arch/sh64/mach-cayman/irq.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * arch/sh64/kernel/irq_cayman.c
   7  *
   8  * SH-5 Cayman Interrupt Support
   9  *
  10  * This file handles the board specific parts of the Cayman interrupt system
  11  *
  12  * Copyright (C) 2002 Stuart Menefy
  13  */
  14
  15 #include <asm/irq.h>
  16 #include <asm/page.h>
  17 #include <asm/io.h>
  18 #include <linux/irq.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/signal.h>
  21 #include <asm/cayman.h>
  22
  23 unsigned long epld_virt;
  24
  25 #define EPLD_BASE        0x04002000
  26 #define EPLD_STATUS_BASE (epld_virt + 0x10)
  27 #define EPLD_MASK_BASE   (epld_virt + 0x20)
  28
  29 /* Note the SMSC SuperIO chip and SMSC LAN chip interrupts are all muxed onto
  30    the same SH-5 interrupt */
  31
  32 static irqreturn_t cayman_interrupt_smsc(int irq, void *dev_id)
  33 {
  34         printk(KERN_INFO "CAYMAN: spurious SMSC interrupt\n");
  35         return IRQ_NONE;
  36 }
  37
  38 static irqreturn_t cayman_interrupt_pci2(int irq, void *dev_id)
  39 {
  40         printk(KERN_INFO "CAYMAN: spurious PCI interrupt, IRQ %d\n", irq);
  41         return IRQ_NONE;
  42 }
  43
  44 static struct irqaction cayman_action_smsc = {
  45         .name           = "Cayman SMSC Mux",
  46         .handler        = cayman_interrupt_smsc,
  47         .flags          = IRQF_DISABLED,
  48 };
  49
  50 static struct irqaction cayman_action_pci2 = {
  51         .name           = "Cayman PCI2 Mux",
  52         .handler        = cayman_interrupt_pci2,
  53         .flags          = IRQF_DISABLED,
  54 };
  55
  56 static void enable_cayman_irq(unsigned int irq)
  57 {
  58         unsigned long flags;
  59         unsigned long mask;
  60         unsigned int reg;
  61         unsigned char bit;
  62
  63         irq -= START_EXT_IRQS;
  64         reg = EPLD_MASK_BASE + ((irq / 8) << 2);
  65         bit = 1<<(irq % 8);
  66         local_irq_save(flags);
  67         mask = ctrl_inl(reg);
  68         mask |= bit;
  69         ctrl_outl(mask, reg);
  70         local_irq_restore(flags);
  71 }
  72
  73 void disable_cayman_irq(unsigned int irq)
  74 {
  75         unsigned long flags;
  76         unsigned long mask;
  77         unsigned int reg;
  78         unsigned char bit;
  79
  80         irq -= START_EXT_IRQS;
  81         reg = EPLD_MASK_BASE + ((irq / 8) << 2);
  82         bit = 1<<(irq % 8);
  83         local_irq_save(flags);
  84         mask = ctrl_inl(reg);
  85         mask &= ~bit;
  86         ctrl_outl(mask, reg);
  87         local_irq_restore(flags);
  88 }
  89
  90 static void ack_cayman_irq(unsigned int irq)
  91 {
  92         disable_cayman_irq(irq);
  93 }
  94
  95 static void end_cayman_irq(unsigned int irq)
  96 {
  97         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
  98                 enable_cayman_irq(irq);
  99 }
 100
 101 static unsigned int startup_cayman_irq(unsigned int irq)
 102 {
 103         enable_cayman_irq(irq);
 104         return 0; /* never anything pending */
 105 }
 106
 107 static void shutdown_cayman_irq(unsigned int irq)
 108 {
 109         disable_cayman_irq(irq);
 110 }
 111
 112 struct hw_interrupt_type cayman_irq_type = {
 113         .typename       = "Cayman-IRQ",
 114         .startup        = startup_cayman_irq,
 115         .shutdown       = shutdown_cayman_irq,
 116         .enable         = enable_cayman_irq,
 117         .disable        = disable_cayman_irq,
 118         .ack            = ack_cayman_irq,
 119         .end            = end_cayman_irq,
 120 };
 121
 122 int cayman_irq_demux(int evt)
 123 {
 124         int irq = intc_evt_to_irq[evt];
 125
 126         if (irq == SMSC_IRQ) {
 127                 unsigned long status;
 128                 int i;
 129
 130                 status = ctrl_inl(EPLD_STATUS_BASE) &
 131                          ctrl_inl(EPLD_MASK_BASE) & 0xff;
 132                 if (status == 0) {
 133                         irq = -1;
 134                 } else {
 135                         for (i=0; i<8; i++) {
 136                                 if (status & (1<<i))
 137                                         break;
 138                         }
 139                         irq = START_EXT_IRQS + i;
 140                 }
 141         }
 142
 143         if (irq == PCI2_IRQ) {
 144                 unsigned long status;
 145                 int i;
 146
 147                 status = ctrl_inl(EPLD_STATUS_BASE + 3 * sizeof(u32)) &
 148                          ctrl_inl(EPLD_MASK_BASE + 3 * sizeof(u32)) & 0xff;
 149                 if (status == 0) {
 150                         irq = -1;
 151                 } else {
 152                         for (i=0; i<8; i++) {
 153                                 if (status & (1<<i))
 154                                         break;
 155                         }
 156                         irq = START_EXT_IRQS + (3 * 8) + i;
 157                 }
 158         }
 159
 160         return irq;
 161 }
 162
 163 #if defined(CONFIG_PROC_FS) && defined(CONFIG_SYSCTL)
 164 int cayman_irq_describe(char* p, int irq)
 165 {
 166         if (irq < NR_INTC_IRQS) {
 167                 return intc_irq_describe(p, irq);
 168         } else if (irq < NR_INTC_IRQS + 8) {
 169                 return sprintf(p, "(SMSC %d)", irq - NR_INTC_IRQS);
 170         } else if ((irq >= NR_INTC_IRQS + 24) && (irq < NR_INTC_IRQS + 32)) {
 171                 return sprintf(p, "(PCI2 %d)", irq - (NR_INTC_IRQS + 24));
 172         }
 173
 174         return 0;
 175 }
 176 #endif
 177
 178 void init_cayman_irq(void)
 179 {
 180         int i;
 181
 182         epld_virt = onchip_remap(EPLD_BASE, 1024, "EPLD");
 183         if (!epld_virt) {
 184                 printk(KERN_ERR "Cayman IRQ: Unable to remap EPLD\n");
 185                 return;
 186         }
 187
 188         for (i=0; i<NR_EXT_IRQS; i++) {
 189                 irq_desc[START_EXT_IRQS + i].chip = &cayman_irq_type;
 190         }
 191
 192         /* Setup the SMSC interrupt */
 193         setup_irq(SMSC_IRQ, &cayman_action_smsc);
 194         setup_irq(PCI2_IRQ, &cayman_action_pci2);
 195 }