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14#include <linux/platform_device.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18#include <linux/rtc.h>
19#include <linux/iio/iio.h>
20#include <linux/iio/trigger.h>
21
22static LIST_HEAD(iio_prtc_trigger_list);
23static DEFINE_MUTEX(iio_prtc_trigger_list_lock);
24
25struct iio_prtc_trigger_info {
26 struct rtc_device *rtc;
27 int frequency;
28 struct rtc_task task;
29};
30
31static int iio_trig_periodic_rtc_set_state(struct iio_trigger *trig, bool state)
32{
33 struct iio_prtc_trigger_info *trig_info = iio_trigger_get_drvdata(trig);
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
40static ssize_t iio_trig_periodic_read_freq(struct device *dev,
41 struct device_attribute *attr,
42 char *buf)
43{
44 struct iio_trigger *trig = to_iio_trigger(dev);
45 struct iio_prtc_trigger_info *trig_info = iio_trigger_get_drvdata(trig);
46 return sprintf(buf, "%u\n", trig_info->frequency);
47}
48
49static 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 = to_iio_trigger(dev);
55 struct iio_prtc_trigger_info *trig_info = iio_trigger_get_drvdata(trig);
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
71error_ret:
72 return ret;
73}
74
75static DEVICE_ATTR(frequency, S_IRUGO | S_IWUSR,
76 iio_trig_periodic_read_freq,
77 iio_trig_periodic_write_freq);
78
79static struct attribute *iio_trig_prtc_attrs[] = {
80 &dev_attr_frequency.attr,
81 NULL,
82};
83
84static const struct attribute_group iio_trig_prtc_attr_group = {
85 .attrs = iio_trig_prtc_attrs,
86};
87
88static const struct attribute_group *iio_trig_prtc_attr_groups[] = {
89 &iio_trig_prtc_attr_group,
90 NULL
91};
92
93static void iio_prtc_trigger_poll(void *private_data)
94{
95
96 iio_trigger_poll(private_data, 0);
97}
98
99static 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
104static 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;
115 trig = iio_trigger_alloc("periodic%s", pdata[i]);
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 iio_trigger_set_drvdata(trig, trig_info);
128 trig->ops = &iio_prtc_trigger_ops;
129
130 trig_info->rtc
131 = rtc_class_open(pdata[i]);
132 if (trig_info->rtc == NULL) {
133 ret = -EINVAL;
134 goto error_free_trig_info;
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;
141 trig->dev.groups = iio_trig_prtc_attr_groups;
142 ret = iio_trigger_register(trig);
143 if (ret)
144 goto error_unregister_rtc_irq;
145 }
146 return 0;
147error_unregister_rtc_irq:
148 rtc_irq_unregister(trig_info->rtc, &trig_info->task);
149error_close_rtc:
150 rtc_class_close(trig_info->rtc);
151error_free_trig_info:
152 kfree(trig_info);
153error_put_trigger_and_remove_from_list:
154 list_del(&trig->alloc_list);
155 iio_trigger_put(trig);
156error_free_completed_registrations:
157 list_for_each_entry_safe(trig,
158 trig2,
159 &iio_prtc_trigger_list,
160 alloc_list) {
161 trig_info = iio_trigger_get_drvdata(trig);
162 rtc_irq_unregister(trig_info->rtc, &trig_info->task);
163 rtc_class_close(trig_info->rtc);
164 kfree(trig_info);
165 iio_trigger_unregister(trig);
166 }
167 return ret;
168}
169
170static 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 = iio_trigger_get_drvdata(trig);
180 rtc_irq_unregister(trig_info->rtc, &trig_info->task);
181 rtc_class_close(trig_info->rtc);
182 kfree(trig_info);
183 iio_trigger_unregister(trig);
184 }
185 mutex_unlock(&iio_prtc_trigger_list_lock);
186 return 0;
187}
188
189static 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
198module_platform_driver(iio_trig_periodic_rtc_driver);
199
200MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
201MODULE_DESCRIPTION("Periodic realtime clock trigger for the iio subsystem");
202MODULE_LICENSE("GPL v2");
203
