/*
   * MUSB OTG driver virtual root hub support
   *
   * Copyright 2005 Mentor Graphics Corporation
   * Copyright (C) 2005-2006 by Texas Instruments
   * Copyright (C) 2006-2007 Nokia Corporation
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * version 2 as published by the Free Software Foundation.
   *
   * 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., 51 Franklin St, Fifth Floor, Boston, MA
   * 02110-1301 USA
   *
   * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
   * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/sched.h>

  #include <linux/errno.h>
  #include <linux/init.h>
  #include <linux/time.h>
  #include <linux/timer.h>
  
  #include <asm/unaligned.h>
  
  #include "musb_core.h"
  
  
  static void musb_port_suspend(struct musb *musb, bool do_suspend)
  {
  	u8		power;
  	void __iomem	*mbase = musb->mregs;
  
  	if (!is_host_active(musb))
  		return;
  
  	/* NOTE:  this doesn't necessarily put PHY into low power mode,
  	 * turning off its clock; that's a function of PHY integration and
  	 * MUSB_POWER_ENSUSPEND.  PHY may need a clock (sigh) to detect
  	 * SE0 changing to connect (J) or wakeup (K) states.
  	 */
  	power = musb_readb(mbase, MUSB_POWER);
  	if (do_suspend) {
  		int retries = 10000;
  
  		power &= ~MUSB_POWER_RESUME;
  		power |= MUSB_POWER_SUSPENDM;
  		musb_writeb(mbase, MUSB_POWER, power);
  
  		/* Needed for OPT A tests */
  		power = musb_readb(mbase, MUSB_POWER);
  		while (power & MUSB_POWER_SUSPENDM) {
  			power = musb_readb(mbase, MUSB_POWER);
  			if (retries-- < 1)
  				break;
  		}

  		dev_dbg(musb->controller, "Root port suspended, power %02x
  ", power);

  
  		musb->port1_status |= USB_PORT_STAT_SUSPEND;

  		switch (musb->xceiv->state) {

  		case OTG_STATE_A_HOST:

  			musb->xceiv->state = OTG_STATE_A_SUSPEND;

  			musb->is_active = is_otg_enabled(musb)

  					&& musb->xceiv->host->b_hnp_enable;

  			if (musb->is_active)
  				mod_timer(&musb->otg_timer, jiffies
  					+ msecs_to_jiffies(
  						OTG_TIME_A_AIDL_BDIS));

  			musb_platform_try_idle(musb, 0);
  			break;

  		case OTG_STATE_B_HOST:

  			musb->xceiv->state = OTG_STATE_B_WAIT_ACON;

  			musb->is_active = is_otg_enabled(musb)

  					&& musb->xceiv->host->b_hnp_enable;

  			musb_platform_try_idle(musb, 0);
  			break;

  		default:

  			dev_dbg(musb->controller, "bogus rh suspend? %s
  ",

  				otg_state_string(musb->xceiv->state));

  		}
  	} else if (power & MUSB_POWER_SUSPENDM) {
  		power &= ~MUSB_POWER_SUSPENDM;
  		power |= MUSB_POWER_RESUME;
  		musb_writeb(mbase, MUSB_POWER, power);

  		dev_dbg(musb->controller, "Root port resuming, power %02x
  ", power);

  
  		/* later, GetPortStatus will stop RESUME signaling */
  		musb->port1_status |= MUSB_PORT_STAT_RESUME;
  		musb->rh_timer = jiffies + msecs_to_jiffies(20);
  	}
  }
  
  static void musb_port_reset(struct musb *musb, bool do_reset)
  {
  	u8		power;
  	void __iomem	*mbase = musb->mregs;

  	if (musb->xceiv->state == OTG_STATE_B_IDLE) {

  		dev_dbg(musb->controller, "HNP: Returning from HNP; no hub reset from b_idle
  ");

  		musb->port1_status &= ~USB_PORT_STAT_RESET;
  		return;
  	}

  
  	if (!is_host_active(musb))
  		return;
  
  	/* NOTE:  caller guarantees it will turn off the reset when
  	 * the appropriate amount of time has passed
  	 */
  	power = musb_readb(mbase, MUSB_POWER);
  	if (do_reset) {
  
  		/*
  		 * If RESUME is set, we must make sure it stays minimum 20 ms.
  		 * Then we must clear RESUME and wait a bit to let musb start
  		 * generating SOFs. If we don't do this, OPT HS A 6.8 tests
  		 * fail with "Error! Did not receive an SOF before suspend
  		 * detected".
  		 */
  		if (power &  MUSB_POWER_RESUME) {
  			while (time_before(jiffies, musb->rh_timer))
  				msleep(1);
  			musb_writeb(mbase, MUSB_POWER,
  				power & ~MUSB_POWER_RESUME);
  			msleep(1);
  		}
  
  		musb->ignore_disconnect = true;
  		power &= 0xf0;
  		musb_writeb(mbase, MUSB_POWER,
  				power | MUSB_POWER_RESET);
  
  		musb->port1_status |= USB_PORT_STAT_RESET;
  		musb->port1_status &= ~USB_PORT_STAT_ENABLE;
  		musb->rh_timer = jiffies + msecs_to_jiffies(50);
  	} else {

  		dev_dbg(musb->controller, "root port reset stopped
  ");

  		musb_writeb(mbase, MUSB_POWER,
  				power & ~MUSB_POWER_RESET);
  
  		musb->ignore_disconnect = false;
  
  		power = musb_readb(mbase, MUSB_POWER);
  		if (power & MUSB_POWER_HSMODE) {

  			dev_dbg(musb->controller, "high-speed device connected
  ");

  			musb->port1_status |= USB_PORT_STAT_HIGH_SPEED;
  		}
  
  		musb->port1_status &= ~USB_PORT_STAT_RESET;
  		musb->port1_status |= USB_PORT_STAT_ENABLE
  					| (USB_PORT_STAT_C_RESET << 16)
  					| (USB_PORT_STAT_C_ENABLE << 16);
  		usb_hcd_poll_rh_status(musb_to_hcd(musb));
  
  		musb->vbuserr_retry = VBUSERR_RETRY_COUNT;
  	}
  }
  
  void musb_root_disconnect(struct musb *musb)
  {

  	musb->port1_status = USB_PORT_STAT_POWER
  			| (USB_PORT_STAT_C_CONNECTION << 16);

  
  	usb_hcd_poll_rh_status(musb_to_hcd(musb));
  	musb->is_active = 0;

  	switch (musb->xceiv->state) {

  	case OTG_STATE_A_SUSPEND:

  		if (is_otg_enabled(musb)
  				&& musb->xceiv->host->b_hnp_enable) {
  			musb->xceiv->state = OTG_STATE_A_PERIPHERAL;
  			musb->g.is_a_peripheral = 1;
  			break;
  		}

  		/* FALLTHROUGH */
  	case OTG_STATE_A_HOST:

  		musb->xceiv->state = OTG_STATE_A_WAIT_BCON;

  		musb->is_active = 0;
  		break;
  	case OTG_STATE_A_WAIT_VFALL:

  		musb->xceiv->state = OTG_STATE_B_IDLE;

  		break;
  	default:

  		dev_dbg(musb->controller, "host disconnect (%s)
  ",

  			otg_state_string(musb->xceiv->state));

  	}
  }
  
  
  /*---------------------------------------------------------------------*/
  
  /* Caller may or may not hold musb->lock */
  int musb_hub_status_data(struct usb_hcd *hcd, char *buf)
  {
  	struct musb	*musb = hcd_to_musb(hcd);
  	int		retval = 0;
  
  	/* called in_irq() via usb_hcd_poll_rh_status() */
  	if (musb->port1_status & 0xffff0000) {
  		*buf = 0x02;
  		retval = 1;
  	}
  	return retval;
  }
  
  int musb_hub_control(
  	struct usb_hcd	*hcd,
  	u16		typeReq,
  	u16		wValue,
  	u16		wIndex,
  	char		*buf,
  	u16		wLength)
  {
  	struct musb	*musb = hcd_to_musb(hcd);
  	u32		temp;
  	int		retval = 0;
  	unsigned long	flags;
  
  	spin_lock_irqsave(&musb->lock, flags);

  	if (unlikely(!HCD_HW_ACCESSIBLE(hcd))) {

  		spin_unlock_irqrestore(&musb->lock, flags);
  		return -ESHUTDOWN;
  	}
  
  	/* hub features:  always zero, setting is a NOP
  	 * port features: reported, sometimes updated when host is active
  	 * no indicators
  	 */
  	switch (typeReq) {
  	case ClearHubFeature:
  	case SetHubFeature:
  		switch (wValue) {
  		case C_HUB_OVER_CURRENT:
  		case C_HUB_LOCAL_POWER:
  			break;
  		default:
  			goto error;
  		}
  		break;
  	case ClearPortFeature:
  		if ((wIndex & 0xff) != 1)
  			goto error;
  
  		switch (wValue) {
  		case USB_PORT_FEAT_ENABLE:
  			break;
  		case USB_PORT_FEAT_SUSPEND:
  			musb_port_suspend(musb, false);
  			break;
  		case USB_PORT_FEAT_POWER:
  			if (!(is_otg_enabled(musb) && hcd->self.is_b_host))

  				musb_platform_set_vbus(musb, 0);

  			break;
  		case USB_PORT_FEAT_C_CONNECTION:
  		case USB_PORT_FEAT_C_ENABLE:
  		case USB_PORT_FEAT_C_OVER_CURRENT:
  		case USB_PORT_FEAT_C_RESET:
  		case USB_PORT_FEAT_C_SUSPEND:
  			break;
  		default:
  			goto error;
  		}

  		dev_dbg(musb->controller, "clear feature %d
  ", wValue);

  		musb->port1_status &= ~(1 << wValue);
  		break;
  	case GetHubDescriptor:
  		{
  		struct usb_hub_descriptor *desc = (void *)buf;
  
  		desc->bDescLength = 9;
  		desc->bDescriptorType = 0x29;
  		desc->bNbrPorts = 1;

  		desc->wHubCharacteristics = cpu_to_le16(

  				  0x0001	/* per-port power switching */
  				| 0x0010	/* no overcurrent reporting */
  				);
  		desc->bPwrOn2PwrGood = 5;	/* msec/2 */
  		desc->bHubContrCurrent = 0;
  
  		/* workaround bogus struct definition */

  		desc->u.hs.DeviceRemovable[0] = 0x02;	/* port 1 */
  		desc->u.hs.DeviceRemovable[1] = 0xff;

  		}
  		break;
  	case GetHubStatus:
  		temp = 0;
  		*(__le32 *) buf = cpu_to_le32(temp);
  		break;
  	case GetPortStatus:
  		if (wIndex != 1)
  			goto error;
  
  		/* finish RESET signaling? */
  		if ((musb->port1_status & USB_PORT_STAT_RESET)
  				&& time_after_eq(jiffies, musb->rh_timer))
  			musb_port_reset(musb, false);
  
  		/* finish RESUME signaling? */
  		if ((musb->port1_status & MUSB_PORT_STAT_RESUME)
  				&& time_after_eq(jiffies, musb->rh_timer)) {
  			u8		power;
  
  			power = musb_readb(musb->mregs, MUSB_POWER);
  			power &= ~MUSB_POWER_RESUME;

  			dev_dbg(musb->controller, "root port resume stopped, power %02x
  ",

  					power);
  			musb_writeb(musb->mregs, MUSB_POWER, power);
  
  			/* ISSUE:  DaVinci (RTL 1.300) disconnects after
  			 * resume of high speed peripherals (but not full
  			 * speed ones).
  			 */
  
  			musb->is_active = 1;
  			musb->port1_status &= ~(USB_PORT_STAT_SUSPEND
  					| MUSB_PORT_STAT_RESUME);
  			musb->port1_status |= USB_PORT_STAT_C_SUSPEND << 16;
  			usb_hcd_poll_rh_status(musb_to_hcd(musb));
  			/* NOTE: it might really be A_WAIT_BCON ... */

  			musb->xceiv->state = OTG_STATE_A_HOST;

  		}
  
  		put_unaligned(cpu_to_le32(musb->port1_status
  					& ~MUSB_PORT_STAT_RESUME),
  				(__le32 *) buf);
  
  		/* port change status is more interesting */

  		dev_dbg(musb->controller, "port status %08x
  ",

  				musb->port1_status);
  		break;
  	case SetPortFeature:
  		if ((wIndex & 0xff) != 1)
  			goto error;
  
  		switch (wValue) {
  		case USB_PORT_FEAT_POWER:
  			/* NOTE: this controller has a strange state machine
  			 * that involves "requesting sessions" according to
  			 * magic side effects from incompletely-described
  			 * rules about startup...
  			 *
  			 * This call is what really starts the host mode; be
  			 * very careful about side effects if you reorder any
  			 * initialization logic, e.g. for OTG, or change any
  			 * logic relating to VBUS power-up.
  			 */
  			if (!(is_otg_enabled(musb) && hcd->self.is_b_host))
  				musb_start(musb);
  			break;
  		case USB_PORT_FEAT_RESET:
  			musb_port_reset(musb, true);
  			break;
  		case USB_PORT_FEAT_SUSPEND:
  			musb_port_suspend(musb, true);
  			break;
  		case USB_PORT_FEAT_TEST:
  			if (unlikely(is_host_active(musb)))
  				goto error;
  
  			wIndex >>= 8;
  			switch (wIndex) {
  			case 1:
  				pr_debug("TEST_J
  ");
  				temp = MUSB_TEST_J;
  				break;
  			case 2:
  				pr_debug("TEST_K
  ");
  				temp = MUSB_TEST_K;
  				break;
  			case 3:
  				pr_debug("TEST_SE0_NAK
  ");
  				temp = MUSB_TEST_SE0_NAK;
  				break;
  			case 4:
  				pr_debug("TEST_PACKET
  ");
  				temp = MUSB_TEST_PACKET;
  				musb_load_testpacket(musb);
  				break;
  			case 5:
  				pr_debug("TEST_FORCE_ENABLE
  ");
  				temp = MUSB_TEST_FORCE_HOST
  					| MUSB_TEST_FORCE_HS;
  
  				musb_writeb(musb->mregs, MUSB_DEVCTL,
  						MUSB_DEVCTL_SESSION);
  				break;
  			case 6:
  				pr_debug("TEST_FIFO_ACCESS
  ");
  				temp = MUSB_TEST_FIFO_ACCESS;
  				break;
  			default:
  				goto error;
  			}
  			musb_writeb(musb->mregs, MUSB_TESTMODE, temp);
  			break;
  		default:
  			goto error;
  		}

  		dev_dbg(musb->controller, "set feature %d
  ", wValue);

  		musb->port1_status |= 1 << wValue;
  		break;
  
  	default:
  error:
  		/* "protocol stall" on error */
  		retval = -EPIPE;
  	}
  	spin_unlock_irqrestore(&musb->lock, flags);
  	return retval;
  }