drivers/usb/host/ehci-lpm.c

   1 /* ehci-lpm.c EHCI HCD LPM support code
   2  * Copyright (c) 2008 - 2010,  Intel Corporation.
   3  * Author: Jacob Pan <jacob.jun.pan@intel.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17 */
  18
  19 /* this file is part of ehci-hcd.c */
  20 static int __maybe_unused ehci_lpm_set_da(struct ehci_hcd *ehci,
  21         int dev_addr, int port_num)
  22 {
  23         u32 __iomem portsc;
  24
  25         ehci_dbg(ehci, "set dev address %d for port %d\n", dev_addr, port_num);
  26         if (port_num > HCS_N_PORTS(ehci->hcs_params)) {
  27                 ehci_dbg(ehci, "invalid port number %d\n", port_num);
  28                 return -ENODEV;
  29         }
  30         portsc = ehci_readl(ehci, &ehci->regs->port_status[port_num-1]);
  31         portsc &= ~PORT_DEV_ADDR;
  32         portsc |= dev_addr<<25;
  33         ehci_writel(ehci, portsc, &ehci->regs->port_status[port_num-1]);
  34         return 0;
  35 }
  36
  37 /*
  38  * this function is used to check if the device support LPM
  39  * if yes, mark the PORTSC register with PORT_LPM bit
  40  */
  41 static int __maybe_unused ehci_lpm_check(struct ehci_hcd *ehci, int port)
  42 {
  43         u32 __iomem     *portsc ;
  44         u32 val32;
  45         int retval;
  46
  47         portsc = &ehci->regs->port_status[port-1];
  48         val32 = ehci_readl(ehci, portsc);
  49         if (!(val32 & PORT_DEV_ADDR)) {
  50                 ehci_dbg(ehci, "LPM: no device attached\n");
  51                 return -ENODEV;
  52         }
  53         val32 |= PORT_LPM;
  54         ehci_writel(ehci, val32, portsc);
  55         msleep(5);
  56         val32 |= PORT_SUSPEND;
  57         ehci_dbg(ehci, "Sending LPM 0x%08x to port %d\n", val32, port);
  58         ehci_writel(ehci, val32, portsc);
  59         /* wait for ACK */
  60         msleep(10);
  61         retval = handshake(ehci, &ehci->regs->port_status[port-1], PORT_SSTS,
  62                         PORTSC_SUSPEND_STS_ACK, 125);
  63         dbg_port(ehci, "LPM", port, val32);
  64         if (retval != -ETIMEDOUT) {
  65                 ehci_dbg(ehci, "LPM: device ACK for LPM\n");
  66                 val32 |= PORT_LPM;
  67                 /*
  68                  * now device should be in L1 sleep, let's wake up the device
  69                  * so that we can complete enumeration.
  70                  */
  71                 ehci_writel(ehci, val32, portsc);
  72                 msleep(10);
  73                 val32 |= PORT_RESUME;
  74                 ehci_writel(ehci, val32, portsc);
  75         } else {
  76                 ehci_dbg(ehci, "LPM: device does not ACK, disable LPM %d\n",
  77                         retval);
  78                 val32 &= ~PORT_LPM;
  79                 retval = -ETIMEDOUT;
  80                 ehci_writel(ehci, val32, portsc);
  81         }
  82
  83         return retval;
  84 }