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 ---
Changes in v3: None Changes in v2: None
drivers/core/Kconfig | 4 + include/dm/read.h | 383 +++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 387 insertions(+) create mode 100644 include/dm/read.h
diff --git a/drivers/core/Kconfig b/drivers/core/Kconfig index 405e9ad8ef..fb5c4e834d 100644 --- a/drivers/core/Kconfig +++ b/drivers/core/Kconfig @@ -215,4 +215,8 @@ config OF_ISA_BUS mistranslation of device addresses, so ensure that this is enabled if your board does include an ISA bus.
+config DM_DEV_READ_INLINE + bool + default y if !OF_LIVE + endmenu diff --git a/include/dm/read.h b/include/dm/read.h new file mode 100644 index 0000000000..4ce2bc2d6e --- /dev/null +++ b/include/dm/read.h @@ -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