[U-Boot-Users] [PATCH] Fix boot from NOR due to incorrect reset delay.

[Stelian Pop]

AT91 RSTC registers are battery-backuped, so their values
are not reset across power cycles. One of those registers,
the AT91_RSTC_MR register, is being modified by U-Boot, in
the ethernet initialisation routine, to generate a 500ms
user reset.

Unfortunately, this value is not being restored afterwards,
causing subsequent resets to also last for 500ms.

This long reset sequence causes problems (at least) in the
boot sequence from NOR: by the time the CPU tries to load
a program from the NOR flash, the latter is still in reset
and not yet available.

Additionaly, this patch fixes a bug in the original code which
caused the reset delay to last for 2s instead of 500ms.

Signed-off-by: Stelian Pop <stelian at popies.net>
---

This patch applies on top of the latest AT91 patches,
as integrated in the testing-V2 branch of the u-boot-at91
repository.

 board/atmel/at91cap9adk/at91cap9adk.c     |    7 ++++++-
 board/atmel/at91sam9260ek/at91sam9260ek.c |    4 ++--
 board/atmel/at91sam9263ek/at91sam9263ek.c |    7 ++++++-
 3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/board/atmel/at91cap9adk/at91cap9adk.c b/board/atmel/at91cap9adk/at91cap9adk.c
index a3eaf19..c5082a0 100644
--- a/board/atmel/at91cap9adk/at91cap9adk.c
+++ b/board/atmel/at91cap9adk/at91cap9adk.c
@@ -196,7 +196,7 @@ static void at91cap9_macb_hw_init(void)
 
 	/* Need to reset PHY -> 500ms reset */
 	at91_sys_write(AT91_RSTC_MR, AT91_RSTC_KEY |
-				     AT91_RSTC_ERSTL | (0x0D << 8) |
+				     (AT91_RSTC_ERSTL & (0x0D << 8)) |
 				     AT91_RSTC_URSTEN);
 
 	at91_sys_write(AT91_RSTC_CR, AT91_RSTC_KEY | AT91_RSTC_EXTRST);
@@ -204,6 +204,11 @@ static void at91cap9_macb_hw_init(void)
 	/* Wait for end hardware reset */
 	while (!(at91_sys_read(AT91_RSTC_SR) & AT91_RSTC_NRSTL));
 
+	/* Restore NRST value */
+	at91_sys_write(AT91_RSTC_MR, AT91_RSTC_KEY |
+				     (AT91_RSTC_ERSTL & (0x0 << 8)) |
+				     AT91_RSTC_URSTEN);
+
 	/* Re-enable pull-up */
 	writel(pin_to_mask(AT91_PIN_PB22) |
 	       pin_to_mask(AT91_PIN_PB25) |
diff --git a/board/atmel/at91sam9260ek/at91sam9260ek.c b/board/atmel/at91sam9260ek/at91sam9260ek.c
index 4635f0f..3572b16 100644
--- a/board/atmel/at91sam9260ek/at91sam9260ek.c
+++ b/board/atmel/at91sam9260ek/at91sam9260ek.c
@@ -149,7 +149,7 @@ static void at91sam9260ek_macb_hw_init(void)
 
 	/* Need to reset PHY -> 500ms reset */
 	at91_sys_write(AT91_RSTC_MR, AT91_RSTC_KEY |
-				     AT91_RSTC_ERSTL | (0x0D << 8) |
+				     (AT91_RSTC_ERSTL & (0x0D << 8)) |
 				     AT91_RSTC_URSTEN);
 
 	at91_sys_write(AT91_RSTC_CR, AT91_RSTC_KEY | AT91_RSTC_EXTRST);
@@ -159,7 +159,7 @@ static void at91sam9260ek_macb_hw_init(void)
 
 	/* Restore NRST value */
 	at91_sys_write(AT91_RSTC_MR, AT91_RSTC_KEY |
-				     AT91_RSTC_ERSTL | (0x0 << 8) |
+				     (AT91_RSTC_ERSTL & (0x0 << 8)) |
 				     AT91_RSTC_URSTEN);
 
 	/* Re-enable pull-up */
diff --git a/board/atmel/at91sam9263ek/at91sam9263ek.c b/board/atmel/at91sam9263ek/at91sam9263ek.c
index ba7fc71..169ee25 100644
--- a/board/atmel/at91sam9263ek/at91sam9263ek.c
+++ b/board/atmel/at91sam9263ek/at91sam9263ek.c
@@ -147,7 +147,7 @@ static void at91sam9263ek_macb_hw_init(void)
 
 	/* Need to reset PHY -> 500ms reset */
 	at91_sys_write(AT91_RSTC_MR, AT91_RSTC_KEY |
-				     AT91_RSTC_ERSTL | (0x0D << 8) |
+				     (AT91_RSTC_ERSTL & (0x0D << 8)) |
 				     AT91_RSTC_URSTEN);
 
 	at91_sys_write(AT91_RSTC_CR, AT91_RSTC_KEY | AT91_RSTC_EXTRST);
@@ -155,6 +155,11 @@ static void at91sam9263ek_macb_hw_init(void)
 	/* Wait for end hardware reset */
 	while (!(at91_sys_read(AT91_RSTC_SR) & AT91_RSTC_NRSTL));
 
+	/* Restore NRST value */
+	at91_sys_write(AT91_RSTC_MR, AT91_RSTC_KEY |
+				     (AT91_RSTC_ERSTL & (0x0 << 8)) |
+				     AT91_RSTC_URSTEN);
+
 	/* Re-enable pull-up */
 	writel(pin_to_mask(AT91_PIN_PC25),
 	       pin_to_controller(AT91_PIN_PC0) + PIO_PUER);
-- 
1.5.3.3