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sensors: generalise lps22 pressure sensor for HH and DF models #663

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151 changes: 121 additions & 30 deletions sensors/baro/lps22xx.c
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Original file line number Diff line number Diff line change
Expand Up @@ -23,28 +23,57 @@
#include <libsensors/bus.h>

/* self identification register */
#define REG_WHOAMI 0x0f
#define REG_VAL_WHOAMI 0xb3

/* control register 1 */
#define REG_CTRL_REG1 0x10
#define VAL_ODR_200 0x70
#define VAL_ODR_100 0x60
#define VAL_ODR_75 0x50
#define VAL_ODR_50 0x40
#define VAL_ODR_25 0x30
#define VAL_EN_LPFP 0x08
#define VAL_LPFP_CFG 0x04
#define VAL_BDU 0x02

/* control register 2 */
#define REG_CTRL_REG2 0x11
#define VAL_BOOT 0x80
#define VAL_LOW_NOISE_EN 0x02
#define IF_ADD_INC 0x10

/* control register 3 */
#define REG_CTRL_REG3 0x12
#define REG_WHOAMI 0x0f
#define REG_VAL_WHOAMI_HH 0xb3
#define REG_VAL_WHOAMI_DF 0xb4

/* control register 1 - LPS22HH */
#define HH_REG_CTRL_REG1 0x10
#define HH_VAL_ODR_200 0x70
#define HH_VAL_ODR_100 0x60
#define HH_VAL_ODR_75 0x50
#define HH_VAL_ODR_50 0x40
#define HH_VAL_ODR_25 0x30
#define HH_VAL_EN_LPFP 0x08
#define HH_VAL_LPFP_CFG 0x04
#define HH_VAL_BDU 0x02

/* control register 2 - LPS22HH */
#define HH_REG_CTRL_REG2 0x11
#define HH_VAL_BOOT 0x80
#define HH_VAL_LOW_NOISE_EN 0x02
#define HH_IF_ADD_INC 0x10

/* control register 3 - LPS22HH */
#define HH_REG_CTRL_REG3 0x12

/* control register 1 - LPS22DF */
#define DF_REG_CTRL_REG1 0x10
#define DF_VAL_ODR_200 0x40
#define DF_VAL_ODR_100 0x38
#define DF_VAL_ODR_75 0x30
#define DF_VAL_ODR_50 0x28
#define DF_VAL_ODR_25 0x20
#define DF_VAL_AVG_4 0x00
#define DF_VAL_AVG_8 0x01
#define DF_VAL_AVG_16 0x02
#define DF_VAL_AVG_32 0x03
#define DF_VAL_AVG_64 0x04
#define DF_VAL_AVG_128 0x06
#define DF_VAL_AVG_512 0x07


/* control register 2 - LPS22DF */
#define DF_REG_CTRL_REG2 0x11
#define DF_VAL_BOOT 0x80
#define DF_VAL_LPFP_CFG 0x20
#define DF_VAL_EN_LPFP 0x10
#define DF_VAL_BDU 0x08

/* control register 3 - LPS22DF */
#define DF_REG_CTRL_REG3 0x12
#define DF_IF_ADD_INC 0x01


/* data storage addresses */
#define REG_DATA_OUT 0x28
Expand All @@ -68,6 +97,13 @@ typedef struct {
} lps22xx_ctx_t;


static struct {
int whoAmI;
} common = {
.whoAmI = -1
};


static uint32_t translatePress(uint8_t lbyte, uint8_t mbyte, uint8_t hbyte)
{
/**
Expand Down Expand Up @@ -116,34 +152,67 @@ static int lps22xx_whoamiCheck(sensor_bus_t *bus)
cmd = REG_WHOAMI | SPI_READ_BIT;
val = 0;
err = bus->ops.bus_xfer(bus, &cmd, sizeof(cmd), &val, sizeof(val), sizeof(cmd));
if ((err < 0) || (val != REG_VAL_WHOAMI)) {
fprintf(stderr, "whoami: %x\n", val);
if (err < 0) {
fprintf(stderr, "whoami xfer: %d\n", err);
return -1;
}

switch (val) {
case REG_VAL_WHOAMI_HH:
case REG_VAL_WHOAMI_DF:
common.whoAmI = val;
break;

default:
fprintf(stderr, "whoami: %x\n", val);
return -1;
}

return 0;
}


static int lps22xx_hwSetup(sensor_bus_t *bus)
static int lps22x_setupHH(sensor_bus_t *bus)
{
if (lps22xx_whoamiCheck(bus) != 0) {
printf("lps22xx: cannot read/wrong WHOAMI returned!\n");
/* Boot process: refresh the content of the internal registers stored in the flash memory block */
if (spiWriteReg(bus, HH_REG_CTRL_REG2, HH_VAL_BOOT) < 0) {
return -1;
}
usleep(LPS22XX_BOOT_DELAY_US); /* The boot process takes 2.2 msec. Waiting more for safety */

if (spiWriteReg(bus, HH_REG_CTRL_REG1, (HH_VAL_ODR_75 | HH_VAL_BDU | HH_VAL_EN_LPFP)) < 0) {
return -1;
}
usleep(LPS22XX_CONFIG_DELAY_US); /* Arbitrary wait */

if (spiWriteReg(bus, HH_REG_CTRL_REG2, (HH_IF_ADD_INC | HH_VAL_LOW_NOISE_EN)) < 0) {
return -1;
}
usleep(LPS22XX_CONFIG_DELAY_US); /* Arbitrary wait */

return 0;
}


static int lps22x_setupDF(sensor_bus_t *bus)
{
/* Boot process: refresh the content of the internal registers stored in the flash memory block */
if (spiWriteReg(bus, REG_CTRL_REG2, VAL_BOOT) < 0) {
if (spiWriteReg(bus, DF_REG_CTRL_REG2, DF_VAL_BOOT) < 0) {
return -1;
}
usleep(LPS22XX_BOOT_DELAY_US); /* The boot process takes 2.2 msec. Waiting more for safety */

if (spiWriteReg(bus, REG_CTRL_REG1, (VAL_ODR_75 | VAL_BDU | VAL_EN_LPFP)) < 0) {
if (spiWriteReg(bus, DF_REG_CTRL_REG1, (DF_VAL_ODR_75 | DF_VAL_AVG_128)) < 0) {
return -1;
}
usleep(LPS22XX_CONFIG_DELAY_US); /* Arbitrary wait */

if (spiWriteReg(bus, REG_CTRL_REG2, (IF_ADD_INC | VAL_LOW_NOISE_EN)) < 0) {
if (spiWriteReg(bus, DF_REG_CTRL_REG2, (DF_VAL_EN_LPFP | DF_VAL_BDU)) < 0) {
return -1;
}
usleep(LPS22XX_CONFIG_DELAY_US); /* Arbitrary wait */

if (spiWriteReg(bus, DF_REG_CTRL_REG3, DF_IF_ADD_INC) < 0) {
return -1;
}
usleep(LPS22XX_CONFIG_DELAY_US); /* Arbitrary wait */
Expand All @@ -152,6 +221,28 @@ static int lps22xx_hwSetup(sensor_bus_t *bus)
}


static int lps22xx_hwSetup(sensor_bus_t *bus)
{
if (lps22xx_whoamiCheck(bus) != 0) {
printf("lps22xx: cannot read/wrong WHOAMI returned!\n");
return -1;
}

switch (common.whoAmI) {
case REG_VAL_WHOAMI_HH:
return lps22x_setupHH(bus);

case REG_VAL_WHOAMI_DF:
return lps22x_setupDF(bus);

default:
return -1;
}

return -1;

@gemini-code-assist gemini-code-assist Bot May 19, 2026

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medium

This return statement is unreachable because the switch block above handles all possible cases (including default) and returns from the function in every branch.

}


static int lps22xx_read(const sensor_info_t *info, const sensor_event_t **evt)
{
int err;
Expand Down
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