include/drm/drm_print.h

   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_ */