usb: phy: twl4030: use the new generic PHY framework

Used the generic PHY framework API to create the PHY. For powering on
and powering off the PHY, power_on and power_off ops are used. Once the
MUSB OMAP glue is adapted to the new framework, the suspend and resume
ops of usb phy library will be removed. Also twl4030-usb driver is moved
to drivers/phy/.

However using the old usb phy library cannot be completely removed
because otg is intertwined with phy and moving to the new
framework completely will break otg. Once we have a separate otg state machine,
we can get rid of the usb phy library.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 856 insertions, 0 deletions

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 38c3477ead4..ac239aca77e 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -27,4 +27,15 @@ config OMAP_USB2
 	  The USB OTG controller communicates with the comparator using this
 	  driver.
 
+config TWL4030_USB
+	tristate "TWL4030 USB Transceiver Driver"
+	depends on TWL4030_CORE && REGULATOR_TWL4030 && USB_MUSB_OMAP2PLUS
+	select GENERIC_PHY
+	select USB_PHY
+	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.
+
 endmenu
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index ed5b088abae..0dd8a983454 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -4,3 +4,4 @@
 
 obj-$(CONFIG_GENERIC_PHY)	+= phy-core.o
 obj-$(CONFIG_OMAP_USB2)		+= phy-omap-usb2.o
+obj-$(CONFIG_TWL4030_USB)	+= phy-twl4030-usb.o
diff --git a/drivers/phy/phy-twl4030-usb.c b/drivers/phy/phy-twl4030-usb.c
new file mode 100644
index 00000000000..d02913f9a6b
--- /dev/null
+++ b/drivers/phy/phy-twl4030-usb.c
@@ -0,0 +1,844 @@
+/*
+ * 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/phy/phy.h>
+#include <linux/usb/musb-omap.h>
+#include <linux/usb/ulpi.h>
+#include <linux/i2c/twl.h>
+#include <linux/regulator/consumer.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+
+/* Register defines */
+
+#define MCPC_CTRL			0x30
+#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_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_MCPC_CK_EN		(1 << 0)
+
+#define OTHER_FUNC_CTRL			0x80
+#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_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_FALL		0x89
+#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_OTG_ENAB		(1 << 5)
+
+#define OTHER_IFC_CTRL2			0xAF
+#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_ERROR			0xB5
+#define ULPI_I2C_CONFLICT_INTEN		(1 << 0)
+
+#define OTHER_FUNC_CTRL2		0xB8
+#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 TWL_MODULE_PM_MASTER */
+#define STS_HW_CONDITIONS		0x0F
+
+/* In module TWL_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)
+
+struct twl4030_usb {
+	struct usb_phy		phy;
+	struct device		*dev;
+
+	/* TWL4030 internal USB regulator supplies */
+	struct regulator	*usb1v5;
+	struct regulator	*usb1v8;
+	struct regulator	*usb3v1;
+
+	/* for vbus reporting with irqs disabled */
+	spinlock_t		lock;
+
+	/* pin configuration */
+	enum twl4030_usb_mode	usb_mode;
+
+	int			irq;
+	enum omap_musb_vbus_id_status linkstat;
+	bool			vbus_supplied;
+	u8			asleep;
+	bool			irq_enabled;
+
+	struct delayed_work	id_workaround_work;
+};
+
+/* internal define on top of container_of */
+#define phy_to_twl(x)		container_of((x), struct twl4030_usb, phy)
+
+/*-------------------------------------------------------------------------*/
+
+static int twl4030_i2c_write_u8_verify(struct twl4030_usb *twl,
+		u8 module, u8 data, u8 address)
+{
+	u8 check;
+
+	if ((twl_i2c_write_u8(module, data, address) >= 0) &&
+	    (twl_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 ((twl_i2c_write_u8(module, data, address) >= 0) &&
+	    (twl_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, TWL_MODULE_USB, (data), (address))
+
+static inline int twl4030_usb_write(struct twl4030_usb *twl,
+		u8 address, u8 data)
+{
+	int ret = 0;
+
+	ret = twl_i2c_write_u8(TWL_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 = twl_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, TWL_MODULE_USB, address);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static inline int
+twl4030_usb_set_bits(struct twl4030_usb *twl, u8 reg, u8 bits)
+{
+	return twl4030_usb_write(twl, ULPI_SET(reg), bits);
+}
+
+static inline int
+twl4030_usb_clear_bits(struct twl4030_usb *twl, u8 reg, u8 bits)
+{
+	return twl4030_usb_write(twl, ULPI_CLR(reg), bits);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static bool twl4030_is_driving_vbus(struct twl4030_usb *twl)
+{
+	int ret;
+
+	ret = twl4030_usb_read(twl, PHY_CLK_CTRL_STS);
+	if (ret < 0 || !(ret & PHY_DPLL_CLK))
+		/*
+		 * if clocks are off, registers are not updated,
+		 * but we can assume we don't drive VBUS in this case
+		 */
+		return false;
+
+	ret = twl4030_usb_read(twl, ULPI_OTG_CTRL);
+	if (ret < 0)
+		return false;
+
+	return (ret & (ULPI_OTG_DRVVBUS | ULPI_OTG_CHRGVBUS)) ? true : false;
+}
+
+static enum omap_musb_vbus_id_status
+	twl4030_usb_linkstat(struct twl4030_usb *twl)
+{
+	int	status;
+	enum omap_musb_vbus_id_status linkstat = OMAP_MUSB_UNKNOWN;
+
+	twl->vbus_supplied = false;
+
+	/*
+	 * For ID/VBUS sensing, see manual section 15.4.8 ...
+	 * except when using only battery backup power, two
+	 * comparators produce VBUS_PRES and ID_PRES signals,
+	 * which don't match docs elsewhere.  But ... BIT(7)
+	 * and BIT(2) of STS_HW_CONDITIONS, respectively, do
+	 * seem to match up.  If either is true the USB_PRES
+	 * signal is active, the OTG module is activated, and
+	 * its interrupt may be raised (may wake the system).
+	 */
+	status = twl4030_readb(twl, TWL_MODULE_PM_MASTER, STS_HW_CONDITIONS);
+	if (status < 0)
+		dev_err(twl->dev, "USB link status err %d\n", status);
+	else if (status & (BIT(7) | BIT(2))) {
+		if (status & BIT(7)) {
+			if (twl4030_is_driving_vbus(twl))
+				status &= ~BIT(7);
+			else
+				twl->vbus_supplied = true;
+		}
+
+		if (status & BIT(2))
+			linkstat = OMAP_MUSB_ID_GROUND;
+		else if (status & BIT(7))
+			linkstat = OMAP_MUSB_VBUS_VALID;
+		else
+			linkstat = OMAP_MUSB_VBUS_OFF;
+	} else {
+		if (twl->linkstat != OMAP_MUSB_UNKNOWN)
+			linkstat = OMAP_MUSB_VBUS_OFF;
+	}
+
+	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...
+	 */
+
+	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, ULPI_IFC_CTRL,
+					ULPI_IFC_CTRL_CARKITMODE);
+		twl4030_usb_set_bits(twl, POWER_CTRL, POWER_CTRL_OTG_ENAB);
+		twl4030_usb_clear_bits(twl, ULPI_FUNC_CTRL,
+					ULPI_FUNC_CTRL_XCVRSEL_MASK |
+					ULPI_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 = twl4030_usb_read(twl, PHY_PWR_CTRL);
+
+	if (on)
+		pwr &= ~PHY_PWR_PHYPWD;
+	else
+		pwr |= PHY_PWR_PHYPWD;
+
+	WARN_ON(twl4030_usb_write_verify(twl, PHY_PWR_CTRL, pwr) < 0);
+}
+
+static void twl4030_phy_power(struct twl4030_usb *twl, int on)
+{
+	int ret;
+
+	if (on) {
+		ret = regulator_enable(twl->usb3v1);
+		if (ret)
+			dev_err(twl->dev, "Failed to enable usb3v1\n");
+
+		ret = regulator_enable(twl->usb1v8);
+		if (ret)
+			dev_err(twl->dev, "Failed to enable usb1v8\n");
+
+		/*
+		 * Disabling usb3v1 regulator (= writing 0 to VUSB3V1_DEV_GRP
+		 * in twl4030) resets the VUSB_DEDICATED2 register. This reset
+		 * enables VUSB3V1_SLEEP bit that remaps usb3v1 ACTIVE state to
+		 * SLEEP. We work around this by clearing the bit after usv3v1
+		 * is re-activated. This ensures that VUSB3V1 is really active.
+		 */
+		twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, 0, VUSB_DEDICATED2);
+
+		ret = regulator_enable(twl->usb1v5);
+		if (ret)
+			dev_err(twl->dev, "Failed to enable usb1v5\n");
+
+		__twl4030_phy_power(twl, 1);
+		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 {
+		__twl4030_phy_power(twl, 0);
+		regulator_disable(twl->usb1v5);
+		regulator_disable(twl->usb1v8);
+		regulator_disable(twl->usb3v1);
+	}
+}
+
+static void twl4030_phy_suspend(struct twl4030_usb *twl, int controller_off)
+{
+	if (twl->asleep)
+		return;
+
+	twl4030_phy_power(twl, 0);
+	twl->asleep = 1;
+	dev_dbg(twl->dev, "%s\n", __func__);
+}
+
+static int twl4030_phy_power_off(struct phy *phy)
+{
+	struct twl4030_usb *twl = phy_get_drvdata(phy);
+
+	twl4030_phy_suspend(twl, 0);
+	return 0;
+}
+
+static void __twl4030_phy_resume(struct twl4030_usb *twl)
+{
+	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);
+}
+
+static void twl4030_phy_resume(struct twl4030_usb *twl)
+{
+	if (!twl->asleep)
+		return;
+	__twl4030_phy_resume(twl);
+	twl->asleep = 0;
+	dev_dbg(twl->dev, "%s\n", __func__);
+
+	/*
+	 * XXX When VBUS gets driven after musb goes to A mode,
+	 * ID_PRES related interrupts no longer arrive, why?
+	 * Register itself is updated fine though, so we must poll.
+	 */
+	if (twl->linkstat == OMAP_MUSB_ID_GROUND) {
+		cancel_delayed_work(&twl->id_workaround_work);
+		schedule_delayed_work(&twl->id_workaround_work, HZ);
+	}
+}
+
+static int twl4030_phy_power_on(struct phy *phy)
+{
+	struct twl4030_usb *twl = phy_get_drvdata(phy);
+
+	twl4030_phy_resume(twl);
+	return 0;
+}
+
+static int twl4030_usb_ldo_init(struct twl4030_usb *twl)
+{
+	/* Enable writing to power configuration registers */
+	twl_i2c_write_u8(TWL_MODULE_PM_MASTER, TWL4030_PM_MASTER_KEY_CFG1,
+			 TWL4030_PM_MASTER_PROTECT_KEY);
+
+	twl_i2c_write_u8(TWL_MODULE_PM_MASTER, TWL4030_PM_MASTER_KEY_CFG2,
+			 TWL4030_PM_MASTER_PROTECT_KEY);
+
+	/* Keep VUSB3V1 LDO in sleep state until VBUS/ID change detected*/
+	/*twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, 0, VUSB_DEDICATED2);*/
+
+	/* input to VUSB3V1 LDO is from VBAT, not VBUS */
+	twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, 0x14, VUSB_DEDICATED1);
+
+	/* Initialize 3.1V regulator */
+	twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, 0, VUSB3V1_DEV_GRP);
+
+	twl->usb3v1 = devm_regulator_get(twl->dev, "usb3v1");
+	if (IS_ERR(twl->usb3v1))
+		return -ENODEV;
+
+	twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, 0, VUSB3V1_TYPE);
+
+	/* Initialize 1.5V regulator */
+	twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, 0, VUSB1V5_DEV_GRP);
+
+	twl->usb1v5 = devm_regulator_get(twl->dev, "usb1v5");
+	if (IS_ERR(twl->usb1v5))
+		return -ENODEV;
+
+	twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, 0, VUSB1V5_TYPE);
+
+	/* Initialize 1.8V regulator */
+	twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, 0, VUSB1V8_DEV_GRP);
+
+	twl->usb1v8 = devm_regulator_get(twl->dev, "usb1v8");
+	if (IS_ERR(twl->usb1v8))
+		return -ENODEV;
+
+	twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, 0, VUSB1V8_TYPE);
+
+	/* disable access to power configuration registers */
+	twl_i2c_write_u8(TWL_MODULE_PM_MASTER, 0,
+			 TWL4030_PM_MASTER_PROTECT_KEY);
+
+	return 0;
+}
+
+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->vbus_supplied ? "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;
+	enum omap_musb_vbus_id_status status;
+	bool status_changed = false;
+
+	status = twl4030_usb_linkstat(twl);
+
+	spin_lock_irq(&twl->lock);
+	if (status >= 0 && status != twl->linkstat) {
+		twl->linkstat = status;
+		status_changed = true;
+	}
+	spin_unlock_irq(&twl->lock);
+
+	if (status_changed) {
+		/* 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.
+		 */
+		omap_musb_mailbox(status);
+	}
+	sysfs_notify(&twl->dev->kobj, NULL, "vbus");
+
+	return IRQ_HANDLED;
+}
+
+static void twl4030_id_workaround_work(struct work_struct *work)
+{
+	struct twl4030_usb *twl = container_of(work, struct twl4030_usb,
+		id_workaround_work.work);
+	enum omap_musb_vbus_id_status status;
+	bool status_changed = false;
+
+	status = twl4030_usb_linkstat(twl);
+
+	spin_lock_irq(&twl->lock);
+	if (status >= 0 && status != twl->linkstat) {
+		twl->linkstat = status;
+		status_changed = true;
+	}
+	spin_unlock_irq(&twl->lock);
+
+	if (status_changed) {
+		dev_dbg(twl->dev, "handle missing status change to %d\n",
+				status);
+		omap_musb_mailbox(status);
+	}
+
+	/* don't schedule during sleep - irq works right then */
+	if (status == OMAP_MUSB_ID_GROUND && !twl->asleep) {
+		cancel_delayed_work(&twl->id_workaround_work);
+		schedule_delayed_work(&twl->id_workaround_work, HZ);
+	}
+}
+
+static int twl4030_usb_phy_init(struct usb_phy *phy)
+{
+	struct twl4030_usb *twl = phy_to_twl(phy);
+	enum omap_musb_vbus_id_status status;
+
+	/*
+	 * Start in sleep state, we'll get called through set_suspend()
+	 * callback when musb is runtime resumed and it's time to start.
+	 */
+	__twl4030_phy_power(twl, 0);
+	twl->asleep = 1;
+
+	status = twl4030_usb_linkstat(twl);
+	twl->linkstat = status;
+
+	if (status == OMAP_MUSB_ID_GROUND || status == OMAP_MUSB_VBUS_VALID) {
+		omap_musb_mailbox(twl->linkstat);
+		twl4030_phy_resume(twl);
+	}
+
+	sysfs_notify(&twl->dev->kobj, NULL, "vbus");
+	return 0;
+}
+
+static int twl4030_phy_init(struct phy *phy)
+{
+	struct twl4030_usb *twl = phy_get_drvdata(phy);
+
+	return twl4030_usb_phy_init(&twl->phy);
+}
+
+static int twl4030_set_suspend(struct usb_phy *x, int suspend)
+{
+	struct twl4030_usb *twl = phy_to_twl(x);
+
+	if (suspend)
+		twl4030_phy_suspend(twl, 1);
+	else
+		twl4030_phy_resume(twl);
+
+	return 0;
+}
+
+static int twl4030_set_peripheral(struct usb_otg *otg,
+					struct usb_gadget *gadget)
+{
+	if (!otg)
+		return -ENODEV;
+
+	otg->gadget = gadget;
+	if (!gadget)
+		otg->phy->state = OTG_STATE_UNDEFINED;
+
+	return 0;
+}
+
+static int twl4030_set_host(struct usb_otg *otg, struct usb_bus *host)
+{
+	if (!otg)
+		return -ENODEV;
+
+	otg->host = host;
+	if (!host)
+		otg->phy->state = OTG_STATE_UNDEFINED;
+
+	return 0;
+}
+
+static const struct phy_ops ops = {
+	.init		= twl4030_phy_init,
+	.power_on	= twl4030_phy_power_on,
+	.power_off	= twl4030_phy_power_off,
+	.owner		= THIS_MODULE,
+};
+
+static int twl4030_usb_probe(struct platform_device *pdev)
+{
+	struct twl4030_usb_data *pdata = dev_get_platdata(&pdev->dev);
+	struct twl4030_usb	*twl;
+	struct phy		*phy;
+	int			status, err;
+	struct usb_otg		*otg;
+	struct device_node	*np = pdev->dev.of_node;
+	struct phy_provider	*phy_provider;
+	struct phy_init_data	*init_data = NULL;
+
+	twl = devm_kzalloc(&pdev->dev, sizeof *twl, GFP_KERNEL);
+	if (!twl)
+		return -ENOMEM;
+
+	if (np)
+		of_property_read_u32(np, "usb_mode",
+				(enum twl4030_usb_mode *)&twl->usb_mode);
+	else if (pdata) {
+		twl->usb_mode = pdata->usb_mode;
+		init_data = pdata->init_data;
+	} else {
+		dev_err(&pdev->dev, "twl4030 initialized without pdata\n");
+		return -EINVAL;
+	}
+
+	otg = devm_kzalloc(&pdev->dev, sizeof *otg, GFP_KERNEL);
+	if (!otg)
+		return -ENOMEM;
+
+	twl->dev		= &pdev->dev;
+	twl->irq		= platform_get_irq(pdev, 0);
+	twl->vbus_supplied	= false;
+	twl->asleep		= 1;
+	twl->linkstat		= OMAP_MUSB_UNKNOWN;
+
+	twl->phy.dev		= twl->dev;
+	twl->phy.label		= "twl4030";
+	twl->phy.otg		= otg;
+	twl->phy.type		= USB_PHY_TYPE_USB2;
+	twl->phy.set_suspend	= twl4030_set_suspend;
+	twl->phy.init		= twl4030_usb_phy_init;
+
+	otg->phy		= &twl->phy;
+	otg->set_host		= twl4030_set_host;
+	otg->set_peripheral	= twl4030_set_peripheral;
+
+	phy_provider = devm_of_phy_provider_register(twl->dev,
+		of_phy_simple_xlate);
+	if (IS_ERR(phy_provider))
+		return PTR_ERR(phy_provider);
+
+	phy = devm_phy_create(twl->dev, &ops, init_data);
+	if (IS_ERR(phy)) {
+		dev_dbg(&pdev->dev, "Failed to create PHY\n");
+		return PTR_ERR(phy);
+	}
+
+	phy_set_drvdata(phy, twl);
+
+	/* init spinlock for workqueue */
+	spin_lock_init(&twl->lock);
+
+	INIT_DELAYED_WORK(&twl->id_workaround_work, twl4030_id_workaround_work);
+
+	err = twl4030_usb_ldo_init(twl);
+	if (err) {
+		dev_err(&pdev->dev, "ldo init failed\n");
+		return err;
+	}
+	usb_add_phy_dev(&twl->phy);
+
+	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 = devm_request_threaded_irq(twl->dev, twl->irq, NULL,
+			twl4030_usb_irq, IRQF_TRIGGER_FALLING |
+			IRQF_TRIGGER_RISING | IRQF_ONESHOT, "twl4030_usb", twl);
+	if (status < 0) {
+		dev_dbg(&pdev->dev, "can't get IRQ %d, err %d\n",
+			twl->irq, status);
+		return status;
+	}
+
+	dev_info(&pdev->dev, "Initialized TWL4030 USB module\n");
+	return 0;
+}
+
+static int twl4030_usb_remove(struct platform_device *pdev)
+{
+	struct twl4030_usb *twl = platform_get_drvdata(pdev);
+	int val;
+
+	cancel_delayed_work(&twl->id_workaround_work);
+	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);
+
+	if (!twl->asleep)
+		twl4030_phy_power(twl, 0);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id twl4030_usb_id_table[] = {
+	{ .compatible = "ti,twl4030-usb" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, twl4030_usb_id_table);
+#endif
+
+static struct platform_driver twl4030_usb_driver = {
+	.probe		= twl4030_usb_probe,
+	.remove		= twl4030_usb_remove,
+	.driver		= {
+		.name	= "twl4030_usb",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(twl4030_usb_id_table),
+	},
+};
+
+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");