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 #include <linux/slab.h>
  19
  20 MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
  21 MODULE_DESCRIPTION("Stantum HID multitouch panels");
  22 MODULE_LICENSE("GPL");
  23
  24 #include "hid-ids.h"
  25
  26 struct stantum_data {
  27         __s32 x, y, z, w, h;    /* x, y, pressure, width, height */
  28         __u16 id;               /* touch id */
  29         bool valid;             /* valid finger data, or just placeholder? */
  30         bool first;             /* first finger in the HID packet? */
  31         bool activity;          /* at least one active finger so far? */
  32 };
  33
  34 static int stantum_input_mapping(struct hid_device *hdev, struct hid_input *hi,
  35                 struct hid_field *field, struct hid_usage *usage,
  36                 unsigned long **bit, int *max)
  37 {
  38         switch (usage->hid & HID_USAGE_PAGE) {
  39
  40         case HID_UP_GENDESK:
  41                 switch (usage->hid) {
  42                 case HID_GD_X:
  43                         hid_map_usage(hi, usage, bit, max,
  44                                         EV_ABS, ABS_MT_POSITION_X);
  45                         /* touchscreen emulation */
  46                         input_set_abs_params(hi->input, ABS_X,
  47                                                 field->logical_minimum,
  48                                                 field->logical_maximum, 0, 0);
  49                         return 1;
  50                 case HID_GD_Y:
  51                         hid_map_usage(hi, usage, bit, max,
  52                                         EV_ABS, ABS_MT_POSITION_Y);
  53                         /* touchscreen emulation */
  54                         input_set_abs_params(hi->input, ABS_Y,
  55                                                 field->logical_minimum,
  56                                                 field->logical_maximum, 0, 0);
  57                         return 1;
  58                 }
  59                 return 0;
  60
  61         case HID_UP_DIGITIZER:
  62                 switch (usage->hid) {
  63                 case HID_DG_INRANGE:
  64                 case HID_DG_CONFIDENCE:
  65                 case HID_DG_INPUTMODE:
  66                 case HID_DG_DEVICEINDEX:
  67                 case HID_DG_CONTACTCOUNT:
  68                 case HID_DG_CONTACTMAX:
  69                         return -1;
  70
  71                 case HID_DG_TIPSWITCH:
  72                         /* touchscreen emulation */
  73                         hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
  74                         return 1;
  75
  76                 case HID_DG_WIDTH:
  77                         hid_map_usage(hi, usage, bit, max,
  78                                         EV_ABS, ABS_MT_TOUCH_MAJOR);
  79                         return 1;
  80                 case HID_DG_HEIGHT:
  81                         hid_map_usage(hi, usage, bit, max,
  82                                         EV_ABS, ABS_MT_TOUCH_MINOR);
  83                         input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
  84                                         1, 1, 0, 0);
  85                         return 1;
  86                 case HID_DG_TIPPRESSURE:
  87                         hid_map_usage(hi, usage, bit, max,
  88                                         EV_ABS, ABS_MT_PRESSURE);
  89                         return 1;
  90
  91                 case HID_DG_CONTACTID:
  92                         hid_map_usage(hi, usage, bit, max,
  93                                         EV_ABS, ABS_MT_TRACKING_ID);
  94                         return 1;
  95
  96                 }
  97                 return 0;
  98
  99         case 0xff000000:
 100                 /* no input-oriented meaning */
 101                 return -1;
 102         }
 103
 104         return 0;
 105 }
 106
 107 static int stantum_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 108                 struct hid_field *field, struct hid_usage *usage,
 109                 unsigned long **bit, int *max)
 110 {
 111         if (usage->type == EV_KEY || usage->type == EV_ABS)
 112                 clear_bit(usage->code, *bit);
 113
 114         return 0;
 115 }
 116
 117 /*
 118  * this function is called when a whole finger has been parsed,
 119  * so that it can decide what to send to the input layer.
 120  */
 121 static void stantum_filter_event(struct stantum_data *sd,
 122                                         struct input_dev *input)
 123 {
 124         bool wide;
 125
 126         if (!sd->valid) {
 127                 /*
 128                  * touchscreen emulation: if the first finger is not valid and
 129                  * there previously was finger activity, this is a release
 130                  */
 131                 if (sd->first && sd->activity) {
 132                         input_event(input, EV_KEY, BTN_TOUCH, 0);
 133                         sd->activity = false;
 134                 }
 135                 return;
 136         }
 137
 138         input_event(input, EV_ABS, ABS_MT_TRACKING_ID, sd->id);
 139         input_event(input, EV_ABS, ABS_MT_POSITION_X, sd->x);
 140         input_event(input, EV_ABS, ABS_MT_POSITION_Y, sd->y);
 141
 142         wide = (sd->w > sd->h);
 143         input_event(input, EV_ABS, ABS_MT_ORIENTATION, wide);
 144         input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, wide ? sd->w : sd->h);
 145         input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, wide ? sd->h : sd->w);
 146
 147         input_event(input, EV_ABS, ABS_MT_PRESSURE, sd->z);
 148
 149         input_mt_sync(input);
 150         sd->valid = false;
 151
 152         /* touchscreen emulation */
 153         if (sd->first) {
 154                 if (!sd->activity) {
 155                         input_event(input, EV_KEY, BTN_TOUCH, 1);
 156                         sd->activity = true;
 157                 }
 158                 input_event(input, EV_ABS, ABS_X, sd->x);
 159                 input_event(input, EV_ABS, ABS_Y, sd->y);
 160         }
 161         sd->first = false;
 162 }
 163
 164
 165 static int stantum_event(struct hid_device *hid, struct hid_field *field,
 166                                 struct hid_usage *usage, __s32 value)
 167 {
 168         struct stantum_data *sd = hid_get_drvdata(hid);
 169
 170         if (hid->claimed & HID_CLAIMED_INPUT) {
 171                 struct input_dev *input = field->hidinput->input;
 172
 173                 switch (usage->hid) {
 174                 case HID_DG_INRANGE:
 175                         /* this is the last field in a finger */
 176                         stantum_filter_event(sd, input);
 177                         break;
 178                 case HID_DG_WIDTH:
 179                         sd->w = value;
 180                         break;
 181                 case HID_DG_HEIGHT:
 182                         sd->h = value;
 183                         break;
 184                 case HID_GD_X:
 185                         sd->x = value;
 186                         break;
 187                 case HID_GD_Y:
 188                         sd->y = value;
 189                         break;
 190                 case HID_DG_TIPPRESSURE:
 191                         sd->z = value;
 192                         break;
 193                 case HID_DG_CONTACTID:
 194                         sd->id = value;
 195                         break;
 196                 case HID_DG_CONFIDENCE:
 197                         sd->valid = !!value;
 198                         break;
 199                 case 0xff000002:
 200                         /* this comes only before the first finger */
 201                         sd->first = true;
 202                         break;
 203
 204                 default:
 205                         /* ignore the others */
 206                         return 1;
 207                 }
 208         }
 209
 210         /* we have handled the hidinput part, now remains hiddev */
 211         if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
 212                 hid->hiddev_hid_event(hid, field, usage, value);
 213
 214         return 1;
 215 }
 216
 217 static int stantum_probe(struct hid_device *hdev,
 218                                 const struct hid_device_id *id)
 219 {
 220         int ret;
 221         struct stantum_data *sd;
 222
 223         sd = kmalloc(sizeof(struct stantum_data), GFP_KERNEL);
 224         if (!sd) {
 225                 dev_err(&hdev->dev, "cannot allocate Stantum data\n");
 226                 return -ENOMEM;
 227         }
 228         sd->valid = false;
 229         sd->first = false;
 230         sd->activity = false;
 231         hid_set_drvdata(hdev, sd);
 232
 233         ret = hid_parse(hdev);
 234         if (!ret)
 235                 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 236
 237         if (ret)
 238                 kfree(sd);
 239
 240         return ret;
 241 }
 242
 243 static void stantum_remove(struct hid_device *hdev)
 244 {
 245         hid_hw_stop(hdev);
 246         kfree(hid_get_drvdata(hdev));
 247         hid_set_drvdata(hdev, NULL);
 248 }
 249
 250 static const struct hid_device_id stantum_devices[] = {
 251         { HID_USB_DEVICE(USB_VENDOR_ID_STANTUM, USB_DEVICE_ID_MTP) },
 252         { }
 253 };
 254 MODULE_DEVICE_TABLE(hid, stantum_devices);
 255
 256 static const struct hid_usage_id stantum_grabbed_usages[] = {
 257         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
 258         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
 259 };
 260
 261 static struct hid_driver stantum_driver = {
 262         .name = "stantum",
 263         .id_table = stantum_devices,
 264         .probe = stantum_probe,
 265         .remove = stantum_remove,
 266         .input_mapping = stantum_input_mapping,
 267         .input_mapped = stantum_input_mapped,
 268         .usage_table = stantum_grabbed_usages,
 269         .event = stantum_event,
 270 };
 271
 272 static int __init stantum_init(void)
 273 {
 274         return hid_register_driver(&stantum_driver);
 275 }
 276
 277 static void __exit stantum_exit(void)
 278 {
 279         hid_unregister_driver(&stantum_driver);
 280 }
 281
 282 module_init(stantum_init);
 283 module_exit(stantum_exit);
 284