kernel/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         regulator_haptic_toggle(haptic, !!magnitude);
  80
  81         return 0;
  82 }
  83
  84 static void regulator_haptic_work(struct work_struct *work)
  85 {
  86         struct regulator_haptic *haptic = container_of(work,
  87                                         struct regulator_haptic, work);
  88
  89         mutex_lock(&haptic->mutex);
  90
  91         if (!haptic->suspended)
  92                 regulator_haptic_set_voltage(haptic, haptic->magnitude);
  93
  94         mutex_unlock(&haptic->mutex);
  95 }
  96
  97 static int regulator_haptic_play_effect(struct input_dev *input, void *data,
  98                                         struct ff_effect *effect)
  99 {
 100         struct regulator_haptic *haptic = input_get_drvdata(input);
 101
 102         haptic->magnitude = effect->u.rumble.strong_magnitude;
 103         if (!haptic->magnitude)
 104                 haptic->magnitude = effect->u.rumble.weak_magnitude;
 105
 106         schedule_work(&haptic->work);
 107
 108         return 0;
 109 }
 110
 111 static void regulator_haptic_close(struct input_dev *input)
 112 {
 113         struct regulator_haptic *haptic = input_get_drvdata(input);
 114
 115         cancel_work_sync(&haptic->work);
 116         regulator_haptic_set_voltage(haptic, 0);
 117 }
 118
 119 static int __maybe_unused
 120 regulator_haptic_parse_dt(struct device *dev, struct regulator_haptic *haptic)
 121 {
 122         struct device_node *node;
 123         int error;
 124
 125         node = dev->of_node;
 126         if(!node) {
 127                 dev_err(dev, "Missing dveice tree data\n");
 128                 return -EINVAL;
 129         }
 130
 131         error = of_property_read_u32(node, "max-microvolt", &haptic->max_volt);
 132         if (error) {
 133                 dev_err(dev, "cannot parse max-microvolt\n");
 134                 return error;
 135         }
 136
 137         error = of_property_read_u32(node, "min-microvolt", &haptic->min_volt);
 138         if (error) {
 139                 dev_err(dev, "cannot parse min-microvolt\n");
 140                 return error;
 141         }
 142
 143         return 0;
 144 }
 145
 146 static int regulator_haptic_probe(struct platform_device *pdev)
 147 {
 148         const struct regulator_haptic_data *pdata = dev_get_platdata(&pdev->dev);
 149         struct regulator_haptic *haptic;
 150         struct input_dev *input_dev;
 151         int error;
 152
 153         haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
 154         if (!haptic)
 155                 return -ENOMEM;
 156
 157         platform_set_drvdata(pdev, haptic);
 158         haptic->dev = &pdev->dev;
 159         mutex_init(&haptic->mutex);
 160         INIT_WORK(&haptic->work, regulator_haptic_work);
 161
 162         if (pdata) {
 163                 haptic->max_volt = pdata->max_volt;
 164                 haptic->min_volt = pdata->min_volt;
 165         } else if (IS_ENABLED(CONFIG_OF)) {
 166                 error = regulator_haptic_parse_dt(&pdev->dev, haptic);
 167                 if (error)
 168                         return error;
 169         } else {
 170                 dev_err(&pdev->dev, "Missing platform data\n");
 171                 return -EINVAL;
 172         }
 173
 174         haptic->regulator = devm_regulator_get_exclusive(&pdev->dev, "haptic");
 175         if (IS_ERR(haptic->regulator)) {
 176                 dev_err(&pdev->dev, "failed to get regulator\n");
 177                 return PTR_ERR(haptic->regulator);
 178         }
 179
 180         input_dev = devm_input_allocate_device(&pdev->dev);
 181         if (!input_dev)
 182                 return  -ENOMEM;
 183
 184         haptic->input_dev = input_dev;
 185         haptic->input_dev->name = "regulator-haptic";
 186         haptic->input_dev->dev.parent = &pdev->dev;
 187         haptic->input_dev->close = regulator_haptic_close;
 188         input_set_drvdata(haptic->input_dev, haptic);
 189         input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
 190
 191         error = input_ff_create_memless(input_dev, NULL,
 192                                         regulator_haptic_play_effect);
 193         if (error) {
 194                 dev_err(&pdev->dev, "failed to create force-feedback\n");
 195                 return error;
 196         }
 197
 198         error = input_register_device(haptic->input_dev);
 199         if (error) {
 200                 dev_err(&pdev->dev, "failed to register input device\n");
 201                 return error;
 202         }
 203
 204         return 0;
 205 }
 206
 207 static int __maybe_unused regulator_haptic_suspend(struct device *dev)
 208 {
 209         struct platform_device *pdev = to_platform_device(dev);
 210         struct regulator_haptic *haptic = platform_get_drvdata(pdev);
 211         int error;
 212
 213         error = mutex_lock_interruptible(&haptic->mutex);
 214         if (error)
 215                 return error;
 216
 217         regulator_haptic_set_voltage(haptic, 0);
 218
 219         haptic->suspended = true;
 220
 221         mutex_unlock(&haptic->mutex);
 222
 223         return 0;
 224 }
 225
 226 static int __maybe_unused regulator_haptic_resume(struct device *dev)
 227 {
 228         struct platform_device *pdev = to_platform_device(dev);
 229         struct regulator_haptic *haptic = platform_get_drvdata(pdev);
 230         unsigned int magnitude;
 231
 232         mutex_lock(&haptic->mutex);
 233
 234         haptic->suspended = false;
 235
 236         magnitude = ACCESS_ONCE(haptic->magnitude);
 237         if (magnitude)
 238                 regulator_haptic_set_voltage(haptic, magnitude);
 239
 240         mutex_unlock(&haptic->mutex);
 241
 242         return 0;
 243 }
 244
 245 static SIMPLE_DEV_PM_OPS(regulator_haptic_pm_ops,
 246                 regulator_haptic_suspend, regulator_haptic_resume);
 247
 248 static const struct of_device_id regulator_haptic_dt_match[] = {
 249         { .compatible = "regulator-haptic" },
 250         { /* sentinel */ },
 251 };
 252
 253 static struct platform_driver regulator_haptic_driver = {
 254         .probe          = regulator_haptic_probe,
 255         .driver         = {
 256                 .name           = "regulator-haptic",
 257                 .of_match_table = regulator_haptic_dt_match,
 258                 .pm             = &regulator_haptic_pm_ops,
 259         },
 260 };
 261 module_platform_driver(regulator_haptic_driver);
 262
 263 MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
 264 MODULE_AUTHOR("Hyunhee Kim <hyunhee.kim@samsung.com>");
 265 MODULE_DESCRIPTION("Regulator haptic driver");
 266 MODULE_LICENSE("GPL");