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 int pow_10(unsigned power)
  30 {
  31         int i;
  32         int ret = 1;
  33         for (i = 0; i < power; ++i)
  34                 ret = ret * 10;
  35
  36         return ret;
  37 }
  38
  39 static void simple_div(int dividend, int divisor, int *whole,
  40                                 int *micro_frac)
  41 {
  42         int rem;
  43         int exp = 0;
  44
  45         *micro_frac = 0;
  46         if (divisor == 0) {
  47                 *whole = 0;
  48                 return;
  49         }
  50         *whole = dividend/divisor;
  51         rem = dividend % divisor;
  52         if (rem) {
  53                 while (rem <= divisor) {
  54                         rem *= 10;
  55                         exp++;
  56                 }
  57                 *micro_frac = (rem / divisor) * pow_10(6-exp);
  58         }
  59 }
  60
  61 static void split_micro_fraction(unsigned int no, int exp, int *val1, int *val2)
  62 {
  63         *val1 = no/pow_10(exp);
  64         *val2 = no%pow_10(exp) * pow_10(6-exp);
  65 }
  66
  67 /*
  68 VTF format uses exponent and variable size format.
  69 For example if the size is 2 bytes
  70 0x0067 with VTF16E14 format -> +1.03
  71 To convert just change to 0x67 to decimal and use two decimal as E14 stands
  72 for 10^-2.
  73 Negative numbers are 2's complement
  74 */
  75 static void convert_from_vtf_format(u32 value, int size, int exp,
  76                                         int *val1, int *val2)
  77 {
  78         int sign = 1;
  79
  80         if (value & BIT(size*8 - 1)) {
  81                 value =  ((1LL << (size * 8)) - value);
  82                 sign = -1;
  83         }
  84         exp = hid_sensor_convert_exponent(exp);
  85         if (exp >= 0) {
  86                 *val1 = sign * value * pow_10(exp);
  87                 *val2 = 0;
  88         } else {
  89                 split_micro_fraction(value, -exp, val1, val2);
  90                 if (*val1)
  91                         *val1 = sign * (*val1);
  92                 else
  93                         *val2 = sign * (*val2);
  94         }
  95 }
  96
  97 static u32 convert_to_vtf_format(int size, int exp, int val1, int val2)
  98 {
  99         u32 value;
 100         int sign = 1;
 101
 102         if (val1 < 0 || val2 < 0)
 103                 sign = -1;
 104         exp = hid_sensor_convert_exponent(exp);
 105         if (exp < 0) {
 106                 value = abs(val1) * pow_10(-exp);
 107                 value += abs(val2) / pow_10(6+exp);
 108         } else
 109                 value = abs(val1) / pow_10(exp);
 110         if (sign < 0)
 111                 value =  ((1LL << (size * 8)) - value);
 112
 113         return value;
 114 }
 115
 116 int hid_sensor_read_samp_freq_value(struct hid_sensor_common *st,
 117                                 int *val1, int *val2)
 118 {
 119         s32 value;
 120         int ret;
 121
 122         ret = sensor_hub_get_feature(st->hsdev,
 123                 st->poll.report_id,
 124                 st->poll.index, &value);
 125         if (ret < 0 || value < 0) {
 126                 *val1 = *val2 = 0;
 127                 return -EINVAL;
 128         } else {
 129                 if (st->poll.units == HID_USAGE_SENSOR_UNITS_MILLISECOND)
 130                         simple_div(1000, value, val1, val2);
 131                 else if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND)
 132                         simple_div(1, value, val1, val2);
 133                 else {
 134                         *val1 = *val2 = 0;
 135                         return -EINVAL;
 136                 }
 137         }
 138
 139         return IIO_VAL_INT_PLUS_MICRO;
 140 }
 141 EXPORT_SYMBOL(hid_sensor_read_samp_freq_value);
 142
 143 int hid_sensor_write_samp_freq_value(struct hid_sensor_common *st,
 144                                 int val1, int val2)
 145 {
 146         s32 value;
 147         int ret;
 148
 149         if (val1 < 0 || val2 < 0)
 150                 ret = -EINVAL;
 151
 152         value = val1 * pow_10(6) + val2;
 153         if (value) {
 154                 if (st->poll.units == HID_USAGE_SENSOR_UNITS_MILLISECOND)
 155                         value = pow_10(9)/value;
 156                 else if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND)
 157                         value = pow_10(6)/value;
 158                 else
 159                         value = 0;
 160         }
 161         ret = sensor_hub_set_feature(st->hsdev,
 162                 st->poll.report_id,
 163                 st->poll.index, value);
 164         if (ret < 0 || value < 0)
 165                 ret = -EINVAL;
 166
 167         return ret;
 168 }
 169 EXPORT_SYMBOL(hid_sensor_write_samp_freq_value);
 170
 171 int hid_sensor_read_raw_hyst_value(struct hid_sensor_common *st,
 172                                 int *val1, int *val2)
 173 {
 174         s32 value;
 175         int ret;
 176
 177         ret = sensor_hub_get_feature(st->hsdev,
 178                 st->sensitivity.report_id,
 179                 st->sensitivity.index, &value);
 180         if (ret < 0 || value < 0) {
 181                 *val1 = *val2 = 0;
 182                 return -EINVAL;
 183         } else {
 184                 convert_from_vtf_format(value, st->sensitivity.size,
 185                                         st->sensitivity.unit_expo,
 186                                         val1, val2);
 187         }
 188
 189         return IIO_VAL_INT_PLUS_MICRO;
 190 }
 191 EXPORT_SYMBOL(hid_sensor_read_raw_hyst_value);
 192
 193 int hid_sensor_write_raw_hyst_value(struct hid_sensor_common *st,
 194                                         int val1, int val2)
 195 {
 196         s32 value;
 197         int ret;
 198
 199         value = convert_to_vtf_format(st->sensitivity.size,
 200                                 st->sensitivity.unit_expo,
 201                                 val1, val2);
 202         ret = sensor_hub_set_feature(st->hsdev,
 203                 st->sensitivity.report_id,
 204                 st->sensitivity.index, value);
 205         if (ret < 0 || value < 0)
 206                 ret = -EINVAL;
 207
 208         return ret;
 209 }
 210 EXPORT_SYMBOL(hid_sensor_write_raw_hyst_value);
 211
 212 int hid_sensor_parse_common_attributes(struct hid_sensor_hub_device *hsdev,
 213                                         u32 usage_id,
 214                                         struct hid_sensor_common *st)
 215 {
 216
 217         sensor_hub_input_get_attribute_info(hsdev,
 218                                         HID_FEATURE_REPORT, usage_id,
 219                                         HID_USAGE_SENSOR_PROP_REPORT_INTERVAL,
 220                                         &st->poll);
 221
 222         sensor_hub_input_get_attribute_info(hsdev,
 223                                         HID_FEATURE_REPORT, usage_id,
 224                                         HID_USAGE_SENSOR_PROP_REPORT_STATE,
 225                                         &st->report_state);
 226
 227         sensor_hub_input_get_attribute_info(hsdev,
 228                                         HID_FEATURE_REPORT, usage_id,
 229                                         HID_USAGE_SENSOR_PROY_POWER_STATE,
 230                                         &st->power_state);
 231
 232         sensor_hub_input_get_attribute_info(hsdev,
 233                         HID_FEATURE_REPORT, usage_id,
 234                         HID_USAGE_SENSOR_PROP_SENSITIVITY_ABS,
 235                          &st->sensitivity);
 236
 237         hid_dbg(hsdev->hdev, "common attributes: %x:%x, %x:%x, %x:%x %x:%x\n",
 238                         st->poll.index, st->poll.report_id,
 239                         st->report_state.index, st->report_state.report_id,
 240                         st->power_state.index, st->power_state.report_id,
 241                         st->sensitivity.index, st->sensitivity.report_id);
 242
 243         return 0;
 244 }
 245 EXPORT_SYMBOL(hid_sensor_parse_common_attributes);
 246
 247 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@intel.com>");
 248 MODULE_DESCRIPTION("HID Sensor common attribute processing");
 249 MODULE_LICENSE("GPL");