hid-sensor-humidity.c

  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/mod_devicetable.h>
 12#include <linux/platform_device.h>
 13
 14#include "hid-sensor-trigger.h"
 15
 16struct hid_humidity_state {
 17	struct hid_sensor_common common_attributes;
 18	struct hid_sensor_hub_attribute_info humidity_attr;
 19	struct {
 20		s32 humidity_data;
 21		aligned_s64 timestamp;
 22	} scan;
 23	int scale_pre_decml;
 24	int scale_post_decml;
 25	int scale_precision;
 26	int value_offset;
 27};
 28
 29static const u32 humidity_sensitivity_addresses[] = {
 30	HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
 31};
 32
 33/* Channel definitions */
 34static const struct iio_chan_spec humidity_channels[] = {
 35	{
 36		.type = IIO_HUMIDITYRELATIVE,
 37		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 38		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
 39			BIT(IIO_CHAN_INFO_SCALE) |
 40			BIT(IIO_CHAN_INFO_SAMP_FREQ) |
 41			BIT(IIO_CHAN_INFO_HYSTERESIS),
 42	},
 43	IIO_CHAN_SOFT_TIMESTAMP(1)
 44};
 45
 46/* Adjust channel real bits based on report descriptor */
 47static void humidity_adjust_channel_bit_mask(struct iio_chan_spec *channels,
 48					int channel, int size)
 49{
 50	channels[channel].scan_type.sign = 's';
 51	/* Real storage bits will change based on the report desc. */
 52	channels[channel].scan_type.realbits = size * 8;
 53	/* Maximum size of a sample to capture is s32 */
 54	channels[channel].scan_type.storagebits = sizeof(s32) * 8;
 55}
 56
 57static int humidity_read_raw(struct iio_dev *indio_dev,
 58				struct iio_chan_spec const *chan,
 59				int *val, int *val2, long mask)
 60{
 61	struct hid_humidity_state *humid_st = iio_priv(indio_dev);
 62
 63	switch (mask) {
 64	case IIO_CHAN_INFO_RAW:
 65		if (chan->type != IIO_HUMIDITYRELATIVE)
 66			return -EINVAL;
 67		hid_sensor_power_state(&humid_st->common_attributes, true);
 68		*val = sensor_hub_input_attr_get_raw_value(
 69				humid_st->common_attributes.hsdev,
 70				HID_USAGE_SENSOR_HUMIDITY,
 71				HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
 72				humid_st->humidity_attr.report_id,
 73				SENSOR_HUB_SYNC,
 74				humid_st->humidity_attr.logical_minimum < 0);
 75		hid_sensor_power_state(&humid_st->common_attributes, false);
 76
 77		return IIO_VAL_INT;
 78
 79	case IIO_CHAN_INFO_SCALE:
 80		*val = humid_st->scale_pre_decml;
 81		*val2 = humid_st->scale_post_decml;
 82
 83		return humid_st->scale_precision;
 84
 85	case IIO_CHAN_INFO_OFFSET:
 86		*val = humid_st->value_offset;
 87
 88		return IIO_VAL_INT;
 89
 90	case IIO_CHAN_INFO_SAMP_FREQ:
 91		return hid_sensor_read_samp_freq_value(
 92				&humid_st->common_attributes, val, val2);
 93
 94	case IIO_CHAN_INFO_HYSTERESIS:
 95		return hid_sensor_read_raw_hyst_value(
 96				&humid_st->common_attributes, val, val2);
 97
 98	default:
 99		return -EINVAL;
100	}
101}
102
103static int humidity_write_raw(struct iio_dev *indio_dev,
104				struct iio_chan_spec const *chan,
105				int val, int val2, long mask)
106{
107	struct hid_humidity_state *humid_st = iio_priv(indio_dev);
108
109	switch (mask) {
110	case IIO_CHAN_INFO_SAMP_FREQ:
111		return hid_sensor_write_samp_freq_value(
112				&humid_st->common_attributes, val, val2);
113
114	case IIO_CHAN_INFO_HYSTERESIS:
115		return hid_sensor_write_raw_hyst_value(
116				&humid_st->common_attributes, val, val2);
117
118	default:
119		return -EINVAL;
120	}
121}
122
123static const struct iio_info humidity_info = {
124	.read_raw = &humidity_read_raw,
125	.write_raw = &humidity_write_raw,
126};
127
128/* Callback handler to send event after all samples are received and captured */
129static int humidity_proc_event(struct hid_sensor_hub_device *hsdev,
130				unsigned int usage_id, void *pdev)
131{
132	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
133	struct hid_humidity_state *humid_st = iio_priv(indio_dev);
134
135	if (atomic_read(&humid_st->common_attributes.data_ready))
136		iio_push_to_buffers_with_timestamp(indio_dev, &humid_st->scan,
137						   iio_get_time_ns(indio_dev));
138
139	return 0;
140}
141
142/* Capture samples in local storage */
143static int humidity_capture_sample(struct hid_sensor_hub_device *hsdev,
144				unsigned int usage_id, size_t raw_len,
145				char *raw_data, void *pdev)
146{
147	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
148	struct hid_humidity_state *humid_st = iio_priv(indio_dev);
149
150	switch (usage_id) {
151	case HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY:
152		humid_st->scan.humidity_data = *(s32 *)raw_data;
153
154		return 0;
155	default:
156		return -EINVAL;
157	}
158}
159
160/* Parse report which is specific to an usage id */
161static int humidity_parse_report(struct platform_device *pdev,
162				struct hid_sensor_hub_device *hsdev,
163				struct iio_chan_spec *channels,
164				unsigned int usage_id,
165				struct hid_humidity_state *st)
166{
167	int ret;
168
169	ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
170					usage_id,
171					HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
172					&st->humidity_attr);
173	if (ret < 0)
174		return ret;
175
176	humidity_adjust_channel_bit_mask(channels, 0, st->humidity_attr.size);
177
178	st->scale_precision = hid_sensor_format_scale(
179						HID_USAGE_SENSOR_HUMIDITY,
180						&st->humidity_attr,
181						&st->scale_pre_decml,
182						&st->scale_post_decml);
183
184	return ret;
185}
186
187static struct hid_sensor_hub_callbacks humidity_callbacks = {
188	.send_event = &humidity_proc_event,
189	.capture_sample = &humidity_capture_sample,
190};
191
192/* Function to initialize the processing for usage id */
193static int hid_humidity_probe(struct platform_device *pdev)
194{
195	static const char *name = "humidity";
196	struct iio_dev *indio_dev;
197	struct hid_humidity_state *humid_st;
198	struct iio_chan_spec *humid_chans;
199	struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
200	int ret;
201
202	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*humid_st));
203	if (!indio_dev)
204		return -ENOMEM;
205
206	humid_st = iio_priv(indio_dev);
207	humid_st->common_attributes.hsdev = hsdev;
208	humid_st->common_attributes.pdev = pdev;
209
210	ret = hid_sensor_parse_common_attributes(hsdev,
211					HID_USAGE_SENSOR_HUMIDITY,
212					&humid_st->common_attributes,
213					humidity_sensitivity_addresses,
214					ARRAY_SIZE(humidity_sensitivity_addresses));
215	if (ret)
216		return ret;
217
218	humid_chans = devm_kmemdup(&indio_dev->dev, humidity_channels,
219					sizeof(humidity_channels), GFP_KERNEL);
220	if (!humid_chans)
221		return -ENOMEM;
222
223	ret = humidity_parse_report(pdev, hsdev, humid_chans,
224				HID_USAGE_SENSOR_HUMIDITY, humid_st);
225	if (ret)
226		return ret;
227
228	indio_dev->channels = humid_chans;
229	indio_dev->num_channels = ARRAY_SIZE(humidity_channels);
230	indio_dev->info = &humidity_info;
231	indio_dev->name = name;
232	indio_dev->modes = INDIO_DIRECT_MODE;
233
234	atomic_set(&humid_st->common_attributes.data_ready, 0);
235
236	ret = hid_sensor_setup_trigger(indio_dev, name,
237				&humid_st->common_attributes);
238	if (ret)
239		return ret;
240
241	platform_set_drvdata(pdev, indio_dev);
242
243	humidity_callbacks.pdev = pdev;
244	ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY,
245					&humidity_callbacks);
246	if (ret)
247		goto error_remove_trigger;
248
249	ret = iio_device_register(indio_dev);
250	if (ret)
251		goto error_remove_callback;
252
253	return ret;
254
255error_remove_callback:
256	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
257error_remove_trigger:
258	hid_sensor_remove_trigger(indio_dev, &humid_st->common_attributes);
259	return ret;
260}
261
262/* Function to deinitialize the processing for usage id */
263static void hid_humidity_remove(struct platform_device *pdev)
264{
265	struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
266	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
267	struct hid_humidity_state *humid_st = iio_priv(indio_dev);
268
269	iio_device_unregister(indio_dev);
270	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
271	hid_sensor_remove_trigger(indio_dev, &humid_st->common_attributes);
272}
273
274static const struct platform_device_id hid_humidity_ids[] = {
275	{
276		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
277		.name = "HID-SENSOR-200032",
278	},
279	{ }
280};
281MODULE_DEVICE_TABLE(platform, hid_humidity_ids);
282
283static struct platform_driver hid_humidity_platform_driver = {
284	.id_table = hid_humidity_ids,
285	.driver = {
286		.name	= KBUILD_MODNAME,
287		.pm	= &hid_sensor_pm_ops,
288	},
289	.probe		= hid_humidity_probe,
290	.remove		= hid_humidity_remove,
291};
292module_platform_driver(hid_humidity_platform_driver);
293
294MODULE_DESCRIPTION("HID Environmental humidity sensor");
295MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
296MODULE_LICENSE("GPL v2");
297MODULE_IMPORT_NS("IIO_HID");