arch/sh/boards/mach-cayman/irq.c

   1 /*
   2  * arch/sh/mach-cayman/irq.c - SH-5 Cayman Interrupt Support
   3  *
   4  * This file handles the board specific parts of the Cayman interrupt system
   5  *
   6  * Copyright (C) 2002 Stuart Menefy
   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 #include <linux/io.h>
  13 #include <linux/irq.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/signal.h>
  16 #include <cpu/irq.h>
  17 #include <asm/page.h>
  18
  19 /* Setup for the SMSC FDC37C935 / LAN91C100FD */
  20 #define SMSC_IRQ         IRQ_IRL1
  21
  22 /* Setup for PCI Bus 2, which transmits interrupts via the EPLD */
  23 #define PCI2_IRQ         IRQ_IRL3
  24
  25 unsigned long epld_virt;
  26
  27 #define EPLD_BASE        0x04002000
  28 #define EPLD_STATUS_BASE (epld_virt + 0x10)
  29 #define EPLD_MASK_BASE   (epld_virt + 0x20)
  30
  31 /* Note the SMSC SuperIO chip and SMSC LAN chip interrupts are all muxed onto
  32    the same SH-5 interrupt */
  33
  34 static irqreturn_t cayman_interrupt_smsc(int irq, void *dev_id)
  35 {
  36         printk(KERN_INFO "CAYMAN: spurious SMSC interrupt\n");
  37         return IRQ_NONE;
  38 }
  39
  40 static irqreturn_t cayman_interrupt_pci2(int irq, void *dev_id)
  41 {
  42         printk(KERN_INFO "CAYMAN: spurious PCI interrupt, IRQ %d\n", irq);
  43         return IRQ_NONE;
  44 }
  45
  46 static struct irqaction cayman_action_smsc = {
  47         .name           = "Cayman SMSC Mux",
  48         .handler        = cayman_interrupt_smsc,
  49         .flags          = IRQF_DISABLED,
  50 };
  51
  52 static struct irqaction cayman_action_pci2 = {
  53         .name           = "Cayman PCI2 Mux",
  54         .handler        = cayman_interrupt_pci2,
  55         .flags          = IRQF_DISABLED,
  56 };
  57
  58 static void enable_cayman_irq(unsigned int irq)
  59 {
  60         unsigned long flags;
  61         unsigned long mask;
  62         unsigned int reg;
  63         unsigned char bit;
  64
  65         irq -= START_EXT_IRQS;
  66         reg = EPLD_MASK_BASE + ((irq / 8) << 2);
  67         bit = 1<<(irq % 8);
  68         local_irq_save(flags);
  69         mask = ctrl_inl(reg);
  70         mask |= bit;
  71         ctrl_outl(mask, reg);
  72         local_irq_restore(flags);
  73 }
  74
  75 void disable_cayman_irq(unsigned int irq)
  76 {
  77         unsigned long flags;
  78         unsigned long mask;
  79         unsigned int reg;
  80         unsigned char bit;
  81
  82         irq -= START_EXT_IRQS;
  83         reg = EPLD_MASK_BASE + ((irq / 8) << 2);
  84         bit = 1<<(irq % 8);
  85         local_irq_save(flags);
  86         mask = ctrl_inl(reg);
  87         mask &= ~bit;
  88         ctrl_outl(mask, reg);
  89         local_irq_restore(flags);
  90 }
  91
  92 static void ack_cayman_irq(unsigned int irq)
  93 {
  94         disable_cayman_irq(irq);
  95 }
  96
  97 struct irq_chip cayman_irq_type = {
  98         .name           = "Cayman-IRQ",
  99         .unmask         = enable_cayman_irq,
 100         .mask           = disable_cayman_irq,
 101         .mask_ack       = ack_cayman_irq,
 102 };
 103
 104 int cayman_irq_demux(int evt)
 105 {
 106         int irq = intc_evt_to_irq[evt];
 107
 108         if (irq == SMSC_IRQ) {
 109                 unsigned long status;
 110                 int i;
 111
 112                 status = ctrl_inl(EPLD_STATUS_BASE) &
 113                          ctrl_inl(EPLD_MASK_BASE) & 0xff;
 114                 if (status == 0) {
 115                         irq = -1;
 116                 } else {
 117                         for (i=0; i<8; i++) {
 118                                 if (status & (1<<i))
 119                                         break;
 120                         }
 121                         irq = START_EXT_IRQS + i;
 122                 }
 123         }
 124
 125         if (irq == PCI2_IRQ) {
 126                 unsigned long status;
 127                 int i;
 128
 129                 status = ctrl_inl(EPLD_STATUS_BASE + 3 * sizeof(u32)) &
 130                          ctrl_inl(EPLD_MASK_BASE + 3 * sizeof(u32)) & 0xff;
 131                 if (status == 0) {
 132                         irq = -1;
 133                 } else {
 134                         for (i=0; i<8; i++) {
 135                                 if (status & (1<<i))
 136                                         break;
 137                         }
 138                         irq = START_EXT_IRQS + (3 * 8) + i;
 139                 }
 140         }
 141
 142         return irq;
 143 }
 144
 145 void init_cayman_irq(void)
 146 {
 147         int i;
 148
 149         epld_virt = (unsigned long)ioremap_nocache(EPLD_BASE, 1024);
 150         if (!epld_virt) {
 151                 printk(KERN_ERR "Cayman IRQ: Unable to remap EPLD\n");
 152                 return;
 153         }
 154
 155         for (i = 0; i < NR_EXT_IRQS; i++) {
 156                 set_irq_chip_and_handler(START_EXT_IRQS + i, &cayman_irq_type,
 157                                          handle_level_irq);
 158         }
 159
 160         /* Setup the SMSC interrupt */
 161         setup_irq(SMSC_IRQ, &cayman_action_smsc);
 162         setup_irq(PCI2_IRQ, &cayman_action_pci2);
 163 }