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: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx>
---
Documentation/ABI/testing/configfs-usb-gadget | 11 ++
drivers/usb/gadget/configfs.c | 159 +++++++++++++++++++++++++-
2 files changed, 169 insertions(+), 1 deletion(-)
diff --git a/Documentation/ABI/testing/configfs-usb-gadget b/Documentation/ABI/testing/configfs-usb-gadget
index 37559a0..0e7b786 100644
--- a/Documentation/ABI/testing/configfs-usb-gadget
+++ b/Documentation/ABI/testing/configfs-usb-gadget
@@ -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
diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 7d1cc01..d37e60f 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -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;
--
1.8.3.2
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