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From: Matt Johnston <matt@codeconstruct.com.au>
To: linux-i2c@vger.kernel.org
Cc: Jeremy Kerr <jk@codeconstruct.com.au>
Subject: [PATCH] i2c: core: export i2c_smbus_pec()
Date: Mon, 17 May 2021 11:11:38 +0800	[thread overview]
Message-ID: <20210517031138.133934-1-matt@codeconstruct.com.au> (raw)

I2C slave interface drivers have to calculate the PEC themselves
in the i2c slave event handler. This will be used for an in-progress
driver for MCTP I2C transport.

Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
---
 drivers/i2c/i2c-core-smbus.c | 3 ++-
 include/linux/i2c.h          | 2 ++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c
index d2d32c0fd8c3..27a06b80decb 100644
--- a/drivers/i2c/i2c-core-smbus.c
+++ b/drivers/i2c/i2c-core-smbus.c
@@ -38,7 +38,7 @@ static u8 crc8(u16 data)
 }
 
 /* Incremental CRC8 over count bytes in the array pointed to by p */
-static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
+u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
 {
 	int i;
 
@@ -46,6 +46,7 @@ static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
 		crc = crc8((crc ^ p[i]) << 8);
 	return crc;
 }
+EXPORT_SYMBOL_GPL(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..9e5e5e8192c3 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -186,6 +186,8 @@ s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
 					      u8 *values);
 int i2c_get_device_id(const struct i2c_client *client,
 		      struct i2c_device_identity *id);
+
+u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count);
 #endif /* I2C */
 
 /**
-- 
2.30.2


             reply	other threads:[~2021-05-17  3:20 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-17  3:11 Matt Johnston [this message]
2021-05-28  8:42 ` [PATCH] i2c: core: export i2c_smbus_pec() Wolfram Sang
2021-06-25 15:06   ` Wolfram Sang

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