include/drivers/console.h

   1 /*
   2  * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
   3  *
   4  * SPDX-License-Identifier: BSD-3-Clause
   5  */
   6
   7 #ifndef CONSOLE_H
   8 #define CONSOLE_H
   9
  10 #include <lib/utils_def.h>
  11
  12 #define CONSOLE_T_NEXT                  (U(0) * REGSZ)
  13 #define CONSOLE_T_FLAGS                 (U(1) * REGSZ)
  14 #define CONSOLE_T_PUTC                  (U(2) * REGSZ)
  15 #define CONSOLE_T_GETC                  (U(3) * REGSZ)
  16 #define CONSOLE_T_FLUSH                 (U(4) * REGSZ)
  17 #define CONSOLE_T_DRVDATA               (U(5) * REGSZ)
  18
  19 #define CONSOLE_FLAG_BOOT               (U(1) << 0)
  20 #define CONSOLE_FLAG_RUNTIME            (U(1) << 1)
  21 #define CONSOLE_FLAG_CRASH              (U(1) << 2)
  22 /* Bits 3 to 7 reserved for additional scopes in future expansion. */
  23 #define CONSOLE_FLAG_SCOPE_MASK         ((U(1) << 8) - 1)
  24 /* Bits 8 to 31 reserved for non-scope use in future expansion. */
  25
  26 /* Returned by getc callbacks when receive FIFO is empty. */
  27 #define ERROR_NO_PENDING_CHAR           (-1)
  28 /* Returned by console_xxx() if no registered console implements xxx. */
  29 #define ERROR_NO_VALID_CONSOLE          (-128)
  30
  31 #ifndef __ASSEMBLY__
  32
  33 #include <stdint.h>
  34
  35 typedef struct console {
  36         struct console *next;
  37         /*
  38          * Only the low 32 bits are used. The type is u_register_t to align the
  39          * fields of the struct to 64 bits in AArch64 and 32 bits in AArch32
  40          */
  41         u_register_t flags;
  42         int (*const putc)(int character, struct console *console);
  43         int (*const getc)(struct console *console);
  44         int (*const flush)(struct console *console);
  45         /* Additional private driver data may follow here. */
  46 } console_t;
  47
  48 /* offset macro assertions for console_t */
  49 #include <drivers/console_assertions.h>
  50
  51 /*
  52  * Add a console_t instance to the console list. This should only be called by
  53  * console drivers after they have initialized all fields in the console
  54  * structure. Platforms seeking to register a new console need to call the
  55  * respective console__register() function instead.
  56  */
  57 int console_register(console_t *console);
  58 /* Remove a single console_t instance from the console list. Return a pointer to
  59  * the console that was removed if it was found, or NULL if not. */
  60 console_t *console_unregister(console_t *console);
  61 /* Returns 1 if this console is already registered, 0 if not */
  62 int console_is_registered(console_t *console);
  63 /*
  64  * Set scope mask of a console that determines in what states it is active.
  65  * By default they are registered with (CONSOLE_FLAG_BOOT|CONSOLE_FLAG_CRASH).
  66  */
  67 void console_set_scope(console_t *console, unsigned int scope);
  68
  69 /* Switch to a new global console state (CONSOLE_FLAG_BOOT/RUNTIME/CRASH). */
  70 void console_switch_state(unsigned int new_state);
  71 /* Output a character on all consoles registered for the current state. */
  72 int console_putc(int c);
  73 /* Read a character (blocking) from any console registered for current state. */
  74 int console_getc(void);
  75 /* Flush all consoles registered for the current state. */
  76 int console_flush(void);
  77
  78 #endif /* __ASSEMBLY__ */
  79
  80 #endif /* CONSOLE_H */