[source] kernel: b53: force BCM531x5 port 5 link state if enabled

[LEDE Commits]

rmilecki pushed a commit to source.git, branch master:
https://git.lede-project.org/80722233476224eb695b186c0add6e9b5cf43d11

commit 80722233476224eb695b186c0add6e9b5cf43d11
Author: Rafał Miłecki <rafal at milecki.pl>
AuthorDate: Thu Aug 18 11:05:12 2016 +0200

    kernel: b53: force BCM531x5 port 5 link state if enabled
    
    Some devices (e.g. Tenda AC9 based on BCM47189B0) have BCM53125 with
    port 5 connected to the second Ethernet interface on the SoC. In such
    case there is no PHY and we need to force link manually.
    
    This assumes port 5 can be marked as enabled for such devices. It's not
    implemented yet unfortunately.
    
    Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
---
 target/linux/generic/files/drivers/net/phy/b53/b53_common.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/target/linux/generic/files/drivers/net/phy/b53/b53_common.c b/target/linux/generic/files/drivers/net/phy/b53/b53_common.c
index d96d8b8..b884010 100644
--- a/target/linux/generic/files/drivers/net/phy/b53/b53_common.c
+++ b/target/linux/generic/files/drivers/net/phy/b53/b53_common.c
@@ -534,6 +534,19 @@ 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);
+
+		/* BCM47189 has another interface connected to the port 5 */
+		if (dev->enabled_ports & BIT(5)) {
+			u8 po_reg = B53_GMII_PORT_OVERRIDE_CTRL(5);
+			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;
+			b53_write8(dev, B53_CTRL_PAGE, po_reg, gmii_po);
+		}
 	} else if (is5301x(dev)) {
 		if (cpu_port == 8) {
 			u8 mii_port_override;