LXR linux/arch/m68k/amiga/cia.c

   1/*
   2 *  linux/arch/m68k/amiga/cia.c - CIA support
   3 *
   4 *  Copyright (C) 1996 Roman Zippel
   5 *
   6 *  The concept of some functions bases on the original Amiga OS function
   7 *
   8 * This file is subject to the terms and conditions of the GNU General Public
   9 * License.  See the file COPYING in the main directory of this archive
  10 * for more details.
  11 */
  12
  13#include <linux/types.h>
  14#include <linux/kernel.h>
  15#include <linux/sched.h>
  16#include <linux/errno.h>
  17#include <linux/kernel_stat.h>
  18#include <linux/init.h>
  19#include <linux/seq_file.h>
  20#include <linux/interrupt.h>
  21
  22#include <asm/irq.h>
  23#include <asm/amigahw.h>
  24#include <asm/amigaints.h>
  25
  26struct ciabase {
  27        volatile struct CIA *cia;
  28        unsigned char icr_mask, icr_data;
  29        unsigned short int_mask;
  30        int handler_irq, cia_irq, server_irq;
  31        char *name;
  32} ciaa_base = {
  33        .cia            = &ciaa,
  34        .int_mask       = IF_PORTS,
  35        .handler_irq    = IRQ_AMIGA_PORTS,
  36        .cia_irq        = IRQ_AMIGA_CIAA,
  37        .name           = "CIAA"
  38}, ciab_base = {
  39        .cia            = &ciab,
  40        .int_mask       = IF_EXTER,
  41        .handler_irq    = IRQ_AMIGA_EXTER,
  42        .cia_irq        = IRQ_AMIGA_CIAB,
  43        .name           = "CIAB"
  44};
  45
  46/*
  47 *  Cause or clear CIA interrupts, return old interrupt status.
  48 */
  49
  50unsigned char cia_set_irq(struct ciabase *base, unsigned char mask)
  51{
  52        unsigned char old;
  53
  54        old = (base->icr_data |= base->cia->icr);
  55        if (mask & CIA_ICR_SETCLR)
  56                base->icr_data |= mask;
  57        else
  58                base->icr_data &= ~mask;
  59        if (base->icr_data & base->icr_mask)
  60                amiga_custom.intreq = IF_SETCLR | base->int_mask;
  61        return old & base->icr_mask;
  62}
  63
  64/*
  65 *  Enable or disable CIA interrupts, return old interrupt mask,
  66 */
  67
  68unsigned char cia_able_irq(struct ciabase *base, unsigned char mask)
  69{
  70        unsigned char old;
  71
  72        old = base->icr_mask;
  73        base->icr_data |= base->cia->icr;
  74        base->cia->icr = mask;
  75        if (mask & CIA_ICR_SETCLR)
  76                base->icr_mask |= mask;
  77        else
  78                base->icr_mask &= ~mask;
  79        base->icr_mask &= CIA_ICR_ALL;
  80        if (base->icr_data & base->icr_mask)
  81                amiga_custom.intreq = IF_SETCLR | base->int_mask;
  82        return old;
  83}
  84
  85static irqreturn_t cia_handler(int irq, void *dev_id)
  86{
  87        struct ciabase *base = dev_id;
  88        int mach_irq;
  89        unsigned char ints;
  90
  91        mach_irq = base->cia_irq;
  92        ints = cia_set_irq(base, CIA_ICR_ALL);
  93        amiga_custom.intreq = base->int_mask;
  94        for (; ints; mach_irq++, ints >>= 1) {
  95                if (ints & 1)
  96                        m68k_handle_int(mach_irq);
  97        }
  98        return IRQ_HANDLED;
  99}
 100
 101static void cia_enable_irq(unsigned int irq)
 102{
 103        unsigned char mask;
 104
 105        if (irq >= IRQ_AMIGA_CIAB) {
 106                mask = 1 << (irq - IRQ_AMIGA_CIAB);
 107                cia_set_irq(&ciab_base, mask);
 108                cia_able_irq(&ciab_base, CIA_ICR_SETCLR | mask);
 109        } else {
 110                mask = 1 << (irq - IRQ_AMIGA_CIAA);
 111                cia_set_irq(&ciaa_base, mask);
 112                cia_able_irq(&ciaa_base, CIA_ICR_SETCLR | mask);
 113        }
 114}
 115
 116static void cia_disable_irq(unsigned int irq)
 117{
 118        if (irq >= IRQ_AMIGA_CIAB)
 119                cia_able_irq(&ciab_base, 1 << (irq - IRQ_AMIGA_CIAB));
 120        else
 121                cia_able_irq(&ciaa_base, 1 << (irq - IRQ_AMIGA_CIAA));
 122}
 123
 124static struct irq_controller cia_irq_controller = {
 125        .name           = "cia",
 126        .lock           = __SPIN_LOCK_UNLOCKED(cia_irq_controller.lock),
 127        .enable         = cia_enable_irq,
 128        .disable        = cia_disable_irq,
 129};
 130
 131/*
 132 * Override auto irq 2 & 6 and use them as general chain
 133 * for external interrupts, we link the CIA interrupt sources
 134 * into this chain.
 135 */
 136
 137static void auto_enable_irq(unsigned int irq)
 138{
 139        switch (irq) {
 140        case IRQ_AUTO_2:
 141                amiga_custom.intena = IF_SETCLR | IF_PORTS;
 142                break;
 143        case IRQ_AUTO_6:
 144                amiga_custom.intena = IF_SETCLR | IF_EXTER;
 145                break;
 146        }
 147}
 148
 149static void auto_disable_irq(unsigned int irq)
 150{
 151        switch (irq) {
 152        case IRQ_AUTO_2:
 153                amiga_custom.intena = IF_PORTS;
 154                break;
 155        case IRQ_AUTO_6:
 156                amiga_custom.intena = IF_EXTER;
 157                break;
 158        }
 159}
 160
 161static struct irq_controller auto_irq_controller = {
 162        .name           = "auto",
 163        .lock           = __SPIN_LOCK_UNLOCKED(auto_irq_controller.lock),
 164        .enable         = auto_enable_irq,
 165        .disable        = auto_disable_irq,
 166};
 167
 168void __init cia_init_IRQ(struct ciabase *base)
 169{
 170        m68k_setup_irq_controller(&cia_irq_controller, base->cia_irq, CIA_IRQS);
 171
 172        /* clear any pending interrupt and turn off all interrupts */
 173        cia_set_irq(base, CIA_ICR_ALL);
 174        cia_able_irq(base, CIA_ICR_ALL);
 175
 176        /* override auto int and install CIA handler */
 177        m68k_setup_irq_controller(&auto_irq_controller, base->handler_irq, 1);
 178        m68k_irq_startup(base->handler_irq);
 179        if (request_irq(base->handler_irq, cia_handler, IRQF_SHARED,
 180                        base->name, base))
 181                pr_err("Couldn't register %s interrupt\n", base->name);
 182}
 183