Merge branch 'driver-core-next' of...

What:		/sys/firmware/efi/vars

Date:		April 2004

Contact:	Matt Domsch <Matt_Domsch@dell.com>

Description:

		This directory exposes interfaces for interactive with

		EFI variables.  For more information on EFI variables,

		see 'Variable Services' in the UEFI specification

		(section 7.2 in specification version 2.3 Errata D).

		In summary, EFI variables are named, and are classified

		into separate namespaces through the use of a vendor

		GUID.  They also have an arbitrary binary value

		associated with them.

		The efivars module enumerates these variables and

		creates a separate directory for each one found.  Each

		directory has a name of the form "<key>-<vendor guid>"

		and contains the following files:

		attributes:	A read-only text file enumerating the

				EFI variable flags.  Potential values

				include:

				EFI_VARIABLE_NON_VOLATILE

				EFI_VARIABLE_BOOTSERVICE_ACCESS

				EFI_VARIABLE_RUNTIME_ACCESS

				EFI_VARIABLE_HARDWARE_ERROR_RECORD

				EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS

				See the EFI documentation for an

				explanation of each of these variables.

		data:		A read-only binary file that can be read

				to attain the value of the EFI variable

		guid:		The vendor GUID of the variable.  This

				should always match the GUID in the

				variable's name.

		raw_var:	A binary file that can be read to obtain

				a structure that contains everything

				there is to know about the variable.

				For structure definition see "struct

				efi_variable" in the kernel sources.

				This file can also be written to in

				order to update the value of a variable.

				For this to work however, all fields of

				the "struct efi_variable" passed must

				match byte for byte with the structure

				read out of the file, save for the value

				portion.

				**Note** the efi_variable structure

				read/written with this file contains a

				'long' type that may change widths

				depending on your underlying

				architecture.

		size:		As ASCII representation of the size of

				the variable's value.

		In addition, two other magic binary files are provided

		in the top-level directory and are used for adding and

		removing variables:

		new_var:	Takes a "struct efi_variable" and

				instructs the EFI firmware to create a

				new variable.

		del_var:	Takes a "struct efi_variable" and

				instructs the EFI firmware to remove any

				variable that has a matching vendor GUID

				and variable key name.

What:		/sys/firmware/dmi/

Date:		February 2011

Contact:	Mike Waychison <mikew@google.com>

Description:

		Many machines' firmware (x86 and ia64) export DMI /

		SMBIOS tables to the operating system.  Getting at this

		information is often valuable to userland, especially in

		cases where there are OEM extensions used.

		The kernel itself does not rely on the majority of the

		information in these tables being correct.  It equally

		cannot ensure that the data as exported to userland is

		without error either.

		DMI is structured as a large table of entries, where

		each entry has a common header indicating the type and

		length of the entry, as well as 'handle' that is

		supposed to be unique amongst all entries.

		Some entries are required by the specification, but many

		others are optional.  In general though, users should

		never expect to find a specific entry type on their

		system unless they know for certain what their firmware

		is doing.  Machine to machine will vary.

		Multiple entries of the same type are allowed.  In order

		to handle these duplicate entry types, each entry is

		assigned by the operating system an 'instance', which is

		derived from an entry type's ordinal position.  That is

		to say, if there are 'N' multiple entries with the same type

		'T' in the DMI tables (adjacent or spread apart, it

		doesn't matter), they will be represented in sysfs as

		entries "T-0" through "T-(N-1)":

		Example entry directories:

			/sys/firmware/dmi/entries/17-0

			/sys/firmware/dmi/entries/17-1

			/sys/firmware/dmi/entries/17-2

			/sys/firmware/dmi/entries/17-3

			...

		Instance numbers are used in lieu of the firmware

		assigned entry handles as the kernel itself makes no

		guarantees that handles as exported are unique, and

		there are likely firmware images that get this wrong in

		the wild.

		Each DMI entry in sysfs has the common header values

		exported as attributes:

		handle	: The 16bit 'handle' that is assigned to this

			  entry by the firmware.  This handle may be

			  referred to by other entries.

		length	: The length of the entry, as presented in the

			  entry itself.  Note that this is _not the

			  total count of bytes associated with the

			  entry_.  This value represents the length of

			  the "formatted" portion of the entry.  This

			  "formatted" region is sometimes followed by

			  the "unformatted" region composed of nul

			  terminated strings, with termination signalled

			  by a two nul characters in series.

		raw	: The raw bytes of the entry. This includes the

			  "formatted" portion of the entry, the

			  "unformatted" strings portion of the entry,

			  and the two terminating nul characters.

		type	: The type of the entry.  This value is the same

			  as found in the directory name.  It indicates

			  how the rest of the entry should be

			  interpreted.

		instance: The instance ordinal of the entry for the

			  given type.  This value is the same as found

			  in the parent directory name.

		position: The position of the entry within the entirety

			  of the entirety.

		=== Entry Specialization ===

		Some entry types may have other information available in

		sysfs.

		--- Type 15 - System Event Log ---

		This entry allows the firmware to export a log of

		events the system has taken.  This information is

		typically backed by nvram, but the implementation

		details are abstracted by this table.  This entries data

		is exported in the directory:

		/sys/firmware/dmi/entries/15-0/system_event_log

		and has the following attributes (documented in the

		SMBIOS / DMI specification under "System Event Log (Type 15)":

		area_length

		header_start_offset

		data_start_offset

		access_method

		status

		change_token

		access_method_address

		header_format

		per_log_type_descriptor_length

		type_descriptors_supported_count

		As well, the kernel exports the binary attribute:

		raw_event_log	: The raw binary bits of the event log

				  as described by the DMI entry.

What:		/sys/devices/platform/kim/dev_name

Date:		January 2010

KernelVersion:	2.6.38

Contact:	"Pavan Savoy" <pavan_savoy@ti.com>

Description:

		Name of the UART device at which the WL128x chip

		is connected. example: "/dev/ttyS0".

		The device name flows down to architecture specific board

		initialization file from the SFI/ATAGS bootloader

		firmware. The name exposed is read from the user-space

		dameon and opens the device when install is requested.

What:		/sys/devices/platform/kim/baud_rate

Date:		January 2010

KernelVersion:	2.6.38

Contact:	"Pavan Savoy" <pavan_savoy@ti.com>

Description:

		The maximum reliable baud-rate the host can support.

		Different platforms tend to have different high-speed

		UART configurations, so the baud-rate needs to be set

		locally and also sent across to the WL128x via a HCI-VS

		command. The entry is read and made use by the user-space

		daemon when the ldisc install is requested.

What:		/sys/devices/platform/kim/flow_cntrl

Date:		January 2010

KernelVersion:	2.6.38

Contact:	"Pavan Savoy" <pavan_savoy@ti.com>

Description:

		The WL128x makes use of flow control mechanism, and this

		entry most often should be 1, the host's UART is required

		to have the capability of flow-control, or else this

		entry can be made use of for exceptions.

What:		/sys/devices/platform/kim/install

Date:		January 2010

KernelVersion:	2.6.38

Contact:	"Pavan Savoy" <pavan_savoy@ti.com>

Description:

		When one of the protocols Bluetooth, FM or GPS wants to make

		use of the shared UART transport, it registers to the shared

		transport driver, which will signal the user-space for opening,

		configuring baud and install line discipline via this sysfs

		entry. This entry would be polled upon by the user-space

		daemon managing the UART, and is notified about the change

		by the sysfs_notify. The value would be '1' when UART needs

		to be opened/ldisc installed, and would be '0' when UART

		is no more required and needs to be closed.

The flags are:

f

    Include the function name in the printed message

l

    Include line number in the printed message

m

    Include module name in the printed message

p

    Causes a printk() message to be emitted to dmesg

t

    Include thread ID in messages not generated from interrupt context

Note the regexp ^[-+=][scp]+$ matches a flags specification.

Note the regexp ^[-+=][flmpt]+$ matches a flags specification.

Note also that there is no convenient syntax to remove all

the flags at once, you need to use "-psc".

the flags at once, you need to use "-flmpt".

Debug messages during boot process

ancestors of object hierarchies; i.e. the subsystems the objects

belong to. 

Sysfs internally stores the kobject that owns the directory in the

->d_fsdata pointer of the directory's dentry. This allows sysfs to do

reference counting directly on the kobject when the file is opened and

closed. 

Sysfs internally stores a pointer to the kobject that implements a

directory in the sysfs_dirent object associated with the directory. In

the past this kobject pointer has been used by sysfs to do reference

counting directly on the kobject whenever the file is opened or closed.

With the current sysfs implementation the kobject reference count is

only modified directly by the function sysfs_schedule_callback().

Attributes

  is 4096. 

- show() methods should return the number of bytes printed into the

  buffer. This is the return value of snprintf().

  buffer. This is the return value of scnprintf().

- show() should always use snprintf(). 

- show() should always use scnprintf().

- store() should return the number of bytes used from the buffer. If the

  entire buffer has been used, just return the count argument.

static ssize_t show_name(struct device *dev, struct device_attribute *attr,

                         char *buf)

{

	return snprintf(buf, PAGE_SIZE, "%s\n", dev->name);

	return scnprintf(buf, PAGE_SIZE, "%s\n", dev->name);

}

static ssize_t store_name(struct device *dev, struct device_attribute *attr,