Re: [PATCH v2] cpufreq: ti-cpufreq: Only register platform_device when supported

From: Viresh Kumar
Date: Mon Sep 03 2018 - 02:35:02 EST


On 23-08-18, 14:20, 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 platform device.
>
> Reviewed-by: Johan Hovold <johan@xxxxxxxxxx>
> Signed-off-by: Dave Gerlach <d-gerlach@xxxxxx>
> ---
> v1->v2:
> * Return 'match' directly in ti_cpufreq_match_node.
> * Add Johan's Reviewed-by.
>
> drivers/cpufreq/ti-cpufreq.c | 22 +++++++++++++++++-----
> 1 file changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/cpufreq/ti-cpufreq.c b/drivers/cpufreq/ti-cpufreq.c
> index 3f0e2a14895a..6b025953ddee 100644
> --- a/drivers/cpufreq/ti-cpufreq.c
> +++ b/drivers/cpufreq/ti-cpufreq.c
> @@ -201,19 +201,28 @@ 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);
> +
> + return match;
> +}
> +
> 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 +299,10 @@ 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);

Maybe call platform_device_register_resndata() here instead and pass match->data
to it and then you wouldn't be required to match again in probe ?

--
viresh