From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-173.mta1.migadu.com (out-173.mta1.migadu.com [95.215.58.173]) (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 EDB822FDC5E; Tue, 31 Mar 2026 17:05:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774976715; cv=none; b=n8RAfkRmH6DNMtAY+eUCos2fX0brB1CD6aY3SsyH4RGsLCQyVu3OkbptLbKx/MBRtmA0b4WjxjJT056DNhC+aQgs725U9txOzQO9Sd4ms5+LBGCXXiBg6KWh/86ZOsri1bJCBktK3ZmSLMAaoh5++6pmHVRJzmM09i969tAbn3U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774976715; c=relaxed/simple; bh=p91wn6iDlOyNDvq7BGjP8kMFRBLd/B/AzRO79xA2sFA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=WDIuilvd11LhmP9h4dnmIc+twEwg/TvMLTtWj6fNk0v0FXudbv9KlwgBbtSfV8GkmQ/PGcXxSg1Qz4pYQGQOoEk+ucjjEEYL453XeH2qMK5mZktlcur7dvlGqsJZe8cyFIdG+VZ7evsqARQUUW73KEPQ7kwalrP+0yuPKsXyHgk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=packett.cool; spf=pass smtp.mailfrom=packett.cool; dkim=pass (2048-bit key) header.d=packett.cool header.i=@packett.cool header.b=JyaKvKLa; arc=none smtp.client-ip=95.215.58.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=packett.cool Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=packett.cool Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=packett.cool header.i=@packett.cool header.b="JyaKvKLa" Message-ID: <33c0a723-7748-4199-9623-7ed3eed8bfa0@packett.cool> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=packett.cool; s=key1; t=1774976710; h=from:from:reply-to:subject:subject: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=DitiYmGa03P6cnaADhTmkOMLyZ82FG+RUrubTXpBKds=; b=JyaKvKLaSrQo/X0LDC5H3UeOq5dGVtIM9N+kTknXCkQeKviVXKKV7WiC47YzgW0gNXJ07y DaYcrVV3SMmNzrP7qLLf04c0mCgfJniCuZbr+glIfhY5z5+lMAyN9F9WpJsdrRU6qXNYhF f37ooU3CiV3Us73Ed/4sAWq4GFTj+jPA8KH0I7QoQiwV91H5og1tr2Zq/NLNUUO0bxRsJZ Amvx6qEHYQIBIrXmKmoIhczCMPvb6gi9PLx08IojR/iqF3YgYGXdT90WnSpTjDMJxsV0YM J2q6+thH480h4+P+Sjy6PCdV5Mcb8YGqFxoHeLsZX6/+JAjleFHwYggEjbYPdg== Date: Tue, 31 Mar 2026 14:04:56 -0300 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH v2] arm64: dts: qcom: x1e80100-dell-xps13-9345: enable onboard accelerometers To: Aleksandrs Vinarskis , Bjorn Andersson , Konrad Dybcio , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: laurentiu.tudor1@dell.com, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Dmitry Baryshkov References: <20260331-dell-xps-9345-accel-v2-1-7dacbd24b43d@vinarskis.com> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Val Packett In-Reply-To: <20260331-dell-xps-9345-accel-v2-1-7dacbd24b43d@vinarskis.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 3/31/26 10:36 AM, Aleksandrs Vinarskis wrote: > Particular laptop comes with two sets of sensors: > 1. Motherboard: accelerometer > 2. Display/Camera module: accelerometer, ambient ligth (and more) > sensor > > Both i2c busses are bound to Snapdragon Sensor Core (SSC) and are > typically controlled by (A)DSP thus allowing for great power > efficiency. This however requires DSP libraries matching ADSP firmware, > sensors descriptions (must be extracted from Windows) and other > potentially closed-source libraries. Opensource tooling includes > `libssc` and `hexagonrpcd`, but they were not verified to be working. > > Until SSC support for X1E lands, bitbang both i2c busses to enable > accelerometer functionality. In the future if/when sensors on this > platform can be used from DSP directly, this commit can be reverted. > > [..] WDYM by "support lands"? It's a userspace setup thing, nothing new should be required in the kernel. It is amazing that this bitbanging works here, I don't think it was expected to ever work on anything newer than msm89x7 o.0 But this is likely inefficient… and "stealing" GPIOs from ADSP like this sounds rather scary. And would definitely break SSC initialization for anyone wanting to bring up hexagonrpcd/iio-sensor-proxy. ~val