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authorTero Kristo <t-kristo@ti.com>2013-09-13 20:22:27 +0300
committerMike Turquette <mturquette@linaro.org>2014-01-17 12:35:17 -0800
commit6a369c584fbe98264458b9442e780f8078f2f7ad (patch)
treed80be958f33b501a128599a0e31bec400b51fa58 /Documentation/devicetree/bindings/clock/ti
parent3cd4a596224565cff00b69a02d4b5fa7432ea6d3 (diff)
clk: ti: add support for basic mux clock
ti,mux-clock provides now a binding for basic mux support. This is just using the basic clock type. Signed-off-by: Tero Kristo <t-kristo@ti.com> Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Mike Turquette <mturquette@linaro.org>
Diffstat (limited to 'Documentation/devicetree/bindings/clock/ti')
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+Binding for TI mux clock.
+
+Binding status: Unstable - ABI compatibility may be broken in the future
+
+This binding uses the common clock binding[1]. It assumes a
+register-mapped multiplexer with multiple input clock signals or
+parents, one of which can be selected as output. This clock does not
+gate or adjust the parent rate via a divider or multiplier.
+
+By default the "clocks" property lists the parents in the same order
+as they are programmed into the regster. E.g:
+
+ clocks = <&foo_clock>, <&bar_clock>, <&baz_clock>;
+
+results in programming the register as follows:
+
+register value selected parent clock
+0 foo_clock
+1 bar_clock
+2 baz_clock
+
+Some clock controller IPs do not allow a value of zero to be programmed
+into the register, instead indexing begins at 1. The optional property
+"index-starts-at-one" modified the scheme as follows:
+
+register value selected clock parent
+1 foo_clock
+2 bar_clock
+3 baz_clock
+
+The binding must provide the register to control the mux. Optionally
+the number of bits to shift the control field in the register can be
+supplied. If the shift value is missing it is the same as supplying
+a zero shift.
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : shall be "ti,mux-clock" or "ti,composite-mux-clock".
+- #clock-cells : from common clock binding; shall be set to 0.
+- clocks : link phandles of parent clocks
+- reg : register offset for register controlling adjustable mux
+
+Optional properties:
+- ti,bit-shift : number of bits to shift the bit-mask, defaults to
+ 0 if not present
+- ti,index-starts-at-one : valid input select programming starts at 1, not
+ zero
+- ti,set-rate-parent : clk_set_rate is propagated to parent clock,
+ not supported by the composite-mux-clock subtype
+
+Examples:
+
+sys_clkin_ck: sys_clkin_ck@4a306110 {
+ #clock-cells = <0>;
+ compatible = "ti,mux-clock";
+ clocks = <&virt_12000000_ck>, <&virt_13000000_ck>, <&virt_16800000_ck>, <&virt_19200000_ck>, <&virt_26000000_ck>, <&virt_27000000_ck>, <&virt_38400000_ck>;
+ reg = <0x0110>;
+ ti,index-starts-at-one;
+};
+
+abe_dpll_bypass_clk_mux_ck: abe_dpll_bypass_clk_mux_ck@4a306108 {
+ #clock-cells = <0>;
+ compatible = "ti,mux-clock";
+ clocks = <&sys_clkin_ck>, <&sys_32k_ck>;
+ ti,bit-shift = <24>;
+ reg = <0x0108>;
+};
+
+mcbsp5_mux_fck: mcbsp5_mux_fck {
+ #clock-cells = <0>;
+ compatible = "ti,composite-mux-clock";
+ clocks = <&core_96m_fck>, <&mcbsp_clks>;
+ ti,bit-shift = <4>;
+ reg = <0x02d8>;
+};