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Re: [Xen-devel] [PATCH V1 09/29] xen/dts: Add new helpers to use the device tree
On 09/06/2013 05:31 PM, Ian Campbell wrote:
On Wed, 2013-08-28 at 15:47 +0100, Julien Grall wrote:
List of new helpers taken from linux (commit 74b9272):
- dt_property_read_string
- dt_match_node
- dt_find_maching_node
- dt_device_is_available
- dt_prop_cmp
Other new helpers:
- dt_set_cell
- for_each_child
This seems too generic. Perhaps dt_for_each_child or for_each_dt_child?
Right, I will rename the function to dt_for_each_child.
- dt_set_range
- dt_cells_to_size
- dt_next_cell
- dt_get_range
- dt_node_name_is_equal
- dt_node_path_is_equal
- dt_property_name_is_equal
Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
---
Changes in v2:
- Update commit message
- Add for_each_child
- Add dt_get_range
- Update documentation
- Typoes
---
xen/common/device_tree.c | 109 +++++++++++++++++++++++++++--
xen/include/xen/device_tree.h | 151 ++++++++++++++++++++++++++++++++++++++++-
2 files changed, 252 insertions(+), 8 deletions(-)
diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c
index 07a19ac..833d67d 100644
--- a/xen/common/device_tree.c
+++ b/xen/common/device_tree.c
@@ -182,23 +182,38 @@ void __init device_tree_get_reg(const u32 **cell, u32
address_cells,
get_val(cell, size_cells, size);
}
-static void __init set_val(u32 **cell, u32 cells, u64 val)
+void dt_get_range(const __be32 **cell, const struct dt_device_node *np,
+ u64 *address, u64 *size)
{
- u32 c = cells;
+ *address = dt_next_cell(dt_n_addr_cells(np), cell);
+ *size = dt_next_cell(dt_n_size_cells(np), cell);
+}
+
+void dt_set_cell(__be32 **cellp, int size, u64 val)
+{
+ int cells = size;
- while ( c-- )
+ while ( size-- )
{
- (*cell)[c] = cpu_to_fdt32(val);
+ (*cellp)[size] = cpu_to_fdt32(val);
val >>= 32;
}
- (*cell) += cells;
+
+ (*cellp) += cells;
}
void __init device_tree_set_reg(u32 **cell, u32 address_cells, u32 size_cells,
u64 start, u64 size)
{
- set_val(cell, address_cells, start);
- set_val(cell, size_cells, size);
+ dt_set_cell(cell, address_cells, start);
+ dt_set_cell(cell, size_cells, size);
+}
+
+void dt_set_range(__be32 **cellp, const struct dt_device_node *np,
+ u64 address, u64 size)
+{
+ dt_set_cell(cellp, dt_n_addr_cells(np), address);
+ dt_set_cell(cellp, dt_n_size_cells(np), size);
}
u32 __init device_tree_get_u32(const void *fdt, int node, const char
*prop_name,
@@ -583,6 +598,23 @@ bool_t dt_property_read_u32(const struct dt_device_node
*np,
return 1;
}
+int dt_property_read_string(const struct dt_device_node *np,
+ const char *propname, const char **out_string)
+{
+ const struct dt_property *pp = dt_find_property(np, propname, NULL);
+
+ if ( !pp )
+ return -EINVAL;
+ if ( !pp->value )
+ return -ENODATA;
+ if ( strnlen(pp->value, pp->length) >= pp->length )
+ return -EILSEQ;
+
+ *out_string = pp->value;
+
+ return 0;
+}
+
bool_t dt_device_is_compatible(const struct dt_device_node *device,
const char *compat)
{
@@ -655,6 +687,34 @@ struct dt_device_node *dt_find_node_by_alias(const char
*alias)
return NULL;
}
+bool_t dt_match_node(const struct dt_device_match *matches,
+ const struct dt_device_node *node)
+{
+ if ( !matches )
+ return 0;
+
+ while ( matches->path || matches->type || matches->compatible )
+ {
+ bool_t match = 1;
+
+ if ( matches->path )
+ match &= dt_node_path_is_equal(node, matches->path);
+
+ if ( matches->type )
+ match &= dt_device_type_is_equal(node, matches->type);
+
+ if ( matches->compatible )
+ match &= dt_device_is_compatible(node, matches->compatible);
+
+ if ( match )
+ return match;
+
+ matches++;
+ }
+
+ return 0;
+}
+
const struct dt_device_node *dt_get_parent(const struct dt_device_node *node)
{
if ( !node )
@@ -684,6 +744,23 @@ dt_find_compatible_node(struct dt_device_node *from,
return np;
}
+struct dt_device_node *
+dt_find_matching_node(struct dt_device_node *from,
+ const struct dt_device_match *matches)
+{
+ struct dt_device_node *np;
+ struct dt_device_node *dt;
+
+ dt = from ? from->allnext : dt_host;
+ for_each_device_node(dt, np)
+ {
+ if ( dt_match_node(matches, np) )
+ return np;
+ }
+
+ return NULL;
+}
+
int dt_n_addr_cells(const struct dt_device_node *np)
{
const __be32 *ip;
@@ -1372,6 +1449,24 @@ int dt_device_get_irq(const struct dt_device_node
*device, int index,
return dt_irq_translate(&raw, out_irq);
}
+bool_t dt_device_is_available(const struct dt_device_node *device)
+{
+ const char *status;
+ u32 statlen;
+
+ status = dt_get_property(device, "status", &statlen);
+ if ( status == NULL )
+ return 1;
+
+ if ( statlen > 0 )
+ {
+ if ( !strcmp(status, "okay") || !strcmp(status, "ok") )
+ return 1;
+ }
+
+ return 0;
+}
+
/**
* unflatten_dt_node - Alloc and populate a device_node from the flat tree
* @fdt: The parent device tree blob
diff --git a/xen/include/xen/device_tree.h b/xen/include/xen/device_tree.h
index 7cbf736..fa4f314 100644
--- a/xen/include/xen/device_tree.h
+++ b/xen/include/xen/device_tree.h
@@ -54,6 +54,19 @@ struct dt_early_info {
struct dt_module_info modules;
};
+/*
+ * Struct used for matching a device
+ */
+struct dt_device_match {
+ const char *path;
+ const char *type;
+ const char *compatible;
+};
+
+#define DT_MATCH_PATH(p) { .path = p }
+#define DT_MATCH_TYPE(typ) { .type = typ }
+#define DT_MATCH_COMPATIBLE(compat) { .compatible = compat }
+
typedef u32 dt_phandle;
/**
@@ -229,6 +242,7 @@ extern const struct dt_device_node *dt_interrupt_controller;
*/
struct dt_device_node * __init dt_find_interrupt_controller(const char
*compat);
+#define dt_prop_cmp(s1, s2) strcmp((s1), (s2))
#define dt_node_cmp(s1, s2) strcasecmp((s1), (s2))
#define dt_compat_cmp(s1, s2) strcasecmp((s1), (s2))
@@ -242,6 +256,9 @@ struct dt_device_node * __init
dt_find_interrupt_controller(const char *compat);
#define for_each_device_node(dt, dn) \
for ( dn = dt; dn != NULL; dn = dn->allnext )
+#define for_each_child_node(dt, dn) \
+ for ( dn = dt->child; dn != NULL; dn = dn->sibling )
+
/* Helper to read a big number; size is in cells (not bytes) */
static inline u64 dt_read_number(const __be32 *cell, int size)
{
@@ -252,6 +269,20 @@ static inline u64 dt_read_number(const __be32 *cell, int
size)
return r;
}
+/* Helper to convert a number of cells in bytes */
+static inline int dt_cells_to_size(int size)
+{
+ return (size * sizeof (u32));
+}
+
+static inline u64 dt_next_cell(int s, const __be32 **cellp)
+{
+ const __be32 *p = *cellp;
+
+ *cellp = p + s;
+ return dt_read_number(p, s);
+}
+
static inline const char *dt_node_full_name(const struct dt_device_node *np)
{
return (np && np->full_name) ? np->full_name : "<no-node>";
@@ -262,6 +293,18 @@ static inline const char *dt_node_name(const struct
dt_device_node *np)
return (np && np->name) ? np->name : "<no-node>";
}
+static inline bool_t dt_node_name_is_equal(const struct dt_device_node *np,
+ const char *name)
+{
+ return !dt_node_cmp(np->name, name);
+}
+
+static inline bool_t dt_node_path_is_equal(const struct dt_device_node *np,
+ const char *path)
+{
+ return !dt_node_cmp(np->full_name, path);
+}
+
static inline bool_t
dt_device_type_is_equal(const struct dt_device_node *device,
const char *type)
@@ -281,6 +324,12 @@ static inline domid_t dt_device_used_by(const struct
dt_device_node *device)
return device->used_by;
}
+static inline bool_t dt_property_name_is_equal(const struct dt_property *pp,
+ const char *name)
+{
+ return !dt_prop_cmp(pp->name, name);
+}
+
/**
* dt_find_compatible_node - Find a node based on type and one of the
* tokens in its "compatible" property
@@ -315,6 +364,23 @@ const void *dt_get_property(const struct dt_device_node
*np,
*/
bool_t dt_property_read_u32(const struct dt_device_node *np,
const char *name, u32 *out_value);
+/**
+ * dt_property_read_string - Find and read a string from a property
+ * @np: Device node from which the property value is to be read
+ * @propname: Name of the property to be searched
+ * @out_string: Pointer to null terminated return string, modified only
+ * if return value if 0.
+ *
+ * Search for a property in a device tree node and retrieve a null
+ * terminated string value (pointer to data, not a copy). Returns 0 on
+ * success, -EINVAL if the property does not exist, -ENODATA if property
+ * doest not have value, and -EILSEQ if the string is not
+ * null-terminated with the length of the property data.
+ *
+ * The out_string pointer is modified only if a valid string can be decoded.
+ */
+int dt_property_read_string(const struct dt_device_node *np,
+ const char *propname, const char **out_string);
/**
* Checks if the given "compat" string matches one of the strings in
@@ -450,4 +516,87 @@ int dt_n_size_cells(const struct dt_device_node *np);
*/
int dt_n_addr_cells(const struct dt_device_node *np);
-#endif
+/**
+ * dt_device_is_available - Check if a device is available for use
+ *
+ * @device: Node to check for availability
+ *
+ * Returns true if the status property is absent or set to "okay" or "ok",
+ * false otherwise.
+ */
+bool_t dt_device_is_available(const struct dt_device_node *device);
+
+/**
+ * dt_match_node - Tell if a device_node has a matching of dt_device_match
+ * @matches: array of dt_device_match structures to search in
+ * @node: the dt_device_node structure to match against
+ *
+ * Returns true if the device node match one of dt_device_match.
+ */
+bool_t dt_match_node(const struct dt_device_match *matches,
+ const struct dt_device_node *node);
+
+/**
+ * dt_find_matching_node - Find a node based on an dt_device_match match table
+ * @from: The node to start searching from or NULL, the node you pass
+ * will not be searched, only the next one will; typically, you pass
+ * what the returned call returned
+ * @matches: array of dt_device_match structures to search in
+ *
+ * Returns a node pointer.
+ */
+struct dt_device_node *
+dt_find_matching_node(struct dt_device_node *from,
+ const struct dt_device_match *matches);
+
+/**
+ * dt_set_cell - Write a value into a series of cells
+ *
+ * @cellp: Pointer to cells
+ * @size: number of cells to write the value
+ * @value: number to write
+ *
+ * Write a value into a series of cells and update cellp to point to the
+ * cell just after.
+ */
+void dt_set_cell(__be32 **cellp, int size, u64 val);
+
+/**
+ * dt_set_range - Write range into a series of cells
+ *
+ * @cellp: Pointer to cells
+ * @np: Node which contains the encoding for the address and the size
+ * @address: Start of range
+ * @size: Size of the range
+ *
+ * Write a range into a series of cells and update cellp to point to the
+ * cell just after.
+ */
+void dt_set_range(__be32 **cellp, const struct dt_device_node *np,
+ u64 address, u64 size);
+
+/**
+ * dt_get_range - Read a range (address/size) from a series of cells
+ *
+ * @cellp: Pointer to cells
+ * @np Node which contains the encoding for the addresss and the size
+ * @address: Address filled by this function
+ * @size: Size filled by this function
+ *
+ * WARNING: This function should not be used to decode an address
+ * This function reads a range (address/size) from a series of cells and
+ * update cellp to point to the cell just after.
+ */
+void dt_get_range(const __be32 **cellp, const struct dt_device_node *np,
+ u64 *address, u64 *size);
+
+#endif /* __XEN_DEVICE_TREE_H */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
--
Julien Grall
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