On 7/5/2012 4:54 AM, Arnd Bergmann wrote:
On Thursday 05 July 2012, Sebastian Hesselbarth wrote:
Andrew,
is it possible to group all gpio banks into one DT description?
For mach-dove it could be something like:
gpio: gpio-controller {
compatible = "marvell, orion-gpio";
...
bank0@d0400 {
reg = <0xd0400 0x40>;
ngpio = <8>;
mask-offset = <0>;
interrupts = <12>;
};
bank1@d0400 {
reg = <0xd0400 0x40>;
ngpio = <8>;
mask-offset = <8>;
interrupts = <13>;
};
This way you have multiple nodes with the same register
and different names, which is not how it normally works.
The "mask-offset" property is really a "reg" in disguise.
"reg" is considerably more general than just "memory mapped
register address". It really means "any numeric identifier
that makes sense in the context of a parent device".
Therefore, one could say:
gpio: gpio-controller {
compatible = "marvell, orion-gpio";
reg = <0xd0400 0x40>;
#address-cells = <1>;
#size-cells = <0>;
...
bank0@0 {
reg = <0x0>;
ngpio = <8>;
mask-offset = <0>;
interrupts = <12>;
};
bank1@8 {
reg = <0x8>;
ngpio = <8>;
interrupts = <13>;
};
This would have the advantage that DT describes gpio-to-irq dependencies.
Moreover, nodes that reference gpios can do gpios = <&gpio 71 0>; instead of
gpios = <&gpio3 7 0>;
Is that desired?
The device tree representation should match what is in the data sheet
normally. If they are in a single continuous number range, then we should
probably have a single device node with multiple register ranges
rather than one device node for each 32-bit register. Looking at
arch/arm/plat-orion/gpio.c I think that is not actually the case though
and having separate banks is more logical.
Something completely different I just noticed in the original patch:
@@ -90,6 +74,27 @@ static void pmu_irq_handler(unsigned int irq, struct irq_desc *desc)
}
}
+static int __initdata gpio0_irqs[4] = {
+ IRQ_DOVE_GPIO_0_7,
+ IRQ_DOVE_GPIO_8_15,
+ IRQ_DOVE_GPIO_16_23,
+ IRQ_DOVE_GPIO_24_31,
+};
+
+static int __initdata gpio1_irqs[4] = {
+ IRQ_DOVE_HIGH_GPIO,
+ 0,
+ 0,
+ 0,
+};
I think the latter one needs to be
+static int __initdata gpio1_irqs[4] = {
+ IRQ_DOVE_HIGH_GPIO,
+ IRQ_DOVE_HIGH_GPIO,
+ IRQ_DOVE_HIGH_GPIO,
+ IRQ_DOVE_HIGH_GPIO,
+};
so we register all four parts to the same primary IRQ. The
same is true for the devicetree representation.
Arnd
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