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Diffstat (limited to 'src/device/pci_early.c')
-rw-r--r--src/device/pci_early.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/src/device/pci_early.c b/src/device/pci_early.c
new file mode 100644
index 0000000000..c15a4d0f77
--- /dev/null
+++ b/src/device/pci_early.c
@@ -0,0 +1,68 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * 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.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
+ */
+
+#include <arch/io.h>
+#include <device/pci.h>
+#include <device/pci_def.h>
+
+unsigned pci_find_next_capability(device_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(device_t dev, unsigned cap)
+{
+ return pci_find_next_capability(dev, cap, 0);
+}