drivers/input/touchscreen/egalax_ts.c

   1 /*
   2  * Driver for EETI eGalax Multiple Touch Controller
   3  *
   4  * Copyright (C) 2011 Freescale Semiconductor, Inc.
   5  *
   6  * based on max11801_ts.c
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 /* EETI eGalax serial touch screen controller is a I2C based multiple
  14  * touch screen controller, it supports 5 point multiple touch. */
  15
  16 /* TODO:
  17   - auto idle mode support
  18 */
  19
  20 #include <linux/module.h>
  21 #include <linux/i2c.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/input.h>
  24 #include <linux/irq.h>
  25 #include <linux/gpio.h>
  26 #include <linux/delay.h>
  27 #include <linux/slab.h>
  28 #include <linux/bitops.h>
  29 #include <linux/input/mt.h>
  30 #include <linux/of_gpio.h>
  31
  32 /*
  33  * Mouse Mode: some panel may configure the controller to mouse mode,
  34  * which can only report one point at a given time.
  35  * This driver will ignore events in this mode.
  36  */
  37 #define REPORT_MODE_MOUSE               0x1
  38 /*
  39  * Vendor Mode: this mode is used to transfer some vendor specific
  40  * messages.
  41  * This driver will ignore events in this mode.
  42  */
  43 #define REPORT_MODE_VENDOR              0x3
  44 /* Multiple Touch Mode */
  45 #define REPORT_MODE_MTTOUCH             0x4
  46
  47 #define MAX_SUPPORT_POINTS              5
  48
  49 #define EVENT_VALID_OFFSET      7
  50 #define EVENT_VALID_MASK        (0x1 << EVENT_VALID_OFFSET)
  51 #define EVENT_ID_OFFSET         2
  52 #define EVENT_ID_MASK           (0xf << EVENT_ID_OFFSET)
  53 #define EVENT_IN_RANGE          (0x1 << 1)
  54 #define EVENT_DOWN_UP           (0X1 << 0)
  55
  56 #define MAX_I2C_DATA_LEN        10
  57
  58 #define EGALAX_MAX_X    32760
  59 #define EGALAX_MAX_Y    32760
  60 #define EGALAX_MAX_TRIES 100
  61
  62 struct egalax_ts {
  63         struct i2c_client               *client;
  64         struct input_dev                *input_dev;
  65 };
  66
  67 static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
  68 {
  69         struct egalax_ts *ts = dev_id;
  70         struct input_dev *input_dev = ts->input_dev;
  71         struct i2c_client *client = ts->client;
  72         u8 buf[MAX_I2C_DATA_LEN];
  73         int id, ret, x, y, z;
  74         int tries = 0;
  75         bool down, valid;
  76         u8 state;
  77
  78         do {
  79                 ret = i2c_master_recv(client, buf, MAX_I2C_DATA_LEN);
  80         } while (ret == -EAGAIN && tries++ < EGALAX_MAX_TRIES);
  81
  82         if (ret < 0)
  83                 return IRQ_HANDLED;
  84
  85         if (buf[0] != REPORT_MODE_MTTOUCH) {
  86                 /* ignore mouse events and vendor events */
  87                 return IRQ_HANDLED;
  88         }
  89
  90         state = buf[1];
  91         x = (buf[3] << 8) | buf[2];
  92         y = (buf[5] << 8) | buf[4];
  93         z = (buf[7] << 8) | buf[6];
  94
  95         valid = state & EVENT_VALID_MASK;
  96         id = (state & EVENT_ID_MASK) >> EVENT_ID_OFFSET;
  97         down = state & EVENT_DOWN_UP;
  98
  99         if (!valid || id > MAX_SUPPORT_POINTS) {
 100                 dev_dbg(&client->dev, "point invalid\n");
 101                 return IRQ_HANDLED;
 102         }
 103
 104         input_mt_slot(input_dev, id);
 105         input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, down);
 106
 107         dev_dbg(&client->dev, "%s id:%d x:%d y:%d z:%d",
 108                 down ? "down" : "up", id, x, y, z);
 109
 110         if (down) {
 111                 input_report_abs(input_dev, ABS_MT_POSITION_X, x);
 112                 input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
 113                 input_report_abs(input_dev, ABS_MT_PRESSURE, z);
 114         }
 115
 116         input_mt_report_pointer_emulation(input_dev, true);
 117         input_sync(input_dev);
 118
 119         return IRQ_HANDLED;
 120 }
 121
 122 /* wake up controller by an falling edge of interrupt gpio.  */
 123 static int egalax_wake_up_device(struct i2c_client *client)
 124 {
 125         struct device_node *np = client->dev.of_node;
 126         int gpio;
 127         int ret;
 128
 129         if (!np)
 130                 return -ENODEV;
 131
 132         gpio = of_get_named_gpio(np, "wakeup-gpios", 0);
 133         if (!gpio_is_valid(gpio))
 134                 return -ENODEV;
 135
 136         ret = gpio_request(gpio, "egalax_irq");
 137         if (ret < 0) {
 138                 dev_err(&client->dev,
 139                         "request gpio failed, cannot wake up controller: %d\n",
 140                         ret);
 141                 return ret;
 142         }
 143
 144         /* wake up controller via an falling edge on IRQ gpio. */
 145         gpio_direction_output(gpio, 0);
 146         gpio_set_value(gpio, 1);
 147
 148         /* controller should be waken up, return irq.  */
 149         gpio_direction_input(gpio);
 150         gpio_free(gpio);
 151
 152         return 0;
 153 }
 154
 155 static int egalax_firmware_version(struct i2c_client *client)
 156 {
 157         static const u8 cmd[MAX_I2C_DATA_LEN] = { 0x03, 0x03, 0xa, 0x01, 0x41 };
 158         int ret;
 159
 160         ret = i2c_master_send(client, cmd, MAX_I2C_DATA_LEN);
 161         if (ret < 0)
 162                 return ret;
 163
 164         return 0;
 165 }
 166
 167 static int egalax_ts_probe(struct i2c_client *client,
 168                            const struct i2c_device_id *id)
 169 {
 170         struct egalax_ts *ts;
 171         struct input_dev *input_dev;
 172         int error;
 173
 174         ts = devm_kzalloc(&client->dev, sizeof(struct egalax_ts), GFP_KERNEL);
 175         if (!ts) {
 176                 dev_err(&client->dev, "Failed to allocate memory\n");
 177                 return -ENOMEM;
 178         }
 179
 180         input_dev = devm_input_allocate_device(&client->dev);
 181         if (!input_dev) {
 182                 dev_err(&client->dev, "Failed to allocate memory\n");
 183                 return -ENOMEM;
 184         }
 185
 186         ts->client = client;
 187         ts->input_dev = input_dev;
 188
 189         /* controller may be in sleep, wake it up. */
 190         error = egalax_wake_up_device(client);
 191         if (error) {
 192                 dev_err(&client->dev, "Failed to wake up the controller\n");
 193                 return error;
 194         }
 195
 196         error = egalax_firmware_version(client);
 197         if (error < 0) {
 198                 dev_err(&client->dev, "Failed to read firmware version\n");
 199                 return error;
 200         }
 201
 202         input_dev->name = "EETI eGalax Touch Screen";
 203         input_dev->id.bustype = BUS_I2C;
 204
 205         __set_bit(EV_ABS, input_dev->evbit);
 206         __set_bit(EV_KEY, input_dev->evbit);
 207         __set_bit(BTN_TOUCH, input_dev->keybit);
 208
 209         input_set_abs_params(input_dev, ABS_X, 0, EGALAX_MAX_X, 0, 0);
 210         input_set_abs_params(input_dev, ABS_Y, 0, EGALAX_MAX_Y, 0, 0);
 211         input_set_abs_params(input_dev,
 212                              ABS_MT_POSITION_X, 0, EGALAX_MAX_X, 0, 0);
 213         input_set_abs_params(input_dev,
 214                              ABS_MT_POSITION_Y, 0, EGALAX_MAX_Y, 0, 0);
 215         input_mt_init_slots(input_dev, MAX_SUPPORT_POINTS, 0);
 216
 217         error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 218                                           egalax_ts_interrupt,
 219                                           IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 220                                           "egalax_ts", ts);
 221         if (error < 0) {
 222                 dev_err(&client->dev, "Failed to register interrupt\n");
 223                 return error;
 224         }
 225
 226         error = input_register_device(ts->input_dev);
 227         if (error)
 228                 return error;
 229
 230         return 0;
 231 }
 232
 233 static const struct i2c_device_id egalax_ts_id[] = {
 234         { "egalax_ts", 0 },
 235         { }
 236 };
 237 MODULE_DEVICE_TABLE(i2c, egalax_ts_id);
 238
 239 static int __maybe_unused egalax_ts_suspend(struct device *dev)
 240 {
 241         static const u8 suspend_cmd[MAX_I2C_DATA_LEN] = {
 242                 0x3, 0x6, 0xa, 0x3, 0x36, 0x3f, 0x2, 0, 0, 0
 243         };
 244         struct i2c_client *client = to_i2c_client(dev);
 245         int ret;
 246
 247         ret = i2c_master_send(client, suspend_cmd, MAX_I2C_DATA_LEN);
 248         return ret > 0 ? 0 : ret;
 249 }
 250
 251 static int __maybe_unused egalax_ts_resume(struct device *dev)
 252 {
 253         struct i2c_client *client = to_i2c_client(dev);
 254
 255         return egalax_wake_up_device(client);
 256 }
 257
 258 static SIMPLE_DEV_PM_OPS(egalax_ts_pm_ops, egalax_ts_suspend, egalax_ts_resume);
 259
 260 static const struct of_device_id egalax_ts_dt_ids[] = {
 261         { .compatible = "eeti,egalax_ts" },
 262         { /* sentinel */ }
 263 };
 264 MODULE_DEVICE_TABLE(of, egalax_ts_dt_ids);
 265
 266 static struct i2c_driver egalax_ts_driver = {
 267         .driver = {
 268                 .name   = "egalax_ts",
 269                 .pm     = &egalax_ts_pm_ops,
 270                 .of_match_table = egalax_ts_dt_ids,
 271         },
 272         .id_table       = egalax_ts_id,
 273         .probe          = egalax_ts_probe,
 274 };
 275
 276 module_i2c_driver(egalax_ts_driver);
 277
 278 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
 279 MODULE_DESCRIPTION("Touchscreen driver for EETI eGalax touch controller");
 280 MODULE_LICENSE("GPL");