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authorPaul Burton <paul.burton@imgtec.com>2016-09-08 07:47:36 +0100
committerDaniel Schwierzeck <daniel.schwierzeck@gmail.com>2016-09-21 15:04:32 +0200
commitce701721596618afc0affc50f1708ece156891f9 (patch)
tree083c24aed43a6599bfa2dc21223b89e584275565 /drivers/core
parent3bfb8cb43b16aeac138dbdbc1311cd718bbc4066 (diff)
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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>
Diffstat (limited to 'drivers/core')
-rw-r--r--drivers/core/lists.c78
1 files changed, 41 insertions, 37 deletions
diff --git a/drivers/core/lists.c b/drivers/core/lists.c
index 6a634e6..23b6ba7 100644
--- a/drivers/core/lists.c
+++ b/drivers/core/lists.c
@@ -101,36 +101,24 @@ int device_bind_driver_to_node(struct udevice *parent, const char *drv_name,
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
/**
- * driver_check_compatible() - Check if a driver is compatible with this node
+ * driver_check_compatible() - Check if a driver matches a compatible string
*
- * @param blob: Device tree pointer
- * @param offset: Offset of node in device tree
* @param of_match: List of compatible strings to match
* @param of_idp: Returns the match that was found
- * @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
+ * @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 void *blob, int offset,
- const struct udevice_id *of_match,
- const struct udevice_id **of_idp)
+static int driver_check_compatible(const struct udevice_id *of_match,
+ const struct udevice_id **of_idp,
+ const char *compat)
{
- int ret;
-
- *of_idp = NULL;
if (!of_match)
return -ENOENT;
while (of_match->compatible) {
- ret = fdt_node_check_compatible(blob, offset,
- of_match->compatible);
- if (!ret) {
+ if (!strcmp(of_match->compatible, compat)) {
*of_idp = of_match;
return 0;
- } else if (ret == -FDT_ERR_NOTFOUND) {
- return -ENODEV;
- } else if (ret < 0) {
- return -EINVAL;
}
of_match++;
}
@@ -147,28 +135,46 @@ int lists_bind_fdt(struct udevice *parent, const void *blob, int offset,
struct driver *entry;
struct udevice *dev;
bool found = false;
- const char *name;
+ const char *name, *compat_list, *compat;
+ int compat_length, i;
int result = 0;
int ret = 0;
- dm_dbg("bind node %s\n", fdt_get_name(blob, offset, NULL));
+ name = fdt_get_name(blob, offset, NULL);
+ dm_dbg("bind node %s\n", name);
if (devp)
*devp = NULL;
- for (entry = driver; entry != driver + n_ents; entry++) {
- ret = driver_check_compatible(blob, offset, entry->of_match,
- &id);
- name = fdt_get_name(blob, offset, NULL);
- if (ret == -ENOENT) {
- continue;
- } else if (ret == -ENODEV) {
+
+ 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);
- break;
- } else if (ret) {
- dm_warn("Device tree error at offset %d\n", offset);
- result = ret;
- break;
+ 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);
@@ -188,10 +194,8 @@ int lists_bind_fdt(struct udevice *parent, const void *blob, int offset,
break;
}
- if (!found && !result && ret != -ENODEV) {
- dm_dbg("No match for node '%s'\n",
- fdt_get_name(blob, offset, NULL));
- }
+ if (!found && !result && ret != -ENODEV)
+ dm_dbg("No match for node '%s'\n", name);
return result;
}