| Message ID | 1422270840-3039-5-git-send-email-lee.jones@linaro.org |
|---|---|
| State | New |
| Headers | show |
Quoting Lee Jones (2015-01-26 03:14:00) > Signed-off-by: Lee Jones <lee.jones@linaro.org> > --- > .../devicetree/bindings/clock/st/st,clk-domain.txt | 34 ++++++++++++++++++++++ > 1 file changed, 34 insertions(+) > create mode 100644 Documentation/devicetree/bindings/clock/st/st,clk-domain.txt > > diff --git a/Documentation/devicetree/bindings/clock/st/st,clk-domain.txt b/Documentation/devicetree/bindings/clock/st/st,clk-domain.txt > new file mode 100644 > index 0000000..7309937 > --- /dev/null > +++ b/Documentation/devicetree/bindings/clock/st/st,clk-domain.txt > @@ -0,0 +1,34 @@ > +STMicroelectronics Clock Domain > + > +ST hardware have a bunch of clocks which must not be turned off. > +If drivers a) fail to obtain a reference to any of these or b) give > +up a previously obtained reference during suspend, the common clk > +framework will attempt to turn them off and the hardware will > +subsequently die. The only way to recover from this failure is to > +restart. > + > +To avoid either of these two scenarios from catastrophically > +disabling the running system we have implemented a clock domain > +where clocks are consumed and references are taken, thus preventing > +them from being shut down by the framework. > + > +We use the generic clock bindings found in: > + Documentation/devicetree/bindings/clock/clock-bindings.txt > + > +Required properties: > +- compatible : Must be "st,clk-domain" Seems like a useful feature for any clock provider, not just ST's. Have you thought about making this solution generic for DT-based clock providers? We could amend the common clock binding to include a special "always on" clock group that is automagically prepared and enabled when the clock provider/driver is registered, using a common function. Regards, Mike > + > +Example: > + > +clk-domain { > + compatible = "st,clk-domain"; > + clocks = <&clk_s_c0_flexgen CLK_EXT2F_A9>, > + <&clk_s_c0_flexgen CLK_COMPO_DVP>, > + <&clk_s_c0_flexgen CLK_MMC_1>, > + <&clk_s_c0_flexgen CLK_ICN_SBC>, > + <&clk_s_c0_flexgen CLK_ICN_LMI>, > + <&clk_s_c0_flexgen CLK_ICN_CPU>, > + <&clk_s_c0_flexgen CLK_TX_ICN_DMU>, > + <&clk_s_a0_flexgen CLK_IC_LMI0>, > + <&clk_m_a9>; > +}; > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/devicetree/bindings/clock/st/st,clk-domain.txt b/Documentation/devicetree/bindings/clock/st/st,clk-domain.txt new file mode 100644 index 0000000..7309937 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/st/st,clk-domain.txt @@ -0,0 +1,34 @@ +STMicroelectronics Clock Domain + +ST hardware have a bunch of clocks which must not be turned off. +If drivers a) fail to obtain a reference to any of these or b) give +up a previously obtained reference during suspend, the common clk +framework will attempt to turn them off and the hardware will +subsequently die. The only way to recover from this failure is to +restart. + +To avoid either of these two scenarios from catastrophically +disabling the running system we have implemented a clock domain +where clocks are consumed and references are taken, thus preventing +them from being shut down by the framework. + +We use the generic clock bindings found in: + Documentation/devicetree/bindings/clock/clock-bindings.txt + +Required properties: +- compatible : Must be "st,clk-domain" + +Example: + +clk-domain { + compatible = "st,clk-domain"; + clocks = <&clk_s_c0_flexgen CLK_EXT2F_A9>, + <&clk_s_c0_flexgen CLK_COMPO_DVP>, + <&clk_s_c0_flexgen CLK_MMC_1>, + <&clk_s_c0_flexgen CLK_ICN_SBC>, + <&clk_s_c0_flexgen CLK_ICN_LMI>, + <&clk_s_c0_flexgen CLK_ICN_CPU>, + <&clk_s_c0_flexgen CLK_TX_ICN_DMU>, + <&clk_s_a0_flexgen CLK_IC_LMI0>, + <&clk_m_a9>; +};
Signed-off-by: Lee Jones <lee.jones@linaro.org> --- .../devicetree/bindings/clock/st/st,clk-domain.txt | 34 ++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100644 Documentation/devicetree/bindings/clock/st/st,clk-domain.txt