V4L/DVB (8153): Subdriver pac207 added and minor changes.

pac207 added.
Check status on mutex lock.
Call back on frame dequeue.
Free the resources on last close only.
Avoid URB and ISOC errors on close.



Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 939 insertions, 0 deletions

diff --git a/drivers/media/video/gspca/pac207.c b/drivers/media/video/gspca/pac207.c
new file mode 100644
index 0000000..ac16c73
--- /dev/null
+++ b/drivers/media/video/gspca/pac207.c
@@ -0,0 +1,939 @@
+/*
+ * Pixart PAC207BCA library
+ *
+ * Copyright (C) 2008 Hans de Goede <j.w.r.degoede@hhs.nl>
+ * Copyright (C) 2005 Thomas Kaiser thomas@kaiser-linux.li
+ * Copyleft (C) 2005 Michel Xhaard mxhaard@magic.fr
+ *
+ * V4L2 by Jean-Francois Moine <http://moinejf.free.fr>
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#define MODULE_NAME "pac207"
+
+#include "gspca.h"
+
+#define DRIVER_VERSION_NUMBER	KERNEL_VERSION(0, 0, 30)
+static const char version[] = "0.0.30";
+
+MODULE_AUTHOR("Hans de Goede <j.w.r.degoede@hhs.nl>");
+MODULE_DESCRIPTION("Pixart PAC207");
+MODULE_LICENSE("GPL");
+
+#define PAC207_CTRL_TIMEOUT		100  /* ms */
+
+#define PAC207_BRIGHTNESS_MIN		0
+#define PAC207_BRIGHTNESS_MAX		255
+#define PAC207_BRIGHTNESS_DEFAULT	4 /* power on default: 4 */
+
+#define PAC207_EXPOSURE_MIN		4
+#define PAC207_EXPOSURE_MAX		26
+#define PAC207_EXPOSURE_DEFAULT		4 /* power on default: 3 ?? */
+#define PAC207_EXPOSURE_KNEE		11 /* 4 = 30 fps, 11 = 8, 15 = 6 */
+
+#define PAC207_GAIN_MIN			0
+#define PAC207_GAIN_MAX			31
+#define PAC207_GAIN_DEFAULT         	9 /* power on default: 9 */
+#define PAC207_GAIN_KNEE		20
+
+#define PAC207_AUTOGAIN_DEADZONE	30
+/* We calculating the autogain at the end of the transfer of a frame, at this
+   moment a frame with the old settings is being transmitted, and a frame is
+   being captured with the old settings. So if we adjust the autogain we must
+   ignore atleast the 2 next frames for the new settings to come into effect
+   before doing any other adjustments */
+#define PAC207_AUTOGAIN_IGNORE_FRAMES	3
+
+enum pac207_line_state {
+	LINE_HEADER1,
+	LINE_HEADER2,
+	LINE_UNCOMPRESSED,
+	LINE_COMPRESSED,
+};
+
+struct pac207_decoder_state {
+	/* generic state */
+	u16 line_read;
+	u16 line_marker;
+	u8 line_state;
+	u8 header_read;
+	/* compression state */
+	u16 processed_bytes;
+	u8 remaining_bits;
+	s8 no_remaining_bits;
+	u8 get_abs;
+	u8 discard_byte;
+	u8 line_decode_buf[352];
+};
+
+/* specific webcam descriptor */
+struct sd {
+	struct gspca_dev gspca_dev;		/* !! must be the first item */
+
+	struct pac207_decoder_state decoder_state;
+
+	u8 mode;
+
+	u8 brightness;
+	u8 exposure;
+	u8 autogain;
+	u8 gain;
+
+	u8 sof_read;
+	u8 autogain_ignore_frames;
+
+	atomic_t avg_lum;
+};
+
+/* V4L2 controls supported by the driver */
+static int sd_setbrightness(struct gspca_dev *gspca_dev, __s32 val);
+static int sd_getbrightness(struct gspca_dev *gspca_dev, __s32 *val);
+static int sd_setexposure(struct gspca_dev *gspca_dev, __s32 val);
+static int sd_getexposure(struct gspca_dev *gspca_dev, __s32 *val);
+static int sd_setautogain(struct gspca_dev *gspca_dev, __s32 val);
+static int sd_getautogain(struct gspca_dev *gspca_dev, __s32 *val);
+static int sd_setgain(struct gspca_dev *gspca_dev, __s32 val);
+static int sd_getgain(struct gspca_dev *gspca_dev, __s32 *val);
+
+static struct ctrl sd_ctrls[] = {
+#define SD_BRIGHTNESS 0
+	{
+	    {
+		.id      = V4L2_CID_BRIGHTNESS,
+		.type    = V4L2_CTRL_TYPE_INTEGER,
+		.name    = "Brightness",
+		.minimum = PAC207_BRIGHTNESS_MIN,
+		.maximum = PAC207_BRIGHTNESS_MAX,
+		.step = 1,
+		.default_value = PAC207_BRIGHTNESS_DEFAULT,
+		.flags = 0,
+	    },
+	    .set = sd_setbrightness,
+	    .get = sd_getbrightness,
+	},
+#define SD_EXPOSURE 1
+	{
+	    {
+		.id = V4L2_CID_EXPOSURE,
+		.type = V4L2_CTRL_TYPE_INTEGER,
+		.name = "exposure",
+		.minimum = PAC207_EXPOSURE_MIN,
+		.maximum = PAC207_EXPOSURE_MAX,
+		.step = 1,
+		.default_value = PAC207_EXPOSURE_DEFAULT,
+		.flags = 0,
+	    },
+	    .set = sd_setexposure,
+	    .get = sd_getexposure,
+	},
+#define SD_AUTOGAIN 2
+	{
+	    {
+		.id	  = V4L2_CID_AUTOGAIN,
+		.type	= V4L2_CTRL_TYPE_BOOLEAN,
+		.name	= "Auto Gain",
+		.minimum = 0,
+		.maximum = 1,
+		.step	= 1,
+		.default_value = 1,
+		.flags = 0,
+	    },
+	    .set = sd_setautogain,
+	    .get = sd_getautogain,
+	},
+#define SD_GAIN 3
+	{
+	    {
+		.id = V4L2_CID_GAIN,
+		.type = V4L2_CTRL_TYPE_INTEGER,
+		.name = "gain",
+		.minimum = PAC207_GAIN_MIN,
+		.maximum = PAC207_GAIN_MAX,
+		.step = 1,
+		.default_value = PAC207_GAIN_DEFAULT,
+		.flags = 0,
+	    },
+	    .set = sd_setgain,
+	    .get = sd_getgain,
+	},
+};
+
+static struct cam_mode sif_mode[] = {
+	{V4L2_PIX_FMT_SBGGR8, 176, 144, 1},
+	{V4L2_PIX_FMT_SBGGR8, 352, 288, 0},
+};
+
+static const __u8 pac207_sensor_init[][8] = {
+	{0x10, 0x12, 0x0d, 0x12, 0x0c, 0x01, 0x29, 0xf0},
+	{0x00, 0x64, 0x64, 0x64, 0x04, 0x10, 0xf0, 0x30},
+	{0x00, 0x00, 0x00, 0x70, 0xa0, 0xf8, 0x00, 0x00},
+	{0x00, 0x00, 0x32, 0x00, 0x96, 0x00, 0xa2, 0x02},
+	{0x32, 0x00, 0x96, 0x00, 0xA2, 0x02, 0xaf, 0x00},
+};
+
+			/* 48 reg_72 Rate Control end BalSize_4a =0x36 */
+static const __u8 PacReg72[] = { 0x00, 0x00, 0x36, 0x00 };
+
+static const char pac207_sof_marker[5] = { 0xff, 0xff, 0x00, 0xff, 0x96 };
+
+int pac207_write_regs(struct gspca_dev *gspca_dev, u16 index,
+	const u8 *buffer, u16 length)
+{
+	struct usb_device *udev = gspca_dev->dev;
+	int err;
+	u8 kbuf[8];
+
+	memcpy(kbuf, buffer, length);
+
+	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 0x01,
+			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+			0x00, index, kbuf, length, PAC207_CTRL_TIMEOUT);
+	if (err < 0)
+		PDEBUG(D_ERR,
+			"Failed to write registers to index 0x%04X, error %d)",
+			index, err);
+
+	return err;
+}
+
+
+int pac207_write_reg(struct gspca_dev *gspca_dev, u16 index, u16 value)
+{
+	struct usb_device *udev = gspca_dev->dev;
+	int err;
+
+	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 0x00,
+			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+			value, index, NULL, 0, PAC207_CTRL_TIMEOUT);
+	if (err)
+		PDEBUG(D_ERR, "Failed to write a register (index 0x%04X,"
+			" value 0x%02X, error %d)", index, value, err);
+
+	return err;
+}
+
+
+int pac207_read_reg(struct gspca_dev *gspca_dev, u16 index)
+{
+	struct usb_device *udev = gspca_dev->dev;
+	u8 buff;
+	int res;
+
+	res = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), 0x00,
+			USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+			0x00, index, &buff, 1, PAC207_CTRL_TIMEOUT);
+	if (res < 0) {
+		PDEBUG(D_ERR,
+			"Failed to read a register (index 0x%04X, error %d)",
+			index, res);
+		return res;
+	}
+
+	return buff;
+}
+
+
+/* this function is called at probe time */
+static int sd_config(struct gspca_dev *gspca_dev,
+			const struct usb_device_id *id)
+{
+	struct cam *cam;
+	u8 idreg[2];
+
+	idreg[0] = pac207_read_reg(gspca_dev, 0x0000);
+	idreg[1] = pac207_read_reg(gspca_dev, 0x0001);
+	idreg[0] = ((idreg[0] & 0x0F) << 4) | ((idreg[1] & 0xf0) >> 4);
+	idreg[1] = idreg[1] & 0x0f;
+	PDEBUG(D_PROBE, "Pixart Sensor ID 0x%02X Chips ID 0x%02X",
+		idreg[0], idreg[1]);
+
+	if (idreg[0] != 0x27) {
+		PDEBUG(D_PROBE, "Error invalid sensor ID!");
+		return -ENODEV;
+	}
+
+	pac207_write_reg(gspca_dev, 0x41, 0x00);
+				/* Bit_0=Image Format,
+				 * Bit_1=LED,
+				 * Bit_2=Compression test mode enable */
+	pac207_write_reg(gspca_dev, 0x0f, 0x00); /* Power Control */
+	pac207_write_reg(gspca_dev, 0x11, 0x30); /* Analog Bias */
+
+	PDEBUG(D_PROBE,
+		"Pixart PAC207BCA Image Processor and Control Chip detected"
+		" (vid/pid 0x%04X:0x%04X)", id->idVendor, id->idProduct);
+
+	cam = &gspca_dev->cam;
+	cam->dev_name = (char *) id->driver_info;
+	cam->epaddr = 0x05;
+	cam->cam_mode = sif_mode;
+	cam->nmodes = ARRAY_SIZE(sif_mode);
+
+	return 0;
+}
+
+/* this function is called at open time */
+static int sd_open(struct gspca_dev *gspca_dev)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+
+	sd->brightness = PAC207_BRIGHTNESS_DEFAULT;
+	sd->exposure = PAC207_EXPOSURE_DEFAULT;
+	sd->gain = PAC207_GAIN_DEFAULT;
+	sd->autogain = 1;
+
+	return 0;
+}
+
+/* -- start the camera -- */
+static void sd_start(struct gspca_dev *gspca_dev)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+	__u8 mode;
+
+	pac207_write_reg(gspca_dev, 0x0f, 0x10); /* Power control (Bit 6-0) */
+	pac207_write_regs(gspca_dev, 0x0002, pac207_sensor_init[0], 8);
+	pac207_write_regs(gspca_dev, 0x000a, pac207_sensor_init[1], 8);
+	pac207_write_regs(gspca_dev, 0x0012, pac207_sensor_init[2], 8);
+	pac207_write_regs(gspca_dev, 0x0040, pac207_sensor_init[3], 8);
+	pac207_write_regs(gspca_dev, 0x0042, pac207_sensor_init[4], 8);
+	pac207_write_regs(gspca_dev, 0x0048, PacReg72, 4);
+
+	/* Compression Balance */
+	if (gspca_dev->width == 176)
+		pac207_write_reg(gspca_dev, 0x4a, 0xff);
+	else
+		pac207_write_reg(gspca_dev, 0x4a, 0x88);
+	pac207_write_reg(gspca_dev, 0x4b, 0x00); /* Sram test value */
+	pac207_write_reg(gspca_dev, 0x08, sd->brightness);
+
+	/* PGA global gain (Bit 4-0) */
+	pac207_write_reg(gspca_dev, 0x0e, sd->gain);
+	pac207_write_reg(gspca_dev, 0x02, sd->exposure); /* PXCK = 12MHz /n */
+
+	mode = 0x02; /* Image Format (Bit 0), LED (1), Compr. test mode (2) */
+	if (gspca_dev->width == 176) { /* 176x144 */
+		mode |= 0x01;
+		PDEBUG(D_STREAM, "pac207_start mode 176x144");
+	} else/* 352x288 */
+		PDEBUG(D_STREAM, "pac207_start mode 352x288");
+	pac207_write_reg(gspca_dev, 0x41, mode);
+
+	pac207_write_reg(gspca_dev, 0x13, 0x01); /* Bit 0, auto clear */
+	pac207_write_reg(gspca_dev, 0x1c, 0x01); /* not documented */
+	udelay(1000); /* taken from gspca */
+	pac207_write_reg(gspca_dev, 0x40, 0x01); /* Start ISO pipe */
+
+	sd->sof_read = 0;
+	sd->autogain_ignore_frames = 0;
+	atomic_set(&sd->avg_lum, -1);
+}
+
+static void sd_stopN(struct gspca_dev *gspca_dev)
+{
+	pac207_write_reg(gspca_dev, 0x40, 0x00); /* Stop ISO pipe */
+	pac207_write_reg(gspca_dev, 0x41, 0x00); /* Turn of LED */
+	pac207_write_reg(gspca_dev, 0x0f, 0x00); /* Power Control */
+}
+
+static void sd_stop0(struct gspca_dev *gspca_dev)
+{
+}
+
+/* this function is called at close time */
+static void sd_close(struct gspca_dev *gspca_dev)
+{
+}
+
+/* -- convert pixart frames to Bayer -- */
+/* Sonix decompressor struct B.S.(2004) */
+static struct {
+	u8 is_abs;
+	u8 len;
+	s8 val;
+} table[256];
+
+void init_pixart_decoder(void)
+{
+	int i, is_abs, val, len;
+
+	for (i = 0; i < 256; i++) {
+		is_abs = 0;
+		val = 0;
+		len = 0;
+		if ((i & 0xC0) == 0) {
+			/* code 00 */
+			val = 0;
+			len = 2;
+		} else if ((i & 0xC0) == 0x40) {
+			/* code 01 */
+			val = -5;
+			len = 2;
+		} else if ((i & 0xC0) == 0x80) {
+			/* code 10 */
+			val = 5;
+			len = 2;
+		} else if ((i & 0xF0) == 0xC0) {
+			/* code 1100 */
+			val = -10;
+			len = 4;
+		} else if ((i & 0xF0) == 0xD0) {
+			/* code 1101 */
+			val = 10;
+			len = 4;
+		} else if ((i & 0xF8) == 0xE0) {
+			/* code 11100 */
+			val = -15;
+			len = 5;
+		} else if ((i & 0xF8) == 0xE8) {
+			/* code 11101 */
+			val = 15;
+			len = 5;
+		} else if ((i & 0xFC) == 0xF0) {
+			/* code 111100 */
+			val = -20;
+			len = 6;
+		} else if ((i & 0xFC) == 0xF4) {
+			/* code 111101 */
+			val = 20;
+			len = 6;
+		} else if ((i & 0xF8) == 0xF8) {
+			/* code 11111xxxxxx */
+			is_abs = 1;
+			val = 0;
+			len = 5;
+		}
+		table[i].is_abs = is_abs;
+		table[i].val = val;
+		table[i].len = len;
+	}
+}
+
+/* auto gain and exposure algorithm based on the knee algorithm described here:
+   http://ytse.tricolour.net/docs/LowLightOptimization.html */
+static void pac207_do_auto_gain(struct gspca_dev *gspca_dev)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+	int i, steps, desired_avg_lum;
+	int orig_gain = sd->gain;
+	int orig_exposure = sd->exposure;
+	int avg_lum = atomic_read(&sd->avg_lum);
+
+	if (!sd->autogain || avg_lum == -1)
+		return;
+
+	if (sd->autogain_ignore_frames > 0) {
+		sd->autogain_ignore_frames--;
+		return;
+	}
+
+	/* correct desired lumination for the configured brightness */
+	desired_avg_lum = 100 + sd->brightness / 2;
+
+	/* If we are of a multiple of deadzone, do multiple step to reach the
+	   desired lumination fast (with the risc of a slight overshoot) */
+	steps = abs(desired_avg_lum - avg_lum) / PAC207_AUTOGAIN_DEADZONE;
+
+	for (i = 0; i < steps; i++) {
+		if (avg_lum > desired_avg_lum) {
+			if (sd->gain > PAC207_GAIN_KNEE) {
+				sd->gain--;
+			} else if (sd->exposure > PAC207_EXPOSURE_KNEE) {
+				sd->exposure--;
+			} else if (sd->gain > PAC207_GAIN_DEFAULT) {
+				sd->gain--;
+			} else if (sd->exposure > PAC207_EXPOSURE_MIN) {
+				sd->exposure--;
+			} else if (sd->gain > PAC207_GAIN_MIN) {
+				sd->gain--;
+			} else
+				break;
+		} else {
+			if (sd->gain < PAC207_GAIN_DEFAULT) {
+				sd->gain++;
+			} else if (sd->exposure < PAC207_EXPOSURE_KNEE) {
+				sd->exposure++;
+			} else if (sd->gain < PAC207_GAIN_KNEE) {
+				sd->gain++;
+			} else if (sd->exposure < PAC207_EXPOSURE_MAX) {
+				sd->exposure++;
+			} else if (sd->gain < PAC207_GAIN_MAX) {
+				sd->gain++;
+			} else
+				break;
+		}
+	}
+
+	if (sd->exposure != orig_exposure || sd->gain != orig_gain) {
+		if (sd->exposure != orig_exposure)
+			pac207_write_reg(gspca_dev, 0x0002, sd->exposure);
+		if (sd->gain != orig_gain)
+			pac207_write_reg(gspca_dev, 0x000e, sd->gain);
+		pac207_write_reg(gspca_dev, 0x13, 0x01); /* load reg to sen */
+		pac207_write_reg(gspca_dev, 0x1c, 0x01); /* not documented */
+		sd->autogain_ignore_frames = PAC207_AUTOGAIN_IGNORE_FRAMES;
+	}
+}
+
+static unsigned char *pac207_find_sof(struct gspca_dev *gspca_dev,
+	unsigned char *m, int len)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+	int i;
+
+	/* Search for the SOF marker (fixed part) in the header */
+	for (i = 0; i < len; i++) {
+		if (m[i] == pac207_sof_marker[sd->sof_read]) {
+			sd->sof_read++;
+			if (sd->sof_read == sizeof(pac207_sof_marker)) {
+				PDEBUG(D_STREAM,
+					"SOF found, bytes to analyze: %u."
+					" Frame starts at byte #%u",
+					len, i + 1);
+				sd->sof_read = 0;
+				return m + i + 1;
+			}
+		} else
+			sd->sof_read = 0;
+	}
+
+	return NULL;
+}
+
+static int pac207_decompress_row(struct gspca_dev *gspca_dev,
+	struct gspca_frame *f, unsigned char *cdata, int len)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+	struct pac207_decoder_state *decoder_state = &sd->decoder_state;
+	unsigned char *outp = decoder_state->line_decode_buf +
+				decoder_state->line_read;
+	int val, bitlen, bitpos = -decoder_state->no_remaining_bits;
+	u8 code;
+
+	/* first two pixels are stored as raw 8-bit */
+	while (decoder_state->line_read < 2) {
+		*outp++ = *cdata++;
+		decoder_state->line_read++;
+		len--;
+		if (len == 0)
+			return 0;
+	}
+
+	while (decoder_state->line_read < gspca_dev->width) {
+		if (bitpos < 0) {
+			code = decoder_state->remaining_bits << (8 + bitpos) |
+				cdata[0] >> -bitpos;
+		} else {
+			u8 *addr = cdata + bitpos / 8;
+			code = addr[0] << (bitpos & 7) |
+				addr[1] >> (8 - (bitpos & 7));
+		}
+
+		bitlen = decoder_state->get_abs ?
+				6 : table[code].len;
+
+		/* Stop decompressing if we're out of input data */
+		if ((bitpos + bitlen) > (len * 8))
+			break;
+
+		if (decoder_state->get_abs) {
+			*outp++ = code & 0xFC;
+			decoder_state->line_read++;
+			decoder_state->get_abs = 0;
+		} else {
+			if (table[code].is_abs)
+				decoder_state->get_abs = 1;
+			else {
+				/* relative to left pixel */
+				val = outp[-2] +
+					table[code].val;
+				if (val > 0xff)
+					val = 0xff;
+				else if (val < 0)
+					val = 0;
+				*outp++ = val;
+				decoder_state->line_read++;
+			}
+		}
+		bitpos += bitlen;
+	}
+
+	if (decoder_state->line_read == gspca_dev->width) {
+		int compressed_line_len;
+
+		gspca_frame_add(gspca_dev, INTER_PACKET, f,
+				decoder_state->line_decode_buf,
+				gspca_dev->width);
+
+		/* completely decompressed line, round pos to nearest word */
+		compressed_line_len = ((decoder_state->processed_bytes * 8 +
+			bitpos + 15) / 16) * 2;
+
+		len -= compressed_line_len - decoder_state->processed_bytes;
+		if (len < 0) {
+			decoder_state->discard_byte = 1;
+			len = 0;
+		}
+	} else {
+		decoder_state->processed_bytes += len;
+		decoder_state->remaining_bits = cdata[bitpos/8];
+		decoder_state->no_remaining_bits = (8 - bitpos) & 7;
+		len = 0;
+	}
+
+	return len;
+}
+
+static void pac207_decode_line_init(struct gspca_dev *gspca_dev)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+	struct pac207_decoder_state *decoder_state = &sd->decoder_state;
+
+	decoder_state->line_read = 0;
+	decoder_state->line_state = LINE_HEADER1;
+	decoder_state->processed_bytes = 0;
+	decoder_state->no_remaining_bits = 0;
+	decoder_state->get_abs = 0;
+}
+
+static void pac207_decode_frame_init(struct gspca_dev *gspca_dev)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+	struct pac207_decoder_state *decoder_state = &sd->decoder_state;
+
+	decoder_state->header_read = 0;
+	decoder_state->discard_byte = 0;
+
+	pac207_decode_line_init(gspca_dev);
+}
+
+static int pac207_decode_frame_data(struct gspca_dev *gspca_dev,
+	struct gspca_frame *f, unsigned char *data, int len)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+	struct pac207_decoder_state *decoder_state = &sd->decoder_state;
+	int needed = 0;
+
+	/* first 11 bytes after sof marker: frame header */
+	if (decoder_state->header_read < 11) {
+		/* get average lumination from frame header (byte 5) */
+		if (decoder_state->header_read < 5) {
+			needed = 5 - decoder_state->header_read;
+			if (len >= needed)
+				atomic_set(&sd->avg_lum, data[needed-1]);
+		}
+		/* skip the rest of the header */
+		needed = 11 - decoder_state->header_read;
+		if (len <= needed) {
+			decoder_state->header_read += len;
+			return 0;
+		}
+		data += needed;
+		len -= needed;
+		decoder_state->header_read = 11;
+	}
+
+	while (len) {
+		if (decoder_state->discard_byte) {
+			data++;
+			len--;
+			decoder_state->discard_byte = 0;
+			continue;
+		}
+
+		switch (decoder_state->line_state) {
+		case LINE_HEADER1:
+			decoder_state->line_marker = data[0] << 8;
+			decoder_state->line_state = LINE_HEADER2;
+			needed = 1;
+			break;
+		case LINE_HEADER2:
+			decoder_state->line_marker |= data[0];
+			switch (decoder_state->line_marker) {
+			case 0x0FF0:
+				decoder_state->line_state = LINE_UNCOMPRESSED;
+				break;
+			case 0x1EE1:
+				decoder_state->line_state = LINE_COMPRESSED;
+				break;
+			default:
+				PDEBUG(D_STREAM,
+					"Error unknown line-header %04X",
+					(int) decoder_state->line_marker);
+				gspca_dev->last_packet_type = DISCARD_PACKET;
+				return 0;
+			}
+			needed = 1;
+			break;
+		case LINE_UNCOMPRESSED:
+			needed = gspca_dev->width - decoder_state->line_read;
+			if (needed > len)
+				needed = len;
+			gspca_frame_add(gspca_dev, INTER_PACKET, f, data,
+				needed);
+			decoder_state->line_read += needed;
+			break;
+		case LINE_COMPRESSED:
+			needed = len -
+				pac207_decompress_row(gspca_dev, f, data, len);
+			break;
+		}
+
+		data += needed;
+		len -= needed;
+
+		if (decoder_state->line_read == gspca_dev->width) {
+			if ((f->data_end - f->data) ==
+				(gspca_dev->width * gspca_dev->height)) {
+				/* eureka we've got a frame */
+				return 1;
+			}
+			pac207_decode_line_init(gspca_dev);
+		}
+	}
+
+	return 0;
+}
+
+static void sd_pkt_scan(struct gspca_dev *gspca_dev,
+			struct gspca_frame *frame,
+			unsigned char *data,
+			int len)
+{
+	unsigned char *sof;
+	int n;
+
+	sof = pac207_find_sof(gspca_dev, data, len);
+
+	if (sof) {
+		/* finish decoding current frame */
+		if (gspca_dev->last_packet_type == INTER_PACKET) {
+			n = sof - data;
+			if (n > sizeof(pac207_sof_marker))
+				n -= sizeof(pac207_sof_marker);
+			else
+				n = 0;
+			n = pac207_decode_frame_data(gspca_dev, frame,
+							data, n);
+			if (n)
+				frame = gspca_frame_add(gspca_dev,
+						LAST_PACKET,
+						frame,
+						NULL,
+						0);
+			else
+				PDEBUG(D_STREAM, "Incomplete frame");
+		}
+		pac207_decode_frame_init(gspca_dev);
+		gspca_frame_add(gspca_dev, FIRST_PACKET, frame, NULL,
+				0);
+		len -= sof - data;
+		data = sof;
+	}
+
+	if (gspca_dev->last_packet_type == DISCARD_PACKET)
+		return;
+
+	n = pac207_decode_frame_data(gspca_dev, frame, data, len);
+	if (n)
+		frame = gspca_frame_add(gspca_dev, LAST_PACKET,
+					frame, NULL, 0);
+}
+
+static void setbrightness(struct gspca_dev *gspca_dev)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+
+	pac207_write_reg(gspca_dev, 0x08, sd->brightness);
+	pac207_write_reg(gspca_dev, 0x13, 0x01);	/* Bit 0, auto clear */
+	pac207_write_reg(gspca_dev, 0x1c, 0x01);	/* not documented */
+}
+
+static void setexposure(struct gspca_dev *gspca_dev)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+
+	pac207_write_reg(gspca_dev, 0x02, sd->exposure);
+	pac207_write_reg(gspca_dev, 0x13, 0x01);	/* Bit 0, auto clear */
+	pac207_write_reg(gspca_dev, 0x1c, 0x01);	/* not documented */
+}
+
+static void setgain(struct gspca_dev *gspca_dev)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+
+	pac207_write_reg(gspca_dev, 0x0e, sd->gain);
+	pac207_write_reg(gspca_dev, 0x13, 0x01);	/* Bit 0, auto clear */
+	pac207_write_reg(gspca_dev, 0x1c, 0x01);	/* not documented */
+}
+
+static int sd_setbrightness(struct gspca_dev *gspca_dev, __s32 val)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+
+	sd->brightness = val;
+	if (gspca_dev->streaming)
+		setbrightness(gspca_dev);
+	return 0;
+}
+
+static int sd_getbrightness(struct gspca_dev *gspca_dev, __s32 *val)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+
+	*val = sd->brightness;
+	return 0;
+}
+
+static int sd_setexposure(struct gspca_dev *gspca_dev, __s32 val)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+
+	/* don't allow mucking with exposure when using autogain */
+	if (sd->autogain)
+		return -EINVAL;
+
+	sd->exposure = val;
+	if (gspca_dev->streaming)
+		setexposure(gspca_dev);
+	return 0;
+}
+
+static int sd_getexposure(struct gspca_dev *gspca_dev, __s32 *val)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+
+	*val = sd->exposure;
+	return 0;
+}
+
+static int sd_setgain(struct gspca_dev *gspca_dev, __s32 val)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+
+	/* don't allow mucking with gain when using autogain */
+	if (sd->autogain)
+		return -EINVAL;
+
+	sd->gain = val;
+	if (gspca_dev->streaming)
+		setgain(gspca_dev);
+	return 0;
+}
+
+static int sd_getgain(struct gspca_dev *gspca_dev, __s32 *val)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+
+	*val = sd->gain;
+	return 0;
+}
+
+static int sd_setautogain(struct gspca_dev *gspca_dev, __s32 val)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+
+	sd->autogain = val;
+	/* when switching to autogain set defaults to make sure
+	   we are on a valid point of the autogain gain /
+	   exposure knee graph, and give this change time to
+	   take effect before doing autogain. */
+	if (sd->autogain) {
+		sd->exposure = PAC207_EXPOSURE_DEFAULT;
+		sd->gain = PAC207_GAIN_DEFAULT;
+		if (gspca_dev->streaming) {
+			sd->autogain_ignore_frames =
+				PAC207_AUTOGAIN_IGNORE_FRAMES;
+			setexposure(gspca_dev);
+			setgain(gspca_dev);
+		}
+	}
+
+	return 0;
+}
+
+static int sd_getautogain(struct gspca_dev *gspca_dev, __s32 *val)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+
+	*val = sd->autogain;
+	return 0;
+}
+
+/* sub-driver description */
+static struct sd_desc sd_desc = {
+	.name = MODULE_NAME,
+	.ctrls = sd_ctrls,
+	.nctrls = ARRAY_SIZE(sd_ctrls),
+	.config = sd_config,
+	.open = sd_open,
+	.start = sd_start,
+	.stopN = sd_stopN,
+	.stop0 = sd_stop0,
+	.close = sd_close,
+	.dq_callback = pac207_do_auto_gain,
+	.pkt_scan = sd_pkt_scan,
+};
+
+/* -- module initialisation -- */
+#define DVNM(name) .driver_info = (kernel_ulong_t) name
+static __devinitdata struct usb_device_id device_table[] = {
+	{USB_DEVICE(0x041e, 0x4028), DVNM("Creative Webcam Vista Plus")},
+	{USB_DEVICE(0x093a, 0x2460), DVNM("PAC207 Qtec Webcam 100")},
+	{USB_DEVICE(0x093a, 0x2463), DVNM("Philips spc200nc pac207")},
+	{USB_DEVICE(0x093a, 0x2464), DVNM("Labtec Webcam 1200")},
+	{USB_DEVICE(0x093a, 0x2468), DVNM("PAC207")},
+	{USB_DEVICE(0x093a, 0x2470), DVNM("Genius GF112")},
+	{USB_DEVICE(0x093a, 0x2471), DVNM("PAC207 Genius VideoCam ge111")},
+	{USB_DEVICE(0x093a, 0x2472), DVNM("PAC207 Genius VideoCam ge110")},
+	{USB_DEVICE(0x2001, 0xf115), DVNM("D-Link DSB-C120")},
+	{}
+};
+MODULE_DEVICE_TABLE(usb, device_table);
+
+/* -- device connect -- */
+static int sd_probe(struct usb_interface *intf,
+			const struct usb_device_id *id)
+{
+	PDEBUG(D_PROBE, "camera probe");
+	return gspca_dev_probe(intf, id, &sd_desc, sizeof(struct sd));
+}
+
+static struct usb_driver sd_driver = {
+	.name = MODULE_NAME,
+	.id_table = device_table,
+	.probe = sd_probe,
+	.disconnect = gspca_disconnect,
+};
+
+/* -- module insert / remove -- */
+static int __init sd_mod_init(void)
+{
+	init_pixart_decoder();
+	if (usb_register(&sd_driver) < 0)
+		return -1;
+	PDEBUG(D_PROBE, "v%s registered", version);
+	return 0;
+}
+static void __exit sd_mod_exit(void)
+{
+	usb_deregister(&sd_driver);
+	PDEBUG(D_PROBE, "deregistered");
+}
+
+module_init(sd_mod_init);
+module_exit(sd_mod_exit);