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/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include <stdio.h>
#include <string.h>
#include "host_common.h"
#include "crossystem.h"
#include "utility.h"
#include "vboot_common.h"
/* ACPI constants from Chrome OS Main Processor Firmware Spec */
/* GPIO signal types */
#define GPIO_SIGNAL_TYPE_RECOVERY 1
#define GPIO_SIGNAL_TYPE_DEV 2
#define GPIO_SIGNAL_TYPE_WP 3
/* CHSW bitflags */
#define CHSW_RECOVERY_BOOT 0x00000002
#define CHSW_RECOVERY_EC_BOOT 0x00000004
#define CHSW_DEV_BOOT 0x00000020
#define CHSW_WP_BOOT 0x00000200
/* Base name for ACPI files */
#define ACPI_BASE_PATH "/sys/devices/platform/chromeos_acpi"
/* Paths for frequently used ACPI files */
#define ACPI_CHNV_PATH ACPI_BASE_PATH "/CHNV"
#define ACPI_CHSW_PATH ACPI_BASE_PATH "/CHSW"
#define ACPI_GPIO_PATH ACPI_BASE_PATH "/GPIO"
/* Base name for GPIO files */
#define GPIO_BASE_PATH "/sys/class/gpio"
#define GPIO_EXPORT_PATH GPIO_BASE_PATH "/export"
/* Read a string from a file. Passed the destination, dest size, and
* filename to read.
*
* Returns the destination, or NULL if error. */
char* ReadFileString(char* dest, int size, const char* filename) {
char* got;
FILE* f;
f = fopen(filename, "rt");
if (!f)
return NULL;
got = fgets(dest, size, f);
fclose(f);
return got;
}
/* Read an integer from a file.
*
* Returns the parsed integer, or -1 if error. */
int ReadFileInt(const char* filename) {
char buf[64];
int value;
char* e = NULL;
if (!ReadFileString(buf, sizeof(buf), filename))
return -1;
/* Convert to integer. Allow characters after the int ("123 blah"). */
value = strtol(buf, &e, 0);
if (e == buf)
return -1; /* No characters consumed, so conversion failed */
return value;
}
/* Check if a bit is set in a file which contains an integer.
*
* Returns 1 if the bit is set, 0 if clear, or -1 if error. */
int ReadFileBit(const char* filename, int bitmask) {
int value = ReadFileInt(filename);
if (value == -1)
return -1;
else return (value & bitmask ? 1 : 0);
}
/* Return true if the FWID starts with the specified string. */
static int FwidStartsWith(const char *start) {
char fwid[128];
if (!VbGetSystemPropertyString("fwid", fwid, sizeof(fwid)))
return 0;
return 0 == strncmp(fwid, start, strlen(start));
}
/* Read a GPIO of the specified signal type (see ACPI GPIO SignalType).
*
* Returns 1 if the signal is asserted, 0 if not asserted, or -1 if error. */
int ReadGpio(int signal_type) {
char name[128];
int index = 0;
int gpio_type;
int active_high;
int controller_offset;
char controller_name[128];
int value;
/* Scan GPIO.* to find a matching signal type */
for (index = 0; ; index++) {
snprintf(name, sizeof(name), "%s.%d/GPIO.0", ACPI_GPIO_PATH, index);
gpio_type = ReadFileInt(name);
if (gpio_type == signal_type)
break;
else if (gpio_type == -1)
return -1; /* Ran out of GPIOs before finding a match */
}
/* Read attributes and controller info for the GPIO */
snprintf(name, sizeof(name), "%s.%d/GPIO.1", ACPI_GPIO_PATH, index);
active_high = ReadFileBit(name, 0x00000001);
snprintf(name, sizeof(name), "%s.%d/GPIO.2", ACPI_GPIO_PATH, index);
controller_offset = ReadFileInt(name);
if (active_high == -1 || controller_offset == -1)
return -1; /* Missing needed info */
/* We only support the NM10 for now */
snprintf(name, sizeof(name), "%s.%d/GPIO.3", ACPI_GPIO_PATH, index);
if (!ReadFileString(controller_name, sizeof(controller_name), name))
return -1;
if (0 != strcmp(controller_name, "NM10"))
return -1;
/* Assume the NM10 has offset 192 */
/* TODO: should really check gpiochipNNN/label to see if it's the
* address we expect for the NM10, and then read the offset from
* gpiochipNNN/base. */
controller_offset += 192;
/* Try reading the GPIO value */
snprintf(name, sizeof(name), "%s/gpio%d/value",
GPIO_BASE_PATH, controller_offset);
value = ReadFileInt(name);
if (value == -1) {
/* Try exporting the GPIO */
FILE* f = fopen(GPIO_EXPORT_PATH, "wt");
if (!f)
return -1;
fprintf(f, "%d", controller_offset);
fclose(f);
/* Try re-reading the GPIO value */
value = ReadFileInt(name);
}
if (value == -1)
return -1;
/* Compare the GPIO value with the active value and return 1 if match. */
return (value == active_high ? 1 : 0);
}
/* Read a system property integer.
*
* Returns the property value, or -1 if error. */
int VbGetSystemPropertyInt(const char* name) {
int value = -1;
if (!strcasecmp(name,"devsw_cur")) {
value = ReadGpio(GPIO_SIGNAL_TYPE_DEV);
} else if (!strcasecmp(name,"devsw_boot")) {
value = ReadFileBit(ACPI_CHSW_PATH, CHSW_DEV_BOOT);
} else if (!strcasecmp(name,"recoverysw_cur")) {
value = ReadGpio(GPIO_SIGNAL_TYPE_RECOVERY);
} else if (!strcasecmp(name,"recoverysw_boot")) {
value = ReadFileBit(ACPI_CHSW_PATH, CHSW_RECOVERY_BOOT);
} else if (!strcasecmp(name,"recoverysw_ec_boot")) {
value = ReadFileBit(ACPI_CHSW_PATH, CHSW_RECOVERY_EC_BOOT);
} else if (!strcasecmp(name,"wpsw_cur")) {
value = ReadGpio(GPIO_SIGNAL_TYPE_WP);
if (-1 != value && FwidStartsWith("Mario."))
value = 1 - value; /* Mario reports this backwards */
} else if (!strcasecmp(name,"wpsw_boot")) {
value = ReadFileBit(ACPI_CHSW_PATH, CHSW_WP_BOOT);
if (-1 != value && FwidStartsWith("Mario."))
value = 1 - value; /* Mario reports this backwards */
}
/* TODO: remaining properties from spec */
return value;
}
/* Read a system property string into a destination buffer of the specified
* size.
*
* Returns the passed buffer, or NULL if error. */
const char* VbGetSystemPropertyString(const char* name, char* dest, int size) {
if (!strcasecmp(name,"hwid")) {
return ReadFileString(dest, size, ACPI_BASE_PATH "/HWID");
} else if (!strcasecmp(name,"fwid")) {
return ReadFileString(dest, size, ACPI_BASE_PATH "/FWID");
} else if (!strcasecmp(name,"ro_fwid")) {
return ReadFileString(dest, size, ACPI_BASE_PATH "/FRID");
} else
return NULL;
/* TODO: remaining properties from spec */
}
/* Set a system property integer.
*
* Returns 0 if success, -1 if error. */
int VbSetSystemPropertyInt(const char* name, int value) {
/* TODO: support setting */
return -1;
}
/* Set a system property string.
*
* Returns 0 if success, -1 if error. */
int VbSetSystemPropertyString(const char* name, const char* value) {
/* TODO: support setting */
return -1;
}
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