[PATCH v4 07/33] dm: core: Allow finding a uclass device by partial name

Simon Glass
2022-03-06T12:52:19Z

In some cases two devices are related and the only way to tell is to
check that the names partially patch. Add a way to check this without
needing to create a new string for the comparison.

Fix the comment for device_find_child_by_namelen() while we are here.

Signed-off-by: Simon Glass <sjg@chromium.org>
---

Changes in v4:
- Add a test also
- Use new sphynx Return style

Changes in v3:
- Add new patch to support finding a uclass device by partial name

drivers/core/uclass.c | 13 ++++++++++---
include/dm/device.h | 2 +-
include/dm/uclass-internal.h | 16 ++++++++++++++++
test/dm/core.c | 15 +++++++++++++++
4 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c
index 4b9b54f0f1..08d9ed82de 100644
--- a/drivers/core/uclass.c
+++ b/drivers/core/uclass.c
@@ -274,8 +274,8 @@ int uclass_find_next_device(struct udevice **devp)
return 0;
}

-int uclass_find_device_by_name(enum uclass_id id, const char *name,
- struct udevice **devp)
+int uclass_find_device_by_namelen(enum uclass_id id, const char *name, int len,
+ struct udevice **devp)
{
struct uclass *uc;
struct udevice *dev;
@@ -289,7 +289,8 @@ int uclass_find_device_by_name(enum uclass_id id, const char *name,
return ret;

uclass_foreach_dev(dev, uc) {
- if (!strcmp(dev->name, name)) {
+ if (!strncmp(dev->name, name, len) &&
+ strlen(dev->name) == len) {
*devp = dev;
return 0;
}
@@ -298,6 +299,12 @@ int uclass_find_device_by_name(enum uclass_id id, const char *name,
return -ENODEV;
}

+int uclass_find_device_by_name(enum uclass_id id, const char *name,
+ struct udevice **devp)
+{
+ return uclass_find_device_by_namelen(id, name, strlen(name), devp);
+}
+
int uclass_find_next_free_seq(struct uclass *uc)
{
struct udevice *dev;
diff --git a/include/dm/device.h b/include/dm/device.h
index cb52a0997c..4a812bc139 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -791,7 +791,7 @@ int device_find_first_child_by_uclass(const struct udevice *parent,
struct udevice **devp);

/**
- * device_find_child_by_name() - Find a child by device name
+ * device_find_child_by_namelen() - Find a child by device name
*
* @parent: Parent device to search
* @name: Name to look for
diff --git a/include/dm/uclass-internal.h b/include/dm/uclass-internal.h
index e71b86a973..8d0430d677 100644
--- a/include/dm/uclass-internal.h
+++ b/include/dm/uclass-internal.h
@@ -154,6 +154,22 @@ int uclass_find_first_device(enum uclass_id id, struct udevice **devp);
*/
int uclass_find_next_device(struct udevice **devp);

+/**
+ * uclass_find_device_by_namelen() - Find uclass device based on ID and name
+ *
+ * This searches for a device with the exactly given name.
+ *
+ * The device is NOT probed, it is merely returned.
+ *
+ * @id: ID to look up
+ * @name: name of a device to find
+ * @len: Length of @name (the uclass driver name must have the same length)
+ * @devp: Returns pointer to device (the first one with the name)
+ * Return: 0 if OK, -ve on error
+ */
+int uclass_find_device_by_namelen(enum uclass_id id, const char *name, int len,
+ struct udevice **devp);
+
/**
* uclass_find_device_by_name() - Find uclass device based on ID and name
*
diff --git a/test/dm/core.c b/test/dm/core.c
index 2c73ecf54a..ebd504427d 100644
--- a/test/dm/core.c
+++ b/test/dm/core.c
@@ -1260,3 +1260,18 @@ static int dm_test_get_stats(struct unit_test_state *uts)
return 0;
}
DM_TEST(dm_test_get_stats, UT_TESTF_SCAN_FDT);
+
+/* Test uclass_find_device_by_name() */
+static int dm_test_uclass_find_device(struct unit_test_state *uts)
+{
+ struct udevice *dev;
+
+ ut_assertok(uclass_find_device_by_name(UCLASS_I2C, "i2c@0", &dev));
+ ut_asserteq(-ENODEV,
+ uclass_find_device_by_name(UCLASS_I2C, "i2c@0x", &dev));
+ ut_assertok(uclass_find_device_by_namelen(UCLASS_I2C, "i2c@0x", 5,
+ &dev));
+
+ return 0;
+}
+DM_TEST(dm_test_uclass_find_device, UT_TESTF_SCAN_FDT);
--
2.35.1.616.g0bdcbb4464-goog