[U-Boot] [PATCH] i2c: fix SDA contention in read_byte()

[Reinhard Meyer <reinhard.meyer@emk-elektronik.de>]

Thomas Chou schrieb:
> Reinhard Meyer wrote:
>> Its even simpler, provided the  hardware can do open collector. Here
>> was my solution for AVR32AP7000:
>>
> 
> Then we could add a config for open drain similar to that of linux driver.
> 
> # ifndef I2C_SDA
> #  ifdef CONFIG_SOFT_I2C_GPIO_SDA_IS_OPEN_DRAIN
> #   define I2C_SDA(bit) gpio_set_value(CONFIG_SOFT_I2C_GPIO_SDA, bit)
> #  else
> #   define I2C_SDA(bit) \
>     if (bit) {                        \
>         gpio_direction_input(CONFIG_SOFT_I2C_GPIO_SDA);    \
>     } else {                        \
>         gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SDA, 0);\
>     }
> #  endif
> # endif

Why would we need that? Since the defines reside in the board/project specific
include/configs/*.h file, it is well known if the hardware has open drain or
not.

> 
> BTW, will you be interested in using common gpio framework for avr32
> family?

No, AVR32AP7000 is dead for me. Working on AT91SAM9xxx now, which already uses gpio framework...

Reinhard

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