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authorStephen Warren <swarren@nvidia.com>2015-08-06 15:31:02 -0600
committerSimon Glass <sjg@chromium.org>2015-09-15 07:57:13 -0600
commit02464e386bb5f0a022c121f95ae75cf583759d95 (patch)
treedf285b436346479298805f01ffc4dbe33ace1b79 /include/fdtdec.h
parent850f788709cef8f7d53d571aec3bfb73b14c5531 (diff)
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fdt: add new fdt address parsing functions
fdtdec_get_addr_size() hard-codes the number of cells used to represent an address or size in DT. This is incorrect in many cases depending on the DT binding for a particular node or property (e.g. it is incorrect for the "reg" property). In most cases, DT parsing code must use the properties #address-cells and #size-cells to parse addres properties. This change splits up the implementation of fdtdec_get_addr_size() so that the core logic can be used for both hard-coded and non-hard-coded cases. Various wrapper functions are implemented that support cases where hard-coded cell counts should or should not be used, and where the client does and doesn't know the parent node ID that contains the properties #address-cells and #size-cells. dev_get_addr() is updated to use the new functions. Core functionality in fdtdec_get_addr_size_fixed() is widely tested via fdtdec_get_addr_size(). I tested fdtdec_get_addr_size_auto_noparent() and dev_get_addr() by manually modifying the Tegra I2C driver to invoke them. Much of the core implementation of fdtdec_get_addr_size_fixed(), fdtdec_get_addr_size_auto_parent(), and fdtdec_get_addr_size_auto_noparent() comes from Thierry Reding's previous commit "fdt: Fix fdtdec_get_addr_size() for 64-bit". Based-on-work-by: Thierry Reding <treding@nvidia.com> Cc: Thierry Reding <treding@nvidia.com> Cc: Simon Glass <sjg@chromium.org> Cc: Michal Suchanek <hramrach@gmail.com> Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Simon Glass <sjg@chromium.org> Dropped #define DEBUG at the top of fdtdec.c: Signed-off-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'include/fdtdec.h')
-rw-r--r--include/fdtdec.h111
1 files changed, 103 insertions, 8 deletions
diff --git a/include/fdtdec.h b/include/fdtdec.h
index a422ece..2de6dda 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -295,10 +295,90 @@ int fdtdec_next_compatible(const void *blob, int node,
int fdtdec_next_compatible_subnode(const void *blob, int node,
enum fdt_compat_id id, int *depthp);
-/**
- * Look up an address property in a node and return it as an address.
- * The property must hold either one address with no trailing data or
- * one address with a length. This is only tested on 32-bit machines.
+/*
+ * Look up an address property in a node and return the parsed address, and
+ * optionally the parsed size.
+ *
+ * This variant assumes a known and fixed number of cells are used to
+ * represent the address and size.
+ *
+ * You probably don't want to use this function directly except to parse
+ * non-standard properties, and never to parse the "reg" property. Instead,
+ * use one of the "auto" variants below, which automatically honor the
+ * #address-cells and #size-cells properties in the parent node.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param index which address to retrieve from a list of addresses. Often 0.
+ * @param na the number of cells used to represent an address
+ * @param ns the number of cells used to represent a size
+ * @param sizep a pointer to store the size into. Use NULL if not required
+ * @return address, if found, or FDT_ADDR_T_NONE if not
+ */
+fdt_addr_t fdtdec_get_addr_size_fixed(const void *blob, int node,
+ const char *prop_name, int index, int na, int ns,
+ fdt_size_t *sizep);
+
+/*
+ * Look up an address property in a node and return the parsed address, and
+ * optionally the parsed size.
+ *
+ * This variant automatically determines the number of cells used to represent
+ * the address and size by parsing the provided parent node's #address-cells
+ * and #size-cells properties.
+ *
+ * @param blob FDT blob
+ * @param parent parent node of @node
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param index which address to retrieve from a list of addresses. Often 0.
+ * @param sizep a pointer to store the size into. Use NULL if not required
+ * @return address, if found, or FDT_ADDR_T_NONE if not
+ */
+fdt_addr_t fdtdec_get_addr_size_auto_parent(const void *blob, int parent,
+ int node, const char *prop_name, int index, fdt_size_t *sizep);
+
+/*
+ * Look up an address property in a node and return the parsed address, and
+ * optionally the parsed size.
+ *
+ * This variant automatically determines the number of cells used to represent
+ * the address and size by parsing the parent node's #address-cells
+ * and #size-cells properties. The parent node is automatically found.
+ *
+ * The automatic parent lookup implemented by this function is slow.
+ * Consequently, fdtdec_get_addr_size_auto_parent() should be used where
+ * possible.
+ *
+ * @param blob FDT blob
+ * @param parent parent node of @node
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param index which address to retrieve from a list of addresses. Often 0.
+ * @param sizep a pointer to store the size into. Use NULL if not required
+ * @return address, if found, or FDT_ADDR_T_NONE if not
+ */
+fdt_addr_t fdtdec_get_addr_size_auto_noparent(const void *blob, int node,
+ const char *prop_name, int index, fdt_size_t *sizep);
+
+/*
+ * Look up an address property in a node and return the parsed address.
+ *
+ * This variant hard-codes the number of cells used to represent the address
+ * and size based on sizeof(fdt_addr_t) and sizeof(fdt_size_t). It also
+ * always returns the first address value in the property (index 0).
+ *
+ * Use of this function is not recommended due to the hard-coding of cell
+ * counts. There is no programmatic validation that these hard-coded values
+ * actually match the device tree content in any way at all. This assumption
+ * can be satisfied by manually ensuring CONFIG_PHYS_64BIT is appropriately
+ * set in the U-Boot build and exercising strict control over DT content to
+ * ensure use of matching #address-cells/#size-cells properties. However, this
+ * approach is error-prone; those familiar with DT will not expect the
+ * assumption to exist, and could easily invalidate it. If the assumption is
+ * invalidated, this function will not report the issue, and debugging will
+ * be required. Instead, use fdtdec_get_addr_size_auto_parent().
*
* @param blob FDT blob
* @param node node to examine
@@ -308,14 +388,29 @@ int fdtdec_next_compatible_subnode(const void *blob, int node,
fdt_addr_t fdtdec_get_addr(const void *blob, int node,
const char *prop_name);
-/**
- * Look up an address property in a node and return it as an address.
- * The property must hold one address with a length. This is only tested
- * on 32-bit machines.
+/*
+ * Look up an address property in a node and return the parsed address, and
+ * optionally the parsed size.
+ *
+ * This variant hard-codes the number of cells used to represent the address
+ * and size based on sizeof(fdt_addr_t) and sizeof(fdt_size_t). It also
+ * always returns the first address value in the property (index 0).
+ *
+ * Use of this function is not recommended due to the hard-coding of cell
+ * counts. There is no programmatic validation that these hard-coded values
+ * actually match the device tree content in any way at all. This assumption
+ * can be satisfied by manually ensuring CONFIG_PHYS_64BIT is appropriately
+ * set in the U-Boot build and exercising strict control over DT content to
+ * ensure use of matching #address-cells/#size-cells properties. However, this
+ * approach is error-prone; those familiar with DT will not expect the
+ * assumption to exist, and could easily invalidate it. If the assumption is
+ * invalidated, this function will not report the issue, and debugging will
+ * be required. Instead, use fdtdec_get_addr_size_auto_parent().
*
* @param blob FDT blob
* @param node node to examine
* @param prop_name name of property to find
+ * @param sizep a pointer to store the size into. Use NULL if not required
* @return address, if found, or FDT_ADDR_T_NONE if not
*/
fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,