From 9cc323d80f98c8cd37e2bef50884a040e598d03c Mon Sep 17 00:00:00 2001
From: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Date: Wed, 25 Nov 2015 18:16:36 +0100
Subject: [PATCH] hidpp: extract hidpp20_crc_ccitt into hidpp_generic

Looks like the hid++ 1.0 devices are also using the same crc computation,
so put it in the generic part.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---
 src/hidpp-generic.c | 27 +++++++++++++++++++++++++++
 src/hidpp-generic.h |  2 ++
 src/hidpp20.c       | 31 ++-----------------------------
 3 files changed, 31 insertions(+), 29 deletions(-)

diff --git a/src/hidpp-generic.c b/src/hidpp-generic.c
index f7c5f985..04b7eacb 100644
--- a/src/hidpp-generic.c
+++ b/src/hidpp-generic.c
@@ -317,3 +317,30 @@ hidpp_device_set_log_handler(struct hidpp_device *dev,
 	dev->log_priority = priority;
 	dev->userdata = userdata;
 }
+
+/*
+ * The following crc computation has been provided by Logitech
+ */
+#define CRC_CCITT_SEED	0xFFFF
+
+uint16_t
+hidpp_crc_ccitt(uint8_t *data, unsigned int length)
+{
+	uint16_t crc, temp, quick;
+	unsigned int i;
+
+	crc = CRC_CCITT_SEED;
+
+	for (i = 0; i < length; i++) {
+		temp = (crc >> 8) ^ (*data++);
+		crc <<= 8;
+		quick = temp ^ (temp >> 4);
+		crc ^= quick;
+		quick <<= 5;
+		crc ^= quick;
+		quick <<= 7;
+		crc ^= quick;
+	}
+
+	return crc;
+}
diff --git a/src/hidpp-generic.h b/src/hidpp-generic.h
index 3f16fb6e..1ac36fee 100644
--- a/src/hidpp-generic.h
+++ b/src/hidpp-generic.h
@@ -144,6 +144,8 @@ hidpp_log_buffer(struct hidpp_device *dev,
 #define hidpp_log_buf_info(li_, h_, buf_, len_) hidpp_log_buffer(li_, HIDPP_LOG_PRIORITY_INFO, h_, buf_, len_)
 #define hidpp_log_buf_error(li_, h_, buf_, len_) hidpp_log_buffer(li_, HIDPP_LOG_PRIORITY_ERROR, h_, buf_, len_)
 
+uint16_t hidpp_crc_ccitt(uint8_t *data, unsigned int length);
+
 static inline uint16_t
 hidpp_get_unaligned_be_u16(uint8_t *buf)
 {
diff --git a/src/hidpp20.c b/src/hidpp20.c
index 0140a6f3..6ab00c17 100644
--- a/src/hidpp20.c
+++ b/src/hidpp20.c
@@ -920,33 +920,6 @@ int hidpp20_adjustable_dpi_set_sensor_dpi(struct hidpp20_device *device,
 #define HIDPP20_PROFILE_SIZE		HIDPP20_PAGE_SIZE
 #define HIDPP20_BUTTON_HID		0x80
 
-/*
- * The following crc computation has been provided by Logitech
- */
-#define CRC_CCITT_SEED	0xFFFF
-
-static uint16_t
-hidpp20_crc_ccitt(uint8_t *data, unsigned int length)
-{
-	uint16_t crc, temp, quick;
-	unsigned int i;
-
-	crc = CRC_CCITT_SEED;
-
-	for (i = 0; i < length; i++) {
-		temp = (crc >> 8) ^ (*data++);
-		crc <<= 8;
-		quick = temp ^ (temp >> 4);
-		crc ^= quick;
-		quick <<= 5;
-		crc ^= quick;
-		quick <<= 7;
-		crc ^= quick;
-	}
-
-	return crc;
-}
-
 int
 hidpp20_onboard_profiles_read_memory(struct hidpp20_device *device,
 				     uint8_t read_rom,
@@ -1097,7 +1070,7 @@ hidpp20_onboard_profiles_write_page(struct hidpp20_device *device,
 {
 	uint16_t crc;
 
-	crc = hidpp20_crc_ccitt(data, HIDPP20_PAGE_SIZE - 2);
+	crc = hidpp_crc_ccitt(data, HIDPP20_PAGE_SIZE - 2);
 	hidpp_set_unaligned_be_u16(&data[HIDPP20_PROFILE_SIZE - 2], crc);
 
 	return hidpp20_onboard_profiles_write_data(device, page, 0x00, data, HIDPP20_PAGE_SIZE);
@@ -1228,7 +1201,7 @@ hidpp20_onboard_profiles_find_and_read_profile(struct hidpp20_device *device,
 				return rc;
 		}
 
-		crc = hidpp20_crc_ccitt(data, HIDPP20_PROFILE_SIZE - 2);
+		crc = hidpp_crc_ccitt(data, HIDPP20_PROFILE_SIZE - 2);
 		read_crc = hidpp_get_unaligned_be_u16(&data[HIDPP20_PROFILE_SIZE - 2]);
 
 		if (crc == read_crc)