MIPS: EMMA2RH: Use handle_edge_irq() handler for GPIO interrupts

[Shinya Kuribayashi <skuribay@xxxxxxxxxxxxxx>]

EMMA's GPIO interrupts are latched by GPIO interrupt status register.
In this case, we're encouraged to use handle_edge_irq() handler.

The following changes are made along with replacing set_irq_chip() with
set_irq_chip_and_handler_name(,,handle_edge_irq,"edge"):

* Fix emma2rh_gpio_irq_ack not to disable interrupts

 With handle_edge_irq(), we're not expected to disable interrupts
 when chip->ack is served, so fix it accordingly.  We also add a
 new emma2rh_gpio_irq_mask_ack() for chip->mask_ack operation.

* Remove emma2rh_gpio_irq_end() as chip->end is no longer served.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@xxxxxxxxx>
---

Ralf Baechle wrote:
> __do_IRQ() is deprecated since a long time and there are plans to remove
> it for 2.6.30.  The MIPS platforms seem to fall into three classes:
[snip]
>  o Platforms that still seem to rely on __do_IRQ():
>      o All Sibyte platforms:
> 	bigsur_defconfig and sb1250-swarm_defconfig
>
>      o All Alchemy platforms:
> 	db1000_defconfig, db1100_defconfig, db1200_defconfig, db1500_defconfig,
> 	db1550_defconfig, mtx1_defconfig, pb1100_defconfig, pb1500_defconfig
> 	and pb1550_defconfig
>
>      o malta_defconfig.  The platform code itself is ok but irq-gic.c,
> 	irq-msc01.c, irq-msc01.c and irq_cpu.c are still using set_irq_chip
> 	and need fixing.
>
>      o And the rest:
> 	decstation_defconfig, emma2rh_defconfig, ip32_defconfig,
> 	yosemite_defconfig, mipssim_defconfig and rm200_defconfig.

Here's a patch for EMMA2RH not to call __do_IRQ(). Please review.

Thanks,

 Shinya

arch/mips/emma/markeins/irq.c |   28 ++++++++++------------------
1 files changed, 10 insertions(+), 18 deletions(-)

diff --git a/arch/mips/emma/markeins/irq.c b/arch/mips/emma/markeins/irq.c
index ce8f5f2..d15556c 100644
--- a/arch/mips/emma/markeins/irq.c
+++ b/arch/mips/emma/markeins/irq.c
@@ -149,37 +149,28 @@ static void emma2rh_gpio_irq_disable(unsigned int irq)

static void emma2rh_gpio_irq_ack(unsigned int irq)
{
-	u32 reg;
-
	irq -= EMMA2RH_GPIO_IRQ_BASE;
	emma2rh_out32(EMMA2RH_GPIO_INT_ST, ~(1 << irq));
-
-	reg = emma2rh_in32(EMMA2RH_GPIO_INT_MASK);
-	reg &= ~(1 << irq);
-	emma2rh_out32(EMMA2RH_GPIO_INT_MASK, reg);
}

-static void emma2rh_gpio_irq_end(unsigned int irq)
+static void emma2rh_gpio_irq_mask_ack(unsigned int irq)
{
	u32 reg;

-	if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
-
-		irq -= EMMA2RH_GPIO_IRQ_BASE;
+	irq -= EMMA2RH_GPIO_IRQ_BASE;
+	emma2rh_out32(EMMA2RH_GPIO_INT_ST, ~(1 << irq));

-		reg = emma2rh_in32(EMMA2RH_GPIO_INT_MASK);
-		reg |= 1 << irq;
-		emma2rh_out32(EMMA2RH_GPIO_INT_MASK, reg);
-	}
+	reg = emma2rh_in32(EMMA2RH_GPIO_INT_MASK);
+	reg &= ~(1 << irq);
+	emma2rh_out32(EMMA2RH_GPIO_INT_MASK, reg);
}

struct irq_chip emma2rh_gpio_irq_controller = {
	.name = "emma2rh_gpio_irq",
	.ack = emma2rh_gpio_irq_ack,
	.mask = emma2rh_gpio_irq_disable,
-	.mask_ack = emma2rh_gpio_irq_ack,
+	.mask_ack = emma2rh_gpio_irq_mask_ack,
	.unmask = emma2rh_gpio_irq_enable,
-	.end = emma2rh_gpio_irq_end,
};

void emma2rh_gpio_irq_init(void)
@@ -187,8 +178,9 @@ void emma2rh_gpio_irq_init(void)
	u32 i;

	for (i = 0; i < NUM_EMMA2RH_IRQ_GPIO; i++)
-		set_irq_chip(EMMA2RH_GPIO_IRQ_BASE + i,
-			     &emma2rh_gpio_irq_controller);
+		set_irq_chip_and_handler_name(EMMA2RH_GPIO_IRQ_BASE + i,
+					      &emma2rh_gpio_irq_controller,
+					      handle_edge_irq, "edge");
}

static struct irqaction irq_cascade = {