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1a6ca6497a
Driver core holds a reference to the USB interface and its parent USB device while the interface is bound to a driver and there is no need to take additional references unless the structures are needed after disconnect. Drop the redundant device reference to reduce cargo culting, make it easier to spot drivers where an extra reference is needed, and reduce the risk of memory leaks when drivers fail to release it. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20260309082641.15574-1-johan@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
114 lines
2.7 KiB
C
114 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of_mdio.h>
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#include <linux/phy.h>
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#include <linux/usb.h>
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#define USB_MARVELL_VID 0x1286
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static const struct usb_device_id mvusb_mdio_table[] = {
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{ USB_DEVICE(USB_MARVELL_VID, 0x1fa4) },
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{}
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};
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MODULE_DEVICE_TABLE(usb, mvusb_mdio_table);
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enum {
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MVUSB_CMD_PREAMBLE0,
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MVUSB_CMD_PREAMBLE1,
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MVUSB_CMD_ADDR,
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MVUSB_CMD_VAL,
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};
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struct mvusb_mdio {
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struct usb_device *udev;
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struct mii_bus *mdio;
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__le16 buf[4];
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};
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static int mvusb_mdio_read(struct mii_bus *mdio, int dev, int reg)
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{
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struct mvusb_mdio *mvusb = mdio->priv;
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int err, alen;
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mvusb->buf[MVUSB_CMD_ADDR] = cpu_to_le16(0xa400 | (dev << 5) | reg);
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err = usb_bulk_msg(mvusb->udev, usb_sndbulkpipe(mvusb->udev, 2),
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mvusb->buf, 6, &alen, 100);
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if (err)
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return err;
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err = usb_bulk_msg(mvusb->udev, usb_rcvbulkpipe(mvusb->udev, 6),
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&mvusb->buf[MVUSB_CMD_VAL], 2, &alen, 100);
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if (err)
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return err;
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return le16_to_cpu(mvusb->buf[MVUSB_CMD_VAL]);
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}
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static int mvusb_mdio_write(struct mii_bus *mdio, int dev, int reg, u16 val)
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{
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struct mvusb_mdio *mvusb = mdio->priv;
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int alen;
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mvusb->buf[MVUSB_CMD_ADDR] = cpu_to_le16(0x8000 | (dev << 5) | reg);
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mvusb->buf[MVUSB_CMD_VAL] = cpu_to_le16(val);
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return usb_bulk_msg(mvusb->udev, usb_sndbulkpipe(mvusb->udev, 2),
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mvusb->buf, 8, &alen, 100);
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}
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static int mvusb_mdio_probe(struct usb_interface *interface,
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const struct usb_device_id *id)
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{
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struct device *dev = &interface->dev;
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struct mvusb_mdio *mvusb;
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struct mii_bus *mdio;
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mdio = devm_mdiobus_alloc_size(dev, sizeof(*mvusb));
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if (!mdio)
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return -ENOMEM;
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mvusb = mdio->priv;
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mvusb->mdio = mdio;
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mvusb->udev = interface_to_usbdev(interface);
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/* Reversed from USB PCAPs, no idea what these mean. */
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mvusb->buf[MVUSB_CMD_PREAMBLE0] = cpu_to_le16(0xe800);
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mvusb->buf[MVUSB_CMD_PREAMBLE1] = cpu_to_le16(0x0001);
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snprintf(mdio->id, MII_BUS_ID_SIZE, "mvusb-%s", dev_name(dev));
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mdio->name = mdio->id;
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mdio->parent = dev;
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mdio->read = mvusb_mdio_read;
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mdio->write = mvusb_mdio_write;
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usb_set_intfdata(interface, mvusb);
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return of_mdiobus_register(mdio, dev->of_node);
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}
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static void mvusb_mdio_disconnect(struct usb_interface *interface)
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{
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struct mvusb_mdio *mvusb = usb_get_intfdata(interface);
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mdiobus_unregister(mvusb->mdio);
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usb_set_intfdata(interface, NULL);
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}
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static struct usb_driver mvusb_mdio_driver = {
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.name = "mvusb_mdio",
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.id_table = mvusb_mdio_table,
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.probe = mvusb_mdio_probe,
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.disconnect = mvusb_mdio_disconnect,
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};
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module_usb_driver(mvusb_mdio_driver);
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MODULE_AUTHOR("Tobias Waldekranz <tobias@waldekranz.com>");
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MODULE_DESCRIPTION("Marvell USB MDIO Adapter");
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MODULE_LICENSE("GPL");
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