drivers/hid/hid-3m-pct.c

   1 /*
   2  *  HID driver for 3M PCT multitouch panels
   3  *
   4  *  Copyright (c) 2009-2010 Stephane Chatty <chatty@enac.fr>
   5  *  Copyright (c) 2010      Henrik Rydberg <rydberg@euromail.se>
   6  *  Copyright (c) 2010      Canonical, Ltd.
   7  *
   8  */
   9
  10 /*
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU General Public License as published by the Free
  13  * Software Foundation; either version 2 of the License, or (at your option)
  14  * any later version.
  15  */
  16
  17 #include <linux/device.h>
  18 #include <linux/hid.h>
  19 #include <linux/module.h>
  20 #include <linux/slab.h>
  21 #include <linux/usb.h>
  22
  23 MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
  24 MODULE_DESCRIPTION("3M PCT multitouch panels");
  25 MODULE_LICENSE("GPL");
  26
  27 #include "hid-ids.h"
  28
  29 #define MAX_SLOTS               60
  30 #define MAX_TRKID               USHRT_MAX
  31 #define MAX_EVENTS              360
  32
  33 /* estimated signal-to-noise ratios */
  34 #define SN_MOVE                 2048
  35 #define SN_WIDTH                128
  36
  37 struct mmm_finger {
  38         __s32 x, y, w, h;
  39         __u16 id;
  40         bool prev_touch;
  41         bool touch, valid;
  42 };
  43
  44 struct mmm_data {
  45         struct mmm_finger f[MAX_SLOTS];
  46         __u16 id;
  47         __u8 curid;
  48         __u8 nexp, nreal;
  49         bool touch, valid;
  50 };
  51
  52 static int mmm_input_mapping(struct hid_device *hdev, struct hid_input *hi,
  53                 struct hid_field *field, struct hid_usage *usage,
  54                 unsigned long **bit, int *max)
  55 {
  56         int f1 = field->logical_minimum;
  57         int f2 = field->logical_maximum;
  58         int df = f2 - f1;
  59
  60         switch (usage->hid & HID_USAGE_PAGE) {
  61
  62         case HID_UP_BUTTON:
  63                 return -1;
  64
  65         case HID_UP_GENDESK:
  66                 switch (usage->hid) {
  67                 case HID_GD_X:
  68                         hid_map_usage(hi, usage, bit, max,
  69                                         EV_ABS, ABS_MT_POSITION_X);
  70                         input_set_abs_params(hi->input, ABS_MT_POSITION_X,
  71                                              f1, f2, df / SN_MOVE, 0);
  72                         /* touchscreen emulation */
  73                         input_set_abs_params(hi->input, ABS_X,
  74                                              f1, f2, df / SN_MOVE, 0);
  75                         return 1;
  76                 case HID_GD_Y:
  77                         hid_map_usage(hi, usage, bit, max,
  78                                         EV_ABS, ABS_MT_POSITION_Y);
  79                         input_set_abs_params(hi->input, ABS_MT_POSITION_Y,
  80                                              f1, f2, df / SN_MOVE, 0);
  81                         /* touchscreen emulation */
  82                         input_set_abs_params(hi->input, ABS_Y,
  83                                              f1, f2, df / SN_MOVE, 0);
  84                         return 1;
  85                 }
  86                 return 0;
  87
  88         case HID_UP_DIGITIZER:
  89                 switch (usage->hid) {
  90                 /* we do not want to map these: no input-oriented meaning */
  91                 case 0x14:
  92                 case 0x23:
  93                 case HID_DG_INPUTMODE:
  94                 case HID_DG_DEVICEINDEX:
  95                 case HID_DG_CONTACTCOUNT:
  96                 case HID_DG_CONTACTMAX:
  97                 case HID_DG_INRANGE:
  98                 case HID_DG_CONFIDENCE:
  99                         return -1;
 100                 case HID_DG_TIPSWITCH:
 101                         /* touchscreen emulation */
 102                         hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
 103                         input_set_capability(hi->input, EV_KEY, BTN_TOUCH);
 104                         return 1;
 105                 case HID_DG_WIDTH:
 106                         hid_map_usage(hi, usage, bit, max,
 107                                         EV_ABS, ABS_MT_TOUCH_MAJOR);
 108                         input_set_abs_params(hi->input, ABS_MT_TOUCH_MAJOR,
 109                                              f1, f2, df / SN_WIDTH, 0);
 110                         return 1;
 111                 case HID_DG_HEIGHT:
 112                         hid_map_usage(hi, usage, bit, max,
 113                                         EV_ABS, ABS_MT_TOUCH_MINOR);
 114                         input_set_abs_params(hi->input, ABS_MT_TOUCH_MINOR,
 115                                              f1, f2, df / SN_WIDTH, 0);
 116                         input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
 117                                         0, 1, 0, 0);
 118                         return 1;
 119                 case HID_DG_CONTACTID:
 120                         field->logical_maximum = MAX_TRKID;
 121                         hid_map_usage(hi, usage, bit, max,
 122                                         EV_ABS, ABS_MT_TRACKING_ID);
 123                         input_set_abs_params(hi->input, ABS_MT_TRACKING_ID,
 124                                              0, MAX_TRKID, 0, 0);
 125                         if (!hi->input->mt)
 126                                 input_mt_create_slots(hi->input, MAX_SLOTS);
 127                         input_set_events_per_packet(hi->input, MAX_EVENTS);
 128                         return 1;
 129                 }
 130                 /* let hid-input decide for the others */
 131                 return 0;
 132
 133         case 0xff000000:
 134                 /* we do not want to map these: no input-oriented meaning */
 135                 return -1;
 136         }
 137
 138         return 0;
 139 }
 140
 141 static int mmm_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 142                 struct hid_field *field, struct hid_usage *usage,
 143                 unsigned long **bit, int *max)
 144 {
 145         /* tell hid-input to skip setup of these event types */
 146         if (usage->type == EV_KEY || usage->type == EV_ABS)
 147                 set_bit(usage->type, hi->input->evbit);
 148         return -1;
 149 }
 150
 151 /*
 152  * this function is called when a whole packet has been received and processed,
 153  * so that it can decide what to send to the input layer.
 154  */
 155 static void mmm_filter_event(struct mmm_data *md, struct input_dev *input)
 156 {
 157         struct mmm_finger *oldest = 0;
 158         int i;
 159         for (i = 0; i < MAX_SLOTS; ++i) {
 160                 struct mmm_finger *f = &md->f[i];
 161                 if (!f->valid) {
 162                         /* this finger is just placeholder data, ignore */
 163                         continue;
 164                 }
 165                 input_mt_slot(input, i);
 166                 if (f->touch) {
 167                         /* this finger is on the screen */
 168                         int wide = (f->w > f->h);
 169                         /* divided by two to match visual scale of touch */
 170                         int major = max(f->w, f->h) >> 1;
 171                         int minor = min(f->w, f->h) >> 1;
 172
 173                         if (!f->prev_touch)
 174                                 f->id = md->id++;
 175                         input_event(input, EV_ABS, ABS_MT_TRACKING_ID, f->id);
 176                         input_event(input, EV_ABS, ABS_MT_POSITION_X, f->x);
 177                         input_event(input, EV_ABS, ABS_MT_POSITION_Y, f->y);
 178                         input_event(input, EV_ABS, ABS_MT_ORIENTATION, wide);
 179                         input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, major);
 180                         input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, minor);
 181                         /* touchscreen emulation: pick the oldest contact */
 182                         if (!oldest || ((f->id - oldest->id) & (SHRT_MAX + 1)))
 183                                 oldest = f;
 184                 } else {
 185                         /* this finger took off the screen */
 186                         input_event(input, EV_ABS, ABS_MT_TRACKING_ID, -1);
 187                 }
 188                 f->prev_touch = f->touch;
 189                 f->valid = 0;
 190         }
 191
 192         /* touchscreen emulation */
 193         if (oldest) {
 194                 input_event(input, EV_KEY, BTN_TOUCH, 1);
 195                 input_event(input, EV_ABS, ABS_X, oldest->x);
 196                 input_event(input, EV_ABS, ABS_Y, oldest->y);
 197         } else {
 198                 input_event(input, EV_KEY, BTN_TOUCH, 0);
 199         }
 200         input_sync(input);
 201 }
 202
 203 /*
 204  * this function is called upon all reports
 205  * so that we can accumulate contact point information,
 206  * and call input_mt_sync after each point.
 207  */
 208 static int mmm_event(struct hid_device *hid, struct hid_field *field,
 209                                 struct hid_usage *usage, __s32 value)
 210 {
 211         struct mmm_data *md = hid_get_drvdata(hid);
 212         /*
 213          * strangely, this function can be called before
 214          * field->hidinput is initialized!
 215          */
 216         if (hid->claimed & HID_CLAIMED_INPUT) {
 217                 struct input_dev *input = field->hidinput->input;
 218                 switch (usage->hid) {
 219                 case HID_DG_TIPSWITCH:
 220                         md->touch = value;
 221                         break;
 222                 case HID_DG_CONFIDENCE:
 223                         md->valid = value;
 224                         break;
 225                 case HID_DG_WIDTH:
 226                         if (md->valid)
 227                                 md->f[md->curid].w = value;
 228                         break;
 229                 case HID_DG_HEIGHT:
 230                         if (md->valid)
 231                                 md->f[md->curid].h = value;
 232                         break;
 233                 case HID_DG_CONTACTID:
 234                         value = clamp_val(value, 0, MAX_SLOTS - 1);
 235                         if (md->valid) {
 236                                 md->curid = value;
 237                                 md->f[value].touch = md->touch;
 238                                 md->f[value].valid = 1;
 239                                 md->nreal++;
 240                         }
 241                         break;
 242                 case HID_GD_X:
 243                         if (md->valid)
 244                                 md->f[md->curid].x = value;
 245                         break;
 246                 case HID_GD_Y:
 247                         if (md->valid)
 248                                 md->f[md->curid].y = value;
 249                         break;
 250                 case HID_DG_CONTACTCOUNT:
 251                         if (value)
 252                                 md->nexp = value;
 253                         if (md->nreal >= md->nexp) {
 254                                 mmm_filter_event(md, input);
 255                                 md->nreal = 0;
 256                         }
 257                         break;
 258                 }
 259         }
 260
 261         /* we have handled the hidinput part, now remains hiddev */
 262         if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
 263                 hid->hiddev_hid_event(hid, field, usage, value);
 264
 265         return 1;
 266 }
 267
 268 static int mmm_probe(struct hid_device *hdev, const struct hid_device_id *id)
 269 {
 270         int ret;
 271         struct mmm_data *md;
 272
 273         hdev->quirks |= HID_QUIRK_NO_INPUT_SYNC;
 274
 275         md = kzalloc(sizeof(struct mmm_data), GFP_KERNEL);
 276         if (!md) {
 277                 dev_err(&hdev->dev, "cannot allocate 3M data\n");
 278                 return -ENOMEM;
 279         }
 280         hid_set_drvdata(hdev, md);
 281
 282         ret = hid_parse(hdev);
 283         if (!ret)
 284                 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 285
 286         if (ret)
 287                 kfree(md);
 288         return ret;
 289 }
 290
 291 static void mmm_remove(struct hid_device *hdev)
 292 {
 293         hid_hw_stop(hdev);
 294         kfree(hid_get_drvdata(hdev));
 295         hid_set_drvdata(hdev, NULL);
 296 }
 297
 298 static const struct hid_device_id mmm_devices[] = {
 299         { HID_USB_DEVICE(USB_VENDOR_ID_3M, USB_DEVICE_ID_3M1968) },
 300         { HID_USB_DEVICE(USB_VENDOR_ID_3M, USB_DEVICE_ID_3M2256) },
 301         { }
 302 };
 303 MODULE_DEVICE_TABLE(hid, mmm_devices);
 304
 305 static const struct hid_usage_id mmm_grabbed_usages[] = {
 306         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
 307         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
 308 };
 309
 310 static struct hid_driver mmm_driver = {
 311         .name = "3m-pct",
 312         .id_table = mmm_devices,
 313         .probe = mmm_probe,
 314         .remove = mmm_remove,
 315         .input_mapping = mmm_input_mapping,
 316         .input_mapped = mmm_input_mapped,
 317         .usage_table = mmm_grabbed_usages,
 318         .event = mmm_event,
 319 };
 320
 321 static int __init mmm_init(void)
 322 {
 323         return hid_register_driver(&mmm_driver);
 324 }
 325
 326 static void __exit mmm_exit(void)
 327 {
 328         hid_unregister_driver(&mmm_driver);
 329 }
 330
 331 module_init(mmm_init);
 332 module_exit(mmm_exit);
 333