1 /*
2  * HID Sensors Driver
3  * Copyright (c) 2014, 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  */
18 #include <linux/device.h>
19 #include <linux/platform_device.h>
20 #include <linux/module.h>
21 #include <linux/interrupt.h>
22 #include <linux/irq.h>
23 #include <linux/slab.h>
24 #include <linux/delay.h>
25 #include <linux/hid-sensor-hub.h>
26 #include <linux/iio/iio.h>
27 #include <linux/iio/sysfs.h>
28 #include <linux/iio/buffer.h>
29 #include <linux/iio/trigger_consumer.h>
30 #include <linux/iio/triggered_buffer.h>
31 #include "../common/hid-sensors/hid-sensor-trigger.h"
32 
33 #define CHANNEL_SCAN_INDEX_PRESSURE 0
34 
35 struct press_state {
36 	struct hid_sensor_hub_callbacks callbacks;
37 	struct hid_sensor_common common_attributes;
38 	struct hid_sensor_hub_attribute_info press_attr;
39 	u32 press_data;
40 	int scale_pre_decml;
41 	int scale_post_decml;
42 	int scale_precision;
43 	int value_offset;
44 };
45 
46 /* Channel definitions */
47 static const struct iio_chan_spec press_channels[] = {
48 	{
49 		.type = IIO_PRESSURE,
50 		.modified = 1,
51 		.channel2 = IIO_NO_MOD,
52 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
53 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
54 		BIT(IIO_CHAN_INFO_SCALE) |
55 		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
56 		BIT(IIO_CHAN_INFO_HYSTERESIS),
57 		.scan_index = CHANNEL_SCAN_INDEX_PRESSURE,
58 	}
59 };
60 
61 /* Adjust channel real bits based on report descriptor */
62 static void press_adjust_channel_bit_mask(struct iio_chan_spec *channels,
63 					int channel, int size)
64 {
65 	channels[channel].scan_type.sign = 's';
66 	/* Real storage bits will change based on the report desc. */
67 	channels[channel].scan_type.realbits = size * 8;
68 	/* Maximum size of a sample to capture is u32 */
69 	channels[channel].scan_type.storagebits = sizeof(u32) * 8;
70 }
71 
72 /* Channel read_raw handler */
73 static int press_read_raw(struct iio_dev *indio_dev,
74 			      struct iio_chan_spec const *chan,
75 			      int *val, int *val2,
76 			      long mask)
77 {
78 	struct press_state *press_state = iio_priv(indio_dev);
79 	int report_id = -1;
80 	u32 address;
81 	int ret;
82 	int ret_type;
83 	s32 poll_value;
84 
85 	*val = 0;
86 	*val2 = 0;
87 	switch (mask) {
88 	case IIO_CHAN_INFO_RAW:
89 		switch (chan->scan_index) {
90 		case  CHANNEL_SCAN_INDEX_PRESSURE:
91 			report_id = press_state->press_attr.report_id;
92 			address =
93 			HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE;
94 			break;
95 		default:
96 			report_id = -1;
97 			break;
98 		}
99 		if (report_id >= 0) {
100 			poll_value = hid_sensor_read_poll_value(
101 					&press_state->common_attributes);
102 			if (poll_value < 0)
103 				return -EINVAL;
104 			hid_sensor_power_state(&press_state->common_attributes,
105 						true);
106 
107 			msleep_interruptible(poll_value * 2);
108 
109 			*val = sensor_hub_input_attr_get_raw_value(
110 				press_state->common_attributes.hsdev,
111 				HID_USAGE_SENSOR_PRESSURE, address,
112 				report_id);
113 			hid_sensor_power_state(&press_state->common_attributes,
114 						false);
115 		} else {
116 			*val = 0;
117 			return -EINVAL;
118 		}
119 		ret_type = IIO_VAL_INT;
120 		break;
121 	case IIO_CHAN_INFO_SCALE:
122 		*val = press_state->scale_pre_decml;
123 		*val2 = press_state->scale_post_decml;
124 		ret_type = press_state->scale_precision;
125 		break;
126 	case IIO_CHAN_INFO_OFFSET:
127 		*val = press_state->value_offset;
128 		ret_type = IIO_VAL_INT;
129 		break;
130 	case IIO_CHAN_INFO_SAMP_FREQ:
131 		ret = hid_sensor_read_samp_freq_value(
132 				&press_state->common_attributes, val, val2);
133 		ret_type = IIO_VAL_INT_PLUS_MICRO;
134 		break;
135 	case IIO_CHAN_INFO_HYSTERESIS:
136 		ret = hid_sensor_read_raw_hyst_value(
137 				&press_state->common_attributes, val, val2);
138 		ret_type = IIO_VAL_INT_PLUS_MICRO;
139 		break;
140 	default:
141 		ret_type = -EINVAL;
142 		break;
143 	}
144 
145 	return ret_type;
146 }
147 
148 /* Channel write_raw handler */
149 static int press_write_raw(struct iio_dev *indio_dev,
150 			       struct iio_chan_spec const *chan,
151 			       int val,
152 			       int val2,
153 			       long mask)
154 {
155 	struct press_state *press_state = iio_priv(indio_dev);
156 	int ret = 0;
157 
158 	switch (mask) {
159 	case IIO_CHAN_INFO_SAMP_FREQ:
160 		ret = hid_sensor_write_samp_freq_value(
161 				&press_state->common_attributes, val, val2);
162 		break;
163 	case IIO_CHAN_INFO_HYSTERESIS:
164 		ret = hid_sensor_write_raw_hyst_value(
165 				&press_state->common_attributes, val, val2);
166 		break;
167 	default:
168 		ret = -EINVAL;
169 	}
170 
171 	return ret;
172 }
173 
174 static const struct iio_info press_info = {
175 	.driver_module = THIS_MODULE,
176 	.read_raw = &press_read_raw,
177 	.write_raw = &press_write_raw,
178 };
179 
180 /* Function to push data to buffer */
181 static void hid_sensor_push_data(struct iio_dev *indio_dev, const void *data,
182 					int len)
183 {
184 	dev_dbg(&indio_dev->dev, "hid_sensor_push_data\n");
185 	iio_push_to_buffers(indio_dev, data);
186 }
187 
188 /* Callback handler to send event after all samples are received and captured */
189 static int press_proc_event(struct hid_sensor_hub_device *hsdev,
190 				unsigned usage_id,
191 				void *priv)
192 {
193 	struct iio_dev *indio_dev = platform_get_drvdata(priv);
194 	struct press_state *press_state = iio_priv(indio_dev);
195 
196 	dev_dbg(&indio_dev->dev, "press_proc_event\n");
197 	if (atomic_read(&press_state->common_attributes.data_ready))
198 		hid_sensor_push_data(indio_dev,
199 				&press_state->press_data,
200 				sizeof(press_state->press_data));
201 
202 	return 0;
203 }
204 
205 /* Capture samples in local storage */
206 static int press_capture_sample(struct hid_sensor_hub_device *hsdev,
207 				unsigned usage_id,
208 				size_t raw_len, char *raw_data,
209 				void *priv)
210 {
211 	struct iio_dev *indio_dev = platform_get_drvdata(priv);
212 	struct press_state *press_state = iio_priv(indio_dev);
213 	int ret = -EINVAL;
214 
215 	switch (usage_id) {
216 	case HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE:
217 		press_state->press_data = *(u32 *)raw_data;
218 		ret = 0;
219 		break;
220 	default:
221 		break;
222 	}
223 
224 	return ret;
225 }
226 
227 /* Parse report which is specific to an usage id*/
228 static int press_parse_report(struct platform_device *pdev,
229 				struct hid_sensor_hub_device *hsdev,
230 				struct iio_chan_spec *channels,
231 				unsigned usage_id,
232 				struct press_state *st)
233 {
234 	int ret;
235 
236 	ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
237 			usage_id,
238 			HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE,
239 			&st->press_attr);
240 	if (ret < 0)
241 		return ret;
242 	press_adjust_channel_bit_mask(channels, CHANNEL_SCAN_INDEX_PRESSURE,
243 					st->press_attr.size);
244 
245 	dev_dbg(&pdev->dev, "press %x:%x\n", st->press_attr.index,
246 			st->press_attr.report_id);
247 
248 	st->scale_precision = hid_sensor_format_scale(
249 				HID_USAGE_SENSOR_PRESSURE,
250 				&st->press_attr,
251 				&st->scale_pre_decml, &st->scale_post_decml);
252 
253 	/* Set Sensitivity field ids, when there is no individual modifier */
254 	if (st->common_attributes.sensitivity.index < 0) {
255 		sensor_hub_input_get_attribute_info(hsdev,
256 			HID_FEATURE_REPORT, usage_id,
257 			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
258 			HID_USAGE_SENSOR_DATA_ATMOSPHERIC_PRESSURE,
259 			&st->common_attributes.sensitivity);
260 		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
261 			st->common_attributes.sensitivity.index,
262 			st->common_attributes.sensitivity.report_id);
263 	}
264 	return ret;
265 }
266 
267 /* Function to initialize the processing for usage id */
268 static int hid_press_probe(struct platform_device *pdev)
269 {
270 	int ret = 0;
271 	static const char *name = "press";
272 	struct iio_dev *indio_dev;
273 	struct press_state *press_state;
274 	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
275 	struct iio_chan_spec *channels;
276 
277 	indio_dev = devm_iio_device_alloc(&pdev->dev,
278 				sizeof(struct press_state));
279 	if (!indio_dev)
280 		return -ENOMEM;
281 	platform_set_drvdata(pdev, indio_dev);
282 
283 	press_state = iio_priv(indio_dev);
284 	press_state->common_attributes.hsdev = hsdev;
285 	press_state->common_attributes.pdev = pdev;
286 
287 	ret = hid_sensor_parse_common_attributes(hsdev,
288 					HID_USAGE_SENSOR_PRESSURE,
289 					&press_state->common_attributes);
290 	if (ret) {
291 		dev_err(&pdev->dev, "failed to setup common attributes\n");
292 		return ret;
293 	}
294 
295 	channels = kmemdup(press_channels, sizeof(press_channels), GFP_KERNEL);
296 	if (!channels) {
297 		dev_err(&pdev->dev, "failed to duplicate channels\n");
298 		return -ENOMEM;
299 	}
300 
301 	ret = press_parse_report(pdev, hsdev, channels,
302 				HID_USAGE_SENSOR_PRESSURE, press_state);
303 	if (ret) {
304 		dev_err(&pdev->dev, "failed to setup attributes\n");
305 		goto error_free_dev_mem;
306 	}
307 
308 	indio_dev->channels = channels;
309 	indio_dev->num_channels =
310 				ARRAY_SIZE(press_channels);
311 	indio_dev->dev.parent = &pdev->dev;
312 	indio_dev->info = &press_info;
313 	indio_dev->name = name;
314 	indio_dev->modes = INDIO_DIRECT_MODE;
315 
316 	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
317 		NULL, NULL);
318 	if (ret) {
319 		dev_err(&pdev->dev, "failed to initialize trigger buffer\n");
320 		goto error_free_dev_mem;
321 	}
322 	atomic_set(&press_state->common_attributes.data_ready, 0);
323 	ret = hid_sensor_setup_trigger(indio_dev, name,
324 				&press_state->common_attributes);
325 	if (ret) {
326 		dev_err(&pdev->dev, "trigger setup failed\n");
327 		goto error_unreg_buffer_funcs;
328 	}
329 
330 	ret = iio_device_register(indio_dev);
331 	if (ret) {
332 		dev_err(&pdev->dev, "device register failed\n");
333 		goto error_remove_trigger;
334 	}
335 
336 	press_state->callbacks.send_event = press_proc_event;
337 	press_state->callbacks.capture_sample = press_capture_sample;
338 	press_state->callbacks.pdev = pdev;
339 	ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_PRESSURE,
340 					&press_state->callbacks);
341 	if (ret < 0) {
342 		dev_err(&pdev->dev, "callback reg failed\n");
343 		goto error_iio_unreg;
344 	}
345 
346 	return ret;
347 
348 error_iio_unreg:
349 	iio_device_unregister(indio_dev);
350 error_remove_trigger:
351 	hid_sensor_remove_trigger(&press_state->common_attributes);
352 error_unreg_buffer_funcs:
353 	iio_triggered_buffer_cleanup(indio_dev);
354 error_free_dev_mem:
355 	kfree(indio_dev->channels);
356 	return ret;
357 }
358 
359 /* Function to deinitialize the processing for usage id */
360 static int hid_press_remove(struct platform_device *pdev)
361 {
362 	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
363 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
364 	struct press_state *press_state = iio_priv(indio_dev);
365 
366 	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_PRESSURE);
367 	iio_device_unregister(indio_dev);
368 	hid_sensor_remove_trigger(&press_state->common_attributes);
369 	iio_triggered_buffer_cleanup(indio_dev);
370 	kfree(indio_dev->channels);
371 
372 	return 0;
373 }
374 
375 static struct platform_device_id hid_press_ids[] = {
376 	{
377 		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
378 		.name = "HID-SENSOR-200031",
379 	},
380 	{ /* sentinel */ }
381 };
382 MODULE_DEVICE_TABLE(platform, hid_press_ids);
383 
384 static struct platform_driver hid_press_platform_driver = {
385 	.id_table = hid_press_ids,
386 	.driver = {
387 		.name	= KBUILD_MODNAME,
388 		.owner	= THIS_MODULE,
389 	},
390 	.probe		= hid_press_probe,
391 	.remove		= hid_press_remove,
392 };
393 module_platform_driver(hid_press_platform_driver);
394 
395 MODULE_DESCRIPTION("HID Sensor Pressure");
396 MODULE_AUTHOR("Archana Patni <archana.patni@intel.com>");
397 MODULE_LICENSE("GPL");
398