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
11 static const struct usb_device_id mvusb_mdio_table[] = {
12 { USB_DEVICE(USB_MARVELL_VID, 0x1fa4) },
13
14 {}
15 };
16 MODULE_DEVICE_TABLE(usb, mvusb_mdio_table);
17
18 enum {
19 MVUSB_CMD_PREAMBLE0,
20 MVUSB_CMD_PREAMBLE1,
21 MVUSB_CMD_ADDR,
22 MVUSB_CMD_VAL,
23 };
24
25 struct mvusb_mdio {
26 struct usb_device *udev;
27 struct mii_bus *mdio;
28
29 __le16 buf[4];
30 };
31
mvusb_mdio_read(struct mii_bus * mdio,int dev,int reg)32 static 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 if (dev & MII_ADDR_C45)
38 return -EOPNOTSUPP;
39
40 mvusb->buf[MVUSB_CMD_ADDR] = cpu_to_le16(0xa400 | (dev << 5) | reg);
41
42 err = usb_bulk_msg(mvusb->udev, usb_sndbulkpipe(mvusb->udev, 2),
43 mvusb->buf, 6, &alen, 100);
44 if (err)
45 return err;
46
47 err = usb_bulk_msg(mvusb->udev, usb_rcvbulkpipe(mvusb->udev, 6),
48 &mvusb->buf[MVUSB_CMD_VAL], 2, &alen, 100);
49 if (err)
50 return err;
51
52 return le16_to_cpu(mvusb->buf[MVUSB_CMD_VAL]);
53 }
54
mvusb_mdio_write(struct mii_bus * mdio,int dev,int reg,u16 val)55 static int mvusb_mdio_write(struct mii_bus *mdio, int dev, int reg, u16 val)
56 {
57 struct mvusb_mdio *mvusb = mdio->priv;
58 int alen;
59
60 if (dev & MII_ADDR_C45)
61 return -EOPNOTSUPP;
62
63 mvusb->buf[MVUSB_CMD_ADDR] = cpu_to_le16(0x8000 | (dev << 5) | reg);
64 mvusb->buf[MVUSB_CMD_VAL] = cpu_to_le16(val);
65
66 return usb_bulk_msg(mvusb->udev, usb_sndbulkpipe(mvusb->udev, 2),
67 mvusb->buf, 8, &alen, 100);
68 }
69
mvusb_mdio_probe(struct usb_interface * interface,const struct usb_device_id * id)70 static int mvusb_mdio_probe(struct usb_interface *interface,
71 const struct usb_device_id *id)
72 {
73 struct device *dev = &interface->dev;
74 struct mvusb_mdio *mvusb;
75 struct mii_bus *mdio;
76 int ret;
77
78 mdio = devm_mdiobus_alloc_size(dev, sizeof(*mvusb));
79 if (!mdio)
80 return -ENOMEM;
81
82 mvusb = mdio->priv;
83 mvusb->mdio = mdio;
84 mvusb->udev = usb_get_dev(interface_to_usbdev(interface));
85
86 /* Reversed from USB PCAPs, no idea what these mean. */
87 mvusb->buf[MVUSB_CMD_PREAMBLE0] = cpu_to_le16(0xe800);
88 mvusb->buf[MVUSB_CMD_PREAMBLE1] = cpu_to_le16(0x0001);
89
90 snprintf(mdio->id, MII_BUS_ID_SIZE, "mvusb-%s", dev_name(dev));
91 mdio->name = mdio->id;
92 mdio->parent = dev;
93 mdio->read = mvusb_mdio_read;
94 mdio->write = mvusb_mdio_write;
95
96 usb_set_intfdata(interface, mvusb);
97 ret = of_mdiobus_register(mdio, dev->of_node);
98 if (ret)
99 goto put_dev;
100
101 return 0;
102
103 put_dev:
104 usb_put_dev(mvusb->udev);
105 return ret;
106 }
107
mvusb_mdio_disconnect(struct usb_interface * interface)108 static void mvusb_mdio_disconnect(struct usb_interface *interface)
109 {
110 struct mvusb_mdio *mvusb = usb_get_intfdata(interface);
111 struct usb_device *udev = mvusb->udev;
112
113 mdiobus_unregister(mvusb->mdio);
114 usb_set_intfdata(interface, NULL);
115 usb_put_dev(udev);
116 }
117
118 static struct usb_driver mvusb_mdio_driver = {
119 .name = "mvusb_mdio",
120 .id_table = mvusb_mdio_table,
121 .probe = mvusb_mdio_probe,
122 .disconnect = mvusb_mdio_disconnect,
123 };
124
125 module_usb_driver(mvusb_mdio_driver);
126
127 MODULE_AUTHOR("Tobias Waldekranz <tobias@waldekranz.com>");
128 MODULE_DESCRIPTION("Marvell USB MDIO Adapter");
129 MODULE_LICENSE("GPL");
130