Autotest test case to utilized C shared library for TPM SmogCheck
Background
stevenh proposed a project called TPM SmogCheck to define and implement a suite
of Python APIs that would facilitate extensive testing of TPM module
functionalities /features, all from the existing Autotest framework.
What's in this CL?
[1] a new Python library that implements stevenh's API to exercise various
capabilities of his TTCI board (specifically, PCA9555 and INA219B modules)
[2] a new Python Autotest test case that demonstrates the use of this new library
[3] a control file to launch the new Autotest (boiler plate)
Any dependency?
- Yes. [1] above depends on a new C shared library called "libsmogcheck.so".
I've filed a new issue (94960) against Build Infrastructure team to have a
new repo set up to host the C code.
- In order to run test cases built using [1], one needs to have a TTCI board
(custom designed by stevenh)
Why is this CL over 1,000 lines?!
- My apologies!
- This CL was developed over a period of several weeks and started out as
experimental code
BUG=chrome-os-partner:5172
TEST=manual (special hardware required to perform test)
Change-Id: Ida5ff18fe1806586d560910007fd3427a3466bec
Reviewed-on: http://gerrit.chromium.org/gerrit/6907
Reviewed-by: Tan Gao <tgao@chromium.org>
Tested-by: Tan Gao <tgao@chromium.org>
diff --git a/client/common_lib/smogcheck_pca9555.py b/client/common_lib/smogcheck_pca9555.py
new file mode 100644
index 0000000..9f82950
--- /dev/null
+++ b/client/common_lib/smogcheck_pca9555.py
@@ -0,0 +1,254 @@
+# Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""A Python library to interact with PCA9555 module for TPM testing.
+
+Background
+ - PCA9555 is one of two modules on TTCI board
+ - This library provides methods to interact with PCA9555 programmatically
+
+Dependency
+ - This library depends on a new C shared library called "libsmogcheck.so".
+ - In order to run test cases built using this API, one needs a TTCI board
+
+Notes:
+ - An exception is raised if it doesn't make logical sense to continue program
+ flow (e.g. I/O error prevents test case from executing)
+ - An exception is caught and then converted to an error code if the caller
+ expects to check for error code per API definition
+"""
+
+import logging
+from autotest_lib.client.common_lib import i2c_slave
+
+
+# I2C constants
+PCA9555_SLV = 0x27 # I2C slave address of PCA9555
+
+# PCA9555 registers
+PCA_REG = {
+ 'IN0': 0, # Input Port 0
+ 'IN1': 1, # Input Port 1
+ 'OUT0': 2, # Output Port 0
+ 'OUT1': 3, # Output Port 1
+ 'PI0': 4, # Polarity Inversion 0
+ 'PI1': 5, # Polarity Inversion 1
+ 'CONF0': 6, # Configuration 0
+ 'CONF1': 7, # Configuration 1
+ }
+
+# Each '1' represents turning on corresponding LED via writing to PCA9555
+# Output Port Registers
+PCA_BIT_ONE = {
+ 'unalloc_0': 0x01,
+ 'unalloc_1': 0x02,
+ 'unalloc_2': 0x04,
+ 'tpm_i2c': 0x08,
+ 'yellow_led': 0x10,
+ 'main_power': 0x10,
+ 'red_led': 0x20,
+ 'backup_power': 0x20,
+ 'reset': 0x40,
+ 'pp': 0x80,
+ }
+
+# Constants used to initialize PCA registers
+# TODO(tgao): document these bits after stevenh replies
+PCA_OUT0_INIT_VAL = 0xff7f
+PCA_CONF0_INIT_VAL = 0xc007
+
+
+class PcaError(Exception):
+ """Base class for all errors in this module."""
+
+
+class PcaController(i2c_slave.I2cSlave):
+ """Object to control PCA9555 module on TTCI board."""
+
+ def __init__(self):
+ """Initialize PCA9555 module on the TTCI board.
+
+ Raises:
+ PcaError: if error initializing PCA9555 module.
+ """
+ super(PcaController, self).__init__()
+ logging.info('Attempt to initialize PCA9555 module')
+ try:
+ self.setSlaveAddress(PCA9555_SLV)
+ self.writeWord(PCA_REG['OUT0'], PCA_OUT0_INIT_VAL)
+ self.writeWord(PCA_REG['PI0'], 0)
+ self.writeWord(PCA_REG['CONF0'], PCA_CONF0_INIT_VAL)
+ except PcaError, e:
+ raise PcaError('Error initializing PCA9555: %s' % e)
+
+ def setPCAcontrol(self, key, turn_on):
+ """Sets specific bit value in Output Port 0 of PCA9555.
+
+ Args:
+ key: a string, valid dict keys in PCA_BIT_ONE.
+ turn_on: a boolean, true = set bit value to 1.
+
+ Returns:
+ an integer, 0 for success and -1 for error.
+ """
+ logging.info('Attempt to set %r bit to %r', key, turn_on)
+ try:
+ byte_read = self.readByte(PCA_REG['OUT0'])
+ if turn_on:
+ write_byte = byte_read | PCA_BIT_ONE[key]
+ else:
+ write_byte = byte_read & ~PCA_BIT_ONE[key]
+ self.writeByte(PCA_REG['OUT0'], write_byte)
+ return 0
+ except PcaError, e:
+ logging.error('Error setting PCA9555 Output Port 0: %s', e)
+ return -1
+
+ def _computeLEDmask(self, bit_value, failure, warning):
+ """Computes proper bit mask to set LED values.
+
+ Args:
+ <see docstring for TTCI_Set_LEDs()>
+
+ Returns:
+ an integer, 8-bit mask.
+
+ Raises:
+ PcaError: if bit value is out of range.
+ """
+ bit_mask = 0
+ if bit_value < 0 or bit_value > 15:
+ raise PcaError('Error: bit_value out of range [0, 15]')
+
+ bit_mask = bit_value
+ if failure:
+ bit_mask |= 0x20
+ if warning:
+ bit_mask |= 0x10
+
+ return bit_mask
+
+ def getPCAbitStatus(self, key):
+ """Gets specific bit value from Output Port 0 of PCA9555.
+
+ Args:
+ key: a string, valid dict keys in PCA_BIT_ONE.
+
+ Returns:
+ an integer, 0 for success and -1 for error.
+ status: a boolean, True if bit value is '1' and False if bit value
+ is '0'.
+ """
+ status = False
+ try:
+ if PCA_BIT_ONE[key] & self.readByte(PCA_REG['OUT0']):
+ status = True
+ return (0, status)
+ except PcaError, e:
+ logging.error('Error reading from PCA9555 Output Port 0: %s', e)
+ return (-1, status)
+
+ def setLEDs(self, bit_value, failure, warning):
+ """De/activate PCA9555 LEDs.
+
+ Mapping of LED to bit values in Output Port 1 (register 3)
+ (default bit value = 1 <--> LED OFF)
+ LED 0 (GREEN): O1.0 (mask = 0x01)
+ LED 1 (GREEN): O1.1 (mask = 0x02)
+ LED 2 (GREEN): O1.2 (mask = 0x04)
+ LED 3 (GREEN): O1.3 (mask = 0x08)
+ LED 4 (YELLOW): O1.4 (mask = 0x10)
+ LED 5 (RED): O1.5 (mask = 0x20)
+
+ To change LED bit values:
+ 1) read byte value from register 3
+ 2) set all 6 lower bits to 1 (LED OFF) by logical OR with 0x3f
+ 3) set appropriate bits to 0 (LED ON) by logical XOR with proper mask
+ 4) write updated byte value to register 3
+
+ An example: bit_value=9, failure=False, warning=True
+ 1) read back, say, 0x96, or 1001 0110 (LEDs 0, 3, 5 ON)
+ 2) 0x96 | 0x3f = 0xbf (all LEDs OFF)
+ 3) bit_value=9 -> turn on LEDs 1, 2
+ failure=False -> keep LED 5 off
+ warning=True -> turn on LED 4
+ proper mask = 0001 0110, or 0x16
+ 0xbf ^ 0x16 = 0xa9, or 1010 1001 (LEDs 1, 2, 4 ON)
+ 4) write 0xa9 to register 3
+
+ Args:
+ bit_value: an integer between 0 and 15, representing 4-bit binary
+ value for green LEDs (i.e. 0~3).
+ failure: a boolean, true = set red LED value to 0.
+ warning: a boolean, true = set yellow LED value to 0.
+
+ Returns:
+ an integer, 0 for success and -1 for error.
+ """
+ logging.info('Attempt to set LED values: bit_value=%r, failure=%r, '
+ 'warning=%r', bit_value, failure, warning)
+ try:
+ byte_read = self.readByte(PCA_REG['OUT1'])
+ reset_low6 = byte_read | 0x3f
+ bit_mask = self._computeLEDmask(bit_value, failure, warning)
+ write_byte = reset_low6 ^ bit_mask
+ logging.debug('byte_read = 0x%x, reset_low6 = 0x%x, '
+ 'bit_mask = 0x%x, write_byte = 0x%x',
+ byte_read, reset_low6, bit_mask, write_byte)
+ self.writeByte(PCA_REG['OUT1'], write_byte)
+ return 0
+ except PcaError, e:
+ logging.error('Error setting PCA9555 Output Port 0: %s', e)
+ return -1
+
+ def getSwitchStatus(self):
+ """Checks status of DIP Switches (2-bit).
+
+ Returns:
+ ret: an integer, error code. 0 = no error.
+ status: an integer, valid value in range [0, 3].
+ """
+ logging.info('Attempt to read DIP switch status')
+ ret = -1
+ status = -1
+ try:
+ byte_read = self.readByte(PCA_REG['IN1'])
+ # Right shift 6-bit to get 2 high-order bits
+ status = byte_read >> 6
+ logging.info('DIP switch status = 0x%x', status)
+ ret = 0
+ except PcaError, e:
+ logging.error('No byte read from PCA9555 Input Port 1: %s', e)
+
+ return (ret, status)
+
+ def getLEDstatus(self):
+ """Checks LED status.
+
+ Returns:
+ ret: an integer, 0 for success and -1 for error.
+ bit_value: an integer between 0 and 15, representing 4-bit binary
+ value for green LEDs (i.e. 0~3). Default: -1.
+ failure: a boolean, true = red LED has value 0. Default: False.
+ warning: a boolean, true = yellow LED has value 0. Default: False.
+ """
+ ret = -1
+ bit_value = -1
+ failure = False
+ warning = False
+
+ try:
+ byte_read = self.readByte(PCA_REG['OUT1'])
+ if not (byte_read | PCA_BIT_ONE['red_led']):
+ failure = True
+ if not (byte_read | PCA_BIT_ONE['yellow_led']):
+ warning = True
+ bit_value = byte_read & 0xf # Get lower 4-bit value
+ logging.info('LED bit_value = %r, failure = %r, warning = %r',
+ bit_value, failure, warning)
+ ret = 0
+ except PcaError, e:
+ logging.error('No byte read from PCA9555 Output Port 1: %s', e)
+
+ return (ret, bit_value, failure, warning)