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   1 /*
   2  * arch/ppc/syslib/ppc4xx_pic.c
   3  *
   4  * Interrupt controller driver for PowerPC 4xx-based processors.
   5  *
   6  * Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
   7  * Copyright (c) 2004, 2005 Zultys Technologies
   8  *
   9  * Based on original code by
  10  *    Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu>
  11  *    Armin Custer <akuster@mvista.com>
  12  *
  13  * This program is free software; you can redistribute  it and/or modify it
  14  * under  the terms of  the GNU General  Public License as published by the
  15  * Free Software Foundation;  either version 2 of the  License, or (at your
  16  * option) any later version.
  17 */
  18 #include <linux/config.h>
  19 #include <linux/init.h>
  20 #include <linux/sched.h>
  21 #include <linux/signal.h>
  22 #include <linux/stddef.h>
  23
  24 #include <asm/processor.h>
  25 #include <asm/system.h>
  26 #include <asm/irq.h>
  27 #include <asm/ppc4xx_pic.h>
  28
  29 /* See comment in include/arch-ppc/ppc4xx_pic.h
  30  * for more info about these two variables
  31  */
  32 extern struct ppc4xx_uic_settings ppc4xx_core_uic_cfg[NR_UICS]
  33     __attribute__ ((weak));
  34 extern unsigned char ppc4xx_uic_ext_irq_cfg[] __attribute__ ((weak));
  35
  36 #define IRQ_MASK_UIC0(irq)              (1 << (31 - (irq)))
  37 #define IRQ_MASK_UICx(irq)              (1 << (31 - ((irq) & 0x1f)))
  38 #define IRQ_MASK_UIC1(irq)              IRQ_MASK_UICx(irq)
  39 #define IRQ_MASK_UIC2(irq)              IRQ_MASK_UICx(irq)
  40
  41 #define UIC_HANDLERS(n)                                                 \
  42 static void ppc4xx_uic##n##_enable(unsigned int irq)                    \
  43 {                                                                       \
  44         u32 mask = IRQ_MASK_UIC##n(irq);                                \
  45         if (irq_desc[irq].status & IRQ_LEVEL)                           \
  46                 mtdcr(DCRN_UIC_SR(UIC##n), mask);                       \
  47         ppc_cached_irq_mask[n] |= mask;                                 \
  48         mtdcr(DCRN_UIC_ER(UIC##n), ppc_cached_irq_mask[n]);             \
  49 }                                                                       \
  50                                                                         \
  51 static void ppc4xx_uic##n##_disable(unsigned int irq)                   \
  52 {                                                                       \
  53         ppc_cached_irq_mask[n] &= ~IRQ_MASK_UIC##n(irq);                \
  54         mtdcr(DCRN_UIC_ER(UIC##n), ppc_cached_irq_mask[n]);             \
  55         ACK_UIC##n##_PARENT                                             \
  56 }                                                                       \
  57                                                                         \
  58 static void ppc4xx_uic##n##_ack(unsigned int irq)                       \
  59 {                                                                       \
  60         u32 mask = IRQ_MASK_UIC##n(irq);                                \
  61         ppc_cached_irq_mask[n] &= ~mask;                                \
  62         mtdcr(DCRN_UIC_ER(UIC##n), ppc_cached_irq_mask[n]);             \
  63         mtdcr(DCRN_UIC_SR(UIC##n), mask);                               \
  64         ACK_UIC##n##_PARENT                                             \
  65 }                                                                       \
  66                                                                         \
  67 static void ppc4xx_uic##n##_end(unsigned int irq)                       \
  68 {                                                                       \
  69         unsigned int status = irq_desc[irq].status;                     \
  70         u32 mask = IRQ_MASK_UIC##n(irq);                                \
  71         if (status & IRQ_LEVEL) {                                       \
  72                 mtdcr(DCRN_UIC_SR(UIC##n), mask);                       \
  73                 ACK_UIC##n##_PARENT                                     \
  74         }                                                               \
  75         if (!(status & (IRQ_DISABLED | IRQ_INPROGRESS))) {              \
  76                 ppc_cached_irq_mask[n] |= mask;                         \
  77                 mtdcr(DCRN_UIC_ER(UIC##n), ppc_cached_irq_mask[n]);     \
  78         }                                                               \
  79 }
  80
  81 #define DECLARE_UIC(n)                                                  \
  82 {                                                                       \
  83         .typename       = "UIC"#n,                                      \
  84         .enable         = ppc4xx_uic##n##_enable,                       \
  85         .disable        = ppc4xx_uic##n##_disable,                      \
  86         .ack            = ppc4xx_uic##n##_ack,                          \
  87         .end            = ppc4xx_uic##n##_end,                          \
  88 }                                                                       \
  89
  90 #if NR_UICS == 3
  91 #define ACK_UIC0_PARENT mtdcr(DCRN_UIC_SR(UICB), UICB_UIC0NC);
  92 #define ACK_UIC1_PARENT mtdcr(DCRN_UIC_SR(UICB), UICB_UIC1NC);
  93 #define ACK_UIC2_PARENT mtdcr(DCRN_UIC_SR(UICB), UICB_UIC2NC);
  94 UIC_HANDLERS(0);
  95 UIC_HANDLERS(1);
  96 UIC_HANDLERS(2);
  97
  98 static int ppc4xx_pic_get_irq(struct pt_regs *regs)
  99 {
 100         u32 uicb = mfdcr(DCRN_UIC_MSR(UICB));
 101         if (uicb & UICB_UIC0NC)
 102                 return 32 - ffs(mfdcr(DCRN_UIC_MSR(UIC0)));
 103         else if (uicb & UICB_UIC1NC)
 104                 return 64 - ffs(mfdcr(DCRN_UIC_MSR(UIC1)));
 105         else if (uicb & UICB_UIC2NC)
 106                 return 96 - ffs(mfdcr(DCRN_UIC_MSR(UIC2)));
 107         else
 108                 return -1;
 109 }
 110
 111 static void __init ppc4xx_pic_impl_init(void)
 112 {
 113         /* Configure Base UIC */
 114         mtdcr(DCRN_UIC_CR(UICB), 0);
 115         mtdcr(DCRN_UIC_TR(UICB), 0);
 116         mtdcr(DCRN_UIC_PR(UICB), 0xffffffff);
 117         mtdcr(DCRN_UIC_SR(UICB), 0xffffffff);
 118         mtdcr(DCRN_UIC_ER(UICB), UICB_UIC0NC | UICB_UIC1NC | UICB_UIC2NC);
 119 }
 120
 121 #elif NR_UICS == 2
 122 #define ACK_UIC0_PARENT
 123 #define ACK_UIC1_PARENT mtdcr(DCRN_UIC_SR(UIC0), UIC0_UIC1NC);
 124 UIC_HANDLERS(0);
 125 UIC_HANDLERS(1);
 126
 127 static int ppc4xx_pic_get_irq(struct pt_regs *regs)
 128 {
 129         u32 uic0 = mfdcr(DCRN_UIC_MSR(UIC0));
 130         if (uic0 & UIC0_UIC1NC)
 131                 return 64 - ffs(mfdcr(DCRN_UIC_MSR(UIC1)));
 132         else
 133                 return uic0 ? 32 - ffs(uic0) : -1;
 134 }
 135
 136 static void __init ppc4xx_pic_impl_init(void)
 137 {
 138         /* Enable cascade interrupt in UIC0 */
 139         ppc_cached_irq_mask[0] |= UIC0_UIC1NC;
 140         mtdcr(DCRN_UIC_SR(UIC0), UIC0_UIC1NC);
 141         mtdcr(DCRN_UIC_ER(UIC0), ppc_cached_irq_mask[0]);
 142 }
 143
 144 #elif NR_UICS == 1
 145 #define ACK_UIC0_PARENT
 146 UIC_HANDLERS(0);
 147
 148 static int ppc4xx_pic_get_irq(struct pt_regs *regs)
 149 {
 150         u32 uic0 = mfdcr(DCRN_UIC_MSR(UIC0));
 151         return uic0 ? 32 - ffs(uic0) : -1;
 152 }
 153
 154 static inline void ppc4xx_pic_impl_init(void)
 155 {
 156 }
 157 #endif
 158
 159 static struct ppc4xx_uic_impl {
 160         struct hw_interrupt_type decl;
 161         int base;                       /* Base DCR number */
 162 } __uic[] = {
 163         { .decl = DECLARE_UIC(0), .base = UIC0 },
 164 #if NR_UICS > 1
 165         { .decl = DECLARE_UIC(1), .base = UIC1 },
 166 #if NR_UICS > 2
 167         { .decl = DECLARE_UIC(2), .base = UIC2 },
 168 #endif
 169 #endif
 170 };
 171
 172 static inline int is_level_sensitive(int irq)
 173 {
 174         u32 tr = mfdcr(DCRN_UIC_TR(__uic[irq >> 5].base));
 175         return (tr & IRQ_MASK_UICx(irq)) == 0;
 176 }
 177
 178 void __init ppc4xx_pic_init(void)
 179 {
 180         int i;
 181         unsigned char *eirqs = ppc4xx_uic_ext_irq_cfg;
 182
 183         for (i = 0; i < NR_UICS; ++i) {
 184                 int base = __uic[i].base;
 185
 186                 /* Disable everything by default */
 187                 ppc_cached_irq_mask[i] = 0;
 188                 mtdcr(DCRN_UIC_ER(base), 0);
 189
 190                 /* We don't use critical interrupts */
 191                 mtdcr(DCRN_UIC_CR(base), 0);
 192
 193                 /* Configure polarity and triggering */
 194                 if (ppc4xx_core_uic_cfg) {
 195                         struct ppc4xx_uic_settings *p = ppc4xx_core_uic_cfg + i;
 196                         u32 mask = p->ext_irq_mask;
 197                         u32 pr = mfdcr(DCRN_UIC_PR(base)) & mask;
 198                         u32 tr = mfdcr(DCRN_UIC_TR(base)) & mask;
 199
 200                         /* "Fixed" interrupts (on-chip devices) */
 201                         pr |= p->polarity & ~mask;
 202                         tr |= p->triggering & ~mask;
 203
 204                         /* Merge external IRQs settings if board port
 205                          * provided them
 206                          */
 207                         if (eirqs && mask) {
 208                                 pr &= ~mask;
 209                                 tr &= ~mask;
 210                                 while (mask) {
 211                                         /* Extract current external IRQ mask */
 212                                         u32 eirq_mask = 1 << __ilog2(mask);
 213
 214                                         if (!(*eirqs & IRQ_SENSE_LEVEL))
 215                                                 tr |= eirq_mask;
 216
 217                                         if (*eirqs & IRQ_POLARITY_POSITIVE)
 218                                                 pr |= eirq_mask;
 219
 220                                         mask &= ~eirq_mask;
 221                                         ++eirqs;
 222                                 }
 223                         }
 224                         mtdcr(DCRN_UIC_PR(base), pr);
 225                         mtdcr(DCRN_UIC_TR(base), tr);
 226                 }
 227
 228                 /* ACK any pending interrupts to prevent false
 229                  * triggering after first enable
 230                  */
 231                 mtdcr(DCRN_UIC_SR(base), 0xffffffff);
 232         }
 233
 234         /* Perform optional implementation specific setup
 235          * (e.g. enable cascade interrupts for multi-UIC configurations)
 236          */
 237         ppc4xx_pic_impl_init();
 238
 239         /* Attach low-level handlers */
 240         for (i = 0; i < (NR_UICS << 5); ++i) {
 241                 irq_desc[i].handler = &__uic[i >> 5].decl;
 242                 if (is_level_sensitive(i))
 243                         irq_desc[i].status |= IRQ_LEVEL;
 244         }
 245
 246         ppc_md.get_irq = ppc4xx_pic_get_irq;
 247 }