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