linux-kernel - Re: [v2,08/12] hwrng: bcm2835-rng: Abstract I/O accessors

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Message-ID: <720033c0-ccb6-0be1-37b6-c3d38e6174fe@amsat.org>
Date:   Mon, 13 Nov 2017 01:54:45 -0300
From:   Philippe Mathieu-Daudé <f4bug@...at.org>
To:     Florian Fainelli <f.fainelli@...il.com>
Cc:     linux-kernel@...r.kernel.org, Matt Mackall <mpm@...enic.com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Ray Jui <rjui@...adcom.com>,
        Scott Branden <sbranden@...adcom.com>,
        Eric Anholt <eric@...olt.net>,
        Stefan Wahren <stefan.wahren@...e.com>,
        PrasannaKumar Muralidharan <prasannatsmkumar@...il.com>,
        Russell King <rmk+kernel@...linux.org.uk>,
        Krzysztof Kozlowski <krzk@...nel.org>,
        Harald Freudenberger <freude@...ux.vnet.ibm.com>,
        Sean Wang <sean.wang@...iatek.com>,
        Martin Kaiser <martin@...ser.cx>,
        Steffen Trumtrar <s.trumtrar@...gutronix.de>
Subject: Re: [v2,08/12] hwrng: bcm2835-rng: Abstract I/O accessors

On 11/07/2017 09:44 PM, Florian Fainelli wrote:
> In preparation for allowing BCM63xx to use this driver, we abstract I/O
> accessors such that we can easily change those later on.
> 
> Signed-off-by: Florian Fainelli <f.fainelli@...il.com>
> Reviewed-by: Eric Anholt <eric@...olt.net>

Reviewed-by: Philippe Mathieu-Daudé <f4bug@...at.org>

> ---
>  drivers/char/hw_random/bcm2835-rng.c | 27 +++++++++++++++++++--------
>  1 file changed, 19 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c
> index 99b56fd5482c..3a607472687d 100644
> --- a/drivers/char/hw_random/bcm2835-rng.c
> +++ b/drivers/char/hw_random/bcm2835-rng.c
> @@ -42,6 +42,17 @@ static inline struct bcm2835_rng_priv *to_rng_priv(struct hwrng *rng)
>  	return container_of(rng, struct bcm2835_rng_priv, rng);
>  }
>  
> +static inline u32 rng_readl(struct bcm2835_rng_priv *priv, u32 offset)
> +{
> +	return readl(priv->base + offset);
> +}
> +
> +static inline void rng_writel(struct bcm2835_rng_priv *priv, u32 val,
> +			      u32 offset)
> +{
> +	writel(val, priv->base + offset);
> +}
> +
>  static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max,
>  			       bool wait)
>  {
> @@ -49,18 +60,18 @@ static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max,
>  	u32 max_words = max / sizeof(u32);
>  	u32 num_words, count;
>  
> -	while ((__raw_readl(priv->base + RNG_STATUS) >> 24) == 0) {
> +	while ((rng_readl(priv, RNG_STATUS) >> 24) == 0) {
>  		if (!wait)
>  			return 0;
>  		cpu_relax();
>  	}
>  
> -	num_words = readl(priv->base + RNG_STATUS) >> 24;
> +	num_words = rng_readl(priv, RNG_STATUS) >> 24;
>  	if (num_words > max_words)
>  		num_words = max_words;
>  
>  	for (count = 0; count < num_words; count++)
> -		((u32 *)buf)[count] = readl(priv->base + RNG_DATA);
> +		((u32 *)buf)[count] = rng_readl(priv, RNG_DATA);
>  
>  	return num_words * sizeof(u32);
>  }
> @@ -79,14 +90,14 @@ static int bcm2835_rng_init(struct hwrng *rng)
>  
>  	if (priv->mask_interrupts) {
>  		/* mask the interrupt */
> -		val = readl(priv->base + RNG_INT_MASK);
> +		val = rng_readl(priv, RNG_INT_MASK);
>  		val |= RNG_INT_OFF;
> -		writel(val, priv->base + RNG_INT_MASK);
> +		rng_writel(priv, val, RNG_INT_MASK);
>  	}
>  
>  	/* set warm-up count & enable */
> -	__raw_writel(RNG_WARMUP_COUNT, priv->base + RNG_STATUS);
> -	__raw_writel(RNG_RBGEN, priv->base + RNG_CTRL);
> +	rng_writel(priv, RNG_WARMUP_COUNT, RNG_STATUS);
> +	rng_writel(priv, RNG_RBGEN, RNG_CTRL);
>  
>  	return ret;
>  }
> @@ -96,7 +107,7 @@ static void bcm2835_rng_cleanup(struct hwrng *rng)
>  	struct bcm2835_rng_priv *priv = to_rng_priv(rng);
>  
>  	/* disable rng hardware */
> -	__raw_writel(0, priv->base + RNG_CTRL);
> +	rng_writel(priv, 0, RNG_CTRL);
>  
>  	if (!IS_ERR(priv->clk))
>  		clk_disable_unprepare(priv->clk);
> 
>