A common pattern is to call uclass_first_device() and then check if it actually returns a device. Add a new function which does this, returning an error if there are no devices in that uclass.
Signed-off-by: Simon Glass sjg@chromium.org ---
drivers/core/uclass.c | 13 +++++++++++++ include/dm/uclass.h | 15 +++++++++++++-- 2 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c index 12095e7..1141ce1 100644 --- a/drivers/core/uclass.c +++ b/drivers/core/uclass.c @@ -401,6 +401,19 @@ int uclass_first_device(enum uclass_id id, struct udevice **devp) return uclass_get_device_tail(dev, ret, devp); }
+int uclass_first_device_err(enum uclass_id id, struct udevice **devp) +{ + int ret; + + ret = uclass_first_device(id, devp); + if (ret) + return ret; + else if (!*devp) + return -ENODEV; + + return 0; +} + int uclass_next_device(struct udevice **devp) { struct udevice *dev = *devp; diff --git a/include/dm/uclass.h b/include/dm/uclass.h index bfbd27a..fd368b6 100644 --- a/include/dm/uclass.h +++ b/include/dm/uclass.h @@ -200,18 +200,29 @@ int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent, * * @id: Uclass ID to look up * @devp: Returns pointer to the first device in that uclass, or NULL if none - * @return 0 if OK (found or not found), -1 on error + * @return 0 if OK (found or not found), other -ve on error */ int uclass_first_device(enum uclass_id id, struct udevice **devp);
/** + * uclass_first_device_err() - Get the first device in a uclass + * + * The device returned is probed if necessary, and ready for use + * + * @id: Uclass ID to look up + * @devp: Returns pointer to the first device in that uclass, or NULL if none + * @return 0 if found, -ENODEV if not found, other -ve on error + */ +int uclass_first_device_err(enum uclass_id id, struct udevice **devp); + +/** * uclass_next_device() - Get the next device in a uclass * * The device returned is probed if necessary, and ready for use * * @devp: On entry, pointer to device to lookup. On exit, returns pointer * to the next device in the same uclass, or NULL if none - * @return 0 if OK (found or not found), -1 on error + * @return 0 if OK (found or not found), other -ve on error */ int uclass_next_device(struct udevice **devp);