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Date:   Fri, 7 Jul 2023 19:07:38 +0200
From:   Martin Kaiser <martin@kaiser.cx>
To:     Yangtao Li <frank.li@vivo.com>
Cc:     Olivia Mackall <olivia@selenic.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] hwrng: timeriomem - Use
 devm_platform_get_and_ioremap_resource()
Message-ID: <ZKhGWrNip0p9rx0I@martin-debian-2.paytec.ch>
References: <20230705115242.54285-1-frank.li@vivo.com>
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In-Reply-To: <20230705115242.54285-1-frank.li@vivo.com>
Sender: "Martin Kaiser,,," <martin@martin-debian-2.paytec.ch>
Precedence: bulk

Hi,

Thus wrote Yangtao Li (frank.li@vivo.com):

> Convert platform_get_resource(), devm_ioremap_resource() to a single
> call to devm_platform_get_and_ioremap_resource(), as this is exactly
> what this function does.

> Signed-off-by: Yangtao Li <frank.li@vivo.com>
> ---
>  drivers/char/hw_random/timeriomem-rng.c | 25 ++++++++++---------------
>  1 file changed, 10 insertions(+), 15 deletions(-)

> diff --git a/drivers/char/hw_random/timeriomem-rng.c b/drivers/char/hw_random/timeriomem-rng.c
> index 26f322d19a88..3db9d868efb1 100644
> --- a/drivers/char/hw_random/timeriomem-rng.c
> +++ b/drivers/char/hw_random/timeriomem-rng.c
> @@ -113,16 +113,6 @@ static int timeriomem_rng_probe(struct platform_device *pdev)
>  		return -EINVAL;
>  	}

> -	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	if (!res)
> -		return -ENXIO;
> -
> -	if (res->start % 4 != 0 || resource_size(res) < 4) {
> -		dev_err(&pdev->dev,
> -			"address must be at least four bytes wide and 32-bit aligned\n");
> -		return -EINVAL;
> -	}
> -
>  	/* Allocate memory for the device structure (and zero it) */
>  	priv = devm_kzalloc(&pdev->dev,
>  			sizeof(struct timeriomem_rng_private), GFP_KERNEL);
> @@ -131,6 +121,16 @@ static int timeriomem_rng_probe(struct platform_device *pdev)

>  	platform_set_drvdata(pdev, priv);

> +	priv->io_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
> +	if (IS_ERR(priv->io_base))
> +		return PTR_ERR(priv->io_base);
> +
> +	if (res->start % 4 != 0 || resource_size(res) < 4) {
> +		dev_err(&pdev->dev,
> +			"address must be at least four bytes wide and 32-bit aligned\n");
> +		return -EINVAL;
> +	}
> +
>  	if (pdev->dev.of_node) {
>  		int i;

> @@ -158,11 +158,6 @@ static int timeriomem_rng_probe(struct platform_device *pdev)
>  	priv->rng_ops.name = dev_name(&pdev->dev);
>  	priv->rng_ops.read = timeriomem_rng_read;

> -	priv->io_base = devm_ioremap_resource(&pdev->dev, res);
> -	if (IS_ERR(priv->io_base)) {
> -		return PTR_ERR(priv->io_base);
> -	}
> -
>  	/* Assume random data is already available. */
>  	priv->present = 1;
>  	complete(&priv->completion);
> -- 
> 2.39.0

Looks ok to me.

Reviewed-by: Martin Kaiser <martin@kaiser.cx>

I was wondering if we really have to check res->start and resource_size(res)
that we read from the device tree. Other drivers don't check these settings
and use devm_platform_ioremap_resource(pdev, 0).

Best regards,
Martin