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