Commit 7cc97d77 authored by Adam YH Lee's avatar Adam YH Lee Committed by Jonathan Cameron

iio: adc: twl4030: Fix ADC[3:6] readings

MADC[3:6] reads incorrect values without these two following changes:

- enable the 3v1 bias regulator for ADC[3:6]
- configure ADC[3:6] lines as input, not as USB
Signed-off-by: default avatarAdam YH Lee <>
Signed-off-by: default avatarJonathan Cameron <>
parent 9ffecb10
......@@ -45,13 +45,18 @@
#include <linux/types.h>
#include <linux/gfp.h>
#include <linux/err.h>
#include <linux/regulator/consumer.h>
#include <linux/iio/iio.h>
#define TWL4030_USB_SEL_MADC_MCPC (1<<3)
* struct twl4030_madc_data - a container for madc info
* @dev: Pointer to device structure for madc
* @lock: Mutex protecting this data structure
* @regulator: Pointer to bias regulator for madc
* @requests: Array of request struct corresponding to SW1, SW2 and RT
* @use_second_irq: IRQ selection (main or co-processor)
* @imr: Interrupt mask register of MADC
......@@ -60,6 +65,7 @@
struct twl4030_madc_data {
struct device *dev;
struct mutex lock; /* mutex protecting this data structure */
struct regulator *usb3v1;
struct twl4030_madc_request requests[TWL4030_MADC_NUM_METHODS];
bool use_second_irq;
u8 imr;
......@@ -841,6 +847,32 @@ static int twl4030_madc_probe(struct platform_device *pdev)
twl4030_madc = madc;
/* Configure MADC[3:6] */
ret = twl_i2c_read_u8(TWL_MODULE_USB, &regval,
if (ret) {
dev_err(&pdev->dev, "unable to read reg CARKIT_ANA_CTRL 0x%X\n",
goto err_i2c;
regval |= TWL4030_USB_SEL_MADC_MCPC;
ret = twl_i2c_write_u8(TWL_MODULE_USB, regval,
if (ret) {
dev_err(&pdev->dev, "unable to write reg CARKIT_ANA_CTRL 0x%X\n",
goto err_i2c;
/* Enable 3v1 bias regulator for MADC[3:6] */
madc->usb3v1 = devm_regulator_get(madc->dev, "vusb3v1");
if (IS_ERR(madc->usb3v1))
return -ENODEV;
ret = regulator_enable(madc->usb3v1);
if (ret)
dev_err(madc->dev, "could not enable 3v1 bias regulator\n");
ret = iio_device_register(iio_dev);
if (ret) {
dev_err(&pdev->dev, "could not register iio device\n");
......@@ -866,6 +898,8 @@ static int twl4030_madc_remove(struct platform_device *pdev)
twl4030_madc_set_current_generator(madc, 0, 0);
twl4030_madc_set_power(madc, 0);
return 0;
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