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
15 struct 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 */
29 static 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 */
humidity_adjust_channel_bit_mask(struct iio_chan_spec *channels, int channel, int size)42 static 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
humidity_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask)52 static 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
humidity_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask)98 static 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
118 static 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 */
humidity_proc_event(struct hid_sensor_hub_device *hsdev, unsigned int usage_id, void *pdev)124 static 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 */
humidity_capture_sample(struct hid_sensor_hub_device *hsdev, unsigned int usage_id, size_t raw_len, char *raw_data, void *pdev)138 static 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 */
humidity_parse_report(struct platform_device *pdev, struct hid_sensor_hub_device *hsdev, struct iio_chan_spec *channels, unsigned int usage_id, struct hid_humidity_state *st)156 static 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
190 static 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 */
hid_humidity_probe(struct platform_device *pdev)196 static 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
256 error_remove_callback:
257 sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
258 error_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 */
hid_humidity_remove(struct platform_device *pdev)264 static 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
277 static 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 };
284 MODULE_DEVICE_TABLE(platform, hid_humidity_ids);
285
286 static 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 };
295 module_platform_driver(hid_humidity_platform_driver);
296
297 MODULE_DESCRIPTION("HID Environmental humidity sensor");
298 MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
299 MODULE_LICENSE("GPL v2");
300