tpm: add documentation for sysfs interfaces

Reviewed-by: Peter Huewe <peter.huewe@infineon.com>
Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>

diff --git a/Documentation/ABI/stable/sysfs-class-tpm b/Documentation/ABI/stable/sysfs-class-tpm
new file mode 100644 (file)
index 0000000..a60b45e
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+++ b/Documentation/ABI/stable/sysfs-class-tpm
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+What:          /sys/class/misc/tpmX/device/
+Date:          April 2005
+KernelVersion: 2.6.12
+Contact:       tpmdd-devel@lists.sf.net
+Description:   The device/ directory under a specific TPM instance exposes
+               the properties of that TPM chip
+
+
+What:          /sys/class/misc/tpmX/device/active
+Date:          April 2006
+KernelVersion: 2.6.17
+Contact:       tpmdd-devel@lists.sf.net
+Description:   The "active" property prints a '1' if the TPM chip is accepting
+               commands. An inactive TPM chip still contains all the state of
+               an active chip (Storage Root Key, NVRAM, etc), and can be
+               visible to the OS, but will only accept a restricted set of
+               commands. See the TPM Main Specification part 2, Structures,
+               section 17 for more information on which commands are
+               available.
+
+What:          /sys/class/misc/tpmX/device/cancel
+Date:          June 2005
+KernelVersion: 2.6.13
+Contact:       tpmdd-devel@lists.sf.net
+Description:   The "cancel" property allows you to cancel the currently
+               pending TPM command. Writing any value to cancel will call the
+               TPM vendor specific cancel operation.
+
+What:          /sys/class/misc/tpmX/device/caps
+Date:          April 2005
+KernelVersion: 2.6.12
+Contact:       tpmdd-devel@lists.sf.net
+Description:   The "caps" property contains TPM manufacturer and version info.
+
+               Example output:
+
+               Manufacturer: 0x53544d20
+               TCG version: 1.2
+               Firmware version: 8.16
+
+               Manufacturer is a hex dump of the 4 byte manufacturer info
+               space in a TPM. TCG version shows the TCG TPM spec level that
+               the chip supports. Firmware version is that of the chip and
+               is manufacturer specific.
+
+What:          /sys/class/misc/tpmX/device/durations
+Date:          March 2011
+KernelVersion: 3.1
+Contact:       tpmdd-devel@lists.sf.net
+Description:   The "durations" property shows the 3 vendor-specific values
+               used to wait for a short, medium and long TPM command. All
+               TPM commands are categorized as short, medium or long in
+               execution time, so that the driver doesn't have to wait
+               any longer than necessary before starting to poll for a
+               result.
+
+               Example output:
+
+               3015000 4508000 180995000 [original]
+
+               Here the short, medium and long durations are displayed in
+               usecs. "[original]" indicates that the values are displayed
+               unmodified from when they were queried from the chip.
+               Durations can be modified in the case where a buggy chip
+               reports them in msec instead of usec and they need to be
+               scaled to be displayed in usecs. In this case "[adjusted]"
+               will be displayed in place of "[original]".
+
+What:          /sys/class/misc/tpmX/device/enabled
+Date:          April 2006
+KernelVersion: 2.6.17
+Contact:       tpmdd-devel@lists.sf.net
+Description:   The "enabled" property prints a '1' if the TPM chip is enabled,
+               meaning that it should be visible to the OS. This property
+               may be visible but produce a '0' after some operation that
+               disables the TPM.
+
+What:          /sys/class/misc/tpmX/device/owned
+Date:          April 2006
+KernelVersion: 2.6.17
+Contact:       tpmdd-devel@lists.sf.net
+Description:   The "owned" property produces a '1' if the TPM_TakeOwnership
+               ordinal has been executed successfully in the chip. A '0'
+               indicates that ownership hasn't been taken.
+
+What:          /sys/class/misc/tpmX/device/pcrs
+Date:          April 2005
+KernelVersion: 2.6.12
+Contact:       tpmdd-devel@lists.sf.net
+Description:   The "pcrs" property will dump the current value of all Platform
+               Configuration Registers in the TPM. Note that since these
+               values may be constantly changing, the output is only valid
+               for a snapshot in time.
+
+               Example output:
+
+               PCR-00: 3A 3F 78 0F 11 A4 B4 99 69 FC AA 80 CD 6E 39 57 C3 3B 22 75
+               PCR-01: 3A 3F 78 0F 11 A4 B4 99 69 FC AA 80 CD 6E 39 57 C3 3B 22 75
+               PCR-02: 3A 3F 78 0F 11 A4 B4 99 69 FC AA 80 CD 6E 39 57 C3 3B 22 75
+               PCR-03: 3A 3F 78 0F 11 A4 B4 99 69 FC AA 80 CD 6E 39 57 C3 3B 22 75
+               PCR-04: 3A 3F 78 0F 11 A4 B4 99 69 FC AA 80 CD 6E 39 57 C3 3B 22 75
+               ...
+
+               The number of PCRs and hex bytes needed to represent a PCR
+               value will vary depending on TPM chip version. For TPM 1.1 and
+               1.2 chips, PCRs represent SHA-1 hashes, which are 20 bytes
+               long. Use the "caps" property to determine TPM version.
+
+What:          /sys/class/misc/tpmX/device/pubek
+Date:          April 2005
+KernelVersion: 2.6.12
+Contact:       tpmdd-devel@lists.sf.net
+Description:   The "pubek" property will return the TPM's public endorsement
+               key if possible. If the TPM has had ownership established and
+               is version 1.2, the pubek will not be available without the
+               owner's authorization. Since the TPM driver doesn't store any
+               secrets, it can't authorize its own request for the pubek,
+               making it unaccessible. The public endorsement key is gener-
+               ated at TPM menufacture time and exists for the life of the
+               chip.
+
+               Example output:
+
+               Algorithm: 00 00 00 01
+               Encscheme: 00 03
+               Sigscheme: 00 01
+               Parameters: 00 00 08 00 00 00 00 02 00 00 00 00
+               Modulus length: 256
+               Modulus:
+               B4 76 41 82 C9 20 2C 10 18 40 BC 8B E5 44 4C 6C
+               3A B2 92 0C A4 9B 2A 83 EB 5C 12 85 04 48 A0 B6
+               1E E4 81 84 CE B2 F2 45 1C F0 85 99 61 02 4D EB
+               86 C4 F7 F3 29 60 52 93 6B B2 E5 AB 8B A9 09 E3
+               D7 0E 7D CA 41 BF 43 07 65 86 3C 8C 13 7A D0 8B
+               82 5E 96 0B F8 1F 5F 34 06 DA A2 52 C1 A9 D5 26
+               0F F4 04 4B D9 3F 2D F2 AC 2F 74 64 1F 8B CD 3E
+               1E 30 38 6C 70 63 69 AB E2 50 DF 49 05 2E E1 8D
+               6F 78 44 DA 57 43 69 EE 76 6C 38 8A E9 8E A3 F0
+               A7 1F 3C A8 D0 12 15 3E CA 0E BD FA 24 CD 33 C6
+               47 AE A4 18 83 8E 22 39 75 93 86 E6 FD 66 48 B6
+               10 AD 94 14 65 F9 6A 17 78 BD 16 53 84 30 BF 70
+               E0 DC 65 FD 3C C6 B0 1E BF B9 C1 B5 6C EF B1 3A
+               F8 28 05 83 62 26 11 DC B4 6B 5A 97 FF 32 26 B6
+               F7 02 71 CF 15 AE 16 DD D1 C1 8E A8 CF 9B 50 7B
+               C3 91 FF 44 1E CF 7C 39 FE 17 77 21 20 BD CE 9B
+
+               Possible values:
+
+               Algorithm:      TPM_ALG_RSA                     (1)
+               Encscheme:      TPM_ES_RSAESPKCSv15             (2)
+                               TPM_ES_RSAESOAEP_SHA1_MGF1      (3)
+               Sigscheme:      TPM_SS_NONE                     (1)
+               Parameters, a byte string of 3 u32 values:
+                       Key Length (bits):      00 00 08 00     (2048)
+                       Num primes:             00 00 00 02     (2)
+                       Exponent Size:          00 00 00 00     (0 means the
+                                                                default exp)
+               Modulus Length: 256 (bytes)
+               Modulus:        The 256 byte Endorsement Key modulus
+
+What:          /sys/class/misc/tpmX/device/temp_deactivated
+Date:          April 2006
+KernelVersion: 2.6.17
+Contact:       tpmdd-devel@lists.sf.net
+Description:   The "temp_deactivated" property returns a '1' if the chip has
+               been temporarily dectivated, usually until the next power
+               cycle. Whether a warm boot (reboot) will clear a TPM chip
+               from a temp_deactivated state is platform specific.
+
+What:          /sys/class/misc/tpmX/device/timeouts
+Date:          March 2011
+KernelVersion: 3.1
+Contact:       tpmdd-devel@lists.sf.net
+Description:   The "timeouts" property shows the 4 vendor-specific values
+               for the TPM's interface spec timeouts. The use of these
+               timeouts is defined by the TPM interface spec that the chip
+               conforms to.
+
+               Example output:
+
+               750000 750000 750000 750000 [original]
+
+               The four timeout values are shown in usecs, with a trailing
+               "[original]" or "[adjusted]" depending on whether the values
+               were scaled by the driver to be reported in usec from msecs.