/*
   * Logging support
   *
   * Copyright (c) 2017 Google, Inc
   * Written by Simon Glass <sjg@chromium.org>
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #ifndef __LOG_H
  #define __LOG_H
  
  #include <dm/uclass-id.h>
  #include <linux/list.h>
  
  /** Log levels supported, ranging from most to least important */
  enum log_level_t {
  	LOGL_EMERG = 0,		/*U-Boot is unstable */
  	LOGL_ALERT,		/* Action must be taken immediately */
  	LOGL_CRIT,		/* Critical conditions */
  	LOGL_ERR,		/* Error that prevents something from working */
  	LOGL_WARNING,		/* Warning may prevent optimial operation */
  	LOGL_NOTICE,		/* Normal but significant condition, printf() */
  	LOGL_INFO,		/* General information message */
  	LOGL_DEBUG,		/* Basic debug-level message */
  	LOGL_DEBUG_CONTENT,	/* Debug message showing full message content */
  	LOGL_DEBUG_IO,		/* Debug message showing hardware I/O access */
  
  	LOGL_COUNT,
  	LOGL_NONE,
  
  	LOGL_FIRST = LOGL_EMERG,
  	LOGL_MAX = LOGL_DEBUG_IO,
  };
  
  /**
   * Log categories supported. Most of these correspond to uclasses (i.e.
   * enum uclass_id) but there are also some more generic categories
   */
  enum log_category_t {
  	LOGC_FIRST = 0,	/* First part mirrors UCLASS_... */
  
  	LOGC_NONE = UCLASS_COUNT,
  	LOGC_ARCH,
  	LOGC_BOARD,
  	LOGC_CORE,
  	LOGC_DM,	/* Core driver-model */
  	LOGC_DT,	/* Device-tree */
  	LOGL_EFI,	/* EFI implementation */
  
  	LOGC_COUNT,
  	LOGC_END,
  };
  
  /* Helper to cast a uclass ID to a log category */
  static inline int log_uc_cat(enum uclass_id id)
  {
  	return (enum log_category_t)id;
  }
  
  /**
   * _log() - Internal function to emit a new log record
   *
   * @cat: Category of log record (indicating which subsystem generated it)
   * @level: Level of log record (indicating its severity)
   * @file: File name of file where log record was generated
   * @line: Line number in file where log record was generated
   * @func: Function where log record was generated
   * @fmt: printf() format string for log record
   * @...: Optional parameters, according to the format string @fmt
   * @return 0 if log record was emitted, -ve on error
   */
  int _log(enum log_category_t cat, enum log_level_t level, const char *file,
  	 int line, const char *func, const char *fmt, ...);
  
  /* Define this at the top of a file to add a prefix to debug messages */
  #ifndef pr_fmt
  #define pr_fmt(fmt) fmt
  #endif
  
  /* Use a default category if this file does not supply one */
  #ifndef LOG_CATEGORY
  #define LOG_CATEGORY LOGC_NONE
  #endif
  
  /*
   * This header may be including when CONFIG_LOG is disabled, in which case
   * CONFIG_LOG_MAX_LEVEL is not defined. Add a check for this.
   */
  #if CONFIG_IS_ENABLED(LOG)
  #define _LOG_MAX_LEVEL CONFIG_VAL(LOG_MAX_LEVEL)
  #else
  #define _LOG_MAX_LEVEL LOGL_INFO
  #endif
  
  /* Emit a log record if the level is less that the maximum */
  #define log(_cat, _level, _fmt, _args...) ({ \
  	int _l = _level; \
  	if (_l <= _LOG_MAX_LEVEL) \
  		_log((enum log_category_t)(_cat), _l, __FILE__, __LINE__, \
  		      __func__, \
  		      pr_fmt(_fmt), ##_args); \
  	})
  
  #ifdef DEBUG
  #define _DEBUG	1
  #else
  #define _DEBUG	0
  #endif
  
  #ifdef CONFIG_SPL_BUILD
  #define _SPL_BUILD	1
  #else
  #define _SPL_BUILD	0
  #endif
  
  #if !_DEBUG && CONFIG_IS_ENABLED(LOG)
  
  #define debug_cond(cond, fmt, args...)			\
  	do {						\
  		if (1)					\
  			log(LOG_CATEGORY, LOGL_DEBUG, fmt, ##args); \
  	} while (0)
  
  #else /* _DEBUG */
  
  /*
   * Output a debug text when condition "cond" is met. The "cond" should be
   * computed by a preprocessor in the best case, allowing for the best
   * optimization.
   */
  #define debug_cond(cond, fmt, args...)			\
  	do {						\
  		if (cond)				\
  			printf(pr_fmt(fmt), ##args);	\
  	} while (0)
  
  #endif /* _DEBUG */
  
  /* Show a message if DEBUG is defined in a file */
  #define debug(fmt, args...)			\
  	debug_cond(_DEBUG, fmt, ##args)
  
  /* Show a message if not in SPL */
  #define warn_non_spl(fmt, args...)			\
  	debug_cond(!_SPL_BUILD, fmt, ##args)
  
  /*
   * An assertion is run-time check done in debug mode only. If DEBUG is not
   * defined then it is skipped. If DEBUG is defined and the assertion fails,
   * then it calls panic*( which may or may not reset/halt U-Boot (see
   * CONFIG_PANIC_HANG), It is hoped that all failing assertions are found
   * before release, and after release it is hoped that they don't matter. But
   * in any case these failing assertions cannot be fixed with a reset (which
   * may just do the same assertion again).
   */
  void __assert_fail(const char *assertion, const char *file, unsigned int line,
  		   const char *function);
  #define assert(x) \
  	({ if (!(x) && _DEBUG) \
  		__assert_fail(#x, __FILE__, __LINE__, __func__); })
  
  #ifdef CONFIG_LOG_ERROR_RETURN
  #define log_ret(_ret) ({ \
  	int __ret = (_ret); \
  	if (__ret < 0) \
  		log(LOG_CATEGORY, LOGL_ERR, "returning err=%d
  ", __ret); \
  	__ret; \
  	})
  #else
  #define log_ret(_ret) (_ret)
  #endif
  
  /**
   * struct log_rec - a single log record
   *
   * Holds information about a single record in the log
   *
   * Members marked as 'not allocated' are stored as pointers and the caller is
   * responsible for making sure that the data pointed to is not overwritten.
   * Memebers marked as 'allocated' are allocated (e.g. via strdup()) by the log
   * system.
   *
   * @cat: Category, representing a uclass or part of U-Boot
   * @level: Severity level, less severe is higher
   * @file: Name of file where the log record was generated (not allocated)
   * @line: Line number where the log record was generated
   * @func: Function where the log record was generated (not allocated)
   * @msg: Log message (allocated)
   */
  struct log_rec {
  	enum log_category_t cat;
  	enum log_level_t level;
  	const char *file;
  	int line;
  	const char *func;
  	const char *msg;
  };
  
  struct log_device;
  
  /**
   * struct log_driver - a driver which accepts and processes log records
   *
   * @name: Name of driver
   */
  struct log_driver {
  	const char *name;
  	/**
  	 * emit() - emit a log record
  	 *
  	 * Called by the log system to pass a log record to a particular driver
  	 * for processing. The filter is checked before calling this function.
  	 */
  	int (*emit)(struct log_device *ldev, struct log_rec *rec);
  };
  
  /**
   * struct log_device - an instance of a log driver
   *
   * Since drivers are set up at build-time we need to have a separate device for
   * the run-time aspects of drivers (currently just a list of filters to apply
   * to records send to this device).
   *
   * @next_filter_num: Seqence number of next filter filter added (0=no filters
   *	yet). This increments with each new filter on the device, but never
   *	decrements
   * @drv: Pointer to driver for this device
   * @filter_head: List of filters for this device
   * @sibling_node: Next device in the list of all devices
   */
  struct log_device {
  	int next_filter_num;
  	struct log_driver *drv;
  	struct list_head filter_head;
  	struct list_head sibling_node;
  };
  
  enum {
  	LOGF_MAX_CATEGORIES = 5,	/* maximum categories per filter */
  };
  
  enum log_filter_flags {
  	LOGFF_HAS_CAT		= 1 << 0,	/* Filter has a category list */
  };
  
  /**
   * struct log_filter - criterial to filter out log messages
   *
   * @filter_num: Sequence number of this filter.  This is returned when adding a
   *	new filter, and must be provided when removing a previously added
   *	filter.
   * @flags: Flags for this filter (LOGFF_...)
   * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
   *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
   *	can be provided
   * @max_level: Maximum log level to allow
   * @file_list: List of files to allow, separated by comma. If NULL then all
   *	files are permitted
   * @sibling_node: Next filter in the list of filters for this log device
   */
  struct log_filter {
  	int filter_num;
  	int flags;
  	enum log_category_t cat_list[LOGF_MAX_CATEGORIES];
  	enum log_level_t max_level;
  	const char *file_list;
  	struct list_head sibling_node;
  };
  
  #define LOG_DRIVER(_name) \
  	ll_entry_declare(struct log_driver, _name, log_driver)
  
  /**
   * log_get_cat_name() - Get the name of a category
   *
   * @cat: Category to look up
   * @return category name (which may be a uclass driver name)
   */
  const char *log_get_cat_name(enum log_category_t cat);
  
  /**
   * log_get_cat_by_name() - Look up a category by name
   *
   * @name: Name to look up
   * @return category ID, or LOGC_NONE if not found
   */
  enum log_category_t log_get_cat_by_name(const char *name);
  
  /**
   * log_get_level_name() - Get the name of a log level
   *
   * @level: Log level to look up
   * @return log level name (in ALL CAPS)
   */
  const char *log_get_level_name(enum log_level_t level);
  
  /**
   * log_get_level_by_name() - Look up a log level by name
   *
   * @name: Name to look up
   * @return log level ID, or LOGL_NONE if not found
   */
  enum log_level_t log_get_level_by_name(const char *name);
  
  /* Log format flags (bit numbers) for gd->log_fmt. See log_fmt_chars */
  enum log_fmt {
  	LOGF_CAT	= 0,
  	LOGF_LEVEL,
  	LOGF_FILE,
  	LOGF_LINE,
  	LOGF_FUNC,
  	LOGF_MSG,
  
  	LOGF_COUNT,
  	LOGF_DEFAULT = (1 << LOGF_FUNC) | (1 << LOGF_MSG),
  	LOGF_ALL = 0x3f,
  };
  
  /* Handle the 'log test' command */
  int do_log_test(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]);
  
  /**
   * log_add_filter() - Add a new filter to a log device
   *
   * @drv_name: Driver name to add the filter to (since each driver only has a
   *	single device)
   * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
   *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
   *	can be provided
   * @max_level: Maximum log level to allow
   * @file_list: List of files to allow, separated by comma. If NULL then all
   *	files are permitted
   * @return the sequence number of the new filter (>=0) if the filter was added,
   *	or a -ve value on error
   */
  int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
  		   enum log_level_t max_level, const char *file_list);
  
  /**
   * log_remove_filter() - Remove a filter from a log device
   *
   * @drv_name: Driver name to remove the filter from (since each driver only has
   *	a single device)
   * @filter_num: Filter number to remove (as returned by log_add_filter())
   * @return 0 if the filter was removed, -ENOENT if either the driver or the
   *	filter number was not found
   */
  int log_remove_filter(const char *drv_name, int filter_num);
  
  #if CONFIG_IS_ENABLED(LOG)
  /**
   * log_init() - Set up the log system ready for use
   *
   * @return 0 if OK, -ENOMEM if out of memory
   */
  int log_init(void);
  #else
  static inline int log_init(void)
  {
  	return 0;
  }
  #endif
  
  #endif