historical/m0-applesillicon.git/xnu-qemu-arm64-5.1.0/roms/skiboot/external/lpc/lpc.c
2024-01-16 11:20:27 -06:00

187 lines
4 KiB
C

/* Copyright 2014-2016 IBM Corp.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied.
* See the License for the specific language governing permissions and
* imitations under the License.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <byteswap.h>
#include <stdint.h>
#include <stdbool.h>
#include <getopt.h>
#include <limits.h>
#include <arpa/inet.h>
#include <assert.h>
#include <endian.h>
#include <byteswap.h>
#define SYSFS_PREFIX "/sys/kernel/debug/powerpc/lpc"
int main(int argc, char *argv[])
{
char path[256];
char *dot;
char *eq;
int fd, size = 4;
bool do_write = false;
bool big_endian = false;
uint32_t addr, val;
ssize_t rc;
if (argc < 3) {
printf("Usage: %s <space> <addr>[.lLwWbBd[,size]][=value]\n", argv[0]);
return 0;
}
eq = strchr(argv[2], '=');
if (eq) {
do_write = true;
val = strtoul(eq + 1, NULL, 0);
*eq = 0;
}
dot = strchr(argv[2], '.');
if (dot) {
*(dot++) = 0;
switch(*dot) {
case 'L':
big_endian = true;
case 'l':
break;
case 'W':
big_endian = true;
case 'w':
size = 2;
break;
case 'B':
big_endian = true;
case 'b':
size = 1;
break;
default:
fprintf(stderr, "Invalid size specifier\n");
exit(1);
}
}
addr = strtoul(argv[2], NULL, 0);
memset(path, 0, sizeof(path));
snprintf(path, 255, SYSFS_PREFIX "/%s", argv[1]);
fd = open(path, O_RDWR);
if (fd < 0) {
perror("Failed to open sysfs file");
exit(1);
}
lseek(fd, addr, SEEK_SET);
if (do_write) {
uint8_t v8;
uint16_t v16;
uint32_t v32;
switch(size) {
case 1:
val &= 0xff;
v8 = val;
rc = write(fd, &v8, 1);
if (rc != 1) {
perror("Failed to write to LPC");
exit(1);
}
printf("[%s] W 0x%08x.%c=0x%02x\n",
argv[1], addr, big_endian ? 'B' : 'b', val);
break;
case 2:
val &= 0xffff;
#if __BYTE_ORDER == __LITTLE_ENDIAN
v16 = big_endian ? bswap_16(val) : val;
#else
v16 = big_endian ? val : bswap_16(val);
#endif
rc = write(fd, &v16, 2);
if (rc != 2) {
perror("Failed to write to LPC");
exit(1);
}
printf("[%s] W 0x%08x.%c=0x%04x\n",
argv[1], addr, big_endian ? 'W' : 'w', val);
break;
default:
#if __BYTE_ORDER == __LITTLE_ENDIAN
v32 = big_endian ? bswap_32(val) : val;
#else
v32 = big_endian ? val : bswap_32(val);
#endif
rc = write(fd, &v32, 4);
if (rc != 4) {
perror("Failed to write to LPC");
exit(1);
}
printf("[%s] W 0x%08x.%c=0x%08x\n",
argv[1], addr, big_endian ? 'L' : 'l', val);
break;
}
} else {
uint8_t v8;
uint16_t v16;
uint32_t v32;
switch(size) {
case 1:
rc = read(fd, &v8, 1);
if (rc != 1) {
perror("Failed to read from LPC");
exit(1);
}
printf("[%s] R 0x%08x.%c=0x%02x\n", argv[1], addr,
big_endian ? 'B' : 'b', v8);
break;
case 2:
rc = read(fd, &v16, 2);
if (rc != 2) {
perror("Failed to read from LPC");
exit(1);
}
#if __BYTE_ORDER == __LITTLE_ENDIAN
v16 = big_endian ? bswap_16(v16) : v16;
#else
v16 = big_endian ? v16 : bswap_16(v16);
#endif
printf("[%s] R 0x%08x.%c=0x%04x\n", argv[1], addr,
big_endian ? 'W' : 'w', v16);
break;
default:
rc = read(fd, &v32, 4);
if (rc != 4) {
perror("Failed to read from LPC");
exit(1);
}
#if __BYTE_ORDER == __LITTLE_ENDIAN
v32 = big_endian ? bswap_32(v32) : v32;
#else
v32 = big_endian ? v32 : bswap_32(v32);
#endif
printf("[%s] R 0x%08x.%c=0x%08x\n", argv[1], addr,
big_endian ? 'L' : 'l', v32);
break;
}
}
return 0;
}