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35 lines
1.4 KiB
35 lines
1.4 KiB
* avtimer
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Avtimer provides an interface for clients to enable avtimer block
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on qdsp6. 64 bit AVtimer exposed by qdsp6 is used for audio and video
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stream synchronization during capture and playback usecases.
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Required properties:
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- reg : physical address and length of avtimer register
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- reg-names : AVtimer register name
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Required register resource entries are:
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"avtimer_lsb_addr" : AVtimer lsb physical address
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"avtimer_msb_addr" : AVtimer msb physical address
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- compatible : Must be "qcom,avtimer"
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Optional properties:
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- clk-div : Divisor to divide the ticks value to get msec value.
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If the clock is at 27MHz, the ticks value read from AVTimer
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registers will have to be divided by 27, to achieve the msec value.
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- clk-mult : Multiplier to multiply the ticks value in order to avoid
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a floating point operation if the clock is of decimal value.
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E.g. To get msec out of ticks from a 19.2MHz clock source, the ticks
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value will have to be divided by 19.2, which will then become a
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floating point operation. However, to avoid using a floating point
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operation, the msec can be calculated by multiplying ticks with 10
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and dividing the result by 192. i.e. msec = (ticks * 10) / 192;
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Example:
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qcom,avtimer@90f7000 {
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compatible = "qcom,avtimer";
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reg = <0x90f700c 0x4>,
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<0x90f7010 0x4>;
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reg-names = "avtimer_lsb_addr", "avtimer_msb_addr";
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qcom,clk-div = <27>;
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qcom,clk-mult = <10>;
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};
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