From e58f6f4fb4eada7867014bfaec898f03afbce5c2 Mon Sep 17 00:00:00 2001 From: Aida Mynzhasova Date: Fri, 27 Sep 2013 17:40:27 +0400 Subject: powerpc/83xx: gianfar_ptp: select 1588 clock source through dts file Currently IEEE 1588 timer reference clock source is determined through hard-coded value in gianfar_ptp driver. This patch allows to select ptp clock source by means of device tree file node. For instance: fsl,cksel = <0>; for using external (TSEC_TMR_CLK input) high precision timer reference clock. Other acceptable values: <1> : eTSEC system clock <2> : eTSEC1 transmit clock <3> : RTC clock input When this attribute isn't used, eTSEC system clock will serve as IEEE 1588 timer reference clock. Signed-off-by: Aida Mynzhasova Acked-by: Kumar Gala Signed-off-by: David S. Miller --- Documentation/devicetree/bindings/net/fsl-tsec-phy.txt | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/net/fsl-tsec-phy.txt b/Documentation/devicetree/bindings/net/fsl-tsec-phy.txt index 2c6be03..d2ea460 100644 --- a/Documentation/devicetree/bindings/net/fsl-tsec-phy.txt +++ b/Documentation/devicetree/bindings/net/fsl-tsec-phy.txt @@ -86,6 +86,7 @@ General Properties: 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. @@ -97,7 +98,7 @@ Clock Properties: clock. You must choose these carefully for the clock to work right. Here is how to figure good values: - TimerOsc = system clock MHz + 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) @@ -114,6 +115,20 @@ Clock Properties: 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: + + <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. + + When this attribute is not used, eTSEC system clock will serve as + IEEE 1588 timer reference clock. + Example: ptp_clock@24E00 { @@ -121,6 +136,7 @@ Example: 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>; -- cgit v1.1