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Commit 03fe0035 authored by Mark Featherston's avatar Mark Featherston Committed by Bartosz Golaszewski
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gpio: ts4900: Do not set DAT and OE together



This works around an issue with the hardware where both OE and
DAT are exposed in the same register. If both are updated
simultaneously, the harware makes no guarantees that OE or DAT
will actually change in any given order and may result in a
glitch of a few ns on a GPIO pin when changing direction and value
in a single write.

Setting direction to input now only affects OE bit. Setting
direction to output updates DAT first, then OE.

Fixes: 9c668632 ("gpio: add Technologic I2C-FPGA gpio support")
Signed-off-by: default avatarMark Featherston <mark@embeddedTS.com>
Signed-off-by: default avatarKris Bahnsen <kris@embeddedTS.com>
Signed-off-by: default avatarBartosz Golaszewski <brgl@bgdev.pl>
parent a9a5b720
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