diff options
Diffstat (limited to 'arch/mips/jazz/irq.c')
| -rw-r--r-- | arch/mips/jazz/irq.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/mips/jazz/irq.c b/arch/mips/jazz/irq.c new file mode 100644 index 000000000..264d45387 --- /dev/null +++ b/arch/mips/jazz/irq.c @@ -0,0 +1,149 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1992 Linus Torvalds + * Copyright (C) 1994 - 2001, 2003, 07 Ralf Baechle + */ +#include <linux/clockchips.h> +#include <linux/i8253.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/smp.h> +#include <linux/spinlock.h> +#include <linux/irq.h> +#include <linux/pgtable.h> + +#include <asm/irq_cpu.h> +#include <asm/i8259.h> +#include <asm/io.h> +#include <asm/jazz.h> +#include <asm/tlbmisc.h> + +static DEFINE_RAW_SPINLOCK(r4030_lock); + +static void enable_r4030_irq(struct irq_data *d) +{ + unsigned int mask = 1 << (d->irq - JAZZ_IRQ_START); + unsigned long flags; + + raw_spin_lock_irqsave(&r4030_lock, flags); + mask |= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE); + r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask); + raw_spin_unlock_irqrestore(&r4030_lock, flags); +} + +void disable_r4030_irq(struct irq_data *d) +{ + unsigned int mask = ~(1 << (d->irq - JAZZ_IRQ_START)); + unsigned long flags; + + raw_spin_lock_irqsave(&r4030_lock, flags); + mask &= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE); + r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask); + raw_spin_unlock_irqrestore(&r4030_lock, flags); +} + +static struct irq_chip r4030_irq_type = { + .name = "R4030", + .irq_mask = disable_r4030_irq, + .irq_unmask = enable_r4030_irq, +}; + +void __init init_r4030_ints(void) +{ + int i; + + for (i = JAZZ_IRQ_START; i <= JAZZ_IRQ_END; i++) + irq_set_chip_and_handler(i, &r4030_irq_type, handle_level_irq); + + r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, 0); + r4030_read_reg16(JAZZ_IO_IRQ_SOURCE); /* clear pending IRQs */ + r4030_read_reg32(JAZZ_R4030_INVAL_ADDR); /* clear error bits */ +} + +/* + * On systems with i8259-style interrupt controllers we assume for + * driver compatibility reasons interrupts 0 - 15 to be the i8259 + * interrupts even if the hardware uses a different interrupt numbering. + */ +void __init arch_init_irq(void) +{ + /* + * this is a hack to get back the still needed wired mapping + * killed by init_mm() + */ + + /* Map 0xe0000000 -> 0x0:800005C0, 0xe0010000 -> 0x1:30000580 */ + add_wired_entry(0x02000017, 0x03c00017, 0xe0000000, PM_64K); + /* Map 0xe2000000 -> 0x0:900005C0, 0xe3010000 -> 0x0:910005C0 */ + add_wired_entry(0x02400017, 0x02440017, 0xe2000000, PM_16M); + /* Map 0xe4000000 -> 0x0:600005C0, 0xe4100000 -> 400005C0 */ + add_wired_entry(0x01800017, 0x01000017, 0xe4000000, PM_4M); + + init_i8259_irqs(); /* Integrated i8259 */ + mips_cpu_irq_init(); + init_r4030_ints(); + + change_c0_status(ST0_IM, IE_IRQ2 | IE_IRQ1); +} + +asmlinkage void plat_irq_dispatch(void) +{ + unsigned int pending = read_c0_cause() & read_c0_status(); + unsigned int irq; + + if (pending & IE_IRQ4) { + r4030_read_reg32(JAZZ_TIMER_REGISTER); + do_IRQ(JAZZ_TIMER_IRQ); + } else if (pending & IE_IRQ2) { + irq = *(volatile u8 *)JAZZ_EISA_IRQ_ACK; + do_IRQ(irq); + } else if (pending & IE_IRQ1) { + irq = *(volatile u8 *)JAZZ_IO_IRQ_SOURCE >> 2; + if (likely(irq > 0)) + do_IRQ(irq + JAZZ_IRQ_START - 1); + else + panic("Unimplemented loc_no_irq handler"); + } +} + +struct clock_event_device r4030_clockevent = { + .name = "r4030", + .features = CLOCK_EVT_FEAT_PERIODIC, + .rating = 300, + .irq = JAZZ_TIMER_IRQ, +}; + +static irqreturn_t r4030_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *cd = dev_id; + + cd->event_handler(cd); + return IRQ_HANDLED; +} + +void __init plat_time_init(void) +{ + struct clock_event_device *cd = &r4030_clockevent; + unsigned int cpu = smp_processor_id(); + + BUG_ON(HZ != 100); + + cd->cpumask = cpumask_of(cpu); + clockevents_register_device(cd); + if (request_irq(JAZZ_TIMER_IRQ, r4030_timer_interrupt, IRQF_TIMER, + "R4030 timer", cd)) + pr_err("Failed to register R4030 timer interrupt\n"); + + /* + * Set clock to 100Hz. + * + * The R4030 timer receives an input clock of 1kHz which is divided by + * a programmable 4-bit divider. This makes it fairly inflexible. + */ + r4030_write_reg32(JAZZ_TIMER_INTERVAL, 9); + setup_pit_timer(); +} |