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/err.h>
  18 #include <linux/module.h>
  19 #include <linux/i2c.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/input.h>
  22 #include <linux/irq.h>
  23 #include <linux/gpio/consumer.h>
  24 #include <linux/delay.h>
  25 #include <linux/slab.h>
  26 #include <linux/bitops.h>
  27 #include <linux/input/mt.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 gpio_desc *gpio;
 123         int ret;
 124
 125         /* wake up controller via an falling edge on IRQ gpio. */
 126         gpio = gpiod_get(&client->dev, "wakeup", GPIOD_OUT_HIGH);
 127         ret = PTR_ERR_OR_ZERO(gpio);
 128         if (ret) {
 129                 if (ret != -EPROBE_DEFER)
 130                         dev_err(&client->dev,
 131                                 "failed to request wakeup gpio, cannot wake up controller: %d\n",
 132                                 ret);
 133                 return ret;
 134         }
 135
 136         /* release the line */
 137         gpiod_set_value_cansleep(gpio, 0);
 138
 139         /* controller should be woken up, return irq.  */
 140         gpiod_direction_input(gpio);
 141         gpiod_put(gpio);
 142
 143         return 0;
 144 }
 145
 146 static int egalax_firmware_version(struct i2c_client *client)
 147 {
 148         static const u8 cmd[MAX_I2C_DATA_LEN] = { 0x03, 0x03, 0xa, 0x01, 0x41 };
 149         int ret;
 150
 151         ret = i2c_master_send(client, cmd, MAX_I2C_DATA_LEN);
 152         if (ret < 0)
 153                 return ret;
 154
 155         return 0;
 156 }
 157
 158 static int egalax_ts_probe(struct i2c_client *client)
 159 {
 160         struct egalax_ts *ts;
 161         struct input_dev *input_dev;
 162         int error;
 163
 164         ts = devm_kzalloc(&client->dev, sizeof(struct egalax_ts), GFP_KERNEL);
 165         if (!ts) {
 166                 dev_err(&client->dev, "Failed to allocate memory\n");
 167                 return -ENOMEM;
 168         }
 169
 170         input_dev = devm_input_allocate_device(&client->dev);
 171         if (!input_dev) {
 172                 dev_err(&client->dev, "Failed to allocate memory\n");
 173                 return -ENOMEM;
 174         }
 175
 176         ts->client = client;
 177         ts->input_dev = input_dev;
 178
 179         /* controller may be in sleep, wake it up. */
 180         error = egalax_wake_up_device(client);
 181         if (error)
 182                 return error;
 183
 184         error = egalax_firmware_version(client);
 185         if (error < 0) {
 186                 dev_err(&client->dev, "Failed to read firmware version\n");
 187                 return error;
 188         }
 189
 190         input_dev->name = "EETI eGalax Touch Screen";
 191         input_dev->id.bustype = BUS_I2C;
 192
 193         __set_bit(EV_ABS, input_dev->evbit);
 194         __set_bit(EV_KEY, input_dev->evbit);
 195         __set_bit(BTN_TOUCH, input_dev->keybit);
 196
 197         input_set_abs_params(input_dev, ABS_X, 0, EGALAX_MAX_X, 0, 0);
 198         input_set_abs_params(input_dev, ABS_Y, 0, EGALAX_MAX_Y, 0, 0);
 199         input_set_abs_params(input_dev,
 200                              ABS_MT_POSITION_X, 0, EGALAX_MAX_X, 0, 0);
 201         input_set_abs_params(input_dev,
 202                              ABS_MT_POSITION_Y, 0, EGALAX_MAX_Y, 0, 0);
 203         input_mt_init_slots(input_dev, MAX_SUPPORT_POINTS, 0);
 204
 205         error = devm_request_threaded_irq(&client->dev, client->irq,
 206                                           NULL, egalax_ts_interrupt,
 207                                           IRQF_ONESHOT, "egalax_ts", ts);
 208         if (error < 0) {
 209                 dev_err(&client->dev, "Failed to register interrupt\n");
 210                 return error;
 211         }
 212
 213         error = input_register_device(ts->input_dev);
 214         if (error)
 215                 return error;
 216
 217         return 0;
 218 }
 219
 220 static const struct i2c_device_id egalax_ts_id[] = {
 221         { "egalax_ts" },
 222         { }
 223 };
 224 MODULE_DEVICE_TABLE(i2c, egalax_ts_id);
 225
 226 static int egalax_ts_suspend(struct device *dev)
 227 {
 228         static const u8 suspend_cmd[MAX_I2C_DATA_LEN] = {
 229                 0x3, 0x6, 0xa, 0x3, 0x36, 0x3f, 0x2, 0, 0, 0
 230         };
 231         struct i2c_client *client = to_i2c_client(dev);
 232         int ret;
 233
 234         if (device_may_wakeup(dev))
 235                 return enable_irq_wake(client->irq);
 236
 237         ret = i2c_master_send(client, suspend_cmd, MAX_I2C_DATA_LEN);
 238         return ret > 0 ? 0 : ret;
 239 }
 240
 241 static int egalax_ts_resume(struct device *dev)
 242 {
 243         struct i2c_client *client = to_i2c_client(dev);
 244
 245         if (device_may_wakeup(dev))
 246                 return disable_irq_wake(client->irq);
 247
 248         return egalax_wake_up_device(client);
 249 }
 250
 251 static DEFINE_SIMPLE_DEV_PM_OPS(egalax_ts_pm_ops,
 252                                 egalax_ts_suspend, egalax_ts_resume);
 253
 254 static const struct of_device_id egalax_ts_dt_ids[] = {
 255         { .compatible = "eeti,egalax_ts" },
 256         { /* sentinel */ }
 257 };
 258 MODULE_DEVICE_TABLE(of, egalax_ts_dt_ids);
 259
 260 static struct i2c_driver egalax_ts_driver = {
 261         .driver = {
 262                 .name   = "egalax_ts",
 263                 .pm     = pm_sleep_ptr(&egalax_ts_pm_ops),
 264                 .of_match_table = egalax_ts_dt_ids,
 265         },
 266         .id_table       = egalax_ts_id,
 267         .probe          = egalax_ts_probe,
 268 };
 269
 270 module_i2c_driver(egalax_ts_driver);
 271
 272 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
 273 MODULE_DESCRIPTION("Touchscreen driver for EETI eGalax touch controller");
 274 MODULE_LICENSE("GPL");