diff options
Diffstat (limited to 'arch/arm/mach-footbridge/isa-irq.c')
| -rw-r--r-- | arch/arm/mach-footbridge/isa-irq.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/arch/arm/mach-footbridge/isa-irq.c b/arch/arm/mach-footbridge/isa-irq.c new file mode 100644 index 000000000..842ddb412 --- /dev/null +++ b/arch/arm/mach-footbridge/isa-irq.c @@ -0,0 +1,177 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/arch/arm/mach-footbridge/irq.c + * + * Copyright (C) 1996-2000 Russell King + * + * Changelog: + * 22-Aug-1998 RMK Restructured IRQ routines + * 03-Sep-1998 PJB Merged CATS support + * 20-Jan-1998 RMK Started merge of EBSA286, CATS and NetWinder + * 26-Jan-1999 PJB Don't use IACK on CATS + * 16-Mar-1999 RMK Added autodetect of ISA PICs + */ +#include <linux/ioport.h> +#include <linux/interrupt.h> +#include <linux/list.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/spinlock.h> + +#include <asm/mach/irq.h> + +#include <mach/hardware.h> +#include <asm/hardware/dec21285.h> +#include <asm/irq.h> +#include <asm/mach-types.h> + +#include "common.h" + +static void isa_mask_pic_lo_irq(struct irq_data *d) +{ + unsigned int mask = 1 << (d->irq & 7); + + outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO); +} + +static void isa_ack_pic_lo_irq(struct irq_data *d) +{ + unsigned int mask = 1 << (d->irq & 7); + + outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO); + outb(0x20, PIC_LO); +} + +static void isa_unmask_pic_lo_irq(struct irq_data *d) +{ + unsigned int mask = 1 << (d->irq & 7); + + outb(inb(PIC_MASK_LO) & ~mask, PIC_MASK_LO); +} + +static struct irq_chip isa_lo_chip = { + .irq_ack = isa_ack_pic_lo_irq, + .irq_mask = isa_mask_pic_lo_irq, + .irq_unmask = isa_unmask_pic_lo_irq, +}; + +static void isa_mask_pic_hi_irq(struct irq_data *d) +{ + unsigned int mask = 1 << (d->irq & 7); + + outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI); +} + +static void isa_ack_pic_hi_irq(struct irq_data *d) +{ + unsigned int mask = 1 << (d->irq & 7); + + outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI); + outb(0x62, PIC_LO); + outb(0x20, PIC_HI); +} + +static void isa_unmask_pic_hi_irq(struct irq_data *d) +{ + unsigned int mask = 1 << (d->irq & 7); + + outb(inb(PIC_MASK_HI) & ~mask, PIC_MASK_HI); +} + +static struct irq_chip isa_hi_chip = { + .irq_ack = isa_ack_pic_hi_irq, + .irq_mask = isa_mask_pic_hi_irq, + .irq_unmask = isa_unmask_pic_hi_irq, +}; + +static void isa_irq_handler(struct irq_desc *desc) +{ + unsigned int isa_irq = *(unsigned char *)PCIIACK_BASE; + + if (isa_irq < _ISA_IRQ(0) || isa_irq >= _ISA_IRQ(16)) { + do_bad_IRQ(desc); + return; + } + + generic_handle_irq(isa_irq); +} + +static struct resource pic1_resource = { + .name = "pic1", + .start = 0x20, + .end = 0x3f, +}; + +static struct resource pic2_resource = { + .name = "pic2", + .start = 0xa0, + .end = 0xbf, +}; + +void __init isa_init_irq(unsigned int host_irq) +{ + unsigned int irq; + + /* + * Setup, and then probe for an ISA PIC + * If the PIC is not there, then we + * ignore the PIC. + */ + outb(0x11, PIC_LO); + outb(_ISA_IRQ(0), PIC_MASK_LO); /* IRQ number */ + outb(0x04, PIC_MASK_LO); /* Slave on Ch2 */ + outb(0x01, PIC_MASK_LO); /* x86 */ + outb(0xf5, PIC_MASK_LO); /* pattern: 11110101 */ + + outb(0x11, PIC_HI); + outb(_ISA_IRQ(8), PIC_MASK_HI); /* IRQ number */ + outb(0x02, PIC_MASK_HI); /* Slave on Ch1 */ + outb(0x01, PIC_MASK_HI); /* x86 */ + outb(0xfa, PIC_MASK_HI); /* pattern: 11111010 */ + + outb(0x0b, PIC_LO); + outb(0x0b, PIC_HI); + + if (inb(PIC_MASK_LO) == 0xf5 && inb(PIC_MASK_HI) == 0xfa) { + outb(0xff, PIC_MASK_LO);/* mask all IRQs */ + outb(0xff, PIC_MASK_HI);/* mask all IRQs */ + } else { + printk(KERN_INFO "IRQ: ISA PIC not found\n"); + host_irq = (unsigned int)-1; + } + + if (host_irq != (unsigned int)-1) { + for (irq = _ISA_IRQ(0); irq < _ISA_IRQ(8); irq++) { + irq_set_chip_and_handler(irq, &isa_lo_chip, + handle_level_irq); + irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE); + } + + for (irq = _ISA_IRQ(8); irq < _ISA_IRQ(16); irq++) { + irq_set_chip_and_handler(irq, &isa_hi_chip, + handle_level_irq); + irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE); + } + + request_resource(&ioport_resource, &pic1_resource); + request_resource(&ioport_resource, &pic2_resource); + + irq = IRQ_ISA_CASCADE; + if (request_irq(irq, no_action, 0, "cascade", NULL)) + pr_err("Failed to request irq %u (cascade)\n", irq); + + irq_set_chained_handler(host_irq, isa_irq_handler); + + /* + * On the NetWinder, don't automatically + * enable ISA IRQ11 when it is requested. + * There appears to be a missing pull-up + * resistor on this line. + */ + if (machine_is_netwinder()) + irq_modify_status(_ISA_IRQ(11), + IRQ_NOREQUEST | IRQ_NOPROBE, IRQ_NOAUTOEN); + } +} + + |