drivers/input/keyboard/tm2-touchkey.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * TM2 touchkey device driver
   4  *
   5  * Copyright 2005 Phil Blundell
   6  * Copyright 2016 Samsung Electronics Co., Ltd.
   7  *
   8  * Author: Beomho Seo <beomho.seo@samsung.com>
   9  * Author: Jaechul Lee <jcsing.lee@samsung.com>
  10  */
  11
  12 #include <linux/bitops.h>
  13 #include <linux/delay.h>
  14 #include <linux/device.h>
  15 #include <linux/i2c.h>
  16 #include <linux/input.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/irq.h>
  19 #include <linux/leds.h>
  20 #include <linux/module.h>
  21 #include <linux/of.h>
  22 #include <linux/of_device.h>
  23 #include <linux/pm.h>
  24 #include <linux/regulator/consumer.h>
  25
  26 #define TM2_TOUCHKEY_DEV_NAME           "tm2-touchkey"
  27
  28 #define ARIES_TOUCHKEY_CMD_LED_ON       0x1
  29 #define ARIES_TOUCHKEY_CMD_LED_OFF      0x2
  30 #define TM2_TOUCHKEY_CMD_LED_ON         0x10
  31 #define TM2_TOUCHKEY_CMD_LED_OFF        0x20
  32 #define TM2_TOUCHKEY_BIT_PRESS_EV       BIT(3)
  33 #define TM2_TOUCHKEY_BIT_KEYCODE        GENMASK(2, 0)
  34 #define TM2_TOUCHKEY_LED_VOLTAGE_MIN    2500000
  35 #define TM2_TOUCHKEY_LED_VOLTAGE_MAX    3300000
  36
  37 struct touchkey_variant {
  38         u8 keycode_reg;
  39         u8 base_reg;
  40         u8 cmd_led_on;
  41         u8 cmd_led_off;
  42         bool no_reg;
  43         bool fixed_regulator;
  44 };
  45
  46 struct tm2_touchkey_data {
  47         struct i2c_client *client;
  48         struct input_dev *input_dev;
  49         struct led_classdev led_dev;
  50         struct regulator *vdd;
  51         struct regulator_bulk_data regulators[2];
  52         const struct touchkey_variant *variant;
  53         u32 keycodes[4];
  54         int num_keycodes;
  55 };
  56
  57 static const struct touchkey_variant tm2_touchkey_variant = {
  58         .keycode_reg = 0x03,
  59         .base_reg = 0x00,
  60         .cmd_led_on = TM2_TOUCHKEY_CMD_LED_ON,
  61         .cmd_led_off = TM2_TOUCHKEY_CMD_LED_OFF,
  62 };
  63
  64 static const struct touchkey_variant midas_touchkey_variant = {
  65         .keycode_reg = 0x00,
  66         .base_reg = 0x00,
  67         .cmd_led_on = TM2_TOUCHKEY_CMD_LED_ON,
  68         .cmd_led_off = TM2_TOUCHKEY_CMD_LED_OFF,
  69 };
  70
  71 static struct touchkey_variant aries_touchkey_variant = {
  72         .no_reg = true,
  73         .fixed_regulator = true,
  74         .cmd_led_on = ARIES_TOUCHKEY_CMD_LED_ON,
  75         .cmd_led_off = ARIES_TOUCHKEY_CMD_LED_OFF,
  76 };
  77
  78 static int tm2_touchkey_led_brightness_set(struct led_classdev *led_dev,
  79                                             enum led_brightness brightness)
  80 {
  81         struct tm2_touchkey_data *touchkey =
  82                 container_of(led_dev, struct tm2_touchkey_data, led_dev);
  83         u32 volt;
  84         u8 data;
  85
  86         if (brightness == LED_OFF) {
  87                 volt = TM2_TOUCHKEY_LED_VOLTAGE_MIN;
  88                 data = touchkey->variant->cmd_led_off;
  89         } else {
  90                 volt = TM2_TOUCHKEY_LED_VOLTAGE_MAX;
  91                 data = touchkey->variant->cmd_led_on;
  92         }
  93
  94         if (!touchkey->variant->fixed_regulator)
  95                 regulator_set_voltage(touchkey->vdd, volt, volt);
  96
  97         return touchkey->variant->no_reg ?
  98                 i2c_smbus_write_byte(touchkey->client, data) :
  99                 i2c_smbus_write_byte_data(touchkey->client,
 100                                           touchkey->variant->base_reg, data);
 101 }
 102
 103 static int tm2_touchkey_power_enable(struct tm2_touchkey_data *touchkey)
 104 {
 105         int error;
 106
 107         error = regulator_bulk_enable(ARRAY_SIZE(touchkey->regulators),
 108                                       touchkey->regulators);
 109         if (error)
 110                 return error;
 111
 112         /* waiting for device initialization, at least 150ms */
 113         msleep(150);
 114
 115         return 0;
 116 }
 117
 118 static void tm2_touchkey_power_disable(void *data)
 119 {
 120         struct tm2_touchkey_data *touchkey = data;
 121
 122         regulator_bulk_disable(ARRAY_SIZE(touchkey->regulators),
 123                                touchkey->regulators);
 124 }
 125
 126 static irqreturn_t tm2_touchkey_irq_handler(int irq, void *devid)
 127 {
 128         struct tm2_touchkey_data *touchkey = devid;
 129         int data;
 130         int index;
 131         int i;
 132
 133         if (touchkey->variant->no_reg)
 134                 data = i2c_smbus_read_byte(touchkey->client);
 135         else
 136                 data = i2c_smbus_read_byte_data(touchkey->client,
 137                                                 touchkey->variant->keycode_reg);
 138         if (data < 0) {
 139                 dev_err(&touchkey->client->dev,
 140                         "failed to read i2c data: %d\n", data);
 141                 goto out;
 142         }
 143
 144         index = (data & TM2_TOUCHKEY_BIT_KEYCODE) - 1;
 145         if (index < 0 || index >= touchkey->num_keycodes) {
 146                 dev_warn(&touchkey->client->dev,
 147                          "invalid keycode index %d\n", index);
 148                 goto out;
 149         }
 150
 151         if (data & TM2_TOUCHKEY_BIT_PRESS_EV) {
 152                 for (i = 0; i < touchkey->num_keycodes; i++)
 153                         input_report_key(touchkey->input_dev,
 154                                          touchkey->keycodes[i], 0);
 155         } else {
 156                 input_report_key(touchkey->input_dev,
 157                                  touchkey->keycodes[index], 1);
 158         }
 159
 160         input_sync(touchkey->input_dev);
 161
 162 out:
 163         if (touchkey->variant->fixed_regulator &&
 164                                 data & TM2_TOUCHKEY_BIT_PRESS_EV) {
 165                 /* touch turns backlight on, so make sure we're in sync */
 166                 if (touchkey->led_dev.brightness == LED_OFF)
 167                         tm2_touchkey_led_brightness_set(&touchkey->led_dev,
 168                                                         LED_OFF);
 169         }
 170
 171         return IRQ_HANDLED;
 172 }
 173
 174 static int tm2_touchkey_probe(struct i2c_client *client,
 175                               const struct i2c_device_id *id)
 176 {
 177         struct device_node *np = client->dev.of_node;
 178         struct tm2_touchkey_data *touchkey;
 179         int error;
 180         int i;
 181
 182         if (!i2c_check_functionality(client->adapter,
 183                         I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA)) {
 184                 dev_err(&client->dev, "incompatible I2C adapter\n");
 185                 return -EIO;
 186         }
 187
 188         touchkey = devm_kzalloc(&client->dev, sizeof(*touchkey), GFP_KERNEL);
 189         if (!touchkey)
 190                 return -ENOMEM;
 191
 192         touchkey->client = client;
 193         i2c_set_clientdata(client, touchkey);
 194
 195         touchkey->variant = of_device_get_match_data(&client->dev);
 196
 197         touchkey->regulators[0].supply = "vcc";
 198         touchkey->regulators[1].supply = "vdd";
 199         error = devm_regulator_bulk_get(&client->dev,
 200                                         ARRAY_SIZE(touchkey->regulators),
 201                                         touchkey->regulators);
 202         if (error) {
 203                 dev_err(&client->dev, "failed to get regulators: %d\n", error);
 204                 return error;
 205         }
 206
 207         /* Save VDD for easy access */
 208         touchkey->vdd = touchkey->regulators[1].consumer;
 209
 210         touchkey->num_keycodes = of_property_read_variable_u32_array(np,
 211                                         "linux,keycodes", touchkey->keycodes, 0,
 212                                         ARRAY_SIZE(touchkey->keycodes));
 213         if (touchkey->num_keycodes <= 0) {
 214                 /* default keycodes */
 215                 touchkey->keycodes[0] = KEY_PHONE;
 216                 touchkey->keycodes[1] = KEY_BACK;
 217                 touchkey->num_keycodes = 2;
 218         }
 219
 220         error = tm2_touchkey_power_enable(touchkey);
 221         if (error) {
 222                 dev_err(&client->dev, "failed to power up device: %d\n", error);
 223                 return error;
 224         }
 225
 226         error = devm_add_action_or_reset(&client->dev,
 227                                          tm2_touchkey_power_disable, touchkey);
 228         if (error) {
 229                 dev_err(&client->dev,
 230                         "failed to install poweroff handler: %d\n", error);
 231                 return error;
 232         }
 233
 234         /* input device */
 235         touchkey->input_dev = devm_input_allocate_device(&client->dev);
 236         if (!touchkey->input_dev) {
 237                 dev_err(&client->dev, "failed to allocate input device\n");
 238                 return -ENOMEM;
 239         }
 240
 241         touchkey->input_dev->name = TM2_TOUCHKEY_DEV_NAME;
 242         touchkey->input_dev->id.bustype = BUS_I2C;
 243
 244         for (i = 0; i < touchkey->num_keycodes; i++)
 245                 input_set_capability(touchkey->input_dev, EV_KEY,
 246                                      touchkey->keycodes[i]);
 247
 248         error = input_register_device(touchkey->input_dev);
 249         if (error) {
 250                 dev_err(&client->dev,
 251                         "failed to register input device: %d\n", error);
 252                 return error;
 253         }
 254
 255         error = devm_request_threaded_irq(&client->dev, client->irq,
 256                                           NULL, tm2_touchkey_irq_handler,
 257                                           IRQF_ONESHOT,
 258                                           TM2_TOUCHKEY_DEV_NAME, touchkey);
 259         if (error) {
 260                 dev_err(&client->dev,
 261                         "failed to request threaded irq: %d\n", error);
 262                 return error;
 263         }
 264
 265         /* led device */
 266         touchkey->led_dev.name = TM2_TOUCHKEY_DEV_NAME;
 267         touchkey->led_dev.brightness = LED_ON;
 268         touchkey->led_dev.max_brightness = LED_ON;
 269         touchkey->led_dev.brightness_set_blocking =
 270                                         tm2_touchkey_led_brightness_set;
 271
 272         error = devm_led_classdev_register(&client->dev, &touchkey->led_dev);
 273         if (error) {
 274                 dev_err(&client->dev,
 275                         "failed to register touchkey led: %d\n", error);
 276                 return error;
 277         }
 278
 279         if (touchkey->variant->fixed_regulator)
 280                 tm2_touchkey_led_brightness_set(&touchkey->led_dev, LED_ON);
 281
 282         return 0;
 283 }
 284
 285 static int __maybe_unused tm2_touchkey_suspend(struct device *dev)
 286 {
 287         struct i2c_client *client = to_i2c_client(dev);
 288         struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
 289
 290         disable_irq(client->irq);
 291         tm2_touchkey_power_disable(touchkey);
 292
 293         return 0;
 294 }
 295
 296 static int __maybe_unused tm2_touchkey_resume(struct device *dev)
 297 {
 298         struct i2c_client *client = to_i2c_client(dev);
 299         struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
 300         int ret;
 301
 302         enable_irq(client->irq);
 303
 304         ret = tm2_touchkey_power_enable(touchkey);
 305         if (ret)
 306                 dev_err(dev, "failed to enable power: %d\n", ret);
 307
 308         return ret;
 309 }
 310
 311 static SIMPLE_DEV_PM_OPS(tm2_touchkey_pm_ops,
 312                          tm2_touchkey_suspend, tm2_touchkey_resume);
 313
 314 static const struct i2c_device_id tm2_touchkey_id_table[] = {
 315         { TM2_TOUCHKEY_DEV_NAME, 0 },
 316         { },
 317 };
 318 MODULE_DEVICE_TABLE(i2c, tm2_touchkey_id_table);
 319
 320 static const struct of_device_id tm2_touchkey_of_match[] = {
 321         {
 322                 .compatible = "cypress,tm2-touchkey",
 323                 .data = &tm2_touchkey_variant,
 324         }, {
 325                 .compatible = "cypress,midas-touchkey",
 326                 .data = &midas_touchkey_variant,
 327         }, {
 328                 .compatible = "cypress,aries-touchkey",
 329                 .data = &aries_touchkey_variant,
 330         },
 331         { },
 332 };
 333 MODULE_DEVICE_TABLE(of, tm2_touchkey_of_match);
 334
 335 static struct i2c_driver tm2_touchkey_driver = {
 336         .driver = {
 337                 .name = TM2_TOUCHKEY_DEV_NAME,
 338                 .pm = &tm2_touchkey_pm_ops,
 339                 .of_match_table = of_match_ptr(tm2_touchkey_of_match),
 340         },
 341         .probe = tm2_touchkey_probe,
 342         .id_table = tm2_touchkey_id_table,
 343 };
 344 module_i2c_driver(tm2_touchkey_driver);
 345
 346 MODULE_AUTHOR("Beomho Seo <beomho.seo@samsung.com>");
 347 MODULE_AUTHOR("Jaechul Lee <jcsing.lee@samsung.com>");
 348 MODULE_DESCRIPTION("Samsung touchkey driver");
 349 MODULE_LICENSE("GPL v2");