From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH] i2c: davinci: Optimize SCL generation Date: Wed, 17 Jun 2015 14:45:48 +0200 Message-ID: <20150617124547.GF13393@katana> References: <5579565E.1020908@nokia.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="nYySOmuH/HDX6pKp" Return-path: Content-Disposition: inline In-Reply-To: <5579565E.1020908-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Alexander Sverdlin Cc: Sekhar Nori , Kevin Hilman , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Lawnick, Michael (Nokia - DE/Ulm)" List-Id: linux-i2c@vger.kernel.org --nYySOmuH/HDX6pKp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jun 11, 2015 at 11:35:26AM +0200, Alexander Sverdlin wrote: > There are several cases where current clock configuration algorithm produ= ces > not optimal results: > - truncation in "clk" calculation leads to the fact that actual BUS frequ= ency > will be always higher than spec except two exact module frequences 8MHz= and > 12MHz in the whole 7-12MHz range of permitted frequences > - driver configures SCL HIGH to LOW ratio always 1 to 1 and this doesn't = work > well in 400kHz case, namely minimum time of LOW state (according to I2C= Spec > 2.1) 1.3us will not be fulfilled. HIGH to LOW ratio 1 to 2 would be more > approriate here. >=20 > Signed-off-by: Michael Lawnick > Signed-off-by: Alexander Sverdlin Applied to for-next, thanks! --nYySOmuH/HDX6pKp Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJVgWv7AAoJEBQN5MwUoCm29IgQAKhQIB+fKPYA94Mc7Tp3lNlF v3EZCXXlW8+lQQCGETIima7xviLgNfuXAE04+lLD6iHBH4GM5gVgk8NDBN13nuAr XQBV3z6VlMwWTShbu0zW/4NJ/EWgaO9TUbtYoL4DGT2E25hQzg/d3IY6iAHyU3AA tyJGc5T3QusbSUI1fJGJE5PQO+LOhuHLzpQVkK7KKvoIEGQeeI+KTASYEa12rRPk HMI6NSMZAsqqCYsrtebo0giP9rZdUIAicxRQQ8Nc1uFwfS7YeAdhilvjW9K9oQe6 R8CoHZmo9F/hRNKS9UzbWxnTBaUEkPvH6VCUnMpLj1hdO0dEMQvOLHHRNUbrcVc+ 5DF52bXIRGr7556cZ0PO7qtIik8Lfv1760LS7nH752b7E4wY9+3KiZGUGED5gMxj 0/w0OeY8PGsUOw3m4p5ahbZuoCZfTXHqyVUpDH4e2AQU0f0XMUCTrBIvW9fmcQ0k NzC9ADBpgxNmERzvjZBeAXnh6f/M/xl0XEQfwINNKJ9UucXv2rFk7sh9BERSSbxf jyQGuKNoSTS7kJ33IXql/1qBj2Hl0ryvpugN/4szWyQHpzz9WhO6nsTnmo2xVZUv wBYzaKxoHiPWW0rsuawtJWk2eyI241rRI90yjQOz8KUcfeQKyE6LTgfV6RUs0Rt5 GwnsKkRmu6pMi0ZwSF8/ =ZN3e -----END PGP SIGNATURE----- --nYySOmuH/HDX6pKp--