tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 s32 humidity_data;
19 int scale_pre_decml;
20 int scale_post_decml;
21 int scale_precision;
22 int value_offset;
23};
24
25/* Channel definitions */
26static const struct iio_chan_spec humidity_channels[] = {
27 {
28 .type = IIO_HUMIDITYRELATIVE,
29 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
30 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
31 BIT(IIO_CHAN_INFO_SCALE) |
32 BIT(IIO_CHAN_INFO_SAMP_FREQ) |
33 BIT(IIO_CHAN_INFO_HYSTERESIS),
34 },
35 IIO_CHAN_SOFT_TIMESTAMP(1)
36};
37
38/* Adjust channel real bits based on report descriptor */
39static void humidity_adjust_channel_bit_mask(struct iio_chan_spec *channels,
40 int channel, int size)
41{
42 channels[channel].scan_type.sign = 's';
43 /* Real storage bits will change based on the report desc. */
44 channels[channel].scan_type.realbits = size * 8;
45 /* Maximum size of a sample to capture is s32 */
46 channels[channel].scan_type.storagebits = sizeof(s32) * 8;
47}
48
49static int humidity_read_raw(struct iio_dev *indio_dev,
50 struct iio_chan_spec const *chan,
51 int *val, int *val2, long mask)
52{
53 struct hid_humidity_state *humid_st = iio_priv(indio_dev);
54
55 switch (mask) {
56 case IIO_CHAN_INFO_RAW:
57 if (chan->type != IIO_HUMIDITYRELATIVE)
58 return -EINVAL;
59 hid_sensor_power_state(&humid_st->common_attributes, true);
60 *val = sensor_hub_input_attr_get_raw_value(
61 humid_st->common_attributes.hsdev,
62 HID_USAGE_SENSOR_HUMIDITY,
63 HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
64 humid_st->humidity_attr.report_id,
65 SENSOR_HUB_SYNC,
66 humid_st->humidity_attr.logical_minimum < 0);
67 hid_sensor_power_state(&humid_st->common_attributes, false);
68
69 return IIO_VAL_INT;
70
71 case IIO_CHAN_INFO_SCALE:
72 *val = humid_st->scale_pre_decml;
73 *val2 = humid_st->scale_post_decml;
74
75 return humid_st->scale_precision;
76
77 case IIO_CHAN_INFO_OFFSET:
78 *val = humid_st->value_offset;
79
80 return IIO_VAL_INT;
81
82 case IIO_CHAN_INFO_SAMP_FREQ:
83 return hid_sensor_read_samp_freq_value(
84 &humid_st->common_attributes, val, val2);
85
86 case IIO_CHAN_INFO_HYSTERESIS:
87 return hid_sensor_read_raw_hyst_value(
88 &humid_st->common_attributes, val, val2);
89
90 default:
91 return -EINVAL;
92 }
93}
94
95static int humidity_write_raw(struct iio_dev *indio_dev,
96 struct iio_chan_spec const *chan,
97 int val, int val2, long mask)
98{
99 struct hid_humidity_state *humid_st = iio_priv(indio_dev);
100
101 switch (mask) {
102 case IIO_CHAN_INFO_SAMP_FREQ:
103 return hid_sensor_write_samp_freq_value(
104 &humid_st->common_attributes, val, val2);
105
106 case IIO_CHAN_INFO_HYSTERESIS:
107 return hid_sensor_write_raw_hyst_value(
108 &humid_st->common_attributes, val, val2);
109
110 default:
111 return -EINVAL;
112 }
113}
114
115static const struct iio_info humidity_info = {
116 .read_raw = &humidity_read_raw,
117 .write_raw = &humidity_write_raw,
118};
119
120/* Callback handler to send event after all samples are received and captured */
121static int humidity_proc_event(struct hid_sensor_hub_device *hsdev,
122 unsigned int usage_id, void *pdev)
123{
124 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
125 struct hid_humidity_state *humid_st = iio_priv(indio_dev);
126
127 if (atomic_read(&humid_st->common_attributes.data_ready))
128 iio_push_to_buffers_with_timestamp(indio_dev,
129 &humid_st->humidity_data,
130 iio_get_time_ns(indio_dev));
131
132 return 0;
133}
134
135/* Capture samples in local storage */
136static int humidity_capture_sample(struct hid_sensor_hub_device *hsdev,
137 unsigned int usage_id, size_t raw_len,
138 char *raw_data, void *pdev)
139{
140 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
141 struct hid_humidity_state *humid_st = iio_priv(indio_dev);
142
143 switch (usage_id) {
144 case HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY:
145 humid_st->humidity_data = *(s32 *)raw_data;
146
147 return 0;
148 default:
149 return -EINVAL;
150 }
151}
152
153/* Parse report which is specific to an usage id */
154static int humidity_parse_report(struct platform_device *pdev,
155 struct hid_sensor_hub_device *hsdev,
156 struct iio_chan_spec *channels,
157 unsigned int usage_id,
158 struct hid_humidity_state *st)
159{
160 int ret;
161
162 ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
163 usage_id,
164 HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
165 &st->humidity_attr);
166 if (ret < 0)
167 return ret;
168
169 humidity_adjust_channel_bit_mask(channels, 0, st->humidity_attr.size);
170
171 st->scale_precision = hid_sensor_format_scale(
172 HID_USAGE_SENSOR_HUMIDITY,
173 &st->humidity_attr,
174 &st->scale_pre_decml,
175 &st->scale_post_decml);
176
177 /* Set Sensitivity field ids, when there is no individual modifier */
178 if (st->common_attributes.sensitivity.index < 0)
179 sensor_hub_input_get_attribute_info(hsdev,
180 HID_FEATURE_REPORT, usage_id,
181 HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
182 HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
183 &st->common_attributes.sensitivity);
184
185 return ret;
186}
187
188static struct hid_sensor_hub_callbacks humidity_callbacks = {
189 .send_event = &humidity_proc_event,
190 .capture_sample = &humidity_capture_sample,
191};
192
193/* Function to initialize the processing for usage id */
194static int hid_humidity_probe(struct platform_device *pdev)
195{
196 static const char *name = "humidity";
197 struct iio_dev *indio_dev;
198 struct hid_humidity_state *humid_st;
199 struct iio_chan_spec *humid_chans;
200 struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
201 int ret;
202
203 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*humid_st));
204 if (!indio_dev)
205 return -ENOMEM;
206
207 humid_st = iio_priv(indio_dev);
208 humid_st->common_attributes.hsdev = hsdev;
209 humid_st->common_attributes.pdev = pdev;
210
211 ret = hid_sensor_parse_common_attributes(hsdev,
212 HID_USAGE_SENSOR_HUMIDITY,
213 &humid_st->common_attributes);
214 if (ret)
215 return ret;
216
217 humid_chans = devm_kmemdup(&indio_dev->dev, humidity_channels,
218 sizeof(humidity_channels), GFP_KERNEL);
219 if (!humid_chans)
220 return -ENOMEM;
221
222 ret = humidity_parse_report(pdev, hsdev, humid_chans,
223 HID_USAGE_SENSOR_HUMIDITY, humid_st);
224 if (ret)
225 return ret;
226
227 indio_dev->channels = humid_chans;
228 indio_dev->num_channels = ARRAY_SIZE(humidity_channels);
229 indio_dev->dev.parent = &pdev->dev;
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 int 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 return 0;
274}
275
276static const struct platform_device_id hid_humidity_ids[] = {
277 {
278 /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
279 .name = "HID-SENSOR-200032",
280 },
281 { /* sentinel */ }
282};
283MODULE_DEVICE_TABLE(platform, hid_humidity_ids);
284
285static struct platform_driver hid_humidity_platform_driver = {
286 .id_table = hid_humidity_ids,
287 .driver = {
288 .name = KBUILD_MODNAME,
289 .pm = &hid_sensor_pm_ops,
290 },
291 .probe = hid_humidity_probe,
292 .remove = hid_humidity_remove,
293};
294module_platform_driver(hid_humidity_platform_driver);
295
296MODULE_DESCRIPTION("HID Environmental humidity sensor");
297MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
298MODULE_LICENSE("GPL v2");