// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright 2010-2011 Picochip Ltd., Jamie Iles * https://www.picochip.com * * This file implements a driver for the Synopsys DesignWare watchdog device * in the many subsystems. The watchdog has 16 different timeout periods * and these are a function of the input clock frequency. * * The DesignWare watchdog cannot be stopped once it has been started so we * do not implement a stop function. The watchdog core will continue to send * heartbeat requests after the watchdog device has been closed. */ #include <linux/bitops.h> #include <linux/clk.h> #include <linux/debugfs.h> #include <linux/delay.h> #include <linux/err.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/limits.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/pm.h> #include <linux/reset.h> #include <linux/watchdog.h> #define WDOG_CONTROL_REG_OFFSET … #define WDOG_CONTROL_REG_WDT_EN_MASK … #define WDOG_CONTROL_REG_RESP_MODE_MASK … #define WDOG_TIMEOUT_RANGE_REG_OFFSET … #define WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT … #define WDOG_CURRENT_COUNT_REG_OFFSET … #define WDOG_COUNTER_RESTART_REG_OFFSET … #define WDOG_COUNTER_RESTART_KICK_VALUE … #define WDOG_INTERRUPT_STATUS_REG_OFFSET … #define WDOG_INTERRUPT_CLEAR_REG_OFFSET … #define WDOG_COMP_PARAMS_5_REG_OFFSET … #define WDOG_COMP_PARAMS_4_REG_OFFSET … #define WDOG_COMP_PARAMS_3_REG_OFFSET … #define WDOG_COMP_PARAMS_2_REG_OFFSET … #define WDOG_COMP_PARAMS_1_REG_OFFSET … #define WDOG_COMP_PARAMS_1_USE_FIX_TOP … #define WDOG_COMP_VERSION_REG_OFFSET … #define WDOG_COMP_TYPE_REG_OFFSET … /* There are sixteen TOPs (timeout periods) that can be set in the watchdog. */ #define DW_WDT_NUM_TOPS … #define DW_WDT_FIX_TOP(_idx) … #define DW_WDT_DEFAULT_SECONDS … static const u32 dw_wdt_fix_tops[DW_WDT_NUM_TOPS] = …; static bool nowayout = … WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(…) …; enum dw_wdt_rmod { … }; struct dw_wdt_timeout { … }; struct dw_wdt { … }; #define to_dw_wdt(wdd) … static inline int dw_wdt_is_enabled(struct dw_wdt *dw_wdt) { … } static void dw_wdt_update_mode(struct dw_wdt *dw_wdt, enum dw_wdt_rmod rmod) { … } static unsigned int dw_wdt_find_best_top(struct dw_wdt *dw_wdt, unsigned int timeout, u32 *top_val) { … } static unsigned int dw_wdt_get_min_timeout(struct dw_wdt *dw_wdt) { … } static unsigned int dw_wdt_get_max_timeout_ms(struct dw_wdt *dw_wdt) { … } static unsigned int dw_wdt_get_timeout(struct dw_wdt *dw_wdt) { … } static int dw_wdt_ping(struct watchdog_device *wdd) { … } static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s) { … } static int dw_wdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req) { … } static void dw_wdt_arm_system_reset(struct dw_wdt *dw_wdt) { … } static int dw_wdt_start(struct watchdog_device *wdd) { … } static int dw_wdt_stop(struct watchdog_device *wdd) { … } static int dw_wdt_restart(struct watchdog_device *wdd, unsigned long action, void *data) { … } static unsigned int dw_wdt_get_timeleft(struct watchdog_device *wdd) { … } static const struct watchdog_info dw_wdt_ident = …; static const struct watchdog_info dw_wdt_pt_ident = …; static const struct watchdog_ops dw_wdt_ops = …; static irqreturn_t dw_wdt_irq(int irq, void *devid) { … } static int dw_wdt_suspend(struct device *dev) { … } static int dw_wdt_resume(struct device *dev) { … } static DEFINE_SIMPLE_DEV_PM_OPS(dw_wdt_pm_ops, dw_wdt_suspend, dw_wdt_resume); /* * In case if DW WDT IP core is synthesized with fixed TOP feature disabled the * TOPs array can be arbitrary ordered with nearly any sixteen uint numbers * depending on the system engineer imagination. The next method handles the * passed TOPs array to pre-calculate the effective timeouts and to sort the * TOP items out in the ascending order with respect to the timeouts. */ static void dw_wdt_handle_tops(struct dw_wdt *dw_wdt, const u32 *tops) { … } static int dw_wdt_init_timeouts(struct dw_wdt *dw_wdt, struct device *dev) { … } #ifdef CONFIG_DEBUG_FS #define DW_WDT_DBGFS_REG(_name, _off) … static const struct debugfs_reg32 dw_wdt_dbgfs_regs[] = …; static void dw_wdt_dbgfs_init(struct dw_wdt *dw_wdt) { … } static void dw_wdt_dbgfs_clear(struct dw_wdt *dw_wdt) { … } #else /* !CONFIG_DEBUG_FS */ static void dw_wdt_dbgfs_init(struct dw_wdt *dw_wdt) {} static void dw_wdt_dbgfs_clear(struct dw_wdt *dw_wdt) {} #endif /* !CONFIG_DEBUG_FS */ static int dw_wdt_drv_probe(struct platform_device *pdev) { … } static void dw_wdt_drv_remove(struct platform_device *pdev) { … } #ifdef CONFIG_OF static const struct of_device_id dw_wdt_of_match[] = …; MODULE_DEVICE_TABLE(of, dw_wdt_of_match); #endif static struct platform_driver dw_wdt_driver = …; module_platform_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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