hwmon: qpnp-adc: Use buffered 625mV reference channel
Use channel 0xc to read the buffered 625mV reference
channel during calibration if it exists. The channel
may not exist on all the PMIC versions. If the channel
is supported in the PMIC add it as a channel in the
VADC DT channel node.
Change-Id: I49b54e161538f075fcd89ed9beb7ffbdd8034a87
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
diff --git a/drivers/hwmon/qpnp-adc-voltage.c b/drivers/hwmon/qpnp-adc-voltage.c
index d296a47..bd1f098 100644
--- a/drivers/hwmon/qpnp-adc-voltage.c
+++ b/drivers/hwmon/qpnp-adc-voltage.c
@@ -431,12 +431,32 @@
return 0;
}
-static uint32_t qpnp_vadc_calib_device(void)
+static void qpnp_vadc_625mv_channel_sel(uint32_t *ref_channel_sel)
+{
+ struct qpnp_vadc_drv *vadc = qpnp_vadc;
+ uint32_t dt_index = 0;
+
+ /* Check if the buffered 625mV channel exists */
+ while ((vadc->adc->adc_channels[dt_index].channel_num
+ != SPARE1) && (dt_index < vadc->max_channels_available))
+ dt_index++;
+
+ if (dt_index >= vadc->max_channels_available) {
+ pr_debug("Use default 625mV ref channel\n");
+ *ref_channel_sel = REF_625MV;
+ } else {
+ pr_debug("Use buffered 625mV ref channel\n");
+ *ref_channel_sel = SPARE1;
+ }
+}
+
+static int32_t qpnp_vadc_calib_device(void)
{
struct qpnp_vadc_drv *vadc = qpnp_vadc;
struct qpnp_adc_amux_properties conv;
int rc, calib_read_1, calib_read_2, count = 0;
u8 status1 = 0;
+ uint32_t ref_channel_sel = 0;
conv.amux_channel = REF_125V;
conv.decimation = DECIMATION_TYPE2;
@@ -470,7 +490,8 @@
goto calib_fail;
}
- conv.amux_channel = REF_625MV;
+ qpnp_vadc_625mv_channel_sel(&ref_channel_sel);
+ conv.amux_channel = ref_channel_sel;
conv.decimation = DECIMATION_TYPE2;
conv.mode_sel = ADC_OP_NORMAL_MODE << QPNP_VADC_OP_MODE_SHIFT;
conv.hw_settle_time = ADC_CHANNEL_HW_SETTLE_DELAY_0US;
@@ -647,6 +668,7 @@
{
struct qpnp_vadc_drv *vadc = qpnp_vadc;
int rc = 0, scale_type, amux_prescaling, dt_index = 0;
+ uint32_t ref_channel;
if (!vadc || !vadc->vadc_initialized)
return -EPROBE_DEFER;
@@ -666,6 +688,11 @@
vadc->vadc_init_calib = true;
}
+ if (channel == REF_625MV) {
+ qpnp_vadc_625mv_channel_sel(&ref_channel);
+ channel = ref_channel;
+ }
+
vadc->adc->amux_prop->amux_channel = channel;
while ((vadc->adc->adc_channels[dt_index].channel_num