/*
   * Copyright (c) 2011 The Chromium OS Authors.

   * SPDX-License-Identifier:	GPL-2.0+

   */

  #ifndef __fdtdec_h
  #define __fdtdec_h

  
  /*
   * 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;

  typedef u64 fdt_size_t;

  #define FDT_ADDR_T_NONE (-1ULL)
  #define fdt_addr_to_cpu(reg) be64_to_cpu(reg)

  #define fdt_size_to_cpu(reg) be64_to_cpu(reg)

  #else
  typedef u32 fdt_addr_t;

  typedef u32 fdt_size_t;

  #define FDT_ADDR_T_NONE (-1U)
  #define fdt_addr_to_cpu(reg) be32_to_cpu(reg)

  #define fdt_size_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_NVIDIA_TEGRA20_USB,	/* Tegra20 USB port */

  	COMPAT_NVIDIA_TEGRA30_USB,	/* Tegra30 USB port */
  	COMPAT_NVIDIA_TEGRA114_USB,	/* Tegra114 USB port */

  	COMPAT_NVIDIA_TEGRA114_I2C,	/* Tegra114 I2C w/single clock source */

  	COMPAT_NVIDIA_TEGRA20_I2C,	/* Tegra20 i2c */
  	COMPAT_NVIDIA_TEGRA20_DVC,	/* Tegra20 dvc (really just i2c) */
  	COMPAT_NVIDIA_TEGRA20_EMC,	/* Tegra20 memory controller */
  	COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
  	COMPAT_NVIDIA_TEGRA20_KBC,	/* Tegra20 Keyboard */

  	COMPAT_NVIDIA_TEGRA20_NAND,	/* Tegra2 NAND controller */

  	COMPAT_NVIDIA_TEGRA20_PWM,	/* Tegra 2 PWM controller */

  	COMPAT_NVIDIA_TEGRA20_DC,	/* Tegra 2 Display controller */

  	COMPAT_NVIDIA_TEGRA124_SDMMC,	/* Tegra124 SDMMC controller */

  	COMPAT_NVIDIA_TEGRA30_SDMMC,	/* Tegra30 SDMMC controller */
  	COMPAT_NVIDIA_TEGRA20_SDMMC,	/* Tegra20 SDMMC controller */

  	COMPAT_NVIDIA_TEGRA20_SFLASH,	/* Tegra 2 SPI flash controller */

  	COMPAT_NVIDIA_TEGRA20_SLINK,	/* Tegra 2 SPI SLINK controller */

  	COMPAT_NVIDIA_TEGRA114_SPI,	/* Tegra 114 SPI controller */

  	COMPAT_SMSC_LAN9215,		/* SMSC 10/100 Ethernet LAN9215 */
  	COMPAT_SAMSUNG_EXYNOS5_SROMC,	/* Exynos5 SROMC */

  	COMPAT_SAMSUNG_S3C2440_I2C,	/* Exynos I2C Controller */

  	COMPAT_SAMSUNG_EXYNOS5_SOUND,	/* Exynos Sound */
  	COMPAT_WOLFSON_WM8994_CODEC,	/* Wolfson WM8994 Sound Codec */

  	COMPAT_SAMSUNG_EXYNOS_SPI,	/* Exynos SPI */

  	COMPAT_GOOGLE_CROS_EC,		/* Google CROS_EC Protocol */

  	COMPAT_GOOGLE_CROS_EC_KEYB,	/* Google CROS_EC Keyboard */

  	COMPAT_SAMSUNG_EXYNOS_EHCI,	/* Exynos EHCI controller */

  	COMPAT_SAMSUNG_EXYNOS5_XHCI,	/* Exynos5 XHCI controller */

  	COMPAT_SAMSUNG_EXYNOS_USB_PHY,	/* Exynos phy controller for usb2.0 */

  	COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */

  	COMPAT_SAMSUNG_EXYNOS_TMU,	/* Exynos TMU */

  	COMPAT_SAMSUNG_EXYNOS_FIMD,	/* Exynos Display controller */

  	COMPAT_SAMSUNG_EXYNOS5_DP,	/* Exynos Display port controller */

  	COMPAT_SAMSUNG_EXYNOS5_DWMMC,	/* Exynos5 DWMMC controller */

  	COMPAT_SAMSUNG_EXYNOS_SERIAL,	/* Exynos UART */

  	COMPAT_MAXIM_MAX77686_PMIC,	/* MAX77686 PMIC */

  	COMPAT_GENERIC_SPI_FLASH,	/* Generic SPI Flash chip */

  	COMPAT_MAXIM_98095_CODEC,	/* MAX98095 Codec */

  	COMPAT_INFINEON_SLB9635_TPM,	/* Infineon SLB9635 TPM */

  	COMPAT_INFINEON_SLB9645_TPM,	/* Infineon SLB9645 TPM */

  	COMPAT_SAMSUNG_EXYNOS5_I2C,	/* Exynos5 High Speed I2C Controller */

  
  	COMPAT_COUNT,
  };

  /* GPIOs are numbered from 0 */
  enum {
  	FDT_GPIO_NONE = -1U,	/* an invalid GPIO used to end our list */
  
  	FDT_GPIO_ACTIVE_LOW = 1 << 0,	/* input is active low (else high) */
  };
  
  /* This is the state of a GPIO pin as defined by the fdt */
  struct fdt_gpio_state {
  	const char *name;	/* name of the fdt property defining this */
  	uint gpio;		/* GPIO number, or FDT_GPIO_NONE if none */
  	u8 flags;		/* FDT_GPIO_... flags */
  };
  
  /* This tells us whether a fdt_gpio_state record is valid or not */
  #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)

  /**

   * Read the GPIO taking into account the polarity of the pin.
   *
   * @param gpio		pointer to the decoded gpio
   * @return value of the gpio if successful, < 0 if unsuccessful
   */
  int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
  
  /**
   * Write the GPIO taking into account the polarity of the pin.
   *
   * @param gpio		pointer to the decoded gpio
   * @return 0 if successful
   */
  int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
  
  /**

   * 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);
  
  /**

   * Find the compatible ID for a given node.
   *
   * Generally each node has at least one compatible string attached to it.
   * This function looks through our list of known compatible strings and
   * returns the corresponding ID which matches the compatible string.
   *
   * @param blob		FDT blob to use
   * @param node		Node containing compatible string to find
   * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
   */
  enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
  
  /**

   * Find the next compatible node for a peripheral.
   *
   * Do the first call with node = 0. This function will return a pointer to
   * the next compatible node. Next time you call this function, pass the
   * value returned, and the next node will be provided.
   *
   * @param blob		FDT blob to use
   * @param node		Start node for search
   * @param id		Compatible ID to look for (enum fdt_compat_id)
   * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
   */
  int fdtdec_next_compatible(const void *blob, int node,
  		enum fdt_compat_id id);
  
  /**

   * Find the next compatible subnode for a peripheral.
   *
   * Do the first call with node set to the parent and depth = 0. This
   * function will return the offset of the next compatible node. Next time
   * you call this function, pass the node value returned last time, with
   * depth unchanged, and the next node will be provided.
   *
   * @param blob		FDT blob to use
   * @param node		Start node for search
   * @param id		Compatible ID to look for (enum fdt_compat_id)
   * @param depthp	Current depth (set to 0 before first call)
   * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
   */
  int fdtdec_next_compatible_subnode(const void *blob, int node,
  		enum fdt_compat_id id, int *depthp);
  
  /**

   * 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 an address property in a node and return it as an address.
   * The property must hold 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_size(const void *blob, int node,
  		const char *prop_name, fdt_size_t *sizep);
  
  /**

   * 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);
  
  /**

   * Look up a 64-bit integer property in a node and return it. The property
   * must have at least 8 bytes of data (2 cells). The first two cells are
   * concatenated to form a 8 bytes value, where the first cell is top half and
   * the second cell is bottom half.
   *
   * @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
   */
  uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
  		uint64_t 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 1 on the assumption that anything mentioned should be enabled
   * by default.

   *
   * @param blob	FDT blob
   * @param node	node to examine

   * @return integer value 0 (not enabled) or 1 (enabled)

   */

  int fdtdec_get_is_enabled(const void *blob, int node);

  
  /**

   * Make sure we have a valid fdt available to control U-Boot.
   *
   * If not, a message is printed to the console if the console is ready.
   *
   * @return 0 if all ok, -1 if not
   */
  int fdtdec_prepare_fdt(void);
  
  /**
   * Checks that we have a valid fdt available to control U-Boot.
  
   * However, if not then for the moment nothing is done, since this function
   * is called too early to panic().
   *
   * @returns 0

   */
  int fdtdec_check_fdt(void);

  
  /**
   * Find the nodes for a peripheral and return a list of them in the correct
   * order. This is used to enumerate all the peripherals of a certain type.
   *
   * To use this, optionally set up a /aliases node with alias properties for
   * a peripheral. For example, for usb you could have:
   *
   * aliases {
   *		usb0 = "/ehci@c5008000";
   *		usb1 = "/ehci@c5000000";
   * };
   *
   * Pass "usb" as the name to this function and will return a list of two
   * nodes offsets: /ehci@c5008000 and ehci@c5000000.
   *
   * All nodes returned will match the compatible ID, as it is assumed that
   * all peripherals use the same driver.
   *
   * If no alias node is found, then the node list will be returned in the
   * order found in the fdt. If the aliases mention a node which doesn't
   * exist, then this will be ignored. If nodes are found with no aliases,
   * they will be added in any order.
   *
   * If there is a gap in the aliases, then this function return a 0 node at
   * that position. The return value will also count these gaps.
   *
   * This function checks node properties and will not return nodes which are
   * marked disabled (status = "disabled").
   *
   * @param blob		FDT blob to use
   * @param name		Root name of alias to search for
   * @param id		Compatible ID to look for
   * @param node_list	Place to put list of found nodes
   * @param maxcount	Maximum number of nodes to find
   * @return number of nodes found on success, FTD_ERR_... on error
   */
  int fdtdec_find_aliases_for_id(const void *blob, const char *name,
  			enum fdt_compat_id id, int *node_list, int maxcount);
  
  /*

   * This function is similar to fdtdec_find_aliases_for_id() except that it
   * adds to the node_list that is passed in. Any 0 elements are considered
   * available for allocation - others are considered already used and are
   * skipped.
   *
   * You can use this by calling fdtdec_find_aliases_for_id() with an
   * uninitialised array, then setting the elements that are returned to -1,
   * say, then calling this function, perhaps with a different compat id.
   * Any elements you get back that are >0 are new nodes added by the call
   * to this function.
   *
   * Note that if you have some nodes with aliases and some without, you are
   * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
   * one compat_id may fill in positions for which you have aliases defined
   * for another compat_id. When you later call *this* function with the second
   * compat_id, the alias positions may already be used. A debug warning may
   * be generated in this case, but it is safest to define aliases for all
   * nodes when you care about the ordering.
   */
  int fdtdec_add_aliases_for_id(const void *blob, const char *name,
  			enum fdt_compat_id id, int *node_list, int maxcount);
  
  /*

   * Get the name for a compatible ID
   *
   * @param id		Compatible ID to look for
   * @return compatible string for that id
   */
  const char *fdtdec_get_compatible(enum fdt_compat_id id);

  
  /* Look up a phandle and follow it to its node. Then return the offset
   * of that node.
   *
   * @param blob		FDT blob
   * @param node		node to examine
   * @param prop_name	name of property to find
   * @return node offset if found, -ve error code on error
   */
  int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
  
  /**
   * Look up a property in a node and return its contents in an integer
   * array of given length. The property must have at least enough data for
   * the array (4*count bytes). It may have more, but this will be ignored.
   *
   * @param blob		FDT blob
   * @param node		node to examine
   * @param prop_name	name of property to find
   * @param array		array to fill with data
   * @param count		number of array elements
   * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
   *		or -FDT_ERR_BADLAYOUT if not enough data
   */
  int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
  		u32 *array, int count);
  
  /**

   * Look up a property in a node and return a pointer to its contents as a
   * unsigned int array of given length. The property must have at least enough
   * data for the array ('count' cells). It may have more, but this will be
   * ignored. The data is not copied.
   *
   * Note that you must access elements of the array with fdt32_to_cpu(),
   * since the elements will be big endian even on a little endian machine.
   *
   * @param blob		FDT blob
   * @param node		node to examine
   * @param prop_name	name of property to find
   * @param count		number of array elements
   * @return pointer to array if found, or NULL if the property is not
   *		found or there is not enough data
   */
  const u32 *fdtdec_locate_array(const void *blob, int node,
  			       const char *prop_name, int count);
  
  /**

   * Look up a boolean property in a node and return it.
   *
   * A boolean properly is true if present in the device tree and false if not
   * present, regardless of its value.
   *
   * @param blob	FDT blob
   * @param node	node to examine
   * @param prop_name	name of property to find
   * @return 1 if the properly is present; 0 if it isn't present
   */
  int fdtdec_get_bool(const void *blob, int node, const char *prop_name);

  
  /**
   * Decode a single GPIOs from an FDT.
   *
   * If the property is not found, then the GPIO structure will still be
   * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
   * provide optional GPIOs.
   *
   * @param blob		FDT blob to use
   * @param node		Node to look at
   * @param prop_name	Node property name
   * @param gpio		gpio elements to fill from FDT
   * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
   */
  int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
  		struct fdt_gpio_state *gpio);
  
  /**

   * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
   * terminating item.
   *
   * @param blob         FDT blob to use
   * @param node         Node to look at
   * @param prop_name    Node property name
   * @param gpio         Array of gpio elements to fill from FDT. This will be
   *                     untouched if either 0 or an error is returned
   * @param max_count    Maximum number of elements allowed
   * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
   * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
   */
  int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
  		struct fdt_gpio_state *gpio, int max_count);
  
  /**

   * Set up a GPIO pin according to the provided gpio information. At present this
   * just requests the GPIO.
   *
   * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
   * deal with optional GPIOs.
   *
   * @param gpio		GPIO info to use for set up
   * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
   */
  int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);

  /**
   * Look in the FDT for a config item with the given name and return its value
   * as a 32-bit integer. The property must have at least 4 bytes of data. The
   * value of the first cell is returned.
   *
   * @param blob		FDT blob to use
   * @param prop_name	Node property name
   * @param default_val	default value to return if the property is not found
   * @return integer value, if found, or default_val if not
   */
  int fdtdec_get_config_int(const void *blob, const char *prop_name,
  		int default_val);

  /**

   * Look in the FDT for a config item with the given name
   * and return whether it exists.
   *
   * @param blob		FDT blob
   * @param prop_name	property name to look up
   * @return 1, if it exists, or 0 if not
   */
  int fdtdec_get_config_bool(const void *blob, const char *prop_name);
  
  /**

   * Look in the FDT for a config item with the given name and return its value
   * as a string.
   *
   * @param blob          FDT blob
   * @param prop_name     property name to look up
   * @returns property string, NULL on error.
   */
  char *fdtdec_get_config_string(const void *blob, const char *prop_name);

  /*
   * Look up a property in a node and return its contents in 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.
   *
   * @param blob		FDT blob
   * @param node		node to examine
   * @param prop_name	name of property to find
   * @param array		array to fill with data
   * @param count		number of array elements
   * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
   *		or -FDT_ERR_BADLAYOUT if not enough data
   */
  int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
  		u8 *array, int count);
  
  /**
   * Look up a property in a node 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.
   *
   * @param blob		FDT blob
   * @param node		node to examine
   * @param prop_name	name of property to find
   * @param count		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
   */
  const u8 *fdtdec_locate_byte_array(const void *blob, int node,
  			     const char *prop_name, int count);

  
  /**
   * Look up a property in a node which contains a memory region address and
   * size. Then return a pointer to this address.
   *
   * The property must hold 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
   * @param ptrp		returns pointer to region, or NULL if no address
   * @param size		returns size of region
   * @return 0 if ok, -1 on error (propery not found)
   */
  int fdtdec_decode_region(const void *blob, int node,
  		const char *prop_name, void **ptrp, size_t *size);

  #endif