From e835861823130ae47665db5e8039a7097ede14e4 Mon Sep 17 00:00:00 2001 From: Xingyu Wu Date: Tue, 14 Mar 2023 21:24:36 +0800 Subject: [PATCH 105/122] drivers: watchdog: Add StarFive Watchdog driver Add watchdog driver for the StarFive JH7100 and JH7110 SoC. Signed-off-by: Xingyu Wu Reviewed-by: Emil Renner Berthing Reviewed-by: Guenter Roeck --- MAINTAINERS | 7 + drivers/watchdog/Kconfig | 11 + drivers/watchdog/Makefile | 3 + drivers/watchdog/starfive-wdt.c | 606 ++++++++++++++++++++++++++++++++ 4 files changed, 627 insertions(+) create mode 100644 drivers/watchdog/starfive-wdt.c --- a/MAINTAINERS +++ b/MAINTAINERS @@ -19722,6 +19722,13 @@ S: Supported F: Documentation/devicetree/bindings/rng/starfive* F: drivers/char/hw_random/starfive-trng.c +STARFIVE WATCHDOG DRIVER +M: Xingyu Wu +M: Samin Guo +S: Supported +F: Documentation/devicetree/bindings/watchdog/starfive* +F: drivers/watchdog/starfive-wdt.c + STATIC BRANCH/CALL M: Peter Zijlstra M: Josh Poimboeuf --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1991,6 +1991,17 @@ config WATCHDOG_RTAS To compile this driver as a module, choose M here. The module will be called wdrtas. +# RISC-V Architecture + +config STARFIVE_WATCHDOG + tristate "StarFive Watchdog support" + depends on ARCH_STARFIVE || COMPILE_TEST + select WATCHDOG_CORE + default ARCH_STARFIVE + help + Say Y here to support the watchdog of StarFive JH7100 and JH7110 + SoC. This driver can also be built as a module if choose M. + # S390 Architecture config DIAG288_WATCHDOG --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -191,6 +191,9 @@ obj-$(CONFIG_MEN_A21_WDT) += mena21_wdt. obj-$(CONFIG_PSERIES_WDT) += pseries-wdt.o obj-$(CONFIG_WATCHDOG_RTAS) += wdrtas.o +# RISC-V Architecture +obj-$(CONFIG_STARFIVE_WATCHDOG) += starfive-wdt.o + # S390 Architecture obj-$(CONFIG_DIAG288_WATCHDOG) += diag288_wdt.o --- /dev/null +++ b/drivers/watchdog/starfive-wdt.c @@ -0,0 +1,606 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Starfive Watchdog driver + * + * Copyright (C) 2022 StarFive Technology Co., Ltd. + */ + +#include +#include +#include +#include +#include +#include +#include + +/* JH7100 Watchdog register define */ +#define STARFIVE_WDT_JH7100_INTSTAUS 0x000 +#define STARFIVE_WDT_JH7100_CONTROL 0x104 +#define STARFIVE_WDT_JH7100_LOAD 0x108 +#define STARFIVE_WDT_JH7100_EN 0x110 +#define STARFIVE_WDT_JH7100_RELOAD 0x114 /* Write 0 or 1 to reload preset value */ +#define STARFIVE_WDT_JH7100_VALUE 0x118 +#define STARFIVE_WDT_JH7100_INTCLR 0x120 /* + * [0]: Write 1 to clear interrupt + * [1]: 1 mean clearing and 0 mean complete + * [31:2]: reserved. + */ +#define STARFIVE_WDT_JH7100_LOCK 0x13c /* write 0x378f0765 to unlock */ + +/* JH7110 Watchdog register define */ +#define STARFIVE_WDT_JH7110_LOAD 0x000 +#define STARFIVE_WDT_JH7110_VALUE 0x004 +#define STARFIVE_WDT_JH7110_CONTROL 0x008 /* + * [0]: reset enable; + * [1]: interrupt enable && watchdog enable + * [31:2]: reserved. + */ +#define STARFIVE_WDT_JH7110_INTCLR 0x00c /* clear intterupt and reload the counter */ +#define STARFIVE_WDT_JH7110_IMS 0x014 +#define STARFIVE_WDT_JH7110_LOCK 0xc00 /* write 0x1ACCE551 to unlock */ + +/* WDOGCONTROL */ +#define STARFIVE_WDT_ENABLE 0x1 +#define STARFIVE_WDT_EN_SHIFT 0 +#define STARFIVE_WDT_RESET_EN 0x1 +#define STARFIVE_WDT_JH7100_RST_EN_SHIFT 0 +#define STARFIVE_WDT_JH7110_RST_EN_SHIFT 1 + +/* WDOGLOCK */ +#define STARFIVE_WDT_JH7100_UNLOCK_KEY 0x378f0765 +#define STARFIVE_WDT_JH7110_UNLOCK_KEY 0x1acce551 + +/* WDOGINTCLR */ +#define STARFIVE_WDT_INTCLR 0x1 +#define STARFIVE_WDT_JH7100_INTCLR_AVA_SHIFT 1 /* Watchdog can clear interrupt when 0 */ + +#define STARFIVE_WDT_MAXCNT 0xffffffff +#define STARFIVE_WDT_DEFAULT_TIME (15) +#define STARFIVE_WDT_DELAY_US 0 +#define STARFIVE_WDT_TIMEOUT_US 10000 + +/* module parameter */ +#define STARFIVE_WDT_EARLY_ENA 0 + +static bool nowayout = WATCHDOG_NOWAYOUT; +static int heartbeat; +static bool early_enable = STARFIVE_WDT_EARLY_ENA; + +module_param(heartbeat, int, 0); +module_param(early_enable, bool, 0); +module_param(nowayout, bool, 0); + +MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default=" + __MODULE_STRING(STARFIVE_WDT_DEFAULT_TIME) ")"); +MODULE_PARM_DESC(early_enable, + "Watchdog is started at boot time if set to 1, default=" + __MODULE_STRING(STARFIVE_WDT_EARLY_ENA)); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +struct starfive_wdt_variant { + unsigned int control; /* Watchdog Control Resgister for reset enable */ + unsigned int load; /* Watchdog Load register */ + unsigned int reload; /* Watchdog Reload Control register */ + unsigned int enable; /* Watchdog Enable Register */ + unsigned int value; /* Watchdog Counter Value Register */ + unsigned int int_clr; /* Watchdog Interrupt Clear Register */ + unsigned int unlock; /* Watchdog Lock Register */ + unsigned int int_status; /* Watchdog Interrupt Status Register */ + + u32 unlock_key; + char enrst_shift; + char en_shift; + bool intclr_check; /* whether need to check it before clearing interrupt */ + char intclr_ava_shift; + bool double_timeout; /* The watchdog need twice timeout to reboot */ +}; + +struct starfive_wdt { + struct watchdog_device wdd; + spinlock_t lock; /* spinlock for register handling */ + void __iomem *base; + struct clk *core_clk; + struct clk *apb_clk; + const struct starfive_wdt_variant *variant; + unsigned long freq; + u32 count; /* count of timeout */ + u32 reload; /* restore the count */ +}; + +/* Register layout and configuration for the JH7100 */ +static const struct starfive_wdt_variant starfive_wdt_jh7100_variant = { + .control = STARFIVE_WDT_JH7100_CONTROL, + .load = STARFIVE_WDT_JH7100_LOAD, + .reload = STARFIVE_WDT_JH7100_RELOAD, + .enable = STARFIVE_WDT_JH7100_EN, + .value = STARFIVE_WDT_JH7100_VALUE, + .int_clr = STARFIVE_WDT_JH7100_INTCLR, + .unlock = STARFIVE_WDT_JH7100_LOCK, + .unlock_key = STARFIVE_WDT_JH7100_UNLOCK_KEY, + .int_status = STARFIVE_WDT_JH7100_INTSTAUS, + .enrst_shift = STARFIVE_WDT_JH7100_RST_EN_SHIFT, + .en_shift = STARFIVE_WDT_EN_SHIFT, + .intclr_check = true, + .intclr_ava_shift = STARFIVE_WDT_JH7100_INTCLR_AVA_SHIFT, + .double_timeout = false, +}; + +/* Register layout and configuration for the JH7110 */ +static const struct starfive_wdt_variant starfive_wdt_jh7110_variant = { + .control = STARFIVE_WDT_JH7110_CONTROL, + .load = STARFIVE_WDT_JH7110_LOAD, + .enable = STARFIVE_WDT_JH7110_CONTROL, + .value = STARFIVE_WDT_JH7110_VALUE, + .int_clr = STARFIVE_WDT_JH7110_INTCLR, + .unlock = STARFIVE_WDT_JH7110_LOCK, + .unlock_key = STARFIVE_WDT_JH7110_UNLOCK_KEY, + .int_status = STARFIVE_WDT_JH7110_IMS, + .enrst_shift = STARFIVE_WDT_JH7110_RST_EN_SHIFT, + .en_shift = STARFIVE_WDT_EN_SHIFT, + .intclr_check = false, + .double_timeout = true, +}; + +static int starfive_wdt_enable_clock(struct starfive_wdt *wdt) +{ + int ret; + + ret = clk_prepare_enable(wdt->apb_clk); + if (ret) + return dev_err_probe(wdt->wdd.parent, ret, "failed to enable apb clock\n"); + + ret = clk_prepare_enable(wdt->core_clk); + if (ret) + return dev_err_probe(wdt->wdd.parent, ret, "failed to enable core clock\n"); + + return 0; +} + +static void starfive_wdt_disable_clock(struct starfive_wdt *wdt) +{ + clk_disable_unprepare(wdt->core_clk); + clk_disable_unprepare(wdt->apb_clk); +} + +static inline int starfive_wdt_get_clock(struct starfive_wdt *wdt) +{ + struct device *dev = wdt->wdd.parent; + + wdt->apb_clk = devm_clk_get(dev, "apb"); + if (IS_ERR(wdt->apb_clk)) + return dev_err_probe(dev, PTR_ERR(wdt->apb_clk), "failed to get apb clock\n"); + + wdt->core_clk = devm_clk_get(dev, "core"); + if (IS_ERR(wdt->core_clk)) + return dev_err_probe(dev, PTR_ERR(wdt->core_clk), "failed to get core clock\n"); + + return 0; +} + +static inline int starfive_wdt_reset_init(struct device *dev) +{ + struct reset_control *rsts; + int ret; + + rsts = devm_reset_control_array_get_exclusive(dev); + if (IS_ERR(rsts)) + return dev_err_probe(dev, PTR_ERR(rsts), "failed to get resets\n"); + + ret = reset_control_deassert(rsts); + if (ret) + return dev_err_probe(dev, ret, "failed to deassert resets\n"); + + return 0; +} + +static u32 starfive_wdt_ticks_to_sec(struct starfive_wdt *wdt, u32 ticks) +{ + return DIV_ROUND_CLOSEST(ticks, wdt->freq); +} + +/* Write unlock-key to unlock. Write other value to lock. */ +static void starfive_wdt_unlock(struct starfive_wdt *wdt) +{ + spin_lock(&wdt->lock); + writel(wdt->variant->unlock_key, wdt->base + wdt->variant->unlock); +} + +static void starfive_wdt_lock(struct starfive_wdt *wdt) +{ + writel(~wdt->variant->unlock_key, wdt->base + wdt->variant->unlock); + spin_unlock(&wdt->lock); +} + +/* enable watchdog interrupt to reset/reboot */ +static void starfive_wdt_enable_reset(struct starfive_wdt *wdt) +{ + u32 val; + + val = readl(wdt->base + wdt->variant->control); + val |= STARFIVE_WDT_RESET_EN << wdt->variant->enrst_shift; + writel(val, wdt->base + wdt->variant->control); +} + +/* interrupt status whether has been raised from the counter */ +static bool starfive_wdt_raise_irq_status(struct starfive_wdt *wdt) +{ + return !!readl(wdt->base + wdt->variant->int_status); +} + +/* waiting interrupt can be free to clear */ +static int starfive_wdt_wait_int_free(struct starfive_wdt *wdt) +{ + u32 value; + + return readl_poll_timeout_atomic(wdt->base + wdt->variant->int_clr, value, + !(value & BIT(wdt->variant->intclr_ava_shift)), + STARFIVE_WDT_DELAY_US, STARFIVE_WDT_TIMEOUT_US); +} + +/* clear interrupt signal before initialization or reload */ +static int starfive_wdt_int_clr(struct starfive_wdt *wdt) +{ + int ret; + + if (wdt->variant->intclr_check) { + ret = starfive_wdt_wait_int_free(wdt); + if (ret) + return dev_err_probe(wdt->wdd.parent, ret, + "watchdog is not ready to clear interrupt.\n"); + } + writel(STARFIVE_WDT_INTCLR, wdt->base + wdt->variant->int_clr); + + return 0; +} + +static inline void starfive_wdt_set_count(struct starfive_wdt *wdt, u32 val) +{ + writel(val, wdt->base + wdt->variant->load); +} + +static inline u32 starfive_wdt_get_count(struct starfive_wdt *wdt) +{ + return readl(wdt->base + wdt->variant->value); +} + +/* enable watchdog */ +static inline void starfive_wdt_enable(struct starfive_wdt *wdt) +{ + u32 val; + + val = readl(wdt->base + wdt->variant->enable); + val |= STARFIVE_WDT_ENABLE << wdt->variant->en_shift; + writel(val, wdt->base + wdt->variant->enable); +} + +/* disable watchdog */ +static inline void starfive_wdt_disable(struct starfive_wdt *wdt) +{ + u32 val; + + val = readl(wdt->base + wdt->variant->enable); + val &= ~(STARFIVE_WDT_ENABLE << wdt->variant->en_shift); + writel(val, wdt->base + wdt->variant->enable); +} + +static inline void starfive_wdt_set_reload_count(struct starfive_wdt *wdt, u32 count) +{ + starfive_wdt_set_count(wdt, count); + + /* 7100 need set any value to reload register and could reload value to counter */ + if (wdt->variant->reload) + writel(0x1, wdt->base + wdt->variant->reload); +} + +static unsigned int starfive_wdt_max_timeout(struct starfive_wdt *wdt) +{ + if (wdt->variant->double_timeout) + return DIV_ROUND_UP(STARFIVE_WDT_MAXCNT, (wdt->freq / 2)) - 1; + + return DIV_ROUND_UP(STARFIVE_WDT_MAXCNT, wdt->freq) - 1; +} + +static unsigned int starfive_wdt_get_timeleft(struct watchdog_device *wdd) +{ + struct starfive_wdt *wdt = watchdog_get_drvdata(wdd); + u32 count; + + /* + * If the watchdog takes twice timeout and set half count value, + * timeleft value should add the count value before first timeout. + */ + count = starfive_wdt_get_count(wdt); + if (wdt->variant->double_timeout && !starfive_wdt_raise_irq_status(wdt)) + count += wdt->count; + + return starfive_wdt_ticks_to_sec(wdt, count); +} + +static int starfive_wdt_keepalive(struct watchdog_device *wdd) +{ + struct starfive_wdt *wdt = watchdog_get_drvdata(wdd); + int ret; + + starfive_wdt_unlock(wdt); + ret = starfive_wdt_int_clr(wdt); + if (ret) + goto exit; + + starfive_wdt_set_reload_count(wdt, wdt->count); + +exit: + /* exit with releasing spinlock and locking registers */ + starfive_wdt_lock(wdt); + return ret; +} + +static int starfive_wdt_start(struct starfive_wdt *wdt) +{ + int ret; + + starfive_wdt_unlock(wdt); + /* disable watchdog, to be safe */ + starfive_wdt_disable(wdt); + + starfive_wdt_enable_reset(wdt); + ret = starfive_wdt_int_clr(wdt); + if (ret) + goto exit; + + starfive_wdt_set_count(wdt, wdt->count); + starfive_wdt_enable(wdt); + +exit: + starfive_wdt_lock(wdt); + return ret; +} + +static void starfive_wdt_stop(struct starfive_wdt *wdt) +{ + starfive_wdt_unlock(wdt); + starfive_wdt_disable(wdt); + starfive_wdt_lock(wdt); +} + +static int starfive_wdt_pm_start(struct watchdog_device *wdd) +{ + struct starfive_wdt *wdt = watchdog_get_drvdata(wdd); + int ret = pm_runtime_get_sync(wdd->parent); + + if (ret < 0) + return ret; + + return starfive_wdt_start(wdt); +} + +static int starfive_wdt_pm_stop(struct watchdog_device *wdd) +{ + struct starfive_wdt *wdt = watchdog_get_drvdata(wdd); + + starfive_wdt_stop(wdt); + return pm_runtime_put_sync(wdd->parent); +} + +static int starfive_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + struct starfive_wdt *wdt = watchdog_get_drvdata(wdd); + unsigned long count = timeout * wdt->freq; + + /* some watchdogs take two timeouts to reset */ + if (wdt->variant->double_timeout) + count /= 2; + + wdt->count = count; + wdd->timeout = timeout; + + starfive_wdt_unlock(wdt); + starfive_wdt_disable(wdt); + starfive_wdt_set_reload_count(wdt, wdt->count); + starfive_wdt_enable(wdt); + starfive_wdt_lock(wdt); + + return 0; +} + +#define STARFIVE_WDT_OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE) + +static const struct watchdog_info starfive_wdt_info = { + .options = STARFIVE_WDT_OPTIONS, + .identity = "StarFive Watchdog", +}; + +static const struct watchdog_ops starfive_wdt_ops = { + .owner = THIS_MODULE, + .start = starfive_wdt_pm_start, + .stop = starfive_wdt_pm_stop, + .ping = starfive_wdt_keepalive, + .set_timeout = starfive_wdt_set_timeout, + .get_timeleft = starfive_wdt_get_timeleft, +}; + +static int starfive_wdt_probe(struct platform_device *pdev) +{ + struct starfive_wdt *wdt; + int ret; + + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdt->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(wdt->base)) + return dev_err_probe(&pdev->dev, PTR_ERR(wdt->base), "error mapping registers\n"); + + wdt->wdd.parent = &pdev->dev; + ret = starfive_wdt_get_clock(wdt); + if (ret) + return ret; + + platform_set_drvdata(pdev, wdt); + pm_runtime_enable(&pdev->dev); + if (pm_runtime_enabled(&pdev->dev)) { + ret = pm_runtime_get_sync(&pdev->dev); + if (ret < 0) + return ret; + } else { + /* runtime PM is disabled but clocks need to be enabled */ + ret = starfive_wdt_enable_clock(wdt); + if (ret) + return ret; + } + + ret = starfive_wdt_reset_init(&pdev->dev); + if (ret) + goto err_exit; + + watchdog_set_drvdata(&wdt->wdd, wdt); + wdt->wdd.info = &starfive_wdt_info; + wdt->wdd.ops = &starfive_wdt_ops; + wdt->variant = of_device_get_match_data(&pdev->dev); + spin_lock_init(&wdt->lock); + + wdt->freq = clk_get_rate(wdt->core_clk); + if (!wdt->freq) { + dev_err(&pdev->dev, "get clock rate failed.\n"); + ret = -EINVAL; + goto err_exit; + } + + wdt->wdd.min_timeout = 1; + wdt->wdd.max_timeout = starfive_wdt_max_timeout(wdt); + wdt->wdd.timeout = STARFIVE_WDT_DEFAULT_TIME; + watchdog_init_timeout(&wdt->wdd, heartbeat, &pdev->dev); + starfive_wdt_set_timeout(&wdt->wdd, wdt->wdd.timeout); + + watchdog_set_nowayout(&wdt->wdd, nowayout); + watchdog_stop_on_reboot(&wdt->wdd); + watchdog_stop_on_unregister(&wdt->wdd); + + if (early_enable) { + ret = starfive_wdt_start(wdt); + if (ret) + goto err_exit; + set_bit(WDOG_HW_RUNNING, &wdt->wdd.status); + } else { + starfive_wdt_stop(wdt); + } + + ret = watchdog_register_device(&wdt->wdd); + if (ret) + goto err_exit; + + if (!early_enable) + return pm_runtime_put_sync(&pdev->dev); + + return 0; + +err_exit: + starfive_wdt_disable_clock(wdt); + pm_runtime_disable(&pdev->dev); + + return ret; +} + +static int starfive_wdt_remove(struct platform_device *pdev) +{ + struct starfive_wdt *wdt = platform_get_drvdata(pdev); + + starfive_wdt_stop(wdt); + watchdog_unregister_device(&wdt->wdd); + + if (pm_runtime_enabled(&pdev->dev)) + pm_runtime_disable(&pdev->dev); + else + /* disable clock without PM */ + starfive_wdt_disable_clock(wdt); + + return 0; +} + +static void starfive_wdt_shutdown(struct platform_device *pdev) +{ + struct starfive_wdt *wdt = platform_get_drvdata(pdev); + + starfive_wdt_pm_stop(&wdt->wdd); +} + +#ifdef CONFIG_PM_SLEEP +static int starfive_wdt_suspend(struct device *dev) +{ + struct starfive_wdt *wdt = dev_get_drvdata(dev); + + /* Save watchdog state, and turn it off. */ + wdt->reload = starfive_wdt_get_count(wdt); + + /* Note that WTCNT doesn't need to be saved. */ + starfive_wdt_stop(wdt); + + return pm_runtime_force_suspend(dev); +} + +static int starfive_wdt_resume(struct device *dev) +{ + struct starfive_wdt *wdt = dev_get_drvdata(dev); + int ret; + + ret = pm_runtime_force_resume(dev); + if (ret) + return ret; + + starfive_wdt_unlock(wdt); + /* Restore watchdog state. */ + starfive_wdt_set_reload_count(wdt, wdt->reload); + starfive_wdt_lock(wdt); + + return starfive_wdt_start(wdt); +} +#endif /* CONFIG_PM_SLEEP */ + +#ifdef CONFIG_PM +static int starfive_wdt_runtime_suspend(struct device *dev) +{ + struct starfive_wdt *wdt = dev_get_drvdata(dev); + + starfive_wdt_disable_clock(wdt); + + return 0; +} + +static int starfive_wdt_runtime_resume(struct device *dev) +{ + struct starfive_wdt *wdt = dev_get_drvdata(dev); + + return starfive_wdt_enable_clock(wdt); +} +#endif /* CONFIG_PM */ + +static const struct dev_pm_ops starfive_wdt_pm_ops = { + SET_RUNTIME_PM_OPS(starfive_wdt_runtime_suspend, starfive_wdt_runtime_resume, NULL) + SET_SYSTEM_SLEEP_PM_OPS(starfive_wdt_suspend, starfive_wdt_resume) +}; + +static const struct of_device_id starfive_wdt_match[] = { + { .compatible = "starfive,jh7100-wdt", .data = &starfive_wdt_jh7100_variant }, + { .compatible = "starfive,jh7110-wdt", .data = &starfive_wdt_jh7110_variant }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, starfive_wdt_match); + +static struct platform_driver starfive_wdt_driver = { + .probe = starfive_wdt_probe, + .remove = starfive_wdt_remove, + .shutdown = starfive_wdt_shutdown, + .driver = { + .name = "starfive-wdt", + .pm = &starfive_wdt_pm_ops, + .of_match_table = of_match_ptr(starfive_wdt_match), + }, +}; +module_platform_driver(starfive_wdt_driver); + +MODULE_AUTHOR("Xingyu Wu "); +MODULE_AUTHOR("Samin Guo "); +MODULE_DESCRIPTION("StarFive Watchdog Device Driver"); +MODULE_LICENSE("GPL");