1 files changed, 142 insertions, 0 deletions

diff --git a/drivers/staging/altera-stapl/altera-comp.c b/drivers/staging/altera-stapl/altera-comp.c
new file mode 100644
index 00000000000..49b103bedaa
--- /dev/null
+++ b/drivers/staging/altera-stapl/altera-comp.c
@@ -0,0 +1,142 @@
+/*
+ * altera-comp.c
+ *
+ * altera FPGA driver
+ *
+ * Copyright (C) Altera Corporation 1998-2001
+ * Copyright (C) 2010 NetUP Inc.
+ * Copyright (C) 2010 Igor M. Liplianin <liplianin@netup.ru>
+ *
+ * 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 <linux/kernel.h>
+#include "altera-exprt.h"
+
+#define SHORT_BITS              16
+#define CHAR_BITS               8
+#define DATA_BLOB_LENGTH        3
+#define MATCH_DATA_LENGTH       8192
+#define ALTERA_REQUEST_SIZE     1024
+#define ALTERA_BUFFER_SIZE      (MATCH_DATA_LENGTH + ALTERA_REQUEST_SIZE)
+
+static u32 altera_bits_req(u32 n)
+{
+        u32 result = SHORT_BITS;
+
+        if (n == 0)
+                result = 1;
+        else {
+                /* Look for the highest non-zero bit position */
+                while ((n & (1 << (SHORT_BITS - 1))) == 0) {
+                        n <<= 1;
+                        --result;
+                }
+        }
+
+        return result;
+}
+
+static u32 altera_read_packed(u8 *buffer, u32 bits, u32 *bits_avail,
+                                                        u32 *in_index)
+{
+        u32 result = 0;
+        u32 shift = 0;
+        u32 databyte = 0;
+
+        while (bits > 0) {
+                databyte = buffer[*in_index];
+                result |= (((databyte >> (CHAR_BITS - *bits_avail))
+                        & (0xff >> (CHAR_BITS - *bits_avail))) << shift);
+
+                if (bits <= *bits_avail) {
+                        result &= (0xffff >> (SHORT_BITS - (bits + shift)));
+                        *bits_avail -= bits;
+                        bits = 0;
+                } else {
+                        ++(*in_index);
+                        shift += *bits_avail;
+                        bits -= *bits_avail;
+                        *bits_avail = CHAR_BITS;
+                }
+        }
+
+        return result;
+}
+
+u32 altera_shrink(u8 *in, u32 in_length, u8 *out, u32 out_length, s32 version)
+{
+        u32 i, j, data_length = 0L;
+        u32 offset, length;
+        u32 match_data_length = MATCH_DATA_LENGTH;
+        u32 bits_avail = CHAR_BITS;
+        u32 in_index = 0L;
+
+        if (version > 0)
+                --match_data_length;
+
+        for (i = 0; i < out_length; ++i)
+                out[i] = 0;
+
+        /* Read number of bytes in data. */
+        for (i = 0; i < sizeof(in_length); ++i) {
+                data_length = data_length | (
+                        altera_read_packed(in,
+                                        CHAR_BITS,
+                                        &bits_avail,
+                                        &in_index) << (i * CHAR_BITS));
+        }
+
+        if (data_length > out_length) {
+                data_length = 0L;
+                return data_length;
+        }
+
+        i = 0;
+        while (i < data_length) {
+                /* A 0 bit indicates literal data. */
+                if (altera_read_packed(in, 1, &bits_avail,
+                                                &in_index) == 0) {
+                        for (j = 0; j < DATA_BLOB_LENGTH; ++j) {
+                                if (i < data_length) {
+                                        out[i] = (u8)altera_read_packed(in,
+                                                        CHAR_BITS,
+                                                        &bits_avail,
+                                                        &in_index);
+                                        i++;
+                                }
+                        }
+                } else {
+                        /* A 1 bit indicates offset/length to follow. */
+                        offset = altera_read_packed(in, altera_bits_req((s16)
+                                        (i > match_data_length ?
+                                                match_data_length : i)),
+                                        &bits_avail,
+                                        &in_index);
+                        length = altera_read_packed(in, CHAR_BITS,
+                                        &bits_avail,
+                                        &in_index);
+                        for (j = 0; j < length; ++j) {
+                                if (i < data_length) {
+                                        out[i] = out[i - offset];
+                                        i++;
+                                }
+                        }
+                }
+        }
+
+        return data_length;
+}