From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="2RKkF2RM"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="TOc2xSAW" Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A954A2 for ; Sun, 19 Nov 2023 00:39:05 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id D35E0228B8; Sun, 19 Nov 2023 08:39:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1700383143; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VfAceHUWlJwBfoe48AJnPOJCRJwPYKNQdgDMr91G+Cc=; b=2RKkF2RMUktWBscXOisL68kZDjyeoLrrpLr/TowuwCKsxrnL6OSH2QXR1Hg+KUfUmvo6dq h80qECVefwcEVFQJaqtBpqCJzFOEe26TBgjUQhG0PKFzfFWT0F97/YyQFV8uF/x1s3vOet Xg3tWIGJHY+IZJ+PfCY3S06eBYY/RCc= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1700383143; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VfAceHUWlJwBfoe48AJnPOJCRJwPYKNQdgDMr91G+Cc=; b=TOc2xSAWpKrR4tPLWVVZWfdu/yZr4Vi0oXkZ7bjPvge8B3nmzifiEeVe2Yq/ojJvu+8NvH rBPnDZtN+XL8jgDQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id AC188139C4; Sun, 19 Nov 2023 08:39:03 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id rKl8KKfJWWX2FgAAMHmgww (envelope-from ); Sun, 19 Nov 2023 08:39:03 +0000 Date: Sun, 19 Nov 2023 09:39:02 +0100 From: Jean Delvare To: Heiner Kallweit Cc: linux-i2c@vger.kernel.org Subject: Re: [PATCH RFC] i2c: i801: Add i801_register_jc42, similar to i2c_register_spd Message-ID: <20231119093902.739b4602@endymion.delvare> In-Reply-To: <5f2ed562-319c-4439-a235-c1a01373c1fe@gmail.com> References: <79977020-69c3-4f87-b861-b043c7fb9077@gmail.com> <20231114150001.6823e277@endymion.delvare> <37aa2c39-8192-42be-8021-a2147252f27b@gmail.com> <5f2ed562-319c-4439-a235-c1a01373c1fe@gmail.com> Organization: SUSE Linux X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.34; x86_64-suse-linux-gnu) Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Authentication-Results: smtp-out1.suse.de; none X-Spam-Level: X-Spam-Score: -1.76 X-Spamd-Result: default: False [-1.76 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; NEURAL_HAM_LONG(-1.00)[-1.000]; HAS_ORG_HEADER(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; RCPT_COUNT_TWO(0.00)[2]; FREEMAIL_TO(0.00)[gmail.com]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; BAYES_HAM(-0.46)[79.09%] Hi Heiner, On Wed, 15 Nov 2023 12:00:18 +0100, Heiner Kallweit wrote: > After thinking once more about it I think we have to do it from the > ee1004 driver for DDR4. For DDR3 from at24. Only this way we can read > the "temp sensor present" flag from SPD. E.g. for ee1004 the SPD EEPROM > may be switched to the second page and we have to switch it to the first > page first. We indeed need to read the EEPROM data at some point. My initial thinking was to instantiate the at24 or ee1004 device first (from i2c-smbus), then read the value from the EEPROM and instantiate the jc42 device (still from i2c-smbus). This requires an internal read function. I think we already have that in at24, because it uses the nvmem framework, but ee1004 lacks it as far as I can see. But anyway, if you have another approach which works, that's equally fine with me. > I'll send a RFC patch for this. Unfortunately I have no RAM with temp > sensor to test it. Neither do I :-( -- Jean Delvare SUSE L3 Support