From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH 2/3 V3] i2c: mxs: Rework the PIO mode operation Date: Mon, 30 Sep 2013 13:22:01 +0200 Message-ID: <20130930112201.GE3222@katana> References: <1380497035-7457-1-git-send-email-marex@denx.de> <1380497035-7457-2-git-send-email-marex@denx.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="gDGSpKKIBgtShtf+" Return-path: Content-Disposition: inline In-Reply-To: <1380497035-7457-2-git-send-email-marex-ynQEQJNshbs@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Marek Vasut Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Alexandre Belloni , Christoph Baumann , Fabio Estevam , Shawn Guo , Torsten Fleischer List-Id: linux-i2c@vger.kernel.org --gDGSpKKIBgtShtf+ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable 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. >=20 > 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. >=20 > 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. >=20 > This patch also tries to document the investigation within the > code. >=20 > Signed-off-by: Marek Vasut Yay, there it is. Thanks, looks good to me. Will wait a few days so people can donate Tested-by tags. --gDGSpKKIBgtShtf+ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJSSV7YAAoJEBQN5MwUoCm2eBYQAKc82Gnx5Y5yWPzGjc3usAY1 TDqgzU+gnyuadoXMXKPBylP0riYTpz7isY3JC9kqU7F2QxhUOTOn+ANFeIpC9TzW KLWlmzgL5HYNW43hImD2eZ3oih9RtOePfaUMwbtVuQeYFkaZQWgNywsHsIMicLa0 fcFTopWnmcV5kaXOaNAMn+4aFbo4lpU7o1ANUHhpyI/1gOl0OH0wV8riOxFNb5ks dOAJabE2yaqK40yp+biF0hsWchsDuELb+V3SL4EA36TbhkAlpca7I1ipRcwBD6Gj DWBpCUf9ZkVS8NFv3GaeDmwtCtLIDZpaklPxzva65KPPJKYHhxflm0fnRMQz/hjc TcOrCa9dnYGo3WPeg7ZbR6Kg7oQW6/YkdXuDCSK0tEDPmxgJHuV4qG7dTxhM5dWP +IF4xKuQx9rSIPHoMF/LaIpS+MdpFh2Y9ZXB6lIRtY4Ulq+Npjbg3L+UowjKYQM7 AhLOgREMrSAcKhTKl++SSS13Wh/ptne/1CJYN4nGRAh1wOGkLYEpjGzyDXsNlB1F I4yBlbDMW/h9W29TB9mNkesb424cSOQ/YEMKZQRv3fjgfAdPI9nicU4g2Ncy5bi1 oG6SB1R3M9XD+Y6aM37IbcgatKpFr5OLel8NF9aGZueqqR5eZ+WNGd7azdBBq/eS tMMJERsi+GC3CamIfXBE =rY9q -----END PGP SIGNATURE----- --gDGSpKKIBgtShtf+--