[AVR32] GPIO API implementation

Arch-neutral GPIO calls for AVR32. GPIO IRQ support written by
David Brownell.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>

arch/avr32/mach-at32ap/Makefile

-obj-y				+= at32ap.o clock.o pio.o intc.o extint.o hsmc.o
+obj-y				+= at32ap.o clock.o intc.o extint.o pio.o hsmc.o
 obj-$(CONFIG_CPU_AT32AP7000)	+= at32ap7000.o

arch/avr32/mach-at32ap/at32ap7000.c

@@ -498,7 +498,7 @@ DEV_CLK(mck, pio3, pba, 13);
 
 void __init at32_add_system_devices(void)
 {
-	system_manager.eim_first_irq = NR_INTERNAL_IRQS;
+	system_manager.eim_first_irq = EIM_IRQ_BASE;
 
 	platform_device_register(&at32_sm_device);
 	platform_device_register(&at32_intc0_device);

arch/avr32/mach-at32ap/pio.c

@@ -12,7 +12,9 @@
 #include <linux/debugfs.h>
 #include <linux/fs.h>
 #include <linux/platform_device.h>
+#include <linux/irq.h>
 
+#include <asm/gpio.h>
 #include <asm/io.h>
 
 #include <asm/arch/portmux.h>
@@ -26,7 +28,8 @@ struct pio_device {
 	const struct platform_device *pdev;
 	struct clk *clk;
 	u32 pinmux_mask;
-	char name[32];
+	u32 gpio_mask;
+	char name[8];
 };
 
 static struct pio_device pio_dev[MAX_NR_PIO_DEVICES];
@@ -76,6 +79,9 @@ void __init at32_select_periph(unsigned int pin, unsigned int periph,
 	if (!(flags & AT32_GPIOF_PULLUP))
 		pio_writel(pio, PUDR, mask);
 
+	/* gpio_request NOT allowed */
+	set_bit(pin_index, &pio->gpio_mask);
+
 	return;
 
 fail:
@@ -99,19 +105,29 @@ void __init at32_select_gpio(unsigned int pin, unsigned long flags)
 		goto fail;
 	}
 
-	pio_writel(pio, PUER, mask);
-	if (flags & AT32_GPIOF_HIGH)
-		pio_writel(pio, SODR, mask);
-	else
-		pio_writel(pio, CODR, mask);
-	if (flags & AT32_GPIOF_OUTPUT)
+	if (flags & AT32_GPIOF_OUTPUT) {
+		if (flags & AT32_GPIOF_HIGH)
+			pio_writel(pio, SODR, mask);
+		else
+			pio_writel(pio, CODR, mask);
+		pio_writel(pio, PUDR, mask);
 		pio_writel(pio, OER, mask);
-	else
+	} else {
+		if (flags & AT32_GPIOF_PULLUP)
+			pio_writel(pio, PUER, mask);
+		else
+			pio_writel(pio, PUDR, mask);
+		if (flags & AT32_GPIOF_DEGLITCH)
+			pio_writel(pio, IFER, mask);
+		else
+			pio_writel(pio, IFDR, mask);
 		pio_writel(pio, ODR, mask);
+	}
 
 	pio_writel(pio, PER, mask);
-	if (!(flags & AT32_GPIOF_PULLUP))
-		pio_writel(pio, PUDR, mask);
+
+	/* gpio_request now allowed */
+	clear_bit(pin_index, &pio->gpio_mask);
 
 	return;
 
@@ -119,20 +135,199 @@ void __init at32_select_gpio(unsigned int pin, unsigned long flags)
 	dump_stack();
 }
 
+/*--------------------------------------------------------------------------*/
+
+/*--------------------------------------------------------------------------*/
+
+/* GPIO API */
+
+int gpio_request(unsigned int gpio, const char *label)
+{
+	struct pio_device *pio;
+	unsigned int pin;
+
+	pio = gpio_to_pio(gpio);
+	if (!pio)
+		return -ENODEV;
+
+	pin = gpio & 0x1f;
+	if (test_and_set_bit(pin, &pio->gpio_mask))
+		return -EBUSY;
+
+	return 0;
+}
+EXPORT_SYMBOL(gpio_request);
+
+void gpio_free(unsigned int gpio)
+{
+	struct pio_device *pio;
+	unsigned int pin;
+
+	pio = gpio_to_pio(gpio);
+	if (!pio) {
+		printk(KERN_ERR
+		       "gpio: attempted to free invalid pin %u\n", gpio);
+		return;
+	}
+
+	pin = gpio & 0x1f;
+	if (!test_and_clear_bit(pin, &pio->gpio_mask))
+		printk(KERN_ERR "gpio: freeing free or non-gpio pin %s-%u\n",
+		       pio->name, pin);
+}
+EXPORT_SYMBOL(gpio_free);
+
+int gpio_direction_input(unsigned int gpio)
+{
+	struct pio_device *pio;
+	unsigned int pin;
+
+	pio = gpio_to_pio(gpio);
+	if (!pio)
+		return -ENODEV;
+
+	pin = gpio & 0x1f;
+	pio_writel(pio, ODR, 1 << pin);
+
+	return 0;
+}
+EXPORT_SYMBOL(gpio_direction_input);
+
+int gpio_direction_output(unsigned int gpio)
+{
+	struct pio_device *pio;
+	unsigned int pin;
+
+	pio = gpio_to_pio(gpio);
+	if (!pio)
+		return -ENODEV;
+
+	pin = gpio & 0x1f;
+	pio_writel(pio, OER, 1 << pin);
+
+	return 0;
+}
+EXPORT_SYMBOL(gpio_direction_output);
+
+int gpio_get_value(unsigned int gpio)
+{
+	struct pio_device *pio = &pio_dev[gpio >> 5];
+
+	return (pio_readl(pio, PDSR) >> (gpio & 0x1f)) & 1;
+}
+EXPORT_SYMBOL(gpio_get_value);
+
+void gpio_set_value(unsigned int gpio, int value)
+{
+	struct pio_device *pio = &pio_dev[gpio >> 5];
+	u32 mask;
+
+	mask = 1 << (gpio & 0x1f);
+	if (value)
+		pio_writel(pio, SODR, mask);
+	else
+		pio_writel(pio, CODR, mask);
+}
+EXPORT_SYMBOL(gpio_set_value);
+
+/*--------------------------------------------------------------------------*/
+
+/* GPIO IRQ support */
+
+static void gpio_irq_mask(unsigned irq)
+{
+	unsigned		gpio = irq_to_gpio(irq);
+	struct pio_device	*pio = &pio_dev[gpio >> 5];
+
+	pio_writel(pio, IDR, 1 << (gpio & 0x1f));
+}
+
+static void gpio_irq_unmask(unsigned irq)
+{
+	unsigned		gpio = irq_to_gpio(irq);
+	struct pio_device	*pio = &pio_dev[gpio >> 5];
+
+	pio_writel(pio, IER, 1 << (gpio & 0x1f));
+}
+
+static int gpio_irq_type(unsigned irq, unsigned type)
+{
+	if (type != IRQ_TYPE_EDGE_BOTH && type != IRQ_TYPE_NONE)
+		return -EINVAL;
+
+	return 0;
+}
+
+static struct irq_chip gpio_irqchip = {
+	.name		= "gpio",
+	.mask		= gpio_irq_mask,
+	.unmask		= gpio_irq_unmask,
+	.set_type	= gpio_irq_type,
+};
+
+static void gpio_irq_handler(unsigned irq, struct irq_desc *desc)
+{
+	struct pio_device	*pio = get_irq_chip_data(irq);
+	unsigned		gpio_irq;
+
+	gpio_irq = (unsigned) get_irq_data(irq);
+	for (;;) {
+		u32		isr;
+		struct irq_desc	*d;
+
+		/* ack pending GPIO interrupts */
+		isr = pio_readl(pio, ISR) & pio_readl(pio, IMR);
+		if (!isr)
+			break;
+		do {
+			int i;
+
+			i = ffs(isr) - 1;
+			isr &= ~(1 << i);
+
+			i += gpio_irq;
+			d = &irq_desc[i];
+
+			d->handle_irq(i, d);
+		} while (isr);
+	}
+}
+
+static void __init
+gpio_irq_setup(struct pio_device *pio, int irq, int gpio_irq)
+{
+	unsigned	i;
+
+	set_irq_chip_data(irq, pio);
+	set_irq_data(irq, (void *) gpio_irq);
+
+	for (i = 0; i < 32; i++, gpio_irq++) {
+		set_irq_chip_data(gpio_irq, pio);
+		set_irq_chip_and_handler(gpio_irq, &gpio_irqchip,
+				handle_simple_irq);
+	}
+
+	set_irq_chained_handler(irq, gpio_irq_handler);
+}
+
+/*--------------------------------------------------------------------------*/
+
 static int __init pio_probe(struct platform_device *pdev)
 {
 	struct pio_device *pio = NULL;
+	int irq = platform_get_irq(pdev, 0);
+	int gpio_irq_base = GPIO_IRQ_BASE + pdev->id * 32;
 
 	BUG_ON(pdev->id >= MAX_NR_PIO_DEVICES);
 	pio = &pio_dev[pdev->id];
 	BUG_ON(!pio->regs);
 
-	/* TODO: Interrupts */
+	gpio_irq_setup(pio, irq, gpio_irq_base);
 
 	platform_set_drvdata(pdev, pio);
 
-	printk(KERN_INFO "%s: Atmel Port Multiplexer at 0x%p (irq %d)\n",
-	       pio->name, pio->regs, platform_get_irq(pdev, 0));
+	printk(KERN_DEBUG "%s: base 0x%p, irq %d chains %d..%d\n",
+	       pio->name, pio->regs, irq, gpio_irq_base, gpio_irq_base + 31);
 
 	return 0;
 }
@@ -148,7 +343,7 @@ static int __init pio_init(void)
 {
 	return platform_driver_register(&pio_driver);
 }
-subsys_initcall(pio_init);
+postcore_initcall(pio_init);
 
 void __init at32_init_pio(struct platform_device *pdev)
 {
@@ -184,6 +379,16 @@ void __init at32_init_pio(struct platform_device *pdev)
 	pio->pdev = pdev;
 	pio->regs = ioremap(regs->start, regs->end - regs->start + 1);
 
+	/*
+	 * request_gpio() is only valid for pins that have been
+	 * explicitly configured as GPIO and not previously requested
+	 */
+	pio->gpio_mask = ~0UL;
+
 	pio_writel(pio, ODR, ~0UL);
 	pio_writel(pio, PER, ~0UL);
+
+	/* start with irqs disabled and acked */
+	pio_writel(pio, IDR, ~0UL);
+	(void) pio_readl(pio, ISR);
 }

include/asm-avr32/arch-at32ap/gpio.h

+#ifndef __ASM_AVR32_ARCH_GPIO_H
+#define __ASM_AVR32_ARCH_GPIO_H
+
+#include <linux/compiler.h>
+#include <asm/irq.h>
+
+
+/* Arch-neutral GPIO API */
+int __must_check gpio_request(unsigned int gpio, const char *label);
+void gpio_free(unsigned int gpio);
+
+int gpio_direction_input(unsigned int gpio);
+int gpio_direction_output(unsigned int gpio);
+int gpio_get_value(unsigned int gpio);
+void gpio_set_value(unsigned int gpio, int value);
+
+static inline int gpio_to_irq(unsigned int gpio)
+{
+	return gpio + GPIO_IRQ_BASE;
+}
+
+static inline int irq_to_gpio(unsigned int irq)
+{
+	return irq - GPIO_IRQ_BASE;
+}
+
+#endif /* __ASM_AVR32_ARCH_GPIO_H */

include/asm-avr32/arch-at32ap/irq.h

+#ifndef __ASM_AVR32_ARCH_IRQ_H
+#define __ASM_AVR32_ARCH_IRQ_H
+
+#define EIM_IRQ_BASE	NR_INTERNAL_IRQS
+#define NR_EIM_IRQS	32
+
+#define AT32_EXTINT(n)	(EIM_IRQ_BASE + (n))
+
+#define GPIO_IRQ_BASE	(EIM_IRQ_BASE + NR_EIM_IRQS)
+#define NR_GPIO_IRQS	(4 * 32)
+
+#define NR_IRQS		(GPIO_IRQ_BASE + NR_GPIO_IRQS)
+
+#endif /* __ASM_AVR32_ARCH_IRQ_H */

include/asm-avr32/arch-at32ap/portmux.h

@@ -15,9 +15,10 @@
  *
  * The following flags determine the initial state of the pin.
  */
-#define AT32_GPIOF_PULLUP	0x00000001	/* Enable pull-up */
-#define AT32_GPIOF_OUTPUT	0x00000002	/* Enable output driver */
-#define AT32_GPIOF_HIGH		0x00000004	/* Set output high */
+#define AT32_GPIOF_PULLUP	0x00000001	/* (not-OUT) Enable pull-up */
+#define AT32_GPIOF_OUTPUT	0x00000002	/* (OUT) Enable output driver */
+#define AT32_GPIOF_HIGH		0x00000004	/* (OUT) Set output high */
+#define AT32_GPIOF_DEGLITCH	0x00000008	/* (IN) Filter glitches */
 
 void at32_select_periph(unsigned int pin, unsigned int periph,
 			unsigned long flags);

include/asm-avr32/gpio.h

+#ifndef __ASM_AVR32_GPIO_H
+#define __ASM_AVR32_GPIO_H
+
+#include <asm/arch/gpio.h>
+
+#endif /* __ASM_AVR32_GPIO_H */

include/asm-avr32/irq.h

@@ -2,8 +2,12 @@
 #define __ASM_AVR32_IRQ_H
 
 #define NR_INTERNAL_IRQS	64
-#define NR_EXTERNAL_IRQS	64
-#define NR_IRQS			(NR_INTERNAL_IRQS + NR_EXTERNAL_IRQS)
+
+#include <asm/arch/irq.h>
+
+#ifndef NR_IRQS
+#define NR_IRQS			(NR_INTERNAL_IRQS)
+#endif
 
 #define irq_canonicalize(i)	(i)