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/init.h>
  22 #include <linux/i2c.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/input.h>
  25 #include <linux/irq.h>
  26 #include <linux/gpio.h>
  27 #include <linux/delay.h>
  28 #include <linux/slab.h>
  29 #include <linux/bitops.h>
  30 #include <linux/input/mt.h>
  31 #include <linux/of_gpio.h>
  32
  33 /*
  34  * Mouse Mode: some panel may configure the controller to mouse mode,
  35  * which can only report one point at a given time.
  36  * This driver will ignore events in this mode.
  37  */
  38 #define REPORT_MODE_MOUSE               0x1
  39 /*
  40  * Vendor Mode: this mode is used to transfer some vendor specific
  41  * messages.
  42  * This driver will ignore events in this mode.
  43  */
  44 #define REPORT_MODE_VENDOR              0x3
  45 /* Multiple Touch Mode */
  46 #define REPORT_MODE_MTTOUCH             0x4
  47
  48 #define MAX_SUPPORT_POINTS              5
  49
  50 #define EVENT_VALID_OFFSET      7
  51 #define EVENT_VALID_MASK        (0x1 << EVENT_VALID_OFFSET)
  52 #define EVENT_ID_OFFSET         2
  53 #define EVENT_ID_MASK           (0xf << EVENT_ID_OFFSET)
  54 #define EVENT_IN_RANGE          (0x1 << 1)
  55 #define EVENT_DOWN_UP           (0X1 << 0)
  56
  57 #define MAX_I2C_DATA_LEN        10
  58
  59 #define EGALAX_MAX_X    32760
  60 #define EGALAX_MAX_Y    32760
  61 #define EGALAX_MAX_TRIES 100
  62
  63 struct egalax_ts {
  64         struct i2c_client               *client;
  65         struct input_dev                *input_dev;
  66 };
  67
  68 static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
  69 {
  70         struct egalax_ts *ts = dev_id;
  71         struct input_dev *input_dev = ts->input_dev;
  72         struct i2c_client *client = ts->client;
  73         u8 buf[MAX_I2C_DATA_LEN];
  74         int id, ret, x, y, z;
  75         int tries = 0;
  76         bool down, valid;
  77         u8 state;
  78
  79         do {
  80                 ret = i2c_master_recv(client, buf, MAX_I2C_DATA_LEN);
  81         } while (ret == -EAGAIN && tries++ < EGALAX_MAX_TRIES);
  82
  83         if (ret < 0)
  84                 return IRQ_HANDLED;
  85
  86         if (buf[0] != REPORT_MODE_MTTOUCH) {
  87                 /* ignore mouse events and vendor events */
  88                 return IRQ_HANDLED;
  89         }
  90
  91         state = buf[1];
  92         x = (buf[3] << 8) | buf[2];
  93         y = (buf[5] << 8) | buf[4];
  94         z = (buf[7] << 8) | buf[6];
  95
  96         valid = state & EVENT_VALID_MASK;
  97         id = (state & EVENT_ID_MASK) >> EVENT_ID_OFFSET;
  98         down = state & EVENT_DOWN_UP;
  99
 100         if (!valid || id > MAX_SUPPORT_POINTS) {
 101                 dev_dbg(&client->dev, "point invalid\n");
 102                 return IRQ_HANDLED;
 103         }
 104
 105         input_mt_slot(input_dev, id);
 106         input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, down);
 107
 108         dev_dbg(&client->dev, "%s id:%d x:%d y:%d z:%d",
 109                 down ? "down" : "up", id, x, y, z);
 110
 111         if (down) {
 112                 input_report_abs(input_dev, ABS_MT_POSITION_X, x);
 113                 input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
 114                 input_report_abs(input_dev, ABS_MT_PRESSURE, z);
 115         }
 116
 117         input_mt_report_pointer_emulation(input_dev, true);
 118         input_sync(input_dev);
 119
 120         return IRQ_HANDLED;
 121 }
 122
 123 /* wake up controller by an falling edge of interrupt gpio.  */
 124 static int egalax_wake_up_device(struct i2c_client *client)
 125 {
 126         struct device_node *np = client->dev.of_node;
 127         int gpio;
 128         int ret;
 129
 130         if (!np)
 131                 return -ENODEV;
 132
 133         gpio = of_get_named_gpio(np, "wakeup-gpios", 0);
 134         if (!gpio_is_valid(gpio))
 135                 return -ENODEV;
 136
 137         ret = gpio_request(gpio, "egalax_irq");
 138         if (ret < 0) {
 139                 dev_err(&client->dev,
 140                         "request gpio failed, cannot wake up controller: %d\n",
 141                         ret);
 142                 return ret;
 143         }
 144
 145         /* wake up controller via an falling edge on IRQ gpio. */
 146         gpio_direction_output(gpio, 0);
 147         gpio_set_value(gpio, 1);
 148
 149         /* controller should be waken up, return irq.  */
 150         gpio_direction_input(gpio);
 151         gpio_free(gpio);
 152
 153         return 0;
 154 }
 155
 156 static int egalax_firmware_version(struct i2c_client *client)
 157 {
 158         static const u8 cmd[MAX_I2C_DATA_LEN] = { 0x03, 0x03, 0xa, 0x01, 0x41 };
 159         int ret;
 160
 161         ret = i2c_master_send(client, cmd, MAX_I2C_DATA_LEN);
 162         if (ret < 0)
 163                 return ret;
 164
 165         return 0;
 166 }
 167
 168 static int egalax_ts_probe(struct i2c_client *client,
 169                            const struct i2c_device_id *id)
 170 {
 171         struct egalax_ts *ts;
 172         struct input_dev *input_dev;
 173         int error;
 174
 175         ts = devm_kzalloc(&client->dev, sizeof(struct egalax_ts), GFP_KERNEL);
 176         if (!ts) {
 177                 dev_err(&client->dev, "Failed to allocate memory\n");
 178                 return -ENOMEM;
 179         }
 180
 181         input_dev = devm_input_allocate_device(&client->dev);
 182         if (!input_dev) {
 183                 dev_err(&client->dev, "Failed to allocate memory\n");
 184                 return -ENOMEM;
 185         }
 186
 187         ts->client = client;
 188         ts->input_dev = input_dev;
 189
 190         /* controller may be in sleep, wake it up. */
 191         error = egalax_wake_up_device(client);
 192         if (error) {
 193                 dev_err(&client->dev, "Failed to wake up the controller\n");
 194                 return error;
 195         }
 196
 197         error = egalax_firmware_version(client);
 198         if (error < 0) {
 199                 dev_err(&client->dev, "Failed to read firmware version\n");
 200                 return error;
 201         }
 202
 203         input_dev->name = "EETI eGalax Touch Screen";
 204         input_dev->id.bustype = BUS_I2C;
 205
 206         __set_bit(EV_ABS, input_dev->evbit);
 207         __set_bit(EV_KEY, input_dev->evbit);
 208         __set_bit(BTN_TOUCH, input_dev->keybit);
 209
 210         input_set_abs_params(input_dev, ABS_X, 0, EGALAX_MAX_X, 0, 0);
 211         input_set_abs_params(input_dev, ABS_Y, 0, EGALAX_MAX_Y, 0, 0);
 212         input_set_abs_params(input_dev,
 213                              ABS_MT_POSITION_X, 0, EGALAX_MAX_X, 0, 0);
 214         input_set_abs_params(input_dev,
 215                              ABS_MT_POSITION_Y, 0, EGALAX_MAX_Y, 0, 0);
 216         input_mt_init_slots(input_dev, MAX_SUPPORT_POINTS, 0);
 217
 218         input_set_drvdata(input_dev, ts);
 219
 220         error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 221                                           egalax_ts_interrupt,
 222                                           IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 223                                           "egalax_ts", ts);
 224         if (error < 0) {
 225                 dev_err(&client->dev, "Failed to register interrupt\n");
 226                 return error;
 227         }
 228
 229         error = input_register_device(ts->input_dev);
 230         if (error)
 231                 return error;
 232
 233         i2c_set_clientdata(client, ts);
 234         return 0;
 235 }
 236
 237 static const struct i2c_device_id egalax_ts_id[] = {
 238         { "egalax_ts", 0 },
 239         { }
 240 };
 241 MODULE_DEVICE_TABLE(i2c, egalax_ts_id);
 242
 243 #ifdef CONFIG_PM_SLEEP
 244 static int egalax_ts_suspend(struct device *dev)
 245 {
 246         static const u8 suspend_cmd[MAX_I2C_DATA_LEN] = {
 247                 0x3, 0x6, 0xa, 0x3, 0x36, 0x3f, 0x2, 0, 0, 0
 248         };
 249         struct i2c_client *client = to_i2c_client(dev);
 250         int ret;
 251
 252         ret = i2c_master_send(client, suspend_cmd, MAX_I2C_DATA_LEN);
 253         return ret > 0 ? 0 : ret;
 254 }
 255
 256 static int egalax_ts_resume(struct device *dev)
 257 {
 258         struct i2c_client *client = to_i2c_client(dev);
 259
 260         return egalax_wake_up_device(client);
 261 }
 262 #endif
 263
 264 static SIMPLE_DEV_PM_OPS(egalax_ts_pm_ops, egalax_ts_suspend, egalax_ts_resume);
 265
 266 static struct of_device_id egalax_ts_dt_ids[] = {
 267         { .compatible = "eeti,egalax_ts" },
 268         { /* sentinel */ }
 269 };
 270
 271 static struct i2c_driver egalax_ts_driver = {
 272         .driver = {
 273                 .name   = "egalax_ts",
 274                 .owner  = THIS_MODULE,
 275                 .pm     = &egalax_ts_pm_ops,
 276                 .of_match_table = egalax_ts_dt_ids,
 277         },
 278         .id_table       = egalax_ts_id,
 279         .probe          = egalax_ts_probe,
 280 };
 281
 282 module_i2c_driver(egalax_ts_driver);
 283
 284 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
 285 MODULE_DESCRIPTION("Touchscreen driver for EETI eGalax touch controller");
 286 MODULE_LICENSE("GPL");