arch/mn10300/unit-asb2364/irq-fpga.c

   1 /* ASB2364 FPGA interrupt multiplexing
   2  *
   3  * Copyright (C) 2010 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 Licence
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the Licence, or (at your option) any later version.
  10  */
  11
  12 #include <linux/interrupt.h>
  13 #include <linux/init.h>
  14 #include <linux/irq.h>
  15 #include <unit/fpga-regs.h>
  16
  17 /*
  18  * FPGA PIC operations
  19  */
  20 static void asb2364_fpga_mask(struct irq_data *d)
  21 {
  22         ASB2364_FPGA_REG_MASK(d->irq - NR_CPU_IRQS) = 0x0001;
  23         SyncExBus();
  24 }
  25
  26 static void asb2364_fpga_ack(struct irq_data *d)
  27 {
  28         ASB2364_FPGA_REG_IRQ(d->irq - NR_CPU_IRQS) = 0x0001;
  29         SyncExBus();
  30 }
  31
  32 static void asb2364_fpga_mask_ack(struct irq_data *d)
  33 {
  34         ASB2364_FPGA_REG_MASK(d->irq - NR_CPU_IRQS) = 0x0001;
  35         SyncExBus();
  36         ASB2364_FPGA_REG_IRQ(d->irq - NR_CPU_IRQS) = 0x0001;
  37         SyncExBus();
  38 }
  39
  40 static void asb2364_fpga_unmask(struct irq_data *d)
  41 {
  42         ASB2364_FPGA_REG_MASK(d->irq - NR_CPU_IRQS) = 0x0000;
  43         SyncExBus();
  44 }
  45
  46 static struct irq_chip asb2364_fpga_pic = {
  47         .name           = "fpga",
  48         .irq_ack        = asb2364_fpga_ack,
  49         .irq_mask       = asb2364_fpga_mask,
  50         .irq_mask_ack   = asb2364_fpga_mask_ack,
  51         .irq_unmask     = asb2364_fpga_unmask,
  52 };
  53
  54 /*
  55  * FPGA PIC interrupt handler
  56  */
  57 static irqreturn_t fpga_interrupt(int irq, void *_mask)
  58 {
  59         if ((ASB2364_FPGA_REG_IRQ_LAN  & 0x0001) != 0x0001)
  60                 generic_handle_irq(FPGA_LAN_IRQ);
  61         if ((ASB2364_FPGA_REG_IRQ_UART & 0x0001) != 0x0001)
  62                 generic_handle_irq(FPGA_UART_IRQ);
  63         if ((ASB2364_FPGA_REG_IRQ_I2C  & 0x0001) != 0x0001)
  64                 generic_handle_irq(FPGA_I2C_IRQ);
  65         if ((ASB2364_FPGA_REG_IRQ_USB  & 0x0001) != 0x0001)
  66                 generic_handle_irq(FPGA_USB_IRQ);
  67         if ((ASB2364_FPGA_REG_IRQ_FPGA & 0x0001) != 0x0001)
  68                 generic_handle_irq(FPGA_FPGA_IRQ);
  69
  70         return IRQ_HANDLED;
  71 }
  72
  73 /*
  74  * Define an interrupt action for each FPGA PIC output
  75  */
  76 static struct irqaction fpga_irq[]  = {
  77         [0] = {
  78                 .handler        = fpga_interrupt,
  79                 .flags          = IRQF_DISABLED | IRQF_SHARED,
  80                 .name           = "fpga",
  81         },
  82 };
  83
  84 /*
  85  * Initialise the FPGA's PIC
  86  */
  87 void __init irq_fpga_init(void)
  88 {
  89         int irq;
  90
  91         ASB2364_FPGA_REG_MASK_LAN  = 0x0001;
  92         SyncExBus();
  93         ASB2364_FPGA_REG_MASK_UART = 0x0001;
  94         SyncExBus();
  95         ASB2364_FPGA_REG_MASK_I2C  = 0x0001;
  96         SyncExBus();
  97         ASB2364_FPGA_REG_MASK_USB  = 0x0001;
  98         SyncExBus();
  99         ASB2364_FPGA_REG_MASK_FPGA = 0x0001;
 100         SyncExBus();
 101
 102         for (irq = NR_CPU_IRQS; irq < NR_IRQS; irq++)
 103                 irq_set_chip_and_handler(irq, &asb2364_fpga_pic,
 104                                          handle_level_irq);
 105
 106         /* the FPGA drives the XIRQ1 input on the CPU PIC */
 107         setup_irq(XIRQ1, &fpga_irq[0]);
 108 }