https://github.com/torvalds/linux
Tip revision: de9c2c66ad8e787abec7c9d7eff4f8c3cdd28aed authored by Linus Torvalds on 04 August 2024, 20:50:53 UTC
Linux 6.11-rc2
Linux 6.11-rc2
Tip revision: de9c2c6
ops-msc.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 1999, 2000, 2004, 2005 MIPS Technologies, Inc.
* All rights reserved.
* Authors: Carsten Langgaard <carstenl@mips.com>
* Maciej W. Rozycki <macro@mips.com>
* Copyright (C) 2005 Ralf Baechle (ralf@linux-mips.org)
*
* MIPS boards specific PCI support.
*/
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <asm/mips-boards/msc01_pci.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 msc_pcibios_config_access(unsigned char access_type,
struct pci_bus *bus, unsigned int devfn, int where, u32 * data)
{
unsigned char busnum = bus->number;
u32 intr;
/* Clear status register bits. */
MSC_WRITE(MSC01_PCI_INTSTAT,
(MSC01_PCI_INTCFG_MA_BIT | MSC01_PCI_INTCFG_TA_BIT));
MSC_WRITE(MSC01_PCI_CFGADDR,
((busnum << MSC01_PCI_CFGADDR_BNUM_SHF) |
(PCI_SLOT(devfn) << MSC01_PCI_CFGADDR_DNUM_SHF) |
(PCI_FUNC(devfn) << MSC01_PCI_CFGADDR_FNUM_SHF) |
((where / 4) << MSC01_PCI_CFGADDR_RNUM_SHF)));
/* Perform access */
if (access_type == PCI_ACCESS_WRITE)
MSC_WRITE(MSC01_PCI_CFGDATA, *data);
else
MSC_READ(MSC01_PCI_CFGDATA, *data);
/* Detect Master/Target abort */
MSC_READ(MSC01_PCI_INTSTAT, intr);
if (intr & (MSC01_PCI_INTCFG_MA_BIT | MSC01_PCI_INTCFG_TA_BIT)) {
/* Error occurred */
/* Clear bits */
MSC_WRITE(MSC01_PCI_INTSTAT,
(MSC01_PCI_INTCFG_MA_BIT | MSC01_PCI_INTCFG_TA_BIT));
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 msc_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 (msc_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 msc_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 (msc_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 (msc_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn, where,
&data))
return -1;
return PCIBIOS_SUCCESSFUL;
}
struct pci_ops msc_pci_ops = {
.read = msc_pcibios_read,
.write = msc_pcibios_write
};