[PATCH] watchdog: designware: make reset really optional

[Quentin Schulz]

From: Quentin Schulz <quentin.sch...@theobroma-systems.com>

Checking for DM_RESET is not enough since not all watchdog
implementations use a reset lane. Such is the case for Rockchip
implementation for example. Since reset_assert_bulk will only succeed if
the resets property exists in the watchdog DT node, it needs to be
called only if a reset property is present.

This adds a condition on the resets property presence in the watchdog DT
node before assuming a reset lane needs to be fetched with
reset_assert_bulk, by calling ofnode_read_prop.

Cc: Quentin Schulz <foss+ub...@0leil.net>
Signed-off-by: Quentin Schulz <quentin.sch...@theobroma-systems.com>
---
To: Stefan Roese <s...@denx.de>
Cc: u-boot@lists.denx.de
---
 drivers/watchdog/designware_wdt.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/watchdog/designware_wdt.c 
b/drivers/watchdog/designware_wdt.c
index cad756aeaf..6155939f49 100644
--- a/drivers/watchdog/designware_wdt.c
+++ b/drivers/watchdog/designware_wdt.c
@@ -72,13 +72,13 @@ static int designware_wdt_reset(struct udevice *dev)
 static int designware_wdt_stop(struct udevice *dev)
 {
        struct designware_wdt_priv *priv = dev_get_priv(dev);
+       __maybe_unused int ret;
 
        designware_wdt_reset(dev);
        writel(0, priv->base + DW_WDT_CR);
 
-        if (CONFIG_IS_ENABLED(DM_RESET)) {
-               int ret;
-
+        if (CONFIG_IS_ENABLED(DM_RESET) &&
+           ofnode_read_prop(dev_ofnode(dev), "resets", &ret)) {
                ret = reset_assert_bulk(&priv->resets);
                if (ret)
                        return ret;
@@ -135,7 +135,8 @@ static int designware_wdt_probe(struct udevice *dev)
        priv->clk_khz = CONFIG_DW_WDT_CLOCK_KHZ;
 #endif
 
-       if (CONFIG_IS_ENABLED(DM_RESET)) {
+       if (CONFIG_IS_ENABLED(DM_RESET) &&
+           ofnode_read_prop(dev_ofnode(dev), "resets", &ret)) {
                ret = reset_get_bulk(dev, &priv->resets);
                if (ret)
                        goto err;

---
base-commit: 0cbeed4f6648e0e4966475e3544280a69ecb59d3
change-id: 20221114-dw-wdt-no-reset-2296a2bf37b3

Best regards,
-- 
Quentin Schulz <quentin.sch...@theobroma-systems.com>