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drivers: sensor: ccs811: abstract read of status/error

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Read the status and error in one function that provides its own
diagnostics.

Also change name of register to match datasheet.

Signed-off-by: Peter A. Bigot <pab@pabigot.com>
This commit is contained in:
Peter A. Bigot 2018-11-20 10:31:19 -06:00 • committed by Maureen Helm
commit ff5ef271ee
2 changed files with 64 additions and 20 deletions
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82
drivers/sensor/ccs811/ccs811.c
View file

@ -34,12 +34,49 @@ static void set_wake(struct ccs811_data *drv_data, bool enable)
#define set_wake(...)
#endif
/* Get STATUS register in low 8 bits, and if ERROR is set put ERROR_ID
* in bits 8..15. These registers are available in both boot and
* application mode.
*/
static int fetch_status(struct device *i2c)
{
u8_t status;
int rv;
if (i2c_reg_read_byte(i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
CCS811_REG_STATUS, &status) < 0) {
LOG_ERR("Failed to read Status register");
return -EIO;
}
rv = status;
if (status & CCS811_STATUS_ERROR) {
u8_t error_id;
if (i2c_reg_read_byte(i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
CCS811_REG_ERROR_ID, &error_id) < 0) {
LOG_ERR("Failed to read ERROR_ID register");
return -EIO;
}
rv |= (error_id << 8);
}
return rv;
}
static inline u8_t error_from_status(int status)
{
return status >> 8;
}
static int ccs811_sample_fetch(struct device *dev, enum sensor_channel chan)
{
struct ccs811_data *drv_data = dev->driver_data;
int tries;
u16_t buf[4];
u8_t status;
u8_t cmd;
int status;
int rv = -EIO;
/* Check data ready flag for the measurement interval */
@ -53,9 +90,14 @@ static int ccs811_sample_fetch(struct device *dev, enum sensor_channel chan)
while (tries-- > 0) {
set_wake(drv_data, true);
if (i2c_reg_read_byte(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
CCS811_REG_STATUS, &status) < 0) {
LOG_ERR("Failed to read Status register");
status = fetch_status(drv_data->i2c);
if (status < 0) {
goto out;
}
if (status & CCS811_STATUS_ERROR) {
LOG_ERR("CCS811 ERROR ID %02x",
error_from_status(status));
goto out;
}
@ -72,8 +114,10 @@ static int ccs811_sample_fetch(struct device *dev, enum sensor_channel chan)
goto out;
}
if (i2c_burst_read(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
CCS811_REG_ALG_RESULT_DATA, (u8_t *)buf, 8) < 0) {
cmd = CCS811_REG_ALG_RESULT_DATA;
if (i2c_write_read(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
&cmd, sizeof(cmd),
(u8_t *)buf, 8) < 0) {
LOG_ERR("Failed to read conversion data.");
goto out;
}
@ -142,13 +186,13 @@ static const struct sensor_driver_api ccs811_driver_api = {
static int switch_to_app_mode(struct device *i2c)
{
u8_t status, buf;
u8_t buf;
int status;
LOG_DBG("Switching to Application mode...");
if (i2c_reg_read_byte(i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
CCS811_REG_STATUS, &status) < 0) {
LOG_ERR("Failed to read Status register");
status = fetch_status(i2c);
if (status < 0) {
return -EIO;
}
@ -172,9 +216,8 @@ static int switch_to_app_mode(struct device *i2c)
}
k_sleep(1); /* t_APP_START */
if (i2c_reg_read_byte(i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
CCS811_REG_STATUS, &status) < 0) {
LOG_ERR("Failed to read Status register");
status = fetch_status(i2c);
if (status < 0) {
return -EIO;
}
@ -192,8 +235,9 @@ static int switch_to_app_mode(struct device *i2c)
int ccs811_init(struct device *dev)
{
struct ccs811_data *drv_data = dev->driver_data;
int ret;
u8_t hw_id, status;
int ret = 0;
u8_t hw_id;
int status;
drv_data->i2c = device_get_binding(DT_INST_0_AMS_CCS811_BUS_NAME);
if (drv_data->i2c == NULL) {
@ -291,15 +335,15 @@ int ccs811_init(struct device *dev)
}
/* Check for error */
if (i2c_reg_read_byte(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
CCS811_REG_STATUS, &status) < 0) {
LOG_ERR("Failed to read Status register");
status = fetch_status(drv_data->i2c);
if (status < 0) {
ret = -EIO;
goto out;
}
if (status & CCS811_STATUS_ERROR) {
LOG_ERR("Error occurred during sensor configuration");
LOG_ERR("CCS811 Error %02x during sensor configuration",
error_from_status(status));
ret = -EINVAL;
goto out;
}

2
drivers/sensor/ccs811/ccs811.h
View file

@ -20,7 +20,7 @@
#define CCS811_REG_HW_ID 0x20
#define CCS811_REG_HW_VERSION 0x21
#define CCS811_REG_HW_VERSION_MASK 0xF0
#define CCS811_REG_ERR 0xE0
#define CCS811_REG_ERROR_ID 0xE0
#define CCS811_REG_APP_START 0xF4
#define CCS881_HW_ID 0x81