[PATCH 04/19] lib: Allow crc16 code to be dropped

[Simon Glass]

This code is not necessarily needed in VPL, even if SPL uses it, so
adjust the rules to allow it to be dropped.

Do the same for the hash API.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

 common/hash.c | 17 +++++++++++------
 lib/Kconfig   | 10 ++++++++++
 lib/Makefile  |  3 +--
 tools/Kconfig |  5 +++++
 4 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/common/hash.c b/common/hash.c
index 8dd9da85768..0c45992d5c7 100644
--- a/common/hash.c
+++ b/common/hash.c
@@ -143,7 +143,8 @@ static int __maybe_unused hash_finish_sha512(struct hash_algo *algo, void *ctx,
 	return 0;
 }
 
-static int hash_init_crc16_ccitt(struct hash_algo *algo, void **ctxp)
+static int __maybe_unused hash_init_crc16_ccitt(struct hash_algo *algo,
+						void **ctxp)
 {
 	uint16_t *ctx = malloc(sizeof(uint16_t));
 	*ctx = 0;
@@ -151,16 +152,18 @@ static int hash_init_crc16_ccitt(struct hash_algo *algo, void **ctxp)
 	return 0;
 }
 
-static int hash_update_crc16_ccitt(struct hash_algo *algo, void *ctx,
-				   const void *buf, unsigned int size,
-				   int is_last)
+static int __maybe_unused hash_update_crc16_ccitt(struct hash_algo *algo,
+						  void *ctx, const void *buf,
+						  unsigned int size,
+						  int is_last)
 {
 	*((uint16_t *)ctx) = crc16_ccitt(*((uint16_t *)ctx), buf, size);
 	return 0;
 }
 
-static int hash_finish_crc16_ccitt(struct hash_algo *algo, void *ctx,
-				   void *dest_buf, int size)
+static int __maybe_unused hash_finish_crc16_ccitt(struct hash_algo *algo,
+						  void *ctx, void *dest_buf,
+						  int size)
 {
 	if (size < algo->digest_size)
 		return -1;
@@ -295,6 +298,7 @@ static struct hash_algo hash_algo[] = {
 #endif
 	},
 #endif
+#if CONFIG_IS_ENABLED(CRC16)
 	{
 		.name		= "crc16-ccitt",
 		.digest_size	= 2,
@@ -304,6 +308,7 @@ static struct hash_algo hash_algo[] = {
 		.hash_update	= hash_update_crc16_ccitt,
 		.hash_finish	= hash_finish_crc16_ccitt,
 	},
+#endif
 #if CONFIG_IS_ENABLED(CRC8) && IS_ENABLED(CONFIG_HASH_CRC8)
 	{
 		.name		= "crc8",
diff --git a/lib/Kconfig b/lib/Kconfig
index c8ac99df78e..c228e4ca661 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -737,6 +737,16 @@ config VPL_CRC8
 	  checksum with feedback to produce an 8-bit result. The code is small
 	  and it does not require a lookup table (unlike CRC32).
 
+config CRC16
+	bool "Support CRC16"
+	default y
+	help
+	  Enables CRC16 support. This is normally required. Two algorithms are
+	  provided:
+
+	    - CCITT, with a polynomical x^16 + x^12 + x^5 + 1
+	    - standard, with polynomial x^16 + x^15 + x^2 + 1 (0x8005)
+
 config SPL_CRC16
 	bool "Support CRC16 in SPL"
 	depends on SPL
diff --git a/lib/Makefile b/lib/Makefile
index 31cfbb67aa0..3f0936b0a27 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -35,8 +35,6 @@ obj-$(CONFIG_CIRCBUF) += circbuf.o
 endif
 
 obj-y += crc8.o
-obj-y += crc16.o
-obj-y += crc16-ccitt.o
 obj-$(CONFIG_ERRNO_STR) += errno_str.o
 obj-$(CONFIG_FIT) += fdtdec_common.o
 obj-$(CONFIG_TEST_FDTDEC) += fdtdec_test.o
@@ -66,6 +64,7 @@ endif
 
 obj-$(CONFIG_$(PHASE_)CRC8) += crc8.o
 obj-$(CONFIG_$(PHASE_)CRC16) += crc16.o
+obj-$(CONFIG_$(PHASE_)CRC16) += crc16-ccitt.o
 
 obj-y += crypto/
 
diff --git a/tools/Kconfig b/tools/Kconfig
index 5c75af48fe3..01ff0fcf748 100644
--- a/tools/Kconfig
+++ b/tools/Kconfig
@@ -9,6 +9,11 @@ config MKIMAGE_DTC_PATH
 	  some cases the system dtc may not support all required features
 	  and the path to a different version should be given here.
 
+config TOOLS_CRC16
+	def_bool y
+	help
+	  Enable CRC32 support in the tools builds
+
 config TOOLS_CRC32
 	def_bool y
 	help
-- 
2.43.0