diff options
Diffstat (limited to 'arch/mips/momentum/ocelot_g/gt-irq.c')
| -rw-r--r-- | arch/mips/momentum/ocelot_g/gt-irq.c | 214 |
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 index 00000000000..d0b5c9dd0ea --- /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 = >64240_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 +} |