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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 "../common/hid-sensors/hid-sensor-trigger.h"
14 
15 struct temperature_state {
16 	struct hid_sensor_common common_attributes;
17 	struct hid_sensor_hub_attribute_info temperature_attr;
18 	struct {
19 		s32 temperature_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 temperature_channels[] = {
30 	{
31 		.type = IIO_TEMP,
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 */
temperature_adjust_channel_bit_mask(struct iio_chan_spec * channels,int channel,int size)42 static void temperature_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 
temperature_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)52 static int temperature_read_raw(struct iio_dev *indio_dev,
53 				struct iio_chan_spec const *chan,
54 				int *val, int *val2, long mask)
55 {
56 	struct temperature_state *temp_st = iio_priv(indio_dev);
57 
58 	switch (mask) {
59 	case IIO_CHAN_INFO_RAW:
60 		if (chan->type != IIO_TEMP)
61 			return -EINVAL;
62 		hid_sensor_power_state(
63 			&temp_st->common_attributes, true);
64 		*val = sensor_hub_input_attr_get_raw_value(
65 			temp_st->common_attributes.hsdev,
66 			HID_USAGE_SENSOR_TEMPERATURE,
67 			HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
68 			temp_st->temperature_attr.report_id,
69 			SENSOR_HUB_SYNC,
70 			temp_st->temperature_attr.logical_minimum < 0);
71 		hid_sensor_power_state(
72 				&temp_st->common_attributes,
73 				false);
74 
75 		return IIO_VAL_INT;
76 
77 	case IIO_CHAN_INFO_SCALE:
78 		*val = temp_st->scale_pre_decml;
79 		*val2 = temp_st->scale_post_decml;
80 		return temp_st->scale_precision;
81 
82 	case IIO_CHAN_INFO_OFFSET:
83 		*val = temp_st->value_offset;
84 		return IIO_VAL_INT;
85 
86 	case IIO_CHAN_INFO_SAMP_FREQ:
87 		return hid_sensor_read_samp_freq_value(
88 				&temp_st->common_attributes, val, val2);
89 
90 	case IIO_CHAN_INFO_HYSTERESIS:
91 		return hid_sensor_read_raw_hyst_value(
92 				&temp_st->common_attributes, val, val2);
93 	default:
94 		return -EINVAL;
95 	}
96 }
97 
temperature_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)98 static int temperature_write_raw(struct iio_dev *indio_dev,
99 				struct iio_chan_spec const *chan,
100 				int val, int val2, long mask)
101 {
102 	struct temperature_state *temp_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 				&temp_st->common_attributes, val, val2);
108 	case IIO_CHAN_INFO_HYSTERESIS:
109 		return hid_sensor_write_raw_hyst_value(
110 				&temp_st->common_attributes, val, val2);
111 	default:
112 		return -EINVAL;
113 	}
114 }
115 
116 static const struct iio_info temperature_info = {
117 	.read_raw = &temperature_read_raw,
118 	.write_raw = &temperature_write_raw,
119 };
120 
121 /* Callback handler to send event after all samples are received and captured */
temperature_proc_event(struct hid_sensor_hub_device * hsdev,unsigned int usage_id,void * pdev)122 static int temperature_proc_event(struct hid_sensor_hub_device *hsdev,
123 				unsigned int usage_id, void *pdev)
124 {
125 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
126 	struct temperature_state *temp_st = iio_priv(indio_dev);
127 
128 	if (atomic_read(&temp_st->common_attributes.data_ready))
129 		iio_push_to_buffers_with_timestamp(indio_dev, &temp_st->scan,
130 						   iio_get_time_ns(indio_dev));
131 
132 	return 0;
133 }
134 
135 /* Capture samples in local storage */
temperature_capture_sample(struct hid_sensor_hub_device * hsdev,unsigned int usage_id,size_t raw_len,char * raw_data,void * pdev)136 static int temperature_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 temperature_state *temp_st = iio_priv(indio_dev);
142 
143 	switch (usage_id) {
144 	case HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE:
145 		temp_st->scan.temperature_data = *(s32 *)raw_data;
146 		return 0;
147 	default:
148 		return -EINVAL;
149 	}
150 }
151 
152 /* Parse report which is specific to an usage id*/
temperature_parse_report(struct platform_device * pdev,struct hid_sensor_hub_device * hsdev,struct iio_chan_spec * channels,unsigned int usage_id,struct temperature_state * st)153 static int temperature_parse_report(struct platform_device *pdev,
154 				struct hid_sensor_hub_device *hsdev,
155 				struct iio_chan_spec *channels,
156 				unsigned int usage_id,
157 				struct temperature_state *st)
158 {
159 	int ret;
160 
161 	ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
162 			usage_id,
163 			HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
164 			&st->temperature_attr);
165 	if (ret < 0)
166 		return ret;
167 
168 	temperature_adjust_channel_bit_mask(channels, 0,
169 					st->temperature_attr.size);
170 
171 	st->scale_precision = hid_sensor_format_scale(
172 				HID_USAGE_SENSOR_TEMPERATURE,
173 				&st->temperature_attr,
174 				&st->scale_pre_decml, &st->scale_post_decml);
175 
176 	/* Set Sensitivity field ids, when there is no individual modifier */
177 	if (st->common_attributes.sensitivity.index < 0)
178 		sensor_hub_input_get_attribute_info(hsdev,
179 			HID_FEATURE_REPORT, usage_id,
180 			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
181 			HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
182 			&st->common_attributes.sensitivity);
183 
184 	return ret;
185 }
186 
187 static struct hid_sensor_hub_callbacks temperature_callbacks = {
188 	.send_event = &temperature_proc_event,
189 	.capture_sample = &temperature_capture_sample,
190 };
191 
192 /* Function to initialize the processing for usage id */
hid_temperature_probe(struct platform_device * pdev)193 static int hid_temperature_probe(struct platform_device *pdev)
194 {
195 	static const char *name = "temperature";
196 	struct iio_dev *indio_dev;
197 	struct temperature_state *temp_st;
198 	struct iio_chan_spec *temp_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(*temp_st));
203 	if (!indio_dev)
204 		return -ENOMEM;
205 
206 	temp_st = iio_priv(indio_dev);
207 	temp_st->common_attributes.hsdev = hsdev;
208 	temp_st->common_attributes.pdev = pdev;
209 
210 	ret = hid_sensor_parse_common_attributes(hsdev,
211 					HID_USAGE_SENSOR_TEMPERATURE,
212 					&temp_st->common_attributes);
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 
253 error_remove_callback:
254 	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE);
255 error_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 */
hid_temperature_remove(struct platform_device * pdev)261 static int 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 	return 0;
271 }
272 
273 static const struct platform_device_id hid_temperature_ids[] = {
274 	{
275 		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
276 		.name = "HID-SENSOR-200033",
277 	},
278 	{ /* sentinel */ }
279 };
280 MODULE_DEVICE_TABLE(platform, hid_temperature_ids);
281 
282 static struct platform_driver hid_temperature_platform_driver = {
283 	.id_table = hid_temperature_ids,
284 	.driver = {
285 		.name	= "temperature-sensor",
286 		.pm	= &hid_sensor_pm_ops,
287 	},
288 	.probe		= hid_temperature_probe,
289 	.remove		= hid_temperature_remove,
290 };
291 module_platform_driver(hid_temperature_platform_driver);
292 
293 MODULE_DESCRIPTION("HID Environmental temperature sensor");
294 MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
295 MODULE_LICENSE("GPL v2");
296