arch/ppc/syslib/ppc4xx_pic.c

   1 /*
   2  * Interrupt controller driver for PowerPC 4xx-based processors.
   3  *
   4  * Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
   5  * Copyright (c) 2004, 2005 Zultys Technologies
   6  *
   7  * Based on original code by
   8  *    Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu>
   9  *    Armin Custer <akuster@mvista.com>
  10  *
  11  * This program is free software; you can redistribute  it and/or modify it
  12  * under  the terms of  the GNU General  Public License as published by the
  13  * Free Software Foundation;  either version 2 of the  License, or (at your
  14  * option) any later version.
  15 */
  16 #include <linux/config.h>
  17 #include <linux/init.h>
  18 #include <linux/sched.h>
  19 #include <linux/signal.h>
  20 #include <linux/stddef.h>
  21
  22 #include <asm/processor.h>
  23 #include <asm/system.h>
  24 #include <asm/irq.h>
  25 #include <asm/ppc4xx_pic.h>
  26 #include <asm/machdep.h>
  27
  28 /* See comment in include/arch-ppc/ppc4xx_pic.h
  29  * for more info about these two variables
  30  */
  31 extern struct ppc4xx_uic_settings ppc4xx_core_uic_cfg[NR_UICS]
  32     __attribute__ ((weak));
  33 extern unsigned char ppc4xx_uic_ext_irq_cfg[] __attribute__ ((weak));
  34
  35 #define IRQ_MASK_UIC0(irq)              (1 << (31 - (irq)))
  36 #define IRQ_MASK_UICx(irq)              (1 << (31 - ((irq) & 0x1f)))
  37 #define IRQ_MASK_UIC1(irq)              IRQ_MASK_UICx(irq)
  38 #define IRQ_MASK_UIC2(irq)              IRQ_MASK_UICx(irq)
  39 #define IRQ_MASK_UIC3(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 == 4
  91 #define ACK_UIC0_PARENT
  92 #define ACK_UIC1_PARENT mtdcr(DCRN_UIC_SR(UIC0), UIC0_UIC1NC);
  93 #define ACK_UIC2_PARENT mtdcr(DCRN_UIC_SR(UIC0), UIC0_UIC2NC);
  94 #define ACK_UIC3_PARENT mtdcr(DCRN_UIC_SR(UIC0), UIC0_UIC3NC);
  95 UIC_HANDLERS(0);
  96 UIC_HANDLERS(1);
  97 UIC_HANDLERS(2);
  98 UIC_HANDLERS(3);
  99
 100 static int ppc4xx_pic_get_irq(struct pt_regs *regs)
 101 {
 102         u32 uic0 = mfdcr(DCRN_UIC_MSR(UIC0));
 103         if (uic0 & UIC0_UIC1NC)
 104                 return 64 - ffs(mfdcr(DCRN_UIC_MSR(UIC1)));
 105         else if (uic0 & UIC0_UIC2NC)
 106                 return 96 - ffs(mfdcr(DCRN_UIC_MSR(UIC2)));
 107         else if (uic0 & UIC0_UIC3NC)
 108                 return 128 - ffs(mfdcr(DCRN_UIC_MSR(UIC3)));
 109         else
 110                 return uic0 ? 32 - ffs(uic0) : -1;
 111 }
 112
 113 static void __init ppc4xx_pic_impl_init(void)
 114 {
 115         /* Enable cascade interrupts in UIC0 */
 116         ppc_cached_irq_mask[0] |= UIC0_UIC1NC | UIC0_UIC2NC | UIC0_UIC3NC;
 117         mtdcr(DCRN_UIC_SR(UIC0), UIC0_UIC1NC | UIC0_UIC2NC | UIC0_UIC3NC);
 118         mtdcr(DCRN_UIC_ER(UIC0), ppc_cached_irq_mask[0]);
 119 }
 120
 121 #elif NR_UICS == 3
 122 #define ACK_UIC0_PARENT mtdcr(DCRN_UIC_SR(UICB), UICB_UIC0NC);
 123 #define ACK_UIC1_PARENT mtdcr(DCRN_UIC_SR(UICB), UICB_UIC1NC);
 124 #define ACK_UIC2_PARENT mtdcr(DCRN_UIC_SR(UICB), UICB_UIC2NC);
 125 UIC_HANDLERS(0);
 126 UIC_HANDLERS(1);
 127 UIC_HANDLERS(2);
 128
 129 static int ppc4xx_pic_get_irq(struct pt_regs *regs)
 130 {
 131         u32 uicb = mfdcr(DCRN_UIC_MSR(UICB));
 132         if (uicb & UICB_UIC0NC)
 133                 return 32 - ffs(mfdcr(DCRN_UIC_MSR(UIC0)));
 134         else if (uicb & UICB_UIC1NC)
 135                 return 64 - ffs(mfdcr(DCRN_UIC_MSR(UIC1)));
 136         else if (uicb & UICB_UIC2NC)
 137                 return 96 - ffs(mfdcr(DCRN_UIC_MSR(UIC2)));
 138         else
 139                 return -1;
 140 }
 141
 142 static void __init ppc4xx_pic_impl_init(void)
 143 {
 144 #if defined(CONFIG_440GX)
 145         /* Disable 440GP compatibility mode if it was enabled in firmware */
 146         SDR_WRITE(DCRN_SDR_MFR, SDR_READ(DCRN_SDR_MFR) & ~DCRN_SDR_MFR_PCM);
 147 #endif
 148         /* Configure Base UIC */
 149         mtdcr(DCRN_UIC_CR(UICB), 0);
 150         mtdcr(DCRN_UIC_TR(UICB), 0);
 151         mtdcr(DCRN_UIC_PR(UICB), 0xffffffff);
 152         mtdcr(DCRN_UIC_SR(UICB), 0xffffffff);
 153         mtdcr(DCRN_UIC_ER(UICB), UICB_UIC0NC | UICB_UIC1NC | UICB_UIC2NC);
 154 }
 155
 156 #elif NR_UICS == 2
 157 #define ACK_UIC0_PARENT
 158 #define ACK_UIC1_PARENT mtdcr(DCRN_UIC_SR(UIC0), UIC0_UIC1NC);
 159 UIC_HANDLERS(0);
 160 UIC_HANDLERS(1);
 161
 162 static int ppc4xx_pic_get_irq(struct pt_regs *regs)
 163 {
 164         u32 uic0 = mfdcr(DCRN_UIC_MSR(UIC0));
 165         if (uic0 & UIC0_UIC1NC)
 166                 return 64 - ffs(mfdcr(DCRN_UIC_MSR(UIC1)));
 167         else
 168                 return uic0 ? 32 - ffs(uic0) : -1;
 169 }
 170
 171 static void __init ppc4xx_pic_impl_init(void)
 172 {
 173         /* Enable cascade interrupt in UIC0 */
 174         ppc_cached_irq_mask[0] |= UIC0_UIC1NC;
 175         mtdcr(DCRN_UIC_SR(UIC0), UIC0_UIC1NC);
 176         mtdcr(DCRN_UIC_ER(UIC0), ppc_cached_irq_mask[0]);
 177 }
 178
 179 #elif NR_UICS == 1
 180 #define ACK_UIC0_PARENT
 181 UIC_HANDLERS(0);
 182
 183 static int ppc4xx_pic_get_irq(struct pt_regs *regs)
 184 {
 185         u32 uic0 = mfdcr(DCRN_UIC_MSR(UIC0));
 186         return uic0 ? 32 - ffs(uic0) : -1;
 187 }
 188
 189 static inline void ppc4xx_pic_impl_init(void)
 190 {
 191 }
 192 #endif
 193
 194 static struct ppc4xx_uic_impl {
 195         struct hw_interrupt_type decl;
 196         int base;                       /* Base DCR number */
 197 } __uic[] = {
 198         { .decl = DECLARE_UIC(0), .base = UIC0 },
 199 #if NR_UICS > 1
 200         { .decl = DECLARE_UIC(1), .base = UIC1 },
 201 #if NR_UICS > 2
 202         { .decl = DECLARE_UIC(2), .base = UIC2 },
 203 #if NR_UICS > 3
 204         { .decl = DECLARE_UIC(3), .base = UIC3 },
 205 #endif
 206 #endif
 207 #endif
 208 };
 209
 210 static inline int is_level_sensitive(int irq)
 211 {
 212         u32 tr = mfdcr(DCRN_UIC_TR(__uic[irq >> 5].base));
 213         return (tr & IRQ_MASK_UICx(irq)) == 0;
 214 }
 215
 216 void __init ppc4xx_pic_init(void)
 217 {
 218         int i;
 219         unsigned char *eirqs = ppc4xx_uic_ext_irq_cfg;
 220
 221         for (i = 0; i < NR_UICS; ++i) {
 222                 int base = __uic[i].base;
 223
 224                 /* Disable everything by default */
 225                 ppc_cached_irq_mask[i] = 0;
 226                 mtdcr(DCRN_UIC_ER(base), 0);
 227
 228                 /* We don't use critical interrupts */
 229                 mtdcr(DCRN_UIC_CR(base), 0);
 230
 231                 /* Configure polarity and triggering */
 232                 if (ppc4xx_core_uic_cfg) {
 233                         struct ppc4xx_uic_settings *p = ppc4xx_core_uic_cfg + i;
 234                         u32 mask = p->ext_irq_mask;
 235                         u32 pr = mfdcr(DCRN_UIC_PR(base)) & mask;
 236                         u32 tr = mfdcr(DCRN_UIC_TR(base)) & mask;
 237
 238                         /* "Fixed" interrupts (on-chip devices) */
 239                         pr |= p->polarity & ~mask;
 240                         tr |= p->triggering & ~mask;
 241
 242                         /* Merge external IRQs settings if board port
 243                          * provided them
 244                          */
 245                         if (eirqs && mask) {
 246                                 pr &= ~mask;
 247                                 tr &= ~mask;
 248                                 while (mask) {
 249                                         /* Extract current external IRQ mask */
 250                                         u32 eirq_mask = 1 << __ilog2(mask);
 251
 252                                         if (!(*eirqs & IRQ_SENSE_LEVEL))
 253                                                 tr |= eirq_mask;
 254
 255                                         if (*eirqs & IRQ_POLARITY_POSITIVE)
 256                                                 pr |= eirq_mask;
 257
 258                                         mask &= ~eirq_mask;
 259                                         ++eirqs;
 260                                 }
 261                         }
 262                         mtdcr(DCRN_UIC_PR(base), pr);
 263                         mtdcr(DCRN_UIC_TR(base), tr);
 264                 }
 265
 266                 /* ACK any pending interrupts to prevent false
 267                  * triggering after first enable
 268                  */
 269                 mtdcr(DCRN_UIC_SR(base), 0xffffffff);
 270         }
 271
 272         /* Perform optional implementation specific setup
 273          * (e.g. enable cascade interrupts for multi-UIC configurations)
 274          */
 275         ppc4xx_pic_impl_init();
 276
 277         /* Attach low-level handlers */
 278         for (i = 0; i < (NR_UICS << 5); ++i) {
 279                 irq_desc[i].handler = &__uic[i >> 5].decl;
 280                 if (is_level_sensitive(i))
 281                         irq_desc[i].status |= IRQ_LEVEL;
 282         }
 283
 284         ppc_md.get_irq = ppc4xx_pic_get_irq;
 285 }