drivers/usb/input/pid.c

   1 /*
   2  *  PID Force feedback support for hid devices.
   3  *
   4  *  Copyright (c) 2002 Rodrigo Damazio.
   5  *  Portions by Johann Deneux and Bjorn Augustson
   6  */
   7
   8 /*
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  *
  23  * Should you need to contact me, the author, you can do so by
  24  * e-mail - mail your message to <rdamazio@lsi.usp.br>
  25  */
  26
  27 #include <linux/config.h>
  28 #include <linux/module.h>
  29 #include <linux/slab.h>
  30 #include <linux/kernel.h>
  31 #include <linux/init.h>
  32 #include <linux/mm.h>
  33 #include <linux/smp_lock.h>
  34 #include <linux/spinlock.h>
  35 #include <linux/input.h>
  36 #include <linux/usb.h>
  37 #include "hid.h"
  38 #include "pid.h"
  39
  40 #define DEBUG
  41
  42 #define CHECK_OWNERSHIP(i, hid_pid)     \
  43         ((i) < FF_EFFECTS_MAX && i >= 0 && \
  44         test_bit(FF_PID_FLAGS_USED, &hid_pid->effects[(i)].flags) && \
  45         (current->pid == 0 || \
  46         (hid_pid)->effects[(i)].owner == current->pid))
  47
  48 /* Called when a transfer is completed */
  49 static void hid_pid_ctrl_out(struct urb *u, struct pt_regs *regs)
  50 {
  51     dev_dbg(&u->dev->dev, "hid_pid_ctrl_out - Transfer Completed\n");
  52 }
  53
  54 static void hid_pid_exit(struct hid_device* hid)
  55 {
  56     struct hid_ff_pid *private = hid->ff_private;
  57
  58     if (private->urbffout) {
  59         usb_unlink_urb(private->urbffout);
  60         usb_free_urb(private->urbffout);
  61     }
  62 }
  63
  64 static int pid_upload_periodic(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update) {
  65     dev_info(&pid->hid->dev->dev, "requested periodic force upload\n");
  66     return 0;
  67 }
  68
  69 static int pid_upload_constant(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update) {
  70     dev_info(&pid->hid->dev->dev, "requested constant force upload\n");
  71     return 0;
  72 }
  73
  74 static int pid_upload_condition(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update) {
  75     dev_info(&pid->hid->dev->dev, "requested Condition force upload\n");
  76     return 0;
  77 }
  78
  79 static int pid_upload_ramp(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update) {
  80     dev_info(&pid->hid->dev->dev, "request ramp force upload\n");
  81     return 0;
  82 }
  83
  84 static int hid_pid_event(struct hid_device *hid, struct input_dev *input,
  85                           unsigned int type, unsigned int code, int value)
  86 {
  87     dev_dbg(&hid->dev->dev, "PID event received: type=%d,code=%d,value=%d.\n", type, code, value);
  88
  89     if (type != EV_FF)
  90         return -1;
  91
  92
  93
  94     return 0;
  95 }
  96
  97 /* Lock must be held by caller */
  98 static void hid_pid_ctrl_playback(struct hid_device *hid,
  99                                    struct hid_pid_effect *effect, int play)
 100 {
 101         if (play) {
 102                 set_bit(FF_PID_FLAGS_PLAYING, &effect->flags);
 103
 104         } else {
 105                 clear_bit(FF_PID_FLAGS_PLAYING, &effect->flags);
 106         }
 107 }
 108
 109
 110 static int hid_pid_erase(struct input_dev *dev, int id)
 111 {
 112         struct hid_device *hid = dev->private;
 113         struct hid_field* field;
 114         struct hid_report* report;
 115         struct hid_ff_pid *pid = hid->ff_private;
 116         unsigned long flags;
 117         unsigned wanted_report = HID_UP_PID | FF_PID_USAGE_BLOCK_FREE;  /*  PID Block Free Report */
 118         int ret;
 119
 120         if (!CHECK_OWNERSHIP(id, pid))
 121                 return -EACCES;
 122
 123         /* Find report */
 124         ret =  hid_find_report_by_usage(hid, wanted_report, &report, HID_OUTPUT_REPORT);
 125         if(!ret) {
 126                 dev_err(&hid->dev->dev, "couldn't find report\n");
 127                 return ret;
 128         }
 129
 130         /* Find field */
 131         field = (struct hid_field *) kmalloc(sizeof(struct hid_field), GFP_KERNEL);
 132         if(!field) {
 133                 dev_err(&hid->dev->dev, "couldn't allocate field\n");
 134                 return -ENOMEM;
 135         }
 136
 137         ret = hid_set_field(field, ret, pid->effects[id].device_id);
 138         if(!ret) {
 139                 dev_err(&hid->dev->dev, "couldn't set field\n");
 140                 return ret;
 141         }
 142
 143         hid_submit_report(hid, report, USB_DIR_OUT);
 144
 145         spin_lock_irqsave(&pid->lock, flags);
 146         hid_pid_ctrl_playback(hid, pid->effects + id, 0);
 147         pid->effects[id].flags = 0;
 148         spin_unlock_irqrestore(&pid->lock, flags);
 149
 150         return ret;
 151 }
 152
 153 /* Erase all effects this process owns */
 154 static int hid_pid_flush(struct input_dev *dev, struct file *file)
 155 {
 156         struct hid_device *hid = dev->private;
 157         struct hid_ff_pid *pid = hid->ff_private;
 158         int i;
 159
 160         /*NOTE: no need to lock here. The only times EFFECT_USED is
 161           modified is when effects are uploaded or when an effect is
 162           erased. But a process cannot close its dev/input/eventX fd
 163           and perform ioctls on the same fd all at the same time */
 164         for (i=0; i<dev->ff_effects_max; ++i)
 165                 if ( current->pid == pid->effects[i].owner
 166                      && test_bit(FF_PID_FLAGS_USED, &pid->effects[i].flags))
 167                         if (hid_pid_erase(dev, i))
 168                                 dev_warn(&hid->dev->dev, "erase effect %d failed", i);
 169
 170         return 0;
 171 }
 172
 173
 174 static int hid_pid_upload_effect(struct input_dev *dev,
 175                                   struct ff_effect *effect)
 176 {
 177         struct hid_ff_pid* pid_private  = (struct hid_ff_pid*)(dev->private);
 178         int ret;
 179         int is_update;
 180         unsigned long flags = 0;
 181
 182         dev_dbg(&pid_private->hid->dev->dev, "upload effect called: effect_type=%x\n",effect->type);
 183         /* Check this effect type is supported by this device */
 184         if (!test_bit(effect->type, dev->ffbit)) {
 185                 dev_dbg(&pid_private->hid->dev->dev, "invalid kind of effect requested.\n");
 186                 return -EINVAL;
 187         }
 188
 189         /*
 190          * If we want to create a new effect, get a free id
 191          */
 192         if (effect->id == -1) {
 193                 int id=0;
 194
 195                 // Spinlock so we don`t get a race condition when choosing IDs
 196                 spin_lock_irqsave(&pid_private->lock, flags);
 197
 198                 while(id < FF_EFFECTS_MAX)
 199                         if (!test_and_set_bit(FF_PID_FLAGS_USED, &pid_private->effects[id++].flags))
 200                             break;
 201
 202                 if ( id == FF_EFFECTS_MAX) {
 203                         spin_unlock_irqrestore(&pid_private->lock,flags);
 204 // TEMP - We need to get ff_effects_max correctly first:  || id >= dev->ff_effects_max) {
 205                         dev_dbg(&pid_private->hid->dev->dev, "Not enough device memory\n");
 206                         return -ENOMEM;
 207                 }
 208
 209                 effect->id = id;
 210                 dev_dbg(&pid_private->hid->dev->dev, "effect ID is %d\n.",id);
 211                 pid_private->effects[id].owner = current->pid;
 212                 pid_private->effects[id].flags = (1<<FF_PID_FLAGS_USED);
 213                 spin_unlock_irqrestore(&pid_private->lock,flags);
 214
 215                 is_update = FF_PID_FALSE;
 216         }
 217         else {
 218                 /* We want to update an effect */
 219                 if (!CHECK_OWNERSHIP(effect->id, pid_private))
 220                         return -EACCES;
 221
 222                 /* Parameter type cannot be updated */
 223                 if (effect->type != pid_private->effects[effect->id].effect.type)
 224                         return -EINVAL;
 225
 226                 /* Check the effect is not already being updated */
 227                 if (test_bit(FF_PID_FLAGS_UPDATING, &pid_private->effects[effect->id].flags)) {
 228                         return -EAGAIN;
 229                 }
 230
 231                 is_update = FF_PID_TRUE;
 232         }
 233
 234         /*
 235          * Upload the effect
 236          */
 237         switch (effect->type) {
 238                 case FF_PERIODIC:
 239                         ret = pid_upload_periodic(pid_private, effect, is_update);
 240                         break;
 241
 242                 case FF_CONSTANT:
 243                         ret = pid_upload_constant(pid_private, effect, is_update);
 244                         break;
 245
 246                 case FF_SPRING:
 247                 case FF_FRICTION:
 248                 case FF_DAMPER:
 249                 case FF_INERTIA:
 250                         ret = pid_upload_condition(pid_private, effect, is_update);
 251                         break;
 252
 253                 case FF_RAMP:
 254                         ret = pid_upload_ramp(pid_private, effect, is_update);
 255                         break;
 256
 257                 default:
 258                         dev_dbg(&pid_private->hid->dev->dev, "invalid type of effect requested - %x.\n", effect->type);
 259                         return -EINVAL;
 260         }
 261         /* If a packet was sent, forbid new updates until we are notified
 262          * that the packet was updated
 263          */
 264         if (ret == 0)
 265                 set_bit(FF_PID_FLAGS_UPDATING, &pid_private->effects[effect->id].flags);
 266         pid_private->effects[effect->id].effect = *effect;
 267         return ret;
 268 }
 269
 270 int hid_pid_init(struct hid_device *hid)
 271 {
 272     struct hid_ff_pid *private;
 273     struct hid_input *hidinput = list_entry(&hid->inputs, struct hid_input, list);
 274
 275     private = hid->ff_private = kmalloc(sizeof(struct hid_ff_pid), GFP_KERNEL);
 276     if (!private) return -1;
 277
 278     memset(private,0,sizeof(struct hid_ff_pid));
 279
 280     hid->ff_private = private; /* 'cause memset can move the block away */
 281
 282     private->hid = hid;
 283
 284     hid->ff_exit = hid_pid_exit;
 285     hid->ff_event = hid_pid_event;
 286
 287     /* Open output URB */
 288     if (!(private->urbffout = usb_alloc_urb(0, GFP_KERNEL))) {
 289         kfree(private);
 290         return -1;
 291     }
 292
 293     usb_fill_control_urb(private->urbffout, hid->dev,0,(void *) &private->ffcr,private->ctrl_buffer,8,hid_pid_ctrl_out,hid);
 294     hidinput->input.upload_effect = hid_pid_upload_effect;
 295     hidinput->input.flush = hid_pid_flush;
 296     hidinput->input.ff_effects_max = 8;  // A random default
 297     set_bit(EV_FF, hidinput->input.evbit);
 298     set_bit(EV_FF_STATUS, hidinput->input.evbit);
 299
 300     spin_lock_init(&private->lock);
 301
 302     printk(KERN_INFO "Force feedback driver for PID devices by Rodrigo Damazio <rdamazio@lsi.usp.br>.\n");
 303
 304     return 0;
 305 }