xref: /linux/include/drm/drm_print.h (revision 6f52b16c5b29b89d92c0e7236f4655dc8491ad70)
1 /*
2  * Copyright (C) 2016 Red Hat
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors:
23  * Rob Clark <robdclark@gmail.com>
24  */
25 
26 #ifndef DRM_PRINT_H_
27 #define DRM_PRINT_H_
28 
29 #include <linux/compiler.h>
30 #include <linux/printk.h>
31 #include <linux/seq_file.h>
32 #include <linux/device.h>
33 
34 /**
35  * DOC: print
36  *
37  * A simple wrapper for dev_printk(), seq_printf(), etc.  Allows same
38  * debug code to be used for both debugfs and printk logging.
39  *
40  * For example::
41  *
42  *     void log_some_info(struct drm_printer *p)
43  *     {
44  *             drm_printf(p, "foo=%d\n", foo);
45  *             drm_printf(p, "bar=%d\n", bar);
46  *     }
47  *
48  *     #ifdef CONFIG_DEBUG_FS
49  *     void debugfs_show(struct seq_file *f)
50  *     {
51  *             struct drm_printer p = drm_seq_file_printer(f);
52  *             log_some_info(&p);
53  *     }
54  *     #endif
55  *
56  *     void some_other_function(...)
57  *     {
58  *             struct drm_printer p = drm_info_printer(drm->dev);
59  *             log_some_info(&p);
60  *     }
61  */
62 
63 /**
64  * struct drm_printer - drm output "stream"
65  *
66  * Do not use struct members directly.  Use drm_printer_seq_file(),
67  * drm_printer_info(), etc to initialize.  And drm_printf() for output.
68  */
69 struct drm_printer {
70 	/* private: */
71 	void (*printfn)(struct drm_printer *p, struct va_format *vaf);
72 	void *arg;
73 	const char *prefix;
74 };
75 
76 void __drm_printfn_seq_file(struct drm_printer *p, struct va_format *vaf);
77 void __drm_printfn_info(struct drm_printer *p, struct va_format *vaf);
78 void __drm_printfn_debug(struct drm_printer *p, struct va_format *vaf);
79 
80 __printf(2, 3)
81 void drm_printf(struct drm_printer *p, const char *f, ...);
82 
83 
84 /**
85  * drm_seq_file_printer - construct a &drm_printer that outputs to &seq_file
86  * @f:  the &struct seq_file to output to
87  *
88  * RETURNS:
89  * The &drm_printer object
90  */
91 static inline struct drm_printer drm_seq_file_printer(struct seq_file *f)
92 {
93 	struct drm_printer p = {
94 		.printfn = __drm_printfn_seq_file,
95 		.arg = f,
96 	};
97 	return p;
98 }
99 
100 /**
101  * drm_info_printer - construct a &drm_printer that outputs to dev_printk()
102  * @dev: the &struct device pointer
103  *
104  * RETURNS:
105  * The &drm_printer object
106  */
107 static inline struct drm_printer drm_info_printer(struct device *dev)
108 {
109 	struct drm_printer p = {
110 		.printfn = __drm_printfn_info,
111 		.arg = dev,
112 	};
113 	return p;
114 }
115 
116 /**
117  * drm_debug_printer - construct a &drm_printer that outputs to pr_debug()
118  * @prefix: debug output prefix
119  *
120  * RETURNS:
121  * The &drm_printer object
122  */
123 static inline struct drm_printer drm_debug_printer(const char *prefix)
124 {
125 	struct drm_printer p = {
126 		.printfn = __drm_printfn_debug,
127 		.prefix = prefix
128 	};
129 	return p;
130 }
131 #endif /* DRM_PRINT_H_ */
132