[deliverable/linux.git] / drivers / staging / iio / trigger / iio-trig-periodic-rtc.c

/* 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 "../iio.h"
#include "../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;
	int frequency;
	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 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)
{
	/* Timestamp is not provided currently */
	iio_trigger_poll(private_data, 0);
}

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] == NULL)
			break;
		trig = iio_allocate_trigger("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;
		}
		trig->private_data = trig_info;
		trig->ops = &iio_prtc_trigger_ops;
		/* RTC access */
		trig_info->rtc
			= rtc_class_open(pdata[i]);
		if (trig_info->rtc == NULL) {
			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_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_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_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");
Commit	Line	Data
7f3a1fb9 JC	1	/* The industrial I/O periodic RTC trigger driver
	2	*
	3	* Copyright (c) 2008 Jonathan Cameron
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of the GNU General Public License version 2 as published by
	7	* the Free Software Foundation.
	8	*
	9	* This is a heavily rewritten version of the periodic timer system in
	10	* earlier version of industrialio. It supplies the same functionality
	11	* but via a trigger rather than a specific periodic timer system.
	12	*/
	13
	14	#include <linux/platform_device.h>
	15	#include <linux/kernel.h>
	16	#include <linux/module.h>
5a0e3ad6	17	#include <linux/slab.h>
7f3a1fb9 JC	18	#include <linux/rtc.h>
	19	#include "../iio.h"
	20	#include "../trigger.h"
	21
d1d8abdb GKH	22	static LIST_HEAD(iio_prtc_trigger_list);
d1d8abdb GKH	23	static DEFINE_MUTEX(iio_prtc_trigger_list_lock);
7f3a1fb9 JC	24
	25	struct iio_prtc_trigger_info {
	26	struct rtc_device *rtc;
	27	int frequency;
7f3a1fb9 JC	28	struct rtc_task task;
	29	};
	30
	31	static int iio_trig_periodic_rtc_set_state(struct iio_trigger *trig, bool state)
	32	{
	33	struct iio_prtc_trigger_info *trig_info = trig->private_data;
	34	if (trig_info->frequency == 0)
	35	return -EINVAL;
	36	printk(KERN_INFO "trigger frequency is %d\n", trig_info->frequency);
	37	return rtc_irq_set_state(trig_info->rtc, &trig_info->task, state);
	38	}
	39
	40	static ssize_t iio_trig_periodic_read_freq(struct device *dev,
	41	struct device_attribute *attr,
	42	char *buf)
	43	{
	44	struct iio_trigger *trig = dev_get_drvdata(dev);
	45	struct iio_prtc_trigger_info *trig_info = trig->private_data;
	46	return sprintf(buf, "%u\n", trig_info->frequency);
	47	}
	48
	49	static ssize_t iio_trig_periodic_write_freq(struct device *dev,
	50	struct device_attribute *attr,
	51	const char *buf,
	52	size_t len)
	53	{
	54	struct iio_trigger *trig = dev_get_drvdata(dev);
	55	struct iio_prtc_trigger_info *trig_info = trig->private_data;
	56	unsigned long val;
	57	int ret;
	58
	59	ret = strict_strtoul(buf, 10, &val);
	60	if (ret)
	61	goto error_ret;
	62
	63	ret = rtc_irq_set_freq(trig_info->rtc, &trig_info->task, val);
	64	if (ret)
	65	goto error_ret;
	66
	67	trig_info->frequency = val;
	68
	69	return len;
	70
	71	error_ret:
	72	return ret;
	73	}
	74
2fdec576	75	static DEVICE_ATTR(frequency, S_IRUGO \| S_IWUSR,
7f3a1fb9 JC	76	iio_trig_periodic_read_freq,
	77	iio_trig_periodic_write_freq);
	78
	79	static struct attribute *iio_trig_prtc_attrs[] = {
	80	&dev_attr_frequency.attr,
7f3a1fb9 JC	81	NULL,
7f3a1fb9 JC	82	};
59c85e82	83
7f3a1fb9 JC	84	static const struct attribute_group iio_trig_prtc_attr_group = {
	85	.attrs = iio_trig_prtc_attrs,
	86	};
	87
59c85e82 JC	88	static const struct attribute_group *iio_trig_prtc_attr_groups[] = {
	89	&iio_trig_prtc_attr_group,
	90	NULL
	91	};
	92
7f3a1fb9 JC	93	static void iio_prtc_trigger_poll(void *private_data)
7f3a1fb9 JC	94	{
7b2c33b1 JC	95	/* Timestamp is not provided currently */
7b2c33b1 JC	96	iio_trigger_poll(private_data, 0);
7f3a1fb9 JC	97	}
7f3a1fb9 JC	98
d29f73db JC	99	static const struct iio_trigger_ops iio_prtc_trigger_ops = {
	100	.owner = THIS_MODULE,
	101	.set_trigger_state = &iio_trig_periodic_rtc_set_state,
	102	};
	103
7f3a1fb9 JC	104	static int iio_trig_periodic_rtc_probe(struct platform_device *dev)
	105	{
	106	char **pdata = dev->dev.platform_data;
	107	struct iio_prtc_trigger_info *trig_info;
	108	struct iio_trigger trig, trig2;
	109
	110	int i, ret;
	111
	112	for (i = 0;; i++) {
	113	if (pdata[i] == NULL)
	114	break;
59c85e82	115	trig = iio_allocate_trigger("periodic%s", pdata[i]);
7f3a1fb9 JC	116	if (!trig) {
	117	ret = -ENOMEM;
	118	goto error_free_completed_registrations;
	119	}
	120	list_add(&trig->alloc_list, &iio_prtc_trigger_list);
	121
	122	trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
	123	if (!trig_info) {
	124	ret = -ENOMEM;
	125	goto error_put_trigger_and_remove_from_list;
	126	}
	127	trig->private_data = trig_info;
d29f73db	128	trig->ops = &iio_prtc_trigger_ops;
7f3a1fb9 JC	129	/* RTC access */
	130	trig_info->rtc
	131	= rtc_class_open(pdata[i]);
	132	if (trig_info->rtc == NULL) {
	133	ret = -EINVAL;
59c85e82	134	goto error_free_trig_info;
7f3a1fb9 JC	135	}
	136	trig_info->task.func = iio_prtc_trigger_poll;
	137	trig_info->task.private_data = trig;
	138	ret = rtc_irq_register(trig_info->rtc, &trig_info->task);
	139	if (ret)
	140	goto error_close_rtc;
59c85e82	141	trig->dev.groups = iio_trig_prtc_attr_groups;
7f3a1fb9 JC	142	ret = iio_trigger_register(trig);
	143	if (ret)
	144	goto error_unregister_rtc_irq;
	145	}
	146	return 0;
	147	error_unregister_rtc_irq:
	148	rtc_irq_unregister(trig_info->rtc, &trig_info->task);
	149	error_close_rtc:
	150	rtc_class_close(trig_info->rtc);
7f3a1fb9 JC	151	error_free_trig_info:
	152	kfree(trig_info);
	153	error_put_trigger_and_remove_from_list:
	154	list_del(&trig->alloc_list);
	155	iio_put_trigger(trig);
	156	error_free_completed_registrations:
	157	list_for_each_entry_safe(trig,
	158	trig2,
	159	&iio_prtc_trigger_list,
	160	alloc_list) {
	161	trig_info = trig->private_data;
	162	rtc_irq_unregister(trig_info->rtc, &trig_info->task);
	163	rtc_class_close(trig_info->rtc);
7f3a1fb9 JC	164	kfree(trig_info);
	165	iio_trigger_unregister(trig);
	166	}
	167	return ret;
	168	}
	169
	170	static int iio_trig_periodic_rtc_remove(struct platform_device *dev)
	171	{
	172	struct iio_trigger trig, trig2;
	173	struct iio_prtc_trigger_info *trig_info;
	174	mutex_lock(&iio_prtc_trigger_list_lock);
	175	list_for_each_entry_safe(trig,
	176	trig2,
	177	&iio_prtc_trigger_list,
	178	alloc_list) {
	179	trig_info = trig->private_data;
	180	rtc_irq_unregister(trig_info->rtc, &trig_info->task);
	181	rtc_class_close(trig_info->rtc);
7f3a1fb9 JC	182	kfree(trig_info);
	183	iio_trigger_unregister(trig);
	184	}
	185	mutex_unlock(&iio_prtc_trigger_list_lock);
	186	return 0;
	187	}
	188
	189	static struct platform_driver iio_trig_periodic_rtc_driver = {
	190	.probe = iio_trig_periodic_rtc_probe,
	191	.remove = iio_trig_periodic_rtc_remove,
	192	.driver = {
	193	.name = "iio_prtc_trigger",
	194	.owner = THIS_MODULE,
	195	},
	196	};
	197
	198	static int __init iio_trig_periodic_rtc_init(void)
	199	{
	200	return platform_driver_register(&iio_trig_periodic_rtc_driver);
	201	}
	202
	203	static void __exit iio_trig_periodic_rtc_exit(void)
	204	{
	205	return platform_driver_unregister(&iio_trig_periodic_rtc_driver);
	206	}
	207
	208	module_init(iio_trig_periodic_rtc_init);
	209	module_exit(iio_trig_periodic_rtc_exit);
	210	MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
	211	MODULE_DESCRIPTION("Periodic realtime clock trigger for the iio subsystem");
	212	MODULE_LICENSE("GPL v2");