Re: [PATCH] iio/axp288_adc: add missing channel info mask

From: Jonathan Cameron <jic23@kernel.org>
To: Jacob Pan <jacob.jun.pan@linux.intel.com>,
	IIO <linux-iio@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
Cc: Lee Jones <lee.jones@linaro.org>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Hartmut Knaack <knaack.h@gmx.de>, Aaron Lu <aaron.lu@intel.com>,
	Todd Brandt <todd.e.brandt@linux.intel.com>
Subject: Re: [PATCH] iio/axp288_adc: add missing channel info mask
Date: Sat, 21 Mar 2015 12:07:03 +0000	[thread overview]
Message-ID: <550D5EE7.20208@kernel.org> (raw)
In-Reply-To: <1426527265-14979-1-git-send-email-jacob.jun.pan@linux.intel.com>

On 16/03/15 17:34, Jacob Pan wrote:
> Commit 65de7654d39c70c2b ("iio: iio: Fix iio_channel_read return if
> channel havn't info") added a check for valid info masks.
> 
> This patch adds missing channel info masks for all ADC channels.
> Otherwise, iio_read_channel_raw() would return -EINVAL when called
> by consumer drivers.
> 
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
>  drivers/iio/adc/axp288_adc.c | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iio/adc/axp288_adc.c b/drivers/iio/adc/axp288_adc.c
> index 08bcfb0..7ce361c 100644
> --- a/drivers/iio/adc/axp288_adc.c
> +++ b/drivers/iio/adc/axp288_adc.c
> @@ -53,39 +53,45 @@ static const struct iio_chan_spec const axp288_adc_channels[] = {
>  		.channel = 0,
>  		.address = AXP288_TS_ADC_H,
>  		.datasheet_name = "TS_PIN",
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
>  	}, {
>  		.indexed = 1,
>  		.type = IIO_TEMP,
>  		.channel = 1,
>  		.address = AXP288_PMIC_ADC_H,
>  		.datasheet_name = "PMIC_TEMP",
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
>  	}, {
>  		.indexed = 1,
>  		.type = IIO_TEMP,
>  		.channel = 2,
>  		.address = AXP288_GP_ADC_H,
>  		.datasheet_name = "GPADC",
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
These additions are fair enough given otherwise the driver is claiming not to provide
the raw read.  I suppose we might want to hide these from direct userspace exposure
but I doubt anyone cares.
>  	}, {
>  		.indexed = 1,
>  		.type = IIO_CURRENT,
>  		.channel = 3,
>  		.address = AXP20X_BATT_CHRG_I_H,
>  		.datasheet_name = "BATT_CHG_I",
> -		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED)
> +		| BIT(IIO_CHAN_INFO_RAW),
>  	}, {
>  		.indexed = 1,
>  		.type = IIO_CURRENT,
>  		.channel = 4,
>  		.address = AXP20X_BATT_DISCHRG_I_H,
>  		.datasheet_name = "BATT_DISCHRG_I",
> -		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED)
> +		| BIT(IIO_CHAN_INFO_RAW),
>  	}, {
>  		.indexed = 1,
>  		.type = IIO_VOLTAGE,
>  		.channel = 5,
>  		.address = AXP20X_BATT_V_H,
>  		.datasheet_name = "BATT_V",
> -		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED)
> +		| BIT(IIO_CHAN_INFO_RAW),
>  	},
These cases strike me as problematic.  You should not need both.  If the consumer
is reading _raw from a channel that only supplies PROCESSED then that is the bug,
not the lack of support for a raw read.
>  };
>  
> @@ -140,20 +146,19 @@ static int axp288_adc_read_raw(struct iio_dev *indio_dev,
>  	mutex_lock(&indio_dev->mlock);
>  	switch (mask) {
>  	case IIO_CHAN_INFO_RAW:
> +	case IIO_CHAN_INFO_PROCESSED:
>  		if (axp288_adc_set_ts(info->regmap, AXP288_ADC_TS_PIN_GPADC,
>  					chan->address)) {
>  			dev_err(&indio_dev->dev, "GPADC mode\n");
>  			ret = -EINVAL;
>  			break;
>  		}
> +
>  		ret = axp288_adc_read_channel(val, chan->address, info->regmap);
>  		if (axp288_adc_set_ts(info->regmap, AXP288_ADC_TS_PIN_ON,
>  						chan->address))
>  			dev_err(&indio_dev->dev, "TS pin restore\n");
>  		break;
> -	case IIO_CHAN_INFO_PROCESSED:
> -		ret = axp288_adc_read_channel(val, chan->address, info->regmap);
> -		break;
>  	default:
>  		ret = -EINVAL;
>  	}
>