Re: [PATCH v2] extcon: Add an API to get extcon device from dt node

From: Chanwoo Choi <cw00.choi@samsung.com>
To: Kishon Vijay Abraham I <kishon@ti.com>
Cc: myungjoo.ham@samsung.com, balbi@ti.com,
	devicetree-discuss@lists.ozlabs.org, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
	linux-omap@vger.kernel.org, grant.likely@linaro.org,
	rob.herring@calxeda.com, rob@landley.net,
	gregkh@linuxfoundation.org, benoit.cousson@linaro.org,
	anish198519851985@gmail.com, pmeerw@pmeerw.net
Subject: Re: [PATCH v2] extcon: Add an API to get extcon device from dt node
Date: Fri, 14 Jun 2013 17:51:18 +0900	[thread overview]
Message-ID: <51BAD986.30308@samsung.com> (raw)
In-Reply-To: <51BAD611.1070306@ti.com>

On 06/14/2013 05:36 PM, Kishon Vijay Abraham I wrote:
> Hi,
> 
> On Friday 14 June 2013 12:45 PM, Chanwoo Choi wrote:
>> From: Kishon Vijay Abraham I <kishon@ti.com>
>>
>> Added an API of_extcon_get_extcon_dev() to be used by drivers to get
>> extcon device in the case of dt boot (this can be used instead of
>> extcon_get_extcon_dev()).
>>
>> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
>> Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>
>> ---
>> Changes since v1:
>> - If edev->name is NULL, dev_name(dev) is used as edev->name.
>> - Change filename from of-extcon.* to of_extcon.*
>> - Fix build error when CONFIG_OF is not set
>> - Add header file(linux/err.h) to of_extcon.c
>>
>>   drivers/extcon/Makefile          |  2 ++
>>   drivers/extcon/extcon-class.c    |  3 +-
>>   drivers/extcon/of_extcon.c       | 64 ++++++++++++++++++++++++++++++++++++++++
>>   include/linux/extcon/of_extcon.h | 30 +++++++++++++++++++
>>   4 files changed, 98 insertions(+), 1 deletion(-)
>>   create mode 100644 drivers/extcon/of_extcon.c
>>   create mode 100644 include/linux/extcon/of_extcon.h
>>
>> diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
>> index 540e2c3..83468f7 100644
>> --- a/drivers/extcon/Makefile
>> +++ b/drivers/extcon/Makefile
>> @@ -2,6 +2,8 @@
>>   # Makefile for external connector class (extcon) devices
>>   #
>>
>> +obj-$(CONFIG_OF)        += of_extcon.o
>> +
>>   obj-$(CONFIG_EXTCON)        += extcon-class.o
>>   obj-$(CONFIG_EXTCON_GPIO)    += extcon-gpio.o
>>   obj-$(CONFIG_EXTCON_ADC_JACK)    += extcon-adc-jack.o
>> diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
>> index 23f11ea..08509ea 100644
>> --- a/drivers/extcon/extcon-class.c
>> +++ b/drivers/extcon/extcon-class.c
>> @@ -602,7 +602,8 @@ int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
>>       edev->dev->class = extcon_class;
>>       edev->dev->release = extcon_dev_release;
>>
>> -    dev_set_name(edev->dev, edev->name ? edev->name : dev_name(dev));
>> +    edev->name = edev->name ? edev->name : dev_name(dev);
>> +    dev_set_name(edev->dev, edev->name);
>>
>>       if (edev->max_supported) {
>>           char buf[10];
>> diff --git a/drivers/extcon/of_extcon.c b/drivers/extcon/of_extcon.c
>> new file mode 100644
>> index 0000000..72173ec
>> --- /dev/null
>> +++ b/drivers/extcon/of_extcon.c
>> @@ -0,0 +1,64 @@
>> +/*
>> + * OF helpers for External connector (extcon) framework
>> + *
>> + * Copyright (C) 2013 Texas Instruments, Inc.
>> + * Kishon Vijay Abraham I <kishon@ti.com>
>> + *
>> + * Copyright (C) 2013 Samsung Electronics
>> + * Chanwoo Choi <cw00.choi@samsung.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.
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/slab.h>
>> +#include <linux/err.h>
>> +#include <linux/extcon.h>
>> +#include <linux/of.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/extcon/of_extcon.h>
>> +
>> +/*
>> + * of_extcon_get_extcon_dev - Get the name of extcon device from devicetree
>> + * @dev - instance to the given device
>> + * @index - index into list of extcon_dev
>> + *
>> + * return the instance of extcon device
>> + */
>> +struct extcon_dev *of_extcon_get_extcon_dev(struct device *dev, int index)
>> +{
>> +    struct device_node *node;
>> +    struct extcon_dev *edev;
>> +    struct platform_device *extcon_parent_dev;
>> +
>> +    if (!dev->of_node) {
>> +        dev_dbg(dev, "device does not have a device node entry\n");
>> +        return ERR_PTR(-EINVAL);
>> +    }
>> +
>> +    node = of_parse_phandle(dev->of_node, "extcon", index);
>> +    if (!node) {
>> +        dev_dbg(dev, "failed to get phandle in %s node\n",
>> +            dev->of_node->full_name);
>> +        return ERR_PTR(-ENODEV);
>> +    }
>> +
>> +    extcon_parent_dev = of_find_device_by_node(node);
>> +    if (!extcon_parent_dev) {
>> +        dev_dbg(dev, "unable to find device by node\n");
>> +        return ERR_PTR(-EPROBE_DEFER);
>> +    }
>> +
>> +    edev = extcon_get_extcon_dev(dev_name(&extcon_parent_dev->dev));
>> +    if (!edev) {
>> +        dev_dbg(dev, "unable to get extcon device : %s\n",
>> +                dev_name(&extcon_parent_dev->dev));
>> +        return ERR_PTR(-ENODEV);
>> +    }
>> +
>> +    return edev;
>> +}
>> +EXPORT_SYMBOL_GPL(of_extcon_get_extcon_dev);
>> diff --git a/include/linux/extcon/of_extcon.h b/include/linux/extcon/of_extcon.h
>> new file mode 100644
>> index 0000000..462f071
>> --- /dev/null
>> +++ b/include/linux/extcon/of_extcon.h
>> @@ -0,0 +1,30 @@
>> +/*
>> + * OF helpers for External connector (extcon) framework
>> + *
>> + * Copyright (C) 2013 Texas Instruments, Inc.
>> + * Kishon Vijay Abraham I <kishon@ti.com>
>> + *
>> + * Copyright (C) 2013 Samsung Electronics
>> + * Chanwoo Choi <cw00.choi@samsung.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.
>> + */
>> +
>> +#ifndef __LINUX_OF_EXTCON_H
>> +#define __LINUX_OF_EXTCON_H
>> +
>> +#if defined(CONFIG_OF) && defined(CONFIG_EXTCON)
>> +extern struct extcon_dev
>> +    *of_extcon_get_extcon_dev(struct device *dev, int index);
>> +#else
>> +static inline struct extcon_dev
>> +    *of_extcon_get_extcon_dev(struct device *dev, int index)
>> +{
>> +    return NULL;
> 
> Can we have some error value returned here instead of NULL?
> ERR_PTR(-ENOSYS)?
> 

OK, I modified it.

You can check modified patch on below git repo:
http://git.kernel.org/cgit/linux/kernel/git/chanwoo/extcon.git/commit/?h=extcon-next&id=2ae384a41c25d6ff8f12091c426fc7324141096f

Thanks,
Chanwoo Choi