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Diffstat (limited to 'doc/README.POST')
| -rw-r--r-- | doc/README.POST | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/doc/README.POST b/doc/README.POST index eeb218d..6815d49 100644 --- a/doc/README.POST +++ b/doc/README.POST @@ -659,12 +659,19 @@ not need any modifications for porting them to another board/CPU. 2.2.2.1. I2C test For verifying the I2C bus, a full I2C bus scanning will be performed -using the i2c_probe() routine. If any I2C device is found, the test -will be considered as passed, otherwise failed. This particular way -will be used because it provides the most common method of testing. -For example, using the internal loopback mode of the CPM I2C -controller for testing would not work on boards where the software -I2C driver (also known as bit-banged driver) is used. +using the i2c_probe() routine. If a board defines +CONFIG_SYS_POST_I2C_ADDRS the I2C test will pass if all devices +listed in CONFIG_SYS_POST_I2C_ADDRS are found, and no additional +devices are detected. If CONFIG_SYS_POST_I2C_ADDRS is not defined +the test will pass if any I2C device is found. + +The CONFIG_SYS_POST_I2C_IGNORES define can be used to list I2C +devices which may or may not be present when using +CONFIG_SYS_POST_I2C_ADDRS. The I2C POST test will pass regardless +if the devices in CONFIG_SYS_POST_I2C_IGNORES are found or not. +This is useful in cases when I2C devices are optional (eg on a +daughtercard that may or may not be present) or not critical +to board operation. 2.2.2.2. Watchdog timer test |