| 1 | /* |
| 2 | * HID driver for Cando 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/slab.h> |
| 19 | |
| 20 | MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>"); |
| 21 | MODULE_DESCRIPTION("Cando dual-touch panel"); |
| 22 | MODULE_LICENSE("GPL"); |
| 23 | |
| 24 | #include "hid-ids.h" |
| 25 | |
| 26 | struct cando_data { |
| 27 | __u16 x, y; |
| 28 | __u8 id; |
| 29 | __s8 oldest; /* id of the oldest finger in previous frame */ |
| 30 | bool valid; /* valid finger data, or just placeholder? */ |
| 31 | bool first; /* is this the first finger in this frame? */ |
| 32 | __s8 firstid; /* id of the first finger in the frame */ |
| 33 | __u16 firstx, firsty; /* (x, y) of the first finger in the frame */ |
| 34 | }; |
| 35 | |
| 36 | static int cando_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 | case HID_DG_CONTACTMAX: |
| 67 | return -1; |
| 68 | case HID_DG_INRANGE: |
| 69 | /* touchscreen emulation */ |
| 70 | hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH); |
| 71 | return 1; |
| 72 | case HID_DG_CONTACTID: |
| 73 | hid_map_usage(hi, usage, bit, max, |
| 74 | EV_ABS, ABS_MT_TRACKING_ID); |
| 75 | return 1; |
| 76 | } |
| 77 | return 0; |
| 78 | } |
| 79 | |
| 80 | return 0; |
| 81 | } |
| 82 | |
| 83 | static int cando_input_mapped(struct hid_device *hdev, struct hid_input *hi, |
| 84 | struct hid_field *field, struct hid_usage *usage, |
| 85 | unsigned long **bit, int *max) |
| 86 | { |
| 87 | if (usage->type == EV_KEY || usage->type == EV_ABS) |
| 88 | clear_bit(usage->code, *bit); |
| 89 | |
| 90 | return 0; |
| 91 | } |
| 92 | |
| 93 | /* |
| 94 | * this function is called when a whole finger has been parsed, |
| 95 | * so that it can decide what to send to the input layer. |
| 96 | */ |
| 97 | static void cando_filter_event(struct cando_data *td, struct input_dev *input) |
| 98 | { |
| 99 | td->first = !td->first; /* touchscreen emulation */ |
| 100 | |
| 101 | if (!td->valid) { |
| 102 | /* |
| 103 | * touchscreen emulation: if this is the second finger and |
| 104 | * the first was valid, the first was the oldest; if the |
| 105 | * first was not valid and there was a valid finger in the |
| 106 | * previous frame, this is a release. |
| 107 | */ |
| 108 | if (td->first) { |
| 109 | td->firstid = -1; |
| 110 | } else if (td->firstid >= 0) { |
| 111 | input_event(input, EV_ABS, ABS_X, td->firstx); |
| 112 | input_event(input, EV_ABS, ABS_Y, td->firsty); |
| 113 | td->oldest = td->firstid; |
| 114 | } else if (td->oldest >= 0) { |
| 115 | input_event(input, EV_KEY, BTN_TOUCH, 0); |
| 116 | td->oldest = -1; |
| 117 | } |
| 118 | |
| 119 | return; |
| 120 | } |
| 121 | |
| 122 | input_event(input, EV_ABS, ABS_MT_TRACKING_ID, td->id); |
| 123 | input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x); |
| 124 | input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y); |
| 125 | |
| 126 | input_mt_sync(input); |
| 127 | |
| 128 | /* |
| 129 | * touchscreen emulation: if there was no touching finger previously, |
| 130 | * emit touch event |
| 131 | */ |
| 132 | if (td->oldest < 0) { |
| 133 | input_event(input, EV_KEY, BTN_TOUCH, 1); |
| 134 | td->oldest = td->id; |
| 135 | } |
| 136 | |
| 137 | /* |
| 138 | * touchscreen emulation: if this is the first finger, wait for the |
| 139 | * second; the oldest is then the second if it was the oldest already |
| 140 | * or if there was no first, the first otherwise. |
| 141 | */ |
| 142 | if (td->first) { |
| 143 | td->firstx = td->x; |
| 144 | td->firsty = td->y; |
| 145 | td->firstid = td->id; |
| 146 | } else { |
| 147 | int x, y, oldest; |
| 148 | if (td->id == td->oldest || td->firstid < 0) { |
| 149 | x = td->x; |
| 150 | y = td->y; |
| 151 | oldest = td->id; |
| 152 | } else { |
| 153 | x = td->firstx; |
| 154 | y = td->firsty; |
| 155 | oldest = td->firstid; |
| 156 | } |
| 157 | input_event(input, EV_ABS, ABS_X, x); |
| 158 | input_event(input, EV_ABS, ABS_Y, y); |
| 159 | td->oldest = oldest; |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | |
| 164 | static int cando_event(struct hid_device *hid, struct hid_field *field, |
| 165 | struct hid_usage *usage, __s32 value) |
| 166 | { |
| 167 | struct cando_data *td = hid_get_drvdata(hid); |
| 168 | |
| 169 | if (hid->claimed & HID_CLAIMED_INPUT) { |
| 170 | struct input_dev *input = field->hidinput->input; |
| 171 | |
| 172 | switch (usage->hid) { |
| 173 | case HID_DG_INRANGE: |
| 174 | td->valid = value; |
| 175 | break; |
| 176 | case HID_DG_CONTACTID: |
| 177 | td->id = value; |
| 178 | break; |
| 179 | case HID_GD_X: |
| 180 | td->x = value; |
| 181 | break; |
| 182 | case HID_GD_Y: |
| 183 | td->y = value; |
| 184 | cando_filter_event(td, input); |
| 185 | break; |
| 186 | case HID_DG_TIPSWITCH: |
| 187 | /* avoid interference from generic hidinput handling */ |
| 188 | break; |
| 189 | |
| 190 | default: |
| 191 | /* fallback to the generic hidinput handling */ |
| 192 | return 0; |
| 193 | } |
| 194 | } |
| 195 | |
| 196 | /* we have handled the hidinput part, now remains hiddev */ |
| 197 | if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event) |
| 198 | hid->hiddev_hid_event(hid, field, usage, value); |
| 199 | |
| 200 | return 1; |
| 201 | } |
| 202 | |
| 203 | static int cando_probe(struct hid_device *hdev, const struct hid_device_id *id) |
| 204 | { |
| 205 | int ret; |
| 206 | struct cando_data *td; |
| 207 | |
| 208 | td = kmalloc(sizeof(struct cando_data), GFP_KERNEL); |
| 209 | if (!td) { |
| 210 | dev_err(&hdev->dev, "cannot allocate Cando Touch data\n"); |
| 211 | return -ENOMEM; |
| 212 | } |
| 213 | hid_set_drvdata(hdev, td); |
| 214 | td->first = false; |
| 215 | td->oldest = -1; |
| 216 | td->valid = false; |
| 217 | |
| 218 | ret = hid_parse(hdev); |
| 219 | if (!ret) |
| 220 | ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT); |
| 221 | |
| 222 | if (ret) |
| 223 | kfree(td); |
| 224 | |
| 225 | return ret; |
| 226 | } |
| 227 | |
| 228 | static void cando_remove(struct hid_device *hdev) |
| 229 | { |
| 230 | hid_hw_stop(hdev); |
| 231 | kfree(hid_get_drvdata(hdev)); |
| 232 | hid_set_drvdata(hdev, NULL); |
| 233 | } |
| 234 | |
| 235 | static const struct hid_device_id cando_devices[] = { |
| 236 | { HID_USB_DEVICE(USB_VENDOR_ID_CANDO, |
| 237 | USB_DEVICE_ID_CANDO_MULTI_TOUCH) }, |
| 238 | { HID_USB_DEVICE(USB_VENDOR_ID_CANDO, |
| 239 | USB_DEVICE_ID_CANDO_MULTI_TOUCH_11_6) }, |
| 240 | { } |
| 241 | }; |
| 242 | MODULE_DEVICE_TABLE(hid, cando_devices); |
| 243 | |
| 244 | static const struct hid_usage_id cando_grabbed_usages[] = { |
| 245 | { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID }, |
| 246 | { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1} |
| 247 | }; |
| 248 | |
| 249 | static struct hid_driver cando_driver = { |
| 250 | .name = "cando-touch", |
| 251 | .id_table = cando_devices, |
| 252 | .probe = cando_probe, |
| 253 | .remove = cando_remove, |
| 254 | .input_mapping = cando_input_mapping, |
| 255 | .input_mapped = cando_input_mapped, |
| 256 | .usage_table = cando_grabbed_usages, |
| 257 | .event = cando_event, |
| 258 | }; |
| 259 | |
| 260 | static int __init cando_init(void) |
| 261 | { |
| 262 | return hid_register_driver(&cando_driver); |
| 263 | } |
| 264 | |
| 265 | static void __exit cando_exit(void) |
| 266 | { |
| 267 | hid_unregister_driver(&cando_driver); |
| 268 | } |
| 269 | |
| 270 | module_init(cando_init); |
| 271 | module_exit(cando_exit); |
| 272 | |