Re: [PATCH v4] extcon: Palmas Extcon Driver

[Chanwoo Choi <cw00.choi@samsung.com>]

Hi Kishon,

I add some opinion about this patch.

On 05/06/2013 10:17 PM, Kishon Vijay Abraham I wrote:
> From: Graeme Gregory <gg@slimlogic.co.uk>
>
> This is the driver for the USB comparator built into the palmas chip. It
> handles the various USB OTG events that can be generated by cable
> insertion/removal.
>
> Signed-off-by: Graeme Gregory <gg@slimlogic.co.uk>
> Signed-off-by: Moiz Sonasath <m-sonasath@ti.com>
> Signed-off-by: Ruchika Kharwar <ruchika@ti.com>
> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
> [kishon@ti.com: adapted palmas usb driver to use the extcon framework]
> Signed-off-by: Sebastien Guiriec <s-guiriec@ti.com>
> ---
> Changes from v3:
> * adapted the driver to extcon framework (so moved to drivers/extcon)
> * removed palmas_usb_(write/read) and replaced all calls with
>   palmas_(read/write).
> * ignored a checkpatch warning in the line 
> 	static const char *palmas_extcon_cable[] = {
>   as it seemed to be incorrect?
> * removed all references to OMAP in this driver.
> * couldn't test this driver with mainline as omap5 panda is not booting
>   with mainline.
> * A comment to change to platform_get_irq from regmap is not done as I felt
>   the data should come from regmap in this case. Graeme?
> Changes from v2:
> * Moved the driver to drivers/usb/phy/
> * Added a bit more explanation in Kconfig
>  .../devicetree/bindings/extcon/extcon-twl.txt      |   17 +
>  drivers/extcon/Kconfig                             |    7 +
>  drivers/extcon/Makefile                            |    1 +
>  drivers/extcon/extcon-palmas.c                     |  389 ++++++++++++++++++++
>  include/linux/extcon/extcon_palmas.h               |   26 ++
>  include/linux/mfd/palmas.h                         |    8 +-
>  6 files changed, 447 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/extcon/extcon-twl.txt
>  create mode 100644 drivers/extcon/extcon-palmas.c
>  create mode 100644 include/linux/extcon/extcon_palmas.h
>
> diff --git a/Documentation/devicetree/bindings/extcon/extcon-twl.txt b/Documentation/devicetree/bindings/extcon/extcon-twl.txt
> new file mode 100644
> index 0000000..a7f6527
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/extcon/extcon-twl.txt
> @@ -0,0 +1,17 @@
> +EXTCON FOR TWL CHIPS
> +
> +PALMAS USB COMPARATOR
> +Required Properties:
> + - compatible : Should be "ti,palmas-usb" or "ti,twl6035-usb"
> + - vbus-supply : phandle to the regulator device tree node.
> +
> +Optional Properties:
> + - ti,wakeup : To enable the wakeup comparator in probe
> + - ti,no_control_vbus: if the platform wishes its own vbus control
> +
> +palmas-usb {
> +       compatible = "ti,twl6035-usb", "ti,palmas-usb";
> +       vbus-supply = <&smps10_reg>;
> +       ti,wakeup;
> +};
> +
> diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
> index 5168a13..c881899 100644
> --- a/drivers/extcon/Kconfig
> +++ b/drivers/extcon/Kconfig
> @@ -53,4 +53,11 @@ config EXTCON_ARIZONA
>  	  with Wolfson Arizona devices. These are audio CODECs with
>  	  advanced audio accessory detection support.
>  
> +config EXTCON_PALMAS
> +	tristate "Palmas USB EXTCON support"
> +	depends on MFD_PALMAS
> +	help
> +	  Say Y here to enable support for USB peripheral and USB host
> +	  detection by palmas usb.
> +
>  endif # MULTISTATE_SWITCH
> diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
> index f98a3c4..540e2c3 100644
> --- a/drivers/extcon/Makefile
> +++ b/drivers/extcon/Makefile
> @@ -8,3 +8,4 @@ obj-$(CONFIG_EXTCON_ADC_JACK)	+= extcon-adc-jack.o
>  obj-$(CONFIG_EXTCON_MAX77693)	+= extcon-max77693.o
>  obj-$(CONFIG_EXTCON_MAX8997)	+= extcon-max8997.o
>  obj-$(CONFIG_EXTCON_ARIZONA)	+= extcon-arizona.o
> +obj-$(CONFIG_EXTCON_PALMAS)	+= extcon-palmas.o
> diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c
> new file mode 100644
> index 0000000..3ef042f
> --- /dev/null
> +++ b/drivers/extcon/extcon-palmas.c
> @@ -0,0 +1,389 @@
> +/*
> + * Palmas USB transceiver driver
> + *
> + * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.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.
> + *
> + * Author: Graeme Gregory <gg@...mlogic.co.uk>
> + * Author: Kishon Vijay Abraham I <kishon@...com>
> + *
> + * Based on twl6030_usb.c
> + *
> + * Author: Hema HK <hemahk@...com>
> + *
> + * 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.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +#include <linux/usb/phy_companion.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/err.h>
> +#include <linux/notifier.h>
> +#include <linux/slab.h>
> +#include <linux/delay.h>
> +#include <linux/mfd/palmas.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/extcon/extcon_palmas.h>
> +
Remove unnecessary header file. When I remove following header file,
I completed kernel build without any problem.

linux/init.h
linux/io.h
linux/regulator/consumer.h
linux/notifier.h
linux/slab.h
linux/delay.h
> +static const char *palmas_extcon_cable[] = {
> +	[0] = "USB",
> +	[1] = "USB-HOST",
> +	NULL,
> +};
> +
> +static const int mutually_exclusive[] = {0x3, 0x0};
> +
> +static void palmas_usb_wakeup(struct palmas *palmas, int enable)
> +{
> +	if (enable)
> +		palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP,
> +			PALMAS_USB_WAKEUP_ID_WK_UP_COMP);
> +	else
> +		palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP, 0);
> +}
> +
> +static ssize_t palmas_usb_vbus_show(struct device *dev,
> +			struct device_attribute *attr, char *buf)
> +{
> +	unsigned long		flags;
> +	int			ret = -EINVAL;
> +	struct palmas_usb	*palmas_usb = dev_get_drvdata(dev);
> +
> +	spin_lock_irqsave(&palmas_usb->lock, flags);
> +
> +	switch (palmas_usb->linkstat) {
> +	case PALMAS_USB_STATE_VBUS:
> +	       ret = snprintf(buf, PAGE_SIZE, "vbus\n");
> +	       break;
> +	case PALMAS_USB_STATE_ID:
> +	       ret = snprintf(buf, PAGE_SIZE, "id\n");
> +	       break;
> +	case PALMAS_USB_STATE_DISCONNECT:
> +	       ret = snprintf(buf, PAGE_SIZE, "none\n");
> +	       break;
> +	default:
> +	       ret = snprintf(buf, PAGE_SIZE, "UNKNOWN\n");
> +	}
> +	spin_unlock_irqrestore(&palmas_usb->lock, flags);
> +
> +	return ret;
> +}
> +static DEVICE_ATTR(vbus, 0444, palmas_usb_vbus_show, NULL);
I think that 'palmas_usb_vbus' device attribute isn't standard node
of extcon framework. If you want to check USB/USB-HOST state
on user-space, user process should use following standard node
of extcon instead of 'palmas_usb_vbus' node.

- User can get the state of USB/USB-HOST through following node:
/sys/class/extcon/palmas_usb/cable.0/state
    if state is 1, PALMAS_USB_STATE_VBUS
    if state is 0, PALMAS_USB_STATE_DISCONNECT

/sys/class/extcon/palmas_usb/cable.1/state
    if state is 1, PALMAS_USB_STATE_ID
    if state is 0, PALMAS_USB_STATE_DISCONNECT

Certainly, extcon driver have to provide specific information of external connector through
standard sysfs entry.
> +
> +static irqreturn_t palmas_vbus_wakeup_irq(int irq, void *_palmas_usb)
> +{
> +	int ret;
> +	struct palmas_usb *palmas_usb = _palmas_usb;
> +	unsigned int vbus_line_state;
> +
> +	palmas_read(palmas_usb->palmas, PALMAS_INTERRUPT_BASE,
> +		PALMAS_INT3_LINE_STATE, &vbus_line_state);
> +
> +	if (vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS) {
> +		if (palmas_usb->linkstat != PALMAS_USB_STATE_VBUS) {
> +			if (palmas_usb->vbus_reg) {
> +				ret = regulator_enable(palmas_usb->vbus_reg);
> +				if (ret) {
> +					dev_dbg(palmas_usb->dev,
> +						"regulator enable failed\n");
> +					goto ret0;
> +				}
> +			}
> +			palmas_usb->linkstat = PALMAS_USB_STATE_VBUS;
> +			extcon_set_cable_state(&palmas_usb->edev, "USB", true);
> +		} else {
> +			dev_dbg(palmas_usb->dev,
> +				"Spurious connect event detected\n");
> +		}
> +	} else if (!(vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS)) {
> +		if (palmas_usb->linkstat == PALMAS_USB_STATE_VBUS) {
> +			if (palmas_usb->vbus_reg)
> +				regulator_disable(palmas_usb->vbus_reg);
> +			palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
> +			extcon_set_cable_state(&palmas_usb->edev, "USB", false);
> +		} else {
> +			dev_dbg(palmas_usb->dev,
> +				"Spurious disconnect event detected\n");
> +		}
> +	}
> +
> +ret0:
> +	return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t palmas_id_wakeup_irq(int irq, void *_palmas_usb)
> +{
> +	int			ret;
> +	unsigned int		set;
> +	struct palmas_usb	*palmas_usb = _palmas_usb;
> +
> +	palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> +		PALMAS_USB_ID_INT_LATCH_SET, &set);
> +
> +	if (set & PALMAS_USB_ID_INT_SRC_ID_GND) {
> +		if (palmas_usb->vbus_reg) {
> +			ret = regulator_enable(palmas_usb->vbus_reg);
> +			if (ret) {
> +				dev_dbg(palmas_usb->dev,
> +					"regulator enable failed\n");
> +				goto ret0;
> +			}
> +		}
> +		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> +			PALMAS_USB_ID_INT_EN_HI_SET,
> +			PALMAS_USB_ID_INT_EN_HI_SET_ID_FLOAT);
> +		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> +			PALMAS_USB_ID_INT_EN_HI_CLR,
> +			PALMAS_USB_ID_INT_EN_HI_CLR_ID_GND);
> +		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
> +		extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", true);
> +	} else if (set & PALMAS_USB_ID_INT_SRC_ID_FLOAT) {
> +		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> +			PALMAS_USB_ID_INT_EN_HI_SET,
> +			PALMAS_USB_ID_INT_EN_HI_SET_ID_GND);
> +		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> +			PALMAS_USB_ID_INT_EN_HI_CLR,
> +			PALMAS_USB_ID_INT_EN_HI_CLR_ID_FLOAT);
> +		if (palmas_usb->vbus_reg)
> +			regulator_disable(palmas_usb->vbus_reg);
> +		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
> +		extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", false);
> +	}
> +
> +ret0:
> +	return IRQ_HANDLED;
> +}
> +
> +static void palmas_enable_irq(struct palmas_usb *palmas_usb)
> +{
> +	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> +		PALMAS_USB_VBUS_CTRL_SET,
> +		PALMAS_USB_VBUS_CTRL_SET_VBUS_ACT_COMP);
> +
> +	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> +		PALMAS_USB_ID_CTRL_SET, PALMAS_USB_ID_CTRL_SET_ID_ACT_COMP);
> +
> +	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> +		PALMAS_USB_ID_INT_EN_HI_SET,
> +		PALMAS_USB_ID_INT_EN_HI_SET_ID_GND);
> +
> +	palmas_vbus_wakeup_irq(palmas_usb->irq4, palmas_usb);
> +	palmas_id_wakeup_irq(palmas_usb->irq2, palmas_usb);
> +}
> +
> +static void palmas_set_vbus_work(struct work_struct *data)
> +{
> +	int ret;
> +	struct palmas_usb *palmas_usb = container_of(data, struct palmas_usb,
> +								set_vbus_work);
> +
> +	if (IS_ERR_OR_NULL(palmas_usb->vbus_reg)) {
> +		dev_err(palmas_usb->dev, "invalid regulator\n");
> +		return;
> +	}
> +
> +	/*
> +	 * Start driving VBUS. Set OPA_MODE bit in CHARGERUSB_CTRL1
> +	 * register. This enables boost mode.
> +	 */
> +
> +	if (palmas_usb->vbus_enable) {
> +		ret = regulator_enable(palmas_usb->vbus_reg);
> +		if (ret)
> +			dev_dbg(palmas_usb->dev, "regulator enable failed\n");
> +	} else {
> +		regulator_disable(palmas_usb->vbus_reg);
> +	}
> +}
> +
> +static int palmas_set_vbus(struct phy_companion *comparator, bool enabled)
> +{
> +	struct palmas_usb *palmas_usb = comparator_to_palmas(comparator);
> +
> +	palmas_usb->vbus_enable = enabled;
> +	schedule_work(&palmas_usb->set_vbus_work);
> +
> +	return 0;
> +}
> +
> +static int palmas_start_srp(struct phy_companion *comparator)
> +{
> +	struct palmas_usb *palmas_usb = comparator_to_palmas(comparator);
> +
> +	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> +		PALMAS_USB_VBUS_CTRL_SET, PALMAS_USB_VBUS_CTRL_SET_VBUS_DISCHRG
> +		| PALMAS_USB_VBUS_CTRL_SET_VBUS_IADP_SINK);
> +	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> +		PALMAS_USB_VBUS_CTRL_SET,
> +		PALMAS_USB_VBUS_CTRL_SET_VBUS_CHRG_VSYS |
> +		PALMAS_USB_VBUS_CTRL_SET_VBUS_IADP_SINK);
> +
> +	mdelay(100);
> +
> +	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> +		PALMAS_USB_VBUS_CTRL_CLR,
> +		PALMAS_USB_VBUS_CTRL_SET_VBUS_CHRG_VSYS |
> +		PALMAS_USB_VBUS_CTRL_SET_VBUS_CHRG_VSYS);
> +
> +	return 0;
> +}
> +
> +static void palmas_dt_to_pdata(struct device_node *node,
> +		struct palmas_usb_platform_data *pdata)
> +{
> +	pdata->no_control_vbus = of_property_read_bool(node,
> +					"ti,no_control_vbus");
> +	pdata->wakeup = of_property_read_bool(node, "ti,wakeup");
> +}
> +
> +static int palmas_usb_probe(struct platform_device *pdev)
> +{
> +	u32 ret;
> +	struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
> +	struct palmas_usb_platform_data	*pdata = pdev->dev.platform_data;
> +	struct device_node *node = pdev->dev.of_node;
> +	struct palmas_usb *palmas_usb;
> +	int status;
> +
> +	if (node && !pdata) {
> +		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
> +
> +		if (!pdata)
> +			return -ENOMEM;
> +
> +		palmas_dt_to_pdata(node, pdata);
> +	}
> +
> +	if (!pdata)
> +		return -EINVAL;
> +
> +	palmas_usb = devm_kzalloc(&pdev->dev, sizeof(*palmas_usb), GFP_KERNEL);
> +	if (!palmas_usb)
> +		return -ENOMEM;
> +
> +	palmas->usb		= palmas_usb;
> +	palmas_usb->palmas	= palmas;
> +
> +	palmas_usb->dev		= &pdev->dev;
> +
> +	palmas_usb->irq1 = regmap_irq_get_virq(palmas->irq_data,
> +						PALMAS_ID_OTG_IRQ);
> +	palmas_usb->irq2 = regmap_irq_get_virq(palmas->irq_data,
> +						PALMAS_ID_IRQ);
> +	palmas_usb->irq3 = regmap_irq_get_virq(palmas->irq_data,
> +						PALMAS_VBUS_OTG_IRQ);
> +	palmas_usb->irq4 = regmap_irq_get_virq(palmas->irq_data,
> +						PALMAS_VBUS_IRQ);
> +
> +	palmas_usb->comparator.set_vbus	= palmas_set_vbus;
> +	palmas_usb->comparator.start_srp = palmas_start_srp;
> +
> +	palmas_usb_wakeup(palmas, pdata->wakeup);
> +
> +	/* init spinlock for workqueue */
> +	spin_lock_init(&palmas_usb->lock);
> +
> +	if (!pdata->no_control_vbus) {
> +		palmas_usb->vbus_reg = devm_regulator_get(&pdev->dev, "vbus");
> +		if (IS_ERR(palmas_usb->vbus_reg)) {
> +			dev_err(&pdev->dev, "vbus init failed\n");
> +			return PTR_ERR(palmas_usb->vbus_reg);
> +		}
> +	}
> +
> +	platform_set_drvdata(pdev, palmas_usb);
> +
> +	if (device_create_file(&pdev->dev, &dev_attr_vbus))
> +		dev_warn(&pdev->dev, "could not create sysfs file\n");
device_create_file() isn't needed if remove 'palmas_usb_vbus' sysfs entry.
> +
> +	palmas_usb->edev.name = "palmas_usb";
I prefer '-' instead of '_'. change from "palmas_usb" to "palmas-usb".
> +	palmas_usb->edev.supported_cable = palmas_extcon_cable;
> +	palmas_usb->edev.mutually_exclusive = mutually_exclusive;
> +
> +	ret = extcon_dev_register(&palmas_usb->edev, palmas_usb->dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to register extcon device\n");
> +		return ret;
> +	}
> +
> +	/* init spinlock for workqueue */
> +	spin_lock_init(&palmas_usb->lock);
> +
> +	INIT_WORK(&palmas_usb->set_vbus_work, palmas_set_vbus_work);
> +
> +	status = devm_request_threaded_irq(palmas_usb->dev, palmas_usb->irq2,
> +			NULL, palmas_id_wakeup_irq,
> +			IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
> +			"palmas_usb", palmas_usb);
> +	if (status < 0) {
> +		dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
> +					palmas_usb->irq2, status);
> +		goto fail_irq;
> +	}
> +
> +	status = devm_request_threaded_irq(palmas_usb->dev, palmas_usb->irq4,
> +			NULL, palmas_vbus_wakeup_irq,
> +			IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
> +			"palmas_usb", palmas_usb);
> +	if (status < 0) {
> +		dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
> +					palmas_usb->irq4, status);
> +		goto fail_irq;
> +	}
> +
> +	palmas_enable_irq(palmas_usb);
> +
> +	return 0;
> +
> +fail_irq:
> +	cancel_work_sync(&palmas_usb->set_vbus_work);
> +	device_remove_file(palmas_usb->dev, &dev_attr_vbus);
ditto.
> +
> +	return status;
> +}
> +
> +static int palmas_usb_remove(struct platform_device *pdev)
> +{
> +	struct palmas_usb *palmas_usb = platform_get_drvdata(pdev);
> +
> +	device_remove_file(palmas_usb->dev, &dev_attr_vbus);
ditto.
> +	cancel_work_sync(&palmas_usb->set_vbus_work);
> +	extcon_dev_unregister(&palmas_usb->edev);
> +
> +	return 0;
> +}
> +
> +static struct of_device_id of_palmas_match_tbl[] = {
> +	{ .compatible = "ti,palmas-usb", },
> +	{ .compatible = "ti,twl6035-usb", },
> +	{ /* end */ }
> +};
> +
> +static struct platform_driver palmas_usb_driver = {
> +	.probe = palmas_usb_probe,
> +	.remove = palmas_usb_remove,
> +	.driver = {
> +		.name = "palmas-usb",
> +		.of_match_table = of_palmas_match_tbl,
> +		.owner = THIS_MODULE,
> +	},
> +};
> +
> +module_platform_driver(palmas_usb_driver);
> +
> +MODULE_ALIAS("platform:palmas-usb");
> +MODULE_AUTHOR("Graeme Gregory <gg@...mlogic.co.uk>");
> +MODULE_DESCRIPTION("Palmas USB transceiver driver");
> +MODULE_LICENSE("GPL");
> +MODULE_DEVICE_TABLE(of, of_palmas_match_tbl);
> diff --git a/include/linux/extcon/extcon_palmas.h b/include/linux/extcon/extcon_palmas.h
> new file mode 100644
> index 0000000..a5119c9
> --- /dev/null
> +++ b/include/linux/extcon/extcon_palmas.h
> @@ -0,0 +1,26 @@
> +/*
> + * extcon_palmas.h - palmas extcon driver to detect VBUS or ID events
> + *
> + * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.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.
> + *
> + * Author: Kishon Vijay Abraham I <kishon@ti.com>
> + *
> + * 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.
> + *
> + */
> +
> +#ifndef __EXTCON_PALMAS_H__
> +#define __EXTCON_PALMAS_H__
> +
> +#define	PALMAS_USB_STATE_DISCONNECT	0x0
> +#define	PALMAS_USB_STATE_VBUS		BIT(0)
> +#define	PALMAS_USB_STATE_ID		BIT(1)
> +
The defined variable in extcon_palmas.h is used only on extcon-palmas.c.
So, I would like to move definition from extcon_palmas.h to extcon-palmas.c
and remove extcon_palmas.h header file.
> +#endif	/* __EXTCON_PALMAS_H__ */
> diff --git a/include/linux/mfd/palmas.h b/include/linux/mfd/palmas.h
> index 8f21daf..d671679 100644
> --- a/include/linux/mfd/palmas.h
> +++ b/include/linux/mfd/palmas.h
> @@ -18,8 +18,10 @@
>  
>  #include <linux/usb/otg.h>
>  #include <linux/leds.h>
> +#include <linux/extcon.h>
>  #include <linux/regmap.h>
>  #include <linux/regulator/driver.h>
> +#include <linux/usb/phy_companion.h>
>  
>  #define PALMAS_NUM_CLIENTS		3
>  
> @@ -349,6 +351,9 @@ struct palmas_resource {
>  struct palmas_usb {
>  	struct palmas *palmas;
>  	struct device *dev;
> +	struct extcon_dev edev;
> +
> +	struct phy_companion comparator;
>  
>  	/* for vbus reporting with irqs disabled */
>  	spinlock_t lock;
> @@ -365,7 +370,8 @@ struct palmas_usb {
>  
>  	int vbus_enable;
>  
> -	u8 linkstat;
> +	int mailboxstat;
> +	int linkstat;
>  };
>  
>  #define comparator_to_palmas(x) container_of((x), struct palmas_usb, comparator)

Thanks,
Chanwoo Choi