Messages in this thread | | | Date | Wed, 9 Nov 2011 10:13:28 +0100 | From | Sascha Hauer <> | Subject | Re: [RFC 6/8] of: add clock providers |
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On Tue, Nov 08, 2011 at 06:19:41PM -0700, Grant Likely wrote: > Based on work by Ben Herrenschmidt and Jeremy Kerr, this patch adds an > of_clk_get function to allow platforms to retrieve clock data from the > device tree. > > Platform register a provider through of_clk_add_provider, which will be > called when a device references the provider's OF node for a clock > reference. > > Signed-off-by: Grant Likely <grant.likely@secretlab.ca> > --- > .../devicetree/bindings/clock/clock-bindings.txt | 109 +++++++++++++++++ > drivers/of/Kconfig | 6 + > drivers/of/Makefile | 1 + > drivers/of/clock.c | 129 ++++++++++++++++++++ > include/linux/of_clk.h | 37 ++++++ > 5 files changed, 282 insertions(+), 0 deletions(-) > create mode 100644 Documentation/devicetree/bindings/clock/clock-bindings.txt > create mode 100644 drivers/of/clock.c > create mode 100644 include/linux/of_clk.h > > diff --git a/Documentation/devicetree/bindings/clock/clock-bindings.txt b/Documentation/devicetree/bindings/clock/clock-bindings.txt > new file mode 100644 > index 0000000..4770c7e > --- /dev/null > +++ b/Documentation/devicetree/bindings/clock/clock-bindings.txt > @@ -0,0 +1,109 @@ > +This binding is a work-in-progress, and are based on some experimental > +work by benh[1]. > + > +Sources of clock signal can be represented by any node in the device > +tree. Those nodes are designated as clock providers. Clock consumer > +nodes use a phandle and clock specifier pair to connect clock provider > +outputs to clock inputs. Similar to the gpio specifiers, a clock > +specifier is an array of one more more cells identifying the clock > +output on a device. The length of a clock specifier is defined by the > +value of a #clock-cells property in the clock provider node. > + > +[1] http://patchwork.ozlabs.org/patch/31551/ > + > +==Clock providers== > + > +Required properties: > +#clock-cells: Number of cells in a clock specifier; typically will be > + set to 1 > + > +Optional properties: > +clock-output-name: Recommended to be a list of strings of clock output signal > + names indexed by the first cell in the clock specifier. > + However, the meaning of clock-output-names is domain > + specific to the clock provider, and is only provided to > + encourage using the same meaning for the majority of clock > + providers. This format may not work for clock providers > + using a complex clock specifier format. In those cases it > + is recommended to omit this property and create a binding > + specific names property.
If the clock-output-name property is omitted, does this mean a clock provider only has a single output or does it mean that it's not known how many clock outputs a provider actually has?
Sascha
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