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Commit 87213d38 authored by Andrzej Pietrasiewicz's avatar Andrzej Pietrasiewicz Committed by Felipe Balbi
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usb: gadget: configfs: OS String support 



Add handling of OS String extension from the configfs interface.
A directory "os_desc" is added at the top level of a gadget's
directories hierarchy. In the "os_desc" directory there are
three attributes: "use", "b_vendor_code" and "qw_sign".
If "use" contains "0" the OS string is not reported to the host.
"b_vendor_code" contains a one-byte value which is used
for custom per-device and per-interface requests.
"qw_sign" contains an identifier to be reported as the "OS String"
proper.

Signed-off-by: default avatarAndrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
parent de7a8d2d

Documentation/ABI/testing/configfs-usb-gadget

+11 −0
Original line number Diff line number Diff line
@@ -79,3 +79,14 @@ Description: 
		product		- gadget's product description

		manufacturer	- gadget's manufacturer description



What:		/config/usb-gadget/gadget/os_desc

Date:		May 2014

KernelVersion:	3.16

Description:

		This group contains "OS String" extension handling attributes.



		use		- flag turning "OS Desctiptors" support on/off

		b_vendor_code	- one-byte value used for custom per-device and

				per-interface requests

		qw_sign		- an identifier to be reported as "OS String"

				proper

drivers/usb/gadget/configfs.c

+158 −1
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#include <linux/module.h>

#include <linux/slab.h>

#include <linux/device.h>

#include <linux/nls.h>

#include <linux/usb/composite.h>

#include <linux/usb/gadget_configfs.h>

#include "configfs.h"
@@ -43,7 +44,8 @@ struct gadget_info { 
	struct config_group functions_group;

	struct config_group configs_group;

	struct config_group strings_group;

	struct config_group *default_groups[4];

	struct config_group os_desc_group;

	struct config_group *default_groups[5];



	struct mutex lock;

	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
@@ -56,6 +58,9 @@ struct gadget_info { 
#endif

	struct usb_composite_driver composite;

	struct usb_composite_dev cdev;

	bool use_os_desc;

	char b_vendor_code;

	char qw_sign[OS_STRING_QW_SIGN_LEN];

};



struct config_usb_cfg {
@@ -79,6 +84,10 @@ struct gadget_strings { 
	struct list_head list;

};



struct os_desc {

	struct config_group group;

};



struct gadget_config_name {

	struct usb_gadget_strings stringtab_dev;

	struct usb_string strings;
@@ -736,6 +745,145 @@ static void gadget_strings_attr_release(struct config_item *item) 
USB_CONFIG_STRING_RW_OPS(gadget_strings);

USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);



static inline struct os_desc *to_os_desc(struct config_item *item)

{

	return container_of(to_config_group(item), struct os_desc, group);

}



CONFIGFS_ATTR_STRUCT(os_desc);

CONFIGFS_ATTR_OPS(os_desc);



static ssize_t os_desc_use_show(struct os_desc *os_desc, char *page)

{

	struct gadget_info *gi;



	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);



	return sprintf(page, "%d", gi->use_os_desc);

}



static ssize_t os_desc_use_store(struct os_desc *os_desc, const char *page,

				 size_t len)

{

	struct gadget_info *gi;

	int ret;

	bool use;



	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);



	mutex_lock(&gi->lock);

	ret = strtobool(page, &use);

	if (!ret) {

		gi->use_os_desc = use;

		ret = len;

	}

	mutex_unlock(&gi->lock);



	return ret;

}



static struct os_desc_attribute os_desc_use =

	__CONFIGFS_ATTR(use, S_IRUGO | S_IWUSR,

			os_desc_use_show,

			os_desc_use_store);



static ssize_t os_desc_b_vendor_code_show(struct os_desc *os_desc, char *page)

{

	struct gadget_info *gi;



	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);



	return sprintf(page, "%d", gi->b_vendor_code);

}



static ssize_t os_desc_b_vendor_code_store(struct os_desc *os_desc,

					   const char *page, size_t len)

{

	struct gadget_info *gi;

	int ret;

	u8 b_vendor_code;



	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);



	mutex_lock(&gi->lock);

	ret = kstrtou8(page, 0, &b_vendor_code);

	if (!ret) {

		gi->b_vendor_code = b_vendor_code;

		ret = len;

	}

	mutex_unlock(&gi->lock);



	return ret;

}



static struct os_desc_attribute os_desc_b_vendor_code =

	__CONFIGFS_ATTR(b_vendor_code, S_IRUGO | S_IWUSR,

			os_desc_b_vendor_code_show,

			os_desc_b_vendor_code_store);



static ssize_t os_desc_qw_sign_show(struct os_desc *os_desc, char *page)

{

	struct gadget_info *gi;



	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);



	memcpy(page, gi->qw_sign, OS_STRING_QW_SIGN_LEN);



	return OS_STRING_QW_SIGN_LEN;

}



static ssize_t os_desc_qw_sign_store(struct os_desc *os_desc, const char *page,

				     size_t len)

{

	struct gadget_info *gi;

	int res, l;



	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);

	l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);

	if (page[l - 1] == '\n')

		--l;



	mutex_lock(&gi->lock);

	res = utf8s_to_utf16s(page, l,

			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,

			      OS_STRING_QW_SIGN_LEN);

	if (res > 0)

		res = len;

	mutex_unlock(&gi->lock);



	return res;

}



static struct os_desc_attribute os_desc_qw_sign =

	__CONFIGFS_ATTR(qw_sign, S_IRUGO | S_IWUSR,

			os_desc_qw_sign_show,

			os_desc_qw_sign_store);



static struct configfs_attribute *os_desc_attrs[] = {

	&os_desc_use.attr,

	&os_desc_b_vendor_code.attr,

	&os_desc_qw_sign.attr,

	NULL,

};



static void os_desc_attr_release(struct config_item *item)

{

	struct os_desc *os_desc = to_os_desc(item);

	kfree(os_desc);

}



static struct configfs_item_operations os_desc_ops = {

	.release                = os_desc_attr_release,

	.show_attribute         = os_desc_attr_show,

	.store_attribute        = os_desc_attr_store,

};



static struct config_item_type os_desc_type = {

	.ct_item_ops	= &os_desc_ops,

	.ct_attrs	= os_desc_attrs,

	.ct_owner	= THIS_MODULE,

};



static int configfs_do_nothing(struct usb_composite_dev *cdev)

{

	WARN_ON(1);
@@ -839,6 +987,12 @@ static int configfs_composite_bind(struct usb_gadget *gadget, 
		gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;

	}



	if (gi->use_os_desc) {

		cdev->use_os_string = true;

		cdev->b_vendor_code = gi->b_vendor_code;

		memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);

	}



	/* Go through all configs, attach all functions */

	list_for_each_entry(c, &gi->cdev.configs, list) {

		struct config_usb_cfg *cfg;
@@ -929,6 +1083,7 @@ static struct config_group *gadgets_make( 
	gi->group.default_groups[0] = &gi->functions_group;

	gi->group.default_groups[1] = &gi->configs_group;

	gi->group.default_groups[2] = &gi->strings_group;

	gi->group.default_groups[3] = &gi->os_desc_group;



	config_group_init_type_name(&gi->functions_group, "functions",

			&functions_type);
@@ -936,6 +1091,8 @@ static struct config_group *gadgets_make( 
			&config_desc_type);

	config_group_init_type_name(&gi->strings_group, "strings",

			&gadget_strings_strings_type);

	config_group_init_type_name(&gi->os_desc_group, "os_desc",

			&os_desc_type);



	gi->composite.bind = configfs_do_nothing;

	gi->composite.unbind = configfs_do_nothing;