drivers/input/keyboard/tm2-touchkey.c

   1 /*
   2  * TM2 touchkey device driver
   3  *
   4  * Copyright 2005 Phil Blundell
   5  * Copyright 2016 Samsung Electronics Co., Ltd.
   6  *
   7  * Author: Beomho Seo <beomho.seo@samsung.com>
   8  * Author: Jaechul Lee <jcsing.lee@samsung.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/bitops.h>
  16 #include <linux/delay.h>
  17 #include <linux/device.h>
  18 #include <linux/i2c.h>
  19 #include <linux/input.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/irq.h>
  22 #include <linux/leds.h>
  23 #include <linux/module.h>
  24 #include <linux/of.h>
  25 #include <linux/pm.h>
  26 #include <linux/regulator/consumer.h>
  27
  28 #define TM2_TOUCHKEY_DEV_NAME           "tm2-touchkey"
  29 #define TM2_TOUCHKEY_KEYCODE_REG        0x03
  30 #define TM2_TOUCHKEY_BASE_REG           0x00
  31 #define TM2_TOUCHKEY_CMD_LED_ON         0x10
  32 #define TM2_TOUCHKEY_CMD_LED_OFF        0x20
  33 #define TM2_TOUCHKEY_BIT_PRESS_EV       BIT(3)
  34 #define TM2_TOUCHKEY_BIT_KEYCODE        GENMASK(2, 0)
  35 #define TM2_TOUCHKEY_LED_VOLTAGE_MIN    2500000
  36 #define TM2_TOUCHKEY_LED_VOLTAGE_MAX    3300000
  37
  38 enum {
  39         TM2_TOUCHKEY_KEY_MENU = 0x1,
  40         TM2_TOUCHKEY_KEY_BACK,
  41 };
  42
  43 struct tm2_touchkey_data {
  44         struct i2c_client *client;
  45         struct input_dev *input_dev;
  46         struct led_classdev led_dev;
  47         struct regulator *vdd;
  48         struct regulator_bulk_data regulators[2];
  49 };
  50
  51 static void tm2_touchkey_led_brightness_set(struct led_classdev *led_dev,
  52                                             enum led_brightness brightness)
  53 {
  54         struct tm2_touchkey_data *touchkey =
  55                 container_of(led_dev, struct tm2_touchkey_data, led_dev);
  56         u32 volt;
  57         u8 data;
  58
  59         if (brightness == LED_OFF) {
  60                 volt = TM2_TOUCHKEY_LED_VOLTAGE_MIN;
  61                 data = TM2_TOUCHKEY_CMD_LED_OFF;
  62         } else {
  63                 volt = TM2_TOUCHKEY_LED_VOLTAGE_MAX;
  64                 data = TM2_TOUCHKEY_CMD_LED_ON;
  65         }
  66
  67         regulator_set_voltage(touchkey->vdd, volt, volt);
  68         i2c_smbus_write_byte_data(touchkey->client,
  69                                   TM2_TOUCHKEY_BASE_REG, data);
  70 }
  71
  72 static int tm2_touchkey_power_enable(struct tm2_touchkey_data *touchkey)
  73 {
  74         int error;
  75
  76         error = regulator_bulk_enable(ARRAY_SIZE(touchkey->regulators),
  77                                       touchkey->regulators);
  78         if (error)
  79                 return error;
  80
  81         /* waiting for device initialization, at least 150ms */
  82         msleep(150);
  83
  84         return 0;
  85 }
  86
  87 static void tm2_touchkey_power_disable(void *data)
  88 {
  89         struct tm2_touchkey_data *touchkey = data;
  90
  91         regulator_bulk_disable(ARRAY_SIZE(touchkey->regulators),
  92                                touchkey->regulators);
  93 }
  94
  95 static irqreturn_t tm2_touchkey_irq_handler(int irq, void *devid)
  96 {
  97         struct tm2_touchkey_data *touchkey = devid;
  98         int data;
  99         int key;
 100
 101         data = i2c_smbus_read_byte_data(touchkey->client,
 102                                         TM2_TOUCHKEY_KEYCODE_REG);
 103         if (data < 0) {
 104                 dev_err(&touchkey->client->dev,
 105                         "failed to read i2c data: %d\n", data);
 106                 goto out;
 107         }
 108
 109         switch (data & TM2_TOUCHKEY_BIT_KEYCODE) {
 110         case TM2_TOUCHKEY_KEY_MENU:
 111                 key = KEY_PHONE;
 112                 break;
 113
 114         case TM2_TOUCHKEY_KEY_BACK:
 115                 key = KEY_BACK;
 116                 break;
 117
 118         default:
 119                 dev_warn(&touchkey->client->dev,
 120                          "unhandled keycode, data %#02x\n", data);
 121                 goto out;
 122         }
 123
 124         if (data & TM2_TOUCHKEY_BIT_PRESS_EV) {
 125                 input_report_key(touchkey->input_dev, KEY_PHONE, 0);
 126                 input_report_key(touchkey->input_dev, KEY_BACK, 0);
 127         } else {
 128                 input_report_key(touchkey->input_dev, key, 1);
 129         }
 130
 131         input_sync(touchkey->input_dev);
 132
 133 out:
 134         return IRQ_HANDLED;
 135 }
 136
 137 static int tm2_touchkey_probe(struct i2c_client *client,
 138                               const struct i2c_device_id *id)
 139 {
 140         struct tm2_touchkey_data *touchkey;
 141         int error;
 142
 143         if (!i2c_check_functionality(client->adapter,
 144                         I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA)) {
 145                 dev_err(&client->dev, "incompatible I2C adapter\n");
 146                 return -EIO;
 147         }
 148
 149         touchkey = devm_kzalloc(&client->dev, sizeof(*touchkey), GFP_KERNEL);
 150         if (!touchkey)
 151                 return -ENOMEM;
 152
 153         touchkey->client = client;
 154         i2c_set_clientdata(client, touchkey);
 155
 156         touchkey->regulators[0].supply = "vcc";
 157         touchkey->regulators[1].supply = "vdd";
 158         error = devm_regulator_bulk_get(&client->dev,
 159                                         ARRAY_SIZE(touchkey->regulators),
 160                                         touchkey->regulators);
 161         if (error) {
 162                 dev_err(&client->dev, "failed to get regulators: %d\n", error);
 163                 return error;
 164         }
 165
 166         /* Save VDD for easy access */
 167         touchkey->vdd = touchkey->regulators[1].consumer;
 168
 169         error = tm2_touchkey_power_enable(touchkey);
 170         if (error) {
 171                 dev_err(&client->dev, "failed to power up device: %d\n", error);
 172                 return error;
 173         }
 174
 175         error = devm_add_action_or_reset(&client->dev,
 176                                          tm2_touchkey_power_disable, touchkey);
 177         if (error) {
 178                 dev_err(&client->dev,
 179                         "failed to install poweroff handler: %d\n", error);
 180                 return error;
 181         }
 182
 183         /* input device */
 184         touchkey->input_dev = devm_input_allocate_device(&client->dev);
 185         if (!touchkey->input_dev) {
 186                 dev_err(&client->dev, "failed to allocate input device\n");
 187                 return -ENOMEM;
 188         }
 189
 190         touchkey->input_dev->name = TM2_TOUCHKEY_DEV_NAME;
 191         touchkey->input_dev->id.bustype = BUS_I2C;
 192
 193         input_set_capability(touchkey->input_dev, EV_KEY, KEY_PHONE);
 194         input_set_capability(touchkey->input_dev, EV_KEY, KEY_BACK);
 195
 196         error = input_register_device(touchkey->input_dev);
 197         if (error) {
 198                 dev_err(&client->dev,
 199                         "failed to register input device: %d\n", error);
 200                 return error;
 201         }
 202
 203         error = devm_request_threaded_irq(&client->dev, client->irq,
 204                                           NULL, tm2_touchkey_irq_handler,
 205                                           IRQF_ONESHOT,
 206                                           TM2_TOUCHKEY_DEV_NAME, touchkey);
 207         if (error) {
 208                 dev_err(&client->dev,
 209                         "failed to request threaded irq: %d\n", error);
 210                 return error;
 211         }
 212
 213         /* led device */
 214         touchkey->led_dev.name = TM2_TOUCHKEY_DEV_NAME;
 215         touchkey->led_dev.brightness = LED_FULL;
 216         touchkey->led_dev.max_brightness = LED_ON;
 217         touchkey->led_dev.brightness_set = tm2_touchkey_led_brightness_set;
 218
 219         error = devm_led_classdev_register(&client->dev, &touchkey->led_dev);
 220         if (error) {
 221                 dev_err(&client->dev,
 222                         "failed to register touchkey led: %d\n", error);
 223                 return error;
 224         }
 225
 226         return 0;
 227 }
 228
 229 static int __maybe_unused tm2_touchkey_suspend(struct device *dev)
 230 {
 231         struct i2c_client *client = to_i2c_client(dev);
 232         struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
 233
 234         disable_irq(client->irq);
 235         tm2_touchkey_power_disable(touchkey);
 236
 237         return 0;
 238 }
 239
 240 static int __maybe_unused tm2_touchkey_resume(struct device *dev)
 241 {
 242         struct i2c_client *client = to_i2c_client(dev);
 243         struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
 244         int ret;
 245
 246         enable_irq(client->irq);
 247
 248         ret = tm2_touchkey_power_enable(touchkey);
 249         if (ret)
 250                 dev_err(dev, "failed to enable power: %d\n", ret);
 251
 252         return ret;
 253 }
 254
 255 static SIMPLE_DEV_PM_OPS(tm2_touchkey_pm_ops,
 256                          tm2_touchkey_suspend, tm2_touchkey_resume);
 257
 258 static const struct i2c_device_id tm2_touchkey_id_table[] = {
 259         { TM2_TOUCHKEY_DEV_NAME, 0 },
 260         { },
 261 };
 262 MODULE_DEVICE_TABLE(i2c, tm2_touchkey_id_table);
 263
 264 static const struct of_device_id tm2_touchkey_of_match[] = {
 265         { .compatible = "cypress,tm2-touchkey", },
 266         { },
 267 };
 268 MODULE_DEVICE_TABLE(of, tm2_touchkey_of_match);
 269
 270 static struct i2c_driver tm2_touchkey_driver = {
 271         .driver = {
 272                 .name = TM2_TOUCHKEY_DEV_NAME,
 273                 .pm = &tm2_touchkey_pm_ops,
 274                 .of_match_table = of_match_ptr(tm2_touchkey_of_match),
 275         },
 276         .probe = tm2_touchkey_probe,
 277         .id_table = tm2_touchkey_id_table,
 278 };
 279 module_i2c_driver(tm2_touchkey_driver);
 280
 281 MODULE_AUTHOR("Beomho Seo <beomho.seo@samsung.com>");
 282 MODULE_AUTHOR("Jaechul Lee <jcsing.lee@samsung.com>");
 283 MODULE_DESCRIPTION("Samsung touchkey driver");
 284 MODULE_LICENSE("GPL v2");