From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandre Belloni Subject: Re: [PATCH V2 2/3] i2c: mxs: Rework the PIO mode operation Date: Mon, 05 Aug 2013 13:11:09 +0200 Message-ID: <51FF884D.5080009@free-electrons.com> References: <1375219237-9594-1-git-send-email-marex@denx.de> <1375219237-9594-2-git-send-email-marex@denx.de> <20130805103647.GB9694@katana> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130805103647.GB9694@katana> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Wolfram Sang Cc: Marek Vasut , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Christoph Baumann , Fabio Estevam , Shawn Guo , Torsten Fleischer List-Id: linux-i2c@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 05/08/2013 12:36, Wolfram Sang wrote: > On Tue, Jul 30, 2013 at 11:20:36PM +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 > > Thanks. I'd love to see Acked, Reviewed or Tested tags cause I know ppl > have used these patches. Don't be shy :) > > It was on my todo list until now. Tested-by: Alexandre Belloni - -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBCAAGBQJR/4hNAAoJEKbNnwlvZCyzv0gP/1/ED0u/HwbJFU6mxi3ALpLB NJ/RYMlmU+u+4FlNzlAEYBPSIp/2IFhgmTLnf+t1E3VsvjZ0mchYZwp/3IH/Z4X5 HAx5X0/mJ19Nqlq7ARuQvKaF+i7IQxOY61GybxX8W7gvHOL2FXufZFdVh+KjRFDY rOnxgugCF473iZ7YUA5p+qJo9H/uJKaUcHQO56yUJkA3BOM4MVWztMUI0wuICg9H Khq4zKuL6/qXsL1fz3sT5L1pUUYUZFUt75pz1zIYvovEOg+Bk3kSHz2xRQPYHXJ2 UzTDANNnaIEkh9ZzuNoVywOb3Qme9QLufD/ju29QYmOZvVBuTo9oSgdxuZGZ8Wxl u6y02wp3y1zWXhHc2nvOAyWOWYiYvIJrn7dkvMhLmiJbc941gyJdnOgutsKZlBnu atPOVt1muj0sz0wTHe9UvpSqQf18T8kKdtjh+VyI8px5OWfjc7FmJVOPHTUwZ/UV obzNskq/MAFoib/hd6hU3raDpRDQYBmgVet1HHyhWHObn2SC8hRLTwIoZ5YHo+pH SZ62nGJmeVm1Bfk10jUrmWQ7NEMiDEJR0wnGiCmZm3x/fwXe4Gu8eiDKZxYeLCJO zytXpNq3yW+2KuxMvwfsiVJ3kHx6GGHWVLtSLuCV1Nqmw4bpXdOuGGPdLLjgu7Nx w8pZ+BZpzDDmXtZGPXNk =3+JD -----END PGP SIGNATURE-----