drivers/input/misc/regulator-haptic.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Regulator haptic driver
   4  *
   5  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
   6  * Author: Jaewon Kim <[email protected]>
   7  * Author: Hyunhee Kim <[email protected]>
   8  */
   9
  10 #include <linux/input.h>
  11 #include <linux/module.h>
  12 #include <linux/of.h>
  13 #include <linux/platform_data/regulator-haptic.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/regulator/consumer.h>
  16 #include <linux/slab.h>
  17
  18 #define MAX_MAGNITUDE_SHIFT     16
  19
  20 struct regulator_haptic {
  21         struct device *dev;
  22         struct input_dev *input_dev;
  23         struct regulator *regulator;
  24
  25         struct work_struct work;
  26         struct mutex mutex;
  27
  28         bool active;
  29         bool suspended;
  30
  31         unsigned int max_volt;
  32         unsigned int min_volt;
  33         unsigned int magnitude;
  34 };
  35
  36 static int regulator_haptic_toggle(struct regulator_haptic *haptic, bool on)
  37 {
  38         int error;
  39
  40         if (haptic->active != on) {
  41
  42                 error = on ? regulator_enable(haptic->regulator) :
  43                              regulator_disable(haptic->regulator);
  44                 if (error) {
  45                         dev_err(haptic->dev,
  46                                 "failed to switch regulator %s: %d\n",
  47                                 on ? "on" : "off", error);
  48                         return error;
  49                 }
  50
  51                 haptic->active = on;
  52         }
  53
  54         return 0;
  55 }
  56
  57 static int regulator_haptic_set_voltage(struct regulator_haptic *haptic,
  58                                          unsigned int magnitude)
  59 {
  60         u64 volt_mag_multi;
  61         unsigned int intensity;
  62         int error;
  63
  64         volt_mag_multi = (u64)(haptic->max_volt - haptic->min_volt) * magnitude;
  65         intensity = (unsigned int)(volt_mag_multi >> MAX_MAGNITUDE_SHIFT);
  66
  67         error = regulator_set_voltage(haptic->regulator,
  68                                       intensity + haptic->min_volt,
  69                                       haptic->max_volt);
  70         if (error) {
  71                 dev_err(haptic->dev, "cannot set regulator voltage to %d: %d\n",
  72                         intensity + haptic->min_volt, error);
  73                 return error;
  74         }
  75
  76         regulator_haptic_toggle(haptic, !!magnitude);
  77
  78         return 0;
  79 }
  80
  81 static void regulator_haptic_work(struct work_struct *work)
  82 {
  83         struct regulator_haptic *haptic = container_of(work,
  84                                         struct regulator_haptic, work);
  85
  86         mutex_lock(&haptic->mutex);
  87
  88         if (!haptic->suspended)
  89                 regulator_haptic_set_voltage(haptic, haptic->magnitude);
  90
  91         mutex_unlock(&haptic->mutex);
  92 }
  93
  94 static int regulator_haptic_play_effect(struct input_dev *input, void *data,
  95                                         struct ff_effect *effect)
  96 {
  97         struct regulator_haptic *haptic = input_get_drvdata(input);
  98
  99         haptic->magnitude = effect->u.rumble.strong_magnitude;
 100         if (!haptic->magnitude)
 101                 haptic->magnitude = effect->u.rumble.weak_magnitude;
 102
 103         schedule_work(&haptic->work);
 104
 105         return 0;
 106 }
 107
 108 static void regulator_haptic_close(struct input_dev *input)
 109 {
 110         struct regulator_haptic *haptic = input_get_drvdata(input);
 111
 112         cancel_work_sync(&haptic->work);
 113         regulator_haptic_set_voltage(haptic, 0);
 114 }
 115
 116 static int __maybe_unused
 117 regulator_haptic_parse_dt(struct device *dev, struct regulator_haptic *haptic)
 118 {
 119         struct device_node *node;
 120         int error;
 121
 122         node = dev->of_node;
 123         if(!node) {
 124                 dev_err(dev, "Missing device tree data\n");
 125                 return -EINVAL;
 126         }
 127
 128         error = of_property_read_u32(node, "max-microvolt", &haptic->max_volt);
 129         if (error) {
 130                 dev_err(dev, "cannot parse max-microvolt\n");
 131                 return error;
 132         }
 133
 134         error = of_property_read_u32(node, "min-microvolt", &haptic->min_volt);
 135         if (error) {
 136                 dev_err(dev, "cannot parse min-microvolt\n");
 137                 return error;
 138         }
 139
 140         return 0;
 141 }
 142
 143 static int regulator_haptic_probe(struct platform_device *pdev)
 144 {
 145         const struct regulator_haptic_data *pdata = dev_get_platdata(&pdev->dev);
 146         struct regulator_haptic *haptic;
 147         struct input_dev *input_dev;
 148         int error;
 149
 150         haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
 151         if (!haptic)
 152                 return -ENOMEM;
 153
 154         platform_set_drvdata(pdev, haptic);
 155         haptic->dev = &pdev->dev;
 156         mutex_init(&haptic->mutex);
 157         INIT_WORK(&haptic->work, regulator_haptic_work);
 158
 159         if (pdata) {
 160                 haptic->max_volt = pdata->max_volt;
 161                 haptic->min_volt = pdata->min_volt;
 162         } else if (IS_ENABLED(CONFIG_OF)) {
 163                 error = regulator_haptic_parse_dt(&pdev->dev, haptic);
 164                 if (error)
 165                         return error;
 166         } else {
 167                 dev_err(&pdev->dev, "Missing platform data\n");
 168                 return -EINVAL;
 169         }
 170
 171         haptic->regulator = devm_regulator_get_exclusive(&pdev->dev, "haptic");
 172         if (IS_ERR(haptic->regulator)) {
 173                 dev_err(&pdev->dev, "failed to get regulator\n");
 174                 return PTR_ERR(haptic->regulator);
 175         }
 176
 177         input_dev = devm_input_allocate_device(&pdev->dev);
 178         if (!input_dev)
 179                 return  -ENOMEM;
 180
 181         haptic->input_dev = input_dev;
 182         haptic->input_dev->name = "regulator-haptic";
 183         haptic->input_dev->dev.parent = &pdev->dev;
 184         haptic->input_dev->close = regulator_haptic_close;
 185         input_set_drvdata(haptic->input_dev, haptic);
 186         input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
 187
 188         error = input_ff_create_memless(input_dev, NULL,
 189                                         regulator_haptic_play_effect);
 190         if (error) {
 191                 dev_err(&pdev->dev, "failed to create force-feedback\n");
 192                 return error;
 193         }
 194
 195         error = input_register_device(haptic->input_dev);
 196         if (error) {
 197                 dev_err(&pdev->dev, "failed to register input device\n");
 198                 return error;
 199         }
 200
 201         return 0;
 202 }
 203
 204 static int regulator_haptic_suspend(struct device *dev)
 205 {
 206         struct platform_device *pdev = to_platform_device(dev);
 207         struct regulator_haptic *haptic = platform_get_drvdata(pdev);
 208         int error;
 209
 210         error = mutex_lock_interruptible(&haptic->mutex);
 211         if (error)
 212                 return error;
 213
 214         regulator_haptic_set_voltage(haptic, 0);
 215
 216         haptic->suspended = true;
 217
 218         mutex_unlock(&haptic->mutex);
 219
 220         return 0;
 221 }
 222
 223 static int regulator_haptic_resume(struct device *dev)
 224 {
 225         struct platform_device *pdev = to_platform_device(dev);
 226         struct regulator_haptic *haptic = platform_get_drvdata(pdev);
 227         unsigned int magnitude;
 228
 229         mutex_lock(&haptic->mutex);
 230
 231         haptic->suspended = false;
 232
 233         magnitude = READ_ONCE(haptic->magnitude);
 234         if (magnitude)
 235                 regulator_haptic_set_voltage(haptic, magnitude);
 236
 237         mutex_unlock(&haptic->mutex);
 238
 239         return 0;
 240 }
 241
 242 static DEFINE_SIMPLE_DEV_PM_OPS(regulator_haptic_pm_ops,
 243                 regulator_haptic_suspend, regulator_haptic_resume);
 244
 245 static const struct of_device_id regulator_haptic_dt_match[] = {
 246         { .compatible = "regulator-haptic" },
 247         { /* sentinel */ },
 248 };
 249 MODULE_DEVICE_TABLE(of, regulator_haptic_dt_match);
 250
 251 static struct platform_driver regulator_haptic_driver = {
 252         .probe          = regulator_haptic_probe,
 253         .driver         = {
 254                 .name           = "regulator-haptic",
 255                 .of_match_table = regulator_haptic_dt_match,
 256                 .pm             = pm_sleep_ptr(&regulator_haptic_pm_ops),
 257         },
 258 };
 259 module_platform_driver(regulator_haptic_driver);
 260
 261 MODULE_AUTHOR("Jaewon Kim <[email protected]>");
 262 MODULE_AUTHOR("Hyunhee Kim <[email protected]>");
 263 MODULE_DESCRIPTION("Regulator haptic driver");
 264 MODULE_LICENSE("GPL");