--- /dev/null
+/* The industrial I/O periodic RTC trigger driver
+ *
+ * Copyright (c) 2008 Jonathan Cameron
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This is a heavily rewritten version of the periodic timer system in
+ * earlier version of industrialio. It supplies the same functionality
+ * but via a trigger rather than a specific periodic timer system.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include "../iio.h"
+#include "../trigger.h"
+
+LIST_HEAD(iio_prtc_trigger_list);
+DEFINE_MUTEX(iio_prtc_trigger_list_lock);
+
+struct iio_prtc_trigger_info {
+ struct rtc_device *rtc;
+ int frequency;
+ char *name;
+ struct rtc_task task;
+};
+
+static int iio_trig_periodic_rtc_set_state(struct iio_trigger *trig, bool state)
+{
+ struct iio_prtc_trigger_info *trig_info = trig->private_data;
+ if (trig_info->frequency == 0)
+ return -EINVAL;
+ printk(KERN_INFO "trigger frequency is %d\n", trig_info->frequency);
+ return rtc_irq_set_state(trig_info->rtc, &trig_info->task, state);
+}
+
+static ssize_t iio_trig_periodic_read_freq(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_trigger *trig = dev_get_drvdata(dev);
+ struct iio_prtc_trigger_info *trig_info = trig->private_data;
+ return sprintf(buf, "%u\n", trig_info->frequency);
+}
+
+static ssize_t iio_trig_periodic_write_freq(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct iio_trigger *trig = dev_get_drvdata(dev);
+ struct iio_prtc_trigger_info *trig_info = trig->private_data;
+ unsigned long val;
+ int ret;
+
+ ret = strict_strtoul(buf, 10, &val);
+ if (ret)
+ goto error_ret;
+
+ ret = rtc_irq_set_freq(trig_info->rtc, &trig_info->task, val);
+ if (ret)
+ goto error_ret;
+
+ trig_info->frequency = val;
+
+ return len;
+
+error_ret:
+ return ret;
+}
+
+static ssize_t iio_trig_periodic_read_name(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_trigger *trig = dev_get_drvdata(dev);
+ struct iio_prtc_trigger_info *trig_info = trig->private_data;
+ return sprintf(buf, "%s\n", trig_info->name);
+}
+
+DEVICE_ATTR(name, S_IRUGO,
+ iio_trig_periodic_read_name,
+ NULL);
+DEVICE_ATTR(frequency, S_IRUGO | S_IWUSR,
+ iio_trig_periodic_read_freq,
+ iio_trig_periodic_write_freq);
+
+static struct attribute *iio_trig_prtc_attrs[] = {
+ &dev_attr_frequency.attr,
+ &dev_attr_name.attr,
+ NULL,
+};
+static const struct attribute_group iio_trig_prtc_attr_group = {
+ .attrs = iio_trig_prtc_attrs,
+};
+
+static void iio_prtc_trigger_poll(void *private_data)
+{
+ iio_trigger_poll(private_data);
+}
+
+static int iio_trig_periodic_rtc_probe(struct platform_device *dev)
+{
+ char **pdata = dev->dev.platform_data;
+ struct iio_prtc_trigger_info *trig_info;
+ struct iio_trigger *trig, *trig2;
+
+ int i, ret;
+
+ for (i = 0;; i++) {
+ if (pdata[i] == NULL)
+ break;
+ trig = iio_allocate_trigger();
+ if (!trig) {
+ ret = -ENOMEM;
+ goto error_free_completed_registrations;
+ }
+ list_add(&trig->alloc_list, &iio_prtc_trigger_list);
+
+ trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
+ if (!trig_info) {
+ ret = -ENOMEM;
+ goto error_put_trigger_and_remove_from_list;
+ }
+ trig->private_data = trig_info;
+ trig->owner = THIS_MODULE;
+ trig->set_trigger_state = &iio_trig_periodic_rtc_set_state;
+ trig->name = kmalloc(IIO_TRIGGER_NAME_LENGTH, GFP_KERNEL);
+ if (trig->name == NULL) {
+ ret = -ENOMEM;
+ goto error_free_trig_info;
+ }
+ snprintf((char *)trig->name,
+ IIO_TRIGGER_NAME_LENGTH,
+ "periodic%s",
+ pdata[i]);
+ trig_info->name = (char *)trig->name;
+ /* RTC access */
+ trig_info->rtc
+ = rtc_class_open(pdata[i]);
+ if (trig_info->rtc == NULL) {
+ ret = -EINVAL;
+ goto error_free_name;
+ }
+ trig_info->task.func = iio_prtc_trigger_poll;
+ trig_info->task.private_data = trig;
+ ret = rtc_irq_register(trig_info->rtc, &trig_info->task);
+ if (ret)
+ goto error_close_rtc;
+ trig->control_attrs = &iio_trig_prtc_attr_group;
+ ret = iio_trigger_register(trig);
+ if (ret)
+ goto error_unregister_rtc_irq;
+ }
+ return 0;
+error_unregister_rtc_irq:
+ rtc_irq_unregister(trig_info->rtc, &trig_info->task);
+error_close_rtc:
+ rtc_class_close(trig_info->rtc);
+error_free_name:
+ kfree(trig->name);
+error_free_trig_info:
+ kfree(trig_info);
+error_put_trigger_and_remove_from_list:
+ list_del(&trig->alloc_list);
+ iio_put_trigger(trig);
+error_free_completed_registrations:
+ list_for_each_entry_safe(trig,
+ trig2,
+ &iio_prtc_trigger_list,
+ alloc_list) {
+ trig_info = trig->private_data;
+ rtc_irq_unregister(trig_info->rtc, &trig_info->task);
+ rtc_class_close(trig_info->rtc);
+ kfree(trig->name);
+ kfree(trig_info);
+ iio_trigger_unregister(trig);
+ }
+ return ret;
+}
+
+static int iio_trig_periodic_rtc_remove(struct platform_device *dev)
+{
+ struct iio_trigger *trig, *trig2;
+ struct iio_prtc_trigger_info *trig_info;
+ mutex_lock(&iio_prtc_trigger_list_lock);
+ list_for_each_entry_safe(trig,
+ trig2,
+ &iio_prtc_trigger_list,
+ alloc_list) {
+ trig_info = trig->private_data;
+ rtc_irq_unregister(trig_info->rtc, &trig_info->task);
+ rtc_class_close(trig_info->rtc);
+ kfree(trig->name);
+ kfree(trig_info);
+ iio_trigger_unregister(trig);
+ }
+ mutex_unlock(&iio_prtc_trigger_list_lock);
+ return 0;
+}
+
+static struct platform_driver iio_trig_periodic_rtc_driver = {
+ .probe = iio_trig_periodic_rtc_probe,
+ .remove = iio_trig_periodic_rtc_remove,
+ .driver = {
+ .name = "iio_prtc_trigger",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init iio_trig_periodic_rtc_init(void)
+{
+ return platform_driver_register(&iio_trig_periodic_rtc_driver);
+}
+
+static void __exit iio_trig_periodic_rtc_exit(void)
+{
+ return platform_driver_unregister(&iio_trig_periodic_rtc_driver);
+}
+
+module_init(iio_trig_periodic_rtc_init);
+module_exit(iio_trig_periodic_rtc_exit);
+MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
+MODULE_DESCRIPTION("Periodic realtime clock trigger for the iio subsystem");
+MODULE_LICENSE("GPL v2");
projects / firefly-linux-kernel-4.4.55.git / commitdiff