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
29static 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 micros */
34} unit_conversion[] = {
35	{HID_USAGE_SENSOR_ACCEL_3D, 0, 9, 806650},
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, 806650},
40
41	{HID_USAGE_SENSOR_GYRO_3D, 0, 0, 17453},
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, 17453},
46
47	{HID_USAGE_SENSOR_COMPASS_3D, 0, 0, 1000},
48	{HID_USAGE_SENSOR_COMPASS_3D, HID_USAGE_SENSOR_UNITS_GAUSS, 1, 0},
49
50	{HID_USAGE_SENSOR_INCLINOMETER_3D, 0, 0, 17453},
51	{HID_USAGE_SENSOR_INCLINOMETER_3D,
52		HID_USAGE_SENSOR_UNITS_DEGREES, 0, 17453},
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, 100000, 0},
60	{HID_USAGE_SENSOR_PRESSURE, HID_USAGE_SENSOR_UNITS_PASCAL, 1, 0},
61};
62
63static int pow_10(unsigned power)
64{
65	int i;
66	int ret = 1;
67	for (i = 0; i < power; ++i)
68		ret = ret * 10;
69
70	return ret;
71}
72
73static void simple_div(int dividend, int divisor, int *whole,
74				int *micro_frac)
75{
76	int rem;
77	int exp = 0;
78
79	*micro_frac = 0;
80	if (divisor == 0) {
81		*whole = 0;
82		return;
83	}
84	*whole = dividend/divisor;
85	rem = dividend % divisor;
86	if (rem) {
87		while (rem <= divisor) {
88			rem *= 10;
89			exp++;
90		}
91		*micro_frac = (rem / divisor) * pow_10(6-exp);
92	}
93}
94
95static void split_micro_fraction(unsigned int no, int exp, int *val1, int *val2)
96{
97	*val1 = no/pow_10(exp);
98	*val2 = no%pow_10(exp) * pow_10(6-exp);
99}
100
101/*
102VTF format uses exponent and variable size format.
103For example if the size is 2 bytes
1040x0067 with VTF16E14 format -> +1.03
105To convert just change to 0x67 to decimal and use two decimal as E14 stands
106for 10^-2.
107Negative numbers are 2's complement
108*/
109static void convert_from_vtf_format(u32 value, int size, int exp,
110					int *val1, int *val2)
111{
112	int sign = 1;
113
114	if (value & BIT(size*8 - 1)) {
115		value =  ((1LL << (size * 8)) - value);
116		sign = -1;
117	}
118	exp = hid_sensor_convert_exponent(exp);
119	if (exp >= 0) {
120		*val1 = sign * value * pow_10(exp);
121		*val2 = 0;
122	} else {
123		split_micro_fraction(value, -exp, val1, val2);
124		if (*val1)
125			*val1 = sign * (*val1);
126		else
127			*val2 = sign * (*val2);
128	}
129}
130
131static u32 convert_to_vtf_format(int size, int exp, int val1, int val2)
132{
133	u32 value;
134	int sign = 1;
135
136	if (val1 < 0 || val2 < 0)
137		sign = -1;
138	exp = hid_sensor_convert_exponent(exp);
139	if (exp < 0) {
140		value = abs(val1) * pow_10(-exp);
141		value += abs(val2) / pow_10(6+exp);
142	} else
143		value = abs(val1) / pow_10(exp);
144	if (sign < 0)
145		value =  ((1LL << (size * 8)) - value);
146
147	return value;
148}
149
150s32 hid_sensor_read_poll_value(struct hid_sensor_common *st)
151{
152	s32 value = 0;
153	int ret;
154
155	ret = sensor_hub_get_feature(st->hsdev,
156				     st->poll.report_id,
157				     st->poll.index, sizeof(value), &value);
158
159	if (ret < 0 || value < 0) {
160		return -EINVAL;
161	} else {
162		if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND)
163			value = value * 1000;
164	}
165
166	return value;
167}
168EXPORT_SYMBOL(hid_sensor_read_poll_value);
169
170int hid_sensor_read_samp_freq_value(struct hid_sensor_common *st,
171				int *val1, int *val2)
172{
173	s32 value;
174	int ret;
175
176	ret = sensor_hub_get_feature(st->hsdev,
177				     st->poll.report_id,
178				     st->poll.index, sizeof(value), &value);
179	if (ret < 0 || value < 0) {
180		*val1 = *val2 = 0;
181		return -EINVAL;
182	} else {
183		if (st->poll.units == HID_USAGE_SENSOR_UNITS_MILLISECOND)
184			simple_div(1000, value, val1, val2);
185		else if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND)
186			simple_div(1, value, val1, val2);
187		else {
188			*val1 = *val2 = 0;
189			return -EINVAL;
190		}
191	}
192
193	return IIO_VAL_INT_PLUS_MICRO;
194}
195EXPORT_SYMBOL(hid_sensor_read_samp_freq_value);
196
197int hid_sensor_write_samp_freq_value(struct hid_sensor_common *st,
198				int val1, int val2)
199{
200	s32 value;
201	int ret;
202
203	if (val1 < 0 || val2 < 0)
204		ret = -EINVAL;
205
206	value = val1 * pow_10(6) + val2;
207	if (value) {
208		if (st->poll.units == HID_USAGE_SENSOR_UNITS_MILLISECOND)
209			value = pow_10(9)/value;
210		else if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND)
211			value = pow_10(6)/value;
212		else
213			value = 0;
214	}
215	ret = sensor_hub_set_feature(st->hsdev, st->poll.report_id,
216				     st->poll.index, sizeof(value), &value);
217	if (ret < 0 || value < 0)
218		ret = -EINVAL;
219
220	return ret;
221}
222EXPORT_SYMBOL(hid_sensor_write_samp_freq_value);
223
224int hid_sensor_read_raw_hyst_value(struct hid_sensor_common *st,
225				int *val1, int *val2)
226{
227	s32 value;
228	int ret;
229
230	ret = sensor_hub_get_feature(st->hsdev,
231				     st->sensitivity.report_id,
232				     st->sensitivity.index, sizeof(value),
233				     &value);
234	if (ret < 0 || value < 0) {
235		*val1 = *val2 = 0;
236		return -EINVAL;
237	} else {
238		convert_from_vtf_format(value, st->sensitivity.size,
239					st->sensitivity.unit_expo,
240					val1, val2);
241	}
242
243	return IIO_VAL_INT_PLUS_MICRO;
244}
245EXPORT_SYMBOL(hid_sensor_read_raw_hyst_value);
246
247int hid_sensor_write_raw_hyst_value(struct hid_sensor_common *st,
248					int val1, int val2)
249{
250	s32 value;
251	int ret;
252
253	value = convert_to_vtf_format(st->sensitivity.size,
254				st->sensitivity.unit_expo,
255				val1, val2);
256	ret = sensor_hub_set_feature(st->hsdev, st->sensitivity.report_id,
257				     st->sensitivity.index, sizeof(value),
258				     &value);
259	if (ret < 0 || value < 0)
260		ret = -EINVAL;
261
262	return ret;
263}
264EXPORT_SYMBOL(hid_sensor_write_raw_hyst_value);
265
266/*
267 * This fuction applies the unit exponent to the scale.
268 * For example:
269 * 9.806650 ->exp:2-> val0[980]val1[665000]
270 * 9.000806 ->exp:2-> val0[900]val1[80600]
271 * 0.174535 ->exp:2-> val0[17]val1[453500]
272 * 1.001745 ->exp:0-> val0[1]val1[1745]
273 * 1.001745 ->exp:2-> val0[100]val1[174500]
274 * 1.001745 ->exp:4-> val0[10017]val1[450000]
275 * 9.806650 ->exp:-2-> val0[0]val1[98066]
276 */
277static void adjust_exponent_micro(int *val0, int *val1, int scale0,
278				  int scale1, int exp)
279{
280	int i;
281	int x;
282	int res;
283	int rem;
284
285	if (exp > 0) {
286		*val0 = scale0 * pow_10(exp);
287		res = 0;
288		if (exp > 6) {
289			*val1 = 0;
290			return;
291		}
292		for (i = 0; i < exp; ++i) {
293			x = scale1 / pow_10(5 - i);
294			res += (pow_10(exp - 1 - i) * x);
295			scale1 = scale1 % pow_10(5 - i);
296		}
297		*val0 += res;
298			*val1 = scale1 * pow_10(exp);
299	} else if (exp < 0) {
300		exp = abs(exp);
301		if (exp > 6) {
302			*val0 = *val1 = 0;
303			return;
304		}
305		*val0 = scale0 / pow_10(exp);
306		rem = scale0 % pow_10(exp);
307		res = 0;
308		for (i = 0; i < (6 - exp); ++i) {
309			x = scale1 / pow_10(5 - i);
310			res += (pow_10(5 - exp - i) * x);
311			scale1 = scale1 % pow_10(5 - i);
312		}
313		*val1 = rem * pow_10(6 - exp) + res;
314	} else {
315		*val0 = scale0;
316		*val1 = scale1;
317	}
318}
319
320int hid_sensor_format_scale(u32 usage_id,
321			struct hid_sensor_hub_attribute_info *attr_info,
322			int *val0, int *val1)
323{
324	int i;
325	int exp;
326
327	*val0 = 1;
328	*val1 = 0;
329
330	for (i = 0; i < ARRAY_SIZE(unit_conversion); ++i) {
331		if (unit_conversion[i].usage_id == usage_id &&
332			unit_conversion[i].unit == attr_info->units) {
333			exp  = hid_sensor_convert_exponent(
334						attr_info->unit_expo);
335			adjust_exponent_micro(val0, val1,
336					unit_conversion[i].scale_val0,
337					unit_conversion[i].scale_val1, exp);
338			break;
339		}
340	}
341
342	return IIO_VAL_INT_PLUS_MICRO;
343}
344EXPORT_SYMBOL(hid_sensor_format_scale);
345
346static
347int hid_sensor_get_reporting_interval(struct hid_sensor_hub_device *hsdev,
348					u32 usage_id,
349					struct hid_sensor_common *st)
350{
351	sensor_hub_input_get_attribute_info(hsdev,
352					HID_FEATURE_REPORT, usage_id,
353					HID_USAGE_SENSOR_PROP_REPORT_INTERVAL,
354					&st->poll);
355	/* Default unit of measure is milliseconds */
356	if (st->poll.units == 0)
357		st->poll.units = HID_USAGE_SENSOR_UNITS_MILLISECOND;
358	return 0;
359
360}
361
362int hid_sensor_parse_common_attributes(struct hid_sensor_hub_device *hsdev,
363					u32 usage_id,
364					struct hid_sensor_common *st)
365{
366
367
368	hid_sensor_get_reporting_interval(hsdev, usage_id, st);
369
370	sensor_hub_input_get_attribute_info(hsdev,
371					HID_FEATURE_REPORT, usage_id,
372					HID_USAGE_SENSOR_PROP_REPORT_STATE,
373					&st->report_state);
374
375	sensor_hub_input_get_attribute_info(hsdev,
376					HID_FEATURE_REPORT, usage_id,
377					HID_USAGE_SENSOR_PROY_POWER_STATE,
378					&st->power_state);
379
380	sensor_hub_input_get_attribute_info(hsdev,
381			HID_FEATURE_REPORT, usage_id,
382			HID_USAGE_SENSOR_PROP_SENSITIVITY_ABS,
383			 &st->sensitivity);
384
385	hid_dbg(hsdev->hdev, "common attributes: %x:%x, %x:%x, %x:%x %x:%x\n",
386			st->poll.index, st->poll.report_id,
387			st->report_state.index, st->report_state.report_id,
388			st->power_state.index, st->power_state.report_id,
389			st->sensitivity.index, st->sensitivity.report_id);
390
391	return 0;
392}
393EXPORT_SYMBOL(hid_sensor_parse_common_attributes);
394
395MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@intel.com>");
396MODULE_DESCRIPTION("HID Sensor common attribute processing");
397MODULE_LICENSE("GPL");
398