1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (c) 2016 IBM Corporation.
10 #include "../include/asm/opal-api.h"
12 /* Global OPAL struct used by opal-call.S */
18 static u32 opal_con_id;
20 /* see opal-wrappers.S */
21 int64_t opal_console_write(int64_t term_number, u64 *length, const u8 *buffer);
22 int64_t opal_console_read(int64_t term_number, uint64_t *length, u8 *buffer);
23 int64_t opal_console_write_buffer_space(uint64_t term_number, uint64_t *length);
24 int64_t opal_console_flush(uint64_t term_number);
25 int64_t opal_poll_events(uint64_t *outstanding_event_mask);
27 void opal_kentry(unsigned long fdt_addr, void *vmlinux_addr);
29 static int opal_con_open(void)
32 * When OPAL loads the boot kernel it stashes the OPAL base and entry
33 * address in r8 and r9 so the kernel can use the OPAL console
34 * before unflattening the devicetree. While executing the wrapper will
35 * probably trash r8 and r9 so this kentry hook restores them before
36 * entering the decompressed kernel.
38 platform_ops.kentry = opal_kentry;
42 static void opal_con_putc(unsigned char c)
48 rc = opal_console_write_buffer_space(opal_con_id, &olen);
49 len = be64_to_cpu(olen);
52 opal_poll_events(NULL);
56 olen = cpu_to_be64(1);
57 opal_console_write(opal_con_id, &olen, &c);
60 static void opal_con_close(void)
62 opal_console_flush(opal_con_id);
65 static void opal_init(void)
69 opal_node = finddevice("/ibm,opal");
72 if (getprop(opal_node, "opal-base-address", &opal.base, sizeof(u64)) < 0)
74 opal.base = be64_to_cpu(opal.base);
75 if (getprop(opal_node, "opal-entry-address", &opal.entry, sizeof(u64)) < 0)
77 opal.entry = be64_to_cpu(opal.entry);
80 int opal_console_init(void *devp, struct serial_console_data *scdp)
85 int n = getprop(devp, "reg", &opal_con_id, sizeof(u32));
88 opal_con_id = be32_to_cpu(opal_con_id);
92 scdp->open = opal_con_open;
93 scdp->putc = opal_con_putc;
94 scdp->close = opal_con_close;