[U-Boot] [PATCH] gpio: at91: Fix pullup/pulldown configuration on PIO3

[Andreas Bießmann]

On 04.05.16 23:05, Marek Vasut wrote:
> On systems with PIO3 (SAMA5D3/D4/..), the pullup and pulldown configuration
> is mutualy exclusive. This patch assures that the opposite pull resistor gets
> disabled before the requested pull resistor is enabled. This changes behavior
> of at91_set_pio_pulldown() such that the pullup is only disabled if pulldown
> is to be enabled. This changes behavior of at91_set_pio_pullup() such that
> the pulldown is only disabled if pullup is to be enabled.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Andreas Bießmann <andreas.devel at googlemail.com>
> Cc: Josh Wu <josh.wu at atmel.com>
> Cc: Simon Glass <sjg at chromium.org>

Reviewed-by: Andreas Bießmann <andreas at biessmann.org>

> ---
>  drivers/gpio/at91_gpio.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpio/at91_gpio.c b/drivers/gpio/at91_gpio.c
> index 75a32ee..8e52e3d 100644
> --- a/drivers/gpio/at91_gpio.c
> +++ b/drivers/gpio/at91_gpio.c
> @@ -59,6 +59,11 @@ int at91_set_pio_pullup(unsigned port, unsigned pin, int use_pullup)
>  {
>  	struct at91_port *at91_port = at91_pio_get_port(port);
>  
> +#if defined(CPU_HAS_PIO3)
> +	if (use_pullup)
> +		at91_set_pio_pulldown(port, pin, 0);
> +#endif
> +
>  	if (at91_port && (pin < GPIO_PER_BANK))
>  		at91_set_port_pullup(at91_port, pin, use_pullup);
>  
> @@ -305,10 +310,10 @@ int at91_set_pio_pulldown(unsigned port, unsigned pin, int is_on)
>  
>  	if (at91_port && (pin < GPIO_PER_BANK)) {
>  		mask = 1 << pin;
> -		writel(mask, &at91_port->pudr);
> -		if (is_on)
> +		if (is_on) {
> +			at91_set_pio_pullup(port, pin, 0);
>  			writel(mask, &at91_port->ppder);
> -		else
> +		} else
>  			writel(mask, &at91_port->ppddr);
>  	}
>  
>