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  *  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/usb.h>
  21 #include <linux/input/mt.h>
  22 #include <linux/slab.h>
  23 #include "usbhid/usbhid.h"
  24
  25 MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
  26 MODULE_DESCRIPTION("eGalax dual-touch panel");
  27 MODULE_LICENSE("GPL");
  28
  29 #include "hid-ids.h"
  30
  31 #define MAX_SLOTS               2
  32
  33 /* estimated signal-to-noise ratios */
  34 #define SN_MOVE                 4096
  35 #define SN_PRESSURE             32
  36
  37 struct egalax_data {
  38         int valid;
  39         int slot;
  40         int touch;
  41         int x, y, z;
  42 };
  43
  44 static void set_abs(struct input_dev *input, unsigned int code,
  45                     struct hid_field *field, int snratio)
  46 {
  47         int fmin = field->logical_minimum;
  48         int fmax = field->logical_maximum;
  49         int fuzz = snratio ? (fmax - fmin) / snratio : 0;
  50         input_set_abs_params(input, code, fmin, fmax, fuzz, 0);
  51 }
  52
  53 static int egalax_input_mapping(struct hid_device *hdev, struct hid_input *hi,
  54                 struct hid_field *field, struct hid_usage *usage,
  55                 unsigned long **bit, int *max)
  56 {
  57         struct input_dev *input = hi->input;
  58
  59         switch (usage->hid & HID_USAGE_PAGE) {
  60
  61         case HID_UP_GENDESK:
  62                 switch (usage->hid) {
  63                 case HID_GD_X:
  64                         field->logical_maximum = 32760;
  65                         hid_map_usage(hi, usage, bit, max,
  66                                         EV_ABS, ABS_MT_POSITION_X);
  67                         set_abs(input, ABS_MT_POSITION_X, field, SN_MOVE);
  68                         /* touchscreen emulation */
  69                         set_abs(input, ABS_X, field, SN_MOVE);
  70                         return 1;
  71                 case HID_GD_Y:
  72                         field->logical_maximum = 32760;
  73                         hid_map_usage(hi, usage, bit, max,
  74                                         EV_ABS, ABS_MT_POSITION_Y);
  75                         set_abs(input, ABS_MT_POSITION_Y, field, SN_MOVE);
  76                         /* touchscreen emulation */
  77                         set_abs(input, ABS_Y, field, SN_MOVE);
  78                         return 1;
  79                 }
  80                 return 0;
  81
  82         case HID_UP_DIGITIZER:
  83                 switch (usage->hid) {
  84                 case HID_DG_TIPSWITCH:
  85                         /* touchscreen emulation */
  86                         hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
  87                         input_set_capability(input, EV_KEY, BTN_TOUCH);
  88                         return 1;
  89                 case HID_DG_INRANGE:
  90                 case HID_DG_CONFIDENCE:
  91                 case HID_DG_CONTACTCOUNT:
  92                 case HID_DG_CONTACTMAX:
  93                         return -1;
  94                 case HID_DG_CONTACTID:
  95                         input_mt_init_slots(input, MAX_SLOTS);
  96                         return 1;
  97                 case HID_DG_TIPPRESSURE:
  98                         field->logical_minimum = 0;
  99                         hid_map_usage(hi, usage, bit, max,
 100                                         EV_ABS, ABS_MT_PRESSURE);
 101                         set_abs(input, ABS_MT_PRESSURE, field, SN_PRESSURE);
 102                         /* touchscreen emulation */
 103                         set_abs(input, ABS_PRESSURE, field, SN_PRESSURE);
 104                         return 1;
 105                 }
 106                 return 0;
 107         }
 108
 109         /* ignore others (from other reports we won't get anyway) */
 110         return -1;
 111 }
 112
 113 static int egalax_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 114                 struct hid_field *field, struct hid_usage *usage,
 115                 unsigned long **bit, int *max)
 116 {
 117         /* tell hid-input to skip setup of these event types */
 118         if (usage->type == EV_KEY || usage->type == EV_ABS)
 119                 set_bit(usage->type, hi->input->evbit);
 120         return -1;
 121 }
 122
 123 /*
 124  * this function is called when a whole finger has been parsed,
 125  * so that it can decide what to send to the input layer.
 126  */
 127 static void egalax_filter_event(struct egalax_data *td, struct input_dev *input)
 128 {
 129         input_mt_slot(input, td->slot);
 130         input_mt_report_slot_state(input, MT_TOOL_FINGER, td->touch);
 131         if (td->touch) {
 132                 input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x);
 133                 input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y);
 134                 input_event(input, EV_ABS, ABS_MT_PRESSURE, td->z);
 135         }
 136         input_mt_report_pointer_emulation(input, true);
 137 }
 138
 139 static int egalax_event(struct hid_device *hid, struct hid_field *field,
 140                                 struct hid_usage *usage, __s32 value)
 141 {
 142         struct egalax_data *td = hid_get_drvdata(hid);
 143
 144         /* Note, eGalax has two product lines: the first is resistive and
 145          * uses a standard parallel multitouch protocol (product ID ==
 146          * 48xx).  The second is capacitive and uses an unusual "serial"
 147          * protocol with a different message for each multitouch finger
 148          * (product ID == 72xx).
 149          */
 150         if (hid->claimed & HID_CLAIMED_INPUT) {
 151                 struct input_dev *input = field->hidinput->input;
 152
 153                 switch (usage->hid) {
 154                 case HID_DG_INRANGE:
 155                         td->valid = value;
 156                         break;
 157                 case HID_DG_CONFIDENCE:
 158                         /* avoid interference from generic hidinput handling */
 159                         break;
 160                 case HID_DG_TIPSWITCH:
 161                         td->touch = value;
 162                         break;
 163                 case HID_DG_TIPPRESSURE:
 164                         td->z = value;
 165                         break;
 166                 case HID_DG_CONTACTID:
 167                         td->slot = clamp_val(value, 0, MAX_SLOTS - 1);
 168                         break;
 169                 case HID_GD_X:
 170                         td->x = value;
 171                         break;
 172                 case HID_GD_Y:
 173                         td->y = value;
 174                         /* this is the last field in a finger */
 175                         if (td->valid)
 176                                 egalax_filter_event(td, input);
 177                         break;
 178                 case HID_DG_CONTACTCOUNT:
 179                         /* touch emulation: this is the last field in a frame */
 180                         break;
 181
 182                 default:
 183                         /* fallback to the generic hidinput handling */
 184                         return 0;
 185                 }
 186         }
 187
 188         /* we have handled the hidinput part, now remains hiddev */
 189         if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
 190                 hid->hiddev_hid_event(hid, field, usage, value);
 191
 192         return 1;
 193 }
 194
 195 static int egalax_probe(struct hid_device *hdev, const struct hid_device_id *id)
 196 {
 197         int ret;
 198         struct egalax_data *td;
 199         struct hid_report *report;
 200
 201         td = kzalloc(sizeof(struct egalax_data), GFP_KERNEL);
 202         if (!td) {
 203                 hid_err(hdev, "cannot allocate eGalax data\n");
 204                 return -ENOMEM;
 205         }
 206         hid_set_drvdata(hdev, td);
 207
 208         ret = hid_parse(hdev);
 209         if (ret)
 210                 goto end;
 211
 212         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 213         if (ret)
 214                 goto end;
 215
 216         report = hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[5];
 217         if (report) {
 218                 report->field[0]->value[0] = 2;
 219                 usbhid_submit_report(hdev, report, USB_DIR_OUT);
 220         }
 221
 222 end:
 223         if (ret)
 224                 kfree(td);
 225
 226         return ret;
 227 }
 228
 229 static void egalax_remove(struct hid_device *hdev)
 230 {
 231         hid_hw_stop(hdev);
 232         kfree(hid_get_drvdata(hdev));
 233         hid_set_drvdata(hdev, NULL);
 234 }
 235
 236 static const struct hid_device_id egalax_devices[] = {
 237         { HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 238                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH) },
 239         { HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 240                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH1) },
 241         { HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 242                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH2) },
 243         { HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 244                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH3) },
 245         { HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 246                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH4) },
 247         { }
 248 };
 249 MODULE_DEVICE_TABLE(hid, egalax_devices);
 250
 251 static const struct hid_usage_id egalax_grabbed_usages[] = {
 252         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
 253         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
 254 };
 255
 256 static struct hid_driver egalax_driver = {
 257         .name = "egalax-touch",
 258         .id_table = egalax_devices,
 259         .probe = egalax_probe,
 260         .remove = egalax_remove,
 261         .input_mapping = egalax_input_mapping,
 262         .input_mapped = egalax_input_mapped,
 263         .usage_table = egalax_grabbed_usages,
 264         .event = egalax_event,
 265 };
 266
 267 static int __init egalax_init(void)
 268 {
 269         return hid_register_driver(&egalax_driver);
 270 }
 271
 272 static void __exit egalax_exit(void)
 273 {
 274         hid_unregister_driver(&egalax_driver);
 275 }
 276
 277 module_init(egalax_init);
 278 module_exit(egalax_exit);
 279