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_new	= hid_time_remove,
323};
324module_platform_driver(hid_time_platform_driver);
325
326MODULE_DESCRIPTION("HID Sensor Time");
327MODULE_AUTHOR("Alexander Holler <holler@ahsoftware.de>");
328MODULE_LICENSE("GPL");
329MODULE_IMPORT_NS(IIO_HID);
330