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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * HID Sensor Time Driver
4 * Copyright (c) 2012, Alexander Holler.
5 */
6#include <linux/device.h>
7#include <linux/platform_device.h>
8#include <linux/module.h>
9#include <linux/hid-sensor-hub.h>
10#include <linux/iio/iio.h>
11#include <linux/rtc.h>
12
13enum hid_time_channel {
14 CHANNEL_SCAN_INDEX_YEAR,
15 CHANNEL_SCAN_INDEX_MONTH,
16 CHANNEL_SCAN_INDEX_DAY,
17 CHANNEL_SCAN_INDEX_HOUR,
18 CHANNEL_SCAN_INDEX_MINUTE,
19 CHANNEL_SCAN_INDEX_SECOND,
20 TIME_RTC_CHANNEL_MAX,
21};
22
23struct hid_time_state {
24 struct hid_sensor_hub_callbacks callbacks;
25 struct hid_sensor_common common_attributes;
26 struct hid_sensor_hub_attribute_info info[TIME_RTC_CHANNEL_MAX];
27 struct rtc_time last_time;
28 spinlock_t lock_last_time;
29 struct completion comp_last_time;
30 struct rtc_time time_buf;
31 struct rtc_device *rtc;
32};
33
34static const u32 hid_time_addresses[TIME_RTC_CHANNEL_MAX] = {
35 HID_USAGE_SENSOR_TIME_YEAR,
36 HID_USAGE_SENSOR_TIME_MONTH,
37 HID_USAGE_SENSOR_TIME_DAY,
38 HID_USAGE_SENSOR_TIME_HOUR,
39 HID_USAGE_SENSOR_TIME_MINUTE,
40 HID_USAGE_SENSOR_TIME_SECOND,
41};
42
43/* Channel names for verbose error messages */
44static const char * const hid_time_channel_names[TIME_RTC_CHANNEL_MAX] = {
45 "year", "month", "day", "hour", "minute", "second",
46};
47
48/* Callback handler to send event after all samples are received and captured */
49static int hid_time_proc_event(struct hid_sensor_hub_device *hsdev,
50 unsigned usage_id, void *priv)
51{
52 unsigned long flags;
53 struct hid_time_state *time_state = platform_get_drvdata(priv);
54
55 spin_lock_irqsave(&time_state->lock_last_time, flags);
56 time_state->last_time = time_state->time_buf;
57 spin_unlock_irqrestore(&time_state->lock_last_time, flags);
58 complete(&time_state->comp_last_time);
59 return 0;
60}
61
62static u32 hid_time_value(size_t raw_len, char *raw_data)
63{
64 switch (raw_len) {
65 case 1:
66 return *(u8 *)raw_data;
67 case 2:
68 return *(u16 *)raw_data;
69 case 4:
70 return *(u32 *)raw_data;
71 default:
72 return (u32)(~0U); /* 0xff... or -1 to denote an error */
73 }
74}
75
76static int hid_time_capture_sample(struct hid_sensor_hub_device *hsdev,
77 unsigned usage_id, size_t raw_len,
78 char *raw_data, void *priv)
79{
80 struct hid_time_state *time_state = platform_get_drvdata(priv);
81 struct rtc_time *time_buf = &time_state->time_buf;
82
83 switch (usage_id) {
84 case HID_USAGE_SENSOR_TIME_YEAR:
85 /*
86 * The draft for HID-sensors (HUTRR39) currently doesn't define
87 * the range for the year attribute. Therefor we support
88 * 8 bit (0-99) and 16 or 32 bits (full) as size for the year.
89 */
90 if (raw_len == 1) {
91 time_buf->tm_year = *(u8 *)raw_data;
92 if (time_buf->tm_year < 70)
93 /* assume we are in 1970...2069 */
94 time_buf->tm_year += 100;
95 } else
96 time_buf->tm_year =
97 (int)hid_time_value(raw_len, raw_data)-1900;
98 break;
99 case HID_USAGE_SENSOR_TIME_MONTH:
100 /* sensors are sending the month as 1-12, we need 0-11 */
101 time_buf->tm_mon = (int)hid_time_value(raw_len, raw_data)-1;
102 break;
103 case HID_USAGE_SENSOR_TIME_DAY:
104 time_buf->tm_mday = (int)hid_time_value(raw_len, raw_data);
105 break;
106 case HID_USAGE_SENSOR_TIME_HOUR:
107 time_buf->tm_hour = (int)hid_time_value(raw_len, raw_data);
108 break;
109 case HID_USAGE_SENSOR_TIME_MINUTE:
110 time_buf->tm_min = (int)hid_time_value(raw_len, raw_data);
111 break;
112 case HID_USAGE_SENSOR_TIME_SECOND:
113 time_buf->tm_sec = (int)hid_time_value(raw_len, raw_data);
114 break;
115 default:
116 return -EINVAL;
117 }
118 return 0;
119}
120
121/* small helper, haven't found any other way */
122static const char *hid_time_attrib_name(u32 attrib_id)
123{
124 static const char unknown[] = "unknown";
125 unsigned i;
126
127 for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i) {
128 if (hid_time_addresses[i] == attrib_id)
129 return hid_time_channel_names[i];
130 }
131 return unknown; /* should never happen */
132}
133
134static int hid_time_parse_report(struct platform_device *pdev,
135 struct hid_sensor_hub_device *hsdev,
136 unsigned usage_id,
137 struct hid_time_state *time_state)
138{
139 int report_id, i;
140
141 for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i)
142 if (sensor_hub_input_get_attribute_info(hsdev,
143 HID_INPUT_REPORT, usage_id,
144 hid_time_addresses[i],
145 &time_state->info[i]) < 0)
146 return -EINVAL;
147 /* Check the (needed) attributes for sanity */
148 report_id = time_state->info[0].report_id;
149 if (report_id < 0) {
150 dev_err(&pdev->dev, "bad report ID!\n");
151 return -EINVAL;
152 }
153 for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i) {
154 if (time_state->info[i].report_id != report_id) {
155 dev_err(&pdev->dev,
156 "not all needed attributes inside the same report!\n");
157 return -EINVAL;
158 }
159 if (time_state->info[i].size == 3 ||
160 time_state->info[i].size > 4) {
161 dev_err(&pdev->dev,
162 "attribute '%s' not 8, 16 or 32 bits wide!\n",
163 hid_time_attrib_name(
164 time_state->info[i].attrib_id));
165 return -EINVAL;
166 }
167 if (time_state->info[i].units !=
168 HID_USAGE_SENSOR_UNITS_NOT_SPECIFIED &&
169 /* allow attribute seconds with unit seconds */
170 !(time_state->info[i].attrib_id ==
171 HID_USAGE_SENSOR_TIME_SECOND &&
172 time_state->info[i].units ==
173 HID_USAGE_SENSOR_UNITS_SECOND)) {
174 dev_err(&pdev->dev,
175 "attribute '%s' hasn't a unit of type 'none'!\n",
176 hid_time_attrib_name(
177 time_state->info[i].attrib_id));
178 return -EINVAL;
179 }
180 if (time_state->info[i].unit_expo) {
181 dev_err(&pdev->dev,
182 "attribute '%s' hasn't a unit exponent of 1!\n",
183 hid_time_attrib_name(
184 time_state->info[i].attrib_id));
185 return -EINVAL;
186 }
187 }
188
189 return 0;
190}
191
192static int hid_rtc_read_time(struct device *dev, struct rtc_time *tm)
193{
194 unsigned long flags;
195 struct hid_time_state *time_state = dev_get_drvdata(dev);
196 int ret;
197
198 reinit_completion(&time_state->comp_last_time);
199 /* get a report with all values through requesting one value */
200 sensor_hub_input_attr_get_raw_value(time_state->common_attributes.hsdev,
201 HID_USAGE_SENSOR_TIME, hid_time_addresses[0],
202 time_state->info[0].report_id, SENSOR_HUB_SYNC, false);
203 /* wait for all values (event) */
204 ret = wait_for_completion_killable_timeout(
205 &time_state->comp_last_time, HZ*6);
206 if (ret > 0) {
207 /* no error */
208 spin_lock_irqsave(&time_state->lock_last_time, flags);
209 *tm = time_state->last_time;
210 spin_unlock_irqrestore(&time_state->lock_last_time, flags);
211 return 0;
212 }
213 if (!ret)
214 return -EIO; /* timeouted */
215 return ret; /* killed (-ERESTARTSYS) */
216}
217
218static const struct rtc_class_ops hid_time_rtc_ops = {
219 .read_time = hid_rtc_read_time,
220};
221
222static int hid_time_probe(struct platform_device *pdev)
223{
224 int ret = 0;
225 struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
226 struct hid_time_state *time_state = devm_kzalloc(&pdev->dev,
227 sizeof(struct hid_time_state), GFP_KERNEL);
228
229 if (time_state == NULL)
230 return -ENOMEM;
231
232 platform_set_drvdata(pdev, time_state);
233
234 spin_lock_init(&time_state->lock_last_time);
235 init_completion(&time_state->comp_last_time);
236 time_state->common_attributes.hsdev = hsdev;
237 time_state->common_attributes.pdev = pdev;
238
239 ret = hid_sensor_parse_common_attributes(hsdev,
240 HID_USAGE_SENSOR_TIME,
241 &time_state->common_attributes,
242 NULL,
243 0);
244 if (ret) {
245 dev_err(&pdev->dev, "failed to setup common attributes!\n");
246 return ret;
247 }
248
249 ret = hid_time_parse_report(pdev, hsdev, HID_USAGE_SENSOR_TIME,
250 time_state);
251 if (ret) {
252 dev_err(&pdev->dev, "failed to setup attributes!\n");
253 return ret;
254 }
255
256 time_state->callbacks.send_event = hid_time_proc_event;
257 time_state->callbacks.capture_sample = hid_time_capture_sample;
258 time_state->callbacks.pdev = pdev;
259 ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_TIME,
260 &time_state->callbacks);
261 if (ret < 0) {
262 dev_err(&pdev->dev, "register callback failed!\n");
263 return ret;
264 }
265
266 ret = sensor_hub_device_open(hsdev);
267 if (ret) {
268 dev_err(&pdev->dev, "failed to open sensor hub device!\n");
269 goto err_open;
270 }
271
272 /*
273 * Enable HID input processing early in order to be able to read the
274 * clock already in devm_rtc_device_register().
275 */
276 hid_device_io_start(hsdev->hdev);
277
278 time_state->rtc = devm_rtc_device_register(&pdev->dev,
279 "hid-sensor-time", &hid_time_rtc_ops,
280 THIS_MODULE);
281
282 if (IS_ERR(time_state->rtc)) {
283 hid_device_io_stop(hsdev->hdev);
284 ret = PTR_ERR(time_state->rtc);
285 time_state->rtc = NULL;
286 dev_err(&pdev->dev, "rtc device register failed!\n");
287 goto err_rtc;
288 }
289
290 return ret;
291
292err_rtc:
293 sensor_hub_device_close(hsdev);
294err_open:
295 sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
296 return ret;
297}
298
299static void hid_time_remove(struct platform_device *pdev)
300{
301 struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
302
303 sensor_hub_device_close(hsdev);
304 sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
305}
306
307static const struct platform_device_id hid_time_ids[] = {
308 {
309 /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
310 .name = "HID-SENSOR-2000a0",
311 },
312 { /* sentinel */ }
313};
314MODULE_DEVICE_TABLE(platform, hid_time_ids);
315
316static struct platform_driver hid_time_platform_driver = {
317 .id_table = hid_time_ids,
318 .driver = {
319 .name = KBUILD_MODNAME,
320 },
321 .probe = hid_time_probe,
322 .remove = hid_time_remove,
323};
324module_platform_driver(hid_time_platform_driver);
325
326MODULE_DESCRIPTION("HID Sensor Time");
327MODULE_AUTHOR("Alexander Holler <[email protected]>");
328MODULE_LICENSE("GPL");
329MODULE_IMPORT_NS("IIO_HID");