watchdog: atcwdt200: fix return value when watchdog is enabled

atcwdt_get_int_timer_type() returned TMR_UNKNOWN (enum value 3) when
CTRL_WDT_EN was set in the control register.

Because atcwdt_probe() checks "ret = atcwdt_get_int_timer_type(drv_data);
if (ret) return ret;", returning TMR_UNKNOWN caused probe() to return 3
instead of a valid negative error code.

Fix this by returning -EBUSY via dev_err_probe() when the watchdog is
already enabled and update the kernel-doc description accordingly.

Fixes: e4e0848ad046 ("watchdog: atcwdt200: Add driver for Andes ATCWDT200")
Signed-off-by: Surendra Singh Chouhan <kr494167@gmail.com>
Link: https://lore.kernel.org/r/20260723022634.8642-1-kr494167@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/watchdog/atcwdt200_wdt.c b/drivers/watchdog/atcwdt200_wdt.c
index 8e3b18aea368ff1a8049d21d30b1f064af1eaadc..7e757c217b0b53579e49657359898231ee20615e 100644 (file)
--- a/drivers/watchdog/atcwdt200_wdt.c
+++ b/drivers/watchdog/atcwdt200_wdt.c
@@ -260,9 +260,9 @@ static void atcwdt_get_timeout_params(struct atcwdt_drv *drv_data,
  * register to determine the interrupt timer type supported by the hardware.
  *
  * Note: This function must only be called when the ATCWDT200 watchdog is
- * disabled. If the watchdog is enabled, this function returns TMR_UNKNOWN.
+ * disabled. If the watchdog is enabled, this function returns -EBUSY.
  *
- * Returns: The interrupt timer type supported by the hardware.
+ * Returns: 0 on success or negative error code on failure.
  */
 static int atcwdt_get_int_timer_type(struct atcwdt_drv *drv_data)
 {
@@ -274,7 +274,8 @@ static int atcwdt_get_int_timer_type(struct atcwdt_drv *drv_data)
        regmap_read(drv_data->regmap, REG_CTRL, &val);
        if (val & CTRL_WDT_EN) {
                spin_unlock(&drv_data->lock);
-               return TMR_UNKNOWN;
+               return dev_err_probe(dev, -EBUSY,
+                                    "Watchdog is enabled, cannot detect timer type\n");
        }
 
        /*