[PATCH v3 1/7] i2c: i2c-core-smbus: Expose PEC calculate function for generic use
From: Quan Nguyen <quan@os.amperecomputing.com>
Date: 2021-05-19 07:50:28
Also in:
linux-aspeed, linux-devicetree, linux-i2c, lkml, openbmc
Subsystem:
i2c subsystem, the rest · Maintainers:
Wolfram Sang, Linus Torvalds
Expose the PEC calculation i2c_smbus_pec() for generic use. Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com> --- 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
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