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authorThomas Renninger <trenn@suse.de>2014-04-07 15:16:57 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-04-28 12:36:56 +0200
commitd7cddbb07b18cc45e57420005850ca0326b9e074 (patch)
tree7d640a12341524d0227c7829e5ec990dd378ad13 /tools/power/acpi/tools/ec/ec_access.c
parentLinux 3.15-rc3 (diff)
downloadlinux-dev-d7cddbb07b18cc45e57420005850ca0326b9e074.tar.xz
linux-dev-d7cddbb07b18cc45e57420005850ca0326b9e074.zip
ACPI / tools: Introduce ec_access.c - tool to access the EC
This userspace tool accesses the EC through the ec_sys debug driver (through /sys/kernel/debug/ec/ec0/io). The EC command/data registers cannot be accessed directly, because they may be manipulated by the AML interpreter in parallel. The ec_sys driver synchronizes user space (debug) access with the AML interpreter. Signed-off-by: Thomas Renninger <trenn@suse.de> [rjw: Changelog] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to '')
-rw-r--r--tools/power/acpi/tools/ec/ec_access.c238
1 files changed, 238 insertions, 0 deletions
diff --git a/tools/power/acpi/tools/ec/ec_access.c b/tools/power/acpi/tools/ec/ec_access.c
new file mode 100644
index 000000000000..6b8aaed44f2c
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+++ b/tools/power/acpi/tools/ec/ec_access.c
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+/*
+ * ec_access.c
+ *
+ * Copyright (C) 2010 SUSE Linux Products GmbH
+ * Author:
+ * Thomas Renninger <trenn@suse.de>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+
+#include <fcntl.h>
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <libgen.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <stdint.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+
+#define EC_SPACE_SIZE 256
+#define SYSFS_PATH "/sys/kernel/debug/ec/ec0/io"
+
+/* TBD/Enhancements:
+ - Provide param for accessing different ECs (not supported by kernel yet)
+*/
+
+static int read_mode = -1;
+static int sleep_time;
+static int write_byte_offset = -1;
+static int read_byte_offset = -1;
+static uint8_t write_value = -1;
+
+void usage(char progname[], int exit_status)
+{
+ printf("Usage:\n");
+ printf("1) %s -r [-s sleep]\n", basename(progname));
+ printf("2) %s -b byte_offset\n", basename(progname));
+ printf("3) %s -w byte_offset -v value\n\n", basename(progname));
+
+ puts("\t-r [-s sleep] : Dump EC registers");
+ puts("\t If sleep is given, sleep x seconds,");
+ puts("\t re-read EC registers and show changes");
+ puts("\t-b offset : Read value at byte_offset (in hex)");
+ puts("\t-w offset -v value : Write value at byte_offset");
+ puts("\t-h : Print this help\n\n");
+ puts("Offsets and values are in hexadecimal number sytem.");
+ puts("The offset and value must be between 0 and 0xff.");
+ exit(exit_status);
+}
+
+void parse_opts(int argc, char *argv[])
+{
+ int c;
+
+ while ((c = getopt(argc, argv, "rs:b:w:v:h")) != -1) {
+
+ switch (c) {
+ case 'r':
+ if (read_mode != -1)
+ usage(argv[0], EXIT_FAILURE);
+ read_mode = 1;
+ break;
+ case 's':
+ if (read_mode != -1 && read_mode != 1)
+ usage(argv[0], EXIT_FAILURE);
+
+ sleep_time = atoi(optarg);
+ if (sleep_time <= 0) {
+ sleep_time = 0;
+ usage(argv[0], EXIT_FAILURE);
+ printf("Bad sleep time: %s\n", optarg);
+ }
+ break;
+ case 'b':
+ if (read_mode != -1)
+ usage(argv[0], EXIT_FAILURE);
+ read_mode = 1;
+ read_byte_offset = strtoul(optarg, NULL, 16);
+ break;
+ case 'w':
+ if (read_mode != -1)
+ usage(argv[0], EXIT_FAILURE);
+ read_mode = 0;
+ write_byte_offset = strtoul(optarg, NULL, 16);
+ break;
+ case 'v':
+ write_value = strtoul(optarg, NULL, 16);
+ break;
+ case 'h':
+ usage(argv[0], EXIT_SUCCESS);
+ default:
+ fprintf(stderr, "Unknown option!\n");
+ usage(argv[0], EXIT_FAILURE);
+ }
+ }
+ if (read_mode == 0) {
+ if (write_byte_offset < 0 ||
+ write_byte_offset >= EC_SPACE_SIZE) {
+ fprintf(stderr, "Wrong byte offset 0x%.2x, valid: "
+ "[0-0x%.2x]\n",
+ write_byte_offset, EC_SPACE_SIZE - 1);
+ usage(argv[0], EXIT_FAILURE);
+ }
+ if (write_value < 0 ||
+ write_value >= 255) {
+ fprintf(stderr, "Wrong byte offset 0x%.2x, valid:"
+ "[0-0xff]\n", write_byte_offset);
+ usage(argv[0], EXIT_FAILURE);
+ }
+ }
+ if (read_mode == 1 && read_byte_offset != -1) {
+ if (read_byte_offset < -1 ||
+ read_byte_offset >= EC_SPACE_SIZE) {
+ fprintf(stderr, "Wrong byte offset 0x%.2x, valid: "
+ "[0-0x%.2x]\n",
+ read_byte_offset, EC_SPACE_SIZE - 1);
+ usage(argv[0], EXIT_FAILURE);
+ }
+ }
+ /* Add additional parameter checks here */
+}
+
+void dump_ec(int fd)
+{
+ char buf[EC_SPACE_SIZE];
+ char buf2[EC_SPACE_SIZE];
+ int byte_off, bytes_read;
+
+ bytes_read = read(fd, buf, EC_SPACE_SIZE);
+
+ if (bytes_read == -1)
+ err(EXIT_FAILURE, "Could not read from %s\n", SYSFS_PATH);
+
+ if (bytes_read != EC_SPACE_SIZE)
+ fprintf(stderr, "Could only read %d bytes\n", bytes_read);
+
+ printf(" 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F");
+ for (byte_off = 0; byte_off < bytes_read; byte_off++) {
+ if ((byte_off % 16) == 0)
+ printf("\n%.2X: ", byte_off);
+ printf(" %.2x ", (uint8_t)buf[byte_off]);
+ }
+ printf("\n");
+
+ if (!sleep_time)
+ return;
+
+ printf("\n");
+ lseek(fd, 0, SEEK_SET);
+ sleep(sleep_time);
+
+ bytes_read = read(fd, buf2, EC_SPACE_SIZE);
+
+ if (bytes_read == -1)
+ err(EXIT_FAILURE, "Could not read from %s\n", SYSFS_PATH);
+
+ if (bytes_read != EC_SPACE_SIZE)
+ fprintf(stderr, "Could only read %d bytes\n", bytes_read);
+
+ printf(" 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F");
+ for (byte_off = 0; byte_off < bytes_read; byte_off++) {
+ if ((byte_off % 16) == 0)
+ printf("\n%.2X: ", byte_off);
+
+ if (buf[byte_off] == buf2[byte_off])
+ printf(" %.2x ", (uint8_t)buf2[byte_off]);
+ else
+ printf("*%.2x ", (uint8_t)buf2[byte_off]);
+ }
+ printf("\n");
+}
+
+void read_ec_val(int fd, int byte_offset)
+{
+ uint8_t buf;
+ int error;
+
+ error = lseek(fd, byte_offset, SEEK_SET);
+ if (error != byte_offset)
+ err(EXIT_FAILURE, "Cannot set offset to 0x%.2x", byte_offset);
+
+ error = read(fd, &buf, 1);
+ if (error != 1)
+ err(EXIT_FAILURE, "Could not read byte 0x%.2x from %s\n",
+ byte_offset, SYSFS_PATH);
+ printf("0x%.2x\n", buf);
+ return;
+}
+
+void write_ec_val(int fd, int byte_offset, uint8_t value)
+{
+ int error;
+
+ error = lseek(fd, byte_offset, SEEK_SET);
+ if (error != byte_offset)
+ err(EXIT_FAILURE, "Cannot set offset to 0x%.2x", byte_offset);
+
+ error = write(fd, &value, 1);
+ if (error != 1)
+ err(EXIT_FAILURE, "Cannot write value 0x%.2x to offset 0x%.2x",
+ value, byte_offset);
+}
+
+int main(int argc, char *argv[])
+{
+ int file_mode = O_RDONLY;
+ int fd;
+
+ parse_opts(argc, argv);
+
+ if (read_mode == 0)
+ file_mode = O_WRONLY;
+ else if (read_mode == 1)
+ file_mode = O_RDONLY;
+ else
+ usage(argv[0], EXIT_FAILURE);
+
+ fd = open(SYSFS_PATH, file_mode);
+ if (fd == -1)
+ err(EXIT_FAILURE, "%s", SYSFS_PATH);
+
+ if (read_mode)
+ if (read_byte_offset == -1)
+ dump_ec(fd);
+ else if (read_byte_offset < 0 ||
+ read_byte_offset >= EC_SPACE_SIZE)
+ usage(argv[0], EXIT_FAILURE);
+ else
+ read_ec_val(fd, read_byte_offset);
+ else
+ write_ec_val(fd, write_byte_offset, write_value);
+ close(fd);
+
+ exit(EXIT_SUCCESS);
+}