linux/drivers/input/keyboard/tm2-touchkey.c
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   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
  37struct 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
  46struct 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[3];
  52        const struct touchkey_variant *variant;
  53        u32 keycodes[4];
  54        int num_keycodes;
  55};
  56
  57static 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
  64static 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
  71static 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
  78static const struct touchkey_variant tc360_touchkey_variant = {
  79        .keycode_reg = 0x00,
  80        .base_reg = 0x00,
  81        .fixed_regulator = true,
  82        .cmd_led_on = TM2_TOUCHKEY_CMD_LED_ON,
  83        .cmd_led_off = TM2_TOUCHKEY_CMD_LED_OFF,
  84};
  85
  86static int tm2_touchkey_led_brightness_set(struct led_classdev *led_dev,
  87                                            enum led_brightness brightness)
  88{
  89        struct tm2_touchkey_data *touchkey =
  90                container_of(led_dev, struct tm2_touchkey_data, led_dev);
  91        u32 volt;
  92        u8 data;
  93
  94        if (brightness == LED_OFF) {
  95                volt = TM2_TOUCHKEY_LED_VOLTAGE_MIN;
  96                data = touchkey->variant->cmd_led_off;
  97        } else {
  98                volt = TM2_TOUCHKEY_LED_VOLTAGE_MAX;
  99                data = touchkey->variant->cmd_led_on;
 100        }
 101
 102        if (!touchkey->variant->fixed_regulator)
 103                regulator_set_voltage(touchkey->vdd, volt, volt);
 104
 105        return touchkey->variant->no_reg ?
 106                i2c_smbus_write_byte(touchkey->client, data) :
 107                i2c_smbus_write_byte_data(touchkey->client,
 108                                          touchkey->variant->base_reg, data);
 109}
 110
 111static int tm2_touchkey_power_enable(struct tm2_touchkey_data *touchkey)
 112{
 113        int error;
 114
 115        error = regulator_bulk_enable(ARRAY_SIZE(touchkey->regulators),
 116                                      touchkey->regulators);
 117        if (error)
 118                return error;
 119
 120        /* waiting for device initialization, at least 150ms */
 121        msleep(150);
 122
 123        return 0;
 124}
 125
 126static void tm2_touchkey_power_disable(void *data)
 127{
 128        struct tm2_touchkey_data *touchkey = data;
 129
 130        regulator_bulk_disable(ARRAY_SIZE(touchkey->regulators),
 131                               touchkey->regulators);
 132}
 133
 134static irqreturn_t tm2_touchkey_irq_handler(int irq, void *devid)
 135{
 136        struct tm2_touchkey_data *touchkey = devid;
 137        int data;
 138        int index;
 139        int i;
 140
 141        if (touchkey->variant->no_reg)
 142                data = i2c_smbus_read_byte(touchkey->client);
 143        else
 144                data = i2c_smbus_read_byte_data(touchkey->client,
 145                                                touchkey->variant->keycode_reg);
 146        if (data < 0) {
 147                dev_err(&touchkey->client->dev,
 148                        "failed to read i2c data: %d\n", data);
 149                goto out;
 150        }
 151
 152        index = (data & TM2_TOUCHKEY_BIT_KEYCODE) - 1;
 153        if (index < 0 || index >= touchkey->num_keycodes) {
 154                dev_warn(&touchkey->client->dev,
 155                         "invalid keycode index %d\n", index);
 156                goto out;
 157        }
 158
 159        if (data & TM2_TOUCHKEY_BIT_PRESS_EV) {
 160                for (i = 0; i < touchkey->num_keycodes; i++)
 161                        input_report_key(touchkey->input_dev,
 162                                         touchkey->keycodes[i], 0);
 163        } else {
 164                input_report_key(touchkey->input_dev,
 165                                 touchkey->keycodes[index], 1);
 166        }
 167
 168        input_sync(touchkey->input_dev);
 169
 170out:
 171        if (touchkey->variant->fixed_regulator &&
 172                                data & TM2_TOUCHKEY_BIT_PRESS_EV) {
 173                /* touch turns backlight on, so make sure we're in sync */
 174                if (touchkey->led_dev.brightness == LED_OFF)
 175                        tm2_touchkey_led_brightness_set(&touchkey->led_dev,
 176                                                        LED_OFF);
 177        }
 178
 179        return IRQ_HANDLED;
 180}
 181
 182static int tm2_touchkey_probe(struct i2c_client *client,
 183                              const struct i2c_device_id *id)
 184{
 185        struct device_node *np = client->dev.of_node;
 186        struct tm2_touchkey_data *touchkey;
 187        int error;
 188        int i;
 189
 190        if (!i2c_check_functionality(client->adapter,
 191                        I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA)) {
 192                dev_err(&client->dev, "incompatible I2C adapter\n");
 193                return -EIO;
 194        }
 195
 196        touchkey = devm_kzalloc(&client->dev, sizeof(*touchkey), GFP_KERNEL);
 197        if (!touchkey)
 198                return -ENOMEM;
 199
 200        touchkey->client = client;
 201        i2c_set_clientdata(client, touchkey);
 202
 203        touchkey->variant = of_device_get_match_data(&client->dev);
 204
 205        touchkey->regulators[0].supply = "vcc";
 206        touchkey->regulators[1].supply = "vdd";
 207        touchkey->regulators[2].supply = "vddio";
 208        error = devm_regulator_bulk_get(&client->dev,
 209                                        ARRAY_SIZE(touchkey->regulators),
 210                                        touchkey->regulators);
 211        if (error) {
 212                dev_err(&client->dev, "failed to get regulators: %d\n", error);
 213                return error;
 214        }
 215
 216        /* Save VDD for easy access */
 217        touchkey->vdd = touchkey->regulators[1].consumer;
 218
 219        touchkey->num_keycodes = of_property_read_variable_u32_array(np,
 220                                        "linux,keycodes", touchkey->keycodes, 0,
 221                                        ARRAY_SIZE(touchkey->keycodes));
 222        if (touchkey->num_keycodes <= 0) {
 223                /* default keycodes */
 224                touchkey->keycodes[0] = KEY_PHONE;
 225                touchkey->keycodes[1] = KEY_BACK;
 226                touchkey->num_keycodes = 2;
 227        }
 228
 229        error = tm2_touchkey_power_enable(touchkey);
 230        if (error) {
 231                dev_err(&client->dev, "failed to power up device: %d\n", error);
 232                return error;
 233        }
 234
 235        error = devm_add_action_or_reset(&client->dev,
 236                                         tm2_touchkey_power_disable, touchkey);
 237        if (error) {
 238                dev_err(&client->dev,
 239                        "failed to install poweroff handler: %d\n", error);
 240                return error;
 241        }
 242
 243        /* input device */
 244        touchkey->input_dev = devm_input_allocate_device(&client->dev);
 245        if (!touchkey->input_dev) {
 246                dev_err(&client->dev, "failed to allocate input device\n");
 247                return -ENOMEM;
 248        }
 249
 250        touchkey->input_dev->name = TM2_TOUCHKEY_DEV_NAME;
 251        touchkey->input_dev->id.bustype = BUS_I2C;
 252
 253        for (i = 0; i < touchkey->num_keycodes; i++)
 254                input_set_capability(touchkey->input_dev, EV_KEY,
 255                                     touchkey->keycodes[i]);
 256
 257        error = input_register_device(touchkey->input_dev);
 258        if (error) {
 259                dev_err(&client->dev,
 260                        "failed to register input device: %d\n", error);
 261                return error;
 262        }
 263
 264        error = devm_request_threaded_irq(&client->dev, client->irq,
 265                                          NULL, tm2_touchkey_irq_handler,
 266                                          IRQF_ONESHOT,
 267                                          TM2_TOUCHKEY_DEV_NAME, touchkey);
 268        if (error) {
 269                dev_err(&client->dev,
 270                        "failed to request threaded irq: %d\n", error);
 271                return error;
 272        }
 273
 274        /* led device */
 275        touchkey->led_dev.name = TM2_TOUCHKEY_DEV_NAME;
 276        touchkey->led_dev.brightness = LED_ON;
 277        touchkey->led_dev.max_brightness = LED_ON;
 278        touchkey->led_dev.brightness_set_blocking =
 279                                        tm2_touchkey_led_brightness_set;
 280
 281        error = devm_led_classdev_register(&client->dev, &touchkey->led_dev);
 282        if (error) {
 283                dev_err(&client->dev,
 284                        "failed to register touchkey led: %d\n", error);
 285                return error;
 286        }
 287
 288        if (touchkey->variant->fixed_regulator)
 289                tm2_touchkey_led_brightness_set(&touchkey->led_dev, LED_ON);
 290
 291        return 0;
 292}
 293
 294static int __maybe_unused tm2_touchkey_suspend(struct device *dev)
 295{
 296        struct i2c_client *client = to_i2c_client(dev);
 297        struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
 298
 299        disable_irq(client->irq);
 300        tm2_touchkey_power_disable(touchkey);
 301
 302        return 0;
 303}
 304
 305static int __maybe_unused tm2_touchkey_resume(struct device *dev)
 306{
 307        struct i2c_client *client = to_i2c_client(dev);
 308        struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
 309        int ret;
 310
 311        enable_irq(client->irq);
 312
 313        ret = tm2_touchkey_power_enable(touchkey);
 314        if (ret)
 315                dev_err(dev, "failed to enable power: %d\n", ret);
 316
 317        return ret;
 318}
 319
 320static SIMPLE_DEV_PM_OPS(tm2_touchkey_pm_ops,
 321                         tm2_touchkey_suspend, tm2_touchkey_resume);
 322
 323static const struct i2c_device_id tm2_touchkey_id_table[] = {
 324        { TM2_TOUCHKEY_DEV_NAME, 0 },
 325        { },
 326};
 327MODULE_DEVICE_TABLE(i2c, tm2_touchkey_id_table);
 328
 329static const struct of_device_id tm2_touchkey_of_match[] = {
 330        {
 331                .compatible = "cypress,tm2-touchkey",
 332                .data = &tm2_touchkey_variant,
 333        }, {
 334                .compatible = "cypress,midas-touchkey",
 335                .data = &midas_touchkey_variant,
 336        }, {
 337                .compatible = "cypress,aries-touchkey",
 338                .data = &aries_touchkey_variant,
 339        }, {
 340                .compatible = "coreriver,tc360-touchkey",
 341                .data = &tc360_touchkey_variant,
 342        },
 343        { },
 344};
 345MODULE_DEVICE_TABLE(of, tm2_touchkey_of_match);
 346
 347static struct i2c_driver tm2_touchkey_driver = {
 348        .driver = {
 349                .name = TM2_TOUCHKEY_DEV_NAME,
 350                .pm = &tm2_touchkey_pm_ops,
 351                .of_match_table = of_match_ptr(tm2_touchkey_of_match),
 352        },
 353        .probe = tm2_touchkey_probe,
 354        .id_table = tm2_touchkey_id_table,
 355};
 356module_i2c_driver(tm2_touchkey_driver);
 357
 358MODULE_AUTHOR("Beomho Seo <beomho.seo@samsung.com>");
 359MODULE_AUTHOR("Jaechul Lee <jcsing.lee@samsung.com>");
 360MODULE_DESCRIPTION("Samsung touchkey driver");
 361MODULE_LICENSE("GPL v2");
 362