[PATCH v4] ARM: ep93xx: use more reliable CPLD watchdog for reset on ts72xx

[Petr Štetiar]

On all ep93xx based boards from Technologic Systems, there's CPLD watchdog
available, so use this one to reset the board instead of the soft reset in
CPU.  I've seen some weird lockups with the soft reset on ep93xx in the past,
while the reset via CPLD watchdog seems to be rock solid (tm) and works fine
so far.

Cc: Ryan Mallon <ryan at bluewatersys.com>
Acked-by: H Hartley Sweeten <hsweeten at visionengravers.com>
Signed-off-by: Petr Štetiar <ynezz at true.cz>
---
 arch/arm/mach-ep93xx/include/mach/system.h |   18 +++++++++++++-----
 1 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/arch/arm/mach-ep93xx/include/mach/system.h b/arch/arm/mach-ep93xx/include/mach/system.h
index 6d661fe..67ec430 100644
--- a/arch/arm/mach-ep93xx/include/mach/system.h
+++ b/arch/arm/mach-ep93xx/include/mach/system.h
@@ -2,7 +2,10 @@
  * arch/arm/mach-ep93xx/include/mach/system.h
  */
 
+#include <linux/io.h>
+
 #include <mach/hardware.h>
+#include <mach/ts72xx.h>
 
 static inline void arch_idle(void)
 {
@@ -13,11 +16,16 @@ static inline void arch_reset(char mode, const char *cmd)
 {
 	local_irq_disable();
 
-	/*
-	 * Set then clear the SWRST bit to initiate a software reset
-	 */
-	ep93xx_devcfg_set_bits(EP93XX_SYSCON_DEVCFG_SWRST);
-	ep93xx_devcfg_clear_bits(EP93XX_SYSCON_DEVCFG_SWRST);
+	if (board_is_ts7200() || board_is_ts7250() || board_is_ts7260() ||
+	    board_is_ts7300() || board_is_ts7400()) {
+		/* We use more reliable CPLD watchdog to perform the reset */
+		__raw_writeb(0x5, TS72XX_WDT_FEED_PHYS_BASE);
+		__raw_writeb(0x1, TS72XX_WDT_CONTROL_PHYS_BASE);
+	} else {
+		/* Set then clear the SWRST bit to initiate a software reset */
+		ep93xx_devcfg_set_bits(EP93XX_SYSCON_DEVCFG_SWRST);
+		ep93xx_devcfg_clear_bits(EP93XX_SYSCON_DEVCFG_SWRST);
+	}
 
 	while (1)
 		;
-- 
1.7.1