[U-Boot-Users] [AT91] Problems configuring bit-banged I2C

[Jean-Christophe PLAGNIOL-VILLARD]

On 03:36 Sat 24 May     , Sergey Lapin wrote:
> Hi, all!
> 
> I use the following patch on my AT91SAM9260-based custom board to
> configure bit-banged I2C:
> 
> diff --git a/board/atmel/at91sam9260ek/at91sam9260ek.c b/board/atmel/at91sam9260ek/at91sam9260ek.c
> index b30aad8..99fc2bd 100644
> --- a/board/atmel/at91sam9260ek/at91sam9260ek.c
> +++ b/board/atmel/at91sam9260ek/at91sam9260ek.c
> @ -234,3 +234,46 @@ void reset_phy(void)
>  #endif
>  }
>  #endif
Why don't you use the gpio function?
> +
void at91sam9260_i2c_init(void)
{
	at91_set_GPIO_periph(AT91_PIN_PA23, 0);
	at91_set_multi_drive(AT91_PIN_PA23, 1);

	at91_set_A_periph(AT91_PIN_PA24, 0);
	at91_set_multi_drive(AT91_PIN_PA24, 1);
}

void at91sam9260_i2c_scl(unsigned long bit)
{
	at91_set_gpio_value(AT91_PIN_PA24, bit);
}

void at91sam9260_i2c_sda(unsigned long bit)
{
	at91_set_gpio_value(AT91_PIN_PA23, bit)
}
int at91sam9260_i2c_read(void)
{
	retrun at91_get_gpio_value(AT91_PIN_PA23);
}
void at91sam9260_i2c_active()
{
	gpio_direction_output(AT91_PIN_PA23, 0);
}

void at91sam9260_i2c_tristate()
{
	gpio_direction_input(AT91_PIN_PA23);
}
> diff --git a/include/configs/at91sam9260ek.h b/include/configs/at91sam9260ek.h
> index fd9932f..5e66c9e 100644
> --- a/include/configs/at91sam9260ek.h
> +++ b/include/configs/at91sam9260ek.h
> @@ -85,6 +85,8 @@
>  
>  #define CONFIG_CMD_NAND		1
>  #define CONFIG_CMD_USB		1
> +#define CONFIG_CMD_I2C		1
> +#define CONFIG_I2C_CMD_TREE	1
>  
>  /* SDRAM */
>  #define CONFIG_NR_DRAM_BANKS		1
> @ -192,4 +194,20 @@
>  #error CONFIG_USE_IRQ not supported
>  #endif
>  
> +/*
> + * Software (bit-bang) I2C driver configuration
> + */
> +#define CONFIG_SOFT_I2C		1
> +#define CFG_I2C_SPEED		1000000
> +#define I2C_INIT		at91sam9260_i2c_init()
#define I2C_ACTIVE	at91sam9260_i2c_active()
#define I2C_TRISTATE	at91sam9260_i2c_tristate()
> +#define I2C_SCL(bit)	at91sam9260_i2c_scl(bit)
> +#define I2C_SDA(bit)	at91sam9260_i2c_sda(bit)
> +#define I2C_DELAY	udelay(2)
> +#define I2C_READ	at91sam9260_i2c_read()
> +#define CFG_I2C_SLAVE		0
> +#define DEBUG_I2C
>  #endif
> +

I sync it will be better to use the hardware stack which is not too
complicate to implement

Best Regards,
J.