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-rw-r--r--arch/mips/momentum/ocelot_g/gt-irq.c214
1 files changed, 214 insertions, 0 deletions
diff --git a/arch/mips/momentum/ocelot_g/gt-irq.c b/arch/mips/momentum/ocelot_g/gt-irq.c
new file mode 100644
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--- /dev/null
+++ b/arch/mips/momentum/ocelot_g/gt-irq.c
@@ -0,0 +1,214 @@
+/*
+ *
+ * Copyright 2002 Momentum Computer
+ * Author: mdharm@momenco.com
+ *
+ * arch/mips/momentum/ocelot_g/gt_irq.c
+ * Interrupt routines for gt64240. Currently it only handles timer irq.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <asm/ptrace.h>
+#include <linux/sched.h>
+#include <linux/kernel_stat.h>
+#include <asm/gt64240.h>
+#include <asm/io.h>
+
+unsigned long bus_clock;
+
+/*
+ * These are interrupt handlers for the GT on-chip interrupts. They
+ * all come in to the MIPS on a single interrupt line, and have to
+ * be handled and ack'ed differently than other MIPS interrupts.
+ */
+
+#if CURRENTLY_UNUSED
+
+struct tq_struct irq_handlers[MAX_CAUSE_REGS][MAX_CAUSE_REG_WIDTH];
+void hook_irq_handler(int int_cause, int bit_num, void *isr_ptr);
+
+/*
+ * Hooks IRQ handler to the system. When the system is interrupted
+ * the interrupt service routine is called.
+ *
+ * Inputs :
+ * int_cause - The interrupt cause number. In EVB64120 two parameters
+ * are declared, INT_CAUSE_MAIN and INT_CAUSE_HIGH.
+ * bit_num - Indicates which bit number in the cause register
+ * isr_ptr - Pointer to the interrupt service routine
+ */
+void hook_irq_handler(int int_cause, int bit_num, void *isr_ptr)
+{
+ irq_handlers[int_cause][bit_num].routine = isr_ptr;
+}
+
+
+/*
+ * Enables the IRQ on Galileo Chip
+ *
+ * Inputs :
+ * int_cause - The interrupt cause number. In EVB64120 two parameters
+ * are declared, INT_CAUSE_MAIN and INT_CAUSE_HIGH.
+ * bit_num - Indicates which bit number in the cause register
+ *
+ * Outputs :
+ * 1 if succesful, 0 if failure
+ */
+int enable_galileo_irq(int int_cause, int bit_num)
+{
+ if (int_cause == INT_CAUSE_MAIN)
+ SET_REG_BITS(CPU_INTERRUPT_MASK_REGISTER, (1 << bit_num));
+ else if (int_cause == INT_CAUSE_HIGH)
+ SET_REG_BITS(CPU_HIGH_INTERRUPT_MASK_REGISTER,
+ (1 << bit_num));
+ else
+ return 0;
+
+ return 1;
+}
+
+/*
+ * Disables the IRQ on Galileo Chip
+ *
+ * Inputs :
+ * int_cause - The interrupt cause number. In EVB64120 two parameters
+ * are declared, INT_CAUSE_MAIN and INT_CAUSE_HIGH.
+ * bit_num - Indicates which bit number in the cause register
+ *
+ * Outputs :
+ * 1 if succesful, 0 if failure
+ */
+int disable_galileo_irq(int int_cause, int bit_num)
+{
+ if (int_cause == INT_CAUSE_MAIN)
+ RESET_REG_BITS(CPU_INTERRUPT_MASK_REGISTER,
+ (1 << bit_num));
+ else if (int_cause == INT_CAUSE_HIGH)
+ RESET_REG_BITS(CPU_HIGH_INTERRUPT_MASK_REGISTER,
+ (1 << bit_num));
+ else
+ return 0;
+ return 1;
+}
+#endif /* UNUSED */
+
+/*
+ * Interrupt handler for interrupts coming from the Galileo chip via P0_INT#.
+ *
+ * We route the timer interrupt to P0_INT# (IRQ 6), and that's all this
+ * routine can handle, for now.
+ *
+ * In the future, we'll route more interrupts to this pin, and that's why
+ * we keep this particular structure in the function.
+ */
+
+static irqreturn_t gt64240_p0int_irq(int irq, void *dev, struct pt_regs *regs)
+{
+ uint32_t irq_src, irq_src_mask;
+ int handled;
+
+ /* get the low interrupt cause register */
+ irq_src = MV_READ(LOW_INTERRUPT_CAUSE_REGISTER);
+
+ /* get the mask register for this pin */
+ irq_src_mask = MV_READ(PCI_0INTERRUPT_CAUSE_MASK_REGISTER_LOW);
+
+ /* mask off only the interrupts we're interested in */
+ irq_src = irq_src & irq_src_mask;
+
+ handled = IRQ_NONE;
+
+ /* Check for timer interrupt */
+ if (irq_src & 0x00000100) {
+ handled = IRQ_HANDLED;
+ irq_src &= ~0x00000100;
+
+ /* Clear any pending cause bits */
+ MV_WRITE(TIMER_COUNTER_0_3_INTERRUPT_CAUSE, 0x0);
+
+ /* handle the timer call */
+ do_timer(regs);
+#ifndef CONFIG_SMP
+ update_process_times(user_mode(regs));
+#endif
+ }
+
+ if (irq_src) {
+ printk(KERN_INFO
+ "UNKNOWN P0_INT# interrupt received, irq_src=0x%x\n",
+ irq_src);
+ }
+
+ return handled;
+}
+
+/*
+ * Initializes timer using galileo's built in timer.
+ */
+
+/*
+ * This will ignore the standard MIPS timer interrupt handler
+ * that is passed in as *irq (=irq0 in ../kernel/time.c).
+ * We will do our own timer interrupt handling.
+ */
+void gt64240_time_init(void)
+{
+ static struct irqaction timer;
+
+ /* Stop the timer -- we'll use timer #0 */
+ MV_WRITE(TIMER_COUNTER_0_3_CONTROL, 0x0);
+
+ /* Load timer value for 100 Hz */
+ MV_WRITE(TIMER_COUNTER0, bus_clock / 100);
+
+ /*
+ * Create the IRQ structure entry for the timer. Since we're too early
+ * in the boot process to use the "request_irq()" call, we'll hard-code
+ * the values to the correct interrupt line.
+ */
+ timer.handler = &gt64240_p0int_irq;
+ timer.flags = SA_SHIRQ | SA_INTERRUPT;
+ timer.name = "timer";
+ timer.dev_id = NULL;
+ timer.next = NULL;
+ timer.mask = 0;
+ irq_desc[6].action = &timer;
+
+ enable_irq(6);
+
+ /* Clear any pending cause bits */
+ MV_WRITE(TIMER_COUNTER_0_3_INTERRUPT_CAUSE, 0x0);
+
+ /* Enable the interrupt for timer 0 */
+ MV_WRITE(TIMER_COUNTER_0_3_INTERRUPT_MASK, 0x1);
+
+ /* Enable the timer interrupt for GT-64240 pin P0_INT# */
+ MV_WRITE (PCI_0INTERRUPT_CAUSE_MASK_REGISTER_LOW, 0x100);
+
+ /* Configure and start the timer */
+ MV_WRITE(TIMER_COUNTER_0_3_CONTROL, 0x3);
+}
+
+void gt64240_irq_init(void)
+{
+#if CURRENTLY_UNUSED
+ int i, j;
+
+ /* Reset irq handlers pointers to NULL */
+ for (i = 0; i < MAX_CAUSE_REGS; i++) {
+ for (j = 0; j < MAX_CAUSE_REG_WIDTH; j++) {
+ irq_handlers[i][j].next = NULL;
+ irq_handlers[i][j].sync = 0;
+ irq_handlers[i][j].routine = NULL;
+ irq_handlers[i][j].data = NULL;
+ }
+ }
+#endif
+}
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