pinctrl: sunxi: Rework the pin config building code

In order to support more easily the generic pinctrl properties, rework the
pinctrl maps configuration and split it into several sub-functions.

One of the side-effects from that rework is that we only parse the pin
configuration once, since it's going to be common to every pin, instead of
having to parsing once for each pin.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/sunxi/pinctrl-sunxi.c

@@ -145,6 +145,110 @@ static int sunxi_pctrl_get_group_pins(struct pinctrl_dev *pctldev,
 	return 0;
 }
 
+static bool sunxi_pctrl_has_bias_prop(struct device_node *node)
+{
+	return of_find_property(node, "allwinner,pull", NULL);
+}
+
+static bool sunxi_pctrl_has_drive_prop(struct device_node *node)
+{
+	return of_find_property(node, "allwinner,drive", NULL);
+}
+
+static int sunxi_pctrl_parse_bias_prop(struct device_node *node)
+{
+	u32 val;
+
+	if (of_property_read_u32(node, "allwinner,pull", &val))
+		return -EINVAL;
+
+	switch (val) {
+	case 1:
+		return PIN_CONFIG_BIAS_PULL_UP;
+	case 2:
+		return PIN_CONFIG_BIAS_PULL_DOWN;
+	}
+
+	return -EINVAL;
+}
+
+static int sunxi_pctrl_parse_drive_prop(struct device_node *node)
+{
+	u32 val;
+
+	if (of_property_read_u32(node, "allwinner,drive", &val))
+		return -EINVAL;
+
+	return (val + 1) * 10;
+}
+
+static const char *sunxi_pctrl_parse_function_prop(struct device_node *node)
+{
+	const char *function;
+	int ret;
+
+	ret = of_property_read_string(node, "allwinner,function", &function);
+	if (!ret)
+		return function;
+
+	return NULL;
+}
+
+static const char *sunxi_pctrl_find_pins_prop(struct device_node *node,
+					      int *npins)
+{
+	int count;
+
+	count = of_property_count_strings(node, "allwinner,pins");
+	if (count > 0) {
+		*npins = count;
+		return "allwinner,pins";
+	}
+
+	return NULL;
+}
+
+static unsigned long *sunxi_pctrl_build_pin_config(struct device_node *node,
+						   unsigned int *len)
+{
+	unsigned long *pinconfig;
+	unsigned int configlen = 0, idx = 0;
+
+	if (sunxi_pctrl_has_drive_prop(node))
+		configlen++;
+	if (sunxi_pctrl_has_bias_prop(node))
+		configlen++;
+
+	pinconfig = kzalloc(configlen * sizeof(*pinconfig), GFP_KERNEL);
+	if (!pinconfig)
+		return NULL;
+
+	if (sunxi_pctrl_has_drive_prop(node)) {
+		int drive = sunxi_pctrl_parse_drive_prop(node);
+		if (drive < 0)
+			goto err_free;
+
+		pinconfig[idx++] = pinconf_to_config_packed(PIN_CONFIG_DRIVE_STRENGTH,
+							  drive);
+	}
+
+	if (sunxi_pctrl_has_bias_prop(node)) {
+		int pull = sunxi_pctrl_parse_bias_prop(node);
+		if (pull < 0)
+			goto err_free;
+
+		pinconfig[idx++] = pinconf_to_config_packed(pull, 0);
+	}
+
+
+	*len = configlen;
+	return pinconfig;
+
+err_free:
+	kfree(pinconfig);
+	return NULL;
+}
+
 static int sunxi_pctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
 				      struct device_node *node,
 				      struct pinctrl_map **map,
@@ -153,38 +257,45 @@ static int sunxi_pctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
 	struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);
 	unsigned long *pinconfig;
 	struct property *prop;
-	const char *function;
+	const char *function, *pin_prop;
 	const char *group;
-	int ret, nmaps, i = 0;
-	u32 val;
+	int ret, npins, nmaps, configlen = 0, i = 0;
 
 	*map = NULL;
 	*num_maps = 0;
 
-	ret = of_property_read_string(node, "allwinner,function", &function);
-	if (ret) {
-		dev_err(pctl->dev,
-			"missing allwinner,function property in node %s\n",
+	function = sunxi_pctrl_parse_function_prop(node);
+	if (!function) {
+		dev_err(pctl->dev, "missing function property in node %s\n",
 			node->name);
 		return -EINVAL;
 	}
 
-	nmaps = of_property_count_strings(node, "allwinner,pins") * 2;
-	if (nmaps < 0) {
-		dev_err(pctl->dev,
-			"missing allwinner,pins property in node %s\n",
+	pin_prop = sunxi_pctrl_find_pins_prop(node, &npins);
+	if (!pin_prop) {
+		dev_err(pctl->dev, "missing pins property in node %s\n",
 			node->name);
 		return -EINVAL;
 	}
 
+	/*
+	 * We have two maps for each pin: one for the function, one
+	 * for the configuration (bias, strength, etc)
+	 */
+	nmaps = npins * 2;
 	*map = kmalloc(nmaps * sizeof(struct pinctrl_map), GFP_KERNEL);
 	if (!*map)
 		return -ENOMEM;
 
-	of_property_for_each_string(node, "allwinner,pins", prop, group) {
+	pinconfig = sunxi_pctrl_build_pin_config(node, &configlen);
+	if (!pinconfig) {
+		ret = -EINVAL;
+		goto err_free_map;
+	}
+
+	of_property_for_each_string(node, pin_prop, prop, group) {
 		struct sunxi_pinctrl_group *grp =
 			sunxi_pinctrl_find_group_by_name(pctl, group);
-		int j = 0, configlen = 0;
 
 		if (!grp) {
 			dev_err(pctl->dev, "unknown pin %s", group);
@@ -207,34 +318,6 @@ static int sunxi_pctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
 
 		(*map)[i].type = PIN_MAP_TYPE_CONFIGS_GROUP;
 		(*map)[i].data.configs.group_or_pin = group;
-
-		if (of_find_property(node, "allwinner,drive", NULL))
-			configlen++;
-		if (of_find_property(node, "allwinner,pull", NULL))
-			configlen++;
-
-		pinconfig = kzalloc(configlen * sizeof(*pinconfig), GFP_KERNEL);
-		if (!pinconfig) {
-			kfree(*map);
-			return -ENOMEM;
-		}
-
-		if (!of_property_read_u32(node, "allwinner,drive", &val)) {
-			u16 strength = (val + 1) * 10;
-			pinconfig[j++] =
-				pinconf_to_config_packed(PIN_CONFIG_DRIVE_STRENGTH,
-							 strength);
-		}
-
-		if (!of_property_read_u32(node, "allwinner,pull", &val)) {
-			enum pin_config_param pull = PIN_CONFIG_END;
-			if (val == 1)
-				pull = PIN_CONFIG_BIAS_PULL_UP;
-			else if (val == 2)
-				pull = PIN_CONFIG_BIAS_PULL_DOWN;
-			pinconfig[j++] = pinconf_to_config_packed(pull, 0);
-		}
-
 		(*map)[i].data.configs.configs = pinconfig;
 		(*map)[i].data.configs.num_configs = configlen;
 
@@ -244,19 +327,18 @@ static int sunxi_pctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
 	*num_maps = nmaps;
 
 	return 0;
+
+err_free_map:
+	kfree(map);
+	return ret;
 }
 
 static void sunxi_pctrl_dt_free_map(struct pinctrl_dev *pctldev,
 				    struct pinctrl_map *map,
 				    unsigned num_maps)
 {
-	int i;
-
-	for (i = 0; i < num_maps; i++) {
-		if (map[i].type == PIN_MAP_TYPE_CONFIGS_GROUP)
-			kfree(map[i].data.configs.configs);
-	}
-
+	/* All the maps have the same pin config, free only the first one */
+	kfree(map[0].data.configs.configs);
 	kfree(map);
 }