Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / media / usb / gspca / pac_common.h

diff --git a/kernel/drivers/media/usb/gspca/pac_common.h b/kernel/drivers/media/usb/gspca/pac_common.h
new file mode 100644 (file)
index 0000000..fbc5e22
--- /dev/null
+++ b/kernel/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;
+}