Add support for using uvc as a component of a composite gadget
set up with configfs.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
Documentation/ABI/testing/configfs-usb-gadget-uvc | 11 +
drivers/usb/gadget/Kconfig | 12 +
drivers/usb/gadget/f_uvc.c | 229 +++++++++++++++++++++
drivers/usb/gadget/u_uvc.h | 9 +
4 files changed, 261 insertions(+), 0 deletions(-)
create mode 100644 Documentation/ABI/testing/configfs-usb-gadget-uvc
diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uvc b/Documentation/ABI/testing/configfs-usb-gadget-uvc
new file mode 100644
index 0000000..e9f9663
--- /dev/null
+++ b/Documentation/ABI/testing/configfs-usb-gadget-uvc
@@ -0,0 +1,11 @@
+What: /config/usb-gadget/gadget/functions/uvc.name
+Date: Nov 2013
+KenelVersion: 3.13
+Description:
+ The attributes:
+
+ streaming_interval - 1..16
+ streaming_maxpacket - 1..1023 (fs), 1..3072 (hs/ss)
+ streaming_maxburst - 0..15 (ss only)
+ trace - trace level bitmask,
+ common for all uvc instances
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index c8a72e0..1e863ad 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -692,6 +692,18 @@ config USB_CONFIGFS_MASS_STORAGE
device (in much the same way as the "loop" device driver),
specified as a module parameter or sysfs option.
+config USB_CONFIGFS_F_UVC
+ boolean "USB Webcam function"
+ depends on USB_CONFIGFS
+ depends on VIDEO_DEV
+ select USB_LIBCOMPOSITE
+ select VIDEOBUF2_VMALLOC
+ select USB_F_UVC
+ help
+ The Webcam function acts as a composite USB Audio and Video Class
+ device. It provides a userspace API to process UVC control requests
+ and stream video data to the host.
+
config USB_ZERO
tristate "Gadget Zero (DEVELOPMENT)"
select USB_LIBCOMPOSITE
diff --git a/drivers/usb/gadget/f_uvc.c b/drivers/usb/gadget/f_uvc.c
index 9e1deff..4df877b 100644
--- a/drivers/usb/gadget/f_uvc.c
+++ b/drivers/usb/gadget/f_uvc.c
@@ -961,6 +961,220 @@ error:
return ret;
}
+static inline struct f_uvc_opts *to_f_uvc_opts(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct f_uvc_opts,
+ func_inst.group);
+}
+
+CONFIGFS_ATTR_STRUCT(f_uvc_opts);
+CONFIGFS_ATTR_OPS(f_uvc_opts);
+
+static void uvc_attr_release(struct config_item *item)
+{
+ struct f_uvc_opts *opts = to_f_uvc_opts(item);
+
+ usb_put_function_instance(&opts->func_inst);
+}
+
+static struct configfs_item_operations uvc_item_ops = {
+ .release = uvc_attr_release,
+ .show_attribute = f_uvc_opts_attr_show,
+ .store_attribute = f_uvc_opts_attr_store,
+};
+
+static ssize_t uvc_opts_trace_show(struct f_uvc_opts *opts, char *page)
+{
+ int result;
+
+ mutex_lock(&opts->lock);
+ result = sprintf(page, "%d", uvc_gadget_trace_param);
+ mutex_unlock(&opts->lock);
+
+ return result;
+}
+
+static ssize_t uvc_opts_trace_store(struct f_uvc_opts *opts,
+ const char *page, size_t len)
+{
+ int ret;
+ u32 num;
+
+ mutex_lock(&opts->lock);
+ if (opts->refcnt) {
+ ret = -EBUSY;
+ goto end;
+ }
+
+ ret = kstrtou32(page, 0, &num);
+ if (ret)
+ goto end;
+
+ uvc_gadget_trace_param = num;
+ ret = len;
+
+end:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+
+static struct f_uvc_opts_attribute f_uvc_opts_trace =
+ __CONFIGFS_ATTR(trace, S_IRUGO | S_IWUSR, uvc_opts_trace_show,
+ uvc_opts_trace_store);
+
+static ssize_t uvc_opts_streaming_interval_show(struct f_uvc_opts *opts,
+ char *page)
+{
+ int result;
+
+ mutex_lock(&opts->lock);
+ result = sprintf(page, "%d", opts->streaming_interval);
+ mutex_unlock(&opts->lock);
+ result = 0;
+
+ return result;
+}
+
+static ssize_t uvc_opts_streaming_interval_store(struct f_uvc_opts *opts,
+ const char *page, size_t len)
+{
+ int ret;
+ u8 num;
+
+ mutex_lock(&opts->lock);
+ if (opts->refcnt) {
+ ret = -EBUSY;
+ goto end;
+ }
+
+ ret = kstrtou8(page, 0, &num);
+ if (ret)
+ goto end;
+
+ if (num > 16) {
+ ret = -EINVAL;
+ goto end;
+ }
+ opts->streaming_interval = num;
+ ret = len;
+
+end:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+
+static struct f_uvc_opts_attribute f_uvc_opts_streaming_interval =
+ __CONFIGFS_ATTR(streaming_interval, S_IRUGO | S_IWUSR,
+ uvc_opts_streaming_interval_show,
+ uvc_opts_streaming_interval_store);
+
+static ssize_t uvc_opts_streaming_maxpacket_show(struct f_uvc_opts *opts,
+ char *page)
+{
+ int result;
+
+ mutex_lock(&opts->lock);
+ result = sprintf(page, "%d", opts->streaming_maxpacket);
+ mutex_unlock(&opts->lock);
+ result = 0;
+
+ return result;
+}
+
+static ssize_t uvc_opts_streaming_maxpacket_store(struct f_uvc_opts *opts,
+ const char *page, size_t len)
+{
+ int ret;
+ u16 num;
+
+ mutex_lock(&opts->lock);
+ if (opts->refcnt) {
+ ret = -EBUSY;
+ goto end;
+ }
+
+ ret = kstrtou16(page, 0, &num);
+ if (ret)
+ goto end;
+
+ if (num > 3072) {
+ ret = -EINVAL;
+ goto end;
+ }
+ opts->streaming_maxpacket = num;
+ ret = len;
+
+end:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+
+static struct f_uvc_opts_attribute f_uvc_opts_streaming_maxpacket =
+ __CONFIGFS_ATTR(streaming_maxpacket, S_IRUGO | S_IWUSR,
+ uvc_opts_streaming_maxpacket_show,
+ uvc_opts_streaming_maxpacket_store);
+
+static ssize_t uvc_opts_streaming_maxburst_show(struct f_uvc_opts *opts,
+ char *page)
+{
+ int result;
+
+ mutex_lock(&opts->lock);
+ result = sprintf(page, "%d", opts->streaming_maxburst);
+ mutex_unlock(&opts->lock);
+ result = 0;
+
+ return result;
+}
+
+static ssize_t uvc_opts_streaming_maxburst_store(struct f_uvc_opts *opts,
+ const char *page, size_t len)
+{
+ int ret;
+ u8 num;
+
+ mutex_lock(&opts->lock);
+ if (opts->refcnt) {
+ ret = -EBUSY;
+ goto end;
+ }
+
+ ret = kstrtou8(page, 0, &num);
+ if (ret)
+ goto end;
+
+ if (num > 15) {
+ ret = -EINVAL;
+ goto end;
+ }
+ opts->streaming_maxburst = num;
+ ret = len;
+
+end:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+
+static struct f_uvc_opts_attribute f_uvc_opts_streaming_maxburst =
+ __CONFIGFS_ATTR(streaming_maxburst, S_IRUGO | S_IWUSR,
+ uvc_opts_streaming_maxburst_show,
+ uvc_opts_streaming_maxburst_store);
+
+
+static struct configfs_attribute *uvc_attrs[] = {
+ &f_uvc_opts_trace.attr,
+ &f_uvc_opts_streaming_interval.attr,
+ &f_uvc_opts_streaming_maxpacket.attr,
+ &f_uvc_opts_streaming_maxburst.attr,
+ NULL,
+};
+
+static struct config_item_type uvc_func_type = {
+ .ct_item_ops = &uvc_item_ops,
+ .ct_attrs = uvc_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
/* --------------------------------------------------------------------------
* USB gadget function
*/
@@ -981,17 +1195,26 @@ static struct usb_function_instance *uvc_alloc_inst(void)
opts = kzalloc(sizeof(*opts), GFP_KERNEL);
if (!opts)
return ERR_PTR(-ENOMEM);
+ mutex_init(&opts->lock);
opts->func_inst.free_func_inst = uvc_free_inst;
+ config_group_init_type_name(&opts->func_inst.group, "",
+ &uvc_func_type);
+
return &opts->func_inst;
}
static void uvc_free(struct usb_function *f)
{
struct uvc_device *uvc;
+ struct f_uvc_opts *opts;
uvc = to_uvc(f);
+ opts = container_of(f->fi, struct f_uvc_opts, func_inst);
kfree(uvc);
+ mutex_lock(&opts->lock);
+ --opts->refcnt;
+ mutex_unlock(&opts->lock);
}
static void uvc_unbind(struct usb_configuration *c, struct usb_function *f)
@@ -1015,11 +1238,17 @@ static void uvc_unbind(struct usb_configuration *c, struct usb_function *f)
struct usb_function *uvc_alloc(struct usb_function_instance *fi)
{
struct uvc_device *uvc;
+ struct f_uvc_opts *opts;
uvc = kzalloc(sizeof(*uvc), GFP_KERNEL);
if (uvc == NULL)
return ERR_PTR(-ENOMEM);
+ opts = container_of(fi, struct f_uvc_opts, func_inst);
+ mutex_lock(&opts->lock);
+ ++opts->refcnt;
+ mutex_unlock(&opts->lock);
+
uvc->state = UVC_STATE_DISCONNECTED;
uvc->desc.fs_control = uvc_fs_control_cls;
diff --git a/drivers/usb/gadget/u_uvc.h b/drivers/usb/gadget/u_uvc.h
index 6758ba4..85b782e 100644
--- a/drivers/usb/gadget/u_uvc.h
+++ b/drivers/usb/gadget/u_uvc.h
@@ -24,6 +24,15 @@ struct f_uvc_opts {
unsigned int streaming_interval;
unsigned int streaming_maxpacket;
unsigned int streaming_maxburst;
+
+ /*
+ * Read/write access to configfs attributes is handled by configfs.
+ *
+ * This is to protect the data from concurrent access by read/write
+ * and create symlink/remove symlink.
+ */
+ struct mutex lock;
+ int refcnt;
};
void uvc_set_trace_param(unsigned int uvc_gadget_trace_param_webcam);
--
1.7.0.4
--
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