1 // SPDX-License-Identifier: GPL-2.0+
3 * IBM RTAS driver interface to hvc_console.c
5 * (C) Copyright IBM Corporation 2001-2005
6 * (C) Copyright Red Hat, Inc. 2005
8 * Author(s): Maximino Augilar <IBM STI Design Center>
9 * : Ryan S. Arnold <rsa@us.ibm.com>
10 * : Utz Bacher <utz.bacher@de.ibm.com>
11 * : David Woodhouse <dwmw2@infradead.org>
13 * inspired by drivers/char/hvc_console.c
14 * written by Anton Blanchard and Paul Mackerras
17 #include <linux/console.h>
18 #include <linux/delay.h>
19 #include <linux/err.h>
20 #include <linux/init.h>
21 #include <linux/moduleparam.h>
22 #include <linux/types.h>
26 #include "hvc_console.h"
28 #define hvc_rtas_cookie 0x67781e15
29 static struct hvc_struct *hvc_rtas_dev;
31 static int rtascons_put_char_token = RTAS_UNKNOWN_SERVICE;
32 static int rtascons_get_char_token = RTAS_UNKNOWN_SERVICE;
34 static ssize_t hvc_rtas_write_console(uint32_t vtermno, const u8 *buf,
39 for (i = 0; i < count; i++) {
40 if (rtas_call(rtascons_put_char_token, 1, 1, NULL, buf[i]))
47 static ssize_t hvc_rtas_read_console(uint32_t vtermno, u8 *buf, size_t count)
52 for (i = 0; i < count; i++) {
53 if (rtas_call(rtascons_get_char_token, 0, 2, &c))
62 static const struct hv_ops hvc_rtas_get_put_ops = {
63 .get_chars = hvc_rtas_read_console,
64 .put_chars = hvc_rtas_write_console,
67 static int __init hvc_rtas_init(void)
69 struct hvc_struct *hp;
71 if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
72 rtascons_put_char_token = rtas_token("put-term-char");
73 if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
76 if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
77 rtascons_get_char_token = rtas_token("get-term-char");
78 if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
83 /* Allocate an hvc_struct for the console device we instantiated
84 * earlier. Save off hp so that we can return it on exit */
85 hp = hvc_alloc(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops, 16);
93 device_initcall(hvc_rtas_init);
95 /* This will happen prior to module init. There is no tty at this time? */
96 static int __init hvc_rtas_console_init(void)
98 rtascons_put_char_token = rtas_token("put-term-char");
99 if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
102 rtascons_get_char_token = rtas_token("get-term-char");
103 if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
106 hvc_instantiate(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops);
107 add_preferred_console("hvc", 0, NULL);
111 console_initcall(hvc_rtas_console_init);