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Diffstat (limited to 'tmk_core/common/chibios/printf.h')
-rw-r--r-- | tmk_core/common/chibios/printf.h | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/tmk_core/common/chibios/printf.h b/tmk_core/common/chibios/printf.h new file mode 100644 index 000000000..775459e1e --- /dev/null +++ b/tmk_core/common/chibios/printf.h @@ -0,0 +1,110 @@ +/* + * found at: http://www.sparetimelabs.com/tinyprintf/tinyprintf.php + * and: http://www.sparetimelabs.com/printfrevisited/printfrevisited.php + */ + +/* +File: printf.h + +Copyright (C) 2004 Kustaa Nyholm + +This library is free software; you can redistribute it and/or +modify it under the terms of the GNU Lesser General Public +License as published by the Free Software Foundation; either +version 2.1 of the License, or (at your option) any later version. + +This library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. +See the GNU Lesser General Public License for more details. + +You should have received a copy of the GNU Lesser General Public +License along with this library; if not, write to the Free Software +Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + +This library is realy just two files: 'printf.h' and 'printf.c'. + +They provide a simple and small (+200 loc) printf functionality to +be used in embedded systems. + +I've found them so usefull in debugging that I do not bother with a +debugger at all. + +They are distributed in source form, so to use them, just compile them +into your project. + +Two printf variants are provided: printf and sprintf. + +The formats supported by this implementation are: 'd' 'u' 'c' 's' 'x' 'X'. + +Zero padding and field width are also supported. + +If the library is compiled with 'PRINTF_SUPPORT_LONG' defined then the +long specifier is also +supported. Note that this will pull in some long math routines (pun intended!) +and thus make your executable noticably longer. + +The memory foot print of course depends on the target cpu, compiler and +compiler options, but a rough guestimate (based on a H8S target) is about +1.4 kB for code and some twenty 'int's and 'char's, say 60 bytes of stack space. +Not too bad. Your milage may vary. By hacking the source code you can +get rid of some hunred bytes, I'm sure, but personally I feel the balance of +functionality and flexibility versus code size is close to optimal for +many embedded systems. + +To use the printf you need to supply your own character output function, +something like : + + void putc ( void* p, char c) + { + while (!SERIAL_PORT_EMPTY) ; + SERIAL_PORT_TX_REGISTER = c; + } + +Before you can call printf you need to initialize it to use your +character output function with something like: + + init_printf(NULL,putc); + +Notice the 'NULL' in 'init_printf' and the parameter 'void* p' in 'putc', +the NULL (or any pointer) you pass into the 'init_printf' will eventually be +passed to your 'putc' routine. This allows you to pass some storage space (or +anything realy) to the character output function, if necessary. +This is not often needed but it was implemented like that because it made +implementing the sprintf function so neat (look at the source code). + +The code is re-entrant, except for the 'init_printf' function, so it +is safe to call it from interupts too, although this may result in mixed output. +If you rely on re-entrancy, take care that your 'putc' function is re-entrant! + +The printf and sprintf functions are actually macros that translate to +'tfp_printf' and 'tfp_sprintf'. This makes it possible +to use them along with 'stdio.h' printf's in a single source file. +You just need to undef the names before you include the 'stdio.h'. +Note that these are not function like macros, so if you have variables +or struct members with these names, things will explode in your face. +Without variadic macros this is the best we can do to wrap these +fucnction. If it is a problem just give up the macros and use the +functions directly or rename them. + +For further details see source code. + +regs Kusti, 23.10.2004 +*/ + +#ifndef __TFP_PRINTF__ +#define __TFP_PRINTF__ + +#include <stdarg.h> + +void init_printf(void* putp, void (*putf)(void*, char)); + +int tfp_printf(const char* fmt, ...); +int tfp_sprintf(char* s, const char* fmt, ...); + +void tfp_format(void* putp, void (*putf)(void*, char), const char* fmt, va_list va); + +#define printf tfp_printf +#define sprintf tfp_sprintf + +#endif |