tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 */
20static 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 */
41static 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}