swh:1:snp:c2847dfd741eae21606027cf29250d1ebcd63fb4
Tip revision: 9f4ad9e425a1d3b6a34617b8ea226d56a119a717 authored by Linus Torvalds on 25 April 2021, 20:49:08 UTC
Linux 5.12
Linux 5.12
Tip revision: 9f4ad9e
ops-rc32434.c
/*
* BRIEF MODULE DESCRIPTION
* pci_ops for IDT EB434 board
*
* Copyright 2004 IDT Inc. (rischelp@idt.com)
* Copyright 2006 Felix Fietkau <nbd@openwrt.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
* NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* 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.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/pci.h>
#include <linux/types.h>
#include <asm/cpu.h>
#include <asm/mach-rc32434/rc32434.h>
#include <asm/mach-rc32434/pci.h>
#define PCI_ACCESS_READ 0
#define PCI_ACCESS_WRITE 1
#define PCI_CFG_SET(bus, slot, func, off) \
(rc32434_pci->pcicfga = (0x80000000 | \
((bus) << 16) | ((slot)<<11) | \
((func)<<8) | (off)))
static inline int config_access(unsigned char access_type,
struct pci_bus *bus, unsigned int devfn,
unsigned char where, u32 *data)
{
unsigned int slot = PCI_SLOT(devfn);
u8 func = PCI_FUNC(devfn);
/* Setup address */
PCI_CFG_SET(bus->number, slot, func, where);
rc32434_sync();
if (access_type == PCI_ACCESS_WRITE)
rc32434_pci->pcicfgd = *data;
else
*data = rc32434_pci->pcicfgd;
rc32434_sync();
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 read_config_byte(struct pci_bus *bus, unsigned int devfn,
int where, u8 *val)
{
u32 data;
int ret;
ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
*val = (data >> ((where & 3) << 3)) & 0xff;
return ret;
}
static int read_config_word(struct pci_bus *bus, unsigned int devfn,
int where, u16 *val)
{
u32 data;
int ret;
ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
*val = (data >> ((where & 3) << 3)) & 0xffff;
return ret;
}
static int read_config_dword(struct pci_bus *bus, unsigned int devfn,
int where, u32 *val)
{
int ret;
int delay = 1;
/*
* Don't scan too far, else there will be errors with plugged in
* daughterboard (rb564).
*/
if (bus->number == 0 && PCI_SLOT(devfn) > 21)
return 0;
retry:
ret = config_access(PCI_ACCESS_READ, bus, devfn, where, val);
/*
* Certain devices react delayed at device scan time, this
* gives them time to settle
*/
if (where == PCI_VENDOR_ID) {
if (ret == 0xffffffff || ret == 0x00000000 ||
ret == 0x0000ffff || ret == 0xffff0000) {
if (delay > 4)
return 0;
delay *= 2;
msleep(delay);
goto retry;
}
}
return ret;
}
static int
write_config_byte(struct pci_bus *bus, unsigned int devfn, int where,
u8 val)
{
u32 data = 0;
if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
return -1;
data = (data & ~(0xff << ((where & 3) << 3))) |
(val << ((where & 3) << 3));
if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
return -1;
return PCIBIOS_SUCCESSFUL;
}
static int
write_config_word(struct pci_bus *bus, unsigned int devfn, int where,
u16 val)
{
u32 data = 0;
if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
return -1;
data = (data & ~(0xffff << ((where & 3) << 3))) |
(val << ((where & 3) << 3));
if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
return -1;
return PCIBIOS_SUCCESSFUL;
}
static int
write_config_dword(struct pci_bus *bus, unsigned int devfn, int where,
u32 val)
{
if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &val))
return -1;
return PCIBIOS_SUCCESSFUL;
}
static int pci_config_read(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
switch (size) {
case 1:
return read_config_byte(bus, devfn, where, (u8 *) val);
case 2:
return read_config_word(bus, devfn, where, (u16 *) val);
default:
return read_config_dword(bus, devfn, where, val);
}
}
static int pci_config_write(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val)
{
switch (size) {
case 1:
return write_config_byte(bus, devfn, where, (u8) val);
case 2:
return write_config_word(bus, devfn, where, (u16) val);
default:
return write_config_dword(bus, devfn, where, val);
}
}
struct pci_ops rc32434_pci_ops = {
.read = pci_config_read,
.write = pci_config_write,
};