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

[Mikko Perttunen <mperttunen@nvidia.com>]

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