1 files changed, 131 insertions, 0 deletions
diff --git a/drivers/staging/meilhaus/mecirc_buf.h b/drivers/staging/meilhaus/mecirc_buf.h
new file mode 100644
index 000000000000..e9b591eaa349
--- /dev/null
+++ b/drivers/staging/meilhaus/mecirc_buf.h
@@ -0,0 +1,131 @@
+/**
+ * @file mecirc_buf.h
+ *
+ * @brief Meilhaus circular buffer implementation.
+ * @note Copyright (C) 2007 Meilhaus Electronic GmbH (support@meilhaus.de)
+ * @author Guenter Gebhardt
+ * @author Krzysztof Gantzke  (k.gantzke@meilhaus.de)
+ */
+
+/*
+ * Copyright (C) 2007 Meilhaus Electronic GmbH (support@meilhaus.de)
+ *
+ * This file 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 _MECIRC_BUF_H_
+#define _MECIRC_BUF_H_
+
+# ifdef __KERNEL__
+
+#  ifdef BOSCH
+
+typedef struct me_circ_buf {
+	unsigned int mask;
+//      unsigned int count;
+	uint32_t *buf;
+	int volatile head;
+	int volatile tail;
+} me_circ_buf_t;
+
+static int inline me_circ_buf_values(me_circ_buf_t * buf)
+{
+//      return ((buf->head - buf->tail) & (buf->count - 1));
+	return ((buf->head - buf->tail) & (buf->mask));
+}
+
+static int inline me_circ_buf_space(me_circ_buf_t * buf)
+{
+//      return ((buf->tail - (buf->head + 1)) & (buf->count - 1));
+	return ((buf->tail - (buf->head + 1)) & (buf->mask));
+}
+
+static int inline me_circ_buf_values_to_end(me_circ_buf_t * buf)
+{
+	int end;
+	int n;
+//      end = buf->count - buf->tail;
+//      n = (buf->head + end) & (buf->count - 1);
+	end = buf->mask + 1 - buf->tail;
+	n = (buf->head + end) & (buf->mask);
+	return (n < end) ? n : end;
+}
+
+static int inline me_circ_buf_space_to_end(me_circ_buf_t * buf)
+{
+	int end;
+	int n;
+
+//      end = buf->count - 1 - buf->head;
+//      n = (end + buf->tail) & (buf->count - 1);
+	end = buf->mask - buf->head;
+	n = (end + buf->tail) & (buf->mask);
+	return (n <= end) ? n : (end + 1);
+}
+
+#define _CBUFF_32b_t
+
+#  else	//~BOSCH
+/// @note buf->mask = buf->count-1 = ME4600_AI_CIRC_BUF_COUNT-1
+
+#   ifdef _CBUFF_32b_t
+	//32 bit
+typedef struct me_circ_buf_32b {
+	int volatile head;
+	int volatile tail;
+	unsigned int mask;	//buffor size-1 must be 2^n-1 to work
+	uint32_t *buf;
+} me_circ_buf_t;
+#   else
+	//16 bit
+typedef struct me_circ_buf_16b {
+	int volatile head;
+	int volatile tail;
+	unsigned int mask;	//buffor size-1 must be 2^n-1 to work
+	uint16_t *buf;
+} me_circ_buf_t;
+#   endif //_CBUFF_32b_t
+
+/** How many values is in buffer */
+static int inline me_circ_buf_values(me_circ_buf_t * buf)
+{
+	return ((buf->head - buf->tail) & (buf->mask));
+}
+
+/** How many space left */
+static int inline me_circ_buf_space(me_circ_buf_t * buf)
+{
+	return ((buf->tail - (buf->head + 1)) & (buf->mask));
+}
+
+/** How many values can be read from buffor in one chunck. */
+static int inline me_circ_buf_values_to_end(me_circ_buf_t * buf)
+{
+	return (buf->tail <=
+		buf->head) ? (buf->head - buf->tail) : (buf->mask - buf->tail +
+							1);
+}
+
+/** How many values can be write to buffer in one chunck. */
+static int inline me_circ_buf_space_to_end(me_circ_buf_t * buf)
+{
+	return (buf->tail <=
+		buf->head) ? (buf->mask - buf->head + 1) : (buf->tail -
+							    buf->head - 1);
+}
+
+#  endif //BOSCH
+# endif	//__KERNEL__
+#endif //_MECIRC_BUF_H_