USB: otg: twl4030 transceiver driver

Add driver for the high speed USB-OTG transceiver in TI's TWL4030
family of chips.

Given this and various other pending patches, OMAP3 hardware like
that from beagleboard.org, gumstix.com (Overo), and openpandora.org
should now have basic USB host and peripheral connectivity with
mainline kernels.  Ditto for less widely-available boards.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 732 insertions, 0 deletions

diff --git a/drivers/usb/otg/Kconfig b/drivers/usb/otg/Kconfig
index afe91bf..8e8dbdb 100644
--- a/drivers/usb/otg/Kconfig
+++ b/drivers/usb/otg/Kconfig
@@ -41,4 +41,14 @@ config ISP1301_OMAP
 	  This driver can also be built as a module.  If so, the module
 	  will be called isp1301_omap.
 
+config TWL4030_USB
+	tristate "TWL4030 USB Transceiver Driver"
+	depends on TWL4030_CORE
+	select USB_OTG_UTILS
+	help
+	  Enable this to support the USB OTG transceiver on TWL4030
+	  family chips (including the TWL5030 and TPS659x0 devices).
+	  This transceiver supports high and full speed devices plus,
+	  in host mode, low speed.
+
 endif # USB || OTG
diff --git a/drivers/usb/otg/Makefile b/drivers/usb/otg/Makefile
index 7c80fc3..d73c7cf 100644
--- a/drivers/usb/otg/Makefile
+++ b/drivers/usb/otg/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_USB_OTG_UTILS)	+= otg.o
 # transceiver drivers
 obj-$(CONFIG_USB_GPIO_VBUS)	+= gpio_vbus.o
 obj-$(CONFIG_ISP1301_OMAP)	+= isp1301_omap.o
+obj-$(CONFIG_TWL4030_USB)	+= twl4030-usb.o
 
 ccflags-$(CONFIG_USB_DEBUG)	+= -DDEBUG
 ccflags-$(CONFIG_USB_GADGET_DEBUG) += -DDEBUG
diff --git a/drivers/usb/otg/twl4030-usb.c b/drivers/usb/otg/twl4030-usb.c
new file mode 100644
index 0000000..416e441
--- /dev/null
+++ b/drivers/usb/otg/twl4030-usb.c
@@ -0,0 +1,721 @@
+/*
+ * twl4030_usb - TWL4030 USB transceiver, talking to OMAP OTG controller
+ *
+ * Copyright (C) 2004-2007 Texas Instruments
+ * Copyright (C) 2008 Nokia Corporation
+ * Contact: Felipe Balbi <felipe.balbi@nokia.com>
+ *
+ * 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.
+ *
+ * Current status:
+ *	- HS USB ULPI mode works.
+ *	- 3-pin mode support may be added in future.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/usb/otg.h>
+#include <linux/i2c/twl4030.h>
+
+
+/* Register defines */
+
+#define VENDOR_ID_LO			0x00
+#define VENDOR_ID_HI			0x01
+#define PRODUCT_ID_LO			0x02
+#define PRODUCT_ID_HI			0x03
+
+#define FUNC_CTRL			0x04
+#define FUNC_CTRL_SET			0x05
+#define FUNC_CTRL_CLR			0x06
+#define FUNC_CTRL_SUSPENDM		(1 << 6)
+#define FUNC_CTRL_RESET			(1 << 5)
+#define FUNC_CTRL_OPMODE_MASK		(3 << 3) /* bits 3 and 4 */
+#define FUNC_CTRL_OPMODE_NORMAL		(0 << 3)
+#define FUNC_CTRL_OPMODE_NONDRIVING	(1 << 3)
+#define FUNC_CTRL_OPMODE_DISABLE_BIT_NRZI	(2 << 3)
+#define FUNC_CTRL_TERMSELECT		(1 << 2)
+#define FUNC_CTRL_XCVRSELECT_MASK	(3 << 0) /* bits 0 and 1 */
+#define FUNC_CTRL_XCVRSELECT_HS		(0 << 0)
+#define FUNC_CTRL_XCVRSELECT_FS		(1 << 0)
+#define FUNC_CTRL_XCVRSELECT_LS		(2 << 0)
+#define FUNC_CTRL_XCVRSELECT_FS4LS	(3 << 0)
+
+#define IFC_CTRL			0x07
+#define IFC_CTRL_SET			0x08
+#define IFC_CTRL_CLR			0x09
+#define IFC_CTRL_INTERFACE_PROTECT_DISABLE	(1 << 7)
+#define IFC_CTRL_AUTORESUME		(1 << 4)
+#define IFC_CTRL_CLOCKSUSPENDM		(1 << 3)
+#define IFC_CTRL_CARKITMODE		(1 << 2)
+#define IFC_CTRL_FSLSSERIALMODE_3PIN	(1 << 1)
+
+#define TWL4030_OTG_CTRL		0x0A
+#define TWL4030_OTG_CTRL_SET		0x0B
+#define TWL4030_OTG_CTRL_CLR		0x0C
+#define TWL4030_OTG_CTRL_DRVVBUS	(1 << 5)
+#define TWL4030_OTG_CTRL_CHRGVBUS	(1 << 4)
+#define TWL4030_OTG_CTRL_DISCHRGVBUS	(1 << 3)
+#define TWL4030_OTG_CTRL_DMPULLDOWN	(1 << 2)
+#define TWL4030_OTG_CTRL_DPPULLDOWN	(1 << 1)
+#define TWL4030_OTG_CTRL_IDPULLUP	(1 << 0)
+
+#define USB_INT_EN_RISE			0x0D
+#define USB_INT_EN_RISE_SET		0x0E
+#define USB_INT_EN_RISE_CLR		0x0F
+#define USB_INT_EN_FALL			0x10
+#define USB_INT_EN_FALL_SET		0x11
+#define USB_INT_EN_FALL_CLR		0x12
+#define USB_INT_STS			0x13
+#define USB_INT_LATCH			0x14
+#define USB_INT_IDGND			(1 << 4)
+#define USB_INT_SESSEND			(1 << 3)
+#define USB_INT_SESSVALID		(1 << 2)
+#define USB_INT_VBUSVALID		(1 << 1)
+#define USB_INT_HOSTDISCONNECT		(1 << 0)
+
+#define CARKIT_CTRL			0x19
+#define CARKIT_CTRL_SET			0x1A
+#define CARKIT_CTRL_CLR			0x1B
+#define CARKIT_CTRL_MICEN		(1 << 6)
+#define CARKIT_CTRL_SPKRIGHTEN		(1 << 5)
+#define CARKIT_CTRL_SPKLEFTEN		(1 << 4)
+#define CARKIT_CTRL_RXDEN		(1 << 3)
+#define CARKIT_CTRL_TXDEN		(1 << 2)
+#define CARKIT_CTRL_IDGNDDRV		(1 << 1)
+#define CARKIT_CTRL_CARKITPWR		(1 << 0)
+#define CARKIT_PLS_CTRL			0x22
+#define CARKIT_PLS_CTRL_SET		0x23
+#define CARKIT_PLS_CTRL_CLR		0x24
+#define CARKIT_PLS_CTRL_SPKRRIGHT_BIASEN	(1 << 3)
+#define CARKIT_PLS_CTRL_SPKRLEFT_BIASEN	(1 << 2)
+#define CARKIT_PLS_CTRL_RXPLSEN		(1 << 1)
+#define CARKIT_PLS_CTRL_TXPLSEN		(1 << 0)
+
+#define MCPC_CTRL			0x30
+#define MCPC_CTRL_SET			0x31
+#define MCPC_CTRL_CLR			0x32
+#define MCPC_CTRL_RTSOL			(1 << 7)
+#define MCPC_CTRL_EXTSWR		(1 << 6)
+#define MCPC_CTRL_EXTSWC		(1 << 5)
+#define MCPC_CTRL_VOICESW		(1 << 4)
+#define MCPC_CTRL_OUT64K		(1 << 3)
+#define MCPC_CTRL_RTSCTSSW		(1 << 2)
+#define MCPC_CTRL_HS_UART		(1 << 0)
+
+#define MCPC_IO_CTRL			0x33
+#define MCPC_IO_CTRL_SET		0x34
+#define MCPC_IO_CTRL_CLR		0x35
+#define MCPC_IO_CTRL_MICBIASEN		(1 << 5)
+#define MCPC_IO_CTRL_CTS_NPU		(1 << 4)
+#define MCPC_IO_CTRL_RXD_PU		(1 << 3)
+#define MCPC_IO_CTRL_TXDTYP		(1 << 2)
+#define MCPC_IO_CTRL_CTSTYP		(1 << 1)
+#define MCPC_IO_CTRL_RTSTYP		(1 << 0)
+
+#define MCPC_CTRL2			0x36
+#define MCPC_CTRL2_SET			0x37
+#define MCPC_CTRL2_CLR			0x38
+#define MCPC_CTRL2_MCPC_CK_EN		(1 << 0)
+
+#define OTHER_FUNC_CTRL			0x80
+#define OTHER_FUNC_CTRL_SET		0x81
+#define OTHER_FUNC_CTRL_CLR		0x82
+#define OTHER_FUNC_CTRL_BDIS_ACON_EN	(1 << 4)
+#define OTHER_FUNC_CTRL_FIVEWIRE_MODE	(1 << 2)
+
+#define OTHER_IFC_CTRL			0x83
+#define OTHER_IFC_CTRL_SET		0x84
+#define OTHER_IFC_CTRL_CLR		0x85
+#define OTHER_IFC_CTRL_OE_INT_EN	(1 << 6)
+#define OTHER_IFC_CTRL_CEA2011_MODE	(1 << 5)
+#define OTHER_IFC_CTRL_FSLSSERIALMODE_4PIN	(1 << 4)
+#define OTHER_IFC_CTRL_HIZ_ULPI_60MHZ_OUT	(1 << 3)
+#define OTHER_IFC_CTRL_HIZ_ULPI		(1 << 2)
+#define OTHER_IFC_CTRL_ALT_INT_REROUTE	(1 << 0)
+
+#define OTHER_INT_EN_RISE		0x86
+#define OTHER_INT_EN_RISE_SET		0x87
+#define OTHER_INT_EN_RISE_CLR		0x88
+#define OTHER_INT_EN_FALL		0x89
+#define OTHER_INT_EN_FALL_SET		0x8A
+#define OTHER_INT_EN_FALL_CLR		0x8B
+#define OTHER_INT_STS			0x8C
+#define OTHER_INT_LATCH			0x8D
+#define OTHER_INT_VB_SESS_VLD		(1 << 7)
+#define OTHER_INT_DM_HI			(1 << 6) /* not valid for "latch" reg */
+#define OTHER_INT_DP_HI			(1 << 5) /* not valid for "latch" reg */
+#define OTHER_INT_BDIS_ACON		(1 << 3) /* not valid for "fall" regs */
+#define OTHER_INT_MANU			(1 << 1)
+#define OTHER_INT_ABNORMAL_STRESS	(1 << 0)
+
+#define ID_STATUS			0x96
+#define ID_RES_FLOAT			(1 << 4)
+#define ID_RES_440K			(1 << 3)
+#define ID_RES_200K			(1 << 2)
+#define ID_RES_102K			(1 << 1)
+#define ID_RES_GND			(1 << 0)
+
+#define POWER_CTRL			0xAC
+#define POWER_CTRL_SET			0xAD
+#define POWER_CTRL_CLR			0xAE
+#define POWER_CTRL_OTG_ENAB		(1 << 5)
+
+#define OTHER_IFC_CTRL2			0xAF
+#define OTHER_IFC_CTRL2_SET		0xB0
+#define OTHER_IFC_CTRL2_CLR		0xB1
+#define OTHER_IFC_CTRL2_ULPI_STP_LOW	(1 << 4)
+#define OTHER_IFC_CTRL2_ULPI_TXEN_POL	(1 << 3)
+#define OTHER_IFC_CTRL2_ULPI_4PIN_2430	(1 << 2)
+#define OTHER_IFC_CTRL2_USB_INT_OUTSEL_MASK	(3 << 0) /* bits 0 and 1 */
+#define OTHER_IFC_CTRL2_USB_INT_OUTSEL_INT1N	(0 << 0)
+#define OTHER_IFC_CTRL2_USB_INT_OUTSEL_INT2N	(1 << 0)
+
+#define REG_CTRL_EN			0xB2
+#define REG_CTRL_EN_SET			0xB3
+#define REG_CTRL_EN_CLR			0xB4
+#define REG_CTRL_ERROR			0xB5
+#define ULPI_I2C_CONFLICT_INTEN		(1 << 0)
+
+#define OTHER_FUNC_CTRL2		0xB8
+#define OTHER_FUNC_CTRL2_SET		0xB9
+#define OTHER_FUNC_CTRL2_CLR		0xBA
+#define OTHER_FUNC_CTRL2_VBAT_TIMER_EN	(1 << 0)
+
+/* following registers do not have separate _clr and _set registers */
+#define VBUS_DEBOUNCE			0xC0
+#define ID_DEBOUNCE			0xC1
+#define VBAT_TIMER			0xD3
+#define PHY_PWR_CTRL			0xFD
+#define PHY_PWR_PHYPWD			(1 << 0)
+#define PHY_CLK_CTRL			0xFE
+#define PHY_CLK_CTRL_CLOCKGATING_EN	(1 << 2)
+#define PHY_CLK_CTRL_CLK32K_EN		(1 << 1)
+#define REQ_PHY_DPLL_CLK		(1 << 0)
+#define PHY_CLK_CTRL_STS		0xFF
+#define PHY_DPLL_CLK			(1 << 0)
+
+/* In module TWL4030_MODULE_PM_MASTER */
+#define PROTECT_KEY			0x0E
+
+/* In module TWL4030_MODULE_PM_RECEIVER */
+#define VUSB_DEDICATED1			0x7D
+#define VUSB_DEDICATED2			0x7E
+#define VUSB1V5_DEV_GRP			0x71
+#define VUSB1V5_TYPE			0x72
+#define VUSB1V5_REMAP			0x73
+#define VUSB1V8_DEV_GRP			0x74
+#define VUSB1V8_TYPE			0x75
+#define VUSB1V8_REMAP			0x76
+#define VUSB3V1_DEV_GRP			0x77
+#define VUSB3V1_TYPE			0x78
+#define VUSB3V1_REMAP			0x79
+
+/* In module TWL4030_MODULE_INTBR */
+#define PMBR1				0x0D
+#define GPIO_USB_4PIN_ULPI_2430C	(3 << 0)
+
+
+
+enum linkstat {
+	USB_LINK_UNKNOWN = 0,
+	USB_LINK_NONE,
+	USB_LINK_VBUS,
+	USB_LINK_ID,
+};
+
+struct twl4030_usb {
+	struct otg_transceiver	otg;
+	struct device		*dev;
+
+	/* for vbus reporting with irqs disabled */
+	spinlock_t		lock;
+
+	/* pin configuration */
+	enum twl4030_usb_mode	usb_mode;
+
+	int			irq;
+	u8			linkstat;
+	u8			asleep;
+	bool			irq_enabled;
+};
+
+/* internal define on top of container_of */
+#define xceiv_to_twl(x)		container_of((x), struct twl4030_usb, otg);
+
+/*-------------------------------------------------------------------------*/
+
+static int twl4030_i2c_write_u8_verify(struct twl4030_usb *twl,
+		u8 module, u8 data, u8 address)
+{
+	u8 check;
+
+	if ((twl4030_i2c_write_u8(module, data, address) >= 0) &&
+	    (twl4030_i2c_read_u8(module, &check, address) >= 0) &&
+						(check == data))
+		return 0;
+	dev_dbg(twl->dev, "Write%d[%d,0x%x] wrote %02x but read %02x\n",
+			1, module, address, check, data);
+
+	/* Failed once: Try again */
+	if ((twl4030_i2c_write_u8(module, data, address) >= 0) &&
+	    (twl4030_i2c_read_u8(module, &check, address) >= 0) &&
+						(check == data))
+		return 0;
+	dev_dbg(twl->dev, "Write%d[%d,0x%x] wrote %02x but read %02x\n",
+			2, module, address, check, data);
+
+	/* Failed again: Return error */
+	return -EBUSY;
+}
+
+#define twl4030_usb_write_verify(twl, address, data)	\
+	twl4030_i2c_write_u8_verify(twl, TWL4030_MODULE_USB, (data), (address))
+
+static inline int twl4030_usb_write(struct twl4030_usb *twl,
+		u8 address, u8 data)
+{
+	int ret = 0;
+
+	ret = twl4030_i2c_write_u8(TWL4030_MODULE_USB, data, address);
+	if (ret < 0)
+		dev_dbg(twl->dev,
+			"TWL4030:USB:Write[0x%x] Error %d\n", address, ret);
+	return ret;
+}
+
+static inline int twl4030_readb(struct twl4030_usb *twl, u8 module, u8 address)
+{
+	u8 data;
+	int ret = 0;
+
+	ret = twl4030_i2c_read_u8(module, &data, address);
+	if (ret >= 0)
+		ret = data;
+	else
+		dev_dbg(twl->dev,
+			"TWL4030:readb[0x%x,0x%x] Error %d\n",
+					module, address, ret);
+
+	return ret;
+}
+
+static inline int twl4030_usb_read(struct twl4030_usb *twl, u8 address)
+{
+	return twl4030_readb(twl, TWL4030_MODULE_USB, address);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static inline int
+twl4030_usb_set_bits(struct twl4030_usb *twl, u8 reg, u8 bits)
+{
+	return twl4030_usb_write(twl, reg + 1, bits);
+}
+
+static inline int
+twl4030_usb_clear_bits(struct twl4030_usb *twl, u8 reg, u8 bits)
+{
+	return twl4030_usb_write(twl, reg + 2, bits);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static enum linkstat twl4030_usb_linkstat(struct twl4030_usb *twl)
+{
+	int	status;
+	int	linkstat = USB_LINK_UNKNOWN;
+
+	/* STS_HW_CONDITIONS */
+	status = twl4030_readb(twl, TWL4030_MODULE_PM_MASTER, 0x0f);
+	if (status < 0)
+		dev_err(twl->dev, "USB link status err %d\n", status);
+	else if (status & BIT(7))
+		linkstat = USB_LINK_VBUS;
+	else if (status & BIT(2))
+		linkstat = USB_LINK_ID;
+	else
+		linkstat = USB_LINK_NONE;
+
+	dev_dbg(twl->dev, "HW_CONDITIONS 0x%02x/%d; link %d\n",
+			status, status, linkstat);
+
+	/* REVISIT this assumes host and peripheral controllers
+	 * are registered, and that both are active...
+	 */
+
+	spin_lock_irq(&twl->lock);
+	twl->linkstat = linkstat;
+	if (linkstat == USB_LINK_ID) {
+		twl->otg.default_a = true;
+		twl->otg.state = OTG_STATE_A_IDLE;
+	} else {
+		twl->otg.default_a = false;
+		twl->otg.state = OTG_STATE_B_IDLE;
+	}
+	spin_unlock_irq(&twl->lock);
+
+	return linkstat;
+}
+
+static void twl4030_usb_set_mode(struct twl4030_usb *twl, int mode)
+{
+	twl->usb_mode = mode;
+
+	switch (mode) {
+	case T2_USB_MODE_ULPI:
+		twl4030_usb_clear_bits(twl, IFC_CTRL, IFC_CTRL_CARKITMODE);
+		twl4030_usb_set_bits(twl, POWER_CTRL, POWER_CTRL_OTG_ENAB);
+		twl4030_usb_clear_bits(twl, FUNC_CTRL,
+					FUNC_CTRL_XCVRSELECT_MASK |
+					FUNC_CTRL_OPMODE_MASK);
+		break;
+	case -1:
+		/* FIXME: power on defaults */
+		break;
+	default:
+		dev_err(twl->dev, "unsupported T2 transceiver mode %d\n",
+				mode);
+		break;
+	};
+}
+
+static void twl4030_i2c_access(struct twl4030_usb *twl, int on)
+{
+	unsigned long timeout;
+	int val = twl4030_usb_read(twl, PHY_CLK_CTRL);
+
+	if (val >= 0) {
+		if (on) {
+			/* enable DPLL to access PHY registers over I2C */
+			val |= REQ_PHY_DPLL_CLK;
+			WARN_ON(twl4030_usb_write_verify(twl, PHY_CLK_CTRL,
+						(u8)val) < 0);
+
+			timeout = jiffies + HZ;
+			while (!(twl4030_usb_read(twl, PHY_CLK_CTRL_STS) &
+							PHY_DPLL_CLK)
+				&& time_before(jiffies, timeout))
+					udelay(10);
+			if (!(twl4030_usb_read(twl, PHY_CLK_CTRL_STS) &
+							PHY_DPLL_CLK))
+				dev_err(twl->dev, "Timeout setting T2 HSUSB "
+						"PHY DPLL clock\n");
+		} else {
+			/* let ULPI control the DPLL clock */
+			val &= ~REQ_PHY_DPLL_CLK;
+			WARN_ON(twl4030_usb_write_verify(twl, PHY_CLK_CTRL,
+						(u8)val) < 0);
+		}
+	}
+}
+
+static void twl4030_phy_power(struct twl4030_usb *twl, int on)
+{
+	u8 pwr;
+
+	pwr = twl4030_usb_read(twl, PHY_PWR_CTRL);
+	if (on) {
+		pwr &= ~PHY_PWR_PHYPWD;
+		WARN_ON(twl4030_usb_write_verify(twl, PHY_PWR_CTRL, pwr) < 0);
+		twl4030_usb_write(twl, PHY_CLK_CTRL,
+				  twl4030_usb_read(twl, PHY_CLK_CTRL) |
+					(PHY_CLK_CTRL_CLOCKGATING_EN |
+						PHY_CLK_CTRL_CLK32K_EN));
+	} else  {
+		pwr |= PHY_PWR_PHYPWD;
+		WARN_ON(twl4030_usb_write_verify(twl, PHY_PWR_CTRL, pwr) < 0);
+	}
+}
+
+static void twl4030_phy_suspend(struct twl4030_usb *twl, int controller_off)
+{
+	if (twl->asleep)
+		return;
+
+	twl4030_phy_power(twl, 0);
+	twl->asleep = 1;
+}
+
+static void twl4030_phy_resume(struct twl4030_usb *twl)
+{
+	if (!twl->asleep)
+		return;
+
+	twl4030_phy_power(twl, 1);
+	twl4030_i2c_access(twl, 1);
+	twl4030_usb_set_mode(twl, twl->usb_mode);
+	if (twl->usb_mode == T2_USB_MODE_ULPI)
+		twl4030_i2c_access(twl, 0);
+	twl->asleep = 0;
+}
+
+static void twl4030_usb_ldo_init(struct twl4030_usb *twl)
+{
+	/* Enable writing to power configuration registers */
+	twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, 0xC0, PROTECT_KEY);
+	twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, 0x0C, PROTECT_KEY);
+
+	/* put VUSB3V1 LDO in active state */
+	twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0, VUSB_DEDICATED2);
+
+	/* input to VUSB3V1 LDO is from VBAT, not VBUS */
+	twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0x14, VUSB_DEDICATED1);
+
+	/* turn on 3.1V regulator */
+	twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0x20, VUSB3V1_DEV_GRP);
+	twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0, VUSB3V1_TYPE);
+
+	/* turn on 1.5V regulator */
+	twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0x20, VUSB1V5_DEV_GRP);
+	twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0, VUSB1V5_TYPE);
+
+	/* turn on 1.8V regulator */
+	twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0x20, VUSB1V8_DEV_GRP);
+	twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0, VUSB1V8_TYPE);
+
+	/* disable access to power configuration registers */
+	twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, 0, PROTECT_KEY);
+}
+
+static ssize_t twl4030_usb_vbus_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct twl4030_usb *twl = dev_get_drvdata(dev);
+	unsigned long flags;
+	int ret = -EINVAL;
+
+	spin_lock_irqsave(&twl->lock, flags);
+	ret = sprintf(buf, "%s\n",
+			(twl->linkstat == USB_LINK_VBUS) ? "on" : "off");
+	spin_unlock_irqrestore(&twl->lock, flags);
+
+	return ret;
+}
+static DEVICE_ATTR(vbus, 0444, twl4030_usb_vbus_show, NULL);
+
+static irqreturn_t twl4030_usb_irq(int irq, void *_twl)
+{
+	struct twl4030_usb *twl = _twl;
+	int status;
+
+#ifdef CONFIG_LOCKDEP
+	/* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
+	 * we don't want and can't tolerate.  Although it might be
+	 * friendlier not to borrow this thread context...
+	 */
+	local_irq_enable();
+#endif
+
+	status = twl4030_usb_linkstat(twl);
+	if (status != USB_LINK_UNKNOWN) {
+
+		/* FIXME add a set_power() method so that B-devices can
+		 * configure the charger appropriately.  It's not always
+		 * correct to consume VBUS power, and how much current to
+		 * consume is a function of the USB configuration chosen
+		 * by the host.
+		 *
+		 * REVISIT usb_gadget_vbus_connect(...) as needed, ditto
+		 * its disconnect() sibling, when changing to/from the
+		 * USB_LINK_VBUS state.  musb_hdrc won't care until it
+		 * starts to handle softconnect right.
+		 */
+		twl4030charger_usb_en(status == USB_LINK_VBUS);
+
+		if (status == USB_LINK_NONE)
+			twl4030_phy_suspend(twl, 0);
+		else
+			twl4030_phy_resume(twl);
+	}
+	sysfs_notify(&twl->dev->kobj, NULL, "vbus");
+
+	return IRQ_HANDLED;
+}
+
+static int twl4030_set_suspend(struct otg_transceiver *x, int suspend)
+{
+	struct twl4030_usb *twl = xceiv_to_twl(x);
+
+	if (suspend)
+		twl4030_phy_suspend(twl, 1);
+	else
+		twl4030_phy_resume(twl);
+
+	return 0;
+}
+
+static int twl4030_set_peripheral(struct otg_transceiver *x,
+		struct usb_gadget *gadget)
+{
+	struct twl4030_usb *twl;
+
+	if (!x)
+		return -ENODEV;
+
+	twl = xceiv_to_twl(x);
+	twl->otg.gadget = gadget;
+	if (!gadget)
+		twl->otg.state = OTG_STATE_UNDEFINED;
+
+	return 0;
+}
+
+static int twl4030_set_host(struct otg_transceiver *x, struct usb_bus *host)
+{
+	struct twl4030_usb *twl;
+
+	if (!x)
+		return -ENODEV;
+
+	twl = xceiv_to_twl(x);
+	twl->otg.host = host;
+	if (!host)
+		twl->otg.state = OTG_STATE_UNDEFINED;
+
+	return 0;
+}
+
+static int __init twl4030_usb_probe(struct platform_device *pdev)
+{
+	struct twl4030_usb_data *pdata = pdev->dev.platform_data;
+	struct twl4030_usb	*twl;
+	int			status;
+
+	if (!pdata) {
+		dev_dbg(&pdev->dev, "platform_data not available\n");
+		return -EINVAL;
+	}
+
+	twl = kzalloc(sizeof *twl, GFP_KERNEL);
+	if (!twl)
+		return -ENOMEM;
+
+	twl->dev		= &pdev->dev;
+	twl->irq		= platform_get_irq(pdev, 0);
+	twl->otg.dev		= twl->dev;
+	twl->otg.label		= "twl4030";
+	twl->otg.set_host	= twl4030_set_host;
+	twl->otg.set_peripheral	= twl4030_set_peripheral;
+	twl->otg.set_suspend	= twl4030_set_suspend;
+	twl->usb_mode		= pdata->usb_mode;
+	twl->asleep		= 1;
+
+	/* init spinlock for workqueue */
+	spin_lock_init(&twl->lock);
+
+	twl4030_usb_ldo_init(twl);
+	otg_set_transceiver(&twl->otg);
+
+	platform_set_drvdata(pdev, twl);
+	if (device_create_file(&pdev->dev, &dev_attr_vbus))
+		dev_warn(&pdev->dev, "could not create sysfs file\n");
+
+	/* Our job is to use irqs and status from the power module
+	 * to keep the transceiver disabled when nothing's connected.
+	 *
+	 * FIXME we actually shouldn't start enabling it until the
+	 * USB controller drivers have said they're ready, by calling
+	 * set_host() and/or set_peripheral() ... OTG_capable boards
+	 * need both handles, otherwise just one suffices.
+	 */
+	twl->irq_enabled = true;
+	status = request_irq(twl->irq, twl4030_usb_irq,
+			IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
+			"twl4030_usb", twl);
+	if (status < 0) {
+		dev_dbg(&pdev->dev, "can't get IRQ %d, err %d\n",
+			twl->irq, status);
+		kfree(twl);
+		return status;
+	}
+
+	/* The IRQ handler just handles changes from the previous states
+	 * of the ID and VBUS pins ... in probe() we must initialize that
+	 * previous state.  The easy way:  fake an IRQ.
+	 *
+	 * REVISIT:  a real IRQ might have happened already, if PREEMPT is
+	 * enabled.  Else the IRQ may not yet be configured or enabled,
+	 * because of scheduling delays.
+	 */
+	twl4030_usb_irq(twl->irq, twl);
+
+	dev_info(&pdev->dev, "Initialized TWL4030 USB module\n");
+	return 0;
+}
+
+static int __exit twl4030_usb_remove(struct platform_device *pdev)
+{
+	struct twl4030_usb *twl = platform_get_drvdata(pdev);
+	int val;
+
+	free_irq(twl->irq, twl);
+	device_remove_file(twl->dev, &dev_attr_vbus);
+
+	/* set transceiver mode to power on defaults */
+	twl4030_usb_set_mode(twl, -1);
+
+	/* autogate 60MHz ULPI clock,
+	 * clear dpll clock request for i2c access,
+	 * disable 32KHz
+	 */
+	val = twl4030_usb_read(twl, PHY_CLK_CTRL);
+	if (val >= 0) {
+		val |= PHY_CLK_CTRL_CLOCKGATING_EN;
+		val &= ~(PHY_CLK_CTRL_CLK32K_EN | REQ_PHY_DPLL_CLK);
+		twl4030_usb_write(twl, PHY_CLK_CTRL, (u8)val);
+	}
+
+	/* disable complete OTG block */
+	twl4030_usb_clear_bits(twl, POWER_CTRL, POWER_CTRL_OTG_ENAB);
+
+	twl4030_phy_power(twl, 0);
+
+	kfree(twl);
+
+	return 0;
+}
+
+static struct platform_driver twl4030_usb_driver = {
+	.probe		= twl4030_usb_probe,
+	.remove		= __exit_p(twl4030_usb_remove),
+	.driver		= {
+		.name	= "twl4030_usb",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init twl4030_usb_init(void)
+{
+	return platform_driver_register(&twl4030_usb_driver);
+}
+subsys_initcall(twl4030_usb_init);
+
+static void __exit twl4030_usb_exit(void)
+{
+	platform_driver_unregister(&twl4030_usb_driver);
+}
+module_exit(twl4030_usb_exit);
+
+MODULE_ALIAS("platform:twl4030_usb");
+MODULE_AUTHOR("Texas Instruments, Inc, Nokia Corporation");
+MODULE_DESCRIPTION("TWL4030 USB transceiver driver");
+MODULE_LICENSE("GPL");