| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #ifndef __SRC_INCLUDE_BASE3_H__ |
| #define __SRC_INCLUDE_BASE3_H__ |
| |
| /* We translate a floating pin (Z) as the ternary digit 2. */ |
| #define Z 2 |
| |
| /* |
| * This provides a variadic macro BASE3() that can be used to translate a set of |
| * pin states into its base-3 integer representation, even in the context of a |
| * static initializer. You can call it with any number of up to 6 arguments, |
| * e.g. BASE3(1, Z) -> 5 or BASE3(0, Z, 1, 0) -> 21. Just don't look too closely |
| * at how the sausage is made. (Pay extra attention to typos when expanding it!) |
| */ |
| #define _BASE3_IMPL_1(arg0, arg1, arg2, arg3, arg4, arg5) arg0 |
| #define _BASE3_IMPL_2(arg0, arg1, arg2, arg3, arg4, arg5) \ |
| (arg1 + (3 * _BASE3_IMPL_1(arg0, arg1, arg2, arg3, arg4, arg5))) |
| #define _BASE3_IMPL_3(arg0, arg1, arg2, arg3, arg4, arg5) \ |
| (arg2 + (3 * _BASE3_IMPL_2(arg0, arg1, arg2, arg3, arg4, arg5))) |
| #define _BASE3_IMPL_4(arg0, arg1, arg2, arg3, arg4, arg5) \ |
| (arg3 + (3 * _BASE3_IMPL_3(arg0, arg1, arg2, arg3, arg4, arg5))) |
| #define _BASE3_IMPL_5(arg0, arg1, arg2, arg3, arg4, arg5) \ |
| (arg4 + (3 * _BASE3_IMPL_4(arg0, arg1, arg2, arg3, arg4, arg5))) |
| #define _BASE3_IMPL_6(arg0, arg1, arg2, arg3, arg4, arg5) \ |
| (arg5 + (3 * _BASE3_IMPL_5(arg0, arg1, arg2, arg3, arg4, arg5))) |
| #define _BASE3_IMPL(arg0, arg1, arg2, arg3, arg4, arg5, NARGS, ...) \ |
| _BASE3_IMPL##NARGS(arg0, arg1, arg2, arg3, arg4, arg5) |
| #define BASE3(...) _BASE3_IMPL(__VA_ARGS__, _6, _5, _4, _3, _2, _1) |
| |
| #endif /* __SRC_INCLUDE_BASE3_H__ */ |