/*
* PID Force feedback support for hid devices.
*
* Copyright (c) 2002 Rodrigo Damazio.
* Portions by Johann Deneux and Bjorn Augustson
*/
/*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Should you need to contact me, the author, you can do so by
* e-mail - mail your message to <rdamazio@lsi.usp.br>
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <linux/input.h>
#include <linux/usb.h>
#include "hid.h"
#include "pid.h"
#define DEBUG
#define CHECK_OWNERSHIP(i, hid_pid) \
((i) < FF_EFFECTS_MAX && i >= 0 && \
test_bit(FF_PID_FLAGS_USED, &hid_pid->effects[(i)].flags) && \
(current->pid == 0 || \
(hid_pid)->effects[(i)].owner == current->pid))
/* Called when a transfer is completed */
static void hid_pid_ctrl_out(struct urb *u, struct pt_regs *regs)
{
dev_dbg(&u->dev->dev, "hid_pid_ctrl_out - Transfer Completed\n");
}
static void hid_pid_exit(struct hid_device *hid)
{
struct hid_ff_pid *private = hid->ff_private;
if (private->urbffout) {
usb_kill_urb(private->urbffout);
usb_free_urb(private->urbffout);
}
}
static int pid_upload_periodic(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
{
dev_info(&pid->hid->dev->dev, "requested periodic force upload\n");
return 0;
}
static int pid_upload_constant(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
{
dev_info(&pid->hid->dev->dev, "requested constant force upload\n");
return 0;
}
static int pid_upload_condition(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
{
dev_info(&pid->hid->dev->dev, "requested Condition force upload\n");
return 0;
}
static int pid_upload_ramp(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
{
dev_info(&pid->hid->dev->dev, "request ramp force upload\n");
return 0;
}
static int hid_pid_event(struct hid_device *hid, struct input_dev *input,
unsigned int type, unsigned int code, int value)
{
dev_dbg(&hid->dev->dev, "PID event received: type=%d,code=%d,value=%d.\n", type, code, value);
if (type != EV_FF)
return -1;
return 0;
}
/* Lock must be held by caller */
static void hid_pid_ctrl_playback(struct hid_device *hid, struct hid_pid_effect *effect, int play)
{
if (play)
set_bit(FF_PID_FLAGS_PLAYING, &effect->flags);
else
clear_bit(FF_PID_FLAGS_PLAYING, &effect->flags);
}
static int hid_pid_erase(struct input_dev *dev, int id)
{
struct hid_device *hid = dev->private;
struct hid_ff_pid *pid = hid->ff_private;
struct hid_field *field;
unsigned long flags;
int ret;
if (!CHECK_OWNERSHIP(id, pid))
return -EACCES;
/* Find report */
field = hid_find_field_by_usage(hid, HID_UP_PID | FF_PID_USAGE_BLOCK_FREE,
HID_OUTPUT_REPORT);
if (!field) {
dev_err(&hid->dev->dev, "couldn't find report\n");
return -EIO;
}
ret = hid_set_field(field, 0, pid->effects[id].device_id);
if (ret) {
dev_err(&hid->dev->dev, "couldn't set field\n");
return ret;
}
hid_submit_report(hid, field->report, USB_DIR_OUT);
spin_lock_irqsave(&pid->lock, flags);
hid_pid_ctrl_playback(hid, pid->effects + id, 0);
pid->effects[id].flags = 0;
spin_unlock_irqrestore(&pid->lock, flags);
return 0;
}
/* Erase all effects this process owns */
static int hid_pid_flush(struct input_dev *dev, struct file *file)
{
struct hid_device *hid = dev->private;
struct hid_ff_pid *pid = hid->ff_private;
int i;
/*NOTE: no need to lock here. The only times EFFECT_USED is
modified is when effects are uploaded or when an effect is
erased. But a process cannot close its dev/input/eventX fd
and perform ioctls on the same fd all at the same time */
/*FIXME: multiple threads, anyone? */
for (i = 0; i < dev->ff_effects_max; ++i)
if (current->pid == pid->effects[i].owner
&& test_bit(FF_PID_FLAGS_USED, &pid->effects[i].flags))
if (hid_pid_erase(dev, i))
dev_warn(&hid->dev->dev, "erase effect %d failed", i);
return 0;
}
static int hid_pid_upload_effect(struct input_dev *dev,
struct ff_effect *effect)
{
struct hid_ff_pid *pid_private = (struct hid_ff_pid *)(dev->private);
int ret;
int is_update;
unsigned long flags;
dev_dbg(&pid_private->hid->dev->dev, "upload effect called: effect_type=%x\n", effect->type);
/* Check this effect type is supported by this device */
if (!test_bit(effect->type, dev->ffbit)) {
dev_dbg(&pid_private->hid->dev->dev,
"invalid kind of effect requested.\n");
return -EINVAL;
}
/*
* If we want to create a new effect, get a free id
*/
if (effect->id == -1) {
int id = 0;
// Spinlock so we don`t get a race condition when choosing IDs
spin_lock_irqsave(&pid_private->lock, flags);
while (id < FF_EFFECTS_MAX)
if (!test_and_set_bit(FF_PID_FLAGS_USED, &pid_private->effects[id++].flags))
break;
if (id == FF_EFFECTS_MAX) {
spin_unlock_irqrestore(&pid_private->lock, flags);
// TEMP - We need to get ff_effects_max correctly first: || id >= dev->ff_effects_max) {
dev_dbg(&pid_private->hid->dev->dev, "Not enough device memory\n");
return -ENOMEM;
}
effect->id = id;
dev_dbg(&pid_private->hid->dev->dev, "effect ID is %d\n.", id);
pid_private->effects[id].owner = current->pid;
pid_private->effects[id].flags = (1 << FF_PID_FLAGS_USED);
spin_unlock_irqrestore(&pid_private->lock, flags);
is_update = FF_PID_FALSE;
} else {
/* We want to update an effect */
if (!CHECK_OWNERSHIP(effect->id, pid_private))
return -EACCES;
/* Parameter type cannot be updated */
if (effect->type != pid_private->effects[effect->id].effect.type)
return -EINVAL;
/* Check the effect is not already being updated */
if (test_bit(FF_PID_FLAGS_UPDATING, &pid_private->effects[effect->id].flags))
return -EAGAIN;
is_update = FF_PID_TRUE;
}
/*
* Upload the effect
*/
switch (effect->type) {
case FF_PERIODIC:
ret = pid_upload_periodic(pid_private, effect, is_update);
break;
case FF_CONSTANT:
ret = pid_upload_constant(pid_private, effect, is_update);
break;
case FF_SPRING:
case FF_FRICTION:
case FF_DAMPER:
case FF_INERTIA:
ret = pid_upload_condition(pid_private, effect, is_update);
break;
case FF_RAMP:
ret = pid_upload_ramp(pid_private, effect, is_update);
break;
default:
dev_dbg(&pid_private->hid->dev->dev,
"invalid type of effect requested - %x.\n",
effect->type);
return -EINVAL;
}
/* If a packet was sent, forbid new updates until we are notified
* that the packet was updated
*/
if (ret == 0)
set_bit(FF_PID_FLAGS_UPDATING, &pid_private->effects[effect->id].flags);
pid_private->effects[effect->id].effect = *effect;
return ret;
}
int hid_pid_init(struct hid_device *hid)
{
struct hid_ff_pid *private;
struct hid_input *hidinput = list_entry(&hid->inputs, struct hid_input, list);
struct input_dev *input_dev = hidinput->input;
private = hid->ff_private = kzalloc(sizeof(struct hid_ff_pid), GFP_KERNEL);
if (!private)
return -ENOMEM;
private->hid = hid;
hid->ff_exit = hid_pid_exit;
hid->ff_event = hid_pid_event;
/* Open output URB */
if (!(private->urbffout = usb_alloc_urb(0, GFP_KERNEL))) {
kfree(private);
return -1;
}
usb_fill_control_urb(private->urbffout, hid->dev, 0,
(void *)&private->ffcr, private->ctrl_buffer, 8,
hid_pid_ctrl_out, hid);
input_dev->upload_effect = hid_pid_upload_effect;
input_dev->flush = hid_pid_flush;
input_dev->ff_effects_max = 8; // A random default
set_bit(EV_FF, input_dev->evbit);
set_bit(EV_FF_STATUS, input_dev->evbit);
spin_lock_init(&private->lock);
printk(KERN_INFO "Force feedback driver for PID devices by Rodrigo Damazio <rdamazio@lsi.usp.br>.\n");
return 0;
}
