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Driver-Support of I2C_M_RECV_LEN

DISCUSSION Michael Post 2 participants 4 messages Jun 20, 2014 – Jul 4, 2014 1 message not in the archive I2C subsystem host drivers

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#0 lore raw

Hello,

in the documentation i found at
http://ww2.cs.fsu.edu/~rosentha/linux/2.6.26.5/docs/DocBook/kernel-api/re1222.html
the following sentence:

"Note that using this function requires that the client's adapter support the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers support this; its emulation through I2C messaging relies on a specific mechanism (I2C_M_RECV_LEN) which may not be implemented."

The second sentence says that the mechanism I2C_M_RECV_LEN is not all over implemented.

How i can figure out whether this mechanism will be provided of my driver? What is the alternative of using the function i2c_smbus_read_block_data?

Thanks a lot for your support,

Michael Post

A message that is not in the archive (sent off-list or not yet received): 53A42321.5020701-S0/[email protected]

#2 lore raw

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Hello together,

Am 20.06.14 14:03, schrieb Michael Post:

Quoted 6 lines

Hello,

in the documentation i found at
http://ww2.cs.fsu.edu/~rosentha/linux/2.6.26.5/docs/DocBook/kernel-api/re1222.html

the following sentence:

Quoted 7 lines

"Note that using this function requires that the client's adapter support the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers support this; its emulation through I2C messaging relies on a specific mechanism (I2C_M_RECV_LEN) which may not be implemented."

Quoted 7 lines

The second sentence says that the mechanism I2C_M_RECV_LEN is not all over implemented.

How i can figure out whether this mechanism will be provided of my driver? What is the alternative of using the function i2c_smbus_read_block_data?

does nobody has any clue or hints for me? Maybe there is an other mailinglist i can ask?

Thanks a lot,

Michael
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#3 lore raw
In reply to a message not in the archive

Hello together,

Am 20.06.14 14:03, schrieb Michael Post:

Quoted 11 lines

Hello,

in the documentation i found at
http://ww2.cs.fsu.edu/~rosentha/linux/2.6.26.5/docs/DocBook/kernel-api/re1222.html
the following sentence:

"Note that using this function requires that the client's adapter support the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers support this; its emulation through I2C messaging relies on a specific mechanism (I2C_M_RECV_LEN) which may not be implemented."

Quoted 5 lines

The second sentence says that the mechanism I2C_M_RECV_LEN is not all over implemented.

How i can figure out whether this mechanism will be provided of my driver? What is the alternative of using the function i2c_smbus_read_block_data?

does nobody has any clue or hints for me?
Maybe there is an other mailinglist i can ask?

Thanks a lot,

Michael

#4 lore raw
In reply to a message not in the archive

Hi,

Quoted 1 line

How i can figure out whether this mechanism will be provided of my driver?

Use i2c_get_functionality() and check for I2C_FUNC_SMBUS_READ_BLOCK_DATA (or look at the source code).

Quoted 1 line

What is the alternative of using the function i2c_smbus_read_block_data?

That depends solely on your slave device. Check the documentation what transfer types it supports and what alternatives are possible.

Regards,

Wolfram