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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-05-25 08:59:42 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-05-25 08:59:42 -0700 |
commit | 22e12bbc9bc38c6d0bd541d061a0f547596fc19d (patch) | |
tree | 39b93f43b482c5b4cb9d99933384a8a7fcb85d71 /Documentation/devicetree | |
parent | 19426a8f810752b4218e59b1e2187f33e255f7bc (diff) | |
parent | 86ff9baadf16c8a1b452d72f5585be63457d9b15 (diff) | |
download | linux-22e12bbc9bc38c6d0bd541d061a0f547596fc19d.tar.bz2 |
Merge branch 'timers-ptp-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-ptp-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
ptp: Fix dp83640 build warning when building statically
ptp: Added a clock driver for the National Semiconductor PHYTER.
ptp: Added a clock driver for the IXP46x.
ptp: Added a clock that uses the eTSEC found on the MPC85xx.
ptp: Added a brand new class driver for ptp clocks.
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r-- | Documentation/devicetree/bindings/net/fsl-tsec-phy.txt | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/net/fsl-tsec-phy.txt b/Documentation/devicetree/bindings/net/fsl-tsec-phy.txt index edb7ae19e868..2c6be0377f55 100644 --- a/Documentation/devicetree/bindings/net/fsl-tsec-phy.txt +++ b/Documentation/devicetree/bindings/net/fsl-tsec-phy.txt @@ -74,3 +74,57 @@ Example: interrupt-parent = <&mpic>; phy-handle = <&phy0> }; + +* Gianfar PTP clock nodes + +General Properties: + + - compatible Should be "fsl,etsec-ptp" + - 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,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 = system 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. + +Example: + + ptp_clock@24E00 { + compatible = "fsl,etsec-ptp"; + reg = <0x24E00 0xB0>; + interrupts = <12 0x8 13 0x8>; + interrupt-parent = < &ipic >; + fsl,tclk-period = <10>; + fsl,tmr-prsc = <100>; + fsl,tmr-add = <0x999999A4>; + fsl,tmr-fiper1 = <0x3B9AC9F6>; + fsl,tmr-fiper2 = <0x00018696>; + fsl,max-adj = <659999998>; + }; |