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