| # Lint as: python2, python3 |
| # Copyriht (c) 2014 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. |
| |
| from __future__ import absolute_import |
| from __future__ import division |
| from __future__ import print_function |
| import logging |
| import six |
| |
| # Following Beaglebone GPIO pins are used to control the 8 port multiplexer. |
| MUX_EN = '20' |
| MUX_S0 = '115' |
| MUX_S1 = '117' |
| MUX_S2 = '49' |
| |
| ENABLE_MUX = '1' |
| DISABLE_MUX = '0' |
| |
| # Various commands used to control the GPIO pins at the kernel level. |
| LS_GPIO_DIRECTORY = 'ls /sys/class/gpio' |
| EXPORT_GPIO_PIN = 'echo %s > /sys/class/gpio/export' |
| SET_GPIO_DIRECTION = 'echo high > /sys/class/gpio/gpio%s/direction' |
| SET_GPIO_VALUE = 'echo %s > /sys/class/gpio/gpio%s/value' |
| UNEXPORT_GPIO_PIN = 'echo %s > /sys/class/gpio/unexport' |
| |
| # Values passed to each GPIO pin to enable a specific port. |
| # Bit sequence: MUX_S2, MUX_S1, MUX_S0 |
| # Example: To enable port 5, MUX_S2 will be set to 1, MUX_S1 will be set to 0 |
| # and MUX_S0 will be set to 1 |
| ports = {0:'000', 1:'001', 2:'010', 3:'011', 4:'100', 5:'101', 6:'110', 7:'111'} |
| |
| class USBMuxController(object): |
| """Class to control individual ports on a 8 port USB switch/hub. |
| |
| This class is responsible for enabling all the GPIO pins on the beaglebone |
| needed to control the 8 port USB switch/hub. In order to use this USB mux |
| controller you need custom hardware setup which connects to the beaglebone |
| and drives the 8 port relay switch to turn the individual ports on the USB |
| hub 'on'/'off'. |
| |
| TODO(harpreet) Write a USB mux hardware design document and provide a link |
| here. |
| |
| """ |
| |
| version = 1 |
| |
| def __init__(self, host): |
| """Initializes this USB Mux Controller instance. |
| |
| @param host: Host where the test will be run. |
| |
| """ |
| self.host = host |
| |
| def __del__(self): |
| """Destructor of USBMuxController. |
| |
| Disables all GPIO pins used that control the multiplexer. |
| |
| """ |
| self.mux_teardown() |
| |
| def mux_setup(self): |
| """ |
| Enable GPIO pins that control the multiplexer. |
| |
| """ |
| logging.info('Enable GPIO pins that control the multiplexer.') |
| self.enable_gpio_pins(MUX_EN) |
| self.disable_all_ports() |
| self.enable_gpio_pins(MUX_S2) |
| self.enable_gpio_pins(MUX_S1) |
| self.enable_gpio_pins(MUX_S0) |
| |
| def mux_teardown(self): |
| """ |
| Disable the multiplexer and unexport all GPIO pins. |
| |
| """ |
| logging.info('Start USB multiplexer teardown.') |
| self.disable_all_ports() |
| # unexport gpio pins |
| logging.info('Unexport all GPIO pins.') |
| self.host.servo.system(UNEXPORT_GPIO_PIN % MUX_S0) |
| self.host.servo.system(UNEXPORT_GPIO_PIN % MUX_S1) |
| self.host.servo.system(UNEXPORT_GPIO_PIN % MUX_S2) |
| self.host.servo.system(UNEXPORT_GPIO_PIN % MUX_EN) |
| logging.info('Completed USB multiplexer teardown. All USB ports should' |
| 'now be turned off.') |
| |
| def enable_gpio_pins(self, pin): |
| """ |
| Enables the given GPIO pin by exporting the pin and setting the |
| direction. |
| |
| @param pin: GPIO pin to be enabled. |
| |
| """ |
| if 'gpio' + pin not in self.host.servo.system_output(LS_GPIO_DIRECTORY): |
| self.host.servo.system(EXPORT_GPIO_PIN % pin) |
| self.host.servo.system(SET_GPIO_DIRECTION % pin) |
| |
| def enable_port(self, usb_port): |
| """ |
| Enables the given port on the USB hub. |
| |
| @param usb_port: USB port to be enabled. |
| |
| """ |
| port = ports[usb_port] |
| logging.info('Enable port %s.', port) |
| self.mux_setup() |
| self.disable_all_ports() |
| |
| logging.info('Set GPIO pins to correct logic levels.') |
| self.host.servo.system(SET_GPIO_VALUE % (port[0], MUX_S2)) |
| self.host.servo.system(SET_GPIO_VALUE % (port[1], MUX_S1)) |
| self.host.servo.system(SET_GPIO_VALUE % (port[2], MUX_S0)) |
| |
| logging.info('Enable USB multiplexer. Appropriate port should now be' |
| 'enabled') |
| self.host.servo.system(SET_GPIO_VALUE % (ENABLE_MUX, MUX_EN)) |
| |
| def disable_all_ports(self): |
| """ |
| Disables all USB ports that are currently enabled. |
| |
| """ |
| if 'gpio20' in self.host.servo.system_output(LS_GPIO_DIRECTORY): |
| logging.info('Disable USB ports.') |
| self.host.servo.system(SET_GPIO_VALUE % (DISABLE_MUX, MUX_EN)) |