From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4C03BDF58; Mon, 9 Sep 2024 10:06:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725876407; cv=none; b=E2yJeVc8q9PPzR564O5+XL9ocqoMo+3iR+MVgUkcDrDvOBYZW65UmiVNjGTFpZBmQ4vXt1cLOupK8ejxHE98r4rTuHr9JIaA2VZry+OSGzRCd7MG1tz+rV3BBN4FCsZTnS/TvV1Xj7krLGdQONa0wFgAvw+BudkSG3hHue1d4AQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725876407; c=relaxed/simple; bh=71flhjDVi15j6UOFXaKc8Ug8/1DkA1yhZA8lN1pRABk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=m7QDmqILHHdpdD/mpSnaFVg5mLGcDjxOalH15LXquLDJ6yf8n6rd6CGsCJJW9oIvpVOjYF6XfO+vrgDknXfu/CfL77DNftaF2esUFPrXFxiryXv3dch2Tv2cwAV8ul37+Rb1iw6kjHndthTbBVnthuEQHsm87RQiWP3F2hepjHY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=elzn9Bnp; arc=none smtp.client-ip=192.198.163.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="elzn9Bnp" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1725876407; x=1757412407; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=71flhjDVi15j6UOFXaKc8Ug8/1DkA1yhZA8lN1pRABk=; b=elzn9Bnp4oKODy3bOdSRuBAvTQ5Oim4T08RrKef8PtnceFSkr8tT+AQz umEytx3QLp4qYNLcP8FTtXwzt6YaskvgHZjypUiFbwKeoXLv2yCL6UEIG 8houEhYJAB5pBTJX49BAt2BtLoWN5mFd7q/X3cKtlExEDBD1E48rh6RoD odR6PEQ1iut2A+dYa+nf88ArYAno8aKY+46uKI58DcDLUcTnn6rtGxo6w rIBVyxx69KBJblQ/H4wdbH18v+MkTIa3tOuqwYqMv3ZQ03KcUbC1thU2U OFYdkeCbPVFMI6rq8Jj3zCaBzOsA7Ul7WnshFGw5wAzQu9SqOr/kp/FsY A==; X-CSE-ConnectionGUID: AV0NlsOxTi2/wHLCK7EWEg== X-CSE-MsgGUID: m15bmGwHSFuyXHTS8Q4nsQ== X-IronPort-AV: E=McAfee;i="6700,10204,11189"; a="24435282" X-IronPort-AV: E=Sophos;i="6.10,214,1719903600"; d="scan'208";a="24435282" Received: from orviesa008.jf.intel.com ([10.64.159.148]) by fmvoesa111.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Sep 2024 03:06:46 -0700 X-CSE-ConnectionGUID: UF9e/8//TkSKuEGzC6bqNA== X-CSE-MsgGUID: pqAg6/QyRTqrE4iOz+VBaQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,214,1719903600"; d="scan'208";a="67361508" Received: from smile.fi.intel.com ([10.237.72.54]) by orviesa008.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Sep 2024 03:06:44 -0700 Received: from andy by smile.fi.intel.com with local (Exim 4.98) (envelope-from ) id 1snbI8-00000006kHj-43mW; Mon, 09 Sep 2024 13:06:40 +0300 Date: Mon, 9 Sep 2024 13:06:26 +0300 From: Andy Shevchenko To: Parker Newman Cc: Parker Newman , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, Greg Kroah-Hartman , Jiri Slaby Subject: Re: [PATCH v2 00/13] serial: 8250_exar: Clean up the driver Message-ID: References: <20240503171917.2921250-1-andriy.shevchenko@linux.intel.com> <20240503143303.15bf82bc@SWDEV2.connecttech.local> <20240906095141.021318c8@SWDEV2.connecttech.local> <20240906103354.0bf5f3b7@SWDEV2.connecttech.local> <20240906143851.21c97ef9@SWDEV2.connecttech.local> Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240906143851.21c97ef9@SWDEV2.connecttech.local> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo On Fri, Sep 06, 2024 at 02:38:51PM -0400, Parker Newman wrote: > On Fri, 6 Sep 2024 17:42:26 +0300 > Andy Shevchenko wrote: > > On Fri, Sep 06, 2024 at 10:33:54AM -0400, Parker Newman wrote: > > > On Fri, 6 Sep 2024 17:24:44 +0300 > > > Andy Shevchenko wrote: > > > > On Fri, Sep 06, 2024 at 09:51:41AM -0400, Parker Newman wrote: > > > > > On Fri, 6 Sep 2024 15:46:51 +0300 > > > > > Andy Shevchenko wrote: > > > > > > On Fri, May 03, 2024 at 02:33:03PM -0400, Parker Newman wrote: ... > > > > > > Sorry for blast from the past, but I have some instersting information > > > > > > for you. We now have spi-gpio and 93c46 eeprom drivers available to be > > > > > > used from others via software nodes, can you consider updating your code > > > > > > to replace custom bitbanging along with r/w ops by the instantiating the > > > > > > respective drivers? > > > > > > > > > > Hi Andy, > > > > > The Exar UARTs don't actually use MPIO/GPIO for the EEPROM. > > > > > They have a dedicated "EEPROM interface" which is accessed by the > > > > > REGB (0x8E) register. It is a very simple bit-bang interface though, > > > > > one bit per signal. > > > > > > > > > > I guess in theory I could either add GPIO wrapper to toggle these bits > > > > > and use the spi-gpio driver but I am not sure if that really improves things? > > > > > Maybe using the spi-bitbang driver directly is more appropriate? > > > > > What do you think? > > > > > > > > Yes, spi-bitbang seems better in this case. > > > > > > I will try to make some time to implement this... Or if someone else from the > > > community wants to take this on in the mean time I am certainly happy to test > > > and help out! > > > > Sure, I shared this thought due to having lack of time to look myself, > > but I prepared the above mentioned drivers to make them work in this case. > > (If you are curios, see the Git history for the last few releases with > > --author="Andy Shevchenko") > > > > Looking into it a bit more I think we could just use the eeprom_93cx6 > driver without any SPI layer. Just need to add simple register_read() > and register_write() functions to read/write the REB register. > > That should be a pretty easy change to make, I can try to make that > change soon unless anyone has any objections to that method? Thank you, this is pretty wonderful news! -- With Best Regards, Andy Shevchenko