With live tree we need a struct device_node * to reference a node. With the existing flat tree, we need an int offset. We need to unify these into a single value which can represent both.
Add an ofnode union for this and adjust existing code to move to this.
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v3: - Drop struct fdtdec_phandle_args and DECLARE_GLOBAL_DATA_PTR from header
Changes in v2: None
drivers/core/device.c | 2 +- drivers/core/root.c | 2 +- include/dm.h | 1 + include/dm/device.h | 14 +++++--- include/dm/ofnode.h | 96 +++++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 109 insertions(+), 6 deletions(-) create mode 100644 include/dm/ofnode.h
diff --git a/drivers/core/device.c b/drivers/core/device.c index 483f8368f7..2738685092 100644 --- a/drivers/core/device.c +++ b/drivers/core/device.c @@ -60,7 +60,7 @@ static int device_bind_common(struct udevice *parent, const struct driver *drv, dev->platdata = platdata; dev->driver_data = driver_data; dev->name = name; - dev->of_offset = of_offset; + dev->node = offset_to_ofnode(of_offset); dev->parent = parent; dev->driver = drv; dev->uclass = uc; diff --git a/drivers/core/root.c b/drivers/core/root.c index 4bb71f3cac..570b4d855f 100644 --- a/drivers/core/root.c +++ b/drivers/core/root.c @@ -167,7 +167,7 @@ int dm_init(void) if (ret) return ret; #if CONFIG_IS_ENABLED(OF_CONTROL) - DM_ROOT_NON_CONST->of_offset = 0; + DM_ROOT_NON_CONST->node = offset_to_ofnode(0); #endif ret = device_probe(DM_ROOT_NON_CONST); if (ret) diff --git a/include/dm.h b/include/dm.h index 84f789d807..e634814d74 100644 --- a/include/dm.h +++ b/include/dm.h @@ -7,6 +7,7 @@ #ifndef _DM_H_ #define _DM_H_
+#include <dm/ofnode.h> #include <dm/device.h> #include <dm/fdtaddr.h> #include <dm/platdata.h> diff --git a/include/dm/device.h b/include/dm/device.h index 361cdaee48..489cf33987 100644 --- a/include/dm/device.h +++ b/include/dm/device.h @@ -11,6 +11,7 @@ #ifndef _DM_DEVICE_H #define _DM_DEVICE_H
+#include <dm/ofnode.h> #include <dm/uclass-id.h> #include <fdtdec.h> #include <linker_lists.h> @@ -103,7 +104,7 @@ enum { * @platdata: Configuration data for this device * @parent_platdata: The parent bus's configuration data for this device * @uclass_platdata: The uclass's configuration data for this device - * @of_offset: Device tree node offset for this device (- for none) + * @node: Reference to device tree node for this device * @driver_data: Driver data word for the entry that matched this device with * its driver * @parent: Parent of this device, or NULL for the top level device @@ -129,7 +130,7 @@ struct udevice { void *platdata; void *parent_platdata; void *uclass_platdata; - int of_offset; + ofnode node; ulong driver_data; struct udevice *parent; void *priv; @@ -158,12 +159,17 @@ struct udevice {
static inline int dev_of_offset(const struct udevice *dev) { - return dev->of_offset; + return ofnode_to_offset(dev->node); }
static inline void dev_set_of_offset(struct udevice *dev, int of_offset) { - dev->of_offset = of_offset; + dev->node = offset_to_ofnode(of_offset); +} + +static inline bool dev_has_of_node(struct udevice *dev) +{ + return ofnode_valid(dev->node); }
/** diff --git a/include/dm/ofnode.h b/include/dm/ofnode.h new file mode 100644 index 0000000000..ed362e134e --- /dev/null +++ b/include/dm/ofnode.h @@ -0,0 +1,96 @@ +/* + * Copyright (c) 2017 Google, Inc + * Written by Simon Glass sjg@chromium.org + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef _DM_OFNODE_H +#define _DM_OFNODE_H + +/** + * ofnode - reference to a device tree node + * + * This union can hold either a straightforward pointer to a struct device_node + * in the live device tree, or an offset within the flat device tree. In the + * latter case, the pointer value is just the integer offset within the flat DT. + * + * Thus we can reference nodes in both the live tree (once available) and the + * flat tree (until then). Functions are available to translate between an + * ofnode and either an offset or a struct device_node *. + * + * The reference can also hold a null offset, in which case the pointer value + * here is (void *)-1. This corresponds to a struct device_node * value of + * NULL, or an offset of -1. + * + * There is no ambiguity as to whether ofnode holds an offset or a node + * pointer: when the live tree is active it holds a node pointer, otherwise it + * holds an offset. The value itself does not need to be unique and in theory + * the same value could point to a valid device node or a valid offset. We + * could arrange for a unique value to be used (e.g. by making the pointer + * point to an offset within the flat device tree in the case of an offset) but + * this increases code size slightly due to the subtraction. Since it offers no + * real benefit, the approach described here seems best. + * + * For now these points use constant types, since we don't allow writing + * the DT. + * + * @np: Pointer to device node, used for live tree + * @flat_ptr: Pointer into flat device tree, used for flat tree. Note that this + * is not a really a pointer to a node: it is an offset value. See above. + */ +typedef union ofnode_union { + const struct device_node *np; /* will be used for future live tree */ + long of_offset; +} ofnode; + +/** + * ofnode_to_offset() - convert an ofnode to a flat DT offset + * + * This cannot be called if the reference contains a node pointer. + * + * @node: Reference containing offset (possibly invalid) + * @return DT offset (can be -1) + */ +static inline int ofnode_to_offset(ofnode node) +{ + return node.of_offset; +} + +/** + * ofnode_valid() - check if an ofnode is valid + * + * @return true if the reference contains a valid ofnode, false if it is NULL + */ +static inline bool ofnode_valid(ofnode node) +{ + return node.of_offset != -1; +} + +/** + * offset_to_ofnode() - convert a DT offset to an ofnode + * + * @of_offset: DT offset (either valid, or -1) + * @return reference to the associated DT offset + */ +static inline ofnode offset_to_ofnode(int of_offset) +{ + ofnode node; + + node.of_offset = of_offset; + + return node; +} + +/** + * ofnode_equal() - check if two references are equal + * + * @return true if equal, else false + */ +static inline bool ofnode_equal(ofnode ref1, ofnode ref2) +{ + /* We only need to compare the contents */ + return ref1.of_offset == ref2.of_offset; +} + +#endif