iio:adc:twl6030: Enable measurements of VUSB, VBAT and others

commit f804bd0dc2 upstream.

Some inputs need to be wired up to produce proper measurements,
without this change only near zero values are reported.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Fixes: 1696f36482 ("iio: twl6030-gpadc: TWL6030, TWL6032 GPADC driver")
Link: https://lore.kernel.org/r/20221201181635.3522962-1-andreas@kemnade.info
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/iio/adc/twl6030-gpadc.c

@@ -57,6 +57,18 @@
 #define TWL6030_GPADCS				BIT(1)
 #define TWL6030_GPADCR				BIT(0)
 
+#define USB_VBUS_CTRL_SET			0x04
+#define USB_ID_CTRL_SET				0x06
+
+#define TWL6030_MISC1				0xE4
+#define VBUS_MEAS				0x01
+#define ID_MEAS					0x01
+
+#define VAC_MEAS                0x04
+#define VBAT_MEAS               0x02
+#define BB_MEAS                 0x01
+
+
 /**
  * struct twl6030_chnl_calib - channel calibration
  * @gain:		slope coefficient for ideal curve
@@ -927,6 +939,26 @@ static int twl6030_gpadc_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	ret = twl_i2c_write_u8(TWL_MODULE_USB, VBUS_MEAS, USB_VBUS_CTRL_SET);
+	if (ret < 0) {
+		dev_err(dev, "failed to wire up inputs\n");
+		return ret;
+	}
+
+	ret = twl_i2c_write_u8(TWL_MODULE_USB, ID_MEAS, USB_ID_CTRL_SET);
+	if (ret < 0) {
+		dev_err(dev, "failed to wire up inputs\n");
+		return ret;
+	}
+
+	ret = twl_i2c_write_u8(TWL6030_MODULE_ID0,
+				VBAT_MEAS | BB_MEAS | BB_MEAS,
+				TWL6030_MISC1);
+	if (ret < 0) {
+		dev_err(dev, "failed to wire up inputs\n");
+		return ret;
+	}
+
 	indio_dev->name = DRIVER_NAME;
 	indio_dev->info = &twl6030_gpadc_iio_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;