From: Domenico Andreoli Restart hook implementation for the Broadcom BCM4760 based ARM11 SoCs. v4: * moved the watchdog based implementation to drivers/watchdog v2,v3: * unchanged v1: * initial release Cc: devicetree@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Domenico Andreoli --- Documentation/devicetree/bindings/watchdog/brcm,bcm4760-pm-wdt.txt | 14 + arch/arm/boot/dts/bcm4760.dtsi | 5 + arch/arm/mach-bcm/Kconfig | 2 + drivers/watchdog/Kconfig | 11 + drivers/watchdog/Makefile | 1 + drivers/watchdog/bcm4760_wdt.c | 109 ++++++++++ 6 files changed, 142 insertions(+) Index: b/Documentation/devicetree/bindings/watchdog/brcm,bcm4760-pm-wdt.txt =================================================================== --- /dev/null +++ b/Documentation/devicetree/bindings/watchdog/brcm,bcm4760-pm-wdt.txt @@ -0,0 +1,14 @@ +Broadcom BCM4760 watchdog timer device tree bindings +---------------------------------------------------- + +Required properties: + +- compatible : should be "brcm,bcm4760-pm-wdt" +- reg : Specifies base physical address and size of the registers. + +Example: + +watchdog { + compatible = "brcm,bcm4760-pm-wdt"; + reg = <0xbd000 0x1000>; +}; Index: b/arch/arm/boot/dts/bcm4760.dtsi =================================================================== --- a/arch/arm/boot/dts/bcm4760.dtsi +++ b/arch/arm/boot/dts/bcm4760.dtsi @@ -39,6 +39,11 @@ reg = <0xbc000 0x1000>; }; + watchdog { + compatible = "brcm,bcm4760-pm-wdt"; + reg = <0xbd000 0x1000>; + }; + vic0: interrupt-controller@80000 { compatible = "brcm,bcm4760-pl192", "arm,pl192-vic", "arm,primecell"; reg = <0x80000 0x1000>; Index: b/drivers/watchdog/Makefile =================================================================== --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -32,6 +32,7 @@ obj-$(CONFIG_USBPCWATCHDOG) += pcwd_usb. obj-$(CONFIG_ARM_SP805_WATCHDOG) += sp805_wdt.o obj-$(CONFIG_AT91RM9200_WATCHDOG) += at91rm9200_wdt.o obj-$(CONFIG_AT91SAM9X_WATCHDOG) += at91sam9_wdt.o +obj-$(CONFIG_BCM4760_WDT) += bcm4760_wdt.o obj-$(CONFIG_OMAP_WATCHDOG) += omap_wdt.o obj-$(CONFIG_TWL4030_WATCHDOG) += twl4030_wdt.o obj-$(CONFIG_21285_WATCHDOG) += wdt285.o Index: b/drivers/watchdog/bcm4760_wdt.c =================================================================== --- /dev/null +++ b/drivers/watchdog/bcm4760_wdt.c @@ -0,0 +1,109 @@ +/* + * Broadcom BCM4760 based ARM11 SoCs watchdog support + * + * Copyright (C) 2013 Domenico Andreoli + * + * 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. + */ + +#include +#include +#include + +#include +#include + +#define BCM4760_WDT_LOAD 0x000 +#define BCM4760_WDT_CTRL 0x008 +#define BCM4760_WDT_INTCLR 0x00c +#define BCM4760_WDT_LOCK 0xc00 + +#define BCM4760_WDT_PASSWORD 0x1acce551 +#define BCM4760_WDT_INTEN BIT(0) +#define BCM4760_WDT_RESEN BIT(1) + +/* + * The machine restart method can be called from an atomic context so we won't + * be able to ioremap the regs then. + */ +static void __iomem *wdt_regs; + +static void *arm_pm_restart_saved; + +static void bcm4760_restart(enum reboot_mode mode, const char *cmd) +{ + /* unlock watchdog registers */ + writel(BCM4760_WDT_PASSWORD, wdt_regs + BCM4760_WDT_LOCK); + + /* disable watchdog */ + writel(0, wdt_regs + BCM4760_WDT_CTRL); + udelay(20); + + /* clear the irq status */ + writel(1, wdt_regs + BCM4760_WDT_INTCLR); + udelay(20); + + /* expire after 5 cycles (~156us) */ + writel(5, wdt_regs + BCM4760_WDT_LOAD); + /* enable watchdog */ + writel(BCM4760_WDT_INTEN | BCM4760_WDT_RESEN, + wdt_regs + BCM4760_WDT_CTRL); + + /* lock watchdog registers */ + writel(1, wdt_regs + BCM4760_WDT_LOCK); + /* wait the bite */ + udelay(400); +} + +static const struct of_device_id bcm4760_pm_wdt_match[] __initconst = { + { .compatible = "brcm,bcm4760-pm-wdt" }, + {}, +}; + +static int __init bcm4760_wdt_init(void) +{ + struct device_node *node; + + node = of_find_matching_node(NULL, bcm4760_pm_wdt_match); + if (!node) { + pr_info("No bcm4760 watchdog node\n"); + return -1; + } + + wdt_regs = of_iomap(node, 0); + of_node_put(node); + + if (!wdt_regs) { + pr_err("Can't remap watchdog registers\n"); + return -1; + } + + /* unlock watchdog registers */ + writel(BCM4760_WDT_PASSWORD, wdt_regs + BCM4760_WDT_LOCK); + /* disable watchdog */ + writel(0, wdt_regs + BCM4760_WDT_CTRL); + /* lock watchdog registers */ + writel(1, wdt_regs + BCM4760_WDT_LOCK); + + arm_pm_restart_saved = arm_pm_restart; + arm_pm_restart = bcm4760_restart; + return 0; +} + +static int __exit bcm4760_wdt_exit(void) +{ + arm_pm_restart = arm_pm_restart_saved; + iounmap(wdt_regs); + return 0; +} + +module_init(bcm4760_wdt_init); +module_exit(bcm4760_wdt_exit); Index: b/arch/arm/mach-bcm/Kconfig =================================================================== --- a/arch/arm/mach-bcm/Kconfig +++ b/arch/arm/mach-bcm/Kconfig @@ -23,6 +23,8 @@ config ARCH_BCM4760 bool "Broadcom BCM4760 based SoCs (ARM11)" if ARCH_MULTI_V6 select ARM_AMBA select ARM_VIC + select BCM4760_WDT select CLKSRC_OF select GENERIC_CLOCKEVENTS select SOC_BUS + select WATCHDOG Index: b/drivers/watchdog/Kconfig =================================================================== --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -130,6 +130,17 @@ config AT91SAM9X_WATCHDOG Watchdog timer embedded into AT91SAM9X and AT91CAP9 chips. This will reboot your system when the timeout is reached. +config BCM4760_WDT + tristate "Broadcom BCM4760 hardware watchdog" + depends on ARCH_BCM4760 + select WATCHDOG_CORE + help + Watchdog driver for the built in watchdog hardware in Broadcom + BCM4760 SoC, currently used only as restart-hook implementation. + + To compile this driver as a loadable module, choose M here. + The module will be called bcm4760_wdt. + config 21285_WATCHDOG tristate "DC21285 watchdog" depends on FOOTBRIDGE