[PATCH 4/8] ARM: at91: do not configure at91sam9g10 twi pio as open-drain

[Voss, Nikolaus]

ludovic.desroches at atmel.com wrote on Friday, August 31, 2012 11:21 AM
> From: Ludovic Desroches <ludovic.desroches at atmel.com>
> 
> As indicated in the datasheet, TWD and TWCK must not be programmed as
> open-drain.
> 
> Signed-off-by: Ludovic Desroches <ludovic.desroches at atmel.com>
Acked-by: Nikolaus Voss <n.voss at weinmann.de>


> ---
>  arch/arm/mach-at91/at91sam9261_devices.c | 18 ++++++++++--------
>  1 file changed, 10 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/arm/mach-at91/at91sam9261_devices.c b/arch/arm/mach-
> at91/at91sam9261_devices.c
> index c94495d..405f603 100644
> --- a/arch/arm/mach-at91/at91sam9261_devices.c
> +++ b/arch/arm/mach-at91/at91sam9261_devices.c
> @@ -324,20 +324,22 @@ static struct platform_device
> at91sam9261_twi_device = {
> 
>  void __init at91_add_device_i2c(struct i2c_board_info *devices, int
> nr_devices)
>  {
> -	/* IP version is not the same on 9261 and g10 */
> +	/*
> +	 * IP version is not the same on 9261 and g10 and only 9261 one
> +	 * requires to configure PIO as open-drain.
> +	 */
>  	if (cpu_is_at91sam9g10()) {
>  		at91sam9261_twi_device.name = "at91sam9g10_i2c";
> +		at91_set_A_periph(AT91_PIN_PA7, 0);		/* TWD
> */
> +		at91_set_A_periph(AT91_PIN_PA8, 0);		/*
> TWCK */
>  	} else {
>  		at91sam9261_twi_device.name = "at91sam9261_i2c";
> +		at91_set_A_periph(AT91_PIN_PA7, 0);		/* TWD
> */
> +		at91_set_multi_drive(AT91_PIN_PA7, 1);
> +		at91_set_A_periph(AT91_PIN_PA8, 0);		/*
> TWCK */
> +		at91_set_multi_drive(AT91_PIN_PA8, 1);
>  	}
> 
> -	/* pins used for TWI interface */
> -	at91_set_A_periph(AT91_PIN_PA7, 0);		/* TWD */
> -	at91_set_multi_drive(AT91_PIN_PA7, 1);
> -
> -	at91_set_A_periph(AT91_PIN_PA8, 0);		/* TWCK */
> -	at91_set_multi_drive(AT91_PIN_PA8, 1);
> -
>  	i2c_register_board_info(0, devices, nr_devices);
>  	platform_device_register(&at91sam9261_twi_device);
>  }
> --
> 1.7.11.3