1 files changed, 210 insertions, 0 deletions
diff --git a/common/hwconfig.c b/common/hwconfig.c
new file mode 100644
index 0000000..e5c60ba
--- /dev/null
+++ b/common/hwconfig.c
@@ -0,0 +1,210 @@
+/*
+ * An inteface for configuring a hardware via u-boot environment.
+ *
+ * Copyright (c) 2009  MontaVista Software, Inc.
+ *
+ * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+#include <config.h>
+#include <common.h>
+#include <exports.h>
+#include <hwconfig.h>
+#include <linux/types.h>
+#include <linux/string.h>
+
+static const char *hwconfig_parse(const char *opts, size_t maxlen,
+				  const char *opt, char stopch, 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 || str[-1] == stopch) &&
+			(*end == stopch || *end == eqch || *end == '\0')) {
+		const char *arg_end;
+
+		if (!arglen)
+			return str;
+
+		if (*end != eqch)
+			return NULL;
+
+		arg_end = strchr(str, stopch);
+		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 = getenv("hwconfig");
+
+	if (env_hwconfig)
+		return hwconfig_parse(env_hwconfig, strlen(env_hwconfig),
+				      opt, ';', ':', arglen);
+
+	if (board_hwconfig)
+		return hwconfig_parse(board_hwconfig, strlen(board_hwconfig),
+				      opt, ';', ':', arglen);
+
+	if (cpu_hwconfig)
+		return hwconfig_parse(cpu_hwconfig, strlen(cpu_hwconfig),
+				      opt, ';', ':', arglen);
+
+	return NULL;
+}
+
+/*
+ * hwconfig - query if a particular hwconfig option is specified
+ * @opt:	a string representing an option
+ *
+ * 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(const char *opt)
+{
+	return !!__hwconfig(opt, NULL);
+}
+
+/*
+ * hwconfig_arg - get hwconfig option's argument
+ * @opt:	a string representing an option
+ * @arglen:	a pointer to an allocated size_t variable
+ *
+ * Unlike hwconfig() 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(const char *opt, size_t *arglen)
+{
+	return __hwconfig(opt, arglen);
+}
+
+/*
+ * hwconfig_arg_cmp - compare hwconfig option's argument
+ * @opt:	a string representing an option
+ * @arg:	a string for comparing an option's argument
+ *
+ * This call is similar to hwconfig_arg, 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(const char *opt, const char *arg)
+{
+	const char *argstr;
+	size_t arglen;
+
+	argstr = hwconfig_arg(opt, &arglen);
+	if (!argstr || arglen != strlen(arg))
+		return 0;
+
+	return !strncmp(argstr, arg, arglen);
+}
+
+/*
+ * hwconfig_sub - query if a particular hwconfig sub-option is specified
+ * @opt:	a string representing an option
+ * @subopt:	a string representing a sub-option
+ *
+ * This call is similar to hwconfig(), 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(const char *opt, const char *subopt)
+{
+	size_t arglen;
+	const char *arg;
+
+	arg = __hwconfig(opt, &arglen);
+	if (!arg)
+		return 0;
+	return !!hwconfig_parse(arg, arglen, subopt, ',', '=', NULL);
+}
+
+/*
+ * hwconfig_subarg - 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
+ *
+ * This call is similar to hwconfig_arg(), except that it takes an additional
+ * argument @subopt, and so works with sub-options.
+ */
+const char *hwconfig_subarg(const char *opt, const char *subopt,
+			    size_t *subarglen)
+{
+	size_t arglen;
+	const char *arg;
+
+	arg = __hwconfig(opt, &arglen);
+	if (!arg)
+		return NULL;
+	return hwconfig_parse(arg, arglen, subopt, ',', '=', subarglen);
+}
+
+/*
+ * hwconfig_arg_cmp - 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
+ *
+ * This call is similar to hwconfig_arg_cmp, except that it takes an additional
+ * argument @subopt, and so works with sub-options.
+ */
+int hwconfig_subarg_cmp(const char *opt, const char *subopt, const char *subarg)
+{
+	const char *argstr;
+	size_t arglen;
+
+	argstr = hwconfig_subarg(opt, subopt, &arglen);
+	if (!argstr || arglen != strlen(subarg))
+		return 0;
+
+	return !strncmp(argstr, subarg, arglen);
+}