From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH] i2c: pxa: enable high speed mode for i2c bus Date: Sat, 15 Jun 2013 16:48:12 +0200 Message-ID: <20130615144812.GD2923@katana> References: <1370587097-21006-1-git-send-email-shangll@marvell.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="llIrKcgUOe3dCx0c" Return-path: Content-Disposition: inline In-Reply-To: <1370587097-21006-1-git-send-email-shangll-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Leilei Shang Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org --llIrKcgUOe3dCx0c Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Fri, Jun 07, 2013 at 02:38:17PM +0800, Leilei Shang wrote: > To enter high speed mode, following steps should be done: > 1. When running in high speed mode, i2c clock rate is different > from standard mode. Clock rate must be set according to > specification first. > 2. When i2c controller sends a master code and wins arbitration, > high speed mode is entered. >=20 > If you want to enable high speed mode, the following members of > platform data should be set to proper value: I couldn't find any support for hs-mode in pxa2xx and pxa3xx. So it shouldn't be set in platform data, but depending on checks if this is supported on this device at all. And why don't simply switch to it if rate is bigger than what is supported without hs-mode? > 1. "high_mode" should be set to "1". > 2. "master_code" should be set to "8'b 0000_1xxx"(x is 0 or 1). > If no master_code is set, set to default value 0xe. > 3. "rate" should be set according to specification. Note that you should fall back to full-speed mode after sending the stop bit in high-speed mode. I can't find this in the code? >=20 > Signed-off-by: Leilei Shang Which SoC supports this? I'd like to have a look at the datasheet. Thanks, Wolfram --llIrKcgUOe3dCx0c Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJRvH6sAAoJEBQN5MwUoCm2xg0P/iQefYXPz3h8+DSahwI3TVu1 S8c7IYmOsl7oz3vuxpb5U4+alAUXuORVQiqpukjZFOHlduWX7ZYBJKPOgHYLVegQ 8Osk9qkcyvXzuUJIaPdKI2u2+sgWhBhXZtdCXLiv/YWL+v/aOKPERM+lwvmug7dD jDXt0jtE/D++BvbovpOaaFWAnPlkd64VZOeiv0VwahWnrBoEWaw/41iMTP13/lLC Exaw8pEyy7VtwZwBqT2DWOZvi0yKKz2fjC6XrVS4n0bWD5xx0Yv8WbxjL8KdeJIr VHOcrk/Z3mVyCYPG/1VAFMNqGUOoiTg2V8QKK1DT1UrcxIG+SnjCXzvhtcww/Yuq C3Sa4ByFf/J+cNa02L5ZmE41fAaWcHsUS/rQezu7UyIbAly8GTRteJWwGqpWIS7h hlyWJgMm/G3hlsae7MLRlD6RGGYL0Jl1+VYCV8Sw2WcKMftKj4Q/+UX1sBngR6XH aL4ri39gUCMToH/mcDREmDe38mcsqd+e59ub1dhNsF7IClClC8jyZWZoQqx2BgmA lqEwSgGqfTchGL7+uOj5AZnsWyhSAVTqa3tNpGOESIe/seqaKiB6RjLgiSiBB0uQ YX7nG+8xGZr3fEM04AI7llOub0smlthCijFzD5S45Da6V1TCtiRkkazum/V56pfg /uyYmcbfT6PJamqhxsO/ =jkPy -----END PGP SIGNATURE----- --llIrKcgUOe3dCx0c--