From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH] i2c: scx200_acb: avoid I2C bus overclocking. Date: Tue, 12 May 2015 22:19:20 +0200 Message-ID: <20150512201919.GL4449@schokonusskuchen.bad> References: <553955C6.3030000@secomea.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="9JSHP372f+2dzJ8X" Return-path: Content-Disposition: inline In-Reply-To: <553955C6.3030000-sijd2F9aCfdBDgjK7y7TUQ@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Svenning =?utf-8?B?U8O4cmVuc2Vu?= Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org --9JSHP372f+2dzJ8X Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Apr 23, 2015 at 10:27:50PM +0200, Svenning S=C3=B8rensen wrote: > According to I2C spec, max SCL rate is 100 kHz, but SCx200/CS5536 > controller is currently driving it at 214 kHz according to my math. >=20 > SCL is derived from an input clock of 48 MHz, which must be divided > by 480 (240 cycles for each SCL high/low state) to be within spec. >=20 > Signed-off-by: Svenning Soerensen So, did you test/measure the actual frequency? Or is this patch based on specs only? Thanks for caring about this old driver, though! --9JSHP372f+2dzJ8X Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJVUmBHAAoJEBQN5MwUoCm2svMP/R3PItIXu1VvGWmgx+4qnrZ8 euYxQ3LgNDwBZX/Z6m4LSxEuBbhw854/VJlHKhIShU+RcJ2TEXwzPhbYk3Si/V+l 4d0tyGgvjI2kft0KqRQKwEhmNvydu9FHKzT26c0pNU6CxORcGG4Fhr8HuwrrsiCp tMBOhvOXT6REZDKHwCjJGUUM16ugEHa7BpSM7v0YQ5nuAUbsSTRyzXoPSyOo8y4I nXrsJJdDBG9VQcVTKYVoQVuMT+dXycQicracLiNc4XNe3P3dRzdxYPvkYLwo4FS5 epLM5QyD31hgpAgEojrgK6LZTWDA1p5bwj9I1bYRNq9XitVhB1pdCGpFi+6XH4tN zgU4OHGsUKNk8J5kYTO1yH5PJM7ZrSolx7Glu8VpKC0qNlReuMY9IzYx1eUpfZuR NAOK82hIKXxN2gTnSoEi/IYkQGmiDqjtVIe/5SMRyPe+bweerTf6wV21HRJHWSEL HWWMEdgxBkFFt9+sUc1LjdBlmRae0uVMT/f/RzJpqvzQsIauiNBkd4dzBMfZ/JCT CqfsW+srtuB7fU5iAmMxDWhxAGyDP4rRnMQulskWOL0982nMQYNKt9AflarD3WGG D9qs6Nto/hqpGOwQOYmPEg4DwcTg63SKM7nkbt9TOwMwDKSZ02m35icIW0sCx4cu eIFFpfemZndPMiIO6UiH =q3YY -----END PGP SIGNATURE----- --9JSHP372f+2dzJ8X--