diff options
Diffstat (limited to 'arch/mips/pci/pci-bcm1480ht.c')
| -rw-r--r-- | arch/mips/pci/pci-bcm1480ht.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/arch/mips/pci/pci-bcm1480ht.c b/arch/mips/pci/pci-bcm1480ht.c new file mode 100644 index 000000000..3d996acd2 --- /dev/null +++ b/arch/mips/pci/pci-bcm1480ht.c @@ -0,0 +1,203 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2001,2002,2005 Broadcom Corporation + * Copyright (C) 2004 by Ralf Baechle (ralf@linux-mips.org) + */ + +/* + * BCM1480/1455-specific HT support (looking like PCI) + * + * This module provides the glue between Linux's PCI subsystem + * and the hardware. We basically provide glue for accessing + * configuration space, and set up the translation for I/O + * space accesses. + * + * To access configuration space, we use ioremap. In the 32-bit + * kernel, this consumes either 4 or 8 page table pages, and 16MB of + * kernel mapped memory. Hopefully neither of these should be a huge + * problem. + * + */ +#include <linux/types.h> +#include <linux/pci.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/mm.h> +#include <linux/console.h> +#include <linux/tty.h> + +#include <asm/sibyte/bcm1480_regs.h> +#include <asm/sibyte/bcm1480_scd.h> +#include <asm/sibyte/board.h> +#include <asm/io.h> + +/* + * Macros for calculating offsets into config space given a device + * structure or dev/fun/reg + */ +#define CFGOFFSET(bus, devfn, where) (((bus)<<16)+((devfn)<<8)+(where)) +#define CFGADDR(bus, devfn, where) CFGOFFSET((bus)->number, (devfn), where) + +static void *ht_cfg_space; + +#define PCI_BUS_ENABLED 1 +#define PCI_DEVICE_MODE 2 + +static int bcm1480ht_bus_status; + +#define PCI_BRIDGE_DEVICE 0 +#define HT_BRIDGE_DEVICE 1 + +/* + * HT's level-sensitive interrupts require EOI, which is generated + * through a 4MB memory-mapped region + */ +unsigned long ht_eoi_space; + +/* + * Read/write 32-bit values in config space. + */ +static inline u32 READCFG32(u32 addr) +{ + return *(u32 *)(ht_cfg_space + (addr&~3)); +} + +static inline void WRITECFG32(u32 addr, u32 data) +{ + *(u32 *)(ht_cfg_space + (addr & ~3)) = data; +} + +/* + * Some checks before doing config cycles: + * In PCI Device Mode, hide everything on bus 0 except the LDT host + * bridge. Otherwise, access is controlled by bridge MasterEn bits. + */ +static int bcm1480ht_can_access(struct pci_bus *bus, int devfn) +{ + u32 devno; + + if (!(bcm1480ht_bus_status & (PCI_BUS_ENABLED | PCI_DEVICE_MODE))) + return 0; + + if (bus->number == 0) { + devno = PCI_SLOT(devfn); + if (bcm1480ht_bus_status & PCI_DEVICE_MODE) + return 0; + } + return 1; +} + +/* + * Read/write access functions for various sizes of values + * in config space. Return all 1's for disallowed accesses + * for a kludgy but adequate simulation of master aborts. + */ + +static int bcm1480ht_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 (bcm1480ht_can_access(bus, devfn)) + data = READCFG32(CFGADDR(bus, devfn, where)); + else + data = 0xFFFFFFFF; + + 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 bcm1480ht_pcibios_write(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 val) +{ + u32 cfgaddr = CFGADDR(bus, devfn, where); + 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 (!bcm1480ht_can_access(bus, devfn)) + return PCIBIOS_BAD_REGISTER_NUMBER; + + data = READCFG32(cfgaddr); + + 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)); + else + data = val; + + WRITECFG32(cfgaddr, data); + + return PCIBIOS_SUCCESSFUL; +} + +static int bcm1480ht_pcibios_get_busno(void) +{ + return 0; +} + +struct pci_ops bcm1480ht_pci_ops = { + .read = bcm1480ht_pcibios_read, + .write = bcm1480ht_pcibios_write, +}; + +static struct resource bcm1480ht_mem_resource = { + .name = "BCM1480 HT MEM", + .start = A_BCM1480_PHYS_HT_MEM_MATCH_BYTES, + .end = A_BCM1480_PHYS_HT_MEM_MATCH_BYTES + 0x1fffffffUL, + .flags = IORESOURCE_MEM, +}; + +static struct resource bcm1480ht_io_resource = { + .name = "BCM1480 HT I/O", + .start = A_BCM1480_PHYS_HT_IO_MATCH_BYTES, + .end = A_BCM1480_PHYS_HT_IO_MATCH_BYTES + 0x01ffffffUL, + .flags = IORESOURCE_IO, +}; + +struct pci_controller bcm1480ht_controller = { + .pci_ops = &bcm1480ht_pci_ops, + .mem_resource = &bcm1480ht_mem_resource, + .io_resource = &bcm1480ht_io_resource, + .index = 1, + .get_busno = bcm1480ht_pcibios_get_busno, + .io_offset = A_BCM1480_PHYS_HT_IO_MATCH_BYTES, +}; + +static int __init bcm1480ht_pcibios_init(void) +{ + ht_cfg_space = ioremap(A_BCM1480_PHYS_HT_CFG_MATCH_BITS, 16*1024*1024); + + /* CFE doesn't always init all HT paths, so we always scan */ + bcm1480ht_bus_status |= PCI_BUS_ENABLED; + + ht_eoi_space = (unsigned long) + ioremap(A_BCM1480_PHYS_HT_SPECIAL_MATCH_BYTES, + 4 * 1024 * 1024); + bcm1480ht_controller.io_map_base = (unsigned long) + ioremap(A_BCM1480_PHYS_HT_IO_MATCH_BYTES, 65536); + bcm1480ht_controller.io_map_base -= bcm1480ht_controller.io_offset; + + register_pci_controller(&bcm1480ht_controller); + + return 0; +} + +arch_initcall(bcm1480ht_pcibios_init); |