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| author | Andrew Dyer <adyer@righthandtech.com> | 2008-12-29 17:36:01 -0600 |
|---|---|---|
| committer | Wolfgang Denk <wd@denx.de> | 2009-01-27 22:26:31 +0100 |
| commit | 2ac6985a7466a1c8a7aa8b2fa24d360925a82764 (patch) | |
| tree | 81c39426e12780c0c88d7634244203916f9f98cf /README | |
| parent | 3429071700963ca2f944c51d695a7481af0cee33 (diff) | |
| download | u-boot-2ac6985a7466a1c8a7aa8b2fa24d360925a82764.zip u-boot-2ac6985a7466a1c8a7aa8b2fa24d360925a82764.tar.gz u-boot-2ac6985a7466a1c8a7aa8b2fa24d360925a82764.tar.bz2 | |
soft_i2c.c add option for repeated start in i2c_read()
This patch adds a #define to optionally change the behaviour of
i2c_read() in soft_i2c.c to send an I2C repeated start instead of a
stop-start between sending the device address pointer write and
reading back the data. The current behaviour is retained as the
default.
While most devices will work either way, I have a smart battery(*)
that requires repeated start, and someone at some point found a
device that required a stop-start.
(*) http://www.inspired-energy.com/Standard_Products/NL2054/NL2054%20Rev1.0%20Data%20Sheet.pdf
Signed-off-by: Andrew Dyer <adyer@righthandtech.com>
Diffstat (limited to 'README')
| -rw-r--r-- | README | 9 |
1 files changed, 9 insertions, 0 deletions
@@ -1509,6 +1509,15 @@ The following options need to be configured: Bus on the MPC8260. But it should be not so difficult to add this option to other architectures. + CONFIG_SOFT_I2C_READ_REPEATED_START + + defining this will force the i2c_read() function in + the soft_i2c driver to perform an I2C repeated start + between writing the address pointer and reading the + data. If this define is omitted the default behaviour + of doing a stop-start sequence will be used. Most I2C + devices can use either method, but some require one or + the other. - SPI Support: CONFIG_SPI |