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Diffstat (limited to 'Documentation/devicetree/bindings/ptp')
| -rw-r--r-- | Documentation/devicetree/bindings/ptp/brcm,ptp-dte.txt | 19 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/ptp/ptp-qoriq.txt | 78 |
2 files changed, 97 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/ptp/brcm,ptp-dte.txt b/Documentation/devicetree/bindings/ptp/brcm,ptp-dte.txt new file mode 100644 index 000000000..6b1075ee8 --- /dev/null +++ b/Documentation/devicetree/bindings/ptp/brcm,ptp-dte.txt @@ -0,0 +1,19 @@ +* Broadcom Digital Timing Engine(DTE) based PTP clock + +Required properties: +- compatible: should contain the core compatibility string + and the SoC compatibility string. The SoC + compatibility string is to handle SoC specific + hardware differences. + Core compatibility string: + "brcm,ptp-dte" + SoC compatibility strings: + "brcm,iproc-ptp-dte" - for iproc based SoC's +- reg: address and length of the DTE block's NCO registers + +Example: + +ptp: ptp-dte@180af650 { + compatible = "brcm,iproc-ptp-dte", "brcm,ptp-dte"; + reg = <0x180af650 0x10>; +}; diff --git a/Documentation/devicetree/bindings/ptp/ptp-qoriq.txt b/Documentation/devicetree/bindings/ptp/ptp-qoriq.txt new file mode 100644 index 000000000..c5d0e7998 --- /dev/null +++ b/Documentation/devicetree/bindings/ptp/ptp-qoriq.txt @@ -0,0 +1,78 @@ +* Freescale QorIQ 1588 timer based PTP clock + +General Properties: + + - compatible Should be "fsl,etsec-ptp" for eTSEC + Should be "fsl,fman-ptp-timer" for DPAA FMan + - reg Offset and length of the register set for the device + - interrupts There should be at least two interrupts. Some devices + have as many as four PTP related interrupts. + +Clock Properties: + + - fsl,cksel Timer reference clock source. + - fsl,tclk-period Timer reference clock period in nanoseconds. + - fsl,tmr-prsc Prescaler, divides the output clock. + - fsl,tmr-add Frequency compensation value. + - fsl,tmr-fiper1 Fixed interval period pulse generator. + - fsl,tmr-fiper2 Fixed interval period pulse generator. + - fsl,max-adj Maximum frequency adjustment in parts per billion. + + These properties set the operational parameters for the PTP + clock. You must choose these carefully for the clock to work right. + Here is how to figure good values: + + TimerOsc = selected reference clock MHz + tclk_period = desired clock period nanoseconds + NominalFreq = 1000 / tclk_period MHz + FreqDivRatio = TimerOsc / NominalFreq (must be greater that 1.0) + tmr_add = ceil(2^32 / FreqDivRatio) + OutputClock = NominalFreq / tmr_prsc MHz + PulseWidth = 1 / OutputClock microseconds + FiperFreq1 = desired frequency in Hz + FiperDiv1 = 1000000 * OutputClock / FiperFreq1 + tmr_fiper1 = tmr_prsc * tclk_period * FiperDiv1 - tclk_period + max_adj = 1000000000 * (FreqDivRatio - 1.0) - 1 + + The calculation for tmr_fiper2 is the same as for tmr_fiper1. The + driver expects that tmr_fiper1 will be correctly set to produce a 1 + Pulse Per Second (PPS) signal, since this will be offered to the PPS + subsystem to synchronize the Linux clock. + + Reference clock source is determined by the value, which is holded + in CKSEL bits in TMR_CTRL register. "fsl,cksel" property keeps the + value, which will be directly written in those bits, that is why, + according to reference manual, the next clock sources can be used: + + For eTSEC, + <0> - external high precision timer reference clock (TSEC_TMR_CLK + input is used for this purpose); + <1> - eTSEC system clock; + <2> - eTSEC1 transmit clock; + <3> - RTC clock input. + + For DPAA FMan, + <0> - external high precision timer reference clock (TMR_1588_CLK) + <1> - MAC system clock (1/2 FMan clock) + <2> - reserved + <3> - RTC clock oscillator + + When this attribute is not used, the IEEE 1588 timer reference clock + will use the eTSEC system clock (for Gianfar) or the MAC system + clock (for DPAA). + +Example: + + ptp_clock@24e00 { + compatible = "fsl,etsec-ptp"; + reg = <0x24E00 0xB0>; + interrupts = <12 0x8 13 0x8>; + interrupt-parent = < &ipic >; + fsl,cksel = <1>; + fsl,tclk-period = <10>; + fsl,tmr-prsc = <100>; + fsl,tmr-add = <0x999999A4>; + fsl,tmr-fiper1 = <0x3B9AC9F6>; + fsl,tmr-fiper2 = <0x00018696>; + fsl,max-adj = <659999998>; + }; |