USB: EHCI: EHCI 1.1 addendum: Basic LPM feature support
With this patch, the LPM capable EHCI host controller can put device
into L1 sleep state which is a mode that can enter/exit quickly, and
reduce power consumption.
Signed-off-by: Jacob Pan <jacob.jun.pan@intel.com>
Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/ehci-lpm.c b/drivers/usb/host/ehci-lpm.c
new file mode 100644
index 0000000..b4d4d63
--- /dev/null
+++ b/drivers/usb/host/ehci-lpm.c
@@ -0,0 +1,83 @@
+/* ehci-lpm.c EHCI HCD LPM support code
+ * Copyright (c) 2008 - 2010, Intel Corporation.
+ * Author: Jacob Pan <jacob.jun.pan@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+/* this file is part of ehci-hcd.c */
+static int ehci_lpm_set_da(struct ehci_hcd *ehci, int dev_addr, int port_num)
+{
+ u32 __iomem portsc;
+
+ ehci_dbg(ehci, "set dev address %d for port %d\n", dev_addr, port_num);
+ if (port_num > HCS_N_PORTS(ehci->hcs_params)) {
+ ehci_dbg(ehci, "invalid port number %d\n", port_num);
+ return -ENODEV;
+ }
+ portsc = ehci_readl(ehci, &ehci->regs->port_status[port_num-1]);
+ portsc &= ~PORT_DEV_ADDR;
+ portsc |= dev_addr<<25;
+ ehci_writel(ehci, portsc, &ehci->regs->port_status[port_num-1]);
+ return 0;
+}
+
+/*
+ * this function is used to check if the device support LPM
+ * if yes, mark the PORTSC register with PORT_LPM bit
+ */
+static int ehci_lpm_check(struct ehci_hcd *ehci, int port)
+{
+ u32 __iomem *portsc ;
+ u32 val32;
+ int retval;
+
+ portsc = &ehci->regs->port_status[port-1];
+ val32 = ehci_readl(ehci, portsc);
+ if (!(val32 & PORT_DEV_ADDR)) {
+ ehci_dbg(ehci, "LPM: no device attached\n");
+ return -ENODEV;
+ }
+ val32 |= PORT_LPM;
+ ehci_writel(ehci, val32, portsc);
+ msleep(5);
+ val32 |= PORT_SUSPEND;
+ ehci_dbg(ehci, "Sending LPM 0x%08x to port %d\n", val32, port);
+ ehci_writel(ehci, val32, portsc);
+ /* wait for ACK */
+ msleep(10);
+ retval = handshake(ehci, &ehci->regs->port_status[port-1], PORT_SSTS,
+ PORTSC_SUSPEND_STS_ACK, 125);
+ dbg_port(ehci, "LPM", port, val32);
+ if (retval != -ETIMEDOUT) {
+ ehci_dbg(ehci, "LPM: device ACK for LPM\n");
+ val32 |= PORT_LPM;
+ /*
+ * now device should be in L1 sleep, let's wake up the device
+ * so that we can complete enumeration.
+ */
+ ehci_writel(ehci, val32, portsc);
+ msleep(10);
+ val32 |= PORT_RESUME;
+ ehci_writel(ehci, val32, portsc);
+ } else {
+ ehci_dbg(ehci, "LPM: device does not ACK, disable LPM %d\n",
+ retval);
+ val32 &= ~PORT_LPM;
+ retval = -ETIMEDOUT;
+ ehci_writel(ehci, val32, portsc);
+ }
+
+ return retval;
+}