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/* * Allwinner A31 SoCs reset code * * Copyright (C) 2012-2014 Maxime Ripard * * Maxime Ripard <maxime.ripard@free-electrons.com> * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #include <linux/delay.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of_address.h> #include <linux/platform_device.h> #include <linux/reboot.h> #include <asm/system_misc.h> #define SUN6I_WATCHDOG1_IRQ_REG 0x00 #define SUN6I_WATCHDOG1_CTRL_REG 0x10 #define SUN6I_WATCHDOG1_CTRL_RESTART BIT(0) #define SUN6I_WATCHDOG1_CONFIG_REG 0x14 #define SUN6I_WATCHDOG1_CONFIG_RESTART BIT(0) #define SUN6I_WATCHDOG1_CONFIG_IRQ BIT(1) #define SUN6I_WATCHDOG1_MODE_REG 0x18 #define SUN6I_WATCHDOG1_MODE_ENABLE BIT(0) static void __iomem *wdt_base; static void sun6i_wdt_restart(enum reboot_mode mode, const char *cmd) { if (!wdt_base) return; /* Disable interrupts */ writel(0, wdt_base + SUN6I_WATCHDOG1_IRQ_REG); /* We want to disable the IRQ and just reset the whole system */ writel(SUN6I_WATCHDOG1_CONFIG_RESTART, wdt_base + SUN6I_WATCHDOG1_CONFIG_REG); /* Enable timer. The default and lowest interval value is 0.5s */ writel(SUN6I_WATCHDOG1_MODE_ENABLE, wdt_base + SUN6I_WATCHDOG1_MODE_REG); /* Restart the watchdog. */ writel(SUN6I_WATCHDOG1_CTRL_RESTART, wdt_base + SUN6I_WATCHDOG1_CTRL_REG); while (1) { mdelay(5); writel(SUN6I_WATCHDOG1_MODE_ENABLE, wdt_base + SUN6I_WATCHDOG1_MODE_REG); } } static int sun6i_reboot_probe(struct platform_device *pdev) { wdt_base = of_iomap(pdev->dev.of_node, 0); if (!wdt_base) { WARN(1, "failed to map watchdog base address"); return -ENODEV; } arm_pm_restart = sun6i_wdt_restart; return 0; } static struct of_device_id sun6i_reboot_of_match[] = { { .compatible = "allwinner,sun6i-a31-wdt" }, {} }; static struct platform_driver sun6i_reboot_driver = { .probe = sun6i_reboot_probe, .driver = { .name = "sun6i-reboot", .of_match_table = sun6i_reboot_of_match, }, }; module_platform_driver(sun6i_reboot_driver); |