@@ -27,6 +27,10 @@ properties:
description: This is a 1-byte memory-mapped address
maxItems: 1
+ gpios:
+ description: Optional GPIO used for controlling WDI when WDI bit is not mapped to memory
+ maxItems: 1
+
required:
- compatible
- reg
@@ -27,6 +27,7 @@
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/property.h>
+#include <linux/gpio/consumer.h>
#define DEFAULT_HEARTBEAT 60
#define MAX_HEARTBEAT 60
@@ -53,6 +54,9 @@ struct max63xx_wdt {
void __iomem *base;
spinlock_t lock;
+ /* GPIOs */
+ struct gpio_desc *gpio_wdi;
+
/* WDI and WSET bits write access routines */
void (*ping)(struct max63xx_wdt *wdt);
void (*set)(struct max63xx_wdt *wdt, u8 set);
@@ -158,6 +162,17 @@ static const struct watchdog_info max63xx_wdt_info = {
.identity = "max63xx Watchdog",
};
+static void max63xx_gpio_ping(struct max63xx_wdt *wdt)
+{
+ spin_lock(&wdt->lock);
+
+ gpiod_set_value_cansleep(wdt->gpio_wdi, 1);
+ udelay(1);
+ gpiod_set_value_cansleep(wdt->gpio_wdi, 0);
+
+ spin_unlock(&wdt->lock);
+}
+
static void max63xx_mmap_ping(struct max63xx_wdt *wdt)
{
u8 val;
@@ -225,6 +240,19 @@ static int max63xx_wdt_probe(struct platform_device *pdev)
return -EINVAL;
}
+ wdt->gpio_wdi = devm_gpiod_get(dev, NULL, GPIOD_FLAGS_BIT_DIR_OUT);
+ if (IS_ERR(wdt->gpio_wdi) && PTR_ERR(wdt->gpio_wdi) != -ENOENT) {
+ if (PTR_ERR(wdt->gpio_wdi) != -EPROBE_DEFER)
+ dev_err(dev, "unable to request gpio: %ld\n",
+ PTR_ERR(wdt->gpio_wdi));
+ return PTR_ERR(wdt->gpio_wdi);
+ }
+
+ if (!IS_ERR(wdt->gpio_wdi))
+ wdt->ping = max63xx_gpio_ping;
+ else
+ wdt->gpio_wdi = NULL;
+
err = max63xx_mmap_init(pdev, wdt);
if (err)
return err;
On some boards is WDI logic of max6370 chip connected via GPIO. So extend max63xx_wdt driver and DTS schema to allow specifying WDI logic via GPIO. Signed-off-by: Pali Rohár <pali@kernel.org> --- .../bindings/watchdog/maxim,max63xx.yaml | 4 +++ drivers/watchdog/max63xx_wdt.c | 28 +++++++++++++++++++ 2 files changed, 32 insertions(+)