[mvebu-dt,v3,4/7] ARM: dts: turris-omnia: add SFP node

Commit Message

Marek Behún Nov. 15, 2020, 1:59 p.m. UTC

Turris Omnia has an SFP cage that, together with WAN PHY, is connected
to eth2 SerDes via a SerDes multiplexor. When a SFP module is present,
the multiplexor switches the SerDes signal from PHY to SFP.

Describe the SFP cage, but leave it disabled. Until phylink has support
for such configuration, we are leaving it to U-Boot to enable SFP and
disable WAN PHY at boot time depending on whether a SFP module is
present.

Signed-off-by: Marek Behún <[e-mail]>
Fixes: 26ca8b52d6e1 ("ARM: dts: add support for Turris Omnia")
Reviewed-by: Andrew Lunn <[e-mail]>
Cc: Russell King - ARM Linux admin <[e-mail]>
Cc: [e-mail]
Cc: Uwe Kleine-König <[e-mail]>
Cc: Jason Cooper <[e-mail]>
Cc: Gregory CLEMENT <[e-mail]>
Cc: Andreas Färber <[e-mail]>
Cc: Rob Herring <[e-mail]>
Cc: [e-mail]
---
 arch/arm/boot/dts/armada-385-turris-omnia.dts | 29 ++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

Comments

Marek Behún Nov. 16, 2020, 12:28 p.m. UTC | #1

On Mon, 16 Nov 2020 13:24:22 +0100
Marek Behún <[e-mail]> wrote:

JFI, added

> maximum-power-milliwatt = <3000>;

since HW guys just confirmed this.

Marek

Russell King (Oracle) Nov. 16, 2020, 12:34 p.m. UTC | #2

On Mon, Nov 16, 2020 at 01:24:22PM +0100, Marek Behún wrote:
> Describe the SFP cage, but leave it disabled. Until phylink has support
> for such configuration, we are leaving it to U-Boot to enable SFP and
> disable WAN PHY at boot time depending on whether a SFP module is
> present.

Let's be clear: this is _not_ something I have any plans to be working
on adding; this is for others to get involved with.

I am not going to ack or review your patch to hack around this either.

Marek Behún Nov. 16, 2020, 12:53 p.m. UTC | #3

On Mon, 16 Nov 2020 12:34:56 +0000
Russell King - ARM Linux admin <[e-mail]> wrote:

> Let's be clear: this is _not_ something I have any plans to be working
> on adding; this is for others to get involved with.

Russell, I consider this self-evident.

Since Turris Omnia is currently probably the only device with such
configuration, it will be on me to add this support.

I will try to work out the correct solution and send patches for review.

For now though, lets merge this. It will simplify our (the vendor of
the device) patching on TurrisOS.

Marek

Patch

diff --git a/arch/arm/boot/dts/armada-385-turris-omnia.dts b/arch/arm/boot/dts/armada-385-turris-omnia.dts
index 7ccebf7d1757..f7498543c9ad 100644
--- a/arch/arm/boot/dts/armada-385-turris-omnia.dts
+++ b/arch/arm/boot/dts/armada-385-turris-omnia.dts
@@ -82,6 +82,23 @@  pcie@3,0 {
 			};
 		};
 	};
+
+	sfp: sfp {
+		compatible = "sff,sfp";
+		i2c-bus = <&sfp_i2c>;
+		tx-fault-gpios = <&pcawan 0 GPIO_ACTIVE_HIGH>;
+		tx-disable-gpios = <&pcawan 1 GPIO_ACTIVE_HIGH>;
+		rate-select0-gpios = <&pcawan 2 GPIO_ACTIVE_HIGH>;
+		los-gpios = <&pcawan 3 GPIO_ACTIVE_HIGH>;
+		mod-def0-gpios = <&pcawan 4 GPIO_ACTIVE_LOW>;
+
+		/*
+		 * For now this has to be enabled at boot time by U-Boot when
+		 * a SFP module is present. Read more in the comment in the
+		 * eth2 node below.
+		 */
+		status = "disabled";
+	};
 };
 
 &bm {
@@ -126,10 +143,20 @@  fixed-link {
 
 /* WAN port */
 &eth2 {
+	/*
+	 * eth2 is connected via a multiplexor to both the SFP cage and to
+	 * ethernet-phy@1. The multiplexor switches the signal to SFP cage when
+	 * a SFP module is present, as determined by the mode-def0 GPIO.
+	 *
+	 * Until kernel supports this configuration properly, in case SFP module
+	 * is present, U-Boot has to enable the sfp node above, remove phy
+	 * handle and add managed = "in-band-status" property.
+	 */
 	status = "okay";
 	phy-mode = "sgmii";
 	phy = <&phy1>;
 	phys = <&comphy5 2>;
+	sfp = <&sfp>;
 	buffer-manager = <&bm>;
 	bm,pool-long = <2>;
 	bm,pool-short = <3>;
@@ -195,7 +222,7 @@  i2c@3 {
 			/* routed to PCIe2 connector (CN62A) */
 		};
 
-		i2c@4 {
+		sfp_i2c: i2c@4 {
 			#address-cells = <1>;
 			#size-cells = <0>;
 			reg = <4>;