pinctrl: conjure names for unnamed pins

If pins with blank names are registered, we assign them names on-the-fly
on the form "PINn" where n is the pin number for that pin on the specific
controller.
Acked-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/core.c

@@ -158,6 +158,8 @@ static void pinctrl_free_pindescs(struct pinctrl_dev *pctldev,
 		if (pindesc != NULL) {
 			radix_tree_delete(&pctldev->pin_desc_tree,
 					  pins[i].number);
+			if (pindesc->dynamic_name)
+				kfree(pindesc->name);
 		}
 		kfree(pindesc);
 	}
@@ -186,13 +188,20 @@ static int pinctrl_register_one_pin(struct pinctrl_dev *pctldev,
 	pindesc->pctldev = pctldev;
 
 	/* Copy basic pin info */
+	if (pindesc->name) {
 		pindesc->name = name;
+	} else {
+		pindesc->name = kasprintf(GFP_KERNEL, "PIN%u", number);
+		if (pindesc->name == NULL)
+			return -ENOMEM;
+		pindesc->dynamic_name = true;
+	}
 
 	spin_lock(&pctldev->pin_desc_tree_lock);
 	radix_tree_insert(&pctldev->pin_desc_tree, number, pindesc);
 	spin_unlock(&pctldev->pin_desc_tree_lock);
 	pr_debug("registered pin %d (%s) on %s\n",
-		 number, name ? name : "(unnamed)", pctldev->desc->name);
+		 number, pindesc->name, pctldev->desc->name);
 	return 0;
 }
 

drivers/pinctrl/core.h

@@ -52,6 +52,7 @@ struct pinctrl_dev {
  * @pctldev: corresponding pin control device
  * @name: a name for the pin, e.g. the name of the pin/pad/finger on a
  *	datasheet or such
+ * @dynamic_name: if the name of this pin was dynamically allocated
  * @lock: a lock to protect the descriptor structure
  * @mux_requested: whether the pin is already requested by pinmux or not
  * @mux_function: a named muxing function for the pin that will be passed to
@@ -60,6 +61,7 @@ struct pinctrl_dev {
 struct pin_desc {
 	struct pinctrl_dev *pctldev;
 	const char *name;
+	bool dynamic_name;
 	spinlock_t lock;
 	/* These fields only added when supporting pinmux drivers */
 #ifdef CONFIG_PINMUX