48f2497014
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>
83 lines
2.5 KiB
C
83 lines
2.5 KiB
C
/* ehci-lpm.c EHCI HCD LPM support code
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* Copyright (c) 2008 - 2010, Intel Corporation.
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* Author: Jacob Pan <jacob.jun.pan@intel.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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/* this file is part of ehci-hcd.c */
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static int ehci_lpm_set_da(struct ehci_hcd *ehci, int dev_addr, int port_num)
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{
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u32 __iomem portsc;
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ehci_dbg(ehci, "set dev address %d for port %d\n", dev_addr, port_num);
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if (port_num > HCS_N_PORTS(ehci->hcs_params)) {
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ehci_dbg(ehci, "invalid port number %d\n", port_num);
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return -ENODEV;
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}
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portsc = ehci_readl(ehci, &ehci->regs->port_status[port_num-1]);
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portsc &= ~PORT_DEV_ADDR;
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portsc |= dev_addr<<25;
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ehci_writel(ehci, portsc, &ehci->regs->port_status[port_num-1]);
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return 0;
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}
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/*
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* this function is used to check if the device support LPM
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* if yes, mark the PORTSC register with PORT_LPM bit
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*/
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static int ehci_lpm_check(struct ehci_hcd *ehci, int port)
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{
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u32 __iomem *portsc ;
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u32 val32;
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int retval;
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portsc = &ehci->regs->port_status[port-1];
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val32 = ehci_readl(ehci, portsc);
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if (!(val32 & PORT_DEV_ADDR)) {
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ehci_dbg(ehci, "LPM: no device attached\n");
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return -ENODEV;
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}
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val32 |= PORT_LPM;
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ehci_writel(ehci, val32, portsc);
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msleep(5);
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val32 |= PORT_SUSPEND;
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ehci_dbg(ehci, "Sending LPM 0x%08x to port %d\n", val32, port);
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ehci_writel(ehci, val32, portsc);
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/* wait for ACK */
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msleep(10);
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retval = handshake(ehci, &ehci->regs->port_status[port-1], PORT_SSTS,
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PORTSC_SUSPEND_STS_ACK, 125);
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dbg_port(ehci, "LPM", port, val32);
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if (retval != -ETIMEDOUT) {
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ehci_dbg(ehci, "LPM: device ACK for LPM\n");
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val32 |= PORT_LPM;
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/*
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* now device should be in L1 sleep, let's wake up the device
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* so that we can complete enumeration.
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*/
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ehci_writel(ehci, val32, portsc);
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msleep(10);
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val32 |= PORT_RESUME;
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ehci_writel(ehci, val32, portsc);
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} else {
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ehci_dbg(ehci, "LPM: device does not ACK, disable LPM %d\n",
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retval);
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val32 &= ~PORT_LPM;
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retval = -ETIMEDOUT;
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ehci_writel(ehci, val32, portsc);
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}
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return retval;
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}
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