drivers/input/touchscreen/chipone_icn8318.c

   1 /*
   2  * Driver for ChipOne icn8318 i2c touchscreen controller
   3  *
   4  * Copyright (c) 2015 Red Hat Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * Red Hat authors:
  12  * Hans de Goede <hdegoede@redhat.com>
  13  */
  14
  15 #include <linux/gpio/consumer.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/i2c.h>
  18 #include <linux/input.h>
  19 #include <linux/input/mt.h>
  20 #include <linux/module.h>
  21 #include <linux/of.h>
  22
  23 #define ICN8318_REG_POWER               4
  24 #define ICN8318_REG_TOUCHDATA           16
  25
  26 #define ICN8318_POWER_ACTIVE            0
  27 #define ICN8318_POWER_MONITOR           1
  28 #define ICN8318_POWER_HIBERNATE         2
  29
  30 #define ICN8318_MAX_TOUCHES             5
  31
  32 struct icn8318_touch {
  33         __u8 slot;
  34         __be16 x;
  35         __be16 y;
  36         __u8 pressure;  /* Seems more like finger width then pressure really */
  37         __u8 event;
  38 /* The difference between 2 and 3 is unclear */
  39 #define ICN8318_EVENT_NO_DATA   1 /* No finger seen yet since wakeup */
  40 #define ICN8318_EVENT_UPDATE1   2 /* New or updated coordinates */
  41 #define ICN8318_EVENT_UPDATE2   3 /* New or updated coordinates */
  42 #define ICN8318_EVENT_END       4 /* Finger lifted */
  43 } __packed;
  44
  45 struct icn8318_touch_data {
  46         __u8 softbutton;
  47         __u8 touch_count;
  48         struct icn8318_touch touches[ICN8318_MAX_TOUCHES];
  49 } __packed;
  50
  51 struct icn8318_data {
  52         struct i2c_client *client;
  53         struct input_dev *input;
  54         struct gpio_desc *wake_gpio;
  55         u32 max_x;
  56         u32 max_y;
  57         bool invert_x;
  58         bool invert_y;
  59         bool swap_x_y;
  60 };
  61
  62 static int icn8318_read_touch_data(struct i2c_client *client,
  63                                    struct icn8318_touch_data *touch_data)
  64 {
  65         u8 reg = ICN8318_REG_TOUCHDATA;
  66         struct i2c_msg msg[2] = {
  67                 {
  68                         .addr = client->addr,
  69                         .len = 1,
  70                         .buf = &reg
  71                 },
  72                 {
  73                         .addr = client->addr,
  74                         .flags = I2C_M_RD,
  75                         .len = sizeof(struct icn8318_touch_data),
  76                         .buf = (u8 *)touch_data
  77                 }
  78         };
  79
  80         return i2c_transfer(client->adapter, msg, 2);
  81 }
  82
  83 static inline bool icn8318_touch_active(u8 event)
  84 {
  85         return (event == ICN8318_EVENT_UPDATE1) ||
  86                (event == ICN8318_EVENT_UPDATE2);
  87 }
  88
  89 static irqreturn_t icn8318_irq(int irq, void *dev_id)
  90 {
  91         struct icn8318_data *data = dev_id;
  92         struct device *dev = &data->client->dev;
  93         struct icn8318_touch_data touch_data;
  94         int i, ret, x, y;
  95
  96         ret = icn8318_read_touch_data(data->client, &touch_data);
  97         if (ret < 0) {
  98                 dev_err(dev, "Error reading touch data: %d\n", ret);
  99                 return IRQ_HANDLED;
 100         }
 101
 102         if (touch_data.softbutton) {
 103                 /*
 104                  * Other data is invalid when a softbutton is pressed.
 105                  * This needs some extra devicetree bindings to map the icn8318
 106                  * softbutton codes to evdev codes. Currently no known devices
 107                  * use this.
 108                  */
 109                 return IRQ_HANDLED;
 110         }
 111
 112         if (touch_data.touch_count > ICN8318_MAX_TOUCHES) {
 113                 dev_warn(dev, "Too much touches %d > %d\n",
 114                          touch_data.touch_count, ICN8318_MAX_TOUCHES);
 115                 touch_data.touch_count = ICN8318_MAX_TOUCHES;
 116         }
 117
 118         for (i = 0; i < touch_data.touch_count; i++) {
 119                 struct icn8318_touch *touch = &touch_data.touches[i];
 120                 bool act = icn8318_touch_active(touch->event);
 121
 122                 input_mt_slot(data->input, touch->slot);
 123                 input_mt_report_slot_state(data->input, MT_TOOL_FINGER, act);
 124                 if (!act)
 125                         continue;
 126
 127                 x = be16_to_cpu(touch->x);
 128                 y = be16_to_cpu(touch->y);
 129
 130                 if (data->invert_x)
 131                         x = data->max_x - x;
 132
 133                 if (data->invert_y)
 134                         y = data->max_y - y;
 135
 136                 if (!data->swap_x_y) {
 137                         input_event(data->input, EV_ABS, ABS_MT_POSITION_X, x);
 138                         input_event(data->input, EV_ABS, ABS_MT_POSITION_Y, y);
 139                 } else {
 140                         input_event(data->input, EV_ABS, ABS_MT_POSITION_X, y);
 141                         input_event(data->input, EV_ABS, ABS_MT_POSITION_Y, x);
 142                 }
 143         }
 144
 145         input_mt_sync_frame(data->input);
 146         input_sync(data->input);
 147
 148         return IRQ_HANDLED;
 149 }
 150
 151 static int icn8318_start(struct input_dev *dev)
 152 {
 153         struct icn8318_data *data = input_get_drvdata(dev);
 154
 155         enable_irq(data->client->irq);
 156         gpiod_set_value_cansleep(data->wake_gpio, 1);
 157
 158         return 0;
 159 }
 160
 161 static void icn8318_stop(struct input_dev *dev)
 162 {
 163         struct icn8318_data *data = input_get_drvdata(dev);
 164
 165         disable_irq(data->client->irq);
 166         i2c_smbus_write_byte_data(data->client, ICN8318_REG_POWER,
 167                                   ICN8318_POWER_HIBERNATE);
 168         gpiod_set_value_cansleep(data->wake_gpio, 0);
 169 }
 170
 171 #ifdef CONFIG_PM_SLEEP
 172 static int icn8318_suspend(struct device *dev)
 173 {
 174         struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));
 175
 176         mutex_lock(&data->input->mutex);
 177         if (data->input->users)
 178                 icn8318_stop(data->input);
 179         mutex_unlock(&data->input->mutex);
 180
 181         return 0;
 182 }
 183
 184 static int icn8318_resume(struct device *dev)
 185 {
 186         struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));
 187
 188         mutex_lock(&data->input->mutex);
 189         if (data->input->users)
 190                 icn8318_start(data->input);
 191         mutex_unlock(&data->input->mutex);
 192
 193         return 0;
 194 }
 195 #endif
 196
 197 static SIMPLE_DEV_PM_OPS(icn8318_pm_ops, icn8318_suspend, icn8318_resume);
 198
 199 static int icn8318_probe(struct i2c_client *client,
 200                          const struct i2c_device_id *id)
 201 {
 202         struct device *dev = &client->dev;
 203         struct device_node *np = dev->of_node;
 204         struct icn8318_data *data;
 205         struct input_dev *input;
 206         u32 fuzz_x = 0, fuzz_y = 0;
 207         int error;
 208
 209         if (!client->irq) {
 210                 dev_err(dev, "Error no irq specified\n");
 211                 return -EINVAL;
 212         }
 213
 214         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 215         if (!data)
 216                 return -ENOMEM;
 217
 218         data->wake_gpio = devm_gpiod_get(dev, "wake", GPIOD_OUT_LOW);
 219         if (IS_ERR(data->wake_gpio)) {
 220                 error = PTR_ERR(data->wake_gpio);
 221                 if (error != -EPROBE_DEFER)
 222                         dev_err(dev, "Error getting wake gpio: %d\n", error);
 223                 return error;
 224         }
 225
 226         if (of_property_read_u32(np, "touchscreen-size-x", &data->max_x) ||
 227             of_property_read_u32(np, "touchscreen-size-y", &data->max_y)) {
 228                 dev_err(dev, "Error touchscreen-size-x and/or -y missing\n");
 229                 return -EINVAL;
 230         }
 231
 232         /* Optional */
 233         of_property_read_u32(np, "touchscreen-fuzz-x", &fuzz_x);
 234         of_property_read_u32(np, "touchscreen-fuzz-y", &fuzz_y);
 235         data->invert_x = of_property_read_bool(np, "touchscreen-inverted-x");
 236         data->invert_y = of_property_read_bool(np, "touchscreen-inverted-y");
 237         data->swap_x_y = of_property_read_bool(np, "touchscreen-swapped-x-y");
 238
 239         input = devm_input_allocate_device(dev);
 240         if (!input)
 241                 return -ENOMEM;
 242
 243         input->name = client->name;
 244         input->id.bustype = BUS_I2C;
 245         input->open = icn8318_start;
 246         input->close = icn8318_stop;
 247         input->dev.parent = dev;
 248
 249         if (!data->swap_x_y) {
 250                 input_set_abs_params(input, ABS_MT_POSITION_X, 0,
 251                                      data->max_x, fuzz_x, 0);
 252                 input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
 253                                      data->max_y, fuzz_y, 0);
 254         } else {
 255                 input_set_abs_params(input, ABS_MT_POSITION_X, 0,
 256                                      data->max_y, fuzz_y, 0);
 257                 input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
 258                                      data->max_x, fuzz_x, 0);
 259         }
 260
 261         error = input_mt_init_slots(input, ICN8318_MAX_TOUCHES,
 262                                     INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
 263         if (error)
 264                 return error;
 265
 266         data->client = client;
 267         data->input = input;
 268         input_set_drvdata(input, data);
 269
 270         error = devm_request_threaded_irq(dev, client->irq, NULL, icn8318_irq,
 271                                           IRQF_ONESHOT, client->name, data);
 272         if (error) {
 273                 dev_err(dev, "Error requesting irq: %d\n", error);
 274                 return error;
 275         }
 276
 277         /* Stop device till opened */
 278         icn8318_stop(data->input);
 279
 280         error = input_register_device(input);
 281         if (error)
 282                 return error;
 283
 284         i2c_set_clientdata(client, data);
 285
 286         return 0;
 287 }
 288
 289 static const struct of_device_id icn8318_of_match[] = {
 290         { .compatible = "chipone,icn8318" },
 291         { }
 292 };
 293 MODULE_DEVICE_TABLE(of, icn8318_of_match);
 294
 295 /* This is useless for OF-enabled devices, but it is needed by I2C subsystem */
 296 static const struct i2c_device_id icn8318_i2c_id[] = {
 297         { },
 298 };
 299 MODULE_DEVICE_TABLE(i2c, icn8318_i2c_id);
 300
 301 static struct i2c_driver icn8318_driver = {
 302         .driver = {
 303                 .owner  = THIS_MODULE,
 304                 .name   = "chipone_icn8318",
 305                 .pm     = &icn8318_pm_ops,
 306                 .of_match_table = icn8318_of_match,
 307         },
 308         .probe = icn8318_probe,
 309         .id_table = icn8318_i2c_id,
 310 };
 311
 312 module_i2c_driver(icn8318_driver);
 313
 314 MODULE_DESCRIPTION("ChipOne icn8318 I2C Touchscreen Driver");
 315 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 316 MODULE_LICENSE("GPL");