From de55d8716ac50a356cea736c29bb7db5ac3d0190 Mon Sep 17 00:00:00 2001 From: MyungJoo Ham Date: Fri, 20 Apr 2012 14:16:22 +0900 Subject: Extcon (external connector): import Android's switch class and modify. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 switch: Use device_create instead of device_create_drvdata. Author: Arve Hjønnevåg 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 Signed-off-by: Kyungmin Park Reviewed-by: Mark Brown -- Changes from v7 - Compiler error fixed when it is compiled as a module. - Removed out-of-date Kconfig entry Changes from v6 - Updated comment/strings - Revised "Android-compatible" mode. * Automatically activated if CONFIG_ANDROID && !CONFIG_ANDROID_SWITCH * Creates /sys/class/switch/*, which is a copy of /sys/class/extcon/* Changes from v5 - Split the patch - Style fixes - "Android-compatible" mode is enabled by Kconfig option. Changes from v2 - Updated name_show - Sysfs entries are handled by class itself. - Updated the method to add/remove devices for the class - Comments on uevent send - Able to become a module - Compatible with Android platform Changes from RFC - Renamed to extcon (external connector) from multistate switch - Added a seperated directory (drivers/extcon) - Added kerneldoc comments - Removed unused variables from extcon_gpio.c - Added ABI Documentation. Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-class-extcon | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-extcon (limited to 'Documentation/ABI') diff --git a/Documentation/ABI/testing/sysfs-class-extcon b/Documentation/ABI/testing/sysfs-class-extcon new file mode 100644 index 000000000000..59a4b1c708d5 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-extcon @@ -0,0 +1,26 @@ +What: /sys/class/extcon/.../ +Date: December 2011 +Contact: MyungJoo Ham +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 +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 +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. -- cgit v1.2.3 From 806d9dd71ff52ef09764585baaeec23afbb98560 Mon Sep 17 00:00:00 2001 From: MyungJoo Ham Date: Fri, 20 Apr 2012 14:16:25 +0900 Subject: Extcon: support multiple states at a device. 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: Chanwoo Choi Signed-off-by: MyungJoo Ham Signed-off-by: Kyungmin Park -- Changes from V7 - Bugfixed in _call_per_cable() (incorrect nb) (Chanwoo Choi) - Compiler error in header for !CONFIG_EXTCON (Chanwoo Choi) Changes from V5 - Sysfs style reformed: subdirectory per cable. - Updated standard cable names - Removed unnecessary printf - Bugfixes after testing Changes from V4 - Bugfixes after more testing at Exynos4412 boards with userspace processses. Changes from V3 - Bugfixes after more testing at Exynos4412 boards. Changes from V2 - State can be stored by user - Documentation updated Changes from RFC - Switch is renamed to extcon - Added kerneldoc comments - Added APIs to support "standard" cable names - Added helper APIs to support notifier block registration with cable name. - Regrouped function list in the header file. Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-class-extcon | 63 ++++++++++++++++++++++++---- 1 file changed, 56 insertions(+), 7 deletions(-) (limited to 'Documentation/ABI') diff --git a/Documentation/ABI/testing/sysfs-class-extcon b/Documentation/ABI/testing/sysfs-class-extcon index 59a4b1c708d5..19b18e986a57 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 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 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 +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 +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 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). -- cgit v1.2.3 From bde68e60b18208978c50c6fb9bdf29826d2887f3 Mon Sep 17 00:00:00 2001 From: MyungJoo Ham Date: Fri, 20 Apr 2012 14:16:26 +0900 Subject: Extcon: support mutually exclusive relation between cables. 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 Signed-off-by: MyungJoo Ham Signed-off-by: Kyungmin Park -- Changes from V5: - Updated sysfs format Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-class-extcon | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'Documentation/ABI') diff --git a/Documentation/ABI/testing/sysfs-class-extcon b/Documentation/ABI/testing/sysfs-class-extcon index 19b18e986a57..20ab361bd8c6 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 @@ -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 +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. -- cgit v1.2.3 From 3b552b92817c63fdccfe9d5f3ce7424b57e9ee8f Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Tue, 8 May 2012 18:50:50 +0200 Subject: kmsg - add Documentation/ABI/testing/dev-kmsg Signed-off-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/dev-kmsg | 90 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 Documentation/ABI/testing/dev-kmsg (limited to 'Documentation/ABI') diff --git a/Documentation/ABI/testing/dev-kmsg b/Documentation/ABI/testing/dev-kmsg new file mode 100644 index 000000000000..281ecc5f9709 --- /dev/null +++ b/Documentation/ABI/testing/dev-kmsg @@ -0,0 +1,90 @@ +What: /dev/kmsg +Date: Mai 2012 +KernelVersion: 3.5 +Contact: Kay Sievers +Description: The /dev/kmsg character device node provides userspace access + to the kernel's printk buffer. + + Injecting messages: + Every write() to the opened device node places a log entry in + the kernel's printk buffer. + + The logged line can be prefixed with a syslog prefix, which + carries the syslog priority and facility. The single decimal + prefix number is composed of the 3 lowest bits being the syslog + priority and the higher bits the syslog facility number. + + If no prefix is given, the priority number is the default kernel + log priority and the facility number is set to LOG_USER (1). It + is not possible to inject messages from userspace with the + facility number LOG_KERN (0), to make sure that the origin of + the messages can always be reliably determined. + + Accessing the buffer: + Every read() from the opened device node receives one record + of the kernel's printk buffer. + + The first read() directly following an open() always returns + first message in the buffer; there is no kernel-internal + persistent state; many readers can concurrently open the device + and read from it, without affecting other readers. + + Every read() will receive the next available record. If no more + records are available read() will block, or if O_NONBLOCK is + used -EAGAIN returned. + + Messages in the record ring buffer get overwritten as whole, + there are never partial messages received by read(). + + In case messages get overwritten in the circular buffer while + the device is kept open, the next read() will return -EPIPE, + and the seek position be updated to the next available record. + Subsequent reads() will return available records again. + + Unlike the classic syslog() interface, the 64 bit record + sequence numbers allow to calculate the amount of lost + messages, in case the buffer gets overwritten. And they allow + to reconnect to the buffer and reconstruct the read position + if needed, without limiting the interface to a single reader. + + The device supports seek with the following parameters: + SEEK_SET, 0 + seek to the first entry in the buffer + SEEK_END, 0 + seek after the last entry in the buffer + SEEK_DATA, 0 + seek after the last record available at the time + the last SYSLOG_ACTION_CLEAR was issued. + + The output format consists of a prefix carrying the syslog + prefix including priority and facility, the 64 bit message + sequence number and the monotonic timestamp in microseconds. + The values are separated by a ','. Future extensions might + add more comma separated values before the terminating ';'. + Unknown values should be gracefully ignored. + + The human readable text string starts directly after the ';' + and is terminated by a '\n'. Untrusted values derived from + hardware or other facilities are printed, therefore + all non-printable characters in the log message are escaped + by "\x00" C-style hex encoding. + + A line starting with ' ', is a continuation line, adding + key/value pairs to the log message, which provide the machine + readable context of the message, for reliable processing in + userspace. + + Example: + 7,160,424069;pci_root PNP0A03:00: host bridge window [io 0x0000-0x0cf7] (ignored) + SUBSYSTEM=acpi + DEVICE=+acpi:PNP0A03:00 + 6,339,5140900;NET: Registered protocol family 10 + 30,340,5690716;udevd[80]: starting version 181 + + The DEVICE= key uniquely identifies devices the following way: + b12:8 - block dev_t + c127:3 - char dev_t + n8 - netdev ifindex + +sound:card0 - subsystem:devname + +Users: dmesg(1), userspace kernel log consumers -- cgit v1.2.3