On Tue, Mar 14, 2023 at 09:24:36PM +0800, Xingyu Wu wrote:
> Add watchdog driver for the StarFive JH7100 and JH7110 SoC.
>
> Signed-off-by: Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
> Reviewed-by: Emil Renner Berthing <emil.renner.berthing@xxxxxxxxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
> 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
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 8d5bc223f305..721d0e4e8a0d 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -19962,6 +19962,13 @@ S: Supported
> F: Documentation/devicetree/bindings/rng/starfive*
> F: drivers/char/hw_random/jh7110-trng.c
>
> +STARFIVE WATCHDOG DRIVER
> +M: Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
> +M: Samin Guo <samin.guo@xxxxxxxxxxxxxxxx>
> +S: Supported
> +F: Documentation/devicetree/bindings/watchdog/starfive*
> +F: drivers/watchdog/starfive-wdt.c
> +
> STATIC BRANCH/CALL
> M: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> M: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index f0872970daf9..f22138709bf5 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -1999,6 +1999,17 @@ 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
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 9cbf6580f16c..b4c4ccf2d703 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -192,6 +192,9 @@ obj-$(CONFIG_MEN_A21_WDT) += mena21_wdt.o
> obj-$(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
>
> diff --git a/drivers/watchdog/starfive-wdt.c b/drivers/watchdog/starfive-wdt.c
> new file mode 100644
> index 000000000000..1995cceca51e
> --- /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 <linux/clk.h>
> +#include <linux/iopoll.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/reset.h>
> +#include <linux/watchdog.h>
> +
> +/* 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 <xingyu.wu@xxxxxxxxxxxxxxxx>");
> +MODULE_AUTHOR("Samin Guo <samin.guo@xxxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("StarFive Watchdog Device Driver");
> +MODULE_LICENSE("GPL");
