diff options
| -rw-r--r-- | arch/arm/include/asm/arch-am33xx/cpu.h | 20 | ||||
| -rw-r--r-- | drivers/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/watchdog/omap_wdt.c | 121 |
3 files changed, 142 insertions, 0 deletions
diff --git a/arch/arm/include/asm/arch-am33xx/cpu.h b/arch/arm/include/asm/arch-am33xx/cpu.h index 1835c8939b..73e6db8998 100644 --- a/arch/arm/include/asm/arch-am33xx/cpu.h +++ b/arch/arm/include/asm/arch-am33xx/cpu.h @@ -46,6 +46,26 @@ #define PRM_RSTCTRL_RESET 0x01 #define PRM_RSTST_WARM_RESET_MASK 0x232 +/* + * Watchdog: + * Using the prescaler, the OMAP watchdog could go for many + * months before firing. These limits work without scaling, + * with the 60 second default assumed by most tools and docs. + */ +#define TIMER_MARGIN_MAX (24 * 60 * 60) /* 1 day */ +#define TIMER_MARGIN_DEFAULT 60 /* 60 secs */ +#define TIMER_MARGIN_MIN 1 + +#define PTV 0 /* prescale */ +#define GET_WLDR_VAL(secs) (0xffffffff - ((secs) * (32768/(1<<PTV))) + 1) +#define WDT_WWPS_PEND_WCLR BIT(0) +#define WDT_WWPS_PEND_WLDR BIT(2) +#define WDT_WWPS_PEND_WTGR BIT(3) +#define WDT_WWPS_PEND_WSPR BIT(4) + +#define WDT_WCLR_PRE BIT(5) +#define WDT_WCLR_PTV_OFF 2 + #ifndef __KERNEL_STRICT_NAMES #ifndef __ASSEMBLY__ struct gpmc_cs { diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 7e255ce8ae..3ade624702 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -18,6 +18,7 @@ COBJS-$(CONFIG_TNETV107X_WATCHDOG) += tnetv107x_wdt.o COBJS-$(CONFIG_S5P) += s5p_wdt.o COBJS-$(CONFIG_XILINX_TB_WATCHDOG) += xilinx_tb_wdt.o COBJS-$(CONFIG_BFIN_WATCHDOG) += bfin_wdt.o +COBJS-$(CONFIG_OMAP_WATCHDOG) += omap_wdt.o COBJS := $(COBJS-y) SRCS := $(COBJS:.o=.c) diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c new file mode 100644 index 0000000000..7ea4b604cd --- /dev/null +++ b/drivers/watchdog/omap_wdt.c @@ -0,0 +1,121 @@ +/* + * omap_wdt.c + * + * (C) Copyright 2013 + * Heiko Schocher, DENX Software Engineering, hs@denx.de. + * + * SPDX-License-Identifier: GPL-2.0 + * + * Based on: + * + * Watchdog driver for the TI OMAP 16xx & 24xx/34xx 32KHz (non-secure) watchdog + * + * commit 2d991a164a61858012651e13c59521975504e260 + * Author: Bill Pemberton <wfp5p@virginia.edu> + * Date: Mon Nov 19 13:21:41 2012 -0500 + * + * watchdog: remove use of __devinit + * + * CONFIG_HOTPLUG is going away as an option so __devinit is no longer + * needed. + * + * Author: MontaVista Software, Inc. + * <gdavis@mvista.com> or <source@mvista.com> + * + * History: + * + * 20030527: George G. Davis <gdavis@mvista.com> + * Initially based on linux-2.4.19-rmk7-pxa1/drivers/char/sa1100_wdt.c + * (c) Copyright 2000 Oleg Drokin <green@crimea.edu> + * Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk> + * + * Copyright (c) 2004 Texas Instruments. + * 1. Modified to support OMAP1610 32-KHz watchdog timer + * 2. Ported to 2.6 kernel + * + * Copyright (c) 2005 David Brownell + * Use the driver model and standard identifiers; handle bigger timeouts. + */ + +#include <common.h> +#include <watchdog.h> +#include <asm/arch/hardware.h> +#include <asm/io.h> +#include <asm/processor.h> +#include <asm/arch/cpu.h> + +/* Hardware timeout in seconds */ +#define WDT_HW_TIMEOUT 60 + +static unsigned int wdt_trgr_pattern = 0x1234; + +void hw_watchdog_reset(void) +{ + struct wd_timer *wdt = (struct wd_timer *)WDT_BASE; + + /* wait for posted write to complete */ + while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WTGR) + ; + + wdt_trgr_pattern = ~wdt_trgr_pattern; + writel(wdt_trgr_pattern, &wdt->wdtwtgr); + + /* wait for posted write to complete */ + while ((readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WTGR)) + ; +} + +static int omap_wdt_set_timeout(unsigned int timeout) +{ + struct wd_timer *wdt = (struct wd_timer *)WDT_BASE; + u32 pre_margin = GET_WLDR_VAL(timeout); + + /* just count up at 32 KHz */ + while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WLDR) + ; + + writel(pre_margin, &wdt->wdtwldr); + while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WLDR) + ; + + return 0; +} + +void hw_watchdog_init(void) +{ + struct wd_timer *wdt = (struct wd_timer *)WDT_BASE; + + /* initialize prescaler */ + while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WCLR) + ; + + writel(WDT_WCLR_PRE | (PTV << WDT_WCLR_PTV_OFF), &wdt->wdtwclr); + while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WCLR) + ; + + omap_wdt_set_timeout(WDT_HW_TIMEOUT); + + /* Sequence to enable the watchdog */ + writel(0xBBBB, &wdt->wdtwspr); + while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WSPR) + ; + + writel(0x4444, &wdt->wdtwspr); + while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WSPR) + ; +} + +void hw_watchdog_disable(void) +{ + struct wd_timer *wdt = (struct wd_timer *)WDT_BASE; + + /* + * Disable watchdog + */ + writel(0xAAAA, &wdt->wdtwspr); + while (readl(&wdt->wdtwwps) != 0x0) + ; + writel(0x5555, &wdt->wdtwspr); + while (readl(&wdt->wdtwwps) != 0x0) + ; +} |