All the uclass functions for finding a device end up creating a uclass if it doesn't exist. Add a function which instead returns NULL in this case.
This is useful when in the 'unbind' path, since we don't want to undo any unbinding which has already happened.
Signed-off-by: Simon Glass sjg@chromium.org ---
drivers/core/uclass.c | 11 +++++++++++ include/dm/uclass.h | 11 +++++++++++ test/dm/core.c | 22 ++++++++++++++++++++++ 3 files changed, 44 insertions(+)
diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c index 7ae0884a75e..f846a35d6b2 100644 --- a/drivers/core/uclass.c +++ b/drivers/core/uclass.c @@ -304,6 +304,17 @@ int uclass_find_device_by_name(enum uclass_id id, const char *name, return uclass_find_device_by_namelen(id, name, strlen(name), devp); }
+struct udevice *uclass_try_first_device(enum uclass_id id) +{ + struct uclass *uc; + + uc = uclass_find(id); + if (!uc || list_empty(&uc->dev_head)) + return NULL; + + return list_first_entry(&uc->dev_head, struct udevice, uclass_node); +} + int uclass_find_next_free_seq(struct uclass *uc) { struct udevice *dev; diff --git a/include/dm/uclass.h b/include/dm/uclass.h index 456eef7f2f3..c2793040923 100644 --- a/include/dm/uclass.h +++ b/include/dm/uclass.h @@ -435,6 +435,17 @@ int uclass_next_device_check(struct udevice **devp); int uclass_first_device_drvdata(enum uclass_id id, ulong driver_data, struct udevice **devp);
+/** + * uclass_try_first_device()- See if there is a device for a uclass + * + * If the uclass exists, this returns the first device on that uclass, without + * probing it. If the uclass does not exist, it gives up + * + * @id: Uclass ID to check + * Return: Pointer to device, if found, else NULL + */ +struct udevice *uclass_try_first_device(enum uclass_id id); + /** * uclass_probe_all() - Probe all devices based on an uclass ID * diff --git a/test/dm/core.c b/test/dm/core.c index e0c5b9e0017..7371d3ff426 100644 --- a/test/dm/core.c +++ b/test/dm/core.c @@ -1351,3 +1351,25 @@ static int dm_test_dev_get_mem(struct unit_test_state *uts) return 0; } DM_TEST(dm_test_dev_get_mem, UTF_SCAN_FDT); + +/* Test uclass_try_first_device() */ +static int dm_test_try_first_device(struct unit_test_state *uts) +{ + struct udevice *dev; + + /* Check that it doesn't create a device or uclass */ + ut_assertnull(uclass_find(UCLASS_TEST)); + ut_assertnull(uclass_try_first_device(UCLASS_TEST)); + ut_assertnull(uclass_try_first_device(UCLASS_TEST)); + ut_assertnull(uclass_find(UCLASS_TEST)); + + /* Create a test device */ + ut_assertok(device_bind_by_name(uts->root, false, &driver_info_manual, + &dev)); + dev = uclass_try_first_device(UCLASS_TEST); + ut_assertnonnull(dev); + ut_asserteq(UCLASS_TEST, device_get_uclass_id(dev)); + + return 0; +} +DM_TEST(dm_test_try_first_device, 0);