mirror of
https://github.com/torvalds/linux.git
synced 2026-05-12 16:18:45 +02:00
1a408a6778
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> Link: https://patch.msgid.link/20260305104051.15727-1-johan@kernel.org Signed-off-by: Lee Jones <lee@kernel.org>
128 lines
3.0 KiB
C
128 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Nano River Technologies viperboard driver
|
|
*
|
|
* This is the core driver for the viperboard. There are cell drivers
|
|
* available for I2C, ADC and both GPIOs. SPI is not yet supported.
|
|
* The drivers do not support all features the board exposes. See user
|
|
* manual of the viperboard.
|
|
*
|
|
* (C) 2012 by Lemonage GmbH
|
|
* Author: Lars Poeschel <poeschel@lemonage.de>
|
|
* All rights reserved.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/module.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/types.h>
|
|
#include <linux/mutex.h>
|
|
|
|
#include <linux/mfd/core.h>
|
|
#include <linux/mfd/viperboard.h>
|
|
|
|
#include <linux/usb.h>
|
|
|
|
|
|
static const struct usb_device_id vprbrd_table[] = {
|
|
{ USB_DEVICE(0x2058, 0x1005) }, /* Nano River Technologies */
|
|
{ } /* Terminating entry */
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(usb, vprbrd_table);
|
|
|
|
static const struct mfd_cell vprbrd_devs[] = {
|
|
{
|
|
.name = "viperboard-gpio",
|
|
},
|
|
{
|
|
.name = "viperboard-i2c",
|
|
},
|
|
{
|
|
.name = "viperboard-adc",
|
|
},
|
|
};
|
|
|
|
static int vprbrd_probe(struct usb_interface *interface,
|
|
const struct usb_device_id *id)
|
|
{
|
|
struct vprbrd *vb;
|
|
|
|
u16 version = 0;
|
|
int pipe, ret;
|
|
|
|
/* allocate memory for our device state and initialize it */
|
|
vb = kzalloc_obj(*vb);
|
|
if (!vb)
|
|
return -ENOMEM;
|
|
|
|
mutex_init(&vb->lock);
|
|
|
|
vb->usb_dev = interface_to_usbdev(interface);
|
|
|
|
/* save our data pointer in this interface device */
|
|
usb_set_intfdata(interface, vb);
|
|
dev_set_drvdata(&vb->pdev.dev, vb);
|
|
|
|
/* get version information, major first, minor then */
|
|
pipe = usb_rcvctrlpipe(vb->usb_dev, 0);
|
|
ret = usb_control_msg(vb->usb_dev, pipe, VPRBRD_USB_REQUEST_MAJOR,
|
|
VPRBRD_USB_TYPE_IN, 0x0000, 0x0000, vb->buf, 1,
|
|
VPRBRD_USB_TIMEOUT_MS);
|
|
if (ret == 1)
|
|
version = vb->buf[0];
|
|
|
|
ret = usb_control_msg(vb->usb_dev, pipe, VPRBRD_USB_REQUEST_MINOR,
|
|
VPRBRD_USB_TYPE_IN, 0x0000, 0x0000, vb->buf, 1,
|
|
VPRBRD_USB_TIMEOUT_MS);
|
|
if (ret == 1) {
|
|
version <<= 8;
|
|
version = version | vb->buf[0];
|
|
}
|
|
|
|
dev_info(&interface->dev,
|
|
"version %x.%02x found at bus %03d address %03d\n",
|
|
version >> 8, version & 0xff,
|
|
vb->usb_dev->bus->busnum, vb->usb_dev->devnum);
|
|
|
|
ret = mfd_add_hotplug_devices(&interface->dev, vprbrd_devs,
|
|
ARRAY_SIZE(vprbrd_devs));
|
|
if (ret != 0) {
|
|
dev_err(&interface->dev, "Failed to add mfd devices to core.");
|
|
goto error;
|
|
}
|
|
|
|
return 0;
|
|
|
|
error:
|
|
if (vb)
|
|
kfree(vb);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void vprbrd_disconnect(struct usb_interface *interface)
|
|
{
|
|
struct vprbrd *vb = usb_get_intfdata(interface);
|
|
|
|
mfd_remove_devices(&interface->dev);
|
|
usb_set_intfdata(interface, NULL);
|
|
kfree(vb);
|
|
|
|
dev_dbg(&interface->dev, "disconnected\n");
|
|
}
|
|
|
|
static struct usb_driver vprbrd_driver = {
|
|
.name = "viperboard",
|
|
.probe = vprbrd_probe,
|
|
.disconnect = vprbrd_disconnect,
|
|
.id_table = vprbrd_table,
|
|
};
|
|
|
|
module_usb_driver(vprbrd_driver);
|
|
|
|
MODULE_DESCRIPTION("Nano River Technologies viperboard mfd core driver");
|
|
MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
|
|
MODULE_LICENSE("GPL");
|