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 void set_abs(struct input_dev *input, unsigned int code,
  38                     struct hid_field *field, int snratio)
  39 {
  40         int fmin = field->logical_minimum;
  41         int fmax = field->logical_maximum;
  42         int fuzz = snratio ? (fmax - fmin) / snratio : 0;
  43         input_set_abs_params(input, code, fmin, fmax, fuzz, 0);
  44 }
  45
  46 static int egalax_input_mapping(struct hid_device *hdev, struct hid_input *hi,
  47                 struct hid_field *field, struct hid_usage *usage,
  48                 unsigned long **bit, int *max)
  49 {
  50         struct input_dev *input = hi->input;
  51
  52         switch (usage->hid & HID_USAGE_PAGE) {
  53
  54         case HID_UP_GENDESK:
  55                 switch (usage->hid) {
  56                 case HID_GD_X:
  57                         field->logical_maximum = 32760;
  58                         hid_map_usage(hi, usage, bit, max,
  59                                         EV_ABS, ABS_MT_POSITION_X);
  60                         set_abs(input, ABS_MT_POSITION_X, field, 0);
  61                         /* touchscreen emulation */
  62                         set_abs(input, ABS_X, field, 0);
  63                         return 1;
  64                 case HID_GD_Y:
  65                         field->logical_maximum = 32760;
  66                         hid_map_usage(hi, usage, bit, max,
  67                                         EV_ABS, ABS_MT_POSITION_Y);
  68                         set_abs(input, ABS_MT_POSITION_Y, field, 0);
  69                         /* touchscreen emulation */
  70                         set_abs(input, ABS_Y, field, 0);
  71                         return 1;
  72                 }
  73                 return 0;
  74
  75         case HID_UP_DIGITIZER:
  76                 switch (usage->hid) {
  77                 case HID_DG_TIPSWITCH:
  78                         /* touchscreen emulation */
  79                         hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
  80                         input_set_capability(input, EV_KEY, BTN_TOUCH);
  81                         return 1;
  82                 case HID_DG_INRANGE:
  83                 case HID_DG_CONFIDENCE:
  84                 case HID_DG_CONTACTCOUNT:
  85                 case HID_DG_CONTACTMAX:
  86                         return -1;
  87                 case HID_DG_CONTACTID:
  88                         hid_map_usage(hi, usage, bit, max,
  89                                         EV_ABS, ABS_MT_TRACKING_ID);
  90                         set_abs(input, ABS_MT_TRACKING_ID, field, 0);
  91                         return 1;
  92                 case HID_DG_TIPPRESSURE:
  93                         hid_map_usage(hi, usage, bit, max,
  94                                         EV_ABS, ABS_MT_PRESSURE);
  95                         set_abs(input, ABS_MT_PRESSURE, field, 0);
  96                         /* touchscreen emulation */
  97                         set_abs(input, ABS_PRESSURE, field, 0);
  98                         return 1;
  99                 }
 100                 return 0;
 101         }
 102
 103         /* ignore others (from other reports we won't get anyway) */
 104         return -1;
 105 }
 106
 107 static int egalax_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         /* tell hid-input to skip setup of these event types */
 112         if (usage->type == EV_KEY || usage->type == EV_ABS)
 113                 set_bit(usage->type, hi->input->evbit);
 114         return -1;
 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 egalax_filter_event(struct egalax_data *td, struct input_dev *input)
 122 {
 123         td->first = !td->first; /* touchscreen emulation */
 124
 125         if (td->valid) {
 126                 /* emit multitouch events */
 127                 input_event(input, EV_ABS, ABS_MT_TRACKING_ID, td->id);
 128                 input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x >> 3);
 129                 input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y >> 3);
 130                 input_event(input, EV_ABS, ABS_MT_PRESSURE, td->z);
 131
 132                 input_mt_sync(input);
 133
 134                 /*
 135                  * touchscreen emulation: store (x, y) as
 136                  * the last valid values in this frame
 137                  */
 138                 td->lastx = td->x;
 139                 td->lasty = td->y;
 140                 td->lastz = td->z;
 141         }
 142
 143         /*
 144          * touchscreen emulation: if this is the second finger and at least
 145          * one in this frame is valid, the latest valid in the frame is
 146          * the oldest on the panel, the one we want for single touch
 147          */
 148         if (!td->first && td->activity) {
 149                 input_event(input, EV_ABS, ABS_X, td->lastx >> 3);
 150                 input_event(input, EV_ABS, ABS_Y, td->lasty >> 3);
 151                 input_event(input, EV_ABS, ABS_PRESSURE, td->lastz);
 152         }
 153
 154         if (!td->valid) {
 155                 /*
 156                  * touchscreen emulation: if the first finger is invalid
 157                  * and there previously was finger activity, this is a release
 158                  */
 159                 if (td->first && td->activity) {
 160                         input_event(input, EV_KEY, BTN_TOUCH, 0);
 161                         td->activity = false;
 162                 }
 163                 return;
 164         }
 165
 166
 167         /* touchscreen emulation: if no previous activity, emit touch event */
 168         if (!td->activity) {
 169                 input_event(input, EV_KEY, BTN_TOUCH, 1);
 170                 td->activity = true;
 171         }
 172 }
 173
 174
 175 static int egalax_event(struct hid_device *hid, struct hid_field *field,
 176                                 struct hid_usage *usage, __s32 value)
 177 {
 178         struct egalax_data *td = hid_get_drvdata(hid);
 179
 180         /* Note, eGalax has two product lines: the first is resistive and
 181          * uses a standard parallel multitouch protocol (product ID ==
 182          * 48xx).  The second is capacitive and uses an unusual "serial"
 183          * protocol with a different message for each multitouch finger
 184          * (product ID == 72xx).  We do not yet generate a correct event
 185          * sequence for the capacitive/serial protocol.
 186          */
 187         if (hid->claimed & HID_CLAIMED_INPUT) {
 188                 struct input_dev *input = field->hidinput->input;
 189
 190                 switch (usage->hid) {
 191                 case HID_DG_INRANGE:
 192                 case HID_DG_CONFIDENCE:
 193                         /* avoid interference from generic hidinput handling */
 194                         break;
 195                 case HID_DG_TIPSWITCH:
 196                         td->valid = value;
 197                         break;
 198                 case HID_DG_TIPPRESSURE:
 199                         td->z = value;
 200                         break;
 201                 case HID_DG_CONTACTID:
 202                         td->id = value;
 203                         break;
 204                 case HID_GD_X:
 205                         td->x = value;
 206                         break;
 207                 case HID_GD_Y:
 208                         td->y = value;
 209                         /* this is the last field in a finger */
 210                         egalax_filter_event(td, input);
 211                         break;
 212                 case HID_DG_CONTACTCOUNT:
 213                         /* touch emulation: this is the last field in a frame */
 214                         td->first = false;
 215                         break;
 216
 217                 default:
 218                         /* fallback to the generic hidinput handling */
 219                         return 0;
 220                 }
 221         }
 222
 223         /* we have handled the hidinput part, now remains hiddev */
 224         if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
 225                 hid->hiddev_hid_event(hid, field, usage, value);
 226
 227         return 1;
 228 }
 229
 230 static int egalax_probe(struct hid_device *hdev, const struct hid_device_id *id)
 231 {
 232         int ret;
 233         struct egalax_data *td;
 234         struct hid_report *report;
 235
 236         td = kmalloc(sizeof(struct egalax_data), GFP_KERNEL);
 237         if (!td) {
 238                 dev_err(&hdev->dev, "cannot allocate eGalax data\n");
 239                 return -ENOMEM;
 240         }
 241         hid_set_drvdata(hdev, td);
 242
 243         ret = hid_parse(hdev);
 244         if (ret)
 245                 goto end;
 246
 247         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 248         if (ret)
 249                 goto end;
 250
 251         report = hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[5];
 252         if (report) {
 253                 report->field[0]->value[0] = 2;
 254                 usbhid_submit_report(hdev, report, USB_DIR_OUT);
 255         }
 256
 257 end:
 258         if (ret)
 259                 kfree(td);
 260
 261         return ret;
 262 }
 263
 264 static void egalax_remove(struct hid_device *hdev)
 265 {
 266         hid_hw_stop(hdev);
 267         kfree(hid_get_drvdata(hdev));
 268         hid_set_drvdata(hdev, NULL);
 269 }
 270
 271 static const struct hid_device_id egalax_devices[] = {
 272         { HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 273                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH) },
 274         { HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 275                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH1) },
 276         { }
 277 };
 278 MODULE_DEVICE_TABLE(hid, egalax_devices);
 279
 280 static const struct hid_usage_id egalax_grabbed_usages[] = {
 281         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
 282         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
 283 };
 284
 285 static struct hid_driver egalax_driver = {
 286         .name = "egalax-touch",
 287         .id_table = egalax_devices,
 288         .probe = egalax_probe,
 289         .remove = egalax_remove,
 290         .input_mapping = egalax_input_mapping,
 291         .input_mapped = egalax_input_mapped,
 292         .usage_table = egalax_grabbed_usages,
 293         .event = egalax_event,
 294 };
 295
 296 static int __init egalax_init(void)
 297 {
 298         return hid_register_driver(&egalax_driver);
 299 }
 300
 301 static void __exit egalax_exit(void)
 302 {
 303         hid_unregister_driver(&egalax_driver);
 304 }
 305
 306 module_init(egalax_init);
 307 module_exit(egalax_exit);
 308