hid-sensor-temperature.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 "../common/hid-sensors/hid-sensor-trigger.h"
 15
 16struct temperature_state {
 17	struct hid_sensor_common common_attributes;
 18	struct hid_sensor_hub_attribute_info temperature_attr;
 19	struct {
 20		s32 temperature_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 temperature_sensitivity_addresses[] = {
 30	HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
 31};
 32
 33/* Channel definitions */
 34static const struct iio_chan_spec temperature_channels[] = {
 35	{
 36		.type = IIO_TEMP,
 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 temperature_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 temperature_read_raw(struct iio_dev *indio_dev,
 58				struct iio_chan_spec const *chan,
 59				int *val, int *val2, long mask)
 60{
 61	struct temperature_state *temp_st = iio_priv(indio_dev);
 62
 63	switch (mask) {
 64	case IIO_CHAN_INFO_RAW:
 65		if (chan->type != IIO_TEMP)
 66			return -EINVAL;
 67		hid_sensor_power_state(
 68			&temp_st->common_attributes, true);
 69		*val = sensor_hub_input_attr_get_raw_value(
 70			temp_st->common_attributes.hsdev,
 71			HID_USAGE_SENSOR_TEMPERATURE,
 72			HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
 73			temp_st->temperature_attr.report_id,
 74			SENSOR_HUB_SYNC,
 75			temp_st->temperature_attr.logical_minimum < 0);
 76		hid_sensor_power_state(
 77				&temp_st->common_attributes,
 78				false);
 79
 80		return IIO_VAL_INT;
 81
 82	case IIO_CHAN_INFO_SCALE:
 83		*val = temp_st->scale_pre_decml;
 84		*val2 = temp_st->scale_post_decml;
 85		return temp_st->scale_precision;
 86
 87	case IIO_CHAN_INFO_OFFSET:
 88		*val = temp_st->value_offset;
 89		return IIO_VAL_INT;
 90
 91	case IIO_CHAN_INFO_SAMP_FREQ:
 92		return hid_sensor_read_samp_freq_value(
 93				&temp_st->common_attributes, val, val2);
 94
 95	case IIO_CHAN_INFO_HYSTERESIS:
 96		return hid_sensor_read_raw_hyst_value(
 97				&temp_st->common_attributes, val, val2);
 98	default:
 99		return -EINVAL;
100	}
101}
102
103static int temperature_write_raw(struct iio_dev *indio_dev,
104				struct iio_chan_spec const *chan,
105				int val, int val2, long mask)
106{
107	struct temperature_state *temp_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				&temp_st->common_attributes, val, val2);
113	case IIO_CHAN_INFO_HYSTERESIS:
114		return hid_sensor_write_raw_hyst_value(
115				&temp_st->common_attributes, val, val2);
116	default:
117		return -EINVAL;
118	}
119}
120
121static const struct iio_info temperature_info = {
122	.read_raw = &temperature_read_raw,
123	.write_raw = &temperature_write_raw,
124};
125
126/* Callback handler to send event after all samples are received and captured */
127static int temperature_proc_event(struct hid_sensor_hub_device *hsdev,
128				unsigned int usage_id, void *pdev)
129{
130	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
131	struct temperature_state *temp_st = iio_priv(indio_dev);
132
133	if (atomic_read(&temp_st->common_attributes.data_ready))
134		iio_push_to_buffers_with_ts(indio_dev, &temp_st->scan,
135					    sizeof(temp_st->scan),
136					    iio_get_time_ns(indio_dev));
137
138	return 0;
139}
140
141/* Capture samples in local storage */
142static int temperature_capture_sample(struct hid_sensor_hub_device *hsdev,
143				unsigned int usage_id, size_t raw_len,
144				char *raw_data, void *pdev)
145{
146	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
147	struct temperature_state *temp_st = iio_priv(indio_dev);
148
149	switch (usage_id) {
150	case HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE:
151		temp_st->scan.temperature_data = *(s32 *)raw_data;
152		return 0;
153	default:
154		return -EINVAL;
155	}
156}
157
158/* Parse report which is specific to an usage id*/
159static int temperature_parse_report(struct platform_device *pdev,
160				struct hid_sensor_hub_device *hsdev,
161				struct iio_chan_spec *channels,
162				unsigned int usage_id,
163				struct temperature_state *st)
164{
165	int ret;
166
167	ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
168			usage_id,
169			HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
170			&st->temperature_attr);
171	if (ret < 0)
172		return ret;
173
174	temperature_adjust_channel_bit_mask(channels, 0,
175					st->temperature_attr.size);
176
177	st->scale_precision = hid_sensor_format_scale(
178				HID_USAGE_SENSOR_TEMPERATURE,
179				&st->temperature_attr,
180				&st->scale_pre_decml, &st->scale_post_decml);
181
182	return ret;
183}
184
185static struct hid_sensor_hub_callbacks temperature_callbacks = {
186	.send_event = &temperature_proc_event,
187	.capture_sample = &temperature_capture_sample,
188};
189
190/* Function to initialize the processing for usage id */
191static int hid_temperature_probe(struct platform_device *pdev)
192{
193	static const char *name = "temperature";
194	struct iio_dev *indio_dev;
195	struct temperature_state *temp_st;
196	struct iio_chan_spec *temp_chans;
197	struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
198	int ret;
199
200	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*temp_st));
201	if (!indio_dev)
202		return -ENOMEM;
203
204	temp_st = iio_priv(indio_dev);
205	temp_st->common_attributes.hsdev = hsdev;
206	temp_st->common_attributes.pdev = pdev;
207
208	ret = hid_sensor_parse_common_attributes(hsdev,
209					HID_USAGE_SENSOR_TEMPERATURE,
210					&temp_st->common_attributes,
211					temperature_sensitivity_addresses,
212					ARRAY_SIZE(temperature_sensitivity_addresses));
213	if (ret)
214		return ret;
215
216	temp_chans = devm_kmemdup(&indio_dev->dev, temperature_channels,
217				sizeof(temperature_channels), GFP_KERNEL);
218	if (!temp_chans)
219		return -ENOMEM;
220
221	ret = temperature_parse_report(pdev, hsdev, temp_chans,
222				HID_USAGE_SENSOR_TEMPERATURE, temp_st);
223	if (ret)
224		return ret;
225
226	indio_dev->channels = temp_chans;
227	indio_dev->num_channels = ARRAY_SIZE(temperature_channels);
228	indio_dev->info = &temperature_info;
229	indio_dev->name = name;
230	indio_dev->modes = INDIO_DIRECT_MODE;
231
232	atomic_set(&temp_st->common_attributes.data_ready, 0);
233
234	ret = hid_sensor_setup_trigger(indio_dev, name,
235				&temp_st->common_attributes);
236	if (ret)
237		return ret;
238
239	platform_set_drvdata(pdev, indio_dev);
240
241	temperature_callbacks.pdev = pdev;
242	ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE,
243					&temperature_callbacks);
244	if (ret)
245		goto error_remove_trigger;
246
247	ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
248	if (ret)
249		goto error_remove_callback;
250
251	return ret;
252
253error_remove_callback:
254	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE);
255error_remove_trigger:
256	hid_sensor_remove_trigger(indio_dev, &temp_st->common_attributes);
257	return ret;
258}
259
260/* Function to deinitialize the processing for usage id */
261static void hid_temperature_remove(struct platform_device *pdev)
262{
263	struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
264	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
265	struct temperature_state *temp_st = iio_priv(indio_dev);
266
267	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE);
268	hid_sensor_remove_trigger(indio_dev, &temp_st->common_attributes);
269}
270
271static const struct platform_device_id hid_temperature_ids[] = {
272	{
273		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
274		.name = "HID-SENSOR-200033",
275	},
276	{ }
277};
278MODULE_DEVICE_TABLE(platform, hid_temperature_ids);
279
280static struct platform_driver hid_temperature_platform_driver = {
281	.id_table = hid_temperature_ids,
282	.driver = {
283		.name	= "temperature-sensor",
284		.pm	= &hid_sensor_pm_ops,
285	},
286	.probe		= hid_temperature_probe,
287	.remove		= hid_temperature_remove,
288};
289module_platform_driver(hid_temperature_platform_driver);
290
291MODULE_DESCRIPTION("HID Environmental temperature sensor");
292MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
293MODULE_LICENSE("GPL v2");
294MODULE_IMPORT_NS("IIO_HID");