[PATCH v2 net-next 2/2] net: macb: Add capability-based QBV detection and Versal support

[Vineeth Karumanchi <vineeth.karumanchi@amd.com>]

The 'exclude_qbv' bit in the designcfg_debug1 register varies across
MACB/GEM IP revisions, making direct probing unreliable for detecting
QBV support. This patch introduces a capability-based approach for
consistent QBV feature identification across the IP family.

Platform support updates:
- Establish foundation for QBV detection in TAPRIO implementation
- Enable MACB_CAPS_QBV for Xilinx Versal platform configuration
- Fix capability line wrapping, ensuring code stays within 80 columns

Signed-off-by: Vineeth Karumanchi <vineeth.karumanchi@amd.com>
---
v2:
  - Fixed CAPS syntax and resolved related clang error
  - Wrapped capability lines to stay within 80-column limit
v1: https://lore.kernel.org/netdev/20250722154111.1871292-1-vineeth.karumanchi@amd.com/
---
 drivers/net/ethernet/cadence/macb.h      | 1 +
 drivers/net/ethernet/cadence/macb_main.c | 9 +++++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index d1a98b45c92c..904954610611 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -770,6 +770,7 @@
 #define MACB_CAPS_MIIONRGMII			0x00000200
 #define MACB_CAPS_NEED_TSUCLK			0x00000400
 #define MACB_CAPS_QUEUE_DISABLE			0x00000800
+#define MACB_CAPS_QBV				0x00001000
 #define MACB_CAPS_PCS				0x01000000
 #define MACB_CAPS_HIGH_SPEED			0x02000000
 #define MACB_CAPS_CLK_HW_CHG			0x04000000
diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index d4b9737f83eb..f948da429107 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -4602,6 +4602,10 @@ static int macb_init(struct platform_device *pdev)
 		dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
 	if (bp->caps & MACB_CAPS_SG_DISABLED)
 		dev->hw_features &= ~NETIF_F_SG;
+	/* Enable HW_TC if hardware supports QBV */
+	if (bp->caps & MACB_CAPS_QBV)
+		dev->hw_features |= NETIF_F_HW_TC;
+
 	dev->features = dev->hw_features;
 
 	/* Check RX Flow Filters support.
@@ -5345,8 +5349,9 @@ static const struct macb_config sama7g5_emac_config = {
 
 static const struct macb_config versal_config = {
 	.caps = MACB_CAPS_GIGABIT_MODE_AVAILABLE | MACB_CAPS_JUMBO |
-		MACB_CAPS_GEM_HAS_PTP | MACB_CAPS_BD_RD_PREFETCH | MACB_CAPS_NEED_TSUCLK |
-		MACB_CAPS_QUEUE_DISABLE,
+		MACB_CAPS_GEM_HAS_PTP | MACB_CAPS_BD_RD_PREFETCH |
+		MACB_CAPS_NEED_TSUCLK | MACB_CAPS_QUEUE_DISABLE |
+		MACB_CAPS_QBV,
 	.dma_burst_length = 16,
 	.clk_init = macb_clk_init,
 	.init = init_reset_optional,
-- 
2.34.1