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Viewing changes to Documentation/devicetree/bindings/net/fsl-tsec-phy.txt

  • Committer: Bazaar Package Importer
  • Author(s): Paolo Pisati
  • Date: 2011-06-29 15:23:51 UTC
  • mfrom: (26.1.1 natty-proposed)
  • Revision ID: james.westby@ubuntu.com-20110629152351-xs96tm303d95rpbk
Tags: 3.0.0-1200.2
* Rebased against 3.0.0-6.7
* BSP from TI based on 3.0.0

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Documentation/devicetree/bindings/net/fsl-tsec-phy.txt
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                interrupt-parent = <&mpic>;
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                phy-handle = <&phy0>
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        };
 
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* Gianfar PTP clock nodes
 
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General Properties:
 
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  - compatible   Should be "fsl,etsec-ptp"
 
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  - reg          Offset and length of the register set for the device
 
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  - interrupts   There should be at least two interrupts. Some devices
 
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                 have as many as four PTP related interrupts.
 
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Clock Properties:
 
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  - fsl,tclk-period  Timer reference clock period in nanoseconds.
 
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  - fsl,tmr-prsc     Prescaler, divides the output clock.
 
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  - fsl,tmr-add      Frequency compensation value.
 
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  - fsl,tmr-fiper1   Fixed interval period pulse generator.
 
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  - fsl,tmr-fiper2   Fixed interval period pulse generator.
 
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  - fsl,max-adj      Maximum frequency adjustment in parts per billion.
 
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  These properties set the operational parameters for the PTP
 
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  clock. You must choose these carefully for the clock to work right.
 
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  Here is how to figure good values:
 
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  TimerOsc     = system clock               MHz
 
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  tclk_period  = desired clock period       nanoseconds
 
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  NominalFreq  = 1000 / tclk_period         MHz
 
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  FreqDivRatio = TimerOsc / NominalFreq     (must be greater that 1.0)
 
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  tmr_add      = ceil(2^32 / FreqDivRatio)
 
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  OutputClock  = NominalFreq / tmr_prsc     MHz
 
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  PulseWidth   = 1 / OutputClock            microseconds
 
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  FiperFreq1   = desired frequency in Hz
 
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  FiperDiv1    = 1000000 * OutputClock / FiperFreq1
 
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  tmr_fiper1   = tmr_prsc * tclk_period * FiperDiv1 - tclk_period
 
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  max_adj      = 1000000000 * (FreqDivRatio - 1.0) - 1
 
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  The calculation for tmr_fiper2 is the same as for tmr_fiper1. The
 
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  driver expects that tmr_fiper1 will be correctly set to produce a 1
 
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  Pulse Per Second (PPS) signal, since this will be offered to the PPS
 
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  subsystem to synchronize the Linux clock.
 
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Example:
 
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        ptp_clock@24E00 {
 
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                compatible = "fsl,etsec-ptp";
 
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                reg = <0x24E00 0xB0>;
 
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                interrupts = <12 0x8 13 0x8>;
 
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                interrupt-parent = < &ipic >;
 
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                fsl,tclk-period = <10>;
 
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                fsl,tmr-prsc    = <100>;
 
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                fsl,tmr-add     = <0x999999A4>;
 
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                fsl,tmr-fiper1  = <0x3B9AC9F6>;
 
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                fsl,tmr-fiper2  = <0x00018696>;
 
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                fsl,max-adj     = <659999998>;
 
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        };