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