arch/microblaze/kernel/intc.c

   1 /*
   2  * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
   3  * Copyright (C) 2007-2009 PetaLogix
   4  * Copyright (C) 2006 Atmark Techno, Inc.
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License. See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/irq.h>
  13 #include <asm/page.h>
  14 #include <linux/io.h>
  15 #include <linux/bug.h>
  16
  17 #include <asm/prom.h>
  18 #include <asm/irq.h>
  19
  20 #ifdef CONFIG_SELFMOD_INTC
  21 #include <asm/selfmod.h>
  22 #define INTC_BASE       BARRIER_BASE_ADDR
  23 #else
  24 static unsigned int intc_baseaddr;
  25 #define INTC_BASE       intc_baseaddr
  26 #endif
  27
  28 unsigned int nr_irq;
  29
  30 /* No one else should require these constants, so define them locally here. */
  31 #define ISR 0x00                        /* Interrupt Status Register */
  32 #define IPR 0x04                        /* Interrupt Pending Register */
  33 #define IER 0x08                        /* Interrupt Enable Register */
  34 #define IAR 0x0c                        /* Interrupt Acknowledge Register */
  35 #define SIE 0x10                        /* Set Interrupt Enable bits */
  36 #define CIE 0x14                        /* Clear Interrupt Enable bits */
  37 #define IVR 0x18                        /* Interrupt Vector Register */
  38 #define MER 0x1c                        /* Master Enable Register */
  39
  40 #define MER_ME (1<<0)
  41 #define MER_HIE (1<<1)
  42
  43 static void intc_enable_or_unmask(unsigned int irq)
  44 {
  45         unsigned long mask = 1 << irq;
  46         pr_debug("enable_or_unmask: %d\n", irq);
  47         out_be32(INTC_BASE + SIE, mask);
  48
  49         /* ack level irqs because they can't be acked during
  50          * ack function since the handle_level_irq function
  51          * acks the irq before calling the interrupt handler
  52          */
  53         if (irq_desc[irq].status & IRQ_LEVEL)
  54                 out_be32(INTC_BASE + IAR, mask);
  55 }
  56
  57 static void intc_disable_or_mask(unsigned int irq)
  58 {
  59         pr_debug("disable: %d\n", irq);
  60         out_be32(INTC_BASE + CIE, 1 << irq);
  61 }
  62
  63 static void intc_ack(unsigned int irq)
  64 {
  65         pr_debug("ack: %d\n", irq);
  66         out_be32(INTC_BASE + IAR, 1 << irq);
  67 }
  68
  69 static void intc_mask_ack(unsigned int irq)
  70 {
  71         unsigned long mask = 1 << irq;
  72         pr_debug("disable_and_ack: %d\n", irq);
  73         out_be32(INTC_BASE + CIE, mask);
  74         out_be32(INTC_BASE + IAR, mask);
  75 }
  76
  77 static void intc_end(unsigned int irq)
  78 {
  79         unsigned long mask = 1 << irq;
  80         pr_debug("end: %d\n", irq);
  81         if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
  82                 out_be32(INTC_BASE + SIE, mask);
  83                 /* ack level sensitive intr */
  84                 if (irq_desc[irq].status & IRQ_LEVEL)
  85                         out_be32(INTC_BASE + IAR, mask);
  86         }
  87 }
  88
  89 static struct irq_chip intc_dev = {
  90         .name = "Xilinx INTC",
  91         .unmask = intc_enable_or_unmask,
  92         .mask = intc_disable_or_mask,
  93         .ack = intc_ack,
  94         .mask_ack = intc_mask_ack,
  95         .end = intc_end,
  96 };
  97
  98 unsigned int get_irq(struct pt_regs *regs)
  99 {
 100         int irq;
 101
 102         /*
 103          * NOTE: This function is the one that needs to be improved in
 104          * order to handle multiple interrupt controllers. It currently
 105          * is hardcoded to check for interrupts only on the first INTC.
 106          */
 107         irq = in_be32(INTC_BASE + IVR);
 108         pr_debug("get_irq: %d\n", irq);
 109
 110         return irq;
 111 }
 112
 113 void __init init_IRQ(void)
 114 {
 115         u32 i, j, intr_type;
 116         struct device_node *intc = NULL;
 117 #ifdef CONFIG_SELFMOD_INTC
 118         unsigned int intc_baseaddr = 0;
 119         static int arr_func[] = {
 120                                 (int)&get_irq,
 121                                 (int)&intc_enable_or_unmask,
 122                                 (int)&intc_disable_or_mask,
 123                                 (int)&intc_mask_ack,
 124                                 (int)&intc_ack,
 125                                 (int)&intc_end,
 126                                 0
 127                         };
 128 #endif
 129         static char *intc_list[] = {
 130                                 "xlnx,xps-intc-1.00.a",
 131                                 "xlnx,opb-intc-1.00.c",
 132                                 "xlnx,opb-intc-1.00.b",
 133                                 "xlnx,opb-intc-1.00.a",
 134                                 NULL
 135                         };
 136
 137         for (j = 0; intc_list[j] != NULL; j++) {
 138                 intc = of_find_compatible_node(NULL, NULL, intc_list[j]);
 139                 if (intc)
 140                         break;
 141         }
 142         BUG_ON(!intc);
 143
 144         intc_baseaddr = *(int *) of_get_property(intc, "reg", NULL);
 145         intc_baseaddr = (unsigned long) ioremap(intc_baseaddr, PAGE_SIZE);
 146         nr_irq = *(int *) of_get_property(intc, "xlnx,num-intr-inputs", NULL);
 147
 148         intr_type =
 149                 *(int *) of_get_property(intc, "xlnx,kind-of-intr", NULL);
 150         if (intr_type >= (1 << (nr_irq + 1)))
 151                 printk(KERN_INFO " ERROR: Mismatch in kind-of-intr param\n");
 152
 153 #ifdef CONFIG_SELFMOD_INTC
 154         selfmod_function((int *) arr_func, intc_baseaddr);
 155 #endif
 156         printk(KERN_INFO "%s #0 at 0x%08x, num_irq=%d, edge=0x%x\n",
 157                 intc_list[j], intc_baseaddr, nr_irq, intr_type);
 158
 159         /*
 160          * Disable all external interrupts until they are
 161          * explicity requested.
 162          */
 163         out_be32(intc_baseaddr + IER, 0);
 164
 165         /* Acknowledge any pending interrupts just in case. */
 166         out_be32(intc_baseaddr + IAR, 0xffffffff);
 167
 168         /* Turn on the Master Enable. */
 169         out_be32(intc_baseaddr + MER, MER_HIE | MER_ME);
 170
 171         for (i = 0; i < nr_irq; ++i) {
 172                 if (intr_type & (0x00000001 << i)) {
 173                         set_irq_chip_and_handler_name(i, &intc_dev,
 174                                 handle_edge_irq, intc_dev.name);
 175                         irq_desc[i].status &= ~IRQ_LEVEL;
 176                 } else {
 177                         set_irq_chip_and_handler_name(i, &intc_dev,
 178                                 handle_level_irq, intc_dev.name);
 179                         irq_desc[i].status |= IRQ_LEVEL;
 180                 }
 181         }
 182 }