arch/powerpc/platforms/cell/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 #include <linux/ioport.h>
  26
  27 #include <asm/pgtable.h>
  28 #include <asm/prom.h>
  29 #include <asm/io.h>
  30
  31 #include "interrupt.h"
  32
  33 /* register layout taken from Spider spec, table 7.4-4 */
  34 enum {
  35         TIR_DEN         = 0x004, /* Detection Enable Register */
  36         TIR_MSK         = 0x084, /* Mask Level Register */
  37         TIR_EDC         = 0x0c0, /* Edge Detection Clear Register */
  38         TIR_PNDA        = 0x100, /* Pending Register A */
  39         TIR_PNDB        = 0x104, /* Pending Register B */
  40         TIR_CS          = 0x144, /* Current Status Register */
  41         TIR_LCSA        = 0x150, /* Level Current Status Register A */
  42         TIR_LCSB        = 0x154, /* Level Current Status Register B */
  43         TIR_LCSC        = 0x158, /* Level Current Status Register C */
  44         TIR_LCSD        = 0x15c, /* Level Current Status Register D */
  45         TIR_CFGA        = 0x200, /* Setting Register A0 */
  46         TIR_CFGB        = 0x204, /* Setting Register B0 */
  47                         /* 0x208 ... 0x3ff Setting Register An/Bn */
  48         TIR_PPNDA       = 0x400, /* Packet Pending Register A */
  49         TIR_PPNDB       = 0x404, /* Packet Pending Register B */
  50         TIR_PIERA       = 0x408, /* Packet Output Error Register A */
  51         TIR_PIERB       = 0x40c, /* Packet Output Error Register B */
  52         TIR_PIEN        = 0x444, /* Packet Output Enable Register */
  53         TIR_PIPND       = 0x454, /* Packet Output Pending Register */
  54         TIRDID          = 0x484, /* Spider Device ID Register */
  55         REISTIM         = 0x500, /* Reissue Command Timeout Time Setting */
  56         REISTIMEN       = 0x504, /* Reissue Command Timeout Setting */
  57         REISWAITEN      = 0x508, /* Reissue Wait Control*/
  58 };
  59
  60 #define SPIDER_CHIP_COUNT       4
  61 #define SPIDER_SRC_COUNT        64
  62 #define SPIDER_IRQ_INVALID      63
  63
  64 struct spider_pic {
  65         struct irq_domain               *host;
  66         void __iomem            *regs;
  67         unsigned int            node_id;
  68 };
  69 static struct spider_pic spider_pics[SPIDER_CHIP_COUNT];
  70
  71 static struct spider_pic *spider_irq_data_to_pic(struct irq_data *d)
  72 {
  73         return irq_data_get_irq_chip_data(d);
  74 }
  75
  76 static void __iomem *spider_get_irq_config(struct spider_pic *pic,
  77                                            unsigned int src)
  78 {
  79         return pic->regs + TIR_CFGA + 8 * src;
  80 }
  81
  82 static void spider_unmask_irq(struct irq_data *d)
  83 {
  84         struct spider_pic *pic = spider_irq_data_to_pic(d);
  85         void __iomem *cfg = spider_get_irq_config(pic, irqd_to_hwirq(d));
  86
  87         out_be32(cfg, in_be32(cfg) | 0x30000000u);
  88 }
  89
  90 static void spider_mask_irq(struct irq_data *d)
  91 {
  92         struct spider_pic *pic = spider_irq_data_to_pic(d);
  93         void __iomem *cfg = spider_get_irq_config(pic, irqd_to_hwirq(d));
  94
  95         out_be32(cfg, in_be32(cfg) & ~0x30000000u);
  96 }
  97
  98 static void spider_ack_irq(struct irq_data *d)
  99 {
 100         struct spider_pic *pic = spider_irq_data_to_pic(d);
 101         unsigned int src = irqd_to_hwirq(d);
 102
 103         /* Reset edge detection logic if necessary
 104          */
 105         if (irqd_is_level_type(d))
 106                 return;
 107
 108         /* Only interrupts 47 to 50 can be set to edge */
 109         if (src < 47 || src > 50)
 110                 return;
 111
 112         /* Perform the clear of the edge logic */
 113         out_be32(pic->regs + TIR_EDC, 0x100 | (src & 0xf));
 114 }
 115
 116 static int spider_set_irq_type(struct irq_data *d, unsigned int type)
 117 {
 118         unsigned int sense = type & IRQ_TYPE_SENSE_MASK;
 119         struct spider_pic *pic = spider_irq_data_to_pic(d);
 120         unsigned int hw = irqd_to_hwirq(d);
 121         void __iomem *cfg = spider_get_irq_config(pic, hw);
 122         u32 old_mask;
 123         u32 ic;
 124
 125         /* Note that only level high is supported for most interrupts */
 126         if (sense != IRQ_TYPE_NONE && sense != IRQ_TYPE_LEVEL_HIGH &&
 127             (hw < 47 || hw > 50))
 128                 return -EINVAL;
 129
 130         /* Decode sense type */
 131         switch(sense) {
 132         case IRQ_TYPE_EDGE_RISING:
 133                 ic = 0x3;
 134                 break;
 135         case IRQ_TYPE_EDGE_FALLING:
 136                 ic = 0x2;
 137                 break;
 138         case IRQ_TYPE_LEVEL_LOW:
 139                 ic = 0x0;
 140                 break;
 141         case IRQ_TYPE_LEVEL_HIGH:
 142         case IRQ_TYPE_NONE:
 143                 ic = 0x1;
 144                 break;
 145         default:
 146                 return -EINVAL;
 147         }
 148
 149         /* Configure the source. One gross hack that was there before and
 150          * that I've kept around is the priority to the BE which I set to
 151          * be the same as the interrupt source number. I don't know whether
 152          * that's supposed to make any kind of sense however, we'll have to
 153          * decide that, but for now, I'm not changing the behaviour.
 154          */
 155         old_mask = in_be32(cfg) & 0x30000000u;
 156         out_be32(cfg, old_mask | (ic << 24) | (0x7 << 16) |
 157                  (pic->node_id << 4) | 0xe);
 158         out_be32(cfg + 4, (0x2 << 16) | (hw & 0xff));
 159
 160         return 0;
 161 }
 162
 163 static struct irq_chip spider_pic = {
 164         .name = "SPIDER",
 165         .irq_unmask = spider_unmask_irq,
 166         .irq_mask = spider_mask_irq,
 167         .irq_ack = spider_ack_irq,
 168         .irq_set_type = spider_set_irq_type,
 169 };
 170
 171 static int spider_host_map(struct irq_domain *h, unsigned int virq,
 172                         irq_hw_number_t hw)
 173 {
 174         irq_set_chip_data(virq, h->host_data);
 175         irq_set_chip_and_handler(virq, &spider_pic, handle_level_irq);
 176
 177         /* Set default irq type */
 178         irq_set_irq_type(virq, IRQ_TYPE_NONE);
 179
 180         return 0;
 181 }
 182
 183 static int spider_host_xlate(struct irq_domain *h, struct device_node *ct,
 184                            const u32 *intspec, unsigned int intsize,
 185                            irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 186
 187 {
 188         /* Spider interrupts have 2 cells, first is the interrupt source,
 189          * second, well, I don't know for sure yet ... We mask the top bits
 190          * because old device-trees encode a node number in there
 191          */
 192         *out_hwirq = intspec[0] & 0x3f;
 193         *out_flags = IRQ_TYPE_LEVEL_HIGH;
 194         return 0;
 195 }
 196
 197 static const struct irq_domain_ops spider_host_ops = {
 198         .map = spider_host_map,
 199         .xlate = spider_host_xlate,
 200 };
 201
 202 static void spider_irq_cascade(struct irq_desc *desc)
 203 {
 204         struct irq_chip *chip = irq_desc_get_chip(desc);
 205         struct spider_pic *pic = irq_desc_get_handler_data(desc);
 206         unsigned int cs, virq;
 207
 208         cs = in_be32(pic->regs + TIR_CS) >> 24;
 209         if (cs == SPIDER_IRQ_INVALID)
 210                 virq = 0;
 211         else
 212                 virq = irq_linear_revmap(pic->host, cs);
 213
 214         if (virq)
 215                 generic_handle_irq(virq);
 216
 217         chip->irq_eoi(&desc->irq_data);
 218 }
 219
 220 /* For hooking up the cascade we have a problem. Our device-tree is
 221  * crap and we don't know on which BE iic interrupt we are hooked on at
 222  * least not the "standard" way. We can reconstitute it based on two
 223  * informations though: which BE node we are connected to and whether
 224  * we are connected to IOIF0 or IOIF1. Right now, we really only care
 225  * about the IBM cell blade and we know that its firmware gives us an
 226  * interrupt-map property which is pretty strange.
 227  */
 228 static unsigned int __init spider_find_cascade_and_node(struct spider_pic *pic)
 229 {
 230         unsigned int virq;
 231         const u32 *imap, *tmp;
 232         int imaplen, intsize, unit;
 233         struct device_node *iic;
 234         struct device_node *of_node;
 235
 236         of_node = irq_domain_get_of_node(pic->host);
 237
 238         /* First, we check whether we have a real "interrupts" in the device
 239          * tree in case the device-tree is ever fixed
 240          */
 241         virq = irq_of_parse_and_map(of_node, 0);
 242         if (virq)
 243                 return virq;
 244
 245         /* Now do the horrible hacks */
 246         tmp = of_get_property(of_node, "#interrupt-cells", NULL);
 247         if (tmp == NULL)
 248                 return 0;
 249         intsize = *tmp;
 250         imap = of_get_property(of_node, "interrupt-map", &imaplen);
 251         if (imap == NULL || imaplen < (intsize + 1))
 252                 return 0;
 253         iic = of_find_node_by_phandle(imap[intsize]);
 254         if (iic == NULL)
 255                 return 0;
 256         imap += intsize + 1;
 257         tmp = of_get_property(iic, "#interrupt-cells", NULL);
 258         if (tmp == NULL) {
 259                 of_node_put(iic);
 260                 return 0;
 261         }
 262         intsize = *tmp;
 263         /* Assume unit is last entry of interrupt specifier */
 264         unit = imap[intsize - 1];
 265         /* Ok, we have a unit, now let's try to get the node */
 266         tmp = of_get_property(iic, "ibm,interrupt-server-ranges", NULL);
 267         if (tmp == NULL) {
 268                 of_node_put(iic);
 269                 return 0;
 270         }
 271         /* ugly as hell but works for now */
 272         pic->node_id = (*tmp) >> 1;
 273         of_node_put(iic);
 274
 275         /* Ok, now let's get cracking. You may ask me why I just didn't match
 276          * the iic host from the iic OF node, but that way I'm still compatible
 277          * with really really old old firmwares for which we don't have a node
 278          */
 279         /* Manufacture an IIC interrupt number of class 2 */
 280         virq = irq_create_mapping(NULL,
 281                                   (pic->node_id << IIC_IRQ_NODE_SHIFT) |
 282                                   (2 << IIC_IRQ_CLASS_SHIFT) |
 283                                   unit);
 284         if (!virq)
 285                 printk(KERN_ERR "spider_pic: failed to map cascade !");
 286         return virq;
 287 }
 288
 289
 290 static void __init spider_init_one(struct device_node *of_node, int chip,
 291                                    unsigned long addr)
 292 {
 293         struct spider_pic *pic = &spider_pics[chip];
 294         int i, virq;
 295
 296         /* Map registers */
 297         pic->regs = ioremap(addr, 0x1000);
 298         if (pic->regs == NULL)
 299                 panic("spider_pic: can't map registers !");
 300
 301         /* Allocate a host */
 302         pic->host = irq_domain_add_linear(of_node, SPIDER_SRC_COUNT,
 303                                           &spider_host_ops, pic);
 304         if (pic->host == NULL)
 305                 panic("spider_pic: can't allocate irq host !");
 306
 307         /* Go through all sources and disable them */
 308         for (i = 0; i < SPIDER_SRC_COUNT; i++) {
 309                 void __iomem *cfg = pic->regs + TIR_CFGA + 8 * i;
 310                 out_be32(cfg, in_be32(cfg) & ~0x30000000u);
 311         }
 312
 313         /* do not mask any interrupts because of level */
 314         out_be32(pic->regs + TIR_MSK, 0x0);
 315
 316         /* enable interrupt packets to be output */
 317         out_be32(pic->regs + TIR_PIEN, in_be32(pic->regs + TIR_PIEN) | 0x1);
 318
 319         /* Hook up the cascade interrupt to the iic and nodeid */
 320         virq = spider_find_cascade_and_node(pic);
 321         if (!virq)
 322                 return;
 323         irq_set_handler_data(virq, pic);
 324         irq_set_chained_handler(virq, spider_irq_cascade);
 325
 326         printk(KERN_INFO "spider_pic: node %d, addr: 0x%lx %pOF\n",
 327                pic->node_id, addr, of_node);
 328
 329         /* Enable the interrupt detection enable bit. Do this last! */
 330         out_be32(pic->regs + TIR_DEN, in_be32(pic->regs + TIR_DEN) | 0x1);
 331 }
 332
 333 void __init spider_init_IRQ(void)
 334 {
 335         struct resource r;
 336         struct device_node *dn;
 337         int chip = 0;
 338
 339         /* XXX node numbers are totally bogus. We _hope_ we get the device
 340          * nodes in the right order here but that's definitely not guaranteed,
 341          * we need to get the node from the device tree instead.
 342          * There is currently no proper property for it (but our whole
 343          * device-tree is bogus anyway) so all we can do is pray or maybe test
 344          * the address and deduce the node-id
 345          */
 346         for (dn = NULL;
 347              (dn = of_find_node_by_name(dn, "interrupt-controller"));) {
 348                 if (of_device_is_compatible(dn, "CBEA,platform-spider-pic")) {
 349                         if (of_address_to_resource(dn, 0, &r)) {
 350                                 printk(KERN_WARNING "spider-pic: Failed\n");
 351                                 continue;
 352                         }
 353                 } else if (of_device_is_compatible(dn, "sti,platform-spider-pic")
 354                            && (chip < 2)) {
 355                         static long hard_coded_pics[] =
 356                                 { 0x24000008000ul, 0x34000008000ul};
 357                         r.start = hard_coded_pics[chip];
 358                 } else
 359                         continue;
 360                 spider_init_one(dn, chip++, r.start);
 361         }
 362 }