[PATCH] ep93xx: default multiplexed gpio ports to gpio mode

[Ryan Mallon]

On 01/25/2011 12:03 PM, H Hartley Sweeten wrote:
> The EP93xx C and D GPIO ports are multiplexed with the Keypad Interface
> peripheral.  At power-up they default into non-GPIO mode with the Key
> Matrix controller enabled so these ports are unusable for GPIO.  Note
> that the Keypad Interface peripheral is only available in the EP9307,
> EP9312, and EP9315 processor variants.
> 
> The keypad support will clear the DeviceConfig bits appropriately to
> enable the Keypad Interface when the driver is loaded.  And, when the
> driver is unloaded it will set the bits to return the ports to GPIO mode.
> 
> To make these ports available for GPIO after power-up on all EP93xx
> processor variants, set the KEYS and GONK bits in the DeviceConfig
> register.
> 
> Similarly, the E, G, and H ports are multiplexed with the IDE Interface
> peripheral.  At power-up these also default into non-GPIO mode.  Note
> that the IDE peripheral is only available in the EP9312 and EP9315
> processor variants.
> 
> Since an IDE driver is not even available in mainline, set the EONIDE,
> GONIDE, and HONIDE bits in the DeviceConfig register so that these
> ports will be available for GPIO use after power-up.
> 
> Signed-off-by: H Hartley Sweeten <hsweeten at visionengravers.com>
> Cc: Ryan Mallon <ryan at bluewatersys.com>
> 
> ---
> 
> diff --git a/arch/arm/mach-ep93xx/gpio.c b/arch/arm/mach-ep93xx/gpio.c
> index f3dc76f..bec34b8 100644
> --- a/arch/arm/mach-ep93xx/gpio.c
> +++ b/arch/arm/mach-ep93xx/gpio.c
> @@ -427,6 +427,13 @@ void __init ep93xx_gpio_init(void)
>  {
>         int i;
>  
> +       /* Set Ports C, D, E, G, and H for GPIO use */
> +       ep93xx_devcfg_set_bits(EP93XX_SYSCON_DEVCFG_KEYS |
> +                                EP93XX_SYSCON_DEVCFG_GONK |
> +                                EP93XX_SYSCON_DEVCFG_EONIDE |
> +                                EP93XX_SYSCON_DEVCFG_GONIDE |
> +                                EP93XX_SYSCON_DEVCFG_HONIDE);
> +
>         for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++)
>                 gpiochip_add(&ep93xx_gpio_banks[i].chip);
>  }

Seems sensible. We manage the devcfg settings in the kernel based on
what drivers we are loading so it makes sense to default them all to gpios.

Acked-by: Ryan Mallon <ryan at bluewatersys.com>

-- 
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