drivers/input/misc/regulator-haptic.c

   1 /*
   2  * Regulator haptic driver
   3  *
   4  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
   5  * Author: Jaewon Kim <jaewon02.kim@samsung.com>
   6  * Author: Hyunhee Kim <hyunhee.kim@samsung.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/input.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include <linux/platform_data/regulator-haptic.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/regulator/consumer.h>
  19 #include <linux/slab.h>
  20
  21 #define MAX_MAGNITUDE_SHIFT     16
  22
  23 struct regulator_haptic {
  24         struct device *dev;
  25         struct input_dev *input_dev;
  26         struct regulator *regulator;
  27
  28         struct work_struct work;
  29         struct mutex mutex;
  30
  31         bool active;
  32         bool suspended;
  33
  34         unsigned int max_volt;
  35         unsigned int min_volt;
  36         unsigned int magnitude;
  37 };
  38
  39 static int regulator_haptic_toggle(struct regulator_haptic *haptic, bool on)
  40 {
  41         int error;
  42
  43         if (haptic->active != on) {
  44
  45                 error = on ? regulator_enable(haptic->regulator) :
  46                              regulator_disable(haptic->regulator);
  47                 if (error) {
  48                         dev_err(haptic->dev,
  49                                 "failed to switch regulator %s: %d\n",
  50                                 on ? "on" : "off", error);
  51                         return error;
  52                 }
  53
  54                 haptic->active = on;
  55         }
  56
  57         return 0;
  58 }
  59
  60 static int regulator_haptic_set_voltage(struct regulator_haptic *haptic,
  61                                          unsigned int magnitude)
  62 {
  63         u64 volt_mag_multi;
  64         unsigned int intensity;
  65         int error;
  66
  67         volt_mag_multi = (u64)(haptic->max_volt - haptic->min_volt) * magnitude;
  68         intensity = (unsigned int)(volt_mag_multi >> MAX_MAGNITUDE_SHIFT);
  69
  70         error = regulator_set_voltage(haptic->regulator,
  71                                       intensity + haptic->min_volt,
  72                                       haptic->max_volt);
  73         if (error) {
  74                 dev_err(haptic->dev, "cannot set regulator voltage to %d: %d\n",
  75                         intensity + haptic->min_volt, error);
  76                 return error;
  77         }
  78
  79         return 0;
  80 }
  81
  82 static void regulator_haptic_work(struct work_struct *work)
  83 {
  84         struct regulator_haptic *haptic = container_of(work,
  85                                         struct regulator_haptic, work);
  86         unsigned int magnitude;
  87         int error;
  88
  89         mutex_lock(&haptic->mutex);
  90
  91         if (haptic->suspended)
  92                 goto out;
  93
  94         magnitude = ACCESS_ONCE(haptic->magnitude);
  95
  96         error = regulator_haptic_set_voltage(haptic, magnitude);
  97         if (error)
  98                 goto out;
  99
 100         regulator_haptic_toggle(haptic, magnitude != 0);
 101
 102 out:
 103         mutex_unlock(&haptic->mutex);
 104 }
 105
 106 static int regulator_haptic_play_effect(struct input_dev *input, void *data,
 107                                         struct ff_effect *effect)
 108 {
 109         struct regulator_haptic *haptic = input_get_drvdata(input);
 110
 111         haptic->magnitude = effect->u.rumble.strong_magnitude;
 112         if (!haptic->magnitude)
 113                 haptic->magnitude = effect->u.rumble.weak_magnitude;
 114
 115         schedule_work(&haptic->work);
 116
 117         return 0;
 118 }
 119
 120 static void regulator_haptic_close(struct input_dev *input)
 121 {
 122         struct regulator_haptic *haptic = input_get_drvdata(input);
 123
 124         cancel_work_sync(&haptic->work);
 125         regulator_haptic_set_voltage(haptic, 0);
 126         regulator_haptic_toggle(haptic, false);
 127 }
 128
 129 static int __maybe_unused
 130 regulator_haptic_parse_dt(struct device *dev, struct regulator_haptic *haptic)
 131 {
 132         struct device_node *node;
 133         int error;
 134
 135         node = dev->of_node;
 136         if(!node) {
 137                 dev_err(dev, "Missing dveice tree data\n");
 138                 return -EINVAL;
 139         }
 140
 141         error = of_property_read_u32(node, "max-microvolt", &haptic->max_volt);
 142         if (error) {
 143                 dev_err(dev, "cannot parse max-microvolt\n");
 144                 return error;
 145         }
 146
 147         error = of_property_read_u32(node, "min-microvolt", &haptic->min_volt);
 148         if (error) {
 149                 dev_err(dev, "cannot parse min-microvolt\n");
 150                 return error;
 151         }
 152
 153         return 0;
 154 }
 155
 156 static int regulator_haptic_probe(struct platform_device *pdev)
 157 {
 158         const struct regulator_haptic_data *pdata = dev_get_platdata(&pdev->dev);
 159         struct regulator_haptic *haptic;
 160         struct input_dev *input_dev;
 161         int error;
 162
 163         haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
 164         if (!haptic)
 165                 return -ENOMEM;
 166
 167         platform_set_drvdata(pdev, haptic);
 168         haptic->dev = &pdev->dev;
 169         mutex_init(&haptic->mutex);
 170         INIT_WORK(&haptic->work, regulator_haptic_work);
 171
 172         if (pdata) {
 173                 haptic->max_volt = pdata->max_volt;
 174                 haptic->min_volt = pdata->min_volt;
 175         } else if (IS_ENABLED(CONFIG_OF)) {
 176                 error = regulator_haptic_parse_dt(&pdev->dev, haptic);
 177                 if (error)
 178                         return error;
 179         } else {
 180                 dev_err(&pdev->dev, "Missing platform data\n");
 181                 return -EINVAL;
 182         }
 183
 184         haptic->regulator = devm_regulator_get_exclusive(&pdev->dev, "haptic");
 185         if (IS_ERR(haptic->regulator)) {
 186                 dev_err(&pdev->dev, "failed to get regulator\n");
 187                 return PTR_ERR(haptic->regulator);
 188         }
 189
 190         input_dev = devm_input_allocate_device(&pdev->dev);
 191         if (!input_dev)
 192                 return  -ENOMEM;
 193
 194         haptic->input_dev = input_dev;
 195         haptic->input_dev->name = "regulator-haptic";
 196         haptic->input_dev->dev.parent = &pdev->dev;
 197         haptic->input_dev->close = regulator_haptic_close;
 198         input_set_drvdata(haptic->input_dev, haptic);
 199         input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
 200
 201         error = input_ff_create_memless(input_dev, NULL,
 202                                         regulator_haptic_play_effect);
 203         if (error) {
 204                 dev_err(&pdev->dev, "failed to create force-feedback\n");
 205                 return error;
 206         }
 207
 208         error = input_register_device(haptic->input_dev);
 209         if (error) {
 210                 dev_err(&pdev->dev, "failed to register input device\n");
 211                 return error;
 212         }
 213
 214         return 0;
 215 }
 216
 217 static int __maybe_unused regulator_haptic_suspend(struct device *dev)
 218 {
 219         struct platform_device *pdev = to_platform_device(dev);
 220         struct regulator_haptic *haptic = platform_get_drvdata(pdev);
 221         int error;
 222
 223         error = mutex_lock_interruptible(&haptic->mutex);
 224         if (error)
 225                 return error;
 226
 227         regulator_haptic_set_voltage(haptic, 0);
 228         regulator_haptic_toggle(haptic, false);
 229
 230         haptic->suspended = true;
 231
 232         mutex_unlock(&haptic->mutex);
 233
 234         return 0;
 235 }
 236
 237 static int __maybe_unused regulator_haptic_resume(struct device *dev)
 238 {
 239         struct platform_device *pdev = to_platform_device(dev);
 240         struct regulator_haptic *haptic = platform_get_drvdata(pdev);
 241         unsigned int magnitude;
 242
 243         mutex_lock(&haptic->mutex);
 244
 245         haptic->suspended = false;
 246
 247         magnitude = ACCESS_ONCE(haptic->magnitude);
 248         if (magnitude) {
 249                 regulator_haptic_set_voltage(haptic, magnitude);
 250                 regulator_haptic_toggle(haptic, true);
 251         }
 252
 253         mutex_unlock(&haptic->mutex);
 254
 255         return 0;
 256 }
 257
 258 static SIMPLE_DEV_PM_OPS(regulator_haptic_pm_ops,
 259                 regulator_haptic_suspend, regulator_haptic_resume);
 260
 261 static struct of_device_id regulator_haptic_dt_match[] = {
 262         { .compatible = "regulator-haptic" },
 263         { /* sentinel */ },
 264 };
 265
 266 static struct platform_driver regulator_haptic_driver = {
 267         .probe          = regulator_haptic_probe,
 268         .driver         = {
 269                 .name           = "regulator-haptic",
 270                 .of_match_table = regulator_haptic_dt_match,
 271                 .pm             = &regulator_haptic_pm_ops,
 272         },
 273 };
 274 module_platform_driver(regulator_haptic_driver);
 275
 276 MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
 277 MODULE_AUTHOR("Hyunhee Kim <hyunhee.kim@samsung.com>");
 278 MODULE_DESCRIPTION("Regulator haptic driver");
 279 MODULE_LICENSE("GPL");