[PATCH 36 v2] LEON3: GPTIMER timer watchdog driver
Daniel Hellstrom
daniel at gaisler.com
Fri Apr 20 06:22:03 UTC 2012
On 04/19/2012 06:08 PM, Gedare Bloom wrote:
> Looking at this from the perspective of generalizing to a shared BSP
> infrastructure I have a couple of nit-picky comments.
>
> On Thu, Apr 19, 2012 at 9:21 AM, Daniel Hellstrom<daniel at gaisler.com> wrote:
>> Last timer instance of GPTIMER is sometimes a watchdog timer that
>> can reset the system on timer underflow.
>>
>> Signed-off-by: Daniel Hellstrom<daniel at gaisler.com>
>> ---
>> c/src/lib/libbsp/sparc/leon3/Makefile.am | 2 +
>> c/src/lib/libbsp/sparc/leon3/include/watchdog.h | 49 ++++++++++++
>> c/src/lib/libbsp/sparc/leon3/preinstall.am | 4 +
>> c/src/lib/libbsp/sparc/leon3/timer/watchdog.c | 90 +++++++++++++++++++++++
>> 4 files changed, 145 insertions(+), 0 deletions(-)
>> create mode 100644 c/src/lib/libbsp/sparc/leon3/include/watchdog.h
>> create mode 100644 c/src/lib/libbsp/sparc/leon3/timer/watchdog.c
>>
>> diff --git a/c/src/lib/libbsp/sparc/leon3/Makefile.am b/c/src/lib/libbsp/sparc/leon3/Makefile.am
>> index cc25993..09d8b8e 100644
>> --- a/c/src/lib/libbsp/sparc/leon3/Makefile.am
>> +++ b/c/src/lib/libbsp/sparc/leon3/Makefile.am
>> @@ -115,6 +115,8 @@ libbsp_a_SOURCES += ../../sparc/shared/i2c/i2cmst.c
>>
>> # timer
>> libbsp_a_SOURCES += timer/timer.c
>> +libbsp_a_SOURCES += timer/watchdog.c
>> +include_HEADERS += include/watchdog.h
> This new file perhaps should be named bspwatchdog.h
Makes sens, only copied naming from another BSP.
>> if HAS_SMP
>> libbsp_a_SOURCES += smp/getcpuid.c
>> diff --git a/c/src/lib/libbsp/sparc/leon3/include/watchdog.h b/c/src/lib/libbsp/sparc/leon3/include/watchdog.h
>> new file mode 100644
>> index 0000000..8110efd
>> --- /dev/null
>> +++ b/c/src/lib/libbsp/sparc/leon3/include/watchdog.h
>> @@ -0,0 +1,49 @@
>> +/* watchdog.h
>> + *
>> + * The LEON3 BSP timer watch-dog interface
>> + *
>> + * COPYRIGHT (c) 2012
>> + * Aeroflex Gaisler
>> + *
>> + * The license and distribution terms for this file may be
>> + * found in the file LICENSE in this distribution or at
>> + * http://www.rtems.com/license/LICENSE.
>> + */
>> +
>> +#ifndef __WATCHDOG_H__
>> +#define __WATCHDOG_H__
>> +
>> +#ifdef __cplusplus
>> +extern "C" {
>> +#endif
>> +
>> +/* Initialize BSP watchdog routines. Returns number of watchdog timers found.
>> + * Currently only one is supported.
>> + */
>> +int bsp_watchdog_init(void);
> Please name bsp_watchdog_initialize() -- for shared code we prefer to
> avoid abbreviations.
Ok.
>> +
>> +/* Reload watchdog (last timer on the first GPTIMER core), all systems does not
>> + * feature a watchdog, it is expected that if this function is called the
>> + * user knows that there is a watchdog available.
>> + *
>> + * The prescaler is normally set to number of MHz of system, this is to
>> + * make the system clock tick be stable.
>> + *
>> + * Arguments
>> + * watchdog - Always 0 for now
>> + * reload_value - Number of timer clocks (after prescaler) to count before
>> + * watchdog is woken.
>> + */
>> +void bsp_watchdog_reload(int watchdog, unsigned int reload_value);
>> +
>> +/* Stop watchdog timer */
>> +void bsp_watchdog_stop(int watchdog);
>> +
>> +/* Use watchdog0 timer to reset the system */
>> +void bsp_watchdog_system_reset(void);
> Why not pass the watchdog number to use in this function also?
My intention was that it is up to the BSP to select a appropriate watchdog, like the primary watchdog in Joel's driver. Partly the problem is that BSP compile-time code may invoke the watchdog, for
example the reboot code. However, perhaps it is good to let the user configure it some how.
>> +
>> +#ifdef __cplusplus
>> +}
>> +#endif
>> +
>> +#endif
>> diff --git a/c/src/lib/libbsp/sparc/leon3/preinstall.am b/c/src/lib/libbsp/sparc/leon3/preinstall.am
>> index dffbb5a..b55cf35 100644
>> --- a/c/src/lib/libbsp/sparc/leon3/preinstall.am
>> +++ b/c/src/lib/libbsp/sparc/leon3/preinstall.am
>> @@ -149,3 +149,7 @@ $(PROJECT_INCLUDE)/i2cmst.h: ../../sparc/shared/include/i2cmst.h $(PROJECT_INCLU
>> $(INSTALL_DATA) $< $(PROJECT_INCLUDE)/i2cmst.h
>> PREINSTALL_FILES += $(PROJECT_INCLUDE)/i2cmst.h
>>
>> +$(PROJECT_INCLUDE)/watchdog.h: include/watchdog.h $(PROJECT_INCLUDE)/$(dirstamp)
>> + $(INSTALL_DATA) $< $(PROJECT_INCLUDE)/watchdog.h
>> +PREINSTALL_FILES += $(PROJECT_INCLUDE)/watchdog.h
>> +
>> diff --git a/c/src/lib/libbsp/sparc/leon3/timer/watchdog.c b/c/src/lib/libbsp/sparc/leon3/timer/watchdog.c
>> new file mode 100644
>> index 0000000..b09ab9c
>> --- /dev/null
>> +++ b/c/src/lib/libbsp/sparc/leon3/timer/watchdog.c
>> @@ -0,0 +1,90 @@
>> +/* GPTIMER Watchdog timer routines. On some systems the first GPTIMER
>> + * core's last Timer instance underflow signal is connected to system
>> + * reset.
>> + *
>> + * COPYRIGHT (c) 2012
>> + * Aeroflex Gaisler
>> + *
>> + * The license and distribution terms for this file may be
>> + * found in the file LICENSE in this distribution or at
>> + * http://www.rtems.com/license/LICENSE.
>> + */
>> +
>> +#include<bsp.h>
>> +#include<watchdog.h>
>> +#include<grlib.h>
>> +
>> +extern volatile struct gptimer_regs *LEON3_Timer_Regs;
>> +
>> +struct gptimer_watchdog_priv {
>> + struct gptimer_regs *regs;
>> + struct gptimer_timer_regs *timer;
>> + int timerno;
>> +};
>> +
>> +struct gptimer_watchdog_priv bsp_watchdogs[1];
>> +int bsp_watchdog_count = 0;
>> +
>> +int bsp_watchdog_init(void)
>> +{
>> + int timercnt;
>> +
>> + if (!LEON3_Timer_Regs)
>> + return 0;
>> +
>> + /* Get Watchdogs in system, this is implemented for one GPTIMER core
>> + * only.
>> + *
>> + * First watchdog is a special case, we can get the first timer core by
>> + * looking at LEON3_Timer_Regs, the watchdog within a timer core is
>> + * always the last timer. Unfortunately we can not know it the watchdog
>> + * functionality is available or not, we assume that it is if we
>> + * reached this function.
>> + */
>> + bsp_watchdogs[0].regs = (struct gptimer_regs *)LEON3_Timer_Regs;
>> +
>> + /* Find Timer that has watchdog functionality */
>> + timercnt = bsp_watchdogs[0].regs->cfg& 0x7;
>> + if (timercnt< 2) /* First timer system clock timer */
>> + return 0;
>> +
>> + bsp_watchdogs[0].timerno = timercnt - 1;
>> + bsp_watchdogs[0].timer =&bsp_watchdogs[0].regs->timer[bsp_watchdogs[0].timerno];
>> +
>> + bsp_watchdog_count = 1;
> Can we get rid of this global var?
>
>> + return bsp_watchdog_count;
>> +}
>> +
>> +void bsp_watchdog_reload(int watchdog, unsigned int reload_value)
>> +{
>> + if (bsp_watchdog_count == 0)
>> + bsp_watchdog_init();
>> +
>> + if (bsp_watchdog_count<= watchdog)
>> + return;
>> +
>> + /* Kick watchdog, and clear interrupt pending bit */
>> + bsp_watchdogs[watchdog].timer->reload = reload_value;
>> + bsp_watchdogs[watchdog].timer->ctrl =
>> + (LEON3_GPTIMER_LD | LEON3_GPTIMER_EN) |
>> + (bsp_watchdogs[watchdog].timer->ctrl& ~(1<<4));
>> +}
>> +
>> +void bsp_watchdog_stop(int watchdog)
>> +{
>> + if (bsp_watchdog_count == 0)
>> + bsp_watchdog_init();
>> +
>> + if (bsp_watchdog_count<= watchdog)
>> + return;
>> +
>> + /* Stop watchdog timer */
>> + bsp_watchdogs[watchdog].timer->ctrl = 0;
>> +}
>> +
>> +/* Use watchdog timer to reset system */
>> +void bsp_watchdog_system_reset(void)
>> +{
>> + sparc_disable_interrupts();
>> + bsp_watchdog_reload(0, 1);
>> +}
>> --
>> 1.7.0.4
>>
>
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