304 lines
8.3 KiB
C
304 lines
8.3 KiB
C
/* $NetBSD: mpl115a.c,v 1.3 2019/12/23 14:50:43 thorpej Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 2013 The NetBSD Foundation, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to The NetBSD Foundation
|
|
* by Radoslaw Kujawa.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. 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.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
|
|
*/
|
|
|
|
/*
|
|
* Freescale MPL115A2 miniature digital barometer driver.
|
|
*
|
|
* This driver could be split into bus-indepented driver and I2C-specific
|
|
* attachment, as SPI variant of this chip also exist.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__KERNEL_RCSID(0, "$NetBSD: mpl115a.c,v 1.3 2019/12/23 14:50:43 thorpej Exp $");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/device.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/mutex.h>
|
|
#include <sys/endian.h>
|
|
|
|
#include <sys/bus.h>
|
|
#include <dev/i2c/i2cvar.h>
|
|
|
|
#include <dev/sysmon/sysmonvar.h>
|
|
|
|
#include <dev/i2c/mpl115areg.h>
|
|
|
|
#define MPL115A_DEBUG 1
|
|
|
|
struct mpl115a_softc {
|
|
device_t sc_dev;
|
|
|
|
i2c_tag_t sc_tag;
|
|
i2c_addr_t sc_addr;
|
|
|
|
/* raw coefficients */
|
|
int16_t sc_a0;
|
|
int16_t sc_b1;
|
|
int16_t sc_b2;
|
|
int16_t sc_c12;
|
|
|
|
/* envsys(4) stuff */
|
|
struct sysmon_envsys *sc_sme;
|
|
envsys_data_t sc_sensor;
|
|
kmutex_t sc_lock;
|
|
};
|
|
|
|
|
|
static int mpl115a_match(device_t, cfdata_t, void *);
|
|
static void mpl115a_attach(device_t, device_t, void *);
|
|
|
|
static uint8_t mpl115a_reg_read_1(struct mpl115a_softc *sc, uint8_t);
|
|
static void mpl115a_reg_write_1(struct mpl115a_softc *sc, uint8_t, uint8_t);
|
|
|
|
static void mpl115a_load_coeffs(struct mpl115a_softc *sc);
|
|
static uint16_t mpl115a_make_coeff(uint8_t msb, uint8_t lsb);
|
|
static uint32_t mpl115a_pressure(struct mpl115a_softc *sc);
|
|
static uint32_t mpl115a_calc(struct mpl115a_softc *sc, uint16_t padc, uint16_t tadc) ;
|
|
|
|
static void mpl115a_envsys_register(struct mpl115a_softc *);
|
|
static void mpl115a_envsys_refresh(struct sysmon_envsys *, envsys_data_t *);
|
|
|
|
CFATTACH_DECL_NEW(mpl115a, sizeof (struct mpl115a_softc),
|
|
mpl115a_match, mpl115a_attach, NULL, NULL);
|
|
|
|
static int
|
|
mpl115a_match(device_t parent, cfdata_t cf, void *aux)
|
|
{
|
|
struct i2c_attach_args *ia = aux;
|
|
|
|
if (ia->ia_addr == MPL115A_ADDR)
|
|
return I2C_MATCH_ADDRESS_ONLY;
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
mpl115a_attach(device_t parent, device_t self, void *aux)
|
|
{
|
|
struct mpl115a_softc *sc = device_private(self);
|
|
struct i2c_attach_args *ia = aux;
|
|
|
|
sc->sc_dev = self;
|
|
sc->sc_addr = ia->ia_addr;
|
|
sc->sc_tag = ia->ia_tag;
|
|
|
|
aprint_normal(": Freescale MPL115A2 Pressure Sensor\n");
|
|
|
|
/* Since coefficients do not change load them once. */
|
|
mpl115a_load_coeffs(sc);
|
|
|
|
mpl115a_pressure(sc);
|
|
|
|
mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE);
|
|
|
|
mpl115a_envsys_register(sc);
|
|
}
|
|
|
|
/* Construct a coefficients from MSB and LSB bytes. */
|
|
static uint16_t
|
|
mpl115a_make_coeff(uint8_t msb, uint8_t lsb)
|
|
{
|
|
uint16_t rv;
|
|
|
|
rv = le16toh((msb << 8) | lsb);
|
|
|
|
#ifdef MPL115A_DEBUG
|
|
aprint_normal("msb %x, lsb %x, ret val %x\n", msb, lsb, rv);
|
|
#endif /* MPL115A_DEBUG */
|
|
|
|
return rv;
|
|
}
|
|
|
|
static void
|
|
mpl115a_load_coeffs(struct mpl115a_softc *sc)
|
|
{
|
|
sc->sc_a0 = mpl115a_make_coeff(mpl115a_reg_read_1(sc, MPL115A_A0_MSB),
|
|
mpl115a_reg_read_1(sc, MPL115A_A0_LSB));
|
|
sc->sc_b1 = mpl115a_make_coeff(mpl115a_reg_read_1(sc, MPL115A_B1_MSB),
|
|
mpl115a_reg_read_1(sc, MPL115A_B1_LSB));
|
|
sc->sc_b2 = mpl115a_make_coeff(mpl115a_reg_read_1(sc, MPL115A_B2_MSB),
|
|
mpl115a_reg_read_1(sc, MPL115A_B2_LSB));
|
|
sc->sc_c12 = mpl115a_make_coeff(mpl115a_reg_read_1(sc, MPL115A_C12_MSB),
|
|
mpl115a_reg_read_1(sc, MPL115A_C12_LSB));
|
|
}
|
|
|
|
static void
|
|
mpl115a_reg_write_1(struct mpl115a_softc *sc, uint8_t reg, uint8_t val)
|
|
{
|
|
if (iic_acquire_bus(sc->sc_tag, 0) != 0) {
|
|
aprint_error_dev(sc->sc_dev, "cannot acquire bus for write\n");
|
|
return;
|
|
}
|
|
|
|
if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr, ®, 1,
|
|
&val, 1, 0)) {
|
|
aprint_error_dev(sc->sc_dev, "cannot execute write\n");
|
|
}
|
|
iic_release_bus(sc->sc_tag, 0);
|
|
}
|
|
|
|
static uint8_t
|
|
mpl115a_reg_read_1(struct mpl115a_softc *sc, uint8_t reg)
|
|
{
|
|
uint8_t rv, wbuf[2];
|
|
|
|
if (iic_acquire_bus(sc->sc_tag, 0) != 0) {
|
|
#ifdef MPL115A_DEBUG
|
|
aprint_error_dev(sc->sc_dev, "cannot acquire bus for read\n");
|
|
#endif /* MPL115A_DEBUG */
|
|
return 0;
|
|
}
|
|
|
|
wbuf[0] = reg;
|
|
|
|
if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr, wbuf,
|
|
1, &rv, 1, 0)) {
|
|
iic_release_bus(sc->sc_tag, 0);
|
|
aprint_error_dev(sc->sc_dev, "cannot execute read\n");
|
|
return 0;
|
|
}
|
|
iic_release_bus(sc->sc_tag, 0);
|
|
|
|
return rv;
|
|
}
|
|
|
|
|
|
|
|
/* Get pressure in pascals. */
|
|
static uint32_t
|
|
mpl115a_pressure(struct mpl115a_softc *sc)
|
|
{
|
|
uint32_t rv;
|
|
|
|
uint16_t padc, tadc;
|
|
|
|
rv = 0;
|
|
|
|
mpl115a_reg_write_1(sc, MPL115A_CONVERT, 1);
|
|
delay(20); /* even 3 should be enough */
|
|
|
|
padc = mpl115a_make_coeff(mpl115a_reg_read_1(sc, MPL115A_PADC_MSB),
|
|
mpl115a_reg_read_1(sc, MPL115A_PADC_LSB)); /* XXX, this fails */
|
|
padc = mpl115a_make_coeff(mpl115a_reg_read_1(sc, MPL115A_PADC_MSB),
|
|
mpl115a_reg_read_1(sc, MPL115A_PADC_LSB));
|
|
|
|
tadc = mpl115a_make_coeff(mpl115a_reg_read_1(sc, MPL115A_TADC_MSB),
|
|
mpl115a_reg_read_1(sc, MPL115A_TADC_LSB));
|
|
|
|
#ifdef MPL115A_DEBUG
|
|
aprint_normal_dev(sc->sc_dev, "padc %x, tadc %x\n", padc, tadc);
|
|
#endif /* MPL115A_DEBUG */
|
|
|
|
rv = mpl115a_calc(sc, padc, tadc);
|
|
|
|
#ifdef MPL115A_DEBUG
|
|
aprint_normal_dev(sc->sc_dev, "%d Pa\n", rv);
|
|
#endif /* MPL115A_DEBUG */
|
|
|
|
return rv;
|
|
}
|
|
|
|
/* The following calculation routine was suggested by Matt Thomas. */
|
|
static uint32_t
|
|
mpl115a_calc(struct mpl115a_softc *sc, uint16_t padc, uint16_t tadc)
|
|
{
|
|
int32_t fp_a0, fp_b1, fp_b2, fp_c12, fp_padc, fp_tadc;
|
|
int32_t c12x2, a1, a1x2, y1, a2x2, pcomp;
|
|
uint32_t pre_kpa1, pre_kpa2, pa;
|
|
|
|
/* convert coefficients to common fixed point format */
|
|
fp_a0 = sc->sc_a0 << 13; /* 12.3 -> 15.16 */
|
|
fp_b1 = sc->sc_b1 << 3; /* 2.13 -> 15.16 */
|
|
fp_b2 = sc->sc_b2 << 2; /* 1.14 -> 15.16 */
|
|
fp_c12 = sc->sc_c12 >> 2; /* 0.22 */
|
|
|
|
fp_padc = padc >> 6;
|
|
fp_tadc = tadc >> 6;
|
|
|
|
c12x2 = (fp_c12 * fp_tadc + 0x3f) >> 6;
|
|
a1 = fp_b1 + c12x2;
|
|
a1x2 = a1 * fp_padc;
|
|
y1 = fp_a0 + a1x2;
|
|
a2x2 = fp_b2 * fp_tadc;
|
|
pcomp = y1 + a2x2;
|
|
|
|
/* pre_kpa has 16 fractional digits so it's accurate to 1/65536 kPa */
|
|
pre_kpa1 = pcomp * (115 - 50);
|
|
pre_kpa2 = pre_kpa1 / 1023 + (50 << 16);
|
|
|
|
/* but the real accuracy of the sensor is around +/- 1 kPa... */
|
|
pa = ((pre_kpa2 + 32768) >> 16) * 1000;
|
|
|
|
return pa;
|
|
}
|
|
|
|
static void
|
|
mpl115a_envsys_register(struct mpl115a_softc *sc)
|
|
{
|
|
sc->sc_sme = sysmon_envsys_create();
|
|
|
|
strlcpy(sc->sc_sensor.desc, "Absolute pressure",
|
|
sizeof(sc->sc_sensor.desc));
|
|
/* sc->sc_sensor.units = ENVSYS_SPRESSURE; */
|
|
sc->sc_sensor.units = ENVSYS_INTEGER;
|
|
sc->sc_sensor.state = ENVSYS_SINVALID;
|
|
|
|
if (sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor)) {
|
|
aprint_error_dev(sc->sc_dev,
|
|
"error attaching sensor\n");
|
|
return;
|
|
}
|
|
|
|
sc->sc_sme->sme_name = device_xname(sc->sc_dev);
|
|
sc->sc_sme->sme_cookie = sc;
|
|
sc->sc_sme->sme_refresh = mpl115a_envsys_refresh;
|
|
|
|
if (sysmon_envsys_register(sc->sc_sme)) {
|
|
aprint_error_dev(sc->sc_dev, "unable to register in sysmon\n");
|
|
sysmon_envsys_destroy(sc->sc_sme);
|
|
}
|
|
}
|
|
|
|
static void
|
|
mpl115a_envsys_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
|
|
{
|
|
struct mpl115a_softc *sc = sme->sme_cookie;
|
|
|
|
mutex_enter(&sc->sc_lock);
|
|
|
|
edata->value_cur = mpl115a_pressure(sc);
|
|
edata->state = ENVSYS_SVALID;
|
|
|
|
mutex_exit(&sc->sc_lock);
|
|
}
|
|
|