Expose the PEC calculation i2c_smbus_pec() for generic use.
Signed-off-by: Quan Nguyen <quan@xxxxxxxxxxxxxxxxxxxxxx>
---
drivers/i2c/i2c-core-smbus.c | 12 ++++++++++--
include/linux/i2c.h | 1 +
2 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c
index d2d32c0fd8c3..e5b2d1465e7e 100644
--- a/drivers/i2c/i2c-core-smbus.c
+++ b/drivers/i2c/i2c-core-smbus.c
@@ -37,8 +37,15 @@ static u8 crc8(u16 data)
return (u8)(data >> 8);
}
-/* Incremental CRC8 over count bytes in the array pointed to by p */
-static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
+/**
+ * i2c_smbus_pec - Incremental CRC8 over the given input data array
+ * @crc: previous return crc8 value
+ * @p: pointer to data buffer.
+ * @count: number of bytes in data buffer.
+ *
+ * Incremental CRC8 over count bytes in the array pointed to by p
+ */
+u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
{
int i;
@@ -46,6 +53,7 @@ static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
crc = crc8((crc ^ p[i]) << 8);
return crc;
}
+EXPORT_SYMBOL(i2c_smbus_pec);
/* Assume a 7-bit address, which is reasonable for SMBus */
static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg)
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index e8f2ac8c9c3d..2494a007dfda 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -147,6 +147,7 @@ s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
/* Now follow the 'nice' access routines. These also document the calling
conventions of i2c_smbus_xfer. */
+u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count);
s32 i2c_smbus_read_byte(const struct i2c_client *client);
s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command);
--
2.28.0
