Am Mittwoch, 11. Januar 2017, 16:50:10 CET schrieb Doug Anderson: > Hi, > > On Tue, Jan 10, 2017 at 11:58 AM, Heiko Stübner <heiko@xxxxxxxxx> wrote: > > Hi Doug, > > > > Am Dienstag, 10. Januar 2017, 20:46:12 schrieb Heiko Stübner: > >> Am Dienstag, 10. Januar 2017, 10:45:48 schrieb Doug Anderson: > >> > Hi, > >> > > >> > On Mon, Jan 9, 2017 at 10:15 PM, Xing Zheng <zhengxing@xxxxxxxxxxxxxx> > >> > >> wrote: > >> > > The structure rockchip_clk_provider needs to refer the GRF regmap > >> > > in somewhere, if the CRU node has not "rockchip,grf" property, > >> > > calling syscon_regmap_lookup_by_phandle will return an invalid GRF > >> > > regmap, and the MUXGRF type clock will be not supported. > >> > > > >> > > Therefore, we need to add them. > >> > > > >> > > Signed-off-by: Xing Zheng <zhengxing@xxxxxxxxxxxxxx> > >> > > --- > >> > > > >> > > Changes in v4: > >> > > - separte the binding patch > >> > > > >> > > Changes in v3: > >> > > - add optional roperty rockchip,grf in rockchip,rk3399-cru.txt > >> > > > >> > > Changes in v2: > >> > > - referring pmugrf for PMUGRU > >> > > - fix the typo "invaild" in COMMIT message > >> > > > >> > > arch/arm64/boot/dts/rockchip/rk3399.dtsi | 2 ++ > >> > > 1 file changed, 2 insertions(+) > >> > > >> > This seems fine to me, so: > >> > > >> > Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx> > >> > > >> > ...but I will say that before you actually add any real "MUXGRF" > >> > clocks on rk3399 you _might_ need to rework the code to make things > >> > truly "optional". If it turns out that any existing clocks that > >> > already exist today already go through one of these muxes in the GRF > >> > and we've always been assuming one setting of the mux, we'll need to > >> > make sure we keep assuming that setting of the mux even if the "grf" > >> > isn't specified. > >> > >> I guess I see that a bit more relaxed :-) . > >> > >> I.e. the GRF being optional is a remnant of syscons not being available > >> when the clocks get set up- so were coming in later or not at all. For > >> the rk3288 I converted, there we never really had the case of the GRF > >> missing. > >> > >> And the GRF mux for the vcodec now present is not being used by anything > >> yet (neither driver nor binding), so no old devicetree can break. > >> > >> > As I understand it, your motivation for this patch is to eventually be > >> > able to model the EDP reference clock which can either be xin24 or > >> > "edp osc". Presumably the eDP "reference clock" isn't related to any > >> > of the pre-existing eDP clocks so that one should be safe. > >> > >> Same here, so far we don't even have edp or even any other graphical > >> output > >> on the rk3399, so again there is no old devicetree that could break when > >> the grf is not specified. > > > > reading all of the above again, it feels like you essentially also said > > similar things already in your original reply and I misread some of it. > > > > But again, I don't see the need for any more code right now, as hopefully > > the simple stuff we currently only support does not have any grf-based > > muxes in it. Xing + Rockchip people, please correct me if I'm wrong here > > :-) > Right. I have no objection to Xing's patch. I just want to make sure > that if it's listed as "Optional" that it's really optional. > > I was worried that we would introduce some GRF-based mux in the > _middle_ of some existing clock tree because we simply didn't model > the mux before and assumed one particular setting. If nothing like > that ever happens then we're fine. Thankfully the clock diagrams on the old socs were pretty verbose, listing all grf-based clocks as well. For example the rk3288 seems to have two and it seems I've been carrying dummy definitions for those from the time I did the initial clock tree [0]. And thankfully grf-based clocks somehow always only get used for more "esotheric" components like vcodec and iep on the rk3288 :-) . Heiko [0] https://github.com/mmind/linux-rockchip/blob/devel/workbench/drivers/clk/rockchip/clk-rk3288.c lines 371 and 799 .. looks like I'll need to add the iep clock as well at some point. -- 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
