Control_config is a group under gadget that acts
as a normal config group, except it does not
appear in cdev->configs.
Functions that have exactly zero descriptors can
be linked into control_config. These functions
are bound and unbound with the rest of the gadget,
but are never enabled. Also, functions with zero
descriptors cannot be used in real configs.
Create configfs_setup(), which will first attempt
composite setup. If that fails, it will go through
functions in control_config and use req_match to
find and deliver the request to a function that can
handle it.
This allows the user to create a functionfs instance
dedicated to handling non-standard control requests
no matter what functions or configurations are
currently active.
Signed-off-by: Jerry Zhang <zhangje...@google.com>
---
Changes in V2:
- Added config_item_type for control_config without default attrs
- Changed bind to fail if the wrong kind of function is linked to
a normal config or control_config
- Changed bind to fail if a control function has no req_match, instead
of skipping it over
drivers/usb/gadget/configfs.c | 114 ++++++++++++++++++++++++++++------
1 file changed, 96 insertions(+), 18 deletions(-)
diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index efba66ca0719..ed3d675ee7bb 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -44,12 +44,22 @@ int check_user_usb_string(const char *name,
static const struct usb_descriptor_header *otg_desc[2];
+struct config_usb_cfg {
+ struct config_group group;
+ struct config_group strings_group;
+ struct list_head string_list;
+ struct usb_configuration c;
+ struct list_head func_list;
+ struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
+};
+
struct gadget_info {
struct config_group group;
struct config_group functions_group;
struct config_group configs_group;
struct config_group strings_group;
struct config_group os_desc_group;
+ struct config_usb_cfg control_config;
struct mutex lock;
struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
@@ -68,15 +78,6 @@ static inline struct gadget_info *to_gadget_info(struct
config_item *item)
return container_of(to_config_group(item), struct gadget_info, group);
}
-struct config_usb_cfg {
- struct config_group group;
- struct config_group strings_group;
- struct list_head string_list;
- struct usb_configuration c;
- struct list_head func_list;
- struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
-};
-
static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item
*item)
{
return container_of(to_config_group(item), struct config_usb_cfg,
@@ -512,6 +513,16 @@ static const struct config_item_type gadget_config_type = {
.ct_owner = THIS_MODULE,
};
+static struct configfs_item_operations control_config_item_ops = {
+ .allow_link = config_usb_cfg_link,
+ .drop_link = config_usb_cfg_unlink,
+};
+
+static const struct config_item_type control_config_type = {
+ .ct_item_ops = &control_config_item_ops,
+ .ct_owner = THIS_MODULE,
+};
+
static const struct config_item_type gadget_root_type = {
.ct_item_ops = &gadget_root_item_ops,
.ct_attrs = gadget_root_attrs,
@@ -1205,11 +1216,10 @@ int composite_os_desc_req_prepare(struct
usb_composite_dev *cdev,
static void purge_configs_funcs(struct gadget_info *gi)
{
struct usb_configuration *c;
+ struct usb_function *f, *tmp;
+ struct config_usb_cfg *cfg;
list_for_each_entry(c, &gi->cdev.configs, list) {
- struct usb_function *f, *tmp;
- struct config_usb_cfg *cfg;
-
cfg = container_of(c, struct config_usb_cfg, c);
list_for_each_entry_safe(f, tmp, &c->functions, list) {
@@ -1229,6 +1239,14 @@ static void purge_configs_funcs(struct gadget_info *gi)
c->highspeed = 0;
c->fullspeed = 0;
}
+
+ cfg = &gi->control_config;
+ c = &cfg->c;
+ list_for_each_entry_safe(f, tmp, &c->functions, list) {
+ list_move_tail(&f->list, &cfg->func_list);
+ if (f->unbind)
+ f->unbind(c, f);
+ }
}
static int configfs_composite_bind(struct usb_gadget *gadget,
@@ -1242,6 +1260,9 @@ static int configfs_composite_bind(struct usb_gadget
*gadget,
struct usb_string *s;
unsigned i;
int ret;
+ struct config_usb_cfg *cfg;
+ struct usb_function *f;
+ struct usb_function *tmp;
/* the gi->lock is hold by the caller */
cdev->gadget = gadget;
@@ -1260,8 +1281,6 @@ static int configfs_composite_bind(struct usb_gadget
*gadget,
list_for_each_entry(c, &gi->cdev.configs, list) {
- struct config_usb_cfg *cfg;
-
cfg = container_of(c, struct config_usb_cfg, c);
if (list_empty(&cfg->func_list)) {
pr_err("Config %s/%d of %s needs at least one
function.\n",
@@ -1320,9 +1339,6 @@ static int configfs_composite_bind(struct usb_gadget
*gadget,
/* Go through all configs, attach all functions */
list_for_each_entry(c, &gi->cdev.configs, list) {
- struct config_usb_cfg *cfg;
- struct usb_function *f;
- struct usb_function *tmp;
struct gadget_config_name *cn;
if (gadget_is_otg(gadget))
@@ -1349,6 +1365,12 @@ static int configfs_composite_bind(struct usb_gadget
*gadget,
list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
list_del(&f->list);
ret = usb_add_function(c, f);
+ if (!(f->fs_descriptors || f->hs_descriptors
+ || f->ss_descriptors || f->ssp_descriptors)) {
+ pr_err("%s can't be used in a config since it "
+ "has no descriptors\n", f->name);
+ ret = ret < 0 ? ret : -EINVAL;
+ }
if (ret) {
list_add(&f->list, &cfg->func_list);
goto err_purge_funcs;
@@ -1362,6 +1384,27 @@ static int configfs_composite_bind(struct usb_gadget
*gadget,
goto err_purge_funcs;
}
+ cfg = &gi->control_config;
+ c = &cfg->c;
+ list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
+ if (!f->req_match || !f->setup) {
+ ret = -EINVAL;
+ goto err_purge_funcs;
+ }
+ list_del(&f->list);
+ ret = usb_add_function(&cfg->c, f);
+ if (f->fs_descriptors || f->hs_descriptors
+ || f->ss_descriptors || f->ssp_descriptors) {
+ pr_err("Only functions with no descriptors "
+ "can be used in control_config\n");
+ ret = ret < 0 ? ret : -EINVAL;
+ }
+ if (ret) {
+ list_add(&f->list, &cfg->func_list);
+ goto err_purge_funcs;
+ }
+ }
+
usb_ep_autoconfig_reset(cdev->gadget);
return 0;
@@ -1391,11 +1434,34 @@ static void configfs_composite_unbind(struct usb_gadget
*gadget)
set_gadget_data(gadget, NULL);
}
+static int configfs_composite_setup(struct usb_gadget *gadget,
+ const struct usb_ctrlrequest *c)
+{
+ struct usb_composite_dev *cdev = get_gadget_data(gadget);
+ struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
+
+ struct config_usb_cfg *cfg = &gi->control_config;
+ struct usb_function *f;
+ int value;
+
+ value = composite_setup(gadget, c);
+ if (value >= 0)
+ return value;
+
+ list_for_each_entry(f, &cfg->c.functions, list) {
+ if (f->req_match(f, c, false)) {
+ value = f->setup(f, c);
+ break;
+ }
+ }
+ return value;
+}
+
static const struct usb_gadget_driver configfs_driver_template = {
.bind = configfs_composite_bind,
.unbind = configfs_composite_unbind,
- .setup = composite_setup,
+ .setup = configfs_composite_setup,
.reset = composite_disconnect,
.disconnect = composite_disconnect,
@@ -1461,6 +1527,18 @@ static struct config_group *gadgets_make(
if (!gi->composite.gadget_driver.function)
goto err;
+ gi->control_config.c.label = "control_config";
+ /* composite requires some value, but it doesn't matter */
+ gi->control_config.c.bConfigurationValue = 42;
+ INIT_LIST_HEAD(&gi->control_config.func_list);
+ config_group_init_type_name(&gi->control_config.group,
+ "control_config", &control_config_type);
+ configfs_add_default_group(&gi->control_config.group, &gi->group);
+
+ if (usb_add_config_only(&gi->cdev, &gi->control_config.c))
+ goto err;
+ list_del(&gi->control_config.c.list);
+
return &gi->group;
err:
kfree(gi);
--
2.17.0.484.g0c8726318c-goog
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