RE: [PATCH v2 09/16] iio: adc: vf610_adc: add helper function to read samples

[Bough Chen <haibo.chen@nxp.com>]

> -----Original Message-----
> From: Nuno Sá <nuno.sa@analog.com>
> Sent: 2022年10月4日 21:49
> To: linux-amlogic@lists.infradead.org; dl-linux-imx <linux-imx@nxp.com>;
> linux-iio@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> linux-rockchip@lists.infradead.org
> Cc: Heiko Stuebner <heiko@sntech.de>; Martin Blumenstingl
> <martin.blumenstingl@googlemail.com>; Neil Armstrong
> <narmstrong@baylibre.com>; Shawn Guo <shawnguo@kernel.org>; Lars-Peter
> Clausen <lars@metafoo.de>; Jyoti Bhayana <jbhayana@google.com>; Hans de
> Goede <hdegoede@redhat.com>; Andriy Tryshnivskyy
> <andriy.tryshnivskyy@opensynergy.com>; Pengutronix Kernel Team
> <kernel@pengutronix.de>; Miquel Raynal <miquel.raynal@bootlin.com>; Cixi
> Geng <cixi.geng1@unisoc.com>; Baolin Wang
> <baolin.wang@linux.alibaba.com>; Ciprian Regus <ciprian.regus@analog.com>;
> Fabio Estevam <festevam@gmail.com>; Nuno Sá <nuno.sa@analog.com>;
> Sascha Hauer <s.hauer@pengutronix.de>; Alexandru Ardelean
> <aardelean@deviqon.com>; Florian Boor <florian.boor@kernelconcepts.de>;
> Michael Hennerich <Michael.Hennerich@analog.com>; Orson Zhai
> <orsonzhai@gmail.com>; Chen-Yu Tsai <wens@csie.org>; Chunyan Zhang
> <zhang.lyra@gmail.com>; Vladimir Zapolskiy <vz@mleia.com>; Andy
> Shevchenko <andy.shevchenko@gmail.com>; Jerome Brunet
> <jbrunet@baylibre.com>; Bough Chen <haibo.chen@nxp.com>; Kevin Hilman
> <khilman@baylibre.com>; Jonathan Cameron <jic23@kernel.org>
> Subject: [PATCH v2 09/16] iio: adc: vf610_adc: add helper function to read
> samples
> 
> This is a precursor change to make it simpler to remove the 'mlock'
> usage. Having the code in it's own helper function, also makes it easier to read
> the error paths.
> 
> Signed-off-by: Nuno Sá <nuno.sa@analog.com>

Reviewed-by: Haibo Chen <haibo.chen@nxp.com>

> ---
>  drivers/iio/adc/vf610_adc.c | 94 +++++++++++++++++++++----------------
>  1 file changed, 54 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c index
> c6b16cf6e367..a6f9182d7766 100644
> --- a/drivers/iio/adc/vf610_adc.c
> +++ b/drivers/iio/adc/vf610_adc.c
> @@ -622,6 +622,58 @@ static const struct attribute_group
> vf610_attribute_group = {
>  	.attrs = vf610_attributes,
>  };
> 
> +static int vf610_read_sample(struct iio_dev *indio_dev,
> +			     struct iio_chan_spec const *chan, int *val) {
> +	struct vf610_adc *info = iio_priv(indio_dev);
> +	unsigned int hc_cfg;
> +	int ret;
> +
> +	mutex_lock(&indio_dev->mlock);
> +	if (iio_buffer_enabled(indio_dev)) {
> +		ret = -EBUSY;
> +		goto out_unlock;
> +	}
> +
> +	reinit_completion(&info->completion);
> +	hc_cfg = VF610_ADC_ADCHC(chan->channel);
> +	hc_cfg |= VF610_ADC_AIEN;
> +	writel(hc_cfg, info->regs + VF610_REG_ADC_HC0);
> +	ret = wait_for_completion_interruptible_timeout(&info->completion,
> +							VF610_ADC_TIMEOUT);
> +	if (ret == 0) {
> +		ret = -ETIMEDOUT;
> +		goto out_unlock;
> +	}
> +
> +	if (ret < 0)
> +		goto out_unlock;
> +
> +	switch (chan->type) {
> +	case IIO_VOLTAGE:
> +		*val = info->value;
> +		break;
> +	case IIO_TEMP:
> +		/*
> +		 * Calculate in degree Celsius times 1000
> +		 * Using the typical sensor slope of 1.84 mV/°C
> +		 * and VREFH_ADC at 3.3V, V at 25°C of 699 mV
> +		 */
> +		*val = 25000 - ((int)info->value - VF610_VTEMP25_3V3) *
> +				1000000 / VF610_TEMP_SLOPE_COEFF;
> +
> +		break;
> +	default:
> +		ret = -EINVAL;
> +		break;
> +	}
> +
> +out_unlock:
> +	mutex_unlock(&indio_dev->mlock);
> +
> +	return ret;
> +}
> +
>  static int vf610_read_raw(struct iio_dev *indio_dev,
>  			struct iio_chan_spec const *chan,
>  			int *val,
> @@ -629,53 +681,15 @@ static int vf610_read_raw(struct iio_dev *indio_dev,
>  			long mask)
>  {
>  	struct vf610_adc *info = iio_priv(indio_dev);
> -	unsigned int hc_cfg;
>  	long ret;
> 
>  	switch (mask) {
>  	case IIO_CHAN_INFO_RAW:
>  	case IIO_CHAN_INFO_PROCESSED:
> -		mutex_lock(&indio_dev->mlock);
> -		if (iio_buffer_enabled(indio_dev)) {
> -			mutex_unlock(&indio_dev->mlock);
> -			return -EBUSY;
> -		}
> -
> -		reinit_completion(&info->completion);
> -		hc_cfg = VF610_ADC_ADCHC(chan->channel);
> -		hc_cfg |= VF610_ADC_AIEN;
> -		writel(hc_cfg, info->regs + VF610_REG_ADC_HC0);
> -		ret = wait_for_completion_interruptible_timeout
> -				(&info->completion, VF610_ADC_TIMEOUT);
> -		if (ret == 0) {
> -			mutex_unlock(&indio_dev->mlock);
> -			return -ETIMEDOUT;
> -		}
> -		if (ret < 0) {
> -			mutex_unlock(&indio_dev->mlock);
> +		ret = vf610_read_sample(indio_dev, chan, val);
> +		if (ret < 0)
>  			return ret;
> -		}
> -
> -		switch (chan->type) {
> -		case IIO_VOLTAGE:
> -			*val = info->value;
> -			break;
> -		case IIO_TEMP:
> -			/*
> -			 * Calculate in degree Celsius times 1000
> -			 * Using the typical sensor slope of 1.84 mV/°C
> -			 * and VREFH_ADC at 3.3V, V at 25°C of 699 mV
> -			 */
> -			*val = 25000 - ((int)info->value - VF610_VTEMP25_3V3) *
> -					1000000 / VF610_TEMP_SLOPE_COEFF;
> -
> -			break;
> -		default:
> -			mutex_unlock(&indio_dev->mlock);
> -			return -EINVAL;
> -		}
> 
> -		mutex_unlock(&indio_dev->mlock);
>  		return IIO_VAL_INT;
> 
>  	case IIO_CHAN_INFO_SCALE:
> --
> 2.37.3

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