ohci-hub.c

h内核

		ohci_err (ohci, "bogus NDP=%d, rereads as NDP=%d\n", ports,
			  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 (ports > 7) {
		buf [1] = 0;
		length++;
	}

	/* look at each port */
	for (i = 0; i < ports; i++) {
		u32	status = roothub_portstatus (ohci, i);

		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;
		}

		/* can suspend if no ports are enabled; or if all all
		 * enabled ports are suspended AND remote wakeup is on.
		 */
		if (!(status & RH_PS_CCS))
			continue;
		if ((status & RH_PS_PSS) && hcd->remote_wakeup)
			continue;
		can_suspend = 0;
	}
done:
	spin_unlock_irqrestore (&ohci->lock, flags);

#ifdef CONFIG_PM
	/* save power by suspending idle root hubs;
	 * INTR_RD wakes us when there's work
	 * NOTE: if we can do this, we don't need a root hub timer!
	 */
	if (can_suspend
			&& !changed
			&& !ohci->ed_rm_list
			&& ((OHCI_CTRL_HCFS | OHCI_SCHED_ENABLES)
					& ohci->hc_control)
				== OHCI_USB_OPER
			&& time_after (jiffies, ohci->next_statechange)
			&& usb_trylock_device (hcd->self.root_hub)
			) {
		ohci_vdbg (ohci, "autosuspend\n");
		(void) ohci_hub_suspend (hcd);
		hcd->state = USB_STATE_RUNNING;
		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);
	int		ports = rh & RH_A_NDP; 
	u16		temp;

	desc->bDescriptorType = 0x29;
	desc->bPwrOn2PwrGood = (rh & RH_A_POTPGT) >> 24;
	desc->bHubContrCurrent = 0;

	desc->bNbrPorts = ports;
	temp = 1 + (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);
	desc->bitmap [0] = rh & RH_B_DR;
	if (ports > 7) {
		desc->bitmap [1] = (rh & RH_B_DR) >> 8;
		desc->bitmap [2] = desc->bitmap [3] = 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;

	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)
				schedule_work (&ohci->rh_resume);
			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);
		*(__le32 *) buf = cpu_to_le32 (temp);
		break;
	case GetPortStatus:
		if (!wIndex || wIndex > ports)
			goto error;
		wIndex--;
		temp = roothub_portstatus (ohci, wIndex);
		*(__le32 *) buf = cpu_to_le32 (temp);

#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;
}