Check the host's USB2 LPM capability.
USB2 software LPM support is optional for xHCI 0.96 hosts. xHCI 1.0 hosts
should support software LPM, and may support hardware LPM.
Signed-off-by: Andiry Xu <andiry.xu@xxxxxxx>
---
drivers/usb/host/xhci-ext-caps.h | 6 ++++++
drivers/usb/host/xhci-mem.c | 17 +++++++++++++++++
drivers/usb/host/xhci.h | 4 ++++
3 files changed, 27 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/host/xhci-ext-caps.h b/drivers/usb/host/xhci-ext-caps.h
index ce5c9e5..c7f3312 100644
--- a/drivers/usb/host/xhci-ext-caps.h
+++ b/drivers/usb/host/xhci-ext-caps.h
@@ -65,6 +65,12 @@
/* bits 1:2, 5:12, and 17:19 need to be preserved; bits 21:28 should be zero */
#define XHCI_LEGACY_DISABLE_SMI ((0x3 << 1) + (0xff << 5) + (0x7 << 17))
+/* USB 2.0 xHCI 0.96 L1C capability - section 7.2.2.1.3.2 */
+#define XHCI_L1C (1 << 16)
+
+/* USB 2.0 xHCI 1.0 hardware LMP capability - section 7.2.2.1.3.2 */
+#define XHCI_HLC (1 << 19)
+
/* command register values to disable interrupts and halt the HC */
/* start/stop HC execution - do not write unless HC is halted*/
#define XHCI_CMD_RUN (1 << 0)
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index d446886..b590b92 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1762,6 +1762,23 @@ static void xhci_add_in_port(struct xhci_hcd *xhci, unsigned int num_ports,
if (port_offset == 0 || (port_offset + port_count - 1) > num_ports)
/* WTF? "Valid values are ‘1’ to MaxPorts" */
return;
+
+ /* Check the host's USB2 LPM capability */
+ if ((xhci->hci_version == 0x96) && (major_revision != 0x03) &&
+ (temp & XHCI_L1C)) {
+ xhci_dbg(xhci, "xHCI 0.96: support USB2 software lpm\n");
+ xhci->sw_lpm_support = 1;
+ }
+
+ if ((xhci->hci_version >= 0x100) && (major_revision != 0x03)) {
+ xhci_dbg(xhci, "xHCI 1.0: support USB2 software lpm\n");
+ xhci->sw_lpm_support = 1;
+ if (temp & XHCI_HLC) {
+ xhci_dbg(xhci, "xHCI 1.0: support USB2 hardware lpm\n");
+ xhci->hw_lpm_support = 1;
+ }
+ }
+
port_offset--;
for (i = port_offset; i < (port_offset + port_count); i++) {
/* Duplicate entry. Ignore the port if the revisions differ. */
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 2f49554..c4afe54 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1330,6 +1330,10 @@ struct xhci_hcd {
/* Array of pointers to USB 2.0 PORTSC registers */
__le32 __iomem **usb2_ports;
unsigned int num_usb2_ports;
+ /* support xHCI 0.96 spec USB2 software LPM */
+ unsigned sw_lpm_support:1;
+ /* support xHCI 1.0 spec USB2 hardware LPM */
+ unsigned hw_lpm_support:1;
};
/* convert between an HCD pointer and the corresponding EHCI_HCD */
--
1.7.4.1
--
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