Re: [PATCH 11/15] drm/panfrost: set devfreq clock name

[Steven Price <steven.price@arm.com>]

On 10/05/2020 17:55, Clément Péron wrote:
> Some SoCs have  several clocks defined and the OPP core
> needs to know the exact name of the clk to use.
> 
> Set the clock name to "core".
> 
> Signed-off-by: Clément Péron <peron.clem@gmail.com>

This is unfortunately a regression for the RK3288. The device tree 
binding doesn't require "clock-names", and for the RK3288 it currently 
isn't specified. So this breaks the platform.

Adding the "clock-names" to the device tree 'fixes' it, but we really 
need to keep backwards compatibility.

Steve

> ---
>   drivers/gpu/drm/panfrost/panfrost_devfreq.c | 13 +++++++++++++
>   drivers/gpu/drm/panfrost/panfrost_devfreq.h |  1 +
>   2 files changed, 14 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> index 9ffea0d4a087..6bf3541b4d53 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> @@ -103,6 +103,14 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
>   
>   	spin_lock_init(&pfdevfreq->lock);
>   
> +	opp_table = dev_pm_opp_set_clkname(dev, "core");
> +	if (IS_ERR(opp_table)) {
> +		ret = PTR_ERR(opp_table);
> +		goto err_fini;
> +	}
> +
> +	pfdevfreq->clkname_opp_table = opp_table;
> +
>   	opp_table = dev_pm_opp_set_regulators(dev, pfdev->comp->supply_names,
>   					      pfdev->comp->num_supplies);
>   	if (IS_ERR(opp_table)) {
> @@ -176,6 +184,11 @@ void panfrost_devfreq_fini(struct panfrost_device *pfdev)
>   		dev_pm_opp_put_regulators(pfdevfreq->regulators_opp_table);
>   		pfdevfreq->regulators_opp_table = NULL;
>   	}
> +
> +	if (pfdevfreq->clkname_opp_table) {
> +		dev_pm_opp_put_clkname(pfdevfreq->clkname_opp_table);
> +		pfdevfreq->clkname_opp_table = NULL;
> +	}
>   }
>   
>   void panfrost_devfreq_resume(struct panfrost_device *pfdev)
> diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.h b/drivers/gpu/drm/panfrost/panfrost_devfreq.h
> index 347cde4786cf..1f2475e1d034 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.h
> @@ -16,6 +16,7 @@ struct panfrost_device;
>   struct panfrost_devfreq {
>   	struct devfreq *devfreq;
>   	struct opp_table *regulators_opp_table;
> +	struct opp_table *clkname_opp_table;
>   	struct thermal_cooling_device *cooling;
>   	bool opp_of_table_added;
>   
>