[2/2] arm/imx: fix irq_base for gpio

When gpio core dynamically allocate gpio number for a port, it starts
from the end of the total range, 0 ~ ARCH_NR_GPIOS.  That said, the
earlier a port gets probed, the bigger gpio number it gets assigned.
To match this, the irq_base for gpio should be assigned from
'MXC_GPIO_IRQ_START + ARCH_NR_GPIOS' decreasingly.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
---
 arch/arm/mach-imx/mach-imx6q.c |    5 ++---
 arch/arm/mach-mx5/imx51-dt.c   |    5 ++---
 arch/arm/mach-mx5/imx53-dt.c   |    5 ++---
 3 files changed, 6 insertions(+), 9 deletions(-)

On 12/1/2011 1:19 AM, Shawn Guo wrote:
> When gpio core dynamically allocate gpio number for a port, it starts
> from the end of the total range, 0 ~ ARCH_NR_GPIOS.  That said, the
> earlier a port gets probed, the bigger gpio number it gets assigned.
> To match this, the irq_base for gpio should be assigned from
> 'MXC_GPIO_IRQ_START + ARCH_NR_GPIOS' decreasingly.
>
> Signed-off-by: Shawn Guo<shawn.guo@linaro.org>
> ---
>   arch/arm/mach-imx/mach-imx6q.c |    5 ++---
>   arch/arm/mach-mx5/imx51-dt.c   |    5 ++---
>   arch/arm/mach-mx5/imx53-dt.c   |    5 ++---
>   3 files changed, 6 insertions(+), 9 deletions(-)

I thought the rationale for GPIOLIB to start at the end was to more quickly
find a free group. If this isn't important, then I'd rather see GPIOLIB 
changed
to be increasing. Although I do like that gpio_irq_base is always set 
the same
way with your patch. Would

static int gpio_irq_base = MXC_GPIO_IRQ_START;

work as well, if you kept it increasing instead ?

Thanks
Troy

> diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
> index eb7531b..22aa54a 100644
> --- a/arch/arm/mach-imx/mach-imx6q.c
> +++ b/arch/arm/mach-imx/mach-imx6q.c
> @@ -39,11 +39,10 @@ static void __init imx6q_map_io(void)
>   static int __init imx6q_gpio_add_irq_domain(struct device_node *np,
>   				struct device_node *interrupt_parent)
>   {
> -	static int gpio_irq_base = MXC_GPIO_IRQ_START + ARCH_NR_GPIOS -
> -				   32 * 7; /* imx6q gets 7 gpio ports */
> +	static int gpio_irq_base = MXC_GPIO_IRQ_START + ARCH_NR_GPIOS;
>
> +	gpio_irq_base -= 32;
>   	irq_domain_add_simple(np, gpio_irq_base);
> -	gpio_irq_base += 32;
>
>   	return 0;
>   }
> diff --git a/arch/arm/mach-mx5/imx51-dt.c b/arch/arm/mach-mx5/imx51-dt.c
> index 3451a46..596edd9 100644
> --- a/arch/arm/mach-mx5/imx51-dt.c
> +++ b/arch/arm/mach-mx5/imx51-dt.c
> @@ -54,11 +54,10 @@ static int __init imx51_tzic_add_irq_domain(struct device_node *np,
>   static int __init imx51_gpio_add_irq_domain(struct device_node *np,
>   				struct device_node *interrupt_parent)
>   {
> -	static int gpio_irq_base = MXC_GPIO_IRQ_START + ARCH_NR_GPIOS -
> -				   32 * 4; /* imx51 gets 4 gpio ports */
> +	static int gpio_irq_base = MXC_GPIO_IRQ_START + ARCH_NR_GPIOS;
>
> +	gpio_irq_base -= 32;
>   	irq_domain_add_simple(np, gpio_irq_base);
> -	gpio_irq_base += 32;
>
>   	return 0;
>   }
> diff --git a/arch/arm/mach-mx5/imx53-dt.c b/arch/arm/mach-mx5/imx53-dt.c
> index 022bc03..85bfd5f 100644
> --- a/arch/arm/mach-mx5/imx53-dt.c
> +++ b/arch/arm/mach-mx5/imx53-dt.c
> @@ -58,11 +58,10 @@ static int __init imx53_tzic_add_irq_domain(struct device_node *np,
>   static int __init imx53_gpio_add_irq_domain(struct device_node *np,
>   				struct device_node *interrupt_parent)
>   {
> -	static int gpio_irq_base = MXC_GPIO_IRQ_START + ARCH_NR_GPIOS -
> -				   32 * 7; /* imx53 gets 7 gpio ports */
> +	static int gpio_irq_base = MXC_GPIO_IRQ_START + ARCH_NR_GPIOS;
>
> +	gpio_irq_base -= 32;
>   	irq_domain_add_simple(np, gpio_irq_base);
> -	gpio_irq_base += 32;
>
>   	return 0;
>   }

On Thu, Dec 01, 2011 at 11:26:36AM -0700, Troy Kisky wrote:
> On 12/1/2011 1:19 AM, Shawn Guo wrote:
> >When gpio core dynamically allocate gpio number for a port, it starts
> >from the end of the total range, 0 ~ ARCH_NR_GPIOS.  That said, the
> >earlier a port gets probed, the bigger gpio number it gets assigned.
> >To match this, the irq_base for gpio should be assigned from
> >'MXC_GPIO_IRQ_START + ARCH_NR_GPIOS' decreasingly.
> >
> >Signed-off-by: Shawn Guo<shawn.guo@linaro.org>
> >---
> >  arch/arm/mach-imx/mach-imx6q.c |    5 ++---
> >  arch/arm/mach-mx5/imx51-dt.c   |    5 ++---
> >  arch/arm/mach-mx5/imx53-dt.c   |    5 ++---
> >  3 files changed, 6 insertions(+), 9 deletions(-)
> 
> I thought the rationale for GPIOLIB to start at the end was to more quickly
> find a free group. If this isn't important, then I'd rather see
> GPIOLIB changed
> to be increasing. Although I do like that gpio_irq_base is always
> set the same
> way with your patch. Would
> 
> static int gpio_irq_base = MXC_GPIO_IRQ_START;
> 
> work as well, if you kept it increasing instead ?
> 
Inspired by gpio-tegra patches from Stephen, I will send similar
patches for gpio-mxc to clean up the use of MXC_GPIO_IRQ_START, which
will in turn remove the whole dependency between gpio number and gpio
irq.  So, yes, it deserves a thorough fix instead of this temporary one.