linux/drivers/input/touchscreen/elo.c
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   1/*
   2 * Elo serial touchscreen driver
   3 *
   4 * Copyright (c) 2004 Vojtech Pavlik
   5 */
   6
   7/*
   8 * This program is free software; you can redistribute it and/or modify it
   9 * under the terms of the GNU General Public License version 2 as published by
  10 * the Free Software Foundation.
  11 */
  12
  13/*
  14 * This driver can handle serial Elo touchscreens using either the Elo standard
  15 * 'E271-2210' 10-byte protocol, Elo legacy 'E281A-4002' 6-byte protocol, Elo
  16 * legacy 'E271-140' 4-byte protocol and Elo legacy 'E261-280' 3-byte protocol.
  17 */
  18
  19#include <linux/errno.h>
  20#include <linux/kernel.h>
  21#include <linux/module.h>
  22#include <linux/slab.h>
  23#include <linux/input.h>
  24#include <linux/serio.h>
  25#include <linux/ctype.h>
  26
  27#define DRIVER_DESC     "Elo serial touchscreen driver"
  28
  29MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  30MODULE_DESCRIPTION(DRIVER_DESC);
  31MODULE_LICENSE("GPL");
  32
  33/*
  34 * Definitions & global arrays.
  35 */
  36
  37#define ELO_MAX_LENGTH          10
  38
  39#define ELO10_PACKET_LEN        8
  40#define ELO10_TOUCH             0x03
  41#define ELO10_PRESSURE          0x80
  42
  43#define ELO10_LEAD_BYTE         'U'
  44
  45#define ELO10_ID_CMD            'i'
  46
  47#define ELO10_TOUCH_PACKET      'T'
  48#define ELO10_ACK_PACKET        'A'
  49#define ELI10_ID_PACKET         'I'
  50
  51/*
  52 * Per-touchscreen data.
  53 */
  54
  55struct elo {
  56        struct input_dev *dev;
  57        struct serio *serio;
  58        struct mutex cmd_mutex;
  59        struct completion cmd_done;
  60        int id;
  61        int idx;
  62        unsigned char expected_packet;
  63        unsigned char csum;
  64        unsigned char data[ELO_MAX_LENGTH];
  65        unsigned char response[ELO10_PACKET_LEN];
  66        char phys[32];
  67};
  68
  69static void elo_process_data_10(struct elo *elo, unsigned char data)
  70{
  71        struct input_dev *dev = elo->dev;
  72
  73        elo->data[elo->idx] = data;
  74
  75        switch (elo->idx++) {
  76        case 0:
  77                elo->csum = 0xaa;
  78                if (data != ELO10_LEAD_BYTE) {
  79                        dev_dbg(&elo->serio->dev,
  80                                "unsynchronized data: 0x%02x\n", data);
  81                        elo->idx = 0;
  82                }
  83                break;
  84
  85        case 9:
  86                elo->idx = 0;
  87                if (data != elo->csum) {
  88                        dev_dbg(&elo->serio->dev,
  89                                "bad checksum: 0x%02x, expected 0x%02x\n",
  90                                 data, elo->csum);
  91                        break;
  92                }
  93                if (elo->data[1] != elo->expected_packet) {
  94                        if (elo->data[1] != ELO10_TOUCH_PACKET)
  95                                dev_dbg(&elo->serio->dev,
  96                                        "unexpected packet: 0x%02x\n",
  97                                         elo->data[1]);
  98                        break;
  99                }
 100                if (likely(elo->data[1] == ELO10_TOUCH_PACKET)) {
 101                        input_report_abs(dev, ABS_X, (elo->data[4] << 8) | elo->data[3]);
 102                        input_report_abs(dev, ABS_Y, (elo->data[6] << 8) | elo->data[5]);
 103                        if (elo->data[2] & ELO10_PRESSURE)
 104                                input_report_abs(dev, ABS_PRESSURE,
 105                                                (elo->data[8] << 8) | elo->data[7]);
 106                        input_report_key(dev, BTN_TOUCH, elo->data[2] & ELO10_TOUCH);
 107                        input_sync(dev);
 108                } else if (elo->data[1] == ELO10_ACK_PACKET) {
 109                        if (elo->data[2] == '0')
 110                                elo->expected_packet = ELO10_TOUCH_PACKET;
 111                        complete(&elo->cmd_done);
 112                } else {
 113                        memcpy(elo->response, &elo->data[1], ELO10_PACKET_LEN);
 114                        elo->expected_packet = ELO10_ACK_PACKET;
 115                }
 116                break;
 117        }
 118        elo->csum += data;
 119}
 120
 121static void elo_process_data_6(struct elo *elo, unsigned char data)
 122{
 123        struct input_dev *dev = elo->dev;
 124
 125        elo->data[elo->idx] = data;
 126
 127        switch (elo->idx++) {
 128
 129        case 0:
 130                if ((data & 0xc0) != 0xc0)
 131                        elo->idx = 0;
 132                break;
 133
 134        case 1:
 135                if ((data & 0xc0) != 0x80)
 136                        elo->idx = 0;
 137                break;
 138
 139        case 2:
 140                if ((data & 0xc0) != 0x40)
 141                        elo->idx = 0;
 142                break;
 143
 144        case 3:
 145                if (data & 0xc0) {
 146                        elo->idx = 0;
 147                        break;
 148                }
 149
 150                input_report_abs(dev, ABS_X, ((elo->data[0] & 0x3f) << 6) | (elo->data[1] & 0x3f));
 151                input_report_abs(dev, ABS_Y, ((elo->data[2] & 0x3f) << 6) | (elo->data[3] & 0x3f));
 152
 153                if (elo->id == 2) {
 154                        input_report_key(dev, BTN_TOUCH, 1);
 155                        input_sync(dev);
 156                        elo->idx = 0;
 157                }
 158
 159                break;
 160
 161        case 4:
 162                if (data) {
 163                        input_sync(dev);
 164                        elo->idx = 0;
 165                }
 166                break;
 167
 168        case 5:
 169                if ((data & 0xf0) == 0) {
 170                        input_report_abs(dev, ABS_PRESSURE, elo->data[5]);
 171                        input_report_key(dev, BTN_TOUCH, !!elo->data[5]);
 172                }
 173                input_sync(dev);
 174                elo->idx = 0;
 175                break;
 176        }
 177}
 178
 179static void elo_process_data_3(struct elo *elo, unsigned char data)
 180{
 181        struct input_dev *dev = elo->dev;
 182
 183        elo->data[elo->idx] = data;
 184
 185        switch (elo->idx++) {
 186
 187        case 0:
 188                if ((data & 0x7f) != 0x01)
 189                        elo->idx = 0;
 190                break;
 191        case 2:
 192                input_report_key(dev, BTN_TOUCH, !(elo->data[1] & 0x80));
 193                input_report_abs(dev, ABS_X, elo->data[1]);
 194                input_report_abs(dev, ABS_Y, elo->data[2]);
 195                input_sync(dev);
 196                elo->idx = 0;
 197                break;
 198        }
 199}
 200
 201static irqreturn_t elo_interrupt(struct serio *serio,
 202                unsigned char data, unsigned int flags)
 203{
 204        struct elo *elo = serio_get_drvdata(serio);
 205
 206        switch (elo->id) {
 207        case 0:
 208                elo_process_data_10(elo, data);
 209                break;
 210
 211        case 1:
 212        case 2:
 213                elo_process_data_6(elo, data);
 214                break;
 215
 216        case 3:
 217                elo_process_data_3(elo, data);
 218                break;
 219        }
 220
 221        return IRQ_HANDLED;
 222}
 223
 224static int elo_command_10(struct elo *elo, unsigned char *packet)
 225{
 226        int rc = -1;
 227        int i;
 228        unsigned char csum = 0xaa + ELO10_LEAD_BYTE;
 229
 230        mutex_lock(&elo->cmd_mutex);
 231
 232        serio_pause_rx(elo->serio);
 233        elo->expected_packet = toupper(packet[0]);
 234        init_completion(&elo->cmd_done);
 235        serio_continue_rx(elo->serio);
 236
 237        if (serio_write(elo->serio, ELO10_LEAD_BYTE))
 238                goto out;
 239
 240        for (i = 0; i < ELO10_PACKET_LEN; i++) {
 241                csum += packet[i];
 242                if (serio_write(elo->serio, packet[i]))
 243                        goto out;
 244        }
 245
 246        if (serio_write(elo->serio, csum))
 247                goto out;
 248
 249        wait_for_completion_timeout(&elo->cmd_done, HZ);
 250
 251        if (elo->expected_packet == ELO10_TOUCH_PACKET) {
 252                /* We are back in reporting mode, the command was ACKed */
 253                memcpy(packet, elo->response, ELO10_PACKET_LEN);
 254                rc = 0;
 255        }
 256
 257 out:
 258        mutex_unlock(&elo->cmd_mutex);
 259        return rc;
 260}
 261
 262static int elo_setup_10(struct elo *elo)
 263{
 264        static const char *elo_types[] = { "Accu", "Dura", "Intelli", "Carroll" };
 265        struct input_dev *dev = elo->dev;
 266        unsigned char packet[ELO10_PACKET_LEN] = { ELO10_ID_CMD };
 267
 268        if (elo_command_10(elo, packet))
 269                return -1;
 270
 271        dev->id.version = (packet[5] << 8) | packet[4];
 272
 273        input_set_abs_params(dev, ABS_X, 96, 4000, 0, 0);
 274        input_set_abs_params(dev, ABS_Y, 96, 4000, 0, 0);
 275        if (packet[3] & ELO10_PRESSURE)
 276                input_set_abs_params(dev, ABS_PRESSURE, 0, 255, 0, 0);
 277
 278        dev_info(&elo->serio->dev,
 279                 "%sTouch touchscreen, fw: %02x.%02x, features: 0x%02x, controller: 0x%02x\n",
 280                 elo_types[(packet[1] -'0') & 0x03],
 281                 packet[5], packet[4], packet[3], packet[7]);
 282
 283        return 0;
 284}
 285
 286/*
 287 * elo_disconnect() is the opposite of elo_connect()
 288 */
 289
 290static void elo_disconnect(struct serio *serio)
 291{
 292        struct elo *elo = serio_get_drvdata(serio);
 293
 294        input_get_device(elo->dev);
 295        input_unregister_device(elo->dev);
 296        serio_close(serio);
 297        serio_set_drvdata(serio, NULL);
 298        input_put_device(elo->dev);
 299        kfree(elo);
 300}
 301
 302/*
 303 * elo_connect() is the routine that is called when someone adds a
 304 * new serio device that supports Gunze protocol and registers it as
 305 * an input device.
 306 */
 307
 308static int elo_connect(struct serio *serio, struct serio_driver *drv)
 309{
 310        struct elo *elo;
 311        struct input_dev *input_dev;
 312        int err;
 313
 314        elo = kzalloc(sizeof(struct elo), GFP_KERNEL);
 315        input_dev = input_allocate_device();
 316        if (!elo || !input_dev) {
 317                err = -ENOMEM;
 318                goto fail1;
 319        }
 320
 321        elo->serio = serio;
 322        elo->id = serio->id.id;
 323        elo->dev = input_dev;
 324        elo->expected_packet = ELO10_TOUCH_PACKET;
 325        mutex_init(&elo->cmd_mutex);
 326        init_completion(&elo->cmd_done);
 327        snprintf(elo->phys, sizeof(elo->phys), "%s/input0", serio->phys);
 328
 329        input_dev->name = "Elo Serial TouchScreen";
 330        input_dev->phys = elo->phys;
 331        input_dev->id.bustype = BUS_RS232;
 332        input_dev->id.vendor = SERIO_ELO;
 333        input_dev->id.product = elo->id;
 334        input_dev->id.version = 0x0100;
 335        input_dev->dev.parent = &serio->dev;
 336
 337        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 338        input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 339
 340        serio_set_drvdata(serio, elo);
 341        err = serio_open(serio, drv);
 342        if (err)
 343                goto fail2;
 344
 345        switch (elo->id) {
 346
 347        case 0: /* 10-byte protocol */
 348                if (elo_setup_10(elo))
 349                        goto fail3;
 350
 351                break;
 352
 353        case 1: /* 6-byte protocol */
 354                input_set_abs_params(input_dev, ABS_PRESSURE, 0, 15, 0, 0);
 355                /* fall through */
 356
 357        case 2: /* 4-byte protocol */
 358                input_set_abs_params(input_dev, ABS_X, 96, 4000, 0, 0);
 359                input_set_abs_params(input_dev, ABS_Y, 96, 4000, 0, 0);
 360                break;
 361
 362        case 3: /* 3-byte protocol */
 363                input_set_abs_params(input_dev, ABS_X, 0, 255, 0, 0);
 364                input_set_abs_params(input_dev, ABS_Y, 0, 255, 0, 0);
 365                break;
 366        }
 367
 368        err = input_register_device(elo->dev);
 369        if (err)
 370                goto fail3;
 371
 372        return 0;
 373
 374 fail3: serio_close(serio);
 375 fail2: serio_set_drvdata(serio, NULL);
 376 fail1: input_free_device(input_dev);
 377        kfree(elo);
 378        return err;
 379}
 380
 381/*
 382 * The serio driver structure.
 383 */
 384
 385static const struct serio_device_id elo_serio_ids[] = {
 386        {
 387                .type   = SERIO_RS232,
 388                .proto  = SERIO_ELO,
 389                .id     = SERIO_ANY,
 390                .extra  = SERIO_ANY,
 391        },
 392        { 0 }
 393};
 394
 395MODULE_DEVICE_TABLE(serio, elo_serio_ids);
 396
 397static struct serio_driver elo_drv = {
 398        .driver         = {
 399                .name   = "elo",
 400        },
 401        .description    = DRIVER_DESC,
 402        .id_table       = elo_serio_ids,
 403        .interrupt      = elo_interrupt,
 404        .connect        = elo_connect,
 405        .disconnect     = elo_disconnect,
 406};
 407
 408module_serio_driver(elo_drv);
 409