From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 84673C433FE for ; Mon, 23 May 2022 18:27:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242652AbiEWS1j (ORCPT ); Mon, 23 May 2022 14:27:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244914AbiEWS01 (ORCPT ); Mon, 23 May 2022 14:26:27 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 01FE638D83 for ; Mon, 23 May 2022 11:01:50 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1202B614C2 for ; Mon, 23 May 2022 17:58:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 208A5C341DE; Mon, 23 May 2022 17:58:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1653328732; bh=KXCC8IaDurI6U1NFyXpYULJsDt6zjB7jND29xlcCDfY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=o10eZvTXKlX7+xUVB3alNlQbfFQscx4zel5vJwhZBeDwMeJG76V03VxKUmyRVSDwl nmLbGWsXS0bA8f9Kph9DwyIEOj/GuAqOHSAy0H7B40bmR7jwXxlvSMcIWNqc4KHg/H m2ePf1DkJNgs5XMjJvJZMCyVoz+OgnD1ApbeuaqWn/XBMv+KxdnLUwhQ/7LtwO7pzo NRVbUQgmrnU0YcdGpcZu9JCbbtUd6NTbiMmk2bYn3wkR0WLjJ+AHf5BsrO4TXaN2cG KXDKDX7w8iFIJHpgFwGoMFmBcebIYoX0Bt1p7bFg0CMr/xcbAwIPIIkEI+CjFJXkj9 NqSGG3y3azmIg== Date: Mon, 23 May 2022 10:58:50 -0700 From: Jakub Kicinski To: "Kolacinski, Karol" Cc: "davem@davemloft.net" , "pabeni@redhat.com" , "edumazet@google.com" , "netdev@vger.kernel.org" , "richardcochran@gmail.com" , "G, GurucharanX" , "Nguyen, Anthony L" Subject: Re: [PATCH net-next 3/3] ice: add write functionality for GNSS TTY Message-ID: <20220523105850.606a75c1@kernel.org> In-Reply-To: References: <20220517211935.1949447-1-anthony.l.nguyen@intel.com> <20220517211935.1949447-4-anthony.l.nguyen@intel.com> <20220518215723.28383e8e@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, 23 May 2022 16:56:44 +0000 Kolacinski, Karol wrote: > On Thu, 19 May 2022 06:57 +0200 Jakub Kicinski wrote: > > > Create a second read-only TTY device. > > > > Can you say more about how the TTY devices are discovered, and why there > > are two of them? Would be great if that info was present under > > Documentation/ > > Both TTY devices are used for the same GNSS module. First one is > read/write and the second one is read only. They are discovered by > checking ICE_E810T_P0_GNSS_PRSNT_N bit in ICE_PCA9575_P0_IN register. > This means that the GNSS module is physically present on the PCB. > The design with one RW and one RO TTY device was requested by > customers. I meant discovered at the uAPI level. Imagine I plug in a shiny E810T with a GNSS receiver into a box, the PRSNT_N bit is set and the driver registered the ttys. How do I find the GNSS under /dev ?