From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: How to handle SPI components requiring heading/leading clock cycles with CS off Date: Wed, 24 Aug 2016 12:12:06 +0100 Message-ID: <20160824111206.GD22076@sirena.org.uk> References: <79679118-c092-1f9c-1972-0bb81bc59411@c-s.fr> <20160824094456.GB22076@sirena.org.uk> <8c6cbd99-7dd8-bbbf-89ee-a33752ab3063@c-s.fr> <20160824105640.GC22076@sirena.org.uk> <15444613-2f3d-9417-7d81-e545058afdf0@c-s.fr> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="stFzI3XAseUQ09UW" Cc: linux-spi To: Christophe Leroy Return-path: Content-Disposition: inline In-Reply-To: <15444613-2f3d-9417-7d81-e545058afdf0-GgN8y9CXRhA@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: --stFzI3XAseUQ09UW Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Aug 24, 2016 at 01:03:57PM +0200, Christophe Leroy wrote: > CS is asserted inconditionnaly at begining of the function, regardless of > its previous status. > Then for all transfers but the last, when cs_change is set CS is deasserted > for 10us then re-asserted. > If cs_change is set for the last tranfer, the function leaves CS asserted. > So I don't see how I can transfer some data with CS de-asserted. Oh, yes we reset at the start of the function. You'd need to change the core to support this, and even then your compatibility with controllers is going to be very limited. What is this device, is there some reason for this? --stFzI3XAseUQ09UW Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJXvYEFAAoJECTWi3JdVIfQdDMH/3mz/EmxznAu9ixboZmqT0zf JyOAs5/sFpH90WeZFhjAVCkDPuBH4MVPHUq82sdUT/MbyBZLSLFHPn1aU1kflOFY pQTMAHYk+aYUEBlN0nAVbXB2MHHdwhCwh/MjKAScVPOwWTwvL2cysSsEkcjRd1NB 00S6HxoSgTLIj3BE60PWzA9giusbh+SVvVKG3hzR8riewpYAwWs3YZsDoF15S/zT OVxc1FFfepZS9Zhad2j08HKVzA0Lbb4C7+byEbpIXIJAHNmD9kRaWUkTdu3HtX0d K/mkWko06djxHJoawxfppyyRcSzNys8LkGEEPTj0ovpylKQa/ZrCY+tcM8C/CII= =3wiz -----END PGP SIGNATURE----- --stFzI3XAseUQ09UW-- -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html