[linux-2.6-block.git] / drivers / pci / setup-irq.c

/*
 *	drivers/pci/setup-irq.c
 *
 * Extruded from code written by
 *      Dave Rusling (david.rusling@reo.mts.dec.com)
 *      David Mosberger (davidm@cs.arizona.edu)
 *	David Miller (davem@redhat.com)
 *
 * Support routines for initializing a PCI subsystem.
 */


#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/cache.h>
#include "pci.h"

void __weak pcibios_update_irq(struct pci_dev *dev, int irq)
{
	dev_dbg(&dev->dev, "assigning IRQ %02d\n", irq);
	pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
}

void pci_assign_irq(struct pci_dev *dev)
{
	u8 pin;
	u8 slot = -1;
	int irq = 0;
	struct pci_host_bridge *hbrg = pci_find_host_bridge(dev->bus);

	if (!(hbrg->map_irq)) {
		dev_dbg(&dev->dev, "runtime IRQ mapping not provided by arch\n");
		return;
	}

	/* If this device is not on the primary bus, we need to figure out
	   which interrupt pin it will come in on.   We know which slot it
	   will come in on 'cos that slot is where the bridge is.   Each
	   time the interrupt line passes through a PCI-PCI bridge we must
	   apply the swizzle function.  */

	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
	/* Cope with illegal. */
	if (pin > 4)
		pin = 1;

	if (pin) {
		/* Follow the chain of bridges, swizzling as we go.  */
		if (hbrg->swizzle_irq)
			slot = (*(hbrg->swizzle_irq))(dev, &pin);

		/*
		 * If a swizzling function is not used map_irq must
		 * ignore slot
		 */
		irq = (*(hbrg->map_irq))(dev, slot, pin);
		if (irq == -1)
			irq = 0;
	}
	dev->irq = irq;

	dev_dbg(&dev->dev, "assign IRQ: got %d\n", dev->irq);

	/* Always tell the device, so the driver knows what is
	   the real IRQ to use; the device does not use it. */
	pcibios_update_irq(dev, irq);
}

void pci_fixup_irqs(u8 (*swizzle)(struct pci_dev *, u8 *),
		    int (*map_irq)(const struct pci_dev *, u8, u8))
{
	/*
	 * Implement pci_fixup_irqs() through pci_assign_irq().
	 * This code should be remove eventually, it is a wrapper
	 * around pci_assign_irq() interface to keep current
	 * pci_fixup_irqs() behaviour unchanged on architecture
	 * code still relying on its interface.
	 */
	struct pci_dev *dev = NULL;
	struct pci_host_bridge *hbrg = NULL;

	for_each_pci_dev(dev) {
		hbrg = pci_find_host_bridge(dev->bus);
		hbrg->swizzle_irq = swizzle;
		hbrg->map_irq = map_irq;
		pci_assign_irq(dev);
		hbrg->swizzle_irq = NULL;
		hbrg->map_irq = NULL;
	}
}
EXPORT_SYMBOL_GPL(pci_fixup_irqs);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* drivers/pci/setup-irq.c
	3	*
	4	* Extruded from code written by
	5	* Dave Rusling (david.rusling@reo.mts.dec.com)
	6	* David Mosberger (davidm@cs.arizona.edu)
	7	* David Miller (davem@redhat.com)
	8	*
	9	* Support routines for initializing a PCI subsystem.
	10	*/
	11
	12
1da177e4 LT	13	#include <linux/kernel.h>
	14	#include <linux/pci.h>
	15	#include <linux/errno.h>
	16	#include <linux/ioport.h>
	17	#include <linux/cache.h>
47a650f2	18	#include "pci.h"
1da177e4	19
8885b7b6 TR	20	void __weak pcibios_update_irq(struct pci_dev *dev, int irq)
	21	{
	22	dev_dbg(&dev->dev, "assigning IRQ %02d\n", irq);
	23	pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
	24	}
1da177e4	25
47a650f2	26	void pci_assign_irq(struct pci_dev *dev)
1da177e4	27	{
47a650f2 MM	28	u8 pin;
47a650f2 MM	29	u8 slot = -1;
691cd0c2	30	int irq = 0;
47a650f2 MM	31	struct pci_host_bridge *hbrg = pci_find_host_bridge(dev->bus);
	32
	33	if (!(hbrg->map_irq)) {
	34	dev_dbg(&dev->dev, "runtime IRQ mapping not provided by arch\n");
	35	return;
	36	}
1da177e4 LT	37
	38	/* If this device is not on the primary bus, we need to figure out
	39	which interrupt pin it will come in on. We know which slot it
	40	will come in on 'cos that slot is where the bridge is. Each
	41	time the interrupt line passes through a PCI-PCI bridge we must
	42	apply the swizzle function. */
	43
	44	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
691cd0c2 AB	45	/* Cope with illegal. */
691cd0c2 AB	46	if (pin > 4)
1da177e4 LT	47	pin = 1;
1da177e4 LT	48
47a650f2	49	if (pin) {
691cd0c2	50	/* Follow the chain of bridges, swizzling as we go. */
47a650f2 MM	51	if (hbrg->swizzle_irq)
47a650f2 MM	52	slot = (*(hbrg->swizzle_irq))(dev, &pin);
1da177e4	53
47a650f2 MM	54	/*
	55	* If a swizzling function is not used map_irq must
	56	* ignore slot
	57	*/
	58	irq = (*(hbrg->map_irq))(dev, slot, pin);
691cd0c2 AB	59	if (irq == -1)
	60	irq = 0;
	61	}
1da177e4 LT	62	dev->irq = irq;
1da177e4 LT	63
47a650f2	64	dev_dbg(&dev->dev, "assign IRQ: got %d\n", dev->irq);
1da177e4 LT	65
	66	/* Always tell the device, so the driver knows what is
	67	the real IRQ to use; the device does not use it. */
	68	pcibios_update_irq(dev, irq);
	69	}
	70
3c78bc61 RD	71	void pci_fixup_irqs(u8 (swizzle)(struct pci_dev , u8 *),
3c78bc61 RD	72	int (map_irq)(const struct pci_dev , u8, u8))
1da177e4	73	{
47a650f2 MM	74	/*
	75	* Implement pci_fixup_irqs() through pci_assign_irq().
	76	* This code should be remove eventually, it is a wrapper
	77	* around pci_assign_irq() interface to keep current
	78	* pci_fixup_irqs() behaviour unchanged on architecture
	79	* code still relying on its interface.
	80	*/
1da177e4	81	struct pci_dev *dev = NULL;
47a650f2	82	struct pci_host_bridge *hbrg = NULL;
3c78bc61	83
47a650f2 MM	84	for_each_pci_dev(dev) {
	85	hbrg = pci_find_host_bridge(dev->bus);
	86	hbrg->swizzle_irq = swizzle;
	87	hbrg->map_irq = map_irq;
	88	pci_assign_irq(dev);
	89	hbrg->swizzle_irq = NULL;
	90	hbrg->map_irq = NULL;
	91	}
1da177e4	92	}
e6b29dea	93	EXPORT_SYMBOL_GPL(pci_fixup_irqs);