It is common to read a device-tree property from the node associated with a device. Add convenience functions to do this so that drivers do not need to deal with accessing the ofnode from the device. These functions all start with 'dev_read_' to provide consistent naming for all functions which read information from a device's device tree node. These are inlined when using the flat DT to save code size. The live tree implementation is added in a later commit. Signed-off-by: Simon Glass <sjg@chromium.org>master
parent
b7e0d73bad
commit
f11c7ab94d
@ -0,0 +1,383 @@ |
||||
/*
|
||||
* Function to read values from the device tree node attached to a udevice. |
||||
* |
||||
* Copyright (c) 2017 Google, Inc |
||||
* Written by Simon Glass <sjg@chromium.org> |
||||
* |
||||
* SPDX-License-Identifier: GPL-2.0+ |
||||
*/ |
||||
|
||||
#ifndef _DM_READ_H |
||||
#define _DM_READ_H |
||||
|
||||
#include <dm/fdtaddr.h> |
||||
#include <dm/ofnode.h> |
||||
#include <dm/uclass.h> |
||||
|
||||
#if CONFIG_IS_ENABLED(OF_LIVE) |
||||
static inline const struct device_node *dev_np(struct udevice *dev) |
||||
{ |
||||
return ofnode_to_np(dev->node); |
||||
} |
||||
#else |
||||
static inline const struct device_node *dev_np(struct udevice *dev) |
||||
{ |
||||
return NULL; |
||||
} |
||||
#endif |
||||
|
||||
/**
|
||||
* dev_ofnode() - get the DT node reference associated with a udevice |
||||
* |
||||
* @dev: device to check |
||||
* @return reference of the the device's DT node |
||||
*/ |
||||
static inline ofnode dev_ofnode(struct udevice *dev) |
||||
{ |
||||
return dev->node; |
||||
} |
||||
|
||||
static inline bool dev_of_valid(struct udevice *dev) |
||||
{ |
||||
return ofnode_valid(dev_ofnode(dev)); |
||||
} |
||||
|
||||
#ifdef CONFIG_DM_DEV_READ_INLINE |
||||
|
||||
static inline int dev_read_u32_default(struct udevice *dev, |
||||
const char *propname, int def) |
||||
{ |
||||
return ofnode_read_u32_default(dev_ofnode(dev), propname, def); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_string() - Read a string from a device's DT property |
||||
* |
||||
* @dev: device to read DT property from |
||||
* @propname: name of the property to read |
||||
* @return string from property value, or NULL if there is no such property |
||||
*/ |
||||
static inline const char *dev_read_string(struct udevice *dev, |
||||
const char *propname) |
||||
{ |
||||
return ofnode_read_string(dev_ofnode(dev), propname); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_bool() - read a boolean value from a device's DT property |
||||
* |
||||
* @dev: device to read DT property from |
||||
* @propname: name of property to read |
||||
* @return true if property is present (meaning true), false if not present |
||||
*/ |
||||
static inline bool dev_read_bool(struct udevice *dev, const char *propname) |
||||
{ |
||||
return ofnode_read_bool(dev_ofnode(dev), propname); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_subnode() - find a named subnode of a device |
||||
* |
||||
* @dev: device whose DT node contains the subnode |
||||
* @subnode_name: name of subnode to find |
||||
* @return reference to subnode (which can be invalid if there is no such |
||||
* subnode) |
||||
*/ |
||||
static inline ofnode dev_read_subnode(struct udevice *dev, |
||||
const char *subbnode_name) |
||||
{ |
||||
return ofnode_find_subnode(dev_ofnode(dev), subbnode_name); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_size() - read the size of a property |
||||
* |
||||
* @dev: device to check |
||||
* @propname: property to check |
||||
* @return size of property if present, or -EINVAL if not |
||||
*/ |
||||
static inline int dev_read_size(struct udevice *dev, const char *propname) |
||||
{ |
||||
return ofnode_read_size(dev_ofnode(dev), propname); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_addr_index() - Get the indexed reg property of a device |
||||
* |
||||
* @dev: Device to read from |
||||
* @index: the 'reg' property can hold a list of <addr, size> pairs |
||||
* and @index is used to select which one is required |
||||
* |
||||
* @return address or FDT_ADDR_T_NONE if not found |
||||
*/ |
||||
static inline fdt_addr_t dev_read_addr_index(struct udevice *dev, int index) |
||||
{ |
||||
return devfdt_get_addr_index(dev, index); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_addr() - Get the reg property of a device |
||||
* |
||||
* @dev: Device to read from |
||||
* |
||||
* @return address or FDT_ADDR_T_NONE if not found |
||||
*/ |
||||
static inline fdt_addr_t dev_read_addr(struct udevice *dev) |
||||
{ |
||||
return devfdt_get_addr(dev); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_addr_size() - get address and size from a device property |
||||
* |
||||
* This does no address translation. It simply reads an property that contains |
||||
* an address and a size value, one after the other. |
||||
* |
||||
* @dev: Device to read from |
||||
* @propname: property to read |
||||
* @sizep: place to put size value (on success) |
||||
* @return address value, or FDT_ADDR_T_NONE on error |
||||
*/ |
||||
static inline fdt_addr_t dev_read_addr_size(struct udevice *dev, |
||||
const char *propname, |
||||
fdt_size_t *sizep) |
||||
{ |
||||
return ofnode_get_addr_size(dev_ofnode(dev), propname, sizep); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_name() - get the name of a device's node |
||||
* |
||||
* @node: valid node to look up |
||||
* @return name of node |
||||
*/ |
||||
static inline const char *dev_read_name(struct udevice *dev) |
||||
{ |
||||
return ofnode_get_name(dev_ofnode(dev)); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_stringlist_search() - find string in a string list and return index |
||||
* |
||||
* Note that it is possible for this function to succeed on property values |
||||
* that are not NUL-terminated. That's because the function will stop after |
||||
* finding the first occurrence of @string. This can for example happen with |
||||
* small-valued cell properties, such as #address-cells, when searching for |
||||
* the empty string. |
||||
* |
||||
* @dev: device to check |
||||
* @propname: name of the property containing the string list |
||||
* @string: string to look up in the string list |
||||
* |
||||
* @return: |
||||
* the index of the string in the list of strings |
||||
* -ENODATA if the property is not found |
||||
* -EINVAL on some other error |
||||
*/ |
||||
static inline int dev_read_stringlist_search(struct udevice *dev, |
||||
const char *propname, |
||||
const char *string) |
||||
{ |
||||
return ofnode_stringlist_search(dev_ofnode(dev), propname, string); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_phandle_with_args() - Find a node pointed by phandle in a list |
||||
* |
||||
* This function is useful to parse lists of phandles and their arguments. |
||||
* Returns 0 on success and fills out_args, on error returns appropriate |
||||
* errno value. |
||||
* |
||||
* Caller is responsible to call of_node_put() on the returned out_args->np |
||||
* pointer. |
||||
* |
||||
* Example: |
||||
* |
||||
* phandle1: node1 { |
||||
* #list-cells = <2>; |
||||
* } |
||||
* |
||||
* phandle2: node2 { |
||||
* #list-cells = <1>; |
||||
* } |
||||
* |
||||
* node3 { |
||||
* list = <&phandle1 1 2 &phandle2 3>; |
||||
* } |
||||
* |
||||
* To get a device_node of the `node2' node you may call this: |
||||
* dev_read_phandle_with_args(dev, "list", "#list-cells", 0, 1, &args); |
||||
* |
||||
* @dev: device whose node containing a list |
||||
* @list_name: property name that contains a list |
||||
* @cells_name: property name that specifies phandles' arguments count |
||||
* @cells_count: Cell count to use if @cells_name is NULL |
||||
* @index: index of a phandle to parse out |
||||
* @out_args: optional pointer to output arguments structure (will be filled) |
||||
* @return 0 on success (with @out_args filled out if not NULL), -ENOENT if |
||||
* @list_name does not exist, -EINVAL if a phandle was not found, |
||||
* @cells_name could not be found, the arguments were truncated or there |
||||
* were too many arguments. |
||||
*/ |
||||
static inline int dev_read_phandle_with_args(struct udevice *dev, |
||||
const char *list_name, const char *cells_name, int cell_count, |
||||
int index, struct ofnode_phandle_args *out_args) |
||||
{ |
||||
return ofnode_parse_phandle_with_args(dev_ofnode(dev), list_name, |
||||
cells_name, cell_count, index, |
||||
out_args); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_addr_cells() - Get the number of address cells for a device's node |
||||
* |
||||
* This walks back up the tree to find the closest #address-cells property |
||||
* which controls the given node. |
||||
* |
||||
* @dev: devioe to check |
||||
* @return number of address cells this node uses |
||||
*/ |
||||
static inline int dev_read_addr_cells(struct udevice *dev) |
||||
{ |
||||
return fdt_address_cells(gd->fdt_blob, dev_of_offset(dev)); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_size_cells() - Get the number of size cells for a device's node |
||||
* |
||||
* This walks back up the tree to find the closest #size-cells property |
||||
* which controls the given node. |
||||
* |
||||
* @dev: devioe to check |
||||
* @return number of size cells this node uses |
||||
*/ |
||||
static inline int dev_read_size_cells(struct udevice *dev) |
||||
{ |
||||
return fdt_size_cells(gd->fdt_blob, dev_of_offset(dev)); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_phandle() - Get the phandle from a device |
||||
* |
||||
* @dev: device to check |
||||
* @return phandle (1 or greater), or 0 if no phandle or other error |
||||
*/ |
||||
static inline int dev_read_phandle(struct udevice *dev) |
||||
{ |
||||
return fdt_get_phandle(gd->fdt_blob, dev_of_offset(dev)); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_prop()- - read a property from a device's node |
||||
* |
||||
* @dev: device to check |
||||
* @propname: property to read |
||||
* @lenp: place to put length on success |
||||
* @return pointer to property, or NULL if not found |
||||
*/ |
||||
static inline const u32 *dev_read_prop(struct udevice *dev, |
||||
const char *propname, int *lenp) |
||||
{ |
||||
return ofnode_read_prop(dev_ofnode(dev), propname, lenp); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_alias_seq() - Get the alias sequence number of a node |
||||
* |
||||
* This works out whether a node is pointed to by an alias, and if so, the |
||||
* sequence number of that alias. Aliases are of the form <base><num> where |
||||
* <num> is the sequence number. For example spi2 would be sequence number 2. |
||||
* |
||||
* @dev: device to look up |
||||
* @devnump: set to the sequence number if one is found |
||||
* @return 0 if a sequence was found, -ve if not |
||||
*/ |
||||
static inline int dev_read_alias_seq(struct udevice *dev, int *devnump) |
||||
{ |
||||
return fdtdec_get_alias_seq(gd->fdt_blob, dev->uclass->uc_drv->name, |
||||
dev_of_offset(dev), devnump); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_u32_array() - Find and read an array of 32 bit integers |
||||
* |
||||
* Search for a property in a device node and read 32-bit value(s) from |
||||
* it. |
||||
* |
||||
* The out_values is modified only if a valid u32 value can be decoded. |
||||
* |
||||
* @dev: device to look up |
||||
* @propname: name of the property to read |
||||
* @out_values: pointer to return value, modified only if return value is 0 |
||||
* @sz: number of array elements to read |
||||
* @return 0 on success, -EINVAL if the property does not exist, -ENODATA if |
||||
* property does not have a value, and -EOVERFLOW if the property data isn't |
||||
* large enough. |
||||
*/ |
||||
static inline int dev_read_u32_array(struct udevice *dev, const char *propname, |
||||
u32 *out_values, size_t sz) |
||||
{ |
||||
return ofnode_read_u32_array(dev_ofnode(dev), propname, out_values, sz); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_first_subnode() - find the first subnode of a device's node |
||||
* |
||||
* @dev: device to look up |
||||
* @return reference to the first subnode (which can be invalid if the device's |
||||
* node has no subnodes) |
||||
*/ |
||||
static inline ofnode dev_read_first_subnode(struct udevice *dev) |
||||
{ |
||||
return ofnode_first_subnode(dev_ofnode(dev)); |
||||
} |
||||
|
||||
/**
|
||||
* ofnode_next_subnode() - find the next sibling of a subnode |
||||
* |
||||
* @node: valid reference to previous node (sibling) |
||||
* @return reference to the next subnode (which can be invalid if the node |
||||
* has no more siblings) |
||||
*/ |
||||
static inline ofnode dev_read_next_subnode(ofnode node) |
||||
{ |
||||
return ofnode_next_subnode(node); |
||||
} |
||||
|
||||
/**
|
||||
* dev_read_u8_array_ptr() - find an 8-bit array |
||||
* |
||||
* Look up a device's node property and return a pointer to its contents as a |
||||
* byte array of given length. The property must have at least enough data |
||||
* for the array (count bytes). It may have more, but this will be ignored. |
||||
* The data is not copied. |
||||
* |
||||
* @dev: device to look up |
||||
* @propname: name of property to find |
||||
* @sz: number of array elements |
||||
* @return pointer to byte array if found, or NULL if the property is not |
||||
* found or there is not enough data |
||||
*/ |
||||
static inline const uint8_t *dev_read_u8_array_ptr(struct udevice *dev, |
||||
const char *propname, size_t sz) |
||||
{ |
||||
return ofnode_read_u8_array_ptr(dev_ofnode(dev), propname, sz); |
||||
} |
||||
|
||||
#endif /* CONFIG_DM_DEV_READ_INLINE */ |
||||
|
||||
/**
|
||||
* dev_for_each_subnode() - Helper function to iterate through subnodes |
||||
* |
||||
* This creates a for() loop which works through the subnodes in a device's |
||||
* device-tree node. |
||||
* |
||||
* @subnode: ofnode holding the current subnode |
||||
* @dev: device to use for interation (struct udevice *) |
||||
*/ |
||||
#define dev_for_each_subnode(subnode, dev) \ |
||||
for (subnode = dev_read_first_subnode(dev); \
|
||||
ofnode_valid(subnode); \
|
||||
subnode = ofnode_next_subnode(subnode)) |
||||
|
||||
#endif |
Loading…
Reference in new issue