1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * HID Sensors Driver
4 * Copyright (c) 2017, Intel Corporation.
5 */
6#include <linux/device.h>
7#include <linux/hid-sensor-hub.h>
8#include <linux/iio/buffer.h>
9#include <linux/iio/iio.h>
10#include <linux/module.h>
11#include <linux/platform_device.h>
12
13#include "hid-sensor-trigger.h"
14
15struct hid_humidity_state {
16	struct hid_sensor_common common_attributes;
17	struct hid_sensor_hub_attribute_info humidity_attr;
18	struct {
19		s32 humidity_data;
20		u64 timestamp __aligned(8);
21	} scan;
22	int scale_pre_decml;
23	int scale_post_decml;
24	int scale_precision;
25	int value_offset;
26};
27
28/* Channel definitions */
29static const struct iio_chan_spec humidity_channels[] = {
30	{
31		.type = IIO_HUMIDITYRELATIVE,
32		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
33		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
34			BIT(IIO_CHAN_INFO_SCALE) |
35			BIT(IIO_CHAN_INFO_SAMP_FREQ) |
36			BIT(IIO_CHAN_INFO_HYSTERESIS),
37	},
38	IIO_CHAN_SOFT_TIMESTAMP(1)
39};
40
41/* Adjust channel real bits based on report descriptor */
42static void humidity_adjust_channel_bit_mask(struct iio_chan_spec *channels,
43					int channel, int size)
44{
45	channels[channel].scan_type.sign = 's';
46	/* Real storage bits will change based on the report desc. */
47	channels[channel].scan_type.realbits = size * 8;
48	/* Maximum size of a sample to capture is s32 */
49	channels[channel].scan_type.storagebits = sizeof(s32) * 8;
50}
51
52static int humidity_read_raw(struct iio_dev *indio_dev,
53				struct iio_chan_spec const *chan,
54				int *val, int *val2, long mask)
55{
56	struct hid_humidity_state *humid_st = iio_priv(indio_dev);
57
58	switch (mask) {
59	case IIO_CHAN_INFO_RAW:
60		if (chan->type != IIO_HUMIDITYRELATIVE)
61			return -EINVAL;
62		hid_sensor_power_state(&humid_st->common_attributes, true);
63		*val = sensor_hub_input_attr_get_raw_value(
64				humid_st->common_attributes.hsdev,
65				HID_USAGE_SENSOR_HUMIDITY,
66				HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
67				humid_st->humidity_attr.report_id,
68				SENSOR_HUB_SYNC,
69				humid_st->humidity_attr.logical_minimum < 0);
70		hid_sensor_power_state(&humid_st->common_attributes, false);
71
72		return IIO_VAL_INT;
73
74	case IIO_CHAN_INFO_SCALE:
75		*val = humid_st->scale_pre_decml;
76		*val2 = humid_st->scale_post_decml;
77
78		return humid_st->scale_precision;
79
80	case IIO_CHAN_INFO_OFFSET:
81		*val = humid_st->value_offset;
82
83		return IIO_VAL_INT;
84
85	case IIO_CHAN_INFO_SAMP_FREQ:
86		return hid_sensor_read_samp_freq_value(
87				&humid_st->common_attributes, val, val2);
88
89	case IIO_CHAN_INFO_HYSTERESIS:
90		return hid_sensor_read_raw_hyst_value(
91				&humid_st->common_attributes, val, val2);
92
93	default:
94		return -EINVAL;
95	}
96}
97
98static int humidity_write_raw(struct iio_dev *indio_dev,
99				struct iio_chan_spec const *chan,
100				int val, int val2, long mask)
101{
102	struct hid_humidity_state *humid_st = iio_priv(indio_dev);
103
104	switch (mask) {
105	case IIO_CHAN_INFO_SAMP_FREQ:
106		return hid_sensor_write_samp_freq_value(
107				&humid_st->common_attributes, val, val2);
108
109	case IIO_CHAN_INFO_HYSTERESIS:
110		return hid_sensor_write_raw_hyst_value(
111				&humid_st->common_attributes, val, val2);
112
113	default:
114		return -EINVAL;
115	}
116}
117
118static const struct iio_info humidity_info = {
119	.read_raw = &humidity_read_raw,
120	.write_raw = &humidity_write_raw,
121};
122
123/* Callback handler to send event after all samples are received and captured */
124static int humidity_proc_event(struct hid_sensor_hub_device *hsdev,
125				unsigned int usage_id, void *pdev)
126{
127	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
128	struct hid_humidity_state *humid_st = iio_priv(indio_dev);
129
130	if (atomic_read(&humid_st->common_attributes.data_ready))
131		iio_push_to_buffers_with_timestamp(indio_dev, &humid_st->scan,
132						   iio_get_time_ns(indio_dev));
133
134	return 0;
135}
136
137/* Capture samples in local storage */
138static int humidity_capture_sample(struct hid_sensor_hub_device *hsdev,
139				unsigned int usage_id, size_t raw_len,
140				char *raw_data, void *pdev)
141{
142	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
143	struct hid_humidity_state *humid_st = iio_priv(indio_dev);
144
145	switch (usage_id) {
146	case HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY:
147		humid_st->scan.humidity_data = *(s32 *)raw_data;
148
149		return 0;
150	default:
151		return -EINVAL;
152	}
153}
154
155/* Parse report which is specific to an usage id */
156static int humidity_parse_report(struct platform_device *pdev,
157				struct hid_sensor_hub_device *hsdev,
158				struct iio_chan_spec *channels,
159				unsigned int usage_id,
160				struct hid_humidity_state *st)
161{
162	int ret;
163
164	ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
165					usage_id,
166					HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
167					&st->humidity_attr);
168	if (ret < 0)
169		return ret;
170
171	humidity_adjust_channel_bit_mask(channels, 0, st->humidity_attr.size);
172
173	st->scale_precision = hid_sensor_format_scale(
174						HID_USAGE_SENSOR_HUMIDITY,
175						&st->humidity_attr,
176						&st->scale_pre_decml,
177						&st->scale_post_decml);
178
179	/* Set Sensitivity field ids, when there is no individual modifier */
180	if (st->common_attributes.sensitivity.index < 0)
181		sensor_hub_input_get_attribute_info(hsdev,
182			HID_FEATURE_REPORT, usage_id,
183			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
184			HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
185			&st->common_attributes.sensitivity);
186
187	return ret;
188}
189
190static struct hid_sensor_hub_callbacks humidity_callbacks = {
191	.send_event = &humidity_proc_event,
192	.capture_sample = &humidity_capture_sample,
193};
194
195/* Function to initialize the processing for usage id */
196static int hid_humidity_probe(struct platform_device *pdev)
197{
198	static const char *name = "humidity";
199	struct iio_dev *indio_dev;
200	struct hid_humidity_state *humid_st;
201	struct iio_chan_spec *humid_chans;
202	struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
203	int ret;
204
205	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*humid_st));
206	if (!indio_dev)
207		return -ENOMEM;
208
209	humid_st = iio_priv(indio_dev);
210	humid_st->common_attributes.hsdev = hsdev;
211	humid_st->common_attributes.pdev = pdev;
212
213	ret = hid_sensor_parse_common_attributes(hsdev,
214					HID_USAGE_SENSOR_HUMIDITY,
215					&humid_st->common_attributes);
216	if (ret)
217		return ret;
218
219	humid_chans = devm_kmemdup(&indio_dev->dev, humidity_channels,
220					sizeof(humidity_channels), GFP_KERNEL);
221	if (!humid_chans)
222		return -ENOMEM;
223
224	ret = humidity_parse_report(pdev, hsdev, humid_chans,
225				HID_USAGE_SENSOR_HUMIDITY, humid_st);
226	if (ret)
227		return ret;
228
229	indio_dev->channels = humid_chans;
230	indio_dev->num_channels = ARRAY_SIZE(humidity_channels);
231	indio_dev->info = &humidity_info;
232	indio_dev->name = name;
233	indio_dev->modes = INDIO_DIRECT_MODE;
234
235	atomic_set(&humid_st->common_attributes.data_ready, 0);
236
237	ret = hid_sensor_setup_trigger(indio_dev, name,
238				&humid_st->common_attributes);
239	if (ret)
240		return ret;
241
242	platform_set_drvdata(pdev, indio_dev);
243
244	humidity_callbacks.pdev = pdev;
245	ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY,
246					&humidity_callbacks);
247	if (ret)
248		goto error_remove_trigger;
249
250	ret = iio_device_register(indio_dev);
251	if (ret)
252		goto error_remove_callback;
253
254	return ret;
255
256error_remove_callback:
257	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
258error_remove_trigger:
259	hid_sensor_remove_trigger(indio_dev, &humid_st->common_attributes);
260	return ret;
261}
262
263/* Function to deinitialize the processing for usage id */
264static int hid_humidity_remove(struct platform_device *pdev)
265{
266	struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
267	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
268	struct hid_humidity_state *humid_st = iio_priv(indio_dev);
269
270	iio_device_unregister(indio_dev);
271	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
272	hid_sensor_remove_trigger(indio_dev, &humid_st->common_attributes);
273
274	return 0;
275}
276
277static const struct platform_device_id hid_humidity_ids[] = {
278	{
279		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
280		.name = "HID-SENSOR-200032",
281	},
282	{ /* sentinel */ }
283};
284MODULE_DEVICE_TABLE(platform, hid_humidity_ids);
285
286static struct platform_driver hid_humidity_platform_driver = {
287	.id_table = hid_humidity_ids,
288	.driver = {
289		.name	= KBUILD_MODNAME,
290		.pm	= &hid_sensor_pm_ops,
291	},
292	.probe		= hid_humidity_probe,
293	.remove		= hid_humidity_remove,
294};
295module_platform_driver(hid_humidity_platform_driver);
296
297MODULE_DESCRIPTION("HID Environmental humidity sensor");
298MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
299MODULE_LICENSE("GPL v2");
300