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/of_device.h>
  26 #include <linux/pm.h>
  27 #include <linux/regulator/consumer.h>
  28
  29 #define TM2_TOUCHKEY_DEV_NAME           "tm2-touchkey"
  30
  31 #define ARIES_TOUCHKEY_CMD_LED_ON       0x1
  32 #define ARIES_TOUCHKEY_CMD_LED_OFF      0x2
  33 #define TM2_TOUCHKEY_CMD_LED_ON         0x10
  34 #define TM2_TOUCHKEY_CMD_LED_OFF        0x20
  35 #define TM2_TOUCHKEY_BIT_PRESS_EV       BIT(3)
  36 #define TM2_TOUCHKEY_BIT_KEYCODE        GENMASK(2, 0)
  37 #define TM2_TOUCHKEY_LED_VOLTAGE_MIN    2500000
  38 #define TM2_TOUCHKEY_LED_VOLTAGE_MAX    3300000
  39
  40 struct touchkey_variant {
  41         u8 keycode_reg;
  42         u8 base_reg;
  43         u8 cmd_led_on;
  44         u8 cmd_led_off;
  45         bool no_reg;
  46         bool fixed_regulator;
  47 };
  48
  49 struct tm2_touchkey_data {
  50         struct i2c_client *client;
  51         struct input_dev *input_dev;
  52         struct led_classdev led_dev;
  53         struct regulator *vdd;
  54         struct regulator_bulk_data regulators[2];
  55         const struct touchkey_variant *variant;
  56         u32 keycodes[4];
  57         int num_keycodes;
  58 };
  59
  60 static const struct touchkey_variant tm2_touchkey_variant = {
  61         .keycode_reg = 0x03,
  62         .base_reg = 0x00,
  63         .cmd_led_on = TM2_TOUCHKEY_CMD_LED_ON,
  64         .cmd_led_off = TM2_TOUCHKEY_CMD_LED_OFF,
  65 };
  66
  67 static const struct touchkey_variant midas_touchkey_variant = {
  68         .keycode_reg = 0x00,
  69         .base_reg = 0x00,
  70         .cmd_led_on = TM2_TOUCHKEY_CMD_LED_ON,
  71         .cmd_led_off = TM2_TOUCHKEY_CMD_LED_OFF,
  72 };
  73
  74 static struct touchkey_variant aries_touchkey_variant = {
  75         .no_reg = true,
  76         .fixed_regulator = true,
  77         .cmd_led_on = ARIES_TOUCHKEY_CMD_LED_ON,
  78         .cmd_led_off = ARIES_TOUCHKEY_CMD_LED_OFF,
  79 };
  80
  81 static int tm2_touchkey_led_brightness_set(struct led_classdev *led_dev,
  82                                             enum led_brightness brightness)
  83 {
  84         struct tm2_touchkey_data *touchkey =
  85                 container_of(led_dev, struct tm2_touchkey_data, led_dev);
  86         u32 volt;
  87         u8 data;
  88
  89         if (brightness == LED_OFF) {
  90                 volt = TM2_TOUCHKEY_LED_VOLTAGE_MIN;
  91                 data = touchkey->variant->cmd_led_off;
  92         } else {
  93                 volt = TM2_TOUCHKEY_LED_VOLTAGE_MAX;
  94                 data = touchkey->variant->cmd_led_on;
  95         }
  96
  97         if (!touchkey->variant->fixed_regulator)
  98                 regulator_set_voltage(touchkey->vdd, volt, volt);
  99
 100         return touchkey->variant->no_reg ?
 101                 i2c_smbus_write_byte(touchkey->client, data) :
 102                 i2c_smbus_write_byte_data(touchkey->client,
 103                                           touchkey->variant->base_reg, data);
 104 }
 105
 106 static int tm2_touchkey_power_enable(struct tm2_touchkey_data *touchkey)
 107 {
 108         int error;
 109
 110         error = regulator_bulk_enable(ARRAY_SIZE(touchkey->regulators),
 111                                       touchkey->regulators);
 112         if (error)
 113                 return error;
 114
 115         /* waiting for device initialization, at least 150ms */
 116         msleep(150);
 117
 118         return 0;
 119 }
 120
 121 static void tm2_touchkey_power_disable(void *data)
 122 {
 123         struct tm2_touchkey_data *touchkey = data;
 124
 125         regulator_bulk_disable(ARRAY_SIZE(touchkey->regulators),
 126                                touchkey->regulators);
 127 }
 128
 129 static irqreturn_t tm2_touchkey_irq_handler(int irq, void *devid)
 130 {
 131         struct tm2_touchkey_data *touchkey = devid;
 132         int data;
 133         int index;
 134         int i;
 135
 136         if (touchkey->variant->no_reg)
 137                 data = i2c_smbus_read_byte(touchkey->client);
 138         else
 139                 data = i2c_smbus_read_byte_data(touchkey->client,
 140                                                 touchkey->variant->keycode_reg);
 141         if (data < 0) {
 142                 dev_err(&touchkey->client->dev,
 143                         "failed to read i2c data: %d\n", data);
 144                 goto out;
 145         }
 146
 147         index = (data & TM2_TOUCHKEY_BIT_KEYCODE) - 1;
 148         if (index < 0 || index >= touchkey->num_keycodes) {
 149                 dev_warn(&touchkey->client->dev,
 150                          "invalid keycode index %d\n", index);
 151                 goto out;
 152         }
 153
 154         if (data & TM2_TOUCHKEY_BIT_PRESS_EV) {
 155                 for (i = 0; i < touchkey->num_keycodes; i++)
 156                         input_report_key(touchkey->input_dev,
 157                                          touchkey->keycodes[i], 0);
 158         } else {
 159                 input_report_key(touchkey->input_dev,
 160                                  touchkey->keycodes[index], 1);
 161         }
 162
 163         input_sync(touchkey->input_dev);
 164
 165 out:
 166         if (touchkey->variant->fixed_regulator &&
 167                                 data & TM2_TOUCHKEY_BIT_PRESS_EV) {
 168                 /* touch turns backlight on, so make sure we're in sync */
 169                 if (touchkey->led_dev.brightness == LED_OFF)
 170                         tm2_touchkey_led_brightness_set(&touchkey->led_dev,
 171                                                         LED_OFF);
 172         }
 173
 174         return IRQ_HANDLED;
 175 }
 176
 177 static int tm2_touchkey_probe(struct i2c_client *client,
 178                               const struct i2c_device_id *id)
 179 {
 180         struct device_node *np = client->dev.of_node;
 181         struct tm2_touchkey_data *touchkey;
 182         int error;
 183         int i;
 184
 185         if (!i2c_check_functionality(client->adapter,
 186                         I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA)) {
 187                 dev_err(&client->dev, "incompatible I2C adapter\n");
 188                 return -EIO;
 189         }
 190
 191         touchkey = devm_kzalloc(&client->dev, sizeof(*touchkey), GFP_KERNEL);
 192         if (!touchkey)
 193                 return -ENOMEM;
 194
 195         touchkey->client = client;
 196         i2c_set_clientdata(client, touchkey);
 197
 198         touchkey->variant = of_device_get_match_data(&client->dev);
 199
 200         touchkey->regulators[0].supply = "vcc";
 201         touchkey->regulators[1].supply = "vdd";
 202         error = devm_regulator_bulk_get(&client->dev,
 203                                         ARRAY_SIZE(touchkey->regulators),
 204                                         touchkey->regulators);
 205         if (error) {
 206                 dev_err(&client->dev, "failed to get regulators: %d\n", error);
 207                 return error;
 208         }
 209
 210         /* Save VDD for easy access */
 211         touchkey->vdd = touchkey->regulators[1].consumer;
 212
 213         touchkey->num_keycodes = of_property_read_variable_u32_array(np,
 214                                         "linux,keycodes", touchkey->keycodes, 0,
 215                                         ARRAY_SIZE(touchkey->keycodes));
 216         if (touchkey->num_keycodes <= 0) {
 217                 /* default keycodes */
 218                 touchkey->keycodes[0] = KEY_PHONE;
 219                 touchkey->keycodes[1] = KEY_BACK;
 220                 touchkey->num_keycodes = 2;
 221         }
 222
 223         error = tm2_touchkey_power_enable(touchkey);
 224         if (error) {
 225                 dev_err(&client->dev, "failed to power up device: %d\n", error);
 226                 return error;
 227         }
 228
 229         error = devm_add_action_or_reset(&client->dev,
 230                                          tm2_touchkey_power_disable, touchkey);
 231         if (error) {
 232                 dev_err(&client->dev,
 233                         "failed to install poweroff handler: %d\n", error);
 234                 return error;
 235         }
 236
 237         /* input device */
 238         touchkey->input_dev = devm_input_allocate_device(&client->dev);
 239         if (!touchkey->input_dev) {
 240                 dev_err(&client->dev, "failed to allocate input device\n");
 241                 return -ENOMEM;
 242         }
 243
 244         touchkey->input_dev->name = TM2_TOUCHKEY_DEV_NAME;
 245         touchkey->input_dev->id.bustype = BUS_I2C;
 246
 247         for (i = 0; i < touchkey->num_keycodes; i++)
 248                 input_set_capability(touchkey->input_dev, EV_KEY,
 249                                      touchkey->keycodes[i]);
 250
 251         error = input_register_device(touchkey->input_dev);
 252         if (error) {
 253                 dev_err(&client->dev,
 254                         "failed to register input device: %d\n", error);
 255                 return error;
 256         }
 257
 258         error = devm_request_threaded_irq(&client->dev, client->irq,
 259                                           NULL, tm2_touchkey_irq_handler,
 260                                           IRQF_ONESHOT,
 261                                           TM2_TOUCHKEY_DEV_NAME, touchkey);
 262         if (error) {
 263                 dev_err(&client->dev,
 264                         "failed to request threaded irq: %d\n", error);
 265                 return error;
 266         }
 267
 268         /* led device */
 269         touchkey->led_dev.name = TM2_TOUCHKEY_DEV_NAME;
 270         touchkey->led_dev.brightness = LED_ON;
 271         touchkey->led_dev.max_brightness = LED_ON;
 272         touchkey->led_dev.brightness_set_blocking =
 273                                         tm2_touchkey_led_brightness_set;
 274
 275         error = devm_led_classdev_register(&client->dev, &touchkey->led_dev);
 276         if (error) {
 277                 dev_err(&client->dev,
 278                         "failed to register touchkey led: %d\n", error);
 279                 return error;
 280         }
 281
 282         if (touchkey->variant->fixed_regulator)
 283                 tm2_touchkey_led_brightness_set(&touchkey->led_dev, LED_ON);
 284
 285         return 0;
 286 }
 287
 288 static int __maybe_unused tm2_touchkey_suspend(struct device *dev)
 289 {
 290         struct i2c_client *client = to_i2c_client(dev);
 291         struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
 292
 293         disable_irq(client->irq);
 294         tm2_touchkey_power_disable(touchkey);
 295
 296         return 0;
 297 }
 298
 299 static int __maybe_unused tm2_touchkey_resume(struct device *dev)
 300 {
 301         struct i2c_client *client = to_i2c_client(dev);
 302         struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
 303         int ret;
 304
 305         enable_irq(client->irq);
 306
 307         ret = tm2_touchkey_power_enable(touchkey);
 308         if (ret)
 309                 dev_err(dev, "failed to enable power: %d\n", ret);
 310
 311         return ret;
 312 }
 313
 314 static SIMPLE_DEV_PM_OPS(tm2_touchkey_pm_ops,
 315                          tm2_touchkey_suspend, tm2_touchkey_resume);
 316
 317 static const struct i2c_device_id tm2_touchkey_id_table[] = {
 318         { TM2_TOUCHKEY_DEV_NAME, 0 },
 319         { },
 320 };
 321 MODULE_DEVICE_TABLE(i2c, tm2_touchkey_id_table);
 322
 323 static const struct of_device_id tm2_touchkey_of_match[] = {
 324         {
 325                 .compatible = "cypress,tm2-touchkey",
 326                 .data = &tm2_touchkey_variant,
 327         }, {
 328                 .compatible = "cypress,midas-touchkey",
 329                 .data = &midas_touchkey_variant,
 330         }, {
 331                 .compatible = "cypress,aries-touchkey",
 332                 .data = &aries_touchkey_variant,
 333         },
 334         { },
 335 };
 336 MODULE_DEVICE_TABLE(of, tm2_touchkey_of_match);
 337
 338 static struct i2c_driver tm2_touchkey_driver = {
 339         .driver = {
 340                 .name = TM2_TOUCHKEY_DEV_NAME,
 341                 .pm = &tm2_touchkey_pm_ops,
 342                 .of_match_table = of_match_ptr(tm2_touchkey_of_match),
 343         },
 344         .probe = tm2_touchkey_probe,
 345         .id_table = tm2_touchkey_id_table,
 346 };
 347 module_i2c_driver(tm2_touchkey_driver);
 348
 349 MODULE_AUTHOR("Beomho Seo <beomho.seo@samsung.com>");
 350 MODULE_AUTHOR("Jaechul Lee <jcsing.lee@samsung.com>");
 351 MODULE_DESCRIPTION("Samsung touchkey driver");
 352 MODULE_LICENSE("GPL v2");