Introduce iio_channels_mask private struct

This struct will be used later to store a bitmask of enabled channels. Add iio_channels_mask_set_bit(), iio_channels_mask_clear_bit(), and iio_channels_mask_test_bit() inline functions to manipulate this new object. Signed-off-by: Paul Cercueil <[email protected]>
analogdevicesinc · Feb 28, 2022 · 2f33d3b · 2f33d3b
1 parent 46f760f
commit 2f33d3b
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diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -25,7 +25,7 @@ endif()
 
 option(BUILD_SHARED_LIBS "Build shared libraries" ON)
 
-add_library(iio backend.c channel.c device.c context.c buffer.c utilities.c scan.c sort.c
+add_library(iio backend.c channel.c device.c context.c buffer.c mask.c utilities.c scan.c sort.c
 	${CMAKE_CURRENT_BINARY_DIR}/iio-config.h
 )
 

diff --git a/iio-private.h b/iio-private.h
@@ -152,6 +152,35 @@ struct iio_context_info {
 	char *uri;
 };
 
+struct iio_channels_mask {
+	size_t words;
+	uint32_t mask[];
+};
+
+struct iio_channels_mask *iio_create_channels_mask(unsigned int nb_channels);
+
+int iio_channels_mask_copy(struct iio_channels_mask *dst,
+			   const struct iio_channels_mask *src);
+
+static inline bool
+iio_channels_mask_test_bit(const struct iio_channels_mask *mask,
+			   unsigned int bit)
+{
+	return mask->mask[BIT_WORD(bit)] & BIT_MASK(bit);
+}
+
+static inline void
+iio_channels_mask_set_bit(struct iio_channels_mask *mask, unsigned int bit)
+{
+	mask->mask[BIT_WORD(bit)] |= BIT_MASK(bit);
+}
+
+static inline void
+iio_channels_mask_clear_bit(struct iio_channels_mask *mask, unsigned int bit)
+{
+	mask->mask[BIT_WORD(bit)] &= ~BIT_MASK(bit);
+}
+
 struct iio_module * iio_open_module(const struct iio_context_params *params,
 				    const char *name);
 void iio_release_module(struct iio_module *module);

diff --git a/mask.c b/mask.c
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ * libiio - Library for interfacing industrial I/O (IIO) devices
+ *
+ * Copyright (C) 2022 Analog Devices, Inc.
+ * Author: Paul Cercueil <[email protected]>
+ */
+
+#include "iio-private.h"
+
+#include <errno.h>
+#include <string.h>
+
+struct iio_channels_mask * iio_create_channels_mask(unsigned int nb_channels)
+{
+	struct iio_channels_mask *mask;
+	size_t nb_words = (nb_channels + 31) / 32;
+
+	mask = zalloc(sizeof(*mask) + nb_words * sizeof(uint32_t));
+	if (mask)
+		mask->words = nb_words;
+
+	return mask;
+}
+
+int iio_channels_mask_copy(struct iio_channels_mask *dst,
+			   const struct iio_channels_mask *src)
+{
+	if (dst->words != src->words)
+		return -EINVAL;
+
+	memcpy(dst->mask, src->mask, src->words * sizeof(uint32_t));
+
+	return 0;
+}