/* $Id: pci.c,v 1.6 2000/01/29 00:12:05 grundler Exp $
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1997, 1998 Ralf Baechle
 * Copyright (C) 1999 SuSE GmbH
 * Copyright (C) 1999-2001 Hewlett-Packard Company
 * Copyright (C) 1999-2001 Grant Grundler
 */
#include <linux/config.h>
#include <linux/eisa.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/types.h>

#include <asm/io.h>
#include <asm/system.h>
#include <asm/cache.h>		/* for L1_CACHE_BYTES */
#include <asm/superio.h>

#define DEBUG_RESOURCES 0
#define DEBUG_CONFIG 0

#if DEBUG_CONFIG
# define DBGC(x...)	printk(KERN_DEBUG x)
#else
# define DBGC(x...)
#endif


#if DEBUG_RESOURCES
#define DBG_RES(x...)	printk(KERN_DEBUG x)
#else
#define DBG_RES(x...)
#endif

/* To be used as: mdelay(pci_post_reset_delay);
 *
 * post_reset is the time the kernel should stall to prevent anyone from
 * accessing the PCI bus once #RESET is de-asserted. 
 * PCI spec somewhere says 1 second but with multi-PCI bus systems,
 * this makes the boot time much longer than necessary.
 * 20ms seems to work for all the HP PCI implementations to date.
 *
 * XXX: turn into a #defined constant in <asm/pci.h> ?
 */
int pci_post_reset_delay = 50;

struct pci_port_ops *pci_port;
struct pci_bios_ops *pci_bios;

int pci_hba_count = 0;

/* parisc_pci_hba used by pci_port->in/out() ops to lookup bus data.  */
#define PCI_HBA_MAX 32
struct pci_hba_data *parisc_pci_hba[PCI_HBA_MAX];


/********************************************************************
**
** I/O port space support
**
*********************************************************************/

/* EISA port numbers and PCI port numbers share the same interface.  Some
 * machines have both EISA and PCI adapters installed.  Rather than turn
 * pci_port into an array, we reserve bus 0 for EISA and call the EISA
 * routines if the access is to a port on bus 0.  We don't want to fix
 * EISA and ISA drivers which assume port space is <= 0xffff.
 */

#ifdef CONFIG_EISA
#define EISA_IN(size) if (EISA_bus && (b == 0)) return eisa_in##size(addr)
#define EISA_OUT(size) if (EISA_bus && (b == 0)) return eisa_out##size(d, addr)
#else
#define EISA_IN(size)
#define EISA_OUT(size)
#endif

#define PCI_PORT_IN(type, size) \
u##size in##type (int addr) \
{ \
	int b = PCI_PORT_HBA(addr); \
	EISA_IN(size); \
	if (!parisc_pci_hba[b]) return (u##size) -1; \
	return pci_port->in##type(parisc_pci_hba[b], PCI_PORT_ADDR(addr)); \
} \
EXPORT_SYMBOL(in##type);

PCI_PORT_IN(b,  8)
PCI_PORT_IN(w, 16)
PCI_PORT_IN(l, 32)


#define PCI_PORT_OUT(type, size) \
void out##type (u##size d, int addr) \
{ \
	int b = PCI_PORT_HBA(addr); \
	EISA_OUT(size); \
	if (!parisc_pci_hba[b]) return; \
	pci_port->out##type(parisc_pci_hba[b], PCI_PORT_ADDR(addr), d); \
} \
EXPORT_SYMBOL(out##type);

PCI_PORT_OUT(b,  8)
PCI_PORT_OUT(w, 16)
PCI_PORT_OUT(l, 32)


/*
 * BIOS32 replacement.
 */
static int __init pcibios_init(void)
{
	if (!pci_bios)
		return -1;

	if (pci_bios->init) {
		pci_bios->init();
	} else {
		printk(KERN_WARNING "pci_bios != NULL but init() is!\n");
	}
	return 0;
}


/* Called from pci_do_scan_bus() *after* walking a bus but before walking PPBs. */
void pcibios_fixup_bus(struct pci_bus *bus)
{
	if (pci_bios->fixup_bus) {
		pci_bios->fixup_bus(bus);
	} else {
		printk(KERN_WARNING "pci_bios != NULL but fixup_bus() is!\n");
	}
}


char *pcibios_setup(char *str)
{
	return str;
}

/*
 * Called by pci_set_master() - a driver interface.
 *
 * Legacy PDC guarantees to set:
 *	Map Memory BAR's into PA IO space.
 *	Map Expansion ROM BAR into one common PA IO space per bus.
 *	Map IO BAR's into PCI IO space.
 *	Command (see below)
 *	Cache Line Size
 *	Latency Timer
 *	Interrupt Line
 *	PPB: secondary latency timer, io/mmio base/limit,
 *		bus numbers, bridge control
 *
 */
void pcibios_set_master(struct pci_dev *dev)
{
	u8 lat;

	/* If someone already mucked with this, don't touch it. */
	pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
	if (lat >= 16) return;

	/*
	** HP generally has fewer devices on the bus than other architectures.
	** upper byte is PCI_LATENCY_TIMER.
	*/
	pci_write_config_word(dev, PCI_CACHE_LINE_SIZE,
				(0x80 << 8) | (L1_CACHE_BYTES / sizeof(u32)));
}


void __init pcibios_init_bus(struct pci_bus *bus)
{
	struct pci_dev *dev = bus->self;
	unsigned short bridge_ctl;

	/* We deal only with pci controllers and pci-pci bridges. */
	if (!dev || (dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
		return;

	/* PCI-PCI bridge - set the cache line and default latency
	   (32) for primary and secondary buses. */
	pci_write_config_byte(dev, PCI_SEC_LATENCY_TIMER, 32);

	pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bridge_ctl);
	bridge_ctl |= PCI_BRIDGE_CTL_PARITY | PCI_BRIDGE_CTL_SERR;
	pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bridge_ctl);
}


/* KLUGE: Link the child and parent resources - generic PCI didn't */
static void
pcibios_link_hba_resources( struct resource *hba_res, struct resource *r)
{
	if (!r->parent) {
		printk(KERN_EMERG "PCI: Tell willy he's wrong\n");
		r->parent = hba_res;

		/* reverse link is harder *sigh*  */
		if (r->parent->child) {
			if (r->parent->sibling) {
				struct resource *next = r->parent->sibling;
				while (next->sibling)
					 next = next->sibling;
				next->sibling = r;
			} else {
				r->parent->sibling = r;
			}
		} else
			r->parent->child = r;
	}
}

/* called by drivers/pci/setup-bus.c:pci_setup_bridge().  */
void __devinit pcibios_resource_to_bus(struct pci_dev *dev,
		struct pci_bus_region *region, struct resource *res)
{
	struct pci_bus *bus = dev->bus;
	struct pci_hba_data *hba = HBA_DATA(bus->bridge->platform_data);

	if (res->flags & IORESOURCE_IO) {
		/*
		** I/O space may see busnumbers here. Something
		** in the form of 0xbbxxxx where bb is the bus num
		** and xxxx is the I/O port space address.
		** Remaining address translation are done in the
		** PCI Host adapter specific code - ie dino_out8.
		*/
		region->start = PCI_PORT_ADDR(res->start);
		region->end   = PCI_PORT_ADDR(res->end);
	} else if (res->flags & IORESOURCE_MEM) {
		/* Convert MMIO addr to PCI addr (undo global virtualization) */
		region->start = PCI_BUS_ADDR(hba, res->start);
		region->end   = PCI_BUS_ADDR(hba, res->end);
	}

	DBG_RES("pcibios_resource_to_bus(%02x %s [%lx,%lx])\n",
		bus->number, res->flags & IORESOURCE_IO ? "IO" : "MEM",
		region->start, region->end);

	/* KLUGE ALERT
	** if this resource isn't linked to a "parent", then it seems
	** to be a child of the HBA - lets link it in.
	*/
	pcibios_link_hba_resources(&hba->io_space, bus->resource[0]);
	pcibios_link_hba_resources(&hba->lmmio_space, bus->resource[1]);
}

#ifdef CONFIG_HOTPLUG
EXPORT_SYMBOL(pcibios_resource_to_bus);
#endif

/*
 * pcibios align resources() is called every time generic PCI code
 * wants to generate a new address. The process of looking for
 * an available address, each candidate is first "aligned" and
 * then checked if the resource is available until a match is found.
 *
 * Since we are just checking candidates, don't use any fields other
 * than res->start.
 */
void pcibios_align_resource(void *data, struct resource *res,
				unsigned long size, unsigned long alignment)
{
	unsigned long mask, align;

	DBG_RES("pcibios_align_resource(%s, (%p) [%lx,%lx]/%x, 0x%lx, 0x%lx)\n",
		pci_name(((struct pci_dev *) data)),
		res->parent, res->start, res->end,
		(int) res->flags, size, alignment);

	/* If it's not IO, then it's gotta be MEM */
	align = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;

	/* Align to largest of MIN or input size */
	mask = max(alignment, align) - 1;
	res->start += mask;
	res->start &= ~mask;

	/* The caller updates the end field, we don't.  */
}


/*
 * A driver is enabling the device.  We make sure that all the appropriate
 * bits are set to allow the device to operate as the driver is expecting.
 * We enable the port IO and memory IO bits if the device has any BARs of
 * that type, and we enable the PERR and SERR bits unconditionally.
 * Drivers that do not need parity (eg graphics and possibly networking)
 * can clear these bits if they want.
 */
int pcibios_enable_device(struct pci_dev *dev, int mask)
{
	u16 cmd;
	int idx;

	pci_read_config_word(dev, PCI_COMMAND, &cmd);

	for (idx = 0; idx < DEVICE_COUNT_RESOURCE; idx++) {
		struct resource *r = &dev->resource[idx];

		/* only setup requested resources */
		if (!(mask & (1<<idx)))
			continue;

		if (r->flags & IORESOURCE_IO)
			cmd |= PCI_COMMAND_IO;
		if (r->flags & IORESOURCE_MEM)
			cmd |= PCI_COMMAND_MEMORY;
	}

	cmd |= (PCI_COMMAND_SERR | PCI_COMMAND_PARITY);

#if 0
	/* If bridge/bus controller has FBB enabled, child must too. */
	if (dev->bus->bridge_ctl & PCI_BRIDGE_CTL_FAST_BACK)
		cmd |= PCI_COMMAND_FAST_BACK;
#endif
	DBGC("PCIBIOS: Enabling device %s cmd 0x%04x\n", pci_name(dev), cmd);
	pci_write_config_word(dev, PCI_COMMAND, cmd);
	return 0;
}


/* PA-RISC specific */
void pcibios_register_hba(struct pci_hba_data *hba)
{
	if (pci_hba_count >= PCI_HBA_MAX) {
		printk(KERN_ERR "PCI: Too many Host Bus Adapters\n");
		return;
	}

	parisc_pci_hba[pci_hba_count] = hba;
	hba->hba_num = pci_hba_count++;
}

subsys_initcall(pcibios_init);