/* * Copyright 2011 Analog Devices Inc. * * Licensed under the GPL-2. * */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/list.h> #include <linux/irq_work.h> #include <linux/iio/iio.h> #include <linux/iio/trigger.h> struct iio_sysfs_trig { struct iio_trigger *trig; struct irq_work work; int id; struct list_head l; }; static LIST_HEAD(iio_sysfs_trig_list); static DEFINE_MUTEX(iio_sysfs_trig_list_mut); static int iio_sysfs_trigger_probe(int id); static ssize_t iio_sysfs_trig_add(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { int ret; unsigned long input; ret = kstrtoul(buf, 10, &input); if (ret) return ret; ret = iio_sysfs_trigger_probe(input); if (ret) return ret; return len; } static DEVICE_ATTR(add_trigger, S_IWUSR, NULL, &iio_sysfs_trig_add); static int iio_sysfs_trigger_remove(int id); static ssize_t iio_sysfs_trig_remove(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { int ret; unsigned long input; ret = kstrtoul(buf, 10, &input); if (ret) return ret; ret = iio_sysfs_trigger_remove(input); if (ret) return ret; return len; } static DEVICE_ATTR(remove_trigger, S_IWUSR, NULL, &iio_sysfs_trig_remove); static struct attribute *iio_sysfs_trig_attrs[] = { &dev_attr_add_trigger.attr, &dev_attr_remove_trigger.attr, NULL, }; static const struct attribute_group iio_sysfs_trig_group = { .attrs = iio_sysfs_trig_attrs, }; static const struct attribute_group *iio_sysfs_trig_groups[] = { &iio_sysfs_trig_group, NULL }; /* Nothing to actually do upon release */ static void iio_trigger_sysfs_release(struct device *dev) { } static struct device iio_sysfs_trig_dev = { .bus = &iio_bus_type, .groups = iio_sysfs_trig_groups, .release = &iio_trigger_sysfs_release, }; static void iio_sysfs_trigger_work(struct irq_work *work) { struct iio_sysfs_trig *trig = container_of(work, struct iio_sysfs_trig, work); iio_trigger_poll(trig->trig, 0); } static ssize_t iio_sysfs_trigger_poll(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct iio_trigger *trig = to_iio_trigger(dev); struct iio_sysfs_trig *sysfs_trig = iio_trigger_get_drvdata(trig); irq_work_queue(&sysfs_trig->work); return count; } static DEVICE_ATTR(trigger_now, S_IWUSR, NULL, iio_sysfs_trigger_poll); static struct attribute *iio_sysfs_trigger_attrs[] = { &dev_attr_trigger_now.attr, NULL, }; static const struct attribute_group iio_sysfs_trigger_attr_group = { .attrs = iio_sysfs_trigger_attrs, }; static const struct attribute_group *iio_sysfs_trigger_attr_groups[] = { &iio_sysfs_trigger_attr_group, NULL }; static const struct iio_trigger_ops iio_sysfs_trigger_ops = { .owner = THIS_MODULE, }; static int iio_sysfs_trigger_probe(int id) { struct iio_sysfs_trig *t; int ret; bool foundit = false; mutex_lock(&iio_sysfs_trig_list_mut); list_for_each_entry(t, &iio_sysfs_trig_list, l) if (id == t->id) { foundit = true; break; } if (foundit) { ret = -EINVAL; goto out1; } t = kmalloc(sizeof(*t), GFP_KERNEL); if (t == NULL) { ret = -ENOMEM; goto out1; } t->id = id; t->trig = iio_trigger_alloc("sysfstrig%d", id); if (!t->trig) { ret = -ENOMEM; goto free_t; } t->trig->dev.groups = iio_sysfs_trigger_attr_groups; t->trig->ops = &iio_sysfs_trigger_ops; t->trig->dev.parent = &iio_sysfs_trig_dev; iio_trigger_set_drvdata(t->trig, t); init_irq_work(&t->work, iio_sysfs_trigger_work); ret = iio_trigger_register(t->trig); if (ret) goto out2; list_add(&t->l, &iio_sysfs_trig_list); __module_get(THIS_MODULE); mutex_unlock(&iio_sysfs_trig_list_mut); return 0; out2: iio_trigger_put(t->trig); free_t: kfree(t); out1: mutex_unlock(&iio_sysfs_trig_list_mut); return ret; } static int iio_sysfs_trigger_remove(int id) { bool foundit = false; struct iio_sysfs_trig *t; mutex_lock(&iio_sysfs_trig_list_mut); list_for_each_entry(t, &iio_sysfs_trig_list, l) if (id == t->id) { foundit = true; break; } if (!foundit) { mutex_unlock(&iio_sysfs_trig_list_mut); return -EINVAL; } iio_trigger_unregister(t->trig); iio_trigger_free(t->trig); list_del(&t->l); kfree(t); module_put(THIS_MODULE); mutex_unlock(&iio_sysfs_trig_list_mut); return 0; } static int __init iio_sysfs_trig_init(void) { device_initialize(&iio_sysfs_trig_dev); dev_set_name(&iio_sysfs_trig_dev, "iio_sysfs_trigger"); return device_add(&iio_sysfs_trig_dev); } module_init(iio_sysfs_trig_init); static void __exit iio_sysfs_trig_exit(void) { device_unregister(&iio_sysfs_trig_dev); } module_exit(iio_sysfs_trig_exit); MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); MODULE_DESCRIPTION("Sysfs based trigger for the iio subsystem"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:iio-trig-sysfs");