diff options
Diffstat (limited to 'arch/m68k/amiga/cia.c')
| -rw-r--r-- | arch/m68k/amiga/cia.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/arch/m68k/amiga/cia.c b/arch/m68k/amiga/cia.c new file mode 100644 index 000000000..b9aee983e --- /dev/null +++ b/arch/m68k/amiga/cia.c @@ -0,0 +1,195 @@ +/* + * 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 <linux/irq.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; +} ciaa_base = { + .cia = &ciaa, + .int_mask = IF_PORTS, + .handler_irq = IRQ_AMIGA_PORTS, + .cia_irq = IRQ_AMIGA_CIAA, + .name = "CIAA" +}, ciab_base = { + .cia = &ciab, + .int_mask = IF_EXTER, + .handler_irq = IRQ_AMIGA_EXTER, + .cia_irq = IRQ_AMIGA_CIAB, + .name = "CIAB" +}; + +/* + * 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) + amiga_custom.intreq = IF_SETCLR | base->int_mask; + return old & base->icr_mask; +} + +/* + * Enable or disable CIA interrupts, return old interrupt mask, + */ + +unsigned char cia_able_irq(struct ciabase *base, unsigned char mask) +{ + unsigned char old; + + 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; + if (base->icr_data & base->icr_mask) + amiga_custom.intreq = IF_SETCLR | base->int_mask; + return old; +} + +static irqreturn_t cia_handler(int irq, void *dev_id) +{ + struct ciabase *base = dev_id; + int mach_irq; + unsigned char ints; + unsigned long flags; + + /* Interrupts get disabled while the timer irq flag is cleared and + * the timer interrupt serviced. + */ + mach_irq = base->cia_irq; + local_irq_save(flags); + ints = cia_set_irq(base, CIA_ICR_ALL); + amiga_custom.intreq = base->int_mask; + if (ints & 1) + generic_handle_irq(mach_irq); + local_irq_restore(flags); + mach_irq++, ints >>= 1; + for (; ints; mach_irq++, ints >>= 1) { + if (ints & 1) + generic_handle_irq(mach_irq); + } + return IRQ_HANDLED; +} + +static void cia_irq_enable(struct irq_data *data) +{ + unsigned int irq = data->irq; + unsigned char mask; + + if (irq >= IRQ_AMIGA_CIAB) { + mask = 1 << (irq - IRQ_AMIGA_CIAB); + cia_set_irq(&ciab_base, mask); + cia_able_irq(&ciab_base, CIA_ICR_SETCLR | mask); + } else { + mask = 1 << (irq - IRQ_AMIGA_CIAA); + cia_set_irq(&ciaa_base, mask); + cia_able_irq(&ciaa_base, CIA_ICR_SETCLR | mask); + } +} + +static void cia_irq_disable(struct irq_data *data) +{ + unsigned int irq = data->irq; + + if (irq >= IRQ_AMIGA_CIAB) + cia_able_irq(&ciab_base, 1 << (irq - IRQ_AMIGA_CIAB)); + else + cia_able_irq(&ciaa_base, 1 << (irq - IRQ_AMIGA_CIAA)); +} + +static struct irq_chip cia_irq_chip = { + .name = "cia", + .irq_enable = cia_irq_enable, + .irq_disable = cia_irq_disable, +}; + +/* + * Override auto irq 2 & 6 and use them as general chain + * for external interrupts, we link the CIA interrupt sources + * into this chain. + */ + +static void auto_irq_enable(struct irq_data *data) +{ + switch (data->irq) { + case IRQ_AUTO_2: + amiga_custom.intena = IF_SETCLR | IF_PORTS; + break; + case IRQ_AUTO_6: + amiga_custom.intena = IF_SETCLR | IF_EXTER; + break; + } +} + +static void auto_irq_disable(struct irq_data *data) +{ + switch (data->irq) { + case IRQ_AUTO_2: + amiga_custom.intena = IF_PORTS; + break; + case IRQ_AUTO_6: + amiga_custom.intena = IF_EXTER; + break; + } +} + +static struct irq_chip auto_irq_chip = { + .name = "auto", + .irq_enable = auto_irq_enable, + .irq_disable = auto_irq_disable, +}; + +void __init cia_init_IRQ(struct ciabase *base) +{ + m68k_setup_irq_controller(&cia_irq_chip, handle_simple_irq, + base->cia_irq, CIA_IRQS); + + /* clear any pending interrupt and turn off all interrupts */ + cia_set_irq(base, CIA_ICR_ALL); + cia_able_irq(base, CIA_ICR_ALL); + + /* override auto int and install CIA handler */ + m68k_setup_irq_controller(&auto_irq_chip, handle_simple_irq, + base->handler_irq, 1); + m68k_irq_startup_irq(base->handler_irq); + if (request_irq(base->handler_irq, cia_handler, IRQF_SHARED, + base->name, base)) + pr_err("Couldn't register %s interrupt\n", base->name); +} |