drivers/hid/hid-quanta.c

   1 /*
   2  *  HID driver for Quanta Optical Touch dual-touch panels
   3  *
   4  *  Copyright (c) 2009-2010 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/slab.h>
  19
  20 MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
  21 MODULE_DESCRIPTION("Quanta dual-touch panel");
  22 MODULE_LICENSE("GPL");
  23
  24 #include "hid-ids.h"
  25
  26 struct quanta_data {
  27         __u16 x, y;
  28         __u8 id;
  29         bool valid;             /* valid finger data, or just placeholder? */
  30         bool first;             /* is this the first finger in this frame? */
  31         bool activity_now;      /* at least one active finger in this frame? */
  32         bool activity;          /* at least one active finger previously? */
  33 };
  34
  35 static int quanta_input_mapping(struct hid_device *hdev, struct hid_input *hi,
  36                 struct hid_field *field, struct hid_usage *usage,
  37                 unsigned long **bit, int *max)
  38 {
  39         switch (usage->hid & HID_USAGE_PAGE) {
  40
  41         case HID_UP_GENDESK:
  42                 switch (usage->hid) {
  43                 case HID_GD_X:
  44                         hid_map_usage(hi, usage, bit, max,
  45                                         EV_ABS, ABS_MT_POSITION_X);
  46                         /* touchscreen emulation */
  47                         input_set_abs_params(hi->input, ABS_X,
  48                                                 field->logical_minimum,
  49                                                 field->logical_maximum, 0, 0);
  50                         return 1;
  51                 case HID_GD_Y:
  52                         hid_map_usage(hi, usage, bit, max,
  53                                         EV_ABS, ABS_MT_POSITION_Y);
  54                         /* touchscreen emulation */
  55                         input_set_abs_params(hi->input, ABS_Y,
  56                                                 field->logical_minimum,
  57                                                 field->logical_maximum, 0, 0);
  58                         return 1;
  59                 }
  60                 return 0;
  61
  62         case HID_UP_DIGITIZER:
  63                 switch (usage->hid) {
  64                 case HID_DG_CONFIDENCE:
  65                 case HID_DG_TIPSWITCH:
  66                 case HID_DG_INPUTMODE:
  67                 case HID_DG_DEVICEINDEX:
  68                 case HID_DG_CONTACTCOUNT:
  69                 case HID_DG_CONTACTMAX:
  70                 case HID_DG_TIPPRESSURE:
  71                 case HID_DG_WIDTH:
  72                 case HID_DG_HEIGHT:
  73                         return -1;
  74                 case HID_DG_INRANGE:
  75                         /* touchscreen emulation */
  76                         hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
  77                         return 1;
  78                 case HID_DG_CONTACTID:
  79                         hid_map_usage(hi, usage, bit, max,
  80                                         EV_ABS, ABS_MT_TRACKING_ID);
  81                         return 1;
  82                 }
  83                 return 0;
  84
  85         case 0xff000000:
  86                 /* ignore vendor-specific features */
  87                 return -1;
  88         }
  89
  90         return 0;
  91 }
  92
  93 static int quanta_input_mapped(struct hid_device *hdev, struct hid_input *hi,
  94                 struct hid_field *field, struct hid_usage *usage,
  95                 unsigned long **bit, int *max)
  96 {
  97         if (usage->type == EV_KEY || usage->type == EV_ABS)
  98                 clear_bit(usage->code, *bit);
  99
 100         return 0;
 101 }
 102
 103 /*
 104  * this function is called when a whole finger has been parsed,
 105  * so that it can decide what to send to the input layer.
 106  */
 107 static void quanta_filter_event(struct quanta_data *td, struct input_dev *input)
 108 {
 109
 110         td->first = !td->first; /* touchscreen emulation */
 111
 112         if (!td->valid) {
 113                 /*
 114                  * touchscreen emulation: if no finger in this frame is valid
 115                  * and there previously was finger activity, this is a release
 116                  */
 117                 if (!td->first && !td->activity_now && td->activity) {
 118                         input_event(input, EV_KEY, BTN_TOUCH, 0);
 119                         td->activity = false;
 120                 }
 121                 return;
 122         }
 123
 124         input_event(input, EV_ABS, ABS_MT_TRACKING_ID, td->id);
 125         input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x);
 126         input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y);
 127
 128         input_mt_sync(input);
 129         td->valid = false;
 130
 131         /* touchscreen emulation: if first active finger in this frame... */
 132         if (!td->activity_now) {
 133                 /* if there was no previous activity, emit touch event */
 134                 if (!td->activity) {
 135                         input_event(input, EV_KEY, BTN_TOUCH, 1);
 136                         td->activity = true;
 137                 }
 138                 td->activity_now = true;
 139                 /* and in any case this is our preferred finger */
 140                 input_event(input, EV_ABS, ABS_X, td->x);
 141                 input_event(input, EV_ABS, ABS_Y, td->y);
 142         }
 143 }
 144
 145
 146 static int quanta_event(struct hid_device *hid, struct hid_field *field,
 147                                 struct hid_usage *usage, __s32 value)
 148 {
 149         struct quanta_data *td = hid_get_drvdata(hid);
 150
 151         if (hid->claimed & HID_CLAIMED_INPUT) {
 152                 struct input_dev *input = field->hidinput->input;
 153
 154                 switch (usage->hid) {
 155                 case HID_DG_INRANGE:
 156                         td->valid = !!value;
 157                         break;
 158                 case HID_GD_X:
 159                         td->x = value;
 160                         break;
 161                 case HID_GD_Y:
 162                         td->y = value;
 163                         quanta_filter_event(td, input);
 164                         break;
 165                 case HID_DG_CONTACTID:
 166                         td->id = value;
 167                         break;
 168                 case HID_DG_CONTACTCOUNT:
 169                         /* touch emulation: this is the last field in a frame */
 170                         td->first = false;
 171                         td->activity_now = false;
 172                         break;
 173                 case HID_DG_CONFIDENCE:
 174                 case HID_DG_TIPSWITCH:
 175                         /* avoid interference from generic hidinput handling */
 176                         break;
 177
 178                 default:
 179                         /* fallback to the generic hidinput handling */
 180                         return 0;
 181                 }
 182         }
 183
 184         /* we have handled the hidinput part, now remains hiddev */
 185         if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
 186                 hid->hiddev_hid_event(hid, field, usage, value);
 187
 188         return 1;
 189 }
 190
 191 static int quanta_probe(struct hid_device *hdev, const struct hid_device_id *id)
 192 {
 193         int ret;
 194         struct quanta_data *td;
 195
 196         td = kmalloc(sizeof(struct quanta_data), GFP_KERNEL);
 197         if (!td) {
 198                 hid_err(hdev, "cannot allocate Quanta Touch data\n");
 199                 return -ENOMEM;
 200         }
 201         td->valid = false;
 202         td->activity = false;
 203         td->activity_now = false;
 204         td->first = false;
 205         hid_set_drvdata(hdev, td);
 206
 207         ret = hid_parse(hdev);
 208         if (!ret)
 209                 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 210
 211         if (ret)
 212                 kfree(td);
 213
 214         return ret;
 215 }
 216
 217 static void quanta_remove(struct hid_device *hdev)
 218 {
 219         hid_hw_stop(hdev);
 220         kfree(hid_get_drvdata(hdev));
 221         hid_set_drvdata(hdev, NULL);
 222 }
 223
 224 static const struct hid_device_id quanta_devices[] = {
 225         { HID_USB_DEVICE(USB_VENDOR_ID_QUANTA,
 226                         USB_DEVICE_ID_QUANTA_OPTICAL_TOUCH) },
 227         { HID_USB_DEVICE(USB_VENDOR_ID_QUANTA,
 228                         USB_DEVICE_ID_PIXART_IMAGING_INC_OPTICAL_TOUCH_SCREEN) },
 229         { }
 230 };
 231 MODULE_DEVICE_TABLE(hid, quanta_devices);
 232
 233 static const struct hid_usage_id quanta_grabbed_usages[] = {
 234         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
 235         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
 236 };
 237
 238 static struct hid_driver quanta_driver = {
 239         .name = "quanta-touch",
 240         .id_table = quanta_devices,
 241         .probe = quanta_probe,
 242         .remove = quanta_remove,
 243         .input_mapping = quanta_input_mapping,
 244         .input_mapped = quanta_input_mapped,
 245         .usage_table = quanta_grabbed_usages,
 246         .event = quanta_event,
 247 };
 248
 249 static int __init quanta_init(void)
 250 {
 251         return hid_register_driver(&quanta_driver);
 252 }
 253
 254 static void __exit quanta_exit(void)
 255 {
 256         hid_unregister_driver(&quanta_driver);
 257 }
 258
 259 module_init(quanta_init);
 260 module_exit(quanta_exit);
 261