harpreet | 04dae65 | 2014-08-29 16:26:47 -0700 | [diff] [blame] | 1 | # Copyriht (c) 2014 The Chromium OS Authors. All rights reserved. |
| 2 | # Use of this source code is governed by a BSD-style license that can be |
| 3 | # found in the LICENSE file. |
| 4 | |
| 5 | import logging |
| 6 | |
| 7 | # Following Beaglebone GPIO pins are used to control the 8 port multiplexer. |
| 8 | MUX_EN = '20' |
| 9 | MUX_S0 = '115' |
| 10 | MUX_S1 = '117' |
| 11 | MUX_S2 = '49' |
| 12 | |
| 13 | ENABLE_MUX = '1' |
| 14 | DISABLE_MUX = '0' |
| 15 | |
| 16 | # Various commands used to control the GPIO pins at the kernel level. |
| 17 | LS_GPIO_DIRECTORY = 'ls /sys/class/gpio' |
| 18 | EXPORT_GPIO_PIN = 'echo %s > /sys/class/gpio/export' |
| 19 | SET_GPIO_DIRECTION = 'echo high > /sys/class/gpio/gpio%s/direction' |
| 20 | SET_GPIO_VALUE = 'echo %s > /sys/class/gpio/gpio%s/value' |
| 21 | UNEXPORT_GPIO_PIN = 'echo %s > /sys/class/gpio/unexport' |
| 22 | |
| 23 | # Values passed to each GPIO pin to enable a specific port. |
| 24 | # Bit sequence: MUX_S2, MUX_S1, MUX_S0 |
| 25 | # Example: To enable port 5, MUX_S2 will be set to 1, MUX_S1 will be set to 0 |
| 26 | # and MUX_S0 will be set to 1 |
| 27 | ports = {0:'000', 1:'001', 2:'010', 3:'011', 4:'100', 5:'101', 6:'110', 7:'111'} |
| 28 | |
| 29 | class USBMuxController(object): |
| 30 | """Class to control individual ports on a 8 port USB switch/hub. |
| 31 | |
| 32 | This class is responsible for enabling all the GPIO pins on the beaglebone |
| 33 | needed to control the 8 port USB switch/hub. In order to use this USB mux |
| 34 | controller you need custom hardware setup which connects to the beaglebone |
| 35 | and drives the 8 port relay switch to turn the individual ports on the USB |
| 36 | hub 'on'/'off'. |
| 37 | |
| 38 | TODO(harpreet) Write a USB mux hardware design document and provide a link |
| 39 | here. |
| 40 | |
| 41 | """ |
| 42 | |
| 43 | version = 1 |
| 44 | |
| 45 | def __init__(self, host): |
| 46 | """Initializes this USB Mux Controller instance. |
| 47 | |
| 48 | @param host: Host where the test will be run. |
| 49 | |
| 50 | """ |
| 51 | self.host = host |
| 52 | |
| 53 | def __del__(self): |
| 54 | """Destructor of USBMuxController. |
| 55 | |
| 56 | Disables all GPIO pins used that control the multiplexer. |
| 57 | |
| 58 | """ |
| 59 | self.mux_teardown() |
| 60 | |
| 61 | def mux_setup(self): |
| 62 | """ |
| 63 | Enable GPIO pins that control the multiplexer. |
| 64 | |
| 65 | """ |
| 66 | logging.info('Enable GPIO pins that control the multiplexer.') |
| 67 | self.enable_gpio_pins(MUX_EN) |
| 68 | self.disable_all_ports() |
| 69 | self.enable_gpio_pins(MUX_S2) |
| 70 | self.enable_gpio_pins(MUX_S1) |
| 71 | self.enable_gpio_pins(MUX_S0) |
| 72 | |
| 73 | def mux_teardown(self): |
| 74 | """ |
| 75 | Disable the multiplexer and unexport all GPIO pins. |
| 76 | |
| 77 | """ |
| 78 | logging.info('Start USB multiplexer teardown.') |
| 79 | self.disable_all_ports() |
| 80 | # unexport gpio pins |
| 81 | logging.info('Unexport all GPIO pins.') |
| 82 | self.host.servo.system(UNEXPORT_GPIO_PIN % MUX_S0) |
| 83 | self.host.servo.system(UNEXPORT_GPIO_PIN % MUX_S1) |
| 84 | self.host.servo.system(UNEXPORT_GPIO_PIN % MUX_S2) |
| 85 | self.host.servo.system(UNEXPORT_GPIO_PIN % MUX_EN) |
| 86 | logging.info('Completed USB multiplexer teardown. All USB ports should' |
| 87 | 'now be turned off.') |
| 88 | |
| 89 | def enable_gpio_pins(self, pin): |
| 90 | """ |
| 91 | Enables the given GPIO pin by exporting the pin and setting the |
| 92 | direction. |
| 93 | |
| 94 | @param pin: GPIO pin to be enabled. |
| 95 | |
| 96 | """ |
| 97 | if 'gpio' + pin not in self.host.servo.system_output(LS_GPIO_DIRECTORY): |
| 98 | self.host.servo.system(EXPORT_GPIO_PIN % pin) |
| 99 | self.host.servo.system(SET_GPIO_DIRECTION % pin) |
| 100 | |
| 101 | def enable_port(self, usb_port): |
| 102 | """ |
| 103 | Enables the given port on the USB hub. |
| 104 | |
| 105 | @param usb_port: USB port to be enabled. |
| 106 | |
| 107 | """ |
| 108 | port = ports[usb_port] |
| 109 | logging.info('Enable port %s.', port) |
| 110 | self.mux_setup() |
| 111 | self.disable_all_ports() |
| 112 | |
| 113 | logging.info('Set GPIO pins to correct logic levels.') |
| 114 | self.host.servo.system(SET_GPIO_VALUE % (port[0], MUX_S2)) |
| 115 | self.host.servo.system(SET_GPIO_VALUE % (port[1], MUX_S1)) |
| 116 | self.host.servo.system(SET_GPIO_VALUE % (port[2], MUX_S0)) |
| 117 | |
| 118 | logging.info('Enable USB multiplexer. Appropriate port should now be' |
| 119 | 'enabled') |
| 120 | self.host.servo.system(SET_GPIO_VALUE % (ENABLE_MUX, MUX_EN)) |
| 121 | |
| 122 | def disable_all_ports(self): |
| 123 | """ |
| 124 | Disables all USB ports that are currently enabled. |
| 125 | |
| 126 | """ |
harpreet | d851bd8 | 2014-10-21 16:05:21 -0700 | [diff] [blame] | 127 | if 'gpio20' in self.host.servo.system_output(LS_GPIO_DIRECTORY): |
| 128 | logging.info('Disable USB ports.') |
| 129 | self.host.servo.system(SET_GPIO_VALUE % (DISABLE_MUX, MUX_EN)) |