arch/powerpc/platforms/cell/spider-pic.c - linux - Git at Google

 /*
  * 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;
 	struct device_node	*of_node;
 	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);

 	/* We use no locking as we should be covered by the descriptor lock
 	 * for access to invidual source configuration registers
 	 */
 	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);

 	/* We use no locking as we should be covered by the descriptor lock
 	 * for access to invidual source configuration registers
 	 */
 	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 struct irq_chip spider_pic = {
 	.typename = " SPIDER   ",
 	.unmask = spider_unmask_irq,
 	.mask = spider_mask_irq,
 	.ack = spider_ack_irq,
 };

 static int spider_host_match(struct irq_host *h, struct device_node *node)
 {
 	struct spider_pic *pic = h->host_data;
 	return node == pic->of_node;
 }

 static int spider_host_map(struct irq_host *h, unsigned int virq,
 			irq_hw_number_t hw, unsigned int flags)
 {
 	unsigned int sense = flags & IRQ_TYPE_SENSE_MASK;
 	struct spider_pic *pic = h->host_data;
 	void __iomem *cfg = spider_get_irq_config(pic, hw);
 	int level = 0;
 	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;
 		level = 1;
 		break;
 	case IRQ_TYPE_LEVEL_HIGH:
 	case IRQ_TYPE_NONE:
 		ic = 0x1;
 		level = 1;
 		break;
 	default:
 		return -EINVAL;
 	}

 	/* 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.
 	 */
 	out_be32(cfg, (ic << 24) | (0x7 << 16) | (pic->node_id << 4) | 0xe);
 	out_be32(cfg + 4, (0x2 << 16) | (hw & 0xff));

 	if (level)
 		get_irq_desc(virq)->status |= IRQ_LEVEL;
 	set_irq_chip_and_handler(virq, &spider_pic, handle_level_irq);
 	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 = {
 	.match = spider_host_match,
 	.map = spider_host_map,
 	.xlate = spider_host_xlate,
 };

 static void spider_irq_cascade(unsigned int irq, struct irq_desc *desc,
 			       struct pt_regs *regs)
 {
 	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, regs);
 	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;
 	u32 *imap, *tmp;
 	int imaplen, intsize, unit;
 	struct device_node *iic;
 	struct irq_host *iic_host;

 #if 0 /* Enable that when we have a way to retreive the node as well */
 	/* 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->of_node, 0, &oirq) == 0) {
 		virq = irq_create_of_mapping(oirq.controller, oirq.specifier,
 					     oirq.size);
 		goto bail;
 	}
 #endif

 	/* Now do the horrible hacks */
 	tmp = (u32 *)get_property(pic->of_node, "#interrupt-cells", NULL);
 	if (tmp == NULL)
 		return NO_IRQ;
 	intsize = *tmp;
 	imap = (u32 *)get_property(pic->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 = (u32 *)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 = (u32 *)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
 	 */
 	iic_host = iic_get_irq_host(pic->node_id);
 	if (iic_host == NULL)
 		return NO_IRQ;
 	/* Manufacture an IIC interrupt number of class 2 */
 	virq = irq_create_mapping(iic_host, 0x20 | unit, 0);
 	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(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;

 	/* Fill out other bits */
 	pic->of_node = of_node_get(of_node);

 	/* 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 (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 (device_is_compatible(dn, "sti,platform-spider-pic")
 			   && (chip < 2)) {
 			static long hard_coded_pics[] =
 				{ 0x24000008000, 0x34000008000 };
 			r.start = hard_coded_pics[chip];
 		} else
 			continue;
 		spider_init_one(dn, chip++, r.start);
 	}
 }
	/*
	* 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;
	struct device_node *of_node;
	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);

	/* We use no locking as we should be covered by the descriptor lock
	* for access to invidual source configuration registers
	*/
	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);

	/* We use no locking as we should be covered by the descriptor lock
	* for access to invidual source configuration registers
	*/
	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 struct irq_chip spider_pic = {
	.typename = " SPIDER ",
	.unmask = spider_unmask_irq,
	.mask = spider_mask_irq,
	.ack = spider_ack_irq,
	};

	static int spider_host_match(struct irq_host h, struct device_node node)
	{
	struct spider_pic *pic = h->host_data;
	return node == pic->of_node;
	}

	static int spider_host_map(struct irq_host *h, unsigned int virq,
	irq_hw_number_t hw, unsigned int flags)
	{
	unsigned int sense = flags & IRQ_TYPE_SENSE_MASK;
	struct spider_pic *pic = h->host_data;
	void __iomem *cfg = spider_get_irq_config(pic, hw);
	int level = 0;
	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;
	level = 1;
	break;
	case IRQ_TYPE_LEVEL_HIGH:
	case IRQ_TYPE_NONE:
	ic = 0x1;
	level = 1;
	break;
	default:
	return -EINVAL;
	}

	/* 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.
	*/
	out_be32(cfg, (ic << 24) \| (0x7 << 16) \| (pic->node_id << 4) \| 0xe);
	out_be32(cfg + 4, (0x2 << 16) \| (hw & 0xff));

	if (level)
	get_irq_desc(virq)->status \|= IRQ_LEVEL;
	set_irq_chip_and_handler(virq, &spider_pic, handle_level_irq);
	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 = {
	.match = spider_host_match,
	.map = spider_host_map,
	.xlate = spider_host_xlate,
	};

	static void spider_irq_cascade(unsigned int irq, struct irq_desc *desc,
	struct pt_regs *regs)
	{
	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, regs);
	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;
	u32 imap, tmp;
	int imaplen, intsize, unit;
	struct device_node *iic;
	struct irq_host *iic_host;

	#if 0 /* Enable that when we have a way to retreive the node as well */
	/* 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->of_node, 0, &oirq) == 0) {
	virq = irq_create_of_mapping(oirq.controller, oirq.specifier,
	oirq.size);
	goto bail;
	}
	#endif

	/* Now do the horrible hacks */
	tmp = (u32 *)get_property(pic->of_node, "#interrupt-cells", NULL);
	if (tmp == NULL)
	return NO_IRQ;
	intsize = *tmp;
	imap = (u32 *)get_property(pic->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 = (u32 *)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 = (u32 *)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
	*/
	iic_host = iic_get_irq_host(pic->node_id);
	if (iic_host == NULL)
	return NO_IRQ;
	/* Manufacture an IIC interrupt number of class 2 */
	virq = irq_create_mapping(iic_host, 0x20 \| unit, 0);
	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(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;

	/* Fill out other bits */
	pic->of_node = of_node_get(of_node);

	/* 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 (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 (device_is_compatible(dn, "sti,platform-spider-pic")
	&& (chip < 2)) {
	static long hard_coded_pics[] =
	{ 0x24000008000, 0x34000008000 };
	r.start = hard_coded_pics[chip];
	} else
	continue;
	spider_init_one(dn, chip++, r.start);
	}
	}