path: root/drivers/usb/host/ehci-hub.c

/*
 * Copyright (C) 2001-2004 by David Brownell
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * 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 */

/*-------------------------------------------------------------------------*/

/*
 * EHCI Root Hub ... the nonsharable stuff
 *
 * Registers don't need cpu_to_le32, that happens transparently
 */

/*-------------------------------------------------------------------------*/
#include <linux/usb/otg.h>

#define	PORT_WAKE_BITS	(PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E)

#ifdef	CONFIG_PM

static int ehci_hub_control(
	struct usb_hcd	*hcd,
	u16		typeReq,
	u16		wValue,
	u16		wIndex,
	char		*buf,
	u16		wLength
);

/* After a power loss, ports that were owned by the companion must be
 * reset so that the companion can still own them.
 */
static void ehci_handover_companion_ports(struct ehci_hcd *ehci)
{
	u32 __iomem	*reg;
	u32		status;
	int		port;
	__le32		buf;
	struct usb_hcd	*hcd = ehci_to_hcd(ehci);

	if (!ehci->owned_ports)
		return;

	/* Give the connections some time to appear */
	msleep(20);

	port = HCS_N_PORTS(ehci->hcs_params);
	while (port--) {
		if (test_bit(port, &ehci->owned_ports)) {
			reg = &ehci->regs->port_status[port];
			status = ehci_readl(ehci, reg) & ~PORT_RWC_BITS;

			/* Port already owned by companion? */
			if (status & PORT_OWNER)
				clear_bit(port, &ehci->owned_ports);
			else if (test_bit(port, &ehci->companion_ports))
				ehci_writel(ehci, status & ~PORT_PE, reg);
			else
				ehci_hub_control(hcd, SetPortFeature,
						USB_PORT_FEAT_RESET, port + 1,
						NULL, 0);
		}
	}

	if (!ehci->owned_ports)
		return;
	msleep(90);		/* Wait for resets to complete */

	port = HCS_N_PORTS(ehci->hcs_params);
	while (port--) {
		if (test_bit(port, &ehci->owned_ports)) {
			ehci_hub_control(hcd, GetPortStatus,
					0, port + 1,
					(char *) &buf, sizeof(buf));

			/* The companion should now own the port,
			 * but if something went wrong the port must not
			 * remain enabled.
			 */
			reg = &ehci->regs->port_status[port];
			status = ehci_readl(ehci, reg) & ~PORT_RWC_BITS;
			if (status & PORT_OWNER)
				ehci_writel(ehci, status | PORT_CSC, reg);
			else {
				ehci_dbg(ehci, "failed handover port %d: %x\n",
						port + 1, status);
				ehci_writel(ehci, status & ~PORT_PE, reg);
			}
		}
	}

	ehci->owned_ports = 0;
}

static int ehci_port_change(struct ehci_hcd *ehci)
{
	int i = HCS_N_PORTS(ehci->hcs_params);

	/* First check if the controller indicates a change event */

	if (ehci_readl(ehci, &ehci->regs->status) & STS_PCD)
		return 1;

	/*
	 * Not all controllers appear to update this while going from D3 to D0,
	 * so check the individual port status registers as well
	 */

	while (i--)
		if (ehci_readl(ehci, &ehci->regs->port_status[i]) & PORT_CSC)
			return 1