[PATCH 1/8] dt: add property iteration helpers

From: Stephen Warren
Date: Fri Mar 16 2012 - 16:54:47 EST


This patch adds macros for_each_u32_property_value and
for_each_string_property_value, which iterate over an array of values
within a device-tree property. Usage is for example:

struct of_iter_string_prop iter;
for_each_string_property_value(iter, np, "pins")
printk("Got value %s\n", iter.value);

Signed-off-by: Stephen Warren <swarren@xxxxxxxxxxxxx>
---
include/linux/of_iter_prop.h | 139 ++++++++++++++++++++++++++++++++++++++++++
1 files changed, 139 insertions(+), 0 deletions(-)
create mode 100644 include/linux/of_iter_prop.h

diff --git a/include/linux/of_iter_prop.h b/include/linux/of_iter_prop.h
new file mode 100644
index 0000000..57e9e6a
--- /dev/null
+++ b/include/linux/of_iter_prop.h
@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2011-2012 NVIDIA CORPORATION. All rights reserved.
+ *
+ * Iterate over properties that store arrays.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __OF_ITER_PROP_H__
+#define __OF_ITER_PROP_H__
+
+#include <linux/of.h>
+
+#ifdef CONFIG_OF
+struct of_iter_u32_prop {
+ const struct property *prop;
+ int len;
+ const __be32 *pvalue;
+ u32 value;
+};
+
+static inline void of_iter_u32_next(struct of_iter_u32_prop *iter)
+{
+ if (!iter->len)
+ return;
+
+ iter->len--;
+ if (iter->len)
+ iter->value = be32_to_cpup(iter->pvalue++);
+}
+
+static inline void of_iter_u32_init(struct of_iter_u32_prop *iter,
+ const struct device_node *np,
+ const char *name)
+{
+ iter->prop = of_find_property(np, name, &iter->len);
+ if (!iter->prop) {
+ iter->len = 0;
+ return;
+ }
+
+ iter->pvalue = iter->prop->value;
+ if (!iter->pvalue) {
+ iter->len = 0;
+ return;
+ }
+
+ iter->len /= sizeof(*iter->pvalue);
+
+ if (iter->len)
+ iter->value = be32_to_cpup(iter->pvalue++);
+}
+
+static inline bool of_iter_u32_test(struct of_iter_u32_prop *iter)
+{
+ return iter->len > 0;
+}
+
+#define for_each_u32_property_value(iter, np, prop_name) \
+ for (of_iter_u32_init(&iter, np, prop_name); \
+ of_iter_u32_test(&iter); \
+ of_iter_u32_next(&iter))
+
+struct of_iter_string_prop {
+ const struct property *prop;
+ int len;
+ const char *value;
+ const char *after;
+};
+
+static inline void of_iter_string_init(struct of_iter_string_prop *iter,
+ const struct device_node *np,
+ const char *name)
+{
+ iter->prop = of_find_property(np, name, &iter->len);
+ if (!iter->prop) {
+ iter->value = NULL;
+ return;
+ }
+
+ iter->value = iter->prop->value;
+ if (!iter->value)
+ return;
+
+ iter->after = iter->value + iter->len;
+}
+
+static inline bool of_iter_string_test(struct of_iter_string_prop *iter)
+{
+ if (!iter->value)
+ return false;
+
+ return iter->value < iter->after;
+}
+
+static inline void of_iter_string_next(struct of_iter_string_prop *iter)
+{
+ int len;
+
+ if (!iter->value)
+ return;
+
+ len = strnlen(iter->value, iter->len);
+ iter->len -= len + 1;
+ iter->value += len + 1;
+}
+
+#define for_each_string_property_value(iter, np, prop_name) \
+ for (of_iter_string_init(&iter, np, prop_name); \
+ of_iter_string_test(&iter); \
+ of_iter_string_next(&iter))
+
+#else
+struct of_iter_u32_prop {
+ u32 value;
+};
+
+#define for_each_u32_property_value(iter, np, prop_name) \
+ while (0)
+
+struct of_iter_string_prop {
+ const char *value;
+};
+
+#define for_each_string_property_value(iter, np, prop_name) \
+ while (0)
+
+#endif /* CONFIG_OF */
+
+#endif /* __OF_ITER_PROP_H__ */
--
1.7.0.4

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