ARM: 8278/1: sa1100: split irq handling for low GPIOs

Low GPIO pins use an interrupt in SC interrupts space. However it's
possible to handle them as if all the GPIO interrupts are instead tied
to single GPIO handler, which later decodes GEDR register and
chain-calls next IRQ handler. So split first 11 interrupts into system
part (IRQ_GPIO0_SC - IRQ_GPIO10_SC) which work exactly like the rest of
system controller interrupts and real GPIO interrupts
(IRQ_GPIO0..IRQ_GPIO10). A single handler sa1100_gpio_handler then
decodes and calls next handler.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 50 insertions, 37 deletions

diff --git a/arch/arm/mach-sa1100/irq.c b/arch/arm/mach-sa1100/irq.c
index 63e2901db416..2dc6a2a9c60c 100644
--- a/arch/arm/mach-sa1100/irq.c
+++ b/arch/arm/mach-sa1100/irq.c
@@ -87,7 +87,7 @@ static struct irq_domain *sa1100_normal_irqdomain;
  */
 static int GPIO_IRQ_rising_edge;
 static int GPIO_IRQ_falling_edge;
-static int GPIO_IRQ_mask = (1 << 11) - 1;
+static int GPIO_IRQ_mask;
 
 static int sa1100_gpio_type(struct irq_data *d, unsigned int type)
 {
@@ -124,6 +124,26 @@ static void sa1100_gpio_ack(struct irq_data *d)
 	GEDR = BIT(d->hwirq);
 }
 
+static void sa1100_gpio_mask(struct irq_data *d)
+{
+	unsigned int mask = BIT(d->hwirq);
+
+	GPIO_IRQ_mask &= ~mask;
+
+	GRER &= ~mask;
+	GFER &= ~mask;
+}
+
+static void sa1100_gpio_unmask(struct irq_data *d)
+{
+	unsigned int mask = BIT(d->hwirq);
+
+	GPIO_IRQ_mask |= mask;
+
+	GRER = GPIO_IRQ_rising_edge & GPIO_IRQ_mask;
+	GFER = GPIO_IRQ_falling_edge & GPIO_IRQ_mask;
+}
+
 static int sa1100_gpio_wake(struct irq_data *d, unsigned int on)
 {
 	if (on)
@@ -139,8 +159,8 @@ static int sa1100_gpio_wake(struct irq_data *d, unsigned int on)
 static struct irq_chip sa1100_low_gpio_chip = {
 	.name		= "GPIO-l",
 	.irq_ack	= sa1100_gpio_ack,
-	.irq_mask	= sa1100_mask_irq,
-	.irq_unmask	= sa1100_unmask_irq,
+	.irq_mask	= sa1100_gpio_mask,
+	.irq_unmask	= sa1100_gpio_unmask,
 	.irq_set_type	= sa1100_gpio_type,
 	.irq_set_wake	= sa1100_gpio_wake,
 };
@@ -163,16 +183,16 @@ static struct irq_domain_ops sa1100_low_gpio_irqdomain_ops = {
 static struct irq_domain *sa1100_low_gpio_irqdomain;
 
 /*
- * IRQ11 (GPIO11 through 27) handler.  We enter here with the
+ * IRQ 0-11 (GPIO) handler.  We enter here with the
  * irq_controller_lock held, and IRQs disabled.  Decode the IRQ
  * and call the handler.
  */
 static void
-sa1100_high_gpio_handler(unsigned int irq, struct irq_desc *desc)
+sa1100_gpio_handler(unsigned int irq, struct irq_desc *desc)
 {
 	unsigned int mask;
 
-	mask = GEDR & 0xfffff800;
+	mask = GEDR;
 	do {
 		/*
 		 * clear down all currently active IRQ sources.
@@ -180,8 +200,7 @@ sa1100_high_gpio_handler(unsigned int irq, struct irq_desc *desc)
 		 */
 		GEDR = mask;
 
-		irq = IRQ_GPIO11;
-		mask >>= 11;
+		irq = IRQ_GPIO0;
 		do {
 			if (mask & 1)
 				generic_handle_irq(irq);
@@ -189,7 +208,7 @@ sa1100_high_gpio_handler(unsigned int irq, struct irq_desc *desc)
 			irq++;
 		} while (mask);
 
-		mask = GEDR & 0xfffff800;
+		mask = GEDR;
 	} while (mask);
 }
 
@@ -198,31 +217,11 @@ sa1100_high_gpio_handler(unsigned int irq, struct irq_desc *desc)
  * In addition, the IRQs are all collected up into one bit in the
  * interrupt controller registers.
  */
-static void sa1100_high_gpio_mask(struct irq_data *d)
-{
-	unsigned int mask = BIT(d->hwirq);
-
-	GPIO_IRQ_mask &= ~mask;
-
-	GRER &= ~mask;
-	GFER &= ~mask;
-}
-
-static void sa1100_high_gpio_unmask(struct irq_data *d)
-{
-	unsigned int mask = BIT(d->hwirq);
-
-	GPIO_IRQ_mask |= mask;
-
-	GRER = GPIO_IRQ_rising_edge & GPIO_IRQ_mask;
-	GFER = GPIO_IRQ_falling_edge & GPIO_IRQ_mask;
-}
-
 static struct irq_chip sa1100_high_gpio_chip = {
 	.name		= "GPIO-h",
 	.irq_ack	= sa1100_gpio_ack,
-	.irq_mask	= sa1100_high_gpio_mask,
-	.irq_unmask	= sa1100_high_gpio_unmask,
+	.irq_mask	= sa1100_gpio_mask,
+	.irq_unmask	= sa1100_gpio_unmask,
 	.irq_set_type	= sa1100_gpio_type,
 	.irq_set_wake	= sa1100_gpio_wake,
 };
@@ -325,7 +324,7 @@ sa1100_handle_irq(struct pt_regs *regs)
 		if (mask == 0)
 			break;
 
-		handle_IRQ(ffs(mask) - 1 + IRQ_GPIO0, regs);
+		handle_IRQ(ffs(mask) - 1 + IRQ_GPIO0_SC, regs);
 	} while (1);
 }
 
@@ -350,22 +349,36 @@ void __init sa1100_init_irq(void)
 	 */
 	ICCR = 1;
 
+	sa1100_normal_irqdomain = irq_domain_add_legacy(NULL,
+			32, IRQ_GPIO0_SC, 0,
+			&sa1100_normal_irqdomain_ops, NULL);
+
 	sa1100_low_gpio_irqdomain = irq_domain_add_legacy(NULL,
 			11, IRQ_GPIO0, 0,
 			&sa1100_low_gpio_irqdomain_ops, NULL);
 
-	sa1100_normal_irqdomain = irq_domain_add_legacy(NULL,
-			21, IRQ_GPIO11_27, 11,
-			&sa1100_normal_irqdomain_ops, NULL);
-
 	sa1100_high_gpio_irqdomain = irq_domain_add_legacy(NULL,
 			17, IRQ_GPIO11, 11,
 			&sa1100_high_gpio_irqdomain_ops, NULL);
 
 	/*
+	 * Install handlers for GPIO 0-10 edge detect interrupts
+	 */
+	irq_set_chained_handler(IRQ_GPIO0_SC, sa1100_gpio_handler);
+	irq_set_chained_handler(IRQ_GPIO1_SC, sa1100_gpio_handler);
+	irq_set_chained_handler(IRQ_GPIO2_SC, sa1100_gpio_handler);
+	irq_set_chained_handler(IRQ_GPIO3_SC, sa1100_gpio_handler);
+	irq_set_chained_handler(IRQ_GPIO4_SC, sa1100_gpio_handler);
+	irq_set_chained_handler(IRQ_GPIO5_SC, sa1100_gpio_handler);
+	irq_set_chained_handler(IRQ_GPIO6_SC, sa1100_gpio_handler);
+	irq_set_chained_handler(IRQ_GPIO7_SC, sa1100_gpio_handler);
+	irq_set_chained_handler(IRQ_GPIO8_SC, sa1100_gpio_handler);
+	irq_set_chained_handler(IRQ_GPIO9_SC, sa1100_gpio_handler);
+	irq_set_chained_handler(IRQ_GPIO10_SC, sa1100_gpio_handler);
+	/*
 	 * Install handler for GPIO 11-27 edge detect interrupts
 	 */
-	irq_set_chained_handler(IRQ_GPIO11_27, sa1100_high_gpio_handler);
+	irq_set_chained_handler(IRQ_GPIO11_27, sa1100_gpio_handler);
 
 	set_handle_irq(sa1100_handle_irq);