drivers/input/misc/pwm-vibra.c

   1 /*
   2  *  PWM vibrator driver
   3  *
   4  *  Copyright (C) 2017 Collabora Ltd.
   5  *
   6  *  Based on previous work from:
   7  *  Copyright (C) 2012 Dmitry Torokhov <dmitry.torokhov@gmail.com>
   8  *
   9  *  Based on PWM beeper driver:
  10  *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
  11  *
  12  *  This program is free software; you can redistribute it and/or modify it
  13  *  under  the terms of the GNU General  Public License as published by the
  14  *  Free Software Foundation;  either version 2 of the License, or (at your
  15  *  option) any later version.
  16  */
  17
  18 #include <linux/input.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/of_device.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/property.h>
  24 #include <linux/pwm.h>
  25 #include <linux/regulator/consumer.h>
  26 #include <linux/slab.h>
  27
  28 struct pwm_vibrator {
  29         struct input_dev *input;
  30         struct pwm_device *pwm;
  31         struct pwm_device *pwm_dir;
  32         struct regulator *vcc;
  33
  34         struct work_struct play_work;
  35         u16 level;
  36         u32 direction_duty_cycle;
  37         bool vcc_on;
  38 };
  39
  40 static int pwm_vibrator_start(struct pwm_vibrator *vibrator)
  41 {
  42         struct device *pdev = vibrator->input->dev.parent;
  43         struct pwm_state state;
  44         int err;
  45
  46         if (!vibrator->vcc_on) {
  47                 err = regulator_enable(vibrator->vcc);
  48                 if (err) {
  49                         dev_err(pdev, "failed to enable regulator: %d", err);
  50                         return err;
  51                 }
  52                 vibrator->vcc_on = true;
  53         }
  54
  55         pwm_get_state(vibrator->pwm, &state);
  56         pwm_set_relative_duty_cycle(&state, vibrator->level, 0xffff);
  57         state.enabled = true;
  58
  59         err = pwm_apply_state(vibrator->pwm, &state);
  60         if (err) {
  61                 dev_err(pdev, "failed to apply pwm state: %d", err);
  62                 return err;
  63         }
  64
  65         if (vibrator->pwm_dir) {
  66                 pwm_get_state(vibrator->pwm_dir, &state);
  67                 state.duty_cycle = vibrator->direction_duty_cycle;
  68                 state.enabled = true;
  69
  70                 err = pwm_apply_state(vibrator->pwm_dir, &state);
  71                 if (err) {
  72                         dev_err(pdev, "failed to apply dir-pwm state: %d", err);
  73                         pwm_disable(vibrator->pwm);
  74                         return err;
  75                 }
  76         }
  77
  78         return 0;
  79 }
  80
  81 static void pwm_vibrator_stop(struct pwm_vibrator *vibrator)
  82 {
  83         if (vibrator->pwm_dir)
  84                 pwm_disable(vibrator->pwm_dir);
  85         pwm_disable(vibrator->pwm);
  86
  87         if (vibrator->vcc_on) {
  88                 regulator_disable(vibrator->vcc);
  89                 vibrator->vcc_on = false;
  90         }
  91 }
  92
  93 static void pwm_vibrator_play_work(struct work_struct *work)
  94 {
  95         struct pwm_vibrator *vibrator = container_of(work,
  96                                         struct pwm_vibrator, play_work);
  97
  98         if (vibrator->level)
  99                 pwm_vibrator_start(vibrator);
 100         else
 101                 pwm_vibrator_stop(vibrator);
 102 }
 103
 104 static int pwm_vibrator_play_effect(struct input_dev *dev, void *data,
 105                                     struct ff_effect *effect)
 106 {
 107         struct pwm_vibrator *vibrator = input_get_drvdata(dev);
 108
 109         vibrator->level = effect->u.rumble.strong_magnitude;
 110         if (!vibrator->level)
 111                 vibrator->level = effect->u.rumble.weak_magnitude;
 112
 113         schedule_work(&vibrator->play_work);
 114
 115         return 0;
 116 }
 117
 118 static void pwm_vibrator_close(struct input_dev *input)
 119 {
 120         struct pwm_vibrator *vibrator = input_get_drvdata(input);
 121
 122         cancel_work_sync(&vibrator->play_work);
 123         pwm_vibrator_stop(vibrator);
 124 }
 125
 126 static int pwm_vibrator_probe(struct platform_device *pdev)
 127 {
 128         struct pwm_vibrator *vibrator;
 129         struct pwm_state state;
 130         int err;
 131
 132         vibrator = devm_kzalloc(&pdev->dev, sizeof(*vibrator), GFP_KERNEL);
 133         if (!vibrator)
 134                 return -ENOMEM;
 135
 136         vibrator->input = devm_input_allocate_device(&pdev->dev);
 137         if (!vibrator->input)
 138                 return -ENOMEM;
 139
 140         vibrator->vcc = devm_regulator_get(&pdev->dev, "vcc");
 141         err = PTR_ERR_OR_ZERO(vibrator->vcc);
 142         if (err) {
 143                 if (err != -EPROBE_DEFER)
 144                         dev_err(&pdev->dev, "Failed to request regulator: %d",
 145                                 err);
 146                 return err;
 147         }
 148
 149         vibrator->pwm = devm_pwm_get(&pdev->dev, "enable");
 150         err = PTR_ERR_OR_ZERO(vibrator->pwm);
 151         if (err) {
 152                 if (err != -EPROBE_DEFER)
 153                         dev_err(&pdev->dev, "Failed to request main pwm: %d",
 154                                 err);
 155                 return err;
 156         }
 157
 158         INIT_WORK(&vibrator->play_work, pwm_vibrator_play_work);
 159
 160         /* Sync up PWM state and ensure it is off. */
 161         pwm_init_state(vibrator->pwm, &state);
 162         state.enabled = false;
 163         err = pwm_apply_state(vibrator->pwm, &state);
 164         if (err) {
 165                 dev_err(&pdev->dev, "failed to apply initial PWM state: %d",
 166                         err);
 167                 return err;
 168         }
 169
 170         vibrator->pwm_dir = devm_pwm_get(&pdev->dev, "direction");
 171         err = PTR_ERR_OR_ZERO(vibrator->pwm_dir);
 172         switch (err) {
 173         case 0:
 174                 /* Sync up PWM state and ensure it is off. */
 175                 pwm_init_state(vibrator->pwm_dir, &state);
 176                 state.enabled = false;
 177                 err = pwm_apply_state(vibrator->pwm_dir, &state);
 178                 if (err) {
 179                         dev_err(&pdev->dev, "failed to apply initial PWM state: %d",
 180                                 err);
 181                         return err;
 182                 }
 183
 184                 vibrator->direction_duty_cycle =
 185                         pwm_get_period(vibrator->pwm_dir) / 2;
 186                 device_property_read_u32(&pdev->dev, "direction-duty-cycle-ns",
 187                                          &vibrator->direction_duty_cycle);
 188                 break;
 189
 190         case -ENODATA:
 191                 /* Direction PWM is optional */
 192                 vibrator->pwm_dir = NULL;
 193                 break;
 194
 195         default:
 196                 dev_err(&pdev->dev, "Failed to request direction pwm: %d", err);
 197                 /* Fall through */
 198
 199         case -EPROBE_DEFER:
 200                 return err;
 201         }
 202
 203         vibrator->input->name = "pwm-vibrator";
 204         vibrator->input->id.bustype = BUS_HOST;
 205         vibrator->input->dev.parent = &pdev->dev;
 206         vibrator->input->close = pwm_vibrator_close;
 207
 208         input_set_drvdata(vibrator->input, vibrator);
 209         input_set_capability(vibrator->input, EV_FF, FF_RUMBLE);
 210
 211         err = input_ff_create_memless(vibrator->input, NULL,
 212                                       pwm_vibrator_play_effect);
 213         if (err) {
 214                 dev_err(&pdev->dev, "Couldn't create FF dev: %d", err);
 215                 return err;
 216         }
 217
 218         err = input_register_device(vibrator->input);
 219         if (err) {
 220                 dev_err(&pdev->dev, "Couldn't register input dev: %d", err);
 221                 return err;
 222         }
 223
 224         platform_set_drvdata(pdev, vibrator);
 225
 226         return 0;
 227 }
 228
 229 static int __maybe_unused pwm_vibrator_suspend(struct device *dev)
 230 {
 231         struct pwm_vibrator *vibrator = dev_get_drvdata(dev);
 232
 233         cancel_work_sync(&vibrator->play_work);
 234         if (vibrator->level)
 235                 pwm_vibrator_stop(vibrator);
 236
 237         return 0;
 238 }
 239
 240 static int __maybe_unused pwm_vibrator_resume(struct device *dev)
 241 {
 242         struct pwm_vibrator *vibrator = dev_get_drvdata(dev);
 243
 244         if (vibrator->level)
 245                 pwm_vibrator_start(vibrator);
 246
 247         return 0;
 248 }
 249
 250 static SIMPLE_DEV_PM_OPS(pwm_vibrator_pm_ops,
 251                          pwm_vibrator_suspend, pwm_vibrator_resume);
 252
 253 #ifdef CONFIG_OF
 254 static const struct of_device_id pwm_vibra_dt_match_table[] = {
 255         { .compatible = "pwm-vibrator" },
 256         {},
 257 };
 258 MODULE_DEVICE_TABLE(of, pwm_vibra_dt_match_table);
 259 #endif
 260
 261 static struct platform_driver pwm_vibrator_driver = {
 262         .probe  = pwm_vibrator_probe,
 263         .driver = {
 264                 .name   = "pwm-vibrator",
 265                 .pm     = &pwm_vibrator_pm_ops,
 266                 .of_match_table = of_match_ptr(pwm_vibra_dt_match_table),
 267         },
 268 };
 269 module_platform_driver(pwm_vibrator_driver);
 270
 271 MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
 272 MODULE_DESCRIPTION("PWM vibrator driver");
 273 MODULE_LICENSE("GPL");
 274 MODULE_ALIAS("platform:pwm-vibrator");