Messages in this thread | | | From | Doug Anderson <> | Date | Tue, 22 Jan 2019 16:40:36 -0800 | Subject | Re: [PATCH v3 03/10] arm64: dts: sdm845: Introduce ADSP and CDSP PAS nodes |
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Hi,
On Tue, Jan 22, 2019 at 4:26 PM Bjorn Andersson <bjorn.andersson@linaro.org> wrote: > > > + clocks = <&xo_board>; > > > + clock-names = "xo"; > > > > I've found that nearly all the places that refer to xo_board are wrong > > and should actually point to '<&rpmhcc RPMH_CXO_CLK>'. Maybe yours > > should too? > > > > Yes, xo_board is a fake clock representing the 19.2MHz clock feeding the > cxo (or cxo2) pad of the SoC. So you're definitely right in that this > should be referencing the actual 19.2MHz clock. > > We've kept referring to this as xo_board, as we don't handle probe > deferral when gcc will probe earlier than rpmcc in the boot and for > other non-clock drivers the fear of actually hitting 0 on the refcounter > for this (you don't want to disable the cxo while running the system).
Note that, as defined in the device tree, "xo_board" is actually 38.4. IIUC that is not actually a fake/bogus clock but represents the actual crystal on the board. There's a divide by 2 in the CPU though so most peripherals consider "xo" as 19.2.
...OK, confirmed. The actual RF_XO_CLK pin on the board is truly connected to 38.4.
-Doug
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