
+	usb_put_intf(interface);
+	usb_put_dev(interface_to_usbdev(interface));
+}
+
+static struct usb_driver smi2usb_driver = {
+	.name       = "smi2usb",
+	.id_table   = smi2usb_table,
+	.probe      = smi2usb_probe,
+	.disconnect = smi2usb_disconnect,
+};
+
+module_usb_driver(smi2usb_driver);
+
+MODULE_AUTHOR("Tobias Waldekranz <tobias@waldekranz.com>");
+MODULE_DESCRIPTION("Marvell SMI2USB Adapter");
+MODULE_LICENSE("GPL");
-- 
2.17.1

Re: [PATCH 2/2] net: phy: marvell smi2usb mdio controller

[David Miller]

From: Tobias Waldekranz <tobias@waldekranz.com>
Date: Wed, 18 Mar 2020 17:52:32 +0100

> +static int smi2usb_probe(struct usb_interface *interface,
> +			 const struct usb_device_id *id)
> +{
> +	struct smi2usb *smi;
> +	struct mii_bus *mdio;
> +	struct device *dev = &interface->dev;
> +	int err = -ENOMEM;

Please use reverse christmas tree ordering for local variables.

Thank you.