pinctrl: core: Return selector to the pinctrl driver

We must return the selector from pinctrl_generic_add_group() so
pin controller device drivers can remove the right group if needed
for deferred probe for example. And we now must make sure that a
proper name is passed so we can use it to check if the entry already
exists.

Note that fixes are also needed for the pin controller drivers to
use the selector value.

Fixes: c7059c5a ("pinctrl: core: Add generic pinctrl functions
for managing groups")
Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Christ van Willegen <cvwillegen@gmail.com>
Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-By: H. Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/core.c

@@ -616,6 +616,26 @@ struct group_desc *pinctrl_generic_get_group(struct pinctrl_dev *pctldev,
 }
 EXPORT_SYMBOL_GPL(pinctrl_generic_get_group);
 
+static int pinctrl_generic_group_name_to_selector(struct pinctrl_dev *pctldev,
+						  const char *function)
+{
+	const struct pinctrl_ops *ops = pctldev->desc->pctlops;
+	int ngroups = ops->get_groups_count(pctldev);
+	int selector = 0;
+
+	/* See if this pctldev has this group */
+	while (selector < ngroups) {
+		const char *gname = ops->get_group_name(pctldev, selector);
+
+		if (!strcmp(function, gname))
+			return selector;
+
+		selector++;
+	}
+
+	return -EINVAL;
+}
+
 /**
  * pinctrl_generic_add_group() - adds a new pin group
  * @pctldev: pin controller device
@@ -630,6 +650,16 @@ int pinctrl_generic_add_group(struct pinctrl_dev *pctldev, const char *name,
 			      int *pins, int num_pins, void *data)
 {
 	struct group_desc *group;
+	int selector;
+
+	if (!name)
+		return -EINVAL;
+
+	selector = pinctrl_generic_group_name_to_selector(pctldev, name);
+	if (selector >= 0)
+		return selector;
+
+	selector = pctldev->num_groups;
 
 	group = devm_kzalloc(pctldev->dev, sizeof(*group), GFP_KERNEL);
 	if (!group)
@@ -640,12 +670,11 @@ int pinctrl_generic_add_group(struct pinctrl_dev *pctldev, const char *name,
 	group->num_pins = num_pins;
 	group->data = data;
 
-	radix_tree_insert(&pctldev->pin_group_tree, pctldev->num_groups,
-			  group);
+	radix_tree_insert(&pctldev->pin_group_tree, selector, group);
 
 	pctldev->num_groups++;
 
-	return 0;
+	return selector;
 }
 EXPORT_SYMBOL_GPL(pinctrl_generic_add_group);