[PATCH 2/2] dt-bindings: net: ti:add support slave interface using internal clock in dual rmii emac mode

[Xiangyu Chen <xiangyu.chen@aol.com>]

This is the second patch of as subject said topic. It contains dts
 document modification.


Those patches regarding to add a way to setup/config the TI-AM335x series
Soc for 2 ways phy clock mode under RMII mode.

The basic scenario is when we have 2 PHYs connected to AM335x in RMII
mode, either we set the both of phy in external clock mode or we set the phy in internal
clock mode.

As TI suggetsion, when under RMII mode, the clock should use an external
osc due to AM335x cannot generate a low-jitter stable 50MHz clock, this
might cause some PHY cannot work correctly. But in some case (e.g. our
design, no impact on using low speed PHY for debugging/management).
There is no impact on some model phys.

So I think we should provide a way to allow user can set/config the PHY
chose clock mode in dual RMII emac mode.

Tests:

Below is my testing environment:

am335x SOC --RMII 1--> PHY1 (eth0) which using internal clock
          |-RMII 2--> PHY2 (eth1) which using external clock

Booting log:
Booting log:

[    1.843108] cpsw 4a100000.ethernet: Detected MACID = 78:04:73:37:68:6c
[    1.850924] cpsw 4a100000.ethernet: initialized cpsw ale version 1.4
[    1.857842] cpsw 4a100000.ethernet: ALE Table size 1024
[    1.863449] cpsw 4a100000.ethernet: cpts: overflow check period 500 (jiffies)
[    1.874620] cpsw 4a100000.ethernet: cpsw: Detected MACID = 78:04:73:37:68:6e
[    4.017695] net eth0: initializing cpsw version 1.12 (0)
[    5.207867] cpsw 4a100000.ethernet eth0: Link is Up - 10Mbps/Full - flow control off
[  29.747480] net eth1: initializing cpsw version 1.12 (0)
[  30.806444] cpsw 4a100000.ethernet eth1: Link is Up - 100Mbps/Full - flow control off

# ifconfig

eth0      Link encap:Ethernet  HWaddr 00:FA:F9:00:61:88
          inet addr:192.168.0.20  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::2fa:f9ff:fe00:6188/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:20 errors:0 dropped:0 overruns:0 frame:0
          TX packets:35 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1394 (1.3 KiB)  TX bytes:3272 (3.1 KiB)
          Interrupt:50

eth1      Link encap:Ethernet  HWaddr 78:04:73:37:68:6E
          inet addr:10.176.28.165  Bcast:10.176.29.255  Mask:255.255.254.0
          inet6 addr: fe80::7a04:73ff:fe37:686e/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1809 errors:0 dropped:0 overruns:0 frame:0
          TX packets:99 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:123057 (120.1 KiB)  TX bytes:9012 (8.8 KiB)

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:44 errors:0 dropped:0 overruns:0 frame:0
          TX packets:44 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:4872 (4.7 KiB)  TX bytes:4872 (4.7 KiB)

PHY1 (eth0, using internal clock from AM335x) ping:
#ping 192.168.0.20

PING 192.168.0.20 (192.168.0.20): 56 data bytes
64 bytes from 192.168.0.20: seq=0 ttl=64 time=1.340 ms

^C

--- 192.168.0.20 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 1.340/1.340/1.340 ms

PHY2 (eth1, using external clock to AM335x) ping:
# ping 10.176.28.1

PING 10.176.28.1 (10.176.28.1): 56 data bytes
64 bytes from 10.176.28.1: seq=1 ttl=254 time=1.967 ms
64 bytes from 10.176.28.1: seq=2 ttl=254 time=1.652 ms
64 bytes from 10.176.28.1: seq=3 ttl=254 time=1.688 ms

^C

--- 10.176.28.1 ping statistics ---


Both phy working normally.


Thanks and Best regrads,

Xiangyu

From df2b0c2f7723deedcf4195e48e851de16b400775 Mon Sep 17 00:00:00 2001
From: Xiangyu Chen <xiangyu.chen@aol.com>
Date: Fri, 31 Dec 2021 10:38:03 +0800
Subject: [PATCH 2/2] dt-bindings: net: ti:add support slave interface using
 internal clock in dual rmii emac mode

The am335x support dual emac in rmii mode, the rmii clock can be
provided by external osc or internal soc by ref_clk pin.
When rmii-clock-ext has been set in device tree, both emac has been
set to external clock mode, otherwise both emac has been set to internal
clock mode.

In some case, one slave can be used external clock, another slave can be
used internal clock.

This commit to support define a method to tell driver which slave phy
use internal clock when the "rmii-clock-ext" has been set.

Signed-off-by: Xiangyu Chen <xiangyu.chen@aol.com>
---
 .../devicetree/bindings/net/cpsw-phy-sel.txt        | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/cpsw-phy-sel.txt b/Documentation/devicetree/bindings/net/cpsw-phy-sel.txt
index 5d76f991c..d3b91824d 100644
--- a/Documentation/devicetree/bindings/net/cpsw-phy-sel.txt
+++ b/Documentation/devicetree/bindings/net/cpsw-phy-sel.txt
@@ -13,6 +13,10 @@ Optional properties:
 -rmii-clock-ext		: If present, the driver will configure the RMII
 			  interface to external clock usage
 
+-ignore-slave		: If dual rmii emac enabled and rmii-clock-ext present,
+			  this value will tell driver which slave want to use
+			  internal clock instead of external clock
+
 Examples:
 
 	phy_sel: cpsw-phy-sel@44e10650 {
@@ -28,3 +32,12 @@ Examples:
 		reg-names = "gmii-sel";
 		rmii-clock-ext;
 	};
+
+(or)
+	phy_sel: cpsw-phy-sel@44e10650 {
+		compatible = "ti,am3352-cpsw-phy-sel";
+		reg= <0x44e10650 0x4>;
+		reg-names = "gmii-sel";
+		rmii-clock-ext;
+		ignore-slave = <0>;
+	};
-- 
2.25.1