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
  26 struct 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         irq_handler_t irq_list[CIA_IRQS];
  33 } ciaa_base = {
  34         .cia            = &ciaa,
  35         .int_mask       = IF_PORTS,
  36         .handler_irq    = IRQ_AMIGA_AUTO_2,
  37         .cia_irq        = IRQ_AMIGA_CIAA,
  38         .server_irq     = IRQ_AMIGA_PORTS,
  39         .name           = "CIAA handler"
  40 }, ciab_base = {
  41         .cia            = &ciab,
  42         .int_mask       = IF_EXTER,
  43         .handler_irq    = IRQ_AMIGA_AUTO_6,
  44         .cia_irq        = IRQ_AMIGA_CIAB,
  45         .server_irq     = IRQ_AMIGA_EXTER,
  46         .name           = "CIAB handler"
  47 };
  48
  49 /*
  50  *  Cause or clear CIA interrupts, return old interrupt status.
  51  */
  52
  53 unsigned char cia_set_irq(struct ciabase *base, unsigned char mask)
  54 {
  55         unsigned char old;
  56
  57         old = (base->icr_data |= base->cia->icr);
  58         if (mask & CIA_ICR_SETCLR)
  59                 base->icr_data |= mask;
  60         else
  61                 base->icr_data &= ~mask;
  62         if (base->icr_data & base->icr_mask)
  63                 custom.intreq = IF_SETCLR | base->int_mask;
  64         return old & base->icr_mask;
  65 }
  66
  67 /*
  68  *  Enable or disable CIA interrupts, return old interrupt mask,
  69  *  interrupts will only be enabled if a handler exists
  70  */
  71
  72 unsigned char cia_able_irq(struct ciabase *base, unsigned char mask)
  73 {
  74         unsigned char old, tmp;
  75         int i;
  76
  77         old = base->icr_mask;
  78         base->icr_data |= base->cia->icr;
  79         base->cia->icr = mask;
  80         if (mask & CIA_ICR_SETCLR)
  81                 base->icr_mask |= mask;
  82         else
  83                 base->icr_mask &= ~mask;
  84         base->icr_mask &= CIA_ICR_ALL;
  85         for (i = 0, tmp = 1; i < CIA_IRQS; i++, tmp <<= 1) {
  86                 if ((tmp & base->icr_mask) && !base->irq_list[i].handler) {
  87                         base->icr_mask &= ~tmp;
  88                         base->cia->icr = tmp;
  89                 }
  90         }
  91         if (base->icr_data & base->icr_mask)
  92                 custom.intreq = IF_SETCLR | base->int_mask;
  93         return old;
  94 }
  95
  96 int cia_request_irq(struct ciabase *base, unsigned int irq,
  97                     irqreturn_t (*handler)(int, void *, struct pt_regs *),
  98                     unsigned long flags, const char *devname, void *dev_id)
  99 {
 100         unsigned char mask;
 101
 102         base->irq_list[irq].handler = handler;
 103         base->irq_list[irq].flags   = flags;
 104         base->irq_list[irq].dev_id  = dev_id;
 105         base->irq_list[irq].devname = devname;
 106
 107         /* enable the interrupt */
 108         mask = 1 << irq;
 109         cia_set_irq(base, mask);
 110         cia_able_irq(base, CIA_ICR_SETCLR | mask);
 111         return 0;
 112 }
 113
 114 void cia_free_irq(struct ciabase *base, unsigned int irq, void *dev_id)
 115 {
 116         if (base->irq_list[irq].dev_id != dev_id)
 117                 printk("%s: removing probably wrong IRQ %i from %s\n",
 118                        __FUNCTION__, base->cia_irq + irq,
 119                        base->irq_list[irq].devname);
 120
 121         base->irq_list[irq].handler = NULL;
 122         base->irq_list[irq].flags   = 0;
 123
 124         cia_able_irq(base, 1 << irq);
 125 }
 126
 127 static irqreturn_t cia_handler(int irq, void *dev_id, struct pt_regs *fp)
 128 {
 129         struct ciabase *base = (struct ciabase *)dev_id;
 130         int mach_irq, i;
 131         unsigned char ints;
 132
 133         mach_irq = base->cia_irq;
 134         irq = SYS_IRQS + mach_irq;
 135         ints = cia_set_irq(base, CIA_ICR_ALL);
 136         custom.intreq = base->int_mask;
 137         for (i = 0; i < CIA_IRQS; i++, irq++, mach_irq++) {
 138                 if (ints & 1) {
 139                         kstat_cpu(0).irqs[irq]++;
 140                         base->irq_list[i].handler(mach_irq, base->irq_list[i].dev_id, fp);
 141                 }
 142                 ints >>= 1;
 143         }
 144         amiga_do_irq_list(base->server_irq, fp);
 145         return IRQ_HANDLED;
 146 }
 147
 148 void __init cia_init_IRQ(struct ciabase *base)
 149 {
 150         int i;
 151
 152         /* init isr handlers */
 153         for (i = 0; i < CIA_IRQS; i++) {
 154                 base->irq_list[i].handler = NULL;
 155                 base->irq_list[i].flags   = 0;
 156         }
 157
 158         /* clear any pending interrupt and turn off all interrupts */
 159         cia_set_irq(base, CIA_ICR_ALL);
 160         cia_able_irq(base, CIA_ICR_ALL);
 161
 162         /* install CIA handler */
 163         request_irq(base->handler_irq, cia_handler, 0, base->name, base);
 164
 165         custom.intena = IF_SETCLR | base->int_mask;
 166 }
 167
 168 int cia_get_irq_list(struct ciabase *base, struct seq_file *p)
 169 {
 170         int i, j;
 171
 172         j = base->cia_irq;
 173         for (i = 0; i < CIA_IRQS; i++) {
 174                 seq_printf(p, "cia  %2d: %10d ", j + i,
 175                                kstat_cpu(0).irqs[SYS_IRQS + j + i]);
 176                 seq_puts(p, "  ");
 177                 seq_printf(p, "%s\n", base->irq_list[i].devname);
 178         }
 179         return 0;
 180 }