File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/media/usb/gspca/pac_common.h b/drivers/media/usb/gspca/pac_common.h
new file mode 100644
index 0000000..fbc5e22
--- /dev/null
+++ b/drivers/media/usb/gspca/pac_common.h
@@ -0,0 +1,134 @@
+/*
+ * Pixart PAC207BCA / PAC73xx common functions
+ *
+ * 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
+ *
+ */
+
+/* We calculate the autogain at the end of the transfer of a frame, at this
+ moment a frame with the old settings is being captured and transmitted. So
+ if we adjust the gain or exposure we must ignore atleast the next frame for
+ the new settings to come into effect before doing any other adjustments. */
+#define PAC_AUTOGAIN_IGNORE_FRAMES 2
+
+static const unsigned char pac_sof_marker[5] =
+ { 0xff, 0xff, 0x00, 0xff, 0x96 };
+
+/*
+ The following state machine finds the SOF marker sequence
+ 0xff, 0xff, 0x00, 0xff, 0x96 in a byte stream.
+
+ +----------+
+ | 0: START |<---------------\
+ +----------+<-\ |
+ | \---/otherwise |
+ v 0xff |
+ +----------+ otherwise |
+ | 1 |--------------->*
+ | | ^
+ +----------+ |
+ | |
+ v 0xff |
+ +----------+<-\0xff |
+ /->| |--/ |
+ | | 2 |--------------->*
+ | | | otherwise ^
+ | +----------+ |
+ | | |
+ | v 0x00 |
+ | +----------+ |
+ | | 3 | |
+ | | |--------------->*
+ | +----------+ otherwise ^
+ | | |
+ 0xff | v 0xff |
+ | +----------+ |
+ \--| 4 | |
+ | |----------------/
+ +----------+ otherwise
+ |
+ v 0x96
+ +----------+
+ | FOUND |
+ +----------+
+*/
+
+static unsigned char *pac_find_sof(struct gspca_dev *gspca_dev, u8 *sof_read,
+ unsigned char *m, int len)
+{
+ int i;
+
+ /* Search for the SOF marker (fixed part) in the header */
+ for (i = 0; i < len; i++) {
+ switch (*sof_read) {
+ case 0:
+ if (m[i] == 0xff)
+ *sof_read = 1;
+ break;
+ case 1:
+ if (m[i] == 0xff)
+ *sof_read = 2;
+ else
+ *sof_read = 0;
+ break;
+ case 2:
+ switch (m[i]) {
+ case 0x00:
+ *sof_read = 3;
+ break;
+ case 0xff:
+ /* stay in this state */
+ break;
+ default:
+ *sof_read = 0;
+ }
+ break;
+ case 3:
+ if (m[i] == 0xff)
+ *sof_read = 4;
+ else
+ *sof_read = 0;
+ break;
+ case 4:
+ switch (m[i]) {
+ case 0x96:
+ /* Pattern found */
+ PDEBUG(D_FRAM,
+ "SOF found, bytes to analyze: %u."
+ " Frame starts at byte #%u",
+ len, i + 1);
+ *sof_read = 0;
+ return m + i + 1;
+ break;
+ case 0xff:
+ *sof_read = 2;
+ break;
+ default:
+ *sof_read = 0;
+ }
+ break;
+ default:
+ *sof_read = 0;
+ }
+ }
+
+ return NULL;
+}