Hi Gregory, Since there doesn't seem to be anyone opposing this feature I just checked your patch and after adding the CLK_OF_DECLARE macro in the end it works well for us. Tell me if you would like to rebase and resubmit your patch or if I should follow up on our own. Greetings, Christian On Wed, Apr 10, 2013 at 06:27:47PM +0200, christian ruppert wrote: > Hi Gregory, > > We use derived clocks with fixed ratios for our TB10x platform. I > originally had this in the platform code but Vineet (the platform > maintainer) rightly pointed out that the common clock framework would > be the correct place for it. > Is there any reason not to support this functionality? After all, the > generic fixed rate clock also has a device tree binding and I'd guess > we're not the only ones statically deriving one clock from another in > our SOCs. > > Greetings, > Christian > > On Wed, Apr 10, 2013 at 05:56:25PM +0200, Gregory CLEMENT wrote: > > Hi Christian, > > > > On 04/10/2013 05:40 PM, Christian Ruppert wrote: > > > This patch adds a device tree binding for the simple fixed factor clock > > > divider/multiplier of the common clock tree binding. > > > > This patch remind me of something : > > http://lists.infradead.org/pipermail/linux-arm-kernel/2012-August/116405.html > > > > Do you have a use case for it, this time? > > > > My version have been hold off waiting for an user for it. > > Will you need it for a driver? > > > > Regards, > > > > > > > > Signed-off-by: Christian Ruppert <christian.ruppert@xxxxxxxxxx> > > > --- > > > .../bindings/clock/fixed-factor-clkdiv.txt | 24 +++++++++++++++ > > > drivers/clk/clk-fixed-factor.c | 32 ++++++++++++++++++++ > > > include/linux/clk-provider.h | 1 + > > > 3 files changed, 57 insertions(+), 0 deletions(-) > > > create mode 100644 Documentation/devicetree/bindings/clock/fixed-factor-clkdiv.txt > > > > > > diff --git a/Documentation/devicetree/bindings/clock/fixed-factor-clkdiv.txt b/Documentation/devicetree/bindings/clock/fixed-factor-clkdiv.txt > > > new file mode 100644 > > > index 0000000..352bac4 > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/clock/fixed-factor-clkdiv.txt > > > @@ -0,0 +1,24 @@ > > > +Device Tree Clock bindings for plat-tb10x > > > + > > > +This binding uses the common clock binding[1]. > > > + > > > +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt > > > + > > > +Required properties: > > > +- compatible : shall be "fixed-factor-clkdiv" > > > +- #clock-cells: from common clock binding; shall be set to 0 > > > +- clocks: shall be the input parent clock phandle for the clock. > > > +- clock-mult: defines the multiplication factor of the output clock frequency > > > + wrt. the input clock frequency. > > > +- clock-div: defines the division factor of the output clock frequency wrt. > > > + the input clock frequency. > > > + > > > +Example: > > > +cpu_clk: clkdiv_cpu { /* CPU clock derived from pll0. 1/2 of pll frequency */ > > > + compatible = "fixed-factor-clkdiv"; > > > + #clock-cells = <0>; > > > + clocks = <&pll0>; > > > + clock-mult = <1>; > > > + clock-div = <2>; > > > + clock-output-names = "cpu_clk"; > > > +}; > > > diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c > > > index 1ef271e..85e45f1 100644 > > > --- a/drivers/clk/clk-fixed-factor.c > > > +++ b/drivers/clk/clk-fixed-factor.c > > > @@ -11,6 +11,7 @@ > > > #include <linux/clk-provider.h> > > > #include <linux/slab.h> > > > #include <linux/err.h> > > > +#include <linux/of.h> > > > > > > /* > > > * DOC: basic fixed multiplier and divider clock that cannot gate > > > @@ -96,3 +97,34 @@ struct clk *clk_register_fixed_factor(struct device *dev, const char *name, > > > > > > return clk; > > > } > > > + > > > +#ifdef CONFIG_OF > > > +/** > > > + * of_fixed_factor_clkdiv_setup() - Set up simple fixed factor clock divider > > > + */ > > > +void of_fixed_factor_clkdiv_setup(struct device_node *node) > > > +{ > > > + struct clk *clk; > > > + const char *clk_name = node->name; > > > + const char *parent_name; > > > + u32 mult, div; > > > + > > > + if (of_property_read_u32(node, "clock-mult", &mult)) > > > + return; > > > + > > > + if (of_property_read_u32(node, "clock-div", &div)) > > > + return; > > > + > > > + parent_name = of_clk_get_parent_name(node, 0); > > > + > > > + of_property_read_string(node, "clock-output-names", &clk_name); > > > + > > > + clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0, > > > + mult, div); > > > + if (!IS_ERR(clk)) > > > + of_clk_add_provider(node, of_clk_src_simple_get, clk); > > > +} > > > +EXPORT_SYMBOL_GPL(of_fixed_factor_clkdiv_setup); > > > +CLK_OF_DECLARE(fixed_clkdiv, "fixed-factor-clkdiv", > > > + of_fixed_factor_clkdiv_setup); > > > +#endif > > > diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h > > > index 7f197d7..d4937cf 100644 > > > --- a/include/linux/clk-provider.h > > > +++ b/include/linux/clk-provider.h > > > @@ -184,6 +184,7 @@ struct clk *clk_register_fixed_rate(struct device *dev, const char *name, > > > unsigned long fixed_rate); > > > > > > void of_fixed_clk_setup(struct device_node *np); > > > +void of_fixed_factor_clkdiv_setup(struct device_node *node); > > > > > > /** > > > * struct clk_gate - gating clock > > > > > > > > > -- > > Gregory Clement, Free Electrons > > Kernel, drivers, real-time and embedded Linux > > development, consulting, training and support. > > http://free-electrons.com > > -- > Christian Ruppert , <christian.ruppert@xxxxxxxxxx> > /| > Tel: +41/(0)22 816 19-42 //| 3, Chemin du Pré-Fleuri > _// | bilis Systems CH-1228 Plan-les-Ouates -- Christian Ruppert , <christian.ruppert@xxxxxxxxxx> /| Tel: +41/(0)22 816 19-42 //| 3, Chemin du Pré-Fleuri _// | bilis Systems CH-1228 Plan-les-Ouates -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
