add initial 2.6.28 support for brcm47xx target

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@13909 3c298f89-4303-0410-b956-a3cf2f4a3e73

target/linux/brcm47xx/files-2.6.28/arch/mips/bcm47xx/cfe_env.c

@@ -0,0 +1,229 @@
+/*
+ * CFE environment variable access
+ *
+ * Copyright 2001-2003, Broadcom Corporation
+ * Copyright 2006, Felix Fietkau <nbd@openwrt.org>
+ * 
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+#define NVRAM_SIZE       (0x1ff0)
+static char _nvdata[NVRAM_SIZE];
+static char _valuestr[256];
+
+/*
+ * TLV types.  These codes are used in the "type-length-value"
+ * encoding of the items stored in the NVRAM device (flash or EEPROM)
+ *
+ * The layout of the flash/nvram is as follows:
+ *
+ * <type> <length> <data ...> <type> <length> <data ...> <type_end>
+ *
+ * The type code of "ENV_TLV_TYPE_END" marks the end of the list.
+ * The "length" field marks the length of the data section, not
+ * including the type and length fields.
+ *
+ * Environment variables are stored as follows:
+ *
+ * <type_env> <length> <flags> <name> = <value>
+ *
+ * If bit 0 (low bit) is set, the length is an 8-bit value.
+ * If bit 0 (low bit) is clear, the length is a 16-bit value
+ * 
+ * Bit 7 set indicates "user" TLVs.  In this case, bit 0 still
+ * indicates the size of the length field.  
+ *
+ * Flags are from the constants below:
+ *
+ */
+#define ENV_LENGTH_16BITS	0x00	/* for low bit */
+#define ENV_LENGTH_8BITS	0x01
+
+#define ENV_TYPE_USER		0x80
+
+#define ENV_CODE_SYS(n,l) (((n)<<1)|(l))
+#define ENV_CODE_USER(n,l) ((((n)<<1)|(l)) | ENV_TYPE_USER)
+
+/*
+ * The actual TLV types we support
+ */
+
+#define ENV_TLV_TYPE_END	0x00	
+#define ENV_TLV_TYPE_ENV	ENV_CODE_SYS(0,ENV_LENGTH_8BITS)
+
+/*
+ * Environment variable flags 
+ */
+
+#define ENV_FLG_NORMAL		0x00	/* normal read/write */
+#define ENV_FLG_BUILTIN		0x01	/* builtin - not stored in flash */
+#define ENV_FLG_READONLY	0x02	/* read-only - cannot be changed */
+
+#define ENV_FLG_MASK		0xFF	/* mask of attributes we keep */
+#define ENV_FLG_ADMIN		0x100	/* lets us internally override permissions */
+
+
+/*  *********************************************************************
+    *  _nvram_read(buffer,offset,length)
+    *  
+    *  Read data from the NVRAM device
+    *  
+    *  Input parameters: 
+    *  	   buffer - destination buffer
+    *  	   offset - offset of data to read
+    *  	   length - number of bytes to read
+    *  	   
+    *  Return value:
+    *  	   number of bytes read, or <0 if error occured
+    ********************************************************************* */
+static int
+_nvram_read(unsigned char *nv_buf, unsigned char *buffer, int offset, int length)
+{
+    int i;
+    if (offset > NVRAM_SIZE)
+	return -1; 
+
+    for ( i = 0; i < length; i++) {
+	buffer[i] = ((volatile unsigned char*)nv_buf)[offset + i];
+    }
+    return length;
+}
+
+
+static char*
+_strnchr(const char *dest,int c,size_t cnt)
+{
+	while (*dest && (cnt > 0)) {
+	if (*dest == c) return (char *) dest;
+	dest++;
+	cnt--;
+	}
+	return NULL;
+}
+
+
+
+/*
+ * Core support API: Externally visible.
+ */
+
+/*
+ * Get the value of an NVRAM variable
+ * @param	name	name of variable to get
+ * @return	value of variable or NULL if undefined
+ */
+
+char* 
+cfe_env_get(unsigned char *nv_buf, char* name)
+{
+    int size;
+    unsigned char *buffer;
+    unsigned char *ptr;
+    unsigned char *envval;
+    unsigned int reclen;
+    unsigned int rectype;
+    int offset;
+    int flg;
+    
+	if (!strcmp(name, "nvram_type"))
+		return "cfe";
+	
+    size = NVRAM_SIZE;
+    buffer = &_nvdata[0];
+
+    ptr = buffer;
+    offset = 0;
+
+    /* Read the record type and length */
+    if (_nvram_read(nv_buf, ptr,offset,1) != 1) {
+	goto error;
+    }
+    
+    while ((*ptr != ENV_TLV_TYPE_END)  && (size > 1)) {
+
+	/* Adjust pointer for TLV type */
+	rectype = *(ptr);
+	offset++;
+	size--;
+
+	/* 
+	 * Read the length.  It can be either 1 or 2 bytes
+	 * depending on the code 
+	 */
+	if (rectype & ENV_LENGTH_8BITS) {
+	    /* Read the record type and length - 8 bits */
+	    if (_nvram_read(nv_buf, ptr,offset,1) != 1) {
+		goto error;
+	    }
+	    reclen = *(ptr);
+	    size--;
+	    offset++;
+	}
+	else {
+	    /* Read the record type and length - 16 bits, MSB first */
+	    if (_nvram_read(nv_buf, ptr,offset,2) != 2) {
+		goto error;
+	    }
+	    reclen = (((unsigned int) *(ptr)) << 8) + (unsigned int) *(ptr+1);
+	    size -= 2;
+	    offset += 2;
+	}
+
+	if (reclen > size)
+	    break;	/* should not happen, bad NVRAM */
+
+	switch (rectype) {
+	    case ENV_TLV_TYPE_ENV:
+		/* Read the TLV data */
+		if (_nvram_read(nv_buf, ptr,offset,reclen) != reclen)
+		    goto error;
+		flg = *ptr++;
+		envval = (unsigned char *) _strnchr(ptr,'=',(reclen-1));
+		if (envval) {
+		    *envval++ = '\0';
+		    memcpy(_valuestr,envval,(reclen-1)-(envval-ptr));
+		    _valuestr[(reclen-1)-(envval-ptr)] = '\0';
+#if 0			
+		    printk(KERN_INFO "NVRAM:%s=%s\n", ptr, _valuestr);
+#endif
+		    if(!strcmp(ptr, name)){
+			return _valuestr;
+		    }
+		    if((strlen(ptr) > 1) && !strcmp(&ptr[1], name))
+			return _valuestr;
+		}
+		break;
+		
+	    default: 
+		/* Unknown TLV type, skip it. */
+		break;
+	    }
+
+	/*
+	 * Advance to next TLV 
+	 */
+		
+	size -= (int)reclen;
+	offset += reclen;
+
+	/* Read the next record type */
+	ptr = buffer;
+	if (_nvram_read(nv_buf, ptr,offset,1) != 1)
+	    goto error;
+	}
+
+error:
+    return NULL;
+
+}
+