linux_dsm_epyc7002/drivers/usb/misc/phidgetmotorcontrol.c
Greg Kroah-Hartman bfd3a5a96c USB: Phidget: fix race in device_create
There is a race from when a device is created with device_create() and
then the drvdata is set with a call to dev_set_drvdata() in which a
sysfs file could be open, yet the drvdata will be NULL, causing all
sorts of bad things to happen.

This patch fixes the problem by using the new function,
device_create_drvdata().  It fixes all 3 phidget drivers, which all have
the same problem.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Sean Young <sean@mess.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-05-20 13:31:56 -07:00

467 lines
11 KiB
C

/*
* USB Phidget MotorControl driver
*
* Copyright (C) 2006 Sean Young <sean@mess.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/usb.h>
#include "phidget.h"
#define DRIVER_AUTHOR "Sean Young <sean@mess.org>"
#define DRIVER_DESC "USB PhidgetMotorControl Driver"
#define USB_VENDOR_ID_GLAB 0x06c2
#define USB_DEVICE_ID_MOTORCONTROL 0x0058
#define URB_INT_SIZE 8
static unsigned long device_no;
struct motorcontrol {
struct usb_device *udev;
struct usb_interface *intf;
struct device *dev;
int dev_no;
u8 inputs[4];
s8 desired_speed[2];
s8 speed[2];
s16 _current[2];
s8 acceleration[2];
struct urb *irq;
unsigned char *data;
dma_addr_t data_dma;
struct delayed_work do_notify;
unsigned long input_events;
unsigned long speed_events;
unsigned long exceed_events;
};
static struct usb_device_id id_table[] = {
{ USB_DEVICE(USB_VENDOR_ID_GLAB, USB_DEVICE_ID_MOTORCONTROL) },
{}
};
MODULE_DEVICE_TABLE(usb, id_table);
static int set_motor(struct motorcontrol *mc, int motor)
{
u8 *buffer;
int speed, speed2, acceleration;
int retval;
buffer = kzalloc(8, GFP_KERNEL);
if (!buffer) {
dev_err(&mc->intf->dev, "%s - out of memory\n", __func__);
return -ENOMEM;
}
acceleration = mc->acceleration[motor] * 10;
/* -127 <= speed <= 127 */
speed = (mc->desired_speed[motor] * 127) / 100;
/* -0x7300 <= speed2 <= 0x7300 */
speed2 = (mc->desired_speed[motor] * 230 * 128) / 100;
buffer[0] = motor;
buffer[1] = speed;
buffer[2] = acceleration >> 8;
buffer[3] = acceleration;
buffer[4] = speed2 >> 8;
buffer[5] = speed2;
retval = usb_control_msg(mc->udev,
usb_sndctrlpipe(mc->udev, 0),
0x09, 0x21, 0x0200, 0x0000, buffer, 8, 2000);
if (retval != 8)
dev_err(&mc->intf->dev, "usb_control_msg returned %d\n",
retval);
kfree(buffer);
return retval < 0 ? retval : 0;
}
static void motorcontrol_irq(struct urb *urb)
{
struct motorcontrol *mc = urb->context;
unsigned char *buffer = mc->data;
int i, level;
int retval;
int status = urb->status;;
switch (status) {
case 0: /* success */
break;
case -ECONNRESET: /* unlink */
case -ENOENT:
case -ESHUTDOWN:
return;
/* -EPIPE: should clear the halt */
default: /* error */
goto resubmit;
}
/* digital inputs */
for (i=0; i<4; i++) {
level = (buffer[0] >> i) & 1;
if (mc->inputs[i] != level) {
mc->inputs[i] = level;
set_bit(i, &mc->input_events);
}
}
/* motor speed */
if (buffer[2] == 0) {
for (i=0; i<2; i++) {
level = ((s8)buffer[4+i]) * 100 / 127;
if (mc->speed[i] != level) {
mc->speed[i] = level;
set_bit(i, &mc->speed_events);
}
}
} else {
int index = buffer[3] & 1;
level = ((s8)buffer[4] << 8) | buffer[5];
level = level * 100 / 29440;
if (mc->speed[index] != level) {
mc->speed[index] = level;
set_bit(index, &mc->speed_events);
}
level = ((s8)buffer[6] << 8) | buffer[7];
mc->_current[index] = level * 100 / 1572;
}
if (buffer[1] & 1)
set_bit(0, &mc->exceed_events);
if (buffer[1] & 2)
set_bit(1, &mc->exceed_events);
if (mc->input_events || mc->exceed_events || mc->speed_events)
schedule_delayed_work(&mc->do_notify, 0);
resubmit:
retval = usb_submit_urb(urb, GFP_ATOMIC);
if (retval)
dev_err(&mc->intf->dev,
"can't resubmit intr, %s-%s/motorcontrol0, retval %d\n",
mc->udev->bus->bus_name,
mc->udev->devpath, retval);
}
static void do_notify(struct work_struct *work)
{
struct motorcontrol *mc =
container_of(work, struct motorcontrol, do_notify.work);
int i;
char sysfs_file[8];
for (i=0; i<4; i++) {
if (test_and_clear_bit(i, &mc->input_events)) {
sprintf(sysfs_file, "input%d", i);
sysfs_notify(&mc->dev->kobj, NULL, sysfs_file);
}
}
for (i=0; i<2; i++) {
if (test_and_clear_bit(i, &mc->speed_events)) {
sprintf(sysfs_file, "speed%d", i);
sysfs_notify(&mc->dev->kobj, NULL, sysfs_file);
}
}
for (i=0; i<2; i++) {
if (test_and_clear_bit(i, &mc->exceed_events))
dev_warn(&mc->intf->dev,
"motor #%d exceeds 1.5 Amp current limit\n", i);
}
}
#define show_set_speed(value) \
static ssize_t set_speed##value(struct device *dev, \
struct device_attribute *attr, \
const char *buf, size_t count) \
{ \
struct motorcontrol *mc = dev_get_drvdata(dev); \
int speed; \
int retval; \
\
if (sscanf(buf, "%d", &speed) < 1) \
return -EINVAL; \
\
if (speed < -100 || speed > 100) \
return -EINVAL; \
\
mc->desired_speed[value] = speed; \
\
retval = set_motor(mc, value); \
\
return retval ? retval : count; \
} \
\
static ssize_t show_speed##value(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
struct motorcontrol *mc = dev_get_drvdata(dev); \
\
return sprintf(buf, "%d\n", mc->speed[value]); \
}
#define speed_attr(value) \
__ATTR(speed##value, S_IWUGO | S_IRUGO, \
show_speed##value, set_speed##value)
show_set_speed(0);
show_set_speed(1);
#define show_set_acceleration(value) \
static ssize_t set_acceleration##value(struct device *dev, \
struct device_attribute *attr, \
const char *buf, size_t count) \
{ \
struct motorcontrol *mc = dev_get_drvdata(dev); \
int acceleration; \
int retval; \
\
if (sscanf(buf, "%d", &acceleration) < 1) \
return -EINVAL; \
\
if (acceleration < 0 || acceleration > 100) \
return -EINVAL; \
\
mc->acceleration[value] = acceleration; \
\
retval = set_motor(mc, value); \
\
return retval ? retval : count; \
} \
\
static ssize_t show_acceleration##value(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
struct motorcontrol *mc = dev_get_drvdata(dev); \
\
return sprintf(buf, "%d\n", mc->acceleration[value]); \
}
#define acceleration_attr(value) \
__ATTR(acceleration##value, S_IWUGO | S_IRUGO, \
show_acceleration##value, set_acceleration##value)
show_set_acceleration(0);
show_set_acceleration(1);
#define show_current(value) \
static ssize_t show_current##value(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
struct motorcontrol *mc = dev_get_drvdata(dev); \
\
return sprintf(buf, "%dmA\n", (int)mc->_current[value]); \
}
#define current_attr(value) \
__ATTR(current##value, S_IRUGO, show_current##value, NULL)
show_current(0);
show_current(1);
#define show_input(value) \
static ssize_t show_input##value(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
struct motorcontrol *mc = dev_get_drvdata(dev); \
\
return sprintf(buf, "%d\n", (int)mc->inputs[value]); \
}
#define input_attr(value) \
__ATTR(input##value, S_IRUGO, show_input##value, NULL)
show_input(0);
show_input(1);
show_input(2);
show_input(3);
static struct device_attribute dev_attrs[] = {
input_attr(0),
input_attr(1),
input_attr(2),
input_attr(3),
speed_attr(0),
speed_attr(1),
acceleration_attr(0),
acceleration_attr(1),
current_attr(0),
current_attr(1)
};
static int motorcontrol_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
struct usb_device *dev = interface_to_usbdev(intf);
struct usb_host_interface *interface;
struct usb_endpoint_descriptor *endpoint;
struct motorcontrol *mc;
int pipe, maxp, rc = -ENOMEM;
int bit, value, i;
interface = intf->cur_altsetting;
if (interface->desc.bNumEndpoints != 1)
return -ENODEV;
endpoint = &interface->endpoint[0].desc;
if (!usb_endpoint_dir_in(endpoint))
return -ENODEV;
/*
* bmAttributes
*/
pipe = usb_rcvintpipe(dev, endpoint->bEndpointAddress);
maxp = usb_maxpacket(dev, pipe, usb_pipeout(pipe));
mc = kzalloc(sizeof(*mc), GFP_KERNEL);
if (!mc)
goto out;
mc->dev_no = -1;
mc->data = usb_buffer_alloc(dev, URB_INT_SIZE, GFP_ATOMIC, &mc->data_dma);
if (!mc->data)
goto out;
mc->irq = usb_alloc_urb(0, GFP_KERNEL);
if (!mc->irq)
goto out;
mc->udev = usb_get_dev(dev);
mc->intf = intf;
mc->acceleration[0] = mc->acceleration[1] = 10;
INIT_DELAYED_WORK(&mc->do_notify, do_notify);
usb_fill_int_urb(mc->irq, mc->udev, pipe, mc->data,
maxp > URB_INT_SIZE ? URB_INT_SIZE : maxp,
motorcontrol_irq, mc, endpoint->bInterval);
mc->irq->transfer_dma = mc->data_dma;
mc->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
usb_set_intfdata(intf, mc);
do {
bit = find_first_zero_bit(&device_no, sizeof(device_no));
value = test_and_set_bit(bit, &device_no);
} while(value);
mc->dev_no = bit;
mc->dev = device_create_drvdata(phidget_class, &mc->udev->dev,
MKDEV(0, 0), mc,
"motorcontrol%d", mc->dev_no);
if (IS_ERR(mc->dev)) {
rc = PTR_ERR(mc->dev);
mc->dev = NULL;
goto out;
}
if (usb_submit_urb(mc->irq, GFP_KERNEL)) {
rc = -EIO;
goto out;
}
for (i=0; i<ARRAY_SIZE(dev_attrs); i++) {
rc = device_create_file(mc->dev, &dev_attrs[i]);
if (rc)
goto out2;
}
dev_info(&intf->dev, "USB PhidgetMotorControl attached\n");
return 0;
out2:
while (i-- > 0)
device_remove_file(mc->dev, &dev_attrs[i]);
out:
if (mc) {
usb_free_urb(mc->irq);
if (mc->data)
usb_buffer_free(dev, URB_INT_SIZE, mc->data, mc->data_dma);
if (mc->dev)
device_unregister(mc->dev);
if (mc->dev_no >= 0)
clear_bit(mc->dev_no, &device_no);
kfree(mc);
}
return rc;
}
static void motorcontrol_disconnect(struct usb_interface *interface)
{
struct motorcontrol *mc;
int i;
mc = usb_get_intfdata(interface);
usb_set_intfdata(interface, NULL);
if (!mc)
return;
usb_kill_urb(mc->irq);
usb_free_urb(mc->irq);
usb_buffer_free(mc->udev, URB_INT_SIZE, mc->data, mc->data_dma);
cancel_delayed_work(&mc->do_notify);
for (i=0; i<ARRAY_SIZE(dev_attrs); i++)
device_remove_file(mc->dev, &dev_attrs[i]);
device_unregister(mc->dev);
usb_put_dev(mc->udev);
clear_bit(mc->dev_no, &device_no);
kfree(mc);
dev_info(&interface->dev, "USB PhidgetMotorControl detached\n");
}
static struct usb_driver motorcontrol_driver = {
.name = "phidgetmotorcontrol",
.probe = motorcontrol_probe,
.disconnect = motorcontrol_disconnect,
.id_table = id_table
};
static int __init motorcontrol_init(void)
{
int retval = 0;
retval = usb_register(&motorcontrol_driver);
if (retval)
err("usb_register failed. Error number %d", retval);
return retval;
}
static void __exit motorcontrol_exit(void)
{
usb_deregister(&motorcontrol_driver);
}
module_init(motorcontrol_init);
module_exit(motorcontrol_exit);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");