xref: /openbmc/linux/drivers/iio/pressure/hid-sensor-press.c (revision 0e41fd515f94dcfcc24b6e510d29528431e46f60)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * HID Sensors Driver
4  * Copyright (c) 2014, Intel Corporation.
5  */
6 #include <linux/device.h>
7 #include <linux/platform_device.h>
8 #include <linux/module.h>
9 #include <linux/interrupt.h>
10 #include <linux/irq.h>
11 #include <linux/slab.h>
12 #include <linux/delay.h>
13 #include <linux/hid-sensor-hub.h>
14 #include <linux/iio/iio.h>
15 #include <linux/iio/sysfs.h>
16 #include <linux/iio/buffer.h>
17 #include "../common/hid-sensors/hid-sensor-trigger.h"
18 
19 #define CHANNEL_SCAN_INDEX_PRESSURE 0
20 
21 struct press_state {
22 	struct hid_sensor_hub_callbacks callbacks;
23 	struct hid_sensor_common common_attributes;
24 	struct hid_sensor_hub_attribute_info press_attr;
25 	u32 press_data;
26 	int scale_pre_decml;
27 	int scale_post_decml;
28 	int scale_precision;
29 	int value_offset;
30 };
31 
32 static const u32 press_sensitivity_addresses[] = {
33 	HID_USAGE_SENSOR_DATA_ATMOSPHERIC_PRESSURE,
34 };
35 
36 /* Channel definitions */
37 static const struct iio_chan_spec press_channels[] = {
38 	{
39 		.type = IIO_PRESSURE,
40 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
41 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
42 		BIT(IIO_CHAN_INFO_SCALE) |
43 		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
44 		BIT(IIO_CHAN_INFO_HYSTERESIS),
45 		.scan_index = CHANNEL_SCAN_INDEX_PRESSURE,
46 	}
47 };
48 
49 /* Adjust channel real bits based on report descriptor */
50 static void press_adjust_channel_bit_mask(struct iio_chan_spec *channels,
51 					int channel, int size)
52 {
53 	channels[channel].scan_type.sign = 's';
54 	/* Real storage bits will change based on the report desc. */
55 	channels[channel].scan_type.realbits = size * 8;
56 	/* Maximum size of a sample to capture is u32 */
57 	channels[channel].scan_type.storagebits = sizeof(u32) * 8;
58 }
59 
60 /* Channel read_raw handler */
61 static int press_read_raw(struct iio_dev *indio_dev,
62 			      struct iio_chan_spec const *chan,
63 			      int *val, int *val2,
64 			      long mask)
65 {
66 	struct press_state *press_state = iio_priv(indio_dev);
67 	int report_id = -1;
68 	u32 address;
69 	int ret_type;
70 	s32 min;
71 
72 	*val = 0;
73 	*val2 = 0;
74 	switch (mask) {
75 	case IIO_CHAN_INFO_RAW:
76 		switch (chan->scan_index) {
77 		case  CHANNEL_SCAN_INDEX_PRESSURE:
78 			report_id = press_state->press_attr.report_id;
79 			min = press_state->press_attr.logical_minimum;
80 			address = HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE;
81 			break;
82 		default:
83 			report_id = -1;
84 			break;
85 		}
86 		if (report_id >= 0) {
87 			hid_sensor_power_state(&press_state->common_attributes,
88 						true);
89 			*val = sensor_hub_input_attr_get_raw_value(
90 				press_state->common_attributes.hsdev,
91 				HID_USAGE_SENSOR_PRESSURE, address,
92 				report_id,
93 				SENSOR_HUB_SYNC,
94 				min < 0);
95 			hid_sensor_power_state(&press_state->common_attributes,
96 						false);
97 		} else {
98 			*val = 0;
99 			return -EINVAL;
100 		}
101 		ret_type = IIO_VAL_INT;
102 		break;
103 	case IIO_CHAN_INFO_SCALE:
104 		*val = press_state->scale_pre_decml;
105 		*val2 = press_state->scale_post_decml;
106 		ret_type = press_state->scale_precision;
107 		break;
108 	case IIO_CHAN_INFO_OFFSET:
109 		*val = press_state->value_offset;
110 		ret_type = IIO_VAL_INT;
111 		break;
112 	case IIO_CHAN_INFO_SAMP_FREQ:
113 		ret_type = hid_sensor_read_samp_freq_value(
114 				&press_state->common_attributes, val, val2);
115 		break;
116 	case IIO_CHAN_INFO_HYSTERESIS:
117 		ret_type = hid_sensor_read_raw_hyst_value(
118 				&press_state->common_attributes, val, val2);
119 		break;
120 	default:
121 		ret_type = -EINVAL;
122 		break;
123 	}
124 
125 	return ret_type;
126 }
127 
128 /* Channel write_raw handler */
129 static int press_write_raw(struct iio_dev *indio_dev,
130 			       struct iio_chan_spec const *chan,
131 			       int val,
132 			       int val2,
133 			       long mask)
134 {
135 	struct press_state *press_state = iio_priv(indio_dev);
136 	int ret = 0;
137 
138 	switch (mask) {
139 	case IIO_CHAN_INFO_SAMP_FREQ:
140 		ret = hid_sensor_write_samp_freq_value(
141 				&press_state->common_attributes, val, val2);
142 		break;
143 	case IIO_CHAN_INFO_HYSTERESIS:
144 		ret = hid_sensor_write_raw_hyst_value(
145 				&press_state->common_attributes, val, val2);
146 		break;
147 	default:
148 		ret = -EINVAL;
149 	}
150 
151 	return ret;
152 }
153 
154 static const struct iio_info press_info = {
155 	.read_raw = &press_read_raw,
156 	.write_raw = &press_write_raw,
157 };
158 
159 /* Function to push data to buffer */
160 static void hid_sensor_push_data(struct iio_dev *indio_dev, const void *data,
161 					int len)
162 {
163 	dev_dbg(&indio_dev->dev, "hid_sensor_push_data\n");
164 	iio_push_to_buffers(indio_dev, data);
165 }
166 
167 /* Callback handler to send event after all samples are received and captured */
168 static int press_proc_event(struct hid_sensor_hub_device *hsdev,
169 				unsigned usage_id,
170 				void *priv)
171 {
172 	struct iio_dev *indio_dev = platform_get_drvdata(priv);
173 	struct press_state *press_state = iio_priv(indio_dev);
174 
175 	dev_dbg(&indio_dev->dev, "press_proc_event\n");
176 	if (atomic_read(&press_state->common_attributes.data_ready))
177 		hid_sensor_push_data(indio_dev,
178 				&press_state->press_data,
179 				sizeof(press_state->press_data));
180 
181 	return 0;
182 }
183 
184 /* Capture samples in local storage */
185 static int press_capture_sample(struct hid_sensor_hub_device *hsdev,
186 				unsigned usage_id,
187 				size_t raw_len, char *raw_data,
188 				void *priv)
189 {
190 	struct iio_dev *indio_dev = platform_get_drvdata(priv);
191 	struct press_state *press_state = iio_priv(indio_dev);
192 	int ret = -EINVAL;
193 
194 	switch (usage_id) {
195 	case HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE:
196 		press_state->press_data = *(u32 *)raw_data;
197 		ret = 0;
198 		break;
199 	default:
200 		break;
201 	}
202 
203 	return ret;
204 }
205 
206 /* Parse report which is specific to an usage id*/
207 static int press_parse_report(struct platform_device *pdev,
208 				struct hid_sensor_hub_device *hsdev,
209 				struct iio_chan_spec *channels,
210 				unsigned usage_id,
211 				struct press_state *st)
212 {
213 	int ret;
214 
215 	ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
216 			usage_id,
217 			HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE,
218 			&st->press_attr);
219 	if (ret < 0)
220 		return ret;
221 	press_adjust_channel_bit_mask(channels, CHANNEL_SCAN_INDEX_PRESSURE,
222 					st->press_attr.size);
223 
224 	dev_dbg(&pdev->dev, "press %x:%x\n", st->press_attr.index,
225 			st->press_attr.report_id);
226 
227 	st->scale_precision = hid_sensor_format_scale(
228 				HID_USAGE_SENSOR_PRESSURE,
229 				&st->press_attr,
230 				&st->scale_pre_decml, &st->scale_post_decml);
231 
232 	return ret;
233 }
234 
235 /* Function to initialize the processing for usage id */
236 static int hid_press_probe(struct platform_device *pdev)
237 {
238 	int ret = 0;
239 	static const char *name = "press";
240 	struct iio_dev *indio_dev;
241 	struct press_state *press_state;
242 	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
243 
244 	indio_dev = devm_iio_device_alloc(&pdev->dev,
245 				sizeof(struct press_state));
246 	if (!indio_dev)
247 		return -ENOMEM;
248 	platform_set_drvdata(pdev, indio_dev);
249 
250 	press_state = iio_priv(indio_dev);
251 	press_state->common_attributes.hsdev = hsdev;
252 	press_state->common_attributes.pdev = pdev;
253 
254 	ret = hid_sensor_parse_common_attributes(hsdev,
255 					HID_USAGE_SENSOR_PRESSURE,
256 					&press_state->common_attributes,
257 					press_sensitivity_addresses,
258 					ARRAY_SIZE(press_sensitivity_addresses));
259 	if (ret) {
260 		dev_err(&pdev->dev, "failed to setup common attributes\n");
261 		return ret;
262 	}
263 
264 	indio_dev->channels = kmemdup(press_channels, sizeof(press_channels),
265 				      GFP_KERNEL);
266 	if (!indio_dev->channels) {
267 		dev_err(&pdev->dev, "failed to duplicate channels\n");
268 		return -ENOMEM;
269 	}
270 
271 	ret = press_parse_report(pdev, hsdev,
272 				 (struct iio_chan_spec *)indio_dev->channels,
273 				 HID_USAGE_SENSOR_PRESSURE, press_state);
274 	if (ret) {
275 		dev_err(&pdev->dev, "failed to setup attributes\n");
276 		goto error_free_dev_mem;
277 	}
278 
279 	indio_dev->num_channels =
280 				ARRAY_SIZE(press_channels);
281 	indio_dev->info = &press_info;
282 	indio_dev->name = name;
283 	indio_dev->modes = INDIO_DIRECT_MODE;
284 
285 	atomic_set(&press_state->common_attributes.data_ready, 0);
286 
287 	ret = hid_sensor_setup_trigger(indio_dev, name,
288 				&press_state->common_attributes);
289 	if (ret) {
290 		dev_err(&pdev->dev, "trigger setup failed\n");
291 		goto error_free_dev_mem;
292 	}
293 
294 	ret = iio_device_register(indio_dev);
295 	if (ret) {
296 		dev_err(&pdev->dev, "device register failed\n");
297 		goto error_remove_trigger;
298 	}
299 
300 	press_state->callbacks.send_event = press_proc_event;
301 	press_state->callbacks.capture_sample = press_capture_sample;
302 	press_state->callbacks.pdev = pdev;
303 	ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_PRESSURE,
304 					&press_state->callbacks);
305 	if (ret < 0) {
306 		dev_err(&pdev->dev, "callback reg failed\n");
307 		goto error_iio_unreg;
308 	}
309 
310 	return ret;
311 
312 error_iio_unreg:
313 	iio_device_unregister(indio_dev);
314 error_remove_trigger:
315 	hid_sensor_remove_trigger(indio_dev, &press_state->common_attributes);
316 error_free_dev_mem:
317 	kfree(indio_dev->channels);
318 	return ret;
319 }
320 
321 /* Function to deinitialize the processing for usage id */
322 static int hid_press_remove(struct platform_device *pdev)
323 {
324 	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
325 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
326 	struct press_state *press_state = iio_priv(indio_dev);
327 
328 	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_PRESSURE);
329 	iio_device_unregister(indio_dev);
330 	hid_sensor_remove_trigger(indio_dev, &press_state->common_attributes);
331 	kfree(indio_dev->channels);
332 
333 	return 0;
334 }
335 
336 static const struct platform_device_id hid_press_ids[] = {
337 	{
338 		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
339 		.name = "HID-SENSOR-200031",
340 	},
341 	{ /* sentinel */ }
342 };
343 MODULE_DEVICE_TABLE(platform, hid_press_ids);
344 
345 static struct platform_driver hid_press_platform_driver = {
346 	.id_table = hid_press_ids,
347 	.driver = {
348 		.name	= KBUILD_MODNAME,
349 		.pm	= &hid_sensor_pm_ops,
350 	},
351 	.probe		= hid_press_probe,
352 	.remove		= hid_press_remove,
353 };
354 module_platform_driver(hid_press_platform_driver);
355 
356 MODULE_DESCRIPTION("HID Sensor Pressure");
357 MODULE_AUTHOR("Archana Patni <archana.patni@intel.com>");
358 MODULE_LICENSE("GPL");
359