From mboxrd@z Thu Jan 1 00:00:00 1970 From: wsa@the-dreams.de (Wolfram Sang) Date: Fri, 4 Oct 2013 07:20:52 +0200 Subject: [PATCH 2/3 V3] i2c: mxs: Rework the PIO mode operation In-Reply-To: <1380497035-7457-2-git-send-email-marex@denx.de> References: <1380497035-7457-1-git-send-email-marex@denx.de> <1380497035-7457-2-git-send-email-marex@denx.de> Message-ID: <20131004052052.GA3194@katana> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Sep 30, 2013 at 01:23:54AM +0200, Marek Vasut wrote: > Analyze and rework the PIO mode operation. The PIO mode operation > was unreliable on MX28, by analyzing the bus with LA, the checks > for when data were available or were to be sent were wrong. > > The PIO WRITE has to be completely reworked as it multiple problems. > The MX23 datasheet helped here, see comments in the code for details. > The problems boil down to: > - RUN bit in CTRL0 must be set after DATA register was written > - The PIO transfer must be 4 bytes long tops, otherwise use > clock stretching. > Both of these fixes are implemented. > > The PIO READ operation can only be done for up to four bytes as > we are unable to read out the data from the DATA register fast > enough. > > This patch also tries to document the investigation within the > code. > > Signed-off-by: Marek Vasut Please fix the checkpatch errors and build warning. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: