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