drivers/input/touchscreen/wacom_i2c.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Wacom Penabled Driver for I2C
   4  *
   5  * Copyright (c) 2011 - 2013 Tatsunosuke Tobita, Wacom.
   6  * <tobita.tatsunosuke@wacom.co.jp>
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/input.h>
  11 #include <linux/i2c.h>
  12 #include <linux/slab.h>
  13 #include <linux/irq.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/gpio.h>
  16 #include <asm/unaligned.h>
  17
  18 #define WACOM_CMD_QUERY0        0x04
  19 #define WACOM_CMD_QUERY1        0x00
  20 #define WACOM_CMD_QUERY2        0x33
  21 #define WACOM_CMD_QUERY3        0x02
  22 #define WACOM_CMD_THROW0        0x05
  23 #define WACOM_CMD_THROW1        0x00
  24 #define WACOM_QUERY_SIZE        19
  25
  26 struct wacom_features {
  27         int x_max;
  28         int y_max;
  29         int pressure_max;
  30         char fw_version;
  31 };
  32
  33 struct wacom_i2c {
  34         struct i2c_client *client;
  35         struct input_dev *input;
  36         u8 data[WACOM_QUERY_SIZE];
  37         bool prox;
  38         int tool;
  39 };
  40
  41 static int wacom_query_device(struct i2c_client *client,
  42                               struct wacom_features *features)
  43 {
  44         int ret;
  45         u8 cmd1[] = { WACOM_CMD_QUERY0, WACOM_CMD_QUERY1,
  46                         WACOM_CMD_QUERY2, WACOM_CMD_QUERY3 };
  47         u8 cmd2[] = { WACOM_CMD_THROW0, WACOM_CMD_THROW1 };
  48         u8 data[WACOM_QUERY_SIZE];
  49         struct i2c_msg msgs[] = {
  50                 {
  51                         .addr = client->addr,
  52                         .flags = 0,
  53                         .len = sizeof(cmd1),
  54                         .buf = cmd1,
  55                 },
  56                 {
  57                         .addr = client->addr,
  58                         .flags = 0,
  59                         .len = sizeof(cmd2),
  60                         .buf = cmd2,
  61                 },
  62                 {
  63                         .addr = client->addr,
  64                         .flags = I2C_M_RD,
  65                         .len = sizeof(data),
  66                         .buf = data,
  67                 },
  68         };
  69
  70         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
  71         if (ret < 0)
  72                 return ret;
  73         if (ret != ARRAY_SIZE(msgs))
  74                 return -EIO;
  75
  76         features->x_max = get_unaligned_le16(&data[3]);
  77         features->y_max = get_unaligned_le16(&data[5]);
  78         features->pressure_max = get_unaligned_le16(&data[11]);
  79         features->fw_version = get_unaligned_le16(&data[13]);
  80
  81         dev_dbg(&client->dev,
  82                 "x_max:%d, y_max:%d, pressure:%d, fw:%d\n",
  83                 features->x_max, features->y_max,
  84                 features->pressure_max, features->fw_version);
  85
  86         return 0;
  87 }
  88
  89 static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
  90 {
  91         struct wacom_i2c *wac_i2c = dev_id;
  92         struct input_dev *input = wac_i2c->input;
  93         u8 *data = wac_i2c->data;
  94         unsigned int x, y, pressure;
  95         unsigned char tsw, f1, f2, ers;
  96         int error;
  97
  98         error = i2c_master_recv(wac_i2c->client,
  99                                 wac_i2c->data, sizeof(wac_i2c->data));
 100         if (error < 0)
 101                 goto out;
 102
 103         tsw = data[3] & 0x01;
 104         ers = data[3] & 0x04;
 105         f1 = data[3] & 0x02;
 106         f2 = data[3] & 0x10;
 107         x = le16_to_cpup((__le16 *)&data[4]);
 108         y = le16_to_cpup((__le16 *)&data[6]);
 109         pressure = le16_to_cpup((__le16 *)&data[8]);
 110
 111         if (!wac_i2c->prox)
 112                 wac_i2c->tool = (data[3] & 0x0c) ?
 113                         BTN_TOOL_RUBBER : BTN_TOOL_PEN;
 114
 115         wac_i2c->prox = data[3] & 0x20;
 116
 117         input_report_key(input, BTN_TOUCH, tsw || ers);
 118         input_report_key(input, wac_i2c->tool, wac_i2c->prox);
 119         input_report_key(input, BTN_STYLUS, f1);
 120         input_report_key(input, BTN_STYLUS2, f2);
 121         input_report_abs(input, ABS_X, x);
 122         input_report_abs(input, ABS_Y, y);
 123         input_report_abs(input, ABS_PRESSURE, pressure);
 124         input_sync(input);
 125
 126 out:
 127         return IRQ_HANDLED;
 128 }
 129
 130 static int wacom_i2c_open(struct input_dev *dev)
 131 {
 132         struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
 133         struct i2c_client *client = wac_i2c->client;
 134
 135         enable_irq(client->irq);
 136
 137         return 0;
 138 }
 139
 140 static void wacom_i2c_close(struct input_dev *dev)
 141 {
 142         struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
 143         struct i2c_client *client = wac_i2c->client;
 144
 145         disable_irq(client->irq);
 146 }
 147
 148 static int wacom_i2c_probe(struct i2c_client *client,
 149                                      const struct i2c_device_id *id)
 150 {
 151         struct wacom_i2c *wac_i2c;
 152         struct input_dev *input;
 153         struct wacom_features features = { 0 };
 154         int error;
 155
 156         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 157                 dev_err(&client->dev, "i2c_check_functionality error\n");
 158                 return -EIO;
 159         }
 160
 161         error = wacom_query_device(client, &features);
 162         if (error)
 163                 return error;
 164
 165         wac_i2c = kzalloc(sizeof(*wac_i2c), GFP_KERNEL);
 166         input = input_allocate_device();
 167         if (!wac_i2c || !input) {
 168                 error = -ENOMEM;
 169                 goto err_free_mem;
 170         }
 171
 172         wac_i2c->client = client;
 173         wac_i2c->input = input;
 174
 175         input->name = "Wacom I2C Digitizer";
 176         input->id.bustype = BUS_I2C;
 177         input->id.vendor = 0x56a;
 178         input->id.version = features.fw_version;
 179         input->dev.parent = &client->dev;
 180         input->open = wacom_i2c_open;
 181         input->close = wacom_i2c_close;
 182
 183         input->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 184
 185         __set_bit(BTN_TOOL_PEN, input->keybit);
 186         __set_bit(BTN_TOOL_RUBBER, input->keybit);
 187         __set_bit(BTN_STYLUS, input->keybit);
 188         __set_bit(BTN_STYLUS2, input->keybit);
 189         __set_bit(BTN_TOUCH, input->keybit);
 190
 191         input_set_abs_params(input, ABS_X, 0, features.x_max, 0, 0);
 192         input_set_abs_params(input, ABS_Y, 0, features.y_max, 0, 0);
 193         input_set_abs_params(input, ABS_PRESSURE,
 194                              0, features.pressure_max, 0, 0);
 195
 196         input_set_drvdata(input, wac_i2c);
 197
 198         error = request_threaded_irq(client->irq, NULL, wacom_i2c_irq,
 199                                      IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 200                                      "wacom_i2c", wac_i2c);
 201         if (error) {
 202                 dev_err(&client->dev,
 203                         "Failed to enable IRQ, error: %d\n", error);
 204                 goto err_free_mem;
 205         }
 206
 207         /* Disable the IRQ, we'll enable it in wac_i2c_open() */
 208         disable_irq(client->irq);
 209
 210         error = input_register_device(wac_i2c->input);
 211         if (error) {
 212                 dev_err(&client->dev,
 213                         "Failed to register input device, error: %d\n", error);
 214                 goto err_free_irq;
 215         }
 216
 217         i2c_set_clientdata(client, wac_i2c);
 218         return 0;
 219
 220 err_free_irq:
 221         free_irq(client->irq, wac_i2c);
 222 err_free_mem:
 223         input_free_device(input);
 224         kfree(wac_i2c);
 225
 226         return error;
 227 }
 228
 229 static int wacom_i2c_remove(struct i2c_client *client)
 230 {
 231         struct wacom_i2c *wac_i2c = i2c_get_clientdata(client);
 232
 233         free_irq(client->irq, wac_i2c);
 234         input_unregister_device(wac_i2c->input);
 235         kfree(wac_i2c);
 236
 237         return 0;
 238 }
 239
 240 static int __maybe_unused wacom_i2c_suspend(struct device *dev)
 241 {
 242         struct i2c_client *client = to_i2c_client(dev);
 243
 244         disable_irq(client->irq);
 245
 246         return 0;
 247 }
 248
 249 static int __maybe_unused wacom_i2c_resume(struct device *dev)
 250 {
 251         struct i2c_client *client = to_i2c_client(dev);
 252
 253         enable_irq(client->irq);
 254
 255         return 0;
 256 }
 257
 258 static SIMPLE_DEV_PM_OPS(wacom_i2c_pm, wacom_i2c_suspend, wacom_i2c_resume);
 259
 260 static const struct i2c_device_id wacom_i2c_id[] = {
 261         { "WAC_I2C_EMR", 0 },
 262         { },
 263 };
 264 MODULE_DEVICE_TABLE(i2c, wacom_i2c_id);
 265
 266 static struct i2c_driver wacom_i2c_driver = {
 267         .driver = {
 268                 .name   = "wacom_i2c",
 269                 .pm     = &wacom_i2c_pm,
 270         },
 271
 272         .probe          = wacom_i2c_probe,
 273         .remove         = wacom_i2c_remove,
 274         .id_table       = wacom_i2c_id,
 275 };
 276 module_i2c_driver(wacom_i2c_driver);
 277
 278 MODULE_AUTHOR("Tatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>");
 279 MODULE_DESCRIPTION("WACOM EMR I2C Driver");
 280 MODULE_LICENSE("GPL");