b53: improve overriding CPU port state on BCM5301X

On BCM5301X there are two different cases to handle: CPU port 8 vs. any
other one. Support for CPU port 8 was already partially implemented but
it lacked setting some extra bit for 2G speed. It also will need to be
extended to implement "SMP dual core 3 GMAC setup". That's the reason
for handling it in separated code block.
This patch also adds overriding CPU port state for port other than 8. It
requires using recently defined GMII_PORT registers.
It was tested for regressions on BCM53011 revs 2 & 3. It was also
confirmed to fix switch on some internal Broadcom board.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Acked-by: Jonas Gorski <jogo@openwrt.org>

SVN-Revision: 45402

target/linux/generic/files/drivers/net/phy/b53/b53_common.c

@@ -480,6 +480,7 @@ static void b53_switch_reset_gpio(struct b53_device *dev)
 
 static int b53_switch_reset(struct b53_device *dev)
 {
+	u8 cpu_port = dev->sw_dev.cpu_port;
 	u8 mgmt;
 
 	b53_switch_reset_gpio(dev);
@@ -525,8 +526,7 @@ static int b53_switch_reset(struct b53_device *dev)
 				return -EINVAL;
 			}
 		}
-	} else if ((is531x5(dev) || is5301x(dev)) &&
-		   dev->sw_dev.cpu_port == B53_CPU_PORT) {
+	} else if (is531x5(dev) && cpu_port == B53_CPU_PORT) {
 		u8 mii_port_override;
 
 		b53_read8(dev, B53_CTRL_PAGE, B53_PORT_OVERRIDE_CTRL,
@@ -534,6 +534,33 @@ static int b53_switch_reset(struct b53_device *dev)
 		b53_write8(dev, B53_CTRL_PAGE, B53_PORT_OVERRIDE_CTRL,
 			   mii_port_override | PORT_OVERRIDE_EN |
 			   PORT_OVERRIDE_LINK);
+	} else if (is5301x(dev)) {
+		if (cpu_port == 8) {
+			u8 mii_port_override;
+
+			b53_read8(dev, B53_CTRL_PAGE, B53_PORT_OVERRIDE_CTRL,
+				  &mii_port_override);
+			mii_port_override |= PORT_OVERRIDE_LINK |
+					     PORT_OVERRIDE_RX_FLOW |
+					     PORT_OVERRIDE_TX_FLOW |
+					     PORT_OVERRIDE_SPEED_2000M |
+					     PORT_OVERRIDE_EN;
+			b53_write8(dev, B53_CTRL_PAGE, B53_PORT_OVERRIDE_CTRL,
+				   mii_port_override);
+
+			/* TODO: Ports 5 & 7 require some extra handling */
+		} else {
+			u8 po_reg = B53_GMII_PORT_OVERRIDE_CTRL(cpu_port);
+			u8 gmii_po;
+
+			b53_read8(dev, B53_CTRL_PAGE, po_reg, &gmii_po);
+			gmii_po |= GMII_PO_LINK |
+				   GMII_PO_RX_FLOW |
+				   GMII_PO_TX_FLOW |
+				   GMII_PO_EN |
+				   GMII_PO_SPEED_2000M;
+			b53_write8(dev, B53_CTRL_PAGE, po_reg, gmii_po);
+		}
 	}
 
 	b53_enable_mib(dev);

target/linux/generic/files/drivers/net/phy/b53/b53_regs.h

@@ -86,6 +86,7 @@
 #define   PORT_OVERRIDE_RV_MII_25	BIT(4) /* BCM5325 only */
 #define   PORT_OVERRIDE_RX_FLOW		BIT(4)
 #define   PORT_OVERRIDE_TX_FLOW		BIT(5)
+#define   PORT_OVERRIDE_SPEED_2000M	BIT(6) /* BCM5301X only, requires setting 1000M */
 #define   PORT_OVERRIDE_EN		BIT(7) /* Use the register contents */
 
 /* Power-down mode control */