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 ehci_lpm_set_da(struct ehci_hcd *ehci, int dev_addr, int port_num)
  21 {
  22         u32 __iomem portsc;
  23
  24         ehci_dbg(ehci, "set dev address %d for port %d\n", dev_addr, port_num);
  25         if (port_num > HCS_N_PORTS(ehci->hcs_params)) {
  26                 ehci_dbg(ehci, "invalid port number %d\n", port_num);
  27                 return -ENODEV;
  28         }
  29         portsc = ehci_readl(ehci, &ehci->regs->port_status[port_num-1]);
  30         portsc &= ~PORT_DEV_ADDR;
  31         portsc |= dev_addr<<25;
  32         ehci_writel(ehci, portsc, &ehci->regs->port_status[port_num-1]);
  33         return 0;
  34 }
  35
  36 /*
  37  * this function is used to check if the device support LPM
  38  * if yes, mark the PORTSC register with PORT_LPM bit
  39  */
  40 static int ehci_lpm_check(struct ehci_hcd *ehci, int port)
  41 {
  42         u32 __iomem     *portsc ;
  43         u32 val32;
  44         int retval;
  45
  46         portsc = &ehci->regs->port_status[port-1];
  47         val32 = ehci_readl(ehci, portsc);
  48         if (!(val32 & PORT_DEV_ADDR)) {
  49                 ehci_dbg(ehci, "LPM: no device attached\n");
  50                 return -ENODEV;
  51         }
  52         val32 |= PORT_LPM;
  53         ehci_writel(ehci, val32, portsc);
  54         msleep(5);
  55         val32 |= PORT_SUSPEND;
  56         ehci_dbg(ehci, "Sending LPM 0x%08x to port %d\n", val32, port);
  57         ehci_writel(ehci, val32, portsc);
  58         /* wait for ACK */
  59         msleep(10);
  60         retval = handshake(ehci, &ehci->regs->port_status[port-1], PORT_SSTS,
  61                         PORTSC_SUSPEND_STS_ACK, 125);
  62         dbg_port(ehci, "LPM", port, val32);
  63         if (retval != -ETIMEDOUT) {
  64                 ehci_dbg(ehci, "LPM: device ACK for LPM\n");
  65                 val32 |= PORT_LPM;
  66                 /*
  67                  * now device should be in L1 sleep, let's wake up the device
  68                  * so that we can complete enumeration.
  69                  */
  70                 ehci_writel(ehci, val32, portsc);
  71                 msleep(10);
  72                 val32 |= PORT_RESUME;
  73                 ehci_writel(ehci, val32, portsc);
  74         } else {
  75                 ehci_dbg(ehci, "LPM: device does not ACK, disable LPM %d\n",
  76                         retval);
  77                 val32 &= ~PORT_LPM;
  78                 retval = -ETIMEDOUT;
  79                 ehci_writel(ehci, val32, portsc);
  80         }
  81
  82         return retval;
  83 }