1 /*
2  * HID Sensors Driver
3  * Copyright (c) 2012, 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; if not, write to the Free Software Foundation, Inc.,
16  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
17  *
18  */
19 #include <linux/device.h>
20 #include <linux/platform_device.h>
21 #include <linux/module.h>
22 #include <linux/interrupt.h>
23 #include <linux/irq.h>
24 #include <linux/slab.h>
25 #include <linux/hid-sensor-hub.h>
26 #include <linux/iio/iio.h>
27 #include <linux/iio/sysfs.h>
28 
29 static struct {
30 	u32 usage_id;
31 	int unit; /* 0 for default others from HID sensor spec */
32 	int scale_val0; /* scale, whole number */
33 	int scale_val1; /* scale, fraction in nanos */
34 } unit_conversion[] = {
35 	{HID_USAGE_SENSOR_ACCEL_3D, 0, 9, 806650000},
36 	{HID_USAGE_SENSOR_ACCEL_3D,
37 		HID_USAGE_SENSOR_UNITS_METERS_PER_SEC_SQRD, 1, 0},
38 	{HID_USAGE_SENSOR_ACCEL_3D,
39 		HID_USAGE_SENSOR_UNITS_G, 9, 806650000},
40 
41 	{HID_USAGE_SENSOR_GYRO_3D, 0, 0, 17453293},
42 	{HID_USAGE_SENSOR_GYRO_3D,
43 		HID_USAGE_SENSOR_UNITS_RADIANS_PER_SECOND, 1, 0},
44 	{HID_USAGE_SENSOR_GYRO_3D,
45 		HID_USAGE_SENSOR_UNITS_DEGREES_PER_SECOND, 0, 17453293},
46 
47 	{HID_USAGE_SENSOR_COMPASS_3D, 0, 0, 1000000},
48 	{HID_USAGE_SENSOR_COMPASS_3D, HID_USAGE_SENSOR_UNITS_GAUSS, 1, 0},
49 
50 	{HID_USAGE_SENSOR_INCLINOMETER_3D, 0, 0, 17453293},
51 	{HID_USAGE_SENSOR_INCLINOMETER_3D,
52 		HID_USAGE_SENSOR_UNITS_DEGREES, 0, 17453293},
53 	{HID_USAGE_SENSOR_INCLINOMETER_3D,
54 		HID_USAGE_SENSOR_UNITS_RADIANS, 1, 0},
55 
56 	{HID_USAGE_SENSOR_ALS, 0, 1, 0},
57 	{HID_USAGE_SENSOR_ALS, HID_USAGE_SENSOR_UNITS_LUX, 1, 0},
58 
59 	{HID_USAGE_SENSOR_PRESSURE, 0, 100, 0},
60 	{HID_USAGE_SENSOR_PRESSURE, HID_USAGE_SENSOR_UNITS_PASCAL, 0, 1000000},
61 
62 	{HID_USAGE_SENSOR_TIME_TIMESTAMP, 0, 1000000000, 0},
63 	{HID_USAGE_SENSOR_TIME_TIMESTAMP, HID_USAGE_SENSOR_UNITS_MILLISECOND,
64 		1000000, 0},
65 };
66 
67 static int pow_10(unsigned power)
68 {
69 	int i;
70 	int ret = 1;
71 	for (i = 0; i < power; ++i)
72 		ret = ret * 10;
73 
74 	return ret;
75 }
76 
77 static void simple_div(int dividend, int divisor, int *whole,
78 				int *micro_frac)
79 {
80 	int rem;
81 	int exp = 0;
82 
83 	*micro_frac = 0;
84 	if (divisor == 0) {
85 		*whole = 0;
86 		return;
87 	}
88 	*whole = dividend/divisor;
89 	rem = dividend % divisor;
90 	if (rem) {
91 		while (rem <= divisor) {
92 			rem *= 10;
93 			exp++;
94 		}
95 		*micro_frac = (rem / divisor) * pow_10(6-exp);
96 	}
97 }
98 
99 static void split_micro_fraction(unsigned int no, int exp, int *val1, int *val2)
100 {
101 	*val1 = no/pow_10(exp);
102 	*val2 = no%pow_10(exp) * pow_10(6-exp);
103 }
104 
105 /*
106 VTF format uses exponent and variable size format.
107 For example if the size is 2 bytes
108 0x0067 with VTF16E14 format -> +1.03
109 To convert just change to 0x67 to decimal and use two decimal as E14 stands
110 for 10^-2.
111 Negative numbers are 2's complement
112 */
113 static void convert_from_vtf_format(u32 value, int size, int exp,
114 					int *val1, int *val2)
115 {
116 	int sign = 1;
117 
118 	if (value & BIT(size*8 - 1)) {
119 		value =  ((1LL << (size * 8)) - value);
120 		sign = -1;
121 	}
122 	exp = hid_sensor_convert_exponent(exp);
123 	if (exp >= 0) {
124 		*val1 = sign * value * pow_10(exp);
125 		*val2 = 0;
126 	} else {
127 		split_micro_fraction(value, -exp, val1, val2);
128 		if (*val1)
129 			*val1 = sign * (*val1);
130 		else
131 			*val2 = sign * (*val2);
132 	}
133 }
134 
135 static u32 convert_to_vtf_format(int size, int exp, int val1, int val2)
136 {
137 	u32 value;
138 	int sign = 1;
139 
140 	if (val1 < 0 || val2 < 0)
141 		sign = -1;
142 	exp = hid_sensor_convert_exponent(exp);
143 	if (exp < 0) {
144 		value = abs(val1) * pow_10(-exp);
145 		value += abs(val2) / pow_10(6+exp);
146 	} else
147 		value = abs(val1) / pow_10(exp);
148 	if (sign < 0)
149 		value =  ((1LL << (size * 8)) - value);
150 
151 	return value;
152 }
153 
154 s32 hid_sensor_read_poll_value(struct hid_sensor_common *st)
155 {
156 	s32 value = 0;
157 	int ret;
158 
159 	ret = sensor_hub_get_feature(st->hsdev,
160 				     st->poll.report_id,
161 				     st->poll.index, sizeof(value), &value);
162 
163 	if (ret < 0 || value < 0) {
164 		return -EINVAL;
165 	} else {
166 		if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND)
167 			value = value * 1000;
168 	}
169 
170 	return value;
171 }
172 EXPORT_SYMBOL(hid_sensor_read_poll_value);
173 
174 int hid_sensor_read_samp_freq_value(struct hid_sensor_common *st,
175 				int *val1, int *val2)
176 {
177 	s32 value;
178 	int ret;
179 
180 	ret = sensor_hub_get_feature(st->hsdev,
181 				     st->poll.report_id,
182 				     st->poll.index, sizeof(value), &value);
183 	if (ret < 0 || value < 0) {
184 		*val1 = *val2 = 0;
185 		return -EINVAL;
186 	} else {
187 		if (st->poll.units == HID_USAGE_SENSOR_UNITS_MILLISECOND)
188 			simple_div(1000, value, val1, val2);
189 		else if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND)
190 			simple_div(1, value, val1, val2);
191 		else {
192 			*val1 = *val2 = 0;
193 			return -EINVAL;
194 		}
195 	}
196 
197 	return IIO_VAL_INT_PLUS_MICRO;
198 }
199 EXPORT_SYMBOL(hid_sensor_read_samp_freq_value);
200 
201 int hid_sensor_write_samp_freq_value(struct hid_sensor_common *st,
202 				int val1, int val2)
203 {
204 	s32 value;
205 	int ret;
206 
207 	if (val1 < 0 || val2 < 0)
208 		return -EINVAL;
209 
210 	value = val1 * pow_10(6) + val2;
211 	if (value) {
212 		if (st->poll.units == HID_USAGE_SENSOR_UNITS_MILLISECOND)
213 			value = pow_10(9)/value;
214 		else if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND)
215 			value = pow_10(6)/value;
216 		else
217 			value = 0;
218 	}
219 	ret = sensor_hub_set_feature(st->hsdev, st->poll.report_id,
220 				     st->poll.index, sizeof(value), &value);
221 	if (ret < 0 || value < 0)
222 		ret = -EINVAL;
223 
224 	return ret;
225 }
226 EXPORT_SYMBOL(hid_sensor_write_samp_freq_value);
227 
228 int hid_sensor_read_raw_hyst_value(struct hid_sensor_common *st,
229 				int *val1, int *val2)
230 {
231 	s32 value;
232 	int ret;
233 
234 	ret = sensor_hub_get_feature(st->hsdev,
235 				     st->sensitivity.report_id,
236 				     st->sensitivity.index, sizeof(value),
237 				     &value);
238 	if (ret < 0 || value < 0) {
239 		*val1 = *val2 = 0;
240 		return -EINVAL;
241 	} else {
242 		convert_from_vtf_format(value, st->sensitivity.size,
243 					st->sensitivity.unit_expo,
244 					val1, val2);
245 	}
246 
247 	return IIO_VAL_INT_PLUS_MICRO;
248 }
249 EXPORT_SYMBOL(hid_sensor_read_raw_hyst_value);
250 
251 int hid_sensor_write_raw_hyst_value(struct hid_sensor_common *st,
252 					int val1, int val2)
253 {
254 	s32 value;
255 	int ret;
256 
257 	if (val1 < 0 || val2 < 0)
258 		return -EINVAL;
259 
260 	value = convert_to_vtf_format(st->sensitivity.size,
261 				st->sensitivity.unit_expo,
262 				val1, val2);
263 	ret = sensor_hub_set_feature(st->hsdev, st->sensitivity.report_id,
264 				     st->sensitivity.index, sizeof(value),
265 				     &value);
266 	if (ret < 0 || value < 0)
267 		ret = -EINVAL;
268 
269 	return ret;
270 }
271 EXPORT_SYMBOL(hid_sensor_write_raw_hyst_value);
272 
273 /*
274  * This fuction applies the unit exponent to the scale.
275  * For example:
276  * 9.806650000 ->exp:2-> val0[980]val1[665000000]
277  * 9.000806000 ->exp:2-> val0[900]val1[80600000]
278  * 0.174535293 ->exp:2-> val0[17]val1[453529300]
279  * 1.001745329 ->exp:0-> val0[1]val1[1745329]
280  * 1.001745329 ->exp:2-> val0[100]val1[174532900]
281  * 1.001745329 ->exp:4-> val0[10017]val1[453290000]
282  * 9.806650000 ->exp:-2-> val0[0]val1[98066500]
283  */
284 static void adjust_exponent_nano(int *val0, int *val1, int scale0,
285 				  int scale1, int exp)
286 {
287 	int i;
288 	int x;
289 	int res;
290 	int rem;
291 
292 	if (exp > 0) {
293 		*val0 = scale0 * pow_10(exp);
294 		res = 0;
295 		if (exp > 9) {
296 			*val1 = 0;
297 			return;
298 		}
299 		for (i = 0; i < exp; ++i) {
300 			x = scale1 / pow_10(8 - i);
301 			res += (pow_10(exp - 1 - i) * x);
302 			scale1 = scale1 % pow_10(8 - i);
303 		}
304 		*val0 += res;
305 			*val1 = scale1 * pow_10(exp);
306 	} else if (exp < 0) {
307 		exp = abs(exp);
308 		if (exp > 9) {
309 			*val0 = *val1 = 0;
310 			return;
311 		}
312 		*val0 = scale0 / pow_10(exp);
313 		rem = scale0 % pow_10(exp);
314 		res = 0;
315 		for (i = 0; i < (9 - exp); ++i) {
316 			x = scale1 / pow_10(8 - i);
317 			res += (pow_10(8 - exp - i) * x);
318 			scale1 = scale1 % pow_10(8 - i);
319 		}
320 		*val1 = rem * pow_10(9 - exp) + res;
321 	} else {
322 		*val0 = scale0;
323 		*val1 = scale1;
324 	}
325 }
326 
327 int hid_sensor_format_scale(u32 usage_id,
328 			struct hid_sensor_hub_attribute_info *attr_info,
329 			int *val0, int *val1)
330 {
331 	int i;
332 	int exp;
333 
334 	*val0 = 1;
335 	*val1 = 0;
336 
337 	for (i = 0; i < ARRAY_SIZE(unit_conversion); ++i) {
338 		if (unit_conversion[i].usage_id == usage_id &&
339 			unit_conversion[i].unit == attr_info->units) {
340 			exp  = hid_sensor_convert_exponent(
341 						attr_info->unit_expo);
342 			adjust_exponent_nano(val0, val1,
343 					unit_conversion[i].scale_val0,
344 					unit_conversion[i].scale_val1, exp);
345 			break;
346 		}
347 	}
348 
349 	return IIO_VAL_INT_PLUS_NANO;
350 }
351 EXPORT_SYMBOL(hid_sensor_format_scale);
352 
353 int64_t hid_sensor_convert_timestamp(struct hid_sensor_common *st,
354 				     int64_t raw_value)
355 {
356 	return st->timestamp_ns_scale * raw_value;
357 }
358 EXPORT_SYMBOL(hid_sensor_convert_timestamp);
359 
360 static
361 int hid_sensor_get_reporting_interval(struct hid_sensor_hub_device *hsdev,
362 					u32 usage_id,
363 					struct hid_sensor_common *st)
364 {
365 	sensor_hub_input_get_attribute_info(hsdev,
366 					HID_FEATURE_REPORT, usage_id,
367 					HID_USAGE_SENSOR_PROP_REPORT_INTERVAL,
368 					&st->poll);
369 	/* Default unit of measure is milliseconds */
370 	if (st->poll.units == 0)
371 		st->poll.units = HID_USAGE_SENSOR_UNITS_MILLISECOND;
372 	return 0;
373 
374 }
375 
376 int hid_sensor_parse_common_attributes(struct hid_sensor_hub_device *hsdev,
377 					u32 usage_id,
378 					struct hid_sensor_common *st)
379 {
380 
381 	struct hid_sensor_hub_attribute_info timestamp;
382 
383 	hid_sensor_get_reporting_interval(hsdev, usage_id, st);
384 
385 	sensor_hub_input_get_attribute_info(hsdev,
386 					HID_FEATURE_REPORT, usage_id,
387 					HID_USAGE_SENSOR_PROP_REPORT_STATE,
388 					&st->report_state);
389 
390 	sensor_hub_input_get_attribute_info(hsdev,
391 					HID_FEATURE_REPORT, usage_id,
392 					HID_USAGE_SENSOR_PROY_POWER_STATE,
393 					&st->power_state);
394 
395 	sensor_hub_input_get_attribute_info(hsdev,
396 			HID_FEATURE_REPORT, usage_id,
397 			HID_USAGE_SENSOR_PROP_SENSITIVITY_ABS,
398 			 &st->sensitivity);
399 
400 	sensor_hub_input_get_attribute_info(hsdev,
401 					    HID_INPUT_REPORT, usage_id,
402 					    HID_USAGE_SENSOR_TIME_TIMESTAMP,
403 					    &timestamp);
404 	if (timestamp.index >= 0 && timestamp.report_id) {
405 		int val0, val1;
406 
407 		hid_sensor_format_scale(HID_USAGE_SENSOR_TIME_TIMESTAMP,
408 					&timestamp, &val0, &val1);
409 		st->timestamp_ns_scale = val0;
410 	} else
411 		st->timestamp_ns_scale = 1000000000;
412 
413 	hid_dbg(hsdev->hdev, "common attributes: %x:%x, %x:%x, %x:%x %x:%x %x:%x\n",
414 		st->poll.index, st->poll.report_id,
415 		st->report_state.index, st->report_state.report_id,
416 		st->power_state.index, st->power_state.report_id,
417 		st->sensitivity.index, st->sensitivity.report_id,
418 		timestamp.index, timestamp.report_id);
419 
420 	return 0;
421 }
422 EXPORT_SYMBOL(hid_sensor_parse_common_attributes);
423 
424 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@intel.com>");
425 MODULE_DESCRIPTION("HID Sensor common attribute processing");
426 MODULE_LICENSE("GPL");
427