arch/mips/ar7/irq.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2006,2007 Felix Fietkau <nbd@openwrt.org>
   4  * Copyright (C) 2006,2007 Eugene Konev <ejka@openwrt.org>
   5  */
   6
   7 #include <linux/interrupt.h>
   8 #include <linux/io.h>
   9 #include <linux/irq.h>
  10
  11 #include <asm/irq_cpu.h>
  12 #include <asm/mipsregs.h>
  13 #include <asm/mach-ar7/ar7.h>
  14
  15 #define EXCEPT_OFFSET   0x80
  16 #define PACE_OFFSET     0xA0
  17 #define CHNLS_OFFSET    0x200
  18
  19 #define REG_OFFSET(irq, reg)    ((irq) / 32 * 0x4 + reg * 0x10)
  20 #define SEC_REG_OFFSET(reg)     (EXCEPT_OFFSET + reg * 0x8)
  21 #define SEC_SR_OFFSET           (SEC_REG_OFFSET(0))     /* 0x80 */
  22 #define CR_OFFSET(irq)          (REG_OFFSET(irq, 1))    /* 0x10 */
  23 #define SEC_CR_OFFSET           (SEC_REG_OFFSET(1))     /* 0x88 */
  24 #define ESR_OFFSET(irq)         (REG_OFFSET(irq, 2))    /* 0x20 */
  25 #define SEC_ESR_OFFSET          (SEC_REG_OFFSET(2))     /* 0x90 */
  26 #define ECR_OFFSET(irq)         (REG_OFFSET(irq, 3))    /* 0x30 */
  27 #define SEC_ECR_OFFSET          (SEC_REG_OFFSET(3))     /* 0x98 */
  28 #define PIR_OFFSET              (0x40)
  29 #define MSR_OFFSET              (0x44)
  30 #define PM_OFFSET(irq)          (REG_OFFSET(irq, 5))    /* 0x50 */
  31 #define TM_OFFSET(irq)          (REG_OFFSET(irq, 6))    /* 0x60 */
  32
  33 #define REG(addr) ((u32 *)(KSEG1ADDR(AR7_REGS_IRQ) + addr))
  34
  35 #define CHNL_OFFSET(chnl) (CHNLS_OFFSET + (chnl * 4))
  36
  37 static int ar7_irq_base;
  38
  39 static void ar7_unmask_irq(struct irq_data *d)
  40 {
  41         writel(1 << ((d->irq - ar7_irq_base) % 32),
  42                REG(ESR_OFFSET(d->irq - ar7_irq_base)));
  43 }
  44
  45 static void ar7_mask_irq(struct irq_data *d)
  46 {
  47         writel(1 << ((d->irq - ar7_irq_base) % 32),
  48                REG(ECR_OFFSET(d->irq - ar7_irq_base)));
  49 }
  50
  51 static void ar7_ack_irq(struct irq_data *d)
  52 {
  53         writel(1 << ((d->irq - ar7_irq_base) % 32),
  54                REG(CR_OFFSET(d->irq - ar7_irq_base)));
  55 }
  56
  57 static void ar7_unmask_sec_irq(struct irq_data *d)
  58 {
  59         writel(1 << (d->irq - ar7_irq_base - 40), REG(SEC_ESR_OFFSET));
  60 }
  61
  62 static void ar7_mask_sec_irq(struct irq_data *d)
  63 {
  64         writel(1 << (d->irq - ar7_irq_base - 40), REG(SEC_ECR_OFFSET));
  65 }
  66
  67 static void ar7_ack_sec_irq(struct irq_data *d)
  68 {
  69         writel(1 << (d->irq - ar7_irq_base - 40), REG(SEC_CR_OFFSET));
  70 }
  71
  72 static struct irq_chip ar7_irq_type = {
  73         .name = "AR7",
  74         .irq_unmask = ar7_unmask_irq,
  75         .irq_mask = ar7_mask_irq,
  76         .irq_ack = ar7_ack_irq
  77 };
  78
  79 static struct irq_chip ar7_sec_irq_type = {
  80         .name = "AR7",
  81         .irq_unmask = ar7_unmask_sec_irq,
  82         .irq_mask = ar7_mask_sec_irq,
  83         .irq_ack = ar7_ack_sec_irq,
  84 };
  85
  86 static struct irqaction ar7_cascade_action = {
  87         .handler = no_action,
  88         .name = "AR7 cascade interrupt",
  89         .flags = IRQF_NO_THREAD,
  90 };
  91
  92 static void __init ar7_irq_init(int base)
  93 {
  94         int i;
  95         /*
  96          * Disable interrupts and clear pending
  97          */
  98         writel(0xffffffff, REG(ECR_OFFSET(0)));
  99         writel(0xff, REG(ECR_OFFSET(32)));
 100         writel(0xffffffff, REG(SEC_ECR_OFFSET));
 101         writel(0xffffffff, REG(CR_OFFSET(0)));
 102         writel(0xff, REG(CR_OFFSET(32)));
 103         writel(0xffffffff, REG(SEC_CR_OFFSET));
 104
 105         ar7_irq_base = base;
 106
 107         for (i = 0; i < 40; i++) {
 108                 writel(i, REG(CHNL_OFFSET(i)));
 109                 /* Primary IRQ's */
 110                 irq_set_chip_and_handler(base + i, &ar7_irq_type,
 111                                          handle_level_irq);
 112                 /* Secondary IRQ's */
 113                 if (i < 32)
 114                         irq_set_chip_and_handler(base + i + 40,
 115                                                  &ar7_sec_irq_type,
 116                                                  handle_level_irq);
 117         }
 118
 119         setup_irq(2, &ar7_cascade_action);
 120         setup_irq(ar7_irq_base, &ar7_cascade_action);
 121         set_c0_status(IE_IRQ0);
 122 }
 123
 124 void __init arch_init_irq(void)
 125 {
 126         mips_cpu_irq_init();
 127         ar7_irq_init(8);
 128 }
 129
 130 static void ar7_cascade(void)
 131 {
 132         u32 status;
 133         int i, irq;
 134
 135         /* Primary IRQ's */
 136         irq = readl(REG(PIR_OFFSET)) & 0x3f;
 137         if (irq) {
 138                 do_IRQ(ar7_irq_base + irq);
 139                 return;
 140         }
 141
 142         /* Secondary IRQ's are cascaded through primary '0' */
 143         writel(1, REG(CR_OFFSET(irq)));
 144         status = readl(REG(SEC_SR_OFFSET));
 145         for (i = 0; i < 32; i++) {
 146                 if (status & 1) {
 147                         do_IRQ(ar7_irq_base + i + 40);
 148                         return;
 149                 }
 150                 status >>= 1;
 151         }
 152
 153         spurious_interrupt();
 154 }
 155
 156 asmlinkage void plat_irq_dispatch(void)
 157 {
 158         unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
 159         if (pending & STATUSF_IP7)              /* cpu timer */
 160                 do_IRQ(7);
 161         else if (pending & STATUSF_IP2)         /* int0 hardware line */
 162                 ar7_cascade();
 163         else
 164                 spurious_interrupt();
 165 }