The UVC gadget at present has no support for extension units. Add the
infrastructure to uvc_configfs.c that allows users to create XUs via
configfs. These will be stored in a new child of uvcg_control_grp_type
with the name "extensions".
Signed-off-by: Daniel Scally <dan.scally@xxxxxxxxxxxxxxxx>
---
Some questions:
1. Should the bNumControls be freely configurable as it is in the current
implementation, or should it be set automatically to (bControlSize * 8)?
2. Currently for bNrInPins / baSourceID and bControlSize / bmControls,
either can be set which adjusts the other. For example changing bNrInPins
from 1 to 3 would add two entries (set to 0) to the baSourceID array. If
the user subsequently wrote 2 values to baSourceID, bNrInPins would be
automatically lowered to 2. Is that a reasonable approach, or should we
just allow setting baSourceID and bmControls and set bNrInPins and
bControlSize to read only?
3. guidExtensionCode code is read/write as bytes at the moment, which
leads to an in my opinion rather unintuitive means of writing the value.
It's how the uncompressed format's guidFormat attribute works, so I went
with that, but I wonder if it'd be better to have it use the usual format
string, e.g. 123e4567-e89b-12d3-a456-426614174000?
4. bUnitID is currently allocated automatically based on the last used
ID stored in f_uvc_opts. This was to avoid having to do uniqueness
validation when the attribute is set. Is that alright, or ought bUnitID
be a writeable attribute with validation instead?
drivers/usb/gadget/function/f_uvc.c | 9 +
drivers/usb/gadget/function/u_uvc.h | 7 +
drivers/usb/gadget/function/uvc_configfs.c | 412 +++++++++++++++++++++
drivers/usb/gadget/function/uvc_configfs.h | 29 ++
4 files changed, 457 insertions(+)
diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index 6e196e06181e..eca5f36dfa74 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -842,6 +842,13 @@ static struct usb_function_instance *uvc_alloc_inst(void)
od->bSourceID = 2;
od->iTerminal = 0;
+ /*
+ * With the ability to add XUs to the UVC function graph, we need to be
+ * able to allocate unique unit IDs to them. The IDs are 1-based, with
+ * the CT, PU and OT above consuming the first 3.
+ */
+ opts->last_unit_id = 3;
+
md = &opts->uvc_color_matching;
md->bLength = UVC_DT_COLOR_MATCHING_SIZE;
md->bDescriptorType = USB_DT_CS_INTERFACE;
@@ -870,6 +877,8 @@ static struct usb_function_instance *uvc_alloc_inst(void)
opts->ss_control =
(const struct uvc_descriptor_header * const *)ctl_cls;
+ INIT_LIST_HEAD(&opts->extension_units);
+
opts->streaming_interval = 1;
opts->streaming_maxpacket = 1024;
snprintf(opts->function_name, sizeof(opts->function_name), "UVC Camera");
diff --git a/drivers/usb/gadget/function/u_uvc.h b/drivers/usb/gadget/function/u_uvc.h
index 24b8681b0d6f..5119cfe5ee4e 100644
--- a/drivers/usb/gadget/function/u_uvc.h
+++ b/drivers/usb/gadget/function/u_uvc.h
@@ -28,6 +28,7 @@ struct f_uvc_opts {
unsigned int control_interface;
unsigned int streaming_interface;
char function_name[32];
+ unsigned int last_unit_id;
/*
* Control descriptors array pointers for full-/high-speed and
@@ -64,6 +65,12 @@ struct f_uvc_opts {
struct uvc_descriptor_header *uvc_fs_control_cls[5];
struct uvc_descriptor_header *uvc_ss_control_cls[5];
+ /*
+ * Control descriptors for extension units. There could be any number
+ * of these, including none at all.
+ */
+ struct list_head extension_units;
+
/*
* Streaming descriptors for full-speed, high-speed and super-speed.
* Used by configfs only, must not be touched by legacy gadgets. The
diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c
index 9bacd8573a46..f944a75a8063 100644
--- a/drivers/usb/gadget/function/uvc_configfs.c
+++ b/drivers/usb/gadget/function/uvc_configfs.c
@@ -648,8 +648,419 @@ static int __uvcg_iter_item_entries_u##bits(const char *page, size_t len,\
return 0; \
}
+UVCG_ITEM_ENTRY_FUNCS(8)
UVCG_ITEM_ENTRY_FUNCS(32)
+/* -----------------------------------------------------------------------------
+ * control/extensions
+ */
+
+#define UVCG_EXTENSION_ATTR(cname, aname, ro...) \
+static ssize_t uvcg_extension_##cname##_show(struct config_item *item, \
+ char *page) \
+{ \
+ struct uvcg_extension *xu = to_uvcg_extension(item); \
+ struct config_item *opts_item; \
+ struct f_uvc_opts *opts; \
+ int ret; \
+ \
+ opts_item = item->ci_parent->ci_parent->ci_parent; \
+ opts = to_f_uvc_opts(opts_item); \
+ \
+ mutex_lock(&opts->lock); \
+ ret = sprintf(page, "%u\n", xu->desc.aname); \
+ mutex_unlock(&opts->lock); \
+ \
+ return ret; \
+} \
+UVC_ATTR##ro(uvcg_extension_, cname, aname)
+
+UVCG_EXTENSION_ATTR(b_length, bLength, _RO);
+UVCG_EXTENSION_ATTR(b_unit_id, bUnitID, _RO);
+
+static ssize_t uvcg_extension_b_num_controls_store(struct config_item *item,
+ const char *page, size_t len)
+{
+ struct uvcg_extension *xu = to_uvcg_extension(item);
+ struct config_item *opts_item;
+ struct f_uvc_opts *opts;
+ int ret;
+ u8 num;
+
+ opts_item = item->ci_parent->ci_parent->ci_parent;
+ opts = to_f_uvc_opts(opts_item);
+
+ ret = kstrtou8(page, 0, &num);
+ if (ret)
+ return ret;
+
+ mutex_lock(&opts->lock);
+ xu->desc.bNumControls = num;
+ mutex_unlock(&opts->lock);
+
+ return len;
+}
+UVCG_EXTENSION_ATTR(b_num_controls, bNumControls);
+
+/*
+ * In addition to storing bNrInPins, this function needs to realloc the
+ * memory for the baSourceID array and additionally expand bLength.
+ */
+static ssize_t uvcg_extension_b_nr_in_pins_store(struct config_item *item,
+ const char *page, size_t len)
+{
+ struct uvcg_extension *xu = to_uvcg_extension(item);
+ struct config_item *opts_item;
+ struct f_uvc_opts *opts;
+ void *tmp_buf;
+ int ret;
+ u8 num;
+
+ opts_item = item->ci_parent->ci_parent->ci_parent;
+ opts = to_f_uvc_opts(opts_item);
+
+ ret = kstrtou8(page, 0, &num);
+ if (ret)
+ return ret;
+
+ mutex_lock(&opts->lock);
+
+ if (num == xu->desc.bNrInPins) {
+ ret = len;
+ goto unlock;
+ }
+
+ tmp_buf = krealloc_array(xu->desc.baSourceID, num, sizeof(u8),
+ GFP_KERNEL);
+ if (!tmp_buf) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+
+ if (num >= xu->desc.bNrInPins)
+ memset(tmp_buf + xu->desc.bNrInPins, 0,
+ (num - xu->desc.bNrInPins) * sizeof(u8));
+
+ xu->desc.baSourceID = tmp_buf;
+ xu->desc.bNrInPins = num;
+ xu->desc.bLength = 24 + xu->desc.bNrInPins + xu->desc.bControlSize;
+
+ ret = len;
+
+unlock:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+UVCG_EXTENSION_ATTR(b_nr_in_pins, bNrInPins);
+
+/*
+ * In addition to storing bControlSize, this function needs to realloc the
+ * memory for the bmControls array and additionally expand bLength.
+ */
+static ssize_t uvcg_extension_b_control_size_store(struct config_item *item,
+ const char *page, size_t len)
+{
+ struct uvcg_extension *xu = to_uvcg_extension(item);
+ struct config_item *opts_item;
+ struct f_uvc_opts *opts;
+ void *tmp_buf;
+ int ret;
+ u8 num;
+
+ opts_item = item->ci_parent->ci_parent->ci_parent;
+ opts = to_f_uvc_opts(opts_item);
+
+ ret = kstrtou8(page, 0, &num);
+ if (ret)
+ return ret;
+
+ mutex_lock(&opts->lock);
+
+ if (num == xu->desc.bControlSize) {
+ ret = len;
+ goto unlock;
+ }
+
+ tmp_buf = krealloc_array(xu->desc.bmControls, num, sizeof(u8),
+ GFP_KERNEL);
+ if (!tmp_buf) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+
+ if (num >= xu->desc.bControlSize)
+ memset(tmp_buf + xu->desc.bControlSize, 0,
+ (num - xu->desc.bControlSize) * sizeof(u8));
+
+ xu->desc.bmControls = tmp_buf;
+ xu->desc.bControlSize = num;
+ xu->desc.bLength = 24 + xu->desc.bNrInPins + xu->desc.bControlSize;
+
+ ret = len;
+
+unlock:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+
+UVCG_EXTENSION_ATTR(b_control_size, bControlSize);
+
+static ssize_t uvcg_extension_guid_extension_code_show(struct config_item *item,
+ char *page)
+{
+ struct uvcg_extension *xu = to_uvcg_extension(item);
+ struct config_item *opts_item;
+ struct f_uvc_opts *opts;
+
+ opts_item = item->ci_parent->ci_parent->ci_parent;
+ opts = to_f_uvc_opts(opts_item);
+
+ mutex_lock(&opts->lock);
+ memcpy(page, xu->desc.guidExtensionCode, sizeof(xu->desc.guidExtensionCode));
+ mutex_unlock(&opts->lock);
+
+ return sizeof(xu->desc.guidExtensionCode);
+}
+
+static ssize_t uvcg_extension_guid_extension_code_store(struct config_item *item,
+ const char *page, size_t len)
+{
+ struct uvcg_extension *xu = to_uvcg_extension(item);
+ struct config_item *opts_item;
+ struct f_uvc_opts *opts;
+ int ret;
+
+ opts_item = item->ci_parent->ci_parent->ci_parent;
+ opts = to_f_uvc_opts(opts_item);
+
+ mutex_lock(&opts->lock);
+ memcpy(xu->desc.guidExtensionCode, page,
+ min(sizeof(xu->desc.guidExtensionCode), len));
+ mutex_unlock(&opts->lock);
+
+ ret = sizeof(xu->desc.guidExtensionCode);
+
+ return ret;
+}
+
+UVC_ATTR(uvcg_extension_, guid_extension_code, guidExtensionCode);
+
+static ssize_t uvcg_extension_ba_source_id_show(struct config_item *item,
+ char *page)
+{
+ struct uvcg_extension *xu = to_uvcg_extension(item);
+ struct config_item *opts_item;
+ struct f_uvc_opts *opts;
+ char *pg = page;
+ int ret, i;
+
+ opts_item = item->ci_parent->ci_parent->ci_parent;
+ opts = to_f_uvc_opts(opts_item);
+
+ mutex_lock(&opts->lock);
+ for (ret = 0, i = 0; i < xu->desc.bNrInPins; ++i) {
+ ret += sprintf(pg, "%u\n", xu->desc.baSourceID[i]);
+ pg = page + ret;
+ }
+ mutex_unlock(&opts->lock);
+
+ return ret;
+}
+
+static ssize_t uvcg_extension_ba_source_id_store(struct config_item *item,
+ const char *page, size_t len)
+{
+ struct uvcg_extension *xu = to_uvcg_extension(item);
+ struct config_item *opts_item;
+ struct f_uvc_opts *opts;
+ u8 *source_ids, *tmp;
+ int ret, n = 0;
+
+ opts_item = item->ci_parent->ci_parent->ci_parent;
+ opts = to_f_uvc_opts(opts_item);
+
+ mutex_lock(&opts->lock);
+
+ ret = __uvcg_iter_item_entries_u8(page, len, __uvcg_count_item_entries, &n);
+ if (ret)
+ goto unlock;
+
+ tmp = source_ids = kcalloc(n, sizeof(u8), GFP_KERNEL);
+ if (!source_ids) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+
+ ret = __uvcg_iter_item_entries_u8(page, len, __uvcg_fill_item_entries_u8, &tmp);
+ if (ret) {
+ kfree(source_ids);
+ goto unlock;
+ }
+
+ kfree(xu->desc.baSourceID);
+ xu->desc.baSourceID = source_ids;
+ xu->desc.bNrInPins = n;
+ xu->desc.bLength = 24 + xu->desc.bNrInPins + xu->desc.bControlSize;
+
+ ret = len;
+
+unlock:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+UVC_ATTR(uvcg_extension_, ba_source_id, baSourceID);
+
+static ssize_t uvcg_extension_bm_controls_show(struct config_item *item,
+ char *page)
+{
+ struct uvcg_extension *xu = to_uvcg_extension(item);
+ struct config_item *opts_item;
+ struct f_uvc_opts *opts;
+ char *pg = page;
+ int ret, i;
+
+ opts_item = item->ci_parent->ci_parent->ci_parent;
+ opts = to_f_uvc_opts(opts_item);
+
+ mutex_lock(&opts->lock);
+ for (ret = 0, i = 0; i < xu->desc.bControlSize; ++i) {
+ ret += sprintf(pg, "0x%02x\n", xu->desc.bmControls[i]);
+ pg = page + ret;
+ }
+ mutex_unlock(&opts->lock);
+
+ return ret;
+}
+
+static ssize_t uvcg_extension_bm_controls_store(struct config_item *item,
+ const char *page, size_t len)
+{
+ struct uvcg_extension *xu = to_uvcg_extension(item);
+ struct config_item *opts_item;
+ struct f_uvc_opts *opts;
+ u8 *bm_controls, *tmp;
+ int ret, n = 0;
+
+ opts_item = item->ci_parent->ci_parent->ci_parent;
+ opts = to_f_uvc_opts(opts_item);
+
+ mutex_lock(&opts->lock);
+
+ ret = __uvcg_iter_item_entries_u8(page, len, __uvcg_count_item_entries, &n);
+ if (ret)
+ goto unlock;
+
+ tmp = bm_controls = kcalloc(n, sizeof(u8), GFP_KERNEL);
+ if (!bm_controls) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+
+ ret = __uvcg_iter_item_entries_u8(page, len, __uvcg_fill_item_entries_u8, &tmp);
+ if (ret) {
+ kfree(bm_controls);
+ goto unlock;
+ }
+
+ kfree(xu->desc.bmControls);
+ xu->desc.bmControls = bm_controls;
+ xu->desc.bControlSize = n;
+ xu->desc.bLength = 24 + xu->desc.bNrInPins + xu->desc.bControlSize;
+
+ ret = len;
+
+unlock:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+
+UVC_ATTR(uvcg_extension_, bm_controls, bmControls);
+
+static struct configfs_attribute *uvcg_extension_attrs[] = {
+ &uvcg_extension_attr_b_length,
+ &uvcg_extension_attr_b_unit_id,
+ &uvcg_extension_attr_b_num_controls,
+ &uvcg_extension_attr_b_nr_in_pins,
+ &uvcg_extension_attr_b_control_size,
+ &uvcg_extension_attr_guid_extension_code,
+ &uvcg_extension_attr_ba_source_id,
+ &uvcg_extension_attr_bm_controls,
+ NULL,
+};
+
+static const struct config_item_type uvcg_extension_type = {
+ .ct_item_ops = &uvcg_config_item_ops,
+ .ct_attrs = uvcg_extension_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static void uvcg_extension_drop(struct config_group *group, struct config_item *item)
+{
+ struct uvcg_extension *xu = container_of(item, struct uvcg_extension, item);
+ struct config_item *opts_item;
+ struct f_uvc_opts *opts;
+
+ opts_item = group->cg_item.ci_parent->ci_parent;
+ opts = to_f_uvc_opts(opts_item);
+
+ mutex_lock(&opts->lock);
+
+ config_item_put(item);
+ list_del(&xu->list);
+ kfree(xu->desc.baSourceID);
+ kfree(xu->desc.bmControls);
+ kfree(xu);
+
+ mutex_unlock(&opts->lock);
+}
+
+static struct config_item *uvcg_extension_make(struct config_group *group, const char *name)
+{
+ struct config_item *opts_item;
+ struct uvcg_extension *xu;
+ struct f_uvc_opts *opts;
+
+ opts_item = group->cg_item.ci_parent->ci_parent;
+ opts = to_f_uvc_opts(opts_item);
+
+ mutex_lock(&opts->lock);
+
+ xu = kzalloc(sizeof(*xu), GFP_KERNEL);
+ if (!xu)
+ return ERR_PTR(-ENOMEM);
+
+ xu->desc.bLength = UVC_DT_EXTENSION_UNIT_SIZE(0, 0);
+ xu->desc.bDescriptorType = USB_DT_CS_INTERFACE;
+ xu->desc.bDescriptorSubType = UVC_VC_EXTENSION_UNIT;
+ xu->desc.bUnitID = ++opts->last_unit_id;
+ xu->desc.bNumControls = 0;
+ xu->desc.bNrInPins = 0;
+ xu->desc.baSourceID = NULL;
+ xu->desc.bControlSize = 0;
+ xu->desc.bmControls = NULL;
+
+ config_item_init_type_name(&xu->item, name, &uvcg_extension_type);
+ list_add_tail(&xu->list, &opts->extension_units);
+
+ mutex_unlock(&opts->lock);
+
+ return &xu->item;
+}
+
+static struct configfs_group_operations uvcg_extensions_grp_ops = {
+ .make_item = uvcg_extension_make,
+ .drop_item = uvcg_extension_drop,
+};
+
+static const struct uvcg_config_group_type uvcg_extensions_grp_type = {
+ .type = {
+ .ct_item_ops = &uvcg_config_item_ops,
+ .ct_group_ops = &uvcg_extensions_grp_ops,
+ .ct_owner = THIS_MODULE,
+ },
+ .name = "extensions",
+};
+
/* -----------------------------------------------------------------------------
* control/class/{fs|ss}
*/
@@ -844,6 +1255,7 @@ static const struct uvcg_config_group_type uvcg_control_grp_type = {
&uvcg_processing_grp_type,
&uvcg_terminal_grp_type,
&uvcg_control_class_grp_type,
+ &uvcg_extensions_grp_type,
NULL,
},
};
diff --git a/drivers/usb/gadget/function/uvc_configfs.h b/drivers/usb/gadget/function/uvc_configfs.h
index ad2ec8c4c78c..c9a4182fb26f 100644
--- a/drivers/usb/gadget/function/uvc_configfs.h
+++ b/drivers/usb/gadget/function/uvc_configfs.h
@@ -132,6 +132,35 @@ static inline struct uvcg_mjpeg *to_uvcg_mjpeg(struct config_item *item)
return container_of(to_uvcg_format(item), struct uvcg_mjpeg, fmt);
}
+/* -----------------------------------------------------------------------------
+ * control/extensions/<NAME>
+ */
+
+struct uvcg_extension_unit_descriptor {
+ u8 bLength;
+ u8 bDescriptorType;
+ u8 bDescriptorSubType;
+ u8 bUnitID;
+ u8 guidExtensionCode[16];
+ u8 bNumControls;
+ u8 bNrInPins;
+ u8 *baSourceID;
+ u8 bControlSize;
+ u8 *bmControls;
+ u8 iExtension;
+} __packed;
+
+struct uvcg_extension {
+ struct config_item item;
+ struct list_head list;
+ struct uvcg_extension_unit_descriptor desc;
+};
+
+static inline struct uvcg_extension *to_uvcg_extension(struct config_item *item)
+{
+ return container_of(item, struct uvcg_extension, item);
+}
+
int uvcg_attach_configfs(struct f_uvc_opts *opts);
#endif /* UVC_CONFIGFS_H */
--
2.34.1
