Hello Jonathan, thanks for your comment. Just submitted V4 with corrections: 1. regulator configuration is now done before iio_device_register 2. devm_regulator_put has been removed as it is not necessary Let me know! Adam On Sun, Aug 2, 2015 at 9:55 AM, Jonathan Cameron <jic23@xxxxxxxxxx> wrote: > On 21/07/15 01:49, Adam YH Lee wrote: >> 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: Adam YH Lee <adam.yh.lee@xxxxxxxxx> >> --- >> drivers/iio/adc/twl4030-madc.c | 36 ++++++++++++++++++++++++++++++++++++ >> 1 file changed, 36 insertions(+) >> >> diff --git a/drivers/iio/adc/twl4030-madc.c b/drivers/iio/adc/twl4030-madc.c >> index 94c5f05..ae33eba 100644 >> --- a/drivers/iio/adc/twl4030-madc.c >> +++ b/drivers/iio/adc/twl4030-madc.c >> @@ -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) >> +#define TWL4030_USB_CARKIT_ANA_CTRL 0xBB >> + >> /** >> * 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; >> @@ -848,6 +854,33 @@ static int twl4030_madc_probe(struct platform_device *pdev) >> goto err_i2c; >> } >> > At this point in the driver the userspace (an in kernel) interfaces to read > from the device are exposed. Thus if you need this stuff set up right, it > wants to be done before the iio_device_register call. >> + /* Configure MADC[3:6] */ >> + ret = twl_i2c_read_u8(TWL_MODULE_USB, ®val, >> + TWL4030_USB_CARKIT_ANA_CTRL); >> + if (ret) { >> + dev_err(&pdev->dev, "unable to read reg CARKIT_ANA_CTRL 0x%X\n", >> + TWL4030_USB_CARKIT_ANA_CTRL); >> + goto err_i2c; >> + } >> + regval |= TWL4030_USB_SEL_MADC_MCPC; >> + ret = twl_i2c_write_u8(TWL_MODULE_USB, regval, >> + TWL4030_USB_CARKIT_ANA_CTRL); >> + if (ret) { >> + dev_err(&pdev->dev, "unable to write reg CARKIT_ANA_CTRL 0x%X\n", >> + TWL4030_USB_CARKIT_ANA_CTRL); >> + 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"); >> + >> return 0; >> >> err_i2c: >> @@ -867,6 +900,9 @@ static int twl4030_madc_remove(struct platform_device *pdev) >> twl4030_madc_set_current_generator(madc, 0, 0); >> twl4030_madc_set_power(madc, 0); >> >> + regulator_disable(madc->usb3v1); >> + devm_regulator_put(madc->usb3v1); > The whole point of devm_ allocators (or in this case _gets) is that when > the driver is removed they are cleaned up automatically. Hence you don't > need them in your remove call. Obviously it also clears up the error > handling in probe as well. >> + >> return 0; >> } >> >> > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html