Logo Search packages:      
Sourcecode: linux version File versions  Download package

spider-pic.c

/*
 * External Interrupt Controller on Spider South Bridge
 *
 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
 *
 * Author: Arnd Bergmann <arndb@de.ibm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/ioport.h>

#include <asm/pgtable.h>
#include <asm/prom.h>
#include <asm/io.h>

#include "interrupt.h"

/* register layout taken from Spider spec, table 7.4-4 */
enum {
      TIR_DEN           = 0x004, /* Detection Enable Register */
      TIR_MSK           = 0x084, /* Mask Level Register */
      TIR_EDC           = 0x0c0, /* Edge Detection Clear Register */
      TIR_PNDA    = 0x100, /* Pending Register A */
      TIR_PNDB    = 0x104, /* Pending Register B */
      TIR_CS            = 0x144, /* Current Status Register */
      TIR_LCSA    = 0x150, /* Level Current Status Register A */
      TIR_LCSB    = 0x154, /* Level Current Status Register B */
      TIR_LCSC    = 0x158, /* Level Current Status Register C */
      TIR_LCSD    = 0x15c, /* Level Current Status Register D */
      TIR_CFGA    = 0x200, /* Setting Register A0 */
      TIR_CFGB    = 0x204, /* Setting Register B0 */
                  /* 0x208 ... 0x3ff Setting Register An/Bn */
      TIR_PPNDA   = 0x400, /* Packet Pending Register A */
      TIR_PPNDB   = 0x404, /* Packet Pending Register B */
      TIR_PIERA   = 0x408, /* Packet Output Error Register A */
      TIR_PIERB   = 0x40c, /* Packet Output Error Register B */
      TIR_PIEN    = 0x444, /* Packet Output Enable Register */
      TIR_PIPND   = 0x454, /* Packet Output Pending Register */
      TIRDID            = 0x484, /* Spider Device ID Register */
      REISTIM           = 0x500, /* Reissue Command Timeout Time Setting */
      REISTIMEN   = 0x504, /* Reissue Command Timeout Setting */
      REISWAITEN  = 0x508, /* Reissue Wait Control*/
};

#define SPIDER_CHIP_COUNT     4
#define SPIDER_SRC_COUNT      64
#define SPIDER_IRQ_INVALID    63

struct spider_pic {
      struct irq_host         *host;
      void __iomem            *regs;
      unsigned int            node_id;
};
static struct spider_pic spider_pics[SPIDER_CHIP_COUNT];

static struct spider_pic *spider_virq_to_pic(unsigned int virq)
{
      return irq_map[virq].host->host_data;
}

static void __iomem *spider_get_irq_config(struct spider_pic *pic,
                                 unsigned int src)
{
      return pic->regs + TIR_CFGA + 8 * src;
}

static void spider_unmask_irq(unsigned int virq)
{
      struct spider_pic *pic = spider_virq_to_pic(virq);
      void __iomem *cfg = spider_get_irq_config(pic, irq_map[virq].hwirq);

      out_be32(cfg, in_be32(cfg) | 0x30000000u);
}

static void spider_mask_irq(unsigned int virq)
{
      struct spider_pic *pic = spider_virq_to_pic(virq);
      void __iomem *cfg = spider_get_irq_config(pic, irq_map[virq].hwirq);

      out_be32(cfg, in_be32(cfg) & ~0x30000000u);
}

static void spider_ack_irq(unsigned int virq)
{
      struct spider_pic *pic = spider_virq_to_pic(virq);
      unsigned int src = irq_map[virq].hwirq;

      /* Reset edge detection logic if necessary
       */
      if (get_irq_desc(virq)->status & IRQ_LEVEL)
            return;

      /* Only interrupts 47 to 50 can be set to edge */
      if (src < 47 || src > 50)
            return;

      /* Perform the clear of the edge logic */
      out_be32(pic->regs + TIR_EDC, 0x100 | (src & 0xf));
}

static int spider_set_irq_type(unsigned int virq, unsigned int type)
{
      unsigned int sense = type & IRQ_TYPE_SENSE_MASK;
      struct spider_pic *pic = spider_virq_to_pic(virq);
      unsigned int hw = irq_map[virq].hwirq;
      void __iomem *cfg = spider_get_irq_config(pic, hw);
      struct irq_desc *desc = get_irq_desc(virq);
      u32 old_mask;
      u32 ic;

      /* Note that only level high is supported for most interrupts */
      if (sense != IRQ_TYPE_NONE && sense != IRQ_TYPE_LEVEL_HIGH &&
          (hw < 47 || hw > 50))
            return -EINVAL;

      /* Decode sense type */
      switch(sense) {
      case IRQ_TYPE_EDGE_RISING:
            ic = 0x3;
            break;
      case IRQ_TYPE_EDGE_FALLING:
            ic = 0x2;
            break;
      case IRQ_TYPE_LEVEL_LOW:
            ic = 0x0;
            break;
      case IRQ_TYPE_LEVEL_HIGH:
      case IRQ_TYPE_NONE:
            ic = 0x1;
            break;
      default:
            return -EINVAL;
      }

      /* Update irq_desc */
      desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
      desc->status |= type & IRQ_TYPE_SENSE_MASK;
      if (type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
            desc->status |= IRQ_LEVEL;

      /* Configure the source. One gross hack that was there before and
       * that I've kept around is the priority to the BE which I set to
       * be the same as the interrupt source number. I don't know wether
       * that's supposed to make any kind of sense however, we'll have to
       * decide that, but for now, I'm not changing the behaviour.
       */
      old_mask = in_be32(cfg) & 0x30000000u;
      out_be32(cfg, old_mask | (ic << 24) | (0x7 << 16) |
             (pic->node_id << 4) | 0xe);
      out_be32(cfg + 4, (0x2 << 16) | (hw & 0xff));

      return 0;
}

static struct irq_chip spider_pic = {
      .typename = " SPIDER   ",
      .unmask = spider_unmask_irq,
      .mask = spider_mask_irq,
      .ack = spider_ack_irq,
      .set_type = spider_set_irq_type,
};

static int spider_host_map(struct irq_host *h, unsigned int virq,
                  irq_hw_number_t hw)
{
      set_irq_chip_and_handler(virq, &spider_pic, handle_level_irq);

      /* Set default irq type */
      set_irq_type(virq, IRQ_TYPE_NONE);

      return 0;
}

static int spider_host_xlate(struct irq_host *h, struct device_node *ct,
                     u32 *intspec, unsigned int intsize,
                     irq_hw_number_t *out_hwirq, unsigned int *out_flags)

{
      /* Spider interrupts have 2 cells, first is the interrupt source,
       * second, well, I don't know for sure yet ... We mask the top bits
       * because old device-trees encode a node number in there
       */
      *out_hwirq = intspec[0] & 0x3f;
      *out_flags = IRQ_TYPE_LEVEL_HIGH;
      return 0;
}

static struct irq_host_ops spider_host_ops = {
      .map = spider_host_map,
      .xlate = spider_host_xlate,
};

static void spider_irq_cascade(unsigned int irq, struct irq_desc *desc)
{
      struct spider_pic *pic = desc->handler_data;
      unsigned int cs, virq;

      cs = in_be32(pic->regs + TIR_CS) >> 24;
      if (cs == SPIDER_IRQ_INVALID)
            virq = NO_IRQ;
      else
            virq = irq_linear_revmap(pic->host, cs);
      if (virq != NO_IRQ)
            generic_handle_irq(virq);
      desc->chip->eoi(irq);
}

/* For hooking up the cascace we have a problem. Our device-tree is
 * crap and we don't know on which BE iic interrupt we are hooked on at
 * least not the "standard" way. We can reconstitute it based on two
 * informations though: which BE node we are connected to and wether
 * we are connected to IOIF0 or IOIF1. Right now, we really only care
 * about the IBM cell blade and we know that its firmware gives us an
 * interrupt-map property which is pretty strange.
 */
static unsigned int __init spider_find_cascade_and_node(struct spider_pic *pic)
{
      unsigned int virq;
      const u32 *imap, *tmp;
      int imaplen, intsize, unit;
      struct device_node *iic;

      /* First, we check wether we have a real "interrupts" in the device
       * tree in case the device-tree is ever fixed
       */
      struct of_irq oirq;
      if (of_irq_map_one(pic->host->of_node, 0, &oirq) == 0) {
            virq = irq_create_of_mapping(oirq.controller, oirq.specifier,
                                   oirq.size);
            return virq;
      }

      /* Now do the horrible hacks */
      tmp = of_get_property(pic->host->of_node, "#interrupt-cells", NULL);
      if (tmp == NULL)
            return NO_IRQ;
      intsize = *tmp;
      imap = of_get_property(pic->host->of_node, "interrupt-map", &imaplen);
      if (imap == NULL || imaplen < (intsize + 1))
            return NO_IRQ;
      iic = of_find_node_by_phandle(imap[intsize]);
      if (iic == NULL)
            return NO_IRQ;
      imap += intsize + 1;
      tmp = of_get_property(iic, "#interrupt-cells", NULL);
      if (tmp == NULL)
            return NO_IRQ;
      intsize = *tmp;
      /* Assume unit is last entry of interrupt specifier */
      unit = imap[intsize - 1];
      /* Ok, we have a unit, now let's try to get the node */
      tmp = of_get_property(iic, "ibm,interrupt-server-ranges", NULL);
      if (tmp == NULL) {
            of_node_put(iic);
            return NO_IRQ;
      }
      /* ugly as hell but works for now */
      pic->node_id = (*tmp) >> 1;
      of_node_put(iic);

      /* Ok, now let's get cracking. You may ask me why I just didn't match
       * the iic host from the iic OF node, but that way I'm still compatible
       * with really really old old firmwares for which we don't have a node
       */
      /* Manufacture an IIC interrupt number of class 2 */
      virq = irq_create_mapping(NULL,
                          (pic->node_id << IIC_IRQ_NODE_SHIFT) |
                          (2 << IIC_IRQ_CLASS_SHIFT) |
                          unit);
      if (virq == NO_IRQ)
            printk(KERN_ERR "spider_pic: failed to map cascade !");
      return virq;
}


static void __init spider_init_one(struct device_node *of_node, int chip,
                           unsigned long addr)
{
      struct spider_pic *pic = &spider_pics[chip];
      int i, virq;

      /* Map registers */
      pic->regs = ioremap(addr, 0x1000);
      if (pic->regs == NULL)
            panic("spider_pic: can't map registers !");

      /* Allocate a host */
      pic->host = irq_alloc_host(of_node_get(of_node), IRQ_HOST_MAP_LINEAR,
                           SPIDER_SRC_COUNT, &spider_host_ops,
                           SPIDER_IRQ_INVALID);
      if (pic->host == NULL)
            panic("spider_pic: can't allocate irq host !");
      pic->host->host_data = pic;

      /* Go through all sources and disable them */
      for (i = 0; i < SPIDER_SRC_COUNT; i++) {
            void __iomem *cfg = pic->regs + TIR_CFGA + 8 * i;
            out_be32(cfg, in_be32(cfg) & ~0x30000000u);
      }

      /* do not mask any interrupts because of level */
      out_be32(pic->regs + TIR_MSK, 0x0);

      /* enable interrupt packets to be output */
      out_be32(pic->regs + TIR_PIEN, in_be32(pic->regs + TIR_PIEN) | 0x1);

      /* Hook up the cascade interrupt to the iic and nodeid */
      virq = spider_find_cascade_and_node(pic);
      if (virq == NO_IRQ)
            return;
      set_irq_data(virq, pic);
      set_irq_chained_handler(virq, spider_irq_cascade);

      printk(KERN_INFO "spider_pic: node %d, addr: 0x%lx %s\n",
             pic->node_id, addr, of_node->full_name);

      /* Enable the interrupt detection enable bit. Do this last! */
      out_be32(pic->regs + TIR_DEN, in_be32(pic->regs + TIR_DEN) | 0x1);
}

void __init spider_init_IRQ(void)
{
      struct resource r;
      struct device_node *dn;
      int chip = 0;

      /* XXX node numbers are totally bogus. We _hope_ we get the device
       * nodes in the right order here but that's definitely not guaranteed,
       * we need to get the node from the device tree instead.
       * There is currently no proper property for it (but our whole
       * device-tree is bogus anyway) so all we can do is pray or maybe test
       * the address and deduce the node-id
       */
      for (dn = NULL;
           (dn = of_find_node_by_name(dn, "interrupt-controller"));) {
            if (of_device_is_compatible(dn, "CBEA,platform-spider-pic")) {
                  if (of_address_to_resource(dn, 0, &r)) {
                        printk(KERN_WARNING "spider-pic: Failed\n");
                        continue;
                  }
            } else if (of_device_is_compatible(dn, "sti,platform-spider-pic")
                     && (chip < 2)) {
                  static long hard_coded_pics[] =
                        { 0x24000008000ul, 0x34000008000ul};
                  r.start = hard_coded_pics[chip];
            } else
                  continue;
            spider_init_one(dn, chip++, r.start);
      }
}

Generated by  Doxygen 1.6.0   Back to index