arch/powerpc/platforms/cell/spider-pic.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * External Interrupt Controller on Spider South Bridge
   4  *
   5  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
   6  *
   7  * Author: Arnd Bergmann <arndb@de.ibm.com>
   8  */
   9
  10 #include <linux/interrupt.h>
  11 #include <linux/irq.h>
  12 #include <linux/ioport.h>
  13 #include <linux/pgtable.h>
  14
  15 #include <asm/prom.h>
  16 #include <asm/io.h>
  17
  18 #include "interrupt.h"
  19
  20 /* register layout taken from Spider spec, table 7.4-4 */
  21 enum {
  22         TIR_DEN         = 0x004, /* Detection Enable Register */
  23         TIR_MSK         = 0x084, /* Mask Level Register */
  24         TIR_EDC         = 0x0c0, /* Edge Detection Clear Register */
  25         TIR_PNDA        = 0x100, /* Pending Register A */
  26         TIR_PNDB        = 0x104, /* Pending Register B */
  27         TIR_CS          = 0x144, /* Current Status Register */
  28         TIR_LCSA        = 0x150, /* Level Current Status Register A */
  29         TIR_LCSB        = 0x154, /* Level Current Status Register B */
  30         TIR_LCSC        = 0x158, /* Level Current Status Register C */
  31         TIR_LCSD        = 0x15c, /* Level Current Status Register D */
  32         TIR_CFGA        = 0x200, /* Setting Register A0 */
  33         TIR_CFGB        = 0x204, /* Setting Register B0 */
  34                         /* 0x208 ... 0x3ff Setting Register An/Bn */
  35         TIR_PPNDA       = 0x400, /* Packet Pending Register A */
  36         TIR_PPNDB       = 0x404, /* Packet Pending Register B */
  37         TIR_PIERA       = 0x408, /* Packet Output Error Register A */
  38         TIR_PIERB       = 0x40c, /* Packet Output Error Register B */
  39         TIR_PIEN        = 0x444, /* Packet Output Enable Register */
  40         TIR_PIPND       = 0x454, /* Packet Output Pending Register */
  41         TIRDID          = 0x484, /* Spider Device ID Register */
  42         REISTIM         = 0x500, /* Reissue Command Timeout Time Setting */
  43         REISTIMEN       = 0x504, /* Reissue Command Timeout Setting */
  44         REISWAITEN      = 0x508, /* Reissue Wait Control*/
  45 };
  46
  47 #define SPIDER_CHIP_COUNT       4
  48 #define SPIDER_SRC_COUNT        64
  49 #define SPIDER_IRQ_INVALID      63
  50
  51 struct spider_pic {
  52         struct irq_domain               *host;
  53         void __iomem            *regs;
  54         unsigned int            node_id;
  55 };
  56 static struct spider_pic spider_pics[SPIDER_CHIP_COUNT];
  57
  58 static struct spider_pic *spider_irq_data_to_pic(struct irq_data *d)
  59 {
  60         return irq_data_get_irq_chip_data(d);
  61 }
  62
  63 static void __iomem *spider_get_irq_config(struct spider_pic *pic,
  64                                            unsigned int src)
  65 {
  66         return pic->regs + TIR_CFGA + 8 * src;
  67 }
  68
  69 static void spider_unmask_irq(struct irq_data *d)
  70 {
  71         struct spider_pic *pic = spider_irq_data_to_pic(d);
  72         void __iomem *cfg = spider_get_irq_config(pic, irqd_to_hwirq(d));
  73
  74         out_be32(cfg, in_be32(cfg) | 0x30000000u);
  75 }
  76
  77 static void spider_mask_irq(struct irq_data *d)
  78 {
  79         struct spider_pic *pic = spider_irq_data_to_pic(d);
  80         void __iomem *cfg = spider_get_irq_config(pic, irqd_to_hwirq(d));
  81
  82         out_be32(cfg, in_be32(cfg) & ~0x30000000u);
  83 }
  84
  85 static void spider_ack_irq(struct irq_data *d)
  86 {
  87         struct spider_pic *pic = spider_irq_data_to_pic(d);
  88         unsigned int src = irqd_to_hwirq(d);
  89
  90         /* Reset edge detection logic if necessary
  91          */
  92         if (irqd_is_level_type(d))
  93                 return;
  94
  95         /* Only interrupts 47 to 50 can be set to edge */
  96         if (src < 47 || src > 50)
  97                 return;
  98
  99         /* Perform the clear of the edge logic */
 100         out_be32(pic->regs + TIR_EDC, 0x100 | (src & 0xf));
 101 }
 102
 103 static int spider_set_irq_type(struct irq_data *d, unsigned int type)
 104 {
 105         unsigned int sense = type & IRQ_TYPE_SENSE_MASK;
 106         struct spider_pic *pic = spider_irq_data_to_pic(d);
 107         unsigned int hw = irqd_to_hwirq(d);
 108         void __iomem *cfg = spider_get_irq_config(pic, hw);
 109         u32 old_mask;
 110         u32 ic;
 111
 112         /* Note that only level high is supported for most interrupts */
 113         if (sense != IRQ_TYPE_NONE && sense != IRQ_TYPE_LEVEL_HIGH &&
 114             (hw < 47 || hw > 50))
 115                 return -EINVAL;
 116
 117         /* Decode sense type */
 118         switch(sense) {
 119         case IRQ_TYPE_EDGE_RISING:
 120                 ic = 0x3;
 121                 break;
 122         case IRQ_TYPE_EDGE_FALLING:
 123                 ic = 0x2;
 124                 break;
 125         case IRQ_TYPE_LEVEL_LOW:
 126                 ic = 0x0;
 127                 break;
 128         case IRQ_TYPE_LEVEL_HIGH:
 129         case IRQ_TYPE_NONE:
 130                 ic = 0x1;
 131                 break;
 132         default:
 133                 return -EINVAL;
 134         }
 135
 136         /* Configure the source. One gross hack that was there before and
 137          * that I've kept around is the priority to the BE which I set to
 138          * be the same as the interrupt source number. I don't know whether
 139          * that's supposed to make any kind of sense however, we'll have to
 140          * decide that, but for now, I'm not changing the behaviour.
 141          */
 142         old_mask = in_be32(cfg) & 0x30000000u;
 143         out_be32(cfg, old_mask | (ic << 24) | (0x7 << 16) |
 144                  (pic->node_id << 4) | 0xe);
 145         out_be32(cfg + 4, (0x2 << 16) | (hw & 0xff));
 146
 147         return 0;
 148 }
 149
 150 static struct irq_chip spider_pic = {
 151         .name = "SPIDER",
 152         .irq_unmask = spider_unmask_irq,
 153         .irq_mask = spider_mask_irq,
 154         .irq_ack = spider_ack_irq,
 155         .irq_set_type = spider_set_irq_type,
 156 };
 157
 158 static int spider_host_map(struct irq_domain *h, unsigned int virq,
 159                         irq_hw_number_t hw)
 160 {
 161         irq_set_chip_data(virq, h->host_data);
 162         irq_set_chip_and_handler(virq, &spider_pic, handle_level_irq);
 163
 164         /* Set default irq type */
 165         irq_set_irq_type(virq, IRQ_TYPE_NONE);
 166
 167         return 0;
 168 }
 169
 170 static int spider_host_xlate(struct irq_domain *h, struct device_node *ct,
 171                            const u32 *intspec, unsigned int intsize,
 172                            irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 173
 174 {
 175         /* Spider interrupts have 2 cells, first is the interrupt source,
 176          * second, well, I don't know for sure yet ... We mask the top bits
 177          * because old device-trees encode a node number in there
 178          */
 179         *out_hwirq = intspec[0] & 0x3f;
 180         *out_flags = IRQ_TYPE_LEVEL_HIGH;
 181         return 0;
 182 }
 183
 184 static const struct irq_domain_ops spider_host_ops = {
 185         .map = spider_host_map,
 186         .xlate = spider_host_xlate,
 187 };
 188
 189 static void spider_irq_cascade(struct irq_desc *desc)
 190 {
 191         struct irq_chip *chip = irq_desc_get_chip(desc);
 192         struct spider_pic *pic = irq_desc_get_handler_data(desc);
 193         unsigned int cs, virq;
 194
 195         cs = in_be32(pic->regs + TIR_CS) >> 24;
 196         if (cs == SPIDER_IRQ_INVALID)
 197                 virq = 0;
 198         else
 199                 virq = irq_linear_revmap(pic->host, cs);
 200
 201         if (virq)
 202                 generic_handle_irq(virq);
 203
 204         chip->irq_eoi(&desc->irq_data);
 205 }
 206
 207 /* For hooking up the cascade we have a problem. Our device-tree is
 208  * crap and we don't know on which BE iic interrupt we are hooked on at
 209  * least not the "standard" way. We can reconstitute it based on two
 210  * informations though: which BE node we are connected to and whether
 211  * we are connected to IOIF0 or IOIF1. Right now, we really only care
 212  * about the IBM cell blade and we know that its firmware gives us an
 213  * interrupt-map property which is pretty strange.
 214  */
 215 static unsigned int __init spider_find_cascade_and_node(struct spider_pic *pic)
 216 {
 217         unsigned int virq;
 218         const u32 *imap, *tmp;
 219         int imaplen, intsize, unit;
 220         struct device_node *iic;
 221         struct device_node *of_node;
 222
 223         of_node = irq_domain_get_of_node(pic->host);
 224
 225         /* First, we check whether we have a real "interrupts" in the device
 226          * tree in case the device-tree is ever fixed
 227          */
 228         virq = irq_of_parse_and_map(of_node, 0);
 229         if (virq)
 230                 return virq;
 231
 232         /* Now do the horrible hacks */
 233         tmp = of_get_property(of_node, "#interrupt-cells", NULL);
 234         if (tmp == NULL)
 235                 return 0;
 236         intsize = *tmp;
 237         imap = of_get_property(of_node, "interrupt-map", &imaplen);
 238         if (imap == NULL || imaplen < (intsize + 1))
 239                 return 0;
 240         iic = of_find_node_by_phandle(imap[intsize]);
 241         if (iic == NULL)
 242                 return 0;
 243         imap += intsize + 1;
 244         tmp = of_get_property(iic, "#interrupt-cells", NULL);
 245         if (tmp == NULL) {
 246                 of_node_put(iic);
 247                 return 0;
 248         }
 249         intsize = *tmp;
 250         /* Assume unit is last entry of interrupt specifier */
 251         unit = imap[intsize - 1];
 252         /* Ok, we have a unit, now let's try to get the node */
 253         tmp = of_get_property(iic, "ibm,interrupt-server-ranges", NULL);
 254         if (tmp == NULL) {
 255                 of_node_put(iic);
 256                 return 0;
 257         }
 258         /* ugly as hell but works for now */
 259         pic->node_id = (*tmp) >> 1;
 260         of_node_put(iic);
 261
 262         /* Ok, now let's get cracking. You may ask me why I just didn't match
 263          * the iic host from the iic OF node, but that way I'm still compatible
 264          * with really really old old firmwares for which we don't have a node
 265          */
 266         /* Manufacture an IIC interrupt number of class 2 */
 267         virq = irq_create_mapping(NULL,
 268                                   (pic->node_id << IIC_IRQ_NODE_SHIFT) |
 269                                   (2 << IIC_IRQ_CLASS_SHIFT) |
 270                                   unit);
 271         if (!virq)
 272                 printk(KERN_ERR "spider_pic: failed to map cascade !");
 273         return virq;
 274 }
 275
 276
 277 static void __init spider_init_one(struct device_node *of_node, int chip,
 278                                    unsigned long addr)
 279 {
 280         struct spider_pic *pic = &spider_pics[chip];
 281         int i, virq;
 282
 283         /* Map registers */
 284         pic->regs = ioremap(addr, 0x1000);
 285         if (pic->regs == NULL)
 286                 panic("spider_pic: can't map registers !");
 287
 288         /* Allocate a host */
 289         pic->host = irq_domain_add_linear(of_node, SPIDER_SRC_COUNT,
 290                                           &spider_host_ops, pic);
 291         if (pic->host == NULL)
 292                 panic("spider_pic: can't allocate irq host !");
 293
 294         /* Go through all sources and disable them */
 295         for (i = 0; i < SPIDER_SRC_COUNT; i++) {
 296                 void __iomem *cfg = pic->regs + TIR_CFGA + 8 * i;
 297                 out_be32(cfg, in_be32(cfg) & ~0x30000000u);
 298         }
 299
 300         /* do not mask any interrupts because of level */
 301         out_be32(pic->regs + TIR_MSK, 0x0);
 302
 303         /* enable interrupt packets to be output */
 304         out_be32(pic->regs + TIR_PIEN, in_be32(pic->regs + TIR_PIEN) | 0x1);
 305
 306         /* Hook up the cascade interrupt to the iic and nodeid */
 307         virq = spider_find_cascade_and_node(pic);
 308         if (!virq)
 309                 return;
 310         irq_set_handler_data(virq, pic);
 311         irq_set_chained_handler(virq, spider_irq_cascade);
 312
 313         printk(KERN_INFO "spider_pic: node %d, addr: 0x%lx %pOF\n",
 314                pic->node_id, addr, of_node);
 315
 316         /* Enable the interrupt detection enable bit. Do this last! */
 317         out_be32(pic->regs + TIR_DEN, in_be32(pic->regs + TIR_DEN) | 0x1);
 318 }
 319
 320 void __init spider_init_IRQ(void)
 321 {
 322         struct resource r;
 323         struct device_node *dn;
 324         int chip = 0;
 325
 326         /* XXX node numbers are totally bogus. We _hope_ we get the device
 327          * nodes in the right order here but that's definitely not guaranteed,
 328          * we need to get the node from the device tree instead.
 329          * There is currently no proper property for it (but our whole
 330          * device-tree is bogus anyway) so all we can do is pray or maybe test
 331          * the address and deduce the node-id
 332          */
 333         for_each_node_by_name(dn, "interrupt-controller") {
 334                 if (of_device_is_compatible(dn, "CBEA,platform-spider-pic")) {
 335                         if (of_address_to_resource(dn, 0, &r)) {
 336                                 printk(KERN_WARNING "spider-pic: Failed\n");
 337                                 continue;
 338                         }
 339                 } else if (of_device_is_compatible(dn, "sti,platform-spider-pic")
 340                            && (chip < 2)) {
 341                         static long hard_coded_pics[] =
 342                                 { 0x24000008000ul, 0x34000008000ul};
 343                         r.start = hard_coded_pics[chip];
 344                 } else
 345                         continue;
 346                 spider_init_one(dn, chip++, r.start);
 347         }
 348 }