[PATCH AUTOSEL 3.18 40/98] ARM: at91: board-dt-sama5: add phy_fixup to override NAND_Tree

Sasha Levin
2018-10-25T14:17:55Z

From: Wenyou Yang <wenyou.yang@atmel.com>

[ Upstream commit b8659752c37ec157ee254cff443b1c9d523aea22 ]

Appearance: On some SAMA5D4EK boards, after power up, the Eth1 doesn't work.

Reason: The PIOE2 pin is connected to the NAND_Tree# of KSZ8081,
But it outputs LOW during the reset period, which cause the NAND_Tree# enabled.

Add phy_fixup() to disable NAND_Tree by overriding the Operation
Mode Strap Override register(i.e. Register 16h) to clear the NAND_Tree bit.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm/mach-at91/board-dt-sama5.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/arch/arm/mach-at91/board-dt-sama5.c b/arch/arm/mach-at91/board-dt-sama5.c
index 129e2917506b..5e4cedfa5c51 100644
--- a/arch/arm/mach-at91/board-dt-sama5.c
+++ b/arch/arm/mach-at91/board-dt-sama5.c
@@ -17,6 +17,7 @@
#include <linux/of_platform.h>
#include <linux/phy.h>
#include <linux/clk-provider.h>
+#include <linux/phy.h>

#include <asm/setup.h>
#include <asm/irq.h>
@@ -27,8 +28,25 @@
#include "at91_aic.h"
#include "generic.h"

+static int ksz8081_phy_fixup(struct phy_device *phy)
+{
+ int value;
+
+ value = phy_read(phy, 0x16);
+ value &= ~0x20;
+ phy_write(phy, 0x16, value);
+
+ return 0;
+}
+
static void __init sama5_dt_device_init(void)
{
+ if (of_machine_is_compatible("atmel,sama5d4ek") &&
+ IS_ENABLED(CONFIG_PHYLIB)) {
+ phy_register_fixup_for_id("fc028000.etherne:00",
+ ksz8081_phy_fixup);
+ }
+
of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
}

--
2.17.1