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

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