// SPDX-License-Identifier: GPL-2.0-only OR MIT /* * Apple SoC Watchdog driver * * Copyright (C) The Asahi Linux Contributors */ #include <linux/bits.h> #include <linux/clk.h> #include <linux/delay.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/limits.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/watchdog.h> /* * Apple Watchdog MMIO registers * * This HW block has three separate watchdogs. WD0 resets the machine * to recovery mode and is not very useful for us. WD1 and WD2 trigger a normal * machine reset. WD0 additionally supports a configurable interrupt. * This information can be used to implement pretimeout support at a later time. * * APPLE_WDT_WDx_CUR_TIME is a simple counter incremented for each tick of the * reference clock. It can also be overwritten to any value. * Whenever APPLE_WDT_CTRL_RESET_EN is set in APPLE_WDT_WDx_CTRL and * APPLE_WDT_WDx_CUR_TIME >= APPLE_WDT_WDx_BITE_TIME the entire machine is * reset. * Whenever APPLE_WDT_CTRL_IRQ_EN is set and APPLE_WDTx_WD1_CUR_TIME >= * APPLE_WDTx_WD1_BARK_TIME an interrupt is triggered and * APPLE_WDT_CTRL_IRQ_STATUS is set. The interrupt can be cleared by writing * 1 to APPLE_WDT_CTRL_IRQ_STATUS. */ #define APPLE_WDT_WD0_CUR_TIME … #define APPLE_WDT_WD0_BITE_TIME … #define APPLE_WDT_WD0_BARK_TIME … #define APPLE_WDT_WD0_CTRL … #define APPLE_WDT_WD1_CUR_TIME … #define APPLE_WDT_WD1_BITE_TIME … #define APPLE_WDT_WD1_CTRL … #define APPLE_WDT_WD2_CUR_TIME … #define APPLE_WDT_WD2_BITE_TIME … #define APPLE_WDT_WD2_CTRL … #define APPLE_WDT_CTRL_IRQ_EN … #define APPLE_WDT_CTRL_IRQ_STATUS … #define APPLE_WDT_CTRL_RESET_EN … #define APPLE_WDT_TIMEOUT_DEFAULT … struct apple_wdt { … }; static struct apple_wdt *to_apple_wdt(struct watchdog_device *wdd) { … } static int apple_wdt_start(struct watchdog_device *wdd) { … } static int apple_wdt_stop(struct watchdog_device *wdd) { … } static int apple_wdt_ping(struct watchdog_device *wdd) { … } static int apple_wdt_set_timeout(struct watchdog_device *wdd, unsigned int s) { … } static unsigned int apple_wdt_get_timeleft(struct watchdog_device *wdd) { … } static int apple_wdt_restart(struct watchdog_device *wdd, unsigned long mode, void *cmd) { … } static struct watchdog_ops apple_wdt_ops = …; static struct watchdog_info apple_wdt_info = …; static int apple_wdt_probe(struct platform_device *pdev) { … } static int apple_wdt_resume(struct device *dev) { … } static int apple_wdt_suspend(struct device *dev) { … } static DEFINE_SIMPLE_DEV_PM_OPS(apple_wdt_pm_ops, apple_wdt_suspend, apple_wdt_resume); static const struct of_device_id apple_wdt_of_match[] = …; MODULE_DEVICE_TABLE(of, apple_wdt_of_match); static struct platform_driver apple_wdt_driver = …; module_platform_driver(…) …; MODULE_DESCRIPTION(…) …; MODULE_AUTHOR(…) …; MODULE_LICENSE(…) …;
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