- 根目录:
- drivers
- base
- property.c
/*
* property.c - Unified device property interface.
*
* Copyright (C) 2014, Intel Corporation
* Authors: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* Mika Westerberg <mika.westerberg@linux.intel.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/acpi.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/property.h>
#include <linux/etherdevice.h>
#include <linux/phy.h>
/**
* device_add_property_set - Add a collection of properties to a device object.
* @dev: Device to add properties to.
* @pset: Collection of properties to add.
*
* Associate a collection of device properties represented by @pset with @dev
* as its secondary firmware node.
*/
void device_add_property_set(struct device *dev, struct property_set *pset)
{
if (!pset)
return;
pset->fwnode.type = FWNODE_PDATA;
set_secondary_fwnode(dev, &pset->fwnode);
}
EXPORT_SYMBOL_GPL(device_add_property_set);
static inline bool is_pset(struct fwnode_handle *fwnode)
{
return fwnode && fwnode->type == FWNODE_PDATA;
}
static inline struct property_set *to_pset(struct fwnode_handle *fwnode)
{
return is_pset(fwnode) ?
container_of(fwnode, struct property_set, fwnode) : NULL;
}
static struct property_entry *pset_prop_get(struct property_set *pset,
const char *name)
{
struct property_entry *prop;
if (!pset || !pset->properties)
return NULL;
for (prop = pset->properties; prop->name; prop++)
if (!strcmp(name, prop->name))
return prop;
return NULL;
}
static int pset_prop_read_array(struct property_set *pset, const char *name,
enum dev_prop_type type, void *val, size_t nval)
{
struct property_entry *prop;
unsigned int item_size;
prop = pset_prop_get(pset, name);
if (!prop)
return -ENODATA;
if (prop->type != type)
return -EPROTO;
if (!val)
return prop->nval;
if (prop->nval < nval)
return -EOVERFLOW;
switch (type) {
case DEV_PROP_U8:
item_size = sizeof(u8);
break;
case DEV_PROP_U16:
item_size = sizeof(u16);
break;
case DEV_PROP_U32:
item_size = sizeof(u32);
break;
case DEV_PROP_U64:
item_size = sizeof(u64);
break;
case DEV_PROP_STRING:
item_size = sizeof(const char *);
break;
default:
return -EINVAL;
}
memcpy(val, prop->value.raw_data, nval * item_size);
return 0;
}
static inline struct fwnode_handle *dev_fwnode(struct device *dev)
{
return IS_ENABLED(CONFIG_OF) && dev->of_node ?
&dev->of_node->fwnode : dev->fwnode;
}
/**
* device_property_present - check if a property of a device is present
* @dev: Device whose property is being checked
* @propname: Name of the property
*
* Check if property @propname is present in the device firmware description.
*/
bool device_property_present(struct device *dev, const char *propname)
{
return fwnode_property_present(dev_fwnode(dev), propname);
}
EXPORT_SYMBOL_GPL(device_property_present);
/**
* fwnode_property_present - check if a property of a firmware node is present
* @fwnode: Firmware node whose property to check
* @propname: Name of the property
*/
bool fwnode_property_present(struct fwnode_handle *fwnode, const char *propname)
{
if (is_of_node(fwnode))
return of_property_read_bool(to_of_node(fwnode), propname);
else if (is_acpi_node(fwnode))
return !acpi_node_prop_get(fwnode, propname, NULL);
return !!pset_prop_get(to_pset(fwnode), propname);
}
EXPORT_SYMBOL_GPL(fwnode_property_present);
/**
* device_property_read_u8_array - return a u8 array property of a device
* @dev: Device to get the property of
* @propname: Name of the property
* @val: The values are stored here or %NULL to return the number of values
* @nval: Size of the @val array
*
* Function reads an array of u8 properties with @propname from the device
* firmware description and stores them to @val if found.
*
* Return: number of values if @val was %NULL,
* %0 if the property was found (success),
* %-EINVAL if given arguments are not valid,
* %-ENODATA if the property does not have a value,
* %-EPROTO if the property is not an array of numbers,
* %-EOVERFLOW if the size of the property is not as expected.
* %-ENXIO if no suitable firmware interface is present.
*/
int device_property_read_u8_array(struct device *dev, const char *propname,
u8 *val, size_t nval)
{
return fwnode_property_read_u8_array(dev_fwnode(dev), propname, val, nval);
}
EXPORT_SYMBOL_GPL(device_property_read_u8_array);
/**
* device_property_read_u16_array - return a u16 array property of a device
* @dev: Device to get the property of
* @propname: Name of the property
* @val: The values are stored here or %NULL to return the number of values
* @nval: Size of the @val array
*
* Function reads an array of u16 properties with @propname from the device
* firmware description and stores them to @val if found.
*
* Return: number of values if @val was %NULL,
* %0 if the property was found (success),
* %-EINVAL if given arguments are not valid,
* %-ENODATA if the property does not have a value,
* %-EPROTO if the property is not an array of numbers,
* %-EOVERFLOW if the size of the property is not as expected.
* %-ENXIO if no suitable firmware interface is present.
*/
int device_property_read_u16_array(struct device *dev, const char *propname,
u16 *val, size_t nval)
{
return fwnode_property_read_u16_array(dev_fwnode(dev), propname, val, nval);
}
EXPORT_SYMBOL_GPL(device_property_read_u16_array);
/**
* device_property_read_u32_array - return a u32 array property of a device
* @dev: Device to get the property of
* @propname: Name of the property
* @val: The values are stored here or %NULL to return the number of values
* @nval: Size of the @val array
*
* Function reads an array of u32 properties with @propname from the device
* firmware description and stores them to @val if found.
*
* Return: number of values if @val was %NULL,
* %0 if the property was found (success),
* %-EINVAL if given arguments are not valid,
* %-ENODATA if the property does not have a value,
* %-EPROTO if the property is not an array of numbers,
* %-EOVERFLOW if the size of the property is not as expected.
* %-ENXIO if no suitable firmware interface is present.
*/
int device_property_read_u32_array(struct device *dev, const char *propname,
u32 *val, size_t nval)
{
return fwnode_property_read_u32_array(dev_fwnode(dev), propname, val, nval);
}
EXPORT_SYMBOL_GPL(device_property_read_u32_array);
/**
* device_property_read_u64_array - return a u64 array property of a device
* @dev: Device to get the property of
* @propname: Name of the property
* @val: The values are stored here or %NULL to return the number of values
* @nval: Size of the @val array
*
* Function reads an array of u64 properties with @propname from the device
* firmware description and stores them to @val if found.
*
* Return: number of values if @val was %NULL,
* %0 if the property was found (success),
* %-EINVAL if given arguments are not valid,
* %-ENODATA if the property does not have a value,
* %-EPROTO if the property is not an array of numbers,
* %-EOVERFLOW if the size of the property is not as expected.
* %-ENXIO if no suitable firmware interface is present.
*/
int device_property_read_u64_array(struct device *dev, const char *propname,
u64 *val, size_t nval)
{
return fwnode_property_read_u64_array(dev_fwnode(dev), propname, val, nval);
}
EXPORT_SYMBOL_GPL(device_property_read_u64_array);
/**
* device_property_read_string_array - return a string array property of device
* @dev: Device to get the property of
* @propname: Name of the property
* @val: The values are stored here or %NULL to return the number of values
* @nval: Size of the @val array
*
* Function reads an array of string properties with @propname from the device
* firmware description and stores them to @val if found.
*
* Return: number of values if @val was %NULL,
* %0 if the property was found (success),
* %-EINVAL if given arguments are not valid,
* %-ENODATA if the property does not have a value,
* %-EPROTO or %-EILSEQ if the property is not an array of strings,
* %-EOVERFLOW if the size of the property is not as expected.
* %-ENXIO if no suitable firmware interface is present.
*/
int device_property_read_string_array(struct device *dev, const char *propname,
const char **val, size_t nval)
{
return fwnode_property_read_string_array(dev_fwnode(dev), propname, val, nval);
}
EXPORT_SYMBOL_GPL(device_property_read_string_array);
/**
* device_property_read_string - return a string property of a device
* @dev: Device to get the property of
* @propname: Name of the property
* @val: The value is stored here
*
* Function reads property @propname from the device firmware description and
* stores the value into @val if found. The value is checked to be a string.
*
* Return: %0 if the property was found (success),
* %-EINVAL if given arguments are not valid,
* %-ENODATA if the property does not have a value,
* %-EPROTO or %-EILSEQ if the property type is not a string.
* %-ENXIO if no suitable firmware interface is present.
*/
int device_property_read_string(struct device *dev, const char *propname,
const char **val)
{
return fwnode_property_read_string(dev_fwnode(dev), propname, val);
}
EXPORT_SYMBOL_GPL(device_property_read_string);
/**
* device_property_match_string - find a string in an array and return index
* @dev: Device to get the property of
* @propname: Name of the property holding the array
* @string: String to look for
*
* Find a given string in a string array and if it is found return the
* index back.
*
* Return: %0 if the property was found (success),
* %-EINVAL if given arguments are not valid,
* %-ENODATA if the property does not have a value,
* %-EPROTO if the property is not an array of strings,
* %-ENXIO if no suitable firmware interface is present.
*/
int device_property_match_string(struct device *dev, const char *propname,
const char *string)
{
return fwnode_property_match_string(dev_fwnode(dev), propname, string);
}
EXPORT_SYMBOL_GPL(device_property_match_string);
#define OF_DEV_PROP_READ_ARRAY(node, propname, type, val, nval) \
(val) ? of_property_read_##type##_array((node), (propname), (val), (nval)) \
: of_property_count_elems_of_size((node), (propname), sizeof(type))
#define FWNODE_PROP_READ_ARRAY(_fwnode_, _propname_, _type_, _proptype_, _val_, _nval_) \
({ \
int _ret_; \
if (is_of_node(_fwnode_)) \
_ret_ = OF_DEV_PROP_READ_ARRAY(to_of_node(_fwnode_), _propname_, \
_type_, _val_, _nval_); \
else if (is_acpi_node(_fwnode_)) \
_ret_ = acpi_node_prop_read(_fwnode_, _propname_, _proptype_, \
_val_, _nval_); \
else if (is_pset(_fwnode_)) \
_ret_ = pset_prop_read_array(to_pset(_fwnode_), _propname_, \
_proptype_, _val_, _nval_); \
else \
_ret_ = -ENXIO; \
_ret_; \
})
/**
* fwnode_property_read_u8_array - return a u8 array property of firmware node
* @fwnode: Firmware node to get the property of
* @propname: Name of the property
* @val: The values are stored here or %NULL to return the number of values
* @nval: Size of the @val array
*
* Read an array of u8 properties with @propname from @fwnode and stores them to
* @val if found.
*
* Return: number of values if @val was %NULL,
* %0 if the property was found (success),
* %-EINVAL if given arguments are not valid,
* %-ENODATA if the property does not have a value,
* %-EPROTO if the property is not an array of numbers,
* %-EOVERFLOW if the size of the property is not as expected,
* %-ENXIO if no suitable firmware interface is present.
*/
int fwnode_property_read_u8_array(struct fwnode_handle *fwnode,
const char *propname, u8 *val, size_t nval)
{
return FWNODE_PROP_READ_ARRAY(fwnode, propname, u8, DEV_PROP_U8,
val, nval);
}
EXPORT_SYMBOL_GPL(fwnode_property_read_u8_array);
/**
* fwnode_property_read_u16_array - return a u16 array property of firmware node
* @fwnode: Firmware node to get the property of
* @propname: Name of the property
* @val: The values are stored here or %NULL to return the number of values
* @nval: Size of the @val array
*
* Read an array of u16 properties with @propname from @fwnode and store them to
* @val if found.
*
* Return: number of values if @val was %NULL,
* %0 if the property was found (success),
* %-EINVAL if given arguments are not valid,
* %-ENODATA if the property does not have a value,
* %-EPROTO if the property is not an array of numbers,
* %-EOVERFLOW if the size of the property is not as expected,
* %-ENXIO if no suitable firmware interface is present.
*/
int fwnode_property_read_u16_array(struct fwnode_handle *fwnode,
const char *propname, u16 *val, size_t nval)
{
return FWNODE_PROP_READ_ARRAY(fwnode, propname, u16, DEV_PROP_U16,
val, nval);
}
EXPORT_SYMBOL_GPL(fwnode_property_read_u16_array);
/**
* fwnode_property_read_u32_array - return a u32 array property of firmware node
* @fwnode: Firmware node to get the property of
* @propname: Name of the property
* @val: The values are stored here or %NULL to return the number of values
* @nval: Size of the @val array
*
* Read an array of u32 properties with @propname from @fwnode store them to
* @val if found.
*
* Return: number of values if @val was %NULL,
* %0 if the property was found (success),
* %-EINVAL if given arguments are not valid,
* %-ENODATA if the property does not have a value,
* %-EPROTO if the property is not an array of numbers,
* %-EOVERFLOW if the size of the property is not as expected,
* %-ENXIO if no suitable firmware interface is present.
*/
int fwnode_property_read_u32_array(struct fwnode_handle *fwnode,
const char *propname, u32 *val, size_t nval)
{
return FWNODE_PROP_READ_ARRAY(fwnode, propname, u32, DEV_PROP_U32,
val, nval);
}
EXPORT_SYMBOL_GPL(fwnode_property_read_u32_array);
/**
* fwnode_property_read_u64_array - return a u64 array property firmware node
* @fwnode: Firmware node to get the property of
* @propname: Name of the property
* @val: The values are stored here or %NULL to return the number of values
* @nval: Size of the @val array
*
* Read an array of u64 properties with @propname from @fwnode and store them to
* @val if found.
*
* Return: number of values if @val was %NULL,
* %0 if the property was found (success),
* %-EINVAL if given arguments are not valid,
* %-ENODATA if the property does not have a value,
* %-EPROTO if the property is not an array of numbers,
* %-EOVERFLOW if the size of the property is not as expected,
* %-ENXIO if no suitable firmware interface is present.
*/
int fwnode_property_read_u64_array(struct fwnode_handle *fwnode,
const char *propname, u64 *val, size_t nval)
{
return FWNODE_PROP_READ_ARRAY(fwnode, propname, u64, DEV_PROP_U64,
val, nval);
}
EXPORT_SYMBOL_GPL(fwnode_property_read_u64_array);
/**
* fwnode_property_read_string_array - return string array property of a node
* @fwnode: Firmware node to get the property of
* @propname: Name of the property
* @val: The values are stored here or %NULL to return the number of values
* @nval: Size of the @val array
*
* Read an string list property @propname from the given firmware node and store
* them to @val if found.
*
* Return: number of values if @val was %NULL,
* %0 if the property was found (success),
* %-EINVAL if given arguments are not valid,
* %-ENODATA if the property does not have a value,
* %-EPROTO if the property is not an array of strings,
* %-EOVERFLOW if the size of the property is not as expected,
* %-ENXIO if no suitable firmware interface is present.
*/
int fwnode_property_read_string_array(struct fwnode_handle *fwnode,
const char *propname, const char **val,
size_t nval)
{
if (is_of_node(fwnode))
return val ?
of_property_read_string_array(to_of_node(fwnode),
propname, val, nval) :
of_property_count_strings(to_of_node(fwnode), propname);
else if (is_acpi_node(fwnode))
return acpi_node_prop_read(fwnode, propname, DEV_PROP_STRING,
val, nval);
else if (is_pset(fwnode))
return pset_prop_read_array(to_pset(fwnode), propname,
DEV_PROP_STRING, val, nval);
return -ENXIO;
}
EXPORT_SYMBOL_GPL(fwnode_property_read_string_array);
/**
* fwnode_property_read_string - return a string property of a firmware node
* @fwnode: Firmware node to get the property of
* @propname: Name of the property
* @val: The value is stored here
*
* Read property @propname from the given firmware node and store the value into
* @val if found. The value is checked to be a string.
*
* Return: %0 if the property was found (success),
* %-EINVAL if given arguments are not valid,
* %-ENODATA if the property does not have a value,
* %-EPROTO or %-EILSEQ if the property is not a string,
* %-ENXIO if no suitable firmware interface is present.
*/
int fwnode_property_read_string(struct fwnode_handle *fwnode,
const char *propname, const char **val)
{
if (is_of_node(fwnode))
return of_property_read_string(to_of_node(fwnode), propname, val);
else if (is_acpi_node(fwnode))
return acpi_node_prop_read(fwnode, propname, DEV_PROP_STRING,
val, 1);
return pset_prop_read_array(to_pset(fwnode), propname,
DEV_PROP_STRING, val, 1);
}
EXPORT_SYMBOL_GPL(fwnode_property_read_string);
/**
* fwnode_property_match_string - find a string in an array and return index
* @fwnode: Firmware node to get the property of
* @propname: Name of the property holding the array
* @string: String to look for
*
* Find a given string in a string array and if it is found return the
* index back.
*
* Return: %0 if the property was found (success),
* %-EINVAL if given arguments are not valid,
* %-ENODATA if the property does not have a value,
* %-EPROTO if the property is not an array of strings,
* %-ENXIO if no suitable firmware interface is present.
*/
int fwnode_property_match_string(struct fwnode_handle *fwnode,
const char *propname, const char *string)
{
const char **values;
int nval, ret, i;
nval = fwnode_property_read_string_array(fwnode, propname, NULL, 0);
if (nval < 0)
return nval;
values = kcalloc(nval, sizeof(*values), GFP_KERNEL);
if (!values)
return -ENOMEM;
ret = fwnode_property_read_string_array(fwnode, propname, values, nval);
if (ret < 0)
goto out;
ret = -ENODATA;
for (i = 0; i < nval; i++) {
if (!strcmp(values[i], string)) {
ret = i;
break;
}
}
out:
kfree(values);
return ret;
}
EXPORT_SYMBOL_GPL(fwnode_property_match_string);
/**
* device_get_next_child_node - Return the next child node handle for a device
* @dev: Device to find the next child node for.
* @child: Handle to one of the device's child nodes or a null handle.
*/
struct fwnode_handle *device_get_next_child_node(struct device *dev,
struct fwnode_handle *child)
{
if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
struct device_node *node;
node = of_get_next_available_child(dev->of_node, to_of_node(child));
if (node)
return &node->fwnode;
} else if (IS_ENABLED(CONFIG_ACPI)) {
return acpi_get_next_subnode(dev, child);
}
return NULL;
}
EXPORT_SYMBOL_GPL(device_get_next_child_node);
/**
* fwnode_handle_put - Drop reference to a device node
* @fwnode: Pointer to the device node to drop the reference to.
*
* This has to be used when terminating device_for_each_child_node() iteration
* with break or return to prevent stale device node references from being left
* behind.
*/
void fwnode_handle_put(struct fwnode_handle *fwnode)
{
if (is_of_node(fwnode))
of_node_put(to_of_node(fwnode));
}
EXPORT_SYMBOL_GPL(fwnode_handle_put);
/**
* device_get_child_node_count - return the number of child nodes for device
* @dev: Device to cound the child nodes for
*/
unsigned int device_get_child_node_count(struct device *dev)
{
struct fwnode_handle *child;
unsigned int count = 0;
device_for_each_child_node(dev, child)
count++;
return count;
}
EXPORT_SYMBOL_GPL(device_get_child_node_count);
bool device_dma_supported(struct device *dev)
{
/* For DT, this is always supported.
* For ACPI, this depends on CCA, which
* is determined by the acpi_dma_supported().
*/
if (IS_ENABLED(CONFIG_OF) && dev->of_node)
return true;
return acpi_dma_supported(ACPI_COMPANION(dev));
}
EXPORT_SYMBOL_GPL(device_dma_supported);
enum dev_dma_attr device_get_dma_attr(struct device *dev)
{
enum dev_dma_attr attr = DEV_DMA_NOT_SUPPORTED;
if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
if (of_dma_is_coherent(dev->of_node))
attr = DEV_DMA_COHERENT;
else
attr = DEV_DMA_NON_COHERENT;
} else
attr = acpi_get_dma_attr(ACPI_COMPANION(dev));
return attr;
}
EXPORT_SYMBOL_GPL(device_get_dma_attr);
/**
* device_get_phy_mode - Get phy mode for given device
* @dev: Pointer to the given device
*
* The function gets phy interface string from property 'phy-mode' or
* 'phy-connection-type', and return its index in phy_modes table, or errno in
* error case.
*/
int device_get_phy_mode(struct device *dev)
{
const char *pm;
int err, i;
err = device_property_read_string(dev, "phy-mode", &pm);
if (err < 0)
err = device_property_read_string(dev,
"phy-connection-type", &pm);
if (err < 0)
return err;
for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
if (!strcasecmp(pm, phy_modes(i)))
return i;
return -ENODEV;
}
EXPORT_SYMBOL_GPL(device_get_phy_mode);
static void *device_get_mac_addr(struct device *dev,
const char *name, char *addr,
int alen)
{
int ret = device_property_read_u8_array(dev, name, addr, alen);
if (ret == 0 && alen == ETH_ALEN && is_valid_ether_addr(addr))
return addr;
return NULL;
}
/**
* device_get_mac_address - Get the MAC for a given device
* @dev: Pointer to the device
* @addr: Address of buffer to store the MAC in
* @alen: Length of the buffer pointed to by addr, should be ETH_ALEN
*
* Search the firmware node for the best MAC address to use. 'mac-address' is
* checked first, because that is supposed to contain to "most recent" MAC
* address. If that isn't set, then 'local-mac-address' is checked next,
* because that is the default address. If that isn't set, then the obsolete
* 'address' is checked, just in case we're using an old device tree.
*
* Note that the 'address' property is supposed to contain a virtual address of
* the register set, but some DTS files have redefined that property to be the
* MAC address.
*
* All-zero MAC addresses are rejected, because those could be properties that
* exist in the firmware tables, but were not updated by the firmware. For
* example, the DTS could define 'mac-address' and 'local-mac-address', with
* zero MAC addresses. Some older U-Boots only initialized 'local-mac-address'.
* In this case, the real MAC is in 'local-mac-address', and 'mac-address'
* exists but is all zeros.
*/
void *device_get_mac_address(struct device *dev, char *addr, int alen)
{
char *res;
res = device_get_mac_addr(dev, "mac-address", addr, alen);
if (res)
return res;
res = device_get_mac_addr(dev, "local-mac-address", addr, alen);
if (res)
return res;
return device_get_mac_addr(dev, "address", addr, alen);
}
EXPORT_SYMBOL(device_get_mac_address);