[PATCH v2] genirq: replace irq_gc_ack() with {set,clr}_bit variants

[Simon Guinot]

From: Simon Guinot <sguinot at lacie.com>

Depending on the device, interrupts acknowledgement is done by setting
or by clearing a dedicated register. Replace irq_gc_ack() with some
{set,clr}_bit variants allows to handle both cases.

Note that this patch affects the following SoCs: Davinci, Samsung and
Orion. Except for this last, the change is minor: irq_gc_ack() is just
renamed into irq_gc_ack_set_bit().

For the Orion SoCs, the edge GPIO interrupts support is currently
broken. irq_gc_ack() try to acknowledge a such interrupt by setting
the corresponding cause register bit. The Orion GPIO device expect the
opposite. To fix this issue, the irq_gc_ack_clr_bit() variant is used.

Tested on Network Space v2.

Reported-by: Joey Oravec <joravec at drewtech.com>
Signed-off-by: Simon Guinot <sguinot at lacie.com>
---
Changes for v2: update patch description (mention the affected SoCs).

 arch/arm/mach-davinci/irq.c      |    2 +-
 arch/arm/plat-orion/gpio.c       |    2 +-
 arch/arm/plat-s5p/irq-gpioint.c  |    2 +-
 arch/arm/plat-samsung/irq-uart.c |    2 +-
 include/linux/irq.h              |    3 ++-
 kernel/irq/generic-chip.c        |   18 ++++++++++++++++--
 6 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-davinci/irq.c b/arch/arm/mach-davinci/irq.c
index bfe68ec..d8c1af0 100644
--- a/arch/arm/mach-davinci/irq.c
+++ b/arch/arm/mach-davinci/irq.c
@@ -53,7 +53,7 @@ davinci_alloc_gc(void __iomem *base, unsigned int irq_start, unsigned int num)
 
 	gc = irq_alloc_generic_chip("AINTC", 1, irq_start, base, handle_edge_irq);
 	ct = gc->chip_types;
-	ct->chip.irq_ack = irq_gc_ack;
+	ct->chip.irq_ack = irq_gc_ack_set_bit;
 	ct->chip.irq_mask = irq_gc_mask_clr_bit;
 	ct->chip.irq_unmask = irq_gc_mask_set_bit;
 
diff --git a/arch/arm/plat-orion/gpio.c b/arch/arm/plat-orion/gpio.c
index 5b4fffa..41ab97e 100644
--- a/arch/arm/plat-orion/gpio.c
+++ b/arch/arm/plat-orion/gpio.c
@@ -432,7 +432,7 @@ void __init orion_gpio_init(int gpio_base, int ngpio,
 	ct->regs.mask = ochip->mask_offset + GPIO_EDGE_MASK_OFF;
 	ct->regs.ack = GPIO_EDGE_CAUSE_OFF;
 	ct->type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
-	ct->chip.irq_ack = irq_gc_ack;
+	ct->chip.irq_ack = irq_gc_ack_clr_bit;
 	ct->chip.irq_mask = irq_gc_mask_clr_bit;
 	ct->chip.irq_unmask = irq_gc_mask_set_bit;
 	ct->chip.irq_set_type = gpio_irq_set_type;
diff --git a/arch/arm/plat-s5p/irq-gpioint.c b/arch/arm/plat-s5p/irq-gpioint.c
index 135abda..327ab9f 100644
--- a/arch/arm/plat-s5p/irq-gpioint.c
+++ b/arch/arm/plat-s5p/irq-gpioint.c
@@ -152,7 +152,7 @@ static __init int s5p_gpioint_add(struct s3c_gpio_chip *chip)
 	if (!gc)
 		return -ENOMEM;
 	ct = gc->chip_types;
-	ct->chip.irq_ack = irq_gc_ack;
+	ct->chip.irq_ack = irq_gc_ack_set_bit;
 	ct->chip.irq_mask = irq_gc_mask_set_bit;
 	ct->chip.irq_unmask = irq_gc_mask_clr_bit;
 	ct->chip.irq_set_type = s5p_gpioint_set_type,
diff --git a/arch/arm/plat-samsung/irq-uart.c b/arch/arm/plat-samsung/irq-uart.c
index 32582c0..0e46588 100644
--- a/arch/arm/plat-samsung/irq-uart.c
+++ b/arch/arm/plat-samsung/irq-uart.c
@@ -55,7 +55,7 @@ static void __init s3c_init_uart_irq(struct s3c_uart_irq *uirq)
 	gc = irq_alloc_generic_chip("s3c-uart", 1, uirq->base_irq, reg_base,
 				    handle_level_irq);
 	ct = gc->chip_types;
-	ct->chip.irq_ack = irq_gc_ack;
+	ct->chip.irq_ack = irq_gc_ack_set_bit;
 	ct->chip.irq_mask = irq_gc_mask_set_bit;
 	ct->chip.irq_unmask = irq_gc_mask_clr_bit;
 	ct->regs.ack = S3C64XX_UINTP;
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 8b45384..baa397e 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -676,7 +676,8 @@ void irq_gc_mask_disable_reg(struct irq_data *d);
 void irq_gc_mask_set_bit(struct irq_data *d);
 void irq_gc_mask_clr_bit(struct irq_data *d);
 void irq_gc_unmask_enable_reg(struct irq_data *d);
-void irq_gc_ack(struct irq_data *d);
+void irq_gc_ack_set_bit(struct irq_data *d);
+void irq_gc_ack_clr_bit(struct irq_data *d);
 void irq_gc_mask_disable_reg_and_ack(struct irq_data *d);
 void irq_gc_eoi(struct irq_data *d);
 int irq_gc_set_wake(struct irq_data *d, unsigned int on);
diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c
index 31a9db7..3a2cab4 100644
--- a/kernel/irq/generic-chip.c
+++ b/kernel/irq/generic-chip.c
@@ -101,10 +101,10 @@ void irq_gc_unmask_enable_reg(struct irq_data *d)
 }
 
 /**
- * irq_gc_ack - Ack pending interrupt
+ * irq_gc_ack_set_bit - Ack pending interrupt via setting bit
  * @d: irq_data
  */
-void irq_gc_ack(struct irq_data *d)
+void irq_gc_ack_set_bit(struct irq_data *d)
 {
 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 	u32 mask = 1 << (d->irq - gc->irq_base);
@@ -115,6 +115,20 @@ void irq_gc_ack(struct irq_data *d)
 }
 
 /**
+ * irq_gc_ack_clr_bit - Ack pending interrupt via clearing bit
+ * @d: irq_data
+ */
+void irq_gc_ack_clr_bit(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	u32 mask = ~(1 << (d->irq - gc->irq_base));
+
+	irq_gc_lock(gc);
+	irq_reg_writel(mask, gc->reg_base + cur_regs(d)->ack);
+	irq_gc_unlock(gc);
+}
+
+/**
  * irq_gc_mask_disable_reg_and_ack- Mask and ack pending interrupt
  * @d: irq_data
  */
-- 
1.7.5.1