drivers/tty/hvc/hvc_riscv_sbi.c

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2008 David Gibson, IBM Corporation
   4  * Copyright (C) 2012 Regents of the University of California
   5  * Copyright (C) 2017 SiFive
   6  */
   7
   8 #include <linux/console.h>
   9 #include <linux/err.h>
  10 #include <linux/init.h>
  11 #include <linux/moduleparam.h>
  12 #include <linux/types.h>
  13
  14 #include <asm/sbi.h>
  15
  16 #include "hvc_console.h"
  17
  18 static int hvc_sbi_tty_put(uint32_t vtermno, const char *buf, int count)
  19 {
  20         int i;
  21
  22         for (i = 0; i < count; i++)
  23                 sbi_console_putchar(buf[i]);
  24
  25         return i;
  26 }
  27
  28 static int hvc_sbi_tty_get(uint32_t vtermno, char *buf, int count)
  29 {
  30         int i, c;
  31
  32         for (i = 0; i < count; i++) {
  33                 c = sbi_console_getchar();
  34                 if (c < 0)
  35                         break;
  36                 buf[i] = c;
  37         }
  38
  39         return i;
  40 }
  41
  42 static const struct hv_ops hvc_sbi_ops = {
  43         .get_chars = hvc_sbi_tty_get,
  44         .put_chars = hvc_sbi_tty_put,
  45 };
  46
  47 static int __init hvc_sbi_init(void)
  48 {
  49         return PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_ops, 16));
  50 }
  51 device_initcall(hvc_sbi_init);
  52
  53 static int __init hvc_sbi_console_init(void)
  54 {
  55         hvc_instantiate(0, 0, &hvc_sbi_ops);
  56         add_preferred_console("hvc", 0, NULL);
  57
  58         return 0;
  59 }
  60 console_initcall(hvc_sbi_console_init);