usb: Add Intel Langwell USB OTG Transceiver Driver

This adds support for the USB transceiver driver in the Langwell chipset used
on the Intel MID platforms. It folds up the original patch set which includes
basic support for the device, PHY low power mode (Please notice that there is
a limitation, after we drive VBus down, 2ms delay is required from SCU FW to
sync up OTGSC register with USBCFG register), software timers (the hardware
timers do not work in low power mode), HNP, SRP.


Signed-off-by: Hao Wu <hao.wu@intel.com>
Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 2423 insertions, 0 deletions

diff --git a/drivers/usb/otg/Kconfig b/drivers/usb/otg/Kconfig
index 3b12895..299dfd2 100644
--- a/drivers/usb/otg/Kconfig
+++ b/drivers/usb/otg/Kconfig
@@ -67,4 +67,18 @@ config NOP_USB_XCEIV
 	 built-in with usb ip or which are autonomous and doesn't require any
 	 phy programming such as ISP1x04 etc.
 
+config USB_LANGWELL_OTG
+	tristate "Intel Langwell USB OTG dual-role support"
+	depends on USB && X86_MRST
+	select USB_OTG
+	select USB_OTG_UTILS
+	help
+	  Say Y here if you want to build Intel Langwell USB OTG
+	  transciever driver in kernel. This driver implements role
+	  switch between EHCI host driver and Langwell USB OTG
+	  client driver.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called langwell_otg.
+
 endif # USB || OTG
diff --git a/drivers/usb/otg/Makefile b/drivers/usb/otg/Makefile
index aeb49a8..b6609db 100644
--- a/drivers/usb/otg/Makefile
+++ b/drivers/usb/otg/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_USB_OTG_UTILS)	+= otg.o
 obj-$(CONFIG_USB_GPIO_VBUS)	+= gpio_vbus.o
 obj-$(CONFIG_ISP1301_OMAP)	+= isp1301_omap.o
 obj-$(CONFIG_TWL4030_USB)	+= twl4030-usb.o
+obj-$(CONFIG_USB_LANGWELL_OTG)	+= langwell_otg.o
 obj-$(CONFIG_NOP_USB_XCEIV)	+= nop-usb-xceiv.o
 obj-$(CONFIG_USB_ULPI)		+= ulpi.o
 
diff --git a/drivers/usb/otg/langwell_otg.c b/drivers/usb/otg/langwell_otg.c
new file mode 100644
index 0000000..8791880
--- /dev/null
+++ b/drivers/usb/otg/langwell_otg.c
@@ -0,0 +1,2408 @@
+/*
+ * Intel Langwell USB OTG transceiver driver
+ * Copyright (C) 2008 - 2009, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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 driver helps to switch Langwell OTG controller function between host
+ * and peripheral. It works with EHCI driver and Langwell client controller
+ * driver together.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/moduleparam.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb.h>
+#include <linux/usb/otg.h>
+#include <linux/usb/hcd.h>
+#include <linux/notifier.h>
+#include <linux/delay.h>
+#include <asm/intel_scu_ipc.h>
+
+#include <linux/usb/langwell_otg.h>
+
+#define	DRIVER_DESC		"Intel Langwell USB OTG transceiver driver"
+#define	DRIVER_VERSION		"3.0.0.32L.0003"
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Henry Yuan <hang.yuan@intel.com>, Hao Wu <hao.wu@intel.com>");
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL");
+
+static const char driver_name[] = "langwell_otg";
+
+static int langwell_otg_probe(struct pci_dev *pdev,
+			const struct pci_device_id *id);
+static void langwell_otg_remove(struct pci_dev *pdev);
+static int langwell_otg_suspend(struct pci_dev *pdev, pm_message_t message);
+static int langwell_otg_resume(struct pci_dev *pdev);
+
+static int langwell_otg_set_host(struct otg_transceiver *otg,
+				struct usb_bus *host);
+static int langwell_otg_set_peripheral(struct otg_transceiver *otg,
+				struct usb_gadget *gadget);
+static int langwell_otg_start_srp(struct otg_transceiver *otg);
+
+static const struct pci_device_id pci_ids[] = {{
+	.class =        ((PCI_CLASS_SERIAL_USB << 8) | 0xfe),
+	.class_mask =   ~0,
+	.vendor =	0x8086,
+	.device =	0x0811,
+	.subvendor =	PCI_ANY_ID,
+	.subdevice =	PCI_ANY_ID,
+}, { /* end: all zeroes */ }
+};
+
+static struct pci_driver otg_pci_driver = {
+	.name =		(char *) driver_name,
+	.id_table =	pci_ids,
+
+	.probe =	langwell_otg_probe,
+	.remove =	langwell_otg_remove,
+
+	.suspend =	langwell_otg_suspend,
+	.resume =	langwell_otg_resume,
+};
+
+static const char *state_string(enum usb_otg_state state)
+{
+	switch (state) {
+	case OTG_STATE_A_IDLE:
+		return "a_idle";
+	case OTG_STATE_A_WAIT_VRISE:
+		return "a_wait_vrise";
+	case OTG_STATE_A_WAIT_BCON:
+		return "a_wait_bcon";
+	case OTG_STATE_A_HOST:
+		return "a_host";
+	case OTG_STATE_A_SUSPEND:
+		return "a_suspend";
+	case OTG_STATE_A_PERIPHERAL:
+		return "a_peripheral";
+	case OTG_STATE_A_WAIT_VFALL:
+		return "a_wait_vfall";
+	case OTG_STATE_A_VBUS_ERR:
+		return "a_vbus_err";
+	case OTG_STATE_B_IDLE:
+		return "b_idle";
+	case OTG_STATE_B_SRP_INIT:
+		return "b_srp_init";
+	case OTG_STATE_B_PERIPHERAL:
+		return "b_peripheral";
+	case OTG_STATE_B_WAIT_ACON:
+		return "b_wait_acon";
+	case OTG_STATE_B_HOST:
+		return "b_host";
+	default:
+		return "UNDEFINED";
+	}
+}
+
+/* HSM timers */
+static inline struct langwell_otg_timer *otg_timer_initializer
+(void (*function)(unsigned long), unsigned long expires, unsigned long data)
+{
+	struct langwell_otg_timer *timer;
+	timer = kmalloc(sizeof(struct langwell_otg_timer), GFP_KERNEL);
+	if (timer == NULL)
+		return timer;
+
+	timer->function = function;
+	timer->expires = expires;
+	timer->data = data;
+	return timer;
+}
+
+static struct langwell_otg_timer *a_wait_vrise_tmr, *a_aidl_bdis_tmr,
+	*b_se0_srp_tmr, *b_srp_init_tmr;
+
+static struct list_head active_timers;
+
+static struct langwell_otg *the_transceiver;
+
+/* host/client notify transceiver when event affects HNP state */
+void langwell_update_transceiver(void)
+{
+	struct langwell_otg *lnw = the_transceiver;
+
+	dev_dbg(lnw->dev, "transceiver is updated\n");
+
+	if (!lnw->qwork)
+		return ;
+
+	queue_work(lnw->qwork, &lnw->work);
+}
+EXPORT_SYMBOL(langwell_update_transceiver);
+
+static int langwell_otg_set_host(struct otg_transceiver *otg,
+					struct usb_bus *host)
+{
+	otg->host = host;
+
+	return 0;
+}
+
+static int langwell_otg_set_peripheral(struct otg_transceiver *otg,
+					struct usb_gadget *gadget)
+{
+	otg->gadget = gadget;
+
+	return 0;
+}
+
+static int langwell_otg_set_power(struct otg_transceiver *otg,
+				unsigned mA)
+{
+	return 0;
+}
+
+/* A-device drives vbus, controlled through PMIC CHRGCNTL register*/
+static int langwell_otg_set_vbus(struct otg_transceiver *otg, bool enabled)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	u8 r;
+
+	dev_dbg(lnw->dev, "%s <--- %s\n", __func__, enabled ? "on" : "off");
+
+	/* FIXME: surely we should cache this on the first read. If not use
+	   readv to avoid two transactions */
+	if (intel_scu_ipc_ioread8(0x00, &r) < 0) {
+		dev_dbg(lnw->dev, "Failed to read PMIC register 0xD2");
+		return -EBUSY;
+	}
+	if ((r & 0x03) != 0x02) {
+		dev_dbg(lnw->dev, "not NEC PMIC attached\n");
+		return -EBUSY;
+	}
+
+	if (intel_scu_ipc_ioread8(0x20, &r) < 0) {
+		dev_dbg(lnw->dev, "Failed to read PMIC register 0xD2");
+		return -EBUSY;
+	}
+
+	if ((r & 0x20) == 0) {
+		dev_dbg(lnw->dev, "no battery attached\n");
+		return -EBUSY;
+	}
+
+	/* Workaround for battery attachment issue */
+	if (r == 0x34) {
+		dev_dbg(lnw->dev, "no battery attached on SH\n");
+		return -EBUSY;
+	}
+
+	dev_dbg(lnw->dev, "battery attached. 2 reg = %x\n", r);
+
+	/* workaround: FW detect writing 0x20/0xc0 to d4 event.
+	 * this is only for NEC PMIC.
+	 */
+
+	if (intel_scu_ipc_iowrite8(0xD4, enabled ? 0x20 : 0xC0))
+		dev_dbg(lnw->dev, "Failed to write PMIC.\n");
+
+	dev_dbg(lnw->dev, "%s --->\n", __func__);
+
+	return 0;
+}
+
+/* charge vbus or discharge vbus through a resistor to ground */
+static void langwell_otg_chrg_vbus(int on)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+	u32	val;
+
+	val = readl(lnw->iotg.base + CI_OTGSC);
+
+	if (on)
+		writel((val & ~OTGSC_INTSTS_MASK) | OTGSC_VC,
+				lnw->iotg.base + CI_OTGSC);
+	else
+		writel((val & ~OTGSC_INTSTS_MASK) | OTGSC_VD,
+				lnw->iotg.base + CI_OTGSC);
+}
+
+/* Start SRP */
+static int langwell_otg_start_srp(struct otg_transceiver *otg)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+	u32				val;
+
+	dev_dbg(lnw->dev, "%s --->\n", __func__);
+
+	val = readl(iotg->base + CI_OTGSC);
+
+	writel((val & ~OTGSC_INTSTS_MASK) | OTGSC_HADP,
+				iotg->base + CI_OTGSC);
+
+	/* Check if the data plus is finished or not */
+	msleep(8);
+	val = readl(iotg->base + CI_OTGSC);
+	if (val & (OTGSC_HADP | OTGSC_DP))
+		dev_dbg(lnw->dev, "DataLine SRP Error\n");
+
+	/* Disable interrupt - b_sess_vld */
+	val = readl(iotg->base + CI_OTGSC);
+	val &= (~(OTGSC_BSVIE | OTGSC_BSEIE));
+	writel(val, iotg->base + CI_OTGSC);
+
+	/* Start VBus SRP, drive vbus to generate VBus pulse */
+	iotg->otg.set_vbus(&iotg->otg, true);
+	msleep(15);
+	iotg->otg.set_vbus(&iotg->otg, false);
+
+	/* Enable interrupt - b_sess_vld*/
+	val = readl(iotg->base + CI_OTGSC);
+	dev_dbg(lnw->dev, "after VBUS pulse otgsc = %x\n", val);
+
+	val |= (OTGSC_BSVIE | OTGSC_BSEIE);
+	writel(val, iotg->base + CI_OTGSC);
+
+	/* If Vbus is valid, then update the hsm */
+	if (val & OTGSC_BSV) {
+		dev_dbg(lnw->dev, "no b_sess_vld interrupt\n");
+
+		lnw->iotg.hsm.b_sess_vld = 1;
+		langwell_update_transceiver();
+	}
+
+	dev_dbg(lnw->dev, "%s <---\n", __func__);
+	return 0;
+}
+
+/* stop SOF via bus_suspend */
+static void langwell_otg_loc_sof(int on)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+	struct usb_hcd		*hcd;
+	int			err;
+
+	dev_dbg(lnw->dev, "%s ---> %s\n", __func__, on ? "suspend" : "resume");
+
+	hcd = bus_to_hcd(lnw->iotg.otg.host);
+	if (on)
+		err = hcd->driver->bus_resume(hcd);
+	else
+		err = hcd->driver->bus_suspend(hcd);
+
+	if (err)
+		dev_dbg(lnw->dev, "Fail to resume/suspend USB bus - %d\n", err);
+
+	dev_dbg(lnw->dev, "%s <---\n", __func__);
+}
+
+static int langwell_otg_check_otgsc(void)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	u32				otgsc, usbcfg;
+
+	dev_dbg(lnw->dev, "check sync OTGSC and USBCFG registers\n");
+
+	otgsc = readl(lnw->iotg.base + CI_OTGSC);
+	usbcfg = readl(lnw->usbcfg);
+
+	dev_dbg(lnw->dev, "OTGSC = %08x, USBCFG = %08x\n",
+					otgsc, usbcfg);
+	dev_dbg(lnw->dev, "OTGSC_AVV = %d\n", !!(otgsc & OTGSC_AVV));
+	dev_dbg(lnw->dev, "USBCFG.VBUSVAL = %d\n",
+					!!(usbcfg & USBCFG_VBUSVAL));
+	dev_dbg(lnw->dev, "OTGSC_ASV = %d\n", !!(otgsc & OTGSC_ASV));
+	dev_dbg(lnw->dev, "USBCFG.AVALID = %d\n",
+					!!(usbcfg & USBCFG_AVALID));
+	dev_dbg(lnw->dev, "OTGSC_BSV = %d\n", !!(otgsc & OTGSC_BSV));
+	dev_dbg(lnw->dev, "USBCFG.BVALID = %d\n",
+					!!(usbcfg & USBCFG_BVALID));
+	dev_dbg(lnw->dev, "OTGSC_BSE = %d\n", !!(otgsc & OTGSC_BSE));
+	dev_dbg(lnw->dev, "USBCFG.SESEND = %d\n",
+					!!(usbcfg & USBCFG_SESEND));
+
+	/* Check USBCFG VBusValid/AValid/BValid/SessEnd */
+	if (!!(otgsc & OTGSC_AVV) ^ !!(usbcfg & USBCFG_VBUSVAL)) {
+		dev_dbg(lnw->dev, "OTGSC.AVV != USBCFG.VBUSVAL\n");
+		goto err;
+	}
+	if (!!(otgsc & OTGSC_ASV) ^ !!(usbcfg & USBCFG_AVALID)) {
+		dev_dbg(lnw->dev, "OTGSC.ASV != USBCFG.AVALID\n");
+		goto err;
+	}
+	if (!!(otgsc & OTGSC_BSV) ^ !!(usbcfg & USBCFG_BVALID)) {
+		dev_dbg(lnw->dev, "OTGSC.BSV != USBCFG.BVALID\n");
+		goto err;
+	}
+	if (!!(otgsc & OTGSC_BSE) ^ !!(usbcfg & USBCFG_SESEND)) {
+		dev_dbg(lnw->dev, "OTGSC.BSE != USBCFG.SESSEN\n");
+		goto err;
+	}
+
+	dev_dbg(lnw->dev, "OTGSC and USBCFG are synced\n");
+
+	return 0;
+
+err:
+	dev_warn(lnw->dev, "OTGSC isn't equal to USBCFG\n");
+	return -EPIPE;
+}
+
+
+static void langwell_otg_phy_low_power(int on)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+	u8				val, phcd;
+	int				retval;
+
+	dev_dbg(lnw->dev, "%s ---> %s mode\n",
+			__func__, on ? "Low power" : "Normal");
+
+	phcd = 0x40;
+
+	val = readb(iotg->base + CI_HOSTPC1 + 2);
+
+	if (on) {
+		/* Due to hardware issue, after set PHCD, sync will failed
+		 * between USBCFG and OTGSC, so before set PHCD, check if
+		 * sync is in process now. If the answer is "yes", then do
+		 * not touch PHCD bit */
+		retval = langwell_otg_check_otgsc();
+		if (retval) {
+			dev_dbg(lnw->dev, "Skip PHCD programming..\n");
+			return ;
+		}
+
+		writeb(val | phcd, iotg->base + CI_HOSTPC1 + 2);
+	} else
+		writeb(val & ~phcd, iotg->base + CI_HOSTPC1 + 2);
+
+	dev_dbg(lnw->dev, "%s <--- done\n", __func__);
+}
+
+/* After drv vbus, add 2 ms delay to set PHCD */
+static void langwell_otg_phy_low_power_wait(int on)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+
+	dev_dbg(lnw->dev, "add 2ms delay before programing PHCD\n");
+
+	mdelay(2);
+	langwell_otg_phy_low_power(on);
+}
+
+/* Enable/Disable OTG interrupt */
+static void langwell_otg_intr(int on)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+	u32				val;
+
+	dev_dbg(lnw->dev, "%s ---> %s\n", __func__, on ? "on" : "off");
+
+	val = readl(iotg->base + CI_OTGSC);
+
+	/* OTGSC_INT_MASK doesn't contains 1msInt */
+	if (on) {
+		val = val | (OTGSC_INT_MASK);
+		writel(val, iotg->base + CI_OTGSC);
+	} else {
+		val = val & ~(OTGSC_INT_MASK);
+		writel(val, iotg->base + CI_OTGSC);
+	}
+
+	dev_dbg(lnw->dev, "%s <---\n", __func__);
+}
+
+/* set HAAR: Hardware Assist Auto-Reset */
+static void langwell_otg_HAAR(int on)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+	u32				val;
+
+	dev_dbg(lnw->dev, "%s ---> %s\n", __func__, on ? "on" : "off");
+
+	val = readl(iotg->base + CI_OTGSC);
+	if (on)
+		writel((val & ~OTGSC_INTSTS_MASK) | OTGSC_HAAR,
+					iotg->base + CI_OTGSC);
+	else
+		writel((val & ~OTGSC_INTSTS_MASK) & ~OTGSC_HAAR,
+					iotg->base + CI_OTGSC);
+
+	dev_dbg(lnw->dev, "%s <---\n", __func__);
+}
+
+/* set HABA: Hardware Assist B-Disconnect to A-Connect */
+static void langwell_otg_HABA(int on)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+	u32				val;
+
+	dev_dbg(lnw->dev, "%s ---> %s\n", __func__, on ? "on" : "off");
+
+	val = readl(iotg->base + CI_OTGSC);
+	if (on)
+		writel((val & ~OTGSC_INTSTS_MASK) | OTGSC_HABA,
+					iotg->base + CI_OTGSC);
+	else
+		writel((val & ~OTGSC_INTSTS_MASK) & ~OTGSC_HABA,
+					iotg->base + CI_OTGSC);
+
+	dev_dbg(lnw->dev, "%s <---\n", __func__);
+}
+
+static int langwell_otg_check_se0_srp(int on)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+	int			delay_time = TB_SE0_SRP * 10;
+	u32			val;
+
+	dev_dbg(lnw->dev, "%s --->\n", __func__);
+
+	do {
+		udelay(100);
+		if (!delay_time--)
+			break;
+		val = readl(lnw->iotg.base + CI_PORTSC1);
+		val &= PORTSC_LS;
+	} while (!val);
+
+	dev_dbg(lnw->dev, "%s <---\n", __func__);
+	return val;
+}
+
+/* The timeout callback function to set time out bit */
+static void set_tmout(unsigned long indicator)
+{
+	*(int *)indicator = 1;
+}
+
+void langwell_otg_nsf_msg(unsigned long indicator)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+
+	switch (indicator) {
+	case 2:
+	case 4:
+	case 6:
+	case 7:
+		dev_warn(lnw->dev,
+			"OTG:NSF-%lu - deivce not responding\n", indicator);
+		break;
+	case 3:
+		dev_warn(lnw->dev,
+			"OTG:NSF-%lu - deivce not supported\n", indicator);
+		break;
+	default:
+		dev_warn(lnw->dev, "Do not have this kind of NSF\n");
+		break;
+	}
+}
+
+/* Initialize timers */
+static int langwell_otg_init_timers(struct otg_hsm *hsm)
+{
+	/* HSM used timers */
+	a_wait_vrise_tmr = otg_timer_initializer(&set_tmout, TA_WAIT_VRISE,
+				(unsigned long)&hsm->a_wait_vrise_tmout);
+	if (a_wait_vrise_tmr == NULL)
+		return -ENOMEM;
+	a_aidl_bdis_tmr = otg_timer_initializer(&set_tmout, TA_AIDL_BDIS,
+				(unsigned long)&hsm->a_aidl_bdis_tmout);
+	if (a_aidl_bdis_tmr == NULL)
+		return -ENOMEM;
+	b_se0_srp_tmr = otg_timer_initializer(&set_tmout, TB_SE0_SRP,
+				(unsigned long)&hsm->b_se0_srp);
+	if (b_se0_srp_tmr == NULL)
+		return -ENOMEM;
+	b_srp_init_tmr = otg_timer_initializer(&set_tmout, TB_SRP_INIT,
+				(unsigned long)&hsm->b_srp_init_tmout);
+	if (b_srp_init_tmr == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+/* Free timers */
+static void langwell_otg_free_timers(void)
+{
+	kfree(a_wait_vrise_tmr);
+	kfree(a_aidl_bdis_tmr);
+	kfree(b_se0_srp_tmr);
+	kfree(b_srp_init_tmr);
+}
+
+/* The timeout callback function to set time out bit */
+static void langwell_otg_timer_fn(unsigned long indicator)
+{
+	struct langwell_otg *lnw = the_transceiver;
+
+	*(int *)indicator = 1;
+
+	dev_dbg(lnw->dev, "kernel timer - timeout\n");
+
+	langwell_update_transceiver();
+}
+
+/* kernel timer used instead of HW based interrupt */
+static void langwell_otg_add_ktimer(enum langwell_otg_timer_type timers)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+	unsigned long		j = jiffies;
+	unsigned long		data, time;
+
+	switch (timers) {
+	case TA_WAIT_VRISE_TMR:
+		iotg->hsm.a_wait_vrise_tmout = 0;
+		data = (unsigned long)&iotg->hsm.a_wait_vrise_tmout;
+		time = TA_WAIT_VRISE;
+		break;
+	case TA_WAIT_BCON_TMR:
+		iotg->hsm.a_wait_bcon_tmout = 0;
+		data = (unsigned long)&iotg->hsm.a_wait_bcon_tmout;
+		time = TA_WAIT_BCON;
+		break;
+	case TA_AIDL_BDIS_TMR:
+		iotg->hsm.a_aidl_bdis_tmout = 0;
+		data = (unsigned long)&iotg->hsm.a_aidl_bdis_tmout;
+		time = TA_AIDL_BDIS;
+		break;
+	case TB_ASE0_BRST_TMR:
+		iotg->hsm.b_ase0_brst_tmout = 0;
+		data = (unsigned long)&iotg->hsm.b_ase0_brst_tmout;
+		time = TB_ASE0_BRST;
+		break;
+	case TB_SRP_INIT_TMR:
+		iotg->hsm.b_srp_init_tmout = 0;
+		data = (unsigned long)&iotg->hsm.b_srp_init_tmout;
+		time = TB_SRP_INIT;
+		break;
+	case TB_SRP_FAIL_TMR:
+		iotg->hsm.b_srp_fail_tmout = 0;
+		data = (unsigned long)&iotg->hsm.b_srp_fail_tmout;
+		time = TB_SRP_FAIL;
+		break;
+	case TB_BUS_SUSPEND_TMR:
+		iotg->hsm.b_bus_suspend_tmout = 0;
+		data = (unsigned long)&iotg->hsm.b_bus_suspend_tmout;
+		time = TB_BUS_SUSPEND;
+		break;
+	default:
+		dev_dbg(lnw->dev, "unkown timer, cannot enable it\n");
+		return;
+	}
+
+	lnw->hsm_timer.data = data;
+	lnw->hsm_timer.function = langwell_otg_timer_fn;
+	lnw->hsm_timer.expires = j + time * HZ / 1000; /* milliseconds */
+
+	add_timer(&lnw->hsm_timer);
+
+	dev_dbg(lnw->dev, "add timer successfully\n");
+}
+
+/* Add timer to timer list */
+static void langwell_otg_add_timer(void *gtimer)
+{
+	struct langwell_otg_timer *timer = (struct langwell_otg_timer *)gtimer;
+	struct langwell_otg_timer *tmp_timer;
+	struct intel_mid_otg_xceiv *iotg = &the_transceiver->iotg;
+	u32	val32;
+
+	/* Check if the timer is already in the active list,
+	 * if so update timer count
+	 */
+	list_for_each_entry(tmp_timer, &active_timers, list)
+		if (tmp_timer == timer) {
+			timer->count = timer->expires;
+			return;
+		}
+	timer->count = timer->expires;
+
+	if (list_empty(&active_timers)) {
+		val32 = readl(iotg->base + CI_OTGSC);
+		writel(val32 | OTGSC_1MSE, iotg->base + CI_OTGSC);
+	}
+
+	list_add_tail(&timer->list, &active_timers);
+}
+
+/* Remove timer from the timer list; clear timeout status */
+static void langwell_otg_del_timer(void *gtimer)
+{
+	struct langwell_otg *lnw = the_transceiver;
+	struct langwell_otg_timer *timer = (struct langwell_otg_timer *)gtimer;
+	struct langwell_otg_timer *tmp_timer, *del_tmp;
+	u32 val32;
+
+	list_for_each_entry_safe(tmp_timer, del_tmp, &active_timers, list)
+		if (tmp_timer == timer)
+			list_del(&timer->list);
+
+	if (list_empty(&active_timers)) {
+		val32 = readl(lnw->iotg.base + CI_OTGSC);
+		writel(val32 & ~OTGSC_1MSE, lnw->iotg.base + CI_OTGSC);
+	}
+}
+
+/* Reduce timer count by 1, and find timeout conditions.*/
+static int langwell_otg_tick_timer(u32 *int_sts)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+	struct langwell_otg_timer *tmp_timer, *del_tmp;
+	int expired = 0;
+
+	list_for_each_entry_safe(tmp_timer, del_tmp, &active_timers, list) {
+		tmp_timer->count--;
+		/* check if timer expires */
+		if (!tmp_timer->count) {
+			list_del(&tmp_timer->list);
+			tmp_timer->function(tmp_timer->data);
+			expired = 1;
+		}
+	}
+
+	if (list_empty(&active_timers)) {
+		dev_dbg(lnw->dev, "tick timer: disable 1ms int\n");
+		*int_sts = *int_sts & ~OTGSC_1MSE;
+	}
+	return expired;
+}
+
+static void reset_otg(void)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+	int			delay_time = 1000;
+	u32			val;
+
+	dev_dbg(lnw->dev, "reseting OTG controller ...\n");
+	val = readl(lnw->iotg.base + CI_USBCMD);
+	writel(val | USBCMD_RST, lnw->iotg.base + CI_USBCMD);
+	do {
+		udelay(100);
+		if (!delay_time--)
+			dev_dbg(lnw->dev, "reset timeout\n");
+		val = readl(lnw->iotg.base + CI_USBCMD);
+		val &= USBCMD_RST;
+	} while (val != 0);
+	dev_dbg(lnw->dev, "reset done.\n");
+}
+
+static void set_host_mode(void)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+	u32			val;
+
+	reset_otg();
+	val = readl(lnw->iotg.base + CI_USBMODE);
+	val = (val & (~USBMODE_CM)) | USBMODE_HOST;
+	writel(val, lnw->iotg.base + CI_USBMODE);
+}
+
+static void set_client_mode(void)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+	u32			val;
+
+	reset_otg();
+	val = readl(lnw->iotg.base + CI_USBMODE);
+	val = (val & (~USBMODE_CM)) | USBMODE_DEVICE;
+	writel(val, lnw->iotg.base + CI_USBMODE);
+}
+
+static void init_hsm(void)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+	u32				val32;
+
+	/* read OTGSC after reset */
+	val32 = readl(lnw->iotg.base + CI_OTGSC);
+	dev_dbg(lnw->dev, "%s: OTGSC init value = 0x%x\n", __func__, val32);
+
+	/* set init state */
+	if (val32 & OTGSC_ID) {
+		iotg->hsm.id = 1;
+		iotg->otg.default_a = 0;
+		set_client_mode();
+		iotg->otg.state = OTG_STATE_B_IDLE;
+	} else {
+		iotg->hsm.id = 0;
+		iotg->otg.default_a = 1;
+		set_host_mode();
+		iotg->otg.state = OTG_STATE_A_IDLE;
+	}
+
+	/* set session indicator */
+	if (val32 & OTGSC_BSE)
+		iotg->hsm.b_sess_end = 1;
+	if (val32 & OTGSC_BSV)
+		iotg->hsm.b_sess_vld = 1;
+	if (val32 & OTGSC_ASV)
+		iotg->hsm.a_sess_vld = 1;
+	if (val32 & OTGSC_AVV)
+		iotg->hsm.a_vbus_vld = 1;
+
+	/* defautly power the bus */
+	iotg->hsm.a_bus_req = 1;
+	iotg->hsm.a_bus_drop = 0;
+	/* defautly don't request bus as B device */
+	iotg->hsm.b_bus_req = 0;
+	/* no system error */
+	iotg->hsm.a_clr_err = 0;
+
+	langwell_otg_phy_low_power_wait(1);
+}
+
+static void update_hsm(void)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+	u32				val32;
+
+	/* read OTGSC */
+	val32 = readl(lnw->iotg.base + CI_OTGSC);
+	dev_dbg(lnw->dev, "%s: OTGSC value = 0x%x\n", __func__, val32);
+
+	iotg->hsm.id = !!(val32 & OTGSC_ID);
+	iotg->hsm.b_sess_end = !!(val32 & OTGSC_BSE);
+	iotg->hsm.b_sess_vld = !!(val32 & OTGSC_BSV);
+	iotg->hsm.a_sess_vld = !!(val32 & OTGSC_ASV);
+	iotg->hsm.a_vbus_vld = !!(val32 & OTGSC_AVV);
+}
+
+static irqreturn_t otg_dummy_irq(int irq, void *_dev)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+	void __iomem		*reg_base = _dev;
+	u32			val;
+	u32			int_mask = 0;
+
+	val = readl(reg_base + CI_USBMODE);
+	if ((val & USBMODE_CM) != USBMODE_DEVICE)
+		return IRQ_NONE;
+
+	val = readl(reg_base + CI_USBSTS);
+	int_mask = val & INTR_DUMMY_MASK;
+
+	if (int_mask == 0)
+		return IRQ_NONE;
+
+	/* clear hsm.b_conn here since host driver can't detect it
+	*  otg_dummy_irq called means B-disconnect happened.
+	*/
+	if (lnw->iotg.hsm.b_conn) {
+		lnw->iotg.hsm.b_conn = 0;
+		if (spin_trylock(&lnw->wq_lock)) {
+			langwell_update_transceiver();
+			spin_unlock(&lnw->wq_lock);
+		}
+	}
+
+	/* Clear interrupts */
+	writel(int_mask, reg_base + CI_USBSTS);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t otg_irq(int irq, void *_dev)
+{
+	struct langwell_otg		*lnw = _dev;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+	u32				int_sts, int_en;
+	u32				int_mask = 0;
+	int				flag = 0;
+
+	int_sts = readl(lnw->iotg.base + CI_OTGSC);
+	int_en = (int_sts & OTGSC_INTEN_MASK) >> 8;
+	int_mask = int_sts & int_en;
+	if (int_mask == 0)
+		return IRQ_NONE;
+
+	if (int_mask & OTGSC_IDIS) {
+		dev_dbg(lnw->dev, "%s: id change int\n", __func__);
+		iotg->hsm.id = (int_sts & OTGSC_ID) ? 1 : 0;
+		dev_dbg(lnw->dev, "id = %d\n", iotg->hsm.id);
+		flag = 1;
+	}
+	if (int_mask & OTGSC_DPIS) {
+		dev_dbg(lnw->dev, "%s: data pulse int\n", __func__);
+		iotg->hsm.a_srp_det = (int_sts & OTGSC_DPS) ? 1 : 0;
+		dev_dbg(lnw->dev, "data pulse = %d\n", iotg->hsm.a_srp_det);
+		flag = 1;
+	}
+	if (int_mask & OTGSC_BSEIS) {
+		dev_dbg(lnw->dev, "%s: b session end int\n", __func__);
+		iotg->hsm.b_sess_end = (int_sts & OTGSC_BSE) ? 1 : 0;
+		dev_dbg(lnw->dev, "b_sess_end = %d\n", iotg->hsm.b_sess_end);
+		flag = 1;
+	}
+	if (int_mask & OTGSC_BSVIS) {
+		dev_dbg(lnw->dev, "%s: b session valid int\n", __func__);
+		iotg->hsm.b_sess_vld = (int_sts & OTGSC_BSV) ? 1 : 0;
+		dev_dbg(lnw->dev, "b_sess_vld = %d\n", iotg->hsm.b_sess_end);
+		flag = 1;
+	}
+	if (int_mask & OTGSC_ASVIS) {
+		dev_dbg(lnw->dev, "%s: a session valid int\n", __func__);
+		iotg->hsm.a_sess_vld = (int_sts & OTGSC_ASV) ? 1 : 0;
+		dev_dbg(lnw->dev, "a_sess_vld = %d\n", iotg->hsm.a_sess_vld);
+		flag = 1;
+	}
+	if (int_mask & OTGSC_AVVIS) {
+		dev_dbg(lnw->dev, "%s: a vbus valid int\n", __func__);
+		iotg->hsm.a_vbus_vld = (int_sts & OTGSC_AVV) ? 1 : 0;
+		dev_dbg(lnw->dev, "a_vbus_vld = %d\n", iotg->hsm.a_vbus_vld);
+		flag = 1;
+	}
+
+	if (int_mask & OTGSC_1MSS) {
+		/* need to schedule otg_work if any timer is expired */
+		if (langwell_otg_tick_timer(&int_sts))
+			flag = 1;
+	}
+
+	writel((int_sts & ~OTGSC_INTSTS_MASK) | int_mask,
+					lnw->iotg.base + CI_OTGSC);
+	if (flag)
+		langwell_update_transceiver();
+
+	return IRQ_HANDLED;
+}
+
+static int langwell_otg_iotg_notify(struct notifier_block *nb,
+				unsigned long action, void *data)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = data;
+	int				flag = 0;
+
+	if (iotg == NULL)
+		return NOTIFY_BAD;
+
+	if (lnw == NULL)
+		return NOTIFY_BAD;
+
+	switch (action) {
+	case MID_OTG_NOTIFY_CONNECT:
+		dev_dbg(lnw->dev, "Lnw OTG Notify Connect Event\n");
+		if (iotg->otg.default_a == 1)
+			iotg->hsm.b_conn = 1;
+		else
+			iotg->hsm.a_conn = 1;
+		flag = 1;
+		break;
+	case MID_OTG_NOTIFY_DISCONN:
+		dev_dbg(lnw->dev, "Lnw OTG Notify Disconnect Event\n");
+		if (iotg->otg.default_a == 1)
+			iotg->hsm.b_conn = 0;
+		else
+			iotg->hsm.a_conn = 0;
+		flag = 1;
+		break;
+	case MID_OTG_NOTIFY_HSUSPEND:
+		dev_dbg(lnw->dev, "Lnw OTG Notify Host Bus suspend Event\n");
+		if (iotg->otg.default_a == 1)
+			iotg->hsm.a_suspend_req = 1;
+		else
+			iotg->hsm.b_bus_req = 0;
+		flag = 1;
+		break;
+	case MID_OTG_NOTIFY_HRESUME:
+		dev_dbg(lnw->dev, "Lnw OTG Notify Host Bus resume Event\n");
+		if (iotg->otg.default_a == 1)
+			iotg->hsm.b_bus_resume = 1;
+		flag = 1;
+		break;
+	case MID_OTG_NOTIFY_CSUSPEND:
+		dev_dbg(lnw->dev, "Lnw OTG Notify Client Bus suspend Event\n");
+		if (iotg->otg.default_a == 1) {
+			if (iotg->hsm.b_bus_suspend_vld == 2) {
+				iotg->hsm.b_bus_suspend = 1;
+				iotg->hsm.b_bus_suspend_vld = 0;
+				flag = 1;
+			} else {
+				iotg->hsm.b_bus_suspend_vld++;
+				flag = 0;
+			}
+		} else {
+			if (iotg->hsm.a_bus_suspend == 0) {
+				iotg->hsm.a_bus_suspend = 1;
+				flag = 1;
+			}
+		}
+		break;
+	case MID_OTG_NOTIFY_CRESUME:
+		dev_dbg(lnw->dev, "Lnw OTG Notify Client Bus resume Event\n");
+		if (iotg->otg.default_a == 0)
+			iotg->hsm.a_bus_suspend = 0;
+		flag = 0;
+		break;
+	case MID_OTG_NOTIFY_HOSTADD:
+		dev_dbg(lnw->dev, "Lnw OTG Nofity Host Driver Add\n");
+		flag = 1;
+		break;
+	case MID_OTG_NOTIFY_HOSTREMOVE:
+		dev_dbg(lnw->dev, "Lnw OTG Nofity Host Driver remove\n");
+		flag = 1;
+		break;
+	case MID_OTG_NOTIFY_CLIENTADD:
+		dev_dbg(lnw->dev, "Lnw OTG Nofity Client Driver Add\n");
+		flag = 1;
+		break;
+	case MID_OTG_NOTIFY_CLIENTREMOVE:
+		dev_dbg(lnw->dev, "Lnw OTG Nofity Client Driver remove\n");
+		flag = 1;
+		break;
+	default:
+		dev_dbg(lnw->dev, "Lnw OTG Nofity unknown notify message\n");
+		return NOTIFY_DONE;
+	}
+
+	if (flag)
+		langwell_update_transceiver();
+
+	return NOTIFY_OK;
+}
+
+static void langwell_otg_work(struct work_struct *work)
+{
+	struct langwell_otg		*lnw;
+	struct intel_mid_otg_xceiv	*iotg;
+	int				retval;
+	struct pci_dev			*pdev;
+
+	lnw = container_of(work, struct langwell_otg, work);
+	iotg = &lnw->iotg;
+	pdev = to_pci_dev(lnw->dev);
+
+	dev_dbg(lnw->dev, "%s: old state = %s\n", __func__,
+			state_string(iotg->otg.state));
+
+	switch (iotg->otg.state) {
+	case OTG_STATE_UNDEFINED:
+	case OTG_STATE_B_IDLE:
+		if (!iotg->hsm.id) {
+			langwell_otg_del_timer(b_srp_init_tmr);
+			del_timer_sync(&lnw->hsm_timer);
+
+			iotg->otg.default_a = 1;
+			iotg->hsm.a_srp_det = 0;
+
+			langwell_otg_chrg_vbus(0);
+			set_host_mode();
+			langwell_otg_phy_low_power(1);
+
+			iotg->otg.state = OTG_STATE_A_IDLE;
+			langwell_update_transceiver();
+		} else if (iotg->hsm.b_sess_vld) {
+			langwell_otg_del_timer(b_srp_init_tmr);
+			del_timer_sync(&lnw->hsm_timer);
+			iotg->hsm.b_sess_end = 0;
+			iotg->hsm.a_bus_suspend = 0;
+			langwell_otg_chrg_vbus(0);
+
+			if (lnw->iotg.start_peripheral) {
+				lnw->iotg.start_peripheral(&lnw->iotg);
+				iotg->otg.state = OTG_STATE_B_PERIPHERAL;
+			} else
+				dev_dbg(lnw->dev, "client driver not loaded\n");
+
+		} else if (iotg->hsm.b_srp_init_tmout) {
+			iotg->hsm.b_srp_init_tmout = 0;
+			dev_warn(lnw->dev, "SRP init timeout\n");
+		} else if (iotg->hsm.b_srp_fail_tmout) {
+			iotg->hsm.b_srp_fail_tmout = 0;
+			iotg->hsm.b_bus_req = 0;
+
+			/* No silence failure */
+			langwell_otg_nsf_msg(6);
+		} else if (iotg->hsm.b_bus_req && iotg->hsm.b_sess_end) {
+			del_timer_sync(&lnw->hsm_timer);
+			/* workaround for b_se0_srp detection */
+			retval = langwell_otg_check_se0_srp(0);
+			if (retval) {
+				iotg->hsm.b_bus_req = 0;
+				dev_dbg(lnw->dev, "LS isn't SE0, try later\n");
+			} else {
+				/* clear the PHCD before start srp */
+				langwell_otg_phy_low_power(0);
+
+				/* Start SRP */
+				langwell_otg_add_timer(b_srp_init_tmr);
+				iotg->otg.start_srp(&iotg->otg);
+				langwell_otg_del_timer(b_srp_init_tmr);
+				langwell_otg_add_ktimer(TB_SRP_FAIL_TMR);
+
+				/* reset PHY low power mode here */
+				langwell_otg_phy_low_power_wait(1);
+			}
+		}
+		break;
+	case OTG_STATE_B_SRP_INIT:
+		if (!iotg->hsm.id) {
+			iotg->otg.default_a = 1;
+			iotg->hsm.a_srp_det = 0;
+
+			/* Turn off VBus */
+			iotg->otg.set_vbus(&iotg->otg, false);
+			langwell_otg_chrg_vbus(0);
+			set_host_mode();
+			langwell_otg_phy_low_power(1);
+			iotg->otg.state = OTG_STATE_A_IDLE;
+			langwell_update_transceiver();
+		} else if (iotg->hsm.b_sess_vld) {
+			langwell_otg_chrg_vbus(0);
+			if (lnw->iotg.start_peripheral) {
+				lnw->iotg.start_peripheral(&lnw->iotg);
+				iotg->otg.state = OTG_STATE_B_PERIPHERAL;
+			} else
+				dev_dbg(lnw->dev, "client driver not loaded\n");
+		}
+		break;
+	case OTG_STATE_B_PERIPHERAL:
+		if (!iotg->hsm.id) {
+			iotg->otg.default_a = 1;
+			iotg->hsm.a_srp_det = 0;
+
+			langwell_otg_chrg_vbus(0);
+
+			if (lnw->iotg.stop_peripheral)
+				lnw->iotg.stop_peripheral(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"client driver has been removed.\n");
+
+			set_host_mode();
+			langwell_otg_phy_low_power(1);
+			iotg->otg.state = OTG_STATE_A_IDLE;
+			langwell_update_transceiver();
+		} else if (!iotg->hsm.b_sess_vld) {
+			iotg->hsm.b_hnp_enable = 0;
+
+			if (lnw->iotg.stop_peripheral)
+				lnw->iotg.stop_peripheral(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"client driver has been removed.\n");
+
+			iotg->otg.state = OTG_STATE_B_IDLE;
+		} else if (iotg->hsm.b_bus_req && iotg->otg.gadget &&
+					iotg->otg.gadget->b_hnp_enable &&
+					iotg->hsm.a_bus_suspend) {
+
+			if (lnw->iotg.stop_peripheral)
+				lnw->iotg.stop_peripheral(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"client driver has been removed.\n");
+
+			langwell_otg_HAAR(1);
+			iotg->hsm.a_conn = 0;
+
+			if (lnw->iotg.start_host) {
+				lnw->iotg.start_host(&lnw->iotg);
+				iotg->otg.state = OTG_STATE_B_WAIT_ACON;
+			} else
+				dev_dbg(lnw->dev,
+						"host driver not loaded.\n");
+
+			iotg->hsm.a_bus_resume = 0;
+			langwell_otg_add_ktimer(TB_ASE0_BRST_TMR);
+		}
+		break;
+
+	case OTG_STATE_B_WAIT_ACON:
+		if (!iotg->hsm.id) {
+			/* delete hsm timer for b_ase0_brst_tmr */
+			del_timer_sync(&lnw->hsm_timer);
+
+			iotg->otg.default_a = 1;
+			iotg->hsm.a_srp_det = 0;
+
+			langwell_otg_chrg_vbus(0);
+
+			langwell_otg_HAAR(0);
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			set_host_mode();
+			langwell_otg_phy_low_power(1);
+			iotg->otg.state = OTG_STATE_A_IDLE;
+			langwell_update_transceiver();
+		} else if (!iotg->hsm.b_sess_vld) {
+			/* delete hsm timer for b_ase0_brst_tmr */
+			del_timer_sync(&lnw->hsm_timer);
+
+			iotg->hsm.b_hnp_enable = 0;
+			iotg->hsm.b_bus_req = 0;
+
+			langwell_otg_chrg_vbus(0);
+			langwell_otg_HAAR(0);
+
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			set_client_mode();
+			langwell_otg_phy_low_power(1);
+			iotg->otg.state = OTG_STATE_B_IDLE;
+		} else if (iotg->hsm.a_conn) {
+			/* delete hsm timer for b_ase0_brst_tmr */
+			del_timer_sync(&lnw->hsm_timer);
+
+			langwell_otg_HAAR(0);
+			iotg->otg.state = OTG_STATE_B_HOST;
+			langwell_update_transceiver();
+		} else if (iotg->hsm.a_bus_resume ||
+				iotg->hsm.b_ase0_brst_tmout) {
+			/* delete hsm timer for b_ase0_brst_tmr */
+			del_timer_sync(&lnw->hsm_timer);
+
+			langwell_otg_HAAR(0);
+			langwell_otg_nsf_msg(7);
+
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			iotg->hsm.a_bus_suspend = 0;
+			iotg->hsm.b_bus_req = 0;
+
+			if (lnw->iotg.start_peripheral)
+				lnw->iotg.start_peripheral(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"client driver not loaded.\n");
+
+			iotg->otg.state = OTG_STATE_B_PERIPHERAL;
+		}
+		break;
+
+	case OTG_STATE_B_HOST:
+		if (!iotg->hsm.id) {
+			iotg->otg.default_a = 1;
+			iotg->hsm.a_srp_det = 0;
+
+			langwell_otg_chrg_vbus(0);
+
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			set_host_mode();
+			langwell_otg_phy_low_power(1);
+			iotg->otg.state = OTG_STATE_A_IDLE;
+			langwell_update_transceiver();
+		} else if (!iotg->hsm.b_sess_vld) {
+			iotg->hsm.b_hnp_enable = 0;
+			iotg->hsm.b_bus_req = 0;
+
+			langwell_otg_chrg_vbus(0);
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			set_client_mode();
+			langwell_otg_phy_low_power(1);
+			iotg->otg.state = OTG_STATE_B_IDLE;
+		} else if ((!iotg->hsm.b_bus_req) ||
+				(!iotg->hsm.a_conn)) {
+			iotg->hsm.b_bus_req = 0;
+			langwell_otg_loc_sof(0);
+
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			iotg->hsm.a_bus_suspend = 0;
+
+			if (lnw->iotg.start_peripheral)
+				lnw->iotg.start_peripheral(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+						"client driver not loaded.\n");
+
+			iotg->otg.state = OTG_STATE_B_PERIPHERAL;
+		}
+		break;
+
+	case OTG_STATE_A_IDLE:
+		iotg->otg.default_a = 1;
+		if (iotg->hsm.id) {
+			iotg->otg.default_a = 0;
+			iotg->hsm.b_bus_req = 0;
+			iotg->hsm.vbus_srp_up = 0;
+
+			langwell_otg_chrg_vbus(0);
+			set_client_mode();
+			langwell_otg_phy_low_power(1);
+			iotg->otg.state = OTG_STATE_B_IDLE;
+			langwell_update_transceiver();
+		} else if (!iotg->hsm.a_bus_drop &&
+			(iotg->hsm.a_srp_det || iotg->hsm.a_bus_req)) {
+			langwell_otg_phy_low_power(0);
+
+			/* Turn on VBus */
+			iotg->otg.set_vbus(&iotg->otg, true);
+
+			iotg->hsm.vbus_srp_up = 0;
+			iotg->hsm.a_wait_vrise_tmout = 0;
+			langwell_otg_add_timer(a_wait_vrise_tmr);
+			iotg->otg.state = OTG_STATE_A_WAIT_VRISE;
+			langwell_update_transceiver();
+		} else if (!iotg->hsm.a_bus_drop && iotg->hsm.a_sess_vld) {
+			iotg->hsm.vbus_srp_up = 1;
+		} else if (!iotg->hsm.a_sess_vld && iotg->hsm.vbus_srp_up) {
+			msleep(10);
+			langwell_otg_phy_low_power(0);
+
+			/* Turn on VBus */
+			iotg->otg.set_vbus(&iotg->otg, true);
+			iotg->hsm.a_srp_det = 1;
+			iotg->hsm.vbus_srp_up = 0;
+			iotg->hsm.a_wait_vrise_tmout = 0;
+			langwell_otg_add_timer(a_wait_vrise_tmr);
+			iotg->otg.state = OTG_STATE_A_WAIT_VRISE;
+			langwell_update_transceiver();
+		} else if (!iotg->hsm.a_sess_vld &&
+				!iotg->hsm.vbus_srp_up) {
+			langwell_otg_phy_low_power(1);
+		}
+		break;
+	case OTG_STATE_A_WAIT_VRISE:
+		if (iotg->hsm.id) {
+			langwell_otg_del_timer(a_wait_vrise_tmr);
+			iotg->hsm.b_bus_req = 0;
+			iotg->otg.default_a = 0;
+
+			/* Turn off VBus */
+			iotg->otg.set_vbus(&iotg->otg, false);
+			set_client_mode();
+			langwell_otg_phy_low_power_wait(1);
+			iotg->otg.state = OTG_STATE_B_IDLE;
+		} else if (iotg->hsm.a_vbus_vld) {
+			langwell_otg_del_timer(a_wait_vrise_tmr);
+			iotg->hsm.b_conn = 0;
+			if (lnw->iotg.start_host)
+				lnw->iotg.start_host(&lnw->iotg);
+			else {
+				dev_dbg(lnw->dev, "host driver not loaded.\n");
+				break;
+			}
+
+			langwell_otg_add_ktimer(TA_WAIT_BCON_TMR);
+			iotg->otg.state = OTG_STATE_A_WAIT_BCON;
+		} else if (iotg->hsm.a_wait_vrise_tmout) {
+			iotg->hsm.b_conn = 0;
+			if (iotg->hsm.a_vbus_vld) {
+				if (lnw->iotg.start_host)
+					lnw->iotg.start_host(&lnw->iotg);
+				else {
+					dev_dbg(lnw->dev,
+						"host driver not loaded.\n");
+					break;
+				}
+				langwell_otg_add_ktimer(TA_WAIT_BCON_TMR);
+				iotg->otg.state = OTG_STATE_A_WAIT_BCON;
+			} else {
+
+				/* Turn off VBus */
+				iotg->otg.set_vbus(&iotg->otg, false);
+				langwell_otg_phy_low_power_wait(1);
+				iotg->otg.state = OTG_STATE_A_VBUS_ERR;
+			}
+		}
+		break;
+	case OTG_STATE_A_WAIT_BCON:
+		if (iotg->hsm.id) {
+			/* delete hsm timer for a_wait_bcon_tmr */
+			del_timer_sync(&lnw->hsm_timer);
+
+			iotg->otg.default_a = 0;
+			iotg->hsm.b_bus_req = 0;
+
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			/* Turn off VBus */
+			iotg->otg.set_vbus(&iotg->otg, false);
+			set_client_mode();
+			langwell_otg_phy_low_power_wait(1);
+			iotg->otg.state = OTG_STATE_B_IDLE;
+			langwell_update_transceiver();
+		} else if (!iotg->hsm.a_vbus_vld) {
+			/* delete hsm timer for a_wait_bcon_tmr */
+			del_timer_sync(&lnw->hsm_timer);
+
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			/* Turn off VBus */
+			iotg->otg.set_vbus(&iotg->otg, false);
+			langwell_otg_phy_low_power_wait(1);
+			iotg->otg.state = OTG_STATE_A_VBUS_ERR;
+		} else if (iotg->hsm.a_bus_drop ||
+				(iotg->hsm.a_wait_bcon_tmout &&
+				!iotg->hsm.a_bus_req)) {
+			/* delete hsm timer for a_wait_bcon_tmr */
+			del_timer_sync(&lnw->hsm_timer);
+
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			/* Turn off VBus */
+			iotg->otg.set_vbus(&iotg->otg, false);
+			iotg->otg.state = OTG_STATE_A_WAIT_VFALL;
+		} else if (iotg->hsm.b_conn) {
+			/* delete hsm timer for a_wait_bcon_tmr */
+			del_timer_sync(&lnw->hsm_timer);
+
+			iotg->hsm.a_suspend_req = 0;
+			iotg->otg.state = OTG_STATE_A_HOST;
+			if (iotg->hsm.a_srp_det && iotg->otg.host &&
+					!iotg->otg.host->b_hnp_enable) {
+				/* SRP capable peripheral-only device */
+				iotg->hsm.a_bus_req = 1;
+				iotg->hsm.a_srp_det = 0;
+			} else if (!iotg->hsm.a_bus_req && iotg->otg.host &&
+					iotg->otg.host->b_hnp_enable) {
+				/* It is not safe enough to do a fast
+				 * transistion from A_WAIT_BCON to
+				 * A_SUSPEND */
+				msleep(10000);
+				if (iotg->hsm.a_bus_req)
+					break;
+
+				if (request_irq(pdev->irq,
+					otg_dummy_irq, IRQF_SHARED,
+					driver_name, iotg->base) != 0) {
+					dev_dbg(lnw->dev,
+						"request interrupt %d fail\n",
+						pdev->irq);
+				}
+
+				langwell_otg_HABA(1);
+				iotg->hsm.b_bus_resume = 0;
+				iotg->hsm.a_aidl_bdis_tmout = 0;
+
+				langwell_otg_loc_sof(0);
+				/* clear PHCD to enable HW timer */
+				langwell_otg_phy_low_power(0);
+				langwell_otg_add_timer(a_aidl_bdis_tmr);
+				iotg->otg.state = OTG_STATE_A_SUSPEND;
+			} else if (!iotg->hsm.a_bus_req && iotg->otg.host &&
+				!iotg->otg.host->b_hnp_enable) {
+				if (lnw->iotg.stop_host)
+					lnw->iotg.stop_host(&lnw->iotg);
+				else
+					dev_dbg(lnw->dev,
+						"host driver removed.\n");
+
+				/* Turn off VBus */
+				iotg->otg.set_vbus(&iotg->otg, false);
+				iotg->otg.state = OTG_STATE_A_WAIT_VFALL;
+			}
+		}
+		break;
+	case OTG_STATE_A_HOST:
+		if (iotg->hsm.id) {
+			iotg->otg.default_a = 0;
+			iotg->hsm.b_bus_req = 0;
+
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			/* Turn off VBus */
+			iotg->otg.set_vbus(&iotg->otg, false);
+			set_client_mode();
+			langwell_otg_phy_low_power_wait(1);
+			iotg->otg.state = OTG_STATE_B_IDLE;
+			langwell_update_transceiver();
+		} else if (iotg->hsm.a_bus_drop ||
+				(iotg->otg.host &&
+				!iotg->otg.host->b_hnp_enable &&
+					!iotg->hsm.a_bus_req)) {
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			/* Turn off VBus */
+			iotg->otg.set_vbus(&iotg->otg, false);
+			iotg->otg.state = OTG_STATE_A_WAIT_VFALL;
+		} else if (!iotg->hsm.a_vbus_vld) {
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			/* Turn off VBus */
+			iotg->otg.set_vbus(&iotg->otg, false);
+			langwell_otg_phy_low_power_wait(1);
+			iotg->otg.state = OTG_STATE_A_VBUS_ERR;
+		} else if (iotg->otg.host &&
+				iotg->otg.host->b_hnp_enable &&
+				!iotg->hsm.a_bus_req) {
+			/* Set HABA to enable hardware assistance to signal
+			 *  A-connect after receiver B-disconnect. Hardware
+			 *  will then set client mode and enable URE, SLE and
+			 *  PCE after the assistance. otg_dummy_irq is used to
+			 *  clean these ints when client driver is not resumed.
+			 */
+			if (request_irq(pdev->irq, otg_dummy_irq, IRQF_SHARED,
+					driver_name, iotg->base) != 0) {
+				dev_dbg(lnw->dev,
+					"request interrupt %d failed\n",
+						pdev->irq);
+			}
+
+			/* set HABA */
+			langwell_otg_HABA(1);
+			iotg->hsm.b_bus_resume = 0;
+			iotg->hsm.a_aidl_bdis_tmout = 0;
+			langwell_otg_loc_sof(0);
+			/* clear PHCD to enable HW timer */
+			langwell_otg_phy_low_power(0);
+			langwell_otg_add_timer(a_aidl_bdis_tmr);
+			iotg->otg.state = OTG_STATE_A_SUSPEND;
+		} else if (!iotg->hsm.b_conn || !iotg->hsm.a_bus_req) {
+			langwell_otg_add_ktimer(TA_WAIT_BCON_TMR);
+			iotg->otg.state = OTG_STATE_A_WAIT_BCON;
+		}
+		break;
+	case OTG_STATE_A_SUSPEND:
+		if (iotg->hsm.id) {
+			langwell_otg_del_timer(a_aidl_bdis_tmr);
+			langwell_otg_HABA(0);
+			free_irq(pdev->irq, iotg->base);
+			iotg->otg.default_a = 0;
+			iotg->hsm.b_bus_req = 0;
+
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			/* Turn off VBus */
+			iotg->otg.set_vbus(&iotg->otg, false);
+			set_client_mode();
+			langwell_otg_phy_low_power(1);
+			iotg->otg.state = OTG_STATE_B_IDLE;
+			langwell_update_transceiver();
+		} else if (iotg->hsm.a_bus_req ||
+				iotg->hsm.b_bus_resume) {
+			langwell_otg_del_timer(a_aidl_bdis_tmr);
+			langwell_otg_HABA(0);
+			free_irq(pdev->irq, iotg->base);
+			iotg->hsm.a_suspend_req = 0;
+			langwell_otg_loc_sof(1);
+			iotg->otg.state = OTG_STATE_A_HOST;
+		} else if (iotg->hsm.a_aidl_bdis_tmout ||
+				iotg->hsm.a_bus_drop) {
+			langwell_otg_del_timer(a_aidl_bdis_tmr);
+			langwell_otg_HABA(0);
+			free_irq(pdev->irq, iotg->base);
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			/* Turn off VBus */
+			iotg->otg.set_vbus(&iotg->otg, false);
+			iotg->otg.state = OTG_STATE_A_WAIT_VFALL;
+		} else if (!iotg->hsm.b_conn && iotg->otg.host &&
+				iotg->otg.host->b_hnp_enable) {
+			langwell_otg_del_timer(a_aidl_bdis_tmr);
+			langwell_otg_HABA(0);
+			free_irq(pdev->irq, iotg->base);
+
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			iotg->hsm.b_bus_suspend = 0;
+			iotg->hsm.b_bus_suspend_vld = 0;
+
+			/* msleep(200); */
+			if (lnw->iotg.start_peripheral)
+				lnw->iotg.start_peripheral(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"client driver not loaded.\n");
+
+			langwell_otg_add_ktimer(TB_BUS_SUSPEND_TMR);
+			iotg->otg.state = OTG_STATE_A_PERIPHERAL;
+			break;
+		} else if (!iotg->hsm.a_vbus_vld) {
+			langwell_otg_del_timer(a_aidl_bdis_tmr);
+			langwell_otg_HABA(0);
+			free_irq(pdev->irq, iotg->base);
+			if (lnw->iotg.stop_host)
+				lnw->iotg.stop_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"host driver has been removed.\n");
+
+			/* Turn off VBus */
+			iotg->otg.set_vbus(&iotg->otg, false);
+			langwell_otg_phy_low_power_wait(1);
+			iotg->otg.state = OTG_STATE_A_VBUS_ERR;
+		}
+		break;
+	case OTG_STATE_A_PERIPHERAL:
+		if (iotg->hsm.id) {
+			/* delete hsm timer for b_bus_suspend_tmr */
+			del_timer_sync(&lnw->hsm_timer);
+			iotg->otg.default_a = 0;
+			iotg->hsm.b_bus_req = 0;
+			if (lnw->iotg.stop_peripheral)
+				lnw->iotg.stop_peripheral(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"client driver has been removed.\n");
+
+			/* Turn off VBus */
+			iotg->otg.set_vbus(&iotg->otg, false);
+			set_client_mode();
+			langwell_otg_phy_low_power_wait(1);
+			iotg->otg.state = OTG_STATE_B_IDLE;
+			langwell_update_transceiver();
+		} else if (!iotg->hsm.a_vbus_vld) {
+			/* delete hsm timer for b_bus_suspend_tmr */
+			del_timer_sync(&lnw->hsm_timer);
+
+			if (lnw->iotg.stop_peripheral)
+				lnw->iotg.stop_peripheral(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"client driver has been removed.\n");
+
+			/* Turn off VBus */
+			iotg->otg.set_vbus(&iotg->otg, false);
+			langwell_otg_phy_low_power_wait(1);
+			iotg->otg.state = OTG_STATE_A_VBUS_ERR;
+		} else if (iotg->hsm.a_bus_drop) {
+			/* delete hsm timer for b_bus_suspend_tmr */
+			del_timer_sync(&lnw->hsm_timer);
+
+			if (lnw->iotg.stop_peripheral)
+				lnw->iotg.stop_peripheral(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"client driver has been removed.\n");
+
+			/* Turn off VBus */
+			iotg->otg.set_vbus(&iotg->otg, false);
+			iotg->otg.state = OTG_STATE_A_WAIT_VFALL;
+		} else if (iotg->hsm.b_bus_suspend) {
+			/* delete hsm timer for b_bus_suspend_tmr */
+			del_timer_sync(&lnw->hsm_timer);
+
+			if (lnw->iotg.stop_peripheral)
+				lnw->iotg.stop_peripheral(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"client driver has been removed.\n");
+
+			if (lnw->iotg.start_host)
+				lnw->iotg.start_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+						"host driver not loaded.\n");
+			langwell_otg_add_ktimer(TA_WAIT_BCON_TMR);
+			iotg->otg.state = OTG_STATE_A_WAIT_BCON;
+		} else if (iotg->hsm.b_bus_suspend_tmout) {
+			u32	val;
+			val = readl(lnw->iotg.base + CI_PORTSC1);
+			if (!(val & PORTSC_SUSP))
+				break;
+
+			if (lnw->iotg.stop_peripheral)
+				lnw->iotg.stop_peripheral(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+					"client driver has been removed.\n");
+
+			if (lnw->iotg.start_host)
+				lnw->iotg.start_host(&lnw->iotg);
+			else
+				dev_dbg(lnw->dev,
+						"host driver not loaded.\n");
+			langwell_otg_add_ktimer(TA_WAIT_BCON_TMR);
+			iotg->otg.state = OTG_STATE_A_WAIT_BCON;
+		}
+		break;
+	case OTG_STATE_A_VBUS_ERR:
+		if (iotg->hsm.id) {
+			iotg->otg.default_a = 0;
+			iotg->hsm.a_clr_err = 0;
+			iotg->hsm.a_srp_det = 0;
+			set_client_mode();
+			langwell_otg_phy_low_power(1);
+			iotg->otg.state = OTG_STATE_B_IDLE;
+			langwell_update_transceiver();
+		} else if (iotg->hsm.a_clr_err) {
+			iotg->hsm.a_clr_err = 0;
+			iotg->hsm.a_srp_det = 0;
+			reset_otg();
+			init_hsm();
+			if (iotg->otg.state == OTG_STATE_A_IDLE)
+				langwell_update_transceiver();
+		} else {
+			/* FW will clear PHCD bit when any VBus
+			 * event detected. Reset PHCD to 1 again */
+			langwell_otg_phy_low_power(1);
+		}
+		break;
+	case OTG_STATE_A_WAIT_VFALL:
+		if (iotg->hsm.id) {
+			iotg->otg.default_a = 0;
+			set_client_mode();
+			langwell_otg_phy_low_power(1);
+			iotg->otg.state = OTG_STATE_B_IDLE;
+			langwell_update_transceiver();
+		} else if (iotg->hsm.a_bus_req) {
+
+			/* Turn on VBus */
+			iotg->otg.set_vbus(&iotg->otg, true);
+			iotg->hsm.a_wait_vrise_tmout = 0;
+			langwell_otg_add_timer(a_wait_vrise_tmr);
+			iotg->otg.state = OTG_STATE_A_WAIT_VRISE;
+		} else if (!iotg->hsm.a_sess_vld) {
+			iotg->hsm.a_srp_det = 0;
+			set_host_mode();
+			langwell_otg_phy_low_power(1);
+			iotg->otg.state = OTG_STATE_A_IDLE;
+		}
+		break;
+	default:
+		;
+	}
+
+	dev_dbg(lnw->dev, "%s: new state = %s\n", __func__,
+			state_string(iotg->otg.state));
+}
+
+static ssize_t
+show_registers(struct device *_dev, struct device_attribute *attr, char *buf)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+	char			*next;
+	unsigned		size, t;
+
+	next = buf;
+	size = PAGE_SIZE;
+
+	t = scnprintf(next, size,
+		"\n"
+		"USBCMD = 0x%08x\n"
+		"USBSTS = 0x%08x\n"
+		"USBINTR = 0x%08x\n"
+		"ASYNCLISTADDR = 0x%08x\n"
+		"PORTSC1 = 0x%08x\n"
+		"HOSTPC1 = 0x%08x\n"
+		"OTGSC = 0x%08x\n"
+		"USBMODE = 0x%08x\n",
+		readl(lnw->iotg.base + 0x30),
+		readl(lnw->iotg.base + 0x34),
+		readl(lnw->iotg.base + 0x38),
+		readl(lnw->iotg.base + 0x48),
+		readl(lnw->iotg.base + 0x74),
+		readl(lnw->iotg.base + 0xb4),
+		readl(lnw->iotg.base + 0xf4),
+		readl(lnw->iotg.base + 0xf8)
+	     );
+	size -= t;
+	next += t;
+
+	return PAGE_SIZE - size;
+}
+static DEVICE_ATTR(registers, S_IRUGO, show_registers, NULL);
+
+static ssize_t
+show_hsm(struct device *_dev, struct device_attribute *attr, char *buf)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+	char				*next;
+	unsigned			size, t;
+
+	next = buf;
+	size = PAGE_SIZE;
+
+	if (iotg->otg.host)
+		iotg->hsm.a_set_b_hnp_en = iotg->otg.host->b_hnp_enable;
+
+	if (iotg->otg.gadget)
+		iotg->hsm.b_hnp_enable = iotg->otg.gadget->b_hnp_enable;
+
+	t = scnprintf(next, size,
+		"\n"
+		"current state = %s\n"
+		"a_bus_resume = \t%d\n"
+		"a_bus_suspend = \t%d\n"
+		"a_conn = \t%d\n"
+		"a_sess_vld = \t%d\n"
+		"a_srp_det = \t%d\n"
+		"a_vbus_vld = \t%d\n"
+		"b_bus_resume = \t%d\n"
+		"b_bus_suspend = \t%d\n"
+		"b_conn = \t%d\n"
+		"b_se0_srp = \t%d\n"
+		"b_sess_end = \t%d\n"
+		"b_sess_vld = \t%d\n"
+		"id = \t%d\n"
+		"a_set_b_hnp_en = \t%d\n"
+		"b_srp_done = \t%d\n"
+		"b_hnp_enable = \t%d\n"
+		"a_wait_vrise_tmout = \t%d\n"
+		"a_wait_bcon_tmout = \t%d\n"
+		"a_aidl_bdis_tmout = \t%d\n"
+		"b_ase0_brst_tmout = \t%d\n"
+		"a_bus_drop = \t%d\n"
+		"a_bus_req = \t%d\n"
+		"a_clr_err = \t%d\n"
+		"a_suspend_req = \t%d\n"
+		"b_bus_req = \t%d\n"
+		"b_bus_suspend_tmout = \t%d\n"
+		"b_bus_suspend_vld = \t%d\n",
+		state_string(iotg->otg.state),
+		iotg->hsm.a_bus_resume,
+		iotg->hsm.a_bus_suspend,
+		iotg->hsm.a_conn,
+		iotg->hsm.a_sess_vld,
+		iotg->hsm.a_srp_det,
+		iotg->hsm.a_vbus_vld,
+		iotg->hsm.b_bus_resume,
+		iotg->hsm.b_bus_suspend,
+		iotg->hsm.b_conn,
+		iotg->hsm.b_se0_srp,
+		iotg->hsm.b_sess_end,
+		iotg->hsm.b_sess_vld,
+		iotg->hsm.id,
+		iotg->hsm.a_set_b_hnp_en,
+		iotg->hsm.b_srp_done,
+		iotg->hsm.b_hnp_enable,
+		iotg->hsm.a_wait_vrise_tmout,
+		iotg->hsm.a_wait_bcon_tmout,
+		iotg->hsm.a_aidl_bdis_tmout,
+		iotg->hsm.b_ase0_brst_tmout,
+		iotg->hsm.a_bus_drop,
+		iotg->hsm.a_bus_req,
+		iotg->hsm.a_clr_err,
+		iotg->hsm.a_suspend_req,
+		iotg->hsm.b_bus_req,
+		iotg->hsm.b_bus_suspend_tmout,
+		iotg->hsm.b_bus_suspend_vld
+		);
+	size -= t;
+	next += t;
+
+	return PAGE_SIZE - size;
+}
+static DEVICE_ATTR(hsm, S_IRUGO, show_hsm, NULL);
+
+static ssize_t
+get_a_bus_req(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+	char			*next;
+	unsigned		size, t;
+
+	next = buf;
+	size = PAGE_SIZE;
+
+	t = scnprintf(next, size, "%d", lnw->iotg.hsm.a_bus_req);
+	size -= t;
+	next += t;
+
+	return PAGE_SIZE - size;
+}
+
+static ssize_t
+set_a_bus_req(struct device *dev, struct device_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+
+	if (!iotg->otg.default_a)
+		return -1;
+	if (count > 2)
+		return -1;
+
+	if (buf[0] == '0') {
+		iotg->hsm.a_bus_req = 0;
+		dev_dbg(lnw->dev, "User request: a_bus_req = 0\n");
+	} else if (buf[0] == '1') {
+		/* If a_bus_drop is TRUE, a_bus_req can't be set */
+		if (iotg->hsm.a_bus_drop)
+			return -1;
+		iotg->hsm.a_bus_req = 1;
+		dev_dbg(lnw->dev, "User request: a_bus_req = 1\n");
+	}
+	if (spin_trylock(&lnw->wq_lock)) {
+		langwell_update_transceiver();
+		spin_unlock(&lnw->wq_lock);
+	}
+	return count;
+}
+static DEVICE_ATTR(a_bus_req, S_IRUGO | S_IWUGO, get_a_bus_req, set_a_bus_req);
+
+static ssize_t
+get_a_bus_drop(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+	char			*next;
+	unsigned		size, t;
+
+	next = buf;
+	size = PAGE_SIZE;
+
+	t = scnprintf(next, size, "%d", lnw->iotg.hsm.a_bus_drop);
+	size -= t;
+	next += t;
+
+	return PAGE_SIZE - size;
+}
+
+static ssize_t
+set_a_bus_drop(struct device *dev, struct device_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+
+	if (!iotg->otg.default_a)
+		return -1;
+	if (count > 2)
+		return -1;
+
+	if (buf[0] == '0') {
+		iotg->hsm.a_bus_drop = 0;
+		dev_dbg(lnw->dev, "User request: a_bus_drop = 0\n");
+	} else if (buf[0] == '1') {
+		iotg->hsm.a_bus_drop = 1;
+		iotg->hsm.a_bus_req = 0;
+		dev_dbg(lnw->dev, "User request: a_bus_drop = 1\n");
+		dev_dbg(lnw->dev, "User request: and a_bus_req = 0\n");
+	}
+	if (spin_trylock(&lnw->wq_lock)) {
+		langwell_update_transceiver();
+		spin_unlock(&lnw->wq_lock);
+	}
+	return count;
+}
+static DEVICE_ATTR(a_bus_drop, S_IRUGO | S_IWUGO,
+	get_a_bus_drop, set_a_bus_drop);
+
+static ssize_t
+get_b_bus_req(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+	char			*next;
+	unsigned		size, t;
+
+	next = buf;
+	size = PAGE_SIZE;
+
+	t = scnprintf(next, size, "%d", lnw->iotg.hsm.b_bus_req);
+	size -= t;
+	next += t;
+
+	return PAGE_SIZE - size;
+}
+
+static ssize_t
+set_b_bus_req(struct device *dev, struct device_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+
+	if (iotg->otg.default_a)
+		return -1;
+
+	if (count > 2)
+		return -1;
+
+	if (buf[0] == '0') {
+		iotg->hsm.b_bus_req = 0;
+		dev_dbg(lnw->dev, "User request: b_bus_req = 0\n");
+	} else if (buf[0] == '1') {
+		iotg->hsm.b_bus_req = 1;
+		dev_dbg(lnw->dev, "User request: b_bus_req = 1\n");
+	}
+	if (spin_trylock(&lnw->wq_lock)) {
+		langwell_update_transceiver();
+		spin_unlock(&lnw->wq_lock);
+	}
+	return count;
+}
+static DEVICE_ATTR(b_bus_req, S_IRUGO | S_IWUGO, get_b_bus_req, set_b_bus_req);
+
+static ssize_t
+set_a_clr_err(struct device *dev, struct device_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+
+	if (!iotg->otg.default_a)
+		return -1;
+	if (count > 2)
+		return -1;
+
+	if (buf[0] == '1') {
+		iotg->hsm.a_clr_err = 1;
+		dev_dbg(lnw->dev, "User request: a_clr_err = 1\n");
+	}
+	if (spin_trylock(&lnw->wq_lock)) {
+		langwell_update_transceiver();
+		spin_unlock(&lnw->wq_lock);
+	}
+	return count;
+}
+static DEVICE_ATTR(a_clr_err, S_IWUGO, NULL, set_a_clr_err);
+
+static struct attribute *inputs_attrs[] = {
+	&dev_attr_a_bus_req.attr,
+	&dev_attr_a_bus_drop.attr,
+	&dev_attr_b_bus_req.attr,
+	&dev_attr_a_clr_err.attr,
+	NULL,
+};
+
+static struct attribute_group debug_dev_attr_group = {
+	.name = "inputs",
+	.attrs = inputs_attrs,
+};
+
+static int langwell_otg_probe(struct pci_dev *pdev,
+		const struct pci_device_id *id)
+{
+	unsigned long		resource, len;
+	void __iomem		*base = NULL;
+	int			retval;
+	u32			val32;
+	struct langwell_otg	*lnw;
+	char			qname[] = "langwell_otg_queue";
+
+	retval = 0;
+	dev_dbg(&pdev->dev, "\notg controller is detected.\n");
+	if (pci_enable_device(pdev) < 0) {
+		retval = -ENODEV;
+		goto done;
+	}
+
+	lnw = kzalloc(sizeof *lnw, GFP_KERNEL);
+	if (lnw == NULL) {
+		retval = -ENOMEM;
+		goto done;
+	}
+	the_transceiver = lnw;
+
+	/* control register: BAR 0 */
+	resource = pci_resource_start(pdev, 0);
+	len = pci_resource_len(pdev, 0);
+	if (!request_mem_region(resource, len, driver_name)) {
+		retval = -EBUSY;
+		goto err;
+	}
+	lnw->region = 1;
+
+	base = ioremap_nocache(resource, len);
+	if (base == NULL) {
+		retval = -EFAULT;
+		goto err;
+	}
+	lnw->iotg.base = base;
+
+	if (!request_mem_region(USBCFG_ADDR, USBCFG_LEN, driver_name)) {
+		retval = -EBUSY;
+		goto err;
+	}
+	lnw->cfg_region = 1;
+
+	/* For the SCCB.USBCFG register */
+	base = ioremap_nocache(USBCFG_ADDR, USBCFG_LEN);
+	if (base == NULL) {
+		retval = -EFAULT;
+		goto err;
+	}
+	lnw->usbcfg = base;
+
+	if (!pdev->irq) {
+		dev_dbg(&pdev->dev, "No IRQ.\n");
+		retval = -ENODEV;
+		goto err;
+	}
+
+	lnw->qwork = create_singlethread_workqueue(qname);
+	if (!lnw->qwork) {
+		dev_dbg(&pdev->dev, "cannot create workqueue %s\n", qname);
+		retval = -ENOMEM;
+		goto err;
+	}
+	INIT_WORK(&lnw->work, langwell_otg_work);
+
+	/* OTG common part */
+	lnw->dev = &pdev->dev;
+	lnw->iotg.otg.dev = lnw->dev;
+	lnw->iotg.otg.label = driver_name;
+	lnw->iotg.otg.set_host = langwell_otg_set_host;
+	lnw->iotg.otg.set_peripheral = langwell_otg_set_peripheral;
+	lnw->iotg.otg.set_power = langwell_otg_set_power;
+	lnw->iotg.otg.set_vbus = langwell_otg_set_vbus;
+	lnw->iotg.otg.start_srp = langwell_otg_start_srp;
+	lnw->iotg.otg.state = OTG_STATE_UNDEFINED;
+
+	if (otg_set_transceiver(&lnw->iotg.otg)) {
+		dev_dbg(lnw->dev, "can't set transceiver\n");
+		retval = -EBUSY;
+		goto err;
+	}
+
+	reset_otg();
+	init_hsm();
+
+	spin_lock_init(&lnw->lock);
+	spin_lock_init(&lnw->wq_lock);
+	INIT_LIST_HEAD(&active_timers);
+	retval = langwell_otg_init_timers(&lnw->iotg.hsm);
+	if (retval) {
+		dev_dbg(&pdev->dev, "Failed to init timers\n");
+		goto err;
+	}
+
+	init_timer(&lnw->hsm_timer);
+	ATOMIC_INIT_NOTIFIER_HEAD(&lnw->iotg.iotg_notifier);
+
+	lnw->iotg_notifier.notifier_call = langwell_otg_iotg_notify;
+
+	retval = intel_mid_otg_register_notifier(&lnw->iotg,
+						&lnw->iotg_notifier);
+	if (retval) {
+		dev_dbg(lnw->dev, "Failed to register notifier\n");
+		goto err;
+	}
+
+	if (request_irq(pdev->irq, otg_irq, IRQF_SHARED,
+				driver_name, lnw) != 0) {
+		dev_dbg(lnw->dev, "request interrupt %d failed\n", pdev->irq);
+		retval = -EBUSY;
+		goto err;
+	}
+
+	/* enable OTGSC int */
+	val32 = OTGSC_DPIE | OTGSC_BSEIE | OTGSC_BSVIE |
+		OTGSC_ASVIE | OTGSC_AVVIE | OTGSC_IDIE | OTGSC_IDPU;
+	writel(val32, lnw->iotg.base + CI_OTGSC);
+
+	retval = device_create_file(&pdev->dev, &dev_attr_registers);
+	if (retval < 0) {
+		dev_dbg(lnw->dev,
+			"Can't register sysfs attribute: %d\n", retval);
+		goto err;
+	}
+
+	retval = device_create_file(&pdev->dev, &dev_attr_hsm);
+	if (retval < 0) {
+		dev_dbg(lnw->dev, "Can't hsm sysfs attribute: %d\n", retval);
+		goto err;
+	}
+
+	retval = sysfs_create_group(&pdev->dev.kobj, &debug_dev_attr_group);
+	if (retval < 0) {
+		dev_dbg(lnw->dev,
+			"Can't register sysfs attr group: %d\n", retval);
+		goto err;
+	}
+
+	if (lnw->iotg.otg.state == OTG_STATE_A_IDLE)
+		langwell_update_transceiver();
+
+	return 0;
+
+err:
+	if (the_transceiver)
+		langwell_otg_remove(pdev);
+done:
+	return retval;
+}
+
+static void langwell_otg_remove(struct pci_dev *pdev)
+{
+	struct langwell_otg *lnw = the_transceiver;
+
+	if (lnw->qwork) {
+		flush_workqueue(lnw->qwork);
+		destroy_workqueue(lnw->qwork);
+	}
+	intel_mid_otg_unregister_notifier(&lnw->iotg, &lnw->iotg_notifier);
+	langwell_otg_free_timers();
+
+	/* disable OTGSC interrupt as OTGSC doesn't change in reset */
+	writel(0, lnw->iotg.base + CI_OTGSC);
+
+	if (pdev->irq)
+		free_irq(pdev->irq, lnw);
+	if (lnw->usbcfg)
+		iounmap(lnw->usbcfg);
+	if (lnw->cfg_region)
+		release_mem_region(USBCFG_ADDR, USBCFG_LEN);
+	if (lnw->iotg.base)
+		iounmap(lnw->iotg.base);
+	if (lnw->region)
+		release_mem_region(pci_resource_start(pdev, 0),
+				pci_resource_len(pdev, 0));
+
+	otg_set_transceiver(NULL);
+	pci_disable_device(pdev);
+	sysfs_remove_group(&pdev->dev.kobj, &debug_dev_attr_group);
+	device_remove_file(&pdev->dev, &dev_attr_hsm);
+	device_remove_file(&pdev->dev, &dev_attr_registers);
+	kfree(lnw);
+	lnw = NULL;
+}
+
+static void transceiver_suspend(struct pci_dev *pdev)
+{
+	pci_save_state(pdev);
+	pci_set_power_state(pdev, PCI_D3hot);
+	langwell_otg_phy_low_power(1);
+}
+
+static int langwell_otg_suspend(struct pci_dev *pdev, pm_message_t message)
+{
+	struct langwell_otg		*lnw = the_transceiver;
+	struct intel_mid_otg_xceiv	*iotg = &lnw->iotg;
+	int				ret = 0;
+
+	/* Disbale OTG interrupts */
+	langwell_otg_intr(0);
+
+	if (pdev->irq)
+		free_irq(pdev->irq, lnw);
+
+	/* Prevent more otg_work */
+	flush_workqueue(lnw->qwork);
+	destroy_workqueue(lnw->qwork);
+	lnw->qwork = NULL;
+
+	/* start actions */
+	switch (iotg->otg.state) {
+	case OTG_STATE_A_WAIT_VFALL:
+		iotg->otg.state = OTG_STATE_A_IDLE;
+	case OTG_STATE_A_IDLE:
+	case OTG_STATE_B_IDLE:
+	case OTG_STATE_A_VBUS_ERR:
+		transceiver_suspend(pdev);
+		break;
+	case OTG_STATE_A_WAIT_VRISE:
+		langwell_otg_del_timer(a_wait_vrise_tmr);
+		iotg->hsm.a_srp_det = 0;
+
+		/* Turn off VBus */
+		iotg->otg.set_vbus(&iotg->otg, false);
+		iotg->otg.state = OTG_STATE_A_IDLE;
+		transceiver_suspend(pdev);
+		break;
+	case OTG_STATE_A_WAIT_BCON:
+		del_timer_sync(&lnw->hsm_timer);
+		if (lnw->iotg.stop_host)
+			lnw->iotg.stop_host(&lnw->iotg);
+		else
+			dev_dbg(&pdev->dev, "host driver has been removed.\n");
+
+		iotg->hsm.a_srp_det = 0;
+
+		/* Turn off VBus */
+		iotg->otg.set_vbus(&iotg->otg, false);
+		iotg->otg.state = OTG_STATE_A_IDLE;
+		transceiver_suspend(pdev);
+		break;
+	case OTG_STATE_A_HOST:
+		if (lnw->iotg.stop_host)
+			lnw->iotg.stop_host(&lnw->iotg);
+		else
+			dev_dbg(&pdev->dev, "host driver has been removed.\n");
+
+		iotg->hsm.a_srp_det = 0;
+
+		/* Turn off VBus */
+		iotg->otg.set_vbus(&iotg->otg, false);
+
+		iotg->otg.state = OTG_STATE_A_IDLE;
+		transceiver_suspend(pdev);
+		break;
+	case OTG_STATE_A_SUSPEND:
+		langwell_otg_del_timer(a_aidl_bdis_tmr);
+		langwell_otg_HABA(0);
+		if (lnw->iotg.stop_host)
+			lnw->iotg.stop_host(&lnw->iotg);
+		else
+			dev_dbg(lnw->dev, "host driver has been removed.\n");
+		iotg->hsm.a_srp_det = 0;
+
+		/* Turn off VBus */
+		iotg->otg.set_vbus(&iotg->otg, false);
+		iotg->otg.state = OTG_STATE_A_IDLE;
+		transceiver_suspend(pdev);
+		break;
+	case OTG_STATE_A_PERIPHERAL:
+		del_timer_sync(&lnw->hsm_timer);
+
+		if (lnw->iotg.stop_peripheral)
+			lnw->iotg.stop_peripheral(&lnw->iotg);
+		else
+			dev_dbg(&pdev->dev,
+				"client driver has been removed.\n");
+		iotg->hsm.a_srp_det = 0;
+
+		/* Turn off VBus */
+		iotg->otg.set_vbus(&iotg->otg, false);
+		iotg->otg.state = OTG_STATE_A_IDLE;
+		transceiver_suspend(pdev);
+		break;
+	case OTG_STATE_B_HOST:
+		if (lnw->iotg.stop_host)
+			lnw->iotg.stop_host(&lnw->iotg);
+		else
+			dev_dbg(&pdev->dev, "host driver has been removed.\n");
+		iotg->hsm.b_bus_req = 0;
+		iotg->otg.state = OTG_STATE_B_IDLE;
+		transceiver_suspend(pdev);
+		break;
+	case OTG_STATE_B_PERIPHERAL:
+		if (lnw->iotg.stop_peripheral)
+			lnw->iotg.stop_peripheral(&lnw->iotg);
+		else
+			dev_dbg(&pdev->dev,
+				"client driver has been removed.\n");
+		iotg->otg.state = OTG_STATE_B_IDLE;
+		transceiver_suspend(pdev);
+		break;
+	case OTG_STATE_B_WAIT_ACON:
+		/* delete hsm timer for b_ase0_brst_tmr */
+		del_timer_sync(&lnw->hsm_timer);
+
+		langwell_otg_HAAR(0);
+
+		if (lnw->iotg.stop_host)
+			lnw->iotg.stop_host(&lnw->iotg);
+		else
+			dev_dbg(&pdev->dev, "host driver has been removed.\n");
+		iotg->hsm.b_bus_req = 0;
+		iotg->otg.state = OTG_STATE_B_IDLE;
+		transceiver_suspend(pdev);
+		break;
+	default:
+		dev_dbg(lnw->dev, "error state before suspend\n");
+		break;
+	}
+
+	return ret;
+}
+
+static void transceiver_resume(struct pci_dev *pdev)
+{
+	pci_restore_state(pdev);
+	pci_set_power_state(pdev, PCI_D0);
+}
+
+static int langwell_otg_resume(struct pci_dev *pdev)
+{
+	struct langwell_otg	*lnw = the_transceiver;
+	int			ret = 0;
+
+	transceiver_resume(pdev);
+
+	lnw->qwork = create_singlethread_workqueue("langwell_otg_queue");
+	if (!lnw->qwork) {
+		dev_dbg(&pdev->dev, "cannot create langwell otg workqueuen");
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	if (request_irq(pdev->irq, otg_irq, IRQF_SHARED,
+				driver_name, lnw) != 0) {
+		dev_dbg(&pdev->dev, "request interrupt %d failed\n", pdev->irq);
+		ret = -EBUSY;
+		goto error;
+	}
+
+	/* enable OTG interrupts */
+	langwell_otg_intr(1);
+
+	update_hsm();
+
+	langwell_update_transceiver();
+
+	return ret;
+error:
+	langwell_otg_intr(0);
+	transceiver_suspend(pdev);
+	return ret;
+}
+
+static int __init langwell_otg_init(void)
+{
+	return pci_register_driver(&otg_pci_driver);
+}
+module_init(langwell_otg_init);
+
+static void __exit langwell_otg_cleanup(void)
+{
+	pci_unregister_driver(&otg_pci_driver);
+}
+module_exit(langwell_otg_cleanup);