pinctrl: add more info to error msgs in pin_request

Additionally print which pin the request failed for, which entity already
claimed it, and what entity was trying to claim it.

Remove duplicate device name from a debug message.

Clean up some indentation.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinmux.c

@@ -92,7 +92,8 @@ static int pin_request(struct pinctrl_dev *pctldev,
 	desc = pin_desc_get(pctldev, pin);
 	if (desc == NULL) {
 		dev_err(pctldev->dev,
-			"pin is not registered so it cannot be requested\n");
+			"pin %d is not registered so it cannot be requested\n",
+			pin);
 		goto out;
 	}
 
@@ -103,7 +104,8 @@ static int pin_request(struct pinctrl_dev *pctldev,
 		/* There's no need to support multiple GPIO requests */
 		if (desc->gpio_owner) {
 			dev_err(pctldev->dev,
-				"pin already requested\n");
+				"pin %s already requested by %s; cannot claim for %s\n",
+				desc->name, desc->gpio_owner, owner);
 			goto out;
 		}
 
@@ -111,7 +113,8 @@ static int pin_request(struct pinctrl_dev *pctldev,
 	} else {
 		if (desc->mux_usecount && strcmp(desc->mux_owner, owner)) {
 			dev_err(pctldev->dev,
-				"pin already requested\n");
+				"pin %s already requested by %s; cannot claim for %s\n",
+				desc->name, desc->mux_owner, owner);
 			goto out;
 		}
 
@@ -144,8 +147,7 @@ static int pin_request(struct pinctrl_dev *pctldev,
 		status = 0;
 
 	if (status) {
-		dev_err(pctldev->dev, "request on device %s failed for pin %d\n",
-		       pctldev->desc->name, pin);
+		dev_err(pctldev->dev, "request() failed for pin %d\n", pin);
 		module_put(pctldev->owner);
 	}