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 /*
  29  * Definitions & global arrays.
  30  */
  31
  32 #define W8001_MAX_LENGTH        11
  33 #define W8001_PACKET_LEN        11
  34 #define W8001_LEAD_MASK 0x80
  35 #define W8001_LEAD_BYTE 0x80
  36 #define W8001_TAB_MASK 0x40
  37 #define W8001_TAB_BYTE 0x40
  38
  39 #define W8001_QUERY_PACKET 0x20
  40
  41 struct w8001_coord {
  42         u8 rdy;
  43         u8 tsw;
  44         u8 f1;
  45         u8 f2;
  46         u16 x;
  47         u16 y;
  48         u16 pen_pressure;
  49         u8 tilt_x;
  50         u8 tilt_y;
  51 };
  52
  53 /*
  54  * Per-touchscreen data.
  55  */
  56
  57 struct w8001 {
  58         struct input_dev *dev;
  59         struct serio *serio;
  60         struct mutex cmd_mutex;
  61         struct completion cmd_done;
  62         int id;
  63         int idx;
  64         unsigned char expected_packet;
  65         unsigned char data[W8001_MAX_LENGTH];
  66         unsigned char response[W8001_PACKET_LEN];
  67         char phys[32];
  68 };
  69
  70 static int parse_data(u8 *data, struct w8001_coord *coord)
  71 {
  72         coord->rdy = data[0] & 0x20;
  73         coord->tsw = data[0] & 0x01;
  74         coord->f1 = data[0] & 0x02;
  75         coord->f2 = data[0] & 0x04;
  76
  77         coord->x = (data[1] & 0x7F) << 9;
  78         coord->x |= (data[2] & 0x7F) << 2;
  79         coord->x |= (data[6] & 0x60) >> 5;
  80
  81         coord->y = (data[3] & 0x7F) << 9;
  82         coord->y |= (data[4] & 0x7F) << 2;
  83         coord->y |= (data[6] & 0x18) >> 3;
  84
  85         coord->pen_pressure = data[5] & 0x7F;
  86         coord->pen_pressure |= (data[6] & 0x07) << 7 ;
  87
  88         coord->tilt_x = data[7] & 0x7F;
  89         coord->tilt_y = data[8] & 0x7F;
  90
  91         return 0;
  92 }
  93
  94 static void w8001_process_data(struct w8001 *w8001, unsigned char data)
  95 {
  96         struct input_dev *dev = w8001->dev;
  97         u8 tmp;
  98         struct w8001_coord coord;
  99
 100         w8001->data[w8001->idx] = data;
 101         switch (w8001->idx++) {
 102         case 0:
 103                 if ((data & W8001_LEAD_MASK) != W8001_LEAD_BYTE) {
 104                         pr_debug("w8001: unsynchronized data: 0x%02x\n", data);
 105                         w8001->idx = 0;
 106                 }
 107                 break;
 108         case 8:
 109                 tmp = w8001->data[0] & W8001_TAB_MASK;
 110                 if (unlikely(tmp == W8001_TAB_BYTE))
 111                         break;
 112                 w8001->idx = 0;
 113                 memset(&coord, 0, sizeof(coord));
 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         case 10:
 122                 w8001->idx = 0;
 123                 memcpy(w8001->response, &w8001->data, W8001_PACKET_LEN);
 124                 w8001->expected_packet = W8001_QUERY_PACKET;
 125                 complete(&w8001->cmd_done);
 126                 break;
 127         }
 128 }
 129
 130
 131 static irqreturn_t w8001_interrupt(struct serio *serio,
 132                 unsigned char data, unsigned int flags)
 133 {
 134         struct w8001 *w8001 = serio_get_drvdata(serio);
 135
 136         w8001_process_data(w8001, data);
 137
 138         return IRQ_HANDLED;
 139 }
 140
 141 static int w8001_async_command(struct w8001 *w8001, unsigned char *packet,
 142                                         int len)
 143 {
 144         int rc = -1;
 145         int i;
 146
 147         mutex_lock(&w8001->cmd_mutex);
 148
 149         for (i = 0; i < len; i++) {
 150                 if (serio_write(w8001->serio, packet[i]))
 151                         goto out;
 152         }
 153         rc = 0;
 154
 155 out:
 156         mutex_unlock(&w8001->cmd_mutex);
 157         return rc;
 158 }
 159
 160 static int w8001_command(struct w8001 *w8001, unsigned char *packet, int len)
 161 {
 162         int rc = -1;
 163         int i;
 164
 165         mutex_lock(&w8001->cmd_mutex);
 166
 167         serio_pause_rx(w8001->serio);
 168         init_completion(&w8001->cmd_done);
 169         serio_continue_rx(w8001->serio);
 170
 171         for (i = 0; i < len; i++) {
 172                 if (serio_write(w8001->serio, packet[i]))
 173                         goto out;
 174         }
 175
 176         wait_for_completion_timeout(&w8001->cmd_done, HZ);
 177
 178         if (w8001->expected_packet == W8001_QUERY_PACKET) {
 179                 /* We are back in reporting mode, the query was ACKed */
 180                 memcpy(packet, w8001->response, W8001_PACKET_LEN);
 181                 rc = 0;
 182         }
 183
 184 out:
 185         mutex_unlock(&w8001->cmd_mutex);
 186         return rc;
 187 }
 188
 189 static int w8001_setup(struct w8001 *w8001)
 190 {
 191         struct w8001_coord coord;
 192         struct input_dev *dev = w8001->dev;
 193         unsigned char start[1] = { '1' };
 194         unsigned char query[11] = { '*' };
 195
 196         if (w8001_command(w8001, query, 1))
 197                 return -1;
 198
 199         memset(&coord, 0, sizeof(coord));
 200         parse_data(query, &coord);
 201
 202         input_set_abs_params(dev, ABS_X, 0, coord.x, 0, 0);
 203         input_set_abs_params(dev, ABS_Y, 0, coord.y, 0, 0);
 204         input_set_abs_params(dev, ABS_PRESSURE, 0, coord.pen_pressure, 0, 0);
 205         input_set_abs_params(dev, ABS_TILT_X, 0, coord.tilt_x, 0, 0);
 206         input_set_abs_params(dev, ABS_TILT_Y, 0, coord.tilt_y, 0, 0);
 207
 208         if (w8001_async_command(w8001, start, 1))
 209                 return -1;
 210
 211         return 0;
 212 }
 213
 214 /*
 215  * w8001_disconnect() is the opposite of w8001_connect()
 216  */
 217
 218 static void w8001_disconnect(struct serio *serio)
 219 {
 220         struct w8001 *w8001 = serio_get_drvdata(serio);
 221
 222         input_get_device(w8001->dev);
 223         input_unregister_device(w8001->dev);
 224         serio_close(serio);
 225         serio_set_drvdata(serio, NULL);
 226         input_put_device(w8001->dev);
 227         kfree(w8001);
 228 }
 229
 230 /*
 231  * w8001_connect() is the routine that is called when someone adds a
 232  * new serio device that supports the w8001 protocol and registers it as
 233  * an input device.
 234  */
 235
 236 static int w8001_connect(struct serio *serio, struct serio_driver *drv)
 237 {
 238         struct w8001 *w8001;
 239         struct input_dev *input_dev;
 240         int err;
 241
 242         w8001 = kzalloc(sizeof(struct w8001), GFP_KERNEL);
 243         input_dev = input_allocate_device();
 244         if (!w8001 || !input_dev) {
 245                 err = -ENOMEM;
 246                 goto fail1;
 247         }
 248
 249         w8001->serio = serio;
 250         w8001->id = serio->id.id;
 251         w8001->dev = input_dev;
 252         mutex_init(&w8001->cmd_mutex);
 253         init_completion(&w8001->cmd_done);
 254         snprintf(w8001->phys, sizeof(w8001->phys), "%s/input0", serio->phys);
 255
 256         input_dev->name = "Wacom W8001 Penabled Serial TouchScreen";
 257         input_dev->phys = w8001->phys;
 258         input_dev->id.bustype = BUS_RS232;
 259         input_dev->id.vendor = SERIO_W8001;
 260         input_dev->id.product = w8001->id;
 261         input_dev->id.version = 0x0100;
 262         input_dev->dev.parent = &serio->dev;
 263
 264         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 265         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 266
 267         serio_set_drvdata(serio, w8001);
 268         err = serio_open(serio, drv);
 269         if (err)
 270                 goto fail2;
 271
 272         if (w8001_setup(w8001))
 273                 goto fail3;
 274
 275         err = input_register_device(w8001->dev);
 276         if (err)
 277                 goto fail3;
 278
 279         return 0;
 280
 281 fail3:
 282         serio_close(serio);
 283 fail2:
 284         serio_set_drvdata(serio, NULL);
 285 fail1:
 286         input_free_device(input_dev);
 287         kfree(w8001);
 288         return err;
 289 }
 290
 291 static struct serio_device_id w8001_serio_ids[] = {
 292         {
 293                 .type   = SERIO_RS232,
 294                 .proto  = SERIO_W8001,
 295                 .id     = SERIO_ANY,
 296                 .extra  = SERIO_ANY,
 297         },
 298         { 0 }
 299 };
 300
 301 MODULE_DEVICE_TABLE(serio, w8001_serio_ids);
 302
 303 static struct serio_driver w8001_drv = {
 304         .driver         = {
 305                 .name   = "w8001",
 306         },
 307         .description    = DRIVER_DESC,
 308         .id_table       = w8001_serio_ids,
 309         .interrupt      = w8001_interrupt,
 310         .connect        = w8001_connect,
 311         .disconnect     = w8001_disconnect,
 312 };
 313
 314 static int __init w8001_init(void)
 315 {
 316         return serio_register_driver(&w8001_drv);
 317 }
 318
 319 static void __exit w8001_exit(void)
 320 {
 321         serio_unregister_driver(&w8001_drv);
 322 }
 323
 324 module_init(w8001_init);
 325 module_exit(w8001_exit);