Re: [PATCH v8 2/5] i2c: Add STM32F4 I2C driver

[Uwe Kleine-König]

Hello,

On Thu, Jan 12, 2017 at 10:28:20PM +0100, M'boumba Cedric Madianga wrote:
> Please see below a quote from datasheet that clearly described how to handle
> For 2-byte reception:
> â Wait until ADDR = 1 (SCL stretched low until the ADDR flag is cleared)
> â Set ACK low, set POS high
> â Clear ADDR flag
> â Wait until BTF = 1 (Data 1 in DR, Data2 in shift register, SCL
> stretched low until a data1 is read)
> â Set STOP high
> â Read data 1 and 2

The problem is that you only know that you have a 2 byte transfer after
you read the first byte (and it's a 1). (But note that this is
irrelevant for the patch as the driver doesn't claim to support this
kind of transfer.)

Best regards
Uwe

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Pengutronix e.K.                           | Uwe Kleine-KÃnig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |