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A driver for the Sensirion SGP40 MOx gas sensor. An example of this 

chip from Adafruit is:

https://www.adafruit.com/product/4829

This is a moderately priced gas sensor that can detect volatile
organic compounds in the air.  The driver uses the 3-clause BSD
licensed VOC algorithm provided by Sensirion to turn the raw sensor
metric into a VOC index which can indicate the quality of the air in a
particular indoor environment.  All published functions of the chip
are supported and one unpublished feature.
This commit is contained in:
brad 2021-10-14 13:54:45 +00:00
parent bb8e9cddaa
commit ea034c40cb
15 changed files with 2095 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
distrib/sets/lists/debug/module.mi
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@ -1,4 +1,4 @@
# $NetBSD: module.mi,v 1.13 2021/10/04 07:04:39 brad Exp $
# $NetBSD: module.mi,v 1.14 2021/10/14 13:54:46 brad Exp $
./usr/libdata/debug/@MODULEDIR@ modules-base-kernel kmod,debug
./usr/libdata/debug/@MODULEDIR@/accf_dataready modules-base-kernel kmod,debug
./usr/libdata/debug/@MODULEDIR@/accf_dataready/accf_dataready.kmod.debug modules-base-kernel kmod,debug
@ -332,6 +332,8 @@
./usr/libdata/debug/@MODULEDIR@/securelevel/securelevel.kmod.debug modules-base-kernel kmod,debug
./usr/libdata/debug/@MODULEDIR@/sequencer modules-base-kernel kmod,debug
./usr/libdata/debug/@MODULEDIR@/sequencer/sequencer.kmod.debug modules-base-kernel kmod,debug
./usr/libdata/debug/@MODULEDIR@/sgp40mox modules-base-kernel kmod,debug
./usr/libdata/debug/@MODULEDIR@/sgp40mox/sgp40mox.kmod.debug modules-base-kernel kmod,debug
./usr/libdata/debug/@MODULEDIR@/sht4xtemp modules-base-kernel kmod,debug
./usr/libdata/debug/@MODULEDIR@/sht4xtemp/sht4xtemp.kmod.debug modules-base-kernel kmod,debug
./usr/libdata/debug/@MODULEDIR@/si70xxtemp modules-base-kernel kmod,debug

5
distrib/sets/lists/man/mi
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@ -1,4 +1,4 @@
# $NetBSD: mi,v 1.1727 2021/10/12 04:55:19 msaitoh Exp $
# $NetBSD: mi,v 1.1728 2021/10/14 13:54:46 brad Exp $
#
# Note: don't delete entries from here - mark them as "obsolete" instead.
#
@ -1720,6 +1720,7 @@
./usr/share/man/cat4/sgimips/pic.0 man-sys-catman .cat
./usr/share/man/cat4/sgimips/sq.0 man-sys-catman .cat
./usr/share/man/cat4/sgimips/wdsc.0 man-sys-catman .cat
./usr/share/man/cat4/sgp40mox.0 man-sys-catman .cat
./usr/share/man/cat4/sgsmix.0 man-sys-catman .cat
./usr/share/man/cat4/shb.0 man-sys-catman .cat
./usr/share/man/cat4/shmif.0 man-sys-catman .cat
@ -4895,6 +4896,7 @@
./usr/share/man/html4/sgimips/pic.html man-sys-htmlman html
./usr/share/man/html4/sgimips/sq.html man-sys-htmlman html
./usr/share/man/html4/sgimips/wdsc.html man-sys-htmlman html
./usr/share/man/html4/sgp40mox.html man-sys-htmlman html
./usr/share/man/html4/sgsmix.html man-sys-htmlman html
./usr/share/man/html4/shb.html man-sys-htmlman html
./usr/share/man/html4/shmif.html man-sys-htmlman html
@ -7976,6 +7978,7 @@
./usr/share/man/man4/sgimips/pic.4 man-sys-man .man
./usr/share/man/man4/sgimips/sq.4 man-sys-man .man
./usr/share/man/man4/sgimips/wdsc.4 man-sys-man .man
./usr/share/man/man4/sgp40mox.4 man-sys-man .man
./usr/share/man/man4/sgsmix.4 man-sys-man .man
./usr/share/man/man4/shb.4 man-sys-man .man
./usr/share/man/man4/shmif.4 man-sys-man .man

4
distrib/sets/lists/modules/mi
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@ -1,4 +1,4 @@
# $NetBSD: mi,v 1.147 2021/10/03 17:27:02 brad Exp $
# $NetBSD: mi,v 1.148 2021/10/14 13:54:46 brad Exp $
#
# Note: don't delete entries from here - mark them as "obsolete" instead.
#
@ -397,6 +397,8 @@
./@MODULEDIR@/securelevel/securelevel.kmod modules-base-kernel kmod
./@MODULEDIR@/sequencer modules-base-kernel kmod
./@MODULEDIR@/sequencer/sequencer.kmod modules-base-kernel kmod
./@MODULEDIR@/sgp40mox modules-base-kernel kmod
./@MODULEDIR@/sgp40mox/sgp40mox.kmod modules-base-kernel kmod
./@MODULEDIR@/sht4xtemp modules-base-kernel kmod
./@MODULEDIR@/sht4xtemp/sht4xtemp.kmod modules-base-kernel kmod
./@MODULEDIR@/si70xxtemp modules-base-kernel kmod

6
share/man/man4/Makefile
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@ -1,4 +1,4 @@
# $NetBSD: Makefile,v 1.717 2021/10/12 04:55:19 msaitoh Exp $
# $NetBSD: Makefile,v 1.718 2021/10/14 13:54:45 brad Exp $
# @(#)Makefile 8.1 (Berkeley) 6/18/93
MAN= aac.4 ac97.4 acardide.4 aceride.4 acphy.4 \
@ -56,8 +56,8 @@ MAN= aac.4 ac97.4 acardide.4 aceride.4 acphy.4 \
rnd.4 route.4 rs5c372rtc.4 rtk.4 rtsx.4 rtw.4 rtwn.4 rum.4 run.4 \
s390rtc.4 satalink.4 sbus.4 schide.4 \
scsi.4 sctp.4 sd.4 se.4 seeprom.4 sem.4 \
ses.4 sf.4 sfb.4 sgsmix.4 shb.4 shmif.4 shpcic.4 sht4xtemp.4 si70xxtemp.4 \
siisata.4 siop.4 sip.4 siside.4 sk.4 sl.4 slide.4 \
ses.4 sf.4 sfb.4 sgp40mox.4 sgsmix.4 shb.4 shmif.4 shpcic.4 sht4xtemp.4 \
si70xxtemp.4 siisata.4 siop.4 sip.4 siside.4 sk.4 sl.4 slide.4 \
sm.4 smscphy.4 smsh.4 sn.4 sony.4 spc.4 speaker.4 spif.4 sqphy.4 \
srt.4 ss.4 \
ssdfb.4 st.4 ste.4 stge.4 sti.4 stpcide.4 sv.4 \

107
share/man/man4/sgp40mox.4 Normal file
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@ -0,0 +1,107 @@
.\" $NetBSD: sgp40mox.4,v 1.1 2021/10/14 13:54:45 brad Exp $
.\"
.\" Copyright (c) 2021 Brad Spencer <brad@anduin.eldar.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd October 7, 2021
.Dt SGP40MOX 4
.Os
.Sh NAME
.Nm sgp40mox
.Nd Driver for Sensirion SGP40 MOx gas sensor
.Sh SYNOPSIS
.Cd "sgp40mox* at iic? addr 0x59"
.Sh DESCRIPTION
The
.Nm
driver provides an air quality measurement from the SGP40
sensor via the
.Xr envsys 4
framework.
The
.Nm
.Ar addr
argument selects the address at the
.Xr iic 4
bus.
The crc validity and temperature and %RH compensation can be changed through
.Xr sysctl 8
nodes.
.Pp
In order to calculate the VOC index, the volatile organic compounds index, which
is the measure of air quality the sensor is polled once a second and the raw sensor
value is fed into the Sensirion VOC algorithm. This VOC algorithm used in this driver
is licensed under a 3 clause BSD license and was pulled from the Sensirion Github
repository at
.Rs
.%U https://github.com/Sensirion/embedded-sgp
.Re
.Sh SYSCTL VARIABLES
The following
.Xr sysctl 3
variables are provided:
.Bl -tag -width indent
.It Li hw.sgp40mox0.compensation.temperature
This should be set to the temperature in Celsius of the environment that the sensor
is in. The valid values are from -45 to 130 degrees Celsius.
.It Li hw.sgp40mox0.compensation.humidity
This should be set to the %RH of the environment that the sensor is in. The valid
values are from 0 to 100.
.Pp
For the best performance of the VOC algorithm it is important that the temperature
and %RH compensation values be current and set using the
.Xr sysctl 3
variables mentioned above.
This data will need to be pulled from another source, such as a another sensor in
the environment that the SGP40 is in.
.It Li hw.sgp40mox0.ignorecrc
If set, the crc calculation will be ignored on the calls to the chip for the purposes
of measurement.
.It Li hw.sgp40mox0.debug
If the driver is compiled with
.Dv SGP40_DEBUG ,
this node will appear and can be used to set the debugging level.
.It Li hw.sgp40mox0.readattempts
To read the air quality metric from the chip requires that the command be sent,
then a delay must be observed before a read can be done to get the values
back.
The delays are documented in the data sheet for the chip.
The driver will attempt to read back the values readattempts number of
times.
The default is 10 which should be more than enough for most purposes.
.El
.Sh SEE ALSO
.Xr envsys 4 ,
.Xr iic 4 ,
.Xr envstat 8 ,
.Xr sysctl 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Nx 10.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Brad Spencer Aq Mt brad@anduin.eldar.org .
.Sh BUGS
The driver does not make complete use of the VOC algorithm. In particular, there is no
need to restart the algorithm from scratch if there is a stoppage of polling for less than
10 minutes. The driver does not have the ability to determine that, and therefore
assumes that the sensor is completely cold each time the driver attaches to the chip.
.Pp
The temperature and humidity compensation could be allowed to contain fractional degrees Celsius
and %RH. The driver only supports setting whole numbers for either of those.

8
sys/dev/i2c/files.i2c
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@ -1,4 +1,4 @@
# $NetBSD: files.i2c,v 1.117 2021/10/03 17:27:02 brad Exp $
# $NetBSD: files.i2c,v 1.118 2021/10/14 13:54:46 brad Exp $
obsolete defflag opt_i2cbus.h I2C_SCAN
define i2cbus { }
@ -400,6 +400,12 @@ device sht4xtemp
attach sht4xtemp at iic
file dev/i2c/sht4x.c sht4xtemp
# Sensirion SGP40 MOx gas sensor
device sgp40mox
attach sgp40mox at iic
file dev/i2c/sgp40.c sgp40mox
file dev/i2c/sensirion_voc_algorithm.c sgp40mox
# Philips PCA955x GPIO
device pcagpio: leds
attach pcagpio at iic

33
sys/dev/i2c/sensirion_arch_config.h Normal file
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@ -0,0 +1,33 @@
/* $NetBSD: sensirion_arch_config.h,v 1.1 2021/10/14 13:54:46 brad Exp $ */
/*
* Copyright (c) 2021 Brad Spencer <brad@anduin.eldar.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGL`IGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* The Sensirion code wants a file called sensirion_arch_config.h. This
is the shim for NetBSD
*/
#ifndef SENSIRION_ARCH_CONFIG_H
#define SENSIRION_ARCH_CONFIG_H
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#endif /* SENSIRION_ARCH_CONFIG_H */

809
sys/dev/i2c/sensirion_voc_algorithm.c Normal file
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@ -0,0 +1,809 @@
/*
* $NetBSD: sensirion_voc_algorithm.c,v 1.1 2021/10/14 13:54:46 brad Exp $
*/
/*
* Copyright (c) 2021, Sensirion AG
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of Sensirion AG nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "sensirion_voc_algorithm.h"
/* The fixed point arithmetic parts of this code were originally created by
* https://github.com/PetteriAimonen/libfixmath
*/
/*!< the maximum value of fix16_t */
#define FIX16_MAXIMUM 0x7FFFFFFF
/*!< the minimum value of fix16_t */
#define FIX16_MINIMUM 0x80000000
/*!< the value used to indicate overflows when FIXMATH_NO_OVERFLOW is not
* specified */
#define FIX16_OVERFLOW 0x80000000
/*!< fix16_t value of 1 */
#define FIX16_ONE 0x00010000
static inline fix16_t fix16_from_int(int32_t a) {
return a * FIX16_ONE;
}
static inline int32_t fix16_cast_to_int(fix16_t a) {
return (a >= 0) ? (a >> 16) : -((-a) >> 16);
}
/*! Multiplies the two given fix16_t's and returns the result. */
static fix16_t fix16_mul(fix16_t inArg0, fix16_t inArg1);
/*! Divides the first given fix16_t by the second and returns the result. */
static fix16_t fix16_div(fix16_t inArg0, fix16_t inArg1);
/*! Returns the square root of the given fix16_t. */
static fix16_t fix16_sqrt(fix16_t inValue);
/*! Returns the exponent (e^) of the given fix16_t. */
static fix16_t fix16_exp(fix16_t inValue);
static fix16_t fix16_mul(fix16_t inArg0, fix16_t inArg1) {
// Each argument is divided to 16-bit parts.
// AB
// * CD
// -----------
// BD 16 * 16 -> 32 bit products
// CB
// AD
// AC
// |----| 64 bit product
uint32_t absArg0 = (uint32_t)((inArg0 >= 0) ? inArg0 : (-inArg0));
uint32_t absArg1 = (uint32_t)((inArg1 >= 0) ? inArg1 : (-inArg1));
uint32_t A = (absArg0 >> 16), C = (absArg1 >> 16);
uint32_t B = (absArg0 & 0xFFFF), D = (absArg1 & 0xFFFF);
uint32_t AC = A * C;
uint32_t AD_CB = A * D + C * B;
uint32_t BD = B * D;
uint32_t product_hi = AC + (AD_CB >> 16);
// Handle carry from lower 32 bits to upper part of result.
uint32_t ad_cb_temp = AD_CB << 16;
uint32_t product_lo = BD + ad_cb_temp;
if (product_lo < BD)
product_hi++;
#ifndef FIXMATH_NO_OVERFLOW
// The upper 17 bits should all be zero.
if (product_hi >> 15)
return (fix16_t)FIX16_OVERFLOW;
#endif
#ifdef FIXMATH_NO_ROUNDING
fix16_t result = (fix16_t)((product_hi << 16) | (product_lo >> 16));
if ((inArg0 < 0) != (inArg1 < 0))
result = -result;
return result;
#else
// Adding 0x8000 (= 0.5) and then using right shift
// achieves proper rounding to result.
// Handle carry from lower to upper part.
uint32_t product_lo_tmp = product_lo;
product_lo += 0x8000;
if (product_lo < product_lo_tmp)
product_hi++;
// Discard the lowest 16 bits and convert back to signed result.
fix16_t result = (fix16_t)((product_hi << 16) | (product_lo >> 16));
if ((inArg0 < 0) != (inArg1 < 0))
result = -result;
return result;
#endif
}
static fix16_t fix16_div(fix16_t a, fix16_t b) {
// This uses the basic binary restoring division algorithm.
// It appears to be faster to do the whole division manually than
// trying to compose a 64-bit divide out of 32-bit divisions on
// platforms without hardware divide.
if (b == 0)
return (fix16_t)FIX16_MINIMUM;
uint32_t remainder = (uint32_t)((a >= 0) ? a : (-a));
uint32_t divider = (uint32_t)((b >= 0) ? b : (-b));
uint32_t quotient = 0;
uint32_t bit = 0x10000;
/* The algorithm requires D >= R */
while (divider < remainder) {
divider <<= 1;
bit <<= 1;
}
#ifndef FIXMATH_NO_OVERFLOW
if (!bit)
return (fix16_t)FIX16_OVERFLOW;
#endif
if (divider & 0x80000000) {
// Perform one step manually to avoid overflows later.
// We know that divider's bottom bit is 0 here.
if (remainder >= divider) {
quotient |= bit;
remainder -= divider;
}
divider >>= 1;
bit >>= 1;
}
/* Main division loop */
while (bit && remainder) {
if (remainder >= divider) {
quotient |= bit;
remainder -= divider;
}
remainder <<= 1;
bit >>= 1;
}
#ifndef FIXMATH_NO_ROUNDING
if (remainder >= divider) {
quotient++;
}
#endif
fix16_t result = (fix16_t)quotient;
/* Figure out the sign of result */
if ((a < 0) != (b < 0)) {
#ifndef FIXMATH_NO_OVERFLOW
if (result == FIX16_MINIMUM)
return (fix16_t)FIX16_OVERFLOW;
#endif
result = -result;
}
return result;
}
static fix16_t fix16_sqrt(fix16_t x) {
// It is assumed that x is not negative
uint32_t num = (uint32_t)x;
uint32_t result = 0;
uint32_t bit;
uint8_t n;
bit = (uint32_t)1 << 30;
while (bit > num)
bit >>= 2;
// The main part is executed twice, in order to avoid
// using 64 bit values in computations.
for (n = 0; n < 2; n++) {
// First we get the top 24 bits of the answer.
while (bit) {
if (num >= result + bit) {
num -= result + bit;
result = (result >> 1) + bit;
} else {
result = (result >> 1);
}
bit >>= 2;
}
if (n == 0) {
// Then process it again to get the lowest 8 bits.
if (num > 65535) {
// The remainder 'num' is too large to be shifted left
// by 16, so we have to add 1 to result manually and
// adjust 'num' accordingly.
// num = a - (result + 0.5)^2
// = num + result^2 - (result + 0.5)^2
// = num - result - 0.5
num -= result;
num = (num << 16) - 0x8000;
result = (result << 16) + 0x8000;
} else {
num <<= 16;
result <<= 16;
}
bit = 1 << 14;
}
}
#ifndef FIXMATH_NO_ROUNDING
// Finally, if next bit would have been 1, round the result upwards.
if (num > result) {
result++;
}
#endif
return (fix16_t)result;
}
static fix16_t fix16_exp(fix16_t x) {
// Function to approximate exp(); optimized more for code size than speed
// exp(x) for x = +/- {1, 1/8, 1/64, 1/512}
#define NUM_EXP_VALUES 4
static const fix16_t exp_pos_values[NUM_EXP_VALUES] = {
F16(2.7182818), F16(1.1331485), F16(1.0157477), F16(1.0019550)};
static const fix16_t exp_neg_values[NUM_EXP_VALUES] = {
F16(0.3678794), F16(0.8824969), F16(0.9844964), F16(0.9980488)};
const fix16_t* exp_values;
fix16_t res, arg;
uint16_t i;
if (x >= F16(10.3972))
return FIX16_MAXIMUM;
if (x <= F16(-11.7835))
return 0;
if (x < 0) {
x = -x;
exp_values = exp_neg_values;
} else {
exp_values = exp_pos_values;
}
res = FIX16_ONE;
arg = FIX16_ONE;
for (i = 0; i < NUM_EXP_VALUES; i++) {
while (x >= arg) {
res = fix16_mul(res, exp_values[i]);
x -= arg;
}
arg >>= 3;
}
return res;
}
static void VocAlgorithm__init_instances(VocAlgorithmParams* params);
static void
VocAlgorithm__mean_variance_estimator__init(VocAlgorithmParams* params);
static void VocAlgorithm__mean_variance_estimator___init_instances(
VocAlgorithmParams* params);
static void VocAlgorithm__mean_variance_estimator__set_parameters(
VocAlgorithmParams* params, fix16_t std_initial,
fix16_t tau_mean_variance_hours, fix16_t gating_max_duration_minutes);
static void
VocAlgorithm__mean_variance_estimator__set_states(VocAlgorithmParams* params,
fix16_t mean, fix16_t std,
fix16_t uptime_gamma);
static fix16_t
VocAlgorithm__mean_variance_estimator__get_std(VocAlgorithmParams* params);
static fix16_t
VocAlgorithm__mean_variance_estimator__get_mean(VocAlgorithmParams* params);
static void VocAlgorithm__mean_variance_estimator___calculate_gamma(
VocAlgorithmParams* params, fix16_t voc_index_from_prior);
static void VocAlgorithm__mean_variance_estimator__process(
VocAlgorithmParams* params, fix16_t sraw, fix16_t voc_index_from_prior);
static void VocAlgorithm__mean_variance_estimator___sigmoid__init(
VocAlgorithmParams* params);
static void VocAlgorithm__mean_variance_estimator___sigmoid__set_parameters(
VocAlgorithmParams* params, fix16_t L, fix16_t X0, fix16_t K);
static fix16_t VocAlgorithm__mean_variance_estimator___sigmoid__process(
VocAlgorithmParams* params, fix16_t sample);
static void VocAlgorithm__mox_model__init(VocAlgorithmParams* params);
static void VocAlgorithm__mox_model__set_parameters(VocAlgorithmParams* params,
fix16_t SRAW_STD,
fix16_t SRAW_MEAN);
static fix16_t VocAlgorithm__mox_model__process(VocAlgorithmParams* params,
fix16_t sraw);
static void VocAlgorithm__sigmoid_scaled__init(VocAlgorithmParams* params);
static void
VocAlgorithm__sigmoid_scaled__set_parameters(VocAlgorithmParams* params,
fix16_t offset);
static fix16_t VocAlgorithm__sigmoid_scaled__process(VocAlgorithmParams* params,
fix16_t sample);
static void VocAlgorithm__adaptive_lowpass__init(VocAlgorithmParams* params);
static void
VocAlgorithm__adaptive_lowpass__set_parameters(VocAlgorithmParams* params);
static fix16_t
VocAlgorithm__adaptive_lowpass__process(VocAlgorithmParams* params,
fix16_t sample);
void VocAlgorithm_init(VocAlgorithmParams* params) {
params->mVoc_Index_Offset = F16(VocAlgorithm_VOC_INDEX_OFFSET_DEFAULT);
params->mTau_Mean_Variance_Hours =
F16(VocAlgorithm_TAU_MEAN_VARIANCE_HOURS);
params->mGating_Max_Duration_Minutes =
F16(VocAlgorithm_GATING_MAX_DURATION_MINUTES);
params->mSraw_Std_Initial = F16(VocAlgorithm_SRAW_STD_INITIAL);
params->mUptime = F16(0.);
params->mSraw = F16(0.);
params->mVoc_Index = 0;
VocAlgorithm__init_instances(params);
}
static void VocAlgorithm__init_instances(VocAlgorithmParams* params) {
VocAlgorithm__mean_variance_estimator__init(params);
VocAlgorithm__mean_variance_estimator__set_parameters(
params, params->mSraw_Std_Initial, params->mTau_Mean_Variance_Hours,
params->mGating_Max_Duration_Minutes);
VocAlgorithm__mox_model__init(params);
VocAlgorithm__mox_model__set_parameters(
params, VocAlgorithm__mean_variance_estimator__get_std(params),
VocAlgorithm__mean_variance_estimator__get_mean(params));
VocAlgorithm__sigmoid_scaled__init(params);
VocAlgorithm__sigmoid_scaled__set_parameters(params,
params->mVoc_Index_Offset);
VocAlgorithm__adaptive_lowpass__init(params);
VocAlgorithm__adaptive_lowpass__set_parameters(params);
}
void VocAlgorithm_get_states(VocAlgorithmParams* params, int32_t* state0,
int32_t* state1) {
*state0 = VocAlgorithm__mean_variance_estimator__get_mean(params);
*state1 = VocAlgorithm__mean_variance_estimator__get_std(params);
return;
}
void VocAlgorithm_set_states(VocAlgorithmParams* params, int32_t state0,
int32_t state1) {
VocAlgorithm__mean_variance_estimator__set_states(
params, state0, state1, F16(VocAlgorithm_PERSISTENCE_UPTIME_GAMMA));
params->mSraw = state0;
}
void VocAlgorithm_set_tuning_parameters(VocAlgorithmParams* params,
int32_t voc_index_offset,
int32_t learning_time_hours,
int32_t gating_max_duration_minutes,
int32_t std_initial) {
params->mVoc_Index_Offset = (fix16_from_int(voc_index_offset));
params->mTau_Mean_Variance_Hours = (fix16_from_int(learning_time_hours));
params->mGating_Max_Duration_Minutes =
(fix16_from_int(gating_max_duration_minutes));
params->mSraw_Std_Initial = (fix16_from_int(std_initial));
VocAlgorithm__init_instances(params);
}
void VocAlgorithm_process(VocAlgorithmParams* params, int32_t sraw,
int32_t* voc_index) {
if ((params->mUptime <= F16(VocAlgorithm_INITIAL_BLACKOUT))) {
params->mUptime =
(params->mUptime + F16(VocAlgorithm_SAMPLING_INTERVAL));
} else {
if (((sraw > 0) && (sraw < 65000))) {
if ((sraw < 20001)) {
sraw = 20001;
} else if ((sraw > 52767)) {
sraw = 52767;
}
params->mSraw = (fix16_from_int((sraw - 20000)));
}
params->mVoc_Index =
VocAlgorithm__mox_model__process(params, params->mSraw);
params->mVoc_Index =
VocAlgorithm__sigmoid_scaled__process(params, params->mVoc_Index);
params->mVoc_Index =
VocAlgorithm__adaptive_lowpass__process(params, params->mVoc_Index);
if ((params->mVoc_Index < F16(0.5))) {
params->mVoc_Index = F16(0.5);
}
if ((params->mSraw > F16(0.))) {
VocAlgorithm__mean_variance_estimator__process(
params, params->mSraw, params->mVoc_Index);
VocAlgorithm__mox_model__set_parameters(
params, VocAlgorithm__mean_variance_estimator__get_std(params),
VocAlgorithm__mean_variance_estimator__get_mean(params));
}
}
*voc_index = (fix16_cast_to_int((params->mVoc_Index + F16(0.5))));
return;
}
static void
VocAlgorithm__mean_variance_estimator__init(VocAlgorithmParams* params) {
VocAlgorithm__mean_variance_estimator__set_parameters(params, F16(0.),
F16(0.), F16(0.));
VocAlgorithm__mean_variance_estimator___init_instances(params);
}
static void VocAlgorithm__mean_variance_estimator___init_instances(
VocAlgorithmParams* params) {
VocAlgorithm__mean_variance_estimator___sigmoid__init(params);
}
static void VocAlgorithm__mean_variance_estimator__set_parameters(
VocAlgorithmParams* params, fix16_t std_initial,
fix16_t tau_mean_variance_hours, fix16_t gating_max_duration_minutes) {
params->m_Mean_Variance_Estimator__Gating_Max_Duration_Minutes =
gating_max_duration_minutes;
params->m_Mean_Variance_Estimator___Initialized = false;
params->m_Mean_Variance_Estimator___Mean = F16(0.);
params->m_Mean_Variance_Estimator___Sraw_Offset = F16(0.);
params->m_Mean_Variance_Estimator___Std = std_initial;
params->m_Mean_Variance_Estimator___Gamma =
(fix16_div(F16((VocAlgorithm_MEAN_VARIANCE_ESTIMATOR__GAMMA_SCALING *
(VocAlgorithm_SAMPLING_INTERVAL / 3600.))),
(tau_mean_variance_hours +
F16((VocAlgorithm_SAMPLING_INTERVAL / 3600.)))));
params->m_Mean_Variance_Estimator___Gamma_Initial_Mean =
F16(((VocAlgorithm_MEAN_VARIANCE_ESTIMATOR__GAMMA_SCALING *
VocAlgorithm_SAMPLING_INTERVAL) /
(VocAlgorithm_TAU_INITIAL_MEAN + VocAlgorithm_SAMPLING_INTERVAL)));
params->m_Mean_Variance_Estimator___Gamma_Initial_Variance = F16(
((VocAlgorithm_MEAN_VARIANCE_ESTIMATOR__GAMMA_SCALING *
VocAlgorithm_SAMPLING_INTERVAL) /
(VocAlgorithm_TAU_INITIAL_VARIANCE + VocAlgorithm_SAMPLING_INTERVAL)));
params->m_Mean_Variance_Estimator__Gamma_Mean = F16(0.);
params->m_Mean_Variance_Estimator__Gamma_Variance = F16(0.);
params->m_Mean_Variance_Estimator___Uptime_Gamma = F16(0.);
params->m_Mean_Variance_Estimator___Uptime_Gating = F16(0.);
params->m_Mean_Variance_Estimator___Gating_Duration_Minutes = F16(0.);
}
static void
VocAlgorithm__mean_variance_estimator__set_states(VocAlgorithmParams* params,
fix16_t mean, fix16_t std,
fix16_t uptime_gamma) {
params->m_Mean_Variance_Estimator___Mean = mean;
params->m_Mean_Variance_Estimator___Std = std;
params->m_Mean_Variance_Estimator___Uptime_Gamma = uptime_gamma;
params->m_Mean_Variance_Estimator___Initialized = true;
}
static fix16_t
VocAlgorithm__mean_variance_estimator__get_std(VocAlgorithmParams* params) {
return params->m_Mean_Variance_Estimator___Std;
}
static fix16_t
VocAlgorithm__mean_variance_estimator__get_mean(VocAlgorithmParams* params) {
return (params->m_Mean_Variance_Estimator___Mean +
params->m_Mean_Variance_Estimator___Sraw_Offset);
}
static void VocAlgorithm__mean_variance_estimator___calculate_gamma(
VocAlgorithmParams* params, fix16_t voc_index_from_prior) {
fix16_t uptime_limit;
fix16_t sigmoid_gamma_mean;
fix16_t gamma_mean;
fix16_t gating_threshold_mean;
fix16_t sigmoid_gating_mean;
fix16_t sigmoid_gamma_variance;
fix16_t gamma_variance;
fix16_t gating_threshold_variance;
fix16_t sigmoid_gating_variance;
uptime_limit = F16((VocAlgorithm_MEAN_VARIANCE_ESTIMATOR__FIX16_MAX -
VocAlgorithm_SAMPLING_INTERVAL));
if ((params->m_Mean_Variance_Estimator___Uptime_Gamma < uptime_limit)) {
params->m_Mean_Variance_Estimator___Uptime_Gamma =
(params->m_Mean_Variance_Estimator___Uptime_Gamma +
F16(VocAlgorithm_SAMPLING_INTERVAL));
}
if ((params->m_Mean_Variance_Estimator___Uptime_Gating < uptime_limit)) {
params->m_Mean_Variance_Estimator___Uptime_Gating =
(params->m_Mean_Variance_Estimator___Uptime_Gating +
F16(VocAlgorithm_SAMPLING_INTERVAL));
}
VocAlgorithm__mean_variance_estimator___sigmoid__set_parameters(
params, F16(1.), F16(VocAlgorithm_INIT_DURATION_MEAN),
F16(VocAlgorithm_INIT_TRANSITION_MEAN));
sigmoid_gamma_mean =
VocAlgorithm__mean_variance_estimator___sigmoid__process(
params, params->m_Mean_Variance_Estimator___Uptime_Gamma);
gamma_mean =
(params->m_Mean_Variance_Estimator___Gamma +
(fix16_mul((params->m_Mean_Variance_Estimator___Gamma_Initial_Mean -
params->m_Mean_Variance_Estimator___Gamma),
sigmoid_gamma_mean)));
gating_threshold_mean =
(F16(VocAlgorithm_GATING_THRESHOLD) +
(fix16_mul(
F16((VocAlgorithm_GATING_THRESHOLD_INITIAL -
VocAlgorithm_GATING_THRESHOLD)),
VocAlgorithm__mean_variance_estimator___sigmoid__process(
params, params->m_Mean_Variance_Estimator___Uptime_Gating))));
VocAlgorithm__mean_variance_estimator___sigmoid__set_parameters(
params, F16(1.), gating_threshold_mean,
F16(VocAlgorithm_GATING_THRESHOLD_TRANSITION));
sigmoid_gating_mean =
VocAlgorithm__mean_variance_estimator___sigmoid__process(
params, voc_index_from_prior);
params->m_Mean_Variance_Estimator__Gamma_Mean =
(fix16_mul(sigmoid_gating_mean, gamma_mean));
VocAlgorithm__mean_variance_estimator___sigmoid__set_parameters(
params, F16(1.), F16(VocAlgorithm_INIT_DURATION_VARIANCE),
F16(VocAlgorithm_INIT_TRANSITION_VARIANCE));
sigmoid_gamma_variance =
VocAlgorithm__mean_variance_estimator___sigmoid__process(
params, params->m_Mean_Variance_Estimator___Uptime_Gamma);
gamma_variance =
(params->m_Mean_Variance_Estimator___Gamma +
(fix16_mul(
(params->m_Mean_Variance_Estimator___Gamma_Initial_Variance -
params->m_Mean_Variance_Estimator___Gamma),
(sigmoid_gamma_variance - sigmoid_gamma_mean))));
gating_threshold_variance =
(F16(VocAlgorithm_GATING_THRESHOLD) +
(fix16_mul(
F16((VocAlgorithm_GATING_THRESHOLD_INITIAL -
VocAlgorithm_GATING_THRESHOLD)),
VocAlgorithm__mean_variance_estimator___sigmoid__process(
params, params->m_Mean_Variance_Estimator___Uptime_Gating))));
VocAlgorithm__mean_variance_estimator___sigmoid__set_parameters(
params, F16(1.), gating_threshold_variance,
F16(VocAlgorithm_GATING_THRESHOLD_TRANSITION));
sigmoid_gating_variance =
VocAlgorithm__mean_variance_estimator___sigmoid__process(
params, voc_index_from_prior);
params->m_Mean_Variance_Estimator__Gamma_Variance =
(fix16_mul(sigmoid_gating_variance, gamma_variance));
params->m_Mean_Variance_Estimator___Gating_Duration_Minutes =
(params->m_Mean_Variance_Estimator___Gating_Duration_Minutes +
(fix16_mul(F16((VocAlgorithm_SAMPLING_INTERVAL / 60.)),
((fix16_mul((F16(1.) - sigmoid_gating_mean),
F16((1. + VocAlgorithm_GATING_MAX_RATIO)))) -
F16(VocAlgorithm_GATING_MAX_RATIO)))));
if ((params->m_Mean_Variance_Estimator___Gating_Duration_Minutes <
F16(0.))) {
params->m_Mean_Variance_Estimator___Gating_Duration_Minutes = F16(0.);
}
if ((params->m_Mean_Variance_Estimator___Gating_Duration_Minutes >
params->m_Mean_Variance_Estimator__Gating_Max_Duration_Minutes)) {
params->m_Mean_Variance_Estimator___Uptime_Gating = F16(0.);
}
}
static void VocAlgorithm__mean_variance_estimator__process(
VocAlgorithmParams* params, fix16_t sraw, fix16_t voc_index_from_prior) {
fix16_t delta_sgp;
fix16_t c;
fix16_t additional_scaling;
if ((params->m_Mean_Variance_Estimator___Initialized == false)) {
params->m_Mean_Variance_Estimator___Initialized = true;
params->m_Mean_Variance_Estimator___Sraw_Offset = sraw;
params->m_Mean_Variance_Estimator___Mean = F16(0.);
} else {
if (((params->m_Mean_Variance_Estimator___Mean >= F16(100.)) ||
(params->m_Mean_Variance_Estimator___Mean <= F16(-100.)))) {
params->m_Mean_Variance_Estimator___Sraw_Offset =
(params->m_Mean_Variance_Estimator___Sraw_Offset +
params->m_Mean_Variance_Estimator___Mean);
params->m_Mean_Variance_Estimator___Mean = F16(0.);
}
sraw = (sraw - params->m_Mean_Variance_Estimator___Sraw_Offset);
VocAlgorithm__mean_variance_estimator___calculate_gamma(
params, voc_index_from_prior);
delta_sgp = (fix16_div(
(sraw - params->m_Mean_Variance_Estimator___Mean),
F16(VocAlgorithm_MEAN_VARIANCE_ESTIMATOR__GAMMA_SCALING)));
if ((delta_sgp < F16(0.))) {
c = (params->m_Mean_Variance_Estimator___Std - delta_sgp);
} else {
c = (params->m_Mean_Variance_Estimator___Std + delta_sgp);
}
additional_scaling = F16(1.);
if ((c > F16(1440.))) {
additional_scaling = F16(4.);
}
params->m_Mean_Variance_Estimator___Std = (fix16_mul(
fix16_sqrt((fix16_mul(
additional_scaling,
(F16(VocAlgorithm_MEAN_VARIANCE_ESTIMATOR__GAMMA_SCALING) -
params->m_Mean_Variance_Estimator__Gamma_Variance)))),
fix16_sqrt((
(fix16_mul(
params->m_Mean_Variance_Estimator___Std,
(fix16_div(
params->m_Mean_Variance_Estimator___Std,
(fix16_mul(
F16(VocAlgorithm_MEAN_VARIANCE_ESTIMATOR__GAMMA_SCALING),
additional_scaling)))))) +
(fix16_mul(
(fix16_div(
(fix16_mul(
params->m_Mean_Variance_Estimator__Gamma_Variance,
delta_sgp)),
additional_scaling)),
delta_sgp))))));
params->m_Mean_Variance_Estimator___Mean =
(params->m_Mean_Variance_Estimator___Mean +
(fix16_mul(params->m_Mean_Variance_Estimator__Gamma_Mean,
delta_sgp)));
}
}
static void VocAlgorithm__mean_variance_estimator___sigmoid__init(
VocAlgorithmParams* params) {
VocAlgorithm__mean_variance_estimator___sigmoid__set_parameters(
params, F16(0.), F16(0.), F16(0.));
}
static void VocAlgorithm__mean_variance_estimator___sigmoid__set_parameters(
VocAlgorithmParams* params, fix16_t L, fix16_t X0, fix16_t K) {
params->m_Mean_Variance_Estimator___Sigmoid__L = L;
params->m_Mean_Variance_Estimator___Sigmoid__K = K;
params->m_Mean_Variance_Estimator___Sigmoid__X0 = X0;
}
static fix16_t VocAlgorithm__mean_variance_estimator___sigmoid__process(
VocAlgorithmParams* params, fix16_t sample) {
fix16_t x;
x = (fix16_mul(params->m_Mean_Variance_Estimator___Sigmoid__K,
(sample - params->m_Mean_Variance_Estimator___Sigmoid__X0)));
if ((x < F16(-50.))) {
return params->m_Mean_Variance_Estimator___Sigmoid__L;
} else if ((x > F16(50.))) {
return F16(0.);
} else {
return (fix16_div(params->m_Mean_Variance_Estimator___Sigmoid__L,
(F16(1.) + fix16_exp(x))));
}
}
static void VocAlgorithm__mox_model__init(VocAlgorithmParams* params) {
VocAlgorithm__mox_model__set_parameters(params, F16(1.), F16(0.));
}
static void VocAlgorithm__mox_model__set_parameters(VocAlgorithmParams* params,
fix16_t SRAW_STD,
fix16_t SRAW_MEAN) {
params->m_Mox_Model__Sraw_Std = SRAW_STD;
params->m_Mox_Model__Sraw_Mean = SRAW_MEAN;
}
static fix16_t VocAlgorithm__mox_model__process(VocAlgorithmParams* params,
fix16_t sraw) {
return (fix16_mul((fix16_div((sraw - params->m_Mox_Model__Sraw_Mean),
(-(params->m_Mox_Model__Sraw_Std +
F16(VocAlgorithm_SRAW_STD_BONUS))))),
F16(VocAlgorithm_VOC_INDEX_GAIN)));
}
static void VocAlgorithm__sigmoid_scaled__init(VocAlgorithmParams* params) {
VocAlgorithm__sigmoid_scaled__set_parameters(params, F16(0.));
}
static void
VocAlgorithm__sigmoid_scaled__set_parameters(VocAlgorithmParams* params,
fix16_t offset) {
params->m_Sigmoid_Scaled__Offset = offset;
}
static fix16_t VocAlgorithm__sigmoid_scaled__process(VocAlgorithmParams* params,
fix16_t sample) {
fix16_t x;
fix16_t shift;
x = (fix16_mul(F16(VocAlgorithm_SIGMOID_K),
(sample - F16(VocAlgorithm_SIGMOID_X0))));
if ((x < F16(-50.))) {
return F16(VocAlgorithm_SIGMOID_L);
} else if ((x > F16(50.))) {
return F16(0.);
} else {
if ((sample >= F16(0.))) {
shift = (fix16_div(
(F16(VocAlgorithm_SIGMOID_L) -
(fix16_mul(F16(5.), params->m_Sigmoid_Scaled__Offset))),
F16(4.)));
return ((fix16_div((F16(VocAlgorithm_SIGMOID_L) + shift),
(F16(1.) + fix16_exp(x)))) -
shift);
} else {
return (fix16_mul(
(fix16_div(params->m_Sigmoid_Scaled__Offset,
F16(VocAlgorithm_VOC_INDEX_OFFSET_DEFAULT))),
(fix16_div(F16(VocAlgorithm_SIGMOID_L),
(F16(1.) + fix16_exp(x))))));
}
}
}
static void VocAlgorithm__adaptive_lowpass__init(VocAlgorithmParams* params) {
VocAlgorithm__adaptive_lowpass__set_parameters(params);
}
static void
VocAlgorithm__adaptive_lowpass__set_parameters(VocAlgorithmParams* params) {
params->m_Adaptive_Lowpass__A1 =
F16((VocAlgorithm_SAMPLING_INTERVAL /
(VocAlgorithm_LP_TAU_FAST + VocAlgorithm_SAMPLING_INTERVAL)));
params->m_Adaptive_Lowpass__A2 =
F16((VocAlgorithm_SAMPLING_INTERVAL /
(VocAlgorithm_LP_TAU_SLOW + VocAlgorithm_SAMPLING_INTERVAL)));
params->m_Adaptive_Lowpass___Initialized = false;
}
static fix16_t
VocAlgorithm__adaptive_lowpass__process(VocAlgorithmParams* params,
fix16_t sample) {
fix16_t abs_delta;
fix16_t F1;
fix16_t tau_a;
fix16_t a3;
if ((params->m_Adaptive_Lowpass___Initialized == false)) {
params->m_Adaptive_Lowpass___X1 = sample;
params->m_Adaptive_Lowpass___X2 = sample;
params->m_Adaptive_Lowpass___X3 = sample;
params->m_Adaptive_Lowpass___Initialized = true;
}
params->m_Adaptive_Lowpass___X1 =
((fix16_mul((F16(1.) - params->m_Adaptive_Lowpass__A1),
params->m_Adaptive_Lowpass___X1)) +
(fix16_mul(params->m_Adaptive_Lowpass__A1, sample)));
params->m_Adaptive_Lowpass___X2 =
((fix16_mul((F16(1.) - params->m_Adaptive_Lowpass__A2),
params->m_Adaptive_Lowpass___X2)) +
(fix16_mul(params->m_Adaptive_Lowpass__A2, sample)));
abs_delta =
(params->m_Adaptive_Lowpass___X1 - params->m_Adaptive_Lowpass___X2);
if ((abs_delta < F16(0.))) {
abs_delta = (-abs_delta);
}
F1 = fix16_exp((fix16_mul(F16(VocAlgorithm_LP_ALPHA), abs_delta)));
tau_a =
((fix16_mul(F16((VocAlgorithm_LP_TAU_SLOW - VocAlgorithm_LP_TAU_FAST)),
F1)) +
F16(VocAlgorithm_LP_TAU_FAST));
a3 = (fix16_div(F16(VocAlgorithm_SAMPLING_INTERVAL),
(F16(VocAlgorithm_SAMPLING_INTERVAL) + tau_a)));
params->m_Adaptive_Lowpass___X3 =
((fix16_mul((F16(1.) - a3), params->m_Adaptive_Lowpass___X3)) +
(fix16_mul(a3, sample)));
return params->m_Adaptive_Lowpass___X3;
}

191
sys/dev/i2c/sensirion_voc_algorithm.h Normal file
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@ -0,0 +1,191 @@
/*
* $NetBSD: sensirion_voc_algorithm.h,v 1.1 2021/10/14 13:54:46 brad Exp $
*/
/*
* Copyright (c) 2021, Sensirion AG
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of Sensirion AG nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef VOCALGORITHM_H_
#define VOCALGORITHM_H_
#include "sensirion_arch_config.h"
/* The fixed point arithmetic parts of this code were originally created by
* https://github.com/PetteriAimonen/libfixmath
*/
typedef int32_t fix16_t;
#define F16(x) \
((fix16_t)(((x) >= 0) ? ((x)*65536.0 + 0.5) : ((x)*65536.0 - 0.5)))
// Should be set by the building toolchain
#ifndef LIBRARY_VERSION_NAME
#define LIBRARY_VERSION_NAME "custom build"
#endif
#define VocAlgorithm_SAMPLING_INTERVAL (1.)
#define VocAlgorithm_INITIAL_BLACKOUT (45.)
#define VocAlgorithm_VOC_INDEX_GAIN (230.)
#define VocAlgorithm_SRAW_STD_INITIAL (50.)
#define VocAlgorithm_SRAW_STD_BONUS (220.)
#define VocAlgorithm_TAU_MEAN_VARIANCE_HOURS (12.)
#define VocAlgorithm_TAU_INITIAL_MEAN (20.)
#define VocAlgorithm_INIT_DURATION_MEAN ((3600. * 0.75))
#define VocAlgorithm_INIT_TRANSITION_MEAN (0.01)
#define VocAlgorithm_TAU_INITIAL_VARIANCE (2500.)
#define VocAlgorithm_INIT_DURATION_VARIANCE ((3600. * 1.45))
#define VocAlgorithm_INIT_TRANSITION_VARIANCE (0.01)
#define VocAlgorithm_GATING_THRESHOLD (340.)
#define VocAlgorithm_GATING_THRESHOLD_INITIAL (510.)
#define VocAlgorithm_GATING_THRESHOLD_TRANSITION (0.09)
#define VocAlgorithm_GATING_MAX_DURATION_MINUTES ((60. * 3.))
#define VocAlgorithm_GATING_MAX_RATIO (0.3)
#define VocAlgorithm_SIGMOID_L (500.)
#define VocAlgorithm_SIGMOID_K (-0.0065)
#define VocAlgorithm_SIGMOID_X0 (213.)
#define VocAlgorithm_VOC_INDEX_OFFSET_DEFAULT (100.)
#define VocAlgorithm_LP_TAU_FAST (20.0)
#define VocAlgorithm_LP_TAU_SLOW (500.0)
#define VocAlgorithm_LP_ALPHA (-0.2)
#define VocAlgorithm_PERSISTENCE_UPTIME_GAMMA ((3. * 3600.))
#define VocAlgorithm_MEAN_VARIANCE_ESTIMATOR__GAMMA_SCALING (64.)
#define VocAlgorithm_MEAN_VARIANCE_ESTIMATOR__FIX16_MAX (32767.)
/**
* Struct to hold all the states of the VOC algorithm.
*/
typedef struct {
fix16_t mVoc_Index_Offset;
fix16_t mTau_Mean_Variance_Hours;
fix16_t mGating_Max_Duration_Minutes;
fix16_t mSraw_Std_Initial;
fix16_t mUptime;
fix16_t mSraw;
fix16_t mVoc_Index;
fix16_t m_Mean_Variance_Estimator__Gating_Max_Duration_Minutes;
bool m_Mean_Variance_Estimator___Initialized;
fix16_t m_Mean_Variance_Estimator___Mean;
fix16_t m_Mean_Variance_Estimator___Sraw_Offset;
fix16_t m_Mean_Variance_Estimator___Std;
fix16_t m_Mean_Variance_Estimator___Gamma;
fix16_t m_Mean_Variance_Estimator___Gamma_Initial_Mean;
fix16_t m_Mean_Variance_Estimator___Gamma_Initial_Variance;
fix16_t m_Mean_Variance_Estimator__Gamma_Mean;
fix16_t m_Mean_Variance_Estimator__Gamma_Variance;
fix16_t m_Mean_Variance_Estimator___Uptime_Gamma;
fix16_t m_Mean_Variance_Estimator___Uptime_Gating;
fix16_t m_Mean_Variance_Estimator___Gating_Duration_Minutes;
fix16_t m_Mean_Variance_Estimator___Sigmoid__L;
fix16_t m_Mean_Variance_Estimator___Sigmoid__K;
fix16_t m_Mean_Variance_Estimator___Sigmoid__X0;
fix16_t m_Mox_Model__Sraw_Std;
fix16_t m_Mox_Model__Sraw_Mean;
fix16_t m_Sigmoid_Scaled__Offset;
fix16_t m_Adaptive_Lowpass__A1;
fix16_t m_Adaptive_Lowpass__A2;
bool m_Adaptive_Lowpass___Initialized;
fix16_t m_Adaptive_Lowpass___X1;
fix16_t m_Adaptive_Lowpass___X2;
fix16_t m_Adaptive_Lowpass___X3;
} VocAlgorithmParams;
/**
* Initialize the VOC algorithm parameters. Call this once at the beginning or
* whenever the sensor stopped measurements.
* @param params Pointer to the VocAlgorithmParams struct
*/
void VocAlgorithm_init(VocAlgorithmParams* params);
/**
* Get current algorithm states. Retrieved values can be used in
* VocAlgorithm_set_states() to resume operation after a short interruption,
* skipping initial learning phase. This feature can only be used after at least
* 3 hours of continuous operation.
* @param params Pointer to the VocAlgorithmParams struct
* @param state0 State0 to be stored
* @param state1 State1 to be stored
*/
void VocAlgorithm_get_states(VocAlgorithmParams* params, int32_t* state0,
int32_t* state1);
/**
* Set previously retrieved algorithm states to resume operation after a short
* interruption, skipping initial learning phase. This feature should not be
* used after inerruptions of more than 10 minutes. Call this once after
* VocAlgorithm_init() and the optional VocAlgorithm_set_tuning_parameters(), if
* desired. Otherwise, the algorithm will start with initial learning phase.
* @param params Pointer to the VocAlgorithmParams struct
* @param state0 State0 to be restored
* @param state1 State1 to be restored
*/
void VocAlgorithm_set_states(VocAlgorithmParams* params, int32_t state0,
int32_t state1);
/**
* Set parameters to customize the VOC algorithm. Call this once after
* VocAlgorithm_init(), if desired. Otherwise, the default values will be used.
*
* @param params Pointer to the VocAlgorithmParams struct
* @param voc_index_offset VOC index representing typical (average)
* conditions. Range 1..250, default 100
* @param learning_time_hours Time constant of long-term estimator.
* Past events will be forgotten after about
* twice the learning time.
* Range 1..72 [hours], default 12 [hours]
* @param gating_max_duration_minutes Maximum duration of gating (freeze of
* estimator during high VOC index signal).
* 0 (no gating) or range 1..720 [minutes],
* default 180 [minutes]
* @param std_initial Initial estimate for standard deviation.
* Lower value boosts events during initial
* learning period, but may result in larger
* device-to-device variations.
* Range 10..500, default 50
*/
void VocAlgorithm_set_tuning_parameters(VocAlgorithmParams* params,
int32_t voc_index_offset,
int32_t learning_time_hours,
int32_t gating_max_duration_minutes,
int32_t std_initial);
/**
* Calculate the VOC index value from the raw sensor value.
*
* @param params Pointer to the VocAlgorithmParams struct
* @param sraw Raw value from the SGP40 sensor
* @param voc_index Calculated VOC index value from the raw sensor value. Zero
* during initial blackout period and 1..500 afterwards
*/
void VocAlgorithm_process(VocAlgorithmParams* params, int32_t sraw,
int32_t* voc_index);
#endif /* VOCALGORITHM_H_ */

802
sys/dev/i2c/sgp40.c Normal file
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@ -0,0 +1,802 @@
/* $NetBSD: sgp40.c,v 1.1 2021/10/14 13:54:46 brad Exp $ */
/*
* Copyright (c) 2021 Brad Spencer <brad@anduin.eldar.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGL`IGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sgp40.c,v 1.1 2021/10/14 13:54:46 brad Exp $");
/*
Driver for the Sensirion SGP40 MOx gas sensor for air quality
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <sys/mutex.h>
#include <sys/condvar.h>
#include <sys/kthread.h>
#include <dev/sysmon/sysmonvar.h>
#include <dev/i2c/i2cvar.h>
#include <dev/i2c/sgp40reg.h>
#include <dev/i2c/sgp40var.h>
#include <dev/i2c/sensirion_arch_config.h>
#include <dev/i2c/sensirion_voc_algorithm.h>
static uint8_t sgp40_crc(uint8_t *, size_t);
static int sgp40_cmdr(struct sgp40_sc *, uint16_t, uint8_t *, uint8_t, uint8_t *, size_t);
static int sgp40_poke(i2c_tag_t, i2c_addr_t, bool);
static int sgp40_match(device_t, cfdata_t, void *);
static void sgp40_attach(device_t, device_t, void *);
static int sgp40_detach(device_t, int);
static void sgp40_refresh(struct sysmon_envsys *, envsys_data_t *);
static int sgp40_verify_sysctl(SYSCTLFN_ARGS);
static int sgp40_verify_temp_sysctl(SYSCTLFN_ARGS);
static int sgp40_verify_rh_sysctl(SYSCTLFN_ARGS);
static void sgp40_thread(void *);
static void sgp40_stop_thread(void *);
static void sgp40_take_measurement(void *, VocAlgorithmParams *);
#define SGP40_DEBUG
#ifdef SGP40_DEBUG
#define DPRINTF(s, l, x) \
do { \
if (l <= s->sc_sgp40debug) \
printf x; \
} while (/*CONSTCOND*/0)
#else
#define DPRINTF(s, l, x)
#endif
CFATTACH_DECL_NEW(sgp40mox, sizeof(struct sgp40_sc),
sgp40_match, sgp40_attach, sgp40_detach, NULL);
static struct sgp40_sensor sgp40_sensors[] = {
{
.desc = "VOC index",
.type = ENVSYS_INTEGER,
}
};
static struct sgp40_timing sgp40_timings[] = {
{
.cmd = SGP40_MEASURE_RAW,
.typicaldelay = 25000,
},
{
.cmd = SGP40_MEASURE_TEST,
.typicaldelay = 240000,
},
{
.cmd = SGP40_HEATER_OFF,
.typicaldelay = 100,
},
{
.cmd = SGP40_GET_SERIAL_NUMBER,
.typicaldelay = 100,
},
{
.cmd = SGP40_GET_FEATURESET,
.typicaldelay = 1000,
}
};
void
sgp40_thread(void *aux)
{
struct sgp40_sc *sc = aux;
int rv;
VocAlgorithmParams voc_algorithm_params;
mutex_enter(&sc->sc_threadmutex);
VocAlgorithm_init(&voc_algorithm_params);
while (sc->sc_stopping == false) {
rv = cv_timedwait(&sc->sc_condvar, &sc->sc_threadmutex, mstohz(1000));
if (rv == EWOULDBLOCK && sc->sc_stopping == false) {
sgp40_take_measurement(sc,&voc_algorithm_params);
}
}
mutex_exit(&sc->sc_threadmutex);
kthread_exit(0);
}
static void
sgp40_stop_thread(void *aux)
{
struct sgp40_sc *sc;
sc = aux;
int error;
mutex_enter(&sc->sc_threadmutex);
sc->sc_stopping = true;
cv_signal(&sc->sc_condvar);
mutex_exit(&sc->sc_threadmutex);
/* wait for the thread to exit */
kthread_join(sc->sc_thread);
mutex_enter(&sc->sc_mutex);
error = iic_acquire_bus(sc->sc_tag, 0);
if (error) {
DPRINTF(sc, 2, ("%s: Could not acquire iic bus for heater off in stop thread: %d\n",
device_xname(sc->sc_dev), error));
} else {
error = sgp40_cmdr(sc, SGP40_HEATER_OFF,NULL,0,NULL,0);
if (error) {
DPRINTF(sc, 2, ("%s: Error turning heater off: %d\n",
device_xname(sc->sc_dev), error));
}
iic_release_bus(sc->sc_tag, 0);
}
mutex_exit(&sc->sc_mutex);
}
static int
sgp40_compute_temp_comp(int unconverted)
{
/* The published algorithm for this conversion is:
(temp_in_celcius + 45) * 65535 / 175
However, this did not exactly yield the results that
the example in the data sheet, so something a little
different was done.
(temp_in_celcius + 45) * 65536 / 175
This was also scaled up by 10^2 and then scaled back to
preserve some percision. 37449 is simply (65536 * 100) / 175
and rounded.
*/
return (((unconverted + 45) * 100) * 37449) / 10000;
}
static int
sgp40_compute_rh_comp(int unconverted)
{
int q;
/* The published algorithm for this conversion is:
%rh * 65535 / 100
However, this did not exactly yield the results that
the example in the data sheet, so something a little
different was done.
%rh * 65536 / 100
This was also scaled up by 10^2 and then scaled back to
preserve some percision. The value is also latched to 65535
as an upper limit.
*/
q = ((unconverted * 100) * 65536) / 10000;
if (q > 65535)
q = 65535;
return q;
}
static void
sgp40_take_measurement(void *aux, VocAlgorithmParams* params)
{
struct sgp40_sc *sc;
sc = aux;
uint8_t args[6];
uint8_t buf[3];
uint16_t rawmeasurement;
int error;
uint8_t crc;
uint16_t convertedrh, convertedtemp;
int32_t voc_index;
mutex_enter(&sc->sc_mutex);
convertedrh = (uint16_t)sgp40_compute_rh_comp(sc->sc_rhcomp);
convertedtemp = (uint16_t)sgp40_compute_temp_comp(sc->sc_tempcomp);
DPRINTF(sc, 2, ("%s: Converted RH and Temp: %04x %04x\n",
device_xname(sc->sc_dev), convertedrh, convertedtemp));
args[0] = convertedrh >> 8;
args[1] = convertedrh & 0x00ff;
args[2] = sgp40_crc(&args[0],2);
args[3] = convertedtemp >> 8;
args[4] = convertedtemp & 0x00ff;
args[5] = sgp40_crc(&args[3],2);
/* The VOC algoritm has a black out time when it first starts to run
and does not return any indicator that is going on, so voc_index
in that case would be 0.. however, that is also a valid response
otherwise, although an unlikely one.
*/
error = iic_acquire_bus(sc->sc_tag, 0);
if (error) {
DPRINTF(sc, 2, ("%s: Could not acquire iic bus for take measurement: %d\n",
device_xname(sc->sc_dev), error));
sc->sc_voc = 0;
sc->sc_vocvalid = false;
} else {
error = sgp40_cmdr(sc, SGP40_MEASURE_RAW, args, 6, buf, 3);
iic_release_bus(sc->sc_tag, 0);
if (error == 0) {
crc = sgp40_crc(&buf[0],2);
DPRINTF(sc, 2, ("%s: Raw ticks and crc: %02x%02x %02x %02x\n",
device_xname(sc->sc_dev), buf[0], buf[1], buf[2],crc));
if (buf[2] == crc) {
rawmeasurement = buf[0] << 8;
rawmeasurement |= buf[1];
VocAlgorithm_process(params, rawmeasurement, &voc_index);
DPRINTF(sc, 2, ("%s: VOC index: %d\n",
device_xname(sc->sc_dev), voc_index));
sc->sc_voc = voc_index;
sc->sc_vocvalid = true;
} else {
sc->sc_voc = 0;
sc->sc_vocvalid = false;
}
} else {
DPRINTF(sc, 2, ("%s: Failed to get measurement %d\n",
device_xname(sc->sc_dev), error));
sc->sc_voc = 0;
sc->sc_vocvalid = false;
}
}
mutex_exit(&sc->sc_mutex);
}
int
sgp40_verify_sysctl(SYSCTLFN_ARGS)
{
int error, t;
struct sysctlnode node;
node = *rnode;
t = *(int *)rnode->sysctl_data;
node.sysctl_data = &t;
error = sysctl_lookup(SYSCTLFN_CALL(&node));
if (error || newp == NULL)
return error;
if (t < 0)
return EINVAL;
*(int *)rnode->sysctl_data = t;
return 0;
}
int
sgp40_verify_temp_sysctl(SYSCTLFN_ARGS)
{
int error, t;
struct sysctlnode node;
node = *rnode;
t = *(int *)rnode->sysctl_data;
node.sysctl_data = &t;
error = sysctl_lookup(SYSCTLFN_CALL(&node));
if (error || newp == NULL)
return error;
if (t < -45 || t > 130)
return EINVAL;
*(int *)rnode->sysctl_data = t;
return 0;
}
int
sgp40_verify_rh_sysctl(SYSCTLFN_ARGS)
{
int error, t;
struct sysctlnode node;
node = *rnode;
t = *(int *)rnode->sysctl_data;
node.sysctl_data = &t;
error = sysctl_lookup(SYSCTLFN_CALL(&node));
if (error || newp == NULL)
return error;
if (t < 0 || t > 100)
return EINVAL;
*(int *)rnode->sysctl_data = t;
return 0;
}
static int
sgp40_cmddelay(uint16_t cmd)
{
int r = -1;
for(int i = 0;i < __arraycount(sgp40_timings);i++) {
if (cmd == sgp40_timings[i].cmd) {
r = sgp40_timings[i].typicaldelay;
break;
}
}
if (r == -1) {
panic("Bad command look up in cmd delay: cmd: %d\n",cmd);
}
return r;
}
static int
sgp40_cmd(i2c_tag_t tag, i2c_addr_t addr, uint8_t *cmd,
uint8_t clen, uint8_t *buf, size_t blen, int readattempts)
{
int error;
int cmddelay;
uint16_t cmd16;
cmd16 = cmd[0] << 8;
cmd16 = cmd16 | cmd[1];
error = iic_exec(tag,I2C_OP_WRITE_WITH_STOP,addr,cmd,clen,NULL,0,0);
/* Every command returns something except for turning the heater off
and the general soft reset which returns nothing. */
if (error == 0 && cmd16 != SGP40_HEATER_OFF) {
/* Every command has a particular delay for how long
it typically takes and the max time it will take. */
cmddelay = sgp40_cmddelay(cmd16);
delay(cmddelay);
for (int aint = 0; aint < readattempts; aint++) {
error = iic_exec(tag,I2C_OP_READ_WITH_STOP,addr,NULL,0,buf,blen,0);
if (error == 0)
break;
delay(1000);
}
}
return error;
}
static int
sgp40_cmdr(struct sgp40_sc *sc, uint16_t cmd, uint8_t *extraargs, uint8_t argslen, uint8_t *buf, size_t blen)
{
uint8_t fullcmd[8];
uint8_t cmdlen;
int n;
/* The biggest documented command + arguments is 8 uint8_t bytes long. */
/* Catch anything that ties to have an arglen more than 6 */
KASSERT(argslen <= 6);
memset(fullcmd, 0, 8);
fullcmd[0] = cmd >> 8;
fullcmd[1] = cmd & 0x00ff;
cmdlen = 2;
n = 0;
while (extraargs != NULL && n < argslen && cmdlen <= 7) {
fullcmd[cmdlen] = extraargs[n];
cmdlen++;
n++;
}
DPRINTF(sc, 2, ("%s: Full command and arguments: %02x %02x %02x %02x %02x %02x %02x %02x\n",
device_xname(sc->sc_dev), fullcmd[0], fullcmd[1],
fullcmd[2], fullcmd[3], fullcmd[4], fullcmd[5],
fullcmd[6], fullcmd[7]));
return sgp40_cmd(sc->sc_tag, sc->sc_addr, fullcmd, cmdlen, buf, blen, sc->sc_readattempts);
}
static uint8_t
sgp40_crc(uint8_t * data, size_t size)
{
uint8_t crc = 0xFF;
for (size_t i = 0; i < size; i++) {
crc ^= data[i];
for (size_t j = 8; j > 0; j--) {
if (crc & 0x80)
crc = (crc << 1) ^ 0x31;
else
crc <<= 1;
}
}
return crc;
}
static int
sgp40_poke(i2c_tag_t tag, i2c_addr_t addr, bool matchdebug)
{
uint8_t reg[2];
uint8_t buf[9];
int error;
/* Possible bug... this command may not work if the chip is not idle,
however, it appears to be used by a lot of other code as a probe.
*/
reg[0] = SGP40_GET_SERIAL_NUMBER >> 8;
reg[1] = SGP40_GET_SERIAL_NUMBER & 0x00ff;
error = sgp40_cmd(tag, addr, reg, 2, buf, 9, 10);
if (matchdebug) {
printf("poke X 1: %d\n", error);
}
return error;
}
static int
sgp40_sysctl_init(struct sgp40_sc *sc)
{
int error;
const struct sysctlnode *cnode;
int sysctlroot_num;
if ((error = sysctl_createv(&sc->sc_sgp40log, 0, NULL, &cnode,
0, CTLTYPE_NODE, device_xname(sc->sc_dev),
SYSCTL_DESCR("SGP40 controls"), NULL, 0, NULL, 0, CTL_HW,
CTL_CREATE, CTL_EOL)) != 0)
return error;
sysctlroot_num = cnode->sysctl_num;
#ifdef SGP40_DEBUG
if ((error = sysctl_createv(&sc->sc_sgp40log, 0, NULL, &cnode,
CTLFLAG_READWRITE, CTLTYPE_INT, "debug",
SYSCTL_DESCR("Debug level"), sgp40_verify_sysctl, 0,
&sc->sc_sgp40debug, 0, CTL_HW, sysctlroot_num, CTL_CREATE,
CTL_EOL)) != 0)
return error;
#endif
if ((error = sysctl_createv(&sc->sc_sgp40log, 0, NULL, &cnode,
CTLFLAG_READWRITE, CTLTYPE_INT, "readattempts",
SYSCTL_DESCR("The number of times to attempt to read the values"),
sgp40_verify_sysctl, 0, &sc->sc_readattempts, 0, CTL_HW,
sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
return error;
if ((error = sysctl_createv(&sc->sc_sgp40log, 0, NULL, &cnode,
CTLFLAG_READWRITE, CTLTYPE_BOOL, "ignorecrc",
SYSCTL_DESCR("Ignore the CRC byte"), NULL, 0, &sc->sc_ignorecrc,
0, CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
return error;
if ((error = sysctl_createv(&sc->sc_sgp40log, 0, NULL, &cnode,
0, CTLTYPE_NODE, "compensation",
SYSCTL_DESCR("SGP40 measurement compensations"), NULL, 0, NULL, 0, CTL_HW,
sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
return error;
int compensation_num = cnode->sysctl_num;
if ((error = sysctl_createv(&sc->sc_sgp40log, 0, NULL, &cnode,
CTLFLAG_READWRITE, CTLTYPE_INT, "temperature",
SYSCTL_DESCR("Temperature compensation in celsius"),
sgp40_verify_temp_sysctl, 0, &sc->sc_tempcomp, 0, CTL_HW,
sysctlroot_num, compensation_num, CTL_CREATE, CTL_EOL)) != 0)
return error;
if ((error = sysctl_createv(&sc->sc_sgp40log, 0, NULL, &cnode,
CTLFLAG_READWRITE, CTLTYPE_INT, "humidity",
SYSCTL_DESCR("Humidity compensation in %RH"),
sgp40_verify_rh_sysctl, 0, &sc->sc_rhcomp, 0, CTL_HW,
sysctlroot_num, compensation_num, CTL_CREATE, CTL_EOL)) != 0)
return error;
return 0;
}
static int
sgp40_match(device_t parent, cfdata_t match, void *aux)
{
struct i2c_attach_args *ia = aux;
int error, match_result;
const bool matchdebug = false;
if (matchdebug)
printf("in match\n");
if (iic_use_direct_match(ia, match, NULL, &match_result))
return match_result;
/* indirect config - check for configured address */
if (ia->ia_addr != SGP40_TYPICAL_ADDR)
return 0;
/*
* Check to see if something is really at this i2c address. This will
* keep phantom devices from appearing
*/
if (iic_acquire_bus(ia->ia_tag, 0) != 0) {
if (matchdebug)
printf("in match acquire bus failed\n");
return 0;
}
error = sgp40_poke(ia->ia_tag, ia->ia_addr, matchdebug);
iic_release_bus(ia->ia_tag, 0);
return error == 0 ? I2C_MATCH_ADDRESS_AND_PROBE : 0;
}
static void
sgp40_attach(device_t parent, device_t self, void *aux)
{
struct sgp40_sc *sc;
struct i2c_attach_args *ia;
int error, i;
int ecount = 0;
uint8_t buf[9];
uint8_t tstcrc;
uint16_t chiptestvalue;
uint64_t serial_number = 0;
uint8_t sn_crc1, sn_crc2, sn_crc3, sn_crcv1, sn_crcv2, sn_crcv3;
uint8_t fs_crc, fs_crcv;
uint16_t featureset;
ia = aux;
sc = device_private(self);
sc->sc_dev = self;
sc->sc_tag = ia->ia_tag;
sc->sc_addr = ia->ia_addr;
sc->sc_sgp40debug = 0;
sc->sc_readattempts = 10;
sc->sc_ignorecrc = false;
sc->sc_stopping = false;
sc->sc_voc = 0;
sc->sc_vocvalid = false;
sc->sc_tempcomp = SGP40_DEFAULT_TEMP_COMP;
sc->sc_rhcomp = SGP40_DEFAULT_RH_COMP;
sc->sc_sme = NULL;
aprint_normal("\n");
mutex_init(&sc->sc_threadmutex, MUTEX_DEFAULT, IPL_NONE);
mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_NONE);
cv_init(&sc->sc_condvar, "sgp40cv");
sc->sc_numsensors = __arraycount(sgp40_sensors);
if ((sc->sc_sme = sysmon_envsys_create()) == NULL) {
aprint_error_dev(self,
"Unable to create sysmon structure\n");
sc->sc_sme = NULL;
return;
}
if ((error = sgp40_sysctl_init(sc)) != 0) {
aprint_error_dev(self, "Can't setup sysctl tree (%d)\n", error);
goto out;
}
error = iic_acquire_bus(sc->sc_tag, 0);
if (error) {
aprint_error_dev(self, "Could not acquire iic bus: %d\n",
error);
goto out;
}
/* Usually one would reset the chip here, but that is not possible
without resetting the entire bus, so we won't do that.
What we will do is make sure that the chip is idle by running the
turn-the-heater command.
*/
error = sgp40_cmdr(sc, SGP40_HEATER_OFF, NULL, 0, NULL, 0);
if (error) {
aprint_error_dev(self, "Failed to turn off the heater: %d\n",
error);
ecount++;
}
error = sgp40_cmdr(sc, SGP40_GET_SERIAL_NUMBER, NULL, 0, buf, 9);
if (error) {
aprint_error_dev(self, "Failed to get serial number: %d\n",
error);
ecount++;
}
sn_crc1 = sgp40_crc(&buf[0],2);
sn_crc2 = sgp40_crc(&buf[3],2);
sn_crc3 = sgp40_crc(&buf[6],2);
sn_crcv1 = buf[2];
sn_crcv2 = buf[5];
sn_crcv3 = buf[8];
serial_number = buf[0];
serial_number = (serial_number << 8) | buf[1];
serial_number = (serial_number << 8) | buf[3];
serial_number = (serial_number << 8) | buf[4];
serial_number = (serial_number << 8) | buf[6];
serial_number = (serial_number << 8) | buf[7];
DPRINTF(sc, 2, ("%s: raw serial number: %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",
device_xname(sc->sc_dev), buf[0], buf[1], buf[2], buf[3], buf[4],
buf[5], buf[6], buf[7], buf[8]));
error = sgp40_cmdr(sc, SGP40_GET_FEATURESET, NULL, 0, buf, 3);
if (error) {
aprint_error_dev(self, "Failed to get featureset: %d\n",
error);
ecount++;
}
fs_crc = sgp40_crc(&buf[0],2);
fs_crcv = buf[2];
featureset = buf[0];
featureset = (featureset << 8) | buf[1];
DPRINTF(sc, 2, ("%s: raw feature set: %02x %02x %02x\n",
device_xname(sc->sc_dev), buf[0], buf[1], buf[2]));
error = sgp40_cmdr(sc, SGP40_MEASURE_TEST, NULL, 0, buf, 3);
if (error) {
aprint_error_dev(self, "Failed to perform a chip test: %d\n",
error);
ecount++;
}
tstcrc = sgp40_crc(&buf[0],2);
DPRINTF(sc, 2, ("%s: chip test values: %02x%02x - %02x ; %02x\n",
device_xname(sc->sc_dev), buf[0], buf[1], buf[2], tstcrc));
iic_release_bus(sc->sc_tag, 0);
if (error != 0) {
aprint_error_dev(self, "Unable to setup device\n");
goto out;
}
chiptestvalue = buf[0] << 8;
chiptestvalue |= buf[1];
for (i = 0; i < sc->sc_numsensors; i++) {
strlcpy(sc->sc_sensors[i].desc, sgp40_sensors[i].desc,
sizeof(sc->sc_sensors[i].desc));
sc->sc_sensors[i].units = sgp40_sensors[i].type;
sc->sc_sensors[i].state = ENVSYS_SINVALID;
DPRINTF(sc, 2, ("%s: registering sensor %d (%s)\n", __func__, i,
sc->sc_sensors[i].desc));
error = sysmon_envsys_sensor_attach(sc->sc_sme,
&sc->sc_sensors[i]);
if (error) {
aprint_error_dev(self,
"Unable to attach sensor %d: %d\n", i, error);
goto out;
}
}
sc->sc_sme->sme_name = device_xname(sc->sc_dev);
sc->sc_sme->sme_cookie = sc;
sc->sc_sme->sme_refresh = sgp40_refresh;
DPRINTF(sc, 2, ("sgp40_attach: registering with envsys\n"));
if (sysmon_envsys_register(sc->sc_sme)) {
aprint_error_dev(self,
"unable to register with sysmon\n");
sysmon_envsys_destroy(sc->sc_sme);
sc->sc_sme = NULL;
return;
}
error = kthread_create(PRI_NONE, KTHREAD_MUSTJOIN, NULL,
sgp40_thread, sc, &sc->sc_thread,
device_xname(sc->sc_dev));
if (error) {
aprint_error_dev(self,"Unable to create measurement thread\n");
goto out;
}
aprint_normal_dev(self, "Sensirion SGP40, Serial number: %jx%sFeature set word: 0x%jx%s%s%s",
serial_number,
(sn_crc1 == sn_crcv1 && sn_crc2 == sn_crcv2 && sn_crc3 == sn_crcv3) ? ", " : " (bad crc), ",
(uintmax_t)featureset,
(fs_crc == fs_crcv) ? ", " : " (bad crc), ",
(chiptestvalue == SGP40_TEST_RESULTS_ALL_PASSED) ? "All chip tests passed" :
(chiptestvalue == SGP40_TEST_RESULTS_SOME_FAILED) ? "Some chip tests failed" :
"Unknown test results",
(tstcrc == buf[2]) ? "\n" : " (bad crc)\n");
return;
out:
sysmon_envsys_destroy(sc->sc_sme);
sc->sc_sme = NULL;
}
static void
sgp40_refresh(struct sysmon_envsys * sme, envsys_data_t * edata)
{
struct sgp40_sc *sc;
sc = sme->sme_cookie;
mutex_enter(&sc->sc_mutex);
if (sc->sc_vocvalid == true) {
edata->value_cur = (uint32_t)sc->sc_voc;
edata->state = ENVSYS_SVALID;
} else {
edata->state = ENVSYS_SINVALID;
}
mutex_exit(&sc->sc_mutex);
}
static int
sgp40_detach(device_t self, int flags)
{
struct sgp40_sc *sc;
sc = device_private(self);
/* stop the measurement thread */
sgp40_stop_thread(sc);
/* Remove the sensors */
mutex_enter(&sc->sc_mutex);
if (sc->sc_sme != NULL) {
sysmon_envsys_unregister(sc->sc_sme);
sc->sc_sme = NULL;
}
mutex_exit(&sc->sc_mutex);
/* Remove the sysctl tree */
sysctl_teardown(&sc->sc_sgp40log);
/* Remove the mutex */
mutex_destroy(&sc->sc_mutex);
mutex_destroy(&sc->sc_threadmutex);
return 0;
}
MODULE(MODULE_CLASS_DRIVER, sgp40mox, "i2cexec,sysmon_envsys");
#ifdef _MODULE
#include "ioconf.c"
#endif
static int
sgp40mox_modcmd(modcmd_t cmd, void *opaque)
{
switch (cmd) {
case MODULE_CMD_INIT:
#ifdef _MODULE
return config_init_component(cfdriver_ioconf_sgp40mox,
cfattach_ioconf_sgp40mox, cfdata_ioconf_sgp40mox);
#else
return 0;
#endif
case MODULE_CMD_FINI:
#ifdef _MODULE
return config_fini_component(cfdriver_ioconf_sgp40mox,
cfattach_ioconf_sgp40mox, cfdata_ioconf_sgp40mox);
#else
return 0;
#endif
default:
return ENOTTY;
}
}

50
sys/dev/i2c/sgp40reg.h Normal file
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@ -0,0 +1,50 @@
/* $NetBSD: sgp40reg.h,v 1.1 2021/10/14 13:54:46 brad Exp $ */
/*
* Copyright (c) 2021 Brad Spencer <brad@anduin.eldar.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef _DEV_I2C_SGP40REG_H_
#define _DEV_I2C_SGP40REG_H_
#define SGP40_TYPICAL_ADDR 0x59
/* There are three documented commands for this chip, plus one that is called a
soft reset. But really the soft reset is a general reset of all devices on
the bus, hence it is not as usable as one would hope
*/
#define SGP40_MEASURE_RAW 0x260f
#define SGP40_MEASURE_TEST 0x280e
#define SGP40_HEATER_OFF 0x3615
/* The get serial number command is documented in version 1.1 of the
datasheet.
*/
#define SGP40_GET_SERIAL_NUMBER 0x3682
/* The get featureset command is not documented in any datasheet that could
be found. However, it is present and used in a lot of example code.
It has no additional arguments aside from the command itself, and returns
a uint16_t for the data and a uint8_t for the crc.
*/
#define SGP40_GET_FEATURESET 0x202f
/* The results of a self test are documented as being either everything is ok, or
something failed.
*/
#define SGP40_TEST_RESULTS_ALL_PASSED 0xd400
#define SGP40_TEST_RESULTS_SOME_FAILED 0x4b00
#endif

61
sys/dev/i2c/sgp40var.h Normal file
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@ -0,0 +1,61 @@
/* $NetBSD: sgp40var.h,v 1.1 2021/10/14 13:54:46 brad Exp $ */
/*
* Copyright (c) 2021 Brad Spencer <brad@anduin.eldar.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef _DEV_I2C_SGP40VAR_H_
#define _DEV_I2C_SGP40VAR_H_
#define SGP40_NUM_SENSORS 1
#define SGP40_VOC_SENSOR 0
#define SGP40_DEFAULT_TEMP_COMP 25
#define SGP40_DEFAULT_RH_COMP 50
struct sgp40_sc {
int sc_sgp40debug;
device_t sc_dev;
i2c_tag_t sc_tag;
i2c_addr_t sc_addr;
kmutex_t sc_threadmutex; /* for the measurement kthread */
kmutex_t sc_mutex; /* for reading the i2c bus */
kcondvar_t sc_condvar;
struct lwp *sc_thread;
int sc_numsensors;
struct sysmon_envsys *sc_sme;
struct sysctllog *sc_sgp40log;
envsys_data_t sc_sensors[SGP40_NUM_SENSORS];
uint16_t sc_voc;
bool sc_vocvalid;
bool sc_ignorecrc;
int sc_readattempts;
bool sc_stopping;
int sc_tempcomp;
int sc_rhcomp;
};
struct sgp40_sensor {
const char *desc;
enum envsys_units type;
};
struct sgp40_timing {
uint16_t cmd;
int typicaldelay;
};
#endif

3
sys/modules/Makefile
View File

@ -1,4 +1,4 @@
# $NetBSD: Makefile,v 1.258 2021/10/09 07:01:34 ryo Exp $
# $NetBSD: Makefile,v 1.259 2021/10/14 13:54:45 brad Exp $
.include <bsd.own.mk>
@ -70,6 +70,7 @@ SUBDIR+= hythygtemp
SUBDIR+= si70xxtemp
SUBDIR+= am2315temp
SUBDIR+= sht4xtemp
SUBDIR+= sgp40mox
SUBDIR+= i2cexec
SUBDIR+= i2c_bitbang
SUBDIR+= if_agr

12
sys/modules/sgp40mox/Makefile Normal file
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@ -0,0 +1,12 @@
.include "../Makefile.inc"
.PATH: ${S}/dev/i2c
KMOD= sgp40mox
IOCONF= sgp40mox.ioconf
SRCS= sgp40.c
SRCS+= sensirion_voc_algorithm.c
WARNS= 3
.include <bsd.kmodule.mk>

8
sys/modules/sgp40mox/sgp40mox.ioconf Normal file
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@ -0,0 +1,8 @@
ioconf sgp40mox
include "conf/files"
pseudo-root iic*
sgp40mox* at iic? addr 0x59