incubator-nuttx/drivers/devicetree/fdt.c

158 lines
3.9 KiB
C

/****************************************************************************
* drivers/devicetree/fdt.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <stddef.h>
#include <endian.h>
#include <errno.h>
#include <assert.h>
#include <nuttx/compiler.h>
#include <nuttx/fdt.h>
#include <libfdt.h>
/****************************************************************************
* Private Data
****************************************************************************/
/* Location of the fdt data for this system. */
static FAR const char *g_fdt_base = NULL;
/****************************************************************************
* Public Functions
****************************************************************************/
int fdt_register(FAR const char *fdt_base)
{
struct fdt_header_s *fdt_header;
DEBUGASSERT(fdt_base);
fdt_header = (struct fdt_header_s *)fdt_base;
if (fdt_header->magic != be32toh(FDT_MAGIC))
{
return -EINVAL; /* Bad magic byte read */
}
g_fdt_base = fdt_base;
return OK;
}
FAR const char *fdt_get(void)
{
return g_fdt_base;
}
int fdt_get_irq(FAR const void *fdt, int nodeoffset,
int offset, int irqbase)
{
FAR const fdt32_t *pv;
int irq = -1;
pv = fdt_getprop(fdt, nodeoffset, "interrupts", NULL);
if (pv != NULL)
{
irq = fdt32_ld(pv + offset) + irqbase;
}
return irq;
}
int fdt_get_irq_by_path(FAR const void *fdt, int offset,
const char *path, int irqbase)
{
return fdt_get_irq(fdt, fdt_path_offset(fdt, path), offset, irqbase);
}
int fdt_get_parent_address_cells(FAR const void *fdt, int offset)
{
int parentoff;
parentoff = fdt_parent_offset(fdt, offset);
if (parentoff < 0)
{
return parentoff;
}
return fdt_address_cells(fdt, parentoff);
}
int fdt_get_parent_size_cells(FAR const void *fdt, int offset)
{
int parentoff;
parentoff = fdt_parent_offset(fdt, offset);
if (parentoff < 0)
{
return parentoff;
}
return fdt_size_cells(fdt, parentoff);
}
uintptr_t fdt_ld_by_cells(FAR const void *value, int cells)
{
if (cells == 2)
{
return fdt64_ld(value);
}
else
{
return fdt32_ld(value);
}
}
uintptr_t fdt_get_reg_base(FAR const void *fdt, int offset)
{
FAR const void *reg;
uintptr_t addr = 0;
reg = fdt_getprop(fdt, offset, "reg", NULL);
if (reg != NULL)
{
addr = fdt_ld_by_cells(reg, fdt_get_parent_address_cells(fdt, offset));
}
return addr;
}
uintptr_t fdt_get_reg_size(FAR const void *fdt, int offset)
{
FAR const void *reg;
uintptr_t size = 0;
reg = fdt_getprop(fdt, offset, "reg", NULL);
if (reg != NULL)
{
size = fdt_ld_by_cells(reg, fdt_get_parent_size_cells(fdt, offset));
}
return size;
}
uintptr_t fdt_get_reg_base_by_path(FAR const void *fdt, FAR const char *path)
{
return fdt_get_reg_base(fdt, fdt_path_offset(fdt, path));
}