pinctrl: samsung: accept GPIO bank nodes with a suffix

Existing dt-bindings expected that each GPIO/pin bank within pin
controller has its own node with name matching the bank (e.g. gpa0,
gpx2) and "gpio-controller" property.  The node name is then used for
matching between driver data and DTS.

Newly introduced dtschema expects to have nodes ending with "-gpio-bank"
suffix, so rewrite bank-devicetree matching to look for old and new
style of naming.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Link: https://lore.kernel.org/r/20220111201426.326777-3-krzysztof.kozlowski@canonical.com

drivers/pinctrl/samsung/pinctrl-samsung.c

@@ -1012,13 +1012,56 @@ static void samsung_banks_of_node_put(struct samsung_pinctrl_drv_data *d)
 		of_node_put(bank->of_node);
 }
 
+/*
+ * Iterate over all driver pin banks to find one matching the name of node,
+ * skipping optional "-gpio" node suffix. When found, assign node to the bank.
+ */
+static void samsung_banks_of_node_get(struct device *dev,
+				      struct samsung_pinctrl_drv_data *d,
+				      struct device_node *node)
+{
+	const char *suffix = "-gpio-bank";
+	struct samsung_pin_bank *bank;
+	struct device_node *child;
+	/* Pin bank names are up to 4 characters */
+	char node_name[20];
+	unsigned int i;
+	size_t len;
+
+	bank = d->pin_banks;
+	for (i = 0; i < d->nr_banks; ++i, ++bank) {
+		strscpy(node_name, bank->name, sizeof(node_name));
+		len = strlcat(node_name, suffix, sizeof(node_name));
+		if (len >= sizeof(node_name)) {
+			dev_err(dev, "Too long pin bank name '%s', ignoring\n",
+				bank->name);
+			continue;
+		}
+
+		for_each_child_of_node(node, child) {
+			if (!of_find_property(child, "gpio-controller", NULL))
+				continue;
+			if (of_node_name_eq(child, node_name))
+				break;
+			else if (of_node_name_eq(child, bank->name))
+				break;
+		}
+
+		if (child)
+			bank->of_node = child;
+		else
+			dev_warn(dev, "Missing node for bank %s - invalid DTB\n",
+				 bank->name);
+		/* child reference dropped in samsung_drop_banks_of_node() */
+	}
+}
+
 /* retrieve the soc specific data */
 static const struct samsung_pin_ctrl *
 samsung_pinctrl_get_soc_data(struct samsung_pinctrl_drv_data *d,
 			     struct platform_device *pdev)
 {
 	struct device_node *node = pdev->dev.of_node;
-	struct device_node *np;
 	const struct samsung_pin_bank_data *bdata;
 	const struct samsung_pin_ctrl *ctrl;
 	struct samsung_pin_bank *bank;
@@ -1082,17 +1125,7 @@ samsung_pinctrl_get_soc_data(struct samsung_pinctrl_drv_data *d,
 	 */
 	d->virt_base = virt_base[0];
 
-	for_each_child_of_node(node, np) {
-		if (!of_find_property(np, "gpio-controller", NULL))
-			continue;
-		bank = d->pin_banks;
-		for (i = 0; i < d->nr_banks; ++i, ++bank) {
-			if (of_node_name_eq(np, bank->name)) {
-				bank->of_node = np;
-				break;
-			}
-		}
-	}
+	samsung_banks_of_node_get(&pdev->dev, d, node);
 
 	d->pin_base = pin_base;
 	pin_base += d->nr_pins;