hwmon: qpnp-adc-current: Fix IADC current units
At low current values, not using the correct units
for scaling the voltage and dividing it by the appropriate
units for rsense causes incorrect resolution in units for
current. Fix it by using the correct units.
Change-Id: Ia76382268b69db194f5f17f5a129140e75d66298
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
diff --git a/drivers/hwmon/qpnp-adc-current.c b/drivers/hwmon/qpnp-adc-current.c
index 4292e18..a136bef 100644
--- a/drivers/hwmon/qpnp-adc-current.c
+++ b/drivers/hwmon/qpnp-adc-current.c
@@ -115,7 +115,7 @@
#define QPNP_ADC_GAIN_NV 17857
#define QPNP_OFFSET_CALIBRATION_SHORT_CADC_LEADS_IDEAL 0
#define QPNP_IADC_INTERNAL_RSENSE_N_OHMS_FACTOR 10000000
-#define QPNP_IADC_NANO_VOLTS_FACTOR 1000000000
+#define QPNP_IADC_NANO_VOLTS_FACTOR 1000000
#define QPNP_IADC_CALIB_SECONDS 300000
#define QPNP_IADC_RSENSE_LSB_N_OHMS_PER_BIT 15625
#define QPNP_IADC_DIE_TEMP_CALIB_OFFSET 5000
@@ -599,6 +599,7 @@
{
struct qpnp_iadc_drv *iadc = qpnp_iadc;
int32_t rc, rsense_n_ohms, sign = 0, num, mode_sel = 0;
+ int32_t rsense_u_ohms = 0;
int64_t result_current;
uint16_t raw_data;
@@ -624,7 +625,7 @@
rc = qpnp_iadc_get_rsense(&rsense_n_ohms);
pr_debug("current raw:0%x and rsense:%d\n",
raw_data, rsense_n_ohms);
-
+ rsense_u_ohms = rsense_n_ohms/1000;
num = raw_data - iadc->adc->calib.offset_raw;
if (num < 0) {
sign = 1;
@@ -635,7 +636,7 @@
(iadc->adc->calib.gain_raw - iadc->adc->calib.offset_raw);
result_current = result->result_uv;
result_current *= QPNP_IADC_NANO_VOLTS_FACTOR;
- do_div(result_current, rsense_n_ohms);
+ do_div(result_current, rsense_u_ohms);
if (sign) {
result->result_uv = -result->result_uv;