GNU Linux-libre 4.4.289-gnu1
[releases.git] / drivers / rtc / rtc-hid-sensor-time.c
1 /*
2  * HID Sensor Time Driver
3  * Copyright (c) 2012, Alexander Holler.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program; if not, write to the Free Software Foundation, Inc.,
16  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
17  *
18  */
19 #include <linux/device.h>
20 #include <linux/platform_device.h>
21 #include <linux/module.h>
22 #include <linux/hid-sensor-hub.h>
23 #include <linux/iio/iio.h>
24 #include <linux/rtc.h>
25
26 enum hid_time_channel {
27         CHANNEL_SCAN_INDEX_YEAR,
28         CHANNEL_SCAN_INDEX_MONTH,
29         CHANNEL_SCAN_INDEX_DAY,
30         CHANNEL_SCAN_INDEX_HOUR,
31         CHANNEL_SCAN_INDEX_MINUTE,
32         CHANNEL_SCAN_INDEX_SECOND,
33         TIME_RTC_CHANNEL_MAX,
34 };
35
36 struct hid_time_state {
37         struct hid_sensor_hub_callbacks callbacks;
38         struct hid_sensor_common common_attributes;
39         struct hid_sensor_hub_attribute_info info[TIME_RTC_CHANNEL_MAX];
40         struct rtc_time last_time;
41         spinlock_t lock_last_time;
42         struct completion comp_last_time;
43         struct rtc_time time_buf;
44         struct rtc_device *rtc;
45 };
46
47 static const u32 hid_time_addresses[TIME_RTC_CHANNEL_MAX] = {
48         HID_USAGE_SENSOR_TIME_YEAR,
49         HID_USAGE_SENSOR_TIME_MONTH,
50         HID_USAGE_SENSOR_TIME_DAY,
51         HID_USAGE_SENSOR_TIME_HOUR,
52         HID_USAGE_SENSOR_TIME_MINUTE,
53         HID_USAGE_SENSOR_TIME_SECOND,
54 };
55
56 /* Channel names for verbose error messages */
57 static const char * const hid_time_channel_names[TIME_RTC_CHANNEL_MAX] = {
58         "year", "month", "day", "hour", "minute", "second",
59 };
60
61 /* Callback handler to send event after all samples are received and captured */
62 static int hid_time_proc_event(struct hid_sensor_hub_device *hsdev,
63                                 unsigned usage_id, void *priv)
64 {
65         unsigned long flags;
66         struct hid_time_state *time_state = platform_get_drvdata(priv);
67
68         spin_lock_irqsave(&time_state->lock_last_time, flags);
69         time_state->last_time = time_state->time_buf;
70         spin_unlock_irqrestore(&time_state->lock_last_time, flags);
71         complete(&time_state->comp_last_time);
72         return 0;
73 }
74
75 static u32 hid_time_value(size_t raw_len, char *raw_data)
76 {
77         switch (raw_len) {
78         case 1:
79                 return *(u8 *)raw_data;
80         case 2:
81                 return *(u16 *)raw_data;
82         case 4:
83                 return *(u32 *)raw_data;
84         default:
85                 return (u32)(~0U); /* 0xff... or -1 to denote an error */
86         }
87 }
88
89 static int hid_time_capture_sample(struct hid_sensor_hub_device *hsdev,
90                                 unsigned usage_id, size_t raw_len,
91                                 char *raw_data, void *priv)
92 {
93         struct hid_time_state *time_state = platform_get_drvdata(priv);
94         struct rtc_time *time_buf = &time_state->time_buf;
95
96         switch (usage_id) {
97         case HID_USAGE_SENSOR_TIME_YEAR:
98                 /*
99                  * The draft for HID-sensors (HUTRR39) currently doesn't define
100                  * the range for the year attribute. Therefor we support
101                  * 8 bit (0-99) and 16 or 32 bits (full) as size for the year.
102                  */
103                 if (raw_len == 1) {
104                         time_buf->tm_year = *(u8 *)raw_data;
105                         if (time_buf->tm_year < 70)
106                                 /* assume we are in 1970...2069 */
107                                 time_buf->tm_year += 100;
108                 } else
109                         time_buf->tm_year =
110                                 (int)hid_time_value(raw_len, raw_data)-1900;
111                 break;
112         case HID_USAGE_SENSOR_TIME_MONTH:
113                 /* sensors are sending the month as 1-12, we need 0-11 */
114                 time_buf->tm_mon = (int)hid_time_value(raw_len, raw_data)-1;
115                 break;
116         case HID_USAGE_SENSOR_TIME_DAY:
117                 time_buf->tm_mday = (int)hid_time_value(raw_len, raw_data);
118                 break;
119         case HID_USAGE_SENSOR_TIME_HOUR:
120                 time_buf->tm_hour = (int)hid_time_value(raw_len, raw_data);
121                 break;
122         case HID_USAGE_SENSOR_TIME_MINUTE:
123                 time_buf->tm_min = (int)hid_time_value(raw_len, raw_data);
124                 break;
125         case HID_USAGE_SENSOR_TIME_SECOND:
126                 time_buf->tm_sec = (int)hid_time_value(raw_len, raw_data);
127                 break;
128         default:
129                 return -EINVAL;
130         }
131         return 0;
132 }
133
134 /* small helper, haven't found any other way */
135 static const char *hid_time_attrib_name(u32 attrib_id)
136 {
137         static const char unknown[] = "unknown";
138         unsigned i;
139
140         for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i) {
141                 if (hid_time_addresses[i] == attrib_id)
142                         return hid_time_channel_names[i];
143         }
144         return unknown; /* should never happen */
145 }
146
147 static int hid_time_parse_report(struct platform_device *pdev,
148                                 struct hid_sensor_hub_device *hsdev,
149                                 unsigned usage_id,
150                                 struct hid_time_state *time_state)
151 {
152         int report_id, i;
153
154         for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i)
155                 if (sensor_hub_input_get_attribute_info(hsdev,
156                                 HID_INPUT_REPORT, usage_id,
157                                 hid_time_addresses[i],
158                                 &time_state->info[i]) < 0)
159                         return -EINVAL;
160         /* Check the (needed) attributes for sanity */
161         report_id = time_state->info[0].report_id;
162         if (report_id < 0) {
163                 dev_err(&pdev->dev, "bad report ID!\n");
164                 return -EINVAL;
165         }
166         for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i) {
167                 if (time_state->info[i].report_id != report_id) {
168                         dev_err(&pdev->dev,
169                                 "not all needed attributes inside the same report!\n");
170                         return -EINVAL;
171                 }
172                 if (time_state->info[i].size == 3 ||
173                                 time_state->info[i].size > 4) {
174                         dev_err(&pdev->dev,
175                                 "attribute '%s' not 8, 16 or 32 bits wide!\n",
176                                 hid_time_attrib_name(
177                                         time_state->info[i].attrib_id));
178                         return -EINVAL;
179                 }
180                 if (time_state->info[i].units !=
181                                 HID_USAGE_SENSOR_UNITS_NOT_SPECIFIED &&
182                                 /* allow attribute seconds with unit seconds */
183                                 !(time_state->info[i].attrib_id ==
184                                 HID_USAGE_SENSOR_TIME_SECOND &&
185                                 time_state->info[i].units ==
186                                 HID_USAGE_SENSOR_UNITS_SECOND)) {
187                         dev_err(&pdev->dev,
188                                 "attribute '%s' hasn't a unit of type 'none'!\n",
189                                 hid_time_attrib_name(
190                                         time_state->info[i].attrib_id));
191                         return -EINVAL;
192                 }
193                 if (time_state->info[i].unit_expo) {
194                         dev_err(&pdev->dev,
195                                 "attribute '%s' hasn't a unit exponent of 1!\n",
196                                 hid_time_attrib_name(
197                                         time_state->info[i].attrib_id));
198                         return -EINVAL;
199                 }
200         }
201
202         return 0;
203 }
204
205 static int hid_rtc_read_time(struct device *dev, struct rtc_time *tm)
206 {
207         unsigned long flags;
208         struct hid_time_state *time_state =
209                 platform_get_drvdata(to_platform_device(dev));
210         int ret;
211
212         reinit_completion(&time_state->comp_last_time);
213         /* get a report with all values through requesting one value */
214         sensor_hub_input_attr_get_raw_value(time_state->common_attributes.hsdev,
215                         HID_USAGE_SENSOR_TIME, hid_time_addresses[0],
216                         time_state->info[0].report_id, SENSOR_HUB_SYNC);
217         /* wait for all values (event) */
218         ret = wait_for_completion_killable_timeout(
219                         &time_state->comp_last_time, HZ*6);
220         if (ret > 0) {
221                 /* no error */
222                 spin_lock_irqsave(&time_state->lock_last_time, flags);
223                 *tm = time_state->last_time;
224                 spin_unlock_irqrestore(&time_state->lock_last_time, flags);
225                 return 0;
226         }
227         if (!ret)
228                 return -EIO; /* timeouted */
229         return ret; /* killed (-ERESTARTSYS) */
230 }
231
232 static const struct rtc_class_ops hid_time_rtc_ops = {
233         .read_time = hid_rtc_read_time,
234 };
235
236 static int hid_time_probe(struct platform_device *pdev)
237 {
238         int ret = 0;
239         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
240         struct hid_time_state *time_state = devm_kzalloc(&pdev->dev,
241                 sizeof(struct hid_time_state), GFP_KERNEL);
242
243         if (time_state == NULL)
244                 return -ENOMEM;
245
246         platform_set_drvdata(pdev, time_state);
247
248         spin_lock_init(&time_state->lock_last_time);
249         init_completion(&time_state->comp_last_time);
250         time_state->common_attributes.hsdev = hsdev;
251         time_state->common_attributes.pdev = pdev;
252
253         ret = hid_sensor_parse_common_attributes(hsdev,
254                                 HID_USAGE_SENSOR_TIME,
255                                 &time_state->common_attributes);
256         if (ret) {
257                 dev_err(&pdev->dev, "failed to setup common attributes!\n");
258                 return ret;
259         }
260
261         ret = hid_time_parse_report(pdev, hsdev, HID_USAGE_SENSOR_TIME,
262                                         time_state);
263         if (ret) {
264                 dev_err(&pdev->dev, "failed to setup attributes!\n");
265                 return ret;
266         }
267
268         time_state->callbacks.send_event = hid_time_proc_event;
269         time_state->callbacks.capture_sample = hid_time_capture_sample;
270         time_state->callbacks.pdev = pdev;
271         ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_TIME,
272                                         &time_state->callbacks);
273         if (ret < 0) {
274                 dev_err(&pdev->dev, "register callback failed!\n");
275                 return ret;
276         }
277
278         ret = sensor_hub_device_open(hsdev);
279         if (ret) {
280                 dev_err(&pdev->dev, "failed to open sensor hub device!\n");
281                 goto err_open;
282         }
283
284         /*
285          * Enable HID input processing early in order to be able to read the
286          * clock already in devm_rtc_device_register().
287          */
288         hid_device_io_start(hsdev->hdev);
289
290         time_state->rtc = devm_rtc_device_register(&pdev->dev,
291                                         "hid-sensor-time", &hid_time_rtc_ops,
292                                         THIS_MODULE);
293
294         if (IS_ERR_OR_NULL(time_state->rtc)) {
295                 hid_device_io_stop(hsdev->hdev);
296                 ret = time_state->rtc ? PTR_ERR(time_state->rtc) : -ENODEV;
297                 time_state->rtc = NULL;
298                 dev_err(&pdev->dev, "rtc device register failed!\n");
299                 goto err_rtc;
300         }
301
302         return ret;
303
304 err_rtc:
305         sensor_hub_device_close(hsdev);
306 err_open:
307         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
308         return ret;
309 }
310
311 static int hid_time_remove(struct platform_device *pdev)
312 {
313         struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
314
315         sensor_hub_device_close(hsdev);
316         sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
317
318         return 0;
319 }
320
321 static const struct platform_device_id hid_time_ids[] = {
322         {
323                 /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
324                 .name = "HID-SENSOR-2000a0",
325         },
326         { /* sentinel */ }
327 };
328 MODULE_DEVICE_TABLE(platform, hid_time_ids);
329
330 static struct platform_driver hid_time_platform_driver = {
331         .id_table = hid_time_ids,
332         .driver = {
333                 .name   = KBUILD_MODNAME,
334         },
335         .probe          = hid_time_probe,
336         .remove         = hid_time_remove,
337 };
338 module_platform_driver(hid_time_platform_driver);
339
340 MODULE_DESCRIPTION("HID Sensor Time");
341 MODULE_AUTHOR("Alexander Holler <holler@ahsoftware.de>");
342 MODULE_LICENSE("GPL");