xref: /openbmc/linux/arch/powerpc/boot/opal.c (revision 80483c3a)
1 /*
2  * Copyright (c) 2016 IBM Corporation.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version
7  * 2 of the License, or (at your option) any later version.
8  */
9 
10 #include "ops.h"
11 #include "stdio.h"
12 #include "io.h"
13 #include <libfdt.h>
14 #include "../include/asm/opal-api.h"
15 
16 #ifdef __powerpc64__
17 
18 /* Global OPAL struct used by opal-call.S */
19 struct opal {
20 	u64 base;
21 	u64 entry;
22 } opal;
23 
24 static u32 opal_con_id;
25 
26 int64_t opal_console_write(int64_t term_number, u64 *length, const u8 *buffer);
27 int64_t opal_console_read(int64_t term_number, uint64_t *length, u8 *buffer);
28 int64_t opal_console_write_buffer_space(uint64_t term_number, uint64_t *length);
29 int64_t opal_console_flush(uint64_t term_number);
30 int64_t opal_poll_events(uint64_t *outstanding_event_mask);
31 
32 static int opal_con_open(void)
33 {
34 	return 0;
35 }
36 
37 static void opal_con_putc(unsigned char c)
38 {
39 	int64_t rc;
40 	uint64_t olen, len;
41 
42 	do {
43 		rc = opal_console_write_buffer_space(opal_con_id, &olen);
44 		len = be64_to_cpu(olen);
45 		if (rc)
46 			return;
47 		opal_poll_events(NULL);
48 	} while (len < 1);
49 
50 
51 	olen = cpu_to_be64(1);
52 	opal_console_write(opal_con_id, &olen, &c);
53 }
54 
55 static void opal_con_close(void)
56 {
57 	opal_console_flush(opal_con_id);
58 }
59 
60 static void opal_init(void)
61 {
62 	void *opal_node;
63 
64 	opal_node = finddevice("/ibm,opal");
65 	if (!opal_node)
66 		return;
67 	if (getprop(opal_node, "opal-base-address", &opal.base, sizeof(u64)) < 0)
68 		return;
69 	opal.base = be64_to_cpu(opal.base);
70 	if (getprop(opal_node, "opal-entry-address", &opal.entry, sizeof(u64)) < 0)
71 		return;
72 	opal.entry = be64_to_cpu(opal.entry);
73 }
74 
75 int opal_console_init(void *devp, struct serial_console_data *scdp)
76 {
77 	opal_init();
78 
79 	if (devp) {
80 		int n = getprop(devp, "reg", &opal_con_id, sizeof(u32));
81 		if (n != sizeof(u32))
82 			return -1;
83 		opal_con_id = be32_to_cpu(opal_con_id);
84 	} else
85 		opal_con_id = 0;
86 
87 	scdp->open = opal_con_open;
88 	scdp->putc = opal_con_putc;
89 	scdp->close = opal_con_close;
90 
91 	return 0;
92 }
93 #else
94 int opal_console_init(void *devp, struct serial_console_data *scdp)
95 {
96 	return -1;
97 }
98 #endif /* __powerpc64__ */
99