[PATCH net-next 12/16] dt-bindings: net: dwmac: Add MTL Tx Queue properties constraints

[Serge Semin <Sergey.Semin@baikalelectronics.ru>]

Currently none of the MTL Tx Queues QoS-related DT-properties have been
equipped with the proper constraints meanwhile they can be specified at
least based on the corresponding CSR field sizes or the DW (x|xG)MAC
IP-core synthesize parameter constraints. Let's do that:
+ snps,tx-queues-to-use - number of Tx queues to utilise is limited with a
number of available queues. DW MAC/GMAC: no queues, DW Eth QoS: <= 8, DW
xGMAC: <= 16.
+ snps,weight - Tx Queue/Traffic Class quantum/weight utilised depending
on enabled algorithm for the Data Center Bridging feature: DWRR (up to
0x1312D0 bytes to add to credit) or WFQ (up to 0x3FFF - least bandwidth)
or WFQ (up to 0x64). DW MAC/GMAC: no queues, DW Eth QoS: <= 0x1312D0, DW
xGMAC: <= 0x1312D0.
+ snps,send_slope - Tx Queue/Traffic Class Send-Slope credit value
subtracted from the accumulated credit for the Audio/Video bridging
feature (CBS algorithm, bits per cycle scaled up by 1,024). DW MAC/GMAC:
no queues, DW Eth QoS: <= 0x2000, DW xGMAC: <= 0x3FFF.
+ snps,idle_slope - same meaning as snps,send_slope except it's determines
the Idle-Slope credit of CBS algorithm. DW MAC/GMAC: no queues, DW Eth
QoS: <= 0x2000, DW xGMAC: <= 0x8000.
+ snps,high_credit/snps,low_credit - maximum and minimum values
accumulated in the credit for the Audio/Video bridging feature (CBS
algorithm, bits scaled up by 1,024). DW MAC/GMAC: no queues, DW Eth
QoS: <= 0x1FFFFFFF, DW xGMAC: <= 0x1FFFFFFF.
+ snps,priority - Tx Queue/Traffic Class priority (enabled by the
PFC-packets) limits determined by the VLAN tag PRI field width (it's 7).
DW MAC/GMAC: no queues, DW Eth QoS: 0xff, DW xGMAC: 0xff.

Since the constraints vary for different IP-cores and the DT-schema is
common for all of them the least restrictive values are chosen. The info
above can be used for the IP-core specific DT-schemas if anybody ever is
bothered with one to create.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
---
 .../bindings/net/snps,dwmac-generic.yaml      |  2 +-
 .../devicetree/bindings/net/snps,dwmac.yaml   | 24 ++++++++++++++++++-
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/snps,dwmac-generic.yaml b/Documentation/devicetree/bindings/net/snps,dwmac-generic.yaml
index ae740a1ab213..2974af79511d 100644
--- a/Documentation/devicetree/bindings/net/snps,dwmac-generic.yaml
+++ b/Documentation/devicetree/bindings/net/snps,dwmac-generic.yaml
@@ -137,7 +137,7 @@ examples:
                 snps,send_slope = <0x1000>;
                 snps,idle_slope = <0x1000>;
                 snps,high_credit = <0x3E800>;
-                snps,low_credit = <0xFFC18000>;
+                snps,low_credit = <0x1FC18000>;
                 snps,priority = <0x1>;
             };
         };
diff --git a/Documentation/devicetree/bindings/net/snps,dwmac.yaml b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
index e5662b1498b7..2ebf7995426b 100644
--- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml
+++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
@@ -250,6 +250,10 @@ properties:
       snps,tx-queues-to-use:
         $ref: /schemas/types.yaml#/definitions/uint32
         description: number of TX queues to be used in the driver
+        default: 1
+        minimum: 1
+        maximum: 16
+
       snps,tx-sched-wrr:
         type: boolean
         description: Weighted Round Robin
@@ -296,13 +300,16 @@ properties:
             snps,tx-sched-wfq: false
             snps,tx-sched-dwrr: false
     patternProperties:
-      "^queue[0-9]$":
+      "^queue([0-9]|1[0-5])$":
         description: Each subnode represents a queue.
         type: object
         properties:
           snps,weight:
             $ref: /schemas/types.yaml#/definitions/uint32
             description: TX queue weight (if using a DCB weight algorithm)
+            minimum: 0
+            maximum: 0x1312D0
+
           snps,dcb-algorithm:
             type: boolean
             description: TX queue will be working in DCB
@@ -315,15 +322,27 @@ properties:
           snps,send_slope:
             $ref: /schemas/types.yaml#/definitions/uint32
             description: enable Low Power Interface
+            minimum: 0
+            maximum: 0x3FFF
+
           snps,idle_slope:
             $ref: /schemas/types.yaml#/definitions/uint32
             description: unlock on WoL
+            minimum: 0
+            maximum: 0x8000
+
           snps,high_credit:
             $ref: /schemas/types.yaml#/definitions/uint32
             description: max write outstanding req. limit
+            minimum: 0
+            maximum: 0x1FFFFFFF
+
           snps,low_credit:
             $ref: /schemas/types.yaml#/definitions/uint32
             description: max read outstanding req. limit
+            minimum: 0
+            maximum: 0x1FFFFFFF
+
           snps,priority:
             $ref: /schemas/types.yaml#/definitions/uint32
             description:
@@ -331,6 +350,9 @@ properties:
               When a PFC frame is received with priorities matching the bitmask,
               the queue is blocked from transmitting for the pause time specified
               in the PFC frame.
+            minimum: 0
+            maximum: 0xFF
+
         allOf:
           - if:
               required:
-- 
2.39.2