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