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Message-Id: <9B020778-D8FB-4D71-9647-4D1505DCAE1E@codeaurora.org>
Date: Wed, 25 Sep 2013 14:38:12 -0500
From: Kumar Gala <galak@...eaurora.org>
To: Aida Mynzhasova <aida.mynzhasova@...tlab.ru>
Cc: linuxppc-dev@...ts.ozlabs.org, devicetree@...r.kernel.org,
netdev@...r.kernel.org, richardcochran@...il.com
Subject: Re: [PATCH v2] powerpc/83xx: gianfar_ptp: select 1588 clock source through dts file
On Sep 25, 2013, at 2:24 AM, Aida Mynzhasova wrote:
> 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
Do these value match some register field to select which clk? If so please add that to the document.
- k
>
> When this attribute isn't used, eTSEC system clock will serve as
> IEEE 1588 timer reference clock.
>
> Signed-off-by: Aida Mynzhasova <aida.mynzhasova@...tlab.ru>
> ---
> Documentation/devicetree/bindings/net/fsl-tsec-phy.txt | 16 +++++++++++++++-
> drivers/net/ethernet/freescale/gianfar_ptp.c | 4 +++-
> 2 files changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/net/fsl-tsec-phy.txt b/Documentation/devicetree/bindings/net/fsl-tsec-phy.txt
> index 2c6be03..eb06059 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 +115,18 @@ Clock Properties:
> Pulse Per Second (PPS) signal, since this will be offered to the PPS
> subsystem to synchronize the Linux clock.
>
> + "fsl,cksel" property allows to select different reference clock
> + sources:
> +
> + <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@...00 {
> @@ -121,6 +134,7 @@ 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>;
> diff --git a/drivers/net/ethernet/freescale/gianfar_ptp.c b/drivers/net/ethernet/freescale/gianfar_ptp.c
> index 098f133..e006a09 100644
> --- a/drivers/net/ethernet/freescale/gianfar_ptp.c
> +++ b/drivers/net/ethernet/freescale/gianfar_ptp.c
> @@ -452,7 +452,9 @@ static int gianfar_ptp_probe(struct platform_device *dev)
> err = -ENODEV;
>
> etsects->caps = ptp_gianfar_caps;
> - etsects->cksel = DEFAULT_CKSEL;
> +
> + if (get_of_u32(node, "fsl,cksel", &etsects->cksel))
> + etsects->cksel = DEFAULT_CKSEL;
>
> if (get_of_u32(node, "fsl,tclk-period", &etsects->tclk_period) ||
> get_of_u32(node, "fsl,tmr-prsc", &etsects->tmr_prsc) ||
> --
> 1.8.1.2
>
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