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 aligned_s64 timestamp;
21 } scan;
22 int scale_pre_decml;
23 int scale_post_decml;
24 int scale_precision;
25 int value_offset;
26 };
27
28 static const u32 humidity_sensitivity_addresses[] = {
29 HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
30 };
31
32 /* Channel definitions */
33 static const struct iio_chan_spec humidity_channels[] = {
34 {
35 .type = IIO_HUMIDITYRELATIVE,
36 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
37 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
38 BIT(IIO_CHAN_INFO_SCALE) |
39 BIT(IIO_CHAN_INFO_SAMP_FREQ) |
40 BIT(IIO_CHAN_INFO_HYSTERESIS),
41 },
42 IIO_CHAN_SOFT_TIMESTAMP(1)
43 };
44
45 /* Adjust channel real bits based on report descriptor */
humidity_adjust_channel_bit_mask(struct iio_chan_spec * channels,int channel,int size)46 static void humidity_adjust_channel_bit_mask(struct iio_chan_spec *channels,
47 int channel, int size)
48 {
49 channels[channel].scan_type.sign = 's';
50 /* Real storage bits will change based on the report desc. */
51 channels[channel].scan_type.realbits = size * 8;
52 /* Maximum size of a sample to capture is s32 */
53 channels[channel].scan_type.storagebits = sizeof(s32) * 8;
54 }
55
humidity_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)56 static int humidity_read_raw(struct iio_dev *indio_dev,
57 struct iio_chan_spec const *chan,
58 int *val, int *val2, long mask)
59 {
60 struct hid_humidity_state *humid_st = iio_priv(indio_dev);
61
62 switch (mask) {
63 case IIO_CHAN_INFO_RAW:
64 if (chan->type != IIO_HUMIDITYRELATIVE)
65 return -EINVAL;
66 hid_sensor_power_state(&humid_st->common_attributes, true);
67 *val = sensor_hub_input_attr_get_raw_value(
68 humid_st->common_attributes.hsdev,
69 HID_USAGE_SENSOR_HUMIDITY,
70 HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
71 humid_st->humidity_attr.report_id,
72 SENSOR_HUB_SYNC,
73 humid_st->humidity_attr.logical_minimum < 0);
74 hid_sensor_power_state(&humid_st->common_attributes, false);
75
76 return IIO_VAL_INT;
77
78 case IIO_CHAN_INFO_SCALE:
79 *val = humid_st->scale_pre_decml;
80 *val2 = humid_st->scale_post_decml;
81
82 return humid_st->scale_precision;
83
84 case IIO_CHAN_INFO_OFFSET:
85 *val = humid_st->value_offset;
86
87 return IIO_VAL_INT;
88
89 case IIO_CHAN_INFO_SAMP_FREQ:
90 return hid_sensor_read_samp_freq_value(
91 &humid_st->common_attributes, val, val2);
92
93 case IIO_CHAN_INFO_HYSTERESIS:
94 return hid_sensor_read_raw_hyst_value(
95 &humid_st->common_attributes, val, val2);
96
97 default:
98 return -EINVAL;
99 }
100 }
101
humidity_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)102 static int humidity_write_raw(struct iio_dev *indio_dev,
103 struct iio_chan_spec const *chan,
104 int val, int val2, long mask)
105 {
106 struct hid_humidity_state *humid_st = iio_priv(indio_dev);
107
108 switch (mask) {
109 case IIO_CHAN_INFO_SAMP_FREQ:
110 return hid_sensor_write_samp_freq_value(
111 &humid_st->common_attributes, val, val2);
112
113 case IIO_CHAN_INFO_HYSTERESIS:
114 return hid_sensor_write_raw_hyst_value(
115 &humid_st->common_attributes, val, val2);
116
117 default:
118 return -EINVAL;
119 }
120 }
121
122 static const struct iio_info humidity_info = {
123 .read_raw = &humidity_read_raw,
124 .write_raw = &humidity_write_raw,
125 };
126
127 /* Callback handler to send event after all samples are received and captured */
humidity_proc_event(struct hid_sensor_hub_device * hsdev,u32 usage_id,void * pdev)128 static int humidity_proc_event(struct hid_sensor_hub_device *hsdev,
129 u32 usage_id, void *pdev)
130 {
131 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
132 struct hid_humidity_state *humid_st = iio_priv(indio_dev);
133
134 if (atomic_read(&humid_st->common_attributes.data_ready))
135 iio_push_to_buffers_with_timestamp(indio_dev, &humid_st->scan,
136 iio_get_time_ns(indio_dev));
137
138 return 0;
139 }
140
141 /* Capture samples in local storage */
humidity_capture_sample(struct hid_sensor_hub_device * hsdev,u32 usage_id,size_t raw_len,char * raw_data,void * pdev)142 static int humidity_capture_sample(struct hid_sensor_hub_device *hsdev,
143 u32 usage_id,
144 size_t raw_len, char *raw_data,
145 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 */
humidity_parse_report(struct platform_device * pdev,struct hid_sensor_hub_device * hsdev,struct iio_chan_spec * channels,u32 usage_id,struct hid_humidity_state * st)161 static int humidity_parse_report(struct platform_device *pdev,
162 struct hid_sensor_hub_device *hsdev,
163 struct iio_chan_spec *channels,
164 u32 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
187 static 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 */
hid_humidity_probe(struct platform_device * pdev)193 static 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(&pdev->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
255 error_remove_callback:
256 sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY);
257 error_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 */
hid_humidity_remove(struct platform_device * pdev)263 static 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
274 static 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 };
281 MODULE_DEVICE_TABLE(platform, hid_humidity_ids);
282
283 static 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 };
292 module_platform_driver(hid_humidity_platform_driver);
293
294 MODULE_DESCRIPTION("HID Environmental humidity sensor");
295 MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
296 MODULE_LICENSE("GPL v2");
297 MODULE_IMPORT_NS("IIO_HID");
298