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/init.h>
  17 #include <linux/sched.h>
  18 #include <linux/signal.h>
  19 #include <linux/stddef.h>
  20
  21 #include <asm/processor.h>
  22 #include <asm/system.h>
  23 #include <asm/irq.h>
  24 #include <asm/ppc4xx_pic.h>
  25 #include <asm/machdep.h>
  26
  27 /* See comment in include/arch-ppc/ppc4xx_pic.h
  28  * for more info about these two variables
  29  */
  30 extern struct ppc4xx_uic_settings ppc4xx_core_uic_cfg[NR_UICS]
  31     __attribute__ ((weak));
  32 extern unsigned char ppc4xx_uic_ext_irq_cfg[] __attribute__ ((weak));
  33
  34 #define IRQ_MASK_UIC0(irq)              (1 << (31 - (irq)))
  35 #define IRQ_MASK_UICx(irq)              (1 << (31 - ((irq) & 0x1f)))
  36 #define IRQ_MASK_UIC1(irq)              IRQ_MASK_UICx(irq)
  37 #define IRQ_MASK_UIC2(irq)              IRQ_MASK_UICx(irq)
  38 #define IRQ_MASK_UIC3(irq)              IRQ_MASK_UICx(irq)
  39
  40 #define UIC_HANDLERS(n)                                                 \
  41 static void ppc4xx_uic##n##_enable(unsigned int irq)                    \
  42 {                                                                       \
  43         u32 mask = IRQ_MASK_UIC##n(irq);                                \
  44         if (irq_desc[irq].status & IRQ_LEVEL)                           \
  45                 mtdcr(DCRN_UIC_SR(UIC##n), mask);                       \
  46         ppc_cached_irq_mask[n] |= mask;                                 \
  47         mtdcr(DCRN_UIC_ER(UIC##n), ppc_cached_irq_mask[n]);             \
  48 }                                                                       \
  49                                                                         \
  50 static void ppc4xx_uic##n##_disable(unsigned int irq)                   \
  51 {                                                                       \
  52         ppc_cached_irq_mask[n] &= ~IRQ_MASK_UIC##n(irq);                \
  53         mtdcr(DCRN_UIC_ER(UIC##n), ppc_cached_irq_mask[n]);             \
  54         ACK_UIC##n##_PARENT                                             \
  55 }                                                                       \
  56                                                                         \
  57 static void ppc4xx_uic##n##_ack(unsigned int irq)                       \
  58 {                                                                       \
  59         u32 mask = IRQ_MASK_UIC##n(irq);                                \
  60         ppc_cached_irq_mask[n] &= ~mask;                                \
  61         mtdcr(DCRN_UIC_ER(UIC##n), ppc_cached_irq_mask[n]);             \
  62         mtdcr(DCRN_UIC_SR(UIC##n), mask);                               \
  63         ACK_UIC##n##_PARENT                                             \
  64 }                                                                       \
  65                                                                         \
  66 static void ppc4xx_uic##n##_end(unsigned int irq)                       \
  67 {                                                                       \
  68         unsigned int status = irq_desc[irq].status;                     \
  69         u32 mask = IRQ_MASK_UIC##n(irq);                                \
  70         if (status & IRQ_LEVEL) {                                       \
  71                 mtdcr(DCRN_UIC_SR(UIC##n), mask);                       \
  72                 ACK_UIC##n##_PARENT                                     \
  73         }                                                               \
  74         if (!(status & (IRQ_DISABLED | IRQ_INPROGRESS))) {              \
  75                 ppc_cached_irq_mask[n] |= mask;                         \
  76                 mtdcr(DCRN_UIC_ER(UIC##n), ppc_cached_irq_mask[n]);     \
  77         }                                                               \
  78 }
  79
  80 #define DECLARE_UIC(n)                                                  \
  81 {                                                                       \
  82         .typename       = "UIC"#n,                                      \
  83         .enable         = ppc4xx_uic##n##_enable,                       \
  84         .disable        = ppc4xx_uic##n##_disable,                      \
  85         .ack            = ppc4xx_uic##n##_ack,                          \
  86         .end            = ppc4xx_uic##n##_end,                          \
  87 }                                                                       \
  88
  89 #if NR_UICS == 4
  90 #define ACK_UIC0_PARENT
  91 #define ACK_UIC1_PARENT mtdcr(DCRN_UIC_SR(UIC0), UIC0_UIC1NC);
  92 #define ACK_UIC2_PARENT mtdcr(DCRN_UIC_SR(UIC0), UIC0_UIC2NC);
  93 #define ACK_UIC3_PARENT mtdcr(DCRN_UIC_SR(UIC0), UIC0_UIC3NC);
  94 UIC_HANDLERS(0);
  95 UIC_HANDLERS(1);
  96 UIC_HANDLERS(2);
  97 UIC_HANDLERS(3);
  98
  99 static int ppc4xx_pic_get_irq(void)
 100 {
 101         u32 uic0 = mfdcr(DCRN_UIC_MSR(UIC0));
 102         if (uic0 & UIC0_UIC1NC)
 103                 return 64 - ffs(mfdcr(DCRN_UIC_MSR(UIC1)));
 104         else if (uic0 & UIC0_UIC2NC)
 105                 return 96 - ffs(mfdcr(DCRN_UIC_MSR(UIC2)));
 106         else if (uic0 & UIC0_UIC3NC)
 107                 return 128 - ffs(mfdcr(DCRN_UIC_MSR(UIC3)));
 108         else
 109                 return uic0 ? 32 - ffs(uic0) : -1;
 110 }
 111
 112 static void __init ppc4xx_pic_impl_init(void)
 113 {
 114         /* Enable cascade interrupts in UIC0 */
 115         ppc_cached_irq_mask[0] |= UIC0_UIC1NC | UIC0_UIC2NC | UIC0_UIC3NC;
 116         mtdcr(DCRN_UIC_SR(UIC0), UIC0_UIC1NC | UIC0_UIC2NC | UIC0_UIC3NC);
 117         mtdcr(DCRN_UIC_ER(UIC0), ppc_cached_irq_mask[0]);
 118 }
 119
 120 #elif NR_UICS == 3
 121 #define ACK_UIC0_PARENT mtdcr(DCRN_UIC_SR(UICB), UICB_UIC0NC);
 122 #define ACK_UIC1_PARENT mtdcr(DCRN_UIC_SR(UICB), UICB_UIC1NC);
 123 #define ACK_UIC2_PARENT mtdcr(DCRN_UIC_SR(UICB), UICB_UIC2NC);
 124 UIC_HANDLERS(0);
 125 UIC_HANDLERS(1);
 126 UIC_HANDLERS(2);
 127
 128 static int ppc4xx_pic_get_irq(void)
 129 {
 130         u32 uicb = mfdcr(DCRN_UIC_MSR(UICB));
 131         if (uicb & UICB_UIC0NC)
 132                 return 32 - ffs(mfdcr(DCRN_UIC_MSR(UIC0)));
 133         else if (uicb & UICB_UIC1NC)
 134                 return 64 - ffs(mfdcr(DCRN_UIC_MSR(UIC1)));
 135         else if (uicb & UICB_UIC2NC)
 136                 return 96 - ffs(mfdcr(DCRN_UIC_MSR(UIC2)));
 137         else
 138                 return -1;
 139 }
 140
 141 static void __init ppc4xx_pic_impl_init(void)
 142 {
 143 #if defined(CONFIG_440GX)
 144         /* Disable 440GP compatibility mode if it was enabled in firmware */
 145         SDR_WRITE(DCRN_SDR_MFR, SDR_READ(DCRN_SDR_MFR) & ~DCRN_SDR_MFR_PCM);
 146 #endif
 147         /* Configure Base UIC */
 148         mtdcr(DCRN_UIC_CR(UICB), 0);
 149         mtdcr(DCRN_UIC_TR(UICB), 0);
 150         mtdcr(DCRN_UIC_PR(UICB), 0xffffffff);
 151         mtdcr(DCRN_UIC_SR(UICB), 0xffffffff);
 152         mtdcr(DCRN_UIC_ER(UICB), UICB_UIC0NC | UICB_UIC1NC | UICB_UIC2NC);
 153 }
 154
 155 #elif NR_UICS == 2
 156 #define ACK_UIC0_PARENT
 157 #define ACK_UIC1_PARENT mtdcr(DCRN_UIC_SR(UIC0), UIC0_UIC1NC);
 158 UIC_HANDLERS(0);
 159 UIC_HANDLERS(1);
 160
 161 static int ppc4xx_pic_get_irq(void)
 162 {
 163         u32 uic0 = mfdcr(DCRN_UIC_MSR(UIC0));
 164         if (uic0 & UIC0_UIC1NC)
 165                 return 64 - ffs(mfdcr(DCRN_UIC_MSR(UIC1)));
 166         else
 167                 return uic0 ? 32 - ffs(uic0) : -1;
 168 }
 169
 170 static void __init ppc4xx_pic_impl_init(void)
 171 {
 172         /* Enable cascade interrupt in UIC0 */
 173         ppc_cached_irq_mask[0] |= UIC0_UIC1NC;
 174         mtdcr(DCRN_UIC_SR(UIC0), UIC0_UIC1NC);
 175         mtdcr(DCRN_UIC_ER(UIC0), ppc_cached_irq_mask[0]);
 176 }
 177
 178 #elif NR_UICS == 1
 179 #define ACK_UIC0_PARENT
 180 UIC_HANDLERS(0);
 181
 182 static int ppc4xx_pic_get_irq(void)
 183 {
 184         u32 uic0 = mfdcr(DCRN_UIC_MSR(UIC0));
 185         return uic0 ? 32 - ffs(uic0) : -1;
 186 }
 187
 188 static inline void ppc4xx_pic_impl_init(void)
 189 {
 190 }
 191 #endif
 192
 193 static struct ppc4xx_uic_impl {
 194         struct hw_interrupt_type decl;
 195         int base;                       /* Base DCR number */
 196 } __uic[] = {
 197         { .decl = DECLARE_UIC(0), .base = UIC0 },
 198 #if NR_UICS > 1
 199         { .decl = DECLARE_UIC(1), .base = UIC1 },
 200 #if NR_UICS > 2
 201         { .decl = DECLARE_UIC(2), .base = UIC2 },
 202 #if NR_UICS > 3
 203         { .decl = DECLARE_UIC(3), .base = UIC3 },
 204 #endif
 205 #endif
 206 #endif
 207 };
 208
 209 static inline int is_level_sensitive(int irq)
 210 {
 211         u32 tr = mfdcr(DCRN_UIC_TR(__uic[irq >> 5].base));
 212         return (tr & IRQ_MASK_UICx(irq)) == 0;
 213 }
 214
 215 void __init ppc4xx_pic_init(void)
 216 {
 217         int i;
 218         unsigned char *eirqs = ppc4xx_uic_ext_irq_cfg;
 219
 220         for (i = 0; i < NR_UICS; ++i) {
 221                 int base = __uic[i].base;
 222
 223                 /* Disable everything by default */
 224                 ppc_cached_irq_mask[i] = 0;
 225                 mtdcr(DCRN_UIC_ER(base), 0);
 226
 227                 /* We don't use critical interrupts */
 228                 mtdcr(DCRN_UIC_CR(base), 0);
 229
 230                 /* Configure polarity and triggering */
 231                 if (ppc4xx_core_uic_cfg) {
 232                         struct ppc4xx_uic_settings *p = ppc4xx_core_uic_cfg + i;
 233                         u32 mask = p->ext_irq_mask;
 234                         u32 pr = mfdcr(DCRN_UIC_PR(base)) & mask;
 235                         u32 tr = mfdcr(DCRN_UIC_TR(base)) & mask;
 236
 237                         /* "Fixed" interrupts (on-chip devices) */
 238                         pr |= p->polarity & ~mask;
 239                         tr |= p->triggering & ~mask;
 240
 241                         /* Merge external IRQs settings if board port
 242                          * provided them
 243                          */
 244                         if (eirqs && mask) {
 245                                 pr &= ~mask;
 246                                 tr &= ~mask;
 247                                 while (mask) {
 248                                         /* Extract current external IRQ mask */
 249                                         u32 eirq_mask = 1 << __ilog2(mask);
 250
 251                                         if (!(*eirqs & IRQ_SENSE_LEVEL))
 252                                                 tr |= eirq_mask;
 253
 254                                         if (*eirqs & IRQ_POLARITY_POSITIVE)
 255                                                 pr |= eirq_mask;
 256
 257                                         mask &= ~eirq_mask;
 258                                         ++eirqs;
 259                                 }
 260                         }
 261                         mtdcr(DCRN_UIC_PR(base), pr);
 262                         mtdcr(DCRN_UIC_TR(base), tr);
 263                 }
 264
 265                 /* ACK any pending interrupts to prevent false
 266                  * triggering after first enable
 267                  */
 268                 mtdcr(DCRN_UIC_SR(base), 0xffffffff);
 269         }
 270
 271         /* Perform optional implementation specific setup
 272          * (e.g. enable cascade interrupts for multi-UIC configurations)
 273          */
 274         ppc4xx_pic_impl_init();
 275
 276         /* Attach low-level handlers */
 277         for (i = 0; i < (NR_UICS << 5); ++i) {
 278                 irq_desc[i].chip = &__uic[i >> 5].decl;
 279                 if (is_level_sensitive(i))
 280                         irq_desc[i].status |= IRQ_LEVEL;
 281         }
 282
 283         ppc_md.get_irq = ppc4xx_pic_get_irq;
 284 }