/* *  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_unlink_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_field* field;	struct hid_report* report;	struct hid_ff_pid *pid = hid->ff_private;	unsigned long flags;	unsigned wanted_report = HID_UP_PID | FF_PID_USAGE_BLOCK_FREE;  /*  PID Block Free Report */	int ret;	if (!CHECK_OWNERSHIP(id, pid))		return -EACCES;	/* Find report */	ret =  hid_find_report_by_usage(hid, wanted_report, &report, HID_OUTPUT_REPORT);	if(!ret) {		dev_err(&hid->dev->dev, "couldn't find report\n");		return ret;	}	/* Find field */	field = (struct hid_field *) kmalloc(sizeof(struct hid_field), GFP_KERNEL);	if(!field) {		dev_err(&hid->dev->dev, "couldn't allocate field\n");		return -ENOMEM;	}	ret = hid_set_field(field, ret, pid->effects[id].device_id);	if(!ret) {		dev_err(&hid->dev->dev, "couldn't set field\n");		return ret;	}	hid_submit_report(hid, 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 ret;}/* 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 */	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 = 0;        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);    private = hid->ff_private = kmalloc(sizeof(struct hid_ff_pid), GFP_KERNEL);    if (!private) return -1;        memset(private,0,sizeof(struct hid_ff_pid));    hid->ff_private = private; /* 'cause memset can move the block away */    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);    hidinput->input.upload_effect = hid_pid_upload_effect;    hidinput->input.flush = hid_pid_flush;    hidinput->input.ff_effects_max = 8;  // A random default    set_bit(EV_FF, hidinput->input.evbit);    set_bit(EV_FF_STATUS, hidinput->input.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;    }