This patch adds a watchdog reset driver that can be used on Samsung SoCs that do not provide dedicated reset method. It replaces the legacy helper function that relies on static IO mapping.
Signed-off-by: Tomasz Figa <[email protected]> --- arch/arm/plat-samsung/Kconfig | 6 ++ arch/arm/plat-samsung/Makefile | 1 + .../arm/plat-samsung/include/plat/watchdog-reset.h | 9 ++ arch/arm/plat-samsung/watchdog-reset.c | 97 ++++++++++++++++++++++ 4 files changed, 113 insertions(+) create mode 100644 arch/arm/plat-samsung/watchdog-reset.c diff --git a/arch/arm/plat-samsung/Kconfig b/arch/arm/plat-samsung/Kconfig index f8ed2de..ec68155 100644 --- a/arch/arm/plat-samsung/Kconfig +++ b/arch/arm/plat-samsung/Kconfig @@ -475,6 +475,12 @@ config SAMSUNG_WAKEMASK and above. This code allows a set of interrupt to wakeup-mask mappings. See <plat/wakeup-mask.h> +config SAMSUNG_WDT_RESET + bool + help + Compile support for system restart by triggering watchdog reset. + Used on SoCs that do not provide dedicated reset control. + config S5P_PM bool help diff --git a/arch/arm/plat-samsung/Makefile b/arch/arm/plat-samsung/Makefile index a23c460..03cea14 100644 --- a/arch/arm/plat-samsung/Makefile +++ b/arch/arm/plat-samsung/Makefile @@ -56,6 +56,7 @@ obj-$(CONFIG_PM) += pm-gpio.o obj-$(CONFIG_SAMSUNG_PM_CHECK) += pm-check.o obj-$(CONFIG_SAMSUNG_WAKEMASK) += wakeup-mask.o +obj-$(CONFIG_SAMSUNG_WDT_RESET) += watchdog-reset.o obj-$(CONFIG_S5P_PM) += s5p-pm.o s5p-irq-pm.o obj-$(CONFIG_S5P_SLEEP) += s5p-sleep.o diff --git a/arch/arm/plat-samsung/include/plat/watchdog-reset.h b/arch/arm/plat-samsung/include/plat/watchdog-reset.h index bc4db9b..4def1b2 100644 --- a/arch/arm/plat-samsung/include/plat/watchdog-reset.h +++ b/arch/arm/plat-samsung/include/plat/watchdog-reset.h @@ -10,6 +10,9 @@ * published by the Free Software Foundation. */ +#ifndef __PLAT_WATCHDOG_RESET_H +#define __PLAT_WATCHDOG_RESET_H + #include <plat/clock.h> #include <plat/regs-watchdog.h> #include <mach/map.h> @@ -44,3 +47,9 @@ static inline void arch_wdt_reset(void) /* delay to allow the serial port to show the message */ mdelay(50); } + +extern void samsung_wdt_reset(void); +extern void samsung_wdt_reset_of_init(void); +extern void samsung_wdt_reset_init(void __iomem *base); + +#endif /* __PLAT_WATCHDOG_RESET_H */ diff --git a/arch/arm/plat-samsung/watchdog-reset.c b/arch/arm/plat-samsung/watchdog-reset.c new file mode 100644 index 0000000..2ecb50be --- /dev/null +++ b/arch/arm/plat-samsung/watchdog-reset.c @@ -0,0 +1,97 @@ +/* arch/arm/plat-samsung/watchdog-reset.c + * + * Copyright (c) 2008 Simtec Electronics + * Ben Dooks <[email protected]> + * + * Coyright (c) 2013 Tomasz Figa <[email protected]> + * + * Watchdog reset support for Samsung SoCs. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. +*/ + +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/delay.h> +#include <linux/of.h> +#include <linux/of_address.h> + +#define S3C2410_WTCON 0x00 +#define S3C2410_WTDAT 0x04 +#define S3C2410_WTCNT 0x08 + +#define S3C2410_WTCON_ENABLE (1 << 5) +#define S3C2410_WTCON_DIV16 (0 << 3) +#define S3C2410_WTCON_RSTEN (1 << 0) +#define S3C2410_WTCON_PRESCALE(x) ((x) << 8) + +static void __iomem *wdt_base; +static struct clk *wdt_clock; + +void samsung_wdt_reset(void) +{ + if (!wdt_base) { + pr_err("%s: wdt reset not initialized\n", __func__); + /* delay to allow the serial port to show the message */ + mdelay(50); + return; + } + + if (!IS_ERR(wdt_clock)) + clk_prepare_enable(wdt_clock); + + /* disable watchdog, to be safe */ + __raw_writel(0, wdt_base + S3C2410_WTCON); + + /* put initial values into count and data */ + __raw_writel(0x80, wdt_base + S3C2410_WTCNT); + __raw_writel(0x80, wdt_base + S3C2410_WTDAT); + + /* set the watchdog to go and reset... */ + __raw_writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV16 | + S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x20), + wdt_base + S3C2410_WTCON); + + /* wait for reset to assert... */ + mdelay(500); + + pr_err("Watchdog reset failed to assert reset\n"); + + /* delay to allow the serial port to show the message */ + mdelay(50); +} + +#ifdef CONFIG_OF +static const struct of_device_id s3c2410_wdt_match[] = { + { .compatible = "samsung,s3c2410-wdt" }, + {}, +}; + +void __init samsung_wdt_reset_of_init(void) +{ + struct device_node *np; + + np = of_find_matching_node(NULL, s3c2410_wdt_match); + if (!np) { + pr_err("%s: failed to find watchdog node\n", __func__); + return; + } + + wdt_base = of_iomap(np, 0); + if (!wdt_base) { + pr_err("%s: failed to map watchdog registers\n", __func__); + return; + } + + wdt_clock = of_clk_get(np, 0); +} +#endif + +void __init samsung_wdt_reset_init(void __iomem *base) +{ + wdt_base = base; + wdt_clock = clk_get(NULL, "watchdog"); +} -- 1.8.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
