diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
index efbc36872670d3a6642fb374a05d50ee1d83bd20..7a171920dd21c2815a50f36e038af454a74fee92 100644
--- a/drivers/watchdog/dw_wdt.c
+++ b/drivers/watchdog/dw_wdt.c
@@ -22,6 +22,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/pm.h>
#include <linux/platform_device.h>
@@ -36,6 +37,8 @@
#define WDOG_CURRENT_COUNT_REG_OFFSET 0x08
#define WDOG_COUNTER_RESTART_REG_OFFSET 0x0c
#define WDOG_COUNTER_RESTART_KICK_VALUE 0x76
+#define WDOG_INTERRUPT_STATUS_REG_OFFSET 0x10
+#define WDOG_INTERRUPT_CLEAR_REG_OFFSET 0x14
#define WDOG_COMP_PARAMS_1_REG_OFFSET 0xf4
#define WDOG_COMP_PARAMS_1_USE_FIX_TOP BIT(6)
@@ -59,6 +62,11 @@ module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+enum dw_wdt_rmod {
+ DW_WDT_RMOD_RESET = 1,
+ DW_WDT_RMOD_IRQ = 2
+};
+
struct dw_wdt_timeout {
u32 top_val;
unsigned int sec;
@@ -70,6 +78,7 @@ struct dw_wdt {
struct clk *clk;
struct clk *pclk;
unsigned long rate;
+ enum dw_wdt_rmod rmod;
struct dw_wdt_timeout timeouts[DW_WDT_NUM_TOPS];
struct watchdog_device wdd;
struct reset_control *rst;
@@ -86,6 +95,20 @@ static inline int dw_wdt_is_enabled(struct dw_wdt *dw_wdt)
WDOG_CONTROL_REG_WDT_EN_MASK;
}
+static void dw_wdt_update_mode(struct dw_wdt *dw_wdt, enum dw_wdt_rmod rmod)
+{
+ u32 val;
+
+ val = readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
+ if (rmod == DW_WDT_RMOD_IRQ)
+ val |= WDOG_CONTROL_REG_RESP_MODE_MASK;
+ else
+ val &= ~WDOG_CONTROL_REG_RESP_MODE_MASK;
+ writel(val, dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
+
+ dw_wdt->rmod = rmod;
+}
+
static unsigned int dw_wdt_find_best_top(struct dw_wdt *dw_wdt,
unsigned int timeout, u32 *top_val)
{
@@ -145,7 +168,11 @@ static unsigned int dw_wdt_get_timeout(struct dw_wdt *dw_wdt)
break;
}
- return dw_wdt->timeouts[idx].sec;
+ /*
+ * In IRQ mode due to the two stages counter, the actual timeout is
+ * twice greater than the TOP setting.
+ */
+ return dw_wdt->timeouts[idx].sec * dw_wdt->rmod;
}
static int dw_wdt_ping(struct watchdog_device *wdd)
@@ -164,7 +191,20 @@ static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s)
unsigned int timeout;
u32 top_val;
- timeout = dw_wdt_find_best_top(dw_wdt, top_s, &top_val);
+ /*
+ * Note IRQ mode being enabled means having a non-zero pre-timeout
+ * setup. In this case we try to find a TOP as close to the half of the
+ * requested timeout as possible since DW Watchdog IRQ mode is designed
+ * in two stages way - first timeout rises the pre-timeout interrupt,
+ * second timeout performs the system reset. So basically the effective
+ * watchdog-caused reset happens after two watchdog TOPs elapsed.
+ */
+ timeout = dw_wdt_find_best_top(dw_wdt, DIV_ROUND_UP(top_s, dw_wdt->rmod),
+ &top_val);
+ if (dw_wdt->rmod == DW_WDT_RMOD_IRQ)
+ wdd->pretimeout = timeout;
+ else
+ wdd->pretimeout = 0;
/*
* Set the new value in the watchdog. Some versions of dw_wdt
@@ -175,25 +215,47 @@ static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s)
writel(top_val | top_val << WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT,
dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
+ /* Kick new TOP value into the watchdog counter if activated. */
+ if (watchdog_active(wdd))
+ dw_wdt_ping(wdd);
+
/*
* In case users set bigger timeout value than HW can support,
* kernel(watchdog_dev.c) helps to feed watchdog before
* wdd->max_hw_heartbeat_ms
*/
if (top_s * 1000 <= wdd->max_hw_heartbeat_ms)
- wdd->timeout = timeout;
+ wdd->timeout = timeout * dw_wdt->rmod;
else
wdd->timeout = top_s;
return 0;
}
+static int dw_wdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req)
+{
+ struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
+
+ /*
+ * We ignore actual value of the timeout passed from user-space
+ * using it as a flag whether the pretimeout functionality is intended
+ * to be activated.
+ */
+ dw_wdt_update_mode(dw_wdt, req ? DW_WDT_RMOD_IRQ : DW_WDT_RMOD_RESET);
+ dw_wdt_set_timeout(wdd, wdd->timeout);
+
+ return 0;
+}
+
static void dw_wdt_arm_system_reset(struct dw_wdt *dw_wdt)
{
u32 val = readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
- /* Disable interrupt mode; always perform system reset. */
- val &= ~WDOG_CONTROL_REG_RESP_MODE_MASK;
+ /* Disable/enable interrupt mode depending on the RMOD flag. */
+ if (dw_wdt->rmod == DW_WDT_RMOD_IRQ)
+ val |= WDOG_CONTROL_REG_RESP_MODE_MASK;
+ else
+ val &= ~WDOG_CONTROL_REG_RESP_MODE_MASK;
/* Enable watchdog. */
val |= WDOG_CONTROL_REG_WDT_EN_MASK;
writel(val, dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
@@ -231,6 +293,7 @@ static int dw_wdt_restart(struct watchdog_device *wdd,
struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
writel(0, dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
+ dw_wdt_update_mode(dw_wdt, DW_WDT_RMOD_RESET);
if (dw_wdt_is_enabled(dw_wdt))
writel(WDOG_COUNTER_RESTART_KICK_VALUE,
dw_wdt->regs + WDOG_COUNTER_RESTART_REG_OFFSET);
@@ -246,9 +309,19 @@ static int dw_wdt_restart(struct watchdog_device *wdd,
static unsigned int dw_wdt_get_timeleft(struct watchdog_device *wdd)
{
struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
+ unsigned int sec;
+ u32 val;
+
+ val = readl(dw_wdt->regs + WDOG_CURRENT_COUNT_REG_OFFSET);
+ sec = val / dw_wdt->rate;
- return readl(dw_wdt->regs + WDOG_CURRENT_COUNT_REG_OFFSET) /
- dw_wdt->rate;
+ if (dw_wdt->rmod == DW_WDT_RMOD_IRQ) {
+ val = readl(dw_wdt->regs + WDOG_INTERRUPT_STATUS_REG_OFFSET);
+ if (!val)
+ sec += wdd->pretimeout;
+ }
+
+ return sec;
}
static const struct watchdog_info dw_wdt_ident = {
@@ -257,16 +330,41 @@ static const struct watchdog_info dw_wdt_ident = {
.identity = "Synopsys DesignWare Watchdog",
};
+static const struct watchdog_info dw_wdt_pt_ident = {
+ .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
+ WDIOF_PRETIMEOUT | WDIOF_MAGICCLOSE,
+ .identity = "Synopsys DesignWare Watchdog",
+};
+
static const struct watchdog_ops dw_wdt_ops = {
.owner = THIS_MODULE,
.start = dw_wdt_start,
.stop = dw_wdt_stop,
.ping = dw_wdt_ping,
.set_timeout = dw_wdt_set_timeout,
+ .set_pretimeout = dw_wdt_set_pretimeout,
.get_timeleft = dw_wdt_get_timeleft,
.restart = dw_wdt_restart,
};
+static irqreturn_t dw_wdt_irq(int irq, void *devid)
+{
+ struct dw_wdt *dw_wdt = devid;
+ u32 val;
+
+ /*
+ * We don't clear the IRQ status. It's supposed to be done by the
+ * following ping operations.
+ */
+ val = readl(dw_wdt->regs + WDOG_INTERRUPT_STATUS_REG_OFFSET);
+ if (!val)
+ return IRQ_NONE;
+
+ watchdog_notify_pretimeout(&dw_wdt->wdd);
+
+ return IRQ_HANDLED;
+}
+
#ifdef CONFIG_PM_SLEEP
static int dw_wdt_suspend(struct device *dev)
{
@@ -447,6 +545,31 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
goto out_disable_pclk;
}
+ /* Enable normal reset without pre-timeout by default. */
+ dw_wdt_update_mode(dw_wdt, DW_WDT_RMOD_RESET);
+
+ /*
+ * Pre-timeout IRQ is optional, since some hardware may lack support
+ * of it. Note we must request rising-edge IRQ, since the lane is left
+ * pending either until the next watchdog kick event or up to the
+ * system reset.
+ */
+ ret = platform_get_irq_optional(pdev, 0);
+ if (ret > 0) {
+ ret = devm_request_irq(dev, ret, dw_wdt_irq,
+ IRQF_SHARED | IRQF_TRIGGER_RISING,
+ pdev->name, dw_wdt);
+ if (ret)
+ goto out_disable_pclk;
+
+ dw_wdt->wdd.info = &dw_wdt_pt_ident;
+ } else {
+ if (ret == -EPROBE_DEFER)
+ goto out_disable_pclk;
+
+ dw_wdt->wdd.info = &dw_wdt_ident;
+ }
+
reset_control_deassert(dw_wdt->rst);
ret = dw_wdt_init_timeouts(dw_wdt, dev);
@@ -454,7 +577,6 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
goto out_disable_clk;
wdd = &dw_wdt->wdd;
- wdd->info = &dw_wdt_ident;
wdd->ops = &dw_wdt_ops;
wdd->min_timeout = dw_wdt_get_min_timeout(dw_wdt);
wdd->max_hw_heartbeat_ms = dw_wdt_get_max_timeout_ms(dw_wdt);