* [PATCH v6 1/5] Extcon (external connector): import Android's switch class and modify.
2012-02-27 12:15 ` [PATCH v6 0/5] Introduce External Connector Class (extcon) MyungJoo Ham
@ 2012-02-27 12:15 ` MyungJoo Ham
2012-03-09 12:41 ` Mark Brown
2012-02-27 12:15 ` [PATCH v6 2/5] Extcon: support generic GPIO extcon driver MyungJoo Ham
` (3 subsequent siblings)
4 siblings, 1 reply; 18+ messages in thread
From: MyungJoo Ham @ 2012-02-27 12:15 UTC (permalink / raw)
To: linux-arm-kernel
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 Hj?nnev?g <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>
--
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.
---
Documentation/ABI/testing/sysfs-class-extcon | 26 +++
drivers/Kconfig | 2 +
drivers/Makefile | 1 +
drivers/extcon/Kconfig | 28 ++++
drivers/extcon/Makefile | 5 +
drivers/extcon/extcon_class.c | 226 ++++++++++++++++++++++++++
include/linux/extcon.h | 82 ++++++++++
7 files changed, 370 insertions(+), 0 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-class-extcon
create mode 100644 drivers/extcon/Kconfig
create mode 100644 drivers/extcon/Makefile
create mode 100644 drivers/extcon/extcon_class.c
create mode 100644 include/linux/extcon.h
diff --git a/Documentation/ABI/testing/sysfs-class-extcon b/Documentation/ABI/testing/sysfs-class-extcon
new file mode 100644
index 0000000..59a4b1c
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-extcon
@@ -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.
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 5afe5d1..537d126 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -136,4 +136,6 @@ source "drivers/virt/Kconfig"
source "drivers/devfreq/Kconfig"
+source "drivers/extcon/Kconfig"
+
endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index c07be02..6faceab 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -132,3 +132,4 @@ obj-$(CONFIG_VIRT_DRIVERS) += virt/
obj-$(CONFIG_HYPERV) += hv/
obj-$(CONFIG_PM_DEVFREQ) += devfreq/
+obj-$(CONFIG_EXTCON) += extcon/
diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
new file mode 100644
index 0000000..11db865
--- /dev/null
+++ b/drivers/extcon/Kconfig
@@ -0,0 +1,28 @@
+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 Class Configuration"
+
+config EXTCON_ANDROID_COMPATIBLE
+ bool "Class name uses 'switch' to be compatible with Android kernel"
+ depends on ANDROID
+ help
+ The class name of extcon device drivers are set 'switch' in order
+ to be compatible with Android kernel switch framework. With this
+ option enabled, Android userspace platform may use extcon device
+ drivers as if they are switch device drivers.
+
+comment "Extcon Device Drivers"
+
+endif # MULTISTATE_SWITCH
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
new file mode 100644
index 0000000..6bc6921
--- /dev/null
+++ b/drivers/extcon/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for external connector class (extcon) devices
+#
+
+obj-$(CONFIG_EXTCON) += extcon_class.o
diff --git a/drivers/extcon/extcon_class.c b/drivers/extcon/extcon_class.c
new file mode 100644
index 0000000..9bc062b
--- /dev/null
+++ b/drivers/extcon/extcon_class.c
@@ -0,0 +1,226 @@
+/*
+ * 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;
+
+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),
+ "SWITCH_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),
+ "SWITCH_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) {
+#ifdef CONFIG_ANDROID
+ extcon_class = class_create(THIS_MODULE, "switch");
+#else /* !CONFIG_ANDROID */
+ extcon_class = class_create(THIS_MODULE, "extcon");
+#endif /* CONFIG_ANDROID */
+ if (IS_ERR(extcon_class))
+ return PTR_ERR(extcon_class);
+ extcon_class->dev_attrs = extcon_attrs;
+ }
+
+ 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;
+ }
+
+ 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");
diff --git a/include/linux/extcon.h b/include/linux/extcon.h
new file mode 100644
index 0000000..cd732ab
--- /dev/null
+++ b/include/linux/extcon.h
@@ -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;
+};
+
+#ifdef 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__ */
--
1.7.4.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 1/5] Extcon (external connector): import Android's switch class and modify.
2012-02-27 12:15 ` [PATCH v6 1/5] Extcon (external connector): import Android's switch class and modify MyungJoo Ham
@ 2012-03-09 12:41 ` Mark Brown
2012-03-12 8:06 ` MyungJoo Ham
2012-03-29 22:27 ` Erik Gilling
0 siblings, 2 replies; 18+ messages in thread
From: Mark Brown @ 2012-03-09 12:41 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Feb 27, 2012 at 09:15:35PM +0900, MyungJoo Ham wrote:
> +#ifdef CONFIG_ANDROID
> + extcon_class = class_create(THIS_MODULE, "switch");
> +#else /* !CONFIG_ANDROID */
> + extcon_class = class_create(THIS_MODULE, "extcon");
> +#endif /* CONFIG_ANDROID */
This seems somewhat sad - if ANDROID is turned on the standard ABI
vanishes. It'd be much nicer to do this with a symlink (or with
symlinks within the android directory if the driver core doesn't support
that). That way userspace code can be written to the new ABI and will
work on Android systems without ifdefery.
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^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v6 1/5] Extcon (external connector): import Android's switch class and modify.
2012-03-09 12:41 ` Mark Brown
@ 2012-03-12 8:06 ` MyungJoo Ham
2012-03-29 22:27 ` Erik Gilling
1 sibling, 0 replies; 18+ messages in thread
From: MyungJoo Ham @ 2012-03-12 8:06 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Mar 9, 2012 at 9:41 PM, Mark Brown
<broonie@opensource.wolfsonmicro.com> wrote:
> On Mon, Feb 27, 2012 at 09:15:35PM +0900, MyungJoo Ham wrote:
>
>> +#ifdef CONFIG_ANDROID
>> + ? ? ? ? ? ? extcon_class = class_create(THIS_MODULE, "switch");
>> +#else /* !CONFIG_ANDROID */
>> + ? ? ? ? ? ? extcon_class = class_create(THIS_MODULE, "extcon");
>> +#endif /* CONFIG_ANDROID */
>
> This seems somewhat sad - if ANDROID is turned on the standard ABI
> vanishes. ?It'd be much nicer to do this with a symlink (or with
> symlinks within the android directory if the driver core doesn't support
> that). ?That way userspace code can be written to the new ABI and will
> work on Android systems without ifdefery.
Yes, this was the itching part.
I'll first look into creating symlinks (either /sys/class/switch -->
/sys/class/extcon or /sys/class/switch/* --> /sys/class/extcon/*).
However, I think this symbolic links are better created selectively w/
CONFIG_ANDROID.
Thanks.
Cheers!
MyungJoo.
--
MyungJoo Ham, Ph.D.
Mobile Software Platform Lab, DMC Business, Samsung Electronics
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v6 1/5] Extcon (external connector): import Android's switch class and modify.
2012-03-09 12:41 ` Mark Brown
2012-03-12 8:06 ` MyungJoo Ham
@ 2012-03-29 22:27 ` Erik Gilling
2012-03-30 8:56 ` MyungJoo Ham
2012-03-30 10:07 ` Mark Brown
1 sibling, 2 replies; 18+ messages in thread
From: Erik Gilling @ 2012-03-29 22:27 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Mar 9, 2012 at 4:41 AM, Mark Brown
<broonie@opensource.wolfsonmicro.com> wrote:
> On Mon, Feb 27, 2012 at 09:15:35PM +0900, MyungJoo Ham wrote:
>
>> +#ifdef CONFIG_ANDROID
>> + ? ? ? ? ? ? extcon_class = class_create(THIS_MODULE, "switch");
>> +#else /* !CONFIG_ANDROID */
>> + ? ? ? ? ? ? extcon_class = class_create(THIS_MODULE, "extcon");
>> +#endif /* CONFIG_ANDROID */
>
> This seems somewhat sad - if ANDROID is turned on the standard ABI
> vanishes. ?It'd be much nicer to do this with a symlink (or with
> symlinks within the android directory if the driver core doesn't support
> that). ?That way userspace code can be written to the new ABI and will
> work on Android systems without ifdefery.
This won't work if userspace code is receiving uevents through netlink
and comparing based on the device name which it does in android. Why
change the name at all? Extcon is much more specific than "switch."
A switch can can be used for more than just external connections such
as availability of HMDI audio (which is only available once a HDMI
mode is chosen and the interface is enabled.)
-Erik
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v6 1/5] Extcon (external connector): import Android's switch class and modify.
2012-03-29 22:27 ` Erik Gilling
@ 2012-03-30 8:56 ` MyungJoo Ham
2012-03-30 10:14 ` Mark Brown
2012-03-30 10:07 ` Mark Brown
1 sibling, 1 reply; 18+ messages in thread
From: MyungJoo Ham @ 2012-03-30 8:56 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Mar 30, 2012 at 7:27 AM, Erik Gilling <konkers@google.com> wrote:
> On Fri, Mar 9, 2012 at 4:41 AM, Mark Brown
> <broonie@opensource.wolfsonmicro.com> wrote:
>> On Mon, Feb 27, 2012 at 09:15:35PM +0900, MyungJoo Ham wrote:
>>
>>> +#ifdef CONFIG_ANDROID
>>> + ? ? ? ? ? ? extcon_class = class_create(THIS_MODULE, "switch");
>>> +#else /* !CONFIG_ANDROID */
>>> + ? ? ? ? ? ? extcon_class = class_create(THIS_MODULE, "extcon");
>>> +#endif /* CONFIG_ANDROID */
>>
>> This seems somewhat sad - if ANDROID is turned on the standard ABI
>> vanishes. ?It'd be much nicer to do this with a symlink (or with
>> symlinks within the android directory if the driver core doesn't support
>> that). ?That way userspace code can be written to the new ABI and will
>> work on Android systems without ifdefery.
>
> This won't work if userspace code is receiving uevents through netlink
> and comparing based on the device name which it does in android. ?Why
> change the name at all? ?Extcon is much more specific than "switch."
> A switch can can be used for more than just external connections such
> as availability of HMDI audio (which is only available once a HDMI
> mode is chosen and the interface is enabled.)
>
> -Erik
With class_compat as in patchset v7, (this thread is w/ v6) does the
issue (missing link from device name directory) still exist? (I don't
think so)
In the earlier iteration of dicussion, the name "switch" was dropped
as "switch" may mislead the concept.
https://lkml.org/lkml/2011/11/29/299
For HDMI and HDMI-audio, although HDMI-audio is not physically
seperated from HDMI-cable and it is available after HDMI-cable is
"attached", HDMI-audio is still an external connection to the kernel
and its device drivers, isn' it?
Cheers!
MyungJoo.
--
MyungJoo Ham, Ph.D.
System S/W Lab, S/W Center, Samsung Electronics
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v6 1/5] Extcon (external connector): import Android's switch class and modify.
2012-03-29 22:27 ` Erik Gilling
2012-03-30 8:56 ` MyungJoo Ham
@ 2012-03-30 10:07 ` Mark Brown
2012-03-30 17:29 ` Erik Gilling
1 sibling, 1 reply; 18+ messages in thread
From: Mark Brown @ 2012-03-30 10:07 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, Mar 29, 2012 at 03:27:01PM -0700, Erik Gilling wrote:
> On Fri, Mar 9, 2012 at 4:41 AM, Mark Brown
> <broonie@opensource.wolfsonmicro.com> wrote:
> > On Mon, Feb 27, 2012 at 09:15:35PM +0900, MyungJoo Ham wrote:
> >> +#ifdef CONFIG_ANDROID
> >> + ? ? ? ? ? ? extcon_class = class_create(THIS_MODULE, "switch");
> >> +#else /* !CONFIG_ANDROID */
> >> + ? ? ? ? ? ? extcon_class = class_create(THIS_MODULE, "extcon");
> >> +#endif /* CONFIG_ANDROID */
> > This seems somewhat sad - if ANDROID is turned on the standard ABI
> > vanishes. ?It'd be much nicer to do this with a symlink (or with
> > symlinks within the android directory if the driver core doesn't support
> > that). ?That way userspace code can be written to the new ABI and will
> > work on Android systems without ifdefery.
> This won't work if userspace code is receiving uevents through netlink
> and comparing based on the device name which it does in android. Why
That's not really the point here - the point is that the new ABI
vanishes as soon as you turn on the legacy Android ABI. You're right
that the particular fix I suggested has issues but the overall problem
exists and should be dealt with more sensibly.
> change the name at all? Extcon is much more specific than "switch."
> A switch can can be used for more than just external connections such
> as availability of HMDI audio (which is only available once a HDMI
> mode is chosen and the interface is enabled.)
I don't know myself, it was called extcon when first proposed for
mainline. Renaming does have the advantage of indicating to userspace
that this is the mainline, reviewed version and that things might be a
bit different as a result of that review.
Things like the HDMI audio example you cite do seem close enough to the
term to still be useful, they're related to an external connection and
it's state. If you were really worrying about it you might expect HDMI
audio to be reported via something like the ALSA APIs rather than a
totally unrelated ABI like this.
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^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v6 1/5] Extcon (external connector): import Android's switch class and modify.
2012-03-30 10:07 ` Mark Brown
@ 2012-03-30 17:29 ` Erik Gilling
2012-03-30 17:38 ` Dima Zavin
2012-03-31 10:19 ` Mark Brown
0 siblings, 2 replies; 18+ messages in thread
From: Erik Gilling @ 2012-03-30 17:29 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Mar 30, 2012 at 3:07 AM, Mark Brown
<broonie@opensource.wolfsonmicro.com> wrote:
> On Thu, Mar 29, 2012 at 03:27:01PM -0700, Erik Gilling wrote:
>> On Fri, Mar 9, 2012 at 4:41 AM, Mark Brown
>
>> > This seems somewhat sad - if ANDROID is turned on the standard ABI
>> > vanishes. ?It'd be much nicer to do this with a symlink (or with
>> > symlinks within the android directory if the driver core doesn't support
>> > that). ?That way userspace code can be written to the new ABI and will
>> > work on Android systems without ifdefery.
>
>> This won't work if userspace code is receiving uevents through netlink
>> and comparing based on the device name which it does in android. ?Why
>
> That's not really the point here - the point is that the new ABI
> vanishes as soon as you turn on the legacy Android ABI. ?You're right
> that the particular fix I suggested has issues but the overall problem
> exists and should be dealt with more sensibly.
I'm also not in favor of having functionality conditionally compiled
based on CONFIG_ANDROID. If fact, going through the patch stack
there's much more that changes the ABI from the switch driver than
just the name. Android asumes that there is a single "switch" for
each logical entity (called cable types in extcon) each with a binary
state (0,1). Here things have changed to have a single extcon
instance that can have a bitmask of states which are sent as strings
in the uevent.
As it stands, this patch does not solve the cases where we use switch
today and we'll probably continue to carry the switch driver in the
common android tree. If, instead, we got rid of the idea of multiple
states and mutual exclusivity and relied on the driver that uses
extcon to have multiple instances for each logical entity and deal
with mutual exclusion itself, we'd have a driver that would be pretty
easy to support in android.
-Erik
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v6 1/5] Extcon (external connector): import Android's switch class and modify.
2012-03-30 17:29 ` Erik Gilling
@ 2012-03-30 17:38 ` Dima Zavin
2012-04-02 5:09 ` MyungJoo Ham
2012-03-31 10:19 ` Mark Brown
1 sibling, 1 reply; 18+ messages in thread
From: Dima Zavin @ 2012-03-30 17:38 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Mar 30, 2012 at 10:29 AM, Erik Gilling <konkers@google.com> wrote:
> On Fri, Mar 30, 2012 at 3:07 AM, Mark Brown
> <broonie@opensource.wolfsonmicro.com> wrote:
>> On Thu, Mar 29, 2012 at 03:27:01PM -0700, Erik Gilling wrote:
>>> On Fri, Mar 9, 2012 at 4:41 AM, Mark Brown
>>
>>> > This seems somewhat sad - if ANDROID is turned on the standard ABI
>>> > vanishes. ?It'd be much nicer to do this with a symlink (or with
>>> > symlinks within the android directory if the driver core doesn't support
>>> > that). ?That way userspace code can be written to the new ABI and will
>>> > work on Android systems without ifdefery.
>>
>>> This won't work if userspace code is receiving uevents through netlink
>>> and comparing based on the device name which it does in android. ?Why
>>
>> That's not really the point here - the point is that the new ABI
>> vanishes as soon as you turn on the legacy Android ABI. ?You're right
>> that the particular fix I suggested has issues but the overall problem
>> exists and should be dealt with more sensibly.
>
> I'm also not in favor of having functionality conditionally compiled
> based on CONFIG_ANDROID. ?If fact, going through the patch stack
> there's much more that changes the ABI from the switch driver than
> just the name. ?Android asumes that there is a single "switch" for
> each logical entity (called cable types in extcon) each with a binary
> state (0,1). ?Here things have changed to have a single extcon
> instance that can have a bitmask of states which are sent as strings
> in the uevent.
In addition to all this added complexity, the fact that you now have
to white-list the possible "cable types" is also undesirable. If I
wanted to expose a new cable type, I now have to modify the extcon.h
file and the extcon.c file and I don't see what that white-list buys
me. The class device itself should not care for which cable types can
be registered, nor how they relate to each other. Let the client
drivers decide, just enforce uniqueness.
--Dima
>
> As it stands, this patch does not solve the cases where we use switch
> today and we'll probably continue to carry the switch driver in the
> common android tree. ?If, instead, we got rid of the idea of multiple
> states and mutual exclusivity and relied on the driver that uses
> extcon to have multiple instances for each logical entity and deal
> with mutual exclusion itself, we'd have a driver that would be pretty
> easy to support in android.
>
> -Erik
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v6 1/5] Extcon (external connector): import Android's switch class and modify.
2012-03-30 17:38 ` Dima Zavin
@ 2012-04-02 5:09 ` MyungJoo Ham
0 siblings, 0 replies; 18+ messages in thread
From: MyungJoo Ham @ 2012-04-02 5:09 UTC (permalink / raw)
To: linux-arm-kernel
On Sat, Mar 31, 2012 at 2:38 AM, Dima Zavin <dima@android.com> wrote:
> On Fri, Mar 30, 2012 at 10:29 AM, Erik Gilling <konkers@google.com> wrote:
>> On Fri, Mar 30, 2012 at 3:07 AM, Mark Brown
>> <broonie@opensource.wolfsonmicro.com> wrote:
>>> On Thu, Mar 29, 2012 at 03:27:01PM -0700, Erik Gilling wrote:
>>>> On Fri, Mar 9, 2012 at 4:41 AM, Mark Brown
>>>
>>>> > This seems somewhat sad - if ANDROID is turned on the standard ABI
>>>> > vanishes. ?It'd be much nicer to do this with a symlink (or with
>>>> > symlinks within the android directory if the driver core doesn't support
>>>> > that). ?That way userspace code can be written to the new ABI and will
>>>> > work on Android systems without ifdefery.
>>>
>>>> This won't work if userspace code is receiving uevents through netlink
>>>> and comparing based on the device name which it does in android. ?Why
>>>
>>> That's not really the point here - the point is that the new ABI
>>> vanishes as soon as you turn on the legacy Android ABI. ?You're right
>>> that the particular fix I suggested has issues but the overall problem
>>> exists and should be dealt with more sensibly.
>>
>> I'm also not in favor of having functionality conditionally compiled
>> based on CONFIG_ANDROID. ?If fact, going through the patch stack
>> there's much more that changes the ABI from the switch driver than
>> just the name. ?Android asumes that there is a single "switch" for
>> each logical entity (called cable types in extcon) each with a binary
>> state (0,1). ?Here things have changed to have a single extcon
>> instance that can have a bitmask of states which are sent as strings
>> in the uevent.
>
> In addition to all this added complexity, the fact that you now have
> to white-list the possible "cable types" is also undesirable. If I
> wanted to expose a new cable type, I now have to modify the extcon.h
> file and the extcon.c file and I don't see what that white-list buys
> me. The class device itself should not care for which cable types can
> be registered, nor how they relate to each other. Let the client
> drivers decide, just enforce uniqueness.
>
> --Dima
They are not a white-list that shows the possible cable types.
It is a suggestion so that different device drivers may use the same
cable names for common cable types.
Any device drivers can still use their own "new" names without any
modifications to extcon_class.c./extcon.h. Especially as long as they
are "new", "rare", or "uncommon" cable types, the device drivers
should be able to use their own created names.
Cheers!
MyungJoo.
>
>>
>> As it stands, this patch does not solve the cases where we use switch
>> today and we'll probably continue to carry the switch driver in the
>> common android tree. ?If, instead, we got rid of the idea of multiple
>> states and mutual exclusivity and relied on the driver that uses
>> extcon to have multiple instances for each logical entity and deal
>> with mutual exclusion itself, we'd have a driver that would be pretty
>> easy to support in android.
>>
>> -Erik
--
MyungJoo Ham, Ph.D.
System S/W Lab, S/W Center, Samsung Electronics
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v6 1/5] Extcon (external connector): import Android's switch class and modify.
2012-03-30 17:29 ` Erik Gilling
2012-03-30 17:38 ` Dima Zavin
@ 2012-03-31 10:19 ` Mark Brown
1 sibling, 0 replies; 18+ messages in thread
From: Mark Brown @ 2012-03-31 10:19 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Mar 30, 2012 at 10:29:27AM -0700, Erik Gilling wrote:
> I'm also not in favor of having functionality conditionally compiled
> based on CONFIG_ANDROID. If fact, going through the patch stack
> there's much more that changes the ABI from the switch driver than
> just the name. Android asumes that there is a single "switch" for
> each logical entity (called cable types in extcon) each with a binary
> state (0,1). Here things have changed to have a single extcon
> instance that can have a bitmask of states which are sent as strings
> in the uevent.
The binary status thing isn't true for the original Android switch API,
at least not in all cases - for headsets it's a tristate indicating if
there's nothing, a headphone or headset plugged in. This does wind up
being a bitmask because the numbers are 0, 1 and 2 but it isn't really
clear to me if this is intentional or just an effect of counting.
> As it stands, this patch does not solve the cases where we use switch
> today and we'll probably continue to carry the switch driver in the
> common android tree. If, instead, we got rid of the idea of multiple
> states and mutual exclusivity and relied on the driver that uses
> extcon to have multiple instances for each logical entity and deal
> with mutual exclusion itself, we'd have a driver that would be pretty
> easy to support in android.
What's the advantage in not having information about mutual exclusion in
the core, and why would a userspace that isn't interested in this care?
It seems like this could be used by userspace to do interesting things,
and I rather suspect you'll find some vendors have added features along
those lines in their Android devices. For example, having different
configurations for desk docks and car docks even if both end up
connecting the same things up.
Even if the userspace ABI doesn't expose the information it seems
sensible to factor out the code for handling this into the core so
there's less work to do in individual drivers.
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^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v6 2/5] Extcon: support generic GPIO extcon driver
2012-02-27 12:15 ` [PATCH v6 0/5] Introduce External Connector Class (extcon) MyungJoo Ham
2012-02-27 12:15 ` [PATCH v6 1/5] Extcon (external connector): import Android's switch class and modify MyungJoo Ham
@ 2012-02-27 12:15 ` MyungJoo Ham
2012-03-29 22:37 ` Stephen Boyd
2012-02-27 12:15 ` [PATCH v6 3/5] Extcon: support notification based on the state changes MyungJoo Ham
` (2 subsequent siblings)
4 siblings, 1 reply; 18+ messages in thread
From: MyungJoo Ham @ 2012-02-27 12:15 UTC (permalink / raw)
To: linux-arm-kernel
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 Hj?nnev?g <arve@android.com>
switch_gpio: Add missing #include <linux/interrupt.h>
Author: Mike Lockwood <lockwood@android.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
--
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().
---
drivers/extcon/Kconfig | 7 ++
drivers/extcon/Makefile | 1 +
drivers/extcon/extcon_gpio.c | 175 ++++++++++++++++++++++++++++++++++++
include/linux/extcon/extcon_gpio.h | 52 +++++++++++
4 files changed, 235 insertions(+), 0 deletions(-)
create mode 100644 drivers/extcon/extcon_gpio.c
create mode 100644 include/linux/extcon/extcon_gpio.h
diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
index 11db865..cc3f5eb 100644
--- a/drivers/extcon/Kconfig
+++ b/drivers/extcon/Kconfig
@@ -25,4 +25,11 @@ config EXTCON_ANDROID_COMPATIBLE
comment "Extcon Device Drivers"
+config EXTCON_GPIO
+ tristate "GPIO extcon support"
+ depends on GENERIC_GPIO
+ help
+ Say Y here to enable GPIO based extcon support. Note that GPIO
+ extcon supports single state per extcon instance.
+
endif # MULTISTATE_SWITCH
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
index 6bc6921..2c46d41 100644
--- a/drivers/extcon/Makefile
+++ b/drivers/extcon/Makefile
@@ -3,3 +3,4 @@
#
obj-$(CONFIG_EXTCON) += extcon_class.o
+obj-$(CONFIG_EXTCON_GPIO) += extcon_gpio.o
diff --git a/drivers/extcon/extcon_gpio.c b/drivers/extcon/extcon_gpio.c
new file mode 100644
index 0000000..f24ec67
--- /dev/null
+++ b/drivers/extcon/extcon_gpio.c
@@ -0,0 +1,175 @@
+/*
+ * drivers/extcon/extcon_gpio.c
+ *
+ * Single-state GPIO extcon driver based on extcon class
+ *
+ * Copyright (C) 2008 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ *
+ * Modified by MyungJoo Ham <myungjoo.ham@samsung.com> to support extcon
+ * (originally switch class is supported)
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/extcon.h>
+#include <linux/workqueue.h>
+#include <linux/gpio.h>
+#include <linux/extcon.h>
+#include <linux/extcon/extcon_gpio.h>
+
+struct gpio_extcon_data {
+ struct extcon_dev edev;
+ unsigned gpio;
+ const char *state_on;
+ const char *state_off;
+ int irq;
+ struct delayed_work work;
+ unsigned long debounce_jiffies;
+};
+
+static void gpio_extcon_work(struct work_struct *work)
+{
+ int state;
+ struct gpio_extcon_data *data =
+ container_of(to_delayed_work(work), struct gpio_extcon_data,
+ work);
+
+ state = gpio_get_value(data->gpio);
+ extcon_set_state(&data->edev, state);
+}
+
+static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
+{
+ struct gpio_extcon_data *extcon_data =
+ (struct gpio_extcon_data *)dev_id;
+
+ schedule_delayed_work(&extcon_data->work,
+ extcon_data->debounce_jiffies);
+ return IRQ_HANDLED;
+}
+
+static ssize_t extcon_gpio_print_state(struct extcon_dev *edev, char *buf)
+{
+ struct gpio_extcon_data *extcon_data =
+ container_of(edev, struct gpio_extcon_data, edev);
+ const char *state;
+ if (extcon_get_state(edev))
+ state = extcon_data->state_on;
+ else
+ state = extcon_data->state_off;
+
+ if (state)
+ return sprintf(buf, "%s\n", state);
+ return -EINVAL;
+}
+
+static int gpio_extcon_probe(struct platform_device *pdev)
+{
+ struct gpio_extcon_platform_data *pdata = pdev->dev.platform_data;
+ struct gpio_extcon_data *extcon_data;
+ int ret = 0;
+
+ if (!pdata)
+ return -EBUSY;
+ if (!pdata->irq_flags) {
+ dev_err(&pdev->dev, "IRQ flag is not specified.\n");
+ return -EINVAL;
+ }
+
+ extcon_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data),
+ GFP_KERNEL);
+ if (!extcon_data)
+ return -ENOMEM;
+
+ extcon_data->edev.name = pdata->name;
+ extcon_data->gpio = pdata->gpio;
+ extcon_data->state_on = pdata->state_on;
+ extcon_data->state_off = pdata->state_off;
+ if (pdata->state_on && pdata->state_off)
+ extcon_data->edev.print_state = extcon_gpio_print_state;
+ extcon_data->debounce_jiffies = msecs_to_jiffies(pdata->debounce);
+
+ ret = extcon_dev_register(&extcon_data->edev, &pdev->dev);
+ if (ret < 0)
+ goto err_extcon_dev_register;
+
+ ret = gpio_request(extcon_data->gpio, pdev->name);
+ if (ret < 0)
+ goto err_request_gpio;
+
+ ret = gpio_direction_input(extcon_data->gpio);
+ if (ret < 0)
+ goto err_set_gpio_input;
+
+ INIT_DELAYED_WORK(&extcon_data->work, gpio_extcon_work);
+
+ extcon_data->irq = gpio_to_irq(extcon_data->gpio);
+ if (extcon_data->irq < 0) {
+ ret = extcon_data->irq;
+ goto err_detect_irq_num_failed;
+ }
+
+ ret = request_any_context_irq(extcon_data->irq, gpio_irq_handler,
+ pdata->irq_flags, pdev->name,
+ extcon_data);
+ if (ret < 0)
+ goto err_request_irq;
+
+ /* Perform initial detection */
+ gpio_extcon_work(&extcon_data->work.work);
+
+ return 0;
+
+err_request_irq:
+err_detect_irq_num_failed:
+err_set_gpio_input:
+ gpio_free(extcon_data->gpio);
+err_request_gpio:
+ extcon_dev_unregister(&extcon_data->edev);
+err_extcon_dev_register:
+ devm_kfree(&pdev->dev, extcon_data);
+
+ return ret;
+}
+
+static int gpio_extcon_remove(struct platform_device *pdev)
+{
+ struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev);
+
+ cancel_delayed_work_sync(&extcon_data->work);
+ gpio_free(extcon_data->gpio);
+ extcon_dev_unregister(&extcon_data->edev);
+ devm_kfree(&pdev->dev, extcon_data);
+
+ return 0;
+}
+
+static struct platform_driver gpio_extcon = {
+ .probe = gpio_extcon_probe,
+ .remove = gpio_extcon_remove,
+ .driver = {
+ .name = "extcon-gpio",
+ .owner = THIS_MODULE,
+ },
+};
+
+module_platform_driver(gpio_extcon);
+
+MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
+MODULE_DESCRIPTION("GPIO extcon driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/extcon/extcon_gpio.h b/include/linux/extcon/extcon_gpio.h
new file mode 100644
index 0000000..a2129b7
--- /dev/null
+++ b/include/linux/extcon/extcon_gpio.h
@@ -0,0 +1,52 @@
+/*
+ * External connector (extcon) class generic GPIO driver
+ *
+ * Copyright (C) 2012 Samsung Electronics
+ * 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 __EXTCON_GPIO_H__
+#define __EXTCON_GPIO_H__ __FILE__
+
+#include <linux/extcon.h>
+
+/**
+ * struct gpio_extcon_platform_data - A simple GPIO-controlled extcon device.
+ * @name The name of this GPIO extcon device.
+ * @gpio Corresponding GPIO.
+ * @debounce Debounce time for GPIO IRQ in ms.
+ * @irq_flags IRQ Flags (e.g., IRQF_TRIGGER_LOW).
+ * @state_on print_state is overriden with state_on if attached. If Null,
+ * default method of extcon class is used.
+ * @state_off print_state is overriden with state_on if dettached. If Null,
+ * default method of extcon class is used.
+ *
+ * Note that in order for state_on or state_off to be valid, both state_on
+ * and state_off should be not NULL. If at least one of them is NULL,
+ * the print_state is not overriden.
+ */
+struct gpio_extcon_platform_data {
+ const char *name;
+ unsigned gpio;
+ unsigned long debounce;
+ unsigned long irq_flags;
+
+ /* if NULL, "0" or "1" will be printed */
+ const char *state_on;
+ const char *state_off;
+};
+
+#endif /* __EXTCON_GPIO_H__ */
--
1.7.4.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 2/5] Extcon: support generic GPIO extcon driver
2012-02-27 12:15 ` [PATCH v6 2/5] Extcon: support generic GPIO extcon driver MyungJoo Ham
@ 2012-03-29 22:37 ` Stephen Boyd
2012-03-30 8:33 ` MyungJoo Ham
0 siblings, 1 reply; 18+ messages in thread
From: Stephen Boyd @ 2012-03-29 22:37 UTC (permalink / raw)
To: linux-arm-kernel
On 02/27/12 04:15, MyungJoo Ham wrote
> +static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
> +{
> + struct gpio_extcon_data *extcon_data =
> + (struct gpio_extcon_data *)dev_id;
Casting from void is unnecessary.
> +
> +static int gpio_extcon_probe(struct platform_device *pdev)
__devinit?
> +{
> + struct gpio_extcon_platform_data *pdata = pdev->dev.platform_data;
> + struct gpio_extcon_data *extcon_data;
> + int ret = 0;
[snip]
> + return ret;
> +}
> +
> +static int gpio_extcon_remove(struct platform_device *pdev)
__devexit?
> +{
> + struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev);
[snip]
> +static struct platform_driver gpio_extcon = {
> + .probe = gpio_extcon_probe,
> + .remove = gpio_extcon_remove,
__devexit_p()?
> + .driver = {
> + .name = "extcon-gpio",
> + .owner = THIS_MODULE,
> + },
> +};
> +
> +module_platform_driver(gpio_extcon);
> +
> +MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
> +MODULE_DESCRIPTION("GPIO extcon driver");
> +MODULE_LICENSE("GPL");
--
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
^ permalink raw reply [flat|nested] 18+ messages in thread* [PATCH v6 2/5] Extcon: support generic GPIO extcon driver
2012-03-29 22:37 ` Stephen Boyd
@ 2012-03-30 8:33 ` MyungJoo Ham
0 siblings, 0 replies; 18+ messages in thread
From: MyungJoo Ham @ 2012-03-30 8:33 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Mar 30, 2012 at 7:37 AM, Stephen Boyd <sboyd@codeaurora.org> wrote:
> On 02/27/12 04:15, MyungJoo Ham wrote
>> +static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
>> +{
>> + ? ? struct gpio_extcon_data *extcon_data =
>> + ? ? ? ? (struct gpio_extcon_data *)dev_id;
>
> Casting from void is unnecessary.
>
>> +
>> +static int gpio_extcon_probe(struct platform_device *pdev)
>
> __devinit?
>
>> +{
>> + ? ? struct gpio_extcon_platform_data *pdata = pdev->dev.platform_data;
>> + ? ? struct gpio_extcon_data *extcon_data;
>> + ? ? int ret = 0;
> [snip]
>> + ? ? return ret;
>> +}
>> +
>> +static int gpio_extcon_remove(struct platform_device *pdev)
>
> __devexit?
>> +{
>> + ? ? struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev);
> [snip]
>> +static struct platform_driver gpio_extcon = {
>> + ? ? .probe ? ? ? ? ?= gpio_extcon_probe,
>> + ? ? .remove ? ? ? ? = gpio_extcon_remove,
>
> __devexit_p()?
>> + ? ? .driver ? ? ? ? = {
>> + ? ? ? ? ? ? .name ? = "extcon-gpio",
>> + ? ? ? ? ? ? .owner ?= THIS_MODULE,
>> + ? ? },
>> +};
>> +
>> +module_platform_driver(gpio_extcon);
>> +
>> +MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
>> +MODULE_DESCRIPTION("GPIO extcon driver");
>> +MODULE_LICENSE("GPL");
> --
> Sent by an employee of the Qualcomm Innovation Center, Inc.
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
>
Thank you for the comments.
I'll apply it and test on patchset v8.
Cheers!
MyungJoo.
--
MyungJoo Ham, Ph.D.
Mobile Software Platform Lab, DMC Business, Samsung Electronics
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v6 3/5] Extcon: support notification based on the state changes.
2012-02-27 12:15 ` [PATCH v6 0/5] Introduce External Connector Class (extcon) MyungJoo Ham
2012-02-27 12:15 ` [PATCH v6 1/5] Extcon (external connector): import Android's switch class and modify MyungJoo Ham
2012-02-27 12:15 ` [PATCH v6 2/5] Extcon: support generic GPIO extcon driver MyungJoo Ham
@ 2012-02-27 12:15 ` MyungJoo Ham
2012-02-27 12:15 ` [PATCH v6 4/5] Extcon: support multiple states at a device MyungJoo Ham
2012-02-27 12:15 ` [PATCH v6 5/5] Extcon: support mutually exclusive relation between cables MyungJoo Ham
4 siblings, 0 replies; 18+ messages in thread
From: MyungJoo Ham @ 2012-02-27 12:15 UTC (permalink / raw)
To: linux-arm-kernel
From: Donggeun Kim <dg77.kim@samsung.com>
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: Donggeun Kim <dg77.kim@samsung.com>
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 RFC
- Renamed switch to extcon
- Bugfix: extcon_dev_unregister()
- Bugfix: "edev->dev" is "internal" data.
- Added kerneldoc comments.
- Reworded comments.
---
drivers/extcon/extcon_class.c | 66 +++++++++++++++++++++++++++++++++++++++++
include/linux/extcon.h | 38 +++++++++++++++++++++++
2 files changed, 104 insertions(+), 0 deletions(-)
diff --git a/drivers/extcon/extcon_class.c b/drivers/extcon/extcon_class.c
index 9bc062b..51b14bd 100644
--- a/drivers/extcon/extcon_class.c
+++ b/drivers/extcon/extcon_class.c
@@ -33,6 +33,9 @@
struct class *extcon_class;
+static LIST_HEAD(extcon_dev_list);
+static DEFINE_MUTEX(extcon_dev_list_lock);
+
static ssize_t state_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
@@ -72,6 +75,9 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr,
* 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.
+ *
+ * Note that notifier provides the which bits are changes in the state
+ * variable with "val" to the callback.
*/
void extcon_set_state(struct extcon_dev *edev, u32 state)
{
@@ -81,10 +87,14 @@ void extcon_set_state(struct extcon_dev *edev, u32 state)
char *envp[3];
int env_offset = 0;
int length;
+ u32 old_state = edev->state;
if (edev->state != state) {
edev->state = state;
+ raw_notifier_call_chain(&edev->nh, old_state ^ edev->state,
+ edev);
+
prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
if (prop_buf) {
length = name_show(edev->dev, NULL, prop_buf);
@@ -114,6 +124,51 @@ void extcon_set_state(struct extcon_dev *edev, u32 state)
}
EXPORT_SYMBOL_GPL(extcon_set_state);
+/**
+ * extcon_get_extcon_dev() - Get the extcon device instance from the name
+ * @extcon_name: The extcon name provided with extcon_dev_register()
+ */
+struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
+{
+ struct extcon_dev *sd;
+
+ mutex_lock(&extcon_dev_list_lock);
+ list_for_each_entry(sd, &extcon_dev_list, entry) {
+ if (!strcmp(sd->name, extcon_name))
+ goto out;
+ }
+ sd = NULL;
+out:
+ mutex_unlock(&extcon_dev_list_lock);
+ return sd;
+}
+EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
+
+/**
+ * extcon_register_notifier() - Register a notifee to get notified by
+ * any attach status changes from the extcon.
+ * @edev: the extcon device.
+ * @nb: a notifier block to be registered.
+ */
+int extcon_register_notifier(struct extcon_dev *edev,
+ struct notifier_block *nb)
+{
+ return raw_notifier_chain_register(&edev->nh, nb);
+}
+EXPORT_SYMBOL_GPL(extcon_register_notifier);
+
+/**
+ * extcon_unregister_notifier() - Unregister a notifee from the extcon device.
+ * @edev: the extcon device.
+ * @nb: a registered notifier block to be unregistered.
+ */
+int extcon_unregister_notifier(struct extcon_dev *edev,
+ struct notifier_block *nb)
+{
+ return raw_notifier_chain_unregister(&edev->nh, nb);
+}
+EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
+
static struct device_attribute extcon_attrs[] = {
__ATTR_RO(state),
__ATTR_RO(name),
@@ -137,6 +192,10 @@ static int create_extcon_class(void)
static void extcon_cleanup(struct extcon_dev *edev, bool skip)
{
+ mutex_lock(&extcon_dev_list_lock);
+ list_del(&edev->entry);
+ mutex_unlock(&extcon_dev_list_lock);
+
if (!skip && get_device(edev->dev)) {
device_unregister(edev->dev);
put_device(edev->dev);
@@ -184,8 +243,15 @@ int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
goto err_dev;
}
+ RAW_INIT_NOTIFIER_HEAD(&edev->nh);
+
dev_set_drvdata(edev->dev, edev);
edev->state = 0;
+
+ mutex_lock(&extcon_dev_list_lock);
+ list_add(&edev->entry, &extcon_dev_list);
+ mutex_unlock(&extcon_dev_list_lock);
+
return 0;
err_dev:
diff --git a/include/linux/extcon.h b/include/linux/extcon.h
index cd732ab..50be845 100644
--- a/include/linux/extcon.h
+++ b/include/linux/extcon.h
@@ -23,6 +23,7 @@
#ifndef __LINUX_EXTCON_H__
#define __LINUX_EXTCON_H__
+#include <linux/notifier.h>
/**
* struct extcon_dev - An extcon device represents one external connector.
* @name The name of this extcon device. Parent device name is used
@@ -34,6 +35,9 @@
* @dev Device of this extcon. Do not provide at register-time.
* @state Attach/detach state of this extcon. Do not provide at
* register-time
+ * @nh Notifier for the state change events from this extcon
+ * @entry To support list of extcon devices so that uses can search
+ * for extcon devices based on the extcon name.
*
* In most cases, users only need to provide "User initializing data" of
* this struct when registering an extcon. In some exceptional cases,
@@ -51,11 +55,19 @@ struct extcon_dev {
/* --- Internal data. Please do not set. --- */
struct device *dev;
u32 state;
+ struct raw_notifier_head nh;
+ struct list_head entry;
};
#ifdef CONFIG_EXTCON
+
+/*
+ * Following APIs are for notifiers or configurations.
+ * Notifiers are the external port and connection devices.
+ */
extern int extcon_dev_register(struct extcon_dev *edev, struct device *dev);
extern void extcon_dev_unregister(struct extcon_dev *edev);
+extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name);
static inline u32 extcon_get_state(struct extcon_dev *edev)
{
@@ -63,6 +75,15 @@ static inline u32 extcon_get_state(struct extcon_dev *edev)
}
extern void extcon_set_state(struct extcon_dev *edev, u32 state);
+
+/*
+ * Following APIs are to monitor every action of a notifier.
+ * Registerer gets notified for every external port of a connection device.
+ */
+extern int extcon_register_notifier(struct extcon_dev *edev,
+ struct notifier_block *nb);
+extern int extcon_unregister_notifier(struct extcon_dev *edev,
+ struct notifier_block *nb);
#else /* CONFIG_EXTCON */
static inline int extcon_dev_register(struct extcon_dev *edev,
struct device *dev)
@@ -78,5 +99,22 @@ static inline u32 extcon_get_state(struct extcon_dev *edev)
}
static inline void extcon_set_state(struct extcon_dev *edev, u32 state) { }
+static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
+{
+ return NULL;
+}
+
+static inline int extcon_register_notifier(struct extcon_dev *edev,
+ struct notifier_block *nb)
+{
+ return 0;
+}
+
+static inline int extcon_unregister_notifier(struct extcon_dev *edev,
+ struct notifier_block *nb)
+{
+ return 0;
+}
+
#endif /* CONFIG_EXTCON */
#endif /* __LINUX_EXTCON_H__ */
--
1.7.4.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 4/5] Extcon: support multiple states at a device.
2012-02-27 12:15 ` [PATCH v6 0/5] Introduce External Connector Class (extcon) MyungJoo Ham
` (2 preceding siblings ...)
2012-02-27 12:15 ` [PATCH v6 3/5] Extcon: support notification based on the state changes MyungJoo Ham
@ 2012-02-27 12:15 ` MyungJoo Ham
2012-02-27 12:15 ` [PATCH v6 5/5] Extcon: support mutually exclusive relation between cables MyungJoo Ham
4 siblings, 0 replies; 18+ messages in thread
From: MyungJoo Ham @ 2012-02-27 12:15 UTC (permalink / raw)
To: linux-arm-kernel
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: Donggeun Kim <dg77.kim@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
--
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.
---
Documentation/ABI/testing/sysfs-class-extcon | 63 ++++-
drivers/extcon/extcon_class.c | 439 +++++++++++++++++++++++++-
include/linux/extcon.h | 184 +++++++++++
3 files changed, 666 insertions(+), 20 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-class-extcon b/Documentation/ABI/testing/sysfs-class-extcon
index 59a4b1c..19b18e9 100644
--- a/Documentation/ABI/testing/sysfs-class-extcon
+++ b/Documentation/ABI/testing/sysfs-class-extcon
@@ -1,5 +1,5 @@
What: /sys/class/extcon/.../
-Date: December 2011
+Date: February 2012
Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
Description:
Provide a place in sysfs for the extcon objects.
@@ -7,8 +7,16 @@ Description:
The name of extcon object denoted as ... is the name given
with extcon_dev_register.
+ One extcon device denotes a single external connector
+ port. An external connector may have multiple cables
+ attached simultaneously. Many of docks, cradles, and
+ accessory cables have such capability. For example,
+ the 30-pin port of Nuri board (/arch/arm/mach-exynos)
+ may have both HDMI and Charger attached, or analog audio,
+ video, and USB cables attached simulteneously.
+
What: /sys/class/extcon/.../name
-Date: December 2011
+Date: February 2012
Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
Description:
The /sys/class/extcon/.../name shows the name of the extcon
@@ -17,10 +25,51 @@ Description:
this sysfs node.
What: /sys/class/extcon/.../state
-Date: December 2011
+Date: February 2012
+Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
+Description:
+ The /sys/class/extcon/.../state shows and stores the cable
+ attach/detach information of the corresponding extcon object.
+ If the extcon object has an optional callback "show_state"
+ defined, the showing function is overriden with the optional
+ callback.
+
+ If the default callback for showing function is used, the
+ format is like this:
+ # cat state
+ USB_OTG=1
+ HDMI=0
+ TA=1
+ EAR_JACK=0
+ #
+ In this example, the extcon device have USB_OTG and TA
+ cables attached and HDMI and EAR_JACK cables detached.
+
+ In order to update the state of an extcon device, enter a hex
+ state number starting with 0x.
+ echo 0xHEX > state
+
+ This updates the whole state of the extcon dev.
+ Inputs of all the methods are required to meet the
+ mutually_exclusive contidions if they exist.
+
+ It is recommended to use this "global" state interface if
+ you need to enter the value atomically. The later state
+ interface associated with each cable cannot update
+ multiple cable states of an extcon device simultaneously.
+
+What: /sys/class/extcon/.../cable.x/name
+Date: February 2012
+Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
+Description:
+ The /sys/class/extcon/.../cable.x/name shows the name of cable
+ "x" (integer between 0 and 31) of an extcon device.
+
+What: /sys/class/extcon/.../cable.x/state
+Date: February 2012
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.
+ The /sys/class/extcon/.../cable.x/name shows and stores the
+ state of cable "x" (integer between 0 and 31) of an extcon
+ device. The state value is either 0 (detached) or 1
+ (attached).
diff --git a/drivers/extcon/extcon_class.c b/drivers/extcon/extcon_class.c
index 51b14bd..55f19c2 100644
--- a/drivers/extcon/extcon_class.c
+++ b/drivers/extcon/extcon_class.c
@@ -31,6 +31,39 @@
#include <linux/extcon.h>
#include <linux/slab.h>
+/*
+ * extcon_cable_name suggests the standard cable names for commonly used
+ * cable types.
+ *
+ * However, please do not use extcon_cable_name directly for extcon_dev
+ * struct's supported_cable pointer unless your device really supports
+ * every single port-type of the following cable names. Please choose cable
+ * names that are actually used in your extcon device.
+ */
+const char *extcon_cable_name[] = {
+ [EXTCON_USB] = "USB",
+ [EXTCON_USB_HOST] = "USB-Host",
+ [EXTCON_TA] = "TA",
+ [EXTCON_FAST_CHARGER] = "Fast-charger",
+ [EXTCON_SLOW_CHARGER] = "Slow-charger",
+ [EXTCON_CHARGE_DOWNSTREAM] = "Charge-downstream",
+ [EXTCON_HDMI] = "HDMI",
+ [EXTCON_MHL] = "MHL",
+ [EXTCON_DVI] = "DVI",
+ [EXTCON_VGA] = "VGA",
+ [EXTCON_DOCK] = "Dock",
+ [EXTCON_LINE_IN] = "Line-in",
+ [EXTCON_LINE_OUT] = "Line-out",
+ [EXTCON_MIC_IN] = "Microphone",
+ [EXTCON_HEADPHONE_OUT] = "Headphone",
+ [EXTCON_SPDIF_IN] = "SPDIF-in",
+ [EXTCON_SPDIF_OUT] = "SPDIF-out",
+ [EXTCON_VIDEO_IN] = "Video-in",
+ [EXTCON_VIDEO_OUT] = "Video-out",
+
+ NULL,
+};
+
struct class *extcon_class;
static LIST_HEAD(extcon_dev_list);
@@ -39,6 +72,7 @@ static DEFINE_MUTEX(extcon_dev_list_lock);
static ssize_t state_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
+ int i, count = 0;
struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
if (edev->print_state) {
@@ -48,7 +82,39 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr,
return ret;
/* Use default if failed */
}
- return sprintf(buf, "%u\n", edev->state);
+
+ if (edev->max_supported == 0)
+ return sprintf(buf, "%u\n", edev->state);
+
+ for (i = 0; i < SUPPORTED_CABLE_MAX; i++) {
+ if (!edev->supported_cable[i])
+ break;
+ count += sprintf(buf + count, "%s=%d\n",
+ edev->supported_cable[i],
+ !!(edev->state & (1 << i)));
+ }
+
+ return count;
+}
+
+void extcon_set_state(struct extcon_dev *edev, u32 state);
+static ssize_t state_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ u32 state;
+ ssize_t ret = 0;
+ struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
+
+ ret = sscanf(buf, "0x%x", &state);
+ if (ret == 0)
+ ret = -EINVAL;
+ else
+ extcon_set_state(edev, state);
+
+ if (ret < 0)
+ return ret;
+
+ return count;
}
static ssize_t name_show(struct device *dev, struct device_attribute *attr,
@@ -66,9 +132,52 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr,
return sprintf(buf, "%s\n", dev_name(edev->dev));
}
+static ssize_t cable_name_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct extcon_cable *cable = container_of(attr, struct extcon_cable,
+ attr_name);
+
+ return sprintf(buf, "%s\n",
+ cable->edev->supported_cable[cable->cable_index]);
+}
+
+static ssize_t cable_state_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct extcon_cable *cable = container_of(attr, struct extcon_cable,
+ attr_state);
+
+ return sprintf(buf, "%d\n",
+ extcon_get_cable_state_(cable->edev,
+ cable->cable_index));
+}
+
+static ssize_t cable_state_store(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ struct extcon_cable *cable = container_of(attr, struct extcon_cable,
+ attr_state);
+ int ret, state;
+
+ ret = sscanf(buf, "%d", &state);
+ if (ret == 0)
+ ret = -EINVAL;
+ else
+ ret = extcon_set_cable_state_(cable->edev, cable->cable_index,
+ state);
+
+ if (ret < 0)
+ return ret;
+ return count;
+}
+
/**
- * extcon_set_state() - Set the cable attach states of the extcon device.
+ * extcon_update_state() - Update the cable attach states of the extcon device
+ * only for the masked bits.
* @edev: the extcon device
+ * @mask: the bit mask to designate updated bits.
* @state: new cable attach status for @edev
*
* Changing the state sends uevent with environment variable containing
@@ -76,10 +185,10 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr,
* Tizen uses this format for extcon device to get events from ports.
* Android uses this format as well.
*
- * Note that notifier provides the which bits are changes in the state
- * variable with "val" to the callback.
+ * Note that the notifier provides which bits are changed in the state
+ * variable with the val parameter (second) to the callback.
*/
-void extcon_set_state(struct extcon_dev *edev, u32 state)
+void extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
{
char name_buf[120];
char state_buf[120];
@@ -87,15 +196,20 @@ void extcon_set_state(struct extcon_dev *edev, u32 state)
char *envp[3];
int env_offset = 0;
int length;
- u32 old_state = edev->state;
+ unsigned long flags;
- if (edev->state != state) {
- edev->state = state;
+ spin_lock_irqsave(&edev->lock, flags);
- raw_notifier_call_chain(&edev->nh, old_state ^ edev->state,
- edev);
+ if (edev->state != ((edev->state & ~mask) | (state & mask))) {
+ u32 old_state = edev->state;
- prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
+ edev->state &= ~mask;
+ edev->state |= state & mask;
+
+ raw_notifier_call_chain(&edev->nh, old_state, edev);
+
+ /* This could be in interrupt handler */
+ prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
if (prop_buf) {
length = name_show(edev->dev, NULL, prop_buf);
if (length > 0) {
@@ -114,17 +228,132 @@ void extcon_set_state(struct extcon_dev *edev, u32 state)
envp[env_offset++] = state_buf;
}
envp[env_offset] = NULL;
+ /* Unlock early before uevent */
+ spin_unlock_irqrestore(&edev->lock, flags);
+
kobject_uevent_env(&edev->dev->kobj, KOBJ_CHANGE, envp);
free_page((unsigned long)prop_buf);
} else {
+ /* Unlock early before uevent */
+ spin_unlock_irqrestore(&edev->lock, flags);
+
dev_err(edev->dev, "out of memory in extcon_set_state\n");
kobject_uevent(&edev->dev->kobj, KOBJ_CHANGE);
}
+ } else {
+ /* No changes */
+ spin_unlock_irqrestore(&edev->lock, flags);
}
}
+EXPORT_SYMBOL_GPL(extcon_update_state);
+
+/**
+ * extcon_set_state() - Set the cable attach states of the extcon device.
+ * @edev: the extcon device
+ * @state: new cable attach status for @edev
+ *
+ * Note that notifier provides which bits are changed in the state
+ * variable with the val parameter (second) to the callback.
+ */
+void extcon_set_state(struct extcon_dev *edev, u32 state)
+{
+ extcon_update_state(edev, 0xffffffff, state);
+}
EXPORT_SYMBOL_GPL(extcon_set_state);
/**
+ * extcon_find_cable_index() - Get the cable index based on the cable name.
+ * @edev: the extcon device that has the cable.
+ * @cable_name: cable name to be searched.
+ *
+ * Note that accessing a cable state based on cable_index is faster than
+ * cable_name because using cable_name induces a loop with strncmp().
+ * Thus, when get/set_cable_state is repeatedly used, using cable_index
+ * is recommended.
+ */
+int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name)
+{
+ int i;
+
+ if (edev->supported_cable) {
+ for (i = 0; edev->supported_cable[i]; i++) {
+ if (!strncmp(edev->supported_cable[i],
+ cable_name, CABLE_NAME_MAX))
+ return i;
+ }
+ }
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(extcon_find_cable_index);
+
+/**
+ * extcon_get_cable_state_() - Get the status of a specific cable.
+ * @edev: the extcon device that has the cable.
+ * @index: cable index that can be retrieved by extcon_find_cable_index().
+ */
+int extcon_get_cable_state_(struct extcon_dev *edev, int index)
+{
+ if (index < 0 || (edev->max_supported && edev->max_supported <= index))
+ return -EINVAL;
+
+ return !!(edev->state & (1 << index));
+}
+EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
+
+/**
+ * extcon_get_cable_state() - Get the status of a specific cable.
+ * @edev: the extcon device that has the cable.
+ * @cable_name: cable name.
+ *
+ * Note that this is slower than extcon_get_cable_state_.
+ */
+int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
+{
+ return extcon_get_cable_state_(edev, extcon_find_cable_index
+ (edev, cable_name));
+}
+EXPORT_SYMBOL_GPL(extcon_get_cable_state);
+
+/**
+ * extcon_get_cable_state_() - Set the status of a specific cable.
+ * @edev: the extcon device that has the cable.
+ * @index: cable index that can be retrieved by extcon_find_cable_index().
+ * @cable_state: the new cable status. The default semantics is
+ * true: attached / false: detached.
+ */
+int extcon_set_cable_state_(struct extcon_dev *edev,
+ int index, bool cable_state)
+{
+ u32 state;
+
+ if (index < 0 || (edev->max_supported && edev->max_supported <= index))
+ return -EINVAL;
+
+ state = cable_state ? (1 << index) : 0;
+ extcon_update_state(edev, 1 << index, state);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
+
+/**
+ * extcon_get_cable_state() - Set the status of a specific cable.
+ * @edev: the extcon device that has the cable.
+ * @cable_name: cable name.
+ * @cable_state: the new cable status. The default semantics is
+ * true: attached / false: detached.
+ *
+ * Note that this is slower than extcon_set_cable_state_.
+ */
+int extcon_set_cable_state(struct extcon_dev *edev,
+ const char *cable_name, bool cable_state)
+{
+ return extcon_set_cable_state_(edev, extcon_find_cable_index
+ (edev, cable_name), cable_state);
+}
+EXPORT_SYMBOL_GPL(extcon_set_cable_state);
+
+/**
* extcon_get_extcon_dev() - Get the extcon device instance from the name
* @extcon_name: The extcon name provided with extcon_dev_register()
*/
@@ -144,11 +373,88 @@ out:
}
EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
+static int _call_per_cable(struct notifier_block *nb, unsigned long val,
+ void *ptr)
+{
+ struct extcon_specific_cable_nb *obj = container_of(nb,
+ struct extcon_specific_cable_nb, internal_nb);
+ struct extcon_dev *edev = ptr;
+
+ if ((val & (1 << obj->cable_index)) !=
+ (edev->state & (1 << obj->cable_index))) {
+ obj->previous_value = val;
+ return obj->user_nb->notifier_call(nb, val, ptr);
+ }
+
+ return NOTIFY_OK;
+}
+
+/**
+ * extcon_register_interest() - Register a notifier for a state change of a
+ * specific cable, not a entier set of cables of a
+ * extcon device.
+ * @obj: an empty extcon_specific_cable_nb object to be returned.
+ * @extcon_name: the name of extcon device.
+ * @cable_name: the target cable name.
+ * @nb: the notifier block to get notified.
+ *
+ * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
+ * the struct for you.
+ *
+ * extcon_register_interest is a helper function for those who want to get
+ * notification for a single specific cable's status change. If a user wants
+ * to get notification for any changes of all cables of a extcon device,
+ * he/she should use the general extcon_register_notifier().
+ *
+ * Note that the second parameter given to the callback of nb (val) is
+ * "old_state", not the current state. The current state can be retrieved
+ * by looking at the third pameter (edev pointer)'s state value.
+ */
+int extcon_register_interest(struct extcon_specific_cable_nb *obj,
+ const char *extcon_name, const char *cable_name,
+ struct notifier_block *nb)
+{
+ if (!obj || !extcon_name || !cable_name || !nb)
+ return -EINVAL;
+
+ obj->edev = extcon_get_extcon_dev(extcon_name);
+ if (!obj->edev)
+ return -ENODEV;
+
+ obj->cable_index = extcon_find_cable_index(obj->edev, cable_name);
+ if (obj->cable_index < 0)
+ return -ENODEV;
+
+ obj->user_nb = nb;
+
+ obj->internal_nb.notifier_call = _call_per_cable;
+
+ return raw_notifier_chain_register(&obj->edev->nh, &obj->internal_nb);
+}
+
+/**
+ * extcon_unregister_interest() - Unregister the notifier registered by
+ * extcon_register_interest().
+ * @obj: the extcon_specific_cable_nb object returned by
+ * extcon_register_interest().
+ */
+int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
+{
+ if (!obj)
+ return -EINVAL;
+
+ return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
+}
+
/**
* extcon_register_notifier() - Register a notifee to get notified by
* any attach status changes from the extcon.
* @edev: the extcon device.
* @nb: a notifier block to be registered.
+ *
+ * Note that the second parameter given to the callback of nb (val) is
+ * "old_state", not the current state. The current state can be retrieved
+ * by looking at the third pameter (edev pointer)'s state value.
*/
int extcon_register_notifier(struct extcon_dev *edev,
struct notifier_block *nb)
@@ -170,8 +476,9 @@ int extcon_unregister_notifier(struct extcon_dev *edev,
EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
static struct device_attribute extcon_attrs[] = {
- __ATTR_RO(state),
+ __ATTR(state, S_IRUGO | S_IWUSR, state_show, state_store),
__ATTR_RO(name),
+ __ATTR_NULL,
};
static int create_extcon_class(void)
@@ -197,6 +504,16 @@ static void extcon_cleanup(struct extcon_dev *edev, bool skip)
mutex_unlock(&extcon_dev_list_lock);
if (!skip && get_device(edev->dev)) {
+ int index;
+
+ for (index = 0; index < edev->max_supported; index++)
+ kfree(edev->cables[index].attr_g.name);
+
+ if (edev->max_supported) {
+ kfree(edev->extcon_dev_type.groups);
+ kfree(edev->cables);
+ }
+
device_unregister(edev->dev);
put_device(edev->dev);
}
@@ -211,6 +528,10 @@ static void extcon_dev_release(struct device *dev)
extcon_cleanup(edev, true);
}
+static void dummy_sysfs_dev_release(struct device *dev)
+{
+}
+
/**
* extcon_dev_register() - Register a new extcon device
* @edev : the new extcon device (should be allocated before calling)
@@ -223,7 +544,7 @@ static void extcon_dev_release(struct device *dev)
*/
int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
{
- int ret;
+ int ret, index = 0;
if (!extcon_class) {
ret = create_extcon_class();
@@ -231,18 +552,101 @@ int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
return ret;
}
+ if (edev->supported_cable) {
+ /* Get size of array */
+ for (index = 0; edev->supported_cable[index]; index++)
+ ;
+ edev->max_supported = index;
+ } else {
+ edev->max_supported = 0;
+ }
+
+ if (index > SUPPORTED_CABLE_MAX) {
+ dev_err(edev->dev, "extcon: maximum number of supported cables exceeded.\n");
+ return -EINVAL;
+ }
+
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));
+
+ if (edev->max_supported) {
+ char buf[10];
+ char *str;
+ struct extcon_cable *cable;
+
+ edev->cables = kzalloc(sizeof(struct extcon_cable) *
+ edev->max_supported, GFP_KERNEL);
+ if (!edev->cables) {
+ ret = -ENOMEM;
+ goto err_sysfs_alloc;
+ }
+ for (index = 0; index < edev->max_supported; index++) {
+ cable = &edev->cables[index];
+
+ snprintf(buf, 10, "cable.%d", index);
+ str = kzalloc(sizeof(char) * (strlen(buf) + 1),
+ GFP_KERNEL);
+ if (!str) {
+ for (index--; index >= 0; index--) {
+ cable = &edev->cables[index];
+ kfree(cable->attr_g.name);
+ }
+ ret = -ENOMEM;
+
+ goto err_alloc_cables;
+ }
+ strcpy(str, buf);
+
+ cable->edev = edev;
+ cable->cable_index = index;
+ cable->attrs[0] = &cable->attr_name.attr;
+ cable->attrs[1] = &cable->attr_state.attr;
+ cable->attrs[2] = NULL;
+ cable->attr_g.name = str;
+ cable->attr_g.attrs = cable->attrs;
+
+ cable->attr_name.attr.name = "name";
+ cable->attr_name.attr.mode = 0444;
+ cable->attr_name.show = cable_name_show;
+
+ cable->attr_state.attr.name = "state";
+ cable->attr_state.attr.mode = 0644;
+ cable->attr_state.show = cable_state_show;
+ cable->attr_state.store = cable_state_store;
+ }
+ }
+
+ if (edev->max_supported) {
+ edev->extcon_dev_type.groups =
+ kzalloc(sizeof(struct attribute_group *) *
+ (edev->max_supported + 1), GFP_KERNEL);
+ if (!edev->extcon_dev_type.groups) {
+ ret = -ENOMEM;
+ goto err_alloc_groups;
+ }
+
+ edev->extcon_dev_type.name = dev_name(edev->dev);
+ edev->extcon_dev_type.release = dummy_sysfs_dev_release;
+
+ for (index = 0; index < edev->max_supported; index++)
+ edev->extcon_dev_type.groups[index] =
+ &edev->cables[index].attr_g;
+
+ edev->dev->type = &edev->extcon_dev_type;
+ }
+
ret = device_register(edev->dev);
if (ret) {
put_device(edev->dev);
goto err_dev;
}
+ spin_lock_init(&edev->lock);
+
RAW_INIT_NOTIFIER_HEAD(&edev->nh);
dev_set_drvdata(edev->dev, edev);
@@ -255,6 +659,15 @@ int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
return 0;
err_dev:
+ if (edev->max_supported)
+ kfree(edev->extcon_dev_type.groups);
+err_alloc_groups:
+ for (index = 0; index < edev->max_supported; index++)
+ kfree(edev->cables[index].attr_g.name);
+err_alloc_cables:
+ if (edev->max_supported)
+ kfree(edev->cables);
+err_sysfs_alloc:
kfree(edev->dev);
return ret;
}
diff --git a/include/linux/extcon.h b/include/linux/extcon.h
index 50be845..99ff60e 100644
--- a/include/linux/extcon.h
+++ b/include/linux/extcon.h
@@ -24,10 +24,60 @@
#define __LINUX_EXTCON_H__
#include <linux/notifier.h>
+
+#define SUPPORTED_CABLE_MAX 32
+#define CABLE_NAME_MAX 30
+
+/*
+ * The standard cable name is to help support general notifier
+ * and notifee device drivers to share the common names.
+ * Please use standard cable names unless your notifier device has
+ * a very unique and abnormal cable or
+ * the cable type is supposed to be used with only one unique
+ * pair of notifier/notifee devices.
+ *
+ * Please add any other "standard" cables used with extcon dev.
+ *
+ * You may add a dot and number to specify version or specification
+ * of the specific cable if it is required. (e.g., "Fast-charger.18"
+ * and "Fast-charger.10" for 1.8A and 1.0A chargers)
+ * However, the notifee and notifier should be able to handle such
+ * string and if the notifee can negotiate the protocol or idenify,
+ * you don't need such convention. This convention is helpful when
+ * notifier can distinguish but notifiee cannot.
+ */
+enum extcon_cable_name {
+ EXTCON_USB = 0,
+ EXTCON_USB_HOST,
+ EXTCON_TA, /* Travel Adaptor */
+ EXTCON_FAST_CHARGER,
+ EXTCON_SLOW_CHARGER,
+ EXTCON_CHARGE_DOWNSTREAM, /* Charging an external device */
+ EXTCON_HDMI,
+ EXTCON_MHL,
+ EXTCON_DVI,
+ EXTCON_VGA,
+ EXTCON_DOCK,
+ EXTCON_LINE_IN,
+ EXTCON_LINE_OUT,
+ EXTCON_MIC_IN,
+ EXTCON_HEADPHONE_OUT,
+ EXTCON_SPDIF_IN,
+ EXTCON_SPDIF_OUT,
+ EXTCON_VIDEO_IN,
+ EXTCON_VIDEO_OUT,
+};
+extern const char *extcon_cable_name[];
+
+struct extcon_cable;
+
/**
* struct extcon_dev - An extcon device represents one external connector.
* @name The name of this extcon device. Parent device name is used
* if NULL.
+ * @supported_cable Array of supported cable name ending with NULL.
+ * If supported_cable is NULL, cable name related APIs
+ * are disabled.
* @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
@@ -38,6 +88,11 @@
* @nh Notifier for the state change events from this extcon
* @entry To support list of extcon devices so that uses can search
* for extcon devices based on the extcon name.
+ * @lock
+ * @max_supported Internal value to store the number of cables.
+ * @extcon_dev_type Device_type struct to provide attribute_groups
+ * customized for each extcon device.
+ * @cables Sysfs subdirectories. Each represents one cable.
*
* In most cases, users only need to provide "User initializing data" of
* this struct when registering an extcon. In some exceptional cases,
@@ -47,6 +102,7 @@
struct extcon_dev {
/* --- Optional user initializing data --- */
const char *name;
+ const char **supported_cable;
/* --- Optional callbacks to override class functions --- */
ssize_t (*print_name)(struct extcon_dev *edev, char *buf);
@@ -57,6 +113,49 @@ struct extcon_dev {
u32 state;
struct raw_notifier_head nh;
struct list_head entry;
+ spinlock_t lock; /* could be called by irq handler */
+ int max_supported;
+
+ /* /sys/class/extcon/.../cable.n/... */
+ struct device_type extcon_dev_type;
+ struct extcon_cable *cables;
+};
+
+/**
+ * struct extcon_cable - An internal data for each cable of extcon device.
+ * @edev The extcon device
+ * @cable_index Index of this cable in the edev
+ * @attr_g Attribute group for the cable
+ * @attr_name "name" sysfs entry
+ * @attr_state "state" sysfs entry
+ * @attrs Array pointing to attr_name and attr_state for attr_g
+ */
+struct extcon_cable {
+ struct extcon_dev *edev;
+ int cable_index;
+
+ struct attribute_group attr_g;
+ struct device_attribute attr_name;
+ struct device_attribute attr_state;
+
+ struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
+};
+
+/**
+ * struct extcon_specific_cable_nb - An internal data for
+ * extcon_register_interest().
+ * @internal_nb a notifier block bridging extcon notifier and cable notifier.
+ * @user_nb user provided notifier block for events from a specific cable.
+ * @cable_index the target cable.
+ * @edev the target extcon device.
+ * @previous_value the saved previous event value.
+ */
+struct extcon_specific_cable_nb {
+ struct notifier_block internal_nb;
+ struct notifier_block *user_nb;
+ int cable_index;
+ struct extcon_dev *edev;
+ unsigned long previous_value;
};
#ifdef CONFIG_EXTCON
@@ -69,16 +168,54 @@ extern int extcon_dev_register(struct extcon_dev *edev, struct device *dev);
extern void extcon_dev_unregister(struct extcon_dev *edev);
extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name);
+/*
+ * get/set/update_state access the 32b encoded state value, which represents
+ * states of all possible cables of the multistate port. For example, if one
+ * calls extcon_set_state(edev, 0x7), it may mean that all the three cables
+ * are attached to the port.
+ */
static inline u32 extcon_get_state(struct extcon_dev *edev)
{
return edev->state;
}
extern void extcon_set_state(struct extcon_dev *edev, u32 state);
+extern void extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state);
+
+/*
+ * get/set_cable_state access each bit of the 32b encoded state value.
+ * They are used to access the status of each cable based on the cable_name
+ * or cable_index, which is retrived by extcon_find_cable_index
+ */
+extern int extcon_find_cable_index(struct extcon_dev *sdev,
+ const char *cable_name);
+extern int extcon_get_cable_state_(struct extcon_dev *edev, int cable_index);
+extern int extcon_set_cable_state_(struct extcon_dev *edev, int cable_index,
+ bool cable_state);
+
+extern int extcon_get_cable_state(struct extcon_dev *edev,
+ const char *cable_name);
+extern int extcon_set_cable_state(struct extcon_dev *edev,
+ const char *cable_name, bool cable_state);
+
+/*
+ * Following APIs are for notifiees (those who want to be notified)
+ * to register a callback for events from a specific cable of the extcon.
+ * Notifiees are the connected device drivers wanting to get notified by
+ * a specific external port of a connection device.
+ */
+extern int extcon_register_interest(struct extcon_specific_cable_nb *obj,
+ const char *extcon_name,
+ const char *cable_name,
+ struct notifier_block *nb);
+extern int extcon_unregister_interest(struct extcon_specific_cable_nb *nb);
/*
* Following APIs are to monitor every action of a notifier.
* Registerer gets notified for every external port of a connection device.
+ * Probably this could be used to debug an action of notifier; however,
+ * we do not recommend to use this at normal 'notifiee' device drivers who
+ * want to be notified by a specific external port of the notifier.
*/
extern int extcon_register_notifier(struct extcon_dev *edev,
struct notifier_block *nb);
@@ -99,6 +236,41 @@ static inline u32 extcon_get_state(struct extcon_dev *edev)
}
static inline void extcon_set_state(struct extcon_dev *edev, u32 state) { }
+
+static inline void extcon_update_state(struct extcon_dev *edev, u32 mask,
+ u32 state)
+{ }
+
+static inline int extcon_find_cable_index(struct extcon_dev *edev,
+ const char *cable_name)
+{
+ return 0;
+}
+
+static inline int extcon_get_cable_state_(struct extcon_dev *edev,
+ int cable_index)
+{
+ return 0;
+}
+
+static inline int extcon_set_cable_state_(struct extcon_dev *edev,
+ int cable_index, bool cable_state)
+{
+ return 0;
+}
+
+static inline int extcon_get_cable_state(struct extcon_dev *edev,
+ const char *cable_name)
+{
+ return 0;
+}
+
+static inline int extcon_set_cable_state(struct extcon_dev *edev,
+ const char *cable_name, int state)
+{
+ return 0;
+}
+
static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
{
return NULL;
@@ -116,5 +288,17 @@ static inline int extcon_unregister_notifier(struct extcon_dev *edev,
return 0;
}
+static inline int extcon_register_interest(struct extcon_specific_cable_nb *obj,
+ const char *extcon_name,
+ const char *cable_name,
+ struct notifier_block *nb)
+{
+ return 0;
+}
+
+static inline int extcon_unregister_interest(struct extcon_specific_cable_nb *)
+{
+ return 0;
+}
#endif /* CONFIG_EXTCON */
#endif /* __LINUX_EXTCON_H__ */
--
1.7.4.1
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 5/5] Extcon: support mutually exclusive relation between cables.
2012-02-27 12:15 ` [PATCH v6 0/5] Introduce External Connector Class (extcon) MyungJoo Ham
` (3 preceding siblings ...)
2012-02-27 12:15 ` [PATCH v6 4/5] Extcon: support multiple states at a device MyungJoo Ham
@ 2012-02-27 12:15 ` MyungJoo Ham
4 siblings, 0 replies; 18+ messages in thread
From: MyungJoo Ham @ 2012-02-27 12:15 UTC (permalink / raw)
To: linux-arm-kernel
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: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
--
Changes from V5:
- Updated sysfs format
---
Documentation/ABI/testing/sysfs-class-extcon | 22 +++++
drivers/extcon/extcon_class.c | 123 ++++++++++++++++++++++++--
include/linux/extcon.h | 28 +++++-
3 files changed, 160 insertions(+), 13 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-class-extcon b/Documentation/ABI/testing/sysfs-class-extcon
index 19b18e9..20ab361 100644
--- a/Documentation/ABI/testing/sysfs-class-extcon
+++ b/Documentation/ABI/testing/sysfs-class-extcon
@@ -15,6 +15,10 @@ Description:
may have both HDMI and Charger attached, or analog audio,
video, and USB cables attached simulteneously.
+ If there are cables mutually exclusive with each other,
+ such binary relations may be expressed with extcon_dev's
+ mutually_exclusive array.
+
What: /sys/class/extcon/.../name
Date: February 2012
Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
@@ -73,3 +77,21 @@ Description:
state of cable "x" (integer between 0 and 31) of an extcon
device. The state value is either 0 (detached) or 1
(attached).
+
+What: /sys/class/extcon/.../mutually_exclusive/...
+Date: December 2011
+Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
+Description:
+ Shows the relations of mutually exclusiveness. For example,
+ if the mutually_exclusive array of extcon_dev is
+ {0x3, 0x5, 0xC, 0x0}, the, the output is:
+ # ls mutually_exclusive/
+ 0x3
+ 0x5
+ 0xc
+ #
+
+ Note that mutually_exclusive is a sub-directory of the extcon
+ device and the file names under the mutually_exclusive
+ directory show the mutually-exclusive sets, not the contents
+ of the files.
diff --git a/drivers/extcon/extcon_class.c b/drivers/extcon/extcon_class.c
index 55f19c2..fb8d3a4 100644
--- a/drivers/extcon/extcon_class.c
+++ b/drivers/extcon/extcon_class.c
@@ -69,6 +69,39 @@ struct class *extcon_class;
static LIST_HEAD(extcon_dev_list);
static DEFINE_MUTEX(extcon_dev_list_lock);
+/**
+ * check_mutually_exclusive - Check if new_state violates mutually_exclusive
+ * condition.
+ * @edev: the extcon device
+ * @new_state: new cable attach status for @edev
+ *
+ * Returns 0 if nothing violates. Returns the index + 1 for the first
+ * violated condition.
+ */
+static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
+{
+ int i = 0;
+
+ if (!edev->mutually_exclusive)
+ return 0;
+
+ for (i = 0; edev->mutually_exclusive[i]; i++) {
+ int count = 0, j;
+ u32 correspondants = new_state & edev->mutually_exclusive[i];
+ u32 exp = 1;
+
+ for (j = 0; j < 32; j++) {
+ if (exp & correspondants)
+ count++;
+ if (count > 1)
+ return i + 1;
+ exp <<= 1;
+ }
+ }
+
+ return 0;
+}
+
static ssize_t state_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
@@ -97,7 +130,7 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr,
return count;
}
-void extcon_set_state(struct extcon_dev *edev, u32 state);
+int extcon_set_state(struct extcon_dev *edev, u32 state);
static ssize_t state_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
@@ -109,7 +142,7 @@ static ssize_t state_store(struct device *dev, struct device_attribute *attr,
if (ret == 0)
ret = -EINVAL;
else
- extcon_set_state(edev, state);
+ ret = extcon_set_state(edev, state);
if (ret < 0)
return ret;
@@ -188,7 +221,7 @@ static ssize_t cable_state_store(struct device *dev,
* Note that the notifier provides which bits are changed in the state
* variable with the val parameter (second) to the callback.
*/
-void extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
+int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
{
char name_buf[120];
char state_buf[120];
@@ -203,6 +236,12 @@ void extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
if (edev->state != ((edev->state & ~mask) | (state & mask))) {
u32 old_state = edev->state;
+ if (check_mutually_exclusive(edev, (edev->state & ~mask) |
+ (state & mask))) {
+ spin_unlock_irqrestore(&edev->lock, flags);
+ return -EPERM;
+ }
+
edev->state &= ~mask;
edev->state |= state & mask;
@@ -244,6 +283,8 @@ void extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
/* No changes */
spin_unlock_irqrestore(&edev->lock, flags);
}
+
+ return 0;
}
EXPORT_SYMBOL_GPL(extcon_update_state);
@@ -255,9 +296,9 @@ EXPORT_SYMBOL_GPL(extcon_update_state);
* Note that notifier provides which bits are changed in the state
* variable with the val parameter (second) to the callback.
*/
-void extcon_set_state(struct extcon_dev *edev, u32 state)
+int extcon_set_state(struct extcon_dev *edev, u32 state)
{
- extcon_update_state(edev, 0xffffffff, state);
+ return extcon_update_state(edev, 0xffffffff, state);
}
EXPORT_SYMBOL_GPL(extcon_set_state);
@@ -331,8 +372,7 @@ int extcon_set_cable_state_(struct extcon_dev *edev,
return -EINVAL;
state = cable_state ? (1 << index) : 0;
- extcon_update_state(edev, 1 << index, state);
- return 0;
+ return extcon_update_state(edev, 1 << index, state);
}
EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
@@ -506,6 +546,14 @@ static void extcon_cleanup(struct extcon_dev *edev, bool skip)
if (!skip && get_device(edev->dev)) {
int index;
+ if (edev->mutually_exclusive && edev->max_supported) {
+ for (index = 0; edev->mutually_exclusive[index];
+ index++)
+ kfree(edev->d_attrs_muex[index].attr.name);
+ kfree(edev->d_attrs_muex);
+ kfree(edev->attrs_muex);
+ }
+
for (index = 0; index < edev->max_supported; index++)
kfree(edev->cables[index].attr_g.name);
@@ -528,6 +576,7 @@ static void extcon_dev_release(struct device *dev)
extcon_cleanup(edev, true);
}
+static const char *muex_name = "mutually_exclusive";
static void dummy_sysfs_dev_release(struct device *dev)
{
}
@@ -620,10 +669,58 @@ int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
}
}
+ if (edev->max_supported && edev->mutually_exclusive) {
+ char buf[80];
+ char *name;
+
+ /* Count the size of mutually_exclusive array */
+ for (index = 0; edev->mutually_exclusive[index]; index++)
+ ;
+
+ edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
+ (index + 1), GFP_KERNEL);
+ if (!edev->attrs_muex) {
+ ret = -ENOMEM;
+ goto err_muex;
+ }
+
+ edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
+ index, GFP_KERNEL);
+ if (!edev->d_attrs_muex) {
+ ret = -ENOMEM;
+ kfree(edev->attrs_muex);
+ goto err_muex;
+ }
+
+ for (index = 0; edev->mutually_exclusive[index]; index++) {
+ sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
+ name = kzalloc(sizeof(char) * (strlen(buf) + 1),
+ GFP_KERNEL);
+ if (!name) {
+ for (index--; index >= 0; index--) {
+ kfree(edev->d_attrs_muex[index].attr.
+ name);
+ }
+ kfree(edev->d_attrs_muex);
+ kfree(edev->attrs_muex);
+ ret = -ENOMEM;
+ goto err_muex;
+ }
+ strcpy(name, buf);
+ edev->d_attrs_muex[index].attr.name = name;
+ edev->d_attrs_muex[index].attr.mode = 0000;
+ edev->attrs_muex[index] = &edev->d_attrs_muex[index]
+ .attr;
+ }
+ edev->attr_g_muex.name = muex_name;
+ edev->attr_g_muex.attrs = edev->attrs_muex;
+
+ }
+
if (edev->max_supported) {
edev->extcon_dev_type.groups =
kzalloc(sizeof(struct attribute_group *) *
- (edev->max_supported + 1), GFP_KERNEL);
+ (edev->max_supported + 2), GFP_KERNEL);
if (!edev->extcon_dev_type.groups) {
ret = -ENOMEM;
goto err_alloc_groups;
@@ -635,6 +732,9 @@ int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
for (index = 0; index < edev->max_supported; index++)
edev->extcon_dev_type.groups[index] =
&edev->cables[index].attr_g;
+ if (edev->mutually_exclusive)
+ edev->extcon_dev_type.groups[index] =
+ &edev->attr_g_muex;
edev->dev->type = &edev->extcon_dev_type;
}
@@ -662,6 +762,13 @@ err_dev:
if (edev->max_supported)
kfree(edev->extcon_dev_type.groups);
err_alloc_groups:
+ if (edev->max_supported && edev->mutually_exclusive) {
+ for (index = 0; edev->mutually_exclusive[index]; index++)
+ kfree(edev->d_attrs_muex[index].attr.name);
+ kfree(edev->d_attrs_muex);
+ kfree(edev->attrs_muex);
+ }
+err_muex:
for (index = 0; index < edev->max_supported; index++)
kfree(edev->cables[index].attr_g.name);
err_alloc_cables:
diff --git a/include/linux/extcon.h b/include/linux/extcon.h
index 99ff60e..c9e2de8 100644
--- a/include/linux/extcon.h
+++ b/include/linux/extcon.h
@@ -78,6 +78,14 @@ struct extcon_cable;
* @supported_cable Array of supported cable name ending with NULL.
* If supported_cable is NULL, cable name related APIs
* are disabled.
+ * @mutually_exclusive Array of mutually exclusive set of cables that cannot
+ * be attached simultaneously. The array should be
+ * ending with NULL or be NULL (no mutually exclusive
+ * cables). For example, if it is { 0x7, 0x30, 0}, then,
+ * {0, 1}, {0, 1, 2}, {0, 2}, {1, 2}, or {4, 5} cannot
+ * be attached simulataneously. {0x7, 0} is equivalent to
+ * {0x3, 0x6, 0x5, 0}. If it is {0xFFFFFFFF, 0}, there
+ * can be no simultaneous connections.
* @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
@@ -103,6 +111,7 @@ struct extcon_dev {
/* --- Optional user initializing data --- */
const char *name;
const char **supported_cable;
+ const u32 *mutually_exclusive;
/* --- Optional callbacks to override class functions --- */
ssize_t (*print_name)(struct extcon_dev *edev, char *buf);
@@ -119,6 +128,10 @@ struct extcon_dev {
/* /sys/class/extcon/.../cable.n/... */
struct device_type extcon_dev_type;
struct extcon_cable *cables;
+ /* /sys/class/extcon/.../mutually_exclusive/... */
+ struct attribute_group attr_g_muex;
+ struct attribute **attrs_muex;
+ struct device_attribute *d_attrs_muex;
};
/**
@@ -179,8 +192,8 @@ static inline u32 extcon_get_state(struct extcon_dev *edev)
return edev->state;
}
-extern void extcon_set_state(struct extcon_dev *edev, u32 state);
-extern void extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state);
+extern int extcon_set_state(struct extcon_dev *edev, u32 state);
+extern int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state);
/*
* get/set_cable_state access each bit of the 32b encoded state value.
@@ -235,11 +248,16 @@ static inline u32 extcon_get_state(struct extcon_dev *edev)
return 0;
}
-static inline void extcon_set_state(struct extcon_dev *edev, u32 state) { }
+static inline int extcon_set_state(struct extcon_dev *edev, u32 state)
+{
+ return 0;
+}
-static inline void extcon_update_state(struct extcon_dev *edev, u32 mask,
+static inline int extcon_update_state(struct extcon_dev *edev, u32 mask,
u32 state)
-{ }
+{
+ return 0;
+}
static inline int extcon_find_cable_index(struct extcon_dev *edev,
const char *cable_name)
--
1.7.4.1
^ permalink raw reply related [flat|nested] 18+ messages in thread