[U-Boot] [PATCH 1/2] at91sam9: add watchdog support
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD plagnioj@jcrosoft.com --- Makefile | 1 + doc/README.at91 | 9 ++++ drivers/serial/atmel_usart.c | 4 +- drivers/watchdog/Makefile | 46 ++++++++++++++++++++ drivers/watchdog/at91sam9_wdt.c | 79 ++++++++++++++++++++++++++++++++++ include/asm-arm/arch-at91/at91_wdt.h | 38 ++++++++++++++++ 6 files changed, 176 insertions(+), 1 deletions(-) create mode 100644 drivers/watchdog/Makefile create mode 100644 drivers/watchdog/at91sam9_wdt.c create mode 100644 include/asm-arm/arch-at91/at91_wdt.h
diff --git a/Makefile b/Makefile index fcf57f3..3e61417 100644 --- a/Makefile +++ b/Makefile @@ -262,6 +262,7 @@ LIBS += drivers/rtc/librtc.a LIBS += drivers/serial/libserial.a LIBS += drivers/usb/libusb.a LIBS += drivers/video/libvideo.a +LIBS += drivers/watchdog/libwatchdog.a LIBS += common/libcommon.a LIBS += libfdt/libfdt.a LIBS += api/libapi.a diff --git a/doc/README.at91 b/doc/README.at91 index 4e3928a..c883c7c 100644 --- a/doc/README.at91 +++ b/doc/README.at91 @@ -2,6 +2,7 @@ Atmel AT91 Evaluation kits
http://atmel.com/dyn/products/tools.asp?family_id=605#1443
+I. Board mapping & boot media ------------------------------------------------------------------------------ AT91SAM9260EK & AT91SAM9XEEK ------------------------------------------------------------------------------ @@ -86,3 +87,11 @@ Environment variables make at91sam9263ek_config - use data flash (spi cs0) (default) make at91sam9263ek_nandflash_config - use nand flash make at91sam9263ek_dataflash_cs0_config - use data flash (spi cs0) + +II. Watchdog support + + The watchdog wan only be activate once so you need to activate in the + bootloader and in the bootstrap if you use it + + The you can activate with + CONFIG_AT91SAM9_WATCHDOG and CONFIG_HW_WATCHDOG diff --git a/drivers/serial/atmel_usart.c b/drivers/serial/atmel_usart.c index f3b146c..f50552a 100644 --- a/drivers/serial/atmel_usart.c +++ b/drivers/serial/atmel_usart.c @@ -16,6 +16,7 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <common.h> +#include <watchdog.h>
#include <asm/io.h> #include <asm/arch/clk.h> @@ -87,7 +88,8 @@ void serial_puts(const char *s)
int serial_getc(void) { - while (!(usart3_readl(CSR) & USART3_BIT(RXRDY))) ; + while (!(usart3_readl(CSR) & USART3_BIT(RXRDY))) + WATCHDOG_RESET(); return usart3_readl(RHR); }
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile new file mode 100644 index 0000000..200968d --- /dev/null +++ b/drivers/watchdog/Makefile @@ -0,0 +1,46 @@ +# +# (C) Copyright 2008 +# Wolfgang Denk, DENX Software Engineering, wd@denx.de. +# +# See file CREDITS for list of people who contributed to this +# project. +# +# This program is free software; you can redistribute it and/or +# modify it under the terms of the GNU General Public License as +# published by the Free Software Foundation; either version 2 of +# the License, or (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 59 Temple Place, Suite 330, Boston, +# MA 02111-1307 USA +# + +include $(TOPDIR)/config.mk + +LIB := $(obj)libwatchdog.a + +COBJS-$(CONFIG_AT91SAM9_WATCHDOG) += at91sam9_wdt.o + +COBJS := $(COBJS-y) +SRCS := $(COBJS:.o=.c) +OBJS := $(addprefix $(obj),$(COBJS)) + +all: $(LIB) + +$(LIB): $(obj).depend $(OBJS) + $(AR) $(ARFLAGS) $@ $(OBJS) + +######################################################################### + +# defines $(obj).depend target +include $(SRCTREE)/rules.mk + +sinclude $(obj).depend + +######################################################################### diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c new file mode 100644 index 0000000..5bb8b77 --- /dev/null +++ b/drivers/watchdog/at91sam9_wdt.c @@ -0,0 +1,79 @@ +/* + * [origin: Linux kernel drivers/watchdog/at91sam9_wdt.c] + * + * Watchdog driver for Atmel AT91SAM9x processors. + * + * Copyright (C) 2008 Jean-Christophe PLAGNIOL-VILLARD plagnioj@jcrosoft.com + * Copyright (C) 2008 Renaud CERRATO r.cerrato@til-technologies.fr + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +/* + * The Watchdog Timer Mode Register can be only written to once. If the + * timeout need to be set from U-Boot, be sure that the bootstrap doesn't + * write to this register. Inform Linux to it too + */ + +#include <common.h> +#include <watchdog.h> +#include <asm/arch/hardware.h> +#include <asm/arch/io.h> +#include <asm/arch/at91_wdt.h> + +/* + * AT91SAM9 watchdog runs a 12bit counter @ 256Hz, + * use this to convert a watchdog + * value from/to milliseconds. + */ +#define ms_to_ticks(t) (((t << 8) / 1000) - 1) +#define ticks_to_ms(t) (((t + 1) * 1000) >> 8) + +/* Hardware timeout in seconds */ +#define WDT_HW_TIMEOUT 2 + +/* + * Set the watchdog time interval in 1/256Hz (write-once) + * Counter is 12 bit. + */ +static int at91_wdt_settimeout(unsigned int timeout) +{ + unsigned int reg; + unsigned int mr; + + /* Check if disabled */ + mr = at91_sys_read(AT91_WDT_MR); + if (mr & AT91_WDT_WDDIS) { + printf("sorry, watchdog is disabled\n"); + return -1; + } + + /* + * All counting occurs at SLOW_CLOCK / 128 = 256 Hz + * + * Since WDV is a 12-bit counter, the maximum period is + * 4096 / 256 = 16 seconds. + */ + reg = AT91_WDT_WDRSTEN /* causes watchdog reset */ + /* | AT91_WDT_WDRPROC causes processor reset only */ + | AT91_WDT_WDDBGHLT /* disabled in debug mode */ + | AT91_WDT_WDD /* restart at any time */ + | (timeout & AT91_WDT_WDV); /* timer value */ + at91_sys_write(AT91_WDT_MR, reg); + + return 0; +} + +void hw_watchdog_reset(void) +{ + at91_sys_write(AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT); +} + +void hw_watchdog_init(void) +{ + /* 16 seconds timer, resets enabled */ + at91_wdt_settimeout(ms_to_ticks(WDT_HW_TIMEOUT * 1000)); +} diff --git a/include/asm-arm/arch-at91/at91_wdt.h b/include/asm-arm/arch-at91/at91_wdt.h new file mode 100644 index 0000000..7e18537 --- /dev/null +++ b/include/asm-arm/arch-at91/at91_wdt.h @@ -0,0 +1,38 @@ +/* + * [origin: Linux kernel arch/arm/mach-at91/include/mach/at91_wdt.h] + * + * Copyright (C) 2008 Jean-Christophe PLAGNIOL-VILLARD plagnioj@jcrosoft.com + * Copyright (C) 2007 Andrew Victor + * Copyright (C) 2007 Atmel Corporation. + * + * Watchdog Timer (WDT) - System peripherals regsters. + * Based on AT91SAM9261 datasheet revision D. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef AT91_WDT_H +#define AT91_WDT_H + +#define AT91_WDT_CR (AT91_WDT + 0x00) /* Watchdog Control Register */ +#define AT91_WDT_WDRSTT (1 << 0) /* Restart */ +#define AT91_WDT_KEY (0xa5 << 24) /* KEY Password */ + +#define AT91_WDT_MR (AT91_WDT + 0x04) /* Watchdog Mode Register */ +#define AT91_WDT_WDV (0xfff << 0) /* Counter Value */ +#define AT91_WDT_WDFIEN (1 << 12) /* Fault Interrupt Enable */ +#define AT91_WDT_WDRSTEN (1 << 13) /* Reset Processor */ +#define AT91_WDT_WDRPROC (1 << 14) /* Timer Restart */ +#define AT91_WDT_WDDIS (1 << 15) /* Watchdog Disable */ +#define AT91_WDT_WDD (0xfff << 16) /* Delta Value */ +#define AT91_WDT_WDDBGHLT (1 << 28) /* Debug Halt */ +#define AT91_WDT_WDIDLEHLT (1 << 29) /* Idle Halt */ + +#define AT91_WDT_SR (AT91_WDT + 0x08) /* Watchdog Status Register */ +#define AT91_WDT_WDUNF (1 << 0) /* Watchdog Underflow */ +#define AT91_WDT_WDERR (1 << 1) /* Watchdog Error */ + +#endif
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD plagnioj@jcrosoft.com --- Makefile | 5 +++++ doc/README.at91 | 2 +- include/configs/at91sam9263ek.h | 5 +++++ 3 files changed, 11 insertions(+), 1 deletions(-)
diff --git a/Makefile b/Makefile index 3e61417..cc3a22e 100644 --- a/Makefile +++ b/Makefile @@ -2680,6 +2680,7 @@ at91sam9261ek_config : unconfig at91sam9263ek_nandflash_config \ at91sam9263ek_dataflash_config \ at91sam9263ek_dataflash_cs0_config \ +at91sam9263ek_wdt_config \ at91sam9263ek_config : unconfig @mkdir -p $(obj)include @if [ "$(findstring _nandflash,$@)" ] ; then \ @@ -2689,6 +2690,10 @@ at91sam9263ek_config : unconfig echo "#define CONFIG_SYS_USE_DATAFLASH 1" >>$(obj)include/config.h ; \ $(XECHO) "... with environment variable in SPI DATAFLASH CS0" ; \ fi; + @if [ "$(findstring _wdt_, $@)" ] ; then \ + echo "#define CONFIG_AT91SAM9_WATCHDOG" >> $(obj)include/config.h ; \ + $(XECHO) "... configured with watchdog active"; \ + fi @$(MKCONFIG) -a at91sam9263ek arm arm926ejs at91sam9263ek atmel at91
at91sam9rlek_nandflash_config \ diff --git a/doc/README.at91 b/doc/README.at91 index c883c7c..1ef3b2a 100644 --- a/doc/README.at91 +++ b/doc/README.at91 @@ -90,7 +90,7 @@ Environment variables
II. Watchdog support
- The watchdog wan only be activate once so you need to activate in the + The watchdog can only be activate once so you need to activate in the bootloader and in the bootstrap if you use it
The you can activate with diff --git a/include/configs/at91sam9263ek.h b/include/configs/at91sam9263ek.h index 09b871a..e28903c 100644 --- a/include/configs/at91sam9263ek.h +++ b/include/configs/at91sam9263ek.h @@ -201,4 +201,9 @@ #error CONFIG_USE_IRQ not supported #endif
+/* WATCHDOG */ +#ifdef CONFIG_AT91SAM9_WATCHDOG +#define CONFIG_HW_WATCHDOG /* watchdog */ +#endif + #endif
Dear Jean-Christophe PLAGNIOL-VILLARD,
In message 1233505762-23290-2-git-send-email-plagnioj@jcrosoft.com you wrote:
II. Watchdog support
- The watchdog wan only be activate once so you need to activate in the
- The watchdog can only be activate once so you need to activate in the bootloader and in the bootstrap if you use it
Also please squash this into the patch where you add that text. Thanks.
Best regards,
Wolfgang Denk
In this way the linux driver won't work(the one by Renaud CERRATO). Because it expects MR register not to be set, or to be set enabled.
After I don't agree refreshing watchdog inside atmel_usart.c If u-boot hangs there instead of execute bootcmd, then the machine lies there forever. In my opinion we should put WATCHDOG_RESET() inside main_loop and nand write and read. What do you think?
Kind regards
On 12:52 Sat 13 Jun , Giulio Benetti wrote:
In this way the linux driver won't work(the one by Renaud CERRATO). Because it expects MR register not to be set, or to be set enabled.
it's work we have test it you need to enable it in the at91bootstrap or in your lowlevel board config
After I don't agree refreshing watchdog inside atmel_usart.c
you MUST do it otherwise you board will be not usable at all simple exammple you stop the boot and get a prompt if you do not type any command you reboot it's not what we expect
If u-boot hangs there instead of execute bootcmd, then the machine lies there forever. In my opinion we should put WATCHDOG_RESET() inside main_loop and nand write and read. What do you think?
NACK for the main_loop
nand read write ok
but if we excecute the bootcmd we have finished and jump to the os so it's over for u-boot
the OS will have to care about the watchdog
Best Regards, J.
Jean-Christophe PLAGNIOL-VILLARD wrote:
On 12:52 Sat 13 Jun , Giulio Benetti wrote:
In this way the linux driver won't work(the one by Renaud CERRATO). Because it expects MR register not to be set, or to be set enabled.
it's work we have test it you need to enable it in the at91bootstrap or in your lowlevel board config
After I don't agree refreshing watchdog inside atmel_usart.c
you MUST do it otherwise you board will be not usable at all simple exammple you stop the boot and get a prompt if you do not type any command you reboot it's not what we expect
If u-boot hangs there instead of execute bootcmd, then the machine lies there forever. In my opinion we should put WATCHDOG_RESET() inside main_loop and nand write and read. What do you think?
NACK for the main_loop
nand read write ok
but if we excecute the bootcmd we have finished and jump to the os so it's over for u-boot
the OS will have to care about the watchdog
Best Regards, J.
Agree with you. But you have to delete hw_watchdog_init(). If you set there MR then linux won't be able to do it. The patch needs only the WATCHDOG_RESET() and nothing more.
On 12:38 Mon 15 Jun , Giulio Benetti wrote:
Jean-Christophe PLAGNIOL-VILLARD wrote:
On 12:52 Sat 13 Jun , Giulio Benetti wrote:
In this way the linux driver won't work(the one by Renaud CERRATO). Because it expects MR register not to be set, or to be set enabled.
it's work we have test it you need to enable it in the at91bootstrap or in your lowlevel board config
After I don't agree refreshing watchdog inside atmel_usart.c
you MUST do it otherwise you board will be not usable at all simple exammple you stop the boot and get a prompt if you do not type any command you reboot it's not what we expect
If u-boot hangs there instead of execute bootcmd, then the machine lies there forever. In my opinion we should put WATCHDOG_RESET() inside main_loop and nand write and read. What do you think?
NACK for the main_loop
nand read write ok
but if we excecute the bootcmd we have finished and jump to the os so it's over for u-boot
the OS will have to care about the watchdog
Best Regards, J.
Agree with you. But you have to delete hw_watchdog_init(). If you set there MR then linux won't be able to do it. The patch needs only the WATCHDOG_RESET() and nothing more.
you need to update linux, the watchdog can be enable in u-boot but as it can only be disable once if u-boot or any other bootloader init we can not disable it so in this case linux will just have to buy time to the watchdog
Best Regards, J.
But you have to delete hw_watchdog_init(). If you set there MR then linux won't be able to do it. The patch needs only the WATCHDOG_RESET() and nothing more.
I agree.
you need to update linux, the watchdog can be enable in u-boot but as it can only be disable once if u-boot or any other bootloader init we can not disable it so in this case linux will just have to buy time to the watchdog
On the sam926x processors It can only be confitured once. So Giulio is right: u-boot shouldn't configure it, just kick it any now and then.
When a client asked to used the watchdog on the 9260 I chose not to disable it in at91boot nor in u-boot. Then Linux (i.e., the final user) could do whatever was fit: either disable it, enable it with a faster timeout or leave it alone (at 13s or whatever the default is) until some application sets a policy.
I don't like this hardware choice of "configure once only": never-disable makes sense, but never-enable doesn't, in my opinion. But based on that the right thing for u-boot is not configuring it a all, or we loose flexibility in later stages.
/alessandro
I think that with this patch at91 watchdog is enough, it reduces code that is not yet used and I think it HAS NOT to be used(no wdt init).
Signed-off-by: giulio.benetti@micronovasrl.com
diff -urpN b/drivers/watchdog/at91sam9_wdt.c a/drivers/watchdog/at91sam9_wdt.c --- b/drivers/watchdog/at91sam9_wdt.c 2009-06-14 21:30:39.000000000 +0200 +++ a/drivers/watchdog/at91sam9_wdt.c 2009-06-18 17:26:26.000000000 +0200 @@ -5,6 +5,7 @@ * * Copyright (C) 2008 Jean-Christophe PLAGNIOL-VILLARD plagnioj@jcrosoft.com * Copyright (C) 2008 Renaud CERRATO r.cerrato@til-technologies.fr + * Giulio Benetti giulio.benetti@micronovasrl.com * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License @@ -24,56 +25,7 @@ #include <asm/arch/io.h> #include <asm/arch/at91_wdt.h>
-/* - * AT91SAM9 watchdog runs a 12bit counter @ 256Hz, - * use this to convert a watchdog - * value from/to milliseconds. - */ -#define ms_to_ticks(t) (((t << 8) / 1000) - 1) -#define ticks_to_ms(t) (((t + 1) * 1000) >> 8) - -/* Hardware timeout in seconds */ -#define WDT_HW_TIMEOUT 2 - -/* - * Set the watchdog time interval in 1/256Hz (write-once) - * Counter is 12 bit. - */ -static int at91_wdt_settimeout(unsigned int timeout) -{ - unsigned int reg; - unsigned int mr; - - /* Check if disabled */ - mr = at91_sys_read(AT91_WDT_MR); - if (mr & AT91_WDT_WDDIS) { - printf("sorry, watchdog is disabled\n"); - return -1; - } - - /* - * All counting occurs at SLOW_CLOCK / 128 = 256 Hz - * - * Since WDV is a 12-bit counter, the maximum period is - * 4096 / 256 = 16 seconds. - */ - reg = AT91_WDT_WDRSTEN /* causes watchdog reset */ - /* | AT91_WDT_WDRPROC causes processor reset only */ - | AT91_WDT_WDDBGHLT /* disabled in debug mode */ - | AT91_WDT_WDD /* restart at any time */ - | (timeout & AT91_WDT_WDV); /* timer value */ - at91_sys_write(AT91_WDT_MR, reg); - - return 0; -} - void hw_watchdog_reset(void) { at91_sys_write(AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT); } - -void hw_watchdog_init(void) -{ - /* 16 seconds timer, resets enabled */ - at91_wdt_settimeout(ms_to_ticks(WDT_HW_TIMEOUT * 1000)); -}
Jean-Christophe PLAGNIOL-VILLARD wrote:
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD plagnioj@jcrosoft.com
Makefile | 1 + doc/README.at91 | 9 ++++ drivers/serial/atmel_usart.c | 4 +- drivers/watchdog/Makefile | 46 ++++++++++++++++++++ drivers/watchdog/at91sam9_wdt.c | 79 ++++++++++++++++++++++++++++++++++ include/asm-arm/arch-at91/at91_wdt.h | 38 ++++++++++++++++ 6 files changed, 176 insertions(+), 1 deletions(-) create mode 100644 drivers/watchdog/Makefile create mode 100644 drivers/watchdog/at91sam9_wdt.c create mode 100644 include/asm-arm/arch-at91/at91_wdt.h
diff --git a/Makefile b/Makefile index fcf57f3..3e61417 100644 --- a/Makefile +++ b/Makefile @@ -262,6 +262,7 @@ LIBS += drivers/rtc/librtc.a LIBS += drivers/serial/libserial.a LIBS += drivers/usb/libusb.a LIBS += drivers/video/libvideo.a +LIBS += drivers/watchdog/libwatchdog.a LIBS += common/libcommon.a LIBS += libfdt/libfdt.a LIBS += api/libapi.a diff --git a/doc/README.at91 b/doc/README.at91 index 4e3928a..c883c7c 100644 --- a/doc/README.at91 +++ b/doc/README.at91 @@ -2,6 +2,7 @@ Atmel AT91 Evaluation kits
http://atmel.com/dyn/products/tools.asp?family_id=605#1443
+I. Board mapping & boot media
AT91SAM9260EK & AT91SAM9XEEK
@@ -86,3 +87,11 @@ Environment variables make at91sam9263ek_config - use data flash (spi cs0) (default) make at91sam9263ek_nandflash_config - use nand flash make at91sam9263ek_dataflash_cs0_config - use data flash (spi cs0)
+II. Watchdog support
The watchdog wan only be activate once so you need to activate in thebootloader and in the bootstrap if you use itThe you can activate withCONFIG_AT91SAM9_WATCHDOG and CONFIG_HW_WATCHDOGdiff --git a/drivers/serial/atmel_usart.c b/drivers/serial/atmel_usart.c index f3b146c..f50552a 100644 --- a/drivers/serial/atmel_usart.c +++ b/drivers/serial/atmel_usart.c @@ -16,6 +16,7 @@
- Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
USA */ #include <common.h> +#include <watchdog.h>
#include <asm/io.h> #include <asm/arch/clk.h> @@ -87,7 +88,8 @@ void serial_puts(const char *s)
int serial_getc(void) {
while (!(usart3_readl(CSR) & USART3_BIT(RXRDY))) ;
while (!(usart3_readl(CSR) & USART3_BIT(RXRDY)))WATCHDOG_RESET();return usart3_readl(RHR); }
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile new file mode 100644 index 0000000..200968d --- /dev/null +++ b/drivers/watchdog/Makefile @@ -0,0 +1,46 @@ +# +# (C) Copyright 2008 +# Wolfgang Denk, DENX Software Engineering, wd@denx.de. +# +# See file CREDITS for list of people who contributed to this +# project. +# +# This program is free software; you can redistribute it and/or +# modify it under the terms of the GNU General Public License as +# published by the Free Software Foundation; either version 2 of +# the License, or (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 59 Temple Place, Suite 330, Boston, +# MA 02111-1307 USA +#
+include $(TOPDIR)/config.mk
+LIB := $(obj)libwatchdog.a
+COBJS-$(CONFIG_AT91SAM9_WATCHDOG) += at91sam9_wdt.o
+COBJS := $(COBJS-y) +SRCS := $(COBJS:.o=.c) +OBJS := $(addprefix $(obj),$(COBJS))
+all: $(LIB)
+$(LIB): $(obj).depend $(OBJS)
$(AR) $(ARFLAGS) $@ $(OBJS)+#########################################################################
+# defines $(obj).depend target +include $(SRCTREE)/rules.mk
+sinclude $(obj).depend
+######################################################################### diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c new file mode 100644 index 0000000..5bb8b77 --- /dev/null +++ b/drivers/watchdog/at91sam9_wdt.c @@ -0,0 +1,79 @@ +/*
- [origin: Linux kernel drivers/watchdog/at91sam9_wdt.c]
- Watchdog driver for Atmel AT91SAM9x processors.
- Copyright (C) 2008 Jean-Christophe PLAGNIOL-VILLARD
plagnioj@jcrosoft.com + * Copyright (C) 2008 Renaud CERRATO r.cerrato@til-technologies.fr + *
- This program is free software; you can redistribute it and/or
- modify it under the terms of the GNU General Public License
- as published by the Free Software Foundation; either version
- 2 of the License, or (at your option) any later version.
- */
+/*
- The Watchdog Timer Mode Register can be only written to once. If the
- timeout need to be set from U-Boot, be sure that the bootstrap doesn't
- write to this register. Inform Linux to it too
- */
+#include <common.h> +#include <watchdog.h> +#include <asm/arch/hardware.h> +#include <asm/arch/io.h> +#include <asm/arch/at91_wdt.h>
+/*
- AT91SAM9 watchdog runs a 12bit counter @ 256Hz,
- use this to convert a watchdog
- value from/to milliseconds.
- */
+#define ms_to_ticks(t) (((t << 8) / 1000) - 1) +#define ticks_to_ms(t) (((t + 1) * 1000) >> 8)
+/* Hardware timeout in seconds */ +#define WDT_HW_TIMEOUT 2
+/*
- Set the watchdog time interval in 1/256Hz (write-once)
- Counter is 12 bit.
- */
+static int at91_wdt_settimeout(unsigned int timeout) +{
unsigned int reg;unsigned int mr;/* Check if disabled */mr = at91_sys_read(AT91_WDT_MR);if (mr & AT91_WDT_WDDIS) {printf("sorry, watchdog is disabled\n");return -1;}/** All counting occurs at SLOW_CLOCK / 128 = 256 Hz** Since WDV is a 12-bit counter, the maximum period is* 4096 / 256 = 16 seconds.*/reg = AT91_WDT_WDRSTEN /* causes watchdog reset *//* | AT91_WDT_WDRPROC causes processor reset only */| AT91_WDT_WDDBGHLT /* disabled in debug mode */| AT91_WDT_WDD /* restart at any time */| (timeout & AT91_WDT_WDV); /* timer value */at91_sys_write(AT91_WDT_MR, reg);return 0;+}
+void hw_watchdog_reset(void) +{
at91_sys_write(AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);+}
+void hw_watchdog_init(void) +{
/* 16 seconds timer, resets enabled */at91_wdt_settimeout(ms_to_ticks(WDT_HW_TIMEOUT * 1000));+} diff --git a/include/asm-arm/arch-at91/at91_wdt.h b/include/asm-arm/arch-at91/at91_wdt.h new file mode 100644 index 0000000..7e18537 --- /dev/null +++ b/include/asm-arm/arch-at91/at91_wdt.h @@ -0,0 +1,38 @@ +/*
- [origin: Linux kernel arch/arm/mach-at91/include/mach/at91_wdt.h]
- Copyright (C) 2008 Jean-Christophe PLAGNIOL-VILLARD
plagnioj@jcrosoft.com + * Copyright (C) 2007 Andrew Victor
- Copyright (C) 2007 Atmel Corporation.
- Watchdog Timer (WDT) - System peripherals regsters.
- Based on AT91SAM9261 datasheet revision D.
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
- */
+#ifndef AT91_WDT_H +#define AT91_WDT_H
+#define AT91_WDT_CR (AT91_WDT + 0x00) /* Watchdog Control Register */ +#define AT91_WDT_WDRSTT (1 << 0) /* Restart */ +#define AT91_WDT_KEY (0xa5 << 24) /* KEY Password */
+#define AT91_WDT_MR (AT91_WDT + 0x04) /* Watchdog Mode Register */ +#define AT91_WDT_WDV (0xfff << 0) /* Counter Value */ +#define AT91_WDT_WDFIEN (1 << 12) /* Fault Interrupt Enable */ +#define AT91_WDT_WDRSTEN (1 << 13) /* Reset Processor */ +#define AT91_WDT_WDRPROC (1 << 14) /* Timer Restart */ +#define AT91_WDT_WDDIS (1 << 15) /* Watchdog Disable */ +#define AT91_WDT_WDD (0xfff << 16) /* Delta Value */ +#define AT91_WDT_WDDBGHLT (1 << 28) /* Debug Halt */ +#define AT91_WDT_WDIDLEHLT (1 << 29) /* Idle Halt */
+#define AT91_WDT_SR (AT91_WDT + 0x08) /* Watchdog Status Register */ +#define AT91_WDT_WDUNF (1 << 0) /* Watchdog Underflow */ +#define AT91_WDT_WDERR (1 << 1) /* Watchdog Error */
+#endif
In this way the linux driver won't work(the one by Renaud CERRATO). Because it expects MR register not to be set, or to be set enabled.
After I don't agree refreshing watchdog inside atmel_usart.c If u-boot hangs there instead of execute bootcmd, then the machine lies there forever. In my opinion we should put WATCHDOG_RESET() inside main_loop and nand write and read. What do you think?
Kind regards
participants (4)
-
Alessandro Rubini -
Giulio Benetti -
Jean-Christophe PLAGNIOL-VILLARD -
Wolfgang Denk