drivers: sensor: ccs811: deassert WAKEn when not active
Asserting the WAKEn increases current draw. Turn it off when I2C is not being used. Signed-off-by: Peter A. Bigot <pab@pabigot.com> Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
This commit is contained in:
parent
11dd504f2a
commit
cc3020ea49
1 changed files with 40 additions and 12 deletions
|
@ -19,37 +19,55 @@
|
|||
|
||||
LOG_MODULE_REGISTER(CCS811, CONFIG_SENSOR_LOG_LEVEL);
|
||||
|
||||
#ifdef DT_INST_0_AMS_CCS811_WAKE_GPIOS_CONTROLLER
|
||||
static void set_wake(struct ccs811_data *drv_data, bool enable)
|
||||
{
|
||||
/* Always active-low */
|
||||
gpio_pin_write(drv_data->gpio, DT_INST_0_AMS_CCS811_WAKE_GPIOS_PIN, !enable);
|
||||
if (enable) {
|
||||
k_busy_wait(50); /* t_WAKE = 50 us */
|
||||
} else {
|
||||
k_busy_wait(20); /* t_DWAKE = 20 us */
|
||||
}
|
||||
}
|
||||
#else
|
||||
#define set_wake(...)
|
||||
#endif
|
||||
|
||||
static int ccs811_sample_fetch(struct device *dev, enum sensor_channel chan)
|
||||
{
|
||||
struct ccs811_data *drv_data = dev->driver_data;
|
||||
int tries = 11;
|
||||
u16_t buf[4];
|
||||
u8_t status;
|
||||
int rv = -EIO;
|
||||
|
||||
/* Check data ready flag for the measurement interval of 1 seconds */
|
||||
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");
|
||||
return -EIO;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if ((status & CCS811_STATUS_DATA_READY) || tries == 0) {
|
||||
break;
|
||||
}
|
||||
|
||||
set_wake(drv_data, false);
|
||||
k_sleep(K_MSEC(100));
|
||||
}
|
||||
|
||||
if (!(status & CCS811_STATUS_DATA_READY)) {
|
||||
LOG_ERR("Sensor data not available");
|
||||
return -EIO;
|
||||
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) {
|
||||
LOG_ERR("Failed to read conversion data.");
|
||||
return -EIO;
|
||||
goto out;
|
||||
}
|
||||
|
||||
drv_data->co2 = sys_be16_to_cpu(buf[0]);
|
||||
|
@ -57,8 +75,11 @@ static int ccs811_sample_fetch(struct device *dev, enum sensor_channel chan)
|
|||
drv_data->status = buf[2] & 0xff;
|
||||
drv_data->error = buf[2] >> 8;
|
||||
drv_data->resistance = sys_be16_to_cpu(buf[3]);
|
||||
rv = 0;
|
||||
|
||||
return 0;
|
||||
out:
|
||||
set_wake(drv_data, false);
|
||||
return rv;
|
||||
}
|
||||
|
||||
static int ccs811_channel_get(struct device *dev,
|
||||
|
@ -211,8 +232,8 @@ int ccs811_init(struct device *dev)
|
|||
#ifdef DT_INST_0_AMS_CCS811_WAKE_GPIOS_PIN
|
||||
gpio_pin_configure(drv_data->gpio, DT_INST_0_AMS_CCS811_WAKE_GPIOS_PIN,
|
||||
GPIO_DIR_OUT);
|
||||
gpio_pin_write(drv_data->gpio, DT_INST_0_AMS_CCS811_WAKE_GPIOS_PIN, 0);
|
||||
|
||||
set_wake(drv_data, true);
|
||||
k_sleep(K_MSEC(1));
|
||||
#endif
|
||||
}
|
||||
|
@ -220,19 +241,21 @@ int ccs811_init(struct device *dev)
|
|||
/* Switch device to application mode */
|
||||
ret = switch_to_app_mode(drv_data->i2c);
|
||||
if (ret) {
|
||||
return ret;
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* Check Hardware ID */
|
||||
if (i2c_reg_read_byte(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
|
||||
CCS811_REG_HW_ID, &hw_id) < 0) {
|
||||
LOG_ERR("Failed to read Hardware ID register");
|
||||
return -EIO;
|
||||
ret = -EIO;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if (hw_id != CCS881_HW_ID) {
|
||||
LOG_ERR("Hardware ID mismatch!");
|
||||
return -EINVAL;
|
||||
ret = -EINVAL;
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* Set Measurement mode for 1 second */
|
||||
|
@ -240,22 +263,27 @@ int ccs811_init(struct device *dev)
|
|||
CCS811_REG_MEAS_MODE,
|
||||
CCS811_MODE_IAQ_1SEC) < 0) {
|
||||
LOG_ERR("Failed to set Measurement mode");
|
||||
return -EIO;
|
||||
ret = -EIO;
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* 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");
|
||||
return -EIO;
|
||||
ret = -EIO;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if (status & CCS811_STATUS_ERROR) {
|
||||
LOG_ERR("Error occurred during sensor configuration");
|
||||
return -EINVAL;
|
||||
ret = -EINVAL;
|
||||
goto out;
|
||||
}
|
||||
|
||||
return 0;
|
||||
out:
|
||||
set_wake(drv_data, false);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static struct ccs811_data ccs811_driver;
|
||||
|
|
Loading…
Add table
Add a link
Reference in a new issue