drivers/net/wireless/brcm80211/brcmfmac/nvram.c

   1 /*
   2  * Copyright (c) 2013 Broadcom Corporation
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  11  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
  13  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  14  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/slab.h>
  19 #include <linux/firmware.h>
  20
  21 #include "nvram.h"
  22
  23 /* brcmf_nvram_strip :Takes a buffer of "<var>=<value>\n" lines read from a file
  24  * and ending in a NUL. Removes carriage returns, empty lines, comment lines,
  25  * and converts newlines to NULs. Shortens buffer as needed and pads with NULs.
  26  * End of buffer is completed with token identifying length of buffer.
  27  */
  28 void *brcmf_nvram_strip(const struct firmware *nv, u32 *new_length)
  29 {
  30         u8 *nvram;
  31         u32 i;
  32         u32 len;
  33         u32 column;
  34         u8 val;
  35         bool comment;
  36         u32 token;
  37         __le32 token_le;
  38
  39         /* Alloc for extra 0 byte + roundup by 4 + length field */
  40         nvram = kmalloc(nv->size + 1 + 3 + sizeof(token_le), GFP_KERNEL);
  41         if (!nvram)
  42                 return NULL;
  43
  44         len = 0;
  45         column = 0;
  46         comment = false;
  47         for (i = 0; i < nv->size; i++) {
  48                 val = nv->data[i];
  49                 if (val == 0)
  50                         break;
  51                 if (val == '\r')
  52                         continue;
  53                 if (comment && (val != '\n'))
  54                         continue;
  55                 comment = false;
  56                 if (val == '#') {
  57                         comment = true;
  58                         continue;
  59                 }
  60                 if (val == '\n') {
  61                         if (column == 0)
  62                                 continue;
  63                         nvram[len] = 0;
  64                         len++;
  65                         column = 0;
  66                         continue;
  67                 }
  68                 nvram[len] = val;
  69                 len++;
  70                 column++;
  71         }
  72         column = len;
  73         *new_length = roundup(len + 1, 4);
  74         while (column != *new_length) {
  75                 nvram[column] = 0;
  76                 column++;
  77         }
  78
  79         token = *new_length / 4;
  80         token = (~token << 16) | (token & 0x0000FFFF);
  81         token_le = cpu_to_le32(token);
  82
  83         memcpy(&nvram[*new_length], &token_le, sizeof(token_le));
  84         *new_length += sizeof(token_le);
  85
  86         return nvram;
  87 }
  88
  89 void brcmf_nvram_free(void *nvram)
  90 {
  91         kfree(nvram);
  92 }
  93
  94