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authorLinus Torvalds <torvalds@linux-foundation.org>2011-05-25 08:59:42 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-05-25 08:59:42 -0700
commit22e12bbc9bc38c6d0bd541d061a0f547596fc19d (patch)
tree39b93f43b482c5b4cb9d99933384a8a7fcb85d71 /Documentation/devicetree
parent19426a8f810752b4218e59b1e2187f33e255f7bc (diff)
parent86ff9baadf16c8a1b452d72f5585be63457d9b15 (diff)
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.txt54
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 edb7ae19e86..2c6be0377f5 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>;
+ };