arch/mips/pci/ops-bonito64.c

/*
 * Carsten Langgaard, carstenl@mips.com
 * Copyright (C) 1999, 2000 MIPS Technologies, Inc.  All rights reserved.
 *
 *  This program is free software; you can distribute it and/or modify it
 *  under the terms of the GNU General Public License (Version 2) as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope 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.,
 *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * MIPS boards specific PCI support.
 */
#include <linux/config.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/init.h>

#include <asm/mips-boards/bonito64.h>

#define PCI_ACCESS_READ  0
#define PCI_ACCESS_WRITE 1

/*
 *  PCI configuration cycle AD bus definition
 */
/* Type 0 */
#define PCI_CFG_TYPE0_REG_SHF           0
#define PCI_CFG_TYPE0_FUNC_SHF          8

/* Type 1 */
#define PCI_CFG_TYPE1_REG_SHF           0
#define PCI_CFG_TYPE1_FUNC_SHF          8
#define PCI_CFG_TYPE1_DEV_SHF           11
#define PCI_CFG_TYPE1_BUS_SHF           16

static int bonito64_pcibios_config_access(unsigned char access_type,
				      struct pci_bus *bus,
				      unsigned int devfn, int where,
				      u32 * data)
{
	unsigned char busnum = bus->number;
	u32 dummy;
	u64 pci_addr;

	/* Algorithmics Bonito64 system controller. */

	if ((busnum == 0) && (PCI_SLOT(devfn) > 21)) {
		/* We number bus 0 devices from 0..21 */
		return -1;
	}

#ifdef CONFIG_MIPS_BOARDS_GEN
	if ((busnum == 0) && (PCI_SLOT(devfn) == 17)) {
		/* MIPS Core boards have Bonito connected as device 17 */
		return -1;
	}
#endif

	/* Clear cause register bits */
	BONITO_PCICMD |= (BONITO_PCICMD_MABORT_CLR |
			  BONITO_PCICMD_MTABORT_CLR);

	/*
	 * Setup pattern to be used as PCI "address" for
	 * Type 0 cycle
	 */
	if (busnum == 0) {
		/* IDSEL */
		pci_addr = (u64) 1 << (PCI_SLOT(devfn) + 10);
	} else {
		/* Bus number */
		pci_addr = busnum << PCI_CFG_TYPE1_BUS_SHF;

		/* Device number */
		pci_addr |=
		    PCI_SLOT(devfn) << PCI_CFG_TYPE1_DEV_SHF;
	}

	/* Function (same for Type 0/1) */
	pci_addr |= PCI_FUNC(devfn) << PCI_CFG_TYPE0_FUNC_SHF;

	/* Register number (same for Type 0/1) */
	pci_addr |= (where & ~0x3) << PCI_CFG_TYPE0_REG_SHF;

	if (busnum == 0) {
		/* Type 0 */
		BONITO_PCIMAP_CFG = pci_addr >> 16;
	} else {
		/* Type 1 */
		BONITO_PCIMAP_CFG = (pci_addr >> 16) | 0x10000;
	}

	pci_addr &= 0xffff;

	/* Flush Bonito register block */
	dummy = BONITO_PCIMAP_CFG;
	iob();		/* sync */

	/* Perform access */
	if (access_type == PCI_ACCESS_WRITE) {
		*(volatile u32 *) (_pcictrl_bonito_pcicfg + (u32)pci_addr) = *(u32 *) data;

		/* Wait till done */
		while (BONITO_PCIMSTAT & 0xF);
	} else {
		*(u32 *) data = *(volatile u32 *) (_pcictrl_bonito_pcicfg + (u32)pci_addr);
	}

	/* Detect Master/Target abort */
	if (BONITO_PCICMD & (BONITO_PCICMD_MABORT_CLR |
			     BONITO_PCICMD_MTABORT_CLR)) {
		/* Error occurred */

		/* Clear bits */
		BONITO_PCICMD |= (BONITO_PCICMD_MABORT_CLR |
				  BONITO_PCICMD_MTABORT_CLR);

		return -1;
	}

	return 0;
}


/*
 * We can't address 8 and 16 bit words directly.  Instead we have to
 * read/write a 32bit word and mask/modify the data we actually want.
 */
static int bonito64_pcibios_read(struct pci_bus *bus, unsigned int devfn,
			     int where, int size, u32 * val)
{
	u32 data = 0;

	if ((size == 2) && (where & 1))
		return PCIBIOS_BAD_REGISTER_NUMBER;
	else if ((size == 4) && (where & 3))
		return PCIBIOS_BAD_REGISTER_NUMBER;

	if (bonito64_pcibios_config_access(PCI_ACCESS_READ, bus, devfn, where,
				       &data))
		return -1;

	if (size == 1)
		*val = (data >> ((where & 3) << 3)) & 0xff;
	else if (size == 2)
		*val = (data >> ((where & 3) << 3)) & 0xffff;
	else
		*val = data;

	return PCIBIOS_SUCCESSFUL;
}

static int bonito64_pcibios_write(struct pci_bus *bus, unsigned int devfn,
			      int where, int size, u32 val)
{
	u32 data = 0;

	if ((size == 2) && (where & 1))
		return PCIBIOS_BAD_REGISTER_NUMBER;
	else if ((size == 4) && (where & 3))
		return PCIBIOS_BAD_REGISTER_NUMBER;

	if (size == 4)
		data = val;
	else {
		if (bonito64_pcibios_config_access(PCI_ACCESS_READ, bus, devfn,
		                               where, &data))
			return -1;

		if (size == 1)
			data = (data & ~(0xff << ((where & 3) << 3))) |
				(val << ((where & 3) << 3));
		else if (size == 2)
			data = (data & ~(0xffff << ((where & 3) << 3))) |
				(val << ((where & 3) << 3));
	}

	if (bonito64_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn, where,
				       &data))
		return -1;

	return PCIBIOS_SUCCESSFUL;
}

struct pci_ops bonito64_pci_ops = {
	.read = bonito64_pcibios_read,
	.write = bonito64_pcibios_write
};