diff options
| -rw-r--r-- | include/fdtdec.h | 128 | ||||
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/fdtdec.c | 147 |
3 files changed, 276 insertions, 0 deletions
diff --git a/include/fdtdec.h b/include/fdtdec.h new file mode 100644 index 0000000000..d871cdd1c1 --- /dev/null +++ b/include/fdtdec.h @@ -0,0 +1,128 @@ +/* + * Copyright (c) 2011 The Chromium OS Authors. + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + + +/* + * This file contains convenience functions for decoding useful and + * enlightening information from FDTs. It is intended to be used by device + * drivers and board-specific code within U-Boot. It aims to reduce the + * amount of FDT munging required within U-Boot itself, so that driver code + * changes to support FDT are minimized. + */ + +#include <libfdt.h> + +/* + * A typedef for a physical address. Note that fdt data is always big + * endian even on a litle endian machine. + */ +#ifdef CONFIG_PHYS_64BIT +typedef u64 fdt_addr_t; +#define FDT_ADDR_T_NONE (-1ULL) +#define fdt_addr_to_cpu(reg) be64_to_cpu(reg) +#else +typedef u32 fdt_addr_t; +#define FDT_ADDR_T_NONE (-1U) +#define fdt_addr_to_cpu(reg) be32_to_cpu(reg) +#endif + +/* Information obtained about memory from the FDT */ +struct fdt_memory { + fdt_addr_t start; + fdt_addr_t end; +}; + +/** + * Compat types that we know about and for which we might have drivers. + * Each is named COMPAT_<dir>_<filename> where <dir> is the directory + * within drivers. + */ +enum fdt_compat_id { + COMPAT_UNKNOWN, + + COMPAT_COUNT, +}; + +/** + * Find the next numbered alias for a peripheral. This is used to enumerate + * all the peripherals of a certain type. + * + * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then + * this function will return a pointer to the node the alias points to, and + * then update *upto to 1. Next time you call this function, the next node + * will be returned. + * + * All nodes returned will match the compatible ID, as it is assumed that + * all peripherals use the same driver. + * + * @param blob FDT blob to use + * @param name Root name of alias to search for + * @param id Compatible ID to look for + * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more + */ +int fdtdec_next_alias(const void *blob, const char *name, + enum fdt_compat_id id, int *upto); + +/** + * 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. + * + * @param blob FDT blob + * @param node node to examine + * @param prop_name name of property to find + * @return address, if found, or FDT_ADDR_T_NONE if not + */ +fdt_addr_t fdtdec_get_addr(const void *blob, int node, + const char *prop_name); + +/** + * Look up a 32-bit integer property in a node and return it. The property + * must have at least 4 bytes of data. The value of the first cell is + * returned. + * + * @param blob FDT blob + * @param node node to examine + * @param prop_name name of property to find + * @param default_val default value to return if the property is not found + * @return integer value, if found, or default_val if not + */ +s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, + s32 default_val); + +/** + * Checks whether a node is enabled. + * This looks for a 'status' property. If this exists, then returns 1 if + * the status is 'ok' and 0 otherwise. If there is no status property, + * it returns the default value. + * + * @param blob FDT blob + * @param node node to examine + * @param default_val default value to return if no 'status' property exists + * @return integer value 0/1, if found, or default_val if not + */ +int fdtdec_get_is_enabled(const void *blob, int node, int default_val); + +/** + * Checks whether we have a valid fdt available to control U-Boot, and panic + * if not. + */ +int fdtdec_check_fdt(void); diff --git a/lib/Makefile b/lib/Makefile index 075bb8c284..54708c261c 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -38,6 +38,7 @@ COBJS-y += crc16.o COBJS-y += crc32.o COBJS-y += display_options.o COBJS-y += errno.o +COBJS-$(CONFIG_OF_CONTROL) += fdtdec.o COBJS-$(CONFIG_GZIP) += gunzip.o COBJS-y += hashtable.o COBJS-$(CONFIG_LMB) += lmb.o diff --git a/lib/fdtdec.c b/lib/fdtdec.c new file mode 100644 index 0000000000..0f871638c6 --- /dev/null +++ b/lib/fdtdec.c @@ -0,0 +1,147 @@ +/* + * Copyright (c) 2011 The Chromium OS Authors. + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <serial.h> +#include <libfdt.h> +#include <fdtdec.h> + +DECLARE_GLOBAL_DATA_PTR; + +/* + * Here are the type we know about. One day we might allow drivers to + * register. For now we just put them here. The COMPAT macro allows us to + * turn this into a sparse list later, and keeps the ID with the name. + */ +#define COMPAT(id, name) name +static const char * const compat_names[COMPAT_COUNT] = { +}; + +/** + * Look in the FDT for an alias with the given name and return its node. + * + * @param blob FDT blob + * @param name alias name to look up + * @return node offset if found, or an error code < 0 otherwise + */ +static int find_alias_node(const void *blob, const char *name) +{ + const char *path; + int alias_node; + + debug("find_alias_node: %s\n", name); + alias_node = fdt_path_offset(blob, "/aliases"); + if (alias_node < 0) + return alias_node; + path = fdt_getprop(blob, alias_node, name, NULL); + if (!path) + return -FDT_ERR_NOTFOUND; + return fdt_path_offset(blob, path); +} + +fdt_addr_t fdtdec_get_addr(const void *blob, int node, + const char *prop_name) +{ + const fdt_addr_t *cell; + int len; + + debug("get_addr: %s\n", prop_name); + cell = fdt_getprop(blob, node, prop_name, &len); + if (cell && (len == sizeof(fdt_addr_t) || + len == sizeof(fdt_addr_t) * 2)) + return fdt_addr_to_cpu(*cell); + return FDT_ADDR_T_NONE; +} + +s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, + s32 default_val) +{ + const s32 *cell; + int len; + + debug("get_size: %s\n", prop_name); + cell = fdt_getprop(blob, node, prop_name, &len); + if (cell && len >= sizeof(s32)) + return fdt32_to_cpu(cell[0]); + return default_val; +} + +int fdtdec_get_is_enabled(const void *blob, int node, int default_val) +{ + const char *cell; + + cell = fdt_getprop(blob, node, "status", NULL); + if (cell) + return 0 == strcmp(cell, "ok"); + return default_val; +} + +enum fdt_compat_id fd_dec_lookup(const void *blob, int node) +{ + enum fdt_compat_id id; + + /* Search our drivers */ + for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++) + if (0 == fdt_node_check_compatible(blob, node, + compat_names[id])) + return id; + return COMPAT_UNKNOWN; +} + +int fdtdec_next_compatible(const void *blob, int node, + enum fdt_compat_id id) +{ + return fdt_node_offset_by_compatible(blob, node, compat_names[id]); +} + +int fdtdec_next_alias(const void *blob, const char *name, + enum fdt_compat_id id, int *upto) +{ +#define MAX_STR_LEN 20 + char str[MAX_STR_LEN + 20]; + int node, err; + + /* snprintf() is not available */ + assert(strlen(name) < MAX_STR_LEN); + sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto); + (*upto)++; + node = find_alias_node(blob, str); + if (node < 0) + return node; + err = fdt_node_check_compatible(blob, node, compat_names[id]); + if (err < 0) + return err; + return err ? -FDT_ERR_NOTFOUND : node; +} + +/* + * This function is a little odd in that it accesses global data. At some + * point if the architecture board.c files merge this will make more sense. + * Even now, it is common code. + */ +int fdtdec_check_fdt(void) +{ + /* We must have an fdt */ + if (fdt_check_header(gd->fdt_blob)) + panic("No valid fdt found - please append one to U-Boot\n" + "binary or define CONFIG_OF_EMBED\n"); + return 0; +} |