[PATCH v3] powerpc/83xx: gianfar_ptp: select 1588 clock source through dts file

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From: Aida Mynzhasova <hidden>
Date: 2013-09-27 13:40:27
Also in: linux-devicetree, netdev
Subsystem: freescale etsec ethernet driver (gianfar), networking drivers, open firmware and flattened device tree bindings, the rest · Maintainers: Claudiu Manoil, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds

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 <redacted>
---
 Documentation/devicetree/bindings/net/fsl-tsec-phy.txt | 18 +++++++++++++++++-
 drivers/net/ethernet/freescale/gianfar_ptp.c           |  4 +++-
 2 files changed, 20 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..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>;
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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