[PATCH v2 03/16] iio: adc: imx7d_adc: do not use internal iio_dev lock

[Bough Chen]

> -----Original Message-----
> From: Nuno Sá <nuno.sa at analog.com>
> Sent: 2022年10月4日 21:49
> To: linux-amlogic at lists.infradead.org; dl-linux-imx <linux-imx at nxp.com>;
> linux-iio at vger.kernel.org; linux-arm-kernel at lists.infradead.org;
> linux-rockchip at lists.infradead.org
> Cc: Heiko Stuebner <heiko at sntech.de>; Martin Blumenstingl
> <martin.blumenstingl at googlemail.com>; Neil Armstrong
> <narmstrong at baylibre.com>; Shawn Guo <shawnguo at kernel.org>; Lars-Peter
> Clausen <lars at metafoo.de>; Jyoti Bhayana <jbhayana at google.com>; Hans de
> Goede <hdegoede at redhat.com>; Andriy Tryshnivskyy
> <andriy.tryshnivskyy at opensynergy.com>; Pengutronix Kernel Team
> <kernel at pengutronix.de>; Miquel Raynal <miquel.raynal at bootlin.com>; Cixi
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> <baolin.wang at linux.alibaba.com>; Ciprian Regus <ciprian.regus at analog.com>;
> Fabio Estevam <festevam at gmail.com>; Nuno Sá <nuno.sa at analog.com>;
> Sascha Hauer <s.hauer at pengutronix.de>; Alexandru Ardelean
> <aardelean at deviqon.com>; Florian Boor <florian.boor at kernelconcepts.de>;
> Michael Hennerich <Michael.Hennerich at analog.com>; Orson Zhai
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> Shevchenko <andy.shevchenko at gmail.com>; Jerome Brunet
> <jbrunet at baylibre.com>; Bough Chen <haibo.chen at nxp.com>; Kevin Hilman
> <khilman at baylibre.com>; Jonathan Cameron <jic23 at kernel.org>
> Subject: [PATCH v2 03/16] iio: adc: imx7d_adc: do not use internal iio_dev lock
> 
> 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>

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

Thanks!
Best Regards
Haibo Chen
> ---
>  drivers/iio/adc/imx7d_adc.c | 14 +++++++++-----
>  1 file changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iio/adc/imx7d_adc.c b/drivers/iio/adc/imx7d_adc.c index
> 86caff1d006b..22da81bac97f 100644
> --- a/drivers/iio/adc/imx7d_adc.c
> +++ b/drivers/iio/adc/imx7d_adc.c
> @@ -13,6 +13,7 @@
>  #include <linux/kernel.h>
>  #include <linux/mod_devicetable.h>
>  #include <linux/module.h>
> +#include <linux/mutex.h>
>  #include <linux/platform_device.h>
>  #include <linux/regulator/consumer.h>
> 
> @@ -108,7 +109,8 @@ struct imx7d_adc {
>  	struct device *dev;
>  	void __iomem *regs;
>  	struct clk *clk;
> -
> +	/* lock to protect against multiple access to the device */
> +	struct mutex lock;
>  	u32 vref_uv;
>  	u32 value;
>  	u32 channel;
> @@ -293,7 +295,7 @@ static int imx7d_adc_read_raw(struct iio_dev
> *indio_dev,
> 
>  	switch (mask) {
>  	case IIO_CHAN_INFO_RAW:
> -		mutex_lock(&indio_dev->mlock);
> +		mutex_lock(&info->lock);
>  		reinit_completion(&info->completion);
> 
>  		channel = chan->channel & 0x03;
> @@ -303,16 +305,16 @@ static int imx7d_adc_read_raw(struct iio_dev
> *indio_dev,
>  		ret = wait_for_completion_interruptible_timeout
>  				(&info->completion, IMX7D_ADC_TIMEOUT);
>  		if (ret == 0) {
> -			mutex_unlock(&indio_dev->mlock);
> +			mutex_unlock(&info->lock);
>  			return -ETIMEDOUT;
>  		}
>  		if (ret < 0) {
> -			mutex_unlock(&indio_dev->mlock);
> +			mutex_unlock(&info->lock);
>  			return ret;
>  		}
> 
>  		*val = info->value;
> -		mutex_unlock(&indio_dev->mlock);
> +		mutex_unlock(&info->lock);
>  		return IIO_VAL_INT;
> 
>  	case IIO_CHAN_INFO_SCALE:
> @@ -531,6 +533,8 @@ static int imx7d_adc_probe(struct platform_device
> *pdev)
>  	if (ret)
>  		return ret;
> 
> +	mutex_init(&info->lock);
> +
>  	ret = devm_iio_device_register(dev, indio_dev);
>  	if (ret) {
>  		dev_err(&pdev->dev, "Couldn't register the device.\n");
> --
> 2.37.3