drivers/staging/iio/trigger/iio-trig-sysfs.c

   1 /*
   2  * Copyright 2011 Analog Devices Inc.
   3  *
   4  * Licensed under the GPL-2.
   5  *
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/slab.h>
  12
  13 #include "../iio.h"
  14 #include "../trigger.h"
  15
  16 static ssize_t iio_sysfs_trigger_poll(struct device *dev,
  17                 struct device_attribute *attr, const char *buf, size_t count)
  18 {
  19         struct iio_trigger *trig = dev_get_drvdata(dev);
  20         iio_trigger_poll(trig, 0);
  21
  22         return count;
  23 }
  24
  25 static DEVICE_ATTR(trigger_now, S_IWUSR, NULL, iio_sysfs_trigger_poll);
  26 static IIO_TRIGGER_NAME_ATTR;
  27
  28 static struct attribute *iio_sysfs_trigger_attrs[] = {
  29         &dev_attr_trigger_now.attr,
  30         &dev_attr_name.attr,
  31         NULL,
  32 };
  33
  34 static const struct attribute_group iio_sysfs_trigger_attr_group = {
  35         .attrs = iio_sysfs_trigger_attrs,
  36 };
  37
  38 static int __devinit iio_sysfs_trigger_probe(struct platform_device *pdev)
  39 {
  40         struct iio_trigger *trig;
  41         int ret;
  42
  43         trig = iio_allocate_trigger();
  44         if (!trig) {
  45                 ret = -ENOMEM;
  46                 goto out1;
  47         }
  48
  49         trig->control_attrs = &iio_sysfs_trigger_attr_group;
  50         trig->owner = THIS_MODULE;
  51         trig->name = kasprintf(GFP_KERNEL, "sysfstrig%d", pdev->id);
  52         if (trig->name == NULL) {
  53                 ret = -ENOMEM;
  54                 goto out2;
  55         }
  56
  57         ret = iio_trigger_register(trig);
  58         if (ret)
  59                 goto out3;
  60
  61         platform_set_drvdata(pdev, trig);
  62
  63         return 0;
  64 out3:
  65         kfree(trig->name);
  66 out2:
  67         iio_put_trigger(trig);
  68 out1:
  69
  70         return ret;
  71 }
  72
  73 static int __devexit iio_sysfs_trigger_remove(struct platform_device *pdev)
  74 {
  75         struct iio_trigger *trig = platform_get_drvdata(pdev);
  76
  77         iio_trigger_unregister(trig);
  78         kfree(trig->name);
  79         iio_put_trigger(trig);
  80
  81         return 0;
  82 }
  83
  84 static struct platform_driver iio_sysfs_trigger_driver = {
  85         .driver = {
  86                 .name = "iio_sysfs_trigger",
  87                 .owner = THIS_MODULE,
  88         },
  89         .probe = iio_sysfs_trigger_probe,
  90         .remove = __devexit_p(iio_sysfs_trigger_remove),
  91 };
  92
  93 static int __init iio_sysfs_trig_init(void)
  94 {
  95         return platform_driver_register(&iio_sysfs_trigger_driver);
  96 }
  97 module_init(iio_sysfs_trig_init);
  98
  99 static void __exit iio_sysfs_trig_exit(void)
 100 {
 101         platform_driver_unregister(&iio_sysfs_trigger_driver);
 102 }
 103 module_exit(iio_sysfs_trig_exit);
 104
 105 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 106 MODULE_DESCRIPTION("Sysfs based trigger for the iio subsystem");
 107 MODULE_LICENSE("GPL v2");
 108 MODULE_ALIAS("platform:iio-trig-sysfs");