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 };
  50
  51 static struct irqaction cayman_action_pci2 = {
  52         .name           = "Cayman PCI2 Mux",
  53         .handler        = cayman_interrupt_pci2,
  54 };
  55
  56 static void enable_cayman_irq(struct irq_data *data)
  57 {
  58         unsigned int irq = data->irq;
  59         unsigned long flags;
  60         unsigned long mask;
  61         unsigned int reg;
  62         unsigned char bit;
  63
  64         irq -= START_EXT_IRQS;
  65         reg = EPLD_MASK_BASE + ((irq / 8) << 2);
  66         bit = 1<<(irq % 8);
  67         local_irq_save(flags);
  68         mask = __raw_readl(reg);
  69         mask |= bit;
  70         __raw_writel(mask, reg);
  71         local_irq_restore(flags);
  72 }
  73
  74 static void disable_cayman_irq(struct irq_data *data)
  75 {
  76         unsigned int irq = data->irq;
  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 = __raw_readl(reg);
  87         mask &= ~bit;
  88         __raw_writel(mask, reg);
  89         local_irq_restore(flags);
  90 }
  91
  92 struct irq_chip cayman_irq_type = {
  93         .name           = "Cayman-IRQ",
  94         .irq_unmask     = enable_cayman_irq,
  95         .irq_mask       = disable_cayman_irq,
  96 };
  97
  98 int cayman_irq_demux(int evt)
  99 {
 100         int irq = intc_evt_to_irq[evt];
 101
 102         if (irq == SMSC_IRQ) {
 103                 unsigned long status;
 104                 int i;
 105
 106                 status = __raw_readl(EPLD_STATUS_BASE) &
 107                          __raw_readl(EPLD_MASK_BASE) & 0xff;
 108                 if (status == 0) {
 109                         irq = -1;
 110                 } else {
 111                         for (i=0; i<8; i++) {
 112                                 if (status & (1<<i))
 113                                         break;
 114                         }
 115                         irq = START_EXT_IRQS + i;
 116                 }
 117         }
 118
 119         if (irq == PCI2_IRQ) {
 120                 unsigned long status;
 121                 int i;
 122
 123                 status = __raw_readl(EPLD_STATUS_BASE + 3 * sizeof(u32)) &
 124                          __raw_readl(EPLD_MASK_BASE + 3 * sizeof(u32)) & 0xff;
 125                 if (status == 0) {
 126                         irq = -1;
 127                 } else {
 128                         for (i=0; i<8; i++) {
 129                                 if (status & (1<<i))
 130                                         break;
 131                         }
 132                         irq = START_EXT_IRQS + (3 * 8) + i;
 133                 }
 134         }
 135
 136         return irq;
 137 }
 138
 139 void init_cayman_irq(void)
 140 {
 141         int i;
 142
 143         epld_virt = (unsigned long)ioremap_nocache(EPLD_BASE, 1024);
 144         if (!epld_virt) {
 145                 printk(KERN_ERR "Cayman IRQ: Unable to remap EPLD\n");
 146                 return;
 147         }
 148
 149         for (i = 0; i < NR_EXT_IRQS; i++) {
 150                 irq_set_chip_and_handler(START_EXT_IRQS + i,
 151                                          &cayman_irq_type, handle_level_irq);
 152         }
 153
 154         /* Setup the SMSC interrupt */
 155         setup_irq(SMSC_IRQ, &cayman_action_smsc);
 156         setup_irq(PCI2_IRQ, &cayman_action_pci2);
 157 }