drivers/input/touchscreen/egalax_ts.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Driver for EETI eGalax Multiple Touch Controller
   4  *
   5  * Copyright (C) 2011 Freescale Semiconductor, Inc.
   6  *
   7  * based on max11801_ts.c
   8  */
   9
  10 /* EETI eGalax serial touch screen controller is a I2C based multiple
  11  * touch screen controller, it supports 5 point multiple touch. */
  12
  13 /* TODO:
  14   - auto idle mode support
  15 */
  16
  17 #include <linux/module.h>
  18 #include <linux/i2c.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/input.h>
  21 #include <linux/irq.h>
  22 #include <linux/gpio.h>
  23 #include <linux/delay.h>
  24 #include <linux/slab.h>
  25 #include <linux/bitops.h>
  26 #include <linux/input/mt.h>
  27 #include <linux/of_gpio.h>
  28
  29 /*
  30  * Mouse Mode: some panel may configure the controller to mouse mode,
  31  * which can only report one point at a given time.
  32  * This driver will ignore events in this mode.
  33  */
  34 #define REPORT_MODE_MOUSE               0x1
  35 /*
  36  * Vendor Mode: this mode is used to transfer some vendor specific
  37  * messages.
  38  * This driver will ignore events in this mode.
  39  */
  40 #define REPORT_MODE_VENDOR              0x3
  41 /* Multiple Touch Mode */
  42 #define REPORT_MODE_MTTOUCH             0x4
  43
  44 #define MAX_SUPPORT_POINTS              5
  45
  46 #define EVENT_VALID_OFFSET      7
  47 #define EVENT_VALID_MASK        (0x1 << EVENT_VALID_OFFSET)
  48 #define EVENT_ID_OFFSET         2
  49 #define EVENT_ID_MASK           (0xf << EVENT_ID_OFFSET)
  50 #define EVENT_IN_RANGE          (0x1 << 1)
  51 #define EVENT_DOWN_UP           (0X1 << 0)
  52
  53 #define MAX_I2C_DATA_LEN        10
  54
  55 #define EGALAX_MAX_X    32760
  56 #define EGALAX_MAX_Y    32760
  57 #define EGALAX_MAX_TRIES 100
  58
  59 struct egalax_ts {
  60         struct i2c_client               *client;
  61         struct input_dev                *input_dev;
  62 };
  63
  64 static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
  65 {
  66         struct egalax_ts *ts = dev_id;
  67         struct input_dev *input_dev = ts->input_dev;
  68         struct i2c_client *client = ts->client;
  69         u8 buf[MAX_I2C_DATA_LEN];
  70         int id, ret, x, y, z;
  71         int tries = 0;
  72         bool down, valid;
  73         u8 state;
  74
  75         do {
  76                 ret = i2c_master_recv(client, buf, MAX_I2C_DATA_LEN);
  77         } while (ret == -EAGAIN && tries++ < EGALAX_MAX_TRIES);
  78
  79         if (ret < 0)
  80                 return IRQ_HANDLED;
  81
  82         if (buf[0] != REPORT_MODE_MTTOUCH) {
  83                 /* ignore mouse events and vendor events */
  84                 return IRQ_HANDLED;
  85         }
  86
  87         state = buf[1];
  88         x = (buf[3] << 8) | buf[2];
  89         y = (buf[5] << 8) | buf[4];
  90         z = (buf[7] << 8) | buf[6];
  91
  92         valid = state & EVENT_VALID_MASK;
  93         id = (state & EVENT_ID_MASK) >> EVENT_ID_OFFSET;
  94         down = state & EVENT_DOWN_UP;
  95
  96         if (!valid || id > MAX_SUPPORT_POINTS) {
  97                 dev_dbg(&client->dev, "point invalid\n");
  98                 return IRQ_HANDLED;
  99         }
 100
 101         input_mt_slot(input_dev, id);
 102         input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, down);
 103
 104         dev_dbg(&client->dev, "%s id:%d x:%d y:%d z:%d",
 105                 down ? "down" : "up", id, x, y, z);
 106
 107         if (down) {
 108                 input_report_abs(input_dev, ABS_MT_POSITION_X, x);
 109                 input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
 110                 input_report_abs(input_dev, ABS_MT_PRESSURE, z);
 111         }
 112
 113         input_mt_report_pointer_emulation(input_dev, true);
 114         input_sync(input_dev);
 115
 116         return IRQ_HANDLED;
 117 }
 118
 119 /* wake up controller by an falling edge of interrupt gpio.  */
 120 static int egalax_wake_up_device(struct i2c_client *client)
 121 {
 122         struct device_node *np = client->dev.of_node;
 123         int gpio;
 124         int ret;
 125
 126         if (!np)
 127                 return -ENODEV;
 128
 129         gpio = of_get_named_gpio(np, "wakeup-gpios", 0);
 130         if (!gpio_is_valid(gpio))
 131                 return -ENODEV;
 132
 133         ret = gpio_request(gpio, "egalax_irq");
 134         if (ret < 0) {
 135                 dev_err(&client->dev,
 136                         "request gpio failed, cannot wake up controller: %d\n",
 137                         ret);
 138                 return ret;
 139         }
 140
 141         /* wake up controller via an falling edge on IRQ gpio. */
 142         gpio_direction_output(gpio, 0);
 143         gpio_set_value(gpio, 1);
 144
 145         /* controller should be waken up, return irq.  */
 146         gpio_direction_input(gpio);
 147         gpio_free(gpio);
 148
 149         return 0;
 150 }
 151
 152 static int egalax_firmware_version(struct i2c_client *client)
 153 {
 154         static const u8 cmd[MAX_I2C_DATA_LEN] = { 0x03, 0x03, 0xa, 0x01, 0x41 };
 155         int ret;
 156
 157         ret = i2c_master_send(client, cmd, MAX_I2C_DATA_LEN);
 158         if (ret < 0)
 159                 return ret;
 160
 161         return 0;
 162 }
 163
 164 static int egalax_ts_probe(struct i2c_client *client,
 165                            const struct i2c_device_id *id)
 166 {
 167         struct egalax_ts *ts;
 168         struct input_dev *input_dev;
 169         int error;
 170
 171         ts = devm_kzalloc(&client->dev, sizeof(struct egalax_ts), GFP_KERNEL);
 172         if (!ts) {
 173                 dev_err(&client->dev, "Failed to allocate memory\n");
 174                 return -ENOMEM;
 175         }
 176
 177         input_dev = devm_input_allocate_device(&client->dev);
 178         if (!input_dev) {
 179                 dev_err(&client->dev, "Failed to allocate memory\n");
 180                 return -ENOMEM;
 181         }
 182
 183         ts->client = client;
 184         ts->input_dev = input_dev;
 185
 186         /* controller may be in sleep, wake it up. */
 187         error = egalax_wake_up_device(client);
 188         if (error) {
 189                 dev_err(&client->dev, "Failed to wake up the controller\n");
 190                 return error;
 191         }
 192
 193         error = egalax_firmware_version(client);
 194         if (error < 0) {
 195                 dev_err(&client->dev, "Failed to read firmware version\n");
 196                 return error;
 197         }
 198
 199         input_dev->name = "EETI eGalax Touch Screen";
 200         input_dev->id.bustype = BUS_I2C;
 201
 202         __set_bit(EV_ABS, input_dev->evbit);
 203         __set_bit(EV_KEY, input_dev->evbit);
 204         __set_bit(BTN_TOUCH, input_dev->keybit);
 205
 206         input_set_abs_params(input_dev, ABS_X, 0, EGALAX_MAX_X, 0, 0);
 207         input_set_abs_params(input_dev, ABS_Y, 0, EGALAX_MAX_Y, 0, 0);
 208         input_set_abs_params(input_dev,
 209                              ABS_MT_POSITION_X, 0, EGALAX_MAX_X, 0, 0);
 210         input_set_abs_params(input_dev,
 211                              ABS_MT_POSITION_Y, 0, EGALAX_MAX_Y, 0, 0);
 212         input_mt_init_slots(input_dev, MAX_SUPPORT_POINTS, 0);
 213
 214         error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 215                                           egalax_ts_interrupt,
 216                                           IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 217                                           "egalax_ts", ts);
 218         if (error < 0) {
 219                 dev_err(&client->dev, "Failed to register interrupt\n");
 220                 return error;
 221         }
 222
 223         error = input_register_device(ts->input_dev);
 224         if (error)
 225                 return error;
 226
 227         return 0;
 228 }
 229
 230 static const struct i2c_device_id egalax_ts_id[] = {
 231         { "egalax_ts", 0 },
 232         { }
 233 };
 234 MODULE_DEVICE_TABLE(i2c, egalax_ts_id);
 235
 236 static int __maybe_unused egalax_ts_suspend(struct device *dev)
 237 {
 238         static const u8 suspend_cmd[MAX_I2C_DATA_LEN] = {
 239                 0x3, 0x6, 0xa, 0x3, 0x36, 0x3f, 0x2, 0, 0, 0
 240         };
 241         struct i2c_client *client = to_i2c_client(dev);
 242         int ret;
 243
 244         if (device_may_wakeup(dev))
 245                 return enable_irq_wake(client->irq);
 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         if (device_may_wakeup(dev))
 256                 return disable_irq_wake(client->irq);
 257
 258         return egalax_wake_up_device(client);
 259 }
 260
 261 static SIMPLE_DEV_PM_OPS(egalax_ts_pm_ops, egalax_ts_suspend, egalax_ts_resume);
 262
 263 static const struct of_device_id egalax_ts_dt_ids[] = {
 264         { .compatible = "eeti,egalax_ts" },
 265         { /* sentinel */ }
 266 };
 267 MODULE_DEVICE_TABLE(of, egalax_ts_dt_ids);
 268
 269 static struct i2c_driver egalax_ts_driver = {
 270         .driver = {
 271                 .name   = "egalax_ts",
 272                 .pm     = &egalax_ts_pm_ops,
 273                 .of_match_table = egalax_ts_dt_ids,
 274         },
 275         .id_table       = egalax_ts_id,
 276         .probe          = egalax_ts_probe,
 277 };
 278
 279 module_i2c_driver(egalax_ts_driver);
 280
 281 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
 282 MODULE_DESCRIPTION("Touchscreen driver for EETI eGalax touch controller");
 283 MODULE_LICENSE("GPL");