diff mbox series

[net-next,v3,1/4] dt-bindings: net: ethernet-phy: add property mac-termination-ohms

Message ID 20250416-dp83822-mac-impedance-v3-1-028ac426cddb@liebherr.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series net: phy: dp83822: Add support for changing the MAC series termination | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 12 of 12 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 16 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2025-04-18--09-00 (tests: 916)

Commit Message

Dimitri Fedrau April 16, 2025, 5:14 p.m. UTC 
From: Dimitri Fedrau <dimitri.fedrau@liebherr.com>

Add property mac-termination-ohms in the device tree bindings for selecting
the resistance value of the builtin series termination resistors of the
PHY. Changing the resistance to an appropriate value can reduce signal
reflections and therefore improve signal quality.

Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
---
 Documentation/devicetree/bindings/net/ethernet-phy.yaml | 10 ++++++++++
 1 file changed, 10 insertions(+)
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
index 824bbe4333b7ed95cc39737d3c334a20aa890f01..71e2cd32580f2e9e1af88e6f74517ccb92d1c20f 100644
--- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml
+++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
@@ -238,6 +238,16 @@  properties:
       peak-to-peak specified in ANSI X3.263. When omitted, the PHYs default
       will be left as is.
 
+  mac-termination-ohms:
+    maximum: 200
+    description:
+      The xMII signals need series termination on the driver side to match both
+      the output driver impedance and the line characteristic impedance, to
+      prevent reflections and EMI problems. Select a resistance value which is
+      supported by the builtin resistors of the PHY, otherwise the resistors may
+      have to be placed on board. When omitted, the PHYs default will be left as
+      is.
+
   leds:
     type: object