diff mbox series

[v2,2/2] net: phy: marvell smi2usb mdio controller

Message ID 20200319135952.16258-2-tobias@waldekranz.com
State Superseded
Headers show
Series None | expand

Commit Message

Tobias Waldekranz March 19, 2020, 1:59 p.m. UTC 
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>
---

v1->v2:
- Reverse christmas tree ordering of local variables.

---
 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 mbox series

Patch

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..c4f7f555a091
--- /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 device *dev = &interface->dev;
+	struct mii_bus *mdio;
+	struct smi2usb *smi;
+	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");