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

From: Johan Hovold
Date: Thu Aug 23 2018 - 03:51:04 EST


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@xxxxxx>
> ---
> 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"?

> +}
> +
> 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@xxxxxxxxxx>

Johan