u-boot/drivers/core/lists.c
Simon Glass 00606d7e39 dm: Allow drivers to be marked 'before relocation'
Driver model currently only operates after relocation is complete. In this
state U-Boot typically has a small amount of memory available. In adding
support for driver model prior to relocation we must try to use as little
memory as possible.

In addition, on some machines the memory has not be inited and/or the CPU
is not running at full speed or the data cache is off. These can reduce
execution performance, so the less initialisation that is done before
relocation the better.

An immediately-obvious improvement is to only initialise drivers which are
actually going to be used before relocation. On many boards the only such
driver is a serial UART, so this provides a very large potential benefit.

Allow drivers to mark themselves as 'pre-reloc' which means that they will
be initialised prior to relocation. This can be done either with a driver
flag or with a 'dm,pre-reloc' device tree property.

To support this, the various dm scanning function now take a 'pre_reloc_only'
parameter which indicates that only drivers marked pre-reloc should be
bound.

Signed-off-by: Simon Glass <sjg@chromium.org>
2014-07-23 14:07:24 +01:00

157 lines
3.6 KiB
C

/*
* Copyright (c) 2013 Google, Inc
*
* (C) Copyright 2012
* Marek Vasut <marex@denx.de>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <errno.h>
#include <dm/device.h>
#include <dm/device-internal.h>
#include <dm/lists.h>
#include <dm/platdata.h>
#include <dm/uclass.h>
#include <dm/util.h>
#include <fdtdec.h>
#include <linux/compiler.h>
struct driver *lists_driver_lookup_name(const char *name)
{
struct driver *drv =
ll_entry_start(struct driver, driver);
const int n_ents = ll_entry_count(struct driver, driver);
struct driver *entry;
int len;
if (!drv || !n_ents)
return NULL;
len = strlen(name);
for (entry = drv; entry != drv + n_ents; entry++) {
if (strncmp(name, entry->name, len))
continue;
/* Full match */
if (len == strlen(entry->name))
return entry;
}
/* Not found */
return NULL;
}
struct uclass_driver *lists_uclass_lookup(enum uclass_id id)
{
struct uclass_driver *uclass =
ll_entry_start(struct uclass_driver, uclass);
const int n_ents = ll_entry_count(struct uclass_driver, uclass);
struct uclass_driver *entry;
if ((id == UCLASS_INVALID) || !uclass)
return NULL;
for (entry = uclass; entry != uclass + n_ents; entry++) {
if (entry->id == id)
return entry;
}
return NULL;
}
int lists_bind_drivers(struct udevice *parent, bool pre_reloc_only)
{
struct driver_info *info =
ll_entry_start(struct driver_info, driver_info);
const int n_ents = ll_entry_count(struct driver_info, driver_info);
struct driver_info *entry;
struct udevice *dev;
int result = 0;
int ret;
for (entry = info; entry != info + n_ents; entry++) {
ret = device_bind_by_name(parent, pre_reloc_only, entry, &dev);
if (ret && ret != -EPERM) {
dm_warn("No match for driver '%s'\n", entry->name);
if (!result || ret != -ENOENT)
result = ret;
}
}
return result;
}
#ifdef CONFIG_OF_CONTROL
/**
* driver_check_compatible() - Check if a driver is compatible with this node
*
* @param blob: Device tree pointer
* @param offset: Offset of node in device tree
* @param of_matchL List of compatible strings to match
* @return 0 if there is a match, -ENOENT if no match, -ENODEV if the node
* does not have a compatible string, other error <0 if there is a device
* tree error
*/
static int driver_check_compatible(const void *blob, int offset,
const struct udevice_id *of_match)
{
int ret;
if (!of_match)
return -ENOENT;
while (of_match->compatible) {
ret = fdt_node_check_compatible(blob, offset,
of_match->compatible);
if (!ret)
return 0;
else if (ret == -FDT_ERR_NOTFOUND)
return -ENODEV;
else if (ret < 0)
return -EINVAL;
of_match++;
}
return -ENOENT;
}
int lists_bind_fdt(struct udevice *parent, const void *blob, int offset)
{
struct driver *driver = ll_entry_start(struct driver, driver);
const int n_ents = ll_entry_count(struct driver, driver);
struct driver *entry;
struct udevice *dev;
const char *name;
int result = 0;
int ret;
dm_dbg("bind node %s\n", fdt_get_name(blob, offset, NULL));
for (entry = driver; entry != driver + n_ents; entry++) {
ret = driver_check_compatible(blob, offset, entry->of_match);
if (ret == -ENOENT) {
continue;
} else if (ret == -ENODEV) {
break;
} else if (ret) {
dm_warn("Device tree error at offset %d\n", offset);
if (!result || ret != -ENOENT)
result = ret;
break;
}
name = fdt_get_name(blob, offset, NULL);
dm_dbg(" - found match at '%s'\n", entry->name);
ret = device_bind(parent, entry, name, NULL, offset, &dev);
if (ret) {
dm_warn("No match for driver '%s'\n", entry->name);
if (!result || ret != -ENOENT)
result = ret;
}
}
return result;
}
#endif