It is common for one node to reference another via a phandle. Add support for obtaining an attached device by this method. As an example, a node may have a 'power-supply' property which references a regulator, allowing the driver to turn on its power.
Signed-off-by: Simon Glass sjg@chromium.org ---
drivers/core/uclass.c | 42 ++++++++++++++++++++++++++++++++++++++++++ include/dm/uclass.h | 17 +++++++++++++++++ 2 files changed, 59 insertions(+)
diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c index 7de8173..89532db 100644 --- a/drivers/core/uclass.c +++ b/drivers/core/uclass.c @@ -271,6 +271,37 @@ static int uclass_find_device_by_of_offset(enum uclass_id id, int node, return -ENODEV; }
+static int uclass_find_device_by_phandle(enum uclass_id id, + struct udevice *parent, + const char *name, + struct udevice **devp) +{ + struct udevice *dev; + struct uclass *uc; + int find_phandle; + int ret; + + *devp = NULL; + find_phandle = fdtdec_get_int(gd->fdt_blob, parent->of_offset, name, + -1); + if (find_phandle <= 0) + return -ENOENT; + ret = uclass_get(id, &uc); + if (ret) + return ret; + + list_for_each_entry(dev, &uc->dev_head, uclass_node) { + uint phandle = fdt_get_phandle(gd->fdt_blob, dev->of_offset); + + if (phandle == find_phandle) { + *devp = dev; + return 0; + } + } + + return -ENODEV; +} + int uclass_get_device_tail(struct udevice *dev, int ret, struct udevice **devp) { @@ -336,6 +367,17 @@ int uclass_get_device_by_of_offset(enum uclass_id id, int node, return uclass_get_device_tail(dev, ret, devp); }
+int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent, + const char *name, struct udevice **devp) +{ + struct udevice *dev; + int ret; + + *devp = NULL; + ret = uclass_find_device_by_phandle(id, parent, name, &dev); + return uclass_get_device_tail(dev, ret, devp); +} + int uclass_first_device(enum uclass_id id, struct udevice **devp) { struct udevice *dev; diff --git a/include/dm/uclass.h b/include/dm/uclass.h index 4cfc0df..3fe1739 100644 --- a/include/dm/uclass.h +++ b/include/dm/uclass.h @@ -177,6 +177,23 @@ int uclass_get_device_by_of_offset(enum uclass_id id, int node, struct udevice **devp);
/** + * uclass_get_device_by_phandle() - Get a uclass device by phandle + * + * This searches the devices in the uclass for one with the given phandle. + * + * The device is probed to activate it ready for use. + * + * @id: uclass ID to look up + * @parent: Parent device containing the phandle pointer + * @name: Name of property in the parent device node + * @devp: Returns pointer to device (there is only one for each node) + * @return 0 if OK, -ENOENT if there is no @name present in the node, other + * -ve on error + */ +int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent, + const char *name, struct udevice **devp); + +/** * uclass_first_device() - Get the first device in a uclass * * The device returned is probed if necessary, and ready for use