linux-kernel - Re: [PATCH] cpufreq: ti-cpufreq: Only register platform

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Message-ID: <27e25e06-2721-87dd-3e9b-8d91f6c49449@ti.com>
Date:   Thu, 23 Aug 2018 11:24:58 -0500
From:   Dave Gerlach <d-gerlach@...com>
To:     Johan Hovold <johan@...nel.org>
CC:     Viresh Kumar <viresh.kumar@...aro.org>,
        "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Nishanth Menon <nm@...com>, <linux-pm@...r.kernel.org>,
        Tony Lindgren <tony@...mide.com>, Keerthy J <j-keerthy@...com>,
        <linux-kernel@...r.kernel.org>, Tero Kristo <t-kristo@...com>,
        Stephen Boyd <sboyd@...nel.org>, <linux-omap@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH] cpufreq: ti-cpufreq: Only register platform_device when
 supported

On 08/23/2018 02:50 AM, Johan Hovold wrote:
> On Wed, Aug 22, 2018 at 09:44:32PM -0500, Dave Gerlach wrote:
>> Currently the ti-cpufreq driver blindly registers a 'ti-cpufreq' to force
>> the driver to probe on any platforms where the driver is built in.
>> However, this should only happen on platforms that actually can make use
>> of the driver. There is already functionality in place to match the
>> SoC compatible so let's factor this out into a separate call and
>> make sure we find a match before creating the ti-cpufreq driver device.
>>
>> Signed-off-by: Dave Gerlach <d-gerlach@...com>
>> ---
>>  drivers/cpufreq/ti-cpufreq.c | 25 ++++++++++++++++++++-----
>>  1 file changed, 20 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/cpufreq/ti-cpufreq.c b/drivers/cpufreq/ti-cpufreq.c
>> index 3f0e2a14895a..541fdcf17b57 100644
>> --- a/drivers/cpufreq/ti-cpufreq.c
>> +++ b/drivers/cpufreq/ti-cpufreq.c
>> @@ -201,19 +201,31 @@ static const struct of_device_id ti_cpufreq_of_match[] = {
>>  	{},
>>  };
>>  
>> +static const struct of_device_id *ti_cpufreq_match_node(void)
>> +{
>> +	struct device_node *np;
>> +	const struct of_device_id *match;
>> +
>> +	np = of_find_node_by_path("/");
>> +	match = of_match_node(ti_cpufreq_of_match, np);
>> +	of_node_put(np);
>> +
>> +	if (!match)
>> +		return NULL;
>> +	else
>> +		return match;
> 
> Shouldn't this just be "return match"?

Whoops, yes that's an entirely pointless check I added.

> 
>> +}
>> +
>>  static int ti_cpufreq_probe(struct platform_device *pdev)
>>  {
>>  	u32 version[VERSION_COUNT];
>> -	struct device_node *np;
>>  	const struct of_device_id *match;
>>  	struct opp_table *ti_opp_table;
>>  	struct ti_cpufreq_data *opp_data;
>>  	const char * const reg_names[] = {"vdd", "vbb"};
>>  	int ret;
>>  
>> -	np = of_find_node_by_path("/");
>> -	match = of_match_node(ti_cpufreq_of_match, np);
>> -	of_node_put(np);
>> +	match = ti_cpufreq_match_node();
>>  	if (!match)
>>  		return -ENODEV;
>>  
>> @@ -290,7 +302,10 @@ static int ti_cpufreq_probe(struct platform_device *pdev)
>>  
>>  static int ti_cpufreq_init(void)
>>  {
>> -	platform_device_register_simple("ti-cpufreq", -1, NULL, 0);
>> +	/* Check to ensure we are on a compatible platform */
>> +	if (ti_cpufreq_match_node())
>> +		platform_device_register_simple("ti-cpufreq", -1, NULL, 0);
>> +
>>  	return 0;
>>  }
>>  module_init(ti_cpufreq_init);
> 
> With that fixed, feel free to add:
> 
> Reviewed-by: Johan Hovold <johan@...nel.org>

Thanks for the review I will update and resend.

Regards,
Dave

> 
> Johan
>