drivers/staging/greybus/vibrator.c

   1 /*
   2  * Greybus Vibrator protocol driver.
   3  *
   4  * Copyright 2014 Google Inc.
   5  * Copyright 2014 Linaro Ltd.
   6  *
   7  * Released under the GPLv2 only.
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/slab.h>
  13 #include <linux/device.h>
  14 #include <linux/kdev_t.h>
  15 #include <linux/idr.h>
  16 #include <linux/pm_runtime.h>
  17
  18 #include "greybus.h"
  19
  20 struct gb_vibrator_device {
  21         struct gb_connection    *connection;
  22         struct device           *dev;
  23         int                     minor;          /* vibrator minor number */
  24         struct delayed_work     delayed_work;
  25 };
  26
  27 /* Greybus Vibrator operation types */
  28 #define GB_VIBRATOR_TYPE_ON                     0x02
  29 #define GB_VIBRATOR_TYPE_OFF                    0x03
  30
  31 static int turn_off(struct gb_vibrator_device *vib)
  32 {
  33         struct gb_bundle *bundle = vib->connection->bundle;
  34         int ret;
  35
  36         ret = gb_operation_sync(vib->connection, GB_VIBRATOR_TYPE_OFF,
  37                                 NULL, 0, NULL, 0);
  38
  39         gb_pm_runtime_put_autosuspend(bundle);
  40
  41         return ret;
  42 }
  43
  44 static int turn_on(struct gb_vibrator_device *vib, u16 timeout_ms)
  45 {
  46         struct gb_bundle *bundle = vib->connection->bundle;
  47         int ret;
  48
  49         ret = gb_pm_runtime_get_sync(bundle);
  50         if (ret)
  51                 return ret;
  52
  53         /* Vibrator was switched ON earlier */
  54         if (cancel_delayed_work_sync(&vib->delayed_work))
  55                 turn_off(vib);
  56
  57         ret = gb_operation_sync(vib->connection, GB_VIBRATOR_TYPE_ON,
  58                                 NULL, 0, NULL, 0);
  59         if (ret) {
  60                 gb_pm_runtime_put_autosuspend(bundle);
  61                 return ret;
  62         }
  63
  64         schedule_delayed_work(&vib->delayed_work, msecs_to_jiffies(timeout_ms));
  65
  66         return 0;
  67 }
  68
  69 static void gb_vibrator_worker(struct work_struct *work)
  70 {
  71         struct delayed_work *delayed_work = to_delayed_work(work);
  72         struct gb_vibrator_device *vib =
  73                 container_of(delayed_work,
  74                              struct gb_vibrator_device,
  75                              delayed_work);
  76
  77         turn_off(vib);
  78 }
  79
  80 static ssize_t timeout_store(struct device *dev, struct device_attribute *attr,
  81                              const char *buf, size_t count)
  82 {
  83         struct gb_vibrator_device *vib = dev_get_drvdata(dev);
  84         unsigned long val;
  85         int retval;
  86
  87         retval = kstrtoul(buf, 10, &val);
  88         if (retval < 0) {
  89                 dev_err(dev, "could not parse timeout value %d\n", retval);
  90                 return retval;
  91         }
  92
  93         if (val)
  94                 retval = turn_on(vib, (u16)val);
  95         else
  96                 retval = turn_off(vib);
  97         if (retval)
  98                 return retval;
  99
 100         return count;
 101 }
 102 static DEVICE_ATTR_WO(timeout);
 103
 104 static struct attribute *vibrator_attrs[] = {
 105         &dev_attr_timeout.attr,
 106         NULL,
 107 };
 108 ATTRIBUTE_GROUPS(vibrator);
 109
 110 static struct class vibrator_class = {
 111         .name           = "vibrator",
 112         .owner          = THIS_MODULE,
 113         .dev_groups     = vibrator_groups,
 114 };
 115
 116 static DEFINE_IDA(minors);
 117
 118 static int gb_vibrator_probe(struct gb_bundle *bundle,
 119                              const struct greybus_bundle_id *id)
 120 {
 121         struct greybus_descriptor_cport *cport_desc;
 122         struct gb_connection *connection;
 123         struct gb_vibrator_device *vib;
 124         struct device *dev;
 125         int retval;
 126
 127         if (bundle->num_cports != 1)
 128                 return -ENODEV;
 129
 130         cport_desc = &bundle->cport_desc[0];
 131         if (cport_desc->protocol_id != GREYBUS_PROTOCOL_VIBRATOR)
 132                 return -ENODEV;
 133
 134         vib = kzalloc(sizeof(*vib), GFP_KERNEL);
 135         if (!vib)
 136                 return -ENOMEM;
 137
 138         connection = gb_connection_create(bundle, le16_to_cpu(cport_desc->id),
 139                                           NULL);
 140         if (IS_ERR(connection)) {
 141                 retval = PTR_ERR(connection);
 142                 goto err_free_vib;
 143         }
 144         gb_connection_set_data(connection, vib);
 145
 146         vib->connection = connection;
 147
 148         greybus_set_drvdata(bundle, vib);
 149
 150         retval = gb_connection_enable(connection);
 151         if (retval)
 152                 goto err_connection_destroy;
 153
 154         /*
 155          * For now we create a device in sysfs for the vibrator, but odds are
 156          * there is a "real" device somewhere in the kernel for this, but I
 157          * can't find it at the moment...
 158          */
 159         vib->minor = ida_simple_get(&minors, 0, 0, GFP_KERNEL);
 160         if (vib->minor < 0) {
 161                 retval = vib->minor;
 162                 goto err_connection_disable;
 163         }
 164         dev = device_create(&vibrator_class, &bundle->dev,
 165                             MKDEV(0, 0), vib, "vibrator%d", vib->minor);
 166         if (IS_ERR(dev)) {
 167                 retval = -EINVAL;
 168                 goto err_ida_remove;
 169         }
 170         vib->dev = dev;
 171
 172         INIT_DELAYED_WORK(&vib->delayed_work, gb_vibrator_worker);
 173
 174         gb_pm_runtime_put_autosuspend(bundle);
 175
 176         return 0;
 177
 178 err_ida_remove:
 179         ida_simple_remove(&minors, vib->minor);
 180 err_connection_disable:
 181         gb_connection_disable(connection);
 182 err_connection_destroy:
 183         gb_connection_destroy(connection);
 184 err_free_vib:
 185         kfree(vib);
 186
 187         return retval;
 188 }
 189
 190 static void gb_vibrator_disconnect(struct gb_bundle *bundle)
 191 {
 192         struct gb_vibrator_device *vib = greybus_get_drvdata(bundle);
 193         int ret;
 194
 195         ret = gb_pm_runtime_get_sync(bundle);
 196         if (ret)
 197                 gb_pm_runtime_get_noresume(bundle);
 198
 199         if (cancel_delayed_work_sync(&vib->delayed_work))
 200                 turn_off(vib);
 201
 202         device_unregister(vib->dev);
 203         ida_simple_remove(&minors, vib->minor);
 204         gb_connection_disable(vib->connection);
 205         gb_connection_destroy(vib->connection);
 206         kfree(vib);
 207 }
 208
 209 static const struct greybus_bundle_id gb_vibrator_id_table[] = {
 210         { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_VIBRATOR) },
 211         { }
 212 };
 213 MODULE_DEVICE_TABLE(greybus, gb_vibrator_id_table);
 214
 215 static struct greybus_driver gb_vibrator_driver = {
 216         .name           = "vibrator",
 217         .probe          = gb_vibrator_probe,
 218         .disconnect     = gb_vibrator_disconnect,
 219         .id_table       = gb_vibrator_id_table,
 220 };
 221
 222 static __init int gb_vibrator_init(void)
 223 {
 224         int retval;
 225
 226         retval = class_register(&vibrator_class);
 227         if (retval)
 228                 return retval;
 229
 230         retval = greybus_register(&gb_vibrator_driver);
 231         if (retval)
 232                 goto err_class_unregister;
 233
 234         return 0;
 235
 236 err_class_unregister:
 237         class_unregister(&vibrator_class);
 238
 239         return retval;
 240 }
 241 module_init(gb_vibrator_init);
 242
 243 static __exit void gb_vibrator_exit(void)
 244 {
 245         greybus_deregister(&gb_vibrator_driver);
 246         class_unregister(&vibrator_class);
 247         ida_destroy(&minors);
 248 }
 249 module_exit(gb_vibrator_exit);
 250
 251 MODULE_LICENSE("GPL v2");