/*
* pci.c -- PCI bus support for ColdFire processors
*
* (C) Copyright 2012, Greg Ungerer <gerg@uclinux.com>
*
* 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.
*/
#include <linux/types.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <asm/coldfire.h>
#include <asm/mcfsim.h>
#include <asm/m54xxpci.h>
/*
* Memory and IO mappings. We use a 1:1 mapping for local host memory to
* PCI bus memory (no reason not to really). IO space is mapped in its own
* separate address region. The device configuration space is mapped over
* the IO map space when we enable it in the PCICAR register.
*/
static struct pci_bus *rootbus;
static unsigned long iospace;
/*
* We need to be careful probing on bus 0 (directly connected to host
* bridge). We should only access the well defined possible devices in
* use, ignore aliases and the like.
*/
static unsigned char mcf_host_slot2sid[32] = {
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 1, 2, 0, 3, 4, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
};
static unsigned char mcf_host_irq[] = {
0, 69, 69, 71, 71,
};
/*
* Configuration space access functions. Configuration space access is
* through the IO mapping window, enabling it via the PCICAR register.
*/
static unsigned long mcf_mk_pcicar(int bus, unsigned int devfn, int where)
{
return (bus << PCICAR_BUSN) | (devfn << PCICAR_DEVFNN) | (where & 0xfc);
}
static int mcf_pci_readconfig(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *value)
{
unsigned long addr;
*value = 0xffffffff;
if (bus->number == 0) {
if (mcf_host_slot2sid[PCI_SLOT(devfn)] == 0)
return PCIBIOS_SUCCESSFUL;
}
addr = mcf_mk_pcicar(bus->number, devfn, where);
__raw_writel(PCICAR_E | addr, PCICAR);
__raw_readl(PCICAR);
addr = iospace + (where & 0x3);
switch (size) {
case 1:
*value = __raw_readb(addr);
break;
case 2:
*value = le16_to_cpu(__raw_readw(addr));
break;
default:
*value = le32_to_cpu(__raw_readl(addr));
break;
}
__raw_writel(0, PCICAR);
__raw_readl(PCICAR);
return PCIBIOS_SUCCESSFUL;
}
static int mcf_pci_writeconfig(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 value)
{
unsigned long addr;
if (bus->number == 0) {
if (mcf_host_slot2sid[PCI_SLOT(devfn)] == 0)
return PCIBIOS_SUCCESSFUL;
}
addr = mcf_mk_pcicar(bus->number, devfn, where);
__raw_writel(PCICAR_E | addr, PCICAR);
__raw_readl(PCICAR);
addr = iospace + (where & 0x3);
switch (size) {
case 1:
__raw_writeb(value, addr);
break;
case 2:
__raw_writew(cpu_to_le16(value), addr);
break;
default:
__raw_writel(cpu_to_le32(value), addr);
break;
}
__raw_writel(0, PCICAR);
__raw_readl(PCICAR);
return PCIBIOS_SUCCESSFUL;
}
static struct pci_ops mcf_pci_ops = {
.read = mcf_pci_readconfig,
.write = mcf_pci_writeconfig,
};
/*
* Initialize the PCI bus registers, and scan the bus.
*/
static struct resource mcf_pci_mem = {
.name = "PCI Memory space",
.start = PCI_MEM_PA,
.end = PCI_MEM_PA + PCI_MEM_SIZE - 1,
.flags = IORESOURCE_MEM,
};
static struct resource mcf_pci_io = {
.name = "PCI IO space",
.start = 0x400,
.end = 0x10000 - 1,
.flags = IORESOURCE_IO,
};
static struct resource busn_resource = {
.name = "PCI busn",
.start = 0,
.end = 255,
.flags = IORESOURCE_BUS,
};
/*
* Interrupt mapping and setting.
*/
static int mcf_pci_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
{
int sid;
sid = mcf_host_slot2sid[slot];
if (sid)
return mcf_host_irq[sid];
return 0;
}
static int __init mcf_pci_init(void)
{
struct pci_host_bridge *bridge;
int ret;
bridge = pci_alloc_host_bridge(0);
if (!bridge)
return -ENOMEM;
pr_info("ColdFire: PCI bus initialization...\n");
/* Reset the external PCI bus */
__raw_writel(PCIGSCR_RESET, PCIGSCR);
__raw_writel(0, PCITCR);
request_resource(&iomem_resource, &mcf_pci_mem);
request_resource(&iomem_resource, &mcf_pci_io);
/* Configure PCI arbiter */
__raw_writel(PACR_INTMPRI | PACR_INTMINTE | PACR_EXTMPRI(0x1f) |
PACR_EXTMINTE(0x1f), PACR);
/* Set required multi-function pins for PCI bus use */
__raw_writew(0x3ff, MCFGPIO_PAR_PCIBG);
__raw_writew(0x3ff, MCFGPIO_PAR_PCIBR);
/* Set up config space for local host bus controller */
__raw_writel(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
PCI_COMMAND_INVALIDATE, PCISCR);
__raw_writel(PCICR1_LT(32) | PCICR1_CL(8), PCICR1);
__raw_writel(0, PCICR2);
/*
* Set up the initiator windows for memory and IO mapping.
* These give the CPU bus access onto the PCI bus. One for each of
* PCI memory and IO address spaces.
*/
__raw_writel(WXBTAR(PCI_MEM_PA, PCI_MEM_BA, PCI_MEM_SIZE),
PCIIW0BTAR);
__raw_writel(WXBTAR(PCI_IO_PA, PCI_IO_BA, PCI_IO_SIZE),
PCIIW1BTAR);
__raw_writel(PCIIWCR_W0_MEM /*| PCIIWCR_W0_MRDL*/ | PCIIWCR_W0_E |
PCIIWCR_W1_IO | PCIIWCR_W1_E, PCIIWCR);
/*
* Set up the target windows for access from the PCI bus back to the
* CPU bus. All we need is access to system RAM (for mastering).
*/
__raw_writel(CONFIG_RAMBASE, PCIBAR1);
__raw_writel(CONFIG_RAMBASE | PCITBATR1_E, PCITBATR1);
/* Keep a virtual mapping to IO/config space active */
iospace = (unsigned long) ioremap(PCI_IO_PA, PCI_IO_SIZE);
if (iospace == 0) {
pci_free_host_bridge(bridge);
return -ENODEV;
}
pr_info("Coldfire: PCI IO/config window mapped to 0x%x\n",
(u32) iospace);
/* Turn of PCI reset, and wait for devices to settle */
__raw_writel(0, PCIGSCR);
set_current_state(TASK_UNINTERRUPTIBLE);
schedule_timeout(msecs_to_jiffies(200));
pci_add_resource(&bridge->windows, &ioport_resource);
pci_add_resource(&bridge->windows, &iomem_resource);
pci_add_resource(&bridge->windows, &busn_resource);
bridge->dev.parent = NULL;
bridge->sysdata = NULL;
bridge->busnr = 0;
bridge->ops = &mcf_pci_ops;
bridge->swizzle_irq = pci_common_swizzle;
bridge->map_irq = mcf_pci_map_irq;
ret = pci_scan_root_bus_bridge(bridge);
if (ret) {
pci_free_host_bridge(bridge);
return ret;
}
rootbus = bridge->bus;
rootbus->resource[0] = &mcf_pci_io;
rootbus->resource[1] = &mcf_pci_mem;
pci_bus_size_bridges(rootbus);
pci_bus_assign_resources(rootbus);
pci_bus_add_devices(rootbus);
return 0;
}
subsys_initcall(mcf_pci_init);