include/fdtdec.h

   1 /*
   2  * Copyright (c) 2011 The Chromium OS Authors.
   3  * SPDX-License-Identifier:     GPL-2.0+
   4  */
   5
   6 #ifndef __fdtdec_h
   7 #define __fdtdec_h
   8
   9 /*
  10  * This file contains convenience functions for decoding useful and
  11  * enlightening information from FDTs. It is intended to be used by device
  12  * drivers and board-specific code within U-Boot. It aims to reduce the
  13  * amount of FDT munging required within U-Boot itself, so that driver code
  14  * changes to support FDT are minimized.
  15  */
  16
  17 #include <libfdt.h>
  18
  19 /*
  20  * A typedef for a physical address. Note that fdt data is always big
  21  * endian even on a litle endian machine.
  22  */
  23 #ifdef CONFIG_PHYS_64BIT
  24 typedef u64 fdt_addr_t;
  25 typedef u64 fdt_size_t;
  26 #define FDT_ADDR_T_NONE (-1ULL)
  27 #define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
  28 #define fdt_size_to_cpu(reg) be64_to_cpu(reg)
  29 #else
  30 typedef u32 fdt_addr_t;
  31 typedef u32 fdt_size_t;
  32 #define FDT_ADDR_T_NONE (-1U)
  33 #define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
  34 #define fdt_size_to_cpu(reg) be32_to_cpu(reg)
  35 #endif
  36
  37 /* Information obtained about memory from the FDT */
  38 struct fdt_memory {
  39         fdt_addr_t start;
  40         fdt_addr_t end;
  41 };
  42
  43 /*
  44  * Information about a resource. start is the first address of the resource
  45  * and end is the last address (inclusive). The length of the resource will
  46  * be equal to: end - start + 1.
  47  */
  48 struct fdt_resource {
  49         fdt_addr_t start;
  50         fdt_addr_t end;
  51 };
  52
  53 /**
  54  * Compute the size of a resource.
  55  *
  56  * @param res   the resource to operate on
  57  * @return the size of the resource
  58  */
  59 static inline fdt_size_t fdt_resource_size(const struct fdt_resource *res)
  60 {
  61         return res->end - res->start + 1;
  62 }
  63
  64 /**
  65  * Compat types that we know about and for which we might have drivers.
  66  * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
  67  * within drivers.
  68  */
  69 enum fdt_compat_id {
  70         COMPAT_UNKNOWN,
  71         COMPAT_NVIDIA_TEGRA20_USB,      /* Tegra20 USB port */
  72         COMPAT_NVIDIA_TEGRA30_USB,      /* Tegra30 USB port */
  73         COMPAT_NVIDIA_TEGRA114_USB,     /* Tegra114 USB port */
  74         COMPAT_NVIDIA_TEGRA114_I2C,     /* Tegra114 I2C w/single clock source */
  75         COMPAT_NVIDIA_TEGRA20_I2C,      /* Tegra20 i2c */
  76         COMPAT_NVIDIA_TEGRA20_DVC,      /* Tegra20 dvc (really just i2c) */
  77         COMPAT_NVIDIA_TEGRA20_EMC,      /* Tegra20 memory controller */
  78         COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
  79         COMPAT_NVIDIA_TEGRA20_KBC,      /* Tegra20 Keyboard */
  80         COMPAT_NVIDIA_TEGRA20_NAND,     /* Tegra2 NAND controller */
  81         COMPAT_NVIDIA_TEGRA20_PWM,      /* Tegra 2 PWM controller */
  82         COMPAT_NVIDIA_TEGRA20_DC,       /* Tegra 2 Display controller */
  83         COMPAT_NVIDIA_TEGRA124_SDMMC,   /* Tegra124 SDMMC controller */
  84         COMPAT_NVIDIA_TEGRA30_SDMMC,    /* Tegra30 SDMMC controller */
  85         COMPAT_NVIDIA_TEGRA20_SDMMC,    /* Tegra20 SDMMC controller */
  86         COMPAT_NVIDIA_TEGRA20_SFLASH,   /* Tegra 2 SPI flash controller */
  87         COMPAT_NVIDIA_TEGRA20_SLINK,    /* Tegra 2 SPI SLINK controller */
  88         COMPAT_NVIDIA_TEGRA114_SPI,     /* Tegra 114 SPI controller */
  89         COMPAT_SMSC_LAN9215,            /* SMSC 10/100 Ethernet LAN9215 */
  90         COMPAT_SAMSUNG_EXYNOS5_SROMC,   /* Exynos5 SROMC */
  91         COMPAT_SAMSUNG_S3C2440_I2C,     /* Exynos I2C Controller */
  92         COMPAT_SAMSUNG_EXYNOS5_SOUND,   /* Exynos Sound */
  93         COMPAT_WOLFSON_WM8994_CODEC,    /* Wolfson WM8994 Sound Codec */
  94         COMPAT_SAMSUNG_EXYNOS_SPI,      /* Exynos SPI */
  95         COMPAT_GOOGLE_CROS_EC,          /* Google CROS_EC Protocol */
  96         COMPAT_GOOGLE_CROS_EC_KEYB,     /* Google CROS_EC Keyboard */
  97         COMPAT_SAMSUNG_EXYNOS_EHCI,     /* Exynos EHCI controller */
  98         COMPAT_SAMSUNG_EXYNOS5_XHCI,    /* Exynos5 XHCI controller */
  99         COMPAT_SAMSUNG_EXYNOS_USB_PHY,  /* Exynos phy controller for usb2.0 */
 100         COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
 101         COMPAT_SAMSUNG_EXYNOS_TMU,      /* Exynos TMU */
 102         COMPAT_SAMSUNG_EXYNOS_FIMD,     /* Exynos Display controller */
 103         COMPAT_SAMSUNG_EXYNOS_MIPI_DSI, /* Exynos mipi dsi */
 104         COMPAT_SAMSUNG_EXYNOS5_DP,      /* Exynos Display port controller */
 105         COMPAT_SAMSUNG_EXYNOS_DWMMC,    /* Exynos DWMMC controller */
 106         COMPAT_SAMSUNG_EXYNOS_MMC,      /* Exynos MMC controller */
 107         COMPAT_SAMSUNG_EXYNOS_SERIAL,   /* Exynos UART */
 108         COMPAT_MAXIM_MAX77686_PMIC,     /* MAX77686 PMIC */
 109         COMPAT_GENERIC_SPI_FLASH,       /* Generic SPI Flash chip */
 110         COMPAT_MAXIM_98095_CODEC,       /* MAX98095 Codec */
 111         COMPAT_INFINEON_SLB9635_TPM,    /* Infineon SLB9635 TPM */
 112         COMPAT_INFINEON_SLB9645_TPM,    /* Infineon SLB9645 TPM */
 113         COMPAT_SAMSUNG_EXYNOS5_I2C,     /* Exynos5 High Speed I2C Controller */
 114         COMPAT_SANDBOX_HOST_EMULATION,  /* Sandbox emulation of a function */
 115         COMPAT_SANDBOX_LCD_SDL,         /* Sandbox LCD emulation with SDL */
 116         COMPAT_TI_TPS65090,             /* Texas Instrument TPS65090 */
 117         COMPAT_NXP_PTN3460,             /* NXP PTN3460 DP/LVDS bridge */
 118         COMPAT_SAMSUNG_EXYNOS_SYSMMU,   /* Exynos sysmmu */
 119         COMPAT_PARADE_PS8625,           /* Parade PS8622 EDP->LVDS bridge */
 120         COMPAT_INTEL_LPC,               /* Intel Low Pin Count I/F */
 121
 122         COMPAT_COUNT,
 123 };
 124
 125 /* GPIOs are numbered from 0 */
 126 enum {
 127         FDT_GPIO_NONE = -1U,    /* an invalid GPIO used to end our list */
 128
 129         FDT_GPIO_ACTIVE_LOW = 1 << 0,   /* input is active low (else high) */
 130 };
 131
 132 /* This is the state of a GPIO pin as defined by the fdt */
 133 struct fdt_gpio_state {
 134         const char *name;       /* name of the fdt property defining this */
 135         uint gpio;              /* GPIO number, or FDT_GPIO_NONE if none */
 136         u8 flags;               /* FDT_GPIO_... flags */
 137 };
 138
 139 /* This tells us whether a fdt_gpio_state record is valid or not */
 140 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
 141
 142 /**
 143  * Read the GPIO taking into account the polarity of the pin.
 144  *
 145  * @param gpio          pointer to the decoded gpio
 146  * @return value of the gpio if successful, < 0 if unsuccessful
 147  */
 148 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
 149
 150 /**
 151  * Write the GPIO taking into account the polarity of the pin.
 152  *
 153  * @param gpio          pointer to the decoded gpio
 154  * @return 0 if successful
 155  */
 156 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
 157
 158 /**
 159  * Find the next numbered alias for a peripheral. This is used to enumerate
 160  * all the peripherals of a certain type.
 161  *
 162  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
 163  * this function will return a pointer to the node the alias points to, and
 164  * then update *upto to 1. Next time you call this function, the next node
 165  * will be returned.
 166  *
 167  * All nodes returned will match the compatible ID, as it is assumed that
 168  * all peripherals use the same driver.
 169  *
 170  * @param blob          FDT blob to use
 171  * @param name          Root name of alias to search for
 172  * @param id            Compatible ID to look for
 173  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 174  */
 175 int fdtdec_next_alias(const void *blob, const char *name,
 176                 enum fdt_compat_id id, int *upto);
 177
 178 /**
 179  * Find the compatible ID for a given node.
 180  *
 181  * Generally each node has at least one compatible string attached to it.
 182  * This function looks through our list of known compatible strings and
 183  * returns the corresponding ID which matches the compatible string.
 184  *
 185  * @param blob          FDT blob to use
 186  * @param node          Node containing compatible string to find
 187  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
 188  */
 189 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
 190
 191 /**
 192  * Find the next compatible node for a peripheral.
 193  *
 194  * Do the first call with node = 0. This function will return a pointer to
 195  * the next compatible node. Next time you call this function, pass the
 196  * value returned, and the next node will be provided.
 197  *
 198  * @param blob          FDT blob to use
 199  * @param node          Start node for search
 200  * @param id            Compatible ID to look for (enum fdt_compat_id)
 201  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 202  */
 203 int fdtdec_next_compatible(const void *blob, int node,
 204                 enum fdt_compat_id id);
 205
 206 /**
 207  * Find the next compatible subnode for a peripheral.
 208  *
 209  * Do the first call with node set to the parent and depth = 0. This
 210  * function will return the offset of the next compatible node. Next time
 211  * you call this function, pass the node value returned last time, with
 212  * depth unchanged, and the next node will be provided.
 213  *
 214  * @param blob          FDT blob to use
 215  * @param node          Start node for search
 216  * @param id            Compatible ID to look for (enum fdt_compat_id)
 217  * @param depthp        Current depth (set to 0 before first call)
 218  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 219  */
 220 int fdtdec_next_compatible_subnode(const void *blob, int node,
 221                 enum fdt_compat_id id, int *depthp);
 222
 223 /**
 224  * Look up an address property in a node and return it as an address.
 225  * The property must hold either one address with no trailing data or
 226  * one address with a length. This is only tested on 32-bit machines.
 227  *
 228  * @param blob  FDT blob
 229  * @param node  node to examine
 230  * @param prop_name     name of property to find
 231  * @return address, if found, or FDT_ADDR_T_NONE if not
 232  */
 233 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
 234                 const char *prop_name);
 235
 236 /**
 237  * Look up an address property in a node and return it as an address.
 238  * The property must hold one address with a length. This is only tested
 239  * on 32-bit machines.
 240  *
 241  * @param blob  FDT blob
 242  * @param node  node to examine
 243  * @param prop_name     name of property to find
 244  * @return address, if found, or FDT_ADDR_T_NONE if not
 245  */
 246 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
 247                 const char *prop_name, fdt_size_t *sizep);
 248
 249 /**
 250  * Look up a 32-bit integer property in a node and return it. The property
 251  * must have at least 4 bytes of data. The value of the first cell is
 252  * returned.
 253  *
 254  * @param blob  FDT blob
 255  * @param node  node to examine
 256  * @param prop_name     name of property to find
 257  * @param default_val   default value to return if the property is not found
 258  * @return integer value, if found, or default_val if not
 259  */
 260 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
 261                 s32 default_val);
 262
 263 /**
 264  * Look up a 64-bit integer property in a node and return it. The property
 265  * must have at least 8 bytes of data (2 cells). The first two cells are
 266  * concatenated to form a 8 bytes value, where the first cell is top half and
 267  * the second cell is bottom half.
 268  *
 269  * @param blob  FDT blob
 270  * @param node  node to examine
 271  * @param prop_name     name of property to find
 272  * @param default_val   default value to return if the property is not found
 273  * @return integer value, if found, or default_val if not
 274  */
 275 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
 276                 uint64_t default_val);
 277
 278 /**
 279  * Checks whether a node is enabled.
 280  * This looks for a 'status' property. If this exists, then returns 1 if
 281  * the status is 'ok' and 0 otherwise. If there is no status property,
 282  * it returns 1 on the assumption that anything mentioned should be enabled
 283  * by default.
 284  *
 285  * @param blob  FDT blob
 286  * @param node  node to examine
 287  * @return integer value 0 (not enabled) or 1 (enabled)
 288  */
 289 int fdtdec_get_is_enabled(const void *blob, int node);
 290
 291 /**
 292  * Make sure we have a valid fdt available to control U-Boot.
 293  *
 294  * If not, a message is printed to the console if the console is ready.
 295  *
 296  * @return 0 if all ok, -1 if not
 297  */
 298 int fdtdec_prepare_fdt(void);
 299
 300 /**
 301  * Checks that we have a valid fdt available to control U-Boot.
 302
 303  * However, if not then for the moment nothing is done, since this function
 304  * is called too early to panic().
 305  *
 306  * @returns 0
 307  */
 308 int fdtdec_check_fdt(void);
 309
 310 /**
 311  * Find the nodes for a peripheral and return a list of them in the correct
 312  * order. This is used to enumerate all the peripherals of a certain type.
 313  *
 314  * To use this, optionally set up a /aliases node with alias properties for
 315  * a peripheral. For example, for usb you could have:
 316  *
 317  * aliases {
 318  *              usb0 = "/ehci@c5008000";
 319  *              usb1 = "/ehci@c5000000";
 320  * };
 321  *
 322  * Pass "usb" as the name to this function and will return a list of two
 323  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
 324  *
 325  * All nodes returned will match the compatible ID, as it is assumed that
 326  * all peripherals use the same driver.
 327  *
 328  * If no alias node is found, then the node list will be returned in the
 329  * order found in the fdt. If the aliases mention a node which doesn't
 330  * exist, then this will be ignored. If nodes are found with no aliases,
 331  * they will be added in any order.
 332  *
 333  * If there is a gap in the aliases, then this function return a 0 node at
 334  * that position. The return value will also count these gaps.
 335  *
 336  * This function checks node properties and will not return nodes which are
 337  * marked disabled (status = "disabled").
 338  *
 339  * @param blob          FDT blob to use
 340  * @param name          Root name of alias to search for
 341  * @param id            Compatible ID to look for
 342  * @param node_list     Place to put list of found nodes
 343  * @param maxcount      Maximum number of nodes to find
 344  * @return number of nodes found on success, FTD_ERR_... on error
 345  */
 346 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
 347                         enum fdt_compat_id id, int *node_list, int maxcount);
 348
 349 /*
 350  * This function is similar to fdtdec_find_aliases_for_id() except that it
 351  * adds to the node_list that is passed in. Any 0 elements are considered
 352  * available for allocation - others are considered already used and are
 353  * skipped.
 354  *
 355  * You can use this by calling fdtdec_find_aliases_for_id() with an
 356  * uninitialised array, then setting the elements that are returned to -1,
 357  * say, then calling this function, perhaps with a different compat id.
 358  * Any elements you get back that are >0 are new nodes added by the call
 359  * to this function.
 360  *
 361  * Note that if you have some nodes with aliases and some without, you are
 362  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
 363  * one compat_id may fill in positions for which you have aliases defined
 364  * for another compat_id. When you later call *this* function with the second
 365  * compat_id, the alias positions may already be used. A debug warning may
 366  * be generated in this case, but it is safest to define aliases for all
 367  * nodes when you care about the ordering.
 368  */
 369 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
 370                         enum fdt_compat_id id, int *node_list, int maxcount);
 371
 372 /**
 373  * Get the alias sequence number of a node
 374  *
 375  * This works out whether a node is pointed to by an alias, and if so, the
 376  * sequence number of that alias. Aliases are of the form <base><num> where
 377  * <num> is the sequence number. For example spi2 would be sequence number
 378  * 2.
 379  *
 380  * @param blob          Device tree blob (if NULL, then error is returned)
 381  * @param base          Base name for alias (before the underscore)
 382  * @param node          Node to look up
 383  * @param seqp          This is set to the sequence number if one is found,
 384  *                      but otherwise the value is left alone
 385  * @return 0 if a sequence was found, -ve if not
 386  */
 387 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
 388                          int *seqp);
 389
 390 /**
 391  * Get the offset of the given alias node
 392  *
 393  * This looks up an alias in /aliases then finds the offset of that node.
 394  *
 395  * @param blob          Device tree blob (if NULL, then error is returned)
 396  * @param name          Alias name, e.g. "console"
 397  * @return Node offset referred to by that alias, or -ve FDT_ERR_...
 398  */
 399 int fdtdec_get_alias_node(const void *blob, const char *name);
 400
 401 /**
 402  * Get the offset of the given chosen node
 403  *
 404  * This looks up a property in /chosen containing the path to another node,
 405  * then finds the offset of that node.
 406  *
 407  * @param blob          Device tree blob (if NULL, then error is returned)
 408  * @param name          Property name, e.g. "stdout-path"
 409  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
 410  */
 411 int fdtdec_get_chosen_node(const void *blob, const char *name);
 412
 413 /*
 414  * Get the name for a compatible ID
 415  *
 416  * @param id            Compatible ID to look for
 417  * @return compatible string for that id
 418  */
 419 const char *fdtdec_get_compatible(enum fdt_compat_id id);
 420
 421 /* Look up a phandle and follow it to its node. Then return the offset
 422  * of that node.
 423  *
 424  * @param blob          FDT blob
 425  * @param node          node to examine
 426  * @param prop_name     name of property to find
 427  * @return node offset if found, -ve error code on error
 428  */
 429 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
 430
 431 /**
 432  * Look up a property in a node and return its contents in an integer
 433  * array of given length. The property must have at least enough data for
 434  * the array (4*count bytes). It may have more, but this will be ignored.
 435  *
 436  * @param blob          FDT blob
 437  * @param node          node to examine
 438  * @param prop_name     name of property to find
 439  * @param array         array to fill with data
 440  * @param count         number of array elements
 441  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
 442  *              or -FDT_ERR_BADLAYOUT if not enough data
 443  */
 444 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
 445                 u32 *array, int count);
 446
 447 /**
 448  * Look up a property in a node and return a pointer to its contents as a
 449  * unsigned int array of given length. The property must have at least enough
 450  * data for the array ('count' cells). It may have more, but this will be
 451  * ignored. The data is not copied.
 452  *
 453  * Note that you must access elements of the array with fdt32_to_cpu(),
 454  * since the elements will be big endian even on a little endian machine.
 455  *
 456  * @param blob          FDT blob
 457  * @param node          node to examine
 458  * @param prop_name     name of property to find
 459  * @param count         number of array elements
 460  * @return pointer to array if found, or NULL if the property is not
 461  *              found or there is not enough data
 462  */
 463 const u32 *fdtdec_locate_array(const void *blob, int node,
 464                                const char *prop_name, int count);
 465
 466 /**
 467  * Look up a boolean property in a node and return it.
 468  *
 469  * A boolean properly is true if present in the device tree and false if not
 470  * present, regardless of its value.
 471  *
 472  * @param blob  FDT blob
 473  * @param node  node to examine
 474  * @param prop_name     name of property to find
 475  * @return 1 if the properly is present; 0 if it isn't present
 476  */
 477 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
 478
 479 /**
 480  * Decode a single GPIOs from an FDT.
 481  *
 482  * If the property is not found, then the GPIO structure will still be
 483  * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
 484  * provide optional GPIOs.
 485  *
 486  * @param blob          FDT blob to use
 487  * @param node          Node to look at
 488  * @param prop_name     Node property name
 489  * @param gpio          gpio elements to fill from FDT
 490  * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
 491  */
 492 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
 493                 struct fdt_gpio_state *gpio);
 494
 495 /**
 496  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
 497  * terminating item.
 498  *
 499  * @param blob         FDT blob to use
 500  * @param node         Node to look at
 501  * @param prop_name    Node property name
 502  * @param gpio         Array of gpio elements to fill from FDT. This will be
 503  *                     untouched if either 0 or an error is returned
 504  * @param max_count    Maximum number of elements allowed
 505  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
 506  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
 507  */
 508 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
 509                 struct fdt_gpio_state *gpio, int max_count);
 510
 511 /**
 512  * Set up a GPIO pin according to the provided gpio information. At present this
 513  * just requests the GPIO.
 514  *
 515  * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
 516  * deal with optional GPIOs.
 517  *
 518  * @param gpio          GPIO info to use for set up
 519  * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
 520  */
 521 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
 522
 523 /**
 524  * Look in the FDT for a config item with the given name and return its value
 525  * as a 32-bit integer. The property must have at least 4 bytes of data. The
 526  * value of the first cell is returned.
 527  *
 528  * @param blob          FDT blob to use
 529  * @param prop_name     Node property name
 530  * @param default_val   default value to return if the property is not found
 531  * @return integer value, if found, or default_val if not
 532  */
 533 int fdtdec_get_config_int(const void *blob, const char *prop_name,
 534                 int default_val);
 535
 536 /**
 537  * Look in the FDT for a config item with the given name
 538  * and return whether it exists.
 539  *
 540  * @param blob          FDT blob
 541  * @param prop_name     property name to look up
 542  * @return 1, if it exists, or 0 if not
 543  */
 544 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
 545
 546 /**
 547  * Look in the FDT for a config item with the given name and return its value
 548  * as a string.
 549  *
 550  * @param blob          FDT blob
 551  * @param prop_name     property name to look up
 552  * @returns property string, NULL on error.
 553  */
 554 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
 555
 556 /*
 557  * Look up a property in a node and return its contents in a byte
 558  * array of given length. The property must have at least enough data for
 559  * the array (count bytes). It may have more, but this will be ignored.
 560  *
 561  * @param blob          FDT blob
 562  * @param node          node to examine
 563  * @param prop_name     name of property to find
 564  * @param array         array to fill with data
 565  * @param count         number of array elements
 566  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
 567  *              or -FDT_ERR_BADLAYOUT if not enough data
 568  */
 569 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
 570                 u8 *array, int count);
 571
 572 /**
 573  * Look up a property in a node and return a pointer to its contents as a
 574  * byte array of given length. The property must have at least enough data
 575  * for the array (count bytes). It may have more, but this will be ignored.
 576  * The data is not copied.
 577  *
 578  * @param blob          FDT blob
 579  * @param node          node to examine
 580  * @param prop_name     name of property to find
 581  * @param count         number of array elements
 582  * @return pointer to byte array if found, or NULL if the property is not
 583  *              found or there is not enough data
 584  */
 585 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
 586                              const char *prop_name, int count);
 587
 588 /**
 589  * Look up a property in a node which contains a memory region address and
 590  * size. Then return a pointer to this address.
 591  *
 592  * The property must hold one address with a length. This is only tested on
 593  * 32-bit machines.
 594  *
 595  * @param blob          FDT blob
 596  * @param node          node to examine
 597  * @param prop_name     name of property to find
 598  * @param ptrp          returns pointer to region, or NULL if no address
 599  * @param size          returns size of region
 600  * @return 0 if ok, -1 on error (propery not found)
 601  */
 602 int fdtdec_decode_region(const void *blob, int node,
 603                 const char *prop_name, void **ptrp, size_t *size);
 604
 605 /* A flash map entry, containing an offset and length */
 606 struct fmap_entry {
 607         uint32_t offset;
 608         uint32_t length;
 609 };
 610
 611 /**
 612  * Read a flash entry from the fdt
 613  *
 614  * @param blob          FDT blob
 615  * @param node          Offset of node to read
 616  * @param name          Name of node being read
 617  * @param entry         Place to put offset and size of this node
 618  * @return 0 if ok, -ve on error
 619  */
 620 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
 621                            struct fmap_entry *entry);
 622
 623 /**
 624  * Obtain an indexed resource from a device property.
 625  *
 626  * @param fdt           FDT blob
 627  * @param node          node to examine
 628  * @param property      name of the property to parse
 629  * @param index         index of the resource to retrieve
 630  * @param res           returns the resource
 631  * @return 0 if ok, negative on error
 632  */
 633 int fdt_get_resource(const void *fdt, int node, const char *property,
 634                      unsigned int index, struct fdt_resource *res);
 635
 636 /**
 637  * Obtain a named resource from a device property.
 638  *
 639  * Look up the index of the name in a list of strings and return the resource
 640  * at that index.
 641  *
 642  * @param fdt           FDT blob
 643  * @param node          node to examine
 644  * @param property      name of the property to parse
 645  * @param prop_names    name of the property containing the list of names
 646  * @param name          the name of the entry to look up
 647  * @param res           returns the resource
 648  */
 649 int fdt_get_named_resource(const void *fdt, int node, const char *property,
 650                            const char *prop_names, const char *name,
 651                            struct fdt_resource *res);
 652
 653 /**
 654  * Look at the reg property of a device node that represents a PCI device
 655  * and parse the bus, device and function number from it.
 656  *
 657  * @param fdt           FDT blob
 658  * @param node          node to examine
 659  * @param bdf           returns bus, device, function triplet
 660  * @return 0 if ok, negative on error
 661  */
 662 int fdtdec_pci_get_bdf(const void *fdt, int node, int *bdf);
 663
 664 #endif