Jon Hunter <jonathanh@xxxxxxxxxx> writes: > On 18/02/16 16:00, Ulf Hansson wrote: >> [...] >> >>>> >>>> What about the pm_clk_* API which was built for tracking clocks >>>> associated with devices for runtime PM. >>>> >>>> IOW, you could pm_clk_add(pg->pmc->dev, pg->clks[i]) and then your >>>> _enable_clocks() would become pm_clk_suspend() an dyour >>>> _disable_clocks() would become pm_clk_resume(). >>> >>> Very interesting, I was not aware of this. >>> >>>> I might not be following the mapping between PMC and PGs though so not >>>> sure pg->pmc->dev is the right struct device, but you get the idea. >>> >>> Yes, so this will not work here as-is, because the pmc->dev is common to >>> all pm-domains (it is the device that creates all the pm-domains). So to >>> make this work, I would need to create a device for each pm-domain and >>> add the clocks to that. >>> >>> I see that this works very well for normal drivers, but it does not feel >>> so natural for pm-domains where we don't have a device struct today. By >>> the way, the rockchip pm-domains implementation is very much in the same >>> boat as tegra, where there are multiple clocks per pm-domain and it is >>> handled by a simple list. So I am not sure if you think that we should >>> be turning all pm-domains registered by pm_genpd_init() into a device >>> and then we can make use of these pm_clk_XXXX() APIs? >>> >>> I have implemented the generic clk APIs that Ulf and I discussed for >>> handling multiple clocks, but if we think that this is a better way, >>> then I will hold off for now. >> >> I think Kevin has a point that we already have PM clocks to build upon. >> Could we perhaps try to extend that API instead to suite this needs as well? > > We certainly could and I am not against it, however, it means that we > need to create a device structure for each pm-domain. If you and Kevin > are ok with me adding this to pm_genpd_init(), then I can give it a try. At this point, I'm thinking that the added complexity of a per-pm-domain struct device isn't justified. Managing simple lists of clocks in the SoC specific PM domains is quite easy to review and maintain, IMO. So I recommend just keeping it that way for now. If it starts to get unwieldy for tegra, rockchip and any others, we can revisit a common way of doing it then. Kevin -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
