xref: /kernel/linux/linux-5.10/arch/mips/pci/ops-lantiq.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 *  Copyright (C) 2010 John Crispin <john@phrozen.org>
 */

#include <linux/types.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <asm/addrspace.h>
#include <linux/vmalloc.h>

#include <lantiq_soc.h>

#include "pci-lantiq.h"

#define LTQ_PCI_CFG_BUSNUM_SHF 16
#define LTQ_PCI_CFG_DEVNUM_SHF 11
#define LTQ_PCI_CFG_FUNNUM_SHF 8

#define PCI_ACCESS_READ	 0
#define PCI_ACCESS_WRITE 1

static int ltq_pci_config_access(unsigned char access_type, struct pci_bus *bus,
	unsigned int devfn, unsigned int where, u32 *data)
{
	unsigned long cfg_base;
	unsigned long flags;
	u32 temp;

	/* we support slot from 0 to 15 dev_fn & 0x68 (AD29) is the
	   SoC itself */
	if ((bus->number != 0) || ((devfn & 0xf8) > 0x78)
		|| ((devfn & 0xf8) == 0) || ((devfn & 0xf8) == 0x68))
		return 1;

	spin_lock_irqsave(&ebu_lock, flags);

	cfg_base = (unsigned long) ltq_pci_mapped_cfg;
	cfg_base |= (bus->number << LTQ_PCI_CFG_BUSNUM_SHF) | (devfn <<
			LTQ_PCI_CFG_FUNNUM_SHF) | (where & ~0x3);

	/* Perform access */
	if (access_type == PCI_ACCESS_WRITE) {
		ltq_w32(swab32(*data), ((u32 *)cfg_base));
	} else {
		*data = ltq_r32(((u32 *)(cfg_base)));
		*data = swab32(*data);
	}
	wmb();

	/* clean possible Master abort */
	cfg_base = (unsigned long) ltq_pci_mapped_cfg;
	cfg_base |= (0x0 << LTQ_PCI_CFG_FUNNUM_SHF) + 4;
	temp = ltq_r32(((u32 *)(cfg_base)));
	temp = swab32(temp);
	cfg_base = (unsigned long) ltq_pci_mapped_cfg;
	cfg_base |= (0x68 << LTQ_PCI_CFG_FUNNUM_SHF) + 4;
	ltq_w32(temp, ((u32 *)cfg_base));

	spin_unlock_irqrestore(&ebu_lock, flags);

	if (((*data) == 0xffffffff) && (access_type == PCI_ACCESS_READ))
		return 1;

	return 0;
}

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

	if (ltq_pci_config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
		return PCIBIOS_DEVICE_NOT_FOUND;

	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;
}

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

	if (size == 4) {
		data = val;
	} else {
		if (ltq_pci_config_access(PCI_ACCESS_READ, bus,
				devfn, where, &data))
			return PCIBIOS_DEVICE_NOT_FOUND;

		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 (ltq_pci_config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
		return PCIBIOS_DEVICE_NOT_FOUND;

	return PCIBIOS_SUCCESSFUL;
}