Extcon (external connector): import Android's switch class and modify.
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: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Mark 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 - Removed out-of-date Kconfig entry Changes from v6 - Updated comment/strings - Revised "Android-compatible" mode.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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
MyungJoo Ham
Greg Kroah-Hartman
parent
7cd9c9bb57
commit
de55d8716a
|
|
@ -0,0 +1,26 @@
|
|||
What: /sys/class/extcon/.../
|
||||
Date: December 2011
|
||||
Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
|
||||
Description:
|
||||
Provide a place in sysfs for the extcon objects.
|
||||
This allows accessing extcon specific variables.
|
||||
The name of extcon object denoted as ... is the name given
|
||||
with extcon_dev_register.
|
||||
|
||||
What: /sys/class/extcon/.../name
|
||||
Date: December 2011
|
||||
Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
|
||||
Description:
|
||||
The /sys/class/extcon/.../name shows the name of the extcon
|
||||
object. If the extcon object has an optional callback
|
||||
"show_name" defined, the callback will provide the name with
|
||||
this sysfs node.
|
||||
|
||||
What: /sys/class/extcon/.../state
|
||||
Date: December 2011
|
||||
Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
|
||||
Description:
|
||||
The /sys/class/extcon/.../state shows the cable attach/detach
|
||||
information of the corresponding extcon object. If the extcon
|
||||
objecct has an optional callback "show_state" defined, the
|
||||
callback will provide the name with this sysfs node.
|
||||
|
|
@ -140,4 +140,6 @@ source "drivers/virt/Kconfig"
|
|||
|
||||
source "drivers/devfreq/Kconfig"
|
||||
|
||||
source "drivers/extcon/Kconfig"
|
||||
|
||||
endmenu
|
||||
|
|
|
|||
|
|
@ -134,3 +134,4 @@ obj-$(CONFIG_VIRT_DRIVERS) += virt/
|
|||
obj-$(CONFIG_HYPERV) += hv/
|
||||
|
||||
obj-$(CONFIG_PM_DEVFREQ) += devfreq/
|
||||
obj-$(CONFIG_EXTCON) += extcon/
|
||||
|
|
|
|||
|
|
@ -0,0 +1,17 @@
|
|||
menuconfig EXTCON
|
||||
tristate "External Connector Class (extcon) support"
|
||||
help
|
||||
Say Y here to enable external connector class (extcon) support.
|
||||
This allows monitoring external connectors by userspace
|
||||
via sysfs and uevent and supports external connectors with
|
||||
multiple states; i.e., an extcon that may have multiple
|
||||
cables attached. For example, an external connector of a device
|
||||
may be used to connect an HDMI cable and a AC adaptor, and to
|
||||
host USB ports. Many of 30-pin connectors including PDMI are
|
||||
also good examples.
|
||||
|
||||
if EXTCON
|
||||
|
||||
comment "Extcon Device Drivers"
|
||||
|
||||
endif # MULTISTATE_SWITCH
|
||||
|
|
@ -0,0 +1,5 @@
|
|||
#
|
||||
# Makefile for external connector class (extcon) devices
|
||||
#
|
||||
|
||||
obj-$(CONFIG_EXTCON) += extcon_class.o
|
||||
|
|
@ -0,0 +1,236 @@
|
|||
/*
|
||||
* drivers/extcon/extcon_class.c
|
||||
*
|
||||
* External connector (extcon) class driver
|
||||
*
|
||||
* Copyright (C) 2012 Samsung Electronics
|
||||
* Author: Donggeun Kim <dg77.kim@samsung.com>
|
||||
* Author: MyungJoo Ham <myungjoo.ham@samsung.com>
|
||||
*
|
||||
* based on android/drivers/switch/switch_class.c
|
||||
* Copyright (C) 2008 Google, Inc.
|
||||
* Author: Mike Lockwood <lockwood@android.com>
|
||||
*
|
||||
* This software is licensed under the terms of the GNU General Public
|
||||
* License version 2, as published by the Free Software Foundation, and
|
||||
* may be copied, distributed, and modified under those terms.
|
||||
*
|
||||
* 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/types.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/device.h>
|
||||
#include <linux/fs.h>
|
||||
#include <linux/err.h>
|
||||
#include <linux/extcon.h>
|
||||
#include <linux/slab.h>
|
||||
|
||||
struct class *extcon_class;
|
||||
#if defined(CONFIG_ANDROID) && !defined(CONFIG_ANDROID_SWITCH)
|
||||
static struct class_compat *switch_class;
|
||||
#endif /* CONFIG_ANDROID && !defined(CONFIG_ANDROID_SWITCH) */
|
||||
|
||||
static ssize_t state_show(struct device *dev, struct device_attribute *attr,
|
||||
char *buf)
|
||||
{
|
||||
struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
|
||||
|
||||
if (edev->print_state) {
|
||||
int ret = edev->print_state(edev, buf);
|
||||
|
||||
if (ret >= 0)
|
||||
return ret;
|
||||
/* Use default if failed */
|
||||
}
|
||||
return sprintf(buf, "%u\n", edev->state);
|
||||
}
|
||||
|
||||
static ssize_t name_show(struct device *dev, struct device_attribute *attr,
|
||||
char *buf)
|
||||
{
|
||||
struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
|
||||
|
||||
/* Optional callback given by the user */
|
||||
if (edev->print_name) {
|
||||
int ret = edev->print_name(edev, buf);
|
||||
if (ret >= 0)
|
||||
return ret;
|
||||
}
|
||||
|
||||
return sprintf(buf, "%s\n", dev_name(edev->dev));
|
||||
}
|
||||
|
||||
/**
|
||||
* extcon_set_state() - Set the cable attach states of the extcon device.
|
||||
* @edev: the extcon device
|
||||
* @state: new cable attach status for @edev
|
||||
*
|
||||
* Changing the state sends uevent with environment variable containing
|
||||
* the name of extcon device (envp[0]) and the state output (envp[1]).
|
||||
* Tizen uses this format for extcon device to get events from ports.
|
||||
* Android uses this format as well.
|
||||
*/
|
||||
void extcon_set_state(struct extcon_dev *edev, u32 state)
|
||||
{
|
||||
char name_buf[120];
|
||||
char state_buf[120];
|
||||
char *prop_buf;
|
||||
char *envp[3];
|
||||
int env_offset = 0;
|
||||
int length;
|
||||
|
||||
if (edev->state != state) {
|
||||
edev->state = state;
|
||||
|
||||
prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
|
||||
if (prop_buf) {
|
||||
length = name_show(edev->dev, NULL, prop_buf);
|
||||
if (length > 0) {
|
||||
if (prop_buf[length - 1] == '\n')
|
||||
prop_buf[length - 1] = 0;
|
||||
snprintf(name_buf, sizeof(name_buf),
|
||||
"NAME=%s", prop_buf);
|
||||
envp[env_offset++] = name_buf;
|
||||
}
|
||||
length = state_show(edev->dev, NULL, prop_buf);
|
||||
if (length > 0) {
|
||||
if (prop_buf[length - 1] == '\n')
|
||||
prop_buf[length - 1] = 0;
|
||||
snprintf(state_buf, sizeof(state_buf),
|
||||
"STATE=%s", prop_buf);
|
||||
envp[env_offset++] = state_buf;
|
||||
}
|
||||
envp[env_offset] = NULL;
|
||||
kobject_uevent_env(&edev->dev->kobj, KOBJ_CHANGE, envp);
|
||||
free_page((unsigned long)prop_buf);
|
||||
} else {
|
||||
dev_err(edev->dev, "out of memory in extcon_set_state\n");
|
||||
kobject_uevent(&edev->dev->kobj, KOBJ_CHANGE);
|
||||
}
|
||||
}
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(extcon_set_state);
|
||||
|
||||
static struct device_attribute extcon_attrs[] = {
|
||||
__ATTR_RO(state),
|
||||
__ATTR_RO(name),
|
||||
};
|
||||
|
||||
static int create_extcon_class(void)
|
||||
{
|
||||
if (!extcon_class) {
|
||||
extcon_class = class_create(THIS_MODULE, "extcon");
|
||||
if (IS_ERR(extcon_class))
|
||||
return PTR_ERR(extcon_class);
|
||||
extcon_class->dev_attrs = extcon_attrs;
|
||||
|
||||
#if defined(CONFIG_ANDROID) && !defined(CONFIG_ANDROID_SWITCH)
|
||||
switch_class = class_compat_register("switch");
|
||||
if (WARN(!switch_class, "cannot allocate"))
|
||||
return -ENOMEM;
|
||||
#endif /* CONFIG_ANDROID && !defined(CONFIG_ANDROID_SWITCH) */
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void extcon_cleanup(struct extcon_dev *edev, bool skip)
|
||||
{
|
||||
if (!skip && get_device(edev->dev)) {
|
||||
device_unregister(edev->dev);
|
||||
put_device(edev->dev);
|
||||
}
|
||||
|
||||
kfree(edev->dev);
|
||||
}
|
||||
|
||||
static void extcon_dev_release(struct device *dev)
|
||||
{
|
||||
struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
|
||||
|
||||
extcon_cleanup(edev, true);
|
||||
}
|
||||
|
||||
/**
|
||||
* extcon_dev_register() - Register a new extcon device
|
||||
* @edev : the new extcon device (should be allocated before calling)
|
||||
* @dev : the parent device for this extcon device.
|
||||
*
|
||||
* Among the members of edev struct, please set the "user initializing data"
|
||||
* in any case and set the "optional callbacks" if required. However, please
|
||||
* do not set the values of "internal data", which are initialized by
|
||||
* this function.
|
||||
*/
|
||||
int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
|
||||
{
|
||||
int ret;
|
||||
|
||||
if (!extcon_class) {
|
||||
ret = create_extcon_class();
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
}
|
||||
|
||||
edev->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
|
||||
edev->dev->parent = dev;
|
||||
edev->dev->class = extcon_class;
|
||||
edev->dev->release = extcon_dev_release;
|
||||
|
||||
dev_set_name(edev->dev, edev->name ? edev->name : dev_name(dev));
|
||||
ret = device_register(edev->dev);
|
||||
if (ret) {
|
||||
put_device(edev->dev);
|
||||
goto err_dev;
|
||||
}
|
||||
#if defined(CONFIG_ANDROID) && !defined(CONFIG_ANDROID_SWITCH)
|
||||
if (switch_class)
|
||||
ret = class_compat_create_link(switch_class, edev->dev,
|
||||
dev);
|
||||
#endif /* CONFIG_ANDROID && !defined(CONFIG_ANDROID_SWITCH) */
|
||||
|
||||
dev_set_drvdata(edev->dev, edev);
|
||||
edev->state = 0;
|
||||
return 0;
|
||||
|
||||
err_dev:
|
||||
kfree(edev->dev);
|
||||
return ret;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(extcon_dev_register);
|
||||
|
||||
/**
|
||||
* extcon_dev_unregister() - Unregister the extcon device.
|
||||
* @edev: the extcon device instance to be unregitered.
|
||||
*
|
||||
* Note that this does not call kfree(edev) because edev was not allocated
|
||||
* by this class.
|
||||
*/
|
||||
void extcon_dev_unregister(struct extcon_dev *edev)
|
||||
{
|
||||
extcon_cleanup(edev, false);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(extcon_dev_unregister);
|
||||
|
||||
static int __init extcon_class_init(void)
|
||||
{
|
||||
return create_extcon_class();
|
||||
}
|
||||
module_init(extcon_class_init);
|
||||
|
||||
static void __exit extcon_class_exit(void)
|
||||
{
|
||||
class_destroy(extcon_class);
|
||||
}
|
||||
module_exit(extcon_class_exit);
|
||||
|
||||
MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
|
||||
MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
|
||||
MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
|
||||
MODULE_DESCRIPTION("External connector (extcon) class driver");
|
||||
MODULE_LICENSE("GPL");
|
||||
|
|
@ -0,0 +1,82 @@
|
|||
/*
|
||||
* External connector (extcon) class driver
|
||||
*
|
||||
* Copyright (C) 2012 Samsung Electronics
|
||||
* Author: Donggeun Kim <dg77.kim@samsung.com>
|
||||
* Author: MyungJoo Ham <myungjoo.ham@samsung.com>
|
||||
*
|
||||
* based on switch class driver
|
||||
* Copyright (C) 2008 Google, Inc.
|
||||
* Author: Mike Lockwood <lockwood@android.com>
|
||||
*
|
||||
* This software is licensed under the terms of the GNU General Public
|
||||
* License version 2, as published by the Free Software Foundation, and
|
||||
* may be copied, distributed, and modified under those terms.
|
||||
*
|
||||
* 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 __LINUX_EXTCON_H__
|
||||
#define __LINUX_EXTCON_H__
|
||||
|
||||
/**
|
||||
* struct extcon_dev - An extcon device represents one external connector.
|
||||
* @name The name of this extcon device. Parent device name is used
|
||||
* if NULL.
|
||||
* @print_name An optional callback to override the method to print the
|
||||
* name of the extcon device.
|
||||
* @print_state An optional callback to override the method to print the
|
||||
* status of the extcon device.
|
||||
* @dev Device of this extcon. Do not provide at register-time.
|
||||
* @state Attach/detach state of this extcon. Do not provide at
|
||||
* register-time
|
||||
*
|
||||
* In most cases, users only need to provide "User initializing data" of
|
||||
* this struct when registering an extcon. In some exceptional cases,
|
||||
* optional callbacks may be needed. However, the values in "internal data"
|
||||
* are overwritten by register function.
|
||||
*/
|
||||
struct extcon_dev {
|
||||
/* --- Optional user initializing data --- */
|
||||
const char *name;
|
||||
|
||||
/* --- Optional callbacks to override class functions --- */
|
||||
ssize_t (*print_name)(struct extcon_dev *edev, char *buf);
|
||||
ssize_t (*print_state)(struct extcon_dev *edev, char *buf);
|
||||
|
||||
/* --- Internal data. Please do not set. --- */
|
||||
struct device *dev;
|
||||
u32 state;
|
||||
};
|
||||
|
||||
#if IS_ENABLED(CONFIG_EXTCON)
|
||||
extern int extcon_dev_register(struct extcon_dev *edev, struct device *dev);
|
||||
extern void extcon_dev_unregister(struct extcon_dev *edev);
|
||||
|
||||
static inline u32 extcon_get_state(struct extcon_dev *edev)
|
||||
{
|
||||
return edev->state;
|
||||
}
|
||||
|
||||
extern void extcon_set_state(struct extcon_dev *edev, u32 state);
|
||||
#else /* CONFIG_EXTCON */
|
||||
static inline int extcon_dev_register(struct extcon_dev *edev,
|
||||
struct device *dev)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline void extcon_dev_unregister(struct extcon_dev *edev) { }
|
||||
|
||||
static inline u32 extcon_get_state(struct extcon_dev *edev)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline void extcon_set_state(struct extcon_dev *edev, u32 state) { }
|
||||
#endif /* CONFIG_EXTCON */
|
||||
#endif /* __LINUX_EXTCON_H__ */
|
||||
Loading…
Reference in New Issue