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 
16 struct 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 		u64 timestamp __aligned(8);
22 	} scan;
23 	int scale_pre_decml;
24 	int scale_post_decml;
25 	int scale_precision;
26 	int value_offset;
27 };
28 
29 static const u32 humidity_sensitivity_addresses[] = {
30 	HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
31 };
32 
33 /* Channel definitions */
34 static 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 */
humidity_adjust_channel_bit_mask(struct iio_chan_spec * channels,int channel,int size)47 static 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 
humidity_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)57 static 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 
humidity_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)103 static 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 
123 static 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 */
humidity_proc_event(struct hid_sensor_hub_device * hsdev,unsigned int usage_id,void * pdev)129 static 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 */
humidity_capture_sample(struct hid_sensor_hub_device * hsdev,unsigned int usage_id,size_t raw_len,char * raw_data,void * pdev)143 static 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 */
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)161 static 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 
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(&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 
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 	{ /* sentinel */ }
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_new	= 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