Jetpack/u-boot/common/hwconfig.c

286 lines
7.7 KiB
C

/*
* An inteface for configuring a hardware via u-boot environment.
*
* Copyright (c) 2009 MontaVista Software, Inc.
* Copyright 2011 Freescale Semiconductor, Inc.
*
* Author: Anton Vorontsov <avorontsov@ru.mvista.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef HWCONFIG_TEST
#include <config.h>
#include <common.h>
#include <exports.h>
#include <hwconfig.h>
#include <linux/types.h>
#include <linux/string.h>
#else
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#define min(a, b) (((a) < (b)) ? (a) : (b))
#endif /* HWCONFIG_TEST */
DECLARE_GLOBAL_DATA_PTR;
static const char *hwconfig_parse(const char *opts, size_t maxlen,
const char *opt, char *stopchs, char eqch,
size_t *arglen)
{
size_t optlen = strlen(opt);
char *str;
const char *start = opts;
const char *end;
next:
str = strstr(opts, opt);
end = str + optlen;
if (end - start > maxlen)
return NULL;
if (str && (str == opts || strpbrk(str - 1, stopchs) == str - 1) &&
(strpbrk(end, stopchs) == end || *end == eqch ||
*end == '\0')) {
const char *arg_end;
if (!arglen)
return str;
if (*end != eqch)
return NULL;
arg_end = strpbrk(str, stopchs);
if (!arg_end)
*arglen = min(maxlen, strlen(str)) - optlen - 1;
else
*arglen = arg_end - end - 1;
return end + 1;
} else if (str) {
opts = end;
goto next;
}
return NULL;
}
const char cpu_hwconfig[] __attribute__((weak)) = "";
const char board_hwconfig[] __attribute__((weak)) = "";
static const char *__hwconfig(const char *opt, size_t *arglen,
const char *env_hwconfig)
{
const char *ret;
/* if we are passed a buffer use it, otherwise try the environment */
if (!env_hwconfig) {
if (!(gd->flags & GD_FLG_ENV_READY)) {
printf("WARNING: Calling __hwconfig without a buffer "
"and before environment is ready\n");
return NULL;
}
env_hwconfig = getenv("hwconfig");
}
if (env_hwconfig) {
ret = hwconfig_parse(env_hwconfig, strlen(env_hwconfig),
opt, ";", ':', arglen);
if (ret)
return ret;
}
ret = hwconfig_parse(board_hwconfig, strlen(board_hwconfig),
opt, ";", ':', arglen);
if (ret)
return ret;
return hwconfig_parse(cpu_hwconfig, strlen(cpu_hwconfig),
opt, ";", ':', arglen);
}
/*
* hwconfig_f - query if a particular hwconfig option is specified
* @opt: a string representing an option
* @buf: if non-NULL use this buffer to parse, otherwise try env
*
* This call can be used to find out whether U-Boot should configure
* a particular hardware option.
*
* Returns non-zero value if the hardware option can be used and thus
* should be configured, 0 otherwise.
*
* This function also returns non-zero value if CONFIG_HWCONFIG is
* undefined.
*
* Returning non-zero value without CONFIG_HWCONFIG has its crucial
* purpose: the hwconfig() call should be a "transparent" interface,
* e.g. if a board doesn't need hwconfig facility, then we assume
* that the board file only calls things that are actually used, so
* hwconfig() will always return true result.
*/
int hwconfig_f(const char *opt, char *buf)
{
return !!__hwconfig(opt, NULL, buf);
}
/*
* hwconfig_arg_f - get hwconfig option's argument
* @opt: a string representing an option
* @arglen: a pointer to an allocated size_t variable
* @buf: if non-NULL use this buffer to parse, otherwise try env
*
* Unlike hwconfig_f() function, this function returns a pointer to the
* start of the hwconfig arguments, if option is not found or it has
* no specified arguments, the function returns NULL pointer.
*
* If CONFIG_HWCONFIG is undefined, the function returns "", and
* arglen is set to 0.
*/
const char *hwconfig_arg_f(const char *opt, size_t *arglen, char *buf)
{
return __hwconfig(opt, arglen, buf);
}
/*
* hwconfig_arg_cmp_f - compare hwconfig option's argument
* @opt: a string representing an option
* @arg: a string for comparing an option's argument
* @buf: if non-NULL use this buffer to parse, otherwise try env
*
* This call is similar to hwconfig_arg_f, but instead of returning
* hwconfig argument and its length, it is comparing it to @arg.
*
* Returns non-zero value if @arg matches, 0 otherwise.
*
* If CONFIG_HWCONFIG is undefined, the function returns a non-zero
* value, i.e. the argument matches.
*/
int hwconfig_arg_cmp_f(const char *opt, const char *arg, char *buf)
{
const char *argstr;
size_t arglen;
argstr = hwconfig_arg_f(opt, &arglen, buf);
if (!argstr || arglen != strlen(arg))
return 0;
return !strncmp(argstr, arg, arglen);
}
/*
* hwconfig_sub_f - query if a particular hwconfig sub-option is specified
* @opt: a string representing an option
* @subopt: a string representing a sub-option
* @buf: if non-NULL use this buffer to parse, otherwise try env
*
* This call is similar to hwconfig_f(), except that it takes additional
* argument @subopt. In this example:
* "dr_usb:mode=peripheral"
* "dr_usb" is an option, "mode" is a sub-option, and "peripheral" is its
* argument.
*/
int hwconfig_sub_f(const char *opt, const char *subopt, char *buf)
{
size_t arglen;
const char *arg;
arg = __hwconfig(opt, &arglen, buf);
if (!arg)
return 0;
return !!hwconfig_parse(arg, arglen, subopt, ",;", '=', NULL);
}
/*
* hwconfig_subarg_f - get hwconfig sub-option's argument
* @opt: a string representing an option
* @subopt: a string representing a sub-option
* @subarglen: a pointer to an allocated size_t variable
* @buf: if non-NULL use this buffer to parse, otherwise try env
*
* This call is similar to hwconfig_arg_f(), except that it takes an
* additional argument @subopt, and so works with sub-options.
*/
const char *hwconfig_subarg_f(const char *opt, const char *subopt,
size_t *subarglen, char *buf)
{
size_t arglen;
const char *arg;
arg = __hwconfig(opt, &arglen, buf);
if (!arg)
return NULL;
return hwconfig_parse(arg, arglen, subopt, ",;", '=', subarglen);
}
/*
* hwconfig_arg_cmp_f - compare hwconfig sub-option's argument
* @opt: a string representing an option
* @subopt: a string representing a sub-option
* @subarg: a string for comparing an sub-option's argument
* @buf: if non-NULL use this buffer to parse, otherwise try env
*
* This call is similar to hwconfig_arg_cmp_f, except that it takes an
* additional argument @subopt, and so works with sub-options.
*/
int hwconfig_subarg_cmp_f(const char *opt, const char *subopt,
const char *subarg, char *buf)
{
const char *argstr;
size_t arglen;
argstr = hwconfig_subarg_f(opt, subopt, &arglen, buf);
if (!argstr || arglen != strlen(subarg))
return 0;
return !strncmp(argstr, subarg, arglen);
}
#ifdef HWCONFIG_TEST
int main()
{
const char *ret;
size_t len;
setenv("hwconfig", "key1:subkey1=value1,subkey2=value2;key2:value3;;;;"
"key3;:,:=;key4", 1);
ret = hwconfig_arg("key1", &len);
printf("%zd %.*s\n", len, (int)len, ret);
assert(len == 29);
assert(hwconfig_arg_cmp("key1", "subkey1=value1,subkey2=value2"));
assert(!strncmp(ret, "subkey1=value1,subkey2=value2", len));
ret = hwconfig_subarg("key1", "subkey1", &len);
printf("%zd %.*s\n", len, (int)len, ret);
assert(len == 6);
assert(hwconfig_subarg_cmp("key1", "subkey1", "value1"));
assert(!strncmp(ret, "value1", len));
ret = hwconfig_subarg("key1", "subkey2", &len);
printf("%zd %.*s\n", len, (int)len, ret);
assert(len == 6);
assert(hwconfig_subarg_cmp("key1", "subkey2", "value2"));
assert(!strncmp(ret, "value2", len));
ret = hwconfig_arg("key2", &len);
printf("%zd %.*s\n", len, (int)len, ret);
assert(len == 6);
assert(hwconfig_arg_cmp("key2", "value3"));
assert(!strncmp(ret, "value3", len));
assert(hwconfig("key3"));
assert(hwconfig_arg("key4", &len) == NULL);
assert(hwconfig_arg("bogus", &len) == NULL);
unsetenv("hwconfig");
assert(hwconfig(NULL) == 0);
assert(hwconfig("") == 0);
assert(hwconfig("key3") == 0);
return 0;
}
#endif /* HWCONFIG_TEST */