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  * Compat types that we know about and for which we might have drivers.
  45  * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
  46  * within drivers.
  47  */
  48 enum fdt_compat_id {
  49         COMPAT_UNKNOWN,
  50         COMPAT_NVIDIA_TEGRA20_USB,      /* Tegra20 USB port */
  51         COMPAT_NVIDIA_TEGRA30_USB,      /* Tegra30 USB port */
  52         COMPAT_NVIDIA_TEGRA114_USB,     /* Tegra114 USB port */
  53         COMPAT_NVIDIA_TEGRA114_I2C,     /* Tegra114 I2C w/single clock source */
  54         COMPAT_NVIDIA_TEGRA20_I2C,      /* Tegra20 i2c */
  55         COMPAT_NVIDIA_TEGRA20_DVC,      /* Tegra20 dvc (really just i2c) */
  56         COMPAT_NVIDIA_TEGRA20_EMC,      /* Tegra20 memory controller */
  57         COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
  58         COMPAT_NVIDIA_TEGRA20_KBC,      /* Tegra20 Keyboard */
  59         COMPAT_NVIDIA_TEGRA20_NAND,     /* Tegra2 NAND controller */
  60         COMPAT_NVIDIA_TEGRA20_PWM,      /* Tegra 2 PWM controller */
  61         COMPAT_NVIDIA_TEGRA20_DC,       /* Tegra 2 Display controller */
  62         COMPAT_NVIDIA_TEGRA30_SDMMC,    /* Tegra30 SDMMC controller */
  63         COMPAT_NVIDIA_TEGRA20_SDMMC,    /* Tegra20 SDMMC controller */
  64         COMPAT_NVIDIA_TEGRA20_SFLASH,   /* Tegra 2 SPI flash controller */
  65         COMPAT_NVIDIA_TEGRA20_SLINK,    /* Tegra 2 SPI SLINK controller */
  66         COMPAT_NVIDIA_TEGRA114_SPI,     /* Tegra 114 SPI controller */
  67         COMPAT_SMSC_LAN9215,            /* SMSC 10/100 Ethernet LAN9215 */
  68         COMPAT_SAMSUNG_EXYNOS5_SROMC,   /* Exynos5 SROMC */
  69         COMPAT_SAMSUNG_S3C2440_I2C,     /* Exynos I2C Controller */
  70         COMPAT_SAMSUNG_EXYNOS5_SOUND,   /* Exynos Sound */
  71         COMPAT_WOLFSON_WM8994_CODEC,    /* Wolfson WM8994 Sound Codec */
  72         COMPAT_SAMSUNG_EXYNOS_SPI,      /* Exynos SPI */
  73         COMPAT_GOOGLE_CROS_EC,          /* Google CROS_EC Protocol */
  74         COMPAT_GOOGLE_CROS_EC_KEYB,     /* Google CROS_EC Keyboard */
  75         COMPAT_SAMSUNG_EXYNOS_EHCI,     /* Exynos EHCI controller */
  76         COMPAT_SAMSUNG_EXYNOS_USB_PHY,  /* Exynos phy controller for usb2.0 */
  77         COMPAT_SAMSUNG_EXYNOS_TMU,      /* Exynos TMU */
  78         COMPAT_SAMSUNG_EXYNOS_FIMD,     /* Exynos Display controller */
  79         COMPAT_SAMSUNG_EXYNOS5_DP,      /* Exynos Display port controller */
  80         COMPAT_SAMSUNG_EXYNOS5_DWMMC,   /* Exynos5 DWMMC controller */
  81         COMPAT_SAMSUNG_EXYNOS_SERIAL,   /* Exynos UART */
  82         COMPAT_MAXIM_MAX77686_PMIC,     /* MAX77686 PMIC */
  83         COMPAT_GENERIC_SPI_FLASH,       /* Generic SPI Flash chip */
  84         COMPAT_MAXIM_98095_CODEC,       /* MAX98095 Codec */
  85         COMPAT_INFINEON_SLB9635_TPM,    /* Infineon SLB9635 TPM */
  86         COMPAT_INFINEON_SLB9645_TPM,    /* Infineon SLB9645 TPM */
  87
  88         COMPAT_COUNT,
  89 };
  90
  91 /* GPIOs are numbered from 0 */
  92 enum {
  93         FDT_GPIO_NONE = -1U,    /* an invalid GPIO used to end our list */
  94
  95         FDT_GPIO_ACTIVE_LOW = 1 << 0,   /* input is active low (else high) */
  96 };
  97
  98 /* This is the state of a GPIO pin as defined by the fdt */
  99 struct fdt_gpio_state {
 100         const char *name;       /* name of the fdt property defining this */
 101         uint gpio;              /* GPIO number, or FDT_GPIO_NONE if none */
 102         u8 flags;               /* FDT_GPIO_... flags */
 103 };
 104
 105 /* This tells us whether a fdt_gpio_state record is valid or not */
 106 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
 107
 108 /**
 109  * Read the GPIO taking into account the polarity of the pin.
 110  *
 111  * @param gpio          pointer to the decoded gpio
 112  * @return value of the gpio if successful, < 0 if unsuccessful
 113  */
 114 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
 115
 116 /**
 117  * Write the GPIO taking into account the polarity of the pin.
 118  *
 119  * @param gpio          pointer to the decoded gpio
 120  * @return 0 if successful
 121  */
 122 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
 123
 124 /**
 125  * Find the next numbered alias for a peripheral. This is used to enumerate
 126  * all the peripherals of a certain type.
 127  *
 128  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
 129  * this function will return a pointer to the node the alias points to, and
 130  * then update *upto to 1. Next time you call this function, the next node
 131  * will be returned.
 132  *
 133  * All nodes returned will match the compatible ID, as it is assumed that
 134  * all peripherals use the same driver.
 135  *
 136  * @param blob          FDT blob to use
 137  * @param name          Root name of alias to search for
 138  * @param id            Compatible ID to look for
 139  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 140  */
 141 int fdtdec_next_alias(const void *blob, const char *name,
 142                 enum fdt_compat_id id, int *upto);
 143
 144 /**
 145  * Find the compatible ID for a given node.
 146  *
 147  * Generally each node has at least one compatible string attached to it.
 148  * This function looks through our list of known compatible strings and
 149  * returns the corresponding ID which matches the compatible string.
 150  *
 151  * @param blob          FDT blob to use
 152  * @param node          Node containing compatible string to find
 153  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
 154  */
 155 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
 156
 157 /**
 158  * Find the next compatible node for a peripheral.
 159  *
 160  * Do the first call with node = 0. This function will return a pointer to
 161  * the next compatible node. Next time you call this function, pass the
 162  * value returned, and the next node will be provided.
 163  *
 164  * @param blob          FDT blob to use
 165  * @param node          Start node for search
 166  * @param id            Compatible ID to look for (enum fdt_compat_id)
 167  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 168  */
 169 int fdtdec_next_compatible(const void *blob, int node,
 170                 enum fdt_compat_id id);
 171
 172 /**
 173  * Find the next compatible subnode for a peripheral.
 174  *
 175  * Do the first call with node set to the parent and depth = 0. This
 176  * function will return the offset of the next compatible node. Next time
 177  * you call this function, pass the node value returned last time, with
 178  * depth unchanged, and the next node will be provided.
 179  *
 180  * @param blob          FDT blob to use
 181  * @param node          Start node for search
 182  * @param id            Compatible ID to look for (enum fdt_compat_id)
 183  * @param depthp        Current depth (set to 0 before first call)
 184  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 185  */
 186 int fdtdec_next_compatible_subnode(const void *blob, int node,
 187                 enum fdt_compat_id id, int *depthp);
 188
 189 /**
 190  * Look up an address property in a node and return it as an address.
 191  * The property must hold either one address with no trailing data or
 192  * one address with a length. This is only tested on 32-bit machines.
 193  *
 194  * @param blob  FDT blob
 195  * @param node  node to examine
 196  * @param prop_name     name of property to find
 197  * @return address, if found, or FDT_ADDR_T_NONE if not
 198  */
 199 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
 200                 const char *prop_name);
 201
 202 /**
 203  * Look up an address property in a node and return it as an address.
 204  * The property must hold one address with a length. This is only tested
 205  * on 32-bit machines.
 206  *
 207  * @param blob  FDT blob
 208  * @param node  node to examine
 209  * @param prop_name     name of property to find
 210  * @return address, if found, or FDT_ADDR_T_NONE if not
 211  */
 212 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
 213                 const char *prop_name, fdt_size_t *sizep);
 214
 215 /**
 216  * Look up a 32-bit integer property in a node and return it. The property
 217  * must have at least 4 bytes of data. The value of the first cell is
 218  * returned.
 219  *
 220  * @param blob  FDT blob
 221  * @param node  node to examine
 222  * @param prop_name     name of property to find
 223  * @param default_val   default value to return if the property is not found
 224  * @return integer value, if found, or default_val if not
 225  */
 226 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
 227                 s32 default_val);
 228
 229 /**
 230  * Look up a 64-bit integer property in a node and return it. The property
 231  * must have at least 8 bytes of data (2 cells). The first two cells are
 232  * concatenated to form a 8 bytes value, where the first cell is top half and
 233  * the second cell is bottom half.
 234  *
 235  * @param blob  FDT blob
 236  * @param node  node to examine
 237  * @param prop_name     name of property to find
 238  * @param default_val   default value to return if the property is not found
 239  * @return integer value, if found, or default_val if not
 240  */
 241 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
 242                 uint64_t default_val);
 243
 244 /**
 245  * Checks whether a node is enabled.
 246  * This looks for a 'status' property. If this exists, then returns 1 if
 247  * the status is 'ok' and 0 otherwise. If there is no status property,
 248  * it returns 1 on the assumption that anything mentioned should be enabled
 249  * by default.
 250  *
 251  * @param blob  FDT blob
 252  * @param node  node to examine
 253  * @return integer value 0 (not enabled) or 1 (enabled)
 254  */
 255 int fdtdec_get_is_enabled(const void *blob, int node);
 256
 257 /**
 258  * Make sure we have a valid fdt available to control U-Boot.
 259  *
 260  * If not, a message is printed to the console if the console is ready.
 261  *
 262  * @return 0 if all ok, -1 if not
 263  */
 264 int fdtdec_prepare_fdt(void);
 265
 266 /**
 267  * Checks that we have a valid fdt available to control U-Boot.
 268
 269  * However, if not then for the moment nothing is done, since this function
 270  * is called too early to panic().
 271  *
 272  * @returns 0
 273  */
 274 int fdtdec_check_fdt(void);
 275
 276 /**
 277  * Find the nodes for a peripheral and return a list of them in the correct
 278  * order. This is used to enumerate all the peripherals of a certain type.
 279  *
 280  * To use this, optionally set up a /aliases node with alias properties for
 281  * a peripheral. For example, for usb you could have:
 282  *
 283  * aliases {
 284  *              usb0 = "/ehci@c5008000";
 285  *              usb1 = "/ehci@c5000000";
 286  * };
 287  *
 288  * Pass "usb" as the name to this function and will return a list of two
 289  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
 290  *
 291  * All nodes returned will match the compatible ID, as it is assumed that
 292  * all peripherals use the same driver.
 293  *
 294  * If no alias node is found, then the node list will be returned in the
 295  * order found in the fdt. If the aliases mention a node which doesn't
 296  * exist, then this will be ignored. If nodes are found with no aliases,
 297  * they will be added in any order.
 298  *
 299  * If there is a gap in the aliases, then this function return a 0 node at
 300  * that position. The return value will also count these gaps.
 301  *
 302  * This function checks node properties and will not return nodes which are
 303  * marked disabled (status = "disabled").
 304  *
 305  * @param blob          FDT blob to use
 306  * @param name          Root name of alias to search for
 307  * @param id            Compatible ID to look for
 308  * @param node_list     Place to put list of found nodes
 309  * @param maxcount      Maximum number of nodes to find
 310  * @return number of nodes found on success, FTD_ERR_... on error
 311  */
 312 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
 313                         enum fdt_compat_id id, int *node_list, int maxcount);
 314
 315 /*
 316  * This function is similar to fdtdec_find_aliases_for_id() except that it
 317  * adds to the node_list that is passed in. Any 0 elements are considered
 318  * available for allocation - others are considered already used and are
 319  * skipped.
 320  *
 321  * You can use this by calling fdtdec_find_aliases_for_id() with an
 322  * uninitialised array, then setting the elements that are returned to -1,
 323  * say, then calling this function, perhaps with a different compat id.
 324  * Any elements you get back that are >0 are new nodes added by the call
 325  * to this function.
 326  *
 327  * Note that if you have some nodes with aliases and some without, you are
 328  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
 329  * one compat_id may fill in positions for which you have aliases defined
 330  * for another compat_id. When you later call *this* function with the second
 331  * compat_id, the alias positions may already be used. A debug warning may
 332  * be generated in this case, but it is safest to define aliases for all
 333  * nodes when you care about the ordering.
 334  */
 335 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
 336                         enum fdt_compat_id id, int *node_list, int maxcount);
 337
 338 /*
 339  * Get the name for a compatible ID
 340  *
 341  * @param id            Compatible ID to look for
 342  * @return compatible string for that id
 343  */
 344 const char *fdtdec_get_compatible(enum fdt_compat_id id);
 345
 346 /* Look up a phandle and follow it to its node. Then return the offset
 347  * of that node.
 348  *
 349  * @param blob          FDT blob
 350  * @param node          node to examine
 351  * @param prop_name     name of property to find
 352  * @return node offset if found, -ve error code on error
 353  */
 354 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
 355
 356 /**
 357  * Look up a property in a node and return its contents in an integer
 358  * array of given length. The property must have at least enough data for
 359  * the array (4*count bytes). It may have more, but this will be ignored.
 360  *
 361  * @param blob          FDT blob
 362  * @param node          node to examine
 363  * @param prop_name     name of property to find
 364  * @param array         array to fill with data
 365  * @param count         number of array elements
 366  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
 367  *              or -FDT_ERR_BADLAYOUT if not enough data
 368  */
 369 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
 370                 u32 *array, int count);
 371
 372 /**
 373  * Look up a property in a node and return a pointer to its contents as a
 374  * unsigned int array of given length. The property must have at least enough
 375  * data for the array ('count' cells). It may have more, but this will be
 376  * ignored. The data is not copied.
 377  *
 378  * Note that you must access elements of the array with fdt32_to_cpu(),
 379  * since the elements will be big endian even on a little endian machine.
 380  *
 381  * @param blob          FDT blob
 382  * @param node          node to examine
 383  * @param prop_name     name of property to find
 384  * @param count         number of array elements
 385  * @return pointer to array if found, or NULL if the property is not
 386  *              found or there is not enough data
 387  */
 388 const u32 *fdtdec_locate_array(const void *blob, int node,
 389                                const char *prop_name, int count);
 390
 391 /**
 392  * Look up a boolean property in a node and return it.
 393  *
 394  * A boolean properly is true if present in the device tree and false if not
 395  * present, regardless of its value.
 396  *
 397  * @param blob  FDT blob
 398  * @param node  node to examine
 399  * @param prop_name     name of property to find
 400  * @return 1 if the properly is present; 0 if it isn't present
 401  */
 402 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
 403
 404 /**
 405  * Decode a single GPIOs from an FDT.
 406  *
 407  * If the property is not found, then the GPIO structure will still be
 408  * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
 409  * provide optional GPIOs.
 410  *
 411  * @param blob          FDT blob to use
 412  * @param node          Node to look at
 413  * @param prop_name     Node property name
 414  * @param gpio          gpio elements to fill from FDT
 415  * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
 416  */
 417 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
 418                 struct fdt_gpio_state *gpio);
 419
 420 /**
 421  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
 422  * terminating item.
 423  *
 424  * @param blob         FDT blob to use
 425  * @param node         Node to look at
 426  * @param prop_name    Node property name
 427  * @param gpio         Array of gpio elements to fill from FDT. This will be
 428  *                     untouched if either 0 or an error is returned
 429  * @param max_count    Maximum number of elements allowed
 430  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
 431  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
 432  */
 433 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
 434                 struct fdt_gpio_state *gpio, int max_count);
 435
 436 /**
 437  * Set up a GPIO pin according to the provided gpio information. At present this
 438  * just requests the GPIO.
 439  *
 440  * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
 441  * deal with optional GPIOs.
 442  *
 443  * @param gpio          GPIO info to use for set up
 444  * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
 445  */
 446 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
 447
 448 /**
 449  * Look in the FDT for a config item with the given name and return its value
 450  * as a 32-bit integer. The property must have at least 4 bytes of data. The
 451  * value of the first cell is returned.
 452  *
 453  * @param blob          FDT blob to use
 454  * @param prop_name     Node property name
 455  * @param default_val   default value to return if the property is not found
 456  * @return integer value, if found, or default_val if not
 457  */
 458 int fdtdec_get_config_int(const void *blob, const char *prop_name,
 459                 int default_val);
 460
 461 /**
 462  * Look in the FDT for a config item with the given name
 463  * and return whether it exists.
 464  *
 465  * @param blob          FDT blob
 466  * @param prop_name     property name to look up
 467  * @return 1, if it exists, or 0 if not
 468  */
 469 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
 470
 471 /**
 472  * Look in the FDT for a config item with the given name and return its value
 473  * as a string.
 474  *
 475  * @param blob          FDT blob
 476  * @param prop_name     property name to look up
 477  * @returns property string, NULL on error.
 478  */
 479 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
 480
 481 /*
 482  * Look up a property in a node and return its contents in a byte
 483  * array of given length. The property must have at least enough data for
 484  * the array (count bytes). It may have more, but this will be ignored.
 485  *
 486  * @param blob          FDT blob
 487  * @param node          node to examine
 488  * @param prop_name     name of property to find
 489  * @param array         array to fill with data
 490  * @param count         number of array elements
 491  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
 492  *              or -FDT_ERR_BADLAYOUT if not enough data
 493  */
 494 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
 495                 u8 *array, int count);
 496
 497 /**
 498  * Look up a property in a node and return a pointer to its contents as a
 499  * byte array of given length. The property must have at least enough data
 500  * for the array (count bytes). It may have more, but this will be ignored.
 501  * The data is not copied.
 502  *
 503  * @param blob          FDT blob
 504  * @param node          node to examine
 505  * @param prop_name     name of property to find
 506  * @param count         number of array elements
 507  * @return pointer to byte array if found, or NULL if the property is not
 508  *              found or there is not enough data
 509  */
 510 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
 511                              const char *prop_name, int count);
 512
 513 /**
 514  * Look up a property in a node which contains a memory region address and
 515  * size. Then return a pointer to this address.
 516  *
 517  * The property must hold one address with a length. This is only tested on
 518  * 32-bit machines.
 519  *
 520  * @param blob          FDT blob
 521  * @param node          node to examine
 522  * @param prop_name     name of property to find
 523  * @param ptrp          returns pointer to region, or NULL if no address
 524  * @param size          returns size of region
 525  * @return 0 if ok, -1 on error (propery not found)
 526  */
 527 int fdtdec_decode_region(const void *blob, int node,
 528                 const char *prop_name, void **ptrp, size_t *size);
 529 #endif