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

[Chanwoo Choi]

On 06/12/2013 03:55 PM, Kishon Vijay Abraham I wrote:
> Hi Chanwoo Choi,
> 
> On Wednesday 12 June 2013 07:09 AM, Chanwoo Choi wrote:
>> From: Kishon Vijay Abraham I <kishon at 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 at ti.com>
>> Signed-off-by: Chanwoo Choi <cw00.choi at samsung.com>
>> Signed-off-by: Myungjoo Ham <myungjoo.ham at samsung.com>
>> ---
>>   drivers/extcon/Makefile          |  3 +++
>>   drivers/extcon/of-extcon.c       | 56 ++++++++++++++++++++++++++++++++++++++++
>>   include/linux/extcon/of-extcon.h | 30 +++++++++++++++++++++
>>   3 files changed, 89 insertions(+)
>>   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..39cdf95 100644
>> --- a/drivers/extcon/Makefile
>> +++ b/drivers/extcon/Makefile
>> @@ -2,9 +2,12 @@
>>   # 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
>> +
>>   obj-$(CONFIG_EXTCON_MAX77693)    += extcon-max77693.o
>>   obj-$(CONFIG_EXTCON_MAX8997)    += extcon-max8997.o
>>   obj-$(CONFIG_EXTCON_ARIZONA)    += extcon-arizona.o
>> diff --git a/drivers/extcon/of-extcon.c b/drivers/extcon/of-extcon.c
>> new file mode 100644
>> index 0000000..29f82b4
>> --- /dev/null
>> +++ b/drivers/extcon/of-extcon.c
>> @@ -0,0 +1,56 @@
>> +/*
>> + * OF helpers for External connector (extcon) framework
>> + *
>> + * Copyright (C) 2013 Texas Instruments, Inc.
>> + * Kishon Vijay Abraham I <kishon at ti.com>
>> + *
>> + * Copyright (C) 2013 Samsung Electronics
>> + * Chanwoo Choi <cw00.choi at 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/extcon.h>
>> +#include <linux/of.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/extcon/of-extcon.h>
>> +
>> +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));
> 
> In order to get this working, I needed a small fix in extcon_dev_register
> 
> -       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);
> 

OK, I added it on this patch.

> Also using extcon_get_extcon_dev here requires the extcon driver not to set edev.name since we use *dev_name* here. Hence I recommend using my initial class iterative approach. Anyway its your call. Let me know if have to float a new version of the patch (either the iterative approach or having the fix I mentioned in extcon_dev_register).

I prefer to imprement "of_extcon_get_extcon_dev()" separately from extcon core.

I will resend modified patch with your comment of extcon_dev_register() at once.

Thanks,
Chanwoo Choi