diff options
Diffstat (limited to 'drivers/staging/iio/trigger/iio-trig-periodic-rtc.c')
| -rw-r--r-- | drivers/staging/iio/trigger/iio-trig-periodic-rtc.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/drivers/staging/iio/trigger/iio-trig-periodic-rtc.c b/drivers/staging/iio/trigger/iio-trig-periodic-rtc.c new file mode 100644 index 000000000..0c1976dde --- /dev/null +++ b/drivers/staging/iio/trigger/iio-trig-periodic-rtc.c @@ -0,0 +1,215 @@ +/* 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/slab.h> +#include <linux/rtc.h> +#include <linux/iio/iio.h> +#include <linux/iio/trigger.h> + +static LIST_HEAD(iio_prtc_trigger_list); +static DEFINE_MUTEX(iio_prtc_trigger_list_lock); + +struct iio_prtc_trigger_info { + struct rtc_device *rtc; + unsigned int frequency; + struct rtc_task task; + bool state; +}; + +static int iio_trig_periodic_rtc_set_state(struct iio_trigger *trig, bool state) +{ + struct iio_prtc_trigger_info *trig_info = iio_trigger_get_drvdata(trig); + int ret; + + if (trig_info->frequency == 0 && state) + return -EINVAL; + dev_dbg(&trig_info->rtc->dev, "trigger frequency is %u\n", + trig_info->frequency); + ret = rtc_irq_set_state(trig_info->rtc, &trig_info->task, state); + if (ret == 0) + trig_info->state = state; + + return ret; +} + +static ssize_t iio_trig_periodic_read_freq(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_trigger *trig = to_iio_trigger(dev); + struct iio_prtc_trigger_info *trig_info = iio_trigger_get_drvdata(trig); + + 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 = to_iio_trigger(dev); + struct iio_prtc_trigger_info *trig_info = iio_trigger_get_drvdata(trig); + unsigned int val; + int ret; + + ret = kstrtouint(buf, 10, &val); + if (ret) + goto error_ret; + + if (val > 0) { + ret = rtc_irq_set_freq(trig_info->rtc, &trig_info->task, val); + if (ret == 0 && trig_info->state && trig_info->frequency == 0) + ret = rtc_irq_set_state(trig_info->rtc, + &trig_info->task, 1); + } else + ret = rtc_irq_set_state(trig_info->rtc, &trig_info->task, 0); + if (ret) + goto error_ret; + + trig_info->frequency = val; + + return len; + +error_ret: + return ret; +} + +static 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, + NULL, +}; + +static const struct attribute_group iio_trig_prtc_attr_group = { + .attrs = iio_trig_prtc_attrs, +}; + +static const struct attribute_group *iio_trig_prtc_attr_groups[] = { + &iio_trig_prtc_attr_group, + NULL +}; + +static void iio_prtc_trigger_poll(void *private_data) +{ + iio_trigger_poll(private_data); +} + +static const struct iio_trigger_ops iio_prtc_trigger_ops = { + .owner = THIS_MODULE, + .set_trigger_state = &iio_trig_periodic_rtc_set_state, +}; + +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]) + break; + trig = iio_trigger_alloc("periodic%s", pdata[i]); + 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; + } + iio_trigger_set_drvdata(trig, trig_info); + trig->ops = &iio_prtc_trigger_ops; + /* RTC access */ + trig_info->rtc = rtc_class_open(pdata[i]); + if (!trig_info->rtc) { + ret = -EINVAL; + goto error_free_trig_info; + } + 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->dev.groups = iio_trig_prtc_attr_groups; + 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_trig_info: + kfree(trig_info); +error_put_trigger_and_remove_from_list: + list_del(&trig->alloc_list); + iio_trigger_put(trig); +error_free_completed_registrations: + list_for_each_entry_safe(trig, + trig2, + &iio_prtc_trigger_list, + alloc_list) { + trig_info = iio_trigger_get_drvdata(trig); + rtc_irq_unregister(trig_info->rtc, &trig_info->task); + rtc_class_close(trig_info->rtc); + 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 = iio_trigger_get_drvdata(trig); + rtc_irq_unregister(trig_info->rtc, &trig_info->task); + rtc_class_close(trig_info->rtc); + 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", + }, +}; + +module_platform_driver(iio_trig_periodic_rtc_driver); + +MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>"); +MODULE_DESCRIPTION("Periodic realtime clock trigger for the iio subsystem"); +MODULE_LICENSE("GPL v2"); |