[PATCH v2 04/16] iio: adc: lpc32xx_adc: do not use internal iio_dev lock

[Jonathan Cameron]

On Tue, 4 Oct 2022 15:48:57 +0200
Nuno Sá <nuno.sa at analog.com> wrote:

> The iio_device lock is only meant for internal use. Hence define a
> device local lock to protect against concurrent accesses.
> 
> While at it, properly include "mutex.h" for mutex related APIs.
> 
> Signed-off-by: Nuno Sá <nuno.sa at analog.com>
Applied.

Thanks,

J

> ---
>  drivers/iio/adc/lpc32xx_adc.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/adc/lpc32xx_adc.c b/drivers/iio/adc/lpc32xx_adc.c
> index b56ce15255cf..732c924a976d 100644
> --- a/drivers/iio/adc/lpc32xx_adc.c
> +++ b/drivers/iio/adc/lpc32xx_adc.c
> @@ -15,6 +15,7 @@
>  #include <linux/io.h>
>  #include <linux/module.h>
>  #include <linux/mod_devicetable.h>
> +#include <linux/mutex.h>
>  #include <linux/platform_device.h>
>  #include <linux/regulator/consumer.h>
>  
> @@ -49,6 +50,8 @@ struct lpc32xx_adc_state {
>  	struct clk *clk;
>  	struct completion completion;
>  	struct regulator *vref;
> +	/* lock to protect against multiple access to the device */
> +	struct mutex lock;
>  
>  	u32 value;
>  };
> @@ -64,10 +67,10 @@ static int lpc32xx_read_raw(struct iio_dev *indio_dev,
>  
>  	switch (mask) {
>  	case IIO_CHAN_INFO_RAW:
> -		mutex_lock(&indio_dev->mlock);
> +		mutex_lock(&st->lock);
>  		ret = clk_prepare_enable(st->clk);
>  		if (ret) {
> -			mutex_unlock(&indio_dev->mlock);
> +			mutex_unlock(&st->lock);
>  			return ret;
>  		}
>  		/* Measurement setup */
> @@ -80,7 +83,7 @@ static int lpc32xx_read_raw(struct iio_dev *indio_dev,
>  		wait_for_completion(&st->completion); /* set by ISR */
>  		clk_disable_unprepare(st->clk);
>  		*val = st->value;
> -		mutex_unlock(&indio_dev->mlock);
> +		mutex_unlock(&st->lock);
>  
>  		return IIO_VAL_INT;
>  
> @@ -201,6 +204,8 @@ static int lpc32xx_adc_probe(struct platform_device *pdev)
>  	iodev->modes = INDIO_DIRECT_MODE;
>  	iodev->num_channels = ARRAY_SIZE(lpc32xx_adc_iio_channels);
>  
> +	mutex_init(&st->lock);
> +
>  	retval = devm_iio_device_register(&pdev->dev, iodev);
>  	if (retval)
>  		return retval;