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 CHECK_OWNERSHIP(i, hid_pid)     \
  41         ((i) < FF_EFFECTS_MAX && i >= 0 && \
  42         test_bit(FF_PID_FLAGS_USED, &hid_pid->effects[(i)].flags) && \
  43         (current->pid == 0 || \
  44         (hid_pid)->effects[(i)].owner == current->pid))
  45
  46 /* Called when a transfer is completed */
  47 static void hid_pid_ctrl_out(struct urb *u, struct pt_regs *regs)
  48 {
  49         dev_dbg(&u->dev->dev, "hid_pid_ctrl_out - Transfer Completed\n");
  50 }
  51
  52 static void hid_pid_exit(struct hid_device *hid)
  53 {
  54         struct hid_ff_pid *private = hid->ff_private;
  55
  56         if (private->urbffout) {
  57                 usb_kill_urb(private->urbffout);
  58                 usb_free_urb(private->urbffout);
  59         }
  60 }
  61
  62 static int pid_upload_periodic(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
  63 {
  64         dev_info(&pid->hid->dev->dev, "requested periodic force upload\n");
  65         return 0;
  66 }
  67
  68 static int pid_upload_constant(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
  69 {
  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 {
  76         dev_info(&pid->hid->dev->dev, "requested Condition force upload\n");
  77         return 0;
  78 }
  79
  80 static int pid_upload_ramp(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
  81 {
  82         dev_info(&pid->hid->dev->dev, "request ramp force upload\n");
  83         return 0;
  84 }
  85
  86 static int hid_pid_event(struct hid_device *hid, struct input_dev *input,
  87                          unsigned int type, unsigned int code, int value)
  88 {
  89         dev_dbg(&hid->dev->dev, "PID event received: type=%d,code=%d,value=%d.\n", type, code, value);
  90
  91         if (type != EV_FF)
  92                 return -1;
  93
  94         return 0;
  95 }
  96
  97 /* Lock must be held by caller */
  98 static void hid_pid_ctrl_playback(struct hid_device *hid, struct hid_pid_effect *effect, int play)
  99 {
 100         if (play)
 101                 set_bit(FF_PID_FLAGS_PLAYING, &effect->flags);
 102         else
 103                 clear_bit(FF_PID_FLAGS_PLAYING, &effect->flags);
 104 }
 105
 106 static int hid_pid_erase(struct input_dev *dev, int id)
 107 {
 108         struct hid_device *hid = dev->private;
 109         struct hid_ff_pid *pid = hid->ff_private;
 110         struct hid_field *field;
 111         unsigned long flags;
 112         int ret;
 113
 114         if (!CHECK_OWNERSHIP(id, pid))
 115                 return -EACCES;
 116
 117         /* Find report */
 118         field = hid_find_field_by_usage(hid, HID_UP_PID | FF_PID_USAGE_BLOCK_FREE,
 119                                         HID_OUTPUT_REPORT);
 120         if (!field) {
 121                 dev_err(&hid->dev->dev, "couldn't find report\n");
 122                 return -EIO;
 123         }
 124
 125         ret = hid_set_field(field, 0, pid->effects[id].device_id);
 126         if (ret) {
 127                 dev_err(&hid->dev->dev, "couldn't set field\n");
 128                 return ret;
 129         }
 130
 131         hid_submit_report(hid, field->report, USB_DIR_OUT);
 132
 133         spin_lock_irqsave(&pid->lock, flags);
 134         hid_pid_ctrl_playback(hid, pid->effects + id, 0);
 135         pid->effects[id].flags = 0;
 136         spin_unlock_irqrestore(&pid->lock, flags);
 137
 138         return 0;
 139 }
 140
 141 /* Erase all effects this process owns */
 142 static int hid_pid_flush(struct input_dev *dev, struct file *file)
 143 {
 144         struct hid_device *hid = dev->private;
 145         struct hid_ff_pid *pid = hid->ff_private;
 146         int i;
 147
 148         /*NOTE: no need to lock here. The only times EFFECT_USED is
 149            modified is when effects are uploaded or when an effect is
 150            erased. But a process cannot close its dev/input/eventX fd
 151            and perform ioctls on the same fd all at the same time */
 152         /*FIXME: multiple threads, anyone? */
 153         for (i = 0; i < dev->ff_effects_max; ++i)
 154                 if (current->pid == pid->effects[i].owner
 155                     && test_bit(FF_PID_FLAGS_USED, &pid->effects[i].flags))
 156                         if (hid_pid_erase(dev, i))
 157                                 dev_warn(&hid->dev->dev, "erase effect %d failed", i);
 158
 159         return 0;
 160 }
 161
 162 static int hid_pid_upload_effect(struct input_dev *dev,
 163                                  struct ff_effect *effect)
 164 {
 165         struct hid_ff_pid *pid_private = (struct hid_ff_pid *)(dev->private);
 166         int ret;
 167         int is_update;
 168         unsigned long flags;
 169
 170         dev_dbg(&pid_private->hid->dev->dev, "upload effect called: effect_type=%x\n", effect->type);
 171         /* Check this effect type is supported by this device */
 172         if (!test_bit(effect->type, dev->ffbit)) {
 173                 dev_dbg(&pid_private->hid->dev->dev,
 174                         "invalid kind of effect requested.\n");
 175                 return -EINVAL;
 176         }
 177
 178         /*
 179          * If we want to create a new effect, get a free id
 180          */
 181         if (effect->id == -1) {
 182                 int id = 0;
 183
 184                 // Spinlock so we don`t get a race condition when choosing IDs
 185                 spin_lock_irqsave(&pid_private->lock, flags);
 186
 187                 while (id < FF_EFFECTS_MAX)
 188                         if (!test_and_set_bit(FF_PID_FLAGS_USED, &pid_private->effects[id++].flags))
 189                                 break;
 190
 191                 if (id == FF_EFFECTS_MAX) {
 192                         spin_unlock_irqrestore(&pid_private->lock, flags);
 193 // TEMP - We need to get ff_effects_max correctly first:  || id >= dev->ff_effects_max) {
 194                         dev_dbg(&pid_private->hid->dev->dev, "Not enough device memory\n");
 195                         return -ENOMEM;
 196                 }
 197
 198                 effect->id = id;
 199                 dev_dbg(&pid_private->hid->dev->dev, "effect ID is %d.\n", id);
 200                 pid_private->effects[id].owner = current->pid;
 201                 pid_private->effects[id].flags = (1 << FF_PID_FLAGS_USED);
 202                 spin_unlock_irqrestore(&pid_private->lock, flags);
 203
 204                 is_update = FF_PID_FALSE;
 205         } else {
 206                 /* We want to update an effect */
 207                 if (!CHECK_OWNERSHIP(effect->id, pid_private))
 208                         return -EACCES;
 209
 210                 /* Parameter type cannot be updated */
 211                 if (effect->type != pid_private->effects[effect->id].effect.type)
 212                         return -EINVAL;
 213
 214                 /* Check the effect is not already being updated */
 215                 if (test_bit(FF_PID_FLAGS_UPDATING, &pid_private->effects[effect->id].flags))
 216                         return -EAGAIN;
 217
 218                 is_update = FF_PID_TRUE;
 219         }
 220
 221         /*
 222          * Upload the effect
 223          */
 224         switch (effect->type) {
 225         case FF_PERIODIC:
 226                 ret = pid_upload_periodic(pid_private, effect, is_update);
 227                 break;
 228
 229         case FF_CONSTANT:
 230                 ret = pid_upload_constant(pid_private, effect, is_update);
 231                 break;
 232
 233         case FF_SPRING:
 234         case FF_FRICTION:
 235         case FF_DAMPER:
 236         case FF_INERTIA:
 237                 ret = pid_upload_condition(pid_private, effect, is_update);
 238                 break;
 239
 240         case FF_RAMP:
 241                 ret = pid_upload_ramp(pid_private, effect, is_update);
 242                 break;
 243
 244         default:
 245                 dev_dbg(&pid_private->hid->dev->dev,
 246                         "invalid type of effect requested - %x.\n",
 247                         effect->type);
 248                 return -EINVAL;
 249         }
 250         /* If a packet was sent, forbid new updates until we are notified
 251          * that the packet was updated
 252          */
 253         if (ret == 0)
 254                 set_bit(FF_PID_FLAGS_UPDATING, &pid_private->effects[effect->id].flags);
 255         pid_private->effects[effect->id].effect = *effect;
 256         return ret;
 257 }
 258
 259 int hid_pid_init(struct hid_device *hid)
 260 {
 261         struct hid_ff_pid *private;
 262         struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
 263         struct input_dev *input_dev = hidinput->input;
 264
 265         private = hid->ff_private = kzalloc(sizeof(struct hid_ff_pid), GFP_KERNEL);
 266         if (!private)
 267                 return -ENOMEM;
 268
 269         private->hid = hid;
 270
 271         hid->ff_exit = hid_pid_exit;
 272         hid->ff_event = hid_pid_event;
 273
 274         /* Open output URB */
 275         if (!(private->urbffout = usb_alloc_urb(0, GFP_KERNEL))) {
 276                 kfree(private);
 277                 return -1;
 278         }
 279
 280         usb_fill_control_urb(private->urbffout, hid->dev, 0,
 281                              (void *)&private->ffcr, private->ctrl_buffer, 8,
 282                              hid_pid_ctrl_out, hid);
 283
 284         input_dev->upload_effect = hid_pid_upload_effect;
 285         input_dev->flush = hid_pid_flush;
 286         input_dev->ff_effects_max = 8;  // A random default
 287         set_bit(EV_FF, input_dev->evbit);
 288         set_bit(EV_FF_STATUS, input_dev->evbit);
 289
 290         spin_lock_init(&private->lock);
 291
 292         printk(KERN_INFO "Force feedback driver for PID devices by Rodrigo Damazio <rdamazio@lsi.usp.br>.\n");
 293
 294         return 0;
 295 }