Re: [PATCH v4 2/3] drivers: watchdog: Add StarFive Watchdog driver
From: Emil Renner Berthing
Date: Wed Mar 08 2023 - 10:08:16 EST
On Wed, 8 Mar 2023 at 04:43, Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx> wrote:
>
> Add watchdog driver for the StarFive JH7100 and JH7110 SoC.
>
> Signed-off-by: Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
Hi Xingyu,
Thanks for adding the JH7100 support. I tried it on my Starlight board
and it seems to work fine except systemd complains about not being
able to set a 10min timeout on reboot:
systemd-shutdown[1]: Using hardware watchdog 'StarFive Watchdog',
version 0, device /dev/watchdog0
systemd-shutdown[1]: Failed to set timeout to 10min: Invalid argument
systemd-shutdown[1]: Syncing filesystems and block devices.
systemd-shutdown[1]: Sending SIGTERM to remaining processes...
The systemd runtime watchdog seems to work, so I guess this is just
because 10min is too long a timeout for the StarFive watchdog.
More comments below.
> ---
> MAINTAINERS | 7 +
> drivers/watchdog/Kconfig | 9 +
> drivers/watchdog/Makefile | 2 +
> drivers/watchdog/starfive-wdt.c | 675 ++++++++++++++++++++++++++++++++
> 4 files changed, 693 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..9d825ffaf292 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -2090,6 +2090,15 @@ config UML_WATCHDOG
> tristate "UML watchdog"
> depends on UML || COMPILE_TEST
>
> +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.
This file seems to be sorted by architecture, so you probably want to
add something like this at the appropriate place
# RISC-V Architecture
config STARFIVE_WATCHDOG
...
> #
> # ISA-based Watchdog Cards
> #
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 9cbf6580f16c..4c0bd377e92a 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -211,6 +211,8 @@ obj-$(CONFIG_WATCHDOG_SUN4V) += sun4v_wdt.o
> # Xen
> obj-$(CONFIG_XEN_WDT) += xen_wdt.o
>
> +obj-$(CONFIG_STARFIVE_WATCHDOG) += starfive-wdt.o
Again please follow the layout of the file. Eg. something like this at
the appropriate place
# RISC-V Architecture
obj-$(CONFIG_STARFIVE_WATCHDOG) += starfive-wdt.o
> # Architecture Independent
> obj-$(CONFIG_BD957XMUF_WATCHDOG) += bd9576_wdt.o
> obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o
> diff --git a/drivers/watchdog/starfive-wdt.c b/drivers/watchdog/starfive-wdt.c
> new file mode 100644
> index 000000000000..8ce9f985f068
> --- /dev/null
> +++ b/drivers/watchdog/starfive-wdt.c
> @@ -0,0 +1,675 @@
> +// 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 /* RO: [4]: Watchdog Interrupt status */
> +#define STARFIVE_WDT_JH7100_CONTROL 0x104 /* RW: reset enable */
> +#define STARFIVE_WDT_JH7100_LOAD 0x108 /* RW: Watchdog Load register */
> +#define STARFIVE_WDT_JH7100_EN 0x110 /* RW: Watchdog Enable Register */
> +#define STARFIVE_WDT_JH7100_RELOAD 0x114 /* RW: Write 0 or 1 to reload preset value */
> +#define STARFIVE_WDT_JH7100_VALUE 0x118 /* RO: The current value for watchdog counter */
> +#define STARFIVE_WDT_JH7100_INTCLR 0x120 /*
> + * RW: Watchdog Clear Interrupt Register
> + * [0]: Write 1 to clear interrupt
> + * [1]: 1 mean clearing and 0 mean complete
> + */
> +#define STARFIVE_WDT_JH7100_LOCK 0x13c /* RW: Lock Register, write 0x378f0765 to unlock */
> +
> +/* JH7110 Watchdog register define */
> +#define STARFIVE_WDT_JH7110_LOAD 0x000 /* RW: Watchdog Load register */
> +#define STARFIVE_WDT_JH7110_VALUE 0x004 /* RO: The current value for watchdog counter */
> +#define STARFIVE_WDT_JH7110_CONTROL 0x008 /*
> + * RW:
> + * [0]: reset enable;
> + * [1]: int enable/wdt enable/reload counter;
> + * [31:2]: reserved.
> + */
> +#define STARFIVE_WDT_JH7110_INTCLR 0x00c /* WO: clear intterupt && reload the counter */
> +#define STARFIVE_WDT_JH7110_IMS 0x014 /* RO: Enabled interrupt status from the counter */
> +#define STARFIVE_WDT_JH7110_LOCK 0xc00 /* RW: Lock Register, write 0x1ACCE551 to unlock */
Since these register offsets are only used to fill in the
starfive_wdt_variant structures, consider just adding them directly
there with the comments.
> +/* WDOGCONTROL */
> +#define STARFIVE_WDT_ENABLE 0x1
> +#define STARFIVE_WDT_EN_SHIFT 0
> +#define STARFIVE_WDT_RESET_EN 0x1
> +#define STARFIVE_WDT_JH7100_RESEN_SHIFT 0
> +#define STARFIVE_WDT_JH7110_RESEN_SHIFT 1
> +
> +/* WDOGLOCK */
> +#define STARFIVE_WDT_LOCKED BIT(0)
> +#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 {
> + /* resgister */
> + unsigned int control;
> + unsigned int load;
> + unsigned int reload;
> + unsigned int enable;
> + unsigned int value;
> + unsigned int int_clr;
> + unsigned int unlock;
> + unsigned int int_status;
> +
> + u32 unlock_key;
> + u8 enrst_shift;
> + u8 en_shift;
> + bool intclr_check; /* whether need to check it before clearing interrupt */
> + u8 intclr_ava_shift;
The shifts here could just be char.
> + bool double_timeout; /* The watchdog need twice timeout to reboot */
> +};
> +
> +struct starfive_wdt {
> + unsigned long freq;
> + struct device *dev;
This device pointer is also stored in the parent field of struct
watchdog_device below, so not really needed.
> + struct watchdog_device wdt_device;
>From looking at the other watchdog drivers a common name for this is just "wdd".
> + struct clk *core_clk;
> + struct clk *apb_clk;
> + struct reset_control *rsts;
This pointer seems to be only used just after being obtained in the
starfive_wdt_reset_init function, but never needed after that, so why
store it here?
> + u32 count; /*count of timeout*/
> + u32 reload; /*restore the count*/
Missing spaces between /*,*/ and text. Also please align with the comment below.
> + void __iomem *base;
> + spinlock_t lock; /* spinlock for register handling */
> + const struct starfive_wdt_variant *drv_data;
Hmm.. to me "driver data" is this struct, whereas this field points to
SoC data. You already call the struct "variant", so why not just
const struct starfive_wdt_variant *variant;
> +};
Consider sorting fields by size to avoid too many alignment induced
holes in the struct. Eg. something like
struct starfive_wdt {
struct watchdog_device wdd;
spinlock_t lock;
void __iomem *base;
/* clock and reset pointers */
const struct starfive_wdt_variant *variant;
unsigned long freq;
u32 count;
u32 reload;
};
> +/* Register layout and configuration for the JH7100 */
> +static const struct starfive_wdt_variant drv_data_jh7100 = {
Please keep using the starfive_wdt_ prefix here. Eg. something like
starfive_wdt_jh7100_variant and
starfive_wdt_jh7110_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_RESEN_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 drv_data_jh7110 = {
> + .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_RESEN_SHIFT,
> + .en_shift = STARFIVE_WDT_EN_SHIFT,
> + .intclr_check = false,
> + .double_timeout = true,
> +};
> +
> +static const struct of_device_id starfive_wdt_match[] = {
> + { .compatible = "starfive,jh7100-wdt", .data = &drv_data_jh7100 },
> + { .compatible = "starfive,jh7110-wdt", .data = &drv_data_jh7110 },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, starfive_wdt_match);
Please move this struct just above struct platform_driver like most
other drivers. It's nice to be able to open a driver, scroll to the
bottom and immediately find the compatibles it matches on.
> +static int starfive_wdt_get_clock_rate(struct starfive_wdt *wdt)
> +{
> + wdt->freq = clk_get_rate(wdt->core_clk);
> + if (!wdt->freq) {
> + dev_err(wdt->dev, "get clock rate failed.\n");
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
This function seems a bit pointless since it's only used once in the
probe function. Just inline it there. Consider doing the same for the
functions getting clocks and resets.
> +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->dev, ret, "failed to enable apb_clk.\n");
> +
> + ret = clk_prepare_enable(wdt->core_clk);
> + if (ret)
> + return dev_err_probe(wdt->dev, ret, "failed to enable core_clk.\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 int starfive_wdt_get_clock(struct starfive_wdt *wdt)
> +{
> + wdt->apb_clk = devm_clk_get(wdt->dev, "apb");
> + if (IS_ERR(wdt->apb_clk))
> + return dev_err_probe(wdt->dev, PTR_ERR(wdt->apb_clk),
> + "failed to get apb clock.\n");
> +
> + wdt->core_clk = devm_clk_get(wdt->dev, "core");
> + if (IS_ERR(wdt->core_clk))
> + return dev_err_probe(wdt->dev, PTR_ERR(wdt->core_clk),
> + "failed to get core clock.\n");
> +
> + return 0;
> +}
> +
> +static int starfive_wdt_reset_init(struct starfive_wdt *wdt)
> +{
> + int ret;
> +
> + wdt->rsts = devm_reset_control_array_get_exclusive(wdt->dev);
> + if (IS_ERR(wdt->rsts))
> + return dev_err_probe(wdt->dev, PTR_ERR(wdt->rsts),
> + "failed to get resets.\n");
> +
> + ret = reset_control_deassert(wdt->rsts);
> + if (ret)
> + return dev_err_probe(wdt->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. When lock bit is 1,
> + * external accesses to other watchdog registers are ignored.
> + */
> +static bool starfive_wdt_is_locked(struct starfive_wdt *wdt)
> +{
> + u32 val;
> +
> + val = readl(wdt->base + wdt->drv_data->unlock);
u32 val = readl(...);
> + return !!(val & STARFIVE_WDT_LOCKED);
> +}
> +
> +static void starfive_wdt_unlock(struct starfive_wdt *wdt)
> +{
> + if (starfive_wdt_is_locked(wdt))
> + writel(wdt->drv_data->unlock_key,
> + wdt->base + wdt->drv_data->unlock);
> +}
> +
> +static void starfive_wdt_lock(struct starfive_wdt *wdt)
> +{
> + if (!starfive_wdt_is_locked(wdt))
> + writel(~wdt->drv_data->unlock_key,
> + wdt->base + wdt->drv_data->unlock);
> +}
This looks suspicious. Is there really a situation where you
legitimately need to operate on the registers in parallel or is this
just glossing over programming errors? Shouldn't this
locking/unlocking basically happen between taking the spinlock? If
not, then doesn't this risk locking the registers while some other
thread is still using them and expects them to be unlocked?
> +/* enable watchdog interrupt to reset/reboot */
> +static void starfive_wdt_enable_reset(struct starfive_wdt *wdt)
> +{
> + u32 val;
> +
> + val = readl(wdt->base + wdt->drv_data->control);
> + val |= STARFIVE_WDT_RESET_EN << wdt->drv_data->enrst_shift;
> + writel(val, wdt->base + wdt->drv_data->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->drv_data->int_status);
> +}
> +
> +/* waiting interrupt can be free to clear */
> +static int starfive_wdt_wait_int_free(struct starfive_wdt *wdt)
> +{
> + u32 value;
> +
> + value = readl(wdt->base + wdt->drv_data->int_clr);
Doesn't readl_poll_timeout_atomic below read the value before using
it, so this line is redundant?
> + return readl_poll_timeout_atomic(wdt->base + wdt->drv_data->int_clr, value,
> + !(value & BIT(wdt->drv_data->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->drv_data->intclr_check) {
> + ret = starfive_wdt_wait_int_free(wdt);
> + if (ret)
> + return dev_err_probe(wdt->dev, ret,
> + "watchdog is not ready to clear interrupt.\n");
> + }
> + writel(STARFIVE_WDT_INTCLR, wdt->base + wdt->drv_data->int_clr);
> +
> + return 0;
> +}
> +
> +static inline void starfive_wdt_set_count(struct starfive_wdt *wdt, u32 val)
> +{
> + writel(val, wdt->base + wdt->drv_data->load);
> +}
> +
> +static inline u32 starfive_wdt_get_count(struct starfive_wdt *wdt)
> +{
> + return readl(wdt->base + wdt->drv_data->value);
> +}
> +
> +/* enable watchdog */
> +static inline void starfive_wdt_enable(struct starfive_wdt *wdt)
> +{
> + u32 val;
> +
> + val = readl(wdt->base + wdt->drv_data->enable);
> + val |= STARFIVE_WDT_ENABLE << wdt->drv_data->en_shift;
> + writel(val, wdt->base + wdt->drv_data->enable);
> +}
> +
> +/* disable watchdog */
> +static inline void starfive_wdt_disable(struct starfive_wdt *wdt)
> +{
> + u32 val;
> +
> + val = readl(wdt->base + wdt->drv_data->enable);
> + val &= ~(STARFIVE_WDT_ENABLE << wdt->drv_data->en_shift);
> + writel(val, wdt->base + wdt->drv_data->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->drv_data->reload)
> + writel(0x1, wdt->base + wdt->drv_data->reload);
> +}
> +
> +static unsigned int starfive_wdt_max_timeout(struct starfive_wdt *wdt)
> +{
> + unsigned int timeout_num = wdt->drv_data->double_timeout ? 2 : 1;
> +
> + return DIV_ROUND_UP(STARFIVE_WDT_MAXCNT, (wdt->freq / timeout_num)) - 1;
> +}
> +
> +static unsigned int starfive_wdt_get_timeleft(struct watchdog_device *wdd)
> +{
> + struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
> + u32 count;
> +
> + starfive_wdt_unlock(wdt);
> + /*
> + * 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->drv_data->double_timeout && !starfive_wdt_raise_irq_status(wdt))
> + count += wdt->count;
> +
> + starfive_wdt_lock(wdt);
> +
> + 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;
> +
> + spin_lock(&wdt->lock);
> +
> + starfive_wdt_unlock(wdt);
> + ret = starfive_wdt_int_clr(wdt);
> + if (ret)
> + return ret;
> +
> + starfive_wdt_set_reload_count(wdt, wdt->count);
> + starfive_wdt_lock(wdt);
> +
> + spin_unlock(&wdt->lock);
> +
> + return 0;
> +}
> +
> +static int starfive_wdt_stop(struct watchdog_device *wdd)
> +{
> + struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
> +
> + spin_lock(&wdt->lock);
> +
> + starfive_wdt_unlock(wdt);
> + starfive_wdt_disable(wdt);
> + starfive_wdt_lock(wdt);
> +
> + spin_unlock(&wdt->lock);
> +
> + return 0;
> +}
> +
> +static int starfive_wdt_pm_stop(struct watchdog_device *wdd)
> +{
> + struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
> +
> + starfive_wdt_stop(wdd);
> + pm_runtime_put_sync(wdt->dev);
> +
> + return 0;
> +}
> +
> +static int starfive_wdt_start(struct watchdog_device *wdd)
> +{
> + struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
> + int ret;
> +
> + spin_lock(&wdt->lock);
> + 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)
> + return ret;
> +
> + starfive_wdt_set_count(wdt, wdt->count);
> + starfive_wdt_enable(wdt);
> +
> + starfive_wdt_lock(wdt);
> + spin_unlock(&wdt->lock);
> +
> + return 0;
> +}
> +
> +static int starfive_wdt_pm_start(struct watchdog_device *wdd)
> +{
> + struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
> +
> + pm_runtime_get_sync(wdt->dev);
> +
> + return starfive_wdt_start(wdd);
> +}
> +
> +static int starfive_wdt_set_timeout(struct watchdog_device *wdd,
> + unsigned int timeout)
> +{
> + struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
> + unsigned long freq = wdt->freq;
> + unsigned int timeout_num = wdt->drv_data->double_timeout ? 2 : 1;
> +
> + spin_lock(&wdt->lock);
> +
> + /*
> + * This watchdog takes twice timeouts to reset.
> + * In order to reduce time to reset, should set half count value.
> + */
> + wdt->count = timeout * freq / timeout_num;
> + 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);
> +
> + spin_unlock(&wdt->lock);
> +
> + return 0;
> +}
> +
> +#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
This macro needs a much less generic name but it's only used below, so
just set the .options directly there.
> +static const struct watchdog_info starfive_wdt_ident = {
Why invent a new name for this struct and not just follow the watchdog
framework and call it starfive_wdt_info?
> + .options = 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 const struct watchdog_device starfive_wdd = {
> + .info = &starfive_wdt_ident,
> + .ops = &starfive_wdt_ops,
> + .timeout = STARFIVE_WDT_DEFAULT_TIME,
> +};
> +
> +static int starfive_wdt_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct starfive_wdt *wdt;
> + int ret;
> +
> + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
> + if (!wdt)
> + return -ENOMEM;
> +
> + wdt->dev = dev;
> + spin_lock_init(&wdt->lock);
> + wdt->wdt_device = starfive_wdd;
This is a very elaborate way of setting 2 pointers and a timeout. Maybe just
wdt->wdd.info = &starfive_wdt_info;
wdt->wdd.ops = &starfive_wdt_ops;
..and drop the static const copy above. You already set the default
timeout again below.
> + wdt->drv_data = of_device_get_match_data(&pdev->dev);
> +
> + /* get the memory region for the watchdog timer */
> + wdt->base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(wdt->base)) {
> + ret = PTR_ERR(wdt->base);
> + return ret;
> + }
> +
> + platform_set_drvdata(pdev, wdt);
> + pm_runtime_enable(wdt->dev);
> +
> + ret = starfive_wdt_get_clock(wdt);
> + if (ret)
> + return ret;
> +
> + if (pm_runtime_enabled(wdt->dev)) {
> + ret = pm_runtime_get_sync(wdt->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_get_clock_rate(wdt);
> + if (ret)
> + goto err_exit;
> +
> + ret = starfive_wdt_reset_init(wdt);
> + if (ret)
> + goto err_exit;
> +
> + wdt->wdt_device.min_timeout = 1;
> + wdt->wdt_device.max_timeout = starfive_wdt_max_timeout(wdt);
> +
> + watchdog_set_drvdata(&wdt->wdt_device, wdt);
> +
> + wdt->wdt_device.timeout = STARFIVE_WDT_DEFAULT_TIME;
> + watchdog_init_timeout(&wdt->wdt_device, heartbeat, dev);
> + starfive_wdt_set_timeout(&wdt->wdt_device, wdt->wdt_device.timeout);
> +
> + watchdog_set_nowayout(&wdt->wdt_device, nowayout);
> + watchdog_stop_on_reboot(&wdt->wdt_device);
> + watchdog_stop_on_unregister(&wdt->wdt_device);
> +
> + wdt->wdt_device.parent = dev;
This can be set when you first initialise wdt->wdd.
> + if (early_enable) {
> + starfive_wdt_start(&wdt->wdt_device);
> + set_bit(WDOG_HW_RUNNING, &wdt->wdt_device.status);
> + } else {
> + starfive_wdt_stop(&wdt->wdt_device);
> + }
> +
> + ret = watchdog_register_device(&wdt->wdt_device);
> + if (ret)
> + goto err_exit;
> +
> + if (!early_enable)
> + pm_runtime_put_sync(wdt->dev);
> +
> + return 0;
> +
> +err_exit:
> + starfive_wdt_disable_clock(wdt);
> + pm_runtime_disable(wdt->dev);
> +
> + return ret;
> +}
> +
> +static int starfive_wdt_remove(struct platform_device *dev)
> +{
> + struct starfive_wdt *wdt = platform_get_drvdata(dev);
> +
> + starfive_wdt_stop(&wdt->wdt_device);
> + watchdog_unregister_device(&wdt->wdt_device);
> +
> + if (pm_runtime_enabled(wdt->dev))
> + pm_runtime_disable(wdt->dev);
> + else
> + /* disable clock without PM */
> + starfive_wdt_disable_clock(wdt);
> +
> + return 0;
> +}
> +
> +static void starfive_wdt_shutdown(struct platform_device *dev)
> +{
> + struct starfive_wdt *wdt = platform_get_drvdata(dev);
> +
> + starfive_wdt_pm_stop(&wdt->wdt_device);
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int starfive_wdt_suspend(struct device *dev)
> +{
> + int ret;
> + struct starfive_wdt *wdt = dev_get_drvdata(dev);
Please swap these around so initialised local variables come first.
Also other places.
> + starfive_wdt_unlock(wdt);
> +
> + /* 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->wdt_device);
> + pm_runtime_force_suspend(dev);
> +
> + starfive_wdt_lock(wdt);
> +
> + return 0;
> +}
> +
> +static int starfive_wdt_resume(struct device *dev)
> +{
> + int ret;
> + struct starfive_wdt *wdt = dev_get_drvdata(dev);
> +
> + starfive_wdt_unlock(wdt);
> +
> + pm_runtime_force_resume(dev);
> +
> + /* Restore watchdog state. */
> + starfive_wdt_set_reload_count(wdt, wdt->reload);
> +
> + starfive_wdt_start(&wdt->wdt_device);
> +
> + starfive_wdt_lock(wdt);
> +
> + return 0;
> +}
> +#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 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),
> + },
> +};
> +
This empty line not needed.
> +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");
> --
> 2.25.1
>
>
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