drivers/extcon/extcon-intel-cht-wc.c - third_party/linux - Git at Google

 /*
  * Extcon charger detection driver for Intel Cherrytrail Whiskey Cove PMIC
  * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
  *
  * Based on various non upstream patches to support the CHT Whiskey Cove PMIC:
  * Copyright (C) 2013-2015 Intel Corporation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2, as published by the Free Software Foundation.
  *
  * This program is distributed in the hope it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  */

 #include <linux/extcon-provider.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/mfd/intel_soc_pmic.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>

 #define CHT_WC_PHYCTRL			0x5e07

 #define CHT_WC_CHGRCTRL0		0x5e16
 #define CHT_WC_CHGRCTRL0_CHGRRESET	BIT(0)
 #define CHT_WC_CHGRCTRL0_EMRGCHREN	BIT(1)
 #define CHT_WC_CHGRCTRL0_EXTCHRDIS	BIT(2)
 #define CHT_WC_CHGRCTRL0_SWCONTROL	BIT(3)
 #define CHT_WC_CHGRCTRL0_TTLCK_MASK	BIT(4)
 #define CHT_WC_CHGRCTRL0_CCSM_OFF_MASK	BIT(5)
 #define CHT_WC_CHGRCTRL0_DBPOFF_MASK	BIT(6)
 #define CHT_WC_CHGRCTRL0_WDT_NOKICK	BIT(7)

 #define CHT_WC_CHGRCTRL1		0x5e17

 #define CHT_WC_USBSRC			0x5e29
 #define CHT_WC_USBSRC_STS_MASK		GENMASK(1, 0)
 #define CHT_WC_USBSRC_STS_SUCCESS	2
 #define CHT_WC_USBSRC_STS_FAIL		3
 #define CHT_WC_USBSRC_TYPE_SHIFT	2
 #define CHT_WC_USBSRC_TYPE_MASK		GENMASK(5, 2)
 #define CHT_WC_USBSRC_TYPE_NONE		0
 #define CHT_WC_USBSRC_TYPE_SDP		1
 #define CHT_WC_USBSRC_TYPE_DCP		2
 #define CHT_WC_USBSRC_TYPE_CDP		3
 #define CHT_WC_USBSRC_TYPE_ACA		4
 #define CHT_WC_USBSRC_TYPE_SE1		5
 #define CHT_WC_USBSRC_TYPE_MHL		6
 #define CHT_WC_USBSRC_TYPE_FLOAT_DP_DN	7
 #define CHT_WC_USBSRC_TYPE_OTHER	8
 #define CHT_WC_USBSRC_TYPE_DCP_EXTPHY	9

 #define CHT_WC_PWRSRC_IRQ		0x6e03
 #define CHT_WC_PWRSRC_IRQ_MASK		0x6e0f
 #define CHT_WC_PWRSRC_STS		0x6e1e
 #define CHT_WC_PWRSRC_VBUS		BIT(0)
 #define CHT_WC_PWRSRC_DC		BIT(1)
 #define CHT_WC_PWRSRC_BAT		BIT(2)
 #define CHT_WC_PWRSRC_ID_GND		BIT(3)
 #define CHT_WC_PWRSRC_ID_FLOAT		BIT(4)

 #define CHT_WC_VBUS_GPIO_CTLO		0x6e2d
 #define CHT_WC_VBUS_GPIO_CTLO_OUTPUT	BIT(0)
 #define CHT_WC_VBUS_GPIO_CTLO_DRV_OD	BIT(4)
 #define CHT_WC_VBUS_GPIO_CTLO_DIR_OUT	BIT(5)

 enum cht_wc_usb_id {
 	USB_ID_OTG,
 	USB_ID_GND,
 	USB_ID_FLOAT,
 	USB_RID_A,
 	USB_RID_B,
 	USB_RID_C,
 };

 enum cht_wc_mux_select {
 	MUX_SEL_PMIC = 0,
 	MUX_SEL_SOC,
 };

 static const unsigned int cht_wc_extcon_cables[] = {
 	EXTCON_USB,
 	EXTCON_USB_HOST,
 	EXTCON_CHG_USB_SDP,
 	EXTCON_CHG_USB_CDP,
 	EXTCON_CHG_USB_DCP,
 	EXTCON_CHG_USB_ACA,
 	EXTCON_NONE,
 };

 struct cht_wc_extcon_data {
 	struct device *dev;
 	struct regmap *regmap;
 	struct extcon_dev *edev;
 	unsigned int previous_cable;
 	bool usb_host;
 };

 static int cht_wc_extcon_get_id(struct cht_wc_extcon_data *ext, int pwrsrc_sts)
 {
 	if (pwrsrc_sts & CHT_WC_PWRSRC_ID_GND)
 		return USB_ID_GND;
 	if (pwrsrc_sts & CHT_WC_PWRSRC_ID_FLOAT)
 		return USB_ID_FLOAT;

 	/*
 	 * Once we have iio support for the gpadc we should read the USBID
 	 * gpadc channel here and determine ACA role based on that.
 	 */
 	return USB_ID_FLOAT;
 }

 static int cht_wc_extcon_get_charger(struct cht_wc_extcon_data *ext,
 				     bool ignore_errors)
 {
 	int ret, usbsrc, status;
 	unsigned long timeout;

 	/* Charger detection can take upto 600ms, wait 800ms max. */
 	timeout = jiffies + msecs_to_jiffies(800);
 	do {
 		ret = regmap_read(ext->regmap, CHT_WC_USBSRC, &usbsrc);
 		if (ret) {
 			dev_err(ext->dev, "Error reading usbsrc: %d\n", ret);
 			return ret;
 		}

 		status = usbsrc & CHT_WC_USBSRC_STS_MASK;
 		if (status == CHT_WC_USBSRC_STS_SUCCESS ||
 		    status == CHT_WC_USBSRC_STS_FAIL)
 			break;

 		msleep(50); /* Wait a bit before retrying */
 	} while (time_before(jiffies, timeout));

 	if (status != CHT_WC_USBSRC_STS_SUCCESS) {
 		if (ignore_errors)
 			return EXTCON_CHG_USB_SDP; /* Save fallback */

 		if (status == CHT_WC_USBSRC_STS_FAIL)
 			dev_warn(ext->dev, "Could not detect charger type\n");
 		else
 			dev_warn(ext->dev, "Timeout detecting charger type\n");
 		return EXTCON_CHG_USB_SDP; /* Save fallback */
 	}

 	usbsrc = (usbsrc & CHT_WC_USBSRC_TYPE_MASK) >> CHT_WC_USBSRC_TYPE_SHIFT;
 	switch (usbsrc) {
 	default:
 		dev_warn(ext->dev,
 			"Unhandled charger type %d, defaulting to SDP\n",
 			 ret);
 		/* Fall through, treat as SDP */
 	case CHT_WC_USBSRC_TYPE_SDP:
 	case CHT_WC_USBSRC_TYPE_FLOAT_DP_DN:
 	case CHT_WC_USBSRC_TYPE_OTHER:
 		return EXTCON_CHG_USB_SDP;
 	case CHT_WC_USBSRC_TYPE_CDP:
 		return EXTCON_CHG_USB_CDP;
 	case CHT_WC_USBSRC_TYPE_DCP:
 	case CHT_WC_USBSRC_TYPE_DCP_EXTPHY:
 	case CHT_WC_USBSRC_TYPE_MHL: /* MHL2+ delivers upto 2A, treat as DCP */
 		return EXTCON_CHG_USB_DCP;
 	case CHT_WC_USBSRC_TYPE_ACA:
 		return EXTCON_CHG_USB_ACA;
 	}
 }

 static void cht_wc_extcon_set_phymux(struct cht_wc_extcon_data *ext, u8 state)
 {
 	int ret;

 	ret = regmap_write(ext->regmap, CHT_WC_PHYCTRL, state);
 	if (ret)
 		dev_err(ext->dev, "Error writing phyctrl: %d\n", ret);
 }

 static void cht_wc_extcon_set_5v_boost(struct cht_wc_extcon_data *ext,
 				       bool enable)
 {
 	int ret, val;

 	/*
 	 * The 5V boost converter is enabled through a gpio on the PMIC, since
 	 * there currently is no gpio driver we access the gpio reg directly.
 	 */
 	val = CHT_WC_VBUS_GPIO_CTLO_DRV_OD | CHT_WC_VBUS_GPIO_CTLO_DIR_OUT;
 	if (enable)
 		val |= CHT_WC_VBUS_GPIO_CTLO_OUTPUT;

 	ret = regmap_write(ext->regmap, CHT_WC_VBUS_GPIO_CTLO, val);
 	if (ret)
 		dev_err(ext->dev, "Error writing Vbus GPIO CTLO: %d\n", ret);
 }

 /* Small helper to sync EXTCON_CHG_USB_SDP and EXTCON_USB state */
 static void cht_wc_extcon_set_state(struct cht_wc_extcon_data *ext,
 				    unsigned int cable, bool state)
 {
 	extcon_set_state_sync(ext->edev, cable, state);
 	if (cable == EXTCON_CHG_USB_SDP)
 		extcon_set_state_sync(ext->edev, EXTCON_USB, state);
 }

 static void cht_wc_extcon_pwrsrc_event(struct cht_wc_extcon_data *ext)
 {
 	int ret, pwrsrc_sts, id;
 	unsigned int cable = EXTCON_NONE;
 	/* Ignore errors in host mode, as the 5v boost converter is on then */
 	bool ignore_get_charger_errors = ext->usb_host;

 	ret = regmap_read(ext->regmap, CHT_WC_PWRSRC_STS, &pwrsrc_sts);
 	if (ret) {
 		dev_err(ext->dev, "Error reading pwrsrc status: %d\n", ret);
 		return;
 	}

 	id = cht_wc_extcon_get_id(ext, pwrsrc_sts);
 	if (id == USB_ID_GND) {
 		/* The 5v boost causes a false VBUS / SDP detect, skip */
 		goto charger_det_done;
 	}

 	/* Plugged into a host/charger or not connected? */
 	if (!(pwrsrc_sts & CHT_WC_PWRSRC_VBUS)) {
 		/* Route D+ and D- to PMIC for future charger detection */
 		cht_wc_extcon_set_phymux(ext, MUX_SEL_PMIC);
 		goto set_state;
 	}

 	ret = cht_wc_extcon_get_charger(ext, ignore_get_charger_errors);
 	if (ret >= 0)
 		cable = ret;

 charger_det_done:
 	/* Route D+ and D- to SoC for the host or gadget controller */
 	cht_wc_extcon_set_phymux(ext, MUX_SEL_SOC);

 set_state:
 	if (cable != ext->previous_cable) {
 		cht_wc_extcon_set_state(ext, cable, true);
 		cht_wc_extcon_set_state(ext, ext->previous_cable, false);
 		ext->previous_cable = cable;
 	}

 	ext->usb_host = ((id == USB_ID_GND) || (id == USB_RID_A));
 	extcon_set_state_sync(ext->edev, EXTCON_USB_HOST, ext->usb_host);
 }

 static irqreturn_t cht_wc_extcon_isr(int irq, void *data)
 {
 	struct cht_wc_extcon_data *ext = data;
 	int ret, irqs;

 	ret = regmap_read(ext->regmap, CHT_WC_PWRSRC_IRQ, &irqs);
 	if (ret) {
 		dev_err(ext->dev, "Error reading irqs: %d\n", ret);
 		return IRQ_NONE;
 	}

 	cht_wc_extcon_pwrsrc_event(ext);

 	ret = regmap_write(ext->regmap, CHT_WC_PWRSRC_IRQ, irqs);
 	if (ret) {
 		dev_err(ext->dev, "Error writing irqs: %d\n", ret);
 		return IRQ_NONE;
 	}

 	return IRQ_HANDLED;
 }

 static int cht_wc_extcon_sw_control(struct cht_wc_extcon_data *ext, bool enable)
 {
 	int ret, mask, val;

 	mask = CHT_WC_CHGRCTRL0_SWCONTROL | CHT_WC_CHGRCTRL0_CCSM_OFF_MASK;
 	val = enable ? mask : 0;
 	ret = regmap_update_bits(ext->regmap, CHT_WC_CHGRCTRL0, mask, val);
 	if (ret)
 		dev_err(ext->dev, "Error setting sw control: %d\n", ret);

 	return ret;
 }

 static int cht_wc_extcon_probe(struct platform_device *pdev)
 {
 	struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
 	struct cht_wc_extcon_data *ext;
 	int irq, ret;

 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
 		return irq;

 	ext = devm_kzalloc(&pdev->dev, sizeof(*ext), GFP_KERNEL);
 	if (!ext)
 		return -ENOMEM;

 	ext->dev = &pdev->dev;
 	ext->regmap = pmic->regmap;
 	ext->previous_cable = EXTCON_NONE;

 	/* Initialize extcon device */
 	ext->edev = devm_extcon_dev_allocate(ext->dev, cht_wc_extcon_cables);
 	if (IS_ERR(ext->edev))
 		return PTR_ERR(ext->edev);

 	/*
 	 * When a host-cable is detected the BIOS enables an external 5v boost
 	 * converter to power connected devices there are 2 problems with this:
 	 * 1) This gets seen by the external battery charger as a valid Vbus
 	 *    supply and it then tries to feed Vsys from this creating a
 	 *    feedback loop which causes aprox. 300 mA extra battery drain
 	 *    (and unless we drive the external-charger-disable pin high it
 	 *    also tries to charge the battery causing even more feedback).
 	 * 2) This gets seen by the pwrsrc block as a SDP USB Vbus supply
 	 * Since the external battery charger has its own 5v boost converter
 	 * which does not have these issues, we simply turn the separate
 	 * external 5v boost converter off and leave it off entirely.
 	 */
 	cht_wc_extcon_set_5v_boost(ext, false);

 	/* Enable sw control */
 	ret = cht_wc_extcon_sw_control(ext, true);
 	if (ret)
 		return ret;

 	/* Register extcon device */
 	ret = devm_extcon_dev_register(ext->dev, ext->edev);
 	if (ret) {
 		dev_err(ext->dev, "Error registering extcon device: %d\n", ret);
 		goto disable_sw_control;
 	}

 	/* Route D+ and D- to PMIC for initial charger detection */
 	cht_wc_extcon_set_phymux(ext, MUX_SEL_PMIC);

 	/* Get initial state */
 	cht_wc_extcon_pwrsrc_event(ext);

 	ret = devm_request_threaded_irq(ext->dev, irq, NULL, cht_wc_extcon_isr,
 					IRQF_ONESHOT, pdev->name, ext);
 	if (ret) {
 		dev_err(ext->dev, "Error requesting interrupt: %d\n", ret);
 		goto disable_sw_control;
 	}

 	/* Unmask irqs */
 	ret = regmap_write(ext->regmap, CHT_WC_PWRSRC_IRQ_MASK,
 			   (int)~(CHT_WC_PWRSRC_VBUS | CHT_WC_PWRSRC_ID_GND |
 				  CHT_WC_PWRSRC_ID_FLOAT));
 	if (ret) {
 		dev_err(ext->dev, "Error writing irq-mask: %d\n", ret);
 		goto disable_sw_control;
 	}

 	platform_set_drvdata(pdev, ext);

 	return 0;

 disable_sw_control:
 	cht_wc_extcon_sw_control(ext, false);
 	return ret;
 }

 static int cht_wc_extcon_remove(struct platform_device *pdev)
 {
 	struct cht_wc_extcon_data *ext = platform_get_drvdata(pdev);

 	cht_wc_extcon_sw_control(ext, false);

 	return 0;
 }

 static const struct platform_device_id cht_wc_extcon_table[] = {
 	{ .name = "cht_wcove_pwrsrc" },
 	{},
 };
 MODULE_DEVICE_TABLE(platform, cht_wc_extcon_table);

 static struct platform_driver cht_wc_extcon_driver = {
 	.probe = cht_wc_extcon_probe,
 	.remove = cht_wc_extcon_remove,
 	.id_table = cht_wc_extcon_table,
 	.driver = {
 		.name = "cht_wcove_pwrsrc",
 	},
 };
 module_platform_driver(cht_wc_extcon_driver);

 MODULE_DESCRIPTION("Intel Cherrytrail Whiskey Cove PMIC extcon driver");
 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 MODULE_LICENSE("GPL v2");
	/*
	* Extcon charger detection driver for Intel Cherrytrail Whiskey Cove PMIC
	* Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
	*
	* Based on various non upstream patches to support the CHT Whiskey Cove PMIC:
	* Copyright (C) 2013-2015 Intel Corporation. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms and conditions of the GNU General Public License,
	* version 2, as published by the Free Software Foundation.
	*
	* This program is distributed in the hope it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	* more details.
	*/

	#include <linux/extcon-provider.h>
	#include <linux/interrupt.h>
	#include <linux/kernel.h>
	#include <linux/mfd/intel_soc_pmic.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/regmap.h>
	#include <linux/slab.h>

	#define CHT_WC_PHYCTRL 0x5e07

	#define CHT_WC_CHGRCTRL0 0x5e16
	#define CHT_WC_CHGRCTRL0_CHGRRESET BIT(0)
	#define CHT_WC_CHGRCTRL0_EMRGCHREN BIT(1)
	#define CHT_WC_CHGRCTRL0_EXTCHRDIS BIT(2)
	#define CHT_WC_CHGRCTRL0_SWCONTROL BIT(3)
	#define CHT_WC_CHGRCTRL0_TTLCK_MASK BIT(4)
	#define CHT_WC_CHGRCTRL0_CCSM_OFF_MASK BIT(5)
	#define CHT_WC_CHGRCTRL0_DBPOFF_MASK BIT(6)
	#define CHT_WC_CHGRCTRL0_WDT_NOKICK BIT(7)

	#define CHT_WC_CHGRCTRL1 0x5e17

	#define CHT_WC_USBSRC 0x5e29
	#define CHT_WC_USBSRC_STS_MASK GENMASK(1, 0)
	#define CHT_WC_USBSRC_STS_SUCCESS 2
	#define CHT_WC_USBSRC_STS_FAIL 3
	#define CHT_WC_USBSRC_TYPE_SHIFT 2
	#define CHT_WC_USBSRC_TYPE_MASK GENMASK(5, 2)
	#define CHT_WC_USBSRC_TYPE_NONE 0
	#define CHT_WC_USBSRC_TYPE_SDP 1
	#define CHT_WC_USBSRC_TYPE_DCP 2
	#define CHT_WC_USBSRC_TYPE_CDP 3
	#define CHT_WC_USBSRC_TYPE_ACA 4
	#define CHT_WC_USBSRC_TYPE_SE1 5
	#define CHT_WC_USBSRC_TYPE_MHL 6
	#define CHT_WC_USBSRC_TYPE_FLOAT_DP_DN 7
	#define CHT_WC_USBSRC_TYPE_OTHER 8
	#define CHT_WC_USBSRC_TYPE_DCP_EXTPHY 9

	#define CHT_WC_PWRSRC_IRQ 0x6e03
	#define CHT_WC_PWRSRC_IRQ_MASK 0x6e0f
	#define CHT_WC_PWRSRC_STS 0x6e1e
	#define CHT_WC_PWRSRC_VBUS BIT(0)
	#define CHT_WC_PWRSRC_DC BIT(1)
	#define CHT_WC_PWRSRC_BAT BIT(2)
	#define CHT_WC_PWRSRC_ID_GND BIT(3)
	#define CHT_WC_PWRSRC_ID_FLOAT BIT(4)

	#define CHT_WC_VBUS_GPIO_CTLO 0x6e2d
	#define CHT_WC_VBUS_GPIO_CTLO_OUTPUT BIT(0)
	#define CHT_WC_VBUS_GPIO_CTLO_DRV_OD BIT(4)
	#define CHT_WC_VBUS_GPIO_CTLO_DIR_OUT BIT(5)

	enum cht_wc_usb_id {
	USB_ID_OTG,
	USB_ID_GND,
	USB_ID_FLOAT,
	USB_RID_A,
	USB_RID_B,
	USB_RID_C,
	};

	enum cht_wc_mux_select {
	MUX_SEL_PMIC = 0,
	MUX_SEL_SOC,
	};

	static const unsigned int cht_wc_extcon_cables[] = {
	EXTCON_USB,
	EXTCON_USB_HOST,
	EXTCON_CHG_USB_SDP,
	EXTCON_CHG_USB_CDP,
	EXTCON_CHG_USB_DCP,
	EXTCON_CHG_USB_ACA,
	EXTCON_NONE,
	};

	struct cht_wc_extcon_data {
	struct device *dev;
	struct regmap *regmap;
	struct extcon_dev *edev;
	unsigned int previous_cable;
	bool usb_host;
	};

	static int cht_wc_extcon_get_id(struct cht_wc_extcon_data *ext, int pwrsrc_sts)
	{
	if (pwrsrc_sts & CHT_WC_PWRSRC_ID_GND)
	return USB_ID_GND;
	if (pwrsrc_sts & CHT_WC_PWRSRC_ID_FLOAT)
	return USB_ID_FLOAT;

	/*
	* Once we have iio support for the gpadc we should read the USBID
	* gpadc channel here and determine ACA role based on that.
	*/
	return USB_ID_FLOAT;
	}

	static int cht_wc_extcon_get_charger(struct cht_wc_extcon_data *ext,
	bool ignore_errors)
	{
	int ret, usbsrc, status;
	unsigned long timeout;

	/* Charger detection can take upto 600ms, wait 800ms max. */
	timeout = jiffies + msecs_to_jiffies(800);
	do {
	ret = regmap_read(ext->regmap, CHT_WC_USBSRC, &usbsrc);
	if (ret) {
	dev_err(ext->dev, "Error reading usbsrc: %d\n", ret);
	return ret;
	}

	status = usbsrc & CHT_WC_USBSRC_STS_MASK;
	if (status == CHT_WC_USBSRC_STS_SUCCESS \|\|
	status == CHT_WC_USBSRC_STS_FAIL)
	break;

	msleep(50); /* Wait a bit before retrying */
	} while (time_before(jiffies, timeout));

	if (status != CHT_WC_USBSRC_STS_SUCCESS) {
	if (ignore_errors)
	return EXTCON_CHG_USB_SDP; /* Save fallback */

	if (status == CHT_WC_USBSRC_STS_FAIL)
	dev_warn(ext->dev, "Could not detect charger type\n");
	else
	dev_warn(ext->dev, "Timeout detecting charger type\n");
	return EXTCON_CHG_USB_SDP; /* Save fallback */
	}

	usbsrc = (usbsrc & CHT_WC_USBSRC_TYPE_MASK) >> CHT_WC_USBSRC_TYPE_SHIFT;
	switch (usbsrc) {
	default:
	dev_warn(ext->dev,
	"Unhandled charger type %d, defaulting to SDP\n",
	ret);
	/* Fall through, treat as SDP */
	case CHT_WC_USBSRC_TYPE_SDP:
	case CHT_WC_USBSRC_TYPE_FLOAT_DP_DN:
	case CHT_WC_USBSRC_TYPE_OTHER:
	return EXTCON_CHG_USB_SDP;
	case CHT_WC_USBSRC_TYPE_CDP:
	return EXTCON_CHG_USB_CDP;
	case CHT_WC_USBSRC_TYPE_DCP:
	case CHT_WC_USBSRC_TYPE_DCP_EXTPHY:
	case CHT_WC_USBSRC_TYPE_MHL: /* MHL2+ delivers upto 2A, treat as DCP */
	return EXTCON_CHG_USB_DCP;
	case CHT_WC_USBSRC_TYPE_ACA:
	return EXTCON_CHG_USB_ACA;
	}
	}

	static void cht_wc_extcon_set_phymux(struct cht_wc_extcon_data *ext, u8 state)
	{
	int ret;

	ret = regmap_write(ext->regmap, CHT_WC_PHYCTRL, state);
	if (ret)
	dev_err(ext->dev, "Error writing phyctrl: %d\n", ret);
	}

	static void cht_wc_extcon_set_5v_boost(struct cht_wc_extcon_data *ext,
	bool enable)
	{
	int ret, val;

	/*
	* The 5V boost converter is enabled through a gpio on the PMIC, since
	* there currently is no gpio driver we access the gpio reg directly.
	*/
	val = CHT_WC_VBUS_GPIO_CTLO_DRV_OD \| CHT_WC_VBUS_GPIO_CTLO_DIR_OUT;
	if (enable)
	val \|= CHT_WC_VBUS_GPIO_CTLO_OUTPUT;

	ret = regmap_write(ext->regmap, CHT_WC_VBUS_GPIO_CTLO, val);
	if (ret)
	dev_err(ext->dev, "Error writing Vbus GPIO CTLO: %d\n", ret);
	}

	/* Small helper to sync EXTCON_CHG_USB_SDP and EXTCON_USB state */
	static void cht_wc_extcon_set_state(struct cht_wc_extcon_data *ext,
	unsigned int cable, bool state)
	{
	extcon_set_state_sync(ext->edev, cable, state);
	if (cable == EXTCON_CHG_USB_SDP)
	extcon_set_state_sync(ext->edev, EXTCON_USB, state);
	}

	static void cht_wc_extcon_pwrsrc_event(struct cht_wc_extcon_data *ext)
	{
	int ret, pwrsrc_sts, id;
	unsigned int cable = EXTCON_NONE;
	/* Ignore errors in host mode, as the 5v boost converter is on then */
	bool ignore_get_charger_errors = ext->usb_host;

	ret = regmap_read(ext->regmap, CHT_WC_PWRSRC_STS, &pwrsrc_sts);
	if (ret) {
	dev_err(ext->dev, "Error reading pwrsrc status: %d\n", ret);
	return;
	}

	id = cht_wc_extcon_get_id(ext, pwrsrc_sts);
	if (id == USB_ID_GND) {
	/* The 5v boost causes a false VBUS / SDP detect, skip */
	goto charger_det_done;
	}

	/* Plugged into a host/charger or not connected? */
	if (!(pwrsrc_sts & CHT_WC_PWRSRC_VBUS)) {
	/* Route D+ and D- to PMIC for future charger detection */
	cht_wc_extcon_set_phymux(ext, MUX_SEL_PMIC);
	goto set_state;
	}

	ret = cht_wc_extcon_get_charger(ext, ignore_get_charger_errors);
	if (ret >= 0)
	cable = ret;

	charger_det_done:
	/* Route D+ and D- to SoC for the host or gadget controller */
	cht_wc_extcon_set_phymux(ext, MUX_SEL_SOC);

	set_state:
	if (cable != ext->previous_cable) {
	cht_wc_extcon_set_state(ext, cable, true);
	cht_wc_extcon_set_state(ext, ext->previous_cable, false);
	ext->previous_cable = cable;
	}

	ext->usb_host = ((id == USB_ID_GND) \|\| (id == USB_RID_A));
	extcon_set_state_sync(ext->edev, EXTCON_USB_HOST, ext->usb_host);
	}

	static irqreturn_t cht_wc_extcon_isr(int irq, void *data)
	{
	struct cht_wc_extcon_data *ext = data;
	int ret, irqs;

	ret = regmap_read(ext->regmap, CHT_WC_PWRSRC_IRQ, &irqs);
	if (ret) {
	dev_err(ext->dev, "Error reading irqs: %d\n", ret);
	return IRQ_NONE;
	}

	cht_wc_extcon_pwrsrc_event(ext);

	ret = regmap_write(ext->regmap, CHT_WC_PWRSRC_IRQ, irqs);
	if (ret) {
	dev_err(ext->dev, "Error writing irqs: %d\n", ret);
	return IRQ_NONE;
	}

	return IRQ_HANDLED;
	}

	static int cht_wc_extcon_sw_control(struct cht_wc_extcon_data *ext, bool enable)
	{
	int ret, mask, val;

	mask = CHT_WC_CHGRCTRL0_SWCONTROL \| CHT_WC_CHGRCTRL0_CCSM_OFF_MASK;
	val = enable ? mask : 0;
	ret = regmap_update_bits(ext->regmap, CHT_WC_CHGRCTRL0, mask, val);
	if (ret)
	dev_err(ext->dev, "Error setting sw control: %d\n", ret);

	return ret;
	}

	static int cht_wc_extcon_probe(struct platform_device *pdev)
	{
	struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
	struct cht_wc_extcon_data *ext;
	int irq, ret;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
	return irq;

	ext = devm_kzalloc(&pdev->dev, sizeof(*ext), GFP_KERNEL);
	if (!ext)
	return -ENOMEM;

	ext->dev = &pdev->dev;
	ext->regmap = pmic->regmap;
	ext->previous_cable = EXTCON_NONE;

	/* Initialize extcon device */
	ext->edev = devm_extcon_dev_allocate(ext->dev, cht_wc_extcon_cables);
	if (IS_ERR(ext->edev))
	return PTR_ERR(ext->edev);

	/*
	* When a host-cable is detected the BIOS enables an external 5v boost
	* converter to power connected devices there are 2 problems with this:
	* 1) This gets seen by the external battery charger as a valid Vbus
	* supply and it then tries to feed Vsys from this creating a
	* feedback loop which causes aprox. 300 mA extra battery drain
	* (and unless we drive the external-charger-disable pin high it
	* also tries to charge the battery causing even more feedback).
	* 2) This gets seen by the pwrsrc block as a SDP USB Vbus supply
	* Since the external battery charger has its own 5v boost converter
	* which does not have these issues, we simply turn the separate
	* external 5v boost converter off and leave it off entirely.
	*/
	cht_wc_extcon_set_5v_boost(ext, false);

	/* Enable sw control */
	ret = cht_wc_extcon_sw_control(ext, true);
	if (ret)
	return ret;

	/* Register extcon device */
	ret = devm_extcon_dev_register(ext->dev, ext->edev);
	if (ret) {
	dev_err(ext->dev, "Error registering extcon device: %d\n", ret);
	goto disable_sw_control;
	}

	/* Route D+ and D- to PMIC for initial charger detection */
	cht_wc_extcon_set_phymux(ext, MUX_SEL_PMIC);

	/* Get initial state */
	cht_wc_extcon_pwrsrc_event(ext);

	ret = devm_request_threaded_irq(ext->dev, irq, NULL, cht_wc_extcon_isr,
	IRQF_ONESHOT, pdev->name, ext);
	if (ret) {
	dev_err(ext->dev, "Error requesting interrupt: %d\n", ret);
	goto disable_sw_control;
	}

	/* Unmask irqs */
	ret = regmap_write(ext->regmap, CHT_WC_PWRSRC_IRQ_MASK,
	(int)~(CHT_WC_PWRSRC_VBUS \| CHT_WC_PWRSRC_ID_GND \|
	CHT_WC_PWRSRC_ID_FLOAT));
	if (ret) {
	dev_err(ext->dev, "Error writing irq-mask: %d\n", ret);
	goto disable_sw_control;
	}

	platform_set_drvdata(pdev, ext);

	return 0;

	disable_sw_control:
	cht_wc_extcon_sw_control(ext, false);
	return ret;
	}

	static int cht_wc_extcon_remove(struct platform_device *pdev)
	{
	struct cht_wc_extcon_data *ext = platform_get_drvdata(pdev);

	cht_wc_extcon_sw_control(ext, false);

	return 0;
	}

	static const struct platform_device_id cht_wc_extcon_table[] = {
	{ .name = "cht_wcove_pwrsrc" },
	{},
	};
	MODULE_DEVICE_TABLE(platform, cht_wc_extcon_table);

	static struct platform_driver cht_wc_extcon_driver = {
	.probe = cht_wc_extcon_probe,
	.remove = cht_wc_extcon_remove,
	.id_table = cht_wc_extcon_table,
	.driver = {
	.name = "cht_wcove_pwrsrc",
	},
	};
	module_platform_driver(cht_wc_extcon_driver);

	MODULE_DESCRIPTION("Intel Cherrytrail Whiskey Cove PMIC extcon driver");
	MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
	MODULE_LICENSE("GPL v2");