From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: [RFC 5/5] [powerpc] Implement a p1010rdb clock source. Date: Mon, 08 Aug 2011 15:00:06 +0200 Message-ID: <4E3FDDD6.1020802@pengutronix.de> References: <1312641270-6018-1-git-send-email-holt@sgi.com> <1312641270-6018-6-git-send-email-holt@sgi.com> <4E3FA066.3020301@grandegger.com> <20110808113136.GS4926@sgi.com> <4E3FD184.1070706@pengutronix.de> <20110808124842.GT4926@sgi.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============4177580035502953718==" Cc: socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, U Bhaskar-B22300 , Wolfgang Grandegger To: Robin Holt Return-path: In-Reply-To: <20110808124842.GT4926-sJ/iWh9BUns@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: socketcan-core-bounces-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org Errors-To: socketcan-core-bounces-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org List-Id: netdev.vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --===============4177580035502953718== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig42B3E84E7681BE97C529AB81" This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig42B3E84E7681BE97C529AB81 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 08/08/2011 02:48 PM, Robin Holt wrote: >>> OK. Dug a bit more. The p1010 built-in clocksource seems to be the >>> periphereal clock frequency which is system bus frequency divided >>> by 2. The clock source can not be changed, but the clock divider can= >>> by freezing the interface and setting the CTRL register. This appear= s >> Which bit(s) in the CTRL register is/are this? > PRESDIV bits 24-31. Documented on the P1010 reference manual section 2= 1.3.3.2. We have and use these bits on arm, too. These bits are calculated and set by the driver[1]. These bits are touched in freescale's 2.6.35 version of the flexcan driver, too. =46rom my point of view it makes no sense to specify this divider in the OF-tree. We just need the frequency of the clock entering the flexcan core. Which is, as you say, the system bus freq/2. [1] http://lxr.linux.no/linux+v3.0.1/drivers/net/can/flexcan.c#L597 --=20 Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | --------------enig42B3E84E7681BE97C529AB81 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk4/3eEACgkQjTAFq1RaXHO0XACeKjUzj2FbRGcDeFtpKi7Zr64u HDMAniaUNZNKIXs27vaPu/lHEWpK1p3x =y/yp -----END PGP SIGNATURE----- --------------enig42B3E84E7681BE97C529AB81-- --===============4177580035502953718== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Socketcan-core mailing list Socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org https://lists.berlios.de/mailman/listinfo/socketcan-core --===============4177580035502953718==--