target/linux: Add support for cores with slow WDT clock like bcm5354. (thank you Aleksandar Radovanovic)

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@23415 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 89 insertions, 0 deletions

diff --git a/target/linux/generic/patches-2.6.35/900-bcm47xx_wdt-noprescale.patch b/target/linux/generic/patches-2.6.35/900-bcm47xx_wdt-noprescale.patch
new file mode 100644
index 0000000000..6bc2b12eb0
--- /dev/null
+++ b/target/linux/generic/patches-2.6.35/900-bcm47xx_wdt-noprescale.patch
@@ -0,0 +1,89 @@
+--- a/drivers/watchdog/bcm47xx_wdt.c
++++ b/drivers/watchdog/bcm47xx_wdt.c
+@@ -31,6 +31,7 @@
+ 
+ #define WDT_DEFAULT_TIME	30	/* seconds */
+ #define WDT_MAX_TIME		255	/* seconds */
++#define WDT_SHIFT		15	/* 32.768 KHz on cores with slow WDT clock */
+ 
+ static int wdt_time = WDT_DEFAULT_TIME;
+ static int nowayout = WATCHDOG_NOWAYOUT;
+@@ -50,11 +51,11 @@ static unsigned long bcm47xx_wdt_busy;
+ static char expect_release;
+ static struct timer_list wdt_timer;
+ static atomic_t ticks;
++static int needs_sw_scale;
+ 
+-static inline void bcm47xx_wdt_hw_start(void)
++static inline void bcm47xx_wdt_hw_start(u32 ticks)
+ {
+-	/* this is 2,5s on 100Mhz clock  and 2s on 133 Mhz */
+-	ssb_watchdog_timer_set(&ssb_bcm47xx, 0xfffffff);
++ 	ssb_watchdog_timer_set(&ssb_bcm47xx, ticks);
+ }
+ 
+ static inline int bcm47xx_wdt_hw_stop(void)
+@@ -65,33 +66,34 @@ static inline int bcm47xx_wdt_hw_stop(vo
+ static void bcm47xx_timer_tick(unsigned long unused)
+ {
+ 	if (!atomic_dec_and_test(&ticks)) {
+-		bcm47xx_wdt_hw_start();
++		/* This is 2,5s on 100Mhz clock and 2s on 133 Mhz */
++		bcm47xx_wdt_hw_start(0xfffffff);
+ 		mod_timer(&wdt_timer, jiffies + HZ);
+ 	} else {
+-		printk(KERN_CRIT DRV_NAME "Watchdog will fire soon!!!\n");
++		printk(KERN_CRIT DRV_NAME ": Watchdog will fire soon!!!\n");
+ 	}
+ }
+ 
+-static inline void bcm47xx_wdt_pet(void)
++static void bcm47xx_wdt_pet(void)
+ {
+-	atomic_set(&ticks, wdt_time);
++	if(needs_sw_scale)
++		atomic_set(&ticks, wdt_time);
++	else
++		bcm47xx_wdt_hw_start(wdt_time << WDT_SHIFT);
+ }
+ 
+ static void bcm47xx_wdt_start(void)
+ {
+ 	bcm47xx_wdt_pet();
+-	bcm47xx_timer_tick(0);
+-}
+-
+-static void bcm47xx_wdt_pause(void)
+-{
+-	del_timer_sync(&wdt_timer);
+-	bcm47xx_wdt_hw_stop();
++	if(needs_sw_scale)
++		bcm47xx_timer_tick(0);
+ }
+ 
+ static void bcm47xx_wdt_stop(void)
+ {
+-	bcm47xx_wdt_pause();
++	if(needs_sw_scale)
++		del_timer_sync(&wdt_timer);
++	bcm47xx_wdt_hw_stop();
+ }
+ 
+ static int bcm47xx_wdt_settimeout(int new_time)
+@@ -243,7 +245,15 @@ static int __init bcm47xx_wdt_init(void)
+ 	if (bcm47xx_wdt_hw_stop() < 0)
+ 		return -ENODEV;
+ 
+-	setup_timer(&wdt_timer, bcm47xx_timer_tick, 0L);
++	/* FIXME Other cores */
++	if(ssb_bcm47xx.chip_id == 0x5354) {
++		/* Slow WDT clock, no pre-scaling */
++		needs_sw_scale = 0;
++	} else {
++		/* Fast WDT clock, needs software pre-scaling */
++		needs_sw_scale = 1;
++		setup_timer(&wdt_timer, bcm47xx_timer_tick, 0L);
++	}
+ 
+ 	if (bcm47xx_wdt_settimeout(wdt_time)) {
+ 		bcm47xx_wdt_settimeout(WDT_DEFAULT_TIME);