i2c: tegra: make sure register writes completes
authorLaxman Dewangan <ldewangan@nvidia.com>
Wed, 13 Jun 2012 10:12:36 +0000 (15:42 +0530)
committerWolfram Sang <w.sang@pengutronix.de>
Sun, 8 Jul 2012 10:49:15 +0000 (12:49 +0200)
commitec7aaca2f64f509f45d463d784b41d0b3d2be083
tree1258c7f8706dc0ad72aa1b53b1b85271aa88d4c3
parentb4fde5e7ed1c275986f45fe411ef7a2df58f9652
i2c: tegra: make sure register writes completes

The Tegra PPSB (an peripheral bus) queues writes transactions.
In order to guarantee that writes have completed before a
certain time, a read transaction to a register on the same
bus must be executed.
This is necessary in situations such as when clearing an
interrupt status or enable, so that when returning from an
interrupt handler, the HW has already de-asserted its
interrupt status output, which will avoid spurious interrupts.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
drivers/i2c/busses/i2c-tegra.c