ehci-lpm.c

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/* ehci-lpm.c EHCI HCD LPM support code
 * Copyright (c) 2008 - 2010,  Intel Corporation.
 * Author: Jacob Pan <[email protected]>
 *
 * 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 __maybe_unused 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 __maybe_unused 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;
}