drivers/input/touchscreen/wacom_i2c.c

   1 /*
   2  * Wacom Penabled Driver for I2C
   3  *
   4  * Copyright (c) 2011 - 2013 Tatsunosuke Tobita, Wacom.
   5  * <tobita.tatsunosuke@wacom.co.jp>
   6  *
   7  * This program is free software; you can redistribute it
   8  * and/or modify it under the terms of the GNU General
   9  * Public License as published by the Free Software
  10  * Foundation; either version of 2 of the License,
  11  * or (at your option) any later version.
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/input.h>
  16 #include <linux/i2c.h>
  17 #include <linux/slab.h>
  18 #include <linux/irq.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/gpio.h>
  21 #include <asm/unaligned.h>
  22
  23 #define WACOM_CMD_QUERY0        0x04
  24 #define WACOM_CMD_QUERY1        0x00
  25 #define WACOM_CMD_QUERY2        0x33
  26 #define WACOM_CMD_QUERY3        0x02
  27 #define WACOM_CMD_THROW0        0x05
  28 #define WACOM_CMD_THROW1        0x00
  29 #define WACOM_QUERY_SIZE        19
  30
  31 struct wacom_features {
  32         int x_max;
  33         int y_max;
  34         int pressure_max;
  35         char fw_version;
  36 };
  37
  38 struct wacom_i2c {
  39         struct i2c_client *client;
  40         struct input_dev *input;
  41         u8 data[WACOM_QUERY_SIZE];
  42         bool prox;
  43         int tool;
  44 };
  45
  46 static int wacom_query_device(struct i2c_client *client,
  47                               struct wacom_features *features)
  48 {
  49         int ret;
  50         u8 cmd1[] = { WACOM_CMD_QUERY0, WACOM_CMD_QUERY1,
  51                         WACOM_CMD_QUERY2, WACOM_CMD_QUERY3 };
  52         u8 cmd2[] = { WACOM_CMD_THROW0, WACOM_CMD_THROW1 };
  53         u8 data[WACOM_QUERY_SIZE];
  54         struct i2c_msg msgs[] = {
  55                 {
  56                         .addr = client->addr,
  57                         .flags = 0,
  58                         .len = sizeof(cmd1),
  59                         .buf = cmd1,
  60                 },
  61                 {
  62                         .addr = client->addr,
  63                         .flags = 0,
  64                         .len = sizeof(cmd2),
  65                         .buf = cmd2,
  66                 },
  67                 {
  68                         .addr = client->addr,
  69                         .flags = I2C_M_RD,
  70                         .len = sizeof(data),
  71                         .buf = data,
  72                 },
  73         };
  74
  75         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
  76         if (ret < 0)
  77                 return ret;
  78         if (ret != ARRAY_SIZE(msgs))
  79                 return -EIO;
  80
  81         features->x_max = get_unaligned_le16(&data[3]);
  82         features->y_max = get_unaligned_le16(&data[5]);
  83         features->pressure_max = get_unaligned_le16(&data[11]);
  84         features->fw_version = get_unaligned_le16(&data[13]);
  85
  86         dev_dbg(&client->dev,
  87                 "x_max:%d, y_max:%d, pressure:%d, fw:%d\n",
  88                 features->x_max, features->y_max,
  89                 features->pressure_max, features->fw_version);
  90
  91         return 0;
  92 }
  93
  94 static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
  95 {
  96         struct wacom_i2c *wac_i2c = dev_id;
  97         struct input_dev *input = wac_i2c->input;
  98         u8 *data = wac_i2c->data;
  99         unsigned int x, y, pressure;
 100         unsigned char tsw, f1, f2, ers;
 101         int error;
 102
 103         error = i2c_master_recv(wac_i2c->client,
 104                                 wac_i2c->data, sizeof(wac_i2c->data));
 105         if (error < 0)
 106                 goto out;
 107
 108         tsw = data[3] & 0x01;
 109         ers = data[3] & 0x04;
 110         f1 = data[3] & 0x02;
 111         f2 = data[3] & 0x10;
 112         x = le16_to_cpup((__le16 *)&data[4]);
 113         y = le16_to_cpup((__le16 *)&data[6]);
 114         pressure = le16_to_cpup((__le16 *)&data[8]);
 115
 116         if (!wac_i2c->prox)
 117                 wac_i2c->tool = (data[3] & 0x0c) ?
 118                         BTN_TOOL_RUBBER : BTN_TOOL_PEN;
 119
 120         wac_i2c->prox = data[3] & 0x20;
 121
 122         input_report_key(input, BTN_TOUCH, tsw || ers);
 123         input_report_key(input, wac_i2c->tool, wac_i2c->prox);
 124         input_report_key(input, BTN_STYLUS, f1);
 125         input_report_key(input, BTN_STYLUS2, f2);
 126         input_report_abs(input, ABS_X, x);
 127         input_report_abs(input, ABS_Y, y);
 128         input_report_abs(input, ABS_PRESSURE, pressure);
 129         input_sync(input);
 130
 131 out:
 132         return IRQ_HANDLED;
 133 }
 134
 135 static int wacom_i2c_open(struct input_dev *dev)
 136 {
 137         struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
 138         struct i2c_client *client = wac_i2c->client;
 139
 140         enable_irq(client->irq);
 141
 142         return 0;
 143 }
 144
 145 static void wacom_i2c_close(struct input_dev *dev)
 146 {
 147         struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
 148         struct i2c_client *client = wac_i2c->client;
 149
 150         disable_irq(client->irq);
 151 }
 152
 153 static int wacom_i2c_probe(struct i2c_client *client,
 154                                      const struct i2c_device_id *id)
 155 {
 156         struct wacom_i2c *wac_i2c;
 157         struct input_dev *input;
 158         struct wacom_features features = { 0 };
 159         int error;
 160
 161         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 162                 dev_err(&client->dev, "i2c_check_functionality error\n");
 163                 return -EIO;
 164         }
 165
 166         error = wacom_query_device(client, &features);
 167         if (error)
 168                 return error;
 169
 170         wac_i2c = kzalloc(sizeof(*wac_i2c), GFP_KERNEL);
 171         input = input_allocate_device();
 172         if (!wac_i2c || !input) {
 173                 error = -ENOMEM;
 174                 goto err_free_mem;
 175         }
 176
 177         wac_i2c->client = client;
 178         wac_i2c->input = input;
 179
 180         input->name = "Wacom I2C Digitizer";
 181         input->id.bustype = BUS_I2C;
 182         input->id.vendor = 0x56a;
 183         input->id.version = features.fw_version;
 184         input->dev.parent = &client->dev;
 185         input->open = wacom_i2c_open;
 186         input->close = wacom_i2c_close;
 187
 188         input->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 189
 190         __set_bit(BTN_TOOL_PEN, input->keybit);
 191         __set_bit(BTN_TOOL_RUBBER, input->keybit);
 192         __set_bit(BTN_STYLUS, input->keybit);
 193         __set_bit(BTN_STYLUS2, input->keybit);
 194         __set_bit(BTN_TOUCH, input->keybit);
 195
 196         input_set_abs_params(input, ABS_X, 0, features.x_max, 0, 0);
 197         input_set_abs_params(input, ABS_Y, 0, features.y_max, 0, 0);
 198         input_set_abs_params(input, ABS_PRESSURE,
 199                              0, features.pressure_max, 0, 0);
 200
 201         input_set_drvdata(input, wac_i2c);
 202
 203         error = request_threaded_irq(client->irq, NULL, wacom_i2c_irq,
 204                                      IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 205                                      "wacom_i2c", wac_i2c);
 206         if (error) {
 207                 dev_err(&client->dev,
 208                         "Failed to enable IRQ, error: %d\n", error);
 209                 goto err_free_mem;
 210         }
 211
 212         /* Disable the IRQ, we'll enable it in wac_i2c_open() */
 213         disable_irq(client->irq);
 214
 215         error = input_register_device(wac_i2c->input);
 216         if (error) {
 217                 dev_err(&client->dev,
 218                         "Failed to register input device, error: %d\n", error);
 219                 goto err_free_irq;
 220         }
 221
 222         i2c_set_clientdata(client, wac_i2c);
 223         return 0;
 224
 225 err_free_irq:
 226         free_irq(client->irq, wac_i2c);
 227 err_free_mem:
 228         input_free_device(input);
 229         kfree(wac_i2c);
 230
 231         return error;
 232 }
 233
 234 static int wacom_i2c_remove(struct i2c_client *client)
 235 {
 236         struct wacom_i2c *wac_i2c = i2c_get_clientdata(client);
 237
 238         free_irq(client->irq, wac_i2c);
 239         input_unregister_device(wac_i2c->input);
 240         kfree(wac_i2c);
 241
 242         return 0;
 243 }
 244
 245 static int __maybe_unused wacom_i2c_suspend(struct device *dev)
 246 {
 247         struct i2c_client *client = to_i2c_client(dev);
 248
 249         disable_irq(client->irq);
 250
 251         return 0;
 252 }
 253
 254 static int __maybe_unused wacom_i2c_resume(struct device *dev)
 255 {
 256         struct i2c_client *client = to_i2c_client(dev);
 257
 258         enable_irq(client->irq);
 259
 260         return 0;
 261 }
 262
 263 static SIMPLE_DEV_PM_OPS(wacom_i2c_pm, wacom_i2c_suspend, wacom_i2c_resume);
 264
 265 static const struct i2c_device_id wacom_i2c_id[] = {
 266         { "WAC_I2C_EMR", 0 },
 267         { },
 268 };
 269 MODULE_DEVICE_TABLE(i2c, wacom_i2c_id);
 270
 271 static struct i2c_driver wacom_i2c_driver = {
 272         .driver = {
 273                 .name   = "wacom_i2c",
 274                 .pm     = &wacom_i2c_pm,
 275         },
 276
 277         .probe          = wacom_i2c_probe,
 278         .remove         = wacom_i2c_remove,
 279         .id_table       = wacom_i2c_id,
 280 };
 281 module_i2c_driver(wacom_i2c_driver);
 282
 283 MODULE_AUTHOR("Tatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>");
 284 MODULE_DESCRIPTION("WACOM EMR I2C Driver");
 285 MODULE_LICENSE("GPL");