2 files changed, 102 insertions, 0 deletions

diff --git a/src/soc/intel/common/block/include/intelblocks/xhci.h b/src/soc/intel/common/block/include/intelblocks/xhci.h
index 492c32a002..dd95bfb024 100644
--- a/src/soc/intel/common/block/include/intelblocks/xhci.h
+++ b/src/soc/intel/common/block/include/intelblocks/xhci.h
@@ -56,4 +56,21 @@ void soc_xhci_init(struct device *dev);
  */
 const struct xhci_usb_info *soc_get_xhci_usb_info(void);
 
+/**
+ * usb_xhci_disable_unused() - Disable unused USB devices
+ * @ext_usb_xhci_en_cb: Callback function to be invoked, supplied by mainboard,
+ *			to identify the status of externally visible USB ports.
+ *			(Return true if port is present, false if port is absent)
+ *
+ * This function is used to disable unused USB devices/ports that are configured
+ * in the device tree. For the internal USB ports, the connect status of the port
+ * is probed from the XHCI controller block and the port is disabled if it is not
+ * connected. For the external USB ports, the mainboard provides the connect status
+ * of the concerned port depending on the variants and their SKUs. If the mainboard
+ * supplied callback function is NULL, then all the externally visible USB devices
+ * in the device tree are enabled.
+ */
+void usb_xhci_disable_unused(bool (*ext_usb_xhci_en_cb)(unsigned int port_type,
+							unsigned int port_id));
+
 #endif	/* SOC_INTEL_COMMON_BLOCK_XHCI_H */
diff --git a/src/soc/intel/common/block/xhci/xhci.c b/src/soc/intel/common/block/xhci/xhci.c
index c429e7dd58..0bdf1d97ba 100644
--- a/src/soc/intel/common/block/xhci/xhci.c
+++ b/src/soc/intel/common/block/xhci/xhci.c
@@ -14,11 +14,96 @@
  * GNU General Public License for more details.
  */
 
+#include <arch/acpi_device.h>
+#include <console/console.h>
 #include <device/device.h>
 #include <device/pci.h>
 #include <device/pci_ids.h>
+#include <drivers/usb/acpi/chip.h>
 #include <intelblocks/acpi.h>
 #include <intelblocks/xhci.h>
+#include <soc/pci_devs.h>
+
+#define XHCI_USB2	2
+#define XHCI_USB3	3
+
+/* Current Connect Status */
+#define XHCI_STATUS_CCS		(1 << 0)
+
+static bool is_usb_port_connected(const struct xhci_usb_info *info,
+			unsigned int port_type, unsigned int port_id)
+{
+	uintptr_t port_sts_reg;
+	uint32_t port_status;
+	const struct resource *res;
+
+	/* Support only USB2 or USB3 ports */
+	if (!(port_type == XHCI_USB2 || port_type == XHCI_USB3))
+		return false;
+
+	/* Mark out of bound port id as not connected */
+	if ((port_type == XHCI_USB2 && port_id >= info->num_usb2_ports) ||
+	    (port_type == XHCI_USB3 && port_id >= info->num_usb3_ports))
+		return false;
+
+	/* Calculate port status register address and read the status */
+	res = find_resource(PCH_DEV_XHCI, PCI_BASE_ADDRESS_0);
+	/* If the memory BAR is not allocated for XHCI, leave the devices enabled */
+	if (!res)
+		return true;
+
+	if (port_type == XHCI_USB2)
+		port_sts_reg = (uintptr_t)res->base +
+				info->usb2_port_status_reg + port_id * 0x10;
+	else
+		port_sts_reg = (uintptr_t)res->base +
+				info->usb3_port_status_reg + port_id * 0x10;
+	port_status = read32((void *)port_sts_reg);
+
+	/* Ensure that the status is not all 1s */
+	if (port_status == 0xffffffff)
+		return false;
+
+	return !!(port_status & XHCI_STATUS_CCS);
+}
+
+void usb_xhci_disable_unused(bool (*ext_usb_xhci_en_cb)(unsigned int port_type,
+							unsigned int port_id))
+{
+	struct device *xhci, *hub = NULL, *port = NULL;
+	const struct xhci_usb_info *info = soc_get_xhci_usb_info();
+	struct drivers_usb_acpi_config *config;
+	bool enable;
+
+	xhci = pcidev_path_on_root(PCH_DEVFN_XHCI);
+	if (!xhci) {
+		printk(BIOS_ERR, "%s: Could not locate XHCI device in DT\n", __func__);
+		return;
+	}
+
+	while ((hub = dev_bus_each_child(xhci->link_list, hub)) != NULL) {
+		while ((port = dev_bus_each_child(hub->link_list, port)) != NULL) {
+			enable = true;
+			config = config_of(port);
+			if (config->type == UPC_TYPE_INTERNAL) {
+				/* Probe the connect status of internal ports */
+				enable = is_usb_port_connected(info, port->path.usb.port_type,
+							       port->path.usb.port_id);
+			} else if (ext_usb_xhci_en_cb) {
+				/* Check the mainboard for the status of external ports */
+				enable = ext_usb_xhci_en_cb(port->path.usb.port_type,
+							    port->path.usb.port_id);
+			}
+
+			if (!enable) {
+				printk(BIOS_INFO, "%s: Disabling USB Type%d Id%d\n",
+					__func__, port->path.usb.port_type,
+					port->path.usb.port_id);
+				port->enabled = 0;
+			}
+		}
+	}
+}
 
 __weak void soc_xhci_init(struct device *dev) { /* no-op */ }