Commit 894116bd authored by Aida Mynzhasova's avatar Aida Mynzhasova Committed by David S. Miller

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: default avatarAida Mynzhasova <aida.mynzhasova@skitlab.ru>
Acked-by: default avatarRichard Cochran <richardcochran@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 559835ea
......@@ -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@24E00 {
......@@ -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>;
......
......@@ -452,6 +452,8 @@ static int gianfar_ptp_probe(struct platform_device *dev)
err = -ENODEV;
etsects->caps = ptp_gianfar_caps;
if (get_of_u32(node, "fsl,cksel", &etsects->cksel))
etsects->cksel = DEFAULT_CKSEL;
if (get_of_u32(node, "fsl,tclk-period", &etsects->tclk_period) ||
......
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