Re: [PATCH 03/14 v3] Input: atmel_mxt_ts - refactormxt_read/write_reg to take a length

From: Henrik Rydberg
Date: Tue Apr 24 2012 - 07:19:44 EST


Hi Daniel,

> The i2c bus requires 5 bytes to do a 1 byte read (1-byte i2c address + 2
> byte offset + 1-byte i2c address + 1 byte data), or 4 bytes to do a
> 1-byte write (1 byte i2c address + 2 byte offset + 1 byte data).
>
> By taking a length with reads and writes, the driver can amortize
> transaction overhead by performing larger transactions where appropriate.
>
> This patch just sets up the new API. Later patches refactor reads/writes
> to take advantage of the larger transactions.
>
> These functions are also now return any errors reported by the i2c layer.
>
> Signed-off-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
> ---

In the cyttsp a dedicate tx buffer is used, which is a bit easier on
the eyes. OTOH, the write operation seems infrequent enough to not
matter much, so

Acked-by: Henrik Rydberg <rydberg@xxxxxxxxxxx>

Thanks for your patience,
Henrik
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