From: Romain Izard <romain.izard.pro@xxxxxxxxx>
commit 793409292382027226769d0299987f06cbd97a6e upstream.
To be able to use the default USB class drivers available in Microsoft
Windows, we need to add OS descriptors to the exported USB gadget to
tell the OS that we are compatible with the built-in drivers.
Copy the OS descriptor support from f_rndis into f_ncm. As a result,
using the WINNCM compatible ID, the UsbNcm driver is loaded on
enumeration without the need for a custom driver or inf file.
Signed-off-by: Romain Izard <romain.izard.pro@xxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Joakim Tjernlund <joakim.tjernlund@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/gadget/function/f_ncm.c | 47 +++++++++++++++++++++++++++++++++---
drivers/usb/gadget/function/u_ncm.h | 3 ++
2 files changed, 47 insertions(+), 3 deletions(-)
--- a/drivers/usb/gadget/function/f_ncm.c
+++ b/drivers/usb/gadget/function/f_ncm.c
@@ -23,6 +23,7 @@
#include "u_ether.h"
#include "u_ether_configfs.h"
#include "u_ncm.h"
+#include "configfs.h"
/*
* This function is a "CDC Network Control Model" (CDC NCM) Ethernet link.
@@ -1434,6 +1435,16 @@ static int ncm_bind(struct usb_configura
return -EINVAL;
ncm_opts = container_of(f->fi, struct f_ncm_opts, func_inst);
+
+ if (cdev->use_os_string) {
+ f->os_desc_table = kzalloc(sizeof(*f->os_desc_table),
+ GFP_KERNEL);
+ if (!f->os_desc_table)
+ return -ENOMEM;
+ f->os_desc_n = 1;
+ f->os_desc_table[0].os_desc = &ncm_opts->ncm_os_desc;
+ }
+
/*
* in drivers/usb/gadget/configfs.c:configfs_composite_bind()
* configurations are bound in sequence with list_for_each_entry,
@@ -1447,13 +1458,15 @@ static int ncm_bind(struct usb_configura
status = gether_register_netdev(ncm_opts->net);
mutex_unlock(&ncm_opts->lock);
if (status)
- return status;
+ goto fail;
ncm_opts->bound = true;
}
us = usb_gstrings_attach(cdev, ncm_strings,
ARRAY_SIZE(ncm_string_defs));
- if (IS_ERR(us))
- return PTR_ERR(us);
+ if (IS_ERR(us)) {
+ status = PTR_ERR(us);
+ goto fail;
+ }
ncm_control_intf.iInterface = us[STRING_CTRL_IDX].id;
ncm_data_nop_intf.iInterface = us[STRING_DATA_IDX].id;
ncm_data_intf.iInterface = us[STRING_DATA_IDX].id;
@@ -1470,6 +1483,10 @@ static int ncm_bind(struct usb_configura
ncm_control_intf.bInterfaceNumber = status;
ncm_union_desc.bMasterInterface0 = status;
+ if (cdev->use_os_string)
+ f->os_desc_table[0].if_id =
+ ncm_iad_desc.bFirstInterface;
+
status = usb_interface_id(c, f);
if (status < 0)
goto fail;
@@ -1549,6 +1566,9 @@ static int ncm_bind(struct usb_configura
return 0;
fail:
+ kfree(f->os_desc_table);
+ f->os_desc_n = 0;
+
if (ncm->notify_req) {
kfree(ncm->notify_req->buf);
usb_ep_free_request(ncm->notify, ncm->notify_req);
@@ -1603,16 +1623,22 @@ static void ncm_free_inst(struct usb_fun
gether_cleanup(netdev_priv(opts->net));
else
free_netdev(opts->net);
+ kfree(opts->ncm_interf_group);
kfree(opts);
}
static struct usb_function_instance *ncm_alloc_inst(void)
{
struct f_ncm_opts *opts;
+ struct usb_os_desc *descs[1];
+ char *names[1];
+ struct config_group *ncm_interf_group;
opts = kzalloc(sizeof(*opts), GFP_KERNEL);
if (!opts)
return ERR_PTR(-ENOMEM);
+ opts->ncm_os_desc.ext_compat_id = opts->ncm_ext_compat_id;
+
mutex_init(&opts->lock);
opts->func_inst.free_func_inst = ncm_free_inst;
opts->net = gether_setup_default();
@@ -1621,8 +1647,20 @@ static struct usb_function_instance *ncm
kfree(opts);
return ERR_CAST(net);
}
+ INIT_LIST_HEAD(&opts->ncm_os_desc.ext_prop);
+
+ descs[0] = &opts->ncm_os_desc;
+ names[0] = "ncm";
config_group_init_type_name(&opts->func_inst.group, "", &ncm_func_type);
+ ncm_interf_group =
+ usb_os_desc_prepare_interf_dir(&opts->func_inst.group, 1, descs,
+ names, THIS_MODULE);
+ if (IS_ERR(ncm_interf_group)) {
+ ncm_free_inst(&opts->func_inst);
+ return ERR_CAST(ncm_interf_group);
+ }
+ opts->ncm_interf_group = ncm_interf_group;
return &opts->func_inst;
}
@@ -1648,6 +1686,9 @@ static void ncm_unbind(struct usb_config
hrtimer_cancel(&ncm->task_timer);
+ kfree(f->os_desc_table);
+ f->os_desc_n = 0;
+
ncm_string_defs[0].id = 0;
usb_free_all_descriptors(f);
--- a/drivers/usb/gadget/function/u_ncm.h
+++ b/drivers/usb/gadget/function/u_ncm.h
@@ -20,6 +20,9 @@ struct f_ncm_opts {
struct net_device *net;
bool bound;
+ struct config_group *ncm_interf_group;
+ struct usb_os_desc ncm_os_desc;
+ char ncm_ext_compat_id[16];
/*
* Read/write access to configfs attributes is handled by configfs.
*
