USB gadget: Webcam device

This webcam gadget instantiates a UVC camera (360p and 720p resolutions
in YUYV and MJPEG).

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/Kconfig

@@ -877,8 +877,15 @@ config USB_G_HID
 
 # put drivers that need isochronous transfer support (for audio
 # or video class gadget drivers), or specific hardware, here.
+config USB_G_WEBCAM
+	tristate "USB Webcam Gadget"
+	help
+	  The Webcam Gadget 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.
 
-# - none yet
+	  Say "y" to link the driver statically, or "m" to build a
+	  dynamically linked module called "g_webcam".
 
 endchoice
 

drivers/usb/gadget/Makefile

@@ -45,6 +45,7 @@ g_cdc-objs			:= cdc2.o
 g_multi-objs			:= multi.o
 g_hid-objs			:= hid.o
 g_nokia-objs			:= nokia.o
+g_webcam-objs			:= webcam.o
 
 obj-$(CONFIG_USB_ZERO)		+= g_zero.o
 obj-$(CONFIG_USB_AUDIO)		+= g_audio.o
@@ -59,4 +60,5 @@ obj-$(CONFIG_USB_CDC_COMPOSITE) += g_cdc.o
 obj-$(CONFIG_USB_G_HID)		+= g_hid.o
 obj-$(CONFIG_USB_G_MULTI)	+= g_multi.o
 obj-$(CONFIG_USB_G_NOKIA)	+= g_nokia.o
+obj-$(CONFIG_USB_G_WEBCAM)	+= g_webcam.o
 

drivers/usb/gadget/webcam.c

@@ -0,0 +1,399 @@
+/*
+ *	webcam.c -- USB webcam gadget driver
+ *
+ *	Copyright (C) 2009-2010
+ *	    Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ *	This program is free software; you can redistribute it and/or modify
+ *	it under the terms of the GNU General Public License as published by
+ *	the Free Software Foundation; either version 2 of the License, or
+ *	(at your option) any later version.
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/usb/video.h>
+
+#include "f_uvc.h"
+
+/*
+ * Kbuild is not very cooperative with respect to linking separately
+ * compiled library objects into one module.  So for now we won't use
+ * separate compilation ... ensuring init/exit sections work to shrink
+ * the runtime footprint, and giving us at least some parts of what
+ * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
+ */
+#include "composite.c"
+#include "usbstring.c"
+#include "config.c"
+#include "epautoconf.c"
+
+#include "f_uvc.c"
+#include "uvc_queue.c"
+#include "uvc_v4l2.c"
+#include "uvc_video.c"
+
+/* --------------------------------------------------------------------------
+ * Device descriptor
+ */
+
+#define WEBCAM_VENDOR_ID		0x1d6b	/* Linux Foundation */
+#define WEBCAM_PRODUCT_ID		0x0102	/* Webcam A/V gadget */
+#define WEBCAM_DEVICE_BCD		0x0010	/* 0.10 */
+
+static char webcam_vendor_label[] = "Linux Foundation";
+static char webcam_product_label[] = "Webcam gadget";
+static char webcam_config_label[] = "Video";
+
+/* string IDs are assigned dynamically */
+
+#define STRING_MANUFACTURER_IDX		0
+#define STRING_PRODUCT_IDX		1
+#define STRING_DESCRIPTION_IDX		2
+
+static struct usb_string webcam_strings[] = {
+	[STRING_MANUFACTURER_IDX].s = webcam_vendor_label,
+	[STRING_PRODUCT_IDX].s = webcam_product_label,
+	[STRING_DESCRIPTION_IDX].s = webcam_config_label,
+	{  }
+};
+
+static struct usb_gadget_strings webcam_stringtab = {
+	.language = 0x0409,	/* en-us */
+	.strings = webcam_strings,
+};
+
+static struct usb_gadget_strings *webcam_device_strings[] = {
+	&webcam_stringtab,
+	NULL,
+};
+
+static struct usb_device_descriptor webcam_device_descriptor = {
+	.bLength		= USB_DT_DEVICE_SIZE,
+	.bDescriptorType	= USB_DT_DEVICE,
+	.bcdUSB			= cpu_to_le16(0x0200),
+	.bDeviceClass		= USB_CLASS_MISC,
+	.bDeviceSubClass	= 0x02,
+	.bDeviceProtocol	= 0x01,
+	.bMaxPacketSize0	= 0, /* dynamic */
+	.idVendor		= cpu_to_le16(WEBCAM_VENDOR_ID),
+	.idProduct		= cpu_to_le16(WEBCAM_PRODUCT_ID),
+	.bcdDevice		= cpu_to_le16(WEBCAM_DEVICE_BCD),
+	.iManufacturer		= 0, /* dynamic */
+	.iProduct		= 0, /* dynamic */
+	.iSerialNumber		= 0, /* dynamic */
+	.bNumConfigurations	= 0, /* dynamic */
+};
+
+DECLARE_UVC_HEADER_DESCRIPTOR(1);
+
+static const struct UVC_HEADER_DESCRIPTOR(1) uvc_control_header = {
+	.bLength		= UVC_DT_HEADER_SIZE(1),
+	.bDescriptorType	= USB_DT_CS_INTERFACE,
+	.bDescriptorSubType	= UVC_DT_HEADER,
+	.bcdUVC			= cpu_to_le16(0x0100),
+	.wTotalLength		= 0, /* dynamic */
+	.dwClockFrequency	= cpu_to_le32(48000000),
+	.bInCollection		= 0, /* dynamic */
+	.baInterfaceNr[0]	= 0, /* dynamic */
+};
+
+static const struct uvc_camera_terminal_descriptor uvc_camera_terminal = {
+	.bLength		= UVC_DT_CAMERA_TERMINAL_SIZE(3),
+	.bDescriptorType	= USB_DT_CS_INTERFACE,
+	.bDescriptorSubType	= UVC_DT_INPUT_TERMINAL,
+	.bTerminalID		= 1,
+	.wTerminalType		= cpu_to_le16(0x0201),
+	.bAssocTerminal		= 0,
+	.iTerminal		= 0,
+	.wObjectiveFocalLengthMin	= cpu_to_le16(0),
+	.wObjectiveFocalLengthMax	= cpu_to_le16(0),
+	.wOcularFocalLength		= cpu_to_le16(0),
+	.bControlSize		= 3,
+	.bmControls[0]		= 2,
+	.bmControls[1]		= 0,
+	.bmControls[2]		= 0,
+};
+
+static const struct uvc_processing_unit_descriptor uvc_processing = {
+	.bLength		= UVC_DT_PROCESSING_UNIT_SIZE(2),
+	.bDescriptorType	= USB_DT_CS_INTERFACE,
+	.bDescriptorSubType	= UVC_DT_PROCESSING_UNIT,
+	.bUnitID		= 2,
+	.bSourceID		= 1,
+	.wMaxMultiplier		= cpu_to_le16(16*1024),
+	.bControlSize		= 2,
+	.bmControls[0]		= 1,
+	.bmControls[1]		= 0,
+	.iProcessing		= 0,
+};
+
+static const struct uvc_output_terminal_descriptor uvc_output_terminal = {
+	.bLength		= UVC_DT_OUTPUT_TERMINAL_SIZE,
+	.bDescriptorType	= USB_DT_CS_INTERFACE,
+	.bDescriptorSubType	= UVC_DT_OUTPUT_TERMINAL,
+	.bTerminalID		= 3,
+	.wTerminalType		= cpu_to_le16(0x0101),
+	.bAssocTerminal		= 0,
+	.bSourceID		= 2,
+	.iTerminal		= 0,
+};
+
+DECLARE_UVC_INPUT_HEADER_DESCRIPTOR(1, 2);
+
+static const struct UVC_INPUT_HEADER_DESCRIPTOR(1, 2) uvc_input_header = {
+	.bLength		= UVC_DT_INPUT_HEADER_SIZE(1, 2),
+	.bDescriptorType	= USB_DT_CS_INTERFACE,
+	.bDescriptorSubType	= UVC_DT_INPUT_HEADER,
+	.bNumFormats		= 2,
+	.wTotalLength		= 0, /* dynamic */
+	.bEndpointAddress	= 0, /* dynamic */
+	.bmInfo			= 0,
+	.bTerminalLink		= 3,
+	.bStillCaptureMethod	= 0,
+	.bTriggerSupport	= 0,
+	.bTriggerUsage		= 0,
+	.bControlSize		= 1,
+	.bmaControls[0][0]	= 0,
+	.bmaControls[1][0]	= 4,
+};
+
+static const struct uvc_format_uncompressed uvc_format_yuv = {
+	.bLength		= UVC_DT_FORMAT_UNCOMPRESSED_SIZE,
+	.bDescriptorType	= USB_DT_CS_INTERFACE,
+	.bDescriptorSubType	= UVC_DT_FORMAT_UNCOMPRESSED,
+	.bFormatIndex		= 1,
+	.bNumFrameDescriptors	= 2,
+	.guidFormat		=
+		{ 'Y',  'U',  'Y',  '2', 0x00, 0x00, 0x10, 0x00,
+		 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71},
+	.bBitsPerPixel		= 16,
+	.bDefaultFrameIndex	= 1,
+	.bAspectRatioX		= 0,
+	.bAspectRatioY		= 0,
+	.bmInterfaceFlags	= 0,
+	.bCopyProtect		= 0,
+};
+
+DECLARE_UVC_FRAME_UNCOMPRESSED(1);
+DECLARE_UVC_FRAME_UNCOMPRESSED(3);
+
+static const struct UVC_FRAME_UNCOMPRESSED(3) uvc_frame_yuv_360p = {
+	.bLength		= UVC_DT_FRAME_UNCOMPRESSED_SIZE(3),
+	.bDescriptorType	= USB_DT_CS_INTERFACE,
+	.bDescriptorSubType	= UVC_DT_FRAME_UNCOMPRESSED,
+	.bFrameIndex		= 1,
+	.bmCapabilities		= 0,
+	.wWidth			= cpu_to_le16(640),
+	.wHeight		= cpu_to_le16(360),
+	.dwMinBitRate		= cpu_to_le32(18432000),
+	.dwMaxBitRate		= cpu_to_le32(55296000),
+	.dwMaxVideoFrameBufferSize	= cpu_to_le32(460800),
+	.dwDefaultFrameInterval	= cpu_to_le32(666666),
+	.bFrameIntervalType	= 3,
+	.dwFrameInterval[0]	= cpu_to_le32(666666),
+	.dwFrameInterval[1]	= cpu_to_le32(1000000),
+	.dwFrameInterval[2]	= cpu_to_le32(5000000),
+};
+
+static const struct UVC_FRAME_UNCOMPRESSED(1) uvc_frame_yuv_720p = {
+	.bLength		= UVC_DT_FRAME_UNCOMPRESSED_SIZE(1),
+	.bDescriptorType	= USB_DT_CS_INTERFACE,
+	.bDescriptorSubType	= UVC_DT_FRAME_UNCOMPRESSED,
+	.bFrameIndex		= 2,
+	.bmCapabilities		= 0,
+	.wWidth			= cpu_to_le16(1280),
+	.wHeight		= cpu_to_le16(720),
+	.dwMinBitRate		= cpu_to_le32(29491200),
+	.dwMaxBitRate		= cpu_to_le32(29491200),
+	.dwMaxVideoFrameBufferSize	= cpu_to_le32(1843200),
+	.dwDefaultFrameInterval	= cpu_to_le32(5000000),
+	.bFrameIntervalType	= 1,
+	.dwFrameInterval[0]	= cpu_to_le32(5000000),
+};
+
+static const struct uvc_format_mjpeg uvc_format_mjpg = {
+	.bLength		= UVC_DT_FORMAT_MJPEG_SIZE,
+	.bDescriptorType	= USB_DT_CS_INTERFACE,
+	.bDescriptorSubType	= UVC_DT_FORMAT_MJPEG,
+	.bFormatIndex		= 2,
+	.bNumFrameDescriptors	= 2,
+	.bmFlags		= 0,
+	.bDefaultFrameIndex	= 1,
+	.bAspectRatioX		= 0,
+	.bAspectRatioY		= 0,
+	.bmInterfaceFlags	= 0,
+	.bCopyProtect		= 0,
+};
+
+DECLARE_UVC_FRAME_MJPEG(1);
+DECLARE_UVC_FRAME_MJPEG(3);
+
+static const struct UVC_FRAME_MJPEG(3) uvc_frame_mjpg_360p = {
+	.bLength		= UVC_DT_FRAME_MJPEG_SIZE(3),
+	.bDescriptorType	= USB_DT_CS_INTERFACE,
+	.bDescriptorSubType	= UVC_DT_FRAME_MJPEG,
+	.bFrameIndex		= 1,
+	.bmCapabilities		= 0,
+	.wWidth			= cpu_to_le16(640),
+	.wHeight		= cpu_to_le16(360),
+	.dwMinBitRate		= cpu_to_le32(18432000),
+	.dwMaxBitRate		= cpu_to_le32(55296000),
+	.dwMaxVideoFrameBufferSize	= cpu_to_le32(460800),
+	.dwDefaultFrameInterval	= cpu_to_le32(666666),
+	.bFrameIntervalType	= 3,
+	.dwFrameInterval[0]	= cpu_to_le32(666666),
+	.dwFrameInterval[1]	= cpu_to_le32(1000000),
+	.dwFrameInterval[2]	= cpu_to_le32(5000000),
+};
+
+static const struct UVC_FRAME_MJPEG(1) uvc_frame_mjpg_720p = {
+	.bLength		= UVC_DT_FRAME_MJPEG_SIZE(1),
+	.bDescriptorType	= USB_DT_CS_INTERFACE,
+	.bDescriptorSubType	= UVC_DT_FRAME_MJPEG,
+	.bFrameIndex		= 2,
+	.bmCapabilities		= 0,
+	.wWidth			= cpu_to_le16(1280),
+	.wHeight		= cpu_to_le16(720),
+	.dwMinBitRate		= cpu_to_le32(29491200),
+	.dwMaxBitRate		= cpu_to_le32(29491200),
+	.dwMaxVideoFrameBufferSize	= cpu_to_le32(1843200),
+	.dwDefaultFrameInterval	= cpu_to_le32(5000000),
+	.bFrameIntervalType	= 1,
+	.dwFrameInterval[0]	= cpu_to_le32(5000000),
+};
+
+static const struct uvc_color_matching_descriptor uvc_color_matching = {
+	.bLength		= UVC_DT_COLOR_MATCHING_SIZE,
+	.bDescriptorType	= USB_DT_CS_INTERFACE,
+	.bDescriptorSubType	= UVC_DT_COLOR_MATCHING,
+	.bColorPrimaries	= 1,
+	.bTransferCharacteristics	= 1,
+	.bMatrixCoefficients	= 4,
+};
+
+static const struct uvc_descriptor_header * const uvc_control_cls[] = {
+	(const struct uvc_descriptor_header *) &uvc_control_header,
+	(const struct uvc_descriptor_header *) &uvc_camera_terminal,
+	(const struct uvc_descriptor_header *) &uvc_processing,
+	(const struct uvc_descriptor_header *) &uvc_output_terminal,
+	NULL,
+};
+
+static const struct uvc_descriptor_header * const uvc_fs_streaming_cls[] = {
+	(const struct uvc_descriptor_header *) &uvc_input_header,
+	(const struct uvc_descriptor_header *) &uvc_format_yuv,
+	(const struct uvc_descriptor_header *) &uvc_frame_yuv_360p,
+	(const struct uvc_descriptor_header *) &uvc_frame_yuv_720p,
+	(const struct uvc_descriptor_header *) &uvc_format_mjpg,
+	(const struct uvc_descriptor_header *) &uvc_frame_mjpg_360p,
+	(const struct uvc_descriptor_header *) &uvc_frame_mjpg_720p,
+	(const struct uvc_descriptor_header *) &uvc_color_matching,
+	NULL,
+};
+
+static const struct uvc_descriptor_header * const uvc_hs_streaming_cls[] = {
+	(const struct uvc_descriptor_header *) &uvc_input_header,
+	(const struct uvc_descriptor_header *) &uvc_format_yuv,
+	(const struct uvc_descriptor_header *) &uvc_frame_yuv_360p,
+	(const struct uvc_descriptor_header *) &uvc_frame_yuv_720p,
+	(const struct uvc_descriptor_header *) &uvc_format_mjpg,
+	(const struct uvc_descriptor_header *) &uvc_frame_mjpg_360p,
+	(const struct uvc_descriptor_header *) &uvc_frame_mjpg_720p,
+	(const struct uvc_descriptor_header *) &uvc_color_matching,
+	NULL,
+};
+
+/* --------------------------------------------------------------------------
+ * USB configuration
+ */
+
+static int __init
+webcam_config_bind(struct usb_configuration *c)
+{
+	return uvc_bind_config(c, uvc_control_cls, uvc_fs_streaming_cls,
+			       uvc_hs_streaming_cls);
+}
+
+static struct usb_configuration webcam_config_driver = {
+	.label			= webcam_config_label,
+	.bind			= webcam_config_bind,
+	.bConfigurationValue	= 1,
+	.iConfiguration		= 0, /* dynamic */
+	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
+	.bMaxPower		= CONFIG_USB_GADGET_VBUS_DRAW / 2,
+};
+
+static int /* __init_or_exit */
+webcam_unbind(struct usb_composite_dev *cdev)
+{
+	return 0;
+}
+
+static int __init
+webcam_bind(struct usb_composite_dev *cdev)
+{
+	int ret;
+
+	/* Allocate string descriptor numbers ... note that string contents
+	 * can be overridden by the composite_dev glue.
+	 */
+	if ((ret = usb_string_id(cdev)) < 0)
+		goto error;
+	webcam_strings[STRING_MANUFACTURER_IDX].id = ret;
+	webcam_device_descriptor.iManufacturer = ret;
+
+	if ((ret = usb_string_id(cdev)) < 0)
+		goto error;
+	webcam_strings[STRING_PRODUCT_IDX].id = ret;
+	webcam_device_descriptor.iProduct = ret;
+
+	if ((ret = usb_string_id(cdev)) < 0)
+		goto error;
+	webcam_strings[STRING_DESCRIPTION_IDX].id = ret;
+	webcam_config_driver.iConfiguration = ret;
+
+	/* Register our configuration. */
+	if ((ret = usb_add_config(cdev, &webcam_config_driver)) < 0)
+		goto error;
+
+	INFO(cdev, "Webcam Video Gadget\n");
+	return 0;
+
+error:
+	webcam_unbind(cdev);
+	return ret;
+}
+
+/* --------------------------------------------------------------------------
+ * Driver
+ */
+
+static struct usb_composite_driver webcam_driver = {
+	.name		= "g_webcam",
+	.dev		= &webcam_device_descriptor,
+	.strings	= webcam_device_strings,
+	.bind		= webcam_bind,
+	.unbind		= webcam_unbind,
+};
+
+static int __init
+webcam_init(void)
+{
+	return usb_composite_register(&webcam_driver);
+}
+
+static void __exit
+webcam_cleanup(void)
+{
+	usb_composite_unregister(&webcam_driver);
+}
+
+module_init(webcam_init);
+module_exit(webcam_cleanup);
+
+MODULE_AUTHOR("Laurent Pinchart");
+MODULE_DESCRIPTION("Webcam Video Gadget");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.1.0");
+