pinctrl/lantiq: add pin_config_group_set support

While converting all the boards supported by OpenWrt to OF
I noticed that this feature is missing. Adding it makes the
devicetrees more readable.

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/pinctrl-lantiq.c b/drivers/pinctrl/pinctrl-lantiq.c
index 15f501d..7d11072 100644
--- a/drivers/pinctrl/pinctrl-lantiq.c
+++ b/drivers/pinctrl/pinctrl-lantiq.c
@@ -64,11 +64,13 @@
 	seq_printf(s, " %s", dev_name(pctldev->dev));
 }
 
-static int ltq_pinctrl_dt_subnode_to_map(struct pinctrl_dev *pctldev,
+static void ltq_pinctrl_dt_subnode_to_map(struct pinctrl_dev *pctldev,
 				struct device_node *np,
 				struct pinctrl_map **map)
 {
 	struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctldev);
+	struct property *pins = of_find_property(np, "lantiq,pins", NULL);
+	struct property *groups = of_find_property(np, "lantiq,groups", NULL);
 	unsigned long configs[3];
 	unsigned num_configs = 0;
 	struct property *prop;
@@ -76,8 +78,20 @@
 	const char *function;
 	int ret, i;
 
+	if (!pins && !groups) {
+		dev_err(pctldev->dev, "%s defines neither pins nor groups\n",
+			np->name);
+		return;
+	}
+
+	if (pins && groups) {
+		dev_err(pctldev->dev, "%s defines both pins and groups\n",
+			np->name);
+		return;
+	}
+
 	ret = of_property_read_string(np, "lantiq,function", &function);
-	if (!ret) {
+	if (groups && !ret) {
 		of_property_for_each_string(np, "lantiq,groups", prop, group) {
 			(*map)->type = PIN_MAP_TYPE_MUX_GROUP;
 			(*map)->name = function;
@@ -85,11 +99,6 @@
 			(*map)->data.mux.function = function;
 			(*map)++;
 		}
-		if (of_find_property(np, "lantiq,pins", NULL))
-			dev_err(pctldev->dev,
-				"%s mixes pins and groups settings\n",
-				np->name);
-		return 0;
 	}
 
 	for (i = 0; i < info->num_params; i++) {
@@ -103,7 +112,7 @@
 	}
 
 	if (!num_configs)
-		return -EINVAL;
+		return;
 
 	of_property_for_each_string(np, "lantiq,pins", prop, pin) {
 		(*map)->data.configs.configs = kmemdup(configs,
@@ -115,7 +124,16 @@
 		(*map)->data.configs.num_configs = num_configs;
 		(*map)++;
 	}
-	return 0;
+	of_property_for_each_string(np, "lantiq,groups", prop, group) {
+		(*map)->data.configs.configs = kmemdup(configs,
+					num_configs * sizeof(unsigned long),
+					GFP_KERNEL);
+		(*map)->type = PIN_MAP_TYPE_CONFIGS_GROUP;
+		(*map)->name = group;
+		(*map)->data.configs.group_or_pin = group;
+		(*map)->data.configs.num_configs = num_configs;
+		(*map)++;
+	}
 }
 
 static int ltq_pinctrl_dt_subnode_size(struct device_node *np)
@@ -135,23 +153,19 @@
 {
 	struct pinctrl_map *tmp;
 	struct device_node *np;
-	int ret;
+	int max_maps = 0;
 
-	*num_maps = 0;
 	for_each_child_of_node(np_config, np)
-		*num_maps += ltq_pinctrl_dt_subnode_size(np);
-	*map = kzalloc(*num_maps * sizeof(struct pinctrl_map), GFP_KERNEL);
+		max_maps += ltq_pinctrl_dt_subnode_size(np);
+	*map = kzalloc(max_maps * sizeof(struct pinctrl_map) * 2, GFP_KERNEL);
 	if (!*map)
 		return -ENOMEM;
 	tmp = *map;
 
-	for_each_child_of_node(np_config, np) {
-		ret = ltq_pinctrl_dt_subnode_to_map(pctldev, np, &tmp);
-		if (ret < 0) {
-			ltq_pinctrl_dt_free_map(pctldev, *map, *num_maps);
-			return ret;
-		}
-	}
+	for_each_child_of_node(np_config, np)
+		ltq_pinctrl_dt_subnode_to_map(pctldev, np, &tmp);
+	*num_maps = ((int)(tmp - *map));
+
 	return 0;
 }