On 11/14, Alexey Brodkin wrote: > Hi Vladimir, > > On Tue, 2017-11-14 at 19:01 +0200, Vladimir Zapolskiy wrote: > > On 11/14/2017 02:20 PM, Eugeniy Paltsev wrote: > > > > > > Add option to set initial output frequency of plls via > > > "clock-frequency" property in pll's device tree node. > > > This frequency will be set while pll driver probed. > > > > > > The usage example is setting CPU clock frequency on boot > > > See discussion: > > > https://urldefense.proofpoint.com/v2/url?u=https-3A__www.mail-2Darchive.com_linux-2Dsnps-2Darc-40lists.infradead.org_msg02689.html&d=DwICAg&c=DPL6 > > > _X_6JkXFx7AXWqB0tg&r=lqdeeSSEes0GFDDl656eViXO7breS55ytWkhpk5R81I&m=vTFoSv1E8NyQC8nqe6pwvuTDxGvEefhAdGwAoABOrY4&s=sbmMnczdKP317bN973cZn2WcYF29kVMLW > > > chYfhSGT2M&e= > > > > > > Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev at synopsys.com> > > > --- > > > ?.../bindings/clock/snps,hsdk-pll-clock.txt?????????|??5 ++++ > > > ?.../devicetree/bindings/clock/snps,pll-clock.txt???|??5 ++++ > > > ?drivers/clk/axs10x/pll_clock.c?????????????????????| 34 ++++++++++++++++++++-- > > > ?drivers/clk/clk-hsdk-pll.c?????????????????????????| 34 ++++++++++++++++++++-- > > > ?4 files changed, 74 insertions(+), 4 deletions(-) > > > > > > diff --git a/Documentation/devicetree/bindings/clock/snps,hsdk-pll-clock.txt b/Documentation/devicetree/bindings/clock/snps,hsdk-pll-clock.txt > > > index c56c755..5703059 100644 > > > --- a/Documentation/devicetree/bindings/clock/snps,hsdk-pll-clock.txt > > > +++ b/Documentation/devicetree/bindings/clock/snps,hsdk-pll-clock.txt > > > @@ -13,6 +13,10 @@ Required properties: > > > ?- clocks: shall be the input parent clock phandle for the PLL. > > > ?- #clock-cells: from common clock binding; Should always be set to 0. > > > ? > > > +Optional properties: > > > +- clock-frequency: output frequency generated by pll in Hz which will be set > > > +while probing. Should be a single cell. > > > + > > > ?Example: > > > ? input_clk: input-clk { > > > ? clock-frequency = <33333333>; > > > @@ -25,4 +29,5 @@ Example: > > > ? reg = <0x00 0x10>; > > > ? #clock-cells = <0>; > > > ? clocks = <&input_clk>; > > > + clock-frequency = <1000000000>; > > > ? }; > > > diff --git a/Documentation/devicetree/bindings/clock/snps,pll-clock.txt b/Documentation/devicetree/bindings/clock/snps,pll-clock.txt > > > index 11fe487..5908f99 100644 > > > --- a/Documentation/devicetree/bindings/clock/snps,pll-clock.txt > > > +++ b/Documentation/devicetree/bindings/clock/snps,pll-clock.txt > > > @@ -13,6 +13,10 @@ registers and second for corresponding LOCK CGU register. > > > ?- clocks: shall be the input parent clock phandle for the PLL. > > > ?- #clock-cells: from common clock binding; Should always be set to 0. > > > ? > > > +Optional properties: > > > +- clock-frequency: output frequency generated by pll in Hz which will be set > > > +while probing. Should be a single cell. > > > + > > > ?Example: > > > ? input-clk: input-clk { > > > ? clock-frequency = <33333333>; > > > @@ -25,4 +29,5 @@ Example: > > > ? reg = <0x80 0x10>, <0x100 0x10>; > > > ? #clock-cells = <0>; > > > ? clocks = <&input-clk>; > > > + clock-frequency = <100000000>; > > > ? }; > > > > You may check Documentation/devicetree/bindings/clock/clock-bindings.txt > > about how to assign initial clock rates, in general 'clock-frequency' > > property is a property of clock consumers with two exceptions of simple > > clock sources, namely it is used in fixed clock and PWM clock bindings. > > I think that's what we agreed on with Rob Herring back in the day. > Have you checked this post of him on the topic? > http://lists.infradead.org/pipermail/linux-snps-arc/2017-September/002909.html > > Just FYI it all started from my question here: > http://lists.infradead.org/pipermail/linux-snps-arc/2017-September/002900.html Why can't we use assigned-clock-rates? That would basically call clk_set_rate() on the clk once it's added. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
