linux-kernel - Re: [PATCH 2/3] opp: Allow opp-supported-hw to contain multiple versions

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Date:   Wed, 26 Aug 2020 18:59:36 +0200
From:   Stephan Gerhold <stephan@...hold.net>
To:     Viresh Kumar <viresh.kumar@...aro.org>
Cc:     Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
        Stephen Boyd <sboyd@...nel.org>, linux-pm@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Rafael Wysocki <rjw@...ysocki.net>,
        Rob Herring <robh+dt@...nel.org>,
        Dmitry Osipenko <digetx@...il.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/3] opp: Allow opp-supported-hw to contain multiple
 versions

On Wed, Aug 26, 2020 at 05:20:29PM +0530, Viresh Kumar wrote:
> The bindings allow multiple versions to be passed to "opp-supported-hw"
> property, either of which can result in enabling of the OPP.
> 
> Update code to allow that.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>

This is exactly what I was looking for!
And it works just fine in my tests:

Tested-by: Stephan Gerhold <stephan@...hold.net>

Thank you!
Stephan

> ---
>  drivers/opp/of.c | 47 +++++++++++++++++++++++++++++++++--------------
>  1 file changed, 33 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/opp/of.c b/drivers/opp/of.c
> index e39ddcc779af..5dac8bffd68c 100644
> --- a/drivers/opp/of.c
> +++ b/drivers/opp/of.c
> @@ -434,9 +434,9 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_of_find_icc_paths);
>  static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
>  			      struct device_node *np)
>  {
> -	unsigned int count = opp_table->supported_hw_count;
> -	u32 version;
> -	int ret;
> +	unsigned int levels = opp_table->supported_hw_count;
> +	int count, versions, ret, i, j;
> +	u32 val;
>  
>  	if (!opp_table->supported_hw) {
>  		/*
> @@ -451,21 +451,40 @@ static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
>  			return true;
>  	}
>  
> -	while (count--) {
> -		ret = of_property_read_u32_index(np, "opp-supported-hw", count,
> -						 &version);
> -		if (ret) {
> -			dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
> -				 __func__, count, ret);
> -			return false;
> +	count = of_property_count_u32_elems(np, "opp-supported-hw");
> +	if (count <= 0 || count % levels) {
> +		dev_err(dev, "%s: Invalid opp-supported-hw property (%d)\n",
> +			__func__, count);
> +		return false;
> +	}
> +
> +	versions = count / levels;
> +
> +	/* All levels in at least one of the versions should match */
> +	for (i = 0; i < versions; i++) {
> +		bool supported = true;
> +
> +		for (j = 0; j < levels; j++) {
> +			ret = of_property_read_u32_index(np, "opp-supported-hw",
> +							 i * levels + j, &val);
> +			if (ret) {
> +				dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
> +					 __func__, i * levels + j, ret);
> +				return false;
> +			}
> +
> +			/* Check if the level is supported */
> +			if (!(val & opp_table->supported_hw[j])) {
> +				supported = false;
> +				break;
> +			}
>  		}
>  
> -		/* Both of these are bitwise masks of the versions */
> -		if (!(version & opp_table->supported_hw[count]))
> -			return false;
> +		if (supported)
> +			return true;
>  	}
>  
> -	return true;
> +	return false;
>  }
>  
>  static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
> -- 
> 2.25.0.rc1.19.g042ed3e048af
>