[PATCH] USB: Add ET61X[12]51 Video4Linux2 driver

This patch adds a Video4Linux2 driver giving support
to ET61X151 and ET61X251 PC Camera Controllers made by
Etoms Electronics.

Signed-off-by: Luca Risolia <luca.risolia@studio.unibo.it>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Documentation/usb/et61x251.txt

+
+                       ET61X[12]51 PC Camera Controllers
+                                Driver for Linux
+                       =================================
+
+                               - Documentation -
+
+
+Index
+=====
+1.  Copyright
+2.  Disclaimer
+3.  License
+4.  Overview and features
+5.  Module dependencies
+6.  Module loading
+7.  Module parameters
+8.  Optional device control through "sysfs"
+9.  Supported devices
+10. Notes for V4L2 application developers
+11. Contact information
+
+
+1. Copyright
+============
+Copyright (C) 2006 by Luca Risolia <luca.risolia@studio.unibo.it>
+
+
+2. Disclaimer
+=============
+Etoms is a trademark of Etoms Electronics Corp.
+This software is not developed or sponsored by Etoms Electronics.
+
+
+3. License
+==========
+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.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+
+4. Overview and features
+========================
+This driver supports the video interface of the devices mounting the ET61X151
+or ET61X251 PC Camera Controllers.
+
+It's worth to note that Etoms Electronics has never collaborated with the
+author during the development of this project; despite several requests,
+Etoms Electronics also refused to release enough detailed specifications of
+the video compression engine.
+
+The driver relies on the Video4Linux2 and USB core modules. It has been
+designed to run properly on SMP systems as well.
+
+The latest version of the ET61X[12]51 driver can be found at the following URL:
+http://www.linux-projects.org/
+
+Some of the features of the driver are:
+
+- full compliance with the Video4Linux2 API (see also "Notes for V4L2
+  application developers" paragraph);
+- available mmap or read/poll methods for video streaming through isochronous
+  data transfers;
+- automatic detection of image sensor;
+- support for any window resolutions and optional panning within the maximum
+  pixel area of image sensor;
+- image downscaling with arbitrary scaling factors from 1 and 2 in both
+  directions (see "Notes for V4L2 application developers" paragraph);
+- two different video formats for uncompressed or compressed data in low or
+  high compression quality (see also "Notes for V4L2 application developers"
+  paragraph);
+- full support for the capabilities of every possible image sensors that can
+  be connected to the ET61X[12]51 bridges, including, for istance, red, green,
+  blue and global gain adjustments and exposure control (see "Supported
+  devices" paragraph for details);
+- use of default color settings for sunlight conditions;
+- dynamic I/O interface for both ET61X[12]51 and image sensor control (see
+  "Optional device control through 'sysfs'" paragraph);
+- dynamic driver control thanks to various module parameters (see "Module
+  parameters" paragraph);
+- up to 64 cameras can be handled at the same time; they can be connected and
+  disconnected from the host many times without turning off the computer, if
+  the system supports hotplugging;
+- no known bugs.
+
+
+5. Module dependencies
+======================
+For it to work properly, the driver needs kernel support for Video4Linux and
+USB.
+
+The following options of the kernel configuration file must be enabled and
+corresponding modules must be compiled:
+
+	# Multimedia devices
+	#
+	CONFIG_VIDEO_DEV=m
+
+To enable advanced debugging functionality on the device through /sysfs:
+
+	# Multimedia devices
+	#
+	CONFIG_VIDEO_ADV_DEBUG=y
+
+	# USB support
+	#
+	CONFIG_USB=m
+
+In addition, depending on the hardware being used, the modules below are
+necessary:
+
+	# USB Host Controller Drivers
+	#
+	CONFIG_USB_EHCI_HCD=m
+	CONFIG_USB_UHCI_HCD=m
+	CONFIG_USB_OHCI_HCD=m
+
+And finally:
+
+	# USB Multimedia devices
+	#
+	CONFIG_USB_ET61X251=m
+
+
+6. Module loading
+=================
+To use the driver, it is necessary to load the "et61x251" module into memory
+after every other module required: "videodev", "usbcore" and, depending on
+the USB host controller you have, "ehci-hcd", "uhci-hcd" or "ohci-hcd".
+
+Loading can be done as shown below:
+
+	[root@localhost home]# modprobe et61x251
+
+At this point the devices should be recognized. You can invoke "dmesg" to
+analyze kernel messages and verify that the loading process has gone well:
+
+	[user@localhost home]$ dmesg
+
+
+7. Module parameters
+====================
+Module parameters are listed below:
+-------------------------------------------------------------------------------
+Name:           video_nr
+Type:           short array (min = 0, max = 64)
+Syntax:         <-1|n[,...]>
+Description:    Specify V4L2 minor mode number:
+                -1 = use next available
+                 n = use minor number n
+                You can specify up to 64 cameras this way.
+                For example:
+                video_nr=-1,2,-1 would assign minor number 2 to the second
+                registered camera and use auto for the first one and for every
+                other camera.
+Default:        -1
+-------------------------------------------------------------------------------
+Name:           force_munmap
+Type:           bool array (min = 0, max = 64)
+Syntax:         <0|1[,...]>
+Description:    Force the application to unmap previously mapped buffer memory
+                before calling any VIDIOC_S_CROP or VIDIOC_S_FMT ioctl's. Not
+                all the applications support this feature. This parameter is
+                specific for each detected camera.
+                0 = do not force memory unmapping
+                1 = force memory unmapping (save memory)
+Default:        0
+-------------------------------------------------------------------------------
+Name:           debug
+Type:           ushort
+Syntax:         <n>
+Description:    Debugging information level, from 0 to 3:
+                0 = none (use carefully)
+                1 = critical errors
+                2 = significant informations
+                3 = more verbose messages
+                Level 3 is useful for testing only, when only one device
+                is used at the same time. It also shows some more informations
+                about the hardware being detected. This module parameter can be
+                changed at runtime thanks to the /sys filesystem interface.
+Default:        2
+-------------------------------------------------------------------------------
+
+
+8. Optional device control through "sysfs"
+==========================================
+If the kernel has been compiled with the CONFIG_VIDEO_ADV_DEBUG option enabled,
+it is possible to read and write both the ET61X[12]51 and the image sensor
+registers by using the "sysfs" filesystem interface.
+
+There are four files in the /sys/class/video4linux/videoX directory for each
+registered camera: "reg", "val", "i2c_reg" and "i2c_val". The first two files
+control the ET61X[12]51 bridge, while the other two control the sensor chip.
+"reg" and "i2c_reg" hold the values of the current register index where the
+following reading/writing operations are addressed at through "val" and
+"i2c_val". Their use is not intended for end-users, unless you know what you
+are doing. Remember that you must be logged in as root before writing to them.
+
+As an example, suppose we were to want to read the value contained in the
+register number 1 of the sensor register table - which is usually the product
+identifier - of the camera registered as "/dev/video0":
+
+	[root@localhost #] cd /sys/class/video4linux/video0
+	[root@localhost #] echo 1 > i2c_reg
+	[root@localhost #] cat i2c_val
+
+Note that if the sensor registers can not be read, "cat" will fail.
+To avoid race conditions, all the I/O accesses to the files are serialized.
+
+
+9. Supported devices
+====================
+None of the names of the companies as well as their products will be mentioned
+here. They have never collaborated with the author, so no advertising.
+
+From the point of view of a driver, what unambiguously identify a device are
+its vendor and product USB identifiers. Below is a list of known identifiers of
+devices mounting the ET61X[12]51 PC camera controllers:
+
+Vendor ID  Product ID
+---------  ----------
+0x102c     0x6151
+0x102c     0x6251
+0x102c     0x6253
+0x102c     0x6254
+0x102c     0x6255
+0x102c     0x6256
+0x102c     0x6257
+0x102c     0x6258
+0x102c     0x6259
+0x102c     0x625a
+0x102c     0x625b
+0x102c     0x625c
+0x102c     0x625d
+0x102c     0x625e
+0x102c     0x625f
+0x102c     0x6260
+0x102c     0x6261
+0x102c     0x6262
+0x102c     0x6263
+0x102c     0x6264
+0x102c     0x6265
+0x102c     0x6266
+0x102c     0x6267
+0x102c     0x6268
+0x102c     0x6269
+
+The following image sensors are supported:
+
+Model       Manufacturer
+-----       ------------
+TAS5130D1B  Taiwan Advanced Sensor Corporation
+
+All the available control settings of each image sensor are supported through
+the V4L2 interface.
+
+
+10. Notes for V4L2 application developers
+========================================
+This driver follows the V4L2 API specifications. In particular, it enforces two
+rules:
+
+- exactly one I/O method, either "mmap" or "read", is associated with each
+file descriptor. Once it is selected, the application must close and reopen the
+device to switch to the other I/O method;
+
+- although it is not mandatory, previously mapped buffer memory should always
+be unmapped before calling any "VIDIOC_S_CROP" or "VIDIOC_S_FMT" ioctl's.
+The same number of buffers as before will be allocated again to match the size
+of the new video frames, so you have to map the buffers again before any I/O
+attempts on them.
+
+Consistently with the hardware limits, this driver also supports image
+downscaling with arbitrary scaling factors from 1 and 2 in both directions.
+However, the V4L2 API specifications don't correctly define how the scaling
+factor can be chosen arbitrarily by the "negotiation" of the "source" and
+"target" rectangles. To work around this flaw, we have added the convention
+that, during the negotiation, whenever the "VIDIOC_S_CROP" ioctl is issued, the
+scaling factor is restored to 1.
+
+This driver supports two different video formats: the first one is the "8-bit
+Sequential Bayer" format and can be used to obtain uncompressed video data
+from the device through the current I/O method, while the second one provides
+"raw" compressed video data (without frame headers not related to the
+compressed data). The current compression quality may vary from 0 to 1 and can
+be selected or queried thanks to the VIDIOC_S_JPEGCOMP and VIDIOC_G_JPEGCOMP
+V4L2 ioctl's.
+
+
+11. Contact information
+=======================
+The author may be contacted by e-mail at <luca.risolia@studio.unibo.it>.
+
+GPG/PGP encrypted e-mail's are accepted. The GPG key ID of the author is
+'FCE635A4'; the public 1024-bit key should be available at any keyserver;
+the fingerprint is: '88E8 F32F 7244 68BA 3958  5D40 99DA 5D2A FCE6 35A4'.

MAINTAINERS

@@ -2673,6 +2673,14 @@ M:	dbrownell@users.sourceforge.net
 L:	linux-usb-devel@lists.sourceforge.net
 S:	Maintained
 
+USB ET61X[12]51 DRIVER
+P:	Luca Risolia
+M:	luca.risolia@studio.unibo.it
+L:	linux-usb-devel@lists.sourceforge.net
+L:	video4linux-list@redhat.com
+W:	http://www.linux-projects.org
+S:	Maintained
+
 USB HID/HIDBP DRIVERS
 P:	Vojtech Pavlik
 M:	vojtech@suse.cz
@@ -2836,6 +2844,7 @@ USB SN9C10x DRIVER
 P:	Luca Risolia
 M:	luca.risolia@studio.unibo.it
 L:	linux-usb-devel@lists.sourceforge.net
+L:	video4linux-list@redhat.com
 W:	http://www.linux-projects.org
 S:	Maintained
 
@@ -2865,6 +2874,7 @@ USB W996[87]CF DRIVER
 P:	Luca Risolia
 M:	luca.risolia@studio.unibo.it
 L:	linux-usb-devel@lists.sourceforge.net
+L:	video4linux-list@redhat.com
 W:	http://www.linux-projects.org
 S:	Maintained
 

drivers/usb/Makefile

@@ -38,6 +38,7 @@ obj-$(CONFIG_USB_XPAD)		+= input/
 
 obj-$(CONFIG_USB_DABUSB)	+= media/
 obj-$(CONFIG_USB_DSBR)		+= media/
+obj-$(CONFIG_USB_ET61X251)	+= media/
 obj-$(CONFIG_USB_IBMCAM)	+= media/
 obj-$(CONFIG_USB_KONICAWC)	+= media/
 obj-$(CONFIG_USB_OV511)		+= media/

drivers/usb/media/Kconfig

@@ -53,6 +53,21 @@ config USB_DSBR
 	  To compile this driver as a module, choose M here: the
 	  module will be called dsbr100.
 
+config USB_ET61X251
+	tristate "USB ET61X[12]51 PC Camera Controller support"
+	depends on USB && VIDEO_DEV
+	---help---
+	  Say Y here if you want support for cameras based on Etoms ET61X151
+	  or ET61X251 PC Camera Controllers.
+
+	  See <file:Documentation/usb/et61x251.txt> for more informations.
+
+	  This driver uses the Video For Linux API. You must say Y or M to
+	  "Video For Linux" to use this driver.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called et61x251.
+
 config USB_IBMCAM
 	tristate "USB IBM (Xirlink) C-it Camera support"
 	depends on USB && VIDEO_DEV
@@ -209,5 +224,3 @@ config USB_PWC
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called pwc.
-
-

drivers/usb/media/Makefile

@@ -3,9 +3,11 @@
 #
 
 sn9c102-objs	:= sn9c102_core.o sn9c102_hv7131d.o sn9c102_mi0343.o sn9c102_ov7630.o sn9c102_pas106b.o sn9c102_pas202bcb.o sn9c102_tas5110c1b.o sn9c102_tas5130d1b.o
+et61x251-objs	:= et61x251_core.o et61x251_tas5130d1b.o
 
 obj-$(CONFIG_USB_DABUSB)	+= dabusb.o
 obj-$(CONFIG_USB_DSBR)		+= dsbr100.o
+obj-$(CONFIG_USB_ET61X251)	+= et61x251.o
 obj-$(CONFIG_USB_IBMCAM)	+= ibmcam.o usbvideo.o ultracam.o
 obj-$(CONFIG_USB_KONICAWC)	+= konicawc.o usbvideo.o
 obj-$(CONFIG_USB_OV511)		+= ov511.o

drivers/usb/media/et61x251.h

+/***************************************************************************
+ * V4L2 driver for ET61X[12]51 PC Camera Controllers                       *
+ *                                                                         *
+ * Copyright (C) 2006 by Luca Risolia <luca.risolia@studio.unibo.it>       *
+ *                                                                         *
+ * 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.                                     *
+ *                                                                         *
+ * This program is distributed in the hope that it will be useful,         *
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of          *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           *
+ * GNU General Public License for more details.                            *
+ *                                                                         *
+ * You should have received a copy of the GNU General Public License       *
+ * along with this program; if not, write to the Free Software             *
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.               *
+ ***************************************************************************/
+
+#ifndef _ET61X251_H_
+#define _ET61X251_H_
+
+#include <linux/version.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <media/v4l2-common.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/time.h>
+#include <linux/wait.h>
+#include <linux/types.h>
+#include <linux/param.h>
+#include <linux/rwsem.h>
+#include <asm/semaphore.h>
+
+#include "et61x251_sensor.h"
+
+/*****************************************************************************/
+
+#define ET61X251_DEBUG
+#define ET61X251_DEBUG_LEVEL         2
+#define ET61X251_MAX_DEVICES         64
+#define ET61X251_PRESERVE_IMGSCALE   0
+#define ET61X251_FORCE_MUNMAP        0
+#define ET61X251_MAX_FRAMES          32
+#define ET61X251_COMPRESSION_QUALITY 0
+#define ET61X251_URBS                2
+#define ET61X251_ISO_PACKETS         7
+#define ET61X251_ALTERNATE_SETTING   13
+#define ET61X251_URB_TIMEOUT         msecs_to_jiffies(2 * ET61X251_ISO_PACKETS)
+#define ET61X251_CTRL_TIMEOUT        100
+
+/*****************************************************************************/
+
+static const struct usb_device_id et61x251_id_table[] = {
+	{ USB_DEVICE(0x102c, 0x6151), },
+	{ USB_DEVICE(0x102c, 0x6251), },
+	{ USB_DEVICE(0x102c, 0x6253), },
+	{ USB_DEVICE(0x102c, 0x6254), },
+	{ USB_DEVICE(0x102c, 0x6255), },
+	{ USB_DEVICE(0x102c, 0x6256), },
+	{ USB_DEVICE(0x102c, 0x6257), },
+	{ USB_DEVICE(0x102c, 0x6258), },
+	{ USB_DEVICE(0x102c, 0x6259), },
+	{ USB_DEVICE(0x102c, 0x625a), },
+	{ USB_DEVICE(0x102c, 0x625b), },
+	{ USB_DEVICE(0x102c, 0x625c), },
+	{ USB_DEVICE(0x102c, 0x625d), },
+	{ USB_DEVICE(0x102c, 0x625e), },
+	{ USB_DEVICE(0x102c, 0x625f), },
+	{ USB_DEVICE(0x102c, 0x6260), },
+	{ USB_DEVICE(0x102c, 0x6261), },
+	{ USB_DEVICE(0x102c, 0x6262), },
+	{ USB_DEVICE(0x102c, 0x6263), },
+	{ USB_DEVICE(0x102c, 0x6264), },
+	{ USB_DEVICE(0x102c, 0x6265), },
+	{ USB_DEVICE(0x102c, 0x6266), },
+	{ USB_DEVICE(0x102c, 0x6267), },
+	{ USB_DEVICE(0x102c, 0x6268), },
+	{ USB_DEVICE(0x102c, 0x6269), },
+	{ }
+};
+
+ET61X251_SENSOR_TABLE
+
+/*****************************************************************************/
+
+enum et61x251_frame_state {
+	F_UNUSED,
+	F_QUEUED,
+	F_GRABBING,
+	F_DONE,
+	F_ERROR,
+};
+
+struct et61x251_frame_t {
+	void* bufmem;
+	struct v4l2_buffer buf;
+	enum et61x251_frame_state state;
+	struct list_head frame;
+	unsigned long vma_use_count;
+};
+
+enum et61x251_dev_state {
+	DEV_INITIALIZED = 0x01,
+	DEV_DISCONNECTED = 0x02,
+	DEV_MISCONFIGURED = 0x04,
+};
+
+enum et61x251_io_method {
+	IO_NONE,
+	IO_READ,
+	IO_MMAP,
+};
+
+enum et61x251_stream_state {
+	STREAM_OFF,
+	STREAM_INTERRUPT,
+	STREAM_ON,
+};
+
+struct et61x251_sysfs_attr {
+	u8 reg, i2c_reg;
+};
+
+struct et61x251_module_param {
+	u8 force_munmap;
+};
+
+static DECLARE_MUTEX(et61x251_sysfs_lock);
+static DECLARE_RWSEM(et61x251_disconnect);
+
+struct et61x251_device {
+	struct video_device* v4ldev;
+
+	struct et61x251_sensor* sensor;
+
+	struct usb_device* usbdev;
+	struct urb* urb[ET61X251_URBS];
+	void* transfer_buffer[ET61X251_URBS];
+	u8* control_buffer;
+
+	struct et61x251_frame_t *frame_current, frame[ET61X251_MAX_FRAMES];
+	struct list_head inqueue, outqueue;
+	u32 frame_count, nbuffers, nreadbuffers;
+
+	enum et61x251_io_method io;
+	enum et61x251_stream_state stream;
+
+	struct v4l2_jpegcompression compression;
+
+	struct et61x251_sysfs_attr sysfs;
+	struct et61x251_module_param module_param;
+
+	enum et61x251_dev_state state;
+	u8 users;
+
+	struct semaphore dev_sem, fileop_sem;
+	spinlock_t queue_lock;
+	wait_queue_head_t open, wait_frame, wait_stream;
+};
+
+/*****************************************************************************/
+
+void
+et61x251_attach_sensor(struct et61x251_device* cam,
+                       struct et61x251_sensor* sensor)
+{
+	cam->sensor = sensor;
+	cam->sensor->usbdev = cam->usbdev;
+}
+
+/*****************************************************************************/
+
+#undef DBG
+#undef KDBG
+#ifdef ET61X251_DEBUG
+#	define DBG(level, fmt, args...)                                       \
+do {                                                                          \
+	if (debug >= (level)) {                                               \
+		if ((level) == 1)                                             \
+			dev_err(&cam->usbdev->dev, fmt "\n", ## args);        \
+		else if ((level) == 2)                                        \
+			dev_info(&cam->usbdev->dev, fmt "\n", ## args);       \
+		else if ((level) >= 3)                                        \
+			dev_info(&cam->usbdev->dev, "[%s:%d] " fmt "\n",      \
+			         __FUNCTION__, __LINE__ , ## args);           \
+	}                                                                     \
+} while (0)
+#	define KDBG(level, fmt, args...)                                      \
+do {                                                                          \
+	if (debug >= (level)) {                                               \
+		if ((level) == 1 || (level) == 2)                             \
+			pr_info("et61x251: " fmt "\n", ## args);              \
+		else if ((level) == 3)                                        \
+			pr_debug("et61x251: [%s:%d] " fmt "\n", __FUNCTION__, \
+			         __LINE__ , ## args);                         \
+	}                                                                     \
+} while (0)
+#	define V4LDBG(level, name, cmd)                                       \
+do {                                                                          \
+	if (debug >= (level))                                                 \
+		v4l_print_ioctl(name, cmd);                                   \
+} while (0)
+#else
+#	define DBG(level, fmt, args...) do {;} while(0)
+#	define KDBG(level, fmt, args...) do {;} while(0)
+#	define V4LDBG(level, name, cmd) do {;} while(0)
+#endif
+
+#undef PDBG
+#define PDBG(fmt, args...)                                                    \
+dev_info(&cam->dev, "[%s:%d] " fmt "\n", __FUNCTION__, __LINE__ , ## args)
+
+#undef PDBGG
+#define PDBGG(fmt, args...) do {;} while(0) /* placeholder */
+
+#endif /* _ET61X251_H_ */

drivers/usb/media/et61x251_sensor.h

+/***************************************************************************
+ * API for image sensors connected to ET61X[12]51 PC Camera Controllers    *
+ *                                                                         *
+ * Copyright (C) 2006 by Luca Risolia <luca.risolia@studio.unibo.it>       *
+ *                                                                         *
+ * 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.                                     *
+ *                                                                         *
+ * This program is distributed in the hope that it will be useful,         *
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of          *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           *
+ * GNU General Public License for more details.                            *
+ *                                                                         *
+ * You should have received a copy of the GNU General Public License       *
+ * along with this program; if not, write to the Free Software             *
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.               *
+ ***************************************************************************/
+
+#ifndef _ET61X251_SENSOR_H_
+#define _ET61X251_SENSOR_H_
+
+#include <linux/usb.h>
+#include <linux/videodev.h>
+#include <linux/device.h>
+#include <linux/stddef.h>
+#include <linux/errno.h>
+#include <asm/types.h>
+
+struct et61x251_device;
+struct et61x251_sensor;
+
+/*****************************************************************************/
+
+extern int et61x251_probe_tas5130d1b(struct et61x251_device* cam);
+
+#define ET61X251_SENSOR_TABLE                                                 \
+/* Weak detections must go at the end of the list */                          \
+static int (*et61x251_sensor_table[])(struct et61x251_device*) = {            \
+	&et61x251_probe_tas5130d1b,                                           \
+	NULL,                                                                 \
+};
+
+extern void
+et61x251_attach_sensor(struct et61x251_device* cam,
+                       struct et61x251_sensor* sensor);
+
+/*****************************************************************************/
+
+extern int et61x251_write_reg(struct et61x251_device*, u8 value, u16 index);
+extern int et61x251_read_reg(struct et61x251_device*, u16 index);
+extern int et61x251_i2c_write(struct et61x251_device*, u8 address, u8 value);
+extern int et61x251_i2c_read(struct et61x251_device*, u8 address);
+extern int et61x251_i2c_try_write(struct et61x251_device*,
+                                  struct et61x251_sensor*, u8 address,
+                                  u8 value);
+extern int et61x251_i2c_try_read(struct et61x251_device*,
+                                 struct et61x251_sensor*, u8 address);
+extern int et61x251_i2c_raw_write(struct et61x251_device*, u8 n, u8 data1,
+                                  u8 data2, u8 data3, u8 data4, u8 data5,
+                                  u8 data6, u8 data7, u8 data8, u8 address);
+
+/*****************************************************************************/
+
+enum et61x251_i2c_sysfs_ops {
+	ET61X251_I2C_READ = 0x01,
+	ET61X251_I2C_WRITE = 0x02,
+};
+
+enum et61x251_i2c_interface {
+	ET61X251_I2C_2WIRES,
+	ET61X251_I2C_3WIRES,
+};
+
+/* Repeat start condition when RSTA is high */
+enum et61x251_i2c_rsta {
+	ET61X251_I2C_RSTA_STOP = 0x00, /* stop then start */
+	ET61X251_I2C_RSTA_REPEAT = 0x01, /* repeat start */
+};
+
+#define ET61X251_MAX_CTRLS V4L2_CID_LASTP1-V4L2_CID_BASE+10
+
+struct et61x251_sensor {
+	char name[32];
+
+	enum et61x251_i2c_sysfs_ops sysfs_ops;
+
+	enum et61x251_i2c_interface interface;
+	u8 i2c_slave_id;
+	enum et61x251_i2c_rsta rsta;
+	struct v4l2_rect active_pixel; /* left and top define FVSX and FVSY */
+
+	struct v4l2_queryctrl qctrl[ET61X251_MAX_CTRLS];
+	struct v4l2_cropcap cropcap;
+	struct v4l2_pix_format pix_format;
+
+	int (*init)(struct et61x251_device* cam);
+	int (*get_ctrl)(struct et61x251_device* cam,
+	                struct v4l2_control* ctrl);
+	int (*set_ctrl)(struct et61x251_device* cam,
+	                const struct v4l2_control* ctrl);
+	int (*set_crop)(struct et61x251_device* cam,
+	                const struct v4l2_rect* rect);
+	int (*set_pix_format)(struct et61x251_device* cam,
+	                      const struct v4l2_pix_format* pix);
+
+	const struct usb_device* usbdev;
+
+	/* Private */
+	struct v4l2_queryctrl _qctrl[ET61X251_MAX_CTRLS];
+	struct v4l2_rect _rect;
+};
+
+#endif /* _ET61X251_SENSOR_H_ */

drivers/usb/media/et61x251_tas5130d1b.c

+/***************************************************************************
+ * Plug-in for TAS5130D1B image sensor connected to the ET61X[12]51        *
+ * PC Camera Controllers                                                   *
+ *                                                                         *
+ * Copyright (C) 2006 by Luca Risolia <luca.risolia@studio.unibo.it>       *
+ *                                                                         *
+ * 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.                                     *
+ *                                                                         *
+ * This program is distributed in the hope that it will be useful,         *
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of          *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           *
+ * GNU General Public License for more details.                            *
+ *                                                                         *
+ * You should have received a copy of the GNU General Public License       *
+ * along with this program; if not, write to the Free Software             *
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.               *
+ ***************************************************************************/
+
+#include "et61x251_sensor.h"
+
+
+static int tas5130d1b_init(struct et61x251_device* cam)
+{
+	int err = 0;
+
+	err += et61x251_write_reg(cam, 0x14, 0x01);
+	err += et61x251_write_reg(cam, 0x1b, 0x02);
+	err += et61x251_write_reg(cam, 0x02, 0x12);
+	err += et61x251_write_reg(cam, 0x0e, 0x60);
+	err += et61x251_write_reg(cam, 0x80, 0x61);
+	err += et61x251_write_reg(cam, 0xf0, 0x62);
+	err += et61x251_write_reg(cam, 0x03, 0x63);
+	err += et61x251_write_reg(cam, 0x14, 0x64);
+	err += et61x251_write_reg(cam, 0xf4, 0x65);
+	err += et61x251_write_reg(cam, 0x01, 0x66);
+	err += et61x251_write_reg(cam, 0x05, 0x67);
+	err += et61x251_write_reg(cam, 0x8f, 0x68);
+	err += et61x251_write_reg(cam, 0x0f, 0x8d);
+	err += et61x251_write_reg(cam, 0x08, 0x8e);
+
+	return err;
+}
+
+
+static int tas5130d1b_set_ctrl(struct et61x251_device* cam,
+                               const struct v4l2_control* ctrl)
+{
+	int err = 0;
+
+	switch (ctrl->id) {
+	case V4L2_CID_GAIN:
+		err += et61x251_i2c_raw_write(cam, 2, 0x20,
+		                              0xf6-ctrl->value, 0, 0, 0,
+		                              0, 0, 0, 0);
+		break;
+	case V4L2_CID_EXPOSURE:
+		err += et61x251_i2c_raw_write(cam, 2, 0x40,
+		                              0x47-ctrl->value, 0, 0, 0,
+		                              0, 0, 0, 0);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return err ? -EIO : 0;
+}
+
+
+static struct et61x251_sensor tas5130d1b = {
+	.name = "TAS5130D1B",
+	.interface = ET61X251_I2C_3WIRES,
+	.rsta = ET61X251_I2C_RSTA_STOP,
+	.active_pixel = {
+		.left = 106,
+		.top = 13,
+	},
+	.init = &tas5130d1b_init,
+	.qctrl = {
+		{
+			.id = V4L2_CID_GAIN,
+			.type = V4L2_CTRL_TYPE_INTEGER,
+			.name = "global gain",
+			.minimum = 0x00,
+			.maximum = 0xf6,
+			.step = 0x02,
+			.default_value = 0x0d,
+			.flags = 0,
+		},
+		{
+			.id = V4L2_CID_EXPOSURE,
+			.type = V4L2_CTRL_TYPE_INTEGER,
+			.name = "exposure",
+			.minimum = 0x00,
+			.maximum = 0x47,
+			.step = 0x01,
+			.default_value = 0x23,
+			.flags = 0,
+		},
+	},
+	.set_ctrl = &tas5130d1b_set_ctrl,
+	.cropcap = {
+		.bounds = {
+			.left = 0,
+			.top = 0,
+			.width = 640,
+			.height = 480,
+		},
+		.defrect = {
+			.left = 0,
+			.top = 0,
+			.width = 640,
+			.height = 480,
+		},
+	},
+	.pix_format = {
+		.width = 640,
+		.height = 480,
+		.pixelformat = V4L2_PIX_FMT_SBGGR8,
+		.priv = 8,
+	},
+};
+
+
+int et61x251_probe_tas5130d1b(struct et61x251_device* cam)
+{
+	/* This sensor has no identifiers, so let's attach it anyway */
+	et61x251_attach_sensor(cam, &tas5130d1b);
+
+	/* Sensor detection is based on USB pid/vid */
+	if (le16_to_cpu(tas5130d1b.usbdev->descriptor.idProduct) != 0x6251)
+		return -ENODEV;
+
+	return 0;
+}

include/linux/videodev2.h

@@ -315,6 +315,7 @@ struct v4l2_pix_format
 #define V4L2_PIX_FMT_SN9C10X  v4l2_fourcc('S','9','1','0') /* SN9C10x compression */
 #define V4L2_PIX_FMT_PWC1     v4l2_fourcc('P','W','C','1') /* pwc older webcam */
 #define V4L2_PIX_FMT_PWC2     v4l2_fourcc('P','W','C','2') /* pwc newer webcam */
+#define V4L2_PIX_FMT_ET61X251 v4l2_fourcc('E','6','2','5') /* ET61X251 compression */
 
 /*
  *	F O R M A T   E N U M E R A T I O N