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| author | Quan Nguyen <quan@os.amperecomputing.com> | 2021-05-19 10:49:28 +0300 |
|---|---|---|
| committer | Wolfram Sang <wsa@kernel.org> | 2021-06-25 18:09:34 +0300 |
| commit | 87cf5127968ab3c543ebd98253052b928f9b47da (patch) | |
| tree | 31c4a20b3f7ce890394795b0188ef86ce0741371 | |
| parent | 31df7195b100f7e7b7ac07675d93b3b504400fe9 (diff) | |
| download | linux-87cf5127968ab3c543ebd98253052b928f9b47da.tar.xz | |
i2c: core-smbus: Expose PEC calculate function for generic use
Expose the PEC calculation i2c_smbus_pec() for generic use.
Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com>
Acked-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
| -rw-r--r-- | drivers/i2c/i2c-core-smbus.c | 12 | ||||
| -rw-r--r-- | 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 953a4eecb88f..685f8c73d99e 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -148,6 +148,7 @@ 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); |