devtree.c

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/*
 * devtree.c - convenience functions for device tree manipulation
 * Copyright 2007 David Gibson, IBM Corporation.
 * Copyright (c) 2007 Freescale Semiconductor, Inc.
 *
 * Authors: David Gibson <[email protected]>
 *      Scott Wood <[email protected]>
 *
 * 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 <stdarg.h>
#include <stddef.h>
#include "types.h"
#include "string.h"
#include "stdio.h"
#include "ops.h"

void dt_fixup_memory(u64 start, u64 size)
{
    void *root, *memory;
    int naddr, nsize, i;
    u32 memreg[4];

    root = finddevice("/");
    if (getprop(root, "#address-cells", &naddr, sizeof(naddr)) < 0)
        naddr = 2;
    if (naddr < 1 || naddr > 2)
        fatal("Can't cope with #address-cells == %d in /\n\r", naddr);

    if (getprop(root, "#size-cells", &nsize, sizeof(nsize)) < 0)
        nsize = 1;
    if (nsize < 1 || nsize > 2)
        fatal("Can't cope with #size-cells == %d in /\n\r", nsize);

    i = 0;
    if (naddr == 2)
        memreg[i++] = start >> 32;
    memreg[i++] = start & 0xffffffff;
    if (nsize == 2)
        memreg[i++] = size >> 32;
    memreg[i++] = size & 0xffffffff;

    memory = finddevice("/memory");
    if (! memory) {
        memory = create_node(NULL, "memory");
        setprop_str(memory, "device_type", "memory");
    }

    printf("Memory <- <0x%x", memreg[0]);
    for (i = 1; i < (naddr + nsize); i++)
        printf(" 0x%x", memreg[i]);
    printf("> (%ldMB)\n\r", (unsigned long)(size >> 20));

    setprop(memory, "reg", memreg, (naddr + nsize)*sizeof(u32));
}

#define MHZ(x)  ((x + 500000) / 1000000)

void dt_fixup_cpu_clocks(u32 cpu, u32 tb, u32 bus)
{
    void *devp = NULL;

    printf("CPU clock-frequency <- 0x%x (%dMHz)\n\r", cpu, MHZ(cpu));
    printf("CPU timebase-frequency <- 0x%x (%dMHz)\n\r", tb, MHZ(tb));
    if (bus > 0)
        printf("CPU bus-frequency <- 0x%x (%dMHz)\n\r", bus, MHZ(bus));

    while ((devp = find_node_by_devtype(devp, "cpu"))) {
        setprop_val(devp, "clock-frequency", cpu);
        setprop_val(devp, "timebase-frequency", tb);
        if (bus > 0)
            setprop_val(devp, "bus-frequency", bus);
    }

    timebase_period_ns = 1000000000 / tb;
}

void dt_fixup_clock(const char *path, u32 freq)
{
    void *devp = finddevice(path);

    if (devp) {
        printf("%s: clock-frequency <- %x (%dMHz)\n\r", path, freq, MHZ(freq));
        setprop_val(devp, "clock-frequency", freq);
    }
}

void dt_fixup_mac_address_by_alias(const char *alias, const u8 *addr)
{
    void *devp = find_node_by_alias(alias);

    if (devp) {
        printf("%s: local-mac-address <-"
               " %02x:%02x:%02x:%02x:%02x:%02x\n\r", alias,
               addr[0], addr[1], addr[2],
               addr[3], addr[4], addr[5]);

        setprop(devp, "local-mac-address", addr, 6);
    }
}

void dt_fixup_mac_address(u32 index, const u8 *addr)
{
    void *devp = find_node_by_prop_value(NULL, "linux,network-index",
                                         (void*)&index, sizeof(index));

    if (devp) {
        printf("ENET%d: local-mac-address <-"
               " %02x:%02x:%02x:%02x:%02x:%02x\n\r", index,
               addr[0], addr[1], addr[2],
               addr[3], addr[4], addr[5]);

        setprop(devp, "local-mac-address", addr, 6);
    }
}

void __dt_fixup_mac_addresses(u32 startindex, ...)
{
    va_list ap;
    u32 index = startindex;
    const u8 *addr;

    va_start(ap, startindex);

    while ((addr = va_arg(ap, const u8 *)))
        dt_fixup_mac_address(index++, addr);

    va_end(ap);
}

#define MAX_ADDR_CELLS 4

void dt_get_reg_format(void *node, u32 *naddr, u32 *nsize)
{
    if (getprop(node, "#address-cells", naddr, 4) != 4)
        *naddr = 2;
    if (getprop(node, "#size-cells", nsize, 4) != 4)
        *nsize = 1;
}

static void copy_val(u32 *dest, u32 *src, int naddr)
{
    int pad = MAX_ADDR_CELLS - naddr;

    memset(dest, 0, pad * 4);
    memcpy(dest + pad, src, naddr * 4);
}

static int sub_reg(u32 *reg, u32 *sub)
{
    int i, borrow = 0;

    for (i = MAX_ADDR_CELLS - 1; i >= 0; i--) {
        int prev_borrow = borrow;
        borrow = reg[i] < sub[i] + prev_borrow;
        reg[i] -= sub[i] + prev_borrow;
    }

    return !borrow;
}

static int add_reg(u32 *reg, u32 *add, int naddr)
{
    int i, carry = 0;

    for (i = MAX_ADDR_CELLS - 1; i >= MAX_ADDR_CELLS - naddr; i--) {
        u64 tmp = (u64)reg[i] + add[i] + carry;
        carry = tmp >> 32;
        reg[i] = (u32)tmp;
    }

    return !carry;
}

/* It is assumed that if the first byte of reg fits in a
 * range, then the whole reg block fits.
 */
static int compare_reg(u32 *reg, u32 *range, u32 *rangesize)
{
    int i;
    u32 end;

    for (i = 0; i < MAX_ADDR_CELLS; i++) {
        if (reg[i] < range[i])
            return 0;
        if (reg[i] > range[i])
            break;
    }

    for (i = 0; i < MAX_ADDR_CELLS; i++) {
        end = range[i] + rangesize[i];

        if (reg[i] < end)
            break;
        if (reg[i] > end)
            return 0;
    }

    return reg[i] != end;
}

/* reg must be MAX_ADDR_CELLS */
static int find_range(u32 *reg, u32 *ranges, int nregaddr,
                      int naddr, int nsize, int buflen)
{
    int nrange = nregaddr + naddr + nsize;
    int i;

    for (i = 0; i + nrange <= buflen; i += nrange) {
        u32 range_addr[MAX_ADDR_CELLS];
        u32 range_size[MAX_ADDR_CELLS];

        copy_val(range_addr, ranges + i, nregaddr);
        copy_val(range_size, ranges + i + nregaddr + naddr, nsize);

        if (compare_reg(reg, range_addr, range_size))
            return i;
    }

    return -1;
}

/* Currently only generic buses without special encodings are supported.
 * In particular, PCI is not supported.  Also, only the beginning of the
 * reg block is tracked; size is ignored except in ranges.
 */
static u32 prop_buf[MAX_PROP_LEN / 4];

static int dt_xlate(void *node, int res, int reglen, unsigned long *addr,
        unsigned long *size)
{
    u32 last_addr[MAX_ADDR_CELLS];
    u32 this_addr[MAX_ADDR_CELLS];
    void *parent;
    u64 ret_addr, ret_size;
    u32 naddr, nsize, prev_naddr, prev_nsize;
    int buflen, offset;

    parent = get_parent(node);
    if (!parent)
        return 0;

    dt_get_reg_format(parent, &naddr, &nsize);

    if (nsize > 2)
        return 0;

    offset = (naddr + nsize) * res;

    if (reglen < offset + naddr + nsize ||
        MAX_PROP_LEN < (offset + naddr + nsize) * 4)
        return 0;

    copy_val(last_addr, prop_buf + offset, naddr);

    ret_size = prop_buf[offset + naddr];
    if (nsize == 2) {
        ret_size <<= 32;
        ret_size |= prop_buf[offset + naddr + 1];
    }

    for (;;) {
        prev_naddr = naddr;
        prev_nsize = nsize;
        node = parent;

        parent = get_parent(node);
        if (!parent)
            break;

        dt_get_reg_format(parent, &naddr, &nsize);

        buflen = getprop(node, "ranges", prop_buf,
                sizeof(prop_buf));
        if (buflen == 0)
            continue;
        if (buflen < 0 || buflen > sizeof(prop_buf))
            return 0;

        offset = find_range(last_addr, prop_buf, prev_naddr,
                            naddr, prev_nsize, buflen / 4);

        if (offset < 0)
            return 0;

        copy_val(this_addr, prop_buf + offset, prev_naddr);

        if (!sub_reg(last_addr, this_addr))
            return 0;

        copy_val(this_addr, prop_buf + offset + prev_naddr, naddr);

        if (!add_reg(last_addr, this_addr, naddr))
            return 0;
    }

    if (naddr > 2)
        return 0;

    ret_addr = ((u64)last_addr[2] << 32) | last_addr[3];

    if (sizeof(void *) == 4 &&
        (ret_addr >= 0x100000000ULL || ret_size > 0x100000000ULL ||
         ret_addr + ret_size > 0x100000000ULL))
        return 0;

    *addr = ret_addr;
    if (size)
        *size = ret_size;

    return 1;
}

int dt_xlate_reg(void *node, int res, unsigned long *addr, unsigned long *size)
{
    int reglen;

    reglen = getprop(node, "reg", prop_buf, sizeof(prop_buf)) / 4;
    return dt_xlate(node, res, reglen, addr, size);
}

int dt_xlate_addr(void *node, u32 *buf, int buflen, unsigned long *xlated_addr)
{

    if (buflen > sizeof(prop_buf))
        return 0;

    memcpy(prop_buf, buf, buflen);
    return dt_xlate(node, 0, buflen / 4, xlated_addr, NULL);
}

int dt_is_compatible(void *node, const char *compat)
{
    char *buf = (char *)prop_buf;
    int len, pos;

    len = getprop(node, "compatible", buf, MAX_PROP_LEN);
    if (len < 0)
        return 0;

    for (pos = 0; pos < len; pos++) {
        if (!strcmp(buf + pos, compat))
            return 1;

        pos += strnlen(&buf[pos], len - pos);
    }

    return 0;
}

int dt_get_virtual_reg(void *node, void **addr, int nres)
{
    unsigned long xaddr;
    int n;

    n = getprop(node, "virtual-reg", addr, nres * 4);
    if (n > 0)
        return n / 4;

    for (n = 0; n < nres; n++) {
        if (!dt_xlate_reg(node, n, &xaddr, NULL))
            break;

        addr[n] = (void *)xaddr;
    }

    return n;
}