On 12/2/22 01:39, xingu.wu wrote:
From: Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
Add watchdog driver for the StarFive JH7110 SoC.
Signed-off-by: Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
---
MAINTAINERS | 7 +
drivers/watchdog/Kconfig | 11 +
drivers/watchdog/Makefile | 3 +
drivers/watchdog/starfive-wdt.c | 854 ++++++++++++++++++++++++++++++++
4 files changed, 875 insertions(+)
create mode 100644 drivers/watchdog/starfive-wdt.c
diff --git a/MAINTAINERS b/MAINTAINERS
index a70c1d0f303e..133214dd2f60 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19623,6 +19623,13 @@ F: Documentation/devicetree/bindings/reset/starfive,jh7100-reset.yaml
F: drivers/reset/starfive/
F: include/dt-bindings/reset/starfive*
+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 b64bc49c7f30..658fc9fef4fa 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -2082,6 +2082,17 @@ config UML_WATCHDOG
tristate "UML watchdog"
depends on UML || COMPILE_TEST
+# RISCV Architecture
+
+config STARFIVE_WATCHDOG
+ tristate "StarFive Watchdog support"
+ depends on RISCV
+ select WATCHDOG_CORE
+ default SOC_STARFIVE
+ help
+ Say Y here to support the StarFive watchdog. This driver can also
+ be built as a module if choose M.
+
#
# ISA-based Watchdog Cards
#
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index d41e5f830ae7..9c22f1a43d5c 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -210,6 +210,9 @@ obj-$(CONFIG_WATCHDOG_SUN4V) += sun4v_wdt.o
# Xen
obj-$(CONFIG_XEN_WDT) += xen_wdt.o
+# RISCV 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..dcb6e693ba6c
--- /dev/null
+++ b/drivers/watchdog/starfive-wdt.c
@@ -0,0 +1,854 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Starfive Watchdog driver
+ *
+ * Copyright (C) 2022 StarFive Technology Co., Ltd.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/watchdog.h>
+
+/* 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 the watchdog counter */
+#define STARFIVE_WDT_JH7110_CONTROL 0x008 /*
+ * RW: [0]: reset enable;
+ * [1]: int enable/wdt enable/reload counter;
+ * [31:2]: res.
+ */
+#define STARFIVE_WDT_JH7110_INTCLR 0x00c /* WO: clear intterupt && reload the counter */
+#define STARFIVE_WDT_JH7110_RIS 0x010 /* RO: Raw interrupt status from the counter */
+#define STARFIVE_WDT_JH7110_IMS 0x014 /* RO: Enabled interrupt status from the counter */
+#define STARFIVE_WDT_JH7110_LOCK 0xc00 /*
+ * RO: Enable write access to all other registers
+ * by writing 0x1ACCE551.
+ */
+#define STARFIVE_WDT_JH7110_ITCR 0xf00 /*
+ * RW: When set HIGH,
+ * places the Watchdog into integraeion test mode.\\intetration
+ */
+#define STARFIVE_WDT_JH7110_ITOP 0xf04 /*
+ * WO: [0] WDOGRES value Integration Test Mode.
+ * Value output on WDOGRES when in
+ * Integration Test Mode.
+ * [1] Integration Test WDOGINT value.
+ * Value output on WDOGINT when in
+ * Integration Test Mode.
+ */
+
+#define STARFIVE_WDT_JH7110_UNLOCK_KEY 0x1acce551
+#define STARFIVE_WDT_JH7110_RESEN_SHIFT 1
+#define STARFIVE_WDT_JH7110_EN_SHIFT 0
+#define STARFIVE_WDT_JH7110_INT_EN_SHIFT STARFIVE_WDT_JH7110_EN_SHIFT
+
+/* WDOGCONTROL */
+#define STARFIVE_WDT_INT_EN 0x0
+#define STARFIVE_WDT_INT_DIS BIT(0)
+#define STARFIVE_WDT_RESET_EN 0x1
+
+/* WDOGLOCK */
+#define STARFIVE_WDT_LOCKED BIT(0)
+
+#define STARFIVE_WDT_INTCLR 0x1
+#define STARFIVE_WDT_ENABLE 0x1
+#define STARFIVE_WDT_ATBOOT 0x0
+#define STARFIVE_WDT_MAXCNT 0xffffffff
+
+#define STARFIVE_WDT_DEFAULT_TIME (15)
+#define STARFIVE_WDT_DELAY_US 0
+#define STARFIVE_WDT_TIMEOUT_US 10000
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static int tmr_margin;
+static int tmr_atboot = STARFIVE_WDT_ATBOOT;
+static int soft_noboot;
+
+module_param(tmr_margin, int, 0);
+module_param(tmr_atboot, int, 0);
+module_param(nowayout, bool, 0);
+module_param(soft_noboot, int, 0);
+
+MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. (default="
+ __MODULE_STRING(STARFIVE_WDT_DEFAULT_TIME) ")");
+MODULE_PARM_DESC(tmr_atboot,
+ "Watchdog is started at boot time if set to 1, default="
+ __MODULE_STRING(STARFIVE_WDT_ATBOOT));
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+MODULE_PARM_DESC(soft_noboot,
+ "Watchdog action, set to 1 to ignore reboots, 0 to reboot (default 0)");
+
+struct starfive_wdt_variant_t {
+ u32 unlock_key;
+ u8 enrst_shift;
+ u8 en_shift;
+ u8 intclr_check;
+ u8 intclr_ava_shift;
+};
+
+struct starfive_wdt_variant {
+ u32 control;
+ u32 load;
+ u32 enable;
+ u32 reload;
+ u32 value;
+ u32 int_clr;
+ u32 int_mask;
+ u32 unlock;
+ u32 enter_irq_status;
+ struct starfive_wdt_variant_t *variant;
+};
+
+struct starfive_wdt {
+ u64 freq;
clk_get_rate() returns unsigned long. Why would u64 be needed here ?
+ struct device *dev;
+ struct watchdog_device wdt_device;
+ struct clk *core_clk;
+ struct clk *apb_clk;
+ struct reset_control *rsts;
+ const struct starfive_wdt_variant *drv_data;
+ u32 count; /*count of timeout*/
+ u32 reload; /*restore the count*/
+ void __iomem *base;
+ spinlock_t lock; /* spinlock for register handling */
+
+ int irq;
+};
+
+#ifdef CONFIG_OF
+static struct starfive_wdt_variant_t jh7110_variant = {
+ .unlock_key = STARFIVE_WDT_JH7110_UNLOCK_KEY,
+ .enrst_shift = STARFIVE_WDT_JH7110_RESEN_SHIFT,
+ .en_shift = STARFIVE_WDT_JH7110_EN_SHIFT,
+};
+
+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,
+ .enter_irq_status = STARFIVE_WDT_JH7110_IMS,
+ .variant = &jh7110_variant,
+};
+
If there is no specific reason for all that complexity, drop it and introduce
it if/when necessary.
+static const struct of_device_id starfive_wdt_match[] = {
+ { .compatible = "starfive,jh7110-wdt", .data = &drv_data_jh7110 },
+ {}
+};
+MODULE_DEVICE_TABLE(of, starfive_wdt_match);
+#endif
+
+static const struct platform_device_id starfive_wdt_ids[] = {
+ {
+ .name = "starfive-wdt",
+ .driver_data = (unsigned long)&drv_data_jh7110,
+ },
+ {}
+};
+MODULE_DEVICE_TABLE(platform, starfive_wdt_ids);
+
+static int starfive_wdt_get_clock_rate(struct starfive_wdt *wdt)
+{
+ int ret;
+ u32 freq;
+
+ if (!IS_ERR(wdt->core_clk)) {
+ wdt->freq = clk_get_rate(wdt->core_clk);
+ return 0;
+ }
+ dev_dbg(wdt->dev, "get rate failed, need clock-frequency define in dts.\n");
+
+ /* Next we try to get clock-frequency from dts.*/
+ ret = of_property_read_u32(wdt->dev->of_node, "clock-frequency", &freq);
+ if (!ret) {
+ wdt->freq = (u64)freq;
Unnecessary typecast.
+ return 0;
+ }
+ dev_err(wdt->dev, "get clock-frequency failed\n");
+
+ return -ENOENT;
+}
I have never seen this kind of code before. Why would it be needed ?
+
+static int starfive_wdt_enable_clock(struct starfive_wdt *wdt)
+{
+ int ret = 0;
+
+ wdt->apb_clk = devm_clk_get(wdt->dev, "apb_clk");
+ if (!IS_ERR(wdt->apb_clk)) {
+ ret = clk_prepare_enable(wdt->apb_clk);
+ if (ret) {
+ dev_err(wdt->dev, "failed to enable apb_clk.\n");
+ goto err;
+ }
+ } else {
+ dev_err(wdt->dev, "failed to get apb_clk.\n");
+ ret = PTR_ERR(wdt->apb_clk);
+ goto err;
+ }
Why not use devm_clk_get_enabled() ?
+
+ wdt->core_clk = devm_clk_get(wdt->dev, "core_clk");
+ if (!IS_ERR(wdt->core_clk)) {
+ ret = clk_prepare_enable(wdt->core_clk);
+ if (ret) {
+ dev_err(wdt->dev, "failed to enable core_clk.\n");
+ goto err;
+ }
+ } else {
+ dev_err(wdt->dev, "failed to get core_clk.\n");
+ ret = PTR_ERR(wdt->core_clk);
+ goto err;
+ }
+
+ return 0;
+
+err:
+ return ret;
Unnecessary. Return directly.
+}
+
+static int starfive_wdt_reset_init(struct starfive_wdt *wdt)
+{
+ int ret = 0;
+
+ wdt->rsts = devm_reset_control_array_get_exclusive(wdt->dev);
+ if (!IS_ERR(wdt->rsts)) {
+ ret = reset_control_deassert(wdt->rsts);
+ if (ret) {
+ dev_err(wdt->dev, "failed to deassert rsts.\n");
+ goto err;
+ }
+ } else {
+ dev_err(wdt->dev, "failed to get rsts error.\n");
failed ... error is redundant. Drop "errror".
+ ret = PTR_ERR(wdt->rsts);
+ goto err;
+ }
+
+ return 0;
+
+err:
+ return ret;
Unnecessary. Return directly.
+}
+
+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 int starfive_wdt_is_locked(struct starfive_wdt *wdt)
bool ?
+{
+ u32 val;
+
+ val = readl(wdt->base + wdt->drv_data->unlock);
+ return !!(val & STARFIVE_WDT_LOCKED);
+}
+
+static void starfive_wdt_unlock(struct starfive_wdt *wdt)
+{
+ if (starfive_wdt_is_locked(wdt))
+ writel(wdt->drv_data->variant->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->variant->unlock_key,
+ wdt->base + wdt->drv_data->unlock);
+}
+
+/* enable watchdog interrupt */
+static inline void starfive_wdt_int_enable(struct starfive_wdt *wdt)
+{
+ u32 val;
+
+ if (wdt->drv_data->int_mask) {
+ val = readl(wdt->base + wdt->drv_data->int_mask);
+ val &= ~STARFIVE_WDT_INT_DIS;
+ writel(val, wdt->base + wdt->drv_data->int_mask);
+ }
+}
+
+/* disable watchdog interrupt */
+static inline void starfive_wdt_int_disable(struct starfive_wdt *wdt)
+{
+ u32 val;
+
+ if (wdt->drv_data->int_mask) {
+ val = readl(wdt->base + wdt->drv_data->int_mask);
+ val |= STARFIVE_WDT_INT_DIS;
+ writel(val, wdt->base + wdt->drv_data->int_mask);
+ }
+}
+
+/* enable watchdog interrupt to reset */
+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->variant->enrst_shift;
+ writel(val, wdt->base + wdt->drv_data->control);
+}
+
+/* disable watchdog interrupt to reset */
+static void starfive_wdt_disable_reset(struct starfive_wdt *wdt)
+{
+ u32 val;
+
+ val = readl(wdt->base + wdt->drv_data->control);
+ val &= ~(STARFIVE_WDT_RESET_EN << wdt->drv_data->variant->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->enter_irq_status);
+}
+
+static void starfive_wdt_int_clr(struct starfive_wdt *wdt)
+{
+ void __iomem *addr;
+ u8 clr_check;
+ u8 clr_ava_shift;
+ u32 value;
+ int ret = 0;
+
+ addr = wdt->base + wdt->drv_data->int_clr;
+ clr_ava_shift = wdt->drv_data->variant->intclr_ava_shift;
+ clr_check = wdt->drv_data->variant->intclr_check;
+ if (clr_check) {
+ /* waiting interrupt can be to clearing */
+ value = readl(addr);
+ ret = readl_poll_timeout_atomic(addr, value,
+ !(value & BIT(clr_ava_shift)),
+ STARFIVE_WDT_DELAY_US, STARFIVE_WDT_TIMEOUT_US);
+ }
+
+ if (!ret)
+ writel(STARFIVE_WDT_INTCLR, addr);
+
+ if (starfive_wdt_raise_irq_status(wdt))
+ enable_irq(wdt->irq);
+}
+
+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);
+}
+
+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->variant->en_shift;
+ writel(val, wdt->base + wdt->drv_data->enable);
+}
+
+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->variant->en_shift);
+ writel(val, wdt->base + wdt->drv_data->enable);
+}
+
+static inline void starfive_wdt_set_relod_count(struct starfive_wdt *wdt, u32 count)
+{
+ writel(count, wdt->base + wdt->drv_data->load);
+ if (wdt->drv_data->reload)
+ writel(0x1, wdt->base + wdt->drv_data->reload);
+ else
+ /* jh7110 need enable controller to reload counter */
+ starfive_wdt_enable(wdt);
+}
+
+static void starfive_wdt_mask_and_disable_reset(struct starfive_wdt *wdt, bool mask)
+{
+ starfive_wdt_unlock(wdt);
+
+ if (mask)
+ starfive_wdt_disable_reset(wdt);
+ else
+ starfive_wdt_enable_reset(wdt);
+
+ starfive_wdt_lock(wdt);
+}
+
+static unsigned int starfive_wdt_max_timeout(struct starfive_wdt *wdt)
+{
+ 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;
+ u32 irq_status;
+
+ starfive_wdt_unlock(wdt);
+ /*
+ * Because set half count value,
+ * timeleft value should add the count value before first timeout.
+ */
+ irq_status = starfive_wdt_raise_irq_status(wdt) ? 1 : 0;
+ count = starfive_wdt_get_count(wdt) + (1 - irq_status) * 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);
+
+ spin_lock(&wdt->lock);
+
+ starfive_wdt_unlock(wdt);
+ starfive_wdt_int_clr(wdt);
+ starfive_wdt_set_relod_count(wdt, wdt->count);
+ starfive_wdt_lock(wdt);
+
+ spin_unlock(&wdt->lock);
+
+ return 0;
+}
+
+static irqreturn_t starfive_wdt_interrupt_handler(int irq, void *data)
+{
+ /*
+ * We don't clear the IRQ status. It's supposed to be done by the
+ * following ping operations.
+ */
+ struct platform_device *pdev = data;
+ struct starfive_wdt *wdt = platform_get_drvdata(pdev);
+
+ /* Disable the IRQ and avoid re-entry interrupt. */
+ disable_irq_nosync(wdt->irq);
+
+ return IRQ_HANDLED;
+}
What is the purpose of this interrupt ? It doesn't add any value
as implemented.
+
+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_int_disable(wdt);
+ starfive_wdt_int_clr(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(wdt->dev);
+
+ return 0;
+}
+
+static int starfive_wdt_start(struct watchdog_device *wdd)
+{
+ struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ pm_runtime_get_sync(wdt->dev);
+
+ spin_lock(&wdt->lock);
+
+ starfive_wdt_unlock(wdt);
+
+ if (soft_noboot)
+ starfive_wdt_disable_reset(wdt);
+ else
+ starfive_wdt_enable_reset(wdt);
+
+ starfive_wdt_int_clr(wdt);
+ starfive_wdt_set_count(wdt, wdt->count);
+ starfive_wdt_int_enable(wdt);
+ starfive_wdt_enable(wdt);
+
+ starfive_wdt_lock(wdt);
+
+ spin_unlock(&wdt->lock);
+
+ return 0;
+}
+
+static int starfive_wdt_restart(struct watchdog_device *wdd, unsigned long action,
+ void *data)
+{
+ struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ spin_lock(&wdt->lock);
+ starfive_wdt_unlock(wdt);
+ /* disable watchdog, to be safe */
+ starfive_wdt_disable(wdt);
+
+ if (soft_noboot)
+ starfive_wdt_disable_reset(wdt);
+ else
+ starfive_wdt_enable_reset(wdt);
+
+ /* put initial values into count and data */
+ starfive_wdt_set_count(wdt, wdt->count);
This is supposed to reset the system. Why write wdt->count
instead of 0 or 1 ?
+
+ /* set the watchdog to go and reset... */
+ starfive_wdt_int_clr(wdt);
+ starfive_wdt_int_enable(wdt);
+ starfive_wdt_enable(wdt);
+
+ starfive_wdt_lock(wdt);
+ spin_unlock(&wdt->lock);
+
+ return 0;
+}
+
+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 count;
+
+ spin_lock(&wdt->lock);
+
+ if (timeout < 1)
+ return -EINVAL;
Can not happen if configured properly, ie if min_timeout is set *which it is).
+
+ /*
+ * This watchdog takes twice timeouts to reset.
+ * In order to reduce time to reset, should set half count value.
+ */
+ count = timeout * freq / 2;
+
+ if (count > STARFIVE_WDT_MAXCNT) {
+ dev_warn(wdt->dev, "timeout %d too big,use the MAX-timeout set.\n",
+ timeout);
+ timeout = starfive_wdt_max_timeout(wdt);
+ count = timeout * freq;
+ }
+
+ dev_info(wdt->dev, "Heartbeat: timeout=%d, count/2=%d (%08x)\n",
+ timeout, count, count);
+
+ starfive_wdt_unlock(wdt);
+ starfive_wdt_disable(wdt);
+ starfive_wdt_set_relod_count(wdt, count);
+ starfive_wdt_enable(wdt);
+ starfive_wdt_lock(wdt);
+
+ wdt->count = count;
+ wdd->timeout = timeout;
+
+ spin_unlock(&wdt->lock);
+
+ return 0;
+}
+
+#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
+
+static const struct watchdog_info starfive_wdt_ident = {
+ .options = OPTIONS,
+ .firmware_version = 0,
+ .identity = "StarFive Watchdog",
+};
+
+static const struct watchdog_ops starfive_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = starfive_wdt_start,
+ .stop = starfive_wdt_pm_stop,
+ .ping = starfive_wdt_keepalive,
+ .set_timeout = starfive_wdt_set_timeout,
+ .restart = starfive_wdt_restart,
+ .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 inline const struct starfive_wdt_variant *
+starfive_wdt_get_drv_data(struct platform_device *pdev)
+{
+ const struct starfive_wdt_variant *variant;
+
+ variant = of_device_get_match_data(&pdev->dev);
+ if (!variant) {
+ /* Device matched by platform_device_id */
+ variant = (struct starfive_wdt_variant *)
+ platform_get_device_id(pdev)->driver_data;
+ }
+
+ return variant;
+}
+
+static int starfive_wdt_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct starfive_wdt *wdt;
+ int started = 0;
+ int ret;
+
+ pm_runtime_enable(dev);
+
+ 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;
+
+ wdt->drv_data = starfive_wdt_get_drv_data(pdev);
+
+ wdt->irq = platform_get_irq(pdev, 0);
+ if (wdt->irq < 0) {
+ dev_err(dev, "can not find irq.\n");
+ return wdt->irq;
+ }
+
+ /* 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);
+ goto err;
+ }
+
+ ret = starfive_wdt_enable_clock(wdt);
+ if (ret)
+ goto err;
+
+ starfive_wdt_get_clock_rate(wdt);
+
This can fail, leaving the clock rate uninitialized.
+ ret = starfive_wdt_reset_init(wdt);
+ if (ret)
+ goto err;
+
+ wdt->wdt_device.min_timeout = 1;
+ wdt->wdt_device.max_timeout = starfive_wdt_max_timeout(wdt);
+
+ watchdog_set_drvdata(&wdt->wdt_device, wdt);
+
+ /*
+ * see if we can actually set the requested timer margin,
+ * and if not, try the default value.
+ */
+ watchdog_init_timeout(&wdt->wdt_device, tmr_margin, dev);
+
+ ret = starfive_wdt_set_timeout(&wdt->wdt_device,
+ wdt->wdt_device.timeout);
+ if (ret) {
+ dev_err(dev, "tmr_margin value out of range, default %d used\n",
+ STARFIVE_WDT_DEFAULT_TIME);
+ starfive_wdt_set_timeout(&wdt->wdt_device,
+ STARFIVE_WDT_DEFAULT_TIME);
+ }
+
+ ret = devm_request_irq(dev, wdt->irq, starfive_wdt_interrupt_handler, 0,
+ pdev->name, pdev);
+ if (ret != 0) {
+ dev_err(dev, "failed to install irq (%d)\n", ret);
+ goto err;
+ }
+
That interrupt seems pointless.
+ watchdog_set_nowayout(&wdt->wdt_device, nowayout);
+ watchdog_set_restart_priority(&wdt->wdt_device, 128);
+
+ wdt->wdt_device.parent = dev;
+
+ ret = watchdog_register_device(&wdt->wdt_device);
+ if (ret)
+ goto err;
+
+ starfive_wdt_mask_and_disable_reset(wdt, false);
+
+ if (tmr_atboot && started == 0) {
+ starfive_wdt_start(&wdt->wdt_device);
+ } else if (!tmr_atboot) {
+ /*
+ *if we're not enabling the watchdog, then ensure it is
+ * disabled if it has been left running from the bootloader
+ * or other source.
+ */
+ starfive_wdt_stop(&wdt->wdt_device);
+ }
This should be done before registering the watdhdog, and the watchdog core
should be informed if the watchdog is running.
+
+#ifdef CONFIG_PM
+ clk_disable_unprepare(wdt->core_clk);
+ clk_disable_unprepare(wdt->apb_clk);
+#endif
+
+ platform_set_drvdata(pdev, wdt);
+
+ return 0;
+
+err:
+ return ret;
This is never acceptable. Return directly.
+}
+
+static int starfive_wdt_remove(struct platform_device *dev)
+{
+ struct starfive_wdt *wdt = platform_get_drvdata(dev);
+
+ starfive_wdt_mask_and_disable_reset(wdt, true);
+ watchdog_unregister_device(&wdt->wdt_device);
+
+ clk_disable_unprepare(wdt->core_clk);
+ clk_disable_unprepare(wdt->apb_clk);
+ pm_runtime_disable(wdt->dev);
This is potentially unbalanced. I would suggest to use
watchdog_stop_on_unregister().
+
+ return 0;
+}
+
+static void starfive_wdt_shutdown(struct platform_device *dev)
+{
+ struct starfive_wdt *wdt = platform_get_drvdata(dev);
+
+ starfive_wdt_mask_and_disable_reset(wdt, true);
+
+ starfive_wdt_pm_stop(&wdt->wdt_device);
Use watchdog_stop_on_reboot().
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int starfive_wdt_suspend(struct device *dev)
+{
+ int ret;
+ struct starfive_wdt *wdt = dev_get_drvdata(dev);
+
+ starfive_wdt_unlock(wdt);
+
+ /* Save watchdog state, and turn it off. */
+ wdt->reload = starfive_wdt_get_count(wdt);
+
+ starfive_wdt_mask_and_disable_reset(wdt, true);
+
+ /* 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_relod_count(wdt, wdt->reload);
+
+ starfive_wdt_restart(&wdt->wdt_device, 0, NULL);
+
+ starfive_wdt_mask_and_disable_reset(wdt, false);
+
+ 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);
+
+ clk_disable_unprepare(wdt->apb_clk);
+ clk_disable_unprepare(wdt->core_clk);
+
+ return 0;
+}
+
+static int starfive_wdt_runtime_resume(struct device *dev)
+{
+ struct starfive_wdt *wdt = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_prepare_enable(wdt->apb_clk);
+ if (ret) {
+ dev_err(wdt->dev, "failed to enable apb_clk.\n");
+ goto err;
+ }
+
+ ret = clk_prepare_enable(wdt->core_clk);
+ if (ret) {
+ dev_err(wdt->dev, "failed to enable core_clk.\n");
+ goto err;
+ }
+
+ return 0;
+
+err:
+ return ret;
+}
+#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,
+ .id_table = starfive_wdt_ids,
+ .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 v2");
