diff options
| -rw-r--r-- | Makefile | 1 | ||||
| -rw-r--r-- | doc/README.at91 | 11 | ||||
| -rw-r--r-- | drivers/serial/atmel_usart.c | 4 | ||||
| -rw-r--r-- | drivers/watchdog/Makefile | 46 | ||||
| -rw-r--r-- | drivers/watchdog/at91sam9_wdt.c | 79 | ||||
| -rw-r--r-- | include/asm-arm/arch-at91/at91_wdt.h | 38 |
6 files changed, 178 insertions, 1 deletions
@@ -265,6 +265,7 @@ LIBS += drivers/serial/libserial.a LIBS += drivers/twserial/libtws.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 e460e66..9b4eae6 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, AT91SAM9G20EK & AT91SAM9XEEK ------------------------------------------------------------------------------ @@ -86,3 +87,13 @@ 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 + + For security reasons, the at91 watchdog is running at boot time and, + if deactivated, cannot be used anymore. + If you want to use the watchdog, you will need to keep it running in + your code (make sure not to disable it in AT91Bootstrap for instance). + + In the U-Boot configuration, the AT91 watchdog support is enabled using + the CONFIG_AT91SAM9_WATCHDOG and CONFIG_HW_WATCHDOG options. 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 |