LXR linux/drivers/input/touchscreen/hampshire.c

   1/*
   2 * Hampshire serial touchscreen driver
   3 *
   4 * Copyright (c) 2010 Adam Bennett
   5 * Based on the dynapro driver (c) Tias Guns
   6 *
   7 */
   8
   9/*
  10 * This program is free software; you can redistribute it and/or modify it
  11 * under the terms of the GNU General Public License version 2 as published by
  12 * the Free Software Foundation.
  13 */
  14
  15/*
  16 * 2010/04/08 Adam Bennett <abennett72@gmail.com>
  17 *   Copied dynapro.c and edited for Hampshire 4-byte protocol
  18 */
  19
  20#include <linux/errno.h>
  21#include <linux/kernel.h>
  22#include <linux/module.h>
  23#include <linux/slab.h>
  24#include <linux/input.h>
  25#include <linux/serio.h>
  26
  27#define DRIVER_DESC     "Hampshire serial touchscreen driver"
  28
  29MODULE_AUTHOR("Adam Bennett <abennett72@gmail.com>");
  30MODULE_DESCRIPTION(DRIVER_DESC);
  31MODULE_LICENSE("GPL");
  32
  33/*
  34 * Definitions & global arrays.
  35 */
  36
  37#define HAMPSHIRE_FORMAT_TOUCH_BIT 0x40
  38#define HAMPSHIRE_FORMAT_LENGTH 4
  39#define HAMPSHIRE_RESPONSE_BEGIN_BYTE 0x80
  40
  41#define HAMPSHIRE_MIN_XC 0
  42#define HAMPSHIRE_MAX_XC 0x1000
  43#define HAMPSHIRE_MIN_YC 0
  44#define HAMPSHIRE_MAX_YC 0x1000
  45
  46#define HAMPSHIRE_GET_XC(data) (((data[3] & 0x0c) >> 2) | (data[1] << 2) | ((data[0] & 0x38) << 6))
  47#define HAMPSHIRE_GET_YC(data) ((data[3] & 0x03) | (data[2] << 2) | ((data[0] & 0x07) << 9))
  48#define HAMPSHIRE_GET_TOUCHED(data) (HAMPSHIRE_FORMAT_TOUCH_BIT & data[0])
  49
  50/*
  51 * Per-touchscreen data.
  52 */
  53
  54struct hampshire {
  55        struct input_dev *dev;
  56        struct serio *serio;
  57        int idx;
  58        unsigned char data[HAMPSHIRE_FORMAT_LENGTH];
  59        char phys[32];
  60};
  61
  62static void hampshire_process_data(struct hampshire *phampshire)
  63{
  64        struct input_dev *dev = phampshire->dev;
  65
  66        if (HAMPSHIRE_FORMAT_LENGTH == ++phampshire->idx) {
  67                input_report_abs(dev, ABS_X, HAMPSHIRE_GET_XC(phampshire->data));
  68                input_report_abs(dev, ABS_Y, HAMPSHIRE_GET_YC(phampshire->data));
  69                input_report_key(dev, BTN_TOUCH,
  70                                 HAMPSHIRE_GET_TOUCHED(phampshire->data));
  71                input_sync(dev);
  72
  73                phampshire->idx = 0;
  74        }
  75}
  76
  77static irqreturn_t hampshire_interrupt(struct serio *serio,
  78                unsigned char data, unsigned int flags)
  79{
  80        struct hampshire *phampshire = serio_get_drvdata(serio);
  81
  82        phampshire->data[phampshire->idx] = data;
  83
  84        if (HAMPSHIRE_RESPONSE_BEGIN_BYTE & phampshire->data[0])
  85                hampshire_process_data(phampshire);
  86        else
  87                dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n",
  88                        phampshire->data[0]);
  89
  90        return IRQ_HANDLED;
  91}
  92
  93static void hampshire_disconnect(struct serio *serio)
  94{
  95        struct hampshire *phampshire = serio_get_drvdata(serio);
  96
  97        input_get_device(phampshire->dev);
  98        input_unregister_device(phampshire->dev);
  99        serio_close(serio);
 100        serio_set_drvdata(serio, NULL);
 101        input_put_device(phampshire->dev);
 102        kfree(phampshire);
 103}
 104
 105/*
 106 * hampshire_connect() is the routine that is called when someone adds a
 107 * new serio device that supports hampshire protocol and registers it as
 108 * an input device. This is usually accomplished using inputattach.
 109 */
 110
 111static int hampshire_connect(struct serio *serio, struct serio_driver *drv)
 112{
 113        struct hampshire *phampshire;
 114        struct input_dev *input_dev;
 115        int err;
 116
 117        phampshire = kzalloc(sizeof(struct hampshire), GFP_KERNEL);
 118        input_dev = input_allocate_device();
 119        if (!phampshire || !input_dev) {
 120                err = -ENOMEM;
 121                goto fail1;
 122        }
 123
 124        phampshire->serio = serio;
 125        phampshire->dev = input_dev;
 126        snprintf(phampshire->phys, sizeof(phampshire->phys),
 127                 "%s/input0", serio->phys);
 128
 129        input_dev->name = "Hampshire Serial TouchScreen";
 130        input_dev->phys = phampshire->phys;
 131        input_dev->id.bustype = BUS_RS232;
 132        input_dev->id.vendor = SERIO_HAMPSHIRE;
 133        input_dev->id.product = 0;
 134        input_dev->id.version = 0x0001;
 135        input_dev->dev.parent = &serio->dev;
 136        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 137        input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 138        input_set_abs_params(phampshire->dev, ABS_X,
 139                             HAMPSHIRE_MIN_XC, HAMPSHIRE_MAX_XC, 0, 0);
 140        input_set_abs_params(phampshire->dev, ABS_Y,
 141                             HAMPSHIRE_MIN_YC, HAMPSHIRE_MAX_YC, 0, 0);
 142
 143        serio_set_drvdata(serio, phampshire);
 144
 145        err = serio_open(serio, drv);
 146        if (err)
 147                goto fail2;
 148
 149        err = input_register_device(phampshire->dev);
 150        if (err)
 151                goto fail3;
 152
 153        return 0;
 154
 155 fail3: serio_close(serio);
 156 fail2: serio_set_drvdata(serio, NULL);
 157 fail1: input_free_device(input_dev);
 158        kfree(phampshire);
 159        return err;
 160}
 161
 162/*
 163 * The serio driver structure.
 164 */
 165
 166static struct serio_device_id hampshire_serio_ids[] = {
 167        {
 168                .type   = SERIO_RS232,
 169                .proto  = SERIO_HAMPSHIRE,
 170                .id     = SERIO_ANY,
 171                .extra  = SERIO_ANY,
 172        },
 173        { 0 }
 174};
 175
 176MODULE_DEVICE_TABLE(serio, hampshire_serio_ids);
 177
 178static struct serio_driver hampshire_drv = {
 179        .driver         = {
 180                .name   = "hampshire",
 181        },
 182        .description    = DRIVER_DESC,
 183        .id_table       = hampshire_serio_ids,
 184        .interrupt      = hampshire_interrupt,
 185        .connect        = hampshire_connect,
 186        .disconnect     = hampshire_disconnect,
 187};
 188
 189module_serio_driver(hampshire_drv);
 190