net: dsa: b53: prevent GMII_PORT_OVERRIDE_CTRL access on BCM5325

[ Upstream commit 37883bbc45a8555d6eca88d3a9730504d2dac86c ]

BCM5325 doesn't implement GMII_PORT_OVERRIDE_CTRL register so we should
avoid reading or writing it.
PORT_OVERRIDE_RX_FLOW and PORT_OVERRIDE_TX_FLOW aren't defined on BCM5325
and we should use PORT_OVERRIDE_LP_FLOW_25 instead.

Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Link: https://patch.msgid.link/20250614080000.1884236-12-noltari@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index fef265521e8a2cbe1b6a5235abeb8221a54cc353..0085adecaf2d9f5e57402ce82c8eb4cf0d6469be 100644 (file)
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -1269,6 +1269,8 @@ static void b53_force_link(struct b53_device *dev, int port, int link)
        if (port == dev->imp_port) {
                off = B53_PORT_OVERRIDE_CTRL;
                val = PORT_OVERRIDE_EN;
+       } else if (is5325(dev)) {
+               return;
        } else {
                off = B53_GMII_PORT_OVERRIDE_CTRL(port);
                val = GMII_PO_EN;
@@ -1293,6 +1295,8 @@ static void b53_force_port_config(struct b53_device *dev, int port,
        if (port == dev->imp_port) {
                off = B53_PORT_OVERRIDE_CTRL;
                val = PORT_OVERRIDE_EN;
+       } else if (is5325(dev)) {
+               return;
        } else {
                off = B53_GMII_PORT_OVERRIDE_CTRL(port);
                val = GMII_PO_EN;
@@ -1323,10 +1327,19 @@ static void b53_force_port_config(struct b53_device *dev, int port,
                return;
        }
 
-       if (rx_pause)
-               reg |= PORT_OVERRIDE_RX_FLOW;
-       if (tx_pause)
-               reg |= PORT_OVERRIDE_TX_FLOW;
+       if (rx_pause) {
+               if (is5325(dev))
+                       reg |= PORT_OVERRIDE_LP_FLOW_25;
+               else
+                       reg |= PORT_OVERRIDE_RX_FLOW;
+       }
+
+       if (tx_pause) {
+               if (is5325(dev))
+                       reg |= PORT_OVERRIDE_LP_FLOW_25;
+               else
+                       reg |= PORT_OVERRIDE_TX_FLOW;
+       }
 
        b53_write8(dev, B53_CTRL_PAGE, off, reg);
 }

diff --git a/drivers/net/dsa/b53/b53_regs.h b/drivers/net/dsa/b53/b53_regs.h
index d8900aa433e5e6e00ddde4aac159521c9ee252b2..719c2ac94a4fc98bf1b07384f2deeb51e5c9230d 100644 (file)
--- a/drivers/net/dsa/b53/b53_regs.h
+++ b/drivers/net/dsa/b53/b53_regs.h
@@ -95,6 +95,7 @@
 #define   PORT_OVERRIDE_SPEED_10M      (0 << PORT_OVERRIDE_SPEED_S)
 #define   PORT_OVERRIDE_SPEED_100M     (1 << PORT_OVERRIDE_SPEED_S)
 #define   PORT_OVERRIDE_SPEED_1000M    (2 << PORT_OVERRIDE_SPEED_S)
+#define   PORT_OVERRIDE_LP_FLOW_25     BIT(3) /* BCM5325 only */
 #define   PORT_OVERRIDE_RV_MII_25      BIT(4) /* BCM5325 only */
 #define   PORT_OVERRIDE_RX_FLOW                BIT(4)
 #define   PORT_OVERRIDE_TX_FLOW                BIT(5)