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-rw-r--r--arch/arm/mach-orion5x/irq.c211
1 files changed, 211 insertions, 0 deletions
diff --git a/arch/arm/mach-orion5x/irq.c b/arch/arm/mach-orion5x/irq.c
new file mode 100644
index 000000000000..dd21f38c5d37
--- /dev/null
+++ b/arch/arm/mach-orion5x/irq.c
@@ -0,0 +1,211 @@
+/*
+ * arch/arm/mach-orion5x/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/io.h>
+#include <asm/arch/orion5x.h>
+#include <asm/plat-orion/irq.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 orion5x_gpio_irq_ack(u32 irq)
+{
+ int pin = irq_to_gpio(irq);
+ if (irq_desc[irq].status & IRQ_LEVEL)
+ /*
+ * Mask bit for level interrupt
+ */
+ orion5x_clrbits(GPIO_LEVEL_MASK, 1 << pin);
+ else
+ /*
+ * Clear casue bit for egde interrupt
+ */
+ orion5x_clrbits(GPIO_EDGE_CAUSE, 1 << pin);
+}
+
+static void orion5x_gpio_irq_mask(u32 irq)
+{
+ int pin = irq_to_gpio(irq);
+ if (irq_desc[irq].status & IRQ_LEVEL)
+ orion5x_clrbits(GPIO_LEVEL_MASK, 1 << pin);
+ else
+ orion5x_clrbits(GPIO_EDGE_MASK, 1 << pin);
+}
+
+static void orion5x_gpio_irq_unmask(u32 irq)
+{
+ int pin = irq_to_gpio(irq);
+ if (irq_desc[irq].status & IRQ_LEVEL)
+ orion5x_setbits(GPIO_LEVEL_MASK, 1 << pin);
+ else
+ orion5x_setbits(GPIO_EDGE_MASK, 1 << pin);
+}
+
+static int orion5x_gpio_set_irq_type(u32 irq, u32 type)
+{
+ int pin = irq_to_gpio(irq);
+ struct irq_desc *desc;
+
+ if ((orion5x_read(GPIO_IO_CONF) & (1 << pin)) == 0) {
+ printk(KERN_ERR "orion5x_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;
+ orion5x_clrbits(GPIO_IN_POL, (1 << pin));
+ break;
+ case IRQT_LOW:
+ desc->handle_irq = handle_level_irq;
+ desc->status |= IRQ_LEVEL;
+ orion5x_setbits(GPIO_IN_POL, (1 << pin));
+ break;
+ case IRQT_RISING:
+ desc->handle_irq = handle_edge_irq;
+ desc->status &= ~IRQ_LEVEL;
+ orion5x_clrbits(GPIO_IN_POL, (1 << pin));
+ break;
+ case IRQT_FALLING:
+ desc->handle_irq = handle_edge_irq;
+ desc->status &= ~IRQ_LEVEL;
+ orion5x_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 ((orion5x_read(GPIO_IN_POL) ^ orion5x_read(GPIO_DATA_IN))
+ & (1 << pin))
+ orion5x_setbits(GPIO_IN_POL, (1 << pin)); /* falling */
+ else
+ orion5x_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 orion5x_gpio_irq_chip = {
+ .name = "Orion-IRQ-GPIO",
+ .ack = orion5x_gpio_irq_ack,
+ .mask = orion5x_gpio_irq_mask,
+ .unmask = orion5x_gpio_irq_unmask,
+ .set_type = orion5x_gpio_set_irq_type,
+};
+
+static void orion5x_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+ u32 cause, offs, pin;
+
+ BUG_ON(irq < IRQ_ORION5X_GPIO_0_7 || irq > IRQ_ORION5X_GPIO_24_31);
+ offs = (irq - IRQ_ORION5X_GPIO_0_7) * 8;
+ cause = (orion5x_read(GPIO_DATA_IN) & orion5x_read(GPIO_LEVEL_MASK)) |
+ (orion5x_read(GPIO_EDGE_CAUSE) & orion5x_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 = orion5x_read(GPIO_IN_POL);
+ polarity ^= 1 << pin;
+ orion5x_write(GPIO_IN_POL, polarity);
+ }
+ desc_handle_irq(irq, desc);
+ }
+ }
+}
+
+static void __init orion5x_init_gpio_irq(void)
+{
+ int i;
+ struct irq_desc *desc;
+
+ /*
+ * Mask and clear GPIO IRQ interrupts
+ */
+ orion5x_write(GPIO_LEVEL_MASK, 0x0);
+ orion5x_write(GPIO_EDGE_MASK, 0x0);
+ orion5x_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_ORION5X_GPIO_START; i < NR_IRQS; i++) {
+ set_irq_chip(i, &orion5x_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_ORION5X_GPIO_0_7, orion5x_gpio_irq_handler);
+ set_irq_chained_handler(IRQ_ORION5X_GPIO_8_15, orion5x_gpio_irq_handler);
+ set_irq_chained_handler(IRQ_ORION5X_GPIO_16_23, orion5x_gpio_irq_handler);
+ set_irq_chained_handler(IRQ_ORION5X_GPIO_24_31, orion5x_gpio_irq_handler);
+}
+
+/*****************************************************************************
+ * Orion Main IRQ
+ ****************************************************************************/
+static void __init orion5x_init_main_irq(void)
+{
+ orion_irq_init(0, (void __iomem *)MAIN_IRQ_MASK);
+}
+
+void __init orion5x_init_irq(void)
+{
+ orion5x_init_main_irq();
+ orion5x_init_gpio_irq();
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-17 08:56:20 +0000