[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 <[e-mail]>
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <[e-mail]>

arch/arm/mach-ixp2000/core.c

···
 #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;
 
···
 
 	/* 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;
···
 /*************************************************************************
  * 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);
-}	
+}
 
 
 /*************************************************************************
···
 	}
 }
 
+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)));
 }
 
···
 }
 
 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
···
 
 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 = {
···
 	 * 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);

drivers/i2c/busses/i2c-ixp2000.c

···
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
 
-#include <asm/hardware.h>	/* Pick up IXP42000-specific bits */
+#include <asm/hardware.h>	/* Pick up IXP2000-specific bits */
+#include <asm/arch/gpio.h>
 
 static inline int ixp2000_scl_pin(void *data)
 {

include/asm-arm/arch-ixp2000/gpio.h

···
 /*
- * include/asm-arm/arch-ixp2000/ixp2000-gpio.h
+ * include/asm-arm/arch-ixp2000/gpio.h
  *
  * Copyright (C) 2002 Intel Corporation.
  *
···
  * Use this instead of directly setting the GPIO registers.
  * GPIOs may also be used as GPIOs (e.g. for emulating i2c/smb)
  */
-#ifndef _ASM_ARCH_IXP2000_GPIO_H_
-#define _ASM_ARCH_IXP2000_GPIO_H_
+#ifndef __ASM_ARCH_GPIO_H
+#define __ASM_ARCH_GPIO_H
 
 #ifndef __ASSEMBLY__
-#define GPIO_OUT			0x0
-#define GPIO_IN				0x80
+
+#define GPIO_IN				0
+#define GPIO_OUT			1
 
 #define IXP2000_GPIO_LOW		0
 #define IXP2000_GPIO_HIGH		1
 
-#define GPIO_NO_EDGES           	0
-#define GPIO_FALLING_EDGE       	1
-#define GPIO_RISING_EDGE        	2
-#define GPIO_BOTH_EDGES         	3
-#define GPIO_LEVEL_LOW          	4
-#define GPIO_LEVEL_HIGH         	8
-
-extern void set_GPIO_IRQ_edge(int gpio_nr, int edge);
-extern void set_GPIO_IRQ_level(int gpio_nr, int level);
-extern void gpio_line_config(int line, int style);
+extern void gpio_line_config(int line, int direction);
 
 static inline int gpio_line_get(int line)
 {
···
 static inline void gpio_line_set(int line, int value)
 {
 	if (value == IXP2000_GPIO_HIGH) {
-		ixp_reg_write(IXP2000_GPIO_POSR, BIT(line));
-	} else if (value == IXP2000_GPIO_LOW)
-		ixp_reg_write(IXP2000_GPIO_POCR, BIT(line));
+		ixp2000_reg_write(IXP2000_GPIO_POSR, 1 << line);
+	} else if (value == IXP2000_GPIO_LOW) {
+		ixp2000_reg_write(IXP2000_GPIO_POCR, 1 << line);
+	}
 }
 
 #endif /* !__ASSEMBLY__ */
-#endif /* ASM_ARCH_IXP2000_GPIO_H_ */
 
+#endif /* ASM_ARCH_IXP2000_GPIO_H_ */

include/asm-arm/arch-ixp2000/platform.h

···
 	unsigned long (*bank_setup)(unsigned long);
 };
 
-/*
- * GPIO helper functions
- */
-#define	GPIO_IN		0
-#define	GPIO_OUT	1
-
-extern void gpio_line_config(int line, int style);
-
-static inline int gpio_line_get(int line)
-{
-	return (((*IXP2000_GPIO_PLR) >> line) & 1);
-}
-
-static inline void gpio_line_set(int line, int value)
-{
-	if (value) 
-		ixp2000_reg_write(IXP2000_GPIO_POSR, (1 << line));
-	else 
-		ixp2000_reg_write(IXP2000_GPIO_POCR, (1 << line));
-}
-
 struct ixp2000_i2c_pins {
 	unsigned long sda_pin;
 	unsigned long scl_pin;
 };
+
 
 #endif /*  !__ASSEMBLY__ */