kernel/printk/braille.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   3
   4 #include <linux/kernel.h>
   5 #include <linux/console.h>
   6 #include <linux/errno.h>
   7 #include <linux/string.h>
   8
   9 #include "console_cmdline.h"
  10 #include "braille.h"
  11
  12 int _braille_console_setup(char **str, char **brl_options)
  13 {
  14         size_t len;
  15
  16         len = str_has_prefix(*str, "brl,");
  17         if (len) {
  18                 *brl_options = "";
  19                 *str += len;
  20                 return 0;
  21         }
  22
  23         len = str_has_prefix(*str, "brl=");
  24         if (len) {
  25                 *brl_options = *str + len;
  26                 *str = strchr(*brl_options, ',');
  27                 if (!*str) {
  28                         pr_err("need port name after brl=\n");
  29                         return -EINVAL;
  30                 }
  31                 *((*str)++) = 0;
  32         }
  33
  34         return 0;
  35 }
  36
  37 int
  38 _braille_register_console(struct console *console, struct console_cmdline *c)
  39 {
  40         int rtn = 0;
  41
  42         if (c->brl_options) {
  43                 console->flags |= CON_BRL;
  44                 rtn = braille_register_console(console, c->index, c->options,
  45                                                c->brl_options);
  46         }
  47
  48         return rtn;
  49 }
  50
  51 int
  52 _braille_unregister_console(struct console *console)
  53 {
  54         if (console->flags & CON_BRL)
  55                 return braille_unregister_console(console);
  56
  57         return 0;
  58 }