drivers/hid/hid-stantum.c

   1 /*
   2  *  HID driver for Stantum 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
  19 MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
  20 MODULE_DESCRIPTION("Stantum HID multitouch panels");
  21 MODULE_LICENSE("GPL");
  22
  23 #include "hid-ids.h"
  24
  25 struct stantum_data {
  26         __s32 x, y, z, w, h;    /* x, y, pressure, width, height */
  27         __u16 id;               /* touch id */
  28         bool valid;             /* valid finger data, or just placeholder? */
  29         bool first;             /* first finger in the HID packet? */
  30         bool activity;          /* at least one active finger so far? */
  31 };
  32
  33 static int stantum_input_mapping(struct hid_device *hdev, struct hid_input *hi,
  34                 struct hid_field *field, struct hid_usage *usage,
  35                 unsigned long **bit, int *max)
  36 {
  37         switch (usage->hid & HID_USAGE_PAGE) {
  38
  39         case HID_UP_GENDESK:
  40                 switch (usage->hid) {
  41                 case HID_GD_X:
  42                         hid_map_usage(hi, usage, bit, max,
  43                                         EV_ABS, ABS_MT_POSITION_X);
  44                         /* touchscreen emulation */
  45                         input_set_abs_params(hi->input, ABS_X,
  46                                                 field->logical_minimum,
  47                                                 field->logical_maximum, 0, 0);
  48                         return 1;
  49                 case HID_GD_Y:
  50                         hid_map_usage(hi, usage, bit, max,
  51                                         EV_ABS, ABS_MT_POSITION_Y);
  52                         /* touchscreen emulation */
  53                         input_set_abs_params(hi->input, ABS_Y,
  54                                                 field->logical_minimum,
  55                                                 field->logical_maximum, 0, 0);
  56                         return 1;
  57                 }
  58                 return 0;
  59
  60         case HID_UP_DIGITIZER:
  61                 switch (usage->hid) {
  62                 case HID_DG_INRANGE:
  63                 case HID_DG_CONFIDENCE:
  64                 case HID_DG_INPUTMODE:
  65                 case HID_DG_DEVICEINDEX:
  66                 case HID_DG_CONTACTCOUNT:
  67                 case HID_DG_CONTACTMAX:
  68                         return -1;
  69
  70                 case HID_DG_TIPSWITCH:
  71                         /* touchscreen emulation */
  72                         hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
  73                         return 1;
  74
  75                 case HID_DG_WIDTH:
  76                         hid_map_usage(hi, usage, bit, max,
  77                                         EV_ABS, ABS_MT_TOUCH_MAJOR);
  78                         return 1;
  79                 case HID_DG_HEIGHT:
  80                         hid_map_usage(hi, usage, bit, max,
  81                                         EV_ABS, ABS_MT_TOUCH_MINOR);
  82                         input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
  83                                         1, 1, 0, 0);
  84                         return 1;
  85                 case HID_DG_TIPPRESSURE:
  86                         hid_map_usage(hi, usage, bit, max,
  87                                         EV_ABS, ABS_MT_PRESSURE);
  88                         return 1;
  89
  90                 case HID_DG_CONTACTID:
  91                         hid_map_usage(hi, usage, bit, max,
  92                                         EV_ABS, ABS_MT_TRACKING_ID);
  93                         return 1;
  94
  95                 }
  96                 return 0;
  97
  98         case 0xff000000:
  99                 /* no input-oriented meaning */
 100                 return -1;
 101         }
 102
 103         return 0;
 104 }
 105
 106 static int stantum_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 107                 struct hid_field *field, struct hid_usage *usage,
 108                 unsigned long **bit, int *max)
 109 {
 110         if (usage->type == EV_KEY || usage->type == EV_ABS)
 111                 clear_bit(usage->code, *bit);
 112
 113         return 0;
 114 }
 115
 116 /*
 117  * this function is called when a whole finger has been parsed,
 118  * so that it can decide what to send to the input layer.
 119  */
 120 static void stantum_filter_event(struct stantum_data *sd,
 121                                         struct input_dev *input)
 122 {
 123         bool wide;
 124
 125         if (!sd->valid) {
 126                 /*
 127                  * touchscreen emulation: if the first finger is not valid and
 128                  * there previously was finger activity, this is a release
 129                  */
 130                 if (sd->first && sd->activity) {
 131                         input_event(input, EV_KEY, BTN_TOUCH, 0);
 132                         sd->activity = false;
 133                 }
 134                 return;
 135         }
 136
 137         input_event(input, EV_ABS, ABS_MT_TRACKING_ID, sd->id);
 138         input_event(input, EV_ABS, ABS_MT_POSITION_X, sd->x);
 139         input_event(input, EV_ABS, ABS_MT_POSITION_Y, sd->y);
 140
 141         wide = (sd->w > sd->h);
 142         input_event(input, EV_ABS, ABS_MT_ORIENTATION, wide);
 143         input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, wide ? sd->w : sd->h);
 144         input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, wide ? sd->h : sd->w);
 145
 146         input_event(input, EV_ABS, ABS_MT_PRESSURE, sd->z);
 147
 148         input_mt_sync(input);
 149         sd->valid = false;
 150
 151         /* touchscreen emulation */
 152         if (sd->first) {
 153                 if (!sd->activity) {
 154                         input_event(input, EV_KEY, BTN_TOUCH, 1);
 155                         sd->activity = true;
 156                 }
 157                 input_event(input, EV_ABS, ABS_X, sd->x);
 158                 input_event(input, EV_ABS, ABS_Y, sd->y);
 159         }
 160         sd->first = false;
 161 }
 162
 163
 164 static int stantum_event(struct hid_device *hid, struct hid_field *field,
 165                                 struct hid_usage *usage, __s32 value)
 166 {
 167         struct stantum_data *sd = hid_get_drvdata(hid);
 168
 169         if (hid->claimed & HID_CLAIMED_INPUT) {
 170                 struct input_dev *input = field->hidinput->input;
 171
 172                 switch (usage->hid) {
 173                 case HID_DG_INRANGE:
 174                         /* this is the last field in a finger */
 175                         stantum_filter_event(sd, input);
 176                         break;
 177                 case HID_DG_WIDTH:
 178                         sd->w = value;
 179                         break;
 180                 case HID_DG_HEIGHT:
 181                         sd->h = value;
 182                         break;
 183                 case HID_GD_X:
 184                         sd->x = value;
 185                         break;
 186                 case HID_GD_Y:
 187                         sd->y = value;
 188                         break;
 189                 case HID_DG_TIPPRESSURE:
 190                         sd->z = value;
 191                         break;
 192                 case HID_DG_CONTACTID:
 193                         sd->id = value;
 194                         break;
 195                 case HID_DG_CONFIDENCE:
 196                         sd->valid = !!value;
 197                         break;
 198                 case 0xff000002:
 199                         /* this comes only before the first finger */
 200                         sd->first = true;
 201                         break;
 202
 203                 default:
 204                         /* ignore the others */
 205                         return 1;
 206                 }
 207         }
 208
 209         /* we have handled the hidinput part, now remains hiddev */
 210         if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
 211                 hid->hiddev_hid_event(hid, field, usage, value);
 212
 213         return 1;
 214 }
 215
 216 static int stantum_probe(struct hid_device *hdev,
 217                                 const struct hid_device_id *id)
 218 {
 219         int ret;
 220         struct stantum_data *sd;
 221
 222         sd = kmalloc(sizeof(struct stantum_data), GFP_KERNEL);
 223         if (!sd) {
 224                 dev_err(&hdev->dev, "cannot allocate Stantum data\n");
 225                 return -ENOMEM;
 226         }
 227         sd->valid = false;
 228         sd->first = false;
 229         sd->activity = false;
 230         hid_set_drvdata(hdev, sd);
 231
 232         ret = hid_parse(hdev);
 233         if (!ret)
 234                 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 235
 236         if (ret)
 237                 kfree(sd);
 238
 239         return ret;
 240 }
 241
 242 static void stantum_remove(struct hid_device *hdev)
 243 {
 244         hid_hw_stop(hdev);
 245         kfree(hid_get_drvdata(hdev));
 246         hid_set_drvdata(hdev, NULL);
 247 }
 248
 249 static const struct hid_device_id stantum_devices[] = {
 250         { HID_USB_DEVICE(USB_VENDOR_ID_STANTUM, USB_DEVICE_ID_MTP) },
 251         { }
 252 };
 253 MODULE_DEVICE_TABLE(hid, stantum_devices);
 254
 255 static const struct hid_usage_id stantum_grabbed_usages[] = {
 256         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
 257         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
 258 };
 259
 260 static struct hid_driver stantum_driver = {
 261         .name = "stantum",
 262         .id_table = stantum_devices,
 263         .probe = stantum_probe,
 264         .remove = stantum_remove,
 265         .input_mapping = stantum_input_mapping,
 266         .input_mapped = stantum_input_mapped,
 267         .usage_table = stantum_grabbed_usages,
 268         .event = stantum_event,
 269 };
 270
 271 static int __init stantum_init(void)
 272 {
 273         return hid_register_driver(&stantum_driver);
 274 }
 275
 276 static void __exit stantum_exit(void)
 277 {
 278         hid_unregister_driver(&stantum_driver);
 279 }
 280
 281 module_init(stantum_init);
 282 module_exit(stantum_exit);
 283