linux/drivers/usb/misc/phidgetmotorcontrol.c

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/*
* 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", __FUNCTION__);
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;
}
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 13:55:46 +00:00
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(phidget_class, &mc->udev->dev, 0,
"motorcontrol%d", mc->dev_no);
if (IS_ERR(mc->dev)) {
rc = PTR_ERR(mc->dev);
mc->dev = NULL;
goto out;
}
dev_set_drvdata(mc->dev, mc);
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");