1 #ifndef __LINUX_KCONFIG_H
2 #define __LINUX_KCONFIG_H
3 
4 #include <generated/autoconf.h>
5 
6 /*
7  * Helper macros to use CONFIG_ options in C/CPP expressions. Note that
8  * these only work with boolean and tristate options.
9  */
10 
11 /*
12  * Getting something that works in C and CPP for an arg that may or may
13  * not be defined is tricky.  Here, if we have "#define CONFIG_BOOGER 1"
14  * we match on the placeholder define, insert the "0," for arg1 and generate
15  * the triplet (0, 1, 0).  Then the last step cherry picks the 2nd arg (a one).
16  * When CONFIG_BOOGER is not defined, we generate a (... 1, 0) pair, and when
17  * the last step cherry picks the 2nd arg, we get a zero.
18  */
19 #define __ARG_PLACEHOLDER_1 0,
20 #define config_enabled(cfg) _config_enabled(cfg)
21 #define _config_enabled(value) __config_enabled(__ARG_PLACEHOLDER_##value)
22 #define __config_enabled(arg1_or_junk) ___config_enabled(arg1_or_junk 1, 0)
23 #define ___config_enabled(__ignored, val, ...) val
24 
25 /*
26  * IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y',
27  * 0 otherwise.
28  *
29  */
30 #define IS_ENABLED(option) \
31 	(config_enabled(option))
32 
33 /*
34  * U-Boot add-on: Helper macros to reference to different macros
35  * (CONFIG_ or CONFIG_SPL_ prefixed), depending on the build context.
36  */
37 
38 #if defined(CONFIG_TPL_BUILD)
39 #define _CONFIG_PREFIX TPL_
40 #elif defined(CONFIG_SPL_BUILD)
41 #define _CONFIG_PREFIX SPL_
42 #else
43 #define _CONFIG_PREFIX
44 #endif
45 
46 #define   config_val(cfg)       _config_val(_CONFIG_PREFIX, cfg)
47 #define  _config_val(pfx, cfg) __config_val(pfx, cfg)
48 #define __config_val(pfx, cfg) CONFIG_ ## pfx ## cfg
49 
50 /*
51  * CONFIG_VAL(FOO) evaluates to the value of
52  *  CONFIG_FOO if CONFIG_SPL_BUILD is undefined,
53  *  CONFIG_SPL_FOO if CONFIG_SPL_BUILD is defined.
54  *  CONFIG_TPL_FOO if CONFIG_TPL_BUILD is defined.
55  */
56 #define CONFIG_VAL(option)  config_val(option)
57 
58 /*
59  * Count number of arguments to a variadic macro. Currently only need
60  * it for 1, 2 or 3 arguments.
61  */
62 #define __arg6(a1, a2, a3, a4, a5, a6, ...) a6
63 #define __count_args(...) __arg6(dummy, ##__VA_ARGS__, 4, 3, 2, 1, 0)
64 
65 #define __concat(a, b)   ___concat(a, b)
66 #define ___concat(a, b)  a ## b
67 
68 #define __unwrap(...) __VA_ARGS__
69 #define __unwrap1(case1, case0) __unwrap case1
70 #define __unwrap0(case1, case0) __unwrap case0
71 
72 #define __CONFIG_IS_ENABLED_1(option)        __CONFIG_IS_ENABLED_3(option, (1), (0))
73 #define __CONFIG_IS_ENABLED_2(option, case1) __CONFIG_IS_ENABLED_3(option, case1, ())
74 #define __CONFIG_IS_ENABLED_3(option, case1, case0) \
75 	__concat(__unwrap, config_enabled(CONFIG_VAL(option))) (case1, case0)
76 
77 /*
78  * CONFIG_IS_ENABLED(FOO) expands to
79  *  1 if CONFIG_SPL_BUILD is undefined and CONFIG_FOO is set to 'y',
80  *  1 if CONFIG_SPL_BUILD is defined and CONFIG_SPL_FOO is set to 'y',
81  *  1 if CONFIG_TPL_BUILD is defined and CONFIG_TPL_FOO is set to 'y',
82  *  0 otherwise.
83  *
84  * CONFIG_IS_ENABLED(FOO, (abc)) expands to
85  *  abc if CONFIG_SPL_BUILD is undefined and CONFIG_FOO is set to 'y',
86  *  abc if CONFIG_SPL_BUILD is defined and CONFIG_SPL_FOO is set to 'y',
87  *  abc if CONFIG_TPL_BUILD is defined and CONFIG_TPL_FOO is set to 'y',
88  *  nothing otherwise.
89  *
90  * CONFIG_IS_ENABLED(FOO, (abc), (def)) expands to
91  *  abc if CONFIG_SPL_BUILD is undefined and CONFIG_FOO is set to 'y',
92  *  abc if CONFIG_SPL_BUILD is defined and CONFIG_SPL_FOO is set to 'y',
93  *  abc if CONFIG_TPL_BUILD is defined and CONFIG_TPL_FOO is set to 'y',
94  *  def otherwise.
95  *
96  * The optional second and third arguments must be parenthesized; that
97  * allows one to include a trailing comma, e.g. for use in
98  *
99  * CONFIG_IS_ENABLED(ACME, ({.compatible = "acme,frobnozzle"},))
100  *
101  * which adds an entry to the array being defined if CONFIG_ACME (or
102  * CONFIG_SPL_ACME/CONFIG_TPL_ACME, depending on build context) is
103  * set, and nothing otherwise.
104  */
105 
106 #define CONFIG_IS_ENABLED(option, ...)					\
107 	__concat(__CONFIG_IS_ENABLED_, __count_args(option, ##__VA_ARGS__)) (option, ##__VA_ARGS__)
108 
109 
110 #endif /* __LINUX_KCONFIG_H */
111