From 9ea8a2daa7ffd489898318c038fcfd7edc810adc Mon Sep 17 00:00:00 2001
From: Michael Brown
Date: Fri, 8 May 2015 16:51:12 +0100
Subject: [ehci] Allow UHCI/OHCI controllers to locate the EHCI companion
 controller

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---
 src/drivers/usb/ehci.c | 26 ++++++++++++++++++++++++++
 src/drivers/usb/ehci.h |  2 ++
 2 files changed, 28 insertions(+)

(limited to 'src/drivers')

diff --git a/src/drivers/usb/ehci.c b/src/drivers/usb/ehci.c
index e847c6b75..516ffd8c1 100644
--- a/src/drivers/usb/ehci.c
+++ b/src/drivers/usb/ehci.c
@@ -337,6 +337,32 @@ static void ehci_poll_companions ( struct ehci_device *ehci ) {
 	}
 }
 
+/**
+ * Locate EHCI companion controller
+ *
+ * @v pci		PCI device
+ * @ret busdevfn	EHCI companion controller bus:dev.fn (if any)
+ */
+unsigned int ehci_companion ( struct pci_device *pci ) {
+	struct pci_device tmp;
+	unsigned int busdevfn;
+	int rc;
+
+	/* Look for an EHCI function on the same PCI device */
+	busdevfn = pci->busdevfn;
+	while ( ++busdevfn <= PCI_LAST_FUNC ( pci->busdevfn ) ) {
+		pci_init ( &tmp, busdevfn );
+		if ( ( rc = pci_read_config ( &tmp ) ) != 0 )
+			continue;
+		if ( tmp.class == PCI_CLASS ( PCI_CLASS_SERIAL,
+					      PCI_CLASS_SERIAL_USB,
+					      PCI_CLASS_SERIAL_USB_EHCI ) )
+			return busdevfn;
+	}
+
+	return 0;
+}
+
 /******************************************************************************
  *
  * Run / stop / reset
diff --git a/src/drivers/usb/ehci.h b/src/drivers/usb/ehci.h
index d8814ec70..f35a07ce6 100644
--- a/src/drivers/usb/ehci.h
+++ b/src/drivers/usb/ehci.h
@@ -537,4 +537,6 @@ struct ehci_endpoint {
 	struct ehci_ring ring;
 };
 
+extern unsigned int ehci_companion ( struct pci_device *pci );
+
 #endif /* _IPXE_EHCI_H */
-- 
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