PCI: Add capability list parser to romstage

These are almost one-to-one copies from pci_device.c. However,
devicetree has not been enumerated yet and we have no console.

Change-Id: Ic80c781626521d03adde05bdb1916acce31290ea
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/5196
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Aaron Durbin <adurbin@google.com>

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);
+}