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 
13 enum 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 
23 struct 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 
34 static 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 */
44 static 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 */
hid_time_proc_event(struct hid_sensor_hub_device * hsdev,unsigned usage_id,void * priv)49 static 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 
hid_time_value(size_t raw_len,char * raw_data)62 static 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 
hid_time_capture_sample(struct hid_sensor_hub_device * hsdev,unsigned usage_id,size_t raw_len,char * raw_data,void * priv)76 static 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 */
hid_time_attrib_name(u32 attrib_id)122 static 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 
hid_time_parse_report(struct platform_device * pdev,struct hid_sensor_hub_device * hsdev,unsigned usage_id,struct hid_time_state * time_state)134 static 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 
hid_rtc_read_time(struct device * dev,struct rtc_time * tm)192 static 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 
218 static const struct rtc_class_ops hid_time_rtc_ops = {
219 	.read_time = hid_rtc_read_time,
220 };
221 
hid_time_probe(struct platform_device * pdev)222 static 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 
292 err_rtc:
293 	sensor_hub_device_close(hsdev);
294 err_open:
295 	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
296 	return ret;
297 }
298 
hid_time_remove(struct platform_device * pdev)299 static int 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 	return 0;
307 }
308 
309 static const struct platform_device_id hid_time_ids[] = {
310 	{
311 		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
312 		.name = "HID-SENSOR-2000a0",
313 	},
314 	{ /* sentinel */ }
315 };
316 MODULE_DEVICE_TABLE(platform, hid_time_ids);
317 
318 static struct platform_driver hid_time_platform_driver = {
319 	.id_table = hid_time_ids,
320 	.driver = {
321 		.name	= KBUILD_MODNAME,
322 	},
323 	.probe		= hid_time_probe,
324 	.remove		= hid_time_remove,
325 };
326 module_platform_driver(hid_time_platform_driver);
327 
328 MODULE_DESCRIPTION("HID Sensor Time");
329 MODULE_AUTHOR("Alexander Holler <holler@ahsoftware.de>");
330 MODULE_LICENSE("GPL");
331 MODULE_IMPORT_NS(IIO_HID);
332