This patch add extcon-max8997 driver to support the muic feature
of Maxim max8997 by using Extcon framework.

The extcon-max8997 driver is implemented based on 'drivers/misc/
max8997-muic.c' and then use Extcon interface instead of callback
function in struct max8997_muic_platform_data to notify cable state
of notifee which want to know always newly cable state when external
connector(e.g., USB, TA, JIG) is attached or detached.

v1
- Use Extcon interface to notify cable state of notifee instead of
 callback function when external connector is attached or detached.
- Bug fix of getting platform_data for irq_base value.
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NMyungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some accessory detection mechanisms are able to detect that something is
physically present in the socket separately to identifying what is present
in the socket. This information can be useful to applications, for example
allowing them to indicate that a potentially broken accessory is present,
so provide a standard way to report it to userspace.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix the section mismatch be renaming the struct platform_driver
variable.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch inform the state of only one cable instead of previous data
including the state of 32 cables to notifee which use
extcon_register_interest()
function to monitor whether the specific cable is attachd or detached.
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NMyungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Return -ENOMEM if the kmalloc() fails.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Because extcon can also be a switch class for legacy userspace (Android)
and is a superset of switch class in drivers/staging/android/switch,
switch class may be removed.

- Remove switch class
- Remove switch class consideration in extcon class
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There could be cables that t recannot be attaches simulatenously. Extcon
device drivers may express such information via mutually_exclusive in
struct extcon_dev.

For example, for an extcon device with 16 cables (bits 0 to 15 are
available), if mutually_exclusive = { 0x7, 0xC0, 0x81, 0 }, then, the
following attachments are prohibitted.
{0, 1}
{0, 2}
{1, 2}
{6, 7}
{0, 7}
and every attachment set that are superset of one of the above.
For the detail, please refer to linux/include/linux/extcon.h.

The concept is suggested by NeilBrown <neilb@suse.de>
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>

--
Changes from V5:
- Updated sysfs format
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

One switch device (e.g., MUIC(MAX8997, MAX77686, ...), and some 30-pin
devices) may have multiple cables attached. For example, one
30-pin port may inhabit a USB cable, an HDMI cable, and a mic.
Thus, one switch device requires multiple state bits each representing
a type of cable.

For such purpose, we use the 32bit state variable; thus, up to 32
different type of cables may be defined for a switch device. The list of
possible cables is defined by the array of cable names in the switch_dev
struct given to the class.
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>

--
Changes from V7
- Bugfixed in _call_per_cable() (incorrect nb) (Chanwoo Choi)
- Compiler error in header for !CONFIG_EXTCON (Chanwoo Choi)

Changes from V5
- Sysfs style reformed: subdirectory per cable.
- Updated standard cable names
- Removed unnecessary printf
- Bugfixes after testing

Changes from V4
- Bugfixes after more testing at Exynos4412 boards with userspace
  processses.

Changes from V3
- Bugfixes after more testing at Exynos4412 boards.

Changes from V2
- State can be stored by user
- Documentation updated

Changes from RFC
- Switch is renamed to extcon
- Added kerneldoc comments
- Added APIs to support "standard" cable names
- Added helper APIs to support notifier block registration with cable
  name.
- Regrouped function list in the header file.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

State changes of extcon devices have been notified via kobjet_uevent.
This patch adds notifier interfaces in order to allow device drivers to
get notified easily. Along with notifier interface,
extcon_get_extcon_dev() function is added so that device drivers may
discover a extcon_dev easily.
Signed-off-by: NDonggeun Kim <dg77.kim@samsung.com>
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

--
Changes from RFC
- Renamed switch to extcon
- Bugfix: extcon_dev_unregister()
- Bugfix: "edev->dev" is "internal" data.
- Added kerneldoc comments.
- Reworded comments.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The generic GPIO extcon driver (an external connector device based on
GPIO control) and imported from Android kernel.

switch: switch class and GPIO drivers. (splitted)
Author: Mike Lockwood <lockwood@android.com>

switch: gpio: Don't call request_irq with interrupts disabled
Author: Arve Hjønnevåg <arve@android.com>

switch_gpio: Add missing #include <linux/interrupt.h>
Author: Mike Lockwood <lockwood@android.com>
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

--
Changed from v7:
- Style updates mentioned by Stephen Boyd and Mark Brown
Changed from v5:
- Splitted at v5 from the main extcon patch.
- Added debounce time for irq handlers.
- Use request_any_context_irq instead of request_irq
- User needs to specify irq flags for GPIO interrupts (was fixed to
IRQF_TRIGGER_LOW before)
- Use module_platform_driver().
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

External connector class (extcon) is based on and an extension of
Android kernel's switch class located at linux/drivers/switch/.

This patch provides the before-extension switch class moved to the
location where the extcon will be located (linux/drivers/extcon/) and
updates to handle class properly.

The before-extension class, switch class of Android kernel, commits
imported are:

switch: switch class and GPIO drivers. (splitted)
Author: Mike Lockwood <lockwood@android.com>

switch: Use device_create instead of device_create_drvdata.
Author: Arve Hjønnevåg <arve@android.com>

In this patch, upon the commits of Android kernel, we have added:
- Relocated and renamed for extcon.
- Comments, module name, and author information are updated
- Code clean for successing patches
- Bugfix: enabling write access without write functions
- Class/device/sysfs create/remove handling
- Added comments about uevents
- Format changes for extcon_dev_register() to have a parent dev.
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

--
Changes from v7
- Compiler error fixed when it is compiled as a module.
- Removed out-of-date Kconfig entry

Changes from v6
- Updated comment/strings
- Revised "Android-compatible" mode.
   * Automatically activated if CONFIG_ANDROID && !CONFIG_ANDROID_SWITCH
   * Creates /sys/class/switch/*, which is a copy of /sys/class/extcon/*

Changes from v5
- Split the patch
- Style fixes
- "Android-compatible" mode is enabled by Kconfig option.

Changes from v2
- Updated name_show
- Sysfs entries are handled by class itself.
- Updated the method to add/remove devices for the class
- Comments on uevent send
- Able to become a module
- Compatible with Android platform

Changes from RFC
- Renamed to extcon (external connector) from multistate switch
- Added a seperated directory (drivers/extcon)
- Added kerneldoc comments
- Removed unused variables from extcon_gpio.c
- Added ABI Documentation.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>