text: /*
   * 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/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/arch/usb.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;
  	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_REG */
  
  #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)
  
  
  /*-------------------------------------------------------------------------*/
  
  #ifdef	CONFIG_MACH_OMAP_H2
  
  /* board-specific PM hooks */
  
  #include <asm/gpio.h>
  #include <asm/arch/mux.h>
  #include <asm/mach-types.h>
  
  
  #if	defined(CONFIG_TPS65010) || defined(CONFIG_TPS65010_MODULE)
  
  #include <asm/arch/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
  
  /*-------------------------------------------------------------------------*/
  
  /* only two addresses possible */
  #define	ISP_BASE		0x2c
  static unsigned short normal_i2c[] = {
  	ISP_BASE, ISP_BASE + 1,
  	I2C_CLIENT_END };
  
  I2C_CLIENT_INSMOD;
  
  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_REG		(1 << 0)
  #	define	MC1_SUSPEND_REG		(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);
  }
  
  #ifdef	VERBOSE
  #define	dev_vdbg			dev_dbg
  #else
  #define	dev_vdbg(dev, fmt, arg...)	do{}while(0)
  #endif
  
  /*-------------------------------------------------------------------------*/
  
  /* 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_REG);
  
  	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_REG);
  
  	/* 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.
   */
  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)
  {
  	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;
  	isp->last_otg_ctrl = OTG_CTRL_REG = OTG_CTRL_REG & OTG_XCEIV_OUTPUTS;
  	pr_debug("  --> %s/%s\n", state_name(isp), tag);
  }
  
  /* called from irq handlers */
  static void b_idle(struct isp1301 *isp, const char *tag)
  {
  	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;
  	isp->last_otg_ctrl = OTG_CTRL_REG = OTG_CTRL_REG & OTG_XCEIV_OUTPUTS;
  	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",
  		OTG_CTRL_REG, 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 = OTG_TEST_REG & 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), OTG_CTRL_REG);
  }
  
  #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 = OTG_CTRL_REG
  			& OTG_CTRL_MASK
  			& ~OTG_XCEIV_INPUTS
  			& ~(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;
  		}
  	}
  	OTG_CTRL_REG = otg_ctrl;
  }
  
  /* outputs from ISP1301_OTG_STATUS */
  static void update_otg2(struct isp1301 *isp, u8 otg_status)
  {
  	u32	otg_ctrl;
  
  	otg_ctrl = OTG_CTRL_REG
  			& OTG_CTRL_MASK
  			& ~OTG_XCEIV_INPUTS
  			& ~(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;
  	OTG_CTRL_REG = 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 = OTG_CTRL_REG;
  	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) {
  		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;
  		}
  		OTG_CTRL_REG |= OTG_PULLUP;
  	}
  
  	check_state(isp, __FUNCTION__);
  	dump_regs(isp, "otg->isp1301");
  }
  
  static irqreturn_t omap_otg_irq(int irq, void *_isp)
  {
  	u16		otg_irq = OTG_IRQ_SRC_REG;
  	u32		otg_ctrl;
  	int		ret = IRQ_NONE;
  	struct isp1301	*isp = _isp;
  
  	/* update ISP1301 transciever from OTG controller */
  	if (otg_irq & OPRT_CHG) {
  		OTG_IRQ_SRC_REG = OPRT_CHG;
  		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", OTG_CTRL_REG);
  		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");
  
  		OTG_IRQ_SRC_REG = B_SRP_TMROUT;
  		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), OTG_CTRL_REG);
  		notresponding(isp);
  
  		otg_ctrl = OTG_CTRL_REG;
  		otg_ctrl |= OTG_BUSDROP;
  		otg_ctrl &= OTG_CTRL_MASK & ~OTG_XCEIV_INPUTS;
  		OTG_CTRL_REG = otg_ctrl;
  
  		/* subset of b_peripheral()... */
  		isp->otg.state = OTG_STATE_B_PERIPHERAL;
  		pr_debug("  --> b_peripheral\n");
  
  		OTG_IRQ_SRC_REG = B_HNP_FAIL;
  		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), OTG_CTRL_REG);
  
  		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 = OTG_CTRL_REG;
  			otg_ctrl |= OTG_A_BUSREQ;
  			otg_ctrl &= ~(OTG_BUSDROP|OTG_B_BUSREQ)
  					& ~OTG_XCEIV_INPUTS
  					& OTG_CTRL_MASK;
  			OTG_CTRL_REG = otg_ctrl;
  			break;
  		default:
  			break;
  		}
  
  		OTG_IRQ_SRC_REG = A_SRP_DETECT;
  		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 = OTG_CTRL_REG;
  		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;
  		OTG_CTRL_REG = otg_ctrl;
  		isp->otg.state = OTG_STATE_A_WAIT_VFALL;
  
  		OTG_IRQ_SRC_REG = A_REQ_TMROUT;
  		ret = IRQ_HANDLED;
  
  	/* A-supplied voltage fell too low; overcurrent */
  	} else if (otg_irq & A_VBUS_ERR) {
  		otg_ctrl = OTG_CTRL_REG;
  		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;
  		OTG_CTRL_REG = otg_ctrl;
  		isp->otg.state = OTG_STATE_A_VBUS_ERR;
  
  		OTG_IRQ_SRC_REG = A_VBUS_ERR;
  		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 = OTG_CTRL_REG;
  		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, __FUNCTION__);
  				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;
  				OTG_CTRL_REG = otg_ctrl | OTG_A_BUSREQ;
  			}
  
  			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);
  			}
  		}
  
  		OTG_IRQ_SRC_REG = DRIVER_SWITCH;
  		ret = IRQ_HANDLED;
  
  		if (kick)
  			usb_bus_start_enum(isp->otg.host,
  						isp->otg.host->otg_port);
  	}
  
  	check_state(isp, __FUNCTION__);
  	return ret;
  }
  
  static struct platform_device *otg_dev;
  
  static int otg_init(struct isp1301 *isp)
  {
  	if (!otg_dev)
  		return -ENODEV;
  
  	dump_regs(isp, __FUNCTION__);
  	/* some of these values are board-specific... */
  	OTG_SYSCON_2_REG |= 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 */
  		;
  
  	update_otg1(isp, isp1301_get_u8(isp, ISP1301_INTERRUPT_SOURCE));
  	update_otg2(isp, isp1301_get_u8(isp, ISP1301_OTG_STATUS));
  
  	check_state(isp, __FUNCTION__);
  	pr_debug("otg: %s, %s %06x\n",
  			state_name(isp), __FUNCTION__, OTG_CTRL_REG);
  
  	OTG_IRQ_EN_REG = DRIVER_SWITCH | OPRT_CHG
  			| B_SRP_TMROUT | B_HNP_FAIL
  			| A_VBUS_ERR | A_SRP_DETECT | A_REQ_TMROUT;
  	OTG_SYSCON_2_REG |= OTG_EN;
  
  	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 = 0;
  	return 0;
  }
  
  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)
  {
  	OTG_CTRL_REG = OTG_CTRL_REG & OTG_XCEIV_OUTPUTS;
  	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 {
  		/* 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;
  				OTG_CTRL_REG &= OTG_CTRL_REG & OTG_CTRL_MASK
  						& ~OTG_CTRL_BITS;
  				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, __FUNCTION__);
  #endif
  			/* FALLTHROUGH */
  		case OTG_STATE_B_SRP_INIT:
  			b_idle(isp, __FUNCTION__);
  			OTG_CTRL_REG &= OTG_CTRL_REG & OTG_XCEIV_OUTPUTS;
  			/* 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, __FUNCTION__);
  #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 = OTG_CTRL_REG;
  				otg_ctrl |= OTG_A_BUSREQ;
  				otg_ctrl &= ~(OTG_BUSDROP|OTG_B_BUSREQ)
  						& OTG_CTRL_MASK;
  				OTG_CTRL_REG = 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 = container_of(dev, struct isp1301, client.dev);
  
  	/* 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 isp1301_detach_client(struct i2c_client *i2c)
  {
  	struct isp1301	*isp;
  
  	isp = container_of(i2c, struct isp1301, client);
  
  	isp1301_clear_bits(isp, ISP1301_INTERRUPT_FALLING, ~0);
  	isp1301_clear_bits(isp, ISP1301_INTERRUPT_RISING, ~0);
  	free_irq(isp->irq, isp);
  #ifdef	CONFIG_USB_OTG
  	otg_unbind(isp);
  #endif
  	if (machine_is_omap_h2())
  		omap_free_gpio(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 = 0;
  
  	return i2c_detach_client(i2c);
  }
  
  /*-------------------------------------------------------------------------*/
  
  /* 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) {
  		OTG_IRQ_EN_REG = 0;
  		power_down(isp);
  		isp->otg.host = 0;
  		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, __FUNCTION__);
  
  	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);
  
  	if (!otg || isp != the_transceiver)
  		return -ENODEV;
  
  	if (!gadget) {
  		OTG_IRQ_EN_REG = 0;
  		if (!isp->otg.default_a)
  			enable_vbus_draw(isp, 0);
  		usb_gadget_vbus_disconnect(isp->otg.gadget);
  		isp->otg.gadget = 0;
  		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
  
  	OTG_CTRL_REG = (OTG_CTRL_REG & OTG_CTRL_MASK
  				& ~(OTG_XCEIV_OUTPUTS|OTG_CTRL_BITS))
  			| OTG_ID;
  	power_up(isp);
  	isp->otg.state = OTG_STATE_B_IDLE;
  
  	if (machine_is_omap_h2())
  		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, __FUNCTION__);
  
  	/* 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 = OTG_CTRL_REG;
  	if (!(otg_ctrl & OTG_BSESSEND))
  		return -EINVAL;
  
  	otg_ctrl |= OTG_B_BUSREQ;
  	otg_ctrl &= ~OTG_A_BUSREQ & OTG_CTRL_MASK;
  	OTG_CTRL_REG = otg_ctrl;
  	isp->otg.state = OTG_STATE_B_SRP_INIT;
  
  	pr_debug("otg: SRP, %s ... %06x\n", state_name(isp), OTG_CTRL_REG);
  #ifdef	CONFIG_USB_OTG
  	check_state(isp, __FUNCTION__);
  #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);
  
  	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);
  		OTG_CTRL_REG |= OTG_A_SETB_HNPEN;
  
  		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), OTG_CTRL_REG);
  	check_state(isp, __FUNCTION__);
  	return 0;
  #else
  	/* srp-only */
  	return -EINVAL;
  #endif
  }
  
  /*-------------------------------------------------------------------------*/
  
  /* no error returns, they'd just make bus scanning stop */
  static int isp1301_probe(struct i2c_adapter *bus, int address, int kind)
  {
  	int			status;
  	struct isp1301		*isp;
  	struct i2c_client	*i2c;
  
  	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;
  
  	isp->irq = -1;
  	isp->client.addr = address;
  	i2c_set_clientdata(&isp->client, isp);
  	isp->client.adapter = bus;
  	isp->client.driver = &isp1301_driver;
  	strlcpy(isp->client.name, DRIVER_NAME, I2C_NAME_SIZE);
  	i2c = &isp->client;
  
  	/* if this is a true probe, verify the chip ... */
  	if (kind < 0) {
  		status = isp1301_get_u16(isp, ISP1301_VENDOR_ID);
  		if (status != I2C_VENDOR_ID_PHILIPS) {
  			dev_dbg(&bus->dev, "addr %d not philips id: %d\n",
  				address, status);
  			goto fail1;
  		}
  		status = isp1301_get_u16(isp, ISP1301_PRODUCT_ID);
  		if (status != I2C_PRODUCT_ID_PHILIPS_1301) {
  			dev_dbg(&bus->dev, "%d not isp1301, %d\n",
  				address, status);
  			goto fail1;
  		}
  	}
  
  	status = i2c_attach_client(i2c);
  	if (status < 0) {
  		dev_dbg(&bus->dev, "can't attach %s to device %d, err %d\n",
  				DRIVER_NAME, address, status);
  fail1:
  		kfree(isp);
  		return 0;
  	}
  	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 fail2;
  	}
  #endif
  
  	if (machine_is_omap_h2()) {
  		/* full speed signaling by default */
  		isp1301_set_bits(isp, ISP1301_MODE_CONTROL_1,
  			MC1_SPEED_REG);
  		isp1301_set_bits(isp, ISP1301_MODE_CONTROL_2,
  			MC2_SPD_SUSP_CTRL);
  
  		/* IRQ wired at M14 */
  		omap_cfg_reg(M14_1510_GPIO2);
  		isp->irq = OMAP_GPIO_IRQ(2);
  		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(isp->irq, isp1301_irq,
  			isp->irq_type, DRIVER_NAME, isp);
  	if (status < 0) {
  		dev_dbg(&i2c->dev, "can't get IRQ %d, err %d\n",
  				isp->irq, status);
  #ifdef	CONFIG_USB_OTG
  fail2:
  #endif
  		i2c_detach_client(i2c);
  		goto fail1;
  	}
  
  	isp->otg.dev = &isp->client.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, __FUNCTION__);
  
  #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;
  }
  
  static int isp1301_scan_bus(struct i2c_adapter *bus)
  {
  	if (!i2c_check_functionality(bus, I2C_FUNC_SMBUS_BYTE_DATA
  			| I2C_FUNC_SMBUS_READ_WORD_DATA))
  		return -EINVAL;
  	return i2c_probe(bus, &addr_data, isp1301_probe);
  }
  
  static struct i2c_driver isp1301_driver = {
  	.driver = {
  		.name	= "isp1301_omap",
  	},
  	.attach_adapter	= isp1301_scan_bus,
  	.detach_client	= isp1301_detach_client,
  };
  
  /*-------------------------------------------------------------------------*/
  
  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(0);
  	i2c_del_driver(&isp1301_driver);
  }
  module_exit(isp_exit);
  
  