1 /*
2  * HID Sensors Driver
3  * Copyright (c) 2017, Intel Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program.
16  */
17 #include <linux/device.h>
18 #include <linux/hid-sensor-hub.h>
19 #include <linux/iio/buffer.h>
20 #include <linux/iio/iio.h>
21 #include <linux/iio/triggered_buffer.h>
22 #include <linux/iio/trigger_consumer.h>
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 
26 #include "../common/hid-sensors/hid-sensor-trigger.h"
27 
28 struct temperature_state {
29 	struct hid_sensor_common common_attributes;
30 	struct hid_sensor_hub_attribute_info temperature_attr;
31 	s32 temperature_data;
32 	int scale_pre_decml;
33 	int scale_post_decml;
34 	int scale_precision;
35 	int value_offset;
36 };
37 
38 /* Channel definitions */
39 static const struct iio_chan_spec temperature_channels[] = {
40 	{
41 		.type = IIO_TEMP,
42 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
43 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
44 			BIT(IIO_CHAN_INFO_SCALE) |
45 			BIT(IIO_CHAN_INFO_SAMP_FREQ) |
46 			BIT(IIO_CHAN_INFO_HYSTERESIS),
47 	},
48 	IIO_CHAN_SOFT_TIMESTAMP(3),
49 };
50 
51 /* Adjust channel real bits based on report descriptor */
52 static void temperature_adjust_channel_bit_mask(struct iio_chan_spec *channels,
53 					int channel, int size)
54 {
55 	channels[channel].scan_type.sign = 's';
56 	/* Real storage bits will change based on the report desc. */
57 	channels[channel].scan_type.realbits = size * 8;
58 	/* Maximum size of a sample to capture is s32 */
59 	channels[channel].scan_type.storagebits = sizeof(s32) * 8;
60 }
61 
62 static int temperature_read_raw(struct iio_dev *indio_dev,
63 				struct iio_chan_spec const *chan,
64 				int *val, int *val2, long mask)
65 {
66 	struct temperature_state *temp_st = iio_priv(indio_dev);
67 
68 	switch (mask) {
69 	case IIO_CHAN_INFO_RAW:
70 		if (chan->type != IIO_TEMP)
71 			return -EINVAL;
72 		hid_sensor_power_state(
73 			&temp_st->common_attributes, true);
74 		*val = sensor_hub_input_attr_get_raw_value(
75 			temp_st->common_attributes.hsdev,
76 			HID_USAGE_SENSOR_TEMPERATURE,
77 			HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
78 			temp_st->temperature_attr.report_id,
79 			SENSOR_HUB_SYNC);
80 		hid_sensor_power_state(
81 				&temp_st->common_attributes,
82 				false);
83 
84 		return IIO_VAL_INT;
85 
86 	case IIO_CHAN_INFO_SCALE:
87 		*val = temp_st->scale_pre_decml;
88 		*val2 = temp_st->scale_post_decml;
89 		return temp_st->scale_precision;
90 
91 	case IIO_CHAN_INFO_OFFSET:
92 		*val = temp_st->value_offset;
93 		return IIO_VAL_INT;
94 
95 	case IIO_CHAN_INFO_SAMP_FREQ:
96 		return hid_sensor_read_samp_freq_value(
97 				&temp_st->common_attributes, val, val2);
98 
99 	case IIO_CHAN_INFO_HYSTERESIS:
100 		return hid_sensor_read_raw_hyst_value(
101 				&temp_st->common_attributes, val, val2);
102 	default:
103 		return -EINVAL;
104 	}
105 }
106 
107 static int temperature_write_raw(struct iio_dev *indio_dev,
108 				struct iio_chan_spec const *chan,
109 				int val, int val2, long mask)
110 {
111 	struct temperature_state *temp_st = iio_priv(indio_dev);
112 
113 	switch (mask) {
114 	case IIO_CHAN_INFO_SAMP_FREQ:
115 		return hid_sensor_write_samp_freq_value(
116 				&temp_st->common_attributes, val, val2);
117 	case IIO_CHAN_INFO_HYSTERESIS:
118 		return hid_sensor_write_raw_hyst_value(
119 				&temp_st->common_attributes, val, val2);
120 	default:
121 		return -EINVAL;
122 	}
123 }
124 
125 static const struct iio_info temperature_info = {
126 	.driver_module = THIS_MODULE,
127 	.read_raw = &temperature_read_raw,
128 	.write_raw = &temperature_write_raw,
129 };
130 
131 /* Callback handler to send event after all samples are received and captured */
132 static int temperature_proc_event(struct hid_sensor_hub_device *hsdev,
133 				unsigned int usage_id, void *pdev)
134 {
135 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
136 	struct temperature_state *temp_st = iio_priv(indio_dev);
137 
138 	if (atomic_read(&temp_st->common_attributes.data_ready))
139 		iio_push_to_buffers_with_timestamp(indio_dev,
140 				&temp_st->temperature_data,
141 				iio_get_time_ns(indio_dev));
142 
143 	return 0;
144 }
145 
146 /* Capture samples in local storage */
147 static int temperature_capture_sample(struct hid_sensor_hub_device *hsdev,
148 				unsigned int usage_id, size_t raw_len,
149 				char *raw_data, void *pdev)
150 {
151 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
152 	struct temperature_state *temp_st = iio_priv(indio_dev);
153 
154 	switch (usage_id) {
155 	case HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE:
156 		temp_st->temperature_data = *(s32 *)raw_data;
157 		return 0;
158 	default:
159 		return -EINVAL;
160 	}
161 }
162 
163 /* Parse report which is specific to an usage id*/
164 static int temperature_parse_report(struct platform_device *pdev,
165 				struct hid_sensor_hub_device *hsdev,
166 				struct iio_chan_spec *channels,
167 				unsigned int usage_id,
168 				struct temperature_state *st)
169 {
170 	int ret;
171 
172 	ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
173 			usage_id,
174 			HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
175 			&st->temperature_attr);
176 	if (ret < 0)
177 		return ret;
178 
179 	temperature_adjust_channel_bit_mask(channels, 0,
180 					st->temperature_attr.size);
181 
182 	st->scale_precision = hid_sensor_format_scale(
183 				HID_USAGE_SENSOR_TEMPERATURE,
184 				&st->temperature_attr,
185 				&st->scale_pre_decml, &st->scale_post_decml);
186 
187 	/* Set Sensitivity field ids, when there is no individual modifier */
188 	if (st->common_attributes.sensitivity.index < 0)
189 		sensor_hub_input_get_attribute_info(hsdev,
190 			HID_FEATURE_REPORT, usage_id,
191 			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
192 			HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
193 			&st->common_attributes.sensitivity);
194 
195 	return ret;
196 }
197 
198 static struct hid_sensor_hub_callbacks temperature_callbacks = {
199 	.send_event = &temperature_proc_event,
200 	.capture_sample = &temperature_capture_sample,
201 };
202 
203 /* Function to initialize the processing for usage id */
204 static int hid_temperature_probe(struct platform_device *pdev)
205 {
206 	static const char *name = "temperature";
207 	struct iio_dev *indio_dev;
208 	struct temperature_state *temp_st;
209 	struct iio_chan_spec *temp_chans;
210 	struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
211 	int ret;
212 
213 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*temp_st));
214 	if (!indio_dev)
215 		return -ENOMEM;
216 
217 	temp_st = iio_priv(indio_dev);
218 	temp_st->common_attributes.hsdev = hsdev;
219 	temp_st->common_attributes.pdev = pdev;
220 
221 	ret = hid_sensor_parse_common_attributes(hsdev,
222 					HID_USAGE_SENSOR_TEMPERATURE,
223 					&temp_st->common_attributes);
224 	if (ret)
225 		return ret;
226 
227 	temp_chans = devm_kmemdup(&indio_dev->dev, temperature_channels,
228 				sizeof(temperature_channels), GFP_KERNEL);
229 	if (!temp_chans)
230 		return -ENOMEM;
231 
232 	ret = temperature_parse_report(pdev, hsdev, temp_chans,
233 				HID_USAGE_SENSOR_TEMPERATURE, temp_st);
234 	if (ret)
235 		return ret;
236 
237 	indio_dev->channels = temp_chans;
238 	indio_dev->num_channels = ARRAY_SIZE(temperature_channels);
239 	indio_dev->dev.parent = &pdev->dev;
240 	indio_dev->info = &temperature_info;
241 	indio_dev->name = name;
242 	indio_dev->modes = INDIO_DIRECT_MODE;
243 
244 	ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev,
245 					&iio_pollfunc_store_time, NULL, NULL);
246 	if (ret)
247 		return ret;
248 
249 	atomic_set(&temp_st->common_attributes.data_ready, 0);
250 	ret = hid_sensor_setup_trigger(indio_dev, name,
251 				&temp_st->common_attributes);
252 	if (ret)
253 		return ret;
254 
255 	platform_set_drvdata(pdev, indio_dev);
256 
257 	temperature_callbacks.pdev = pdev;
258 	ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE,
259 					&temperature_callbacks);
260 	if (ret)
261 		goto error_remove_trigger;
262 
263 	ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
264 	if (ret)
265 		goto error_remove_callback;
266 
267 	return ret;
268 
269 error_remove_callback:
270 	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE);
271 error_remove_trigger:
272 	hid_sensor_remove_trigger(&temp_st->common_attributes);
273 	return ret;
274 }
275 
276 /* Function to deinitialize the processing for usage id */
277 static int hid_temperature_remove(struct platform_device *pdev)
278 {
279 	struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
280 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
281 	struct temperature_state *temp_st = iio_priv(indio_dev);
282 
283 	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE);
284 	hid_sensor_remove_trigger(&temp_st->common_attributes);
285 
286 	return 0;
287 }
288 
289 static const struct platform_device_id hid_temperature_ids[] = {
290 	{
291 		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
292 		.name = "HID-SENSOR-200033",
293 	},
294 	{ /* sentinel */ }
295 };
296 MODULE_DEVICE_TABLE(platform, hid_temperature_ids);
297 
298 static struct platform_driver hid_temperature_platform_driver = {
299 	.id_table = hid_temperature_ids,
300 	.driver = {
301 		.name	= "temperature-sensor",
302 		.pm	= &hid_sensor_pm_ops,
303 	},
304 	.probe		= hid_temperature_probe,
305 	.remove		= hid_temperature_remove,
306 };
307 module_platform_driver(hid_temperature_platform_driver);
308 
309 MODULE_DESCRIPTION("HID Environmental temperature sensor");
310 MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>");
311 MODULE_LICENSE("GPL v2");
312