[PATCH v2] watchdog: atcwdt200: fix return value when watchdog is enabled

[kr494167@gmail.com]

From: Surendra Singh Chouhan <kr494167@gmail.com>

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>
---
 drivers/watchdog/atcwdt200_wdt.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/watchdog/atcwdt200_wdt.c b/drivers/watchdog/atcwdt200_wdt.c
index 8e3b18aea368..7e757c217b0b 100644
--- 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");
 	}
 
 	/*
-- 
2.55.0