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 <linux/slab.h>
  20 #include "usbhid/usbhid.h"
  21
  22 MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
  23 MODULE_DESCRIPTION("eGalax dual-touch panel");
  24 MODULE_LICENSE("GPL");
  25
  26 #include "hid-ids.h"
  27
  28 struct egalax_data {
  29         __u16 x, y, z;
  30         __u8 id;
  31         bool first;             /* is this the first finger in the frame? */
  32         bool valid;             /* valid finger data, or just placeholder? */
  33         bool activity;          /* at least one active finger previously? */
  34         __u16 lastx, lasty, lastz;      /* latest valid (x, y, z) in the frame */
  35 };
  36
  37 static int egalax_input_mapping(struct hid_device *hdev, struct hid_input *hi,
  38                 struct hid_field *field, struct hid_usage *usage,
  39                 unsigned long **bit, int *max)
  40 {
  41         switch (usage->hid & HID_USAGE_PAGE) {
  42
  43         case HID_UP_GENDESK:
  44                 switch (usage->hid) {
  45                 case HID_GD_X:
  46                         hid_map_usage(hi, usage, bit, max,
  47                                         EV_ABS, ABS_MT_POSITION_X);
  48                         /* touchscreen emulation */
  49                         input_set_abs_params(hi->input, ABS_X,
  50                                                 field->logical_minimum,
  51                                                 field->logical_maximum, 0, 0);
  52                         return 1;
  53                 case HID_GD_Y:
  54                         hid_map_usage(hi, usage, bit, max,
  55                                         EV_ABS, ABS_MT_POSITION_Y);
  56                         /* touchscreen emulation */
  57                         input_set_abs_params(hi->input, ABS_Y,
  58                                                 field->logical_minimum,
  59                                                 field->logical_maximum, 0, 0);
  60                         return 1;
  61                 }
  62                 return 0;
  63
  64         case HID_UP_DIGITIZER:
  65                 switch (usage->hid) {
  66                 case HID_DG_TIPSWITCH:
  67                         /* touchscreen emulation */
  68                         hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
  69                         return 1;
  70                 case HID_DG_INRANGE:
  71                 case HID_DG_CONFIDENCE:
  72                 case HID_DG_CONTACTCOUNT:
  73                 case HID_DG_CONTACTMAX:
  74                         return -1;
  75                 case HID_DG_CONTACTID:
  76                         hid_map_usage(hi, usage, bit, max,
  77                                         EV_ABS, ABS_MT_TRACKING_ID);
  78                         return 1;
  79                 case HID_DG_TIPPRESSURE:
  80                         hid_map_usage(hi, usage, bit, max,
  81                                         EV_ABS, ABS_MT_PRESSURE);
  82                         /* touchscreen emulation */
  83                         input_set_abs_params(hi->input, ABS_PRESSURE,
  84                                                 field->logical_minimum,
  85                                                 field->logical_maximum, 0, 0);
  86                         return 1;
  87                 }
  88                 return 0;
  89         }
  90
  91         /* ignore others (from other reports we won't get anyway) */
  92         return -1;
  93 }
  94
  95 static int egalax_input_mapped(struct hid_device *hdev, struct hid_input *hi,
  96                 struct hid_field *field, struct hid_usage *usage,
  97                 unsigned long **bit, int *max)
  98 {
  99         if (usage->type == EV_KEY || usage->type == EV_ABS)
 100                 clear_bit(usage->code, *bit);
 101
 102         return 0;
 103 }
 104
 105 /*
 106  * this function is called when a whole finger has been parsed,
 107  * so that it can decide what to send to the input layer.
 108  */
 109 static void egalax_filter_event(struct egalax_data *td, struct input_dev *input)
 110 {
 111         td->first = !td->first; /* touchscreen emulation */
 112
 113         if (td->valid) {
 114                 /* emit multitouch events */
 115                 input_event(input, EV_ABS, ABS_MT_TRACKING_ID, td->id);
 116                 input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x >> 3);
 117                 input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y >> 3);
 118                 input_event(input, EV_ABS, ABS_MT_PRESSURE, td->z);
 119
 120                 input_mt_sync(input);
 121
 122                 /*
 123                  * touchscreen emulation: store (x, y) as
 124                  * the last valid values in this frame
 125                  */
 126                 td->lastx = td->x;
 127                 td->lasty = td->y;
 128                 td->lastz = td->z;
 129         }
 130
 131         /*
 132          * touchscreen emulation: if this is the second finger and at least
 133          * one in this frame is valid, the latest valid in the frame is
 134          * the oldest on the panel, the one we want for single touch
 135          */
 136         if (!td->first && td->activity) {
 137                 input_event(input, EV_ABS, ABS_X, td->lastx >> 3);
 138                 input_event(input, EV_ABS, ABS_Y, td->lasty >> 3);
 139                 input_event(input, EV_ABS, ABS_PRESSURE, td->lastz);
 140         }
 141
 142         if (!td->valid) {
 143                 /*
 144                  * touchscreen emulation: if the first finger is invalid
 145                  * and there previously was finger activity, this is a release
 146                  */
 147                 if (td->first && td->activity) {
 148                         input_event(input, EV_KEY, BTN_TOUCH, 0);
 149                         td->activity = false;
 150                 }
 151                 return;
 152         }
 153
 154
 155         /* touchscreen emulation: if no previous activity, emit touch event */
 156         if (!td->activity) {
 157                 input_event(input, EV_KEY, BTN_TOUCH, 1);
 158                 td->activity = true;
 159         }
 160 }
 161
 162
 163 static int egalax_event(struct hid_device *hid, struct hid_field *field,
 164                                 struct hid_usage *usage, __s32 value)
 165 {
 166         struct egalax_data *td = hid_get_drvdata(hid);
 167
 168         if (hid->claimed & HID_CLAIMED_INPUT) {
 169                 struct input_dev *input = field->hidinput->input;
 170
 171                 switch (usage->hid) {
 172                 case HID_DG_INRANGE:
 173                 case HID_DG_CONFIDENCE:
 174                         /* avoid interference from generic hidinput handling */
 175                         break;
 176                 case HID_DG_TIPSWITCH:
 177                         td->valid = value;
 178                         break;
 179                 case HID_DG_TIPPRESSURE:
 180                         td->z = value;
 181                         break;
 182                 case HID_DG_CONTACTID:
 183                         td->id = value;
 184                         break;
 185                 case HID_GD_X:
 186                         td->x = value;
 187                         break;
 188                 case HID_GD_Y:
 189                         td->y = value;
 190                         /* this is the last field in a finger */
 191                         egalax_filter_event(td, input);
 192                         break;
 193                 case HID_DG_CONTACTCOUNT:
 194                         /* touch emulation: this is the last field in a frame */
 195                         td->first = false;
 196                         break;
 197
 198                 default:
 199                         /* fallback to the generic hidinput handling */
 200                         return 0;
 201                 }
 202         }
 203
 204         /* we have handled the hidinput part, now remains hiddev */
 205         if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
 206                 hid->hiddev_hid_event(hid, field, usage, value);
 207
 208         return 1;
 209 }
 210
 211 static int egalax_probe(struct hid_device *hdev, const struct hid_device_id *id)
 212 {
 213         int ret;
 214         struct egalax_data *td;
 215         struct hid_report *report;
 216
 217         td = kmalloc(sizeof(struct egalax_data), GFP_KERNEL);
 218         if (!td) {
 219                 dev_err(&hdev->dev, "cannot allocate eGalax data\n");
 220                 return -ENOMEM;
 221         }
 222         hid_set_drvdata(hdev, td);
 223
 224         ret = hid_parse(hdev);
 225         if (ret)
 226                 goto end;
 227
 228         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 229         if (ret)
 230                 goto end;
 231
 232         report = hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[5];
 233         if (report) {
 234                 report->field[0]->value[0] = 2;
 235                 usbhid_submit_report(hdev, report, USB_DIR_OUT);
 236         }
 237
 238 end:
 239         if (ret)
 240                 kfree(td);
 241
 242         return ret;
 243 }
 244
 245 static void egalax_remove(struct hid_device *hdev)
 246 {
 247         hid_hw_stop(hdev);
 248         kfree(hid_get_drvdata(hdev));
 249         hid_set_drvdata(hdev, NULL);
 250 }
 251
 252 static const struct hid_device_id egalax_devices[] = {
 253         { HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 254                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH) },
 255         { }
 256 };
 257 MODULE_DEVICE_TABLE(hid, egalax_devices);
 258
 259 static const struct hid_usage_id egalax_grabbed_usages[] = {
 260         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
 261         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
 262 };
 263
 264 static struct hid_driver egalax_driver = {
 265         .name = "egalax-touch",
 266         .id_table = egalax_devices,
 267         .probe = egalax_probe,
 268         .remove = egalax_remove,
 269         .input_mapping = egalax_input_mapping,
 270         .input_mapped = egalax_input_mapped,
 271         .usage_table = egalax_grabbed_usages,
 272         .event = egalax_event,
 273 };
 274
 275 static int __init egalax_init(void)
 276 {
 277         return hid_register_driver(&egalax_driver);
 278 }
 279
 280 static void __exit egalax_exit(void)
 281 {
 282         hid_unregister_driver(&egalax_driver);
 283 }
 284
 285 module_init(egalax_init);
 286 module_exit(egalax_exit);
 287