[PATCH] pinctrl: amlogic: a4: Allow functions without groups

[Xianwei Zhao via B4 Relay <devnull+xianwei.zhao.amlogic.com@kernel.org>]

From: Xianwei Zhao <xianwei.zhao@amlogic.com>

Allow function nodes without child groups during device tree
parsing instead of returning an error.

Only count and parse nodes with the "func-" prefix as pinctrl
functions, ignoring other non-GPIO child nodes.

Also handle zero-sized allocations when no groups are defined
by checking for ZERO_SIZE_PTR in addition to NULL.

This allows the driver to support function nodes without
groups and avoid treating unrelated device tree nodes as
pinctrl functions.

Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
Add debugging information for error dts and Error pinctrl config not affect normal pin work.
---
 drivers/pinctrl/meson/pinctrl-amlogic-a4.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/pinctrl/meson/pinctrl-amlogic-a4.c b/drivers/pinctrl/meson/pinctrl-amlogic-a4.c
index 39eb8cc7fc0d..d0e3cec3ead0 100644
--- a/drivers/pinctrl/meson/pinctrl-amlogic-a4.c
+++ b/drivers/pinctrl/meson/pinctrl-amlogic-a4.c
@@ -821,8 +821,10 @@ static int aml_pctl_parse_functions(struct device_node *np,
 	func = &info->functions[index];
 	func->name = np->name;
 	func->ngroups = of_get_child_count(np);
-	if (func->ngroups == 0)
-		return dev_err_probe(dev, -EINVAL, "No groups defined\n");
+	if (func->ngroups == 0) {
+		dev_dbg(dev, "func %s No groups defined\n", func->name);
+		return  0;
+	}
 
 	func->groups = devm_kcalloc(dev, func->ngroups, sizeof(*func->groups), GFP_KERNEL);
 	if (!func->groups)
@@ -899,8 +901,12 @@ static void aml_pctl_dt_child_count(struct aml_pinctrl *info,
 		if (of_property_read_bool(child, "gpio-controller")) {
 			info->nbanks++;
 		} else {
-			info->nfunctions++;
-			info->ngroups += of_get_child_count(child);
+			if (!strncmp(child->name, "func-", 5)) {
+				info->nfunctions++;
+				info->ngroups += of_get_child_count(child);
+			} else {
+				dev_dbg(info->dev, "func node defined err %s\n", child->name);
+			}
 		}
 	}
 }
@@ -1128,7 +1134,8 @@ static int aml_pctl_probe_dt(struct platform_device *pdev,
 
 	info->banks = devm_kcalloc(dev, info->nbanks, sizeof(*info->banks), GFP_KERNEL);
 
-	if (!info->functions || !info->groups || !info->banks)
+	if (IS_ERR_OR_NULL(info->functions) || IS_ERR_OR_NULL(info->groups) ||
+	    IS_ERR_OR_NULL(info->banks))
 		return -ENOMEM;
 
 	info->data = (struct aml_pctl_data *)of_device_get_match_data(dev);
@@ -1166,10 +1173,11 @@ static int aml_pctl_probe_dt(struct platform_device *pdev,
 			}
 			bank++;
 		} else {
-			ret = aml_pctl_parse_functions(child, info,
-						       i++, &grp_index);
-			if (ret)
-				return ret;
+			if (!strncmp(child->name, "func-", 5)) {
+				ret = aml_pctl_parse_functions(child, info, i++, &grp_index);
+				if (ret)
+					return ret;
+			}
 		}
 	}
 

---
base-commit: 89edcad9f23925f5706b7555b02165d1990444d5
change-id: 20261106-debug-info-bb5611e36717

Best regards,
-- 
Xianwei Zhao <xianwei.zhao@amlogic.com>