1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/kernel.h>
4#include <linux/module.h>
5#include <linux/of_mdio.h>
6#include <linux/phy.h>
7#include <linux/usb.h>
8
9#define USB_MARVELL_VID	0x1286
10
11static const struct usb_device_id mvusb_mdio_table[] = {
12	{ USB_DEVICE(USB_MARVELL_VID, 0x1fa4) },
13
14	{}
15};
16MODULE_DEVICE_TABLE(usb, mvusb_mdio_table);
17
18enum {
19	MVUSB_CMD_PREAMBLE0,
20	MVUSB_CMD_PREAMBLE1,
21	MVUSB_CMD_ADDR,
22	MVUSB_CMD_VAL,
23};
24
25struct mvusb_mdio {
26	struct usb_device *udev;
27	struct mii_bus *mdio;
28
29	__le16 buf[4];
30};
31
32static int mvusb_mdio_read(struct mii_bus *mdio, int dev, int reg)
33{
34	struct mvusb_mdio *mvusb = mdio->priv;
35	int err, alen;
36
37	mvusb->buf[MVUSB_CMD_ADDR] = cpu_to_le16(0xa400 | (dev << 5) | reg);
38
39	err = usb_bulk_msg(mvusb->udev, usb_sndbulkpipe(mvusb->udev, 2),
40			   mvusb->buf, 6, &alen, 100);
41	if (err)
42		return err;
43
44	err = usb_bulk_msg(mvusb->udev, usb_rcvbulkpipe(mvusb->udev, 6),
45			   &mvusb->buf[MVUSB_CMD_VAL], 2, &alen, 100);
46	if (err)
47		return err;
48
49	return le16_to_cpu(mvusb->buf[MVUSB_CMD_VAL]);
50}
51
52static int mvusb_mdio_write(struct mii_bus *mdio, int dev, int reg, u16 val)
53{
54	struct mvusb_mdio *mvusb = mdio->priv;
55	int alen;
56
57	mvusb->buf[MVUSB_CMD_ADDR] = cpu_to_le16(0x8000 | (dev << 5) | reg);
58	mvusb->buf[MVUSB_CMD_VAL]  = cpu_to_le16(val);
59
60	return usb_bulk_msg(mvusb->udev, usb_sndbulkpipe(mvusb->udev, 2),
61			    mvusb->buf, 8, &alen, 100);
62}
63
64static int mvusb_mdio_probe(struct usb_interface *interface,
65			    const struct usb_device_id *id)
66{
67	struct device *dev = &interface->dev;
68	struct mvusb_mdio *mvusb;
69	struct mii_bus *mdio;
70	int ret;
71
72	mdio = devm_mdiobus_alloc_size(dev, sizeof(*mvusb));
73	if (!mdio)
74		return -ENOMEM;
75
76	mvusb = mdio->priv;
77	mvusb->mdio = mdio;
78	mvusb->udev = usb_get_dev(interface_to_usbdev(interface));
79
80	/* Reversed from USB PCAPs, no idea what these mean. */
81	mvusb->buf[MVUSB_CMD_PREAMBLE0] = cpu_to_le16(0xe800);
82	mvusb->buf[MVUSB_CMD_PREAMBLE1] = cpu_to_le16(0x0001);
83
84	snprintf(mdio->id, MII_BUS_ID_SIZE, "mvusb-%s", dev_name(dev));
85	mdio->name = mdio->id;
86	mdio->parent = dev;
87	mdio->read = mvusb_mdio_read;
88	mdio->write = mvusb_mdio_write;
89
90	usb_set_intfdata(interface, mvusb);
91	ret = of_mdiobus_register(mdio, dev->of_node);
92	if (ret)
93		goto put_dev;
94
95	return 0;
96
97put_dev:
98	usb_put_dev(mvusb->udev);
99	return ret;
100}
101
102static void mvusb_mdio_disconnect(struct usb_interface *interface)
103{
104	struct mvusb_mdio *mvusb = usb_get_intfdata(interface);
105	struct usb_device *udev = mvusb->udev;
106
107	mdiobus_unregister(mvusb->mdio);
108	usb_set_intfdata(interface, NULL);
109	usb_put_dev(udev);
110}
111
112static struct usb_driver mvusb_mdio_driver = {
113	.name       = "mvusb_mdio",
114	.id_table   = mvusb_mdio_table,
115	.probe      = mvusb_mdio_probe,
116	.disconnect = mvusb_mdio_disconnect,
117};
118
119module_usb_driver(mvusb_mdio_driver);
120
121MODULE_AUTHOR("Tobias Waldekranz <tobias@waldekranz.com>");
122MODULE_DESCRIPTION("Marvell USB MDIO Adapter");
123MODULE_LICENSE("GPL");
124