drivers/iio/common/hid-sensors/hid-sensor-attributes.c

   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
  63 static 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
  73 static 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
  95 static 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 /*
 102 VTF format uses exponent and variable size format.
 103 For example if the size is 2 bytes
 104 0x0067 with VTF16E14 format -> +1.03
 105 To convert just change to 0x67 to decimal and use two decimal as E14 stands
 106 for 10^-2.
 107 Negative numbers are 2's complement
 108 */
 109 static 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
 131 static 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
 150 s32 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 }
 168 EXPORT_SYMBOL(hid_sensor_read_poll_value);
 169
 170 int 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 }
 195 EXPORT_SYMBOL(hid_sensor_read_samp_freq_value);
 196
 197 int 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                 return -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 }
 222 EXPORT_SYMBOL(hid_sensor_write_samp_freq_value);
 223
 224 int 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 }
 245 EXPORT_SYMBOL(hid_sensor_read_raw_hyst_value);
 246
 247 int 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         if (val1 < 0 || val2 < 0)
 254                 return -EINVAL;
 255
 256         value = convert_to_vtf_format(st->sensitivity.size,
 257                                 st->sensitivity.unit_expo,
 258                                 val1, val2);
 259         ret = sensor_hub_set_feature(st->hsdev, st->sensitivity.report_id,
 260                                      st->sensitivity.index, sizeof(value),
 261                                      &value);
 262         if (ret < 0 || value < 0)
 263                 ret = -EINVAL;
 264
 265         return ret;
 266 }
 267 EXPORT_SYMBOL(hid_sensor_write_raw_hyst_value);
 268
 269 /*
 270  * This fuction applies the unit exponent to the scale.
 271  * For example:
 272  * 9.806650000 ->exp:2-> val0[980]val1[665000000]
 273  * 9.000806000 ->exp:2-> val0[900]val1[80600000]
 274  * 0.174535293 ->exp:2-> val0[17]val1[453529300]
 275  * 1.001745329 ->exp:0-> val0[1]val1[1745329]
 276  * 1.001745329 ->exp:2-> val0[100]val1[174532900]
 277  * 1.001745329 ->exp:4-> val0[10017]val1[453290000]
 278  * 9.806650000 ->exp:-2-> val0[0]val1[98066500]
 279  */
 280 static void adjust_exponent_nano(int *val0, int *val1, int scale0,
 281                                   int scale1, int exp)
 282 {
 283         int i;
 284         int x;
 285         int res;
 286         int rem;
 287
 288         if (exp > 0) {
 289                 *val0 = scale0 * pow_10(exp);
 290                 res = 0;
 291                 if (exp > 9) {
 292                         *val1 = 0;
 293                         return;
 294                 }
 295                 for (i = 0; i < exp; ++i) {
 296                         x = scale1 / pow_10(8 - i);
 297                         res += (pow_10(exp - 1 - i) * x);
 298                         scale1 = scale1 % pow_10(8 - i);
 299                 }
 300                 *val0 += res;
 301                         *val1 = scale1 * pow_10(exp);
 302         } else if (exp < 0) {
 303                 exp = abs(exp);
 304                 if (exp > 9) {
 305                         *val0 = *val1 = 0;
 306                         return;
 307                 }
 308                 *val0 = scale0 / pow_10(exp);
 309                 rem = scale0 % pow_10(exp);
 310                 res = 0;
 311                 for (i = 0; i < (9 - exp); ++i) {
 312                         x = scale1 / pow_10(8 - i);
 313                         res += (pow_10(8 - exp - i) * x);
 314                         scale1 = scale1 % pow_10(8 - i);
 315                 }
 316                 *val1 = rem * pow_10(9 - exp) + res;
 317         } else {
 318                 *val0 = scale0;
 319                 *val1 = scale1;
 320         }
 321 }
 322
 323 int hid_sensor_format_scale(u32 usage_id,
 324                         struct hid_sensor_hub_attribute_info *attr_info,
 325                         int *val0, int *val1)
 326 {
 327         int i;
 328         int exp;
 329
 330         *val0 = 1;
 331         *val1 = 0;
 332
 333         for (i = 0; i < ARRAY_SIZE(unit_conversion); ++i) {
 334                 if (unit_conversion[i].usage_id == usage_id &&
 335                         unit_conversion[i].unit == attr_info->units) {
 336                         exp  = hid_sensor_convert_exponent(
 337                                                 attr_info->unit_expo);
 338                         adjust_exponent_nano(val0, val1,
 339                                         unit_conversion[i].scale_val0,
 340                                         unit_conversion[i].scale_val1, exp);
 341                         break;
 342                 }
 343         }
 344
 345         return IIO_VAL_INT_PLUS_NANO;
 346 }
 347 EXPORT_SYMBOL(hid_sensor_format_scale);
 348
 349 static
 350 int hid_sensor_get_reporting_interval(struct hid_sensor_hub_device *hsdev,
 351                                         u32 usage_id,
 352                                         struct hid_sensor_common *st)
 353 {
 354         sensor_hub_input_get_attribute_info(hsdev,
 355                                         HID_FEATURE_REPORT, usage_id,
 356                                         HID_USAGE_SENSOR_PROP_REPORT_INTERVAL,
 357                                         &st->poll);
 358         /* Default unit of measure is milliseconds */
 359         if (st->poll.units == 0)
 360                 st->poll.units = HID_USAGE_SENSOR_UNITS_MILLISECOND;
 361         return 0;
 362
 363 }
 364
 365 int hid_sensor_parse_common_attributes(struct hid_sensor_hub_device *hsdev,
 366                                         u32 usage_id,
 367                                         struct hid_sensor_common *st)
 368 {
 369
 370
 371         hid_sensor_get_reporting_interval(hsdev, usage_id, st);
 372
 373         sensor_hub_input_get_attribute_info(hsdev,
 374                                         HID_FEATURE_REPORT, usage_id,
 375                                         HID_USAGE_SENSOR_PROP_REPORT_STATE,
 376                                         &st->report_state);
 377
 378         sensor_hub_input_get_attribute_info(hsdev,
 379                                         HID_FEATURE_REPORT, usage_id,
 380                                         HID_USAGE_SENSOR_PROY_POWER_STATE,
 381                                         &st->power_state);
 382
 383         sensor_hub_input_get_attribute_info(hsdev,
 384                         HID_FEATURE_REPORT, usage_id,
 385                         HID_USAGE_SENSOR_PROP_SENSITIVITY_ABS,
 386                          &st->sensitivity);
 387
 388         hid_dbg(hsdev->hdev, "common attributes: %x:%x, %x:%x, %x:%x %x:%x\n",
 389                         st->poll.index, st->poll.report_id,
 390                         st->report_state.index, st->report_state.report_id,
 391                         st->power_state.index, st->power_state.report_id,
 392                         st->sensitivity.index, st->sensitivity.report_id);
 393
 394         return 0;
 395 }
 396 EXPORT_SYMBOL(hid_sensor_parse_common_attributes);
 397
 398 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@intel.com>");
 399 MODULE_DESCRIPTION("HID Sensor common attribute processing");
 400 MODULE_LICENSE("GPL");