[PATCH] ARM: 2744/1: ixp2000 gpio irq support

Patch from Lennert Buytenhek

This patch cleans up the ixp2000 gpio irq code and implements the
set_irq_type method for gpio irqs so that users can select for which
events (falling edge/rising edge/level low/level high) on the gpio
pin they want the corresponding gpio irq to be triggered.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 67 insertions, 18 deletions

diff --git a/arch/arm/mach-ixp2000/core.c b/arch/arm/mach-ixp2000/core.c
index fc0555596d6d..0ee34acb8d7b 100644
--- a/arch/arm/mach-ixp2000/core.c
+++ b/arch/arm/mach-ixp2000/core.c
@@ -40,6 +40,8 @@
 #include <asm/mach/time.h>
 #include <asm/mach/irq.h>
 
+#include <asm/arch/gpio.h>
+
 static DEFINE_SPINLOCK(ixp2000_slowport_lock);
 static unsigned long ixp2000_slowport_irq_flags;
 
@@ -179,7 +181,7 @@ static int ixp2000_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 
         /* clear timer 1 */
         ixp2000_reg_write(IXP2000_T1_CLR, 1);
-        
+
         while ((next_jiffy_time - *missing_jiffy_timer_csr) > ticks_per_jiffy) {
                 timer_tick(regs);
                 next_jiffy_time -= ticks_per_jiffy;
@@ -238,35 +240,40 @@ void __init ixp2000_init_time(unsigned long tick_rate)
 /*************************************************************************
  * GPIO helpers
  *************************************************************************/
-static unsigned long GPIO_IRQ_rising_edge;
 static unsigned long GPIO_IRQ_falling_edge;
+static unsigned long GPIO_IRQ_rising_edge;
 static unsigned long GPIO_IRQ_level_low;
 static unsigned long GPIO_IRQ_level_high;
 
-void gpio_line_config(int line, int style)
+static void update_gpio_int_csrs(void)
+{
+        ixp2000_reg_write(IXP2000_GPIO_FEDR, GPIO_IRQ_falling_edge);
+        ixp2000_reg_write(IXP2000_GPIO_REDR, GPIO_IRQ_rising_edge);
+        ixp2000_reg_write(IXP2000_GPIO_LSLR, GPIO_IRQ_level_low);
+        ixp2000_reg_write(IXP2000_GPIO_LSHR, GPIO_IRQ_level_high);
+}
+
+void gpio_line_config(int line, int direction)
 {
         unsigned long flags;
 
         local_irq_save(flags);
+        if (direction == GPIO_OUT) {
+                irq_desc[line + IRQ_IXP2000_GPIO0].valid = 0;
 
-        if(style == GPIO_OUT) {
                 /* if it's an output, it ain't an interrupt anymore */
-                ixp2000_reg_write(IXP2000_GPIO_PDSR, (1 << line));
                 GPIO_IRQ_falling_edge &= ~(1 << line);
                 GPIO_IRQ_rising_edge &= ~(1 << line);
                 GPIO_IRQ_level_low &= ~(1 << line);
                 GPIO_IRQ_level_high &= ~(1 << line);
-                ixp2000_reg_write(IXP2000_GPIO_FEDR, GPIO_IRQ_falling_edge);
-                ixp2000_reg_write(IXP2000_GPIO_REDR, GPIO_IRQ_rising_edge);
-                ixp2000_reg_write(IXP2000_GPIO_LSHR, GPIO_IRQ_level_high);
-                ixp2000_reg_write(IXP2000_GPIO_LSLR, GPIO_IRQ_level_low);
-                irq_desc[line+IRQ_IXP2000_GPIO0].valid = 0;
-        } else if(style == GPIO_IN) {
-                ixp2000_reg_write(IXP2000_GPIO_PDCR, (1 << line));
+                update_gpio_int_csrs();
+
+                ixp2000_reg_write(IXP2000_GPIO_PDSR, 1 << line);
+        } else if (direction == GPIO_IN) {
+                ixp2000_reg_write(IXP2000_GPIO_PDCR, 1 << line);
         }
-                
         local_irq_restore(flags);
-}       
+}
 
 
 /*************************************************************************
@@ -285,9 +292,50 @@ static void ixp2000_GPIO_irq_handler(unsigned int irq, struct irqdesc *desc, str
         }
 }
 
+static int ixp2000_GPIO_irq_type(unsigned int irq, unsigned int type)
+{
+        int line = irq - IRQ_IXP2000_GPIO0;
+
+        /*
+         * First, configure this GPIO line as an input.
+         */
+        ixp2000_reg_write(IXP2000_GPIO_PDCR, 1 << line);
+
+        /*
+         * Then, set the proper trigger type.
+         */
+        if (type & IRQT_FALLING)
+                GPIO_IRQ_falling_edge |= 1 << line;
+        else
+                GPIO_IRQ_falling_edge &= ~(1 << line);
+        if (type & IRQT_RISING)
+                GPIO_IRQ_rising_edge |= 1 << line;
+        else
+                GPIO_IRQ_rising_edge &= ~(1 << line);
+        if (type & IRQT_LOW)
+                GPIO_IRQ_level_low |= 1 << line;
+        else
+                GPIO_IRQ_level_low &= ~(1 << line);
+        if (type & IRQT_HIGH)
+                GPIO_IRQ_level_high |= 1 << line;
+        else
+                GPIO_IRQ_level_high &= ~(1 << line);
+        update_gpio_int_csrs();
+
+        /*
+         * Finally, mark the corresponding IRQ as valid.
+         */
+        irq_desc[irq].valid = 1;
+
+        return 0;
+}
+
 static void ixp2000_GPIO_irq_mask_ack(unsigned int irq)
 {
         ixp2000_reg_write(IXP2000_GPIO_INCR, (1 << (irq - IRQ_IXP2000_GPIO0)));
+
+        ixp2000_reg_write(IXP2000_GPIO_EDSR, (1 << (irq - IRQ_IXP2000_GPIO0)));
+        ixp2000_reg_write(IXP2000_GPIO_LDSR, (1 << (irq - IRQ_IXP2000_GPIO0)));
         ixp2000_reg_write(IXP2000_GPIO_INST, (1 << (irq - IRQ_IXP2000_GPIO0)));
 }
 
@@ -302,6 +350,7 @@ static void ixp2000_GPIO_irq_unmask(unsigned int irq)
 }
 
 static struct irqchip ixp2000_GPIO_irq_chip = {
+        .type   = ixp2000_GPIO_irq_type,
         .ack    = ixp2000_GPIO_irq_mask_ack,
         .mask   = ixp2000_GPIO_irq_mask,
         .unmask = ixp2000_GPIO_irq_unmask
@@ -338,7 +387,7 @@ static void ixp2000_irq_mask(unsigned int irq)
 
 static void ixp2000_irq_unmask(unsigned int irq)
 {
-        ixp2000_reg_write(IXP2000_IRQ_ENABLE_SET,  (1 << irq));
+        ixp2000_reg_write(IXP2000_IRQ_ENABLE_SET, (1 << irq));
 }
 
 static struct irqchip ixp2000_irq_chip = {
@@ -375,16 +424,16 @@ void __init ixp2000_init_irq(void)
          * our mask/unmask code much simpler.
          */
         for (irq = IRQ_IXP2000_SOFT_INT; irq <= IRQ_IXP2000_THDB3; irq++) {
-                if((1 << irq) & IXP2000_VALID_IRQ_MASK) {
+                if ((1 << irq) & IXP2000_VALID_IRQ_MASK) {
                         set_irq_chip(irq, &ixp2000_irq_chip);
                         set_irq_handler(irq, do_level_IRQ);
                         set_irq_flags(irq, IRQF_VALID);
                 } else set_irq_flags(irq, 0);
         }
-        
+
         /*
          * GPIO IRQs are invalid until someone sets the interrupt mode
-         * by calling gpio_line_set();
+         * by calling set_irq_type().
          */
         for (irq = IRQ_IXP2000_GPIO0; irq <= IRQ_IXP2000_GPIO7; irq++) {
                 set_irq_chip(irq, &ixp2000_GPIO_irq_chip);