static int apds990x_chip_off(struct apds990x_chip *chip)
{
apds990x_write_byte(chip, APDS990X_ENABLE, APDS990X_EN_DISABLE_ALL);
if (chip->pdata->power_on)
chip->pdata->power_on(0);
return 0;
}
static int apds990x_configure(struct apds990x_chip *chip)
{
/* It is recommended to use disabled mode during these operations */
apds990x_write_byte(chip, APDS990X_ENABLE, APDS990X_EN_DISABLE_ALL);
/* conversion and wait times for different state machince states */
apds990x_write_byte(chip, APDS990X_PTIME, APDS990X_PTIME_DEFAULT);
apds990x_write_byte(chip, APDS990X_WTIME, APDS990X_WTIME_DEFAULT);
apds990x_set_atime(chip, APDS_LUX_AVERAGING_TIME);
apds990x_write_byte(chip, APDS990X_CONFIG, 0);
/* Persistence levels */
apds990x_write_byte(chip, APDS990X_PERS,
(chip->lux_persistence << APDS990X_APERS_SHIFT) |
(chip->prox_persistence << APDS990X_PPERS_SHIFT));
apds990x_write_byte(chip, APDS990X_PPCOUNT, chip->pdata->ppcount);
/* Start with relatively small gain */
chip->again_meas = 1;
chip->again_next = 1;
apds990x_write_byte(chip, APDS990X_CONTROL,
(chip->pdrive << 6) |
(chip->pdiode << 4) |
(chip->pgain << 2) |
(chip->again_next << 0));
return 0;
}
static inline int apds990x_set_atime(struct apds990x_chip *chip, u32 time_ms)
{
u8 reg_value;
chip->atime = time_ms;
/* Formula is specified in the data sheet */
reg_value = 256 - ((time_ms * TIME_STEP_SCALER) / TIMESTEP);
/* Calculate max ADC value for given integration time */
chip->a_max_result = (u16)(256 - reg_value) * APDS990X_TIME_TO_ADC;
return apds990x_write_byte(chip, APDS990X_ATIME, reg_value);
}
static int apds990x_mode_on(struct apds990x_chip *chip)
{
/* ALS is mandatory, proximity optional */
u8 reg = APDS990X_EN_AIEN | APDS990X_EN_PON | APDS990X_EN_AEN |
APDS990X_EN_WEN;
if (chip->prox_en)
reg |= APDS990X_EN_PIEN | APDS990X_EN_PEN;
return apds990x_write_byte(chip, APDS990X_ENABLE, reg);
}
/* Called always with mutex locked */
static int apds990x_calc_again(struct apds990x_chip *chip)
{
int curr_again = chip->again_meas;
int next_again = chip->again_meas;
int ret = 0;
/* Calculate suitable als gain */
if (chip->lux_clear == chip->a_max_result)
next_again -= 2; /* ALS saturated. Decrease gain by 2 steps */
else if (chip->lux_clear > chip->a_max_result / 2)
next_again--;
else if (chip->lux_clear < APDS_LUX_GAIN_LO_LIMIT_STRICT)
next_again += 2; /* Too dark. Increase gain by 2 steps */
else if (chip->lux_clear < APDS_LUX_GAIN_LO_LIMIT)
next_again++;
/* Limit gain to available range */
if (next_again < 0)
next_again = 0;
else if (next_again > APDS990X_MAX_AGAIN)
next_again = APDS990X_MAX_AGAIN;
/* Let's check can we trust the measured result */
if (chip->lux_clear == chip->a_max_result)
/* Result can be totally garbage due to saturation */
ret = -ERANGE;
else if (next_again != curr_again &&
chip->lux_clear < APDS_LUX_GAIN_LO_LIMIT_STRICT)
/*
* Gain is changed and measurement result is very small.
* Result can be totally garbage due to underflow
*/
ret = -ERANGE;
chip->again_next = next_again;
apds990x_write_byte(chip, APDS990X_CONTROL,
(chip->pdrive << 6) |
(chip->pdiode << 4) |
(chip->pgain << 2) |
(chip->again_next << 0));
/*
* Error means bad result -> re-measurement is needed. The forced
* refresh uses fastest possible persistence setting to get result
* as soon as possible.
*/
if (ret < 0)
apds990x_force_a_refresh(chip);
else
apds990x_refresh_athres(chip);
return ret;
}
static int apds990x_set_arate(struct apds990x_chip *chip, int rate)
{
int i;
for (i = 0; i < ARRAY_SIZE(arates_hz); i++)
if (rate >= arates_hz[i])
break;
if (i == ARRAY_SIZE(arates_hz))
return -EINVAL;
/* Pick up corresponding persistence value */
chip->lux_persistence = apersis[i];
chip->arate = arates_hz[i];
/* If the chip is not in use, don't try to access it */
if (pm_runtime_suspended(&chip->client->dev))
return 0;
/* Persistence levels */
return apds990x_write_byte(chip, APDS990X_PERS,
(chip->lux_persistence << APDS990X_APERS_SHIFT) |
(chip->prox_persistence << APDS990X_PPERS_SHIFT));
}
static int apds990x_chip_off(struct apds990x_chip *chip)
{
apds990x_write_byte(chip, APDS990X_ENABLE, APDS990X_EN_DISABLE_ALL);
regulator_bulk_disable(ARRAY_SIZE(chip->regs), chip->regs);
return 0;
}
