diff options
Diffstat (limited to 'driver/charger/isl9241.c')
| -rw-r--r-- | driver/charger/isl9241.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/driver/charger/isl9241.c b/driver/charger/isl9241.c index 4db66e0b52..1312388b5a 100644 --- a/driver/charger/isl9241.c +++ b/driver/charger/isl9241.c @@ -232,6 +232,52 @@ int charger_set_voltage(int voltage) return isl9241_write(ISL9241_REG_MAX_SYSTEM_VOLTAGE, voltage); } +int charger_get_vbus_voltage(int port) +{ + int adc_val = 0; + int ctl3_val; + int rv; + + /* Get current Control3 value */ + rv = isl9241_read(ISL9241_REG_CONTROL3, &ctl3_val); + if (rv) + goto error; + + /* Enable ADC */ + if (!(ctl3_val & ISL9241_CONTROL3_ENABLE_ADC)) { + rv = isl9241_write(ISL9241_REG_CONTROL3, + ctl3_val | ISL9241_CONTROL3_ENABLE_ADC); + if (rv) + goto error; + } + + /* Read voltage ADC value */ + rv = isl9241_read(ISL9241_REG_VIN_ADC_RESULTS, &adc_val); + if (rv) + goto error_restore_ctl3; + + /* + * Adjust adc_val + * + * raw adc_val has VIN_ADC in bits [13:6], so shift this down + * this puts adc_val in the range of 0..255, which maps to 0..24.48V + * each step in adc_val is 96mv + */ + adc_val >>= ISL9241_VIN_ADC_BIT_OFFSET; + adc_val *= ISL9241_VIN_ADC_STEP_MV; + +error_restore_ctl3: + /* Restore Control3 value */ + if (!(ctl3_val & ISL9241_CONTROL3_ENABLE_ADC)) + (void)isl9241_write(ISL9241_REG_CONTROL3, ctl3_val); + +error: + if (rv) + CPRINTF("Could not read VBUS ADC! Error: %d\n", rv); + + return adc_val; +} + int charger_post_init(void) { return EC_SUCCESS; |