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authorSimon Glass <sjg@chromium.org>2014-07-23 06:55:03 -0600
committerSimon Glass <sjg@chromium.org>2014-07-23 14:07:24 +0100
commit00606d7e39da4a8ecfbbc19d5af252bdfdd1fcc9 (patch)
tree53f8d51b84e75120a3b673946e515ffcbe250ceb /drivers/core
parent6133683320ece056e49051e52a180adb21992b40 (diff)
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>
Diffstat (limited to 'drivers/core')
-rw-r--r--drivers/core/device.c6
-rw-r--r--drivers/core/lists.c6
-rw-r--r--drivers/core/root.c11
3 files changed, 14 insertions, 9 deletions
diff --git a/drivers/core/device.c b/drivers/core/device.c
index c73c339d18c..86b9ff89111 100644
--- a/drivers/core/device.c
+++ b/drivers/core/device.c
@@ -129,14 +129,16 @@ fail_bind:
return ret;
}
-int device_bind_by_name(struct udevice *parent, const struct driver_info *info,
- struct udevice **devp)
+int device_bind_by_name(struct udevice *parent, bool pre_reloc_only,
+ const struct driver_info *info, struct udevice **devp)
{
struct driver *drv;
drv = lists_driver_lookup_name(info->name);
if (!drv)
return -ENOENT;
+ if (pre_reloc_only && !(drv->flags & DM_FLAG_PRE_RELOC))
+ return -EPERM;
return device_bind(parent, drv, info->name, (void *)info->platdata,
-1, devp);
diff --git a/drivers/core/lists.c b/drivers/core/lists.c
index 87164a5cf9a..5f1c85fd6e4 100644
--- a/drivers/core/lists.c
+++ b/drivers/core/lists.c
@@ -62,7 +62,7 @@ struct uclass_driver *lists_uclass_lookup(enum uclass_id id)
return NULL;
}
-int lists_bind_drivers(struct udevice *parent)
+int lists_bind_drivers(struct udevice *parent, bool pre_reloc_only)
{
struct driver_info *info =
ll_entry_start(struct driver_info, driver_info);
@@ -73,8 +73,8 @@ int lists_bind_drivers(struct udevice *parent)
int ret;
for (entry = info; entry != info + n_ents; entry++) {
- ret = device_bind_by_name(parent, entry, &dev);
- if (ret) {
+ 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;
diff --git a/drivers/core/root.c b/drivers/core/root.c
index 346d462470e..ce4eef30540 100644
--- a/drivers/core/root.c
+++ b/drivers/core/root.c
@@ -46,7 +46,7 @@ int dm_init(void)
}
INIT_LIST_HEAD(&DM_UCLASS_ROOT_NON_CONST);
- ret = device_bind_by_name(NULL, &root_info, &DM_ROOT_NON_CONST);
+ ret = device_bind_by_name(NULL, false, &root_info, &DM_ROOT_NON_CONST);
if (ret)
return ret;
ret = device_probe(DM_ROOT_NON_CONST);
@@ -64,11 +64,11 @@ int dm_uninit(void)
return 0;
}
-int dm_scan_platdata(void)
+int dm_scan_platdata(bool pre_reloc_only)
{
int ret;
- ret = lists_bind_drivers(DM_ROOT_NON_CONST);
+ ret = lists_bind_drivers(DM_ROOT_NON_CONST, pre_reloc_only);
if (ret == -ENOENT) {
dm_warn("Some drivers were not found\n");
ret = 0;
@@ -80,7 +80,7 @@ int dm_scan_platdata(void)
}
#ifdef CONFIG_OF_CONTROL
-int dm_scan_fdt(const void *blob)
+int dm_scan_fdt(const void *blob, bool pre_reloc_only)
{
int offset = 0;
int ret = 0, err;
@@ -89,6 +89,9 @@ int dm_scan_fdt(const void *blob)
do {
offset = fdt_next_node(blob, offset, &depth);
if (offset > 0 && depth == 1) {
+ if (pre_reloc_only &&
+ !fdt_getprop(blob, offset, "u-boot,dm-pre-reloc", NULL))
+ continue;
err = lists_bind_fdt(gd->dm_root, blob, offset);
if (err && !ret)
ret = err;