arch/ppc64/kernel/spider-pic.c

   1 /*
   2  * External Interrupt Controller on Spider South Bridge
   3  *
   4  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
   5  *
   6  * Author: Arnd Bergmann <arndb@de.ibm.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2, or (at your option)
  11  * any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  */
  22
  23 #include <linux/interrupt.h>
  24 #include <linux/irq.h>
  25
  26 #include <asm/pgtable.h>
  27 #include <asm/prom.h>
  28 #include <asm/io.h>
  29
  30 #include "bpa_iic.h"
  31
  32 /* register layout taken from Spider spec, table 7.4-4 */
  33 enum {
  34         TIR_DEN         = 0x004, /* Detection Enable Register */
  35         TIR_MSK         = 0x084, /* Mask Level Register */
  36         TIR_EDC         = 0x0c0, /* Edge Detection Clear Register */
  37         TIR_PNDA        = 0x100, /* Pending Register A */
  38         TIR_PNDB        = 0x104, /* Pending Register B */
  39         TIR_CS          = 0x144, /* Current Status Register */
  40         TIR_LCSA        = 0x150, /* Level Current Status Register A */
  41         TIR_LCSB        = 0x154, /* Level Current Status Register B */
  42         TIR_LCSC        = 0x158, /* Level Current Status Register C */
  43         TIR_LCSD        = 0x15c, /* Level Current Status Register D */
  44         TIR_CFGA        = 0x200, /* Setting Register A0 */
  45         TIR_CFGB        = 0x204, /* Setting Register B0 */
  46                         /* 0x208 ... 0x3ff Setting Register An/Bn */
  47         TIR_PPNDA       = 0x400, /* Packet Pending Register A */
  48         TIR_PPNDB       = 0x404, /* Packet Pending Register B */
  49         TIR_PIERA       = 0x408, /* Packet Output Error Register A */
  50         TIR_PIERB       = 0x40c, /* Packet Output Error Register B */
  51         TIR_PIEN        = 0x444, /* Packet Output Enable Register */
  52         TIR_PIPND       = 0x454, /* Packet Output Pending Register */
  53         TIRDID          = 0x484, /* Spider Device ID Register */
  54         REISTIM         = 0x500, /* Reissue Command Timeout Time Setting */
  55         REISTIMEN       = 0x504, /* Reissue Command Timeout Setting */
  56         REISWAITEN      = 0x508, /* Reissue Wait Control*/
  57 };
  58
  59 static void __iomem *spider_pics[4];
  60
  61 static void __iomem *spider_get_pic(int irq)
  62 {
  63         int node = irq / IIC_NODE_STRIDE;
  64         irq %= IIC_NODE_STRIDE;
  65
  66         if (irq >= IIC_EXT_OFFSET &&
  67             irq < IIC_EXT_OFFSET + IIC_NUM_EXT &&
  68             spider_pics)
  69                 return spider_pics[node];
  70         return NULL;
  71 }
  72
  73 static int spider_get_nr(unsigned int irq)
  74 {
  75         return (irq % IIC_NODE_STRIDE) - IIC_EXT_OFFSET;
  76 }
  77
  78 static void __iomem *spider_get_irq_config(int irq)
  79 {
  80         void __iomem *pic;
  81         pic = spider_get_pic(irq);
  82         return pic + TIR_CFGA + 8 * spider_get_nr(irq);
  83 }
  84
  85 static void spider_enable_irq(unsigned int irq)
  86 {
  87         void __iomem *cfg = spider_get_irq_config(irq);
  88         irq = spider_get_nr(irq);
  89
  90         out_be32(cfg, in_be32(cfg) | 0x3107000eu);
  91         out_be32(cfg + 4, in_be32(cfg + 4) | 0x00020000u | irq);
  92 }
  93
  94 static void spider_disable_irq(unsigned int irq)
  95 {
  96         void __iomem *cfg = spider_get_irq_config(irq);
  97         irq = spider_get_nr(irq);
  98
  99         out_be32(cfg, in_be32(cfg) & ~0x30000000u);
 100 }
 101
 102 static unsigned int spider_startup_irq(unsigned int irq)
 103 {
 104         spider_enable_irq(irq);
 105         return 0;
 106 }
 107
 108 static void spider_shutdown_irq(unsigned int irq)
 109 {
 110         spider_disable_irq(irq);
 111 }
 112
 113 static void spider_end_irq(unsigned int irq)
 114 {
 115         spider_enable_irq(irq);
 116 }
 117
 118 static void spider_ack_irq(unsigned int irq)
 119 {
 120         spider_disable_irq(irq);
 121         iic_local_enable();
 122 }
 123
 124 static struct hw_interrupt_type spider_pic = {
 125         .typename = " SPIDER   ",
 126         .startup = spider_startup_irq,
 127         .shutdown = spider_shutdown_irq,
 128         .enable = spider_enable_irq,
 129         .disable = spider_disable_irq,
 130         .ack = spider_ack_irq,
 131         .end = spider_end_irq,
 132 };
 133
 134
 135 int spider_get_irq(unsigned long int_pending)
 136 {
 137         void __iomem *regs = spider_get_pic(int_pending);
 138         unsigned long cs;
 139         int irq;
 140
 141         cs = in_be32(regs + TIR_CS);
 142
 143         irq = cs >> 24;
 144         if (irq != 63)
 145                 return irq;
 146
 147         return -1;
 148 }
 149
 150 void spider_init_IRQ(void)
 151 {
 152         int node;
 153         struct device_node *dn;
 154         unsigned int *property;
 155         long spiderpic;
 156         int n;
 157
 158 /* FIXME: detect multiple PICs as soon as the device tree has them */
 159         for (node = 0; node < 1; node++) {
 160                 dn = of_find_node_by_path("/");
 161                 n = prom_n_addr_cells(dn);
 162                 property = (unsigned int *) get_property(dn,
 163                                 "platform-spider-pic", NULL);
 164
 165                 if (!property)
 166                         continue;
 167                 for (spiderpic = 0; n > 0; --n)
 168                         spiderpic = (spiderpic << 32) + *property++;
 169                 printk(KERN_DEBUG "SPIDER addr: %lx\n", spiderpic);
 170                 spider_pics[node] = __ioremap(spiderpic, 0x800, _PAGE_NO_CACHE);
 171                 for (n = 0; n < IIC_NUM_EXT; n++) {
 172                         int irq = n + IIC_EXT_OFFSET + node * IIC_NODE_STRIDE;
 173                         get_irq_desc(irq)->handler = &spider_pic;
 174
 175                 /* do not mask any interrupts because of level */
 176                 out_be32(spider_pics[node] + TIR_MSK, 0x0);
 177
 178                 /* disable edge detection clear */
 179                 /* out_be32(spider_pics[node] + TIR_EDC, 0x0); */
 180
 181                 /* enable interrupt packets to be output */
 182                 out_be32(spider_pics[node] + TIR_PIEN,
 183                         in_be32(spider_pics[node] + TIR_PIEN) | 0x1);
 184
 185                 /* Enable the interrupt detection enable bit. Do this last! */
 186                 out_be32(spider_pics[node] + TIR_DEN,
 187                         in_be32(spider_pics[node] +TIR_DEN) | 0x1);
 188
 189                 }
 190         }
 191 }