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Commit f2adc4f8 authored by Michal Nazarewicz's avatar Michal Nazarewicz Committed by Greg Kroah-Hartman
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USB: gadget: composite: usb_string_ids_*() functions added 



usb_string_ids_tab() and usb_string_ids_n() functions added to
the composite framework.  The first accepts an array of
usb_string object and for each registeres a string id and the
second registeres a given number of ids and returns the first.

This may simplify string ids registration since gadgets and
composite functions won't have to call usb_string_id() several
times and each time check for errer status -- all this will be
done with a single call.

Signed-off-by: default avatarMichal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: default avatarKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 7898aee1

drivers/usb/gadget/composite.c

+67 −4
Original line number Original line Diff line number Diff line
@@ -673,20 +673,83 @@ static int get_string(struct usb_composite_dev *cdev, 
 * string IDs.  Drivers for functions, configurations, or gadgets will

 * string IDs.  Drivers for functions, configurations, or gadgets will

 * then store that ID in the appropriate descriptors and string table.

 * then store that ID in the appropriate descriptors and string table.

 *

 *

 * All string identifier should be allocated using this routine, to

 * All string identifier should be allocated using this,

 * ensure that for example different functions don't wrongly assign

 * @usb_string_ids_tab() or @usb_string_ids_n() routine, to ensure

 * different meanings to the same identifier.

 * that for example different functions don't wrongly assign different

 * meanings to the same identifier.

 */

 */

int usb_string_id(struct usb_composite_dev *cdev)

int usb_string_id(struct usb_composite_dev *cdev)

{

{

	if (cdev->next_string_id < 254) {

	if (cdev->next_string_id < 254) {

		/* string id 0 is reserved */

		/* string id 0 is reserved by USB spec for list of

		 * supported languages */

		/* 255 reserved as well? -- mina86 */

		cdev->next_string_id++;

		cdev->next_string_id++;

		return cdev->next_string_id;

		return cdev->next_string_id;

	}

	}

	return -ENODEV;

	return -ENODEV;

}

}





/**

 * usb_string_ids() - allocate unused string IDs in batch

 * @cdev: the device whose string descriptor IDs are being allocated

 * @str: an array of usb_string objects to assign numbers to

 * Context: single threaded during gadget setup

 *

 * @usb_string_ids() is called from bind() callbacks to allocate

 * string IDs.  Drivers for functions, configurations, or gadgets will

 * then copy IDs from the string table to the appropriate descriptors

 * and string table for other languages.

 *

 * All string identifier should be allocated using this,

 * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for

 * example different functions don't wrongly assign different meanings

 * to the same identifier.

 */

int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str)

{

	int next = cdev->next_string_id;



	for (; str->s; ++str) {

		if (unlikely(next >= 254))

			return -ENODEV;

		str->id = ++next;

	}



	cdev->next_string_id = next;



	return 0;

}



/**

 * usb_string_ids_n() - allocate unused string IDs in batch

 * @cdev: the device whose string descriptor IDs are being allocated

 * @n: number of string IDs to allocate

 * Context: single threaded during gadget setup

 *

 * Returns the first requested ID.  This ID and next @n-1 IDs are now

 * valid IDs.  At least providind that @n is non zore because if it

 * is, returns last requested ID which is now very useful information.

 *

 * @usb_string_ids_n() is called from bind() callbacks to allocate

 * string IDs.  Drivers for functions, configurations, or gadgets will

 * then store that ID in the appropriate descriptors and string table.

 *

 * All string identifier should be allocated using this,

 * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for

 * example different functions don't wrongly assign different meanings

 * to the same identifier.

 */

int usb_string_ids_n(struct usb_composite_dev *c, unsigned n)

{

	unsigned next = c->next_string_id;

	if (unlikely(n > 254 || (unsigned)next + n > 254))

		return -ENODEV;

	c->next_string_id += n;

	return next + 1;

}





/*-------------------------------------------------------------------------*/

/*-------------------------------------------------------------------------*/





static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)

static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)

include/linux/usb/composite.h

+4 −0
Original line number Original line Diff line number Diff line
@@ -342,6 +342,10 @@ struct usb_composite_dev { 
};

};





extern int usb_string_id(struct usb_composite_dev *c);

extern int usb_string_id(struct usb_composite_dev *c);

extern int usb_string_ids_tab(struct usb_composite_dev *c,

			      struct usb_string *str);

extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);







/* messaging utils */

/* messaging utils */

#define DBG(d, fmt, args...) \

#define DBG(d, fmt, args...) \