drivers/hid/hid-egalax.c

   1 /*
   2  *  HID driver for eGalax dual-touch panels
   3  *
   4  *  Copyright (c) 2010 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 #include "usbhid/usbhid.h"
  20
  21 MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
  22 MODULE_DESCRIPTION("eGalax dual-touch panel");
  23 MODULE_LICENSE("GPL");
  24
  25 #include "hid-ids.h"
  26
  27 struct egalax_data {
  28         __u16 x, y, z;
  29         __u8 id;
  30         bool first;             /* is this the first finger in the frame? */
  31         bool valid;             /* valid finger data, or just placeholder? */
  32         bool activity;          /* at least one active finger previously? */
  33         __u16 lastx, lasty;     /* latest valid (x, y) in the frame */
  34 };
  35
  36 static int egalax_input_mapping(struct hid_device *hdev, struct hid_input *hi,
  37                 struct hid_field *field, struct hid_usage *usage,
  38                 unsigned long **bit, int *max)
  39 {
  40         switch (usage->hid & HID_USAGE_PAGE) {
  41
  42         case HID_UP_GENDESK:
  43                 switch (usage->hid) {
  44                 case HID_GD_X:
  45                         hid_map_usage(hi, usage, bit, max,
  46                                         EV_ABS, ABS_MT_POSITION_X);
  47                         /* touchscreen emulation */
  48                         input_set_abs_params(hi->input, ABS_X,
  49                                                 field->logical_minimum,
  50                                                 field->logical_maximum, 0, 0);
  51                         return 1;
  52                 case HID_GD_Y:
  53                         hid_map_usage(hi, usage, bit, max,
  54                                         EV_ABS, ABS_MT_POSITION_Y);
  55                         /* touchscreen emulation */
  56                         input_set_abs_params(hi->input, ABS_Y,
  57                                                 field->logical_minimum,
  58                                                 field->logical_maximum, 0, 0);
  59                         return 1;
  60                 }
  61                 return 0;
  62
  63         case HID_UP_DIGITIZER:
  64                 switch (usage->hid) {
  65                 case HID_DG_TIPSWITCH:
  66                         /* touchscreen emulation */
  67                         hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
  68                         return 1;
  69                 case HID_DG_INRANGE:
  70                 case HID_DG_CONFIDENCE:
  71                 case HID_DG_CONTACTCOUNT:
  72                 case HID_DG_CONTACTMAX:
  73                         return -1;
  74                 case HID_DG_CONTACTID:
  75                         hid_map_usage(hi, usage, bit, max,
  76                                         EV_ABS, ABS_MT_TRACKING_ID);
  77                         return 1;
  78                 case HID_DG_TIPPRESSURE:
  79                         hid_map_usage(hi, usage, bit, max,
  80                                         EV_ABS, ABS_MT_PRESSURE);
  81                         return 1;
  82                 }
  83                 return 0;
  84         }
  85
  86         /* ignore others (from other reports we won't get anyway) */
  87         return -1;
  88 }
  89
  90 static int egalax_input_mapped(struct hid_device *hdev, struct hid_input *hi,
  91                 struct hid_field *field, struct hid_usage *usage,
  92                 unsigned long **bit, int *max)
  93 {
  94         if (usage->type == EV_KEY || usage->type == EV_ABS)
  95                 clear_bit(usage->code, *bit);
  96
  97         return 0;
  98 }
  99
 100 /*
 101  * this function is called when a whole finger has been parsed,
 102  * so that it can decide what to send to the input layer.
 103  */
 104 static void egalax_filter_event(struct egalax_data *td, struct input_dev *input)
 105 {
 106         td->first = !td->first; /* touchscreen emulation */
 107
 108         if (td->valid) {
 109                 /* emit multitouch events */
 110                 input_event(input, EV_ABS, ABS_MT_TRACKING_ID, td->id);
 111                 input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x);
 112                 input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y);
 113                 input_event(input, EV_ABS, ABS_MT_PRESSURE, td->z);
 114
 115                 input_mt_sync(input);
 116
 117                 /*
 118                  * touchscreen emulation: store (x, y) as
 119                  * the last valid values in this frame
 120                  */
 121                 td->lastx = td->x;
 122                 td->lasty = td->y;
 123         }
 124
 125         /*
 126          * touchscreen emulation: if this is the second finger and at least
 127          * one in this frame is valid, the latest valid in the frame is
 128          * the oldest on the panel, the one we want for single touch
 129          */
 130         if (!td->first && td->activity) {
 131                 input_event(input, EV_ABS, ABS_X, td->lastx);
 132                 input_event(input, EV_ABS, ABS_Y, td->lasty);
 133         }
 134
 135         if (!td->valid) {
 136                 /*
 137                  * touchscreen emulation: if the first finger is invalid
 138                  * and there previously was finger activity, this is a release
 139                  */
 140                 if (td->first && td->activity) {
 141                         input_event(input, EV_KEY, BTN_TOUCH, 0);
 142                         td->activity = false;
 143                 }
 144                 return;
 145         }
 146
 147
 148         /* touchscreen emulation: if no previous activity, emit touch event */
 149         if (!td->activity) {
 150                 input_event(input, EV_KEY, BTN_TOUCH, 1);
 151                 td->activity = true;
 152         }
 153 }
 154
 155
 156 static int egalax_event(struct hid_device *hid, struct hid_field *field,
 157                                 struct hid_usage *usage, __s32 value)
 158 {
 159         struct egalax_data *td = hid_get_drvdata(hid);
 160
 161         if (hid->claimed & HID_CLAIMED_INPUT) {
 162                 struct input_dev *input = field->hidinput->input;
 163
 164                 switch (usage->hid) {
 165                 case HID_DG_INRANGE:
 166                 case HID_DG_CONFIDENCE:
 167                         /* avoid interference from generic hidinput handling */
 168                         break;
 169                 case HID_DG_TIPSWITCH:
 170                         td->valid = value;
 171                         break;
 172                 case HID_DG_TIPPRESSURE:
 173                         td->z = value;
 174                         break;
 175                 case HID_DG_CONTACTID:
 176                         td->id = value;
 177                         break;
 178                 case HID_GD_X:
 179                         td->x = value;
 180                         break;
 181                 case HID_GD_Y:
 182                         td->y = value;
 183                         /* this is the last field in a finger */
 184                         egalax_filter_event(td, input);
 185                         break;
 186                 case HID_DG_CONTACTCOUNT:
 187                         /* touch emulation: this is the last field in a frame */
 188                         td->first = false;
 189                         break;
 190
 191                 default:
 192                         /* fallback to the generic hidinput handling */
 193                         return 0;
 194                 }
 195         }
 196
 197         /* we have handled the hidinput part, now remains hiddev */
 198         if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
 199                 hid->hiddev_hid_event(hid, field, usage, value);
 200
 201         return 1;
 202 }
 203
 204 static int egalax_probe(struct hid_device *hdev, const struct hid_device_id *id)
 205 {
 206         int ret;
 207         struct egalax_data *td;
 208         struct hid_report *report;
 209
 210         td = kmalloc(sizeof(struct egalax_data), GFP_KERNEL);
 211         if (!td) {
 212                 dev_err(&hdev->dev, "cannot allocate eGalax data\n");
 213                 return -ENOMEM;
 214         }
 215         hid_set_drvdata(hdev, td);
 216
 217         ret = hid_parse(hdev);
 218         if (ret)
 219                 goto end;
 220
 221         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 222         if (ret)
 223                 goto end;
 224
 225         report = hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[5];
 226         if (report) {
 227                 report->field[0]->value[0] = 2;
 228                 usbhid_submit_report(hdev, report, USB_DIR_OUT);
 229         }
 230
 231 end:
 232         if (ret)
 233                 kfree(td);
 234
 235         return ret;
 236 }
 237
 238 static void egalax_remove(struct hid_device *hdev)
 239 {
 240         hid_hw_stop(hdev);
 241         kfree(hid_get_drvdata(hdev));
 242         hid_set_drvdata(hdev, NULL);
 243 }
 244
 245 static const struct hid_device_id egalax_devices[] = {
 246         { HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 247                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH) },
 248         { }
 249 };
 250 MODULE_DEVICE_TABLE(hid, egalax_devices);
 251
 252 static const struct hid_usage_id egalax_grabbed_usages[] = {
 253         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
 254         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
 255 };
 256
 257 static struct hid_driver egalax_driver = {
 258         .name = "egalax-touch",
 259         .id_table = egalax_devices,
 260         .probe = egalax_probe,
 261         .remove = egalax_remove,
 262         .input_mapping = egalax_input_mapping,
 263         .input_mapped = egalax_input_mapped,
 264         .usage_table = egalax_grabbed_usages,
 265         .event = egalax_event,
 266 };
 267
 268 static int __init egalax_init(void)
 269 {
 270         return hid_register_driver(&egalax_driver);
 271 }
 272
 273 static void __exit egalax_exit(void)
 274 {
 275         hid_unregister_driver(&egalax_driver);
 276 }
 277
 278 module_init(egalax_init);
 279 module_exit(egalax_exit);
 280