Merge branch 'linux-2.6'

1 files changed, 241 insertions, 0 deletions

diff --git a/arch/arm/mach-orion/irq.c b/arch/arm/mach-orion/irq.c
new file mode 100644
index 0000000..df7e12a
--- /dev/null
+++ b/arch/arm/mach-orion/irq.c
@@ -0,0 +1,241 @@
+/*
+ * arch/arm/mach-orion/irq.c
+ *
+ * Core IRQ functions for Marvell Orion System On Chip
+ *
+ * Maintainer: Tzachi Perelstein <tzachi@marvell.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <asm/gpio.h>
+#include <asm/arch/orion.h>
+#include "common.h"
+
+/*****************************************************************************
+ * Orion GPIO IRQ
+ *
+ * GPIO_IN_POL register controlls whether GPIO_DATA_IN will hold the same
+ * value of the line or the opposite value.
+ *
+ * Level IRQ handlers: DATA_IN is used directly as cause register.
+ *                     Interrupt are masked by LEVEL_MASK registers.
+ * Edge IRQ handlers:  Change in DATA_IN are latched in EDGE_CAUSE.
+ *                     Interrupt are masked by EDGE_MASK registers.
+ * Both-edge handlers: Similar to regular Edge handlers, but also swaps
+ *                     the polarity to catch the next line transaction.
+ *                     This is a race condition that might not perfectly
+ *                     work on some use cases.
+ *
+ * Every eight GPIO lines are grouped (OR'ed) before going up to main
+ * cause register.
+ *
+ *                    EDGE  cause    mask
+ *        data-in   /--------| |-----| |----\
+ *     -----| |-----                         ---- to main cause reg
+ *           X      \----------------| |----/
+ *        polarity    LEVEL          mask
+ *
+ ****************************************************************************/
+static void orion_gpio_irq_ack(u32 irq)
+{
+	int pin = irq_to_gpio(irq);
+	if (irq_desc[irq].status & IRQ_LEVEL)
+		/*
+		 * Mask bit for level interrupt
+		 */
+		orion_clrbits(GPIO_LEVEL_MASK, 1 << pin);
+	else
+		/*
+		 * Clear casue bit for egde interrupt
+		 */
+		orion_clrbits(GPIO_EDGE_CAUSE, 1 << pin);
+}
+
+static void orion_gpio_irq_mask(u32 irq)
+{
+	int pin = irq_to_gpio(irq);
+	if (irq_desc[irq].status & IRQ_LEVEL)
+		orion_clrbits(GPIO_LEVEL_MASK, 1 << pin);
+	else
+		orion_clrbits(GPIO_EDGE_MASK, 1 << pin);
+}
+
+static void orion_gpio_irq_unmask(u32 irq)
+{
+	int pin = irq_to_gpio(irq);
+	if (irq_desc[irq].status & IRQ_LEVEL)
+		orion_setbits(GPIO_LEVEL_MASK, 1 << pin);
+	else
+		orion_setbits(GPIO_EDGE_MASK, 1 << pin);
+}
+
+static int orion_gpio_set_irq_type(u32 irq, u32 type)
+{
+	int pin = irq_to_gpio(irq);
+	struct irq_desc *desc;
+
+	if ((orion_read(GPIO_IO_CONF) & (1 << pin)) == 0) {
+		printk(KERN_ERR "orion_gpio_set_irq_type failed "
+				"(irq %d, pin %d).\n", irq, pin);
+		return -EINVAL;
+	}
+
+	desc = irq_desc + irq;
+
+	switch (type) {
+	case IRQT_HIGH:
+		desc->handle_irq = handle_level_irq;
+		desc->status |= IRQ_LEVEL;
+		orion_clrbits(GPIO_IN_POL, (1 << pin));
+		break;
+	case IRQT_LOW:
+		desc->handle_irq = handle_level_irq;
+		desc->status |= IRQ_LEVEL;
+		orion_setbits(GPIO_IN_POL, (1 << pin));
+		break;
+	case IRQT_RISING:
+		desc->handle_irq = handle_edge_irq;
+		desc->status &= ~IRQ_LEVEL;
+		orion_clrbits(GPIO_IN_POL, (1 << pin));
+		break;
+	case IRQT_FALLING:
+		desc->handle_irq = handle_edge_irq;
+		desc->status &= ~IRQ_LEVEL;
+		orion_setbits(GPIO_IN_POL, (1 << pin));
+		break;
+	case IRQT_BOTHEDGE:
+		desc->handle_irq = handle_edge_irq;
+		desc->status &= ~IRQ_LEVEL;
+		/*
+		 * set initial polarity based on current input level
+		 */
+		if ((orion_read(GPIO_IN_POL) ^ orion_read(GPIO_DATA_IN))
+		    & (1 << pin))
+			orion_setbits(GPIO_IN_POL, (1 << pin)); /* falling */
+		else
+			orion_clrbits(GPIO_IN_POL, (1 << pin)); /* rising */
+
+		break;
+	default:
+		printk(KERN_ERR "failed to set irq=%d (type=%d)\n", irq, type);
+		return -EINVAL;
+	}
+
+	desc->status &= ~IRQ_TYPE_SENSE_MASK;
+	desc->status |= type & IRQ_TYPE_SENSE_MASK;
+
+	return 0;
+}
+
+static struct irq_chip orion_gpio_irq_chip = {
+	.name		= "Orion-IRQ-GPIO",
+	.ack		= orion_gpio_irq_ack,
+	.mask		= orion_gpio_irq_mask,
+	.unmask		= orion_gpio_irq_unmask,
+	.set_type	= orion_gpio_set_irq_type,
+};
+
+static void orion_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+	u32 cause, offs, pin;
+
+	BUG_ON(irq < IRQ_ORION_GPIO_0_7 || irq > IRQ_ORION_GPIO_24_31);
+	offs = (irq - IRQ_ORION_GPIO_0_7) * 8;
+	cause = (orion_read(GPIO_DATA_IN) & orion_read(GPIO_LEVEL_MASK)) |
+		(orion_read(GPIO_EDGE_CAUSE) & orion_read(GPIO_EDGE_MASK));
+
+	for (pin = offs; pin < offs + 8; pin++) {
+		if (cause & (1 << pin)) {
+			irq = gpio_to_irq(pin);
+			desc = irq_desc + irq;
+			if ((desc->status & IRQ_TYPE_SENSE_MASK) == IRQT_BOTHEDGE) {
+				/* Swap polarity (race with GPIO line) */
+				u32 polarity = orion_read(GPIO_IN_POL);
+				polarity ^= 1 << pin;
+				orion_write(GPIO_IN_POL, polarity);
+			}
+			desc_handle_irq(irq, desc);
+		}
+	}
+}
+
+static void __init orion_init_gpio_irq(void)
+{
+	int i;
+	struct irq_desc *desc;
+
+	/*
+	 * Mask and clear GPIO IRQ interrupts
+	 */
+	orion_write(GPIO_LEVEL_MASK, 0x0);
+	orion_write(GPIO_EDGE_MASK, 0x0);
+	orion_write(GPIO_EDGE_CAUSE, 0x0);
+
+	/*
+	 * Register chained level handlers for GPIO IRQs by default.
+	 * User can use set_type() if he wants to use edge types handlers.
+	 */
+	for (i = IRQ_ORION_GPIO_START; i < NR_IRQS; i++) {
+		set_irq_chip(i, &orion_gpio_irq_chip);
+		set_irq_handler(i, handle_level_irq);
+		desc = irq_desc + i;
+		desc->status |= IRQ_LEVEL;
+		set_irq_flags(i, IRQF_VALID);
+	}
+	set_irq_chained_handler(IRQ_ORION_GPIO_0_7, orion_gpio_irq_handler);
+	set_irq_chained_handler(IRQ_ORION_GPIO_8_15, orion_gpio_irq_handler);
+	set_irq_chained_handler(IRQ_ORION_GPIO_16_23, orion_gpio_irq_handler);
+	set_irq_chained_handler(IRQ_ORION_GPIO_24_31, orion_gpio_irq_handler);
+}
+
+/*****************************************************************************
+ * Orion Main IRQ
+ ****************************************************************************/
+static void orion_main_irq_mask(u32 irq)
+{
+	orion_clrbits(MAIN_IRQ_MASK, 1 << irq);
+}
+
+static void orion_main_irq_unmask(u32 irq)
+{
+	orion_setbits(MAIN_IRQ_MASK, 1 << irq);
+}
+
+static struct irq_chip orion_main_irq_chip = {
+	.name		= "Orion-IRQ-Main",
+	.ack		= orion_main_irq_mask,
+	.mask		= orion_main_irq_mask,
+	.unmask		= orion_main_irq_unmask,
+};
+
+static void __init orion_init_main_irq(void)
+{
+	int i;
+
+	/*
+	 * Mask and clear Main IRQ interrupts
+	 */
+	orion_write(MAIN_IRQ_MASK, 0x0);
+	orion_write(MAIN_IRQ_CAUSE, 0x0);
+
+	/*
+	 * Register level handler for Main IRQs
+	 */
+	for (i = 0; i < IRQ_ORION_GPIO_START; i++) {
+		set_irq_chip(i, &orion_main_irq_chip);
+		set_irq_handler(i, handle_level_irq);
+		set_irq_flags(i, IRQF_VALID);
+	}
+}
+
+void __init orion_init_irq(void)
+{
+	orion_init_main_irq();
+	orion_init_gpio_irq();
+}