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| 1 | +# SPDX-License-Identifier: GPL-2.0-only |
| 2 | +%YAML 1.2 |
| 3 | +--- |
| 4 | +$id: http://devicetree.org/schemas/clock/ti/ti,mux-clock.yaml# |
| 5 | +$schema: http://devicetree.org/meta-schemas/core.yaml# |
| 6 | + |
| 7 | +title: Texas Instruments mux clock |
| 8 | + |
| 9 | +maintainers: |
| 10 | + - Tero Kristo <kristo@kernel.org> |
| 11 | + |
| 12 | +description: | |
| 13 | + This clock assumes a register-mapped multiplexer with multiple inpt clock |
| 14 | + signals or parents, one of which can be selected as output. This clock does |
| 15 | + not gate or adjust the parent rate via a divider or multiplier. |
| 16 | +
|
| 17 | + By default the "clocks" property lists the parents in the same order |
| 18 | + as they are programmed into the register. E.g: |
| 19 | +
|
| 20 | + clocks = <&foo_clock>, <&bar_clock>, <&baz_clock>; |
| 21 | +
|
| 22 | + Results in programming the register as follows: |
| 23 | +
|
| 24 | + register value selected parent clock |
| 25 | + 0 foo_clock |
| 26 | + 1 bar_clock |
| 27 | + 2 baz_clock |
| 28 | +
|
| 29 | + Some clock controller IPs do not allow a value of zero to be programmed |
| 30 | + into the register, instead indexing begins at 1. The optional property |
| 31 | + "index-starts-at-one" modified the scheme as follows: |
| 32 | +
|
| 33 | + register value selected clock parent |
| 34 | + 1 foo_clock |
| 35 | + 2 bar_clock |
| 36 | + 3 baz_clock |
| 37 | +
|
| 38 | + The binding must provide the register to control the mux. Optionally |
| 39 | + the number of bits to shift the control field in the register can be |
| 40 | + supplied. If the shift value is missing it is the same as supplying |
| 41 | + a zero shift. |
| 42 | +
|
| 43 | +properties: |
| 44 | + compatible: |
| 45 | + enum: |
| 46 | + - ti,mux-clock |
| 47 | + - ti,composite-mux-clock |
| 48 | + |
| 49 | + "#clock-cells": |
| 50 | + const: 0 |
| 51 | + |
| 52 | + clocks: true |
| 53 | + |
| 54 | + clock-output-names: |
| 55 | + maxItems: 1 |
| 56 | + |
| 57 | + reg: |
| 58 | + maxItems: 1 |
| 59 | + |
| 60 | + ti,bit-shift: |
| 61 | + $ref: /schemas/types.yaml#/definitions/uint32 |
| 62 | + description: |
| 63 | + Number of bits to shift the bit-mask |
| 64 | + maximum: 31 |
| 65 | + default: 0 |
| 66 | + |
| 67 | + ti,index-starts-at-one: |
| 68 | + type: boolean |
| 69 | + description: |
| 70 | + Valid input select programming starts at 1, not zero |
| 71 | + |
| 72 | + ti,set-rate-parent: |
| 73 | + type: boolean |
| 74 | + description: |
| 75 | + clk_set_rate is propagated to parent clock, |
| 76 | + not supported by the composite-mux-clock subtype. |
| 77 | + |
| 78 | + ti,latch-bit: |
| 79 | + $ref: /schemas/types.yaml#/definitions/uint32 |
| 80 | + description: |
| 81 | + Latch the mux value to HW, only needed if the register |
| 82 | + access requires this. As an example, dra7x DPLL_GMAC H14 muxing |
| 83 | + implements such behavior. |
| 84 | + maximum: 31 |
| 85 | + |
| 86 | +if: |
| 87 | + properties: |
| 88 | + compatible: |
| 89 | + contains: |
| 90 | + const: ti,composite-mux-clock |
| 91 | +then: |
| 92 | + properties: |
| 93 | + ti,set-rate-parent: false |
| 94 | + |
| 95 | +required: |
| 96 | + - compatible |
| 97 | + - "#clock-cells" |
| 98 | + - clocks |
| 99 | + - reg |
| 100 | + |
| 101 | +additionalProperties: false |
| 102 | + |
| 103 | +examples: |
| 104 | + - | |
| 105 | + bus { |
| 106 | + #address-cells = <1>; |
| 107 | + #size-cells = <0>; |
| 108 | +
|
| 109 | + clock-controller@110 { |
| 110 | + compatible = "ti,mux-clock"; |
| 111 | + reg = <0x0110>; |
| 112 | + #clock-cells = <0>; |
| 113 | + clocks = <&virt_12000000_ck>, <&virt_13000000_ck>, <&virt_16800000_ck>; |
| 114 | + ti,index-starts-at-one; |
| 115 | + ti,set-rate-parent; |
| 116 | + }; |
| 117 | +
|
| 118 | + clock-controller@120 { |
| 119 | + compatible = "ti,composite-mux-clock"; |
| 120 | + reg = <0x0120>; |
| 121 | + #clock-cells = <0>; |
| 122 | + clocks = <&core_96m_fck>, <&mcbsp_clks>; |
| 123 | + ti,bit-shift = <4>; |
| 124 | + }; |
| 125 | + }; |
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