[PATCH v2 1/2] watchdog: aspeed: Enable pre-timeout interrupt

From: Eddie James
Date: Tue Nov 01 2022 - 16:54:26 EST


Enable the core pre-timeout interrupt on AST2500 and AST2600.

Signed-off-by: Eddie James <eajames@xxxxxxxxxxxxx>
---
drivers/watchdog/aspeed_wdt.c | 104 ++++++++++++++++++++++++++++------
1 file changed, 88 insertions(+), 16 deletions(-)

diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
index 0cff2adfbfc9..86b5331bc491 100644
--- a/drivers/watchdog/aspeed_wdt.c
+++ b/drivers/watchdog/aspeed_wdt.c
@@ -5,11 +5,14 @@
* Joel Stanley <joel@xxxxxxxxx>
*/

+#include <linux/bits.h>
#include <linux/delay.h>
+#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>

@@ -18,28 +21,41 @@ module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

+struct aspeed_wdt_config {
+ u32 ext_pulse_width_mask;
+ u32 irq_shift;
+ u32 irq_mask;
+};
+
struct aspeed_wdt {
struct watchdog_device wdd;
void __iomem *base;
u32 ctrl;
-};
-
-struct aspeed_wdt_config {
- u32 ext_pulse_width_mask;
+ const struct aspeed_wdt_config *cfg;
};

static const struct aspeed_wdt_config ast2400_config = {
.ext_pulse_width_mask = 0xff,
+ .irq_shift = 0,
+ .irq_mask = 0,
};

static const struct aspeed_wdt_config ast2500_config = {
.ext_pulse_width_mask = 0xfffff,
+ .irq_shift = 12,
+ .irq_mask = GENMASK(31, 12),
+};
+
+static const struct aspeed_wdt_config ast2600_config = {
+ .ext_pulse_width_mask = 0xfffff,
+ .irq_shift = 0,
+ .irq_mask = GENMASK(31, 10),
};

static const struct of_device_id aspeed_wdt_of_table[] = {
{ .compatible = "aspeed,ast2400-wdt", .data = &ast2400_config },
{ .compatible = "aspeed,ast2500-wdt", .data = &ast2500_config },
- { .compatible = "aspeed,ast2600-wdt", .data = &ast2500_config },
+ { .compatible = "aspeed,ast2600-wdt", .data = &ast2600_config },
{ },
};
MODULE_DEVICE_TABLE(of, aspeed_wdt_of_table);
@@ -58,6 +74,7 @@ MODULE_DEVICE_TABLE(of, aspeed_wdt_of_table);
#define WDT_CTRL_RESET_SYSTEM BIT(1)
#define WDT_CTRL_ENABLE BIT(0)
#define WDT_TIMEOUT_STATUS 0x10
+#define WDT_TIMEOUT_STATUS_IRQ BIT(2)
#define WDT_TIMEOUT_STATUS_BOOT_SECONDARY BIT(1)
#define WDT_CLEAR_TIMEOUT_STATUS 0x14
#define WDT_CLEAR_TIMEOUT_AND_BOOT_CODE_SELECTION BIT(0)
@@ -160,6 +177,26 @@ static int aspeed_wdt_set_timeout(struct watchdog_device *wdd,
return 0;
}

+static int aspeed_wdt_set_pretimeout(struct watchdog_device *wdd,
+ unsigned int pretimeout)
+{
+ struct aspeed_wdt *wdt = to_aspeed_wdt(wdd);
+ u32 actual = pretimeout * WDT_RATE_1MHZ;
+ u32 s = wdt->cfg->irq_shift;
+ u32 m = wdt->cfg->irq_mask;
+
+ wdd->pretimeout = pretimeout;
+ wdt->ctrl &= ~m;
+ if (pretimeout)
+ wdt->ctrl |= ((actual << s) & m) | WDT_CTRL_WDT_INTR;
+ else
+ wdt->ctrl &= ~WDT_CTRL_WDT_INTR;
+
+ writel(wdt->ctrl, wdt->base + WDT_CTRL);
+
+ return 0;
+}
+
static int aspeed_wdt_restart(struct watchdog_device *wdd,
unsigned long action, void *data)
{
@@ -232,6 +269,7 @@ static const struct watchdog_ops aspeed_wdt_ops = {
.stop = aspeed_wdt_stop,
.ping = aspeed_wdt_ping,
.set_timeout = aspeed_wdt_set_timeout,
+ .set_pretimeout = aspeed_wdt_set_pretimeout,
.restart = aspeed_wdt_restart,
.owner = THIS_MODULE,
};
@@ -243,10 +281,29 @@ static const struct watchdog_info aspeed_wdt_info = {
.identity = KBUILD_MODNAME,
};

+static const struct watchdog_info aspeed_wdt_pretimeout_info = {
+ .options = WDIOF_KEEPALIVEPING
+ | WDIOF_PRETIMEOUT
+ | WDIOF_MAGICCLOSE
+ | WDIOF_SETTIMEOUT,
+ .identity = KBUILD_MODNAME,
+};
+
+static irqreturn_t aspeed_wdt_irq(int irq, void *arg)
+{
+ struct watchdog_device *wdd = arg;
+ struct aspeed_wdt *wdt = to_aspeed_wdt(wdd);
+ u32 status = readl(wdt->base + WDT_TIMEOUT_STATUS);
+
+ if (status & WDT_TIMEOUT_STATUS_IRQ)
+ watchdog_notify_pretimeout(wdd);
+
+ return IRQ_HANDLED;
+}
+
static int aspeed_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
- const struct aspeed_wdt_config *config;
const struct of_device_id *ofdid;
struct aspeed_wdt *wdt;
struct device_node *np;
@@ -259,11 +316,33 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
if (!wdt)
return -ENOMEM;

+ np = dev->of_node;
+
+ ofdid = of_match_node(aspeed_wdt_of_table, np);
+ if (!ofdid)
+ return -EINVAL;
+ wdt->cfg = ofdid->data;
+
wdt->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(wdt->base))
return PTR_ERR(wdt->base);

wdt->wdd.info = &aspeed_wdt_info;
+
+ if (wdt->cfg->irq_mask) {
+ int irq = platform_get_irq_optional(pdev, 0);
+
+ if (irq > 0) {
+ ret = devm_request_irq(dev, irq, aspeed_wdt_irq,
+ IRQF_SHARED, dev_name(dev),
+ wdt);
+ if (ret)
+ return ret;
+
+ wdt->wdd.info = &aspeed_wdt_pretimeout_info;
+ }
+ }
+
wdt->wdd.ops = &aspeed_wdt_ops;
wdt->wdd.max_hw_heartbeat_ms = WDT_MAX_TIMEOUT_MS;
wdt->wdd.parent = dev;
@@ -273,13 +352,6 @@ static int aspeed_wdt_probe(struct platform_device *pdev)

watchdog_set_nowayout(&wdt->wdd, nowayout);

- np = dev->of_node;
-
- ofdid = of_match_node(aspeed_wdt_of_table, np);
- if (!ofdid)
- return -EINVAL;
- config = ofdid->data;
-
/*
* On clock rates:
* - ast2400 wdt can run at PCLK, or 1MHz
@@ -331,7 +403,7 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
(of_device_is_compatible(np, "aspeed,ast2600-wdt"))) {
u32 reg = readl(wdt->base + WDT_RESET_WIDTH);

- reg &= config->ext_pulse_width_mask;
+ reg &= wdt->cfg->ext_pulse_width_mask;
if (of_property_read_bool(np, "aspeed,ext-active-high"))
reg |= WDT_ACTIVE_HIGH_MAGIC;
else
@@ -339,7 +411,7 @@ static int aspeed_wdt_probe(struct platform_device *pdev)

writel(reg, wdt->base + WDT_RESET_WIDTH);

- reg &= config->ext_pulse_width_mask;
+ reg &= wdt->cfg->ext_pulse_width_mask;
if (of_property_read_bool(np, "aspeed,ext-push-pull"))
reg |= WDT_PUSH_PULL_MAGIC;
else
@@ -349,7 +421,7 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
}

if (!of_property_read_u32(np, "aspeed,ext-pulse-duration", &duration)) {
- u32 max_duration = config->ext_pulse_width_mask + 1;
+ u32 max_duration = wdt->cfg->ext_pulse_width_mask + 1;

if (duration == 0 || duration > max_duration) {
dev_err(dev, "Invalid pulse duration: %uus\n",
--
2.31.1