USB: move isp1301_omap to drivers/usb/otg

This moves the isp1301-omap driver from the drivers/i2c/chips
directory (which will be shrinking) into a new drivers/usb/otg
directory (which will grow, with more drivers and utilities).

Note that OTG infrastructure needs to be initialized before
either host or peripheral side USB support, and may be needed
before for pure host or pure peripheral configurations.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 1724 insertions, 0 deletions

diff --git a/drivers/usb/Kconfig b/drivers/usb/Kconfig
index 289d81adfb9..83babb0a1df 100644
--- a/drivers/usb/Kconfig
+++ b/drivers/usb/Kconfig
@@ -150,4 +150,6 @@ source "drivers/usb/atm/Kconfig"
 
 source "drivers/usb/gadget/Kconfig"
 
+source "drivers/usb/otg/Kconfig"
+
 endif # USB_SUPPORT
diff --git a/drivers/usb/otg/Kconfig b/drivers/usb/otg/Kconfig
new file mode 100644
index 00000000000..860342902bb
--- /dev/null
+++ b/drivers/usb/otg/Kconfig
@@ -0,0 +1,31 @@
+#
+# USB OTG infrastructure may be needed for peripheral-only, host-only,
+# or OTG-capable configurations when OTG transceivers or controllers
+# are used.
+#
+
+comment "OTG and related infrastructure"
+
+if USB || USB_GADGET
+
+config USB_OTG_UTILS
+	bool
+	help
+	  Select this to make sure the build includes objects from
+	  the OTG infrastructure directory.
+
+config ISP1301_OMAP
+	tristate "Philips ISP1301 with OMAP OTG"
+	depends on I2C && ARCH_OMAP_OTG
+	select USB_OTG_UTILS
+	help
+	  If you say yes here you get support for the Philips ISP1301
+	  USB-On-The-Go transceiver working with the OMAP OTG controller.
+	  The ISP1301 is a full speed USB  transceiver which is used in
+	  products including H2, H3, and H4 development boards for Texas
+	  Instruments OMAP processors.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called isp1301_omap.
+
+endif # USB || OTG
diff --git a/drivers/usb/otg/Makefile b/drivers/usb/otg/Makefile
new file mode 100644
index 00000000000..483816685d0
--- /dev/null
+++ b/drivers/usb/otg/Makefile
@@ -0,0 +1,8 @@
+obj-$(CONFIG_ISP1301_OMAP)	+= isp1301_omap.o
+
+ifeq ($(CONFIG_USB_DEBUG),y)
+EXTRA_CFLAGS += -DDEBUG
+else ifeq ($(CONFIG_USB_GADGET_DEBUG),y)
+EXTRA_CFLAGS += -DDEBUG
+endif
+
diff --git a/drivers/usb/otg/isp1301_omap.c b/drivers/usb/otg/isp1301_omap.c
new file mode 100644
index 00000000000..e0d56ef2bcb
--- /dev/null
+++ b/drivers/usb/otg/isp1301_omap.c
@@ -0,0 +1,1683 @@
+/*
+ * isp1301_omap - ISP 1301 USB transceiver, talking to OMAP OTG controller
+ *
+ * Copyright (C) 2004 Texas Instruments
+ * Copyright (C) 2004 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb.h>
+#include <linux/usb/otg.h>
+#include <linux/i2c.h>
+#include <linux/workqueue.h>
+
+#include <asm/irq.h>
+#include <asm/mach-types.h>
+
+#include <mach/usb.h>
+#include <mach/mux.h>
+
+
+#ifndef	DEBUG
+#undef	VERBOSE
+#endif
+
+
+#define	DRIVER_VERSION	"24 August 2004"
+#define	DRIVER_NAME	(isp1301_driver.driver.name)
+
+MODULE_DESCRIPTION("ISP1301 USB OTG Transceiver Driver");
+MODULE_LICENSE("GPL");
+
+struct isp1301 {
+	struct otg_transceiver	otg;
+	struct i2c_client	*client;
+	void			(*i2c_release)(struct device *dev);
+
+	int			irq_type;
+
+	u32			last_otg_ctrl;
+	unsigned		working:1;
+
+	struct timer_list	timer;
+
+	/* use keventd context to change the state for us */
+	struct work_struct	work;
+
+	unsigned long		todo;
+#		define WORK_UPDATE_ISP	0	/* update ISP from OTG */
+#		define WORK_UPDATE_OTG	1	/* update OTG from ISP */
+#		define WORK_HOST_RESUME	4	/* resume host */
+#		define WORK_TIMER	6	/* timer fired */
+#		define WORK_STOP	7	/* don't resubmit */
+};
+
+
+/* bits in OTG_CTRL */
+
+#define	OTG_XCEIV_OUTPUTS \
+	(OTG_ASESSVLD|OTG_BSESSEND|OTG_BSESSVLD|OTG_VBUSVLD|OTG_ID)
+#define	OTG_XCEIV_INPUTS \
+	(OTG_PULLDOWN|OTG_PULLUP|OTG_DRV_VBUS|OTG_PD_VBUS|OTG_PU_VBUS|OTG_PU_ID)
+#define	OTG_CTRL_BITS \
+	(OTG_A_BUSREQ|OTG_A_SETB_HNPEN|OTG_B_BUSREQ|OTG_B_HNPEN|OTG_BUSDROP)
+	/* and OTG_PULLUP is sometimes written */
+
+#define	OTG_CTRL_MASK	(OTG_DRIVER_SEL| \
+	OTG_XCEIV_OUTPUTS|OTG_XCEIV_INPUTS| \
+	OTG_CTRL_BITS)
+
+
+/*-------------------------------------------------------------------------*/
+
+/* board-specific PM hooks */
+
+#if defined(CONFIG_MACH_OMAP_H2) || defined(CONFIG_MACH_OMAP_H3)
+
+#if	defined(CONFIG_TPS65010) || defined(CONFIG_TPS65010_MODULE)
+
+#include <linux/i2c/tps65010.h>
+
+#else
+
+static inline int tps65010_set_vbus_draw(unsigned mA)
+{
+	pr_debug("tps65010: draw %d mA (STUB)\n", mA);
+	return 0;
+}
+
+#endif
+
+static void enable_vbus_draw(struct isp1301 *isp, unsigned mA)
+{
+	int status = tps65010_set_vbus_draw(mA);
+	if (status < 0)
+		pr_debug("  VBUS %d mA error %d\n", mA, status);
+}
+
+static void enable_vbus_source(struct isp1301 *isp)
+{
+	/* this board won't supply more than 8mA vbus power.
+	 * some boards can switch a 100ma "unit load" (or more).
+	 */
+}
+
+
+/* products will deliver OTG messages with LEDs, GUI, etc */
+static inline void notresponding(struct isp1301 *isp)
+{
+	printk(KERN_NOTICE "OTG device not responding.\n");
+}
+
+
+#endif
+
+#if defined(CONFIG_MACH_OMAP_H4)
+
+static void enable_vbus_draw(struct isp1301 *isp, unsigned mA)
+{
+	/* H4 controls this by DIP switch S2.4; no soft control.
+	 * ON means the charger is always enabled.  Leave it OFF
+	 * unless the OTG port is used only in B-peripheral mode.
+	 */
+}
+
+static void enable_vbus_source(struct isp1301 *isp)
+{
+	/* this board won't supply more than 8mA vbus power.
+	 * some boards can switch a 100ma "unit load" (or more).
+	 */
+}
+
+
+/* products will deliver OTG messages with LEDs, GUI, etc */
+static inline void notresponding(struct isp1301 *isp)
+{
+	printk(KERN_NOTICE "OTG device not responding.\n");
+}
+
+
+#endif
+
+/*-------------------------------------------------------------------------*/
+
+static struct i2c_driver isp1301_driver;
+
+/* smbus apis are used for portability */
+
+static inline u8
+isp1301_get_u8(struct isp1301 *isp, u8 reg)
+{
+	return i2c_smbus_read_byte_data(isp->client, reg + 0);
+}
+
+static inline int
+isp1301_get_u16(struct isp1301 *isp, u8 reg)
+{
+	return i2c_smbus_read_word_data(isp->client, reg);
+}
+
+static inline int
+isp1301_set_bits(struct isp1301 *isp, u8 reg, u8 bits)
+{
+	return i2c_smbus_write_byte_data(isp->client, reg + 0, bits);
+}
+
+static inline int
+isp1301_clear_bits(struct isp1301 *isp, u8 reg, u8 bits)
+{
+	return i2c_smbus_write_byte_data(isp->client, reg + 1, bits);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* identification */
+#define	ISP1301_VENDOR_ID		0x00	/* u16 read */
+#define	ISP1301_PRODUCT_ID		0x02	/* u16 read */
+#define	ISP1301_BCD_DEVICE		0x14	/* u16 read */
+
+#define	I2C_VENDOR_ID_PHILIPS		0x04cc
+#define	I2C_PRODUCT_ID_PHILIPS_1301	0x1301
+
+/* operational registers */
+#define	ISP1301_MODE_CONTROL_1		0x04	/* u8 read, set, +1 clear */
+#	define	MC1_SPEED		(1 << 0)
+#	define	MC1_SUSPEND		(1 << 1)
+#	define	MC1_DAT_SE0		(1 << 2)
+#	define	MC1_TRANSPARENT		(1 << 3)
+#	define	MC1_BDIS_ACON_EN	(1 << 4)
+#	define	MC1_OE_INT_EN		(1 << 5)
+#	define	MC1_UART_EN		(1 << 6)
+#	define	MC1_MASK		0x7f
+#define	ISP1301_MODE_CONTROL_2		0x12	/* u8 read, set, +1 clear */
+#	define	MC2_GLOBAL_PWR_DN	(1 << 0)
+#	define	MC2_SPD_SUSP_CTRL	(1 << 1)
+#	define	MC2_BI_DI		(1 << 2)
+#	define	MC2_TRANSP_BDIR0	(1 << 3)
+#	define	MC2_TRANSP_BDIR1	(1 << 4)
+#	define	MC2_AUDIO_EN		(1 << 5)
+#	define	MC2_PSW_EN		(1 << 6)
+#	define	MC2_EN2V7		(1 << 7)
+#define	ISP1301_OTG_CONTROL_1		0x06	/* u8 read, set, +1 clear */
+#	define	OTG1_DP_PULLUP		(1 << 0)
+#	define	OTG1_DM_PULLUP		(1 << 1)
+#	define	OTG1_DP_PULLDOWN	(1 << 2)
+#	define	OTG1_DM_PULLDOWN	(1 << 3)
+#	define	OTG1_ID_PULLDOWN	(1 << 4)
+#	define	OTG1_VBUS_DRV		(1 << 5)
+#	define	OTG1_VBUS_DISCHRG	(1 << 6)
+#	define	OTG1_VBUS_CHRG		(1 << 7)
+#define	ISP1301_OTG_STATUS		0x10	/* u8 readonly */
+#	define	OTG_B_SESS_END		(1 << 6)
+#	define	OTG_B_SESS_VLD		(1 << 7)
+
+#define	ISP1301_INTERRUPT_SOURCE	0x08	/* u8 read */
+#define	ISP1301_INTERRUPT_LATCH		0x0A	/* u8 read, set, +1 clear */
+
+#define	ISP1301_INTERRUPT_FALLING	0x0C	/* u8 read, set, +1 clear */
+#define	ISP1301_INTERRUPT_RISING	0x0E	/* u8 read, set, +1 clear */
+
+/* same bitfields in all interrupt registers */
+#	define	INTR_VBUS_VLD		(1 << 0)
+#	define	INTR_SESS_VLD		(1 << 1)
+#	define	INTR_DP_HI		(1 << 2)
+#	define	INTR_ID_GND		(1 << 3)
+#	define	INTR_DM_HI		(1 << 4)
+#	define	INTR_ID_FLOAT		(1 << 5)
+#	define	INTR_BDIS_ACON		(1 << 6)
+#	define	INTR_CR_INT		(1 << 7)
+
+/*-------------------------------------------------------------------------*/
+
+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";
+	}
+}
+
+static inline const char *state_name(struct isp1301 *isp)
+{
+	return state_string(isp->otg.state);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* NOTE:  some of this ISP1301 setup is specific to H2 boards;
+ * not everything is guarded by board-specific checks, or even using
+ * omap_usb_config data to deduce MC1_DAT_SE0 and MC2_BI_DI.
+ *
+ * ALSO:  this currently doesn't use ISP1301 low-power modes
+ * while OTG is running.
+ */
+
+static void power_down(struct isp1301 *isp)
+{
+	isp->otg.state = OTG_STATE_UNDEFINED;
+
+	// isp1301_set_bits(isp, ISP1301_MODE_CONTROL_2, MC2_GLOBAL_PWR_DN);
+	isp1301_set_bits(isp, ISP1301_MODE_CONTROL_1, MC1_SUSPEND);
+
+	isp1301_clear_bits(isp, ISP1301_OTG_CONTROL_1, OTG1_ID_PULLDOWN);
+	isp1301_clear_bits(isp, ISP1301_MODE_CONTROL_1, MC1_DAT_SE0);
+}
+
+static void power_up(struct isp1301 *isp)
+{
+	// isp1301_clear_bits(isp, ISP1301_MODE_CONTROL_2, MC2_GLOBAL_PWR_DN);
+	isp1301_clear_bits(isp, ISP1301_MODE_CONTROL_1, MC1_SUSPEND);
+
+	/* do this only when cpu is driving transceiver,
+	 * so host won't see a low speed device...
+	 */
+	isp1301_set_bits(isp, ISP1301_MODE_CONTROL_1, MC1_DAT_SE0);
+}
+
+#define	NO_HOST_SUSPEND
+
+static int host_suspend(struct isp1301 *isp)
+{
+#ifdef	NO_HOST_SUSPEND
+	return 0;
+#else
+	struct device	*dev;
+
+	if (!isp->otg.host)
+		return -ENODEV;
+
+	/* Currently ASSUMES only the OTG port matters;
+	 * other ports could be active...
+	 */
+	dev = isp->otg.host->controller;
+	return dev->driver->suspend(dev, 3, 0);
+#endif
+}
+
+static int host_resume(struct isp1301 *isp)
+{
+#ifdef	NO_HOST_SUSPEND
+	return 0;
+#else
+	struct device	*dev;
+
+	if (!isp->otg.host)
+		return -ENODEV;
+
+	dev = isp->otg.host->controller;
+	return dev->driver->resume(dev, 0);
+#endif
+}
+
+static int gadget_suspend(struct isp1301 *isp)
+{
+	isp->otg.gadget->b_hnp_enable = 0;
+	isp->otg.gadget->a_hnp_support = 0;
+	isp->otg.gadget->a_alt_hnp_support = 0;
+	return usb_gadget_vbus_disconnect(isp->otg.gadget);
+}
+
+/*-------------------------------------------------------------------------*/
+
+#define	TIMER_MINUTES	10
+#define	TIMER_JIFFIES	(TIMER_MINUTES * 60 * HZ)
+
+/* Almost all our I2C messaging comes from a work queue's task context.
+ * NOTE: guaranteeing certain response times might mean we shouldn't
+ * share keventd's work queue; a realtime task might be safest.
+ */
+static void isp1301_defer_work(struct isp1301 *isp, int work)
+{
+	int status;
+
+	if (isp && !test_and_set_bit(work, &isp->todo)) {
+		(void) get_device(&isp->client->dev);
+		status = schedule_work(&isp->work);
+		if (!status && !isp->working)
+			dev_vdbg(&isp->client->dev,
+				"work item %d may be lost\n", work);
+	}
+}
+
+/* called from irq handlers */
+static void a_idle(struct isp1301 *isp, const char *tag)
+{
+	u32 l;
+
+	if (isp->otg.state == OTG_STATE_A_IDLE)
+		return;
+
+	isp->otg.default_a = 1;
+	if (isp->otg.host) {
+		isp->otg.host->is_b_host = 0;
+		host_suspend(isp);
+	}
+	if (isp->otg.gadget) {
+		isp->otg.gadget->is_a_peripheral = 1;
+		gadget_suspend(isp);
+	}
+	isp->otg.state = OTG_STATE_A_IDLE;
+	l = omap_readl(OTG_CTRL) & OTG_XCEIV_OUTPUTS;
+	omap_writel(l, OTG_CTRL);
+	isp->last_otg_ctrl = l;
+	pr_debug("  --> %s/%s\n", state_name(isp), tag);
+}
+
+/* called from irq handlers */
+static void b_idle(struct isp1301 *isp, const char *tag)
+{
+	u32 l;
+
+	if (isp->otg.state == OTG_STATE_B_IDLE)
+		return;
+
+	isp->otg.default_a = 0;
+	if (isp->otg.host) {
+		isp->otg.host->is_b_host = 1;
+		host_suspend(isp);
+	}
+	if (isp->otg.gadget) {
+		isp->otg.gadget->is_a_peripheral = 0;
+		gadget_suspend(isp);
+	}
+	isp->otg.state = OTG_STATE_B_IDLE;
+	l = omap_readl(OTG_CTRL) & OTG_XCEIV_OUTPUTS;
+	omap_writel(l, OTG_CTRL);
+	isp->last_otg_ctrl = l;
+	pr_debug("  --> %s/%s\n", state_name(isp), tag);
+}
+
+static void
+dump_regs(struct isp1301 *isp, const char *label)
+{
+#ifdef	DEBUG
+	u8	ctrl = isp1301_get_u8(isp, ISP1301_OTG_CONTROL_1);
+	u8	status = isp1301_get_u8(isp, ISP1301_OTG_STATUS);
+	u8	src = isp1301_get_u8(isp, ISP1301_INTERRUPT_SOURCE);
+
+	pr_debug("otg: %06x, %s %s, otg/%02x stat/%02x.%02x\n",
+		omap_readl(OTG_CTRL), label, state_name(isp),
+		ctrl, status, src);
+	/* mode control and irq enables don't change much */
+#endif
+}
+
+/*-------------------------------------------------------------------------*/
+
+#ifdef	CONFIG_USB_OTG
+
+/*
+ * The OMAP OTG controller handles most of the OTG state transitions.
+ *
+ * We translate isp1301 outputs (mostly voltage comparator status) into
+ * OTG inputs; OTG outputs (mostly pullup/pulldown controls) and HNP state
+ * flags into isp1301 inputs ... and infer state transitions.
+ */
+
+#ifdef	VERBOSE
+
+static void check_state(struct isp1301 *isp, const char *tag)
+{
+	enum usb_otg_state	state = OTG_STATE_UNDEFINED;
+	u8			fsm = omap_readw(OTG_TEST) & 0x0ff;
+	unsigned		extra = 0;
+
+	switch (fsm) {
+
+	/* default-b */
+	case 0x0:
+		state = OTG_STATE_B_IDLE;
+		break;
+	case 0x3:
+	case 0x7:
+		extra = 1;
+	case 0x1:
+		state = OTG_STATE_B_PERIPHERAL;
+		break;
+	case 0x11:
+		state = OTG_STATE_B_SRP_INIT;
+		break;
+
+	/* extra dual-role default-b states */
+	case 0x12:
+	case 0x13:
+	case 0x16:
+		extra = 1;
+	case 0x17:
+		state = OTG_STATE_B_WAIT_ACON;
+		break;
+	case 0x34:
+		state = OTG_STATE_B_HOST;
+		break;
+
+	/* default-a */
+	case 0x36:
+		state = OTG_STATE_A_IDLE;
+		break;
+	case 0x3c:
+		state = OTG_STATE_A_WAIT_VFALL;
+		break;
+	case 0x7d:
+		state = OTG_STATE_A_VBUS_ERR;
+		break;
+	case 0x9e:
+	case 0x9f:
+		extra = 1;
+	case 0x89:
+		state = OTG_STATE_A_PERIPHERAL;
+		break;
+	case 0xb7:
+		state = OTG_STATE_A_WAIT_VRISE;
+		break;
+	case 0xb8:
+		state = OTG_STATE_A_WAIT_BCON;
+		break;
+	case 0xb9:
+		state = OTG_STATE_A_HOST;
+		break;
+	case 0xba:
+		state = OTG_STATE_A_SUSPEND;
+		break;
+	default:
+		break;
+	}
+	if (isp->otg.state == state && !extra)
+		return;
+	pr_debug("otg: %s FSM %s/%02x, %s, %06x\n", tag,
+		state_string(state), fsm, state_name(isp),
+		omap_readl(OTG_CTRL));
+}
+
+#else
+
+static inline void check_state(struct isp1301 *isp, const char *tag) { }
+
+#endif
+
+/* outputs from ISP1301_INTERRUPT_SOURCE */
+static void update_otg1(struct isp1301 *isp, u8 int_src)
+{
+	u32	otg_ctrl;
+
+	otg_ctrl = omap_readl(OTG_CTRL) & OTG_CTRL_MASK;
+	otg_ctrl &= ~OTG_XCEIV_INPUTS;
+	otg_ctrl &= ~(OTG_ID|OTG_ASESSVLD|OTG_VBUSVLD);
+
+	if (int_src & INTR_SESS_VLD)
+		otg_ctrl |= OTG_ASESSVLD;
+	else if (isp->otg.state == OTG_STATE_A_WAIT_VFALL) {
+		a_idle(isp, "vfall");
+		otg_ctrl &= ~OTG_CTRL_BITS;
+	}
+	if (int_src & INTR_VBUS_VLD)
+		otg_ctrl |= OTG_VBUSVLD;
+	if (int_src & INTR_ID_GND) {		/* default-A */
+		if (isp->otg.state == OTG_STATE_B_IDLE
+				|| isp->otg.state == OTG_STATE_UNDEFINED) {
+			a_idle(isp, "init");
+			return;
+		}
+	} else {				/* default-B */
+		otg_ctrl |= OTG_ID;
+		if (isp->otg.state == OTG_STATE_A_IDLE
+				|| isp->otg.state == OTG_STATE_UNDEFINED) {
+			b_idle(isp, "init");
+			return;
+		}
+	}
+	omap_writel(otg_ctrl, OTG_CTRL);
+}
+
+/* outputs from ISP1301_OTG_STATUS */
+static void update_otg2(struct isp1301 *isp, u8 otg_status)
+{
+	u32	otg_ctrl;
+
+	otg_ctrl = omap_readl(OTG_CTRL) & OTG_CTRL_MASK;
+	otg_ctrl &= ~OTG_XCEIV_INPUTS;
+	otg_ctrl &= ~(OTG_BSESSVLD | OTG_BSESSEND);
+	if (otg_status & OTG_B_SESS_VLD)
+		otg_ctrl |= OTG_BSESSVLD;
+	else if (otg_status & OTG_B_SESS_END)
+		otg_ctrl |= OTG_BSESSEND;
+	omap_writel(otg_ctrl, OTG_CTRL);
+}
+
+/* inputs going to ISP1301 */
+static void otg_update_isp(struct isp1301 *isp)
+{
+	u32	otg_ctrl, otg_change;
+	u8	set = OTG1_DM_PULLDOWN, clr = OTG1_DM_PULLUP;
+
+	otg_ctrl = omap_readl(OTG_CTRL);
+	otg_change = otg_ctrl ^ isp->last_otg_ctrl;
+	isp->last_otg_ctrl = otg_ctrl;
+	otg_ctrl = otg_ctrl & OTG_XCEIV_INPUTS;
+
+	switch (isp->otg.state) {
+	case OTG_STATE_B_IDLE:
+	case OTG_STATE_B_PERIPHERAL:
+	case OTG_STATE_B_SRP_INIT:
+		if (!(otg_ctrl & OTG_PULLUP)) {
+			// if (otg_ctrl & OTG_B_HNPEN) {
+			if (isp->otg.gadget->b_hnp_enable) {
+				isp->otg.state = OTG_STATE_B_WAIT_ACON;
+				pr_debug("  --> b_wait_acon\n");
+			}
+			goto pulldown;
+		}
+pullup:
+		set |= OTG1_DP_PULLUP;
+		clr |= OTG1_DP_PULLDOWN;
+		break;
+	case OTG_STATE_A_SUSPEND:
+	case OTG_STATE_A_PERIPHERAL:
+		if (otg_ctrl & OTG_PULLUP)
+			goto pullup;
+		/* FALLTHROUGH */
+	// case OTG_STATE_B_WAIT_ACON:
+	default:
+pulldown:
+		set |= OTG1_DP_PULLDOWN;
+		clr |= OTG1_DP_PULLUP;
+		break;
+	}
+
+#	define toggle(OTG,ISP) do { \
+		if (otg_ctrl & OTG) set |= ISP; \
+		else clr |= ISP; \
+		} while (0)
+
+	if (!(isp->otg.host))
+		otg_ctrl &= ~OTG_DRV_VBUS;
+
+	switch (isp->otg.state) {
+	case OTG_STATE_A_SUSPEND:
+		if (otg_ctrl & OTG_DRV_VBUS) {
+			set |= OTG1_VBUS_DRV;
+			break;
+		}
+		/* HNP failed for some reason (A_AIDL_BDIS timeout) */
+		notresponding(isp);
+
+		/* FALLTHROUGH */
+	case OTG_STATE_A_VBUS_ERR:
+		isp->otg.state = OTG_STATE_A_WAIT_VFALL;
+		pr_debug("  --> a_wait_vfall\n");
+		/* FALLTHROUGH */
+	case OTG_STATE_A_WAIT_VFALL:
+		/* FIXME usbcore thinks port power is still on ... */
+		clr |= OTG1_VBUS_DRV;
+		break;
+	case OTG_STATE_A_IDLE:
+		if (otg_ctrl & OTG_DRV_VBUS) {
+			isp->otg.state = OTG_STATE_A_WAIT_VRISE;
+			pr_debug("  --> a_wait_vrise\n");
+		}
+		/* FALLTHROUGH */
+	default:
+		toggle(OTG_DRV_VBUS, OTG1_VBUS_DRV);
+	}
+
+	toggle(OTG_PU_VBUS, OTG1_VBUS_CHRG);
+	toggle(OTG_PD_VBUS, OTG1_VBUS_DISCHRG);
+
+#	undef toggle
+
+	isp1301_set_bits(isp, ISP1301_OTG_CONTROL_1, set);
+	isp1301_clear_bits(isp, ISP1301_OTG_CONTROL_1, clr);
+
+	/* HNP switch to host or peripheral; and SRP */
+	if (otg_change & OTG_PULLUP) {
+		u32 l;
+
+		switch (isp->otg.state) {
+		case OTG_STATE_B_IDLE:
+			if (clr & OTG1_DP_PULLUP)
+				break;
+			isp->otg.state = OTG_STATE_B_PERIPHERAL;
+			pr_debug("  --> b_peripheral\n");
+			break;
+		case OTG_STATE_A_SUSPEND:
+			if (clr & OTG1_DP_PULLUP)
+				break;
+			isp->otg.state = OTG_STATE_A_PERIPHERAL;
+			pr_debug("  --> a_peripheral\n");
+			break;
+		default:
+			break;
+		}
+		l = omap_readl(OTG_CTRL);
+		l |= OTG_PULLUP;
+		omap_writel(l, OTG_CTRL);
+	}
+
+	check_state(isp, __func__);
+	dump_regs(isp, "otg->isp1301");
+}
+
+static irqreturn_t omap_otg_irq(int irq, void *_isp)
+{
+	u16		otg_irq = omap_readw(OTG_IRQ_SRC);
+	u32		otg_ctrl;
+	int		ret = IRQ_NONE;
+	struct isp1301	*isp = _isp;
+
+	/* update ISP1301 transciever from OTG controller */
+	if (otg_irq & OPRT_CHG) {
+		omap_writew(OPRT_CHG, OTG_IRQ_SRC);
+		isp1301_defer_work(isp, WORK_UPDATE_ISP);
+		ret = IRQ_HANDLED;
+
+	/* SRP to become b_peripheral failed */
+	} else if (otg_irq & B_SRP_TMROUT) {
+		pr_debug("otg: B_SRP_TIMEOUT, %06x\n", omap_readl(OTG_CTRL));
+		notresponding(isp);
+
+		/* gadget drivers that care should monitor all kinds of
+		 * remote wakeup (SRP, normal) using their own timer
+		 * to give "check cable and A-device" messages.
+		 */
+		if (isp->otg.state == OTG_STATE_B_SRP_INIT)
+			b_idle(isp, "srp_timeout");
+
+		omap_writew(B_SRP_TMROUT, OTG_IRQ_SRC);
+		ret = IRQ_HANDLED;
+
+	/* HNP to become b_host failed */
+	} else if (otg_irq & B_HNP_FAIL) {
+		pr_debug("otg: %s B_HNP_FAIL, %06x\n",
+				state_name(isp), omap_readl(OTG_CTRL));
+		notresponding(isp);
+
+		otg_ctrl = omap_readl(OTG_CTRL);
+		otg_ctrl |= OTG_BUSDROP;
+		otg_ctrl &= OTG_CTRL_MASK & ~OTG_XCEIV_INPUTS;
+		omap_writel(otg_ctrl, OTG_CTRL);
+
+		/* subset of b_peripheral()... */
+		isp->otg.state = OTG_STATE_B_PERIPHERAL;
+		pr_debug("  --> b_peripheral\n");
+
+		omap_writew(B_HNP_FAIL, OTG_IRQ_SRC);
+		ret = IRQ_HANDLED;
+
+	/* detect SRP from B-device ... */
+	} else if (otg_irq & A_SRP_DETECT) {
+		pr_debug("otg: %s SRP_DETECT, %06x\n",
+				state_name(isp), omap_readl(OTG_CTRL));
+
+		isp1301_defer_work(isp, WORK_UPDATE_OTG);
+		switch (isp->otg.state) {
+		case OTG_STATE_A_IDLE:
+			if (!isp->otg.host)
+				break;
+			isp1301_defer_work(isp, WORK_HOST_RESUME);
+			otg_ctrl = omap_readl(OTG_CTRL);
+			otg_ctrl |= OTG_A_BUSREQ;
+			otg_ctrl &= ~(OTG_BUSDROP|OTG_B_BUSREQ)
+					& ~OTG_XCEIV_INPUTS
+					& OTG_CTRL_MASK;
+			omap_writel(otg_ctrl, OTG_CTRL);
+			break;
+		default:
+			break;
+		}
+
+		omap_writew(A_SRP_DETECT, OTG_IRQ_SRC);
+		ret = IRQ_HANDLED;
+
+	/* timer expired:  T(a_wait_bcon) and maybe T(a_wait_vrise)
+	 * we don't track them separately
+	 */
+	} else if (otg_irq & A_REQ_TMROUT) {
+		otg_ctrl = omap_readl(OTG_CTRL);
+		pr_info("otg: BCON_TMOUT from %s, %06x\n",
+				state_name(isp), otg_ctrl);
+		notresponding(isp);
+
+		otg_ctrl |= OTG_BUSDROP;
+		otg_ctrl &= ~OTG_A_BUSREQ & OTG_CTRL_MASK & ~OTG_XCEIV_INPUTS;
+		omap_writel(otg_ctrl, OTG_CTRL);
+		isp->otg.state = OTG_STATE_A_WAIT_VFALL;
+
+		omap_writew(A_REQ_TMROUT, OTG_IRQ_SRC);
+		ret = IRQ_HANDLED;
+
+	/* A-supplied voltage fell too low; overcurrent */
+	} else if (otg_irq & A_VBUS_ERR) {
+		otg_ctrl = omap_readl(OTG_CTRL);
+		printk(KERN_ERR "otg: %s, VBUS_ERR %04x ctrl %06x\n",
+			state_name(isp), otg_irq, otg_ctrl);
+
+		otg_ctrl |= OTG_BUSDROP;
+		otg_ctrl &= ~OTG_A_BUSREQ & OTG_CTRL_MASK & ~OTG_XCEIV_INPUTS;
+		omap_writel(otg_ctrl, OTG_CTRL);
+		isp->otg.state = OTG_STATE_A_VBUS_ERR;
+
+		omap_writew(A_VBUS_ERR, OTG_IRQ_SRC);
+		ret = IRQ_HANDLED;
+
+	/* switch driver; the transciever code activates it,
+	 * ungating the udc clock or resuming OHCI.
+	 */
+	} else if (otg_irq & DRIVER_SWITCH) {
+		int	kick = 0;
+
+		otg_ctrl = omap_readl(OTG_CTRL);
+		printk(KERN_NOTICE "otg: %s, SWITCH to %s, ctrl %06x\n",
+				state_name(isp),
+				(otg_ctrl & OTG_DRIVER_SEL)
+					? "gadget" : "host",
+				otg_ctrl);
+		isp1301_defer_work(isp, WORK_UPDATE_ISP);
+
+		/* role is peripheral */
+		if (otg_ctrl & OTG_DRIVER_SEL) {
+			switch (isp->otg.state) {
+			case OTG_STATE_A_IDLE:
+				b_idle(isp, __func__);
+				break;
+			default:
+				break;
+			}
+			isp1301_defer_work(isp, WORK_UPDATE_ISP);
+
+		/* role is host */
+		} else {
+			if (!(otg_ctrl & OTG_ID)) {
+				otg_ctrl &= OTG_CTRL_MASK & ~OTG_XCEIV_INPUTS;
+				omap_writel(otg_ctrl | OTG_A_BUSREQ, OTG_CTRL);
+			}
+
+			if (isp->otg.host) {
+				switch (isp->otg.state) {
+				case OTG_STATE_B_WAIT_ACON:
+					isp->otg.state = OTG_STATE_B_HOST;
+					pr_debug("  --> b_host\n");
+					kick = 1;
+					break;
+				case OTG_STATE_A_WAIT_BCON:
+					isp->otg.state = OTG_STATE_A_HOST;
+					pr_debug("  --> a_host\n");
+					break;
+				case OTG_STATE_A_PERIPHERAL:
+					isp->otg.state = OTG_STATE_A_WAIT_BCON;
+					pr_debug("  --> a_wait_bcon\n");
+					break;
+				default:
+					break;
+				}
+				isp1301_defer_work(isp, WORK_HOST_RESUME);
+			}
+		}
+
+		omap_writew(DRIVER_SWITCH, OTG_IRQ_SRC);
+		ret = IRQ_HANDLED;
+
+		if (kick)
+			usb_bus_start_enum(isp->otg.host,
+						isp->otg.host->otg_port);
+	}
+
+	check_state(isp, __func__);
+	return ret;
+}
+
+static struct platform_device *otg_dev;
+
+static int otg_init(struct isp1301 *isp)
+{
+	u32 l;
+
+	if (!otg_dev)
+		return -ENODEV;
+
+	dump_regs(isp, __func__);
+	/* some of these values are board-specific... */
+	l = omap_readl(OTG_SYSCON_2);
+	l |= OTG_EN
+		/* for B-device: */
+		| SRP_GPDATA		/* 9msec Bdev D+ pulse */
+		| SRP_GPDVBUS		/* discharge after VBUS pulse */
+		// | (3 << 24)		/* 2msec VBUS pulse */
+		/* for A-device: */
+		| (0 << 20)		/* 200ms nominal A_WAIT_VRISE timer */
+		| SRP_DPW		/* detect 167+ns SRP pulses */
+		| SRP_DATA | SRP_VBUS	/* accept both kinds of SRP pulse */
+		;
+	omap_writel(l, OTG_SYSCON_2);
+
+	update_otg1(isp, isp1301_get_u8(isp, ISP1301_INTERRUPT_SOURCE));
+	update_otg2(isp, isp1301_get_u8(isp, ISP1301_OTG_STATUS));
+
+	check_state(isp, __func__);
+	pr_debug("otg: %s, %s %06x\n",
+			state_name(isp), __func__, omap_readl(OTG_CTRL));
+
+	omap_writew(DRIVER_SWITCH | OPRT_CHG
+			| B_SRP_TMROUT | B_HNP_FAIL
+			| A_VBUS_ERR | A_SRP_DETECT | A_REQ_TMROUT, OTG_IRQ_EN);
+
+	l = omap_readl(OTG_SYSCON_2);
+	l |= OTG_EN;
+	omap_writel(l, OTG_SYSCON_2);
+
+	return 0;
+}
+
+static int otg_probe(struct platform_device *dev)
+{
+	// struct omap_usb_config *config = dev->platform_data;
+
+	otg_dev = dev;
+	return 0;
+}
+
+static int otg_remove(struct platform_device *dev)
+{
+	otg_dev = NULL;
+	return 0;
+}
+
+static struct platform_driver omap_otg_driver = {
+	.probe		= otg_probe,
+	.remove		= otg_remove,
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= "omap_otg",
+	},
+};
+
+static int otg_bind(struct isp1301 *isp)
+{
+	int	status;
+
+	if (otg_dev)
+		return -EBUSY;
+
+	status = platform_driver_register(&omap_otg_driver);
+	if (status < 0)
+		return status;
+
+	if (otg_dev)
+		status = request_irq(otg_dev->resource[1].start, omap_otg_irq,
+				IRQF_DISABLED, DRIVER_NAME, isp);
+	else
+		status = -ENODEV;
+
+	if (status < 0)
+		platform_driver_unregister(&omap_otg_driver);
+	return status;
+}
+
+static void otg_unbind(struct isp1301 *isp)
+{
+	if (!otg_dev)
+		return;
+	free_irq(otg_dev->resource[1].start, isp);
+}
+
+#else
+
+/* OTG controller isn't clocked */
+
+#endif	/* CONFIG_USB_OTG */
+
+/*-------------------------------------------------------------------------*/
+
+static void b_peripheral(struct isp1301 *isp)
+{
+	u32 l;
+
+	l = omap_readl(OTG_CTRL) & OTG_XCEIV_OUTPUTS;
+	omap_writel(l, OTG_CTRL);
+
+	usb_gadget_vbus_connect(isp->otg.gadget);
+
+#ifdef	CONFIG_USB_OTG
+	enable_vbus_draw(isp, 8);
+	otg_update_isp(isp);
+#else
+	enable_vbus_draw(isp, 100);
+	/* UDC driver just set OTG_BSESSVLD */
+	isp1301_set_bits(isp, ISP1301_OTG_CONTROL_1, OTG1_DP_PULLUP);
+	isp1301_clear_bits(isp, ISP1301_OTG_CONTROL_1, OTG1_DP_PULLDOWN);
+	isp->otg.state = OTG_STATE_B_PERIPHERAL;
+	pr_debug("  --> b_peripheral\n");
+	dump_regs(isp, "2periph");
+#endif
+}
+
+static void isp_update_otg(struct isp1301 *isp, u8 stat)
+{
+	u8			isp_stat, isp_bstat;
+	enum usb_otg_state	state = isp->otg.state;
+
+	if (stat & INTR_BDIS_ACON)
+		pr_debug("OTG:  BDIS_ACON, %s\n", state_name(isp));
+
+	/* start certain state transitions right away */
+	isp_stat = isp1301_get_u8(isp, ISP1301_INTERRUPT_SOURCE);
+	if (isp_stat & INTR_ID_GND) {
+		if (isp->otg.default_a) {
+			switch (state) {
+			case OTG_STATE_B_IDLE:
+				a_idle(isp, "idle");
+				/* FALLTHROUGH */
+			case OTG_STATE_A_IDLE:
+				enable_vbus_source(isp);
+				/* FALLTHROUGH */
+			case OTG_STATE_A_WAIT_VRISE:
+				/* we skip over OTG_STATE_A_WAIT_BCON, since
+				 * the HC will transition to A_HOST (or
+				 * A_SUSPEND!) without our noticing except
+				 * when HNP is used.
+				 */
+				if (isp_stat & INTR_VBUS_VLD)
+					isp->otg.state = OTG_STATE_A_HOST;
+				break;
+			case OTG_STATE_A_WAIT_VFALL:
+				if (!(isp_stat & INTR_SESS_VLD))
+					a_idle(isp, "vfell");
+				break;
+			default:
+				if (!(isp_stat & INTR_VBUS_VLD))
+					isp->otg.state = OTG_STATE_A_VBUS_ERR;
+				break;
+			}
+			isp_bstat = isp1301_get_u8(isp, ISP1301_OTG_STATUS);
+		} else {
+			switch (state) {
+			case OTG_STATE_B_PERIPHERAL:
+			case OTG_STATE_B_HOST:
+			case OTG_STATE_B_WAIT_ACON:
+				usb_gadget_vbus_disconnect(isp->otg.gadget);
+				break;
+			default:
+				break;
+			}
+			if (state != OTG_STATE_A_IDLE)
+				a_idle(isp, "id");
+			if (isp->otg.host && state == OTG_STATE_A_IDLE)
+				isp1301_defer_work(isp, WORK_HOST_RESUME);
+			isp_bstat = 0;
+		}
+	} else {
+		u32 l;
+
+		/* if user unplugged mini-A end of cable,
+		 * don't bypass A_WAIT_VFALL.
+		 */
+		if (isp->otg.default_a) {
+			switch (state) {
+			default:
+				isp->otg.state = OTG_STATE_A_WAIT_VFALL;
+				break;
+			case OTG_STATE_A_WAIT_VFALL:
+				state = OTG_STATE_A_IDLE;
+				/* khubd may take a while to notice and
+				 * handle this disconnect, so don't go
+				 * to B_IDLE quite yet.
+				 */
+				break;
+			case OTG_STATE_A_IDLE:
+				host_suspend(isp);
+				isp1301_clear_bits(isp, ISP1301_MODE_CONTROL_1,
+						MC1_BDIS_ACON_EN);
+				isp->otg.state = OTG_STATE_B_IDLE;
+				l = omap_readl(OTG_CTRL) & OTG_CTRL_MASK;
+				l &= ~OTG_CTRL_BITS;
+				omap_writel(l, OTG_CTRL);
+				break;
+			case OTG_STATE_B_IDLE:
+				break;
+			}
+		}
+		isp_bstat = isp1301_get_u8(isp, ISP1301_OTG_STATUS);
+
+		switch (isp->otg.state) {
+		case OTG_STATE_B_PERIPHERAL:
+		case OTG_STATE_B_WAIT_ACON:
+		case OTG_STATE_B_HOST:
+			if (likely(isp_bstat & OTG_B_SESS_VLD))
+				break;
+			enable_vbus_draw(isp, 0);
+#ifndef	CONFIG_USB_OTG
+			/* UDC driver will clear OTG_BSESSVLD */
+			isp1301_set_bits(isp, ISP1301_OTG_CONTROL_1,
+						OTG1_DP_PULLDOWN);
+			isp1301_clear_bits(isp, ISP1301_OTG_CONTROL_1,
+						OTG1_DP_PULLUP);
+			dump_regs(isp, __func__);
+#endif
+			/* FALLTHROUGH */
+		case OTG_STATE_B_SRP_INIT:
+			b_idle(isp, __func__);
+			l = omap_readl(OTG_CTRL) & OTG_XCEIV_OUTPUTS;
+			omap_writel(l, OTG_CTRL);
+			/* FALLTHROUGH */
+		case OTG_STATE_B_IDLE:
+			if (isp->otg.gadget && (isp_bstat & OTG_B_SESS_VLD)) {
+#ifdef	CONFIG_USB_OTG
+				update_otg1(isp, isp_stat);
+				update_otg2(isp, isp_bstat);
+#endif
+				b_peripheral(isp);
+			} else if (!(isp_stat & (INTR_VBUS_VLD|INTR_SESS_VLD)))
+				isp_bstat |= OTG_B_SESS_END;
+			break;
+		case OTG_STATE_A_WAIT_VFALL:
+			break;
+		default:
+			pr_debug("otg: unsupported b-device %s\n",
+				state_name(isp));
+			break;
+		}
+	}
+
+	if (state != isp->otg.state)
+		pr_debug("  isp, %s -> %s\n",
+				state_string(state), state_name(isp));
+
+#ifdef	CONFIG_USB_OTG
+	/* update the OTG controller state to match the isp1301; may
+	 * trigger OPRT_CHG irqs for changes going to the isp1301.
+	 */
+	update_otg1(isp, isp_stat);
+	update_otg2(isp, isp_bstat);
+	check_state(isp, __func__);
+#endif
+
+	dump_regs(isp, "isp1301->otg");
+}
+
+/*-------------------------------------------------------------------------*/
+
+static u8 isp1301_clear_latch(struct isp1301 *isp)
+{
+	u8 latch = isp1301_get_u8(isp, ISP1301_INTERRUPT_LATCH);
+	isp1301_clear_bits(isp, ISP1301_INTERRUPT_LATCH, latch);
+	return latch;
+}
+
+static void
+isp1301_work(struct work_struct *work)
+{
+	struct isp1301	*isp = container_of(work, struct isp1301, work);
+	int		stop;
+
+	/* implicit lock:  we're the only task using this device */
+	isp->working = 1;
+	do {
+		stop = test_bit(WORK_STOP, &isp->todo);
+
+#ifdef	CONFIG_USB_OTG
+		/* transfer state from otg engine to isp1301 */
+		if (test_and_clear_bit(WORK_UPDATE_ISP, &isp->todo)) {
+			otg_update_isp(isp);
+			put_device(&isp->client->dev);
+		}
+#endif
+		/* transfer state from isp1301 to otg engine */
+		if (test_and_clear_bit(WORK_UPDATE_OTG, &isp->todo)) {
+			u8		stat = isp1301_clear_latch(isp);
+
+			isp_update_otg(isp, stat);
+			put_device(&isp->client->dev);
+		}
+
+		if (test_and_clear_bit(WORK_HOST_RESUME, &isp->todo)) {
+			u32	otg_ctrl;
+
+			/*
+			 * skip A_WAIT_VRISE; hc transitions invisibly
+			 * skip A_WAIT_BCON; same.
+			 */
+			switch (isp->otg.state) {
+			case OTG_STATE_A_WAIT_BCON:
+			case OTG_STATE_A_WAIT_VRISE:
+				isp->otg.state = OTG_STATE_A_HOST;
+				pr_debug("  --> a_host\n");
+				otg_ctrl = omap_readl(OTG_CTRL);
+				otg_ctrl |= OTG_A_BUSREQ;
+				otg_ctrl &= ~(OTG_BUSDROP|OTG_B_BUSREQ)
+						& OTG_CTRL_MASK;
+				omap_writel(otg_ctrl, OTG_CTRL);
+				break;
+			case OTG_STATE_B_WAIT_ACON:
+				isp->otg.state = OTG_STATE_B_HOST;
+				pr_debug("  --> b_host (acon)\n");
+				break;
+			case OTG_STATE_B_HOST:
+			case OTG_STATE_B_IDLE:
+			case OTG_STATE_A_IDLE:
+				break;
+			default:
+				pr_debug("  host resume in %s\n",
+						state_name(isp));
+			}
+			host_resume(isp);
+			// mdelay(10);
+			put_device(&isp->client->dev);
+		}
+
+		if (test_and_clear_bit(WORK_TIMER, &isp->todo)) {
+#ifdef	VERBOSE
+			dump_regs(isp, "timer");
+			if (!stop)
+				mod_timer(&isp->timer, jiffies + TIMER_JIFFIES);
+#endif
+			put_device(&isp->client->dev);
+		}
+
+		if (isp->todo)
+			dev_vdbg(&isp->client->dev,
+				"work done, todo = 0x%lx\n",
+				isp->todo);
+		if (stop) {
+			dev_dbg(&isp->client->dev, "stop\n");
+			break;
+		}
+	} while (isp->todo);
+	isp->working = 0;
+}
+
+static irqreturn_t isp1301_irq(int irq, void *isp)
+{
+	isp1301_defer_work(isp, WORK_UPDATE_OTG);
+	return IRQ_HANDLED;
+}
+
+static void isp1301_timer(unsigned long _isp)
+{
+	isp1301_defer_work((void *)_isp, WORK_TIMER);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void isp1301_release(struct device *dev)
+{
+	struct isp1301	*isp;
+
+	isp = dev_get_drvdata(dev);
+
+	/* FIXME -- not with a "new style" driver, it doesn't!! */
+
+	/* ugly -- i2c hijacks our memory hook to wait_for_completion() */
+	if (isp->i2c_release)
+		isp->i2c_release(dev);
+	kfree (isp);
+}
+
+static struct isp1301 *the_transceiver;
+
+static int __exit isp1301_remove(struct i2c_client *i2c)
+{
+	struct isp1301	*isp;
+
+	isp = i2c_get_clientdata(i2c);
+
+	isp1301_clear_bits(isp, ISP1301_INTERRUPT_FALLING, ~0);
+	isp1301_clear_bits(isp, ISP1301_INTERRUPT_RISING, ~0);
+	free_irq(i2c->irq, isp);
+#ifdef	CONFIG_USB_OTG
+	otg_unbind(isp);
+#endif
+	if (machine_is_omap_h2())
+		gpio_free(2);
+
+	isp->timer.data = 0;
+	set_bit(WORK_STOP, &isp->todo);
+	del_timer_sync(&isp->timer);
+	flush_scheduled_work();
+
+	put_device(&i2c->dev);
+	the_transceiver = NULL;
+
+	return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* NOTE:  three modes are possible here, only one of which
+ * will be standards-conformant on any given system:
+ *
+ *  - OTG mode (dual-role), required if there's a Mini-AB connector
+ *  - HOST mode, for when there's one or more A (host) connectors
+ *  - DEVICE mode, for when there's a B/Mini-B (device) connector
+ *
+ * As a rule, you won't have an isp1301 chip unless it's there to
+ * support the OTG mode.  Other modes help testing USB controllers
+ * in isolation from (full) OTG support, or maybe so later board
+ * revisions can help to support those feature.
+ */
+
+#ifdef	CONFIG_USB_OTG
+
+static int isp1301_otg_enable(struct isp1301 *isp)
+{
+	power_up(isp);
+	otg_init(isp);
+
+	/* NOTE:  since we don't change this, this provides
+	 * a few more interrupts than are strictly needed.
+	 */
+	isp1301_set_bits(isp, ISP1301_INTERRUPT_RISING,
+		INTR_VBUS_VLD | INTR_SESS_VLD | INTR_ID_GND);
+	isp1301_set_bits(isp, ISP1301_INTERRUPT_FALLING,
+		INTR_VBUS_VLD | INTR_SESS_VLD | INTR_ID_GND);
+
+	dev_info(&isp->client->dev, "ready for dual-role USB ...\n");
+
+	return 0;
+}
+
+#endif
+
+/* add or disable the host device+driver */
+static int
+isp1301_set_host(struct otg_transceiver *otg, struct usb_bus *host)
+{
+	struct isp1301	*isp = container_of(otg, struct isp1301, otg);
+
+	if (!otg || isp != the_transceiver)
+		return -ENODEV;
+
+	if (!host) {
+		omap_writew(0, OTG_IRQ_EN);
+		power_down(isp);
+		isp->otg.host = NULL;
+		return 0;
+	}
+
+#ifdef	CONFIG_USB_OTG
+	isp->otg.host = host;
+	dev_dbg(&isp->client->dev, "registered host\n");
+	host_suspend(isp);
+	if (isp->otg.gadget)
+		return isp1301_otg_enable(isp);
+	return 0;
+
+#elif	!defined(CONFIG_USB_GADGET_OMAP)
+	// FIXME update its refcount
+	isp->otg.host = host;
+
+	power_up(isp);
+
+	if (machine_is_omap_h2())
+		isp1301_set_bits(isp, ISP1301_MODE_CONTROL_1, MC1_DAT_SE0);
+
+	dev_info(&isp->client->dev, "A-Host sessions ok\n");
+	isp1301_set_bits(isp, ISP1301_INTERRUPT_RISING,
+		INTR_ID_GND);
+	isp1301_set_bits(isp, ISP1301_INTERRUPT_FALLING,
+		INTR_ID_GND);
+
+	/* If this has a Mini-AB connector, this mode is highly
+	 * nonstandard ... but can be handy for testing, especially with
+	 * the Mini-A end of an OTG cable.  (Or something nonstandard
+	 * like MiniB-to-StandardB, maybe built with a gender mender.)
+	 */
+	isp1301_set_bits(isp, ISP1301_OTG_CONTROL_1, OTG1_VBUS_DRV);
+
+	dump_regs(isp, __func__);
+
+	return 0;
+
+#else
+	dev_dbg(&isp->client->dev, "host sessions not allowed\n");
+	return -EINVAL;
+#endif
+
+}
+
+static int
+isp1301_set_peripheral(struct otg_transceiver *otg, struct usb_gadget *gadget)
+{
+	struct isp1301	*isp = container_of(otg, struct isp1301, otg);
+#ifndef	CONFIG_USB_OTG
+	u32 l;
+#endif
+
+	if (!otg || isp != the_transceiver)
+		return -ENODEV;
+
+	if (!gadget) {
+		omap_writew(0, OTG_IRQ_EN);
+		if (!isp->otg.default_a)
+			enable_vbus_draw(isp, 0);
+		usb_gadget_vbus_disconnect(isp->otg.gadget);
+		isp->otg.gadget = NULL;
+		power_down(isp);
+		return 0;
+	}
+
+#ifdef	CONFIG_USB_OTG
+	isp->otg.gadget = gadget;
+	dev_dbg(&isp->client->dev, "registered gadget\n");
+	/* gadget driver may be suspended until vbus_connect () */
+	if (isp->otg.host)
+		return isp1301_otg_enable(isp);
+	return 0;
+
+#elif	!defined(CONFIG_USB_OHCI_HCD) && !defined(CONFIG_USB_OHCI_HCD_MODULE)
+	isp->otg.gadget = gadget;
+	// FIXME update its refcount
+
+	l = omap_readl(OTG_CTRL) & OTG_CTRL_MASK;
+	l &= ~(OTG_XCEIV_OUTPUTS|OTG_CTRL_BITS);
+	l |= OTG_ID;
+	omap_writel(l, OTG_CTRL);
+
+	power_up(isp);
+	isp->otg.state = OTG_STATE_B_IDLE;
+
+	if (machine_is_omap_h2() || machine_is_omap_h3())
+		isp1301_set_bits(isp, ISP1301_MODE_CONTROL_1, MC1_DAT_SE0);
+
+	isp1301_set_bits(isp, ISP1301_INTERRUPT_RISING,
+		INTR_SESS_VLD);
+	isp1301_set_bits(isp, ISP1301_INTERRUPT_FALLING,
+		INTR_VBUS_VLD);
+	dev_info(&isp->client->dev, "B-Peripheral sessions ok\n");
+	dump_regs(isp, __func__);
+
+	/* If this has a Mini-AB connector, this mode is highly
+	 * nonstandard ... but can be handy for testing, so long
+	 * as you don't plug a Mini-A cable into the jack.
+	 */
+	if (isp1301_get_u8(isp, ISP1301_INTERRUPT_SOURCE) & INTR_VBUS_VLD)
+		b_peripheral(isp);
+
+	return 0;
+
+#else
+	dev_dbg(&isp->client->dev, "peripheral sessions not allowed\n");
+	return -EINVAL;
+#endif
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+static int
+isp1301_set_power(struct otg_transceiver *dev, unsigned mA)
+{
+	if (!the_transceiver)
+		return -ENODEV;
+	if (dev->state == OTG_STATE_B_PERIPHERAL)
+		enable_vbus_draw(the_transceiver, mA);
+	return 0;
+}
+
+static int
+isp1301_start_srp(struct otg_transceiver *dev)
+{
+	struct isp1301	*isp = container_of(dev, struct isp1301, otg);
+	u32		otg_ctrl;
+
+	if (!dev || isp != the_transceiver
+			|| isp->otg.state != OTG_STATE_B_IDLE)
+		return -ENODEV;
+
+	otg_ctrl = omap_readl(OTG_CTRL);
+	if (!(otg_ctrl & OTG_BSESSEND))
+		return -EINVAL;
+
+	otg_ctrl |= OTG_B_BUSREQ;
+	otg_ctrl &= ~OTG_A_BUSREQ & OTG_CTRL_MASK;
+	omap_writel(otg_ctrl, OTG_CTRL);
+	isp->otg.state = OTG_STATE_B_SRP_INIT;
+
+	pr_debug("otg: SRP, %s ... %06x\n", state_name(isp),
+			omap_readl(OTG_CTRL));
+#ifdef	CONFIG_USB_OTG
+	check_state(isp, __func__);
+#endif
+	return 0;
+}
+
+static int
+isp1301_start_hnp(struct otg_transceiver *dev)
+{
+#ifdef	CONFIG_USB_OTG
+	struct isp1301	*isp = container_of(dev, struct isp1301, otg);
+	u32 l;
+
+	if (!dev || isp != the_transceiver)
+		return -ENODEV;
+	if (isp->otg.default_a && (isp->otg.host == NULL
+			|| !isp->otg.host->b_hnp_enable))
+		return -ENOTCONN;
+	if (!isp->otg.default_a && (isp->otg.gadget == NULL
+			|| !isp->otg.gadget->b_hnp_enable))
+		return -ENOTCONN;
+
+	/* We want hardware to manage most HNP protocol timings.
+	 * So do this part as early as possible...
+	 */
+	switch (isp->otg.state) {
+	case OTG_STATE_B_HOST:
+		isp->otg.state = OTG_STATE_B_PERIPHERAL;
+		/* caller will suspend next */
+		break;
+	case OTG_STATE_A_HOST:
+#if 0
+		/* autoconnect mode avoids irq latency bugs */
+		isp1301_set_bits(isp, ISP1301_MODE_CONTROL_1,
+				MC1_BDIS_ACON_EN);
+#endif
+		/* caller must suspend then clear A_BUSREQ */
+		usb_gadget_vbus_connect(isp->otg.gadget);
+		l = omap_readl(OTG_CTRL);
+		l |= OTG_A_SETB_HNPEN;
+		omap_writel(l, OTG_CTRL);
+
+		break;
+	case OTG_STATE_A_PERIPHERAL:
+		/* initiated by B-Host suspend */
+		break;
+	default:
+		return -EILSEQ;
+	}
+	pr_debug("otg: HNP %s, %06x ...\n",
+		state_name(isp), omap_readl(OTG_CTRL));
+	check_state(isp, __func__);
+	return 0;
+#else
+	/* srp-only */
+	return -EINVAL;
+#endif
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int __init
+isp1301_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
+{
+	int			status;
+	struct isp1301		*isp;
+
+	if (the_transceiver)
+		return 0;
+
+	isp = kzalloc(sizeof *isp, GFP_KERNEL);
+	if (!isp)
+		return 0;
+
+	INIT_WORK(&isp->work, isp1301_work);
+	init_timer(&isp->timer);
+	isp->timer.function = isp1301_timer;
+	isp->timer.data = (unsigned long) isp;
+
+	i2c_set_clientdata(i2c, isp);
+	isp->client = i2c;
+
+	/* verify the chip (shouldn't be necesary) */
+	status = isp1301_get_u16(isp, ISP1301_VENDOR_ID);
+	if (status != I2C_VENDOR_ID_PHILIPS) {
+		dev_dbg(&i2c->dev, "not philips id: %d\n", status);
+		goto fail;
+	}
+	status = isp1301_get_u16(isp, ISP1301_PRODUCT_ID);
+	if (status != I2C_PRODUCT_ID_PHILIPS_1301) {
+		dev_dbg(&i2c->dev, "not isp1301, %d\n", status);
+		goto fail;
+	}
+	isp->i2c_release = i2c->dev.release;
+	i2c->dev.release = isp1301_release;
+
+	/* initial development used chiprev 2.00 */
+	status = i2c_smbus_read_word_data(i2c, ISP1301_BCD_DEVICE);
+	dev_info(&i2c->dev, "chiprev %x.%02x, driver " DRIVER_VERSION "\n",
+		status >> 8, status & 0xff);
+
+	/* make like power-on reset */
+	isp1301_clear_bits(isp, ISP1301_MODE_CONTROL_1, MC1_MASK);
+
+	isp1301_set_bits(isp, ISP1301_MODE_CONTROL_2, MC2_BI_DI);
+	isp1301_clear_bits(isp, ISP1301_MODE_CONTROL_2, ~MC2_BI_DI);
+
+	isp1301_set_bits(isp, ISP1301_OTG_CONTROL_1,
+				OTG1_DM_PULLDOWN | OTG1_DP_PULLDOWN);
+	isp1301_clear_bits(isp, ISP1301_OTG_CONTROL_1,
+				~(OTG1_DM_PULLDOWN | OTG1_DP_PULLDOWN));
+
+	isp1301_clear_bits(isp, ISP1301_INTERRUPT_LATCH, ~0);
+	isp1301_clear_bits(isp, ISP1301_INTERRUPT_FALLING, ~0);
+	isp1301_clear_bits(isp, ISP1301_INTERRUPT_RISING, ~0);
+
+#ifdef	CONFIG_USB_OTG
+	status = otg_bind(isp);
+	if (status < 0) {
+		dev_dbg(&i2c->dev, "can't bind OTG\n");
+		goto fail;
+	}
+#endif
+
+	if (machine_is_omap_h2()) {
+		/* full speed signaling by default */
+		isp1301_set_bits(isp, ISP1301_MODE_CONTROL_1,
+			MC1_SPEED);
+		isp1301_set_bits(isp, ISP1301_MODE_CONTROL_2,
+			MC2_SPD_SUSP_CTRL);
+
+		/* IRQ wired at M14 */
+		omap_cfg_reg(M14_1510_GPIO2);
+		if (gpio_request(2, "isp1301") == 0)
+			gpio_direction_input(2);
+		isp->irq_type = IRQF_TRIGGER_FALLING;
+	}
+
+	isp->irq_type |= IRQF_SAMPLE_RANDOM;
+	status = request_irq(i2c->irq, isp1301_irq,
+			isp->irq_type, DRIVER_NAME, isp);
+	if (status < 0) {
+		dev_dbg(&i2c->dev, "can't get IRQ %d, err %d\n",
+				i2c->irq, status);
+		goto fail;
+	}
+
+	isp->otg.dev = &i2c->dev;
+	isp->otg.label = DRIVER_NAME;
+
+	isp->otg.set_host = isp1301_set_host,
+	isp->otg.set_peripheral = isp1301_set_peripheral,
+	isp->otg.set_power = isp1301_set_power,
+	isp->otg.start_srp = isp1301_start_srp,
+	isp->otg.start_hnp = isp1301_start_hnp,
+
+	enable_vbus_draw(isp, 0);
+	power_down(isp);
+	the_transceiver = isp;
+
+#ifdef	CONFIG_USB_OTG
+	update_otg1(isp, isp1301_get_u8(isp, ISP1301_INTERRUPT_SOURCE));
+	update_otg2(isp, isp1301_get_u8(isp, ISP1301_OTG_STATUS));
+#endif
+
+	dump_regs(isp, __func__);
+
+#ifdef	VERBOSE
+	mod_timer(&isp->timer, jiffies + TIMER_JIFFIES);
+	dev_dbg(&i2c->dev, "scheduled timer, %d min\n", TIMER_MINUTES);
+#endif
+
+	status = otg_set_transceiver(&isp->otg);
+	if (status < 0)
+		dev_err(&i2c->dev, "can't register transceiver, %d\n",
+			status);
+
+	return 0;
+
+fail:
+	kfree(isp);
+	return -ENODEV;
+}
+
+static const struct i2c_device_id isp1301_id[] = {
+	{ "isp1301_omap", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, isp1301_id);
+
+static struct i2c_driver isp1301_driver = {
+	.driver = {
+		.name	= "isp1301_omap",
+	},
+	.probe		= isp1301_probe,
+	.remove		= __exit_p(isp1301_remove),
+	.id_table	= isp1301_id,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int __init isp_init(void)
+{
+	return i2c_add_driver(&isp1301_driver);
+}
+module_init(isp_init);
+
+static void __exit isp_exit(void)
+{
+	if (the_transceiver)
+		otg_set_transceiver(NULL);
+	i2c_del_driver(&isp1301_driver);
+}
+module_exit(isp_exit);
+