Hi all
On 21/11/2022 09:25, Daniel Scally wrote:
Now that extension unit support is available through configfs we need
to copy the descriptors for the XUs during uvc_function_bind() so that
they're exposed to the usb subsystem.
Signed-off-by: Daniel Scally <dan.scally@xxxxxxxxxxxxxxxx>
---
Changes in v2:
- none
drivers/usb/gadget/function/f_uvc.c | 35 +++++++++++++++++++++++++++++
drivers/usb/gadget/function/uvc.h | 1 +
2 files changed, 36 insertions(+)
diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index eca5f36dfa74..e0a308f1355c 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -464,6 +464,25 @@ uvc_register_video(struct uvc_device *uvc)
} \
} while (0)
+#define UVC_COPY_XU_DESCRIPTOR(mem, dst, desc) \
+ do { \
+ *(dst)++ = mem; \
+ memcpy(mem, desc, 22); /* bLength to bNrInPins */ \
+ mem += 22; \
+ \
+ memcpy(mem, desc->baSourceID, desc->bNrInPins); \
+ mem += desc->bNrInPins; \
+ \
+ memcpy(mem, &desc->bControlSize, 1); \
+ mem++; \
+ \
+ memcpy(mem, desc->bmControls, desc->bControlSize); \
+ mem += desc->bControlSize; \
+ \
+ memcpy(mem, &desc->iExtension, 1); \
+ mem++; \
+ } while (0)
+
|I don't especially like UVC_COPY_XU_DESCRIPTOR(), but the need to vary
the array size for baSourceID and bmControls plus the requirement for
the struct to be copied to consecutive bytes of memory constrained it a
bit. An alternative might be to replace baSourceID, bControlSize,
bmControls and iExtension in struct uvcg_extension_unit_descriptor with
a single flexible array member (called data[] or something). That would
allow the copy to be a much more straight forward memcpy(mem, desc,
desc->bLength); - but the cost would be reallocating the entire struct
each time the baSourceID or bmControls attributes was changed. That
might be a better method, but I thought I'd stick with this for this
submission at least on the grounds that it's less confusing.|
static struct usb_descriptor_header **
uvc_copy_descriptors(struct uvc_device *uvc, enum usb_device_speed speed)
{
@@ -475,6 +494,7 @@ uvc_copy_descriptors(struct uvc_device *uvc, enum usb_device_speed speed)
const struct usb_descriptor_header * const *src;
struct usb_descriptor_header **dst;
struct usb_descriptor_header **hdr;
+ struct uvcg_extension *xu;
unsigned int control_size;
unsigned int streaming_size;
unsigned int n_desc;
@@ -539,6 +559,13 @@ uvc_copy_descriptors(struct uvc_device *uvc, enum usb_device_speed speed)
bytes += (*src)->bLength;
n_desc++;
}
+
+ list_for_each_entry(xu, uvc->desc.extension_units, list) {
+ control_size += xu->desc.bLength;
+ bytes += xu->desc.bLength;
+ n_desc++;
+ }
+
for (src = (const struct usb_descriptor_header **)uvc_streaming_cls;
*src; ++src) {
streaming_size += (*src)->bLength;
@@ -565,6 +592,13 @@ uvc_copy_descriptors(struct uvc_device *uvc, enum usb_device_speed speed)
uvc_control_header = mem;
UVC_COPY_DESCRIPTORS(mem, dst,
(const struct usb_descriptor_header **)uvc_control_desc);
+
+ list_for_each_entry(xu, uvc->desc.extension_units, list) {
+ struct uvcg_extension_unit_descriptor *desc = &xu->desc;
+
+ UVC_COPY_XU_DESCRIPTOR(mem, dst, desc);
+ }
+
uvc_control_header->wTotalLength = cpu_to_le16(control_size);
uvc_control_header->bInCollection = 1;
uvc_control_header->baInterfaceNr[0] = uvc->streaming_intf;
@@ -988,6 +1022,7 @@ static struct usb_function *uvc_alloc(struct usb_function_instance *fi)
uvc->desc.fs_streaming = opts->fs_streaming;
uvc->desc.hs_streaming = opts->hs_streaming;
uvc->desc.ss_streaming = opts->ss_streaming;
+ uvc->desc.extension_units = &opts->extension_units;
streaming = config_group_find_item(&opts->func_inst.group, "streaming");
if (!streaming)
diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h
index 40226b1f7e14..f1a016d20bb6 100644
--- a/drivers/usb/gadget/function/uvc.h
+++ b/drivers/usb/gadget/function/uvc.h
@@ -143,6 +143,7 @@ struct uvc_device {
const struct uvc_descriptor_header * const *fs_streaming;
const struct uvc_descriptor_header * const *hs_streaming;
const struct uvc_descriptor_header * const *ss_streaming;
+ struct list_head *extension_units;
} desc;
unsigned int control_intf;
