[U-Boot] omap24xx_i2c: i2c 16-bit write to pcf8575

[Richard Retanubun]

Hello,

My platform is a dra7xx_evm. My code baseline is denx master

I am trying to write to the pcf8575 i2c gpio expander at address 0x21 (bit P4)

I can read 16-bit okay in this version, but 16-bit writing is not working.

// Display current values
i2c md 21 0.0 2
0000: f7 eb    ..

// Set bit P4 to 1
i2c mw 21 0.0 0xffeb 2

// But it remains at 0xf7
i2c md 21 0.0 2
0000: f7 eb    ..

When we put scopes on the i2c lines, it seems that the i2c mw
transaction produces a longer i2c bus sequence that does not map to
the [Start:Addr:W:A:P7-P0:A:P17-P10:A:Stop] that the pcf8575 device
expects.

Either I am invoking "i2c mw" incorrectly, or the oma24xx_i2c driver
is not handling i2c 16-bit writes correctly yet.

Any hints will be appreciated. Thanks for everyone's time

-- Richard Retanubun