arch/frv/kernel/irq-mb93093.c

   1 /* irq-mb93093.c: MB93093 FPGA interrupt handling
   2  *
   3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/config.h>
  13 #include <linux/ptrace.h>
  14 #include <linux/errno.h>
  15 #include <linux/signal.h>
  16 #include <linux/sched.h>
  17 #include <linux/ioport.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/init.h>
  20 #include <linux/irq.h>
  21
  22 #include <asm/io.h>
  23 #include <asm/system.h>
  24 #include <asm/bitops.h>
  25 #include <asm/delay.h>
  26 #include <asm/irq.h>
  27 #include <asm/irc-regs.h>
  28 #include <asm/irq-routing.h>
  29
  30 #define __reg16(ADDR) (*(volatile unsigned short *)(__region_CS2 + (ADDR)))
  31
  32 #define __get_IMR()     ({ __reg16(0x0a); })
  33 #define __set_IMR(M)    do { __reg16(0x0a) = (M);  wmb(); } while(0)
  34 #define __get_IFR()     ({ __reg16(0x02); })
  35 #define __clr_IFR(M)    do { __reg16(0x02) = ~(M); wmb(); } while(0)
  36
  37 static void frv_fpga_doirq(struct irq_source *source);
  38 static void frv_fpga_control(struct irq_group *group, int irq, int on);
  39
  40 /*****************************************************************************/
  41 /*
  42  * FPGA IRQ multiplexor
  43  */
  44 static struct irq_source frv_fpga[4] = {
  45 #define __FPGA(X, M)                                    \
  46         [X] = {                                         \
  47                 .muxname        = "fpga."#X,            \
  48                 .irqmask        = M,                    \
  49                 .doirq          = frv_fpga_doirq,       \
  50         }
  51
  52         __FPGA(0, 0x0700),
  53 };
  54
  55 static struct irq_group frv_fpga_irqs = {
  56         .first_irq      = IRQ_BASE_FPGA,
  57         .control        = frv_fpga_control,
  58         .sources = {
  59                 [ 8] = &frv_fpga[0],
  60                 [ 9] = &frv_fpga[0],
  61                 [10] = &frv_fpga[0],
  62         },
  63 };
  64
  65
  66 static void frv_fpga_control(struct irq_group *group, int index, int on)
  67 {
  68         uint16_t imr = __get_IMR();
  69
  70         if (on)
  71                 imr &= ~(1 << index);
  72         else
  73                 imr |= 1 << index;
  74
  75         __set_IMR(imr);
  76 }
  77
  78 static void frv_fpga_doirq(struct irq_source *source)
  79 {
  80         uint16_t mask, imr;
  81
  82         imr = __get_IMR();
  83         mask = source->irqmask & ~imr & __get_IFR();
  84         if (mask) {
  85                 __set_IMR(imr | mask);
  86                 __clr_IFR(mask);
  87                 distribute_irqs(&frv_fpga_irqs, mask);
  88                 __set_IMR(imr);
  89         }
  90 }
  91
  92 void __init fpga_init(void)
  93 {
  94         __set_IMR(0x0700);
  95         __clr_IFR(0x0000);
  96
  97         frv_irq_route_external(&frv_fpga[0], IRQ_CPU_EXTERNAL2);
  98         frv_irq_set_group(&frv_fpga_irqs);
  99 }