diff options
Diffstat (limited to 'arch/mips/lasat/interrupt.c')
| -rw-r--r-- | arch/mips/lasat/interrupt.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/mips/lasat/interrupt.c b/arch/mips/lasat/interrupt.c new file mode 100644 index 00000000..d608b6ef --- /dev/null +++ b/arch/mips/lasat/interrupt.c @@ -0,0 +1,135 @@ +/* + * Carsten Langgaard, carstenl@mips.com + * Copyright (C) 1999,2000 MIPS Technologies, Inc. All rights reserved. + * + * This program is free software; you can distribute it and/or modify it + * under the terms of the GNU General Public License (Version 2) as + * published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. + * + * Routines for generic manipulation of the interrupts found on the + * Lasat boards. + */ +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irq.h> + +#include <asm/irq_cpu.h> +#include <asm/lasat/lasat.h> +#include <asm/lasat/lasatint.h> + +#include <irq.h> + +static volatile int *lasat_int_status; +static volatile int *lasat_int_mask; +static volatile int lasat_int_mask_shift; + +void disable_lasat_irq(struct irq_data *d) +{ + unsigned int irq_nr = d->irq - LASAT_IRQ_BASE; + + *lasat_int_mask &= ~(1 << irq_nr) << lasat_int_mask_shift; +} + +void enable_lasat_irq(struct irq_data *d) +{ + unsigned int irq_nr = d->irq - LASAT_IRQ_BASE; + + *lasat_int_mask |= (1 << irq_nr) << lasat_int_mask_shift; +} + +static struct irq_chip lasat_irq_type = { + .name = "Lasat", + .irq_mask = disable_lasat_irq, + .irq_unmask = enable_lasat_irq, +}; + +static inline int ls1bit32(unsigned int x) +{ + int b = 31, s; + + s = 16; if (x << 16 == 0) s = 0; b -= s; x <<= s; + s = 8; if (x << 8 == 0) s = 0; b -= s; x <<= s; + s = 4; if (x << 4 == 0) s = 0; b -= s; x <<= s; + s = 2; if (x << 2 == 0) s = 0; b -= s; x <<= s; + s = 1; if (x << 1 == 0) s = 0; b -= s; + + return b; +} + +static unsigned long (*get_int_status)(void); + +static unsigned long get_int_status_100(void) +{ + return *lasat_int_status & *lasat_int_mask; +} + +static unsigned long get_int_status_200(void) +{ + unsigned long int_status; + + int_status = *lasat_int_status; + int_status &= (int_status >> LASATINT_MASK_SHIFT_200) & 0xffff; + return int_status; +} + +asmlinkage void plat_irq_dispatch(void) +{ + unsigned long int_status; + unsigned int cause = read_c0_cause(); + int irq; + + if (cause & CAUSEF_IP7) { /* R4000 count / compare IRQ */ + do_IRQ(7); + return; + } + + int_status = get_int_status(); + + /* if int_status == 0, then the interrupt has already been cleared */ + if (int_status) { + irq = LASAT_IRQ_BASE + ls1bit32(int_status); + + do_IRQ(irq); + } +} + +static struct irqaction cascade = { + .handler = no_action, + .name = "cascade", + .flags = IRQF_NO_THREAD, +}; + +void __init arch_init_irq(void) +{ + int i; + + if (IS_LASAT_200()) { + lasat_int_status = (void *)LASAT_INT_STATUS_REG_200; + lasat_int_mask = (void *)LASAT_INT_MASK_REG_200; + lasat_int_mask_shift = LASATINT_MASK_SHIFT_200; + get_int_status = get_int_status_200; + *lasat_int_mask &= 0xffff; + } else { + lasat_int_status = (void *)LASAT_INT_STATUS_REG_100; + lasat_int_mask = (void *)LASAT_INT_MASK_REG_100; + lasat_int_mask_shift = LASATINT_MASK_SHIFT_100; + get_int_status = get_int_status_100; + *lasat_int_mask = 0; + } + + mips_cpu_irq_init(); + + for (i = LASAT_IRQ_BASE; i <= LASAT_IRQ_END; i++) + irq_set_chip_and_handler(i, &lasat_irq_type, handle_level_irq); + + setup_irq(LASAT_CASCADE_IRQ, &cascade); +} |