Re: [PATCH v4 1/8] of: Add NVIDIA Tegra SATA controller binding

Mikko Perttunen
2014-07-17T07:56:46Z

On 17/07/14 10:39, Thierry Reding wrote:
> ...
> One other thing that I've been thinking about is whether it would make
> sense to make the ahci_platform library use a list of clock names that
> it should request. This would better mirror the clock bindings
> convention and allow drivers (such as the Tegra one) to take ownership
> of clocks that need special handling while at the same time leaving it
> to the helpers to do the bulk of the work.
>
> One way I can think of to handle this would be by adding a struct
> ahci_platform_resources * parameter to ahci_platform_get_resources(),
> sowewhat like this:
>
> struct ahci_platform_resources {
> const char *const *clocks;
> unsigned int num_clocks;
>
> const char *const *resets;
> unsigned int num_resets;
> };
>
> struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev,
> const struct ahci_platform_resources *res)
> {
> ...
>
> for (i = 0; i < res->num_clocks; i++) {
> clk = clk_get(&pdev->dev, res->clocks[i]);
> ...
> }
>
> ...
>
> for (i = 0; i < res->num_resets; i++) {
> rst = reset_control_get(&pdev->dev, res->resets[i]);
> ...
> }
>
> ...
> }
>

I think something like this would be required to support reset_controls
anyway, as you can only get reset controls by name. This is what I
alluded to (in the cover letter) when saying that adding reset control
support would require an API break.

Also: is there a reason to not use the devm_* variants? I note that the
helper code has not been able to prevent any of the ahci_platform
drivers from messing up by not calling ahci_platform_put_resources.

- Mikko