From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Date: Wed, 02 Jul 2014 12:37:10 -0600 Subject: [U-Boot] [PATCH 1/3] i2c: tegra: use repeated start for reads In-Reply-To: <1403715449-2177-1-git-send-email-swarren@wwwdotorg.org> References: <1403715449-2177-1-git-send-email-swarren@wwwdotorg.org> Message-ID: <53B45156.1090202@wwwdotorg.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 06/25/2014 10:57 AM, Stephen Warren wrote: > From: Stephen Warren > > I2C read transactions are typically implemented as follows: > > START(write) address REPEATED_START(read) data... STOP > > However, Tegra's I2C driver currently implements reads as follows: > > START(write) address STOP START(read) data... STOP > > This sequence confuses at least the AS3722 PMIC on the Jetson TK1 board, > leading to corrupted read data in some cases. Fix the driver to chain > the transactions together using repeated starts to solve this. Heiko, do these patches look good?