u-boot-brain/drivers/core/lists.c
Paul Burton ce70172159 dm: core: Match compatible strings in order of priority
Device model drivers have previously been matched to FDT nodes by virtue
of being the first driver in the driver list to be compatible with the
node. This ignores the fact that compatible strings in the device tree
are listed in order of priority - that is, if we have a node with 2
compatible strings & a driver that matches each then we should always
probe the driver that matches the first compatible string.

Fix this by looping through the compatible strings for a node when
attempting to bind it in lists_bind_fdt and checking each driver for
a match of the first string, then each driver for a match of the second
string etc. Effectively this inverts the loops over compatible strings &
drivers.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
2016-09-21 15:04:32 +02:00

203 lines
4.9 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;
for (entry = drv; entry != drv + n_ents; entry++) {
if (!strcmp(name, 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;
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;
}
int device_bind_driver(struct udevice *parent, const char *drv_name,
const char *dev_name, struct udevice **devp)
{
return device_bind_driver_to_node(parent, drv_name, dev_name, -1, devp);
}
int device_bind_driver_to_node(struct udevice *parent, const char *drv_name,
const char *dev_name, int node,
struct udevice **devp)
{
struct driver *drv;
int ret;
drv = lists_driver_lookup_name(drv_name);
if (!drv) {
debug("Cannot find driver '%s'\n", drv_name);
return -ENOENT;
}
ret = device_bind(parent, drv, dev_name, NULL, node, devp);
if (ret) {
debug("Cannot create device named '%s' (err=%d)\n",
dev_name, ret);
return ret;
}
return 0;
}
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
/**
* driver_check_compatible() - Check if a driver matches a compatible string
*
* @param of_match: List of compatible strings to match
* @param of_idp: Returns the match that was found
* @param compat: The compatible string to search for
* @return 0 if there is a match, -ENOENT if no match
*/
static int driver_check_compatible(const struct udevice_id *of_match,
const struct udevice_id **of_idp,
const char *compat)
{
if (!of_match)
return -ENOENT;
while (of_match->compatible) {
if (!strcmp(of_match->compatible, compat)) {
*of_idp = of_match;
return 0;
}
of_match++;
}
return -ENOENT;
}
int lists_bind_fdt(struct udevice *parent, const void *blob, int offset,
struct udevice **devp)
{
struct driver *driver = ll_entry_start(struct driver, driver);
const int n_ents = ll_entry_count(struct driver, driver);
const struct udevice_id *id;
struct driver *entry;
struct udevice *dev;
bool found = false;
const char *name, *compat_list, *compat;
int compat_length, i;
int result = 0;
int ret = 0;
name = fdt_get_name(blob, offset, NULL);
dm_dbg("bind node %s\n", name);
if (devp)
*devp = NULL;
compat_list = fdt_getprop(blob, offset, "compatible", &compat_length);
if (!compat_list) {
if (compat_length == -FDT_ERR_NOTFOUND) {
dm_dbg("Device '%s' has no compatible string\n", name);
return 0;
}
dm_warn("Device tree error at offset %d\n", offset);
return compat_length;
}
/*
* Walk through the compatible string list, attempting to match each
* compatible string in order such that we match in order of priority
* from the first string to the last.
*/
for (i = 0; i < compat_length; i += strlen(compat) + 1) {
compat = compat_list + i;
dm_dbg(" - attempt to match compatible string '%s'\n",
compat);
for (entry = driver; entry != driver + n_ents; entry++) {
ret = driver_check_compatible(entry->of_match, &id,
compat);
if (!ret)
break;
}
if (entry == driver + n_ents)
continue;
dm_dbg(" - found match at '%s'\n", entry->name);
ret = device_bind_with_driver_data(parent, entry, name,
id->data, offset, &dev);
if (ret == -ENODEV) {
dm_dbg("Driver '%s' refuses to bind\n", entry->name);
continue;
}
if (ret) {
dm_warn("Error binding driver '%s': %d\n", entry->name,
ret);
return ret;
} else {
found = true;
if (devp)
*devp = dev;
}
break;
}
if (!found && !result && ret != -ENODEV)
dm_dbg("No match for node '%s'\n", name);
return result;
}
#endif