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_kill_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 {
  66         dev_info(&pid->hid->dev->dev, "requested periodic force upload\n");
  67         return 0;
  68 }
  69
  70 static int pid_upload_constant(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
  71 {
  72         dev_info(&pid->hid->dev->dev, "requested constant force upload\n");
  73         return 0;
  74 }
  75
  76 static int pid_upload_condition(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
  77 {
  78         dev_info(&pid->hid->dev->dev, "requested Condition force upload\n");
  79         return 0;
  80 }
  81
  82 static int pid_upload_ramp(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
  83 {
  84         dev_info(&pid->hid->dev->dev, "request ramp force upload\n");
  85         return 0;
  86 }
  87
  88 static int hid_pid_event(struct hid_device *hid, struct input_dev *input,
  89                          unsigned int type, unsigned int code, int value)
  90 {
  91         dev_dbg(&hid->dev->dev, "PID event received: type=%d,code=%d,value=%d.\n", type, code, value);
  92
  93         if (type != EV_FF)
  94                 return -1;
  95
  96         return 0;
  97 }
  98
  99 /* Lock must be held by caller */
 100 static void hid_pid_ctrl_playback(struct hid_device *hid, struct hid_pid_effect *effect, int play)
 101 {
 102         if (play)
 103                 set_bit(FF_PID_FLAGS_PLAYING, &effect->flags);
 104         else
 105                 clear_bit(FF_PID_FLAGS_PLAYING, &effect->flags);
 106 }
 107
 108 static int hid_pid_erase(struct input_dev *dev, int id)
 109 {
 110         struct hid_device *hid = dev->private;
 111         struct hid_ff_pid *pid = hid->ff_private;
 112         struct hid_field *field;
 113         unsigned long flags;
 114         int ret;
 115
 116         if (!CHECK_OWNERSHIP(id, pid))
 117                 return -EACCES;
 118
 119         /* Find report */
 120         field = hid_find_field_by_usage(hid, HID_UP_PID | FF_PID_USAGE_BLOCK_FREE,
 121                                         HID_OUTPUT_REPORT);
 122         if (!field) {
 123                 dev_err(&hid->dev->dev, "couldn't find report\n");
 124                 return -EIO;
 125         }
 126
 127         ret = hid_set_field(field, 0, pid->effects[id].device_id);
 128         if (ret) {
 129                 dev_err(&hid->dev->dev, "couldn't set field\n");
 130                 return ret;
 131         }
 132
 133         hid_submit_report(hid, field->report, USB_DIR_OUT);
 134
 135         spin_lock_irqsave(&pid->lock, flags);
 136         hid_pid_ctrl_playback(hid, pid->effects + id, 0);
 137         pid->effects[id].flags = 0;
 138         spin_unlock_irqrestore(&pid->lock, flags);
 139
 140         return 0;
 141 }
 142
 143 /* Erase all effects this process owns */
 144 static int hid_pid_flush(struct input_dev *dev, struct file *file)
 145 {
 146         struct hid_device *hid = dev->private;
 147         struct hid_ff_pid *pid = hid->ff_private;
 148         int i;
 149
 150         /*NOTE: no need to lock here. The only times EFFECT_USED is
 151            modified is when effects are uploaded or when an effect is
 152            erased. But a process cannot close its dev/input/eventX fd
 153            and perform ioctls on the same fd all at the same time */
 154         /*FIXME: multiple threads, anyone? */
 155         for (i = 0; i < dev->ff_effects_max; ++i)
 156                 if (current->pid == pid->effects[i].owner
 157                     && test_bit(FF_PID_FLAGS_USED, &pid->effects[i].flags))
 158                         if (hid_pid_erase(dev, i))
 159                                 dev_warn(&hid->dev->dev, "erase effect %d failed", i);
 160
 161         return 0;
 162 }
 163
 164 static int hid_pid_upload_effect(struct input_dev *dev,
 165                                  struct ff_effect *effect)
 166 {
 167         struct hid_ff_pid *pid_private = (struct hid_ff_pid *)(dev->private);
 168         int ret;
 169         int is_update;
 170         unsigned long flags;
 171
 172         dev_dbg(&pid_private->hid->dev->dev, "upload effect called: effect_type=%x\n", effect->type);
 173         /* Check this effect type is supported by this device */
 174         if (!test_bit(effect->type, dev->ffbit)) {
 175                 dev_dbg(&pid_private->hid->dev->dev,
 176                         "invalid kind of effect requested.\n");
 177                 return -EINVAL;
 178         }
 179
 180         /*
 181          * If we want to create a new effect, get a free id
 182          */
 183         if (effect->id == -1) {
 184                 int id = 0;
 185
 186                 // Spinlock so we don`t get a race condition when choosing IDs
 187                 spin_lock_irqsave(&pid_private->lock, flags);
 188
 189                 while (id < FF_EFFECTS_MAX)
 190                         if (!test_and_set_bit(FF_PID_FLAGS_USED, &pid_private->effects[id++].flags))
 191                                 break;
 192
 193                 if (id == FF_EFFECTS_MAX) {
 194                         spin_unlock_irqrestore(&pid_private->lock, flags);
 195 // TEMP - We need to get ff_effects_max correctly first:  || id >= dev->ff_effects_max) {
 196                         dev_dbg(&pid_private->hid->dev->dev, "Not enough device memory\n");
 197                         return -ENOMEM;
 198                 }
 199
 200                 effect->id = id;
 201                 dev_dbg(&pid_private->hid->dev->dev, "effect ID is %d\n.", id);
 202                 pid_private->effects[id].owner = current->pid;
 203                 pid_private->effects[id].flags = (1 << FF_PID_FLAGS_USED);
 204                 spin_unlock_irqrestore(&pid_private->lock, flags);
 205
 206                 is_update = FF_PID_FALSE;
 207         } else {
 208                 /* We want to update an effect */
 209                 if (!CHECK_OWNERSHIP(effect->id, pid_private))
 210                         return -EACCES;
 211
 212                 /* Parameter type cannot be updated */
 213                 if (effect->type != pid_private->effects[effect->id].effect.type)
 214                         return -EINVAL;
 215
 216                 /* Check the effect is not already being updated */
 217                 if (test_bit(FF_PID_FLAGS_UPDATING, &pid_private->effects[effect->id].flags))
 218                         return -EAGAIN;
 219
 220                 is_update = FF_PID_TRUE;
 221         }
 222
 223         /*
 224          * Upload the effect
 225          */
 226         switch (effect->type) {
 227         case FF_PERIODIC:
 228                 ret = pid_upload_periodic(pid_private, effect, is_update);
 229                 break;
 230
 231         case FF_CONSTANT:
 232                 ret = pid_upload_constant(pid_private, effect, is_update);
 233                 break;
 234
 235         case FF_SPRING:
 236         case FF_FRICTION:
 237         case FF_DAMPER:
 238         case FF_INERTIA:
 239                 ret = pid_upload_condition(pid_private, effect, is_update);
 240                 break;
 241
 242         case FF_RAMP:
 243                 ret = pid_upload_ramp(pid_private, effect, is_update);
 244                 break;
 245
 246         default:
 247                 dev_dbg(&pid_private->hid->dev->dev,
 248                         "invalid type of effect requested - %x.\n",
 249                         effect->type);
 250                 return -EINVAL;
 251         }
 252         /* If a packet was sent, forbid new updates until we are notified
 253          * that the packet was updated
 254          */
 255         if (ret == 0)
 256                 set_bit(FF_PID_FLAGS_UPDATING, &pid_private->effects[effect->id].flags);
 257         pid_private->effects[effect->id].effect = *effect;
 258         return ret;
 259 }
 260
 261 int hid_pid_init(struct hid_device *hid)
 262 {
 263         struct hid_ff_pid *private;
 264         struct hid_input *hidinput = list_entry(&hid->inputs, struct hid_input, list);
 265
 266         private = hid->ff_private = kcalloc(1, sizeof(struct hid_ff_pid), GFP_KERNEL);
 267         if (!private)
 268                 return -ENOMEM;
 269
 270         private->hid = hid;
 271
 272         hid->ff_exit = hid_pid_exit;
 273         hid->ff_event = hid_pid_event;
 274
 275         /* Open output URB */
 276         if (!(private->urbffout = usb_alloc_urb(0, GFP_KERNEL))) {
 277                 kfree(private);
 278                 return -1;
 279         }
 280
 281         usb_fill_control_urb(private->urbffout, hid->dev, 0,
 282                              (void *)&private->ffcr, private->ctrl_buffer, 8,
 283                              hid_pid_ctrl_out, hid);
 284         hidinput->input.upload_effect = hid_pid_upload_effect;
 285         hidinput->input.flush = hid_pid_flush;
 286         hidinput->input.ff_effects_max = 8;     // A random default
 287         set_bit(EV_FF, hidinput->input.evbit);
 288         set_bit(EV_FF_STATUS, hidinput->input.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 }