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Commit 48767a4e authored by Tatyana Brokhman's avatar Tatyana Brokhman Committed by Greg Kroah-Hartman
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usb: gadget: configure endpoint according to gadget speed 



Add config_ep_by_speed() to configure the endpoint
according to the gadget speed.

Using this function will spare the FDs from handling
the endpoint chosen descriptor.

Signed-off-by: default avatarTatyana Brokhman <tlinder@codeaurora.org>
Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 72c973dd

drivers/usb/gadget/composite.c

+85 −0
Original line number Diff line number Diff line
@@ -74,6 +74,91 @@ MODULE_PARM_DESC(iSerialNumber, "SerialNumber string"); 
static char composite_manufacturer[50];



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

/**

 * next_ep_desc() - advance to the next EP descriptor

 * @t: currect pointer within descriptor array

 *

 * Return: next EP descriptor or NULL

 *

 * Iterate over @t until either EP descriptor found or

 * NULL (that indicates end of list) encountered

 */

static struct usb_descriptor_header**

next_ep_desc(struct usb_descriptor_header **t)

{

	for (; *t; t++) {

		if ((*t)->bDescriptorType == USB_DT_ENDPOINT)

			return t;

	}

	return NULL;

}



/*

 * for_each_ep_desc()- iterate over endpoint descriptors in the

 *		descriptors list

 * @start:	pointer within descriptor array.

 * @ep_desc:	endpoint descriptor to use as the loop cursor

 */

#define for_each_ep_desc(start, ep_desc) \

	for (ep_desc = next_ep_desc(start); \

	      ep_desc; ep_desc = next_ep_desc(ep_desc+1))



/**

 * config_ep_by_speed() - configures the given endpoint

 * according to gadget speed.

 * @g: pointer to the gadget

 * @f: usb function

 * @_ep: the endpoint to configure

 *

 * Return: error code, 0 on success

 *

 * This function chooses the right descriptors for a given

 * endpoint according to gadget speed and saves it in the

 * endpoint desc field. If the endpoint already has a descriptor

 * assigned to it - overwrites it with currently corresponding

 * descriptor. The endpoint maxpacket field is updated according

 * to the chosen descriptor.

 * Note: the supplied function should hold all the descriptors

 * for supported speeds

 */

int config_ep_by_speed(struct usb_gadget *g,

			struct usb_function *f,

			struct usb_ep *_ep)

{

	struct usb_endpoint_descriptor *chosen_desc = NULL;

	struct usb_descriptor_header **speed_desc = NULL;



	struct usb_descriptor_header **d_spd; /* cursor for speed desc */



	if (!g || !f || !_ep)

		return -EIO;



	/* select desired speed */

	switch (g->speed) {

	case USB_SPEED_HIGH:

		if (gadget_is_dualspeed(g)) {

			speed_desc = f->hs_descriptors;

			break;

		}

		/* else: fall through */

	default:

		speed_desc = f->descriptors;

	}

	/* find descriptors */

	for_each_ep_desc(speed_desc, d_spd) {

		chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;

		if (chosen_desc->bEndpointAddress == _ep->address)

			goto ep_found;

	}

	return -EIO;



ep_found:

	/* commit results */

	_ep->maxpacket = le16_to_cpu(chosen_desc->wMaxPacketSize);

	_ep->desc = chosen_desc;



	return 0;

}



/**

 * usb_add_function() - add a function to a configuration

drivers/usb/gadget/epautoconf.c

+1 −0
Original line number Diff line number Diff line
@@ -191,6 +191,7 @@ ep_matches ( 
			size = 64;

		desc->wMaxPacketSize = cpu_to_le16(size);

	}

	ep->address = desc->bEndpointAddress;

	return 1;

}

include/linux/usb/composite.h

+3 −0
Original line number Diff line number Diff line
@@ -145,6 +145,9 @@ int usb_function_activate(struct usb_function *); 


int usb_interface_id(struct usb_configuration *, struct usb_function *);



int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,

			struct usb_ep *_ep);



/**

 * ep_choose - select descriptor endpoint at current device speed

 * @g: gadget, connected and running at some speed

include/linux/usb/gadget.h

+3 −0
Original line number Diff line number Diff line
@@ -133,6 +133,8 @@ struct usb_ep_ops { 
 *	value can sometimes be reduced (hardware allowing), according to

 *      the endpoint descriptor used to configure the endpoint.

 * @driver_data:for use by the gadget driver.

 * @address: used to identify the endpoint when finding descriptor that

 *	matches connection speed

 * @desc: endpoint descriptor.  This pointer is set before the endpoint is

 *	enabled and remains valid until the endpoint is disabled.

 *
@@ -147,6 +149,7 @@ struct usb_ep { 
	const struct usb_ep_ops	*ops;

	struct list_head	ep_list;

	unsigned		maxpacket:16;

	u8			address;

	const struct usb_endpoint_descriptor	*desc;

};