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
  20 #include <asm/irq.h>
  21 #include <asm/amigahw.h>
  22 #include <asm/amigaints.h>
  23
  24 struct ciabase {
  25         volatile struct CIA *cia;
  26         u_char icr_mask, icr_data;
  27         u_short int_mask;
  28         int handler_irq, cia_irq, server_irq;
  29         char *name;
  30         struct irq_server server;
  31         irq_handler_t irq_list[CIA_IRQS];
  32 } ciaa_base = {
  33         &ciaa, 0, 0, IF_PORTS,
  34         IRQ_AMIGA_AUTO_2, IRQ_AMIGA_CIAA,
  35         IRQ_AMIGA_PORTS,
  36         "CIAA handler", {0, 0}
  37 }, ciab_base = {
  38         &ciab, 0, 0, IF_EXTER,
  39         IRQ_AMIGA_AUTO_6, IRQ_AMIGA_CIAB,
  40         IRQ_AMIGA_EXTER,
  41         "CIAB handler", {0, 0}
  42 };
  43
  44 /*
  45  *  Cause or clear CIA interrupts, return old interrupt status.
  46  */
  47
  48 unsigned char cia_set_irq(struct ciabase *base, unsigned char mask)
  49 {
  50         u_char old;
  51
  52         old = (base->icr_data |= base->cia->icr);
  53         if (mask & CIA_ICR_SETCLR)
  54                 base->icr_data |= mask;
  55         else
  56                 base->icr_data &= ~mask;
  57         if (base->icr_data & base->icr_mask)
  58                 custom.intreq = IF_SETCLR | base->int_mask;
  59         return old & base->icr_mask;
  60 }
  61
  62 /*
  63  *  Enable or disable CIA interrupts, return old interrupt mask,
  64  *  interrupts will only be enabled if a handler exists
  65  */
  66
  67 unsigned char cia_able_irq(struct ciabase *base, unsigned char mask)
  68 {
  69         u_char old, tmp;
  70         int i;
  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         for (i = 0, tmp = 1; i < CIA_IRQS; i++, tmp <<= 1) {
  81                 if ((tmp & base->icr_mask) && !base->irq_list[i].handler) {
  82                         base->icr_mask &= ~tmp;
  83                         base->cia->icr = tmp;
  84                 }
  85         }
  86         if (base->icr_data & base->icr_mask)
  87                 custom.intreq = IF_SETCLR | base->int_mask;
  88         return old;
  89 }
  90
  91 int cia_request_irq(struct ciabase *base, unsigned int irq,
  92                     void (*handler)(int, void *, struct pt_regs *),
  93                     unsigned long flags, const char *devname, void *dev_id)
  94 {
  95         u_char mask;
  96
  97         base->irq_list[irq].handler = handler;
  98         base->irq_list[irq].flags   = flags;
  99         base->irq_list[irq].dev_id  = dev_id;
 100         base->irq_list[irq].devname = devname;
 101
 102         /* enable the interrupt */
 103         mask = 1 << irq;
 104         cia_set_irq(base, mask);
 105         cia_able_irq(base, CIA_ICR_SETCLR | mask);
 106         return 0;
 107 }
 108
 109 void cia_free_irq(struct ciabase *base, unsigned int irq, void *dev_id)
 110 {
 111         if (base->irq_list[irq].dev_id != dev_id)
 112                 printk("%s: removing probably wrong IRQ %i from %s\n",
 113                        __FUNCTION__, base->cia_irq + irq,
 114                        base->irq_list[irq].devname);
 115
 116         base->irq_list[irq].handler = NULL;
 117         base->irq_list[irq].flags   = 0;
 118
 119         cia_able_irq(base, 1 << irq);
 120 }
 121
 122 static void cia_handler(int irq, void *dev_id, struct pt_regs *fp)
 123 {
 124         struct ciabase *base = (struct ciabase *)dev_id;
 125         int mach_irq, i;
 126         unsigned char ints;
 127
 128         mach_irq = base->cia_irq;
 129         irq = SYS_IRQS + mach_irq;
 130         ints = cia_set_irq(base, CIA_ICR_ALL);
 131         custom.intreq = base->int_mask;
 132         for (i = 0; i < CIA_IRQS; i++, irq++, mach_irq++) {
 133                 if (ints & 1) {
 134                         kstat.irqs[0][irq]++;
 135                         base->irq_list[i].handler(mach_irq, base->irq_list[i].dev_id, fp);
 136                 }
 137                 ints >>= 1;
 138         }
 139         amiga_do_irq_list(base->server_irq, fp, &base->server);
 140 }
 141
 142 void __init cia_init_IRQ(struct ciabase *base)
 143 {
 144         int i;
 145
 146         /* init isr handlers */
 147         for (i = 0; i < CIA_IRQS; i++) {
 148                 base->irq_list[i].handler = NULL;
 149                 base->irq_list[i].flags   = 0;
 150         }
 151
 152         /* clear any pending interrupt and turn off all interrupts */
 153         cia_set_irq(base, CIA_ICR_ALL);
 154         cia_able_irq(base, CIA_ICR_ALL);
 155
 156         /* install CIA handler */
 157         request_irq(base->handler_irq, cia_handler, 0, base->name, base);
 158
 159         custom.intena = IF_SETCLR | base->int_mask;
 160 }
 161
 162 int cia_get_irq_list(struct ciabase *base, char *buf)
 163 {
 164         int i, j, len = 0;
 165
 166         j = base->cia_irq;
 167         for (i = 0; i < CIA_IRQS; i++) {
 168                 len += sprintf(buf+len, "cia  %2d: %10d ", j + i,
 169                                kstat.irqs[0][SYS_IRQS + j + i]);
 170                         len += sprintf(buf+len, "  ");
 171                 len += sprintf(buf+len, "%s\n", base->irq_list[i].devname);
 172         }
 173         return len;
 174 }