Merge branch '2020-05-25-misc-fixes'

[oweals/u-boot.git] / doc / README.POST

diff --git a/doc/README.POST b/doc/README.POST
index eeb218d39c64c064cd69143a848676074f3b9404..43f424f60fff243a455951411384fd1538f9c03f 100644 (file)
--- a/doc/README.POST
+++ b/doc/README.POST
@@ -159,17 +159,6 @@ The POST layer will export the following interface routines:
 Also, the following board-specific routines will be called from the
 U-Boot common code:
 
-  o) int board_power_mode(void)
-
-     This routine will return the mode the system is running in
-     (POST_POWERON, POST_NORMAL or POST_SHUTDOWN).
-
-  o) void board_poweroff(void)
-
-     This routine will turn off the power supply of the board. It
-     will be called on power-fail booting after running all POST
-     tests.
-
   o) int post_hotkeys_pressed(gd_t *gd)
 
      This routine will scan the keyboard to detect if a magic key
@@ -494,7 +483,7 @@ This test will verify the following ALU instructions:
      This group will contain: b, bl, bc.
 
      The first 2 instructions (b, bl) will be verified by jumping to
-     a fixed address and checking whether control was transfered to
+     a fixed address and checking whether control was transferred to
      that very point. For the bl instruction the value of the link
      register will be checked as well (using mfspr). To verify the bc
      instruction various combinations of the BI/BO fields, the CTR
@@ -659,12 +648,19 @@ 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