diff mbox series

[4/8] usb: gadget: uvc: configfs: Add interface number attributes

Message ID 20180801002909.2890-5-laurent.pinchart@ideasonboard.com (mailing list archive)
State New, archived
Headers show
Series usb: gadget: uvc: Improve configfs support | expand

Commit Message

Laurent Pinchart Aug. 1, 2018, 12:29 a.m. UTC 
The video control and video streaming interface numbers are needed in
the UVC gadget userspace stack to reply to UVC requests. They are
hardcoded to fixed values at the moment, preventing configurations with
multiple functions.

To fix this, make them dynamically discoverable by userspace through
read-only configfs attributes in <function>/control/bInterfaceNumber and
<function>/streaming/bInterfaceNumber respectively.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/usb/gadget/function/f_uvc.c        |  2 +
 drivers/usb/gadget/function/u_uvc.h        |  3 ++
 drivers/usb/gadget/function/uvc_configfs.c | 62 ++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+)

Comments

Kieran Bingham Aug. 1, 2018, 10:07 a.m. UTC | #1 
Hi Laurent,

Thank you for the patch,

On 01/08/18 01:29, Laurent Pinchart wrote:
> The video control and video streaming interface numbers are needed in
> the UVC gadget userspace stack to reply to UVC requests. They are
> hardcoded to fixed values at the moment, preventing configurations with
> multiple functions.
> 
> To fix this, make them dynamically discoverable by userspace through
> read-only configfs attributes in <function>/control/bInterfaceNumber and
> <function>/streaming/bInterfaceNumber respectively.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  drivers/usb/gadget/function/f_uvc.c        |  2 +
>  drivers/usb/gadget/function/u_uvc.h        |  3 ++
>  drivers/usb/gadget/function/uvc_configfs.c | 62 ++++++++++++++++++++++++++++++



It sounds like this is extending the userspace ABI.

Do we need to document this anywhere?
 Documentation/ABI/testing/configfs-usb-gadget-uvc ?


>  3 files changed, 67 insertions(+)
> 
> diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
> index 95cb1b5f5ffe..4ea987741e6e 100644
> --- a/drivers/usb/gadget/function/f_uvc.c
> +++ b/drivers/usb/gadget/function/f_uvc.c
> @@ -699,12 +699,14 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
>  	uvc_iad.bFirstInterface = ret;
>  	uvc_control_intf.bInterfaceNumber = ret;
>  	uvc->control_intf = ret;
> +	opts->control_interface = ret;
>  
>  	if ((ret = usb_interface_id(c, f)) < 0)
>  		goto error;
>  	uvc_streaming_intf_alt0.bInterfaceNumber = ret;
>  	uvc_streaming_intf_alt1.bInterfaceNumber = ret;
>  	uvc->streaming_intf = ret;
> +	opts->streaming_interface = ret;
>  
>  	/* Copy descriptors */
>  	f->fs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_FULL);
> diff --git a/drivers/usb/gadget/function/u_uvc.h b/drivers/usb/gadget/function/u_uvc.h
> index 2ed292e94fbc..5242d489e20a 100644
> --- a/drivers/usb/gadget/function/u_uvc.h
> +++ b/drivers/usb/gadget/function/u_uvc.h
> @@ -25,6 +25,9 @@ struct f_uvc_opts {
>  	unsigned int					streaming_maxpacket;
>  	unsigned int					streaming_maxburst;
>  
> +	unsigned int					control_interface;
> +	unsigned int					streaming_interface;
> +
>  	/*
>  	 * Control descriptors array pointers for full-/high-speed and
>  	 * super-speed. They point by default to the uvc_fs_control_cls and
> diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c
> index e019ea317c7a..801117686108 100644
> --- a/drivers/usb/gadget/function/uvc_configfs.c
> +++ b/drivers/usb/gadget/function/uvc_configfs.c
> @@ -687,8 +687,39 @@ static const struct uvcg_config_group_type uvcg_control_class_grp_type = {
>   * control
>   */
>  
> +static ssize_t uvcg_default_control_b_interface_number_show(
> +	struct config_item *item, char *page)
> +{
> +	struct config_group *group = to_config_group(item);
> +	struct mutex *su_mutex = &group->cg_subsys->su_mutex;
> +	struct config_item *opts_item;
> +	struct f_uvc_opts *opts;
> +	int result = 0;
> +
> +	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
> +
> +	opts_item = item->ci_parent;
> +	opts = to_f_uvc_opts(opts_item);
> +
> +	mutex_lock(&opts->lock);
> +	result += sprintf(page, "%u\n", opts->control_interface);
> +	mutex_unlock(&opts->lock);
> +
> +	mutex_unlock(su_mutex);
> +
> +	return result;
> +}
> +
> +UVC_ATTR_RO(uvcg_default_control_, b_interface_number, bInterfaceNumber);
> +
> +static struct configfs_attribute *uvcg_default_control_attrs[] = {
> +	&uvcg_default_control_attr_b_interface_number,
> +	NULL,
> +};
> +
>  static const struct uvcg_config_group_type uvcg_control_grp_type = {
>  	.type = {
> +		.ct_attrs = uvcg_default_control_attrs,
>  		.ct_owner = THIS_MODULE,
>  	},
>  	.name = "control",
> @@ -2246,8 +2277,39 @@ static const struct uvcg_config_group_type uvcg_streaming_class_grp_type = {
>   * streaming
>   */
>  
> +static ssize_t uvcg_default_streaming_b_interface_number_show(
> +	struct config_item *item, char *page)
> +{
> +	struct config_group *group = to_config_group(item);
> +	struct mutex *su_mutex = &group->cg_subsys->su_mutex;
> +	struct config_item *opts_item;
> +	struct f_uvc_opts *opts;
> +	int result = 0;
> +
> +	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
> +
> +	opts_item = item->ci_parent;
> +	opts = to_f_uvc_opts(opts_item);
> +
> +	mutex_lock(&opts->lock);
> +	result += sprintf(page, "%u\n", opts->streaming_interface);
> +	mutex_unlock(&opts->lock);
> +
> +	mutex_unlock(su_mutex);
> +
> +	return result;
> +}

That looks like a lot of common boilerplate code copied for each file
which prints a single %u.

Perhaps we should convert those to a macro - but for now they look fine.




> +
> +UVC_ATTR_RO(uvcg_default_streaming_, b_interface_number, bInterfaceNumber);> +
> +static struct configfs_attribute *uvcg_default_streaming_attrs[] = {
> +	&uvcg_default_streaming_attr_b_interface_number,
> +	NULL,
> +};
> +
>  static const struct uvcg_config_group_type uvcg_streaming_grp_type = {
>  	.type = {
> +		.ct_attrs = uvcg_default_streaming_attrs,
>  		.ct_owner = THIS_MODULE,
>  	},
>  	.name = "streaming",
>
Laurent Pinchart Aug. 1, 2018, 9:42 p.m. UTC | #2 
Hi Kieran,

On Wednesday, 1 August 2018 13:07:20 EEST Kieran Bingham wrote:
> On 01/08/18 01:29, Laurent Pinchart wrote:
> > The video control and video streaming interface numbers are needed in
> > the UVC gadget userspace stack to reply to UVC requests. They are
> > hardcoded to fixed values at the moment, preventing configurations with
> > multiple functions.
> > 
> > To fix this, make them dynamically discoverable by userspace through
> > read-only configfs attributes in <function>/control/bInterfaceNumber and
> > <function>/streaming/bInterfaceNumber respectively.
> > 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> > 
> >  drivers/usb/gadget/function/f_uvc.c        |  2 +
> >  drivers/usb/gadget/function/u_uvc.h        |  3 ++
> >  drivers/usb/gadget/function/uvc_configfs.c | 62 +++++++++++++++++++++++++
> It sounds like this is extending the userspace ABI.
> 
> Do we need to document this anywhere?
>  Documentation/ABI/testing/configfs-usb-gadget-uvc ?

You're right, I'll document it.

> >  3 files changed, 67 insertions(+)

[snip]

> > diff --git a/drivers/usb/gadget/function/uvc_configfs.c
> > b/drivers/usb/gadget/function/uvc_configfs.c index
> > e019ea317c7a..801117686108 100644
> > --- a/drivers/usb/gadget/function/uvc_configfs.c
> > +++ b/drivers/usb/gadget/function/uvc_configfs.c
> > @@ -687,8 +687,39 @@ static const struct uvcg_config_group_type
> > uvcg_control_class_grp_type = {> 
> >   * control
> >   */
> > 
> > +static ssize_t uvcg_default_control_b_interface_number_show(
> > +	struct config_item *item, char *page)
> > +{
> > +	struct config_group *group = to_config_group(item);
> > +	struct mutex *su_mutex = &group->cg_subsys->su_mutex;
> > +	struct config_item *opts_item;
> > +	struct f_uvc_opts *opts;
> > +	int result = 0;
> > +
> > +	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
> > +
> > +	opts_item = item->ci_parent;
> > +	opts = to_f_uvc_opts(opts_item);
> > +
> > +	mutex_lock(&opts->lock);
> > +	result += sprintf(page, "%u\n", opts->control_interface);
> > +	mutex_unlock(&opts->lock);
> > +
> > +	mutex_unlock(su_mutex);
> > +
> > +	return result;
> > +}
> > +
> > +UVC_ATTR_RO(uvcg_default_control_, b_interface_number, bInterfaceNumber);
> > +
> > +static struct configfs_attribute *uvcg_default_control_attrs[] = {
> > +	&uvcg_default_control_attr_b_interface_number,
> > +	NULL,
> > +};

[snip]

> > +static ssize_t uvcg_default_streaming_b_interface_number_show(
> > +	struct config_item *item, char *page)
> > +{
> > +	struct config_group *group = to_config_group(item);
> > +	struct mutex *su_mutex = &group->cg_subsys->su_mutex;
> > +	struct config_item *opts_item;
> > +	struct f_uvc_opts *opts;
> > +	int result = 0;
> > +
> > +	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
> > +
> > +	opts_item = item->ci_parent;
> > +	opts = to_f_uvc_opts(opts_item);
> > +
> > +	mutex_lock(&opts->lock);
> > +	result += sprintf(page, "%u\n", opts->streaming_interface);
> > +	mutex_unlock(&opts->lock);
> > +
> > +	mutex_unlock(su_mutex);
> > +
> > +	return result;
> > +}
> 
> That looks like a lot of common boilerplate code copied for each file
> which prints a single %u.
> 
> Perhaps we should convert those to a macro - but for now they look fine.

Feel free to submit patches :-) Helper functions would be event better than 
macros to decrease the object size.

> > +
> > +UVC_ATTR_RO(uvcg_default_streaming_, b_interface_number,
> > bInterfaceNumber);
> > +static struct configfs_attribute
> > *uvcg_default_streaming_attrs[] = {
> > +	&uvcg_default_streaming_attr_b_interface_number,
> > +	NULL,
> > +};

[snip]
diff mbox series

Patch

diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index 95cb1b5f5ffe..4ea987741e6e 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -699,12 +699,14 @@  uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 	uvc_iad.bFirstInterface = ret;
 	uvc_control_intf.bInterfaceNumber = ret;
 	uvc->control_intf = ret;
+	opts->control_interface = ret;
 
 	if ((ret = usb_interface_id(c, f)) < 0)
 		goto error;
 	uvc_streaming_intf_alt0.bInterfaceNumber = ret;
 	uvc_streaming_intf_alt1.bInterfaceNumber = ret;
 	uvc->streaming_intf = ret;
+	opts->streaming_interface = ret;
 
 	/* Copy descriptors */
 	f->fs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_FULL);
diff --git a/drivers/usb/gadget/function/u_uvc.h b/drivers/usb/gadget/function/u_uvc.h
index 2ed292e94fbc..5242d489e20a 100644
--- a/drivers/usb/gadget/function/u_uvc.h
+++ b/drivers/usb/gadget/function/u_uvc.h
@@ -25,6 +25,9 @@  struct f_uvc_opts {
 	unsigned int					streaming_maxpacket;
 	unsigned int					streaming_maxburst;
 
+	unsigned int					control_interface;
+	unsigned int					streaming_interface;
+
 	/*
 	 * Control descriptors array pointers for full-/high-speed and
 	 * super-speed. They point by default to the uvc_fs_control_cls and
diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c
index e019ea317c7a..801117686108 100644
--- a/drivers/usb/gadget/function/uvc_configfs.c
+++ b/drivers/usb/gadget/function/uvc_configfs.c
@@ -687,8 +687,39 @@  static const struct uvcg_config_group_type uvcg_control_class_grp_type = {
  * control
  */
 
+static ssize_t uvcg_default_control_b_interface_number_show(
+	struct config_item *item, char *page)
+{
+	struct config_group *group = to_config_group(item);
+	struct mutex *su_mutex = &group->cg_subsys->su_mutex;
+	struct config_item *opts_item;
+	struct f_uvc_opts *opts;
+	int result = 0;
+
+	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
+
+	opts_item = item->ci_parent;
+	opts = to_f_uvc_opts(opts_item);
+
+	mutex_lock(&opts->lock);
+	result += sprintf(page, "%u\n", opts->control_interface);
+	mutex_unlock(&opts->lock);
+
+	mutex_unlock(su_mutex);
+
+	return result;
+}
+
+UVC_ATTR_RO(uvcg_default_control_, b_interface_number, bInterfaceNumber);
+
+static struct configfs_attribute *uvcg_default_control_attrs[] = {
+	&uvcg_default_control_attr_b_interface_number,
+	NULL,
+};
+
 static const struct uvcg_config_group_type uvcg_control_grp_type = {
 	.type = {
+		.ct_attrs = uvcg_default_control_attrs,
 		.ct_owner = THIS_MODULE,
 	},
 	.name = "control",
@@ -2246,8 +2277,39 @@  static const struct uvcg_config_group_type uvcg_streaming_class_grp_type = {
  * streaming
  */
 
+static ssize_t uvcg_default_streaming_b_interface_number_show(
+	struct config_item *item, char *page)
+{
+	struct config_group *group = to_config_group(item);
+	struct mutex *su_mutex = &group->cg_subsys->su_mutex;
+	struct config_item *opts_item;
+	struct f_uvc_opts *opts;
+	int result = 0;
+
+	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
+
+	opts_item = item->ci_parent;
+	opts = to_f_uvc_opts(opts_item);
+
+	mutex_lock(&opts->lock);
+	result += sprintf(page, "%u\n", opts->streaming_interface);
+	mutex_unlock(&opts->lock);
+
+	mutex_unlock(su_mutex);
+
+	return result;
+}
+
+UVC_ATTR_RO(uvcg_default_streaming_, b_interface_number, bInterfaceNumber);
+
+static struct configfs_attribute *uvcg_default_streaming_attrs[] = {
+	&uvcg_default_streaming_attr_b_interface_number,
+	NULL,
+};
+
 static const struct uvcg_config_group_type uvcg_streaming_grp_type = {
 	.type = {
+		.ct_attrs = uvcg_default_streaming_attrs,
 		.ct_owner = THIS_MODULE,
 	},
 	.name = "streaming",