linux/drivers/usb/host/ohci-hub.c
David Brownell d413984ae9 USB: OHCI avoids root hub timer polling
This teaches OHCI to use the root hub status change (RHSC) IRQ, bypassing
root hub timers most of the time and switching over to the "new" root hub
polling scheme.  It's complicated by the fact that implementations of OHCI
trigger and ack that IRQ differently (the spec is vague there).

Avoiding root hub timers helps mechanisms like "dynamic tick" leave the
CPU in lowpower modes for longer intervals.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-27 11:58:48 -07:00

668 lines
17 KiB
C

/*
* OHCI HCD (Host Controller Driver) for USB.
*
* (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
* (C) Copyright 2000-2004 David Brownell <dbrownell@users.sourceforge.net>
*
* This file is licenced under GPL
*/
/*-------------------------------------------------------------------------*/
/*
* OHCI Root Hub ... the nonsharable stuff
*/
#define dbg_port(hc,label,num,value) \
ohci_dbg (hc, \
"%s roothub.portstatus [%d] " \
"= 0x%08x%s%s%s%s%s%s%s%s%s%s%s%s\n", \
label, num, temp, \
(temp & RH_PS_PRSC) ? " PRSC" : "", \
(temp & RH_PS_OCIC) ? " OCIC" : "", \
(temp & RH_PS_PSSC) ? " PSSC" : "", \
(temp & RH_PS_PESC) ? " PESC" : "", \
(temp & RH_PS_CSC) ? " CSC" : "", \
\
(temp & RH_PS_LSDA) ? " LSDA" : "", \
(temp & RH_PS_PPS) ? " PPS" : "", \
(temp & RH_PS_PRS) ? " PRS" : "", \
(temp & RH_PS_POCI) ? " POCI" : "", \
(temp & RH_PS_PSS) ? " PSS" : "", \
\
(temp & RH_PS_PES) ? " PES" : "", \
(temp & RH_PS_CCS) ? " CCS" : "" \
);
/*-------------------------------------------------------------------------*/
/* hcd->hub_irq_enable() */
static void ohci_rhsc_enable (struct usb_hcd *hcd)
{
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
ohci_writel (ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
}
#ifdef CONFIG_PM
#define OHCI_SCHED_ENABLES \
(OHCI_CTRL_CLE|OHCI_CTRL_BLE|OHCI_CTRL_PLE|OHCI_CTRL_IE)
static void dl_done_list (struct ohci_hcd *, struct pt_regs *);
static void finish_unlinks (struct ohci_hcd *, u16 , struct pt_regs *);
static int ohci_restart (struct ohci_hcd *ohci);
static int ohci_bus_suspend (struct usb_hcd *hcd)
{
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
int status = 0;
unsigned long flags;
spin_lock_irqsave (&ohci->lock, flags);
if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))) {
spin_unlock_irqrestore (&ohci->lock, flags);
return -ESHUTDOWN;
}
ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
switch (ohci->hc_control & OHCI_CTRL_HCFS) {
case OHCI_USB_RESUME:
ohci_dbg (ohci, "resume/suspend?\n");
ohci->hc_control &= ~OHCI_CTRL_HCFS;
ohci->hc_control |= OHCI_USB_RESET;
ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
(void) ohci_readl (ohci, &ohci->regs->control);
/* FALL THROUGH */
case OHCI_USB_RESET:
status = -EBUSY;
ohci_dbg (ohci, "needs reinit!\n");
goto done;
case OHCI_USB_SUSPEND:
ohci_dbg (ohci, "already suspended\n");
goto done;
}
ohci_dbg (ohci, "suspend root hub\n");
/* First stop any processing */
if (ohci->hc_control & OHCI_SCHED_ENABLES) {
int limit;
ohci->hc_control &= ~OHCI_SCHED_ENABLES;
ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrstatus);
/* sched disables take effect on the next frame,
* then the last WDH could take 6+ msec
*/
ohci_dbg (ohci, "stopping schedules ...\n");
limit = 2000;
while (limit > 0) {
udelay (250);
limit =- 250;
if (ohci_readl (ohci, &ohci->regs->intrstatus)
& OHCI_INTR_SF)
break;
}
dl_done_list (ohci, NULL);
mdelay (7);
}
dl_done_list (ohci, NULL);
finish_unlinks (ohci, ohci_frame_no(ohci), NULL);
ohci_writel (ohci, ohci_readl (ohci, &ohci->regs->intrstatus),
&ohci->regs->intrstatus);
/* maybe resume can wake root hub */
if (device_may_wakeup(&ohci_to_hcd(ohci)->self.root_hub->dev))
ohci->hc_control |= OHCI_CTRL_RWE;
else
ohci->hc_control &= ~OHCI_CTRL_RWE;
/* Suspend hub ... this is the "global (to this bus) suspend" mode,
* which doesn't imply ports will first be individually suspended.
*/
ohci->hc_control &= ~OHCI_CTRL_HCFS;
ohci->hc_control |= OHCI_USB_SUSPEND;
ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
(void) ohci_readl (ohci, &ohci->regs->control);
/* no resumes until devices finish suspending */
ohci->next_statechange = jiffies + msecs_to_jiffies (5);
/* no timer polling */
hcd->poll_rh = 0;
done:
/* external suspend vs self autosuspend ... same effect */
if (status == 0)
usb_hcd_suspend_root_hub(hcd);
spin_unlock_irqrestore (&ohci->lock, flags);
return status;
}
static inline struct ed *find_head (struct ed *ed)
{
/* for bulk and control lists */
while (ed->ed_prev)
ed = ed->ed_prev;
return ed;
}
/* caller has locked the root hub */
static int ohci_bus_resume (struct usb_hcd *hcd)
{
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
u32 temp, enables;
int status = -EINPROGRESS;
unsigned long flags;
if (time_before (jiffies, ohci->next_statechange))
msleep(5);
spin_lock_irqsave (&ohci->lock, flags);
if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))) {
spin_unlock_irqrestore (&ohci->lock, flags);
return -ESHUTDOWN;
}
ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
/* this can happen after resuming a swsusp snapshot */
if (hcd->state == HC_STATE_RESUMING) {
ohci_dbg (ohci, "BIOS/SMM active, control %03x\n",
ohci->hc_control);
status = -EBUSY;
/* this happens when pmcore resumes HC then root */
} else {
ohci_dbg (ohci, "duplicate resume\n");
status = 0;
}
} else switch (ohci->hc_control & OHCI_CTRL_HCFS) {
case OHCI_USB_SUSPEND:
ohci->hc_control &= ~(OHCI_CTRL_HCFS|OHCI_SCHED_ENABLES);
ohci->hc_control |= OHCI_USB_RESUME;
ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
(void) ohci_readl (ohci, &ohci->regs->control);
ohci_dbg (ohci, "resume root hub\n");
break;
case OHCI_USB_RESUME:
/* HCFS changes sometime after INTR_RD */
ohci_info (ohci, "wakeup\n");
break;
case OHCI_USB_OPER:
/* this can happen after resuming a swsusp snapshot */
ohci_dbg (ohci, "snapshot resume? reinit\n");
status = -EBUSY;
break;
default: /* RESET, we lost power */
ohci_dbg (ohci, "lost power\n");
status = -EBUSY;
}
spin_unlock_irqrestore (&ohci->lock, flags);
if (status == -EBUSY) {
(void) ohci_init (ohci);
return ohci_restart (ohci);
}
if (status != -EINPROGRESS)
return status;
temp = ohci->num_ports;
enables = 0;
while (temp--) {
u32 stat = ohci_readl (ohci,
&ohci->regs->roothub.portstatus [temp]);
/* force global, not selective, resume */
if (!(stat & RH_PS_PSS))
continue;
ohci_writel (ohci, RH_PS_POCI,
&ohci->regs->roothub.portstatus [temp]);
}
/* Some controllers (lucent erratum) need extra-long delays */
msleep (20 /* usb 11.5.1.10 */ + 12 /* 32 msec counter */ + 1);
temp = ohci_readl (ohci, &ohci->regs->control);
temp &= OHCI_CTRL_HCFS;
if (temp != OHCI_USB_RESUME) {
ohci_err (ohci, "controller won't resume\n");
return -EBUSY;
}
/* disable old schedule state, reinit from scratch */
ohci_writel (ohci, 0, &ohci->regs->ed_controlhead);
ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
ohci_writel (ohci, 0, &ohci->regs->ed_bulkhead);
ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
ohci_writel (ohci, 0, &ohci->regs->ed_periodcurrent);
ohci_writel (ohci, (u32) ohci->hcca_dma, &ohci->regs->hcca);
/* Sometimes PCI D3 suspend trashes frame timings ... */
periodic_reinit (ohci);
/* interrupts might have been disabled */
ohci_writel (ohci, OHCI_INTR_INIT, &ohci->regs->intrenable);
if (ohci->ed_rm_list)
ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
ohci_writel (ohci, ohci_readl (ohci, &ohci->regs->intrstatus),
&ohci->regs->intrstatus);
/* Then re-enable operations */
ohci_writel (ohci, OHCI_USB_OPER, &ohci->regs->control);
(void) ohci_readl (ohci, &ohci->regs->control);
msleep (3);
temp = ohci->hc_control;
temp &= OHCI_CTRL_RWC;
temp |= OHCI_CONTROL_INIT | OHCI_USB_OPER;
ohci->hc_control = temp;
ohci_writel (ohci, temp, &ohci->regs->control);
(void) ohci_readl (ohci, &ohci->regs->control);
/* TRSMRCY */
msleep (10);
/* keep it alive for more than ~5x suspend + resume costs */
ohci->next_statechange = jiffies + STATECHANGE_DELAY;
/* maybe turn schedules back on */
enables = 0;
temp = 0;
if (!ohci->ed_rm_list) {
if (ohci->ed_controltail) {
ohci_writel (ohci,
find_head (ohci->ed_controltail)->dma,
&ohci->regs->ed_controlhead);
enables |= OHCI_CTRL_CLE;
temp |= OHCI_CLF;
}
if (ohci->ed_bulktail) {
ohci_writel (ohci, find_head (ohci->ed_bulktail)->dma,
&ohci->regs->ed_bulkhead);
enables |= OHCI_CTRL_BLE;
temp |= OHCI_BLF;
}
}
if (hcd->self.bandwidth_isoc_reqs || hcd->self.bandwidth_int_reqs)
enables |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
if (enables) {
ohci_dbg (ohci, "restarting schedules ... %08x\n", enables);
ohci->hc_control |= enables;
ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
if (temp)
ohci_writel (ohci, temp, &ohci->regs->cmdstatus);
(void) ohci_readl (ohci, &ohci->regs->control);
}
return 0;
}
#endif /* CONFIG_PM */
/*-------------------------------------------------------------------------*/
/* build "status change" packet (one or two bytes) from HC registers */
static int
ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
{
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
int i, changed = 0, length = 1;
int can_suspend;
unsigned long flags;
can_suspend = device_may_wakeup(&hcd->self.root_hub->dev);
spin_lock_irqsave (&ohci->lock, flags);
/* handle autosuspended root: finish resuming before
* letting khubd or root hub timer see state changes.
*/
if (unlikely((ohci->hc_control & OHCI_CTRL_HCFS) != OHCI_USB_OPER
|| !HC_IS_RUNNING(hcd->state))) {
can_suspend = 0;
goto done;
}
/* undocumented erratum seen on at least rev D */
if ((ohci->flags & OHCI_QUIRK_AMD756)
&& (roothub_a (ohci) & RH_A_NDP) > MAX_ROOT_PORTS) {
ohci_warn (ohci, "bogus NDP, rereads as NDP=%d\n",
ohci_readl (ohci, &ohci->regs->roothub.a) & RH_A_NDP);
/* retry later; "should not happen" */
goto done;
}
/* init status */
if (roothub_status (ohci) & (RH_HS_LPSC | RH_HS_OCIC))
buf [0] = changed = 1;
else
buf [0] = 0;
if (ohci->num_ports > 7) {
buf [1] = 0;
length++;
}
/* look at each port */
for (i = 0; i < ohci->num_ports; i++) {
u32 status = roothub_portstatus (ohci, i);
/* can't autosuspend with active ports */
if ((status & RH_PS_PES) && !(status & RH_PS_PSS))
can_suspend = 0;
if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
| RH_PS_OCIC | RH_PS_PRSC)) {
changed = 1;
if (i < 7)
buf [0] |= 1 << (i + 1);
else
buf [1] |= 1 << (i - 7);
continue;
}
}
/* after root hub changes, stop polling after debouncing
* for a while and maybe kicking in autosuspend
*/
if (changed) {
ohci->next_statechange = jiffies + STATECHANGE_DELAY;
can_suspend = 0;
} else if (time_before (jiffies, ohci->next_statechange)) {
can_suspend = 0;
} else {
#ifdef CONFIG_PM
can_suspend = can_suspend
&& !ohci->ed_rm_list
&& ((OHCI_CTRL_HCFS | OHCI_SCHED_ENABLES)
& ohci->hc_control)
== OHCI_USB_OPER;
#endif
if (hcd->uses_new_polling) {
hcd->poll_rh = 0;
/* use INTR_RHSC iff INTR_RD won't apply */
if (!can_suspend)
ohci_writel (ohci, OHCI_INTR_RHSC,
&ohci->regs->intrenable);
}
}
done:
spin_unlock_irqrestore (&ohci->lock, flags);
#ifdef CONFIG_PM
/* save power by autosuspending idle root hubs;
* INTR_RD wakes us when there's work
*/
if (can_suspend && usb_trylock_device (hcd->self.root_hub) == 0) {
ohci_vdbg (ohci, "autosuspend\n");
(void) ohci_bus_suspend (hcd);
usb_unlock_device (hcd->self.root_hub);
}
#endif
return changed ? length : 0;
}
/*-------------------------------------------------------------------------*/
static void
ohci_hub_descriptor (
struct ohci_hcd *ohci,
struct usb_hub_descriptor *desc
) {
u32 rh = roothub_a (ohci);
u16 temp;
desc->bDescriptorType = 0x29;
desc->bPwrOn2PwrGood = (rh & RH_A_POTPGT) >> 24;
desc->bHubContrCurrent = 0;
desc->bNbrPorts = ohci->num_ports;
temp = 1 + (ohci->num_ports / 8);
desc->bDescLength = 7 + 2 * temp;
temp = 0;
if (rh & RH_A_NPS) /* no power switching? */
temp |= 0x0002;
if (rh & RH_A_PSM) /* per-port power switching? */
temp |= 0x0001;
if (rh & RH_A_NOCP) /* no overcurrent reporting? */
temp |= 0x0010;
else if (rh & RH_A_OCPM) /* per-port overcurrent reporting? */
temp |= 0x0008;
desc->wHubCharacteristics = (__force __u16)cpu_to_hc16(ohci, temp);
/* two bitmaps: ports removable, and usb 1.0 legacy PortPwrCtrlMask */
rh = roothub_b (ohci);
memset(desc->bitmap, 0xff, sizeof(desc->bitmap));
desc->bitmap [0] = rh & RH_B_DR;
if (ohci->num_ports > 7) {
desc->bitmap [1] = (rh & RH_B_DR) >> 8;
desc->bitmap [2] = 0xff;
} else
desc->bitmap [1] = 0xff;
}
/*-------------------------------------------------------------------------*/
#ifdef CONFIG_USB_OTG
static int ohci_start_port_reset (struct usb_hcd *hcd, unsigned port)
{
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
u32 status;
if (!port)
return -EINVAL;
port--;
/* start port reset before HNP protocol times out */
status = ohci_readl(ohci, &ohci->regs->roothub.portstatus [port]);
if (!(status & RH_PS_CCS))
return -ENODEV;
/* khubd will finish the reset later */
ohci_writel(ohci, RH_PS_PRS, &ohci->regs->roothub.portstatus [port]);
return 0;
}
static void start_hnp(struct ohci_hcd *ohci);
#else
#define ohci_start_port_reset NULL
#endif
/*-------------------------------------------------------------------------*/
/* See usb 7.1.7.5: root hubs must issue at least 50 msec reset signaling,
* not necessarily continuous ... to guard against resume signaling.
* The short timeout is safe for non-root hubs, and is backward-compatible
* with earlier Linux hosts.
*/
#ifdef CONFIG_USB_SUSPEND
#define PORT_RESET_MSEC 50
#else
#define PORT_RESET_MSEC 10
#endif
/* this timer value might be vendor-specific ... */
#define PORT_RESET_HW_MSEC 10
/* wrap-aware logic morphed from <linux/jiffies.h> */
#define tick_before(t1,t2) ((s16)(((s16)(t1))-((s16)(t2))) < 0)
/* called from some task, normally khubd */
static inline void root_port_reset (struct ohci_hcd *ohci, unsigned port)
{
__hc32 __iomem *portstat = &ohci->regs->roothub.portstatus [port];
u32 temp;
u16 now = ohci_readl(ohci, &ohci->regs->fmnumber);
u16 reset_done = now + PORT_RESET_MSEC;
/* build a "continuous enough" reset signal, with up to
* 3msec gap between pulses. scheduler HZ==100 must work;
* this might need to be deadline-scheduled.
*/
do {
/* spin until any current reset finishes */
for (;;) {
temp = ohci_readl (ohci, portstat);
if (!(temp & RH_PS_PRS))
break;
udelay (500);
}
if (!(temp & RH_PS_CCS))
break;
if (temp & RH_PS_PRSC)
ohci_writel (ohci, RH_PS_PRSC, portstat);
/* start the next reset, sleep till it's probably done */
ohci_writel (ohci, RH_PS_PRS, portstat);
msleep(PORT_RESET_HW_MSEC);
now = ohci_readl(ohci, &ohci->regs->fmnumber);
} while (tick_before(now, reset_done));
/* caller synchronizes using PRSC */
}
static int ohci_hub_control (
struct usb_hcd *hcd,
u16 typeReq,
u16 wValue,
u16 wIndex,
char *buf,
u16 wLength
) {
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
int ports = hcd_to_bus (hcd)->root_hub->maxchild;
u32 temp;
int retval = 0;
if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
return -ESHUTDOWN;
switch (typeReq) {
case ClearHubFeature:
switch (wValue) {
case C_HUB_OVER_CURRENT:
ohci_writel (ohci, RH_HS_OCIC,
&ohci->regs->roothub.status);
case C_HUB_LOCAL_POWER:
break;
default:
goto error;
}
break;
case ClearPortFeature:
if (!wIndex || wIndex > ports)
goto error;
wIndex--;
switch (wValue) {
case USB_PORT_FEAT_ENABLE:
temp = RH_PS_CCS;
break;
case USB_PORT_FEAT_C_ENABLE:
temp = RH_PS_PESC;
break;
case USB_PORT_FEAT_SUSPEND:
temp = RH_PS_POCI;
if ((ohci->hc_control & OHCI_CTRL_HCFS)
!= OHCI_USB_OPER)
usb_hcd_resume_root_hub(hcd);
break;
case USB_PORT_FEAT_C_SUSPEND:
temp = RH_PS_PSSC;
break;
case USB_PORT_FEAT_POWER:
temp = RH_PS_LSDA;
break;
case USB_PORT_FEAT_C_CONNECTION:
temp = RH_PS_CSC;
break;
case USB_PORT_FEAT_C_OVER_CURRENT:
temp = RH_PS_OCIC;
break;
case USB_PORT_FEAT_C_RESET:
temp = RH_PS_PRSC;
break;
default:
goto error;
}
ohci_writel (ohci, temp,
&ohci->regs->roothub.portstatus [wIndex]);
// ohci_readl (ohci, &ohci->regs->roothub.portstatus [wIndex]);
break;
case GetHubDescriptor:
ohci_hub_descriptor (ohci, (struct usb_hub_descriptor *) buf);
break;
case GetHubStatus:
temp = roothub_status (ohci) & ~(RH_HS_CRWE | RH_HS_DRWE);
put_unaligned(cpu_to_le32 (temp), (__le32 *) buf);
break;
case GetPortStatus:
if (!wIndex || wIndex > ports)
goto error;
wIndex--;
temp = roothub_portstatus (ohci, wIndex);
put_unaligned(cpu_to_le32 (temp), (__le32 *) buf);
#ifndef OHCI_VERBOSE_DEBUG
if (*(u16*)(buf+2)) /* only if wPortChange is interesting */
#endif
dbg_port (ohci, "GetStatus", wIndex, temp);
break;
case SetHubFeature:
switch (wValue) {
case C_HUB_OVER_CURRENT:
// FIXME: this can be cleared, yes?
case C_HUB_LOCAL_POWER:
break;
default:
goto error;
}
break;
case SetPortFeature:
if (!wIndex || wIndex > ports)
goto error;
wIndex--;
switch (wValue) {
case USB_PORT_FEAT_SUSPEND:
#ifdef CONFIG_USB_OTG
if (hcd->self.otg_port == (wIndex + 1)
&& hcd->self.b_hnp_enable)
start_hnp(ohci);
else
#endif
ohci_writel (ohci, RH_PS_PSS,
&ohci->regs->roothub.portstatus [wIndex]);
break;
case USB_PORT_FEAT_POWER:
ohci_writel (ohci, RH_PS_PPS,
&ohci->regs->roothub.portstatus [wIndex]);
break;
case USB_PORT_FEAT_RESET:
root_port_reset (ohci, wIndex);
break;
default:
goto error;
}
break;
default:
error:
/* "protocol stall" on error */
retval = -EPIPE;
}
return retval;
}