/* * This file is part of the coreboot project. * * Copyright (C) 2011 Google Inc * * 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; version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #define __SIMPLE_DEVICE__ #include <arch/io.h> #include <device/pci.h> #include <device/pci_def.h> #include <delay.h> #ifdef __PRE_RAM__ unsigned pci_find_next_capability(pci_devfn_t dev, unsigned cap, unsigned last) { unsigned pos = 0; u16 status; unsigned reps = 48; status = pci_read_config16(dev, PCI_STATUS); if (!(status & PCI_STATUS_CAP_LIST)) return 0; u8 hdr_type = pci_read_config8(dev, PCI_HEADER_TYPE); switch (hdr_type & 0x7f) { case PCI_HEADER_TYPE_NORMAL: case PCI_HEADER_TYPE_BRIDGE: pos = PCI_CAPABILITY_LIST; break; case PCI_HEADER_TYPE_CARDBUS: pos = PCI_CB_CAPABILITY_LIST; break; default: return 0; } pos = pci_read_config8(dev, pos); while (reps-- && (pos >= 0x40)) { /* Loop through the linked list. */ int this_cap; pos &= ~3; this_cap = pci_read_config8(dev, pos + PCI_CAP_LIST_ID); if (this_cap == 0xff) break; if (!last && (this_cap == cap)) return pos; if (last == pos) last = 0; pos = pci_read_config8(dev, pos + PCI_CAP_LIST_NEXT); } return 0; } unsigned pci_find_capability(pci_devfn_t dev, unsigned cap) { return pci_find_next_capability(dev, cap, 0); } #endif /* __PRE_RAM__ */ #if CONFIG_EARLY_PCI_BRIDGE static void pci_bridge_reset_secondary(device_t p2p_bridge) { u16 reg16; /* First we reset the secondary bus. */ reg16 = pci_read_config16(p2p_bridge, PCI_BRIDGE_CONTROL); reg16 |= (1 << 6); /* SRESET */ pci_write_config16(p2p_bridge, PCI_BRIDGE_CONTROL, reg16); /* Assume we don't have to wait here forever */ /* Read back and clear reset bit. */ reg16 = pci_read_config16(p2p_bridge, PCI_BRIDGE_CONTROL); reg16 &= ~(1 << 6); /* SRESET */ pci_write_config16(p2p_bridge, PCI_BRIDGE_CONTROL, reg16); } static void pci_bridge_set_secondary(device_t p2p_bridge, u8 secondary) { /* Disable config transaction forwarding. */ pci_write_config8(p2p_bridge, PCI_SECONDARY_BUS, 0x00); pci_write_config8(p2p_bridge, PCI_SUBORDINATE_BUS, 0x00); /* Enable config transaction forwarding. */ pci_write_config8(p2p_bridge, PCI_SECONDARY_BUS, secondary); pci_write_config8(p2p_bridge, PCI_SUBORDINATE_BUS, secondary); } static void pci_bridge_set_mmio(device_t p2p_bridge, u32 base, u32 size) { u16 reg16; /* Disable MMIO window behind the bridge. */ reg16 = pci_read_config16(p2p_bridge, PCI_COMMAND); reg16 &= ~PCI_COMMAND_MEMORY; pci_write_config16(p2p_bridge, PCI_COMMAND, reg16); pci_write_config32(p2p_bridge, PCI_MEMORY_BASE, 0x10); if (!size) return; /* Enable MMIO window behind the bridge. */ pci_write_config32(p2p_bridge, PCI_MEMORY_BASE, ((base + size - 1) & 0xfff00000) | ((base >> 16) & 0xfff0)); reg16 = pci_read_config16(p2p_bridge, PCI_COMMAND); reg16 |= PCI_COMMAND_MEMORY; pci_write_config16(p2p_bridge, PCI_COMMAND, reg16); } void pci_early_bridge_init(void) { int timeout, ret = -1; /* No PCI-to-PCI bridges are enabled yet, so the one we try to * configure must have its primary on bus 0. */ pci_devfn_t p2p_bridge = PCI_DEV(0, CONFIG_EARLY_PCI_BRIDGE_DEVICE, CONFIG_EARLY_PCI_BRIDGE_FUNCTION); /* Secondary bus number is mostly irrelevant as we disable * configuration transactions right after the probe. */ u8 secondary = 15; u8 dev = 0; u32 mmio_base = CONFIG_EARLY_PCI_MMIO_BASE; /* Enable configuration and MMIO over bridge. */ pci_bridge_reset_secondary(p2p_bridge); pci_bridge_set_secondary(p2p_bridge, secondary); pci_bridge_set_mmio(p2p_bridge, mmio_base, 0x4000); for (timeout = 20000; timeout; timeout--) { u32 id = pci_read_config32(PCI_DEV(secondary, dev, 0), PCI_VENDOR_ID); if (id != 0 && id != 0xffffffff && id != 0xffff0001) break; udelay(10); } if (timeout != 0) ret = pci_early_device_probe(secondary, dev, mmio_base); /* Disable MMIO window if we found no suitable device. */ if (ret) pci_bridge_set_mmio(p2p_bridge, 0, 0); /* Resource allocator will reconfigure bridges and secondary bus * number may change. Thus early device cannot reliably use config * transactions from here on, so we may as well disable them. */ pci_bridge_set_secondary(p2p_bridge, 0); } #endif /* CONFIG_EARLY_PCI_BRIDGE */