extcon: Add an API to get extcon device from dt node

Added an API of_extcon_get_extcon_dev() to be used by drivers to get
extcon device in the case of dt boot (this can be used instead of
extcon_get_extcon_dev()).

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>

drivers/extcon/Kconfig

@@ -14,6 +14,10 @@ if EXTCON
 
 comment "Extcon Device Drivers"
 
+config OF_EXTCON
+	def_tristate y
+	depends on OF
+
 config EXTCON_GPIO
 	tristate "GPIO extcon support"
 	depends on GPIOLIB

drivers/extcon/Makefile

@@ -2,6 +2,8 @@
 # Makefile for external connector class (extcon) devices
 #
 
+obj-$(CONFIG_OF_EXTCON)		+= of_extcon.o
+
 obj-$(CONFIG_EXTCON)		+= extcon-class.o
 obj-$(CONFIG_EXTCON_GPIO)	+= extcon-gpio.o
 obj-$(CONFIG_EXTCON_ADC_JACK)	+= extcon-adc-jack.o

drivers/extcon/extcon-class.c

@@ -602,7 +602,8 @@ int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
 	edev->dev->class = extcon_class;
 	edev->dev->release = extcon_dev_release;
 
-	dev_set_name(edev->dev, "%s", edev->name ? edev->name : dev_name(dev));
+	edev->name = edev->name ? edev->name : dev_name(dev);
+	dev_set_name(edev->dev, "%s", edev->name);
 
 	if (edev->max_supported) {
 		char buf[10];

drivers/extcon/of_extcon.c

@@ -0,0 +1,64 @@
+/*
+ * OF helpers for External connector (extcon) framework
+ *
+ * Copyright (C) 2013 Texas Instruments, Inc.
+ * Kishon Vijay Abraham I <kishon@ti.com>
+ *
+ * Copyright (C) 2013 Samsung Electronics
+ * Chanwoo Choi <cw00.choi@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/extcon.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/extcon/of_extcon.h>
+
+/*
+ * of_extcon_get_extcon_dev - Get the name of extcon device from devicetree
+ * @dev - instance to the given device
+ * @index - index into list of extcon_dev
+ *
+ * return the instance of extcon device
+ */
+struct extcon_dev *of_extcon_get_extcon_dev(struct device *dev, int index)
+{
+	struct device_node *node;
+	struct extcon_dev *edev;
+	struct platform_device *extcon_parent_dev;
+
+	if (!dev->of_node) {
+		dev_dbg(dev, "device does not have a device node entry\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	node = of_parse_phandle(dev->of_node, "extcon", index);
+	if (!node) {
+		dev_dbg(dev, "failed to get phandle in %s node\n",
+			dev->of_node->full_name);
+		return ERR_PTR(-ENODEV);
+	}
+
+	extcon_parent_dev = of_find_device_by_node(node);
+	if (!extcon_parent_dev) {
+		dev_dbg(dev, "unable to find device by node\n");
+		return ERR_PTR(-EPROBE_DEFER);
+	}
+
+	edev = extcon_get_extcon_dev(dev_name(&extcon_parent_dev->dev));
+	if (!edev) {
+		dev_dbg(dev, "unable to get extcon device : %s\n",
+				dev_name(&extcon_parent_dev->dev));
+		return ERR_PTR(-ENODEV);
+	}
+
+	return edev;
+}
+EXPORT_SYMBOL_GPL(of_extcon_get_extcon_dev);

include/linux/extcon/of_extcon.h

@@ -0,0 +1,31 @@
+/*
+ * OF helpers for External connector (extcon) framework
+ *
+ * Copyright (C) 2013 Texas Instruments, Inc.
+ * Kishon Vijay Abraham I <kishon@ti.com>
+ *
+ * Copyright (C) 2013 Samsung Electronics
+ * Chanwoo Choi <cw00.choi@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __LINUX_OF_EXTCON_H
+#define __LINUX_OF_EXTCON_H
+
+#include <linux/err.h>
+
+#if IS_ENABLED(CONFIG_OF_EXTCON)
+extern struct extcon_dev
+	*of_extcon_get_extcon_dev(struct device *dev, int index);
+#else
+static inline struct extcon_dev
+	*of_extcon_get_extcon_dev(struct device *dev, int index)
+{
+	return ERR_PTR(-ENOSYS);
+}
+#endif /* CONFIG_OF_EXTCON */
+#endif /* __LINUX_OF_EXTCON_H */