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

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

[H Hartley Sweeten]

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@visionengravers.com>
Cc: Ryan Mallon <ryan@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);
?}

[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@visionengravers.com>
> Cc: Ryan Mallon <ryan@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@bluewatersys.com>

-- 
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