extcon: Use the unique id for external connector instead of string

This patch uses the unique id to identify the type of external connector instead
of string name. The string name have the many potential issues. So, this patch
defines the 'extcon' enumeration which includes all supported external connector
on EXTCON subsystem. If new external connector is necessary, the unique id of
new connector have to be added in 'extcon' enumeration. There are current
supported external connector in 'enum extcon' as following:

enum extcon {
	EXTCON_NONE		= 0x0,

	/* USB external connector */
	EXTCON_USB		= 0x1,
	EXTCON_USB_HOST		= 0x2,

	/* Charger external connector */
	EXTCON_TA		= 0x10,
	EXTCON_FAST_CHARGER	= 0x11,
	EXTCON_SLOW_CHARGER	= 0x12,
	EXTCON_CHARGE_DOWNSTREAM = 0x13,

	/* Audio and video external connector */
	EXTCON_LINE_IN		= 0x20,
	EXTCON_LINE_OUT		= 0x21,
	EXTCON_MICROPHONE	= 0x22,
	EXTCON_HEADPHONE	= 0x23,

	EXTCON_HDMI		= 0x30,
	EXTCON_MHL		= 0x31,
	EXTCON_DVI		= 0x32,
	EXTCON_VGA		= 0x33,
	EXTCON_SPDIF_IN		= 0x34,
	EXTCON_SPDIF_OUT	= 0x35,
	EXTCON_VIDEO_IN		= 0x36,
	EXTCON_VIDEO_OUT	= 0x37,

	/* Miscellaneous external connector */
	EXTCON_DOCK		= 0x50,
	EXTCON_JIG		= 0x51,
	EXTCON_MECHANICAL	= 0x52,

	EXTCON_END,
};

For example in extcon-arizona.c:
To use unique id removes the potential issue about handling
the inconsistent name of external connector with string.
- Previously, use the string to register the type of arizona jack connector
static const char *arizona_cable[] = {
	"Mechanical",
	"Microphone",
	"Headphone",
	"Line-out",
};
- Newly, use the unique id to register the type of arizona jack connector
static const enum extcon arizona_cable[] = {
	EXTCON_MECHANICAL,
	EXTCON_MICROPHONE,
	EXTCON_HEADPHONE,
	EXTCON_LINE_OUT,

	EXTCON_NONE,
};

And this patch modify the prototype of extcon_{get|set}_cable_state_() which
uses the 'enum extcon id' instead of 'cable_index'. Because although one more
extcon drivers support USB cable, each extcon driver might has the differnt
'cable_index' for USB cable. All extcon drivers can use the unique id number
for same external connector with modified extcon_{get|set}_cable_state_().

- Previously, use 'cable_index' on these functions:
extcon_get_cable_state_(struct extcon_dev*, int cable_index)
extcon_set_cable_state_(struct extcon_dev*, int cable_index, bool state)

-Newly, use 'enum extcon id' on these functions:
extcon_get_cable_state_(struct extcon_dev*, enum extcon id)
extcon_set_cable_state_(struct extcon_dev*, enum extcon id, bool state)

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Roger Quadros <rogerq@ti.com>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
[arnd: Report the build break about drivers/usb/phy/phy-tahvo.c after using the
unique id for external connector insteadf of string]
Reported-by: Arnd Bergmann <arnd@arndb.de>
[dan.carpenter: Report the build warning of extcon_{set|get}_cable_state_()]
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

1 files changed, 48 insertions, 63 deletions

diff --git a/include/linux/extcon.h b/include/linux/extcon.h
index 799474d9dc48..85c882f0029e 100644
--- a/include/linux/extcon.h
+++ b/include/linux/extcon.h
@@ -1,6 +1,9 @@
 /*
  *  External connector (extcon) class driver
  *
+ * Copyright (C) 2015 Samsung Electronics
+ * Author: Chanwoo Choi <cw00.choi@samsung.com>
+ *
  * Copyright (C) 2012 Samsung Electronics
  * Author: Donggeun Kim <dg77.kim@samsung.com>
  * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
@@ -27,50 +30,41 @@
 #include <linux/notifier.h>
 #include <linux/sysfs.h>
 
-#define SUPPORTED_CABLE_MAX	32
-#define CABLE_NAME_MAX		30
-
-/*
- * The standard cable name is to help support general notifier
- * and notifiee device drivers to share the common names.
- * Please use standard cable names unless your notifier device has
- * a very unique and abnormal cable or
- * the cable type is supposed to be used with only one unique
- * pair of notifier/notifiee devices.
- *
- * Please add any other "standard" cables used with extcon dev.
- *
- * You may add a dot and number to specify version or specification
- * of the specific cable if it is required. (e.g., "Fast-charger.18"
- * and "Fast-charger.10" for 1.8A and 1.0A chargers)
- * However, the notifiee and notifier should be able to handle such
- * string and if the notifiee can negotiate the protocol or identify,
- * you don't need such convention. This convention is helpful when
- * notifier can distinguish but notifiee cannot.
- */
-enum extcon_cable_name {
-	EXTCON_USB = 0,
-	EXTCON_USB_HOST,
-	EXTCON_TA,			/* Travel Adaptor */
-	EXTCON_FAST_CHARGER,
-	EXTCON_SLOW_CHARGER,
-	EXTCON_CHARGE_DOWNSTREAM,	/* Charging an external device */
-	EXTCON_HDMI,
-	EXTCON_MHL,
-	EXTCON_DVI,
-	EXTCON_VGA,
-	EXTCON_DOCK,
-	EXTCON_LINE_IN,
-	EXTCON_LINE_OUT,
-	EXTCON_MIC_IN,
-	EXTCON_HEADPHONE_OUT,
-	EXTCON_SPDIF_IN,
-	EXTCON_SPDIF_OUT,
-	EXTCON_VIDEO_IN,
-	EXTCON_VIDEO_OUT,
-	EXTCON_MECHANICAL,
+enum extcon {
+	EXTCON_NONE		= 0x0,
+
+	/* USB external connector */
+	EXTCON_USB		= 0x1,
+	EXTCON_USB_HOST		= 0x2,
+
+	/* Charger external connector */
+	EXTCON_TA		= 0x10,
+	EXTCON_FAST_CHARGER	= 0x11,
+	EXTCON_SLOW_CHARGER	= 0x12,
+	EXTCON_CHARGE_DOWNSTREAM = 0x13,
+
+	/* Audio/Video external connector */
+	EXTCON_LINE_IN		= 0x20,
+	EXTCON_LINE_OUT		= 0x21,
+	EXTCON_MICROPHONE	= 0x22,
+	EXTCON_HEADPHONE	= 0x23,
+
+	EXTCON_HDMI		= 0x30,
+	EXTCON_MHL		= 0x31,
+	EXTCON_DVI		= 0x32,
+	EXTCON_VGA		= 0x33,
+	EXTCON_SPDIF_IN		= 0x34,
+	EXTCON_SPDIF_OUT	= 0x35,
+	EXTCON_VIDEO_IN		= 0x36,
+	EXTCON_VIDEO_OUT	= 0x37,
+
+	/* Etc external connector */
+	EXTCON_DOCK		= 0x50,
+	EXTCON_JIG		= 0x51,
+	EXTCON_MECHANICAL	= 0x52,
+
+	EXTCON_END,
 };
-extern const char extcon_cable_name[][CABLE_NAME_MAX + 1];
 
 struct extcon_cable;
 
@@ -78,7 +72,7 @@ struct extcon_cable;
  * struct extcon_dev - An extcon device represents one external connector.
  * @name:		The name of this extcon device. Parent device name is
  *			used if NULL.
- * @supported_cable:	Array of supported cable names ending with NULL.
+ * @supported_cable:	Array of supported cable names ending with EXTCON_NONE.
  *			If supported_cable is NULL, cable name related APIs
  *			are disabled.
  * @mutually_exclusive:	Array of mutually exclusive set of cables that cannot
@@ -113,7 +107,7 @@ struct extcon_cable;
 struct extcon_dev {
 	/* Optional user initializing data */
 	const char *name;
-	const char **supported_cable;
+	const enum extcon *supported_cable;
 	const u32 *mutually_exclusive;
 
 	/* Optional callbacks to override class functions */
@@ -194,10 +188,10 @@ extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name);
 /*
  * Following APIs control the memory of extcon device.
  */
-extern struct extcon_dev *extcon_dev_allocate(const char **cables);
+extern struct extcon_dev *extcon_dev_allocate(const enum extcon *cable);
 extern void extcon_dev_free(struct extcon_dev *edev);
 extern struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
-						   const char **cables);
+						   const enum extcon *cable);
 extern void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev);
 
 /*
@@ -216,13 +210,10 @@ extern int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state);
 
 /*
  * get/set_cable_state access each bit of the 32b encoded state value.
- * They are used to access the status of each cable based on the cable_name
- * or cable_index, which is retrieved by extcon_find_cable_index
+ * They are used to access the status of each cable based on the cable_name.
  */
-extern int extcon_find_cable_index(struct extcon_dev *sdev,
-				   const char *cable_name);
-extern int extcon_get_cable_state_(struct extcon_dev *edev, int cable_index);
-extern int extcon_set_cable_state_(struct extcon_dev *edev, int cable_index,
+extern int extcon_get_cable_state_(struct extcon_dev *edev, enum extcon id);
+extern int extcon_set_cable_state_(struct extcon_dev *edev, enum extcon id,
 				   bool cable_state);
 
 extern int extcon_get_cable_state(struct extcon_dev *edev,
@@ -281,7 +272,7 @@ static inline int devm_extcon_dev_register(struct device *dev,
 static inline void devm_extcon_dev_unregister(struct device *dev,
 					      struct extcon_dev *edev) { }
 
-static inline struct extcon_dev *extcon_dev_allocate(const char **cables)
+static inline struct extcon_dev *extcon_dev_allocate(const enum extcon *cable)
 {
 	return ERR_PTR(-ENOSYS);
 }
@@ -289,7 +280,7 @@ static inline struct extcon_dev *extcon_dev_allocate(const char **cables)
 static inline void extcon_dev_free(struct extcon_dev *edev) { }
 
 static inline struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
-							  const char **cables)
+						const enum extcon *cable)
 {
 	return ERR_PTR(-ENOSYS);
 }
@@ -312,20 +303,14 @@ static inline int extcon_update_state(struct extcon_dev *edev, u32 mask,
 	return 0;
 }
 
-static inline int extcon_find_cable_index(struct extcon_dev *edev,
-					  const char *cable_name)
-{
-	return 0;
-}
-
 static inline int extcon_get_cable_state_(struct extcon_dev *edev,
-					  int cable_index)
+					  enum extcon id)
 {
 	return 0;
 }
 
 static inline int extcon_set_cable_state_(struct extcon_dev *edev,
-					  int cable_index, bool cable_state)
+					  enum extcon id, bool cable_state)
 {
 	return 0;
 }