drivers/input/touchscreen/wacom_w8001.c

   1 /*
   2  * Wacom W8001 penabled serial touchscreen driver
   3  *
   4  * Copyright (c) 2008 Jaya Kumar
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License. See the file COPYING in the main directory of this archive for
   8  * more details.
   9  *
  10  * Layout based on Elo serial touchscreen driver by Vojtech Pavlik
  11  */
  12
  13 #include <linux/errno.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17 #include <linux/input.h>
  18 #include <linux/serio.h>
  19 #include <linux/init.h>
  20 #include <linux/ctype.h>
  21
  22 #define DRIVER_DESC     "Wacom W8001 serial touchscreen driver"
  23
  24 MODULE_AUTHOR("Jaya Kumar <jayakumar.lkml@gmail.com>");
  25 MODULE_DESCRIPTION(DRIVER_DESC);
  26 MODULE_LICENSE("GPL");
  27
  28 #define W8001_MAX_LENGTH        11
  29 #define W8001_LEAD_MASK         0x80
  30 #define W8001_LEAD_BYTE         0x80
  31 #define W8001_TAB_MASK          0x40
  32 #define W8001_TAB_BYTE          0x40
  33
  34 #define W8001_QUERY_PACKET      0x20
  35
  36 #define W8001_CMD_START         '1'
  37 #define W8001_CMD_QUERY         '*'
  38
  39 struct w8001_coord {
  40         u8 rdy;
  41         u8 tsw;
  42         u8 f1;
  43         u8 f2;
  44         u16 x;
  45         u16 y;
  46         u16 pen_pressure;
  47         u8 tilt_x;
  48         u8 tilt_y;
  49 };
  50
  51 /*
  52  * Per-touchscreen data.
  53  */
  54
  55 struct w8001 {
  56         struct input_dev *dev;
  57         struct serio *serio;
  58         struct completion cmd_done;
  59         int id;
  60         int idx;
  61         unsigned char response_type;
  62         unsigned char response[W8001_MAX_LENGTH];
  63         unsigned char data[W8001_MAX_LENGTH];
  64         char phys[32];
  65 };
  66
  67 static void parse_data(u8 *data, struct w8001_coord *coord)
  68 {
  69         memset(coord, 0, sizeof(*coord));
  70
  71         coord->rdy = data[0] & 0x20;
  72         coord->tsw = data[0] & 0x01;
  73         coord->f1 = data[0] & 0x02;
  74         coord->f2 = data[0] & 0x04;
  75
  76         coord->x = (data[1] & 0x7F) << 9;
  77         coord->x |= (data[2] & 0x7F) << 2;
  78         coord->x |= (data[6] & 0x60) >> 5;
  79
  80         coord->y = (data[3] & 0x7F) << 9;
  81         coord->y |= (data[4] & 0x7F) << 2;
  82         coord->y |= (data[6] & 0x18) >> 3;
  83
  84         coord->pen_pressure = data[5] & 0x7F;
  85         coord->pen_pressure |= (data[6] & 0x07) << 7 ;
  86
  87         coord->tilt_x = data[7] & 0x7F;
  88         coord->tilt_y = data[8] & 0x7F;
  89 }
  90
  91 static irqreturn_t w8001_interrupt(struct serio *serio,
  92                                    unsigned char data, unsigned int flags)
  93 {
  94         struct w8001 *w8001 = serio_get_drvdata(serio);
  95         struct input_dev *dev = w8001->dev;
  96         struct w8001_coord coord;
  97         unsigned char tmp;
  98
  99         w8001->data[w8001->idx] = data;
 100         switch (w8001->idx++) {
 101         case 0:
 102                 if ((data & W8001_LEAD_MASK) != W8001_LEAD_BYTE) {
 103                         pr_debug("w8001: unsynchronized data: 0x%02x\n", data);
 104                         w8001->idx = 0;
 105                 }
 106                 break;
 107
 108         case 8:
 109                 tmp = w8001->data[0] & W8001_TAB_MASK;
 110                 if (unlikely(tmp == W8001_TAB_BYTE))
 111                         break;
 112
 113                 w8001->idx = 0;
 114                 parse_data(w8001->data, &coord);
 115                 input_report_abs(dev, ABS_X, coord.x);
 116                 input_report_abs(dev, ABS_Y, coord.y);
 117                 input_report_abs(dev, ABS_PRESSURE, coord.pen_pressure);
 118                 input_report_key(dev, BTN_TOUCH, coord.tsw);
 119                 input_sync(dev);
 120                 break;
 121
 122         case 10:
 123                 w8001->idx = 0;
 124                 memcpy(w8001->response, w8001->data, W8001_MAX_LENGTH);
 125                 w8001->response_type = W8001_QUERY_PACKET;
 126                 complete(&w8001->cmd_done);
 127                 break;
 128         }
 129
 130         return IRQ_HANDLED;
 131 }
 132
 133 static int w8001_command(struct w8001 *w8001, unsigned char command,
 134                          bool wait_response)
 135 {
 136         int rc;
 137
 138         w8001->response_type = 0;
 139         init_completion(&w8001->cmd_done);
 140
 141         rc = serio_write(w8001->serio, command);
 142         if (rc == 0 && wait_response) {
 143
 144                 wait_for_completion_timeout(&w8001->cmd_done, HZ);
 145                 if (w8001->response_type != W8001_QUERY_PACKET)
 146                         rc = -EIO;
 147         }
 148
 149         return rc;
 150 }
 151
 152 static int w8001_setup(struct w8001 *w8001)
 153 {
 154         struct input_dev *dev = w8001->dev;
 155         struct w8001_coord coord;
 156         int error;
 157
 158         error = w8001_command(w8001, W8001_CMD_QUERY, true);
 159         if (error)
 160                 return error;
 161
 162         parse_data(w8001->response, &coord);
 163
 164         input_set_abs_params(dev, ABS_X, 0, coord.x, 0, 0);
 165         input_set_abs_params(dev, ABS_Y, 0, coord.y, 0, 0);
 166         input_set_abs_params(dev, ABS_PRESSURE, 0, coord.pen_pressure, 0, 0);
 167         input_set_abs_params(dev, ABS_TILT_X, 0, coord.tilt_x, 0, 0);
 168         input_set_abs_params(dev, ABS_TILT_Y, 0, coord.tilt_y, 0, 0);
 169
 170         return w8001_command(w8001, W8001_CMD_START, false);
 171 }
 172
 173 /*
 174  * w8001_disconnect() is the opposite of w8001_connect()
 175  */
 176
 177 static void w8001_disconnect(struct serio *serio)
 178 {
 179         struct w8001 *w8001 = serio_get_drvdata(serio);
 180
 181         input_get_device(w8001->dev);
 182         input_unregister_device(w8001->dev);
 183         serio_close(serio);
 184         serio_set_drvdata(serio, NULL);
 185         input_put_device(w8001->dev);
 186         kfree(w8001);
 187 }
 188
 189 /*
 190  * w8001_connect() is the routine that is called when someone adds a
 191  * new serio device that supports the w8001 protocol and registers it as
 192  * an input device.
 193  */
 194
 195 static int w8001_connect(struct serio *serio, struct serio_driver *drv)
 196 {
 197         struct w8001 *w8001;
 198         struct input_dev *input_dev;
 199         int err;
 200
 201         w8001 = kzalloc(sizeof(struct w8001), GFP_KERNEL);
 202         input_dev = input_allocate_device();
 203         if (!w8001 || !input_dev) {
 204                 err = -ENOMEM;
 205                 goto fail1;
 206         }
 207
 208         w8001->serio = serio;
 209         w8001->id = serio->id.id;
 210         w8001->dev = input_dev;
 211         init_completion(&w8001->cmd_done);
 212         snprintf(w8001->phys, sizeof(w8001->phys), "%s/input0", serio->phys);
 213
 214         input_dev->name = "Wacom W8001 Penabled Serial TouchScreen";
 215         input_dev->phys = w8001->phys;
 216         input_dev->id.bustype = BUS_RS232;
 217         input_dev->id.vendor = SERIO_W8001;
 218         input_dev->id.product = w8001->id;
 219         input_dev->id.version = 0x0100;
 220         input_dev->dev.parent = &serio->dev;
 221
 222         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 223         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 224
 225         serio_set_drvdata(serio, w8001);
 226         err = serio_open(serio, drv);
 227         if (err)
 228                 goto fail2;
 229
 230         err = w8001_setup(w8001);
 231         if (err)
 232                 goto fail3;
 233
 234         err = input_register_device(w8001->dev);
 235         if (err)
 236                 goto fail3;
 237
 238         return 0;
 239
 240 fail3:
 241         serio_close(serio);
 242 fail2:
 243         serio_set_drvdata(serio, NULL);
 244 fail1:
 245         input_free_device(input_dev);
 246         kfree(w8001);
 247         return err;
 248 }
 249
 250 static struct serio_device_id w8001_serio_ids[] = {
 251         {
 252                 .type   = SERIO_RS232,
 253                 .proto  = SERIO_W8001,
 254                 .id     = SERIO_ANY,
 255                 .extra  = SERIO_ANY,
 256         },
 257         { 0 }
 258 };
 259
 260 MODULE_DEVICE_TABLE(serio, w8001_serio_ids);
 261
 262 static struct serio_driver w8001_drv = {
 263         .driver         = {
 264                 .name   = "w8001",
 265         },
 266         .description    = DRIVER_DESC,
 267         .id_table       = w8001_serio_ids,
 268         .interrupt      = w8001_interrupt,
 269         .connect        = w8001_connect,
 270         .disconnect     = w8001_disconnect,
 271 };
 272
 273 static int __init w8001_init(void)
 274 {
 275         return serio_register_driver(&w8001_drv);
 276 }
 277
 278 static void __exit w8001_exit(void)
 279 {
 280         serio_unregister_driver(&w8001_drv);
 281 }
 282
 283 module_init(w8001_init);
 284 module_exit(w8001_exit);