diff options
author | Tero Kristo <t-kristo@ti.com> | 2013-09-13 20:22:27 +0300 |
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committer | Mike Turquette <mturquette@linaro.org> | 2014-01-17 12:35:17 -0800 |
commit | 6a369c584fbe98264458b9442e780f8078f2f7ad (patch) | |
tree | d80be958f33b501a128599a0e31bec400b51fa58 /Documentation/devicetree/bindings/clock/ti | |
parent | 3cd4a596224565cff00b69a02d4b5fa7432ea6d3 (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')
-rw-r--r-- | Documentation/devicetree/bindings/clock/ti/mux.txt | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/clock/ti/mux.txt b/Documentation/devicetree/bindings/clock/ti/mux.txt new file mode 100644 index 000000000000..2d0d170f8001 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/ti/mux.txt @@ -0,0 +1,76 @@ +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>; +}; |