[PATCH 1/1] pinctrl: imx1: Allow parsing DT without function nodes

[Frank Li]

The old format to define pinctrl settings for imx in DT has two hierarchy
levels. The first level are function device nodes. The second level are
pingroups which contain a property fsl,pins. The original ntention was to
define all pin functions in a single dtsi file and just reference the
correct ones in the board files.

The commit ("5fcdf6a7ed95e pinctrl: imx: Allow parsing DT without function
nodes") already make moden i.MX chip support flatten layout.

Make legacy chipes (more than 15 years) support this flatten layout also.

Fixes: e948cbdc41d6f ("ARM: dts: imx: remove redundant intermediate node in pinmux hierarchy")
Signed-off-by: Frank Li <Frank.Li at nxp.com>
---
build test only

Sébastien Szymanski:
	Can you help test it? I am happy i.MX27 still alive.

Frank
---
 drivers/pinctrl/freescale/pinctrl-imx1-core.c | 48 ++++++++++++++++---
 1 file changed, 41 insertions(+), 7 deletions(-)

diff --git a/drivers/pinctrl/freescale/pinctrl-imx1-core.c b/drivers/pinctrl/freescale/pinctrl-imx1-core.c
index b36c8a1461b7c..bf07e0c64a098 100644
--- a/drivers/pinctrl/freescale/pinctrl-imx1-core.c
+++ b/drivers/pinctrl/freescale/pinctrl-imx1-core.c
@@ -540,10 +540,34 @@ static int imx1_pinctrl_parse_functions(struct device_node *np,
 	return 0;
 }
 
+/*
+ * Check if the DT contains pins in the direct child nodes. This indicates the
+ * newer DT format to store pins. This function returns true if the first found
+ * fsl,pins property is in a child of np. Otherwise false is returned.
+ */
+static bool imx1_pinctrl_dt_is_flat_functions(struct device_node *np)
+{
+	struct device_node *function_np;
+	struct device_node *pinctrl_np;
+
+	for_each_child_of_node(np, function_np) {
+		if (of_property_read_bool(function_np, "fsl,pins"))
+			return true;
+
+		for_each_child_of_node(function_np, pinctrl_np) {
+			if (of_property_read_bool(pinctrl_np, "fsl,pins"))
+				return false;
+		}
+	}
+
+	return true;
+}
+
 static int imx1_pinctrl_parse_dt(struct platform_device *pdev,
 		struct imx1_pinctrl *pctl, struct imx1_pinctrl_soc_info *info)
 {
 	struct device_node *np = pdev->dev.of_node;
+	bool flat_funcs;
 	int ret;
 	u32 nfuncs = 0;
 	u32 ngroups = 0;
@@ -552,9 +576,15 @@ static int imx1_pinctrl_parse_dt(struct platform_device *pdev,
 	if (!np)
 		return -ENODEV;
 
-	for_each_child_of_node_scoped(np, child) {
-		++nfuncs;
-		ngroups += of_get_child_count(child);
+	flat_funcs = imx1_pinctrl_dt_is_flat_functions(np);
+	if (flat_funcs) {
+		nfuncs = 1;
+		ngroups = of_get_child_count(np);
+	} else {
+		for_each_child_of_node_scoped(np, child) {
+			++nfuncs;
+			ngroups += of_get_child_count(child);
+		}
 	}
 
 	if (!nfuncs) {
@@ -574,10 +604,14 @@ static int imx1_pinctrl_parse_dt(struct platform_device *pdev,
 	if (!info->functions || !info->groups)
 		return -ENOMEM;
 
-	for_each_child_of_node_scoped(np, child) {
-		ret = imx1_pinctrl_parse_functions(child, info, ifunc++);
-		if (ret == -ENOMEM)
-			return -ENOMEM;
+	if (flat_funcs) {
+		imx1_pinctrl_parse_functions(np, info, 0);
+	} else {
+		for_each_child_of_node_scoped(np, child) {
+			ret = imx1_pinctrl_parse_functions(child, info, ifunc++);
+			if (ret == -ENOMEM)
+				return -ENOMEM;
+		}
 	}
 
 	return 0;
-- 
2.43.0