openwrtv4/target/linux/lantiq/patches-3.7/0126-lantiq_etop-Change-MDIO-clock.patch
John Crispin ae0b9ff1ce Setting the MDC clock to 2.5MHz and changing the mii mode to rgmii seems to fix the communication issues with the ar8316 switch. (ticket #11143)
Tested only on the wbmr-hp-g300h, could affect/break other devices.

Signed-off-by: Sebastian Mayr <sebastian.mayr@student.uibk.ac.at>

SVN-Revision: 34837
2012-12-21 20:04:04 +00:00

47 lines
1.5 KiB
Diff

From 2f9f0ec1ff013934a86a7303c9194f6dc05620c3 Mon Sep 17 00:00:00 2001
From: Sebastian Mayr <sebastian.mayr@student.uibk.ac.at>
Date: Thu, 20 Dec 2012 18:34:45 +0100
Subject: [PATCH 1/2] lantiq_etop: Change MDIO clock
This patch sets the MDC clock to 2.5MHz which fixes the MDIO communication
with the ar8316 switch.
---
drivers/net/ethernet/lantiq_etop.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/net/ethernet/lantiq_etop.c b/drivers/net/ethernet/lantiq_etop.c
index e695f71..fc963f6 100644
--- a/drivers/net/ethernet/lantiq_etop.c
+++ b/drivers/net/ethernet/lantiq_etop.c
@@ -83,6 +83,7 @@
#define LTQ_GBIT_PMAC_HD_CTL 0x8c
#define LTQ_GBIT_P0_CTL 0x4
#define LTQ_GBIT_PMAC_RX_IPG 0xa8
+#define LTQ_GBIT_RGMII_CTL 0x78
#define PMAC_HD_CTL_AS (1 << 19)
#define PMAC_HD_CTL_RXSH (1 << 22)
@@ -92,6 +93,10 @@
/* Disable MDIO auto polling (0=disable, 1=enable) */
#define PX_CTL_DMDIO 0x00400000
+/* MDC clock divider, clock = 25MHz/((MDC_CLOCK + 1) * 2) */
+#define MDC_CLOCK_MASK 0xff000000
+#define MDC_CLOCK_OFFSET 24
+
/* register information for the gbit's MDIO bus */
#define MDIO_XR9_REQUEST 0x00008000
#define MDIO_XR9_READ 0x00000800
@@ -329,6 +334,9 @@ ltq_etop_gbit_init(struct net_device *dev)
/* Due to traffic halt when burst length 8,
replace default IPG value with 0x3B */
ltq_gbit_w32(0x3B, LTQ_GBIT_PMAC_RX_IPG);
+ /* set mdc clock to 2.5 MHz */
+ ltq_gbit_w32_mask(MDC_CLOCK_MASK, 4 << MDC_CLOCK_OFFSET,
+ LTQ_GBIT_RGMII_CTL);
}
static int
--
1.7.11.7