diff options
Diffstat (limited to 'arch/m68k/amiga/cia.c')
| -rw-r--r-- | arch/m68k/amiga/cia.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/arch/m68k/amiga/cia.c b/arch/m68k/amiga/cia.c new file mode 100644 index 00000000000..7d55682615e --- /dev/null +++ b/arch/m68k/amiga/cia.c @@ -0,0 +1,180 @@ +/* + * linux/arch/m68k/amiga/cia.c - CIA support + * + * Copyright (C) 1996 Roman Zippel + * + * The concept of some functions bases on the original Amiga OS function + * + * 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. + */ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/errno.h> +#include <linux/kernel_stat.h> +#include <linux/init.h> +#include <linux/seq_file.h> +#include <linux/interrupt.h> + +#include <asm/irq.h> +#include <asm/amigahw.h> +#include <asm/amigaints.h> + +struct ciabase { + volatile struct CIA *cia; + unsigned char icr_mask, icr_data; + unsigned short int_mask; + int handler_irq, cia_irq, server_irq; + char *name; + irq_handler_t irq_list[CIA_IRQS]; +} ciaa_base = { + .cia = &ciaa, + .int_mask = IF_PORTS, + .handler_irq = IRQ_AMIGA_AUTO_2, + .cia_irq = IRQ_AMIGA_CIAA, + .server_irq = IRQ_AMIGA_PORTS, + .name = "CIAA handler" +}, ciab_base = { + .cia = &ciab, + .int_mask = IF_EXTER, + .handler_irq = IRQ_AMIGA_AUTO_6, + .cia_irq = IRQ_AMIGA_CIAB, + .server_irq = IRQ_AMIGA_EXTER, + .name = "CIAB handler" +}; + +/* + * Cause or clear CIA interrupts, return old interrupt status. + */ + +unsigned char cia_set_irq(struct ciabase *base, unsigned char mask) +{ + unsigned char old; + + old = (base->icr_data |= base->cia->icr); + if (mask & CIA_ICR_SETCLR) + base->icr_data |= mask; + else + base->icr_data &= ~mask; + if (base->icr_data & base->icr_mask) + custom.intreq = IF_SETCLR | base->int_mask; + return old & base->icr_mask; +} + +/* + * Enable or disable CIA interrupts, return old interrupt mask, + * interrupts will only be enabled if a handler exists + */ + +unsigned char cia_able_irq(struct ciabase *base, unsigned char mask) +{ + unsigned char old, tmp; + int i; + + old = base->icr_mask; + base->icr_data |= base->cia->icr; + base->cia->icr = mask; + if (mask & CIA_ICR_SETCLR) + base->icr_mask |= mask; + else + base->icr_mask &= ~mask; + base->icr_mask &= CIA_ICR_ALL; + for (i = 0, tmp = 1; i < CIA_IRQS; i++, tmp <<= 1) { + if ((tmp & base->icr_mask) && !base->irq_list[i].handler) { + base->icr_mask &= ~tmp; + base->cia->icr = tmp; + } + } + if (base->icr_data & base->icr_mask) + custom.intreq = IF_SETCLR | base->int_mask; + return old; +} + +int cia_request_irq(struct ciabase *base, unsigned int irq, + irqreturn_t (*handler)(int, void *, struct pt_regs *), + unsigned long flags, const char *devname, void *dev_id) +{ + unsigned char mask; + + base->irq_list[irq].handler = handler; + base->irq_list[irq].flags = flags; + base->irq_list[irq].dev_id = dev_id; + base->irq_list[irq].devname = devname; + + /* enable the interrupt */ + mask = 1 << irq; + cia_set_irq(base, mask); + cia_able_irq(base, CIA_ICR_SETCLR | mask); + return 0; +} + +void cia_free_irq(struct ciabase *base, unsigned int irq, void *dev_id) +{ + if (base->irq_list[irq].dev_id != dev_id) + printk("%s: removing probably wrong IRQ %i from %s\n", + __FUNCTION__, base->cia_irq + irq, + base->irq_list[irq].devname); + + base->irq_list[irq].handler = NULL; + base->irq_list[irq].flags = 0; + + cia_able_irq(base, 1 << irq); +} + +static irqreturn_t cia_handler(int irq, void *dev_id, struct pt_regs *fp) +{ + struct ciabase *base = (struct ciabase *)dev_id; + int mach_irq, i; + unsigned char ints; + + mach_irq = base->cia_irq; + irq = SYS_IRQS + mach_irq; + ints = cia_set_irq(base, CIA_ICR_ALL); + custom.intreq = base->int_mask; + for (i = 0; i < CIA_IRQS; i++, irq++, mach_irq++) { + if (ints & 1) { + kstat_cpu(0).irqs[irq]++; + base->irq_list[i].handler(mach_irq, base->irq_list[i].dev_id, fp); + } + ints >>= 1; + } + amiga_do_irq_list(base->server_irq, fp); + return IRQ_HANDLED; +} + +void __init cia_init_IRQ(struct ciabase *base) +{ + int i; + + /* init isr handlers */ + for (i = 0; i < CIA_IRQS; i++) { + base->irq_list[i].handler = NULL; + base->irq_list[i].flags = 0; + } + + /* clear any pending interrupt and turn off all interrupts */ + cia_set_irq(base, CIA_ICR_ALL); + cia_able_irq(base, CIA_ICR_ALL); + + /* install CIA handler */ + request_irq(base->handler_irq, cia_handler, 0, base->name, base); + + custom.intena = IF_SETCLR | base->int_mask; +} + +int cia_get_irq_list(struct ciabase *base, struct seq_file *p) +{ + int i, j; + + j = base->cia_irq; + for (i = 0; i < CIA_IRQS; i++) { + seq_printf(p, "cia %2d: %10d ", j + i, + kstat_cpu(0).irqs[SYS_IRQS + j + i]); + seq_puts(p, " "); + seq_printf(p, "%s\n", base->irq_list[i].devname); + } + return 0; +} |