arch/powerpc/boot/opal.c

   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__ */