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/module.h>
  28 #include <linux/slab.h>
  29 #include <linux/kernel.h>
  30 #include <linux/init.h>
  31 #include <linux/mm.h>
  32 #include <linux/smp_lock.h>
  33 #include <linux/spinlock.h>
  34 #include <linux/input.h>
  35 #include <linux/usb.h>
  36 #include "hid.h"
  37 #include "pid.h"
  38
  39 #define CHECK_OWNERSHIP(i, hid_pid)     \
  40         ((i) < FF_EFFECTS_MAX && i >= 0 && \
  41         test_bit(FF_PID_FLAGS_USED, &hid_pid->effects[(i)].flags) && \
  42         (current->pid == 0 || \
  43         (hid_pid)->effects[(i)].owner == current->pid))
  44
  45 /* Called when a transfer is completed */
  46 static void hid_pid_ctrl_out(struct urb *u, struct pt_regs *regs)
  47 {
  48         dev_dbg(&u->dev->dev, "hid_pid_ctrl_out - Transfer Completed\n");
  49 }
  50
  51 static void hid_pid_exit(struct hid_device *hid)
  52 {
  53         struct hid_ff_pid *private = hid->ff_private;
  54
  55         if (private->urbffout) {
  56                 usb_kill_urb(private->urbffout);
  57                 usb_free_urb(private->urbffout);
  58         }
  59 }
  60
  61 static int pid_upload_periodic(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
  62 {
  63         dev_info(&pid->hid->dev->dev, "requested periodic force upload\n");
  64         return 0;
  65 }
  66
  67 static int pid_upload_constant(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
  68 {
  69         dev_info(&pid->hid->dev->dev, "requested constant force upload\n");
  70         return 0;
  71 }
  72
  73 static int pid_upload_condition(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
  74 {
  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 {
  81         dev_info(&pid->hid->dev->dev, "request ramp force upload\n");
  82         return 0;
  83 }
  84
  85 static int hid_pid_event(struct hid_device *hid, struct input_dev *input,
  86                          unsigned int type, unsigned int code, int value)
  87 {
  88         dev_dbg(&hid->dev->dev, "PID event received: type=%d,code=%d,value=%d.\n", type, code, value);
  89
  90         if (type != EV_FF)
  91                 return -1;
  92
  93         return 0;
  94 }
  95
  96 /* Lock must be held by caller */
  97 static void hid_pid_ctrl_playback(struct hid_device *hid, struct hid_pid_effect *effect, int play)
  98 {
  99         if (play)
 100                 set_bit(FF_PID_FLAGS_PLAYING, &effect->flags);
 101         else
 102                 clear_bit(FF_PID_FLAGS_PLAYING, &effect->flags);
 103 }
 104
 105 static int hid_pid_erase(struct input_dev *dev, int id)
 106 {
 107         struct hid_device *hid = dev->private;
 108         struct hid_ff_pid *pid = hid->ff_private;
 109         struct hid_field *field;
 110         unsigned long flags;
 111         int ret;
 112
 113         if (!CHECK_OWNERSHIP(id, pid))
 114                 return -EACCES;
 115
 116         /* Find report */
 117         field = hid_find_field_by_usage(hid, HID_UP_PID | FF_PID_USAGE_BLOCK_FREE,
 118                                         HID_OUTPUT_REPORT);
 119         if (!field) {
 120                 dev_err(&hid->dev->dev, "couldn't find report\n");
 121                 return -EIO;
 122         }
 123
 124         ret = hid_set_field(field, 0, pid->effects[id].device_id);
 125         if (ret) {
 126                 dev_err(&hid->dev->dev, "couldn't set field\n");
 127                 return ret;
 128         }
 129
 130         hid_submit_report(hid, field->report, USB_DIR_OUT);
 131
 132         spin_lock_irqsave(&pid->lock, flags);
 133         hid_pid_ctrl_playback(hid, pid->effects + id, 0);
 134         pid->effects[id].flags = 0;
 135         spin_unlock_irqrestore(&pid->lock, flags);
 136
 137         return 0;
 138 }
 139
 140 /* Erase all effects this process owns */
 141 static int hid_pid_flush(struct input_dev *dev, struct file *file)
 142 {
 143         struct hid_device *hid = dev->private;
 144         struct hid_ff_pid *pid = hid->ff_private;
 145         int i;
 146
 147         /*NOTE: no need to lock here. The only times EFFECT_USED is
 148            modified is when effects are uploaded or when an effect is
 149            erased. But a process cannot close its dev/input/eventX fd
 150            and perform ioctls on the same fd all at the same time */
 151         /*FIXME: multiple threads, anyone? */
 152         for (i = 0; i < dev->ff_effects_max; ++i)
 153                 if (current->pid == pid->effects[i].owner
 154                     && test_bit(FF_PID_FLAGS_USED, &pid->effects[i].flags))
 155                         if (hid_pid_erase(dev, i))
 156                                 dev_warn(&hid->dev->dev, "erase effect %d failed", i);
 157
 158         return 0;
 159 }
 160
 161 static int hid_pid_upload_effect(struct input_dev *dev,
 162                                  struct ff_effect *effect)
 163 {
 164         struct hid_ff_pid *pid_private = (struct hid_ff_pid *)(dev->private);
 165         int ret;
 166         int is_update;
 167         unsigned long flags;
 168
 169         dev_dbg(&pid_private->hid->dev->dev, "upload effect called: effect_type=%x\n", effect->type);
 170         /* Check this effect type is supported by this device */
 171         if (!test_bit(effect->type, dev->ffbit)) {
 172                 dev_dbg(&pid_private->hid->dev->dev,
 173                         "invalid kind of effect requested.\n");
 174                 return -EINVAL;
 175         }
 176
 177         /*
 178          * If we want to create a new effect, get a free id
 179          */
 180         if (effect->id == -1) {
 181                 int id = 0;
 182
 183                 // Spinlock so we don`t get a race condition when choosing IDs
 184                 spin_lock_irqsave(&pid_private->lock, flags);
 185
 186                 while (id < FF_EFFECTS_MAX)
 187                         if (!test_and_set_bit(FF_PID_FLAGS_USED, &pid_private->effects[id++].flags))
 188                                 break;
 189
 190                 if (id == FF_EFFECTS_MAX) {
 191                         spin_unlock_irqrestore(&pid_private->lock, flags);
 192 // TEMP - We need to get ff_effects_max correctly first:  || id >= dev->ff_effects_max) {
 193                         dev_dbg(&pid_private->hid->dev->dev, "Not enough device memory\n");
 194                         return -ENOMEM;
 195                 }
 196
 197                 effect->id = id;
 198                 dev_dbg(&pid_private->hid->dev->dev, "effect ID is %d.\n", id);
 199                 pid_private->effects[id].owner = current->pid;
 200                 pid_private->effects[id].flags = (1 << FF_PID_FLAGS_USED);
 201                 spin_unlock_irqrestore(&pid_private->lock, flags);
 202
 203                 is_update = FF_PID_FALSE;
 204         } else {
 205                 /* We want to update an effect */
 206                 if (!CHECK_OWNERSHIP(effect->id, pid_private))
 207                         return -EACCES;
 208
 209                 /* Parameter type cannot be updated */
 210                 if (effect->type != pid_private->effects[effect->id].effect.type)
 211                         return -EINVAL;
 212
 213                 /* Check the effect is not already being updated */
 214                 if (test_bit(FF_PID_FLAGS_UPDATING, &pid_private->effects[effect->id].flags))
 215                         return -EAGAIN;
 216
 217                 is_update = FF_PID_TRUE;
 218         }
 219
 220         /*
 221          * Upload the effect
 222          */
 223         switch (effect->type) {
 224         case FF_PERIODIC:
 225                 ret = pid_upload_periodic(pid_private, effect, is_update);
 226                 break;
 227
 228         case FF_CONSTANT:
 229                 ret = pid_upload_constant(pid_private, effect, is_update);
 230                 break;
 231
 232         case FF_SPRING:
 233         case FF_FRICTION:
 234         case FF_DAMPER:
 235         case FF_INERTIA:
 236                 ret = pid_upload_condition(pid_private, effect, is_update);
 237                 break;
 238
 239         case FF_RAMP:
 240                 ret = pid_upload_ramp(pid_private, effect, is_update);
 241                 break;
 242
 243         default:
 244                 dev_dbg(&pid_private->hid->dev->dev,
 245                         "invalid type of effect requested - %x.\n",
 246                         effect->type);
 247                 return -EINVAL;
 248         }
 249         /* If a packet was sent, forbid new updates until we are notified
 250          * that the packet was updated
 251          */
 252         if (ret == 0)
 253                 set_bit(FF_PID_FLAGS_UPDATING, &pid_private->effects[effect->id].flags);
 254         pid_private->effects[effect->id].effect = *effect;
 255         return ret;
 256 }
 257
 258 int hid_pid_init(struct hid_device *hid)
 259 {
 260         struct hid_ff_pid *private;
 261         struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
 262         struct input_dev *input_dev = hidinput->input;
 263
 264         private = hid->ff_private = kzalloc(sizeof(struct hid_ff_pid), GFP_KERNEL);
 265         if (!private)
 266                 return -ENOMEM;
 267
 268         private->hid = hid;
 269
 270         hid->ff_exit = hid_pid_exit;
 271         hid->ff_event = hid_pid_event;
 272
 273         /* Open output URB */
 274         if (!(private->urbffout = usb_alloc_urb(0, GFP_KERNEL))) {
 275                 kfree(private);
 276                 return -1;
 277         }
 278
 279         usb_fill_control_urb(private->urbffout, hid->dev, 0,
 280                              (void *)&private->ffcr, private->ctrl_buffer, 8,
 281                              hid_pid_ctrl_out, hid);
 282
 283         input_dev->upload_effect = hid_pid_upload_effect;
 284         input_dev->flush = hid_pid_flush;
 285         input_dev->ff_effects_max = 8;  // A random default
 286         set_bit(EV_FF, input_dev->evbit);
 287         set_bit(EV_FF_STATUS, input_dev->evbit);
 288
 289         spin_lock_init(&private->lock);
 290
 291         printk(KERN_INFO "Force feedback driver for PID devices by Rodrigo Damazio <rdamazio@lsi.usp.br>.\n");
 292
 293         return 0;
 294 }